CN114562437B

CN114562437B - Slide disc type axial plunger pump

Info

Publication number: CN114562437B
Application number: CN202011360815.2A
Authority: CN
Inventors: 钟彪
Original assignee: Shanghai Qiangtian Drive Technology Co ltd
Current assignee: Shanghai Qiangtian Drive Technology Co ltd
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2024-09-10
Anticipated expiration: 2040-11-27
Also published as: CN114562437A

Abstract

The invention discloses a slide plate type axial plunger pump, which comprises a flow distribution slide plate pair, a plunger pair and a flow distribution pair, wherein the flow distribution slide plate pair comprises a swash plate and a slide plate supported on the swash plate, the slide plate is of an integral structure, a waist-shaped hole communicated with a plunger center hole is formed in the slide plate, a low-pressure oil distribution hole serving as an oil inlet channel is formed in a swash plate supporting surface opposite to a low-pressure plunger hole, a static pressure support is formed between the swash plate supporting surface opposite to a high-pressure plunger hole and the waist-shaped hole of the slide plate, the low-pressure oil distribution hole is communicated with a cavity of a shell through an oil inlet groove arranged on the swash plate, and when the plunger pump works, low-pressure oil enters the cylinder body plunger hole through a low-pressure distribution port and the oil inlet groove of the swash plate or a groove-shaped low-pressure port in a double way, and high-pressure oil is discharged from the high-pressure distribution port of the flow distribution plate or the groove-shaped high-pressure port of the swash plate in a single way, so that the suction and discharge of hydraulic oil are realized. The invention can further reduce the axial stress of the bearing, improve the stress working condition of the bearing, improve the self-absorption capacity and reduce the oil temperature, thereby improving the working reliability and the service life of the plunger pump.

Description

Slide disc type axial plunger pump

Technical Field

The invention belongs to the technical field of hydraulic transmission and control, and particularly relates to a sliding disc type axial plunger pump.

Background

Axial piston pumps are one of the most widely used hydraulic components in modern hydraulic transmission, with the backlashless inclined shaft pump and the slipper swashplate type axial piston pumps being the two most widely used and dominant types of axial piston pumps at present. The inclined shaft pump and the slide shoe inclined disc type pump have the characteristics, and the two pumps are competing at present and are continuously improved and developed.

The swash plate type plunger pump has the characteristics of simple and compact structure, small volume, light weight, stepless variable realized by swinging the swash plate, small inertia of the variable, quick variable response speed and the like, but has natural defects of design, such as dynamic unbalance force problem, low-speed performance difference in the movement process, and premature wear of the sliding shoes and the valve plates caused by wedge-shaped contact movement, which are not fundamentally changed for hundreds of years. Compared with a swash plate structure, the conventional inclined shaft structure has the advantages of less leakage, less dynamic unbalance force and good low-speed performance due to the fact that a pair of friction pairs is reduced, and therefore the structure is mainly used as a motor and widely applied, but is limited to be used as a pump due to the fact that a dependent variable is difficult, the response time of the variable is slow, a through shaft cannot be conducted, the service life of a main shaft is short, and the like.

A brand-new axial plunger pump structure combines the structures of the prior swash plate type and inclined shaft type plunger pumps, combines the structure depths of the swash plate type and inclined shaft type plunger pumps, creatively proposes a sliding plate type axial plunger pump, and forms dozens of patents (CN 201910189721.4, CN201910189068.1, CN201910189070.9 and the like), and the structure has the advantages of the swash plate type and inclined shaft type plunger pumps or motors at the same time, namely, the structure of the swash plate type plunger pump is simpler and more compact, the volume is smaller, the weight is lighter, stepless variable can be realized through swinging of the swash plate, the inertia of the variable is smaller, the variable response speed is faster, the through shaft is realized and the like, and meanwhile, the structure also has the characteristics of small dynamic unbalanced force, small lateral force, good friction pair contact performance, good low-speed performance and the like of the inclined shaft type plunger pump. In order to further improve bearing stress, improve life-span, improve from energy-absorbing ability, reduce the influence of the pump body high temperature that fluid caused because of friction and volumetric efficiency loss to friction pair, improve the oil absorption end of slide plate type plunger pump, this novel slide plate type plunger pump is particularly suitable for being applied to in the open type plunger pump.

