Hydraulic pump variable mechanism for improving stability of swash plate

Abstract

The utility model discloses a kind of hydraulic pump variable mechanism of improving swash plate stability, including the variable rod of being installed in shell and the side cover body being installed in variable rod end and being connected with shell, inner built body is provided on side cover body and extends to shell, sliding sleeve is sleeved in the end of variable rod, and sliding sleeve is slidingly fitted in inner built body. Under the premise that existing plunger pump shell and variable rod and variable rod position control structure of oil pressure system are not changed, copper sleeve is sleeved in both ends of variable rod, the oil pressure area of variable rod end is increased, the resistance of swash plate back to zero is improved, and swash plate is overcome and swings back to zero.

Description

Technical Field

[0001] This utility model belongs to the field of piston pumps, specifically a hydraulic pump variable mechanism for improving swashplate stability. Background Technology

[0002] The axial piston pump is a swashplate type axial piston pump that uses a distributor plate for oil distribution, a rotating cylinder, and a variable displacement head for oil displacement. This pump employs an optimal oil film thickness design based on hydrostatic balance, ensuring that the cylinder and distributor plate, and the slipper and variable displacement head operate under pure fluid friction. It boasts advantages such as simple structure, small size, low noise, high efficiency, long service life, and self-priming capability.

[0003] The variable displacement mechanism is a crucial component of an axial piston pump, enabling changes in displacement. It comprises a variable lever, a swashplate, and a hydraulic control mechanism. The axial position of the variable lever is adjusted via the hydraulic control mechanism, thereby altering the angle of the swashplate and thus changing the flow rate. A partial diagram of an existing variable displacement mechanism is shown below. Figure 5 As shown, a sealing ring is used between the outer side of the variable rod and the side cover. Under low pilot pressure (≤3MPa) and high load displacement (≥80% of rated displacement) conditions, the plunger on the swashplate will be subjected to the reverse force of the oil, which will break the torque balance of the swashplate. Under this condition, the oil pressure at the end of the variable rod will increase beyond the set pressure, and the oil in the corresponding oil chamber will be discharged, causing the swashplate to swing back to zero. Utility Model Content

[0004] The technical problem to be solved by this utility model is: how to solve the problem of swashplate oscillation returning to zero in an axial piston pump.

[0005] To solve the above-mentioned technical problems, the inventors of this utility model, through practice and summarization, have derived the technical solution of this utility model, which adopts the following technical solution:

[0006] A hydraulic pump variable displacement mechanism for improving swashplate stability includes a variable rod installed in a housing and a side cover installed at the end of the variable rod and connected to the housing. The side cover has an inner body extending into the housing. The mechanism also includes a sliding sleeve fitted onto the end of the variable rod and slidably fitted into the inner body.

[0007] In the hydraulic pump variable mechanism, the sliding sleeve is a copper sleeve, and the outer wall of the sliding sleeve is distributed with a micro-woven structure. The micro-woven structure consists of multiple equally spaced annular grooves with a width of 0.5-1.0 mm and a depth of 0.5-1.0 mm.

[0008] In the hydraulic pump variable mechanism, a central hole is provided on the inner side of the variable rod. Two sets of symmetrically distributed guide rods and guide nuts fitted on the outer side of the guide rods are installed in the central hole. A spring is installed between the two guide rods, and the two ends of the spring abut against the ends of the guide rods respectively.

[0009] Both sets of guide rods have a socket at their close ends, which are inserted into the spring. Both sets of guide rods have a limiting boss in the middle, located on the side of the guide nut closest to the spring. Both sets of guide rods have a guide head at their far ends.

[0010] In the hydraulic pump variable mechanism, the guide nut and the guide rod are slidably engaged, and a retaining ring is installed in the central hole on the side of the guide nut opposite to the spring.

[0011] In the hydraulic pump variable mechanism, the guide nut is provided with a mounting hole, and a throttling plug is installed in the mounting hole.

[0012] In the hydraulic pump variable mechanism, a limit thread seat is provided at the end of the side cover. The axial position of the limit thread seat relative to the side cover is adjustable. The limit thread seat is provided with an axial guide hole and a radial hole connected to the axial guide hole. A limit rod is installed in the axial guide hole, and the end of the guide head is inserted into the axial guide hole.

