CN116892508A - Crosshead box and plunger pump - Google Patents

Abstract

The present disclosure relates to a crosshead box which is a generally rectangular box body formed by an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face, and side end faces, the crosshead box being provided with a plurality of crosshead cavities, each of which extends along a longitudinal direction of the crosshead box and penetrates the box body, the plurality of crosshead cavities being arranged along a transverse direction of the crosshead box. The cross head box is further provided with an embedded lubricating oil circuit, the embedded lubricating oil circuit is an oil hole and an oil channel which are formed in the box body of the cross head box and are communicated with each other, and the embedded lubricating oil circuit comprises a main oil circuit and a branch oil circuit. The disclosure also relates to a plunger pump provided with the above-mentioned crosshead box. The crosshead box and the plunger pump according to the present disclosure enable a lubrication oil path system to be easily manufactured, more reliable, and easier to maintain by providing an in-line lubrication oil path.

Description

Crosshead box and plunger pump

Technical field

The present invention relates to a crosshead box of a plunger pump and a plunger pump provided with the crosshead box. The crosshead box has an integrally formed structure.

Background technique

Fracturing pumps (also called plunger pumps) are widely used in the petroleum industry as important equipment that can increase oil and gas production. Especially in the production increase of some old oil fields in the middle and late stages and in the development of emerging shale gas, fracturing pumps play an important role.

The fracturing pump is mainly composed of a reduction gearbox, a power end, a hydraulic end, and three major subsystems. The function of the reduction gearbox is to decelerate the high-speed power input from the power source in multiple stages into low-speed power, and then input it to the power end. The power end is connected between the two subsystems of the reduction box and the liquid end valve box, and is responsible for converting the rotating mechanical energy transmitted from the reduction box into reciprocating mechanical energy to drive the liquid suction and discharge operations of the liquid end. The function of the liquid end is to pressurize low-pressure fluid to high-pressure fluid and output it to the high-pressure manifold.

The power end assembly is mainly composed of a housing, a crank connecting rod assembly, a crosshead tie rod assembly and a lubrication system. The power end housing mainly includes the crankcase and crosshead box. The crankcase is connected to one end of the crosshead box, and the other end of the crosshead box is connected to the hydraulic end pump head body through a connecting device. Currently, a common fracturing pump in the industry is a five-cylinder fracturing pump, that is, its crankshaft is often an integral structure with six supports and five cranks. The crankshaft is connected to the big end of the connecting rod, and the small end of the connecting rod, small end bearing bush, shaft pin, etc. are connected to the crosshead in the crosshead box. As the crankshaft rotates, the crosshead reciprocates in the inner cavity of the crosshead box, which in turn drives the connected plunger to reciprocate.

As a key component of the fracturing pump, the casing of the power end component is used to carry all the components of the power end and carry all the loads caused by all the components of the power end during operation. Therefore, the excellent mechanical properties of the power end housing have a decisive impact on the service life of the fracturing pump. According to the different composition methods of the shell structure, the power end shell can be divided into integral and split structures.

At present, the split structure is assembled by combining the crankcase and crosshead case shell welded by high-strength alloy plates. Common processes include welding, heat treatment (stress relief annealing), rough machining, defect grinding, overall welding again, heat treatment of weldments, inspection and other steps before completion. For example, the power end shell of the fracturing pump developed by FMC adopts a split tailor-welded structure. GD Company's 5000thunder power end also adopts a long stroke (11 inch) and split structure design (crankcase + crosshead box split design). In addition, since welding is a local rapid heating and cooling process, the welding area cannot expand and contract freely due to the constraints and limitations of the surrounding body. When the tensile stress on the material at the weld after cooling is close to the material yield limit, adverse consequences such as cracking of the weld and deformation of the shell will occur. Although the above-mentioned defects at the weld can be alleviated to a certain extent by eliminating internal stress through appropriate welding processes and heat treatments, the metallographic structure and mechanics of the base metal (heat-affected zone) that is affected by heat but not melted around the weld will change. Changes in performance produce uneven tissue distribution under the action of welding thermal cycles, which inevitably leads to internal stress in welding and becomes the source of fatigue cracks in components. The application scenarios and operating environment of fracturing pumps are very harsh, and the power end shell will be continuously impacted by high-pressure periodic pulse loads. The impact resistance of the welded power end shell is poor, and it is very easy to produce cracks near the weld, causing the shell to crack, eventually leading to the failure of the support function, affecting the fracturing operation efficiency, and even causing safety hazards. The currently existing welded power end housings have a service life of 2,000 to 3,000 hours at most. Even after a single failure is repaired, it is difficult to exceed the system design life (5,000 hours). In addition, the gradual expansion of welding cracks will greatly reduce the internal consistency and connection strength of the support material, resulting in insufficient overall stiffness and strength of the shell, and the shell will deform under high-voltage pulse loads. This abnormal shell deformation will change the matching gap between the sliding surfaces, affect the input and establishment of the lubricating oil film, and lead to abnormal eccentric wear and even burns on the surfaces of key components such as main bearings and bearing bushes.

In addition, during the high-speed reciprocating motion of the power end, if a large amount of heat is not taken away in time, the internal components including the crankshaft, crosshead, tie rod, plunger and other key parts will fail due to excessive temperature. Therefore The design of the lubrication system is very important for the continuous operation of the power end. The fracturing pump relies on the reciprocating movement of the plunger in the cylinder to change the volume of the sealed working chamber to achieve liquid suction and discharge. Therefore, the lubricating oil also serves as an auxiliary seal. Forced lubrication is often used for power end lubrication, and lubricating oil under a certain pressure is provided by an external lubrication system. In the current power end shell with a welded structure, due to the high hardness and limited thickness of the alloy plate, the lubricating oil circuit mainly relies on adding external connecting oil pipes and adding oil pipes in the shell to establish the oil circuit, thereby transporting lubricating oil to the lubrication system. (such as crankshaft, multiple bearing bushes, connecting rod small end bearings, etc.), and then through overall or partial recovery, filtration and cooling to ensure the best working performance and longest service life of the fracturing pump. Such a lubricating oil circuit requires a large number of high and low pressure lubricating oil pipes, a large number of joints, and a complicated pipeline layout. The pipeline installation process is cumbersome, and the connection reliability is difficult to control, and may become loose under the pressure of internal lubricating oil. In addition, in order to facilitate installation, lubricating oil pipes are often made of flexible hoses. When exposed to the air for a long time, they are prone to corrosion and wear, which increases the risk of leakage. Once leakage occurs, maintenance and repair costs are high. In addition, the shell deformation caused by insufficient stiffness of the tailor-welded shell will also change the relative position of the sealing surfaces that are in close contact, affecting the sealing effect, making it difficult to establish the pressure required for forced lubrication, affecting the lubrication effect, and causing oil and gas leakage. The entry of water vapor caused by seal failure will also affect the performance of lubricating oil, change the viscosity of the oil, weaken the support strength of the oil film, and accelerate the oxidation of the oil. The hydrolysis of additives weakens or even loses the basic properties of lubricating oil such as oxidation stability, extreme pressure anti-wear, and clean dispersion, resulting in poor anti-foam performance of the oil, causing the lubrication system to generate a large amount of foam and reducing the lubrication effect, seriously It will also cause cavitation and hydrogen embrittlement effects on metal materials.

In view of the above various problems of welded shells, increasing the thickness of the shell and increasing the size of the welding fillet are relatively simple and reliable solutions. However, this will increase the quality of the entire pump, increase the load on the chassis/skid, and consume more money. transportation resources. In addition, when a shell with an excessively thick wall is subjected to a load, a large area of internal tissue will squeeze each other, and the stress will accumulate and cannot be released, resulting in local stress concentration, which will also greatly affect the service life of the shell. Even if the weight can be reduced by designing grooves on the inner wall of the casing, legs, etc., this greatly increases the machining process. The large amount of material removed leads to a waste of raw materials, which is not conducive to cost reduction.

In terms of production and manufacturing, the production process of the welded power end shell is very complex, usually including blanking, assembly, spot welding, preheating, welding, grinding, heat treatment, flaw detection, rough machining, secondary heat treatment, finishing, etc. In a series of processes, the manufacturing accuracy and quality of each step in this process need to be strictly guaranteed, otherwise it will easily cause the accumulation and amplification of dimensional and shape errors. Errors generated in each of the above processes may lead to abnormal subsequent matching relationships, resulting in serious consequences such as connection failure, seal leakage, parts wear, and housing vibration. Even though the accumulated errors caused by the above complex processes can be controlled and compensated through precise machining processes, the huge labor costs and time consumption caused by this cannot be ignored and are unbearable.

Contents of the invention

Technical issues to be solved

In view of the above-mentioned problems of tailor-welded structures, some manufacturers have proposed using split casting to manufacture crosshead boxes. For example, the patent application US2022/0163034 A1 filed by KERR discloses a crosshead box body manufactured by split casting. However, due to problems in the design and manufacturing process, such a cast crosshead box is too heavy and bulky, making it inconvenient to transport and assemble. In addition, there are other problems, such as the concentrated stress on the support points, which makes the overall strength and stiffness prone to failure; the overall structure is loose, resulting in large torques during operation and reduced service life; the lubrication system uses high and low pressure oil circuits. Insufficient lubrication and oil supply for some parts while excessive oil supply for other parts results in waste and poor overall lubrication effect; the lubrication pipeline is external, the process flow is increased, and the advantages of casting are not fully utilized; the overall sealing is poor, and oil and gas leakage is prone to occur .

In view of the above problems, the present disclosure hopes to provide an integrated crosshead box that can easily provide a more reliable and easy-to-maintain lubrication system. In addition, it can fully exploit the advantages of the casting one-piece molding process, facilitate manufacturing and processing, have a relatively light overall weight, high structural strength and stiffness, and have a longer service life.

Technical solutions to technical problems

The present disclosure provides a crosshead box. The crosshead box is a substantially rectangular box formed by an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face and a side end face. The crosshead box is provided with There are: a plurality of crosshead inner cavities, each of the crosshead inner cavities extends along the longitudinal direction of the crosshead box and penetrates the box body, and the plurality of crosshead inner cavities are arranged along the transverse direction of the crosshead box. , the crosshead box is also provided with an embedded lubricating oil path, the embedded lubricating oil path is an interconnected oil hole and oil passage formed in the box body of the crosshead box, and the embedded lubricating oil path is formed in the box body of the crosshead box. The lubricating oil circuit includes main oil circuit and branch oil circuit.

Preferably, the main oil passage extends along the transverse direction of the crosshead box, and the branch oil passage extends along the longitudinal direction of the crosshead box.

Preferably, the embedded lubricating oil circuit includes a high-pressure lubricating oil circuit. The high-pressure lubricating oil circuit can lubricate the crosshead bearing bush and connecting rod bearing bush working in the crosshead box. The high-pressure lubricating oil passage may include a high-pressure oil inlet provided on the side end surface of the crosshead box. The high-pressure oil inlet may be disposed on a flat connection plane formed on the side end surface. The high-pressure lubricating oil circuit may have a filter and a relief valve.

Preferably, the embedded lubricating oil circuit includes a low-pressure lubricating oil circuit. The low-pressure lubricating oil circuit can lubricate the crosshead sliding sleeve. The low-pressure lubricating oil passage may include a low-pressure oil inlet provided on the side end surface of the crosshead box. The low-pressure oil inlet may be provided on a flat connection plane formed on the side end surface. The low-pressure lubricating oil circuit may have a filter and a relief valve.

Preferably, the embedded lubricating oil passage is provided with the branch oil passage for supplying oil to the crankcase, and the branch oil passage for supplying oil to the crankcase is located behind the crosshead box. The end face has an oil outlet leading to the crankcase.