Disclosure of Invention

The invention aims at: the novel axial plunger pump structure aims at solving the problems of the existing sliding disc type axial plunger pump, and aims at further reducing axial stress of a bearing, improving stress working conditions of the bearing and self-absorption capacity, reducing influence of overhigh temperature of oil liquid on a friction pair due to friction and volumetric efficiency loss of a pump body, and improving working reliability and service life of the sliding disc type plunger pump.

The implementation mode of the technical scheme of the invention is as follows: a slide disc type axial plunger pump is characterized in that: the hydraulic oil suction and discharge device comprises a flow distribution slide plate pair, a plunger pair and a flow distribution pair, wherein the flow distribution slide plate pair comprises a swash plate and a slide plate supported on the swash plate, the slide plate is of an integral structure, a slide plate waist-shaped hole communicated with a plunger center hole of the plunger pair is arranged on the slide plate, a low-pressure oil distribution hole serving as an oil inlet channel is arranged on a swash plate supporting surface opposite to a low-pressure plunger hole, a hydrostatic bearing is formed between the swash plate supporting surface opposite to a high-pressure plunger hole and the slide plate waist-shaped hole, the low-pressure oil distribution hole is communicated with a shell cavity through an oil inlet groove arranged on the swash plate, a main shaft drives a cylinder body to synchronously rotate and drives the slide plate to slide on the swash plate through a plunger when the plunger pump works, and low-pressure oil enters the cylinder body plunger hole of the cylinder body from a low-pressure flow distribution port of the flow distribution plate and the oil inlet groove of the swash plate or a groove-shaped low-pressure port in a double-way, so that high-pressure oil is sucked and discharged from a high-pressure distribution port of the flow distribution plate or the swash plate in a groove-shaped high-pressure port of the flow distribution plate in a single way.

The invention discloses a slide disc type axial plunger pump, which is characterized in that a slide disc boss surface extending to one side of an inclined disc along the axis of the slide disc is arranged on the slide disc, a plurality of slide disc kidney-shaped holes and sealing parts for sealing oil are arranged on the slide disc boss surface, the sealing parts are arranged on the inner periphery and the outer periphery of the slide disc kidney-shaped holes in a state of surrounding the slide disc kidney-shaped holes, and each sealing part comprises a slide disc inner sealing part, a slide disc outer sealing part and a slide disc interval sealing part, wherein the slide disc inner sealing part and the slide disc outer sealing part are arranged between the slide disc kidney-shaped holes.

The invention discloses a sliding disc type axial plunger pump, wherein the flow distribution pair is a bidirectional high-low pressure flow distribution pair, the flow distribution pair comprises a cylinder body end part and a flow distribution disc supported on a rear end cover, the cylinder body end part and the end surface of the flow distribution disc form a static pressure oil film support in clearance fit, the flow distribution disc is provided with a low-pressure flow distribution port and a high-pressure flow distribution port which are separated, and the low-pressure flow distribution port and the high-pressure flow distribution port are respectively communicated with an oil inlet and an oil outlet of the rear end cover.

The invention discloses a slide plate type axial plunger pump, wherein the flow distribution slide plate pair is a unidirectional low-pressure flow distribution slide plate pair, the flow distribution slide plate pair comprises a swash plate and a slide plate supported on the swash plate, the swash plate and the end surface of the slide plate form a clearance fit static pressure oil film support, the swash plate and the slide plate are in sliding fit, a low-pressure flow distribution window is arranged on one side of the slide plate opposite to a low-pressure plunger hole, and when the pump absorbs oil, low-pressure oil liquid in a cavity of a shell flows through the low-pressure flow distribution window, a slide plate waist-shaped hole, a plunger center hole and a cylinder body plunger hole in sequence.

