Swash plate driving device of plunger pump

Abstract

The utility model discloses a plunger pump swash plate driving device which comprises a pump body, the pump body comprises a mounting hole, an ejector rod is arranged at the front end of the mounting hole in a sliding mode, a plug is fixed to the rear end of the mounting hole in a threaded connection mode and comprises a threaded hole, an adjusting screw is arranged at the threaded hole in a threaded connection mode, and the front end of the plug comprises a sliding cavity connected with the threaded hole. A push rod is slidably arranged in the sliding cavity, the rear end of the push rod and the front end of the adjusting screw form limiting fit, the front end of the piston and the rear end of the ejector rod form limiting fit, and a first sealing ring is arranged at the sliding fit position of the push rod and the sliding cavity. The plunger pump swash plate driving device not only is simple in structure, but also has better reliability.

Description

Technical Field

[0001] The utility model relates to a swash plate driving device for a plunger pump. Background Art

[0002] The swash plate axial piston pump is the heart of the hydraulic system and is a device that converts mechanical energy into hydraulic energy. It is widely used in engineering machinery, agricultural machinery, mining machinery, industrial equipment and other fields because of its high power-to-weight ratio, stepless flow regulation, high continuous use pressure, excellent oil absorption performance, high allowable speed, high reliability, long life, high efficiency and energy saving, good sealing, low noise level, and low flow pulsation. When the user designs a hydraulic system, if the pump does not need to work at the maximum displacement, it is necessary to adjust the maximum displacement adjustment structure of the pump so that the pump can work stably at the maximum displacement required.

[0003] The Chinese invention patent application discloses a floating swash plate type plunger pump (CN117514681A) containing a main shaft constant speed driven rotary plate transmission mechanism. The pump is composed of a pump body, a main shaft installed in the pump body, a swash plate, a distribution plate, a cylinder body, a plunger and other components. When working, the main shaft drives the cylinder body to rotate, and also drives the plunger in the cylinder hole to rotate. Under the action of the inclination angle of the swash plate, the plunger produces reciprocating motion in the cylinder hole. The rotational and reciprocating motion of the plunger causes the volume of the cylinder hole sealing working chamber to change continuously, and the oil is sucked in from the oil suction waist-shaped hole of the distribution plate and discharged from the oil discharge waist-shaped hole, realizing the conversion of mechanical energy and hydraulic energy. In addition, the swash plate is also connected to a variable lever, which can change the inclination of the swash plate through the variable lever, thereby changing the movement stroke of the plunger and realizing the adjustment of the displacement. Combined with the attached figure disclosed in the patent Figure 2 It can be seen that the variable lever and the swash plate are connected by a ball head, and the plunger pump also includes a driving device, which is connected to the variable lever and can drive the variable lever to translate, and then drive the swash plate to achieve tilting and rotation through the variable lever. In the prior art, the driving device of the swash plate usually includes a push rod slidably arranged at the front end of the pump body mounting hole, an adjusting screw screwed arranged at the rear end of the pump body mounting hole, and the front end of the adjusting screw and the push rod form a limit fit. During adjustment, the adjusting screw is driven to rotate by the rear end of the adjusting screw, and the adjusting screw generates axial movement by the screw connection structure when rotating. The adjusting screw can drive the push rod and the variable lever to move while axially moving, thereby achieving driving the swash plate to tilt and rotate. Due to the matching mode of the push rod and the adjusting screw, the control oil inside the pump body is easy to leak out to the outside of the pump body along the sliding connection between the push rod and the mounting hole and the screw connection of the adjusting screw. Therefore, it is usually necessary to set a sealing ring between the push rod and the inner wall of the mounting hole, which easily allows external dust to enter the mounting hole through the screw connection of the adjusting screw, affecting the service life of the product. Utility Model Content

[0004] The utility model provides a plunger pump swash plate driving device, which has a simple structure and better reliability.