Preferably, a sealing ring as a local seal is provided on the outer periphery of the oil outlet.

Preferably, each crosshead inner cavity is approximately cylindrical in shape.

Preferably, the crosshead box further includes a crosshead sliding sleeve, the crosshead sliding sleeve has a shape matching the crosshead inner cavity and can be embedded and installed in the crosshead inner cavity.

Preferably, the crosshead sliding sleeve is provided with an oil hole penetrating the wall of the sliding sleeve, and the oil hole is a part of the branch oil passage.

Preferably, one end of the crosshead sliding sleeve is provided with at least one recessed portion that is concave inward along the longitudinal direction of the crosshead sliding sleeve. Additionally or alternatively, the other end of the crosshead sliding sleeve is provided with at least one protrusion protruding outward along the longitudinal direction of the crosshead sliding sleeve.

Preferably, there are two recessed portions and/or protruding portions, and when the crosshead sliding sleeve is installed into the crosshead inner cavity, the two recessed portions are located on the crosshead. The two protrusions are also located at the top and bottom of the crosshead lumen.

Preferably, the front end surface of the cross head inner cavity is provided with a limiting groove, and the end head of the cross head sliding sleeve located at one end of the front end surface is provided with a positioning pin hole, and the positioning pin hole and The limiting groove is connected through a pin that is inserted into the pin hole to axially position the crosshead sliding sleeve in the crosshead inner cavity.

Preferably, the crosshead box is further provided with at least one first bolt hole, each of the first bolt holes is located above and below the plurality of crosshead inner cavities and along the longitudinal direction of the crosshead box. Extends through the box.

Preferably, the crosshead box is further provided with at least one second bolt hole, each of the second bolt holes extends along the longitudinal direction of the crosshead box and penetrates the box body, and is located between the front end surface and the On the rear end surface, the second bolt holes are located outside the first bolt holes.

Preferably, the second bolt holes are also provided on the front end surface of the crosshead box and on the edges located on both sides of the crosshead box in the lateral direction.

Preferably, on the front end surface of the crosshead box, a flange portion is provided on the outer periphery of the crosshead box, and the second bolt hole is provided on the flange portion.

Preferably, on the rear end surface of the crosshead box, a flange portion is provided on both the upper edge and the lower edge of the crosshead box, and the second bolt hole is provided on the flange portion.

Preferably, sealing grooves are respectively provided on the front end face and the rear end face of the crosshead box, and the sealing area surrounded by the sealing grooves at least includes the crosshead inner cavity and the exhaust cavity.

Preferably, the crosshead box further includes a process hole penetrating the box body of the crosshead box. The process hole may be formed at a position corresponding to the inner cavity of the crosshead. In addition, the process hole may be provided at least at a position close to the embedded lubricating oil passage.

Preferably, the process hole formed on the top of the crosshead box is formed with a downward convex structure protruding toward the inner cavity of the crosshead.

Preferably, the process hole formed at the bottom of the crosshead box is formed with an upward convex structure protruding toward the inner cavity of the crosshead.

Preferably, the crosshead box is further provided with a mounting boss formed on the side end surface.

A second aspect of the present disclosure provides a piston pump including a crankcase, a crosshead box and a spacer as previously described.

Preferably, positioning pin holes are provided at the joint end surfaces of the crankcase, the crosshead box and the spacer for use in the crankcase, the crosshead box and the spacer. alignment positioning.

Preferably, the plunger pump further includes a reduction box, and a support ear plate is provided on the mounting boss formed on the side end surface of the crosshead box, and the support ear plate is connected to the support of the reduction box. components.

beneficial effects

According to the present disclosure, a new one-piece crosshead box is provided with a more reliable and easy-to-maintain lubrication system that can be easily manufactured. The crosshead box according to the present disclosure also has a good internal fluid passage, so that the air pressure inside the box can always be balanced during operation, thereby improving the smooth operation and service life of the equipment. In addition, the crosshead box according to the present disclosure also has a more reliable and easy-to-maintain lubrication system that can be easily manufactured. Crosshead boxes according to the present disclosure also greatly reduce overall weight and increase strength and stiffness. Small deformation in key mating parts makes lubrication, sealing and connection more reliable. It has good bending and torsion resistance, cushioning and shock resistance, and low notch sensitivity. In addition, the manufacturing process is greatly simplified, reducing time, labor and raw material costs. With this integrated crosshead box, various pump components can be improved and optimized to form a disruptive fracturing pump design and a platform development concept.

Description of the drawings

1 is a perspective view illustrating a schematic structure of a crosshead box according to an embodiment of the present disclosure;

2 is a perspective view illustrating a schematic structure of a crosshead box according to an embodiment of the present disclosure;

3 is a schematic diagram illustrating the structure of a crosshead inner cavity of a crosshead box according to an embodiment of the present disclosure;

4 is a schematic diagram illustrating the shape of the crosshead inner cavity of a crosshead box in the related art as a comparative example;

5a and 5b are schematic diagrams illustrating an alternative structure of a crosshead lumen of a crosshead box according to an embodiment of the present disclosure;

6 is a schematic diagram illustrating the structure of a crosshead sliding sleeve of a crosshead box according to an embodiment of the present disclosure;

7 is a schematic diagram illustrating the structure of a crosshead sliding sleeve of a crosshead box according to an embodiment of the present disclosure;

8 is a schematic diagram illustrating a positioning member of a crosshead sliding sleeve of a crosshead box according to an embodiment of the present disclosure;

9 is a schematic diagram illustrating the structure of a protruding portion of a crosshead slide bushing of a crosshead box according to an embodiment of the present disclosure;

10 is a schematic cross-sectional view illustrating the positional cooperation relationship between the protruding portion of the crosshead sliding sleeve and the end of the crosshead oil groove of the crosshead box according to an embodiment of the present disclosure;

11 is a perspective view illustrating the configuration of an exhaust chamber of a crosshead box according to an embodiment of the present disclosure;

12 is a schematic end view illustrating the construction of an exhaust chamber of a crosshead box according to an embodiment of the present disclosure;

13 is a schematic cross-sectional view illustrating the construction of an exhaust chamber of a crosshead box according to an embodiment of the present disclosure;

14 is a partial enlarged view illustrating an exemplary structure of a fluid channel at a front end face of a crosshead box according to an embodiment of the present disclosure;

15 is a partial enlarged view illustrating another exemplary structure of a fluid channel at a front end surface of a crosshead box according to an embodiment of the present disclosure;

16 is a partial enlarged view illustrating yet another exemplary structure of a fluid channel at a front end surface of a crosshead box according to an embodiment of the present disclosure;

17 is a schematic diagram illustrating the principle by which the exhaust chamber and the fluid channel of the crosshead box function according to an embodiment of the present disclosure;

18 is a schematic diagram illustrating the principle by which the exhaust chamber and the fluid passage of the crosshead box function according to an embodiment of the present disclosure;

19 is a schematic diagram illustrating the structure of a reinforcing beam of a crosshead box according to an embodiment of the present disclosure;

20 is a schematic diagram illustrating another structure of a reinforcing beam of a crosshead box according to an embodiment of the present disclosure;

21 is a cross-sectional view illustrating an example of a cross-sectional shape of a reinforcing beam of a crosshead box according to an embodiment of the present disclosure;

22 is a schematic diagram illustrating the structure of a transition region of a reinforcing beam of a crosshead box according to an embodiment of the present disclosure;

23 is a cross-sectional view illustrating the structure of a multifunctional structural hole of a crosshead box according to an embodiment of the present disclosure;

24 is a schematic cross-sectional view illustrating an embedded lubricating oil passage of a crosshead box according to an embodiment of the present disclosure;

Figure 25 is a schematic diagram illustrating a processing process of the embedded lubricating oil circuit of the crosshead box according to an embodiment of the present disclosure;

26 is a schematic diagram illustrating a processing process of the embedded lubricating oil circuit of the crosshead box according to an embodiment of the present disclosure;

27 is a schematic diagram illustrating the overall layout of the embedded lubricating oil circuit of the crosshead box according to an embodiment of the present disclosure;

28 is a schematic diagram illustrating the alignment position of the oil outlet of the embedded lubricating oil passage of the crosshead box according to an embodiment of the present disclosure;

29 is a schematic diagram illustrating a lubricating oil recovery path of an embedded lubricating oil circuit of a crosshead box according to an embodiment of the present disclosure;

30 is a schematic diagram illustrating the structure of the oil filling hole of the lubricating oil passage of the crosshead box according to an embodiment of the present disclosure;

31 is a schematic diagram illustrating a connection end surface of a crosshead case and a crankcase according to an embodiment of the present disclosure;

32 is a schematic diagram illustrating the connection end surface of the crosshead box and the spacer according to an embodiment of the present disclosure;

33 is an exploded schematic diagram illustrating the connection assembly of the crosshead case to the crankcase and spacer in accordance with an embodiment of the present disclosure;

34a and 34b are schematic diagrams illustrating the arrangement of seals connecting the crosshead case to the crankcase and spacer according to an embodiment of the present disclosure;

35 is a schematic diagram illustrating a partial seal around an oil outlet of a lubricating oil passage of a crosshead box according to an embodiment of the present disclosure;

36 is a schematic diagram illustrating the connection positioning of the crosshead case to the crankcase and spacer in accordance with an embodiment of the present disclosure;

37 is a schematic diagram illustrating the structure of a process hole and/or a viewing window of a crosshead box according to an embodiment of the present disclosure;

38 is a partial enlarged view illustrating the structure of the process hole and/or the boss of the observation window of the crosshead box according to an embodiment of the present disclosure;

39 is a schematic diagram illustrating the structure of a mounting boss of a crosshead box and a support lug and a lifting lug mounted thereon according to an embodiment of the present disclosure.

Detailed ways

Below, the technical solutions of various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some, but not all, of the embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without any creative efforts fall within the scope of protection of the present disclosure.

It should be noted that in the following detailed description and claims, expressions such as "approximately" and "approximately" are used in order to take into account manufacturing tolerances, processing accuracy and other factors that are understood by those of ordinary skill in the art, and It will not lead to vague descriptions and unclear scope of protection. In addition, the directions such as "upper", "lower", "left", "right", "front", and "back" appearing in this article are only directions defined in conjunction with the drawings for convenience of explanation. Those of ordinary skill in the art After reading this article, it is obvious that when the device is inconsistent with the orientation explained in this article due to flipping or moving, it is obvious that the orientation corresponding to the orientation explained in this article can be easily known.

Note that the same structures, elements or parts in the drawings are denoted by the same reference numerals.

1. Overview of crosshead box

1 and 2 illustrate a perspective view of a crosshead box 1000 according to a preferred embodiment of the present disclosure. In FIGS. 1 and 2 , a five-cylinder crosshead box 1000 is used as an example for explanation. However, the crosshead box 1000 of the present disclosure can obviously also be used for crosshead boxes 1000 with other numbers of cylinders, such as 3 cylinders, 7 cylinders, etc. As shown in FIGS. 1 and 2 , the crosshead box 1000 has an approximately rectangular parallelepiped shape as a whole and is integrally manufactured through a casting process. It has a front end surface 1001 connected to the spacer 3000, a rear end surface 1002 connected to the crankcase 2000, upper and lower panels 1003 and 1004 respectively located above and below the main body of the crosshead box, and located on both sides of the box. Main components such as the side end plates 1005 and the vertical plates located between the crosshead cavities. It should be noted that in this specification, the direction in which the crosshead reciprocates in the crosshead box 1000 between the front end surface 1001 and the rear end surface 1002 is called the axial direction or longitudinal direction of the crosshead box 1000. The arrangement direction of the heads in the crosshead box 1000 is called the transverse direction of the crosshead box 1000 . In addition, the side of the crosshead box 1000 connected to the spacer 3000 is called the front side or front end of the crosshead box 1000 , and the side of the crosshead box 1000 connected to the crankcase 2000 is called the rear side of the crosshead box 1000 . side or rear end. In addition, the upper panel 1003, the lower panel 1004, the side end panels 1005 and the partition panels 1101 that will be described below are all conventional names in the field for the convenience of reading by those skilled in the art. However, It should be understood that since the crosshead box 1000 according to the embodiment of the present disclosure is integrally formed using a casting process, the upper cover 1003 , the lower cover 1004 , the side end plates 1005 and the partition plates 1101 are not meant to be used herein. The above are separate panels, but they are all different components of the one-piece box. Therefore, the upper panel 1003 may also be regarded as the upper end surface of the crosshead box in this article, the lower panel 1004 may also be regarded as the lower end surface of the crosshead box in this article, and the side end plate 1003 may sometimes be regarded as the lower end surface of the crosshead box in this article. Can also be considered as the side end face of the crosshead box.