[0013] In the hydraulic pump variable mechanism, the variable rod is provided with an adapter groove and a displacement detection structure facing away from the adapter groove.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention, without altering the existing plunger pump housing, variable displacement rod, or variable displacement rod position control structure, increases the hydraulic pressure area at the ends of the variable displacement rod by installing copper sleeves at both ends. This improves the resistance to swashplate return to zero and overcomes the swashplate swing back to zero. The copper sleeves prevent direct contact between the side cover and the variable displacement rod, reducing friction, and an annular groove on the outer wall of the copper sleeve serves as an oil seal. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the hydraulic pump variable mechanism of this utility model;

[0017] Figure 2 This is a cross-sectional view of the variable rod of this utility model;

[0018] Figure 3 This is a structural diagram of the variable rod of this utility model;

[0019] Figure 4 This is a cross-sectional view of the side cover of this utility model;

[0020] Figure 5 This is a diagram showing the relationship between the existing variable rod and the side cover.

[0021] In the diagram: 10. Housing; 20. Variable rod; 21. Center hole; 22. Guide rod; 23. Spring; 24. Guide nut; 25. Socket; 26. Throttling plug; 27. Adapter groove; 28. Displacement detection structure; 29. ​​Retaining ring; 30. Side cover; 31. Internal body; 32. Sliding sleeve; 321. Limiting thread seat; 322. Limiting rod; 323. Radial hole; 324. Axial guide hole; 33. Annular groove. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0023] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] Example 1

[0025] like Figure 1 and Figure 2 As shown, a hydraulic pump variable displacement mechanism for improving swashplate stability includes a variable displacement rod 20 installed within a housing 10 and a side cover 30 installed at the end of the variable displacement rod 20 and connected to the housing 10. The side cover 30 has an inner body 31 extending into the housing 10. It also includes a sliding sleeve 32 fitted onto the end of the variable displacement rod 20, which slidably engages with the inner body 31. By fitting the sliding sleeve 32 onto the outer side of the end of the variable displacement rod 20, the pressure-bearing area of ​​the variable displacement rod 20's end face is increased. Without altering the hydraulic circuit system and control method for adjusting the left and right displacements of the hydraulic pump housing 10 and the variable displacement rod 20, the resistance to reverse displacement changes of the variable displacement rod 20 is increased, thereby eliminating the problem of swashplate swaying back to zero in existing piston pumps. Increasing the end pressure area of ​​the existing variable displacement rod 20 would lead to… Figure 5The sealing ring cannot be installed (the thickness of the side cover and the built-in body inside the housing does not allow it), so the stable operation of the variable rod 20 cannot be guaranteed. The material of the variable rod is similar to that of the side cover. Due to the surface roughness of the variable rod and the side cover during processing, the harder part of the two will be ground down to the edge of the softer part, and the tip of the surface roughness will be ground down, so that hydraulic oil cannot be stored and an oil film cannot be established. This causes the two to deform due to friction and heat generation, and then become scrap.

[0026] Example 2

[0027] Based on Example 1, such as Figure 2 As shown, to avoid direct contact between the variable rod 20 and the side cover 30, which would cause wear due to hard friction between them, the sliding sleeve 32 is made of copper to eliminate the oil pressure. The outer wall of the sliding sleeve 32 is covered with a micro-woven structure, which consists of multiple equally spaced annular grooves 33. The width of the annular grooves 33 is 0.5-1.0 mm and the depth is 0.5-1.0 mm.

[0028] Example 3

[0029] Based on Example 2, such as Figure 2 , Figure 4 As shown, the variable rod 20 has a central hole 21 on its inner side. Two sets of symmetrically distributed guide rods 22 and guide nuts 24 fitted on the outer side of the guide rods 22 are installed in the central hole 21. A spring member 23 is installed between the two guide rods 22, and the two ends of the spring member 23 abut against the ends of the guide rods 22 respectively.

[0030] Both sets of guide rods 22 are provided with a socket 25 at their close ends, which are inserted into the spring member 23. Both sets of guide rods 22 are provided with a limiting boss in the middle, which is located on the side of the guide nut 24 near the spring member 23. Both sets of guide rods 22 are provided with a guide head at their far ends.

[0031] The guide nut 24 and the guide rod 22 are slidably fitted together. A retaining ring 29 is installed in the center hole 21 on the side of the guide nut 24 facing away from the spring member 23. The retaining ring 29 constrains the guide nut 24 to prevent it from changing position.

[0032] The guide nut 24 is provided with a mounting hole 25, and a throttling plug 26 is installed in the mounting hole 25.

[0033] The end of the side cover 30 is provided with a limiting thread seat 321. The axial position of the limiting thread seat 321 relative to the side cover 30 is adjustable. The limiting thread seat 321 is provided with an axial guide hole 324 and a radial hole 323 connected to the axial guide hole 324. A limiting rod 322 is installed in the axial guide hole 324. The end of the guide head is inserted into the axial guide hole 324. The radial hole 323 can supply oil to the axial guide hole 324 and the guide head.

