CN114876755A - Spiral reciprocating single-action plunger pump - Google Patents

Abstract

The screw reciprocating single-acting plunger pump includes a pump body. The left end of the pump body is provided with an end cover. A cavity is formed between the end cover and the pump body. The pump body axially reciprocates the plunger group, and the right side wall of the pump body is provided with an oil inlet and an oil discharge port; the cavity includes a transmission cavity and a plurality of plunger cavities that communicate with each other, and the transmission cavity is located on the left side of the pump body. The multiple plunger cavities are located at the right part of the pump body, and the multiple plunger cavities are evenly distributed along the circumferential direction of the pump body; the right end face of each plunger cavity is provided with an oil suction passage and an oil discharge passage; There is a main shaft, the shaft section on the main shaft and located in the transmission cavity is provided with a reciprocating thread groove; the plunger group includes a claw frame and a plurality of plungers correspondingly arranged in the plunger cavity, the plunger is arranged in the plunger cavity, and The plunger can reciprocate linearly along the axial direction of the pump body. The invention can obtain very high discharge pressure, and the flow rate has nothing to do with the pressure, the suction performance is good, and the efficiency is high.

Description

Screw reciprocating single-acting piston pump

technical field

The invention relates to the technical field of hydraulic pumps, in particular to a screw reciprocating single-acting plunger pump.

Background technique

The hydraulic pump is the power component of the hydraulic system. It is driven by an engine or an electric motor, sucks oil from the hydraulic oil tank, forms the pressure oil and discharges it, and sends it to the actuator. Hydraulic pumps are divided into gear pumps, plunger pumps, vane pumps and screw pumps according to their structure. Their advantages and disadvantages are as follows:

Gear pump: small in volume, simple in structure, less strict on oil cleanliness, and cheaper in price; but the pump shaft is subject to unbalanced force, serious wear, and large leakage.

Vane pump: divided into double-acting vane pump and single-acting vane pump. This kind of pump has uniform flow, stable operation, low noise, higher pressure and volume efficiency than gear pump, and more complicated structure than gear pump.

Plunger pump: high volumetric efficiency, small leakage, can work under high pressure, mostly used in high-power hydraulic systems; but complex structure, high requirements for materials and processing accuracy, high price, and high requirements for oil cleanliness.

Screw pump: low speed is generally 20r/min ~ 90r/min, mechanical wear is small, no cavitation occurs; the flow channel is wide, which can transport oil containing solids; the structure of the pump body is half-open, and the pump can be observed. However, its size is large and the floor area is large; due to the limitation of machining conditions, the pump shaft cannot be too long, so the lift is low, generally not more than 10m.

Plunger pump is a kind of pump of hydraulic system that relies on the reciprocating movement of the plunger in the pump body to change the volume of the sealed working chamber to achieve oil absorption and oil pressure. Traditional plunger pumps can be divided into three categories according to the arrangement of their multiple plungers: axial plunger pumps, radial plunger pumps and reciprocating plunger pumps, all of which are based on the periodic change of the volume in the working chamber. To achieve the purpose of conveying the medium. After the mechanical energy of the prime mover passes through the pump, it is directly converted into the pressure energy of the conveying medium. The flow rate of the pump only depends on the volume change value of the working chamber and its frequency of changes per unit time, and has nothing to do with the discharge pressure in theory. Compared with other forms of hydraulic pumps, plunger pumps are easier to achieve high pressure and large flow on the basis of maintaining high volumetric efficiency, and are widely used in high-pressure and heavy-load applications such as aerospace and construction machinery.

However, the flow rate of the reciprocating plunger pump is not very stable, and the flow rate is smaller than that of the axial plunger pump of the same volume. At the same time, due to the many internal moving parts of the traditional plunger pump, the structure is more complicated, and the rotational inertia is not only large during high-speed movement, but also due to the pump. There are many sliding friction pairs in the body structure, and the wear and heat of the parts will also increase, which directly affects the service life and durability. Due to the above shortcomings, the wider application of the plunger pump is limited.

SUMMARY OF THE INVENTION

To overcome the above problems, the present invention provides a screw reciprocating single-acting plunger pump.