As can be seen from FIGS. 1 and 2 , according to embodiments of the present disclosure, the entire crosshead box 1000 is integrally formed through a casting process. By using the casting process, defects caused by welding are avoided, the structural rigidity is ensured, the fatigue strength of the structure is increased, and the service life is extended. In addition, integral casting can greatly reduce process complexity, save time, labor and raw material costs, and improve yield. It should be understood that other casting materials known in the art may also be selected to form the crosshead box 1000 according to requirements.

As shown in FIGS. 1 and 2 , a plurality of crosshead inner cavities 1100 are formed in the crosshead box 1000 . The crosshead inner cavity 1100 extends along the longitudinal direction of the crosshead box 1000 inside the crosshead box 1000 and penetrates from the front end surface 1001 to the rear end surface 1002 of the crosshead box 1000 . The crosshead cavity 1100 is used to accommodate the crosshead assembly and the sliding sleeve described below. The crosshead assembly reciprocates in the crosshead cavity 1100 along the axial direction of the crosshead box 1000 . A plurality of crosshead inner cavities 1100 are arranged side by side along the transverse direction of the crosshead box 1000 . The number of crosshead lumens 1100 depends on the number of crosshead assemblies.

Preferably, an exhaust chamber 1200 is provided above and/or below the crosshead inner chamber 1100 . Each exhaust chamber 1200 has a flat polygonal shape and extends along the longitudinal direction of the crosshead box 1000 inside the crosshead box 1000 , penetrating from the front end surface 1001 to the rear end surface 1002 of the crosshead box 1000 . The front end of the exhaust chamber 1200 is in fluid communication with an exhaust passage (which will be described in detail later) provided on the front end surface 1001 of the crosshead case 1000 , and the rear end of the exhaust chamber 1200 is in fluid communication with the inner cavity of the crankcase 2000 .

Preferably, at least one multifunctional structural hole 1300, which will be described in detail below, is provided at the junction between the crosshead lumen 1100 and the crosshead lumen 1100. The multifunctional structural hole 1300 may, for example, have a circular or triangular shape as shown and extend along the longitudinal direction of the crosshead box 1000 inside the crosshead box 1000 , penetrating from the front end surface 1001 to the rear end surface 1002 of the crosshead box 1000 . The multifunctional structural hole 1300 can be provided at the upper and/or lower portion of the crosshead box 1000 as needed.

Preferably, an embedded lubricating oil passage 1500 is provided in the crosshead box 1000 . Different from the oil circuits provided through additional connected oil pipes and hoses in the prior art, the embedded lubricating oil circuit 1500 is an interconnected oil hole and oil passage formed in the box of the crosshead box 1000 (for example, by drilling processed). In addition, the embedded lubricating oil circuit 1500 usually includes at least one main oil circuit and at least one branch oil circuit.

In addition, as shown in FIGS. 1 and 2 , the crosshead box 1000 is also provided with components such as connecting holes and observation windows, which will be described in detail below.

2. Cross head inner cavity and sliding sleeve

2.1 Shape of the crosshead cavity

3 shows a schematic diagram of the structure of the crosshead cavity 1100 in the crosshead box 1000 according to the present disclosure. As shown in FIG. 3 , the crosshead inner cavity 1100 has a substantially cylindrical shape, for example. In other words, the crosshead lumen 1100 has a generally circular shape in an axially vertical cross-section of the crosshead box 1000 . In this case, the partition plate 1101 between the crosshead inner cavities 1100 has a corresponding double arc shape that is thicker at the top and thinner at the middle. The crosshead inner cavity 1100 having a cylindrical shape can reduce the box size of the crosshead box 1000, is easy to cast, and facilitates subsequent assembly of the sliding sleeve.

In the prior art, the crosshead inner cavity 1100 is basically shaped like a track and field track as shown in FIG. 4 , that is, an approximate rectangular parallelepiped shape with straight sides on the left and right sides and arcs on the upper and lower sides. This is because if a nearly circular crosshead inner cavity is formed through welding technology, the upper and lower parts formed will be flatter, which will result in the need for a larger distance between cylinders. In addition, although in theory the "race track" design can reduce the contact surface pressure between the crosshead assembly and the crosshead cavity, and the rectangular shape on both sides can reduce the distance between the cylinders, local deformation under heavy load will cause the crosshead to The head assembly and the crosshead cavity change from surface contact to line contact, causing the actual surface pressure to be much greater than the theoretical value. In the crosshead box 1000 according to the present disclosure, due to the adoption of integrated molding technology, the partition plate 1101 between the crosshead inner cavities 1100 and the exterior of the crosshead box 1000 including the side end plates 1005 and the upper and lower masks 1004 The housing is cast in one piece, so the crosshead cavity 1100 can be easily cast to have a generally cylindrical shape if desired. In addition, due to the use of cast one-piece molding, the structure has good rigidity and can easily meet the cylinder diameter requirements, so there is no need to adopt a "race track" design and a simpler cylindrical shape can be used.

It should be understood that, of course, the crosshead inner cavity 1100 according to the present disclosure can also be designed into an approximate rectangular parallelepiped shape similar to that in the prior art, or any other desired shape, so as to fully utilize the advantages of casting. For example, when the crosshead lumen 1100 according to the present disclosure is designed to have an approximate cuboid shape similar to that in the prior art, as shown in FIGS. 5a and 5b , the partition plates 1101 between each crosshead lumen 1100 It may be formed as a plurality of spacer columns 1102 extending up and down arranged side by side in the crosshead axial direction. The gap between the spacer columns allows the two adjacent crosshead inner cavities 1100 to be fluidly connected, which can be used for oil drainage and exhaust gas that will be described in detail later. In this case, a further improved exhaust effect can be expected when used in combination with an exhaust chamber and a fluid passage which will be described later in this article. In addition, in this case, in the two crosshead inner cavities 1100 located at the outermost ends of both sides of the crosshead box 1000, there is also a gap between the crosshead assembly and the side end plates 1005 on both sides of the crosshead box 1000. This gap It can also perform the oil drain and exhaust function that will be explained in detail later. In addition, in this case, the sliding sleeve also adopts a block-shaped upper and lower two-piece structure commonly used in this field. We won’t go into details in this article.

2.2 Cross head sliding sleeve

A crosshead sliding sleeve 1400 is provided in the crosshead inner cavity 1100 . The crosshead sliding sleeve 1400 is in contact with the crosshead and carries the reciprocating motion of the crosshead in the crosshead inner cavity 1100 . In one embodiment of the crosshead box 1000 according to the present disclosure, as shown in FIG. 6 , the crosshead sliding sleeve 1400 has a cylindrical shape capable of being embedded in the cylindrical crosshead inner cavity 1100 . Compared with the upper and lower two-piece split structure mentioned above, this one-piece crosshead sliding sleeve 1400 can enhance the bending stiffness and torsional stiffness of the structure, reduce the wear of the bearing bush at the crosshead position, and solve the fatigue fracture of the bearing bush. And other issues. As shown in Figures 6 and 7, the crosshead sliding sleeve 1400 is designed with a sliding sleeve oil hole 1401 that penetrates the sliding sleeve wall. The oil hole 1401 is used to fluidly communicate with the lubricating oil passage to be described below to allow lubricating oil to circulate. The oil hole can be provided at any position other than the end of the crosshead sliding sleeve 1400 as required. The position, quantity and shape of the oil holes 1401 can be determined according to the lubrication requirements of the oil passages and lubricated components.

In addition, as shown in Figures 7 and 8, the end head of the cross head sliding sleeve 1400 close to one end (ie, the front end) of the spacer 3000 is designed with a sliding sleeve positioning pin hole 1402, in which the cross head sliding sleeve 1400 can be installed. The head sliding sleeve 1400 locates the elastic cylindrical pin. The position of the pin hole 1402 is not limited, as long as it meets the positioning requirements and does not affect other structural functions. Preferably, the pin holes 1402 should generally not be arranged at circumferentially symmetrical positions such as directly above and directly below or directly left and right to prevent it from being difficult to determine the correct angular orientation of the installation when the sliding sleeve is installed. During the assembly process of the crosshead sliding sleeve 1400, the pin hole 1402 can, for example, cooperate with the limiting groove 1006 provided in the crosshead inner cavity 1100 at the edge of the front end surface 1001 of the crosshead box 1000 to realize the crosshead sliding sleeve. 1400 is positioned along the axis of the crosshead box 1000 . For example, during installation, the elastic cylindrical pin is fastened to the positioning pin hole 1402 of the crosshead sliding sleeve 1400, and the crosshead sliding sleeve 1400 is inserted into the crosshead inner cavity 1100 from the front end of the crosshead box 1000 in the axial direction until When the side of the elastic pin contacts the surface of the limiting groove, it is installed in place. During the installation process, for example, the sliding sleeve can be cooled with liquid nitrogen first. The thermal expansion and contraction effects will reduce the size of the sliding sleeve. Then, the cooled sliding sleeve is inserted into the crosshead cavity in a short period of time. After the temperature of the sliding sleeve rises to room temperature, it expands in size and creates an interference fit with the inner cavity of the crosshead, thereby ensuring that the sliding sleeve will not come out of the inner cavity of the crosshead during the operation of the crosshead assembly. It should be understood that the parts used for positioning are not limited to elastic cylindrical pins, and the cross-sectional dimensions of the pins can also be adjusted as needed to adapt to changes in the size of the pin holes caused by the return temperature of the crosshead sliding sleeve 1400 due to cold assembly. The shape, position, and quantity of the above-mentioned pins and grooves can also be selected according to the actual situation, and the two can be matched. In addition, the positioning method can also be other positioning methods such as first aligning the limiting groove of the crosshead box 1000 with the positioning pin hole of the crosshead sliding sleeve 1400, and then driving in the positioning pin for positioning.

As shown in FIG. 7 , an inner recess 1404 is provided at the front end of the crosshead sliding sleeve 1400 . The inner recess 1404 is recessed from the front end to the rear end of the crosshead sliding sleeve 1400 in the axial direction of the crosshead box 1000, thereby matching the shape of the groove of the front end surface 1001 of the crosshead box 1000 that will be described below. , to jointly form a fluid channel 1201 for draining oil and exhaust gas. As shown in FIGS. 7 and 9 , extended protrusions 1403 are respectively formed at the top and bottom of one end (ie, the rear end) of the crosshead sliding sleeve 1400 that is connected to the crankcase 2000 . The protruding portion 1403 protrudes from the rear end of the crosshead sliding sleeve 1400 toward the crankcase 2000 in the axial direction of the crosshead case 1000 . For example, when the crosshead sliding sleeve 1400 is installed into the crosshead cavity 1100, the recessed portion 1404 and the protruding portion 1403 are respectively located at the top and bottom of the crosshead cavity 1100. As shown in FIG. 7 , a transitional fillet is preferably formed in the transition area between the protruding portion 1403 and the non-protruding portion of the rear end surface 1002 of the crosshead sliding sleeve 1400 to maximize the protruding portion 1403 The stiffness at the root of the crosshead is reduced, while reducing the stress accumulation caused by the pressure of the oil groove seal oil pressure at the bottom of the crosshead. FIG. 7 illustrates an example in which there are two concave portions 1404 and two protruding portions 1403 , but it should be understood that the concave portions 1404 and the protruding portions 1403 are not limited to two, and may also be one or more.