The invention relates to a sliding disc type axial plunger pump, wherein the flow distribution pair is a unidirectional low-pressure flow distribution pair, the flow distribution pair comprises a cylinder end and a flow distribution disc supported on a shell, the cylinder end and the end face of the flow distribution disc form a static pressure oil film support in clearance fit, the cylinder end and the end face of the flow distribution disc are in sliding fit, a low-pressure flow distribution port is arranged on one side of the flow distribution disc opposite to a low-pressure plunger hole, and low-pressure oil liquid enters the cylinder plunger hole from a cavity of the pump shell through the low-pressure flow distribution port when oil is pumped.

The invention relates to a slide plate type axial plunger pump, wherein the slide plate pair is a bidirectional high-low pressure slide plate pair, the slide plate pair comprises a swash plate and a slide plate supported on the swash plate, the swash plate and the end face of the slide plate form clearance fit static pressure oil film support and are in sliding fit, a support surface opposite to a rear end cover on the swash plate is provided with a cylindrical sliding cambered surface which is formed into a cylinder shape, the cylindrical sliding cambered surface of the swash plate is provided with a groove-shaped low-pressure port and a groove-shaped high-pressure port which are formed into groove shapes, and the groove-shaped low-pressure port and the groove-shaped high-pressure port are respectively correspondingly communicated with an oil inlet and an oil outlet on the rear end cover.

The thrust disc is supported on the thrust disc and is in sliding fit with the thrust disc, a low-pressure distributing port and/or a high-pressure distributing port are arranged on the thrust disc, and the distributing port of the thrust disc is communicated with a distributing oil groove of the swash plate and a sliding disc waist-shaped hole of the thrust disc.

The invention discloses a slide disc type axial plunger pump, which is characterized in that a spring pre-tightening device is arranged between a slide disc and a cylinder body, and a certain initial contact force is formed between a flow distribution slide disc pair and a slide disc pair through the spring pre-tightening device.

Or the slide plate and/or the cylinder body are/is provided with a constraint device, and the constraint device is provided with a function of limiting the slide plate of the flow distribution slide plate pair to move away from the sloping cam plate and limiting the cylinder body of the flow distribution stop pair to move away from the flow distribution plate.

The invention discloses a slide disc type axial plunger pump, which is characterized in that an impeller device is arranged on a cylinder body, and the impeller device is used for directionally driving low-pressure oil to accelerate from a cavity of a shell into a plunger hole.

The invention discloses a sliding disc type axial plunger pump which is of a through shaft type structure and particularly comprises a main shaft, a shell, a first bearing, a second bearing, a plunger, a cylinder body, a valve plate and a rear end cover, wherein a communicating groove communicated with a cavity of the shell is formed in the rear end cover, the axis of the main shaft is coincident with the axis of the cylinder body, one end of the main shaft penetrates through the valve plate pair to extend out of the shell and support the valve plate pair on the first bearing, the other end penetrates through the valve plate pair and support the valve plate pair on the second bearing, the cylinder body is supported on the main shaft and realizes synchronous rotation with the main shaft through key connection, and the plunger reciprocates in the plunger cavity of the cylinder body so as to realize oil sucking and discharging work of the pump.

The invention discloses a slide disc type axial plunger pump which is of a non-through shaft type structure and particularly comprises a main shaft, a shell, a first bearing, a plunger, a cylinder body, a slide disc and a rear end cover, wherein a communicating groove communicated with a cavity of the shell is formed in the rear end cover, the axis of the main shaft is coincident with the axis of the cylinder body, one end of the main shaft penetrates through a flow distribution pair to extend out of the shell and is supported on the first bearing, the other end of the main shaft is supported in the cylinder body in a cantilever mode and is connected with the cylinder body through a key, the main shaft and the cylinder body synchronously rotate, and the plunger reciprocates in the plunger cavity of the cylinder body to realize oil sucking and discharging work of the pump.