[0005] The utility model provides a plunger pump swash plate drive device, including a pump body, the pump body includes a mounting hole, a push rod is slidably arranged at the front end of the mounting hole (one end corresponding to the inner side of the pump body), a screw plug is screwed and fixed at the rear end of the mounting hole (one end corresponding to the outer side of the pump body), the screw plug includes a threaded hole, an adjusting screw is screwed at the threaded hole, the front end of the screw plug includes a sliding cavity connected to the threaded hole, the sliding cavity is integrally formed at the front end of the screw plug, a push rod is slidably arranged in the sliding cavity, the rear end of the push rod and the front end of the adjusting screw form a limiting fit, the front end of the push rod and the rear end of the push rod form a limiting fit, and the sliding fit between the push rod and the sliding cavity is provided A first sealing ring is provided, and the front end of the push rod and the swash plate form a direct linkage cooperation or an indirect linkage cooperation through a transmission component. When the push rod moves forward, it will push the swash plate to rotate in one circumferential direction, and the swash plate is pushed to return and rotate in another circumferential direction through a return spring matched with the swash plate or the transmission component. At the same time, it can also drive the push rod and the push rod to return and move backward. The rear end of the adjusting screw is placed on the outside of the pump body for operation by the staff. Since the adjusting screw and the screw plug form a threaded cooperation, when the adjusting screw is driven to rotate, it will produce axial movement, and can cooperate with the return spring to drive the push rod and the push rod to move in the front and rear directions.

[0006] In the solution of the utility model, sealing is achieved by a first sealing ring arranged between the push rod and the sliding cavity to prevent the control oil inside the pump body from leaking outwards. In addition, the dust in the outside air can be confined in the sliding cavity due to the obstruction of the first sealing ring, and the dust will not enter between the mounting hole and the push rod, which can avoid wear of the mounting hole and the push rod, thereby extending the service life of the product. In addition, the dust in the sliding cavity can be conveniently cleaned by removing the screw plug, and when the screw plug and the push rod are worn, they can also be conveniently disassembled and replaced.

[0007] Furthermore, an annular groove is provided on the outer side of the screw plug, a second sealing ring is provided in the annular groove, and a conical surface that cooperates with the second sealing ring for sealing is provided at the rear end of the mounting hole. This enables the second sealing ring to be pressed and contacted on the conical surface when the screw plug is fixed to the rear end of the mounting hole by screw connection, thereby improving the sealing effect between the screw plug and the mounting hole.

[0008] Furthermore, the outer peripheral wall of the push rod is provided with a plurality of annular pressure equalizing grooves spaced apart in the axial direction. The provision of the pressure equalizing grooves can reduce the flow velocity difference when the control oil passes through, can avoid the occurrence of excessive liquid pressure, can disperse the pressure of the control oil to the outer peripheral wall of the push rod, and ensure the activity effect of the push rod. The push rod is provided with a plurality of oil passages in the circumferential direction, and the two ends of the oil passages are respectively provided with openings at the outer peripheral wall of the push rod and the rear end of the push rod, and the opening at the outer peripheral wall of the push rod is provided in the middle position of the plurality of annular pressure equalizing grooves in the axial direction. The provision of the oil passages helps to reduce the pressure difference between the front and rear ends of the push rod, reduce the blockage of the push rod, and improve the activity effect of the push rod.

[0009] Furthermore, the rear end of the slide cavity is provided with an annular step surface that cooperates with the rear end of the push rod to limit the position, the threaded hole is connected to the center of the annular step surface, the annular step surface constitutes the bottom inner wall of the slide cavity, the axial length of the push rod is greater than the axial depth of the slide cavity, and the openings at the rear end of the push rod are distributed and arranged at the surrounding positions corresponding to the push rod. The annular step surface has a limiting effect on the push rod, which can prevent the push rod from escaping from the threaded hole. In addition, when the rear end of the push rod abuts against the annular step surface, the front end of the push rod has a limiting effect on the rear end of the push rod, and will not block the rear end opening of the push rod, thereby reducing the blockage of the push rod and improving the activity effect of the push rod.