The existence of the protruding portion 1403 allows the crosshead sliding sleeve 1400 to adapt to crosshead boxes 1000 of different length specifications, thereby meeting the closed space required for contact between crosshead assemblies of different operating lengths and the oil film on the contact surface of the sliding sleeve, thereby Achieve shared platform production of one-piece crosshead box 1000. As shown in Figure 10, the size of the protruding portion 1403 is related to the size and position of the oil groove at the bottom of the crosshead. Specifically, in the actual working state of the crosshead and crosshead box, the protruding portion 1403 of the sliding sleeve needs to cooperate with the oil groove at the bottom of the crosshead to form a seal. Therefore, the size of the protruding portion 1403 of the sliding sleeve should be sufficient to cover the sealing length of the oil groove at the bottom of the crosshead. In Figure 10, the dark shading at the bottom of the crosshead shows the oil groove at the bottom of the crosshead. The "sealing length" of the oil groove refers to the length between the oil groove ends 1502 at both ends of the oil groove. The parts at both ends of the oil groove other than the oil groove ends 1502 cooperate with the sliding sleeves 1400 to form a linear sealing structure. When the crosshead moves in the crosshead sliding sleeve 1400 to the extreme position on one side of the crankcase, a part of the oil groove may be outside the crosshead inner cavity 1100 . That is, as can be seen in FIG. 10 , a portion of the dark shading representing the oil sump is located outside the crosshead cavity 1100 . In this case, the existence of the protruding portion 1403 of the sliding sleeve ensures that the lubricating oil in the crosshead oil groove will not leak out under a certain pressure. In other words, the protruding portion 1403 needs to meet the sealing requirements of the oil groove end 1502 when the crosshead is at the position closest to the crankcase 2000 in the crosshead case 1000 . At the same time, the protruding portion 1403 can adapt to a wide range of plungers of different lengths and plunger strokes. When the plunger is installed and the plunger performs stroke movement within the adaptation range, there is no need to replace the sliding sleeve 1400 of other specifications and lengths.

It should be noted that in the crosshead box 1000 according to the present disclosure, the above-mentioned arrangement of the crosshead sliding sleeve 1400 is preferred, but the crosshead sliding sleeve 1400 may not be provided, that is, the crosshead inner cavity 1100 is The inner surface doubles as a sliding sleeve. This is because the crosshead box 1000 according to the embodiment of the present disclosure is made of ductile iron by adopting an integral casting process. The ductile cast iron material has a high spheroidization rate, and graphite can play a self-lubricating role under non-lubricating conditions. If there is lubrication, graphite can not only absorb and preserve lubricating oil, but also maintain the continuity of the oil film, so it can double as a sliding sleeve. In this case, in order to improve the sliding effect of the crosshead, oil storage structures such as fine mesh patterns can also be processed on the inner surface of the crosshead inner cavity 1100 to enhance the lubrication effect of the lubricating oil. Compared with the technical solution using a copper integrated sliding sleeve mentioned in the above embodiment, the ductile iron material of the crosshead inner cavity 1100 has better lubrication performance, and the structure is simpler and does not require high-precision installation and alignment. Accurate, therefore more economical and cost-saving.

In addition, when the inner surface of the crosshead inner cavity 1100 also serves as a sliding sleeve, the casting material needs to meet the spheroidization rate required by the sliding sleeve performance, and the corresponding protruding portion 1403 and the inner concave portion 1404 are simultaneously cast and machined. For example, a spheroidization rate greater than 80% is preferred. In addition, oil holes, recesses matching the exhaust chamber 1200 that will be described later, and component features such as rounding and contact surfaces that require high precision or cannot be met by casting technology can also be completed through post-machining or other general methods.

In the one-piece cast crosshead box 1000, an exhaust chamber 1200 is provided at the connection position between the upper cover plate 1003 and the lower cover plate 1004 and the crosshead cylindrical inner cavity to maintain the crosshead inner cavity when the crosshead assembly reciprocates. 1100 air pressure balance.

3 Exhaust chamber and fluid channel

3.1 Structure of the exhaust chamber

In the crosshead box 1000 according to the embodiment of the present disclosure, a plurality of crosshead exhaust chambers 1200 are respectively provided above and below the crosshead inner cavity 1100 for maintaining the crosshead assembly to reciprocate in the crosshead inner cavity 1100 The air pressure in the crosshead cavity 1100 is balanced during movement. The exhaust chamber 1200 penetrates the crosshead case 1000 in the axial direction of the crosshead case 1000 , its front end is in fluid communication with a later-described fluid passage 1201 and its rear end is in fluid communication with the internal cavity of the crankcase 2000 . 11 to 13 are perspective views, end views, and cross-sectional views respectively showing an exemplary configuration of the exhaust chamber 1200 of the crosshead box 1000.

As shown in FIGS. 11 to 13 , for example, the exhaust chamber 1200 may be disposed between the crosshead inner cavity 1100 and the upper cover 1003 and the lower cover 1004 of the crosshead box 1000 . In other words, the exhaust chamber 1200 may be provided, for example, between the main body of the crosshead box 1000 in which the crosshead inner cavity 1100 is formed, and the upper and lower panels 1003 and 1004 of the crosshead box 1000 . The shape of the exhaust chamber 1200 can be designed as needed, and there are no special requirements. In the illustrated embodiment, the exhaust chamber 1200 has a polygonal shape with flattened corners and rounded corners in a cross-section perpendicular to the axial direction of the crosshead box 1000 . Such a shape can make full use of the space above and below the crosshead inner cavity 1100, and can enable the arrangement of the exhaust chamber 1200 to give full play to the advantages of the casting process and take into account the exhaust requirements and the structural stiffness requirements of the box. The exhaust chamber 1200 can also be arranged at other locations, as long as it does not affect the structural rigidity of the box and the structural functions of other components.

It should be noted that the specific shape of the exhaust chamber 1200 is not limited to the above-mentioned shape shown in the figure, and may also be circular or other regular or irregular shapes, for example. When an exhaust chamber 1200 is provided above and below each crosshead inner chamber 1100, the shapes of the upper and lower exhaust chambers 1200 may be symmetrical or asymmetrical. From the perspective of ensuring the overall axial stiffness and bending stiffness of the crosshead box 1000, a symmetrical solution is preferred. There are no special restrictions on the number and molding method of the exhaust cavities 1200, as long as they meet the exhaust function described below, avoid the bolt load-bearing affected area, and do not affect other structural functions. For example, only one exhaust chamber 1200 may be provided above or below each crosshead inner chamber. In addition, in the illustrated embodiment, the crosshead inner cavity 1100 and the two exhaust cavities 1200 located above and below it are centrally symmetrical in the transverse direction of the crosshead box 1000, and are vertically perpendicular to the transverse direction. It is also centrally symmetrical in direction. However, the crosshead inner cavity 1100 and the two exhaust cavities 1200 located above and below it can also be arranged to be symmetrical with respect to the horizontal axis and the longitudinal axis, or even staggered in an asymmetric manner according to design requirements.

3.2 Structure of fluid channel

14 is a partial enlarged view illustrating a preferred embodiment of the fluid channel 1201 at the front end face 1001 of the crosshead box 1000 according to an embodiment of the present disclosure. As shown in FIG. 14 , at the front end surface 1001 of the crosshead box 1000 (that is, the end surface connected to the spacer 3000 ), the box body between the crosshead inner cavity 1100 and the exhaust chamber 1200 is formed with a crosshead The groove of the box 1000 is concave axially inward (ie, toward the crankcase side), so that in the assembled state of the crosshead box 1000 and the spacer 3000, the crosshead inner chamber 1100 and the exhaust chamber 1200 pass through like this The grooves are in fluid communication at the end face. Such grooves are also called fluid channels 1201. The fluid channel 1201 and the exhaust chamber 1200 together constitute the exhaust passage of the crosshead box 1000, which plays the role of exhausting oil (lubricating oil) and maintaining the balance of oil and gas in the crosshead inner cavity 1100. In addition, the concave shape of the inner recess 1404 of the crosshead sliding sleeve 1400 described above matches the cross-sectional shape of the groove of the fluid channel 1201, so that when the crosshead sliding sleeve 1400 is installed into the crosshead inner cavity 1100 , the crosshead sliding sleeve 1400 does not block the exhaust passage between the crosshead inner cavity 1100 and the exhaust chamber 1200, and the crosshead inner cavity 1100 is in fluid communication with the exhaust chamber 1200 via the inner recess 1404 and the fluid channel 1201.

The groove forming the exhaust passage shown in FIG. 14 has a wave-like arc shape. This is because due to the inwardly concave groove formed at the end face, the material extension length of the box in the axial direction at the groove is different from the extension length of the areas on both sides of the groove. Therefore, during the casting process, when the groove area transitions to the two side areas, it is easy to generate large internal stress near their junction transition, which will reduce the structural strength of the casting. By adopting a smooth shape design similar to a wave shape, the length of the intersection area can be gradually changed in a smooth manner, which can reduce the risk of generating large internal stress near the intersection area when transitioning from the middle area to the two side areas. Therefore, the structural rigidity here can be improved.

It should be understood that, in addition to the wave-like arc shape shown in FIG. 14 , the fluid channel 1201 can also be formed into other shapes. For example, a fluid channel 1201 having an approximately trapezoidal cross-section is illustrated in FIG. 15 . A fluid channel 1201 having an approximately rectangular cross-section is illustrated in Figure 16 . When the fluid channel 1201 has a non-arc polygonal shape such as a rectangle or a trapezoid, as shown in Figures 15 and 16, in order to achieve the above-mentioned effects of minimizing stress and improving structural stiffness, the groove and the two sides are The junction area, that is, the concave bending area, should be rounded, beveled or otherwise smoothly transitioned. In addition, the size of the fluid channel 1201 is not particularly limited and can be determined based on the size of the exhaust chamber 1200 and the principle of not affecting the structural function of the crosshead box 1000 . In addition, although the drawings only show an example in which the fluid channel 1201 is formed on the front end surface 1001 of the crosshead box 1000, it can be understood that a similar fluid channel can also be formed on the rear end surface 1002 of the crosshead box 1000. This further facilitates the communication between the inner cavity of the crosshead and the exhaust chamber on the connection side of the crosshead case and the crankcase.

3.3 Functions and functions of the exhaust chamber and fluid channel

Next, how the exhaust chamber 1200 and the fluid channel 1201 maintain the air pressure balance of the crosshead inner chamber 1100 will be described with reference to FIGS. 17 and 18 . It should be noted that what is shown in Figures 17 and 18 is the state in which the crosshead case 1000 and the crankcase 2000 are joined together. This is because in the use state, most of the internal cavities of the crosshead case 1000 and the crankcase 2000 are fluidly connected and functionally closely related.