[0034] The hydraulic control mechanism supplies oil to the right oil chamber in the area between the side cover 30 and the housing 10, while the left oil chamber discharges oil outward. The variable lever 20 moves to the left. Before the variable lever 20 moves to the left, the left guide lever 22 contacts the limit lever 322. The right guide lever 22 moves to the left together with the variable lever 20.

[0035] When the variable rod 20 moves to the left, the guide rod 22 on the left side is obstructed and moves to the right relative to the variable rod 20 to compress the spring 23. The guide rod 22 on the right side will be displaced relative to its corresponding shaft guide hole 324, and the oil inside the variable rod 20 will be discharged through the throttle plug 26.

[0036] When the variable lever 20 moves to the right, the hydraulic control mechanism supplies oil to the left oil chamber and discharges oil from the right oil chamber. The variable lever 20 drives the right guide lever 22 to move to the right. The spring 23 inside the variable lever 20 will gradually and elastically reset. At the same time as the elastic reset, the oil will automatically fill into the variable lever 20. During this period, the left guide lever 22 will always remain in contact with the left limit lever 322 until the variable lever 20 is in the middle position.

[0037] Example 4

[0038] Based on the above embodiment 3, such as Figure 2 and Figure 3 As shown, the variable rod 20 is provided with an adapter groove 27 and a displacement detection structure 28 positioned opposite the adapter groove 27. The adapter groove 27 is assembled with the adjustment end of the swashplate. The axial position of the variable rod 20 is adjusted to change the angle of the swashplate, thereby adjusting the flow rate. The displacement detection structure 28 works in conjunction with the displacement sensor on the housing to complete real-time position acquisition.

[0039] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made based on the technical solution and inventive concept of this utility model should all be covered within the protection scope of this utility model.

Claims

1. A hydraulic pump variable displacement mechanism for improving swashplate stability, comprising a variable displacement rod (20) installed within a housing (10) and a side cover (30) installed at the end of the variable displacement rod (20) and connected to the housing (10), wherein the side cover (30) has an internal body (31) extending into the housing (10), characterized in that, It also includes a sliding sleeve (32), which is fitted onto the end of the variable rod (20) and slides within the inner body (31).

2. The hydraulic pump variable mechanism for improving swashplate stability according to claim 1, characterized in that, The sliding sleeve (32) is a copper sleeve. The outer wall of the sliding sleeve (32) is covered with a micro-woven structure. The micro-woven structure consists of multiple equally spaced annular grooves (33). The width of the annular grooves (33) is 0.5-1.0 mm and the depth is 0.5-1.0 mm.

3. The hydraulic pump variable mechanism for improving swashplate stability according to claim 1, characterized in that, The variable rod (20) has a central hole (21) on its inner side. Two sets of symmetrically distributed guide rods (22) and guide nuts (24) fitted on the outer side of the guide rods (22) are installed in the central hole (21). A spring (23) is installed between the two guide rods (22). The two ends of the spring (23) abut against the ends of the guide rods (22) respectively. Both sets of guide rods (22) are provided with a socket (25) at the end that is close to each other. The socket (25) is inserted into the spring (23). Both sets of guide rods (22) are provided with a limiting boss in the middle. The limiting boss is distributed on the side of the guide nut (24) that is close to the spring (23). Both sets of guide rods (22) are provided with a guide head at the end that is far apart from each other.

4. The hydraulic pump variable mechanism for improving swashplate stability according to claim 3, characterized in that, The guide nut (24) and guide rod (22) are slidably fitted together, and a retaining ring (29) is installed in the center hole (21) on the side of the guide nut (24) opposite to the spring (23).

5. A hydraulic pump variable mechanism for improving swashplate stability according to claim 3, characterized in that, The guide nut (24) is provided with a mounting hole, and a throttling plug (26) is installed in the mounting hole.

6. A hydraulic pump variable displacement mechanism for improving swashplate stability according to claim 3, characterized in that, The end of the side cover (30) is provided with a limiting thread seat (321). The axial position of the limiting thread seat (321) relative to the side cover (30) is adjustable. The limiting thread seat (321) is provided with an axial guide hole (324) and a radial hole (323) connected to the axial guide hole (324). A limiting rod (322) is installed in the axial guide hole (324), and the end of the guide head is inserted into the axial guide hole (324).

7. The hydraulic pump variable mechanism for improving swashplate stability according to claim 1, characterized in that, The variable rod (20) is provided with an adapter slot (27) and a displacement detection structure (28) set opposite to the adapter slot (27).

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