The technical scheme adopted in the present invention is as follows: a screw reciprocating single-acting plunger pump includes a pump body, an end cover is arranged on the left end of the pump body, a cavity is formed between the end cover and the pump body, and a cavity is provided with a shaft that can be wound around the pump body. The main shaft that rotates on the center line and the plunger group that can reciprocate along the axial direction of the pump body, the right side wall of the pump body is provided with an oil inlet and an oil discharge port;

The cavity includes a transmission cavity and a plurality of plunger cavities that communicate with each other, wherein the transmission cavity is located on the left part of the pump body, and the multiple plunger cavities are located on the right part of the pump body, and the multiple plunger cavities are evenly distributed along the circumferential direction of the pump body. ;The right end face of each plunger cavity is provided with an oil suction channel and an oil discharge channel, the plurality of oil suction channels are respectively connected with the annular oil suction channel set in the pump body, the annular oil suction channel is connected with the oil inlet, and the oil inlet is provided with There is an oil inlet check valve. The oil inlet check valve only allows oil to enter the plunger cavity from the pump body; a plurality of oil discharge passages are respectively connected with the annular oil discharge passage set in the pump body, and the annular oil discharge passage is connected with the oil discharge port. , There is an oil discharge check valve in the oil discharge port, and the oil discharge check valve only allows the oil to flow out of the pump body from the plunger cavity;

The transmission cavity is provided with a main shaft extending to the left side of the end cover along the axial direction of the pump body. ;The shaft section on the main shaft and located in the transmission cavity is provided with a reciprocating thread groove. The reciprocating thread groove includes two helical grooves with opposite directions of rotation. The ends are butted end to end to form a closed reciprocating spiral groove; a plunger group is sleeved on the shaft section on the main shaft and located in the transmission cavity;

The plunger group includes a claw-shaped frame and a plurality of plungers correspondingly arranged in the plunger cavity. The center of the claw-shaped frame is provided with a through hole for being sleeved on the main shaft. A matching slider; the outside of the claw frame is provided with a plurality of claw feet extending to the right along the axial direction of the pump body, and the right end of each claw foot is correspondingly connected to a plunger; the plunger is arranged in the plunger cavity, and the plunger It can reciprocate in a straight line along the axial direction of the pump body. The right end face of the plunger and the plunger cavity form a closed cavity; the volume of the cavity changes with the reciprocating movement of the plunger. When the plunger moves from the leftmost end to the rightmost end, The volume of the chamber gradually decreases; on the contrary, when the plunger moves from the far right end to the far left end, the chamber volume gradually increases; when the main shaft rotates around the axis of the pump body, it drives the slider to reciprocate in a straight line along the axial direction of the pump body The pump moves, thereby driving the plunger to reciprocate in a straight line along the axial direction of the pump body; the chamber with a gradually increasing volume absorbs oil, and the chamber with a gradually decreasing volume discharges oil.

Further, the number of the plunger chambers and plungers is an odd number to reduce the pulsation of the output high pressure oil.

Further, the left end face of the pump body is provided with four pump body threaded holes uniformly distributed along the circumferential direction, and the end cover is provided with four end cap threaded holes corresponding to the pump body threaded holes one-to-one. A screw is arranged in the threaded hole, and the screw connects the pump body and the end cover fixedly.

The basic principle of the invention is as follows: the reciprocating screw adopts a special thread groove design, which is two left-handed and right-handed helical grooves. Butt to form a closed spiral groove. There is a matching relationship between the stroke and size of the slider and the spiral groove, and the two ends of the spiral screw are rigidly connected to the end cover and the pump body through bearings. When the screw screw is continuously rotated by the motor, the slider moves along the groove from one end of the helical groove to the other end, and moves back through the closed helical groove, without changing the direction of rotation of the screw. Continuous reciprocating motion of the slider. A reciprocating thread groove with a length matching the stroke of the plunger is machined at a suitable position on the main shaft of the screw reciprocating plunger pump. The slider and the plunger group are rigidly connected, and the plunger and the plunger cavity have a matching relationship, which can form a closed cavity. The main shaft and the motor output shaft are connected by a coupling, and the main shaft is driven to rotate continuously by the motor. Driven by the main shaft, the sliding block reciprocates along the reciprocating thread groove from one end to the other, and drives the rigidly connected plunger group to reciprocate together, thereby realizing the change of the volume of the pump chamber. When the volume of the pump cavity becomes larger, the pressure in the cavity decreases. Under the action of atmospheric pressure, the hydraulic oil enters the pump cavity from the oil cylinder through the oil inlet check valve to realize oil suction; when the volume of the pump cavity becomes smaller, the pressure in the cavity increases, and the hydraulic oil The pump chamber is discharged through the oil discharge check valve. The sliding block reciprocates once in the reciprocating thread groove to complete one oil suction and discharge.