FIG. 17 illustrates a schematic diagram of the fluid flow path in the crosshead lumen 1100 when the crosshead assembly slides toward the front end (spacer side) in the crosshead lumen 1100 . As shown in Figure 17, under this working condition, the pressure at the front end of the crosshead inner cavity 1100 gradually increases, and the oil and gas in the front end of the crosshead inner cavity 1100 flows upward and downward into the exhaust through the fluid channel 1201 at the front end face. The air chamber 1200 flows toward the crankcase through the exhaust chamber 1200 . The oil and gas in the crankcase 2000 can enter the rear end of the crosshead inner cavity 1100 through the connecting rod movable window 2001 (see Figure 33) of the crosshead case 1000. As the crosshead continues to slide toward the front end, the space at the front end of the crosshead inner cavity 1100 continues to become smaller, and the pressure at the front end of the crosshead inner cavity 1100 continues to increase. The increased pressure at the front end of the crosshead is transmitted to the exhaust chamber 1200 through the fluid channel 1201, so that a part of the oil and gas in the exhaust chamber 1200 enters the inner cavity of the crosshead from the rear end of the exhaust chamber 1200 through the connecting rod movable window 2001 of the crankcase 2000. 1100, and allows another part of the oil gas in the exhaust chamber 1200 to flow into the crankcase 2000 and diffuse. A schematic diagram of the fluid flow path in the crosshead cavity 1100 as the crosshead assembly slides toward the rear end (crankcase side) in the crosshead cavity 1100 is illustrated in FIG. 18 . As shown in FIG. 18 , when the crosshead slides to the rear end (i.e., the crankcase side) in the crosshead inner cavity 1100 , the pressure at the rear end of the crosshead inner cavity 1100 gradually increases, and the pressure at the rear end of the crosshead inner cavity 1100 increases. Oil and gas can enter the rear end of the exhaust chamber 1200 of the crankcase 2000 and the crosshead case 1000 from the connecting rod movable window 2001 of the crankcase 2000 . As the crosshead continues to slide toward the rear end, the pressure at the rear end of the crosshead inner chamber 1100 continues to increase. This pressure is transmitted to the exhaust chamber 1200, causing the oil and gas in the exhaust chamber 1200 to flow from the rear end to the front end and through the fluid channel. 1201 enters the front end of the crosshead inner cavity 1100.

As mentioned above, since the crosshead box 1000 according to the present disclosure is integrally formed by a casting process, it is possible to provide an exhaust channel that penetrates the crosshead box 1000 in the axial direction of the crosshead box 1000 near the crosshead inner cavity 1100 and the fluid channel 1201 located on the front end face 1001 of the crosshead box 1000, so that the oil (lubricating oil) and air in the crosshead inner cavity 1100 can pass through the fluid channel 1201, the exhaust chamber 1200 and the connecting rod movable window 2001 without the need for external circulation. In the case of the device, self-circulating flow can be achieved, so that the crosshead inner cavity 1100 maintains air pressure balance during the reciprocating motion of the crosshead assembly. The dedicated flow channel and exhaust chamber 1200 also reduce the noise caused by the high-speed flow of gas when the crosshead assembly reciprocates, and also facilitate the assembly and disassembly of components.

In addition, it is also conceivable to adopt other designs or molding methods to form an exhaust chamber in fluid communication with the crosshead inner chamber 1100 to achieve the purpose of balancing air pressure. For example, the front end and the rear end of the crosshead inner cavity 1100 are fluidly connected by opening holes or forming channels at other locations inside the crosshead box 1000 to assist ventilation. Such holes and channels may be formed in any manner as long as they are positioned so as not to interfere with the crosshead assembly, cavity support structure, and bolt tightening function.

4. Reinforced beams and multifunctional structural holes of the crosshead box

The crosshead box 1000 according to an embodiment of the present disclosure is integrally formed through a casting process. In order to overcome the common shortcomings of heavy weight in traditional castings, the crosshead box 1000 according to the embodiment of the present disclosure has undergone special structural optimization in terms of stiffness enhancement and weight reduction of the crosshead box 1000, so that the crosshead box 1000 according to the embodiment of the present disclosure On the premise of ensuring structural rigidity, the weight of the crosshead box 1000 is 10% to 16% lighter than that of the crosshead box 1000 with the same level of welding process.

These structural optimization features of the crosshead box 1000 according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

4.1 Reinforced beam

As shown in FIG. 19 , in the exhaust chamber 1200 , in order to reduce the weight of the crosshead box 1000 , a portion of the main body of the crosshead box corresponding to the crosshead inner cavity 1100 (that is, the exhaust chamber 1200 is located at the crosshead (The inner wall of the inner cavity 1100 side), the box molding materials are all thinned. Reinforcing beams 1210 are only provided between the front and rear end faces 1002 and the front and rear end faces 1002 to form multiple "I-shaped" frame structures to improve the overall bending stiffness, ensure the stiffness and stability of the crosshead inner cavity 1100, and prevent relative displacement. and deformation. It should be noted that, for clarity of illustration, the upper cover 1003 is omitted in FIG. 19 and subsequent related drawings, and only the main part of the crosshead box 1000 is shown. In addition, it is easy to imagine that although FIG. 19 only illustrates the reinforcing beam in the upper part of the crosshead inner cavity 1100, it is obvious that the same or similar ones can also be formed in the exhaust chamber 1200 located in the lower part of the crosshead inner cavity 1100. Reinforced beam structure.

In this embodiment, reinforcing beams 1210 are designed in both the upper and lower exhaust chambers 1200 . In addition to the I-shaped reinforcing beam 1210 shown in FIG. 19 , the reinforcing beam 1210 can also adopt other shapes of frame structures. The number, angle, and position of the longitudinal reinforcing beams 1210 extending along the axial direction of the crosshead box 1000 and the transverse reinforcing beams 1210 extending along the transverse direction of the crosshead box 1000 are not limited, as long as they can play a supporting role and do not affect the lower The setting of the lubricating oil circuit and the setting of the bolts will be explained in the article. For example, FIG. 20 illustrates a king-shaped reinforcing beam 1210. The added middle beam further enhances the support stiffness of the middle part of the crosshead box 1000. In addition, a reinforcing beam 1210 structure such as a "Ⅱ" shape, a "Ш" shape, a "field" shape or a "mesh" shape can also be used. The forming method of the reinforcing beam 1210 is not limited to casting, and may also be machined or other methods. In addition, other structures can be used to support the crosshead assembly, such as irregular support plates on the upper and lower sides or one side.

As shown in FIG. 21 , the cross section of the reinforcing beam 1210 has a substantially rectangular shape, but the cross section may also be other shapes such as triangle, trapezoid, circle, etc. Rectangle is preferred because compared with other solid regular cross-sections of the same area (such as circles, trapezoids, triangles, etc.), the cross-sectional moment of inertia of the long axis of the rectangle is larger, which can ensure that the stiffeners have sufficient bending stiffness and are restrained from being located within the crosshead. Displacement and deformation between the spacer plates 1101 between the cavities 1100 .

In addition, as shown in Figure 22, a rounded transition structure 1211 is provided at the junction of the reinforcing beam 1210 and the first bolt hole 1610 to be described below, and at the connection between the root of the reinforcing beam 1210 and the main body of the crosshead box 1000 There is also a rounded transition structure 1211. The rounded corner transition structure 1211 can increase the bending strength of the corresponding parts, reduce stress concentration, and meet the casting process requirements. The size and shape of the fillet are mainly affected by the shape and position of the reinforcing beam 1210 and the bolt hole. For example, the transition fillet at the interface between the reinforcing beam 1210 and the bolt hole should be as concentric as possible with the bolt hole and smoothly transition to the upper surface of the reinforcing beam 1210 . The transition fillet located at the connection between the root of the reinforcing beam 1210 and the main body of the crosshead box 1000 can smoothly transition to the main body of the crosshead box 1000 at the root of the reinforcing beam 1210 according to the shape of the reinforcing beam 1210, so that the overall extension arc remains consistent with the inside of the crosshead. The arc segments of the inner wall of the cavity 1100 are concentric. During actual fillet processing, you can set the bevel or arc (equal curvature or variable curvature) according to your needs.

4.2 Multifunctional structural hole

As mentioned above, in the crosshead box 1000 according to the embodiment of the present disclosure, at least one multifunctional structural hole 1300 is also provided. As shown in FIGS. 1 and 2 , it is preferable that a plurality of multifunctional structural holes 1300 are arranged, for example, at a portion of the crosshead box 1000 that is close to the crosshead inner cavity 1100 and has a thicker thickness. For example, in addition to the outermost side end of the crosshead box 1000 , the multifunctional structural hole 1300 may be arranged, for example, at the shoulder between the two crosshead inner cavities 1100 . FIG. 23 illustrates a longitudinal cross-sectional view of the multifunctional structural hole 1300 taken along the axial direction of the crosshead box 1000 . As can be seen from the figure, the multifunctional structural hole 1300 penetrates the crosshead box 1000 along the axial direction of the crosshead box 1000 . As shown in the figure, a first bolt hole, which will be described below, is arranged on the outside of the multifunctional structural hole 1300 . Preferably, as shown in Figures 1, 2 and 22, each multi-functional structural hole 1300 can be centrally aligned with the first bolt hole located on its outer side in a direction perpendicular to the transverse direction of the crosshead box. at the shoulder position between the two crosshead lumens 1100 to make the stress distribution more uniform. Of course, according to specific design needs, the multifunctional structural hole 1300 and the first bolt hole may not be aligned but may be staggered by a certain distance from each other. In addition, considering the circular shape of the crosshead inner cavity 1100 on both sides of the multifunctional structural hole 1300 and the lubricating oil passages inside the crosshead box 1000 that need to be avoided (for example, the circular hole shown in FIG. 23 ), therefore Although the multifunctional structural hole 1300 can have any polygonal cross-sectional shape, it preferably has a triangular shape with rounded corners, and can be designed to have appropriate dimensions. Through the selection of shape and size, the wall thickness of the functional structure around the multifunctional structure hole 1300 can be made uniform, that is, the thickness is basically the same. For example, the triangular multifunctional structural hole 1300 is disposed on the shoulder between the two crosshead inner cavities 1100. One vertex of the multifunctional structural hole 1300 located on the upper shoulder of the crosshead inner cavity 1100 points downward, and is located on the crosshead inner cavity 1100. A vertex angle of the multifunctional structural hole 1300 on the lower shoulder of the head cavity 1100 is oriented upward to ensure that the wall thickness between the two adjacent cross head cavities 1100 is the same and to avoid support deviation during operation to cause a cross The head box 1000 is damaged. Two vertically symmetrical multifunctional structural holes 1300 may also be arranged at the transverse outermost edge of the crosshead box 1000 to ensure that the inner cavity 1100 of the crosshead is evenly stressed. Of course, in actual design, the shape of the multifunctional structural hole 1300 can also be circular, diamond or other shapes, as long as the above casting structure requirements are met.

By arranging the multi-functional structural hole 1300 at the thicker portion between the two crosshead inner cavities 1100, the weight of the entire crosshead box 1000 can be greatly reduced while meeting the structural stiffness requirements. In addition, since the multifunctional structural hole 1300 is also located in the area between the crosshead inner cavity 1100 and the bolt hole, the stress on the crosshead inner cavity 1100 and the bolt hole can be released at this hole to avoid excessive extrusion. Structural damage occurs to the internal tissue surrounding the functional structural hole 1300. In addition, the multifunctional structural hole 1300 can also have the function of preventing shrinkage in the casting process. During the casting process, hot cracking and cold cracking problems often occur. After the liquid metal is injected into the mold cavity, it begins to condense. When the crystalline skeleton has formed and begins to linearly shrink, stress or plastic deformation will occur in the casting because the internal molten steel has not completely solidified and its shrinkage is blocked. When the stress or deformation exceeds the material strength limit at this high temperature, the casting will crack, which is called hot cracking. Cold cracking refers to cracking caused by the local casting stress being greater than the ultimate strength of the alloy when the casting is cooled to an elastic state after solidification. Cold cracking always occurs in the parts that bear tensile stress during the cooling process, especially the parts where the tensile stress is concentrated. Therefore, the casting process also requires an anti-shrinkage structure to avoid casting defects, ensure a uniform wall surface of the cylindrical crosshead inner cavity 1100, and reduce stress concentration.

