CN105526050B - A fully floating cylinder axial piston pump or motor - Google Patents

Abstract

The present invention discloses a kind of axial plunger pump or motor of full floating cylinder body, is related to technical field of hydraulic.Including housing, valve plate, power transmission shaft, cylinder body and swash plate, described swash plate has the first inclined-plane and the second inclined-plane, and described the first inclined-plane and the second bevel direction is opposite；Described cylinder body has inclined interior organ timbering consent and inclined outer organ timbering consent, and described interior organ timbering consent and outer organ timbering consent incline direction are opposite.Coordinated by the diclinic of swash plate and plunger, it is poor to reduce inside and outside row's discharge capacity, reduction noise；Realize that plunger pump or motor run at high speed down, keep the axial force of cylinder body and the balance of radial load, realize the full floating of cylinder body.

Description

A fully floating cylinder axial piston pump or motor

technical field

The invention relates to the technical field of hydraulic control, in particular to an axial piston pump or motor of a fully floating cylinder.

Background technique

Axial piston pumps or motors are important hydraulic power or actuators in hydraulic transmission systems. They are widely used in construction machinery, coal mining machinery, agricultural machinery, aerospace and other occasions. They are the first choice for high pressure and large flow hydraulic systems. With the rapid development of modern machinery industry, higher requirements are put forward for the working performance and service life of pumps or motors. It is of great significance to develop high-performance pumps or motors.

Ordinary axial piston pumps or motors can be divided into straight-axis type (swash plate type) and inclined-axis type, which are characterized by the reciprocating motion of the plunger relative to the rotating cylinder, the relative rotation of the cylinder and the valve plate, through the cylinder The waist-shaped mouth of the valve plate is tangent to and covered with the waist-shaped mouth of the valve plate to realize oil suction and discharge. Ordinary axial piston pumps or motors have axial floating, which ensures the normal operation of rotating parts such as cylinders and flow plates, but there is no radial floating. When the flow plate absorbs and discharges oil, it always maintains high pressure on one side , Low pressure on one side, resulting in unbalanced force on the axial piston pump or motor, that is, unbalanced force on the main parts such as the distribution plate, swash plate, cylinder block, etc., and there is a large partial load on the shaft parts, which will inevitably lead to This will lead to increased friction and wear of the plunger pump or motor, increased noise, increased leakage, and reduced volumetric efficiency, thereby greatly reducing its working performance and service life. At the same time, when an ordinary axial piston pump or motor rotates one revolution, only a single row of plungers performs oil suction and discharge, which limits the increase in flow rate.

Balanced large-flow axial piston pump can achieve high-speed and high-pressure operation of the plunger pump under high-speed and high-pressure operation by reasonably setting the inclination direction of the swash plate slope, the size of different rows of concentric cylindrical plug holes, and the size of different oil discharge ports. Balance of axial hydraulic pressure and large displacement of valve plate, etc. Due to its unique multi-swash plate inclined-plane structure, the double-sided drive axial piston motor can generate driving torque in the same direction on both sides of the cylinder, thereby driving the transmission shaft to drive the load to rotate. Its key components such as the cylinder, flow distribution The plate, swash plate, and drive shaft are all loaded on both sides, which can further achieve axial floating, improve the mechanical characteristics of key components, and improve the working stability of the axial piston motor under low speed and heavy load. Regardless of whether it is a balanced high-flow axial piston pump or a double-sided drive axial piston motor, although they can float axially to a certain extent, they cannot completely eliminate the difference in torque on both sides of the drive shaft. And wear, vibration and other issues have yet to be resolved.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention discloses an axial plunger pump or motor with a fully floating cylinder, which can solve the problems of high wear, high noise and short life of the existing plunger pump or motor.

To achieve the above object, the present invention is achieved through the following technical solutions:

An axial piston pump or motor with a fully floating cylinder, including a housing, a valve plate, a transmission shaft, a cylinder and a swash plate. The swash plate has a first inclined plane and a second inclined plane, and the directions of the first inclined plane and the second inclined plane are opposite; the cylinder block has an inclined inner row of plunger holes and an inclined outer row of plunger holes, so The inclination directions of the inner row of plunger holes and the outer row of plunger holes are opposite.