Based on the technical scheme, the invention has the beneficial effects that:

1. According to the invention, two disc-shaped static pressure bearing surfaces (namely the flow distribution pair and the flow distribution sliding disc pair structure) are arranged in the pump body, so that mutual offset can be formed in the axial direction, the axial force action of the bearing is greatly reduced, and meanwhile, compared with the traditional sliding shoe pair and the flow distribution pair structure, an oil film is more stable, so that the reliability and the service life of the pump are further improved.

2. According to the invention, the two-way oil inlet structure is arranged in the pump body, namely, the oil enters the cylinder body plunger hole from the low-pressure distributing port of the valve plate and the oil inlet groove of the swash plate or the groove-shaped low-pressure port in a double way, so that on one hand, the oil suction side oil quantity is increased, the self-absorption capacity is greatly improved, and the self-absorption rotating speed is improved; on the other hand, one path of oil flowing through the inner cavity of the pump housing and entering the plunger hole can bring heat converted by friction and volumetric efficiency loss into a hydraulic system, so that the hot oil is not retained in the pump body for a long time, the adverse effect of high temperature on a friction pair is avoided, and the service life is prolonged; furthermore, an oil return pipeline is omitted structurally, and the structure is simplified.

3. The invention integrates the functions of flow distribution, variable inclination and static pressure bearing into the sliding plate pair, and the plunger adopts a conical structure, so that the lateral force of the plunger is greatly reduced, and the overturning phenomenon of the cylinder body is eliminated or reduced; the variable of the pump is realized by changing the inclination mode of the swash plate, and the variable response speed is relatively high due to the fact that the inertia of the swash plate variable is small and the variable is convenient; meanwhile, the structure is simpler and more compact, the volume is smaller, the weight is lighter, and the characteristics of the existing swash plate type plunger pump and the inclined shaft type plunger pump are achieved.

4. The invention adopts the structure of the flow distribution slide plate pair and the flow distribution pair, which are better than the slide shoe pair in the aspect of keeping the stability of an oil film, especially in the aspect of low-speed performance, and still have better performance, and the characteristics have the advantages of the existing inclined shaft type plunger pump.

5. The invention adopts the flow distribution slide plate pair with a disc-shaped structure, has the characteristic of large inclination angle of the inclined shaft type plunger pump, and can break through the limit of the maximum inclination angle of the prior inclined plate type plunger pump, thereby having larger discharge capacity and more outstanding power density under the same volume.

6. The axial plunger pump of the invention has the advantages that the structure is greatly simplified, the size is smaller, the structure is more compact, the weight of the pump is smaller, and therefore, the unit mass power density is improved because the oil inlet and the oil outlet are integrated on the rear end cover; meanwhile, the cylinder body is closer to the bearing, so that the bending moment acting on the cantilever main shaft is reduced, the main shaft is more favorably stressed, the service life of the bearing is longer, and the mechanical noise is smaller in the working process.

7. The functions of flow distribution, variable inclination and static pressure support are integrated in the sliding disc pair, and as the plunger ball socket and the plunger ball head on the sliding disc can relatively tilt in the working process, the sliding disc can adapt to various tilting such as tilting of the swash plate, tilting of the cylinder body and the like, so that the sliding disc can always be closely attached to the swash plate to complete the functions of flow distribution, variable inclination, support and the like, and a wedge-shaped gap is avoided; meanwhile, compared with the replacement of the cylinder body, the sliding plate or the valve plate is easier and more economical to replace.

8. According to the invention, the oil through hole and the plunger central hole on the slide plate are large-aperture main oil holes, so that the blockage of greasy dirt can be prevented, and the sensitivity of the greasy dirt is reduced; meanwhile, the mass of the plunger is reduced by the large-aperture plunger center hole, and the centrifugal force of the plunger is reduced.