[0010] Furthermore, the rear end of the adjusting screw is threaded with a locking nut, and the locking nut is in abutment with the rear end of the screw plug. When the adjusting screw is adjusted, the adjusting screw can be locked by tightening the locking nut to prevent it from rotating automatically under the action of thrust. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A cross-sectional view of an embodiment of the utility model;

[0012] Figure 2 This is a usage status diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0013] The implementation example of the utility model plunger pump swash plate drive device is as follows Figure 1-2As shown: it includes a pump body 1, which is a component of a plunger pump. The pump body 1 includes a mounting hole 10. The front end of the mounting hole 10, that is, the end corresponding to the inner side of the pump body 1, is slidably provided with a push rod 2. The rear end of the mounting hole 10, that is, the end corresponding to the outer side of the pump body 1, is threadedly fixed with a screw plug 3. The screw plug 3 includes a threaded hole 31. An adjusting screw 4 is threadedly provided at the threaded hole 31. The front end of the screw plug 3 includes a sliding cavity 32 connected to the threaded hole 31. The sliding cavity 32 is integrally formed at the front end of the screw plug 3. A push rod 5 is slidably provided in the sliding cavity 32. The rear end of the push rod 5 and the front end of the adjusting screw 4 form a limiting fit. The front end of the push rod 5 and the rear end of the push rod 2 form a limiting fit. A first sealing ring 61 is provided at the sliding fit between the push rod 5 and the sliding cavity 32.

[0014] In this embodiment, the front end of the push rod 2 and the swash plate 7 form a push fit, and when the push rod 2 moves forward, the swash plate 7 is pushed to rotate, and when the push rod 2 moves backward, the swash plate 7 can be pushed to return and rotate by the return spring 8 connected to the swash plate 7. In other embodiments, the front end of the push rod 2 and the variable lever in the above-mentioned existing patent form a push fit, and the swash plate 7 is indirectly driven to rotate by the variable lever, and the return spring drives the swash plate 7 and the push rod 2 to return to motion at the same time.

[0015] The rear end of the adjusting screw 4 is placed outside the pump body 1 for operation by the staff. The rear end of the adjusting screw 4 is provided with a hexagonal hole, which can be driven to rotate by a hexagonal tool. Since the adjusting screw 4 and the screw plug 3 form a threaded fit, when the adjusting screw 4 is driven to rotate, it will generate axial movement, and can cooperate with the reset spring 8 to drive the push rod 5 and the push rod 2 to move in the front-rear direction.

[0016] In this embodiment, sealing is achieved by providing a first sealing ring 61 between the push rod 5 and the sliding cavity 32 to prevent the control oil inside the pump body 1 from leaking outward. In addition, the dust in the outside air can be confined in the sliding cavity 32 by the obstruction of the first sealing ring 61, and the dust will not enter the sliding fit between the mounting hole 10 and the push rod 2, thereby avoiding wear of the mounting hole 10 and the push rod 2, thereby extending the service life of the product. In addition, the dust in the sliding cavity 32 can be conveniently cleaned by removing the screw plug 3, and when the screw plug 3 and the push rod 5 are worn, the screw plug 3 and the push rod 5 can also be conveniently disassembled and replaced.

[0017] The outer side of the screw plug 3 is provided with an annular groove, which is provided at the annular step surface of the outer side of the screw plug 3. A second sealing ring 62 is provided in the annular groove, and a conical surface that cooperates with the second sealing ring 62 for sealing is provided at the rear end of the mounting hole 10. This enables the second sealing ring 62 to be pressed and contacted on the conical surface when the screw plug 3 is fixed to the rear end of the mounting hole 10 by screw connection, thereby improving the sealing effect between the screw plug 3 and the mounting hole 10.

[0018] The outer peripheral wall of the push rod 2 is provided with a plurality of annular pressure equalizing grooves 21 distributed at intervals along the axial direction. The provision of the pressure equalizing grooves 21 can reduce the flow velocity difference of the control oil passing through the four sides of the push rod 2, can avoid the occurrence of excessive liquid pressure, can disperse the pressure of the control oil to the outer peripheral wall of the push rod 2, and ensure the activity effect of the push rod 2. The push rod 2 is provided with a plurality of oil passages 22 along the circumferential direction, and the two ends of the oil passages 22 are respectively provided with openings at the outer peripheral wall of the push rod 2 and the rear end of the push rod 2. The openings at the outer peripheral wall of the push rod 2 are provided at the middle position of the plurality of annular pressure equalizing grooves 21 along the axial direction. For example, in the present embodiment, the axial front and rear sides of the openings at the outer peripheral wall of the push rod 2 are respectively provided with three annular pressure equalizing grooves 21. The provision of the oil passages 22 helps to reduce the pressure difference between the front and rear ends of the push rod 2, reduce the blockage of the push rod 2, and improve the activity effect of the push rod 2.