Preferably, the inner row of plunger holes is inclined inwardly relative to the swash plate or is parallel to the cylinder axis; the outer row of plunger holes is inclined relative to the swash plate.

Preferably, the housing includes a pump casing, a left pump cover, a right pump cover and a left end cover, and the left pump cover and the right pump cover are fixedly connected to the pump casing by hexagon socket cap screws; the left end The cover is fixedly connected with the left pump cover by screws.

Preferably, the transmission shaft includes an oil seal, a shaft, a rolling bearing, a shaft circlip, a shaft sleeve, a compression sleeve and a sliding bearing, and the oil seal, a rolling bearing, a shaft circlip, a shaft sleeve, a compression The shaft sleeve and the sliding bearing are sequentially arranged on the shaft along the axial direction.

Preferably, the valve plate is arranged between the cylinder body and the right pump cover, and the valve plate is fixedly connected with the right pump cover through pins.

Preferably, the right pump cover is provided with an O-shaped rubber sealing ring.

The invention discloses an axial plunger pump or motor with a fully floating cylinder body. The full floating of the cylinder body is realized by utilizing the double oblique cooperation of two slopes of a swash plate with opposite inclination angles and two rows of plungers with opposite inclination angles. Compared with traditional axial piston pumps or motors, there are three advantages: first, the double oblique cooperation between the swash plate and the plunger maintains the balance of the axial force and radial force of the cylinder, and realizes the full floating of the cylinder; Reduce the difference in displacement between the inner and outer rows, reduce noise and vibration; third, the combination of the inclination of the plunger and the compression structure of the outer row can enhance the anti-slipping ability of the inner and outer row shoes, especially in plunger pumps or motors. Anti-slip capability at high speeds.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

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

Fig. 2 is a schematic cross-sectional structure diagram of a swash plate in the present invention;

Fig. 3 is the sectional structure schematic diagram of cylinder body in the present invention;

Figure 4 is a schematic diagram of the comparison of the effective strokes of the straight plunger and the oblique plunger;

Fig. 5 is a schematic diagram of the reaction force of the swash plate to the inclined plunger assembly;

Fig. 6 is a schematic diagram of the reaction force of the swash plate to the straight plunger assembly;

Fig. 7 is a schematic cross-sectional structure diagram of an embodiment of the present invention.

In the figure 1. Right pump cover; 2. Hexagon socket head cap screw; 3. O-type rubber sealing ring; 4. Pump casing; 5. Compression ring; 6. Outer discharge pressure plate; 7. Left pump cover; 8. Screw ;9. Left end cover; 10. Oil seal; 11. Shaft; 12. Rolling bearing; 13. Retaining ring for shaft; 14. Shaft sleeve; 18. Outer row sliding boots; 19. Compression bushing; 20. Outer row compression spring; 21. Inner row compression spring; 22. Valve plate; 23. Sliding bearing; 24. Inner row plunger; 25. Outer Row of plungers; 26. pins; 27. cylinder block; 1701. first slope; 1702. second slope; 2701. inner row of plunger holes; 2702. outer row of plunger holes; 401. swash plate; 402. cylinder body ;403. Inclined plunger; 404. Straight plunger; 501. Swash plate; 502. Plunger; 503. Cylinder; 601. Swash plate; 602. Plunger; 603. Cylinder; Cylinder block; 703. Inner row straight plunger; 704. Outer row oblique plunger; γ. Incline angle of swash plate; β. Incline angle of plunger.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