9. The sliding disc structure is an integral structure, replaces a plurality of independent sliding shoes and a structure for returning by using a return disc in the prior art, is more reliable in connection between the plunger and the sliding disc and between the sliding disc and the pressure disc, and avoids the phenomena of abrasion and shearing damage of the neck and the shoulder of the sliding shoes, cracking of the drilling part of the return disc and the like in the prior art, thereby improving the working reliability of the swash plate type plunger pump. Meanwhile, centrifugal force and friction force of all parts of the sliding plate are mutually offset, so that the phenomenon that a single sliding shoe is overturned under the combined action of centrifugal moment caused by circumferential motion and friction moment generated along with the rotation of a cylinder body in the high-speed motion process is avoided, the integral sliding plate structure is even in abrasion, and the phenomenon of eccentric wear of the original sliding shoe pair is eliminated or reduced.

10. The axial plunger pump can be made into a through shaft type structure or a non-through shaft type structure, and parts of the two structures have strong universality, so that the axial plunger pump can well adapt to various requirements of the market, and the manufacturing cost is not changed remarkably. When used as a through-shaft type structure, an oil supplementing pump can be connected in series at the shaft end, realizing the oil supplementing effect.

Drawings

Fig. 1 shows an embodiment of a through-shaft slide-disc axial plunger pump according to the present invention.

FIG. 2 is a cross-sectional view of FIG. 1 A-A in accordance with the present invention.

Fig. 3 is a view showing a structure of a port plate in the present invention.

Fig. 4 is a schematic diagram of an end face structure of a cylinder body side in the present invention.

FIG. 5 is a cross-sectional view B-B of FIG. 4 in accordance with the present invention.

Fig. 6 is a schematic diagram of the structure of the other side of the cylinder according to the present invention.

Fig. 7 is a plan view of one end of the slide plate in the present invention.

FIG. 8 is a cross-sectional view of the slider structure of FIG. 7 in accordance with the present invention.

Fig. 9 is a plan view of the other end of the slide plate in the present invention.

FIG. 10 is a plan view of one end bearing surface of the swash plate of the embodiment of FIG. 1 in accordance with the present invention.

FIG. 11 is a block diagram of the swash plate bearing surface of the embodiment of FIG. 1 in accordance with the present invention.

Fig. 12 shows an embodiment of the plunger pump with a central spring pretensioner according to the present invention.

Fig. 13 shows an embodiment of the plunger pump with impeller structure according to the present invention.

Fig. 14 shows another embodiment of a slide-disc axial plunger pump according to the present invention.

FIG. 15 is a cross-sectional view A-A of FIG. 14 in accordance with the present invention.

Fig. 16 shows a configuration of the port plate of the embodiment of fig. 14 in accordance with the present invention.

Fig. 17 shows a structure of one side of the swash plate in the embodiment of fig. 14 according to the present invention.

Fig. 18 is a view showing a structure of the other side of the swash plate in the embodiment of fig. 14 according to the present invention.

Fig. 19 shows an embodiment of a non-through shaft axial plunger pump according to the present invention.