Therefore, the crosshead box 1000 according to the embodiment of the present disclosure not only greatly reduces the weight of the crosshead box 1000 but also reduces the crosshead inner cavity 1100 by arranging the multifunctional structural hole 1300 between the bolt hole and the crosshead inner cavity 1100 It also greatly reduces the stress concentration on the bolt holes when in use, and also greatly reduces the possibility of cold cracking and hot cracking in the molding materials around the bolt holes and the crosshead inner cavity 1100 during the casting process of the crosshead box 1000, which is the crosshead box 1000. The design of the head box 1000 provides structural and functional guarantee.

It should be noted that in the case where a spacer column 1102 is provided between the crosshead inner cavity 1100 as shown in Figure 5a and Figure 5b instead of the spacer plate 1101, although it is not shown in the figure, it is also possible. Multifunctional structural holes 1300 may be formed at similar locations.

4.3 Side end plates of the crosshead box

The side end plates 1005 on both sides of the crosshead box 1000 may also have a curved surface shape to reduce the overall weight of the crosshead box 1000 and make the wall thickness of the crosshead inner cavity 1100 as uniform as possible to reduce stress concentration. The side end plates 1005 may also be selected to have other structural features such as grooves, multiple cut sections, etc., to achieve similar effects.

5. Lubricating oil circuit

In the traditional crosshead box 1000 manufactured by the welding process, the lubricating oil circuit can only be set up through additional oil pipes. This is because the alloy plate has high hardness and density and limited thickness, so it is difficult to form an oil passage inside the plate through drilling and other processes. Since the crosshead box 1000 according to the present disclosure adopts a casting process, the box body is made of a material with relatively low hardness such as ductile iron, and the casting process enables the local thickness of the component to be flexibly controlled, thereby directly forming an integrated body. It becomes possible to have an embedded oil circuit structure in the molding material of the crosshead box.

A schematic cross-sectional view of the embedded lubricating oil passage 1500 of the crosshead box 1000 according to an embodiment of the present disclosure is illustrated in FIG. 24 . The oil holes and oil passages are processed into the molding material of the crosshead box 1000 box body. Compared with external oil passages, a series of complicated pipeline installation steps are reduced. The overall layout is simpler and a large number of lubrication pipes and pipes are reduced. The consumption of joints ensures reliable sealing of lubricating oil and avoids oil and gas leakage. The arrangement of the main oil circuit and the branch oil circuit inside the crosshead inner cavity 1100 needs to avoid the load-bearing affected area of the threaded hole to avoid weakening the strength of the threaded connection or deforming and blocking the oil hole caused by screwing in the bolt. In addition, it is also necessary to avoid affecting the surrounding structural functions (such as the supporting function of the reinforced beam 1210). As long as the above conditions are met, the angle, extension direction and number of oil passages can be designed flexibly for lubrication. As shown in Figure 25, the lubricating oil passage 1500 can be formed by processing a through hole downward through the process hole/observation window 1810 described later, or it can be drilled from the inside to the outside in the crosshead inner cavity 1100 using a right-angle drill as shown in Figure 26 Made by drilling holes. Other methods can also be used to form embedded oil passages according to actual needs.

In the working state, the crosshead assembly reciprocates at high speed in the crosshead box 1000, and many components require lubrication of lubricating fluid to function normally. Since the working conditions of different components are different, the amount and flow rate of lubricating oil required are also different. Therefore, it is necessary to provide high-pressure lubricating oil circuit 1510 and low-pressure lubricating oil circuit 1520 respectively. For example, the high-pressure lubricating oil line 1510 lubricates the crosshead bearing bushes and connecting rod bearings working in the crosshead box 1000 under working conditions, and the low-pressure lubricating oil line 1520 lubricates the crosshead sliding sleeve 1400 . For example, the high-pressure lubricating oil circuit 1510 has a rated lubricating oil pressure of 200-350 PSI, and the low-pressure lubricating oil circuit 1520 has a rated lubricating oil pressure of 60-150 PSI, for example.

27 illustrates a schematic diagram of the overall layout of the embedded lubricating oil circuit 1500 of the crosshead box 1000 according to an embodiment of the present disclosure. It should be noted that in FIG. 27 , in order to clearly illustrate the layout of the embedded lubricating oil circuit, illustration of some components in the crosshead box 1000 such as the sliding sleeve 1400 is omitted. As shown in FIG. 27 , in the crosshead box 1000 according to the embodiment of the present disclosure, the lubricating oil passages 1500 are all embedded oil passages formed by drilling holes in the box body of the crosshead box 1000 . That is to say, the embedded lubricating oil circuit 1500 of the crosshead box 1000 according to the embodiment of the present disclosure does not require additional pipeline components such as oil pipes and corresponding connecting components, sealing components, etc. In the embodiment shown in FIG. 27 , both the low-pressure lubricating oil circuit 1520 and the high-pressure lubricating oil circuit 1510 include a main oil circuit and a branch oil circuit. The main oil passage is an oil passage extending along the transverse direction of the crosshead box 1000 (ie, the direction extending between two side end surfaces) as shown in the figure, and is connected to the oil inlet. Each oil passage branched from the main oil passage along the longitudinal direction of the crosshead box 1000 (ie, the extension direction of the crosshead inner cavity) is a branch oil passage, used to supply the oil in the main oil passage to the corresponding lubricant respectively. object. In this embodiment, the lubricating oil in the low-pressure oil circuit is injected from the low-pressure oil inlet 1512 located on the side of the crosshead box 1000 (the side close to the reduction box 4000 in the figure). A part of the low-pressure lubricating oil in the embedded oil circuit flows to the crosshead sliding sleeves 1400 in the five crosshead inner cavities 1100 to lubricate the sliding sleeves and the connecting rod small end bearing assembly (flowing to the low-pressure branch oil pipe on the right side in Figure 27). Another part of the low-pressure lubricating oil flows to the rear end face of the crosshead box 1000 (the low-pressure branch oil pipe flowing to the left in Figure 27), and then flows into the crankcase oil circuit to lubricate the roller bearings and bearing seats. For this part of the branch oil path, as shown in Figure 28, the position of the oil outlet 1503 at the rear end of the crosshead box 1000 leading to the outside of the crosshead box 1000 needs to be aligned with the position of the oil inlet hole in the outer ring of the crankshaft bearing. For the high-pressure lubricating oil circuit 1510, as shown in Figure 27, oil enters from the high-pressure oil inlet 1511 on the side of the crosshead box 1000 (the side close to the reduction box 4000 in the figure), and flows into the crosshead through the oil passage. Then it passes through the internal oil passage of the crosshead and enters the small end of the connecting rod as the connecting rod swings to lubricate the small end bearing bush. As shown in Figure 29, the lubricating oil in the crosshead box 1000 flows into the bottom of the crosshead box 1000 through the design gap between the front and rear ends of the sliding sleeve, the rear end plate of the spacer, and the front end plate of the crankcase, and then flows into the crankcase oil. sump, and ultimately flows back to the oil tank through the oil return pipe at the bottom of the crankcase.

As shown in Figure 30, the high-pressure oil inlet 1511 and the low-pressure oil inlet 1512 provided on the side end plate of the crosshead box 1000 are both provided with boss structures 1504 to provide a flat connection plane protruding from the side end plate. . It should be noted that, for convenience of illustration, FIG. 30 only shows part of the structure on the side of the crosshead box 1000 near the oil filling hole. A rounded corner transition is used around the boss structure 1504 to increase the stiffness of the connection. The location and number of oil filling holes are not limited, as long as they correspond to the embedded oil passage and do not affect other structural functions. As shown in Figure 30, the crosshead box 1000 and the external oil pipe are preferably connected by flange. The interface is easy to replace, which avoids the risk of thread breakage when the internal thread connection is used in the past, and the sealing performance is ensured. According to actual needs, other connection methods such as ordinary threaded connections can also be selected.

As shown in Figure 27, the high-pressure oil circuit and the low-pressure oil circuit are each provided with a filter, a relief valve 1501, etc. When the oil pressure in the embedded oil passage of the lubricating oil circuit 1500 is higher than the set pressure, the relief valve 1501 will overflow part of the oil to maintain the lubricating oil pressure at the set pressure. The overflowed lubricating oil is connected to the oil return pipe through the oil pipe, and finally flows to the oil tank together for recovery, filtration, and cooling to achieve the purpose of lubricating oil recycling. For example, the filter and the relief valve 1501 are both provided at the other side end plate 1005 of the crosshead box 1000 opposite to the side end plate 1005 provided with the oil inlet.

In the crosshead box 1000 according to the embodiment of the present disclosure, oil is injected from the side of the crosshead box 1000 , and the main oil path embedded in the crosshead box 1000 is designed into multiple branches to lead to the crosshead box 1000 and the crankcase. 2000 oil supply, which reduces the volume occupied by the embedded oil circuit in the box and avoids the thinning of the box wall caused by excessive oil channels. Therefore, it can reduce the process difficulty while ensuring the rigidity of the box. In addition, by supplying oil separately through two oil pumps (high-pressure pump and low-pressure pump), the oil supply volume of each oil circuit can be better ensured, the lubricating oil can be better distributed, and the uneven distribution of lubricating oil caused by too many lubrication branches can be avoided. , the problem of insufficient lubricating oil at each lubrication point, improves lubricating oil utilization, reduces abnormalities, and better assists the continuous and stable operation of high-power plunger pumps.

In addition, it should be noted that, in addition to the above method, the lubricating oil path of the crankcase 2000 may not be supplied from the crosshead box 1000, but may be separately opened on the side of the crankcase for oil filling, forming a self-contained path. This method increases the hole processing process, external pipelines and oil inlet interfaces, increases the area occupied by the oil passage inside the crankcase 2000, and has an impact on the crankcase stiffness. In addition, sealing devices need to be added at the internal and external pipeline interfaces to seal the oil pipe connections to prevent oil and gas leakage and pollution. The crankcase oil inlet position can be set at the upper or lower part of the crankcase, or on the left or right side of the crankcase. The oil circuit can then change its position laterally or longitudinally.

6. Connection and sealing design

6.1 Connection design

In the assembled operating state of the fracturing pump, one end of the crosshead box 1000 is connected to the crankcase 2000 and the other end is connected to the spacer 3000 . As shown in FIGS. 31 and 32 , double bolts are preferably used to fasten the connection between the crosshead case 1000 and the crankcase 2000 and between the crosshead case 1000 and the spacer 3000 . Among them, the first bolt fastening is integrally fixed and pre-tightened by the first bolt 1611 (long bolt). As shown in Figure 33, the long bolt penetrates the first bolt hole 1610 of the crosshead box 1000 and extends to the crankcase 2000 and the spacer 3000 to connect the hydraulic end and the power end of the fracturing pump. . The long bolt sets a reasonable initial axial force to ensure that the fluid end and power end bolt joint surfaces are always connected during the operation of the plunger pump. The second bolt used between the crosshead box 1000 and the crankcase 2000 and the third bolt used between the crosshead box 1000 and the spacer 3000 mainly play the role of sealing and tightening. Therefore, the first bolt 1611 can also be called a fastening bolt or a first bolt, and the second bolt and the third bolt are collectively called a sealing bolt or a second bolt. It can be understood that the connection method between the crosshead case 1000 and the crankcase 2000 or the spacer frame 3000 is not limited to the threaded connection described above, and any connection method that ensures that the two are tightly connected without relative displacement can be used, for example, for example, Use an external clamping structure to clamp and position the two contact surfaces, or use electromagnetic suction connection, hydraulic connection, automatic connection hook, etc. In addition, the arrangement positions and numbers of the first bolts and the second bolts are not limited to the preferred embodiments described herein, and may be changed according to the requirements of fastening and sealing.