The beneficial effects of the present invention are:

1. High discharge pressure can be obtained, and the flow rate has nothing to do with pressure, with good suction performance and high efficiency;

2. In principle, any medium can be transported, almost not limited by the physical or chemical properties of the medium;

3. Reduce the friction pair of the sliding shoe and swash plate of the traditional axial piston pump, and improve the service life and durability of the pump;

4. The reversing direction of the reciprocating screw (reciprocating thread groove) is reliable, the service cycle is long, and the manufacturing cost is low;

5. Simple structure and low cost. Compared with other reciprocating plunger pumps, the solution provided by the present invention has a small number of parts, easy processing and assembly, and low manufacturing cost, which is beneficial to practical industrial application and large-scale mass production.

Description of drawings

Fig. 1 is the schematic diagram of the present invention;

Fig. 2 is the assembly schematic diagram of the present invention;

Fig. 3 is the structural representation of the main shaft of the present invention;

Fig. 4 is the structural representation of the pump body of the present invention;

5 is a schematic structural diagram of the oil discharge oil passage in the pump body of the present invention;

Fig. 6 is the structural representation of the plunger group of the present invention;

Fig. 7 is the structural representation of the left end cap of the present invention;

Description of reference numerals: 1 is the main shaft, 2 is the end cover, 3 is the screw, 4 is the pump body, 5 is the plunger group, 6 is the bearing, 7 is the oil discharge check valve, 8 is the oil inlet check valve, 9 is the reciprocating thread groove, 10 is the pump body threaded hole, 11 is the pump body bearing hole, 12 is the plunger cavity, 13 is the oil drain channel, 14 is the annular oil drain channel, 15 is the oil drain port, 16 is the slider, 17 is the threaded hole of the end cover, and 18 is the bearing hole of the end cover.

Detailed ways

The technical solutions of the patent of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that when the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear. The orientation or positional relationship indicated by ” and the like is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, a specific orientation, and a specific orientation. The orientation configuration and operation of the device should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third," as they appear, are for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a Removable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Referring to the drawings, the screw reciprocating single-acting plunger pump includes a pump body 4, the left end of the pump body 4 is provided with an end cover 2, and the left end face of the pump body 4 is provided with four pump body threaded holes 10 uniformly distributed along the circumferential direction , the end cover 2 is provided with four end cover threaded holes 17 corresponding to the pump body threaded holes 10 one-to-one, the end cover threaded holes 17 and the pump body threaded holes 10 are provided with screws 3, and the screws 3 connect the pump body 4 to the end The covers 2 are fixedly connected together.

A cavity is formed between the end cover 2 and the pump body 4, and the cavity is provided with a main shaft 1 that can rotate around the axis of the pump body 4 and a plunger group 5 that can reciprocate along the axial direction of the pump body 4. The pump body 4 There are oil inlet and oil discharge port 15 on the right side wall;

The cavity includes a transmission cavity and a plurality of plunger cavities 12 that communicate with each other, wherein, the transmission cavity is located on the left part of the pump body 4, the plurality of plunger cavities 12 are located on the right part of the pump body 4, and the plurality of plunger cavities 12 are located along the The circumferential direction of the pump body 4 is evenly distributed; the right end face of each plunger cavity is provided with an oil suction channel and an oil discharge channel. The oil inlet is provided with an oil inlet check valve. The oil inlet check valve only allows the oil to enter the plunger cavity from outside the pump body 4; the multiple oil discharge passages are respectively connected with the annular oil discharge set in the pump body 4. The annular oil discharge passage is connected with the oil discharge port 15. The oil discharge port 15 is provided with an oil discharge check valve, and the oil discharge check valve only allows the oil to flow out of the pump body 4 from the plunger cavity;