As shown in Figures 1 to 6, an axial piston pump or motor with a fully floating cylinder described in the embodiment of the present invention includes a swash plate 17, a cylinder body 27, an inner row of plungers 24, and an outer row of plungers. 25. Parts such as the distribution plate 22, the housing, and the shaft 11. Power transmission shaft 11 is connected with cylinder body 27 with spline and drives cylinder body 27 to rotate, two rows are evenly distributed along the conical surface on cylinder body 27 and the cylinder hole of different size angle that is the opposite direction with main shaft axis, plunger is housed in the hole ( Inner row plunger 24, outer row plunger 25) to form a sealed working volume; when transmission shaft 11 drives cylinder body 27 to rotate clockwise, the outer row plunger on the upper part of the shaft in Fig. 1 begins to absorb oil, and the outer row column on the lower part of the shaft The plug starts to discharge oil, and at the same time, the inner row plunger on the upper part of the shaft starts to discharge oil, and the inner row plunger on the lower part of the shaft starts to absorb oil. The suction force in the upper outer plunger chamber will move the plunger together with the sliding shoe to the right to break away from the swash plate 17, and the pressing force on the outer row pressure plate 6 will make the sliding shoe press against the swash plate 17, forming a suction force and a pressing force The torque will make the sliding shoe in balance; the suction force in the lower inner row of plunger cavity will make the plunger move rightward together with the sliding shoe to break away from the swash plate 17, and the pressing force on the inner row of pressure plate 16 will make the sliding shoe press toward The swash plate 17, the moment formed by the suction force and the pressing force will make the sliding shoes in balance, ensuring the normal oil suction of the axial piston pump. When the main shaft 11 (or cylinder 27) makes one revolution, each row of plungers completes a reciprocating motion and oil suction and discharge process. Wherein, the pressing force on the outer row pressing plate 6 is provided by the outer row pressing spring 20 , and the pressing force on the inner row pressing plate 16 is provided by the inner row pressing spring 21 .

The swash plate consists of two stepped slopes arranged in layers. The inclination angles of the two slopes are set in opposite directions. Each slope has a plunger connected to it through a sliding shoe. The plunger on the same slope corresponds to the cylinder body. The matching plunger holes are in the same row and distributed along the cone surface; the inclination direction of the plunger matches the inclination direction of the swash plate slope, the inclination direction of the inner row of plungers is opposite to that of the outer row of plungers, and the double row of plunger holes of the distribution plate corresponds to The direction of the suction and discharge ports is opposite. For the valve plate, the oil ports on the same side of the inner and outer rings are fixed as one suction and one row. Through design calculations, the pressure on the valve plate and the cylinder body can be kept in balance.

From the comparison diagram of the effective strokes of the straight plunger 4 and the oblique plunger 3, it can be found that under the same conditions, the double oblique cooperation of the two slopes of the swash plate with the inclination angle in the opposite direction and the two rows of plungers with the inclination angle in the opposite direction makes the oblique column The plunger has a larger effective stroke than the straight plunger of an ordinary axial piston pump or motor, so when the plunger pump or motor operates, the displacement value achieved by the double inclined pump or motor for one rotation will be greater than that of the ordinary axial plunger The displacement of the pump or motor. At the same time, the distribution radius of the suction and discharge chamber-shaped holes of the cylinder where the inner row plunger is located becomes smaller, and the distribution radius of the shape holes of the cylinder body where the outer row plunger is located becomes larger, so that the internal discharge flow increases and the external discharge flow decreases. , through reasonable setting of the inclination direction of the different slopes of the swash plate and the inclination angle of the plunger, the internal and external discharge flow can be balanced through calculation, and the radial force balance of the main parts such as the cylinder body can be ensured, so as to reduce noise, reduce vibration and make the cylinder body fully purpose of floating. At the same time, the inclination of the inner row of plungers is beneficial to enhance the anti-off ability of the inner row of skates during high-speed operation. Although the inclination of the outer row of plungers relatively increases the risk of the outer row of slippers, but because the outer row The pressing function ensures the anti-slipping ability of the outer row of slide boots, and prevents the phenomenon of the outer row of boots from taking off.