The position and number of the first bolt holes 1610 (ie, long bolt holes) for the first bolts 1611 correspond to the connecting threaded holes of the crankcase 2000 . In principle, the positions of the second bolt hole 1620 for the second bolt and the third bolt hole 1630 for the third bolt should be located away from the first bolt hole 1610 and protruding from the box body of the crosshead box 1000 of thin walls. The protruding thin wall can be formed in any way. It is preferred to use rounded transitions on all sides to consider casting convenience and improve root stiffness. This can minimize the influence of the pre-tightening force of the first bolt 1611 on the second bolt and the third bolt, ensuring the sealing of the second bolt and the third bolt. 31 illustrates a schematic diagram of the layout of the first bolt hole 1610 and the second bolt hole 1620 on the rear end surface of the crosshead box 1000. FIG. 32 illustrates the first bolt hole 1610 and the second bolt hole 1620 on the front end surface of the crosshead box 1000. Schematic diagram of the arrangement of the third bolt holes 1630 . As shown in the figure, the first bolt hole 1610 is disposed between two adjacent crosshead inner cavities 1100 and two adjacent exhaust cavities 1200 , and is located outside the multifunctional structural hole 1300 . Preferably, the centers of the first bolt hole 1610 and the multifunctional structural hole 1300 are aligned with each other. In addition, as shown in the figure, in the crosshead box 1000 according to the embodiment of the present disclosure, the number and arrangement of the second bolt holes 1620 at the rear end of the crosshead box 1000 and the third bolt holes 1630 at the front end may be different. The crosshead case 1000 is connected to the crankcase 2000 on one side (i.e., the rear end face) by two rows of larger bolts in the upper and lower rows. For example, a flange portion may be provided on the upper and lower sides of the rear end of the crosshead box 1000, and a second bolt hole 1620 may be provided in the flange portion. In addition, a circle of slightly smaller bolts is provided on the side where the crosshead box 1000 and the spacer frame 3000 are connected (ie, the front end surface). For example, flange portions may be provided on the upper, lower, left and right sides of the front end of the crosshead box 1000, and the third bolt holes 1630 may be provided in the flange portion. This is because the range of the crosshead's reciprocating movement in the crosshead case 1000 is more toward the crankcase 2000 side, so the reaction force of the bolts acting on the crankcase 2000 side is greater and the bending moment force arm is shorter. In addition, both the crankcase 2000 and the crosshead case 1000 have relatively large stiffnesses, and the left and right sides of the connection surface will basically not deform and separate. Therefore, only two rows of larger bolts are arranged up and down to withstand greater axial force. The connection end face of the crosshead box 1000 and the spacer frame 3000 has low stiffness, long arm, and a certain degree of deflection, and the lateral sides of the connection end face may deform and separate. Therefore, bolts on the left and right sides were added to ensure a good contact surface fit. It should be understood that the second bolt hole 1620 and the third bolt hole 1630 are not necessarily arranged in the flange portion, as long as they are located outside the first bolt hole 1610 and are suitable to form an anti-loosening function together with the first bolt hole. Just tighten the structure at its location. For example, the second bolt hole 1620 and the third bolt hole 1630 may also be provided in recesses located on the upper and lower panels of the crosshead box. Since the second bolt hole and the third bolt hole are both located outside the first bolt hole and have similar functions, the first bolt hole can also be called the inner bolt hole, and the second bolt hole and the third bolt hole can also be called the inner bolt hole. Collectively called outer bolt holes.

6.2 Sealing design

The front and rear end faces 1002 of the crosshead case 1000 are respectively connected to the spacer 3000 and the crankcase 2000, so sealing design is required at the front and rear end faces 1002. For example, by setting up a sealing structure such as a sealing groove or using sealing means such as sealant, the crosshead inner cavity 1100 and the exhaust cavity 1200 are sealed to ensure the tightness between both sides of the crosshead box 1000 and the spacer 3000 and the crankcase 2000 Oil and gas seal. FIG. 33 and FIGS. 34 a and 34 b illustrate an example of the arrangement of the sealing rings 1701 on the front and rear end faces of the crosshead box 1000 . There are no special restrictions on the positions of the sealing groove and sealing ring 1701 of the crosshead box 1000, as well as the positions of the sealant and other multiple sealing means. It is only necessary to ensure that the crosshead inner cavity 1100 and the exhaust cavity 1200 are included in the sealing area to meet this requirement. The technical field requires sealing of oil and gas sealing surfaces without affecting the surrounding structural functions.

A local seal 1702 may be added at the junction of the lubricating oil passage at the contact surface between the crosshead case 1000 and the crankcase 2000 . FIG. 35 illustrates a sealing ring as a partial seal 1702 provided around the oil outlet 1503 of the lubricating oil passage. The sealing range of the partial seal 1702 is not limited, as long as it meets the required sealing at the oil port. There are no special restrictions on the form of seals, such as sealing rings (no limit on shape), sealants, etc.

In addition, as shown in Figure 36, a pair of positioning pin holes 1703 are provided on both sides of the crosshead box 1000 for connection of positioning pins when the crosshead box 1000 is assembled with the spacer 3000 and the crankcase 2000. To achieve mutual alignment and positioning among the three (only one end face is shown in Figure 36). Corresponding pin holes are also formed on the crankcase 2000 and the spacer frame 3000 . The size and shape of the positioning pin hole 1703 corresponds to the positioning pin used. The location of the positioning pin hole 1703 is not limited, as long as it meets the positioning requirements and does not affect the functions of the surrounding structures. It is preferable to set it at the diagonal corner of the end face to facilitate positioning.

7. Other structural components of the crosshead box

7.1 Process holes and/or observation windows

The crosshead box 1000 is also formed with a number of process holes and/or viewing windows 1810 . Since the process hole and the observation window are both formed through the box body of the crosshead box 1000 and have similar functions and structures, they can also be collectively referred to as process holes in this article. For example, the upper cover 1003 and/or the lower cover 1004 may be provided with process holes and/or observation windows 1810 for processing the internal oil passages or other processes after the box is cast, as well as for maintenance and inspection during later use. Referring to the drawings, it can be seen that the process hole and/or the observation window 1810 is preferably formed on the upper mask 1003 and/or the lower mask 1004 at a position corresponding to the crosshead inner cavity 1100 to facilitate future maintenance and repair. In addition, as mentioned above, the process hole and/or observation window 1810 is preferably formed close to the embedded oil circuit 1500, so as to facilitate the processing and maintenance of the oil circuit. In the crosshead case 1000 according to the embodiment of the present disclosure, since the bottom of the crosshead case 1000 has lubricating oil flowing to the crankcase 2000 for recovery, as shown in FIG. 37 , a lower cover of the crosshead case 1000 is provided. The process hole and/or observation window 1810 of the board 1004 has a raised structure 1811 such as a boss protruding toward the inside of the box. By providing an upward convex structure, environmental pollution caused by lubricating oil outflow holes at the bottom of the crosshead box 1000 can be avoided. Such an upward convex structure 1811 can also increase the screwing length of the fixing bolt and enhance the fastening here. In addition, the upper process window provided on the upper panel 1003 of the crosshead box 1000 adopts a downward convex structure 1812 protruding toward the box body to increase the screwing length of the fixing bolts and enhance the fastening here. Since workers will stand above the crosshead box 1000 during equipment maintenance, considering the safety of the operation and reducing the possibility of workers tripping, the upward convex structure is not selected here. FIG. 38 illustrates a schematic structure of a boss forming an upper convex structure 1811 or a lower convex structure 1812 of the process hole and/or the observation window 1810 . In this figure, illustration of other components is omitted for clarity of illustration. If other methods are used to collect lubricating oil, the bottom process hole/observation window can be designed with other structures. The number of process holes/observation windows is not limited, and the shape is not limited to circles, as long as the position does not block post-processing. In addition, the process holes/observation windows can also be processed in other ways according to actual needs, or no process holes/windows can be provided. Observation window.

7.2 Installation boss and related design

On both sides of the crosshead box 1000, the side end plates 1005 are provided with mounting planes for arranging lifting lug plates and supporting lug plates. For example, as shown in Figure 39, such a mounting surface may be in the form of a mounting boss 1820. The mounting boss 1820 is integrally formed with the main body of the crosshead box 1000, and is surrounded by arcs or bevel transitions to increase root stiffness. The position, quantity, and cross-sectional shape of the mounting bosses 1820 are determined according to the installation requirements of the lifting ear plate and the supporting ear plate. In addition to the mounting boss 1820 (outer convex plane), a mounting plane (inner concave plane) can also be provided by thinning the hoisting position according to actual conditions.

7.3 Support ear plate

The crosshead box 1000 according to an embodiment of the present disclosure is further provided with support lugs 1830 . As shown in FIG. 39 , the support ear plate 1830 according to this embodiment is installed on the mounting boss 1820 and is disposed on the rear end of the crosshead box 1000 on the side close to the reduction gearbox for connecting the screw support assembly of the reduction gearbox. A reasonable arrangement of the support ear plates 1830 can effectively reduce the deformation of the reduction gearbox toward the power transmission axis and the direction of gravity, and improve the rigidity of the reduction gearbox box. The position, quantity, and cross-sectional shape of the support ear plates 1830 are not limited, and they only need to match the screw support assembly.

7.4 Lifting ear plate

The crosshead box 1000 according to an embodiment of the present disclosure is further provided with lifting lugs 1840. As shown in Figure 39, the lifting ear plate 1840 according to this embodiment is installed on the mounting boss 1820 located on the upper part of the box. When the fluid end is disassembled, the lifting lugs 1840 can be used for lifting operations between the crosshead box 1000 and the crankcase assembly or the crosshead box 1000 itself. The shape, position and quantity of the lifting ear plates 1840 are not limited. Just ensure that the force is even during hoisting and the crosshead box 1000 does not tilt. The molding method of the lifting ear plate 1840 is not limited, and it can be integrally molded or processed by casting or other methods. In the embodiment shown in FIG. 39 , the lifting lug 1840 and the supporting lug 1830 are integrally formed on the mounting boss located on the upper part of the crosshead box. Such a structure reduces the occupied area and processing steps of the mounting boss 1820 and saves costs. It should be understood that the supporting ear plates 1830 and the lifting ear plates 1840 can also be respectively formed on the mounting boss 1820 at different positions according to design requirements.

The preferred embodiments of the one-piece crosshead box according to the present invention have been described in detail above with reference to the accompanying drawings. It should be understood that the one-piece crosshead box according to the present invention does not necessarily need to have all the technical features shown in the drawings, but the technical features described herein can be combined as needed. For example, in the various preferred structures of the one-piece crosshead box according to the present invention described above, structures such as exhaust chambers, embedded oil passages, multi-functional structural holes, etc. can be selectively set according to specific needs. . They are not essential structures for realizing the basic functions of the one-piece crosshead box according to the present invention. For example, the one-piece crosshead box according to the present invention may not use an embedded oil circuit, but may use an external oil pipe in the prior art.

For example, a crosshead box according to one embodiment of the present invention is a substantially rectangular box formed by an integral molding process, and has a front end face, a rear end face, an upper end face, a lower end face and a side end face. The crosshead box is provided with multiple Each of the crosshead inner cavities extends along the longitudinal direction of the crosshead box and penetrates the box body, and the plurality of crosshead inner cavities are arranged along the transverse direction of the crosshead box. The crosshead box is also provided with a plurality of exhaust chambers, and each exhaust chamber penetrates the crosshead box in the longitudinal direction of the crosshead box and is connected with the corresponding crosshead inner cavity.