The main shaft 1 extends to the left side of the end cover 2 along the axis of the pump body 4 in the transmission cavity. On the inner wall of the right side of the transmission cavity; the first bearing is installed in the end cover bearing hole 18 on the right side of the end cover 2, and the second bearing is installed in the pump body bearing hole 11 on the right side wall of the transmission cavity; on the main shaft 1 and located in the transmission cavity The shaft section is provided with a reciprocating thread groove 9. The reciprocating thread groove 9 includes two helical grooves with opposite directions of rotation. The reciprocating helical groove 9 of the main shaft 1; a plunger group 5 is sleeved on the shaft section of the main shaft 1 and located in the transmission cavity;

The plunger group 5 includes a claw-shaped frame and a plurality of plungers correspondingly arranged in the plunger cavity. The center of the claw-shaped frame is provided with a through hole for being sleeved on the main shaft 1, and the size of the through hole is the same as that of the main shaft 1. The diameter of the shaft section of the reciprocating thread groove 9 is matched, and a slider 16 is rigidly connected with the reciprocating thread groove 9; The right end of each claw foot is connected to a corresponding plunger; the plunger is arranged in the plunger cavity 12, and the plunger can reciprocate linearly along the axial direction of the pump body 4, and the right end face of the plunger and the plunger cavity 12 are enclosed into a closed Chamber; the volume of the chamber changes with the reciprocating motion of the plunger. When the plunger moves from the leftmost end to the rightmost end, the chamber volume gradually decreases; on the contrary, when the plunger moves from the rightmost end to the leftmost end, the chamber The volume gradually increases; when the main shaft 1 rotates around the axis of the pump body 4, it drives the slider 16 to reciprocate in a straight line along the axial direction of the pump body 4, thereby driving the plunger to reciprocate in a straight line along the axial direction of the pump body 4; the volume gradually increases The larger chamber absorbs oil, and the gradually decreasing chamber drains oil.

In some embodiments of the present invention, the number of plungers in the plunger cavity and the plunger group is an odd number, such as 7, 9, 11, etc., which can reduce the pulsation of the output high-pressure oil.

By increasing or decreasing the number of plungers in the plunger cavity and the plunger group, thereby changing the volume of the pump cavity, the displacement of the plunger pump can be increased or decreased. Changing the size of the plunger can also change the displacement of the plunger pump.

By adjusting the length of the reciprocating thread groove on the main shaft, the stroke of the slider along the axial direction of the main shaft can be adjusted, and the stroke of the plunger group rigidly connected to the slider also changes accordingly. In this way, the displacement of the output oil can be adjusted.

When the length of the thread groove is unchanged, that is, when the stroke of the plunger group is unchanged, changing the pitch of the reciprocating thread groove within an appropriate range can change the speed of the slider in the thread groove under the condition that the spindle speed remains unchanged, that is, the plunger group. The speed of the reciprocating movement, thereby changing the speed of action and the output flow of the reciprocating plunger pump.

The above-mentioned plunger pump is a single-acting reciprocating threaded groove plunger pump. In other implementations of the present invention, two sets of plunger groups are installed by machining two sections of reciprocating threads on the main shaft, which are matched with two sets of pump cavities, that is, Can be used as a double-acting pump.

The working principle of the screw reciprocating single-acting piston pump is as follows:

When the main shaft 1 is continuously rotated by the motor or the motor, the slider 16 fixed on the plunger group 5 reciprocates along the reciprocating thread groove 9 under the action of friction, thereby driving each plunger in the plunger cavity 12 Internal reciprocating motion, resulting in volume change. When the plunger moves out of the plunger cavity 12, the volume of the pump cavity increases and the pressure in the cavity decreases. Under the action of atmospheric pressure, the oil enters the plunger cavity 12 from the oil cylinder through the oil suction oil passage and the oil suction check valve 8. When the plunger moves into the plunger cavity 12, the volume of the pump cavity decreases, the pressure in the cavity increases, and the oil flows out of the plunger cavity 12 through the oil discharge oil passage 13 and the oil discharge check valve 7. The sliding block 16 reciprocates once in the reciprocating thread groove 9 to complete one oil suction and discharge.

The content described in the embodiments of the present specification is only an enumeration of the realization forms of the inventive concept, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also extends to those skilled in the art. Equivalent technical means that can be conceived by a person based on the inventive concept.