When the reaction force of the swash plate to the assembly is F _N , which is decomposed into the component force F _P along the axial direction of the plunger and the component force F _F perpendicular to the axial direction of the plunger, the double inclined plunger pump or motor F _N and F The included angle of _P is one plunger inclination angle larger than that of a straight plunger pump or motor. Component force along the plunger axis, where d is the diameter of the plunger, p is the oil pressure, for each plunger, F _P is a constant, for a double-slope plunger pump or motor, perpendicular to the plunger axis Component force; for ordinary straight plunger pumps or motors, the component force perpendicular to the axial direction of the plunger. Because the function is an increasing function in the first quadrant, the component force F _F of the double oblique plunger pump or motor perpendicular to the plunger axis is greater than that of the ordinary straight plunger pump or motor. By reasonably setting the diameter of the conical surface on which the plunger is distributed, the forces on the main components such as the swash plate and the cylinder body can be balanced.

As shown in Figure 7, the axis of the inner row of plungers is parallel to the axis of the cylinder body, and the axis of the outer row of plungers is inclined to the axis of the cylinder body. The holes are angled outward relative to the swash plate. Although the distribution radius of the suction and discharge cavity of the cylinder where the inner row plunger is located has not changed significantly, the distribution radius of the cylinder suction and discharge cavity where the outer row plunger is located becomes larger, which reduces the discharge flow rate. The inclination direction of the different inclined surfaces of the swash plate and the inclination angle of the plunger can be calculated to balance the internal and external discharge flow, ensure the radial force balance of the main parts such as the cylinder block, and achieve the purpose of reducing noise, reducing vibration and making the cylinder body fully floating.

To sum up, the present invention discloses an axial plunger pump or motor with a fully floating cylinder body. The double-oblique cooperation between the two slopes of the swash plate with opposite inclination angles and the two rows of plungers with opposite inclination angles is used to realize the cylinder Compared with the traditional axial piston pump or motor, it has three advantages: first, the double oblique cooperation between the swash plate and the plunger maintains the balance of the axial force and radial force of the cylinder, and realizes the full balance of the cylinder. The second is to reduce the difference in displacement between the inner and outer rows, reducing noise and vibration; the third is that the combination of the inclination of the plunger and the compression structure of the outer row can enhance the ability of the inner and outer row of sliding shoes to prevent slipping off, especially in the column Anti-slip capability at high pump or motor speeds.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Moreover, in this document, the terms "comprises", "comprising", or any other variation thereof are intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a series of elements includes not only those elements, but also includes Other elements not expressly listed, or elements inherent in the process, method, article, or apparatus are also included. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be described in the foregoing embodiments Modifications are made to the recorded technical solutions, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (3)

1. a kind of axial plunger pump or motor of full floating cylinder body, including housing, valve plate, power transmission shaft, cylinder body and swash plate, it is special Levy and be：Described swash plate has the first inclined-plane and the second inclined-plane, and described the first inclined-plane and the second bevel direction is opposite；It is described Cylinder body there is inclined interior organ timbering consent and inclined outer organ timbering consent, described interior organ timbering consent and outer organ timbering consent are tilted In the opposite direction, the interior organ timbering consent relative to swash plate slope inwardly or with cylinder body diameter parallel；The outer organ timbering consent is relative Tilted in swash plate, described housing includes pump case, left pump cover, right pump cover and left end cap, described left pump cover and right pump cover lead to Hexagon socket cap head screw is crossed to be connected with pump case；Described left end cap is connected by screw and left pump cover, and described valve plate is set Put between cylinder body and right pump cover, valve plate is connected by pin and right pump cover.

2. the axial plunger pump or motor of full floating cylinder body as claimed in claim 1, it is characterised in that：Described power transmission shaft bag Include oil sealing, axle, rolling bearing, circlip for shaft, axle sleeve, compress axle sleeve and sliding bearing, described oil sealing, rolling bearing, Circlip for shaft, axle sleeve, compression axle sleeve and sliding bearing are successively set on axle vertically.

3. the axial plunger pump or motor of full floating cylinder body as claimed in claim 1, it is characterised in that：On described right pump cover It is provided with O-shaped rubber seal.