For example, a crosshead box according to another embodiment of the present invention is a substantially rectangular box formed by an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face and a side end face, and the crosshead box is provided with There are a plurality of crosshead inner cavities, each of the crosshead inner cavities extends along the longitudinal direction of the crosshead box and penetrates the box body, and the plurality of crosshead inner cavities are arranged along the transverse direction of the crosshead box. The crosshead box is also provided with a plurality of multifunctional structural holes, and each of the multifunctional structural holes extends along the longitudinal direction of the crosshead box and penetrates the box body.

For example, a crosshead box according to yet another embodiment of the present invention is a substantially rectangular box formed by an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face and a side end face, and the crosshead box is provided with There are a plurality of crosshead inner cavities, each of the crosshead inner cavities extends along the longitudinal direction of the crosshead box and penetrates the box body, and the plurality of crosshead inner cavities are arranged along the transverse direction of the crosshead box. The crosshead box is also provided with an embedded lubricating oil passage. The embedded lubricating oil passage is an interconnected oil hole and oil passage formed in the box body of the crosshead box, and the embedded lubricating oil passage is formed in the box body of the crosshead box. The lubricating oil circuit includes main oil circuit and branch oil circuit.

The crosshead box according to the present disclosure adopts the casting process to be integrally formed and the platform design improves the versatility and adaptability of parts, greatly reduces the types of accessories in different models of fracturing pumps, and saves a lot of parts purchase and maintenance. the cost of. Once the traditional tailor-welded power end shell is partially cracked and damaged, it will need to be repaired or even scrapped as a whole, which affects the efficiency of fracturing operations and increases maintenance costs. In addition, the integrated crosshead box not only improves the strength and rigidity of the power end housing, prolongs the life of the housing and maintenance cycle, but also enables individual maintenance and replacement of part of the housing, reducing maintenance difficulty and rework costs.

In addition, the integrally formed crosshead box according to embodiments of the present disclosure may be provided with structures such as multifunctional structural holes, thereby ensuring structural rigidity while also reducing the weight of the box body. The integrated crosshead box according to the embodiment of the present disclosure can provide a dedicated exhaust cavity and fluid channel to provide a good fluid circulation path inside the box, so that the air pressure inside the box can always be maintained during operation. Balance, thus improving the smooth operation and service life of the equipment. According to embodiments of the present disclosure, the lubricating oil circuit of the crosshead box can adopt an embedded structure to replace the traditional external oil pipe arrangement, thereby eliminating a large number of flexible hoses and pipe joints, and greatly reducing the risk of oxidation of the pipes. Oil pressure leakage problems caused by potential risks such as corrosion and loose pipe joints. Therefore, the maintenance cycle of the lubrication system can be effectively extended and troubleshooting and maintenance can be facilitated.

The crosshead box according to the present disclosure is designed with lifting points on both sides to facilitate individual and various combination lifting. The cylindrical crosshead inner cavity of the crosshead box allows the use of a cylindrical crosshead sliding sleeve to replace the two-piece bearing bush, which reduces the installation process and facilitates the inspection and replacement of the bearing bush. The crosshead box is also equipped with sensors to monitor the vibration of the equipment, the temperature of the shell, the temperature and flow rate of the lubricating oil in real time, so that on-site personnel can promptly detect and take response actions in the initial stage of abnormality in the equipment. Such as shutdown inspection, component replacement, etc.

Although the one-piece crosshead box according to the present disclosure has been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiment. And those skilled in the art will understand that various changes, combinations, sub-combinations and modifications can be made without departing from the spirit or scope of the invention as defined by the appended claims. In addition, the beneficial effects of the present disclosure are not limited to the effects mentioned above, but may be other effects that can be thought of by reading the present disclosure.

List of reference signs

1000 crosshead box

2000 crankcase

3000 spacer rack

4000 reduction box

1001 front face

1002 rear end face

1003 Upper mask, upper end surface

1004 lower panel, lower end face

1005 side end plate, side end face

1006 Limit slot

1100 crosshead lumen

1200 exhaust chamber

1300 multifunctional structural holes

1101 partition board

1102 spacer column

1400 cross head sliding sleeve

1401 Sliding sleeve oil hole

1402 Sliding sleeve positioning pin hole

1403 Sliding sleeve protrusion

1404 Recessed part of sliding sleeve

1201 fluid channel

1210 reinforced beam

1211 transition structure

1500 Lubricating oil line

1510 high pressure lubricating oil circuit

1520 low pressure lubricating oil circuit

1511 high pressure oil inlet

1512 low pressure oil inlet

1501 relief valve

1502 oil tank end

1503 oil outlet

1504 boss structure

1610 First bolt hole

1620 Second bolt hole

1630 Third bolt hole

1611 First Bolt

1701 sealing ring

1702 Partial seal

1703 Positioning pin hole

1810 process hole/observation window

1811 convex structure

1812 downward convex structure

1820 Installation boss

1830 support ear plate

1840 Suspension ear plate

2001 linkage movable window

Claims (39)

1. A crosshead box which is a substantially rectangular box body formed by an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face, and side end faces, the crosshead box being provided with:

a plurality of cross head inner cavities, each cross head inner cavity extends along the longitudinal direction of the cross head box and penetrates through the box body, the plurality of cross head inner cavities are arranged along the transverse direction of the cross head box,

the cross head box is characterized in that the cross head box is further provided with an embedded lubricating oil circuit, the embedded lubricating oil circuit is an oil hole and an oil channel which are formed in the box body of the cross head box and are communicated with each other, and the embedded lubricating oil circuit comprises a main oil circuit and a branch oil circuit.

2. The crosshead box according to claim 1, wherein the main oil passage extends in a lateral direction of the crosshead box, and the branch oil passage extends in a longitudinal direction of the crosshead box.

3. The crosshead box of claim 1, wherein the in-line lubrication circuit comprises a high pressure lubrication circuit.

4. A crosshead box according to claim 3, wherein the high pressure lubrication circuit lubricates a crosshead shoe and a connecting rod shoe operating within the crosshead box.

5. The crosshead box according to claim 3, wherein the high-pressure lubrication oil passage includes a high-pressure oil inlet port provided on the side end surface of the crosshead box body.

6. The crosshead box of claim 5, wherein the high pressure oil inlet is provided on a flat connection plane formed on the side end surface.

7. The crosshead box of claim 3, wherein the high pressure lubrication circuit has a filter and a relief valve.

8. The crosshead box of claim 1, wherein the in-line lubrication circuit comprises a low pressure lubrication circuit.

9. The crosshead box of claim 8, wherein the low pressure lubrication oil passage lubricates the crosshead slide.

10. The crosshead box of claim 8, wherein the low pressure lubrication passage includes a low pressure oil inlet port provided on the side end face of the crosshead box.

11. The crosshead box of claim 10, wherein the low pressure oil inlet is disposed on a flat connection plane formed on the side end surfaces.

12. The crosshead box of claim 8, wherein the low pressure lubrication circuit has a filter and a relief valve.

13. The crosshead box according to claim 1, wherein the in-line lubrication oil passage is provided with the branch oil passage for supplying oil to a crankcase, and the branch oil passage for supplying oil to a crankcase has an oil outlet opening into the crankcase at the rear end face of the crosshead box.

14. The crosshead box of claim 13, wherein an outer periphery of the oil outlet is provided with a seal ring as a partial seal.

15. The crosshead box of any one of claims 1 to 14, wherein each of the crosshead lumens is approximately cylindrical in shape.

16. The crosshead box of any of claims 1 to 14, further comprising a crosshead slide sleeve having a shape that matches the crosshead lumen and is capable of being insert-mounted therein.

17. The crosshead box of claim 16, wherein the crosshead slide sleeve is provided with an oil hole through a wall of the sleeve, the oil hole being a part of the branched oil passage.

18. The crosshead box of claim 16, wherein one end of the crosshead slide is provided with at least one indent recessed inwardly along a longitudinal direction of the crosshead slide.

19. The crosshead box of claim 16, wherein one end of the crosshead slide is provided with at least one projection protruding outwardly along a longitudinal direction of the crosshead slide.

20. The crosshead box of claim 18, wherein the other end of the crosshead slide is provided with at least one projection protruding outwardly along a longitudinal direction of the crosshead slide.

21. The crosshead box of claim 18, wherein the recess is two and

in a state that the cross-head sliding sleeve is installed in the cross-head inner cavity, the two concave parts are positioned at the top and the bottom of the cross-head inner cavity.

22. The crosshead box of claim 19, wherein the number of lugs is two and

in a state that the cross-head sliding sleeve is installed in the cross-head inner cavity, the two protruding parts are positioned at the top and the bottom of the cross-head inner cavity.

23. The crosshead box of claim 20, wherein the recess and the projection are two and

in a state that the cross head sliding sleeve is installed in the cross head inner cavity, two concave parts are positioned at the top and the bottom of the cross head inner cavity, and two convex parts are also positioned at the top and the bottom of the cross head inner cavity.

24. The crosshead box of claim 16, wherein the front end face of the crosshead inner cavity is provided with a limit groove, an end head portion of one end of the crosshead slide sleeve at the front end face is provided with a dowel hole, and the dowel hole and the limit groove are connected in a matched manner via a pin shaft to be inserted into the dowel hole so as to axially position the crosshead slide sleeve in the crosshead inner cavity.

25. The crosshead box of any one of claims 1 to 14, wherein the crosshead box is further provided with at least one first bolt hole, each first bolt hole being located above and below the plurality of crosshead lumens and extending longitudinally of the crosshead box and through the box body.

26. The crosshead box of claim 25, wherein the crosshead box is further provided with at least one second bolt hole, each of the second bolt holes extending longitudinally of the crosshead box and extending through the box body, and on the front end face and the rear end face, the second bolt holes are located outside the first bolt holes.

27. The crosshead box according to claim 26, wherein the second bolt holes are also provided in the front end surface of the crosshead box at edge portions located on both lateral sides of the crosshead box.

28. The crosshead box according to claim 26, wherein a flange portion is provided on an outer periphery of the crosshead box at the front end surface of the crosshead box, and the second bolt holes are provided in the flange portion.

29. The crosshead box according to claim 26, wherein flange portions are provided at both upper and lower edges of the crosshead box at the rear end face of the crosshead box, and the second bolt holes are provided at the flange portions.

30. The crosshead box according to any one of claims 1 to 14, wherein seal grooves are provided in the front end face and the rear end face of the crosshead box, respectively, and a seal area surrounded by the seal grooves contains at least the crosshead inner chamber and the vent chamber.

31. The crosshead box of any of claims 1 to 14, wherein the crosshead box further comprises a process hole through a box body of the crosshead box.

32. The crosshead box of claim 31, wherein the process holes are formed at locations corresponding to the crosshead interior cavities.

33. The crosshead box of claim 31, wherein the process bore is disposed at least proximate to the in-line lubrication circuit.

34. The crosshead box of claim 31, wherein the process holes formed at the top of the crosshead box are formed with a downward protruding structure protruding toward the inner chamber of the crosshead.

35. The crosshead box according to claim 31, wherein the process hole formed at the bottom of the crosshead box is formed with an upward protruding structure protruding toward the crosshead inner chamber.

36. The crosshead box according to any one of claims 1 to 14, wherein the crosshead box is further provided with a mounting boss formed on the side end surface.

37. A plunger pump comprising a crankcase, a crosshead box according to any one of claims 1 to 36, and a spacer.

38. The plunger pump of claim 37, wherein dowel holes are provided in each of the crankcase, the crosshead box and the spacer frame at mutually engaging end surfaces for aligned positioning of the crankcase, the crosshead box and the spacer frame.

39. The plunger pump of claim 37 or 38, wherein the plunger pump further comprises a reduction gearbox, and

A support lug plate is provided on a mounting boss formed on a side end face of the crosshead box, the support lug plate being connected to a support assembly of the reduction box.