Claims (3)

1. Reciprocating type single-action plunger pump of spiral, its characterized in that: the oil pump comprises a pump body (4), wherein an end cover (2) is arranged at the left end of the pump body (4), a cavity is formed between the end cover (2) and the pump body (4), a main shaft (1) capable of rotating around the axial lead of the pump body (4) and a plunger group (5) capable of axially reciprocating along the pump body (4) are arranged in the cavity, and an oil inlet and an oil outlet (15) are formed in the right side wall surface of the pump body (4);

the cavity comprises a transmission cavity and a plurality of plunger cavities which are mutually communicated, wherein the transmission cavity is positioned at the left part of the pump body (4), the plunger cavities are positioned at the right part of the pump body (4), and the plunger cavities are uniformly distributed along the circumferential direction of the pump body (4); the right end face of each plunger cavity is provided with an oil suction duct and an oil discharge duct, the oil suction ducts are respectively communicated with an annular oil suction duct arranged in the pump body (4), the annular oil suction duct is communicated with an oil inlet, an oil inlet one-way valve is arranged in the oil inlet, and the oil inlet one-way valve only allows oil to enter the plunger cavity from the outside of the pump body (4); the oil discharge channels are respectively communicated with an annular oil discharge channel arranged in the pump body (4), the annular oil discharge channel is communicated with an oil discharge port (15), an oil discharge one-way valve is arranged in the oil discharge port (15), and the oil discharge one-way valve only allows oil to flow out of the pump body (4) from the plunger cavity;

a main shaft (1) extending to the left side of the end cover (2) along the axial lead direction of the pump body (4) is arranged in the transmission cavity, the left end of the main shaft (1) is installed on the end cover (2) in a penetrating mode through a first bearing, and the right end of the main shaft (1) is installed on the inner wall of the right side of the transmission cavity through a second bearing; a reciprocating thread groove (9) is arranged on the main shaft (1) and on the shaft section in the transmission cavity, the reciprocating thread groove (9) comprises two spiral grooves with opposite rotation directions, the thread pitches and the lead lengths of the two spiral grooves are the same, and the two threads are butted end to end at the two ends of the screw rod to form a closed reciprocating spiral groove (9); a plunger group (5) is sleeved on a shaft section on the main shaft (1) and positioned in the transmission cavity;

the plunger group (5) comprises a claw-shaped frame and a plurality of plungers correspondingly arranged in plunger cavities, the center of the claw-shaped frame is provided with a through hole for sleeving the main shaft (1), and a sliding block (16) matched with the reciprocating spiral groove (9) is arranged in the through hole; a plurality of claw feet extending rightwards along the axial direction of the pump body (4) are arranged on the outer side of the claw-shaped frame, and the right end of each claw foot is correspondingly connected with a plunger piston; the plunger is arranged in the plunger cavity, the plunger can do linear reciprocating motion along the axial direction of the pump body (4), and the right end surface of the plunger and the plunger cavity enclose to form a closed cavity; the volume of the chamber changes along with the reciprocating motion of the plunger, and when the plunger moves from the leftmost end to the rightmost end, the volume of the chamber gradually becomes smaller; conversely, as the plunger moves from the rightmost end to the leftmost end, the chamber volume gradually increases; when the main shaft (1) rotates around the axial lead of the pump body (4), the sliding block (16) is driven to do linear reciprocating motion along the axial direction of the pump body (4), so that the plunger is driven to do linear reciprocating motion along the axial direction of the pump body (4); the chamber with gradually increased volume absorbs oil, and the chamber with gradually decreased volume discharges oil.

2. The spiral reciprocating single action plunger pump of claim 1, wherein: the number of the plunger cavities and the number of the plungers are odd so as to reduce the pulsation of the output high-pressure oil.

3. The spiral reciprocating single action plunger pump of claim 1, wherein: the left end face of the pump body (4) is provided with four pump body threaded holes (10) which are uniformly distributed along the circumferential direction, the end cover (2) is provided with four end cover threaded holes (17) which correspond to the pump body threaded holes (10) one by one, the end cover threaded holes (17) and the pump body threaded holes (10) are internally provided with screws (3), and the screws (3) fixedly connect the pump body (4) and the end cover (2) together.

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