[0019] The rear end of the slide cavity 32 is provided with an annular step surface 321 which cooperates with the rear end of the push rod 5 to limit the position. The threaded hole 31 is connected to the center of the annular step surface 321. The annular step surface 321 constitutes the bottom inner wall of the slide cavity 32. The axial length of the push rod 5 is greater than the axial depth of the slide cavity 32. The openings at the rear end of the push rod 2 are distributed and arranged at the surrounding positions corresponding to the push rod 5. The annular step surface 321 has a limiting effect on the push rod 5, which can prevent the push rod 5 from coming out of the threaded hole 31. In addition, when the rear end of the push rod 5 abuts against the annular step surface 321, the front end of the push rod 5 can extend from the slide cavity 32, which has a limiting effect on the rear end of the push rod 5, which can prevent the rear end of the push rod 5 from contacting the screw plug 3, and will not block the opening of the oil passage 22 at the rear end of the push rod 5, thereby reducing the blockage of the push rod 5 and improving the activity effect of the push rod 5.

[0020] The rear end of the adjusting screw 4 is threaded with a locking nut 9, which abuts against the rear end of the screw plug 3. When the adjusting screw 4 is adjusted, the adjusting screw 4 can be locked by tightening the locking nut 9 to prevent it from rotating by itself under the action of the reset spring 8 or the internal oil pressure.

[0021] The above embodiment is only one of the preferred specific embodiments of the present invention. Common changes and substitutions made by those skilled in the art within the technical solution of the present invention are all included in the protection scope of the present invention.

Claims

1. A plunger pump swash plate drive device, comprising a pump body, the pump body comprising a mounting hole, a push rod being slidably disposed at the front end of the mounting hole, a screw plug being screwed and fixed at the rear end of the mounting hole, the screw plug comprising a threaded hole, an adjusting screw being screwed and disposed at the threaded hole, characterized in that: The front end of the screw plug includes a sliding cavity connected to the threaded hole, a push rod is slidably arranged in the sliding cavity, the rear end of the push rod and the front end of the adjusting screw form a limiting fit, the front end of the push rod and the rear end of the push rod form a limiting fit, and a first sealing ring is arranged at the sliding fit between the push rod and the sliding cavity.

2. The plunger pump swash plate drive device according to claim 1, characterized in that: An annular groove is arranged on the outer side of the screw plug, a second sealing ring is arranged in the annular groove, and a conical surface which cooperates with the second sealing ring for sealing is arranged at the rear end of the mounting hole.

3. The plunger pump swash plate drive device according to claim 1, characterized in that: The outer circumferential wall of the push rod is provided with a plurality of annular pressure equalizing grooves spaced apart in the axial direction, and the push rod is provided with a plurality of oil passages in the circumferential direction. The two ends of the oil passages are respectively provided with openings at the outer circumferential wall of the push rod and the rear end of the push rod, and the opening at the outer circumferential wall of the push rod is provided in the middle position of the plurality of annular pressure equalizing grooves in the axial direction.

4. The plunger pump swash plate drive device according to claim 3, characterized in that: The rear end of the sliding cavity is provided with an annular step surface that cooperates with the rear end of the push rod to limit the position. The threaded hole is connected to the center of the annular step surface. The annular step surface constitutes the bottom inner wall of the sliding cavity. The axial length of the push rod is greater than the axial depth of the sliding cavity. The openings at the rear end of the push rod are distributed and arranged at surrounding positions corresponding to the push rod.

5. The plunger pump swash plate drive device according to claim 1, characterized in that: The rear end of the adjusting screw is threadedly connected with a locking nut, and the locking nut is abutted and matched with the rear end of the screw plug.

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