The marks in the figure: 10 is a main shaft, 10C is a main shaft axis, 11 is a first bearing support, 12 is a second bearing support, 21 is a first bearing, 22 is a second bearing, 23 is a third bearing, 24 is a thrust disc, 31 is a housing, 32 is a front end cover, 33 is a rear end cover, 33a is an oil inlet, 33b is an oil outlet, 35 is a housing cavity, 37 is a communication groove, 39 is a swash plate oil through hole, 40 is a swash plate, 41 is a swash plate support surface, 41a is a support baffle, 42 is a flow distribution oil groove, 43 is a low pressure flow distribution window, 44 is a high pressure flow distribution window, 43a is a throttling groove or orifice, 45 is a cylindrical sliding arc surface, 46 is a groove-shaped low pressure port, 47 is a groove-shaped high pressure port, 47a is a groove-shaped oil chamber, 48 is an oil inlet groove, 49 is a shaft pin, 50 is a sliding disc, 50C is a sliding disc axis, 51 is a sliding disc static pressure support surface, 52 is a sliding disc convex table surface, 53 is a sliding disc waist-shaped hole, 54 is a sliding disc outer sealing part, 55 is a slide inner sealing part, 56 is a slide interval sealing part, 57 is a slide auxiliary supporting surface, 57a is a slide annular oil drain groove, 57b is a slide radial oil drain groove, 58 is a plunger ball socket, 60 is a pressing plate, 70 is a plunger, 71 is a plunger ball head, 72 is a plunger center hole, 73 is a conical rod part, 74 is a plunger part, 80 is a cylinder body, 81 is a plunger hole, 82 is a main shaft assembly hole, 83 is a cylinder static pressure supporting surface, 83a is a cylinder convex table surface, 84 is an oil through hole, 85 is a cylinder waist-shaped hole, 86 is a cylinder outer sealing part, 87 is a cylinder inner sealing part, 88 is a cylinder interval sealing part, 80C is a cylinder axle center, 90 is a valve plate, 91 is a static pressure supporting surface, 92 is a low pressure distributing port, 93 is a high pressure distributing port, 94 is an outer sealing band, 95 is an inner sealing band, 100 is a center spring, 101 is a retainer ring, 102 is a spherical hinge, 140 is a clamping device 141 is a clamping spring, and 150 is an impeller.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

While this invention is susceptible of embodiment in different forms, this specification and the accompanying drawings disclose only some specific forms as examples of the invention. The invention is not intended to be limited to the embodiments so described. The scope of the invention is given in the appended claims.

For ease of description, embodiments of the present invention are shown in a typical orientation such that when the central axis of the main shaft of an axial plunger pump is horizontally stationary, with the coupling end side of the main shaft to the left and the rear end cap to the right, terms such as "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "horizontal", "bottom", "inner", "outer", etc., as used in the description are used with reference to this location, are used for ease of description and simplicity of description only, and do not indicate or imply that the devices or elements referred to must have a particular orientation, as well as a particular azimuthal configuration and operation, it should be understood that the present invention may be manufactured, stored, transported, used, and sold in orientations other than the locations described.

Example 1:

As shown in fig. 1 to 11, in the preferred embodiment of the axial plunger pump according to the present invention, the plunger pump is a through-shaft plunger pump, and includes a main shaft 10, a housing 31, a first bearing 21, a second bearing 22, a flow distribution slide plate pair, a plunger pair, a flow distribution pair, and a rear end cover 33, a communication groove 37 communicating with a housing cavity 35 is provided on the rear end cover 33, a main shaft axis 10C of the main shaft 10 coincides with a cylinder axis 80C of a cylinder 80, one end of the main shaft 10 extends through the flow distribution slide plate pair out of the housing 31 and is supported on the first bearing 21, the other end extends through the flow distribution pair and is supported on the second bearing 22, the cylinder 80 is supported on the main shaft 10 and is synchronously rotated with the main shaft through a key connection, and the plunger 70 reciprocates in a plunger cavity of the cylinder 80, so as to realize oil sucking and discharging operations of the pump.

Specifically, the flow distribution slide plate pair comprises a slide plate 50 and a swash plate 40, wherein a slide plate static pressure bearing surface 51 of the slide plate 50 is supported on the swash plate 40 and is tightly matched with the bearing surface of the swash plate 40, one end of the slide plate 50 is provided with a plurality of slide plate waist-shaped holes 53, the other end surface of the slide plate 50 is provided with a plurality of plunger ball sockets 58, the slide plate waist-shaped holes 53 on the slide plate 50 penetrate through the plunger ball sockets 58, and the swash plate 40 is provided with a flow distribution oil groove 42 communicated with the oil inlet 33a and the oil outlet 33 b.

Specifically, the plunger pair includes a plunger 70 and a cylinder bore wall, the plunger 70 has a conical structure, and the plunger is provided with a large-bore plunger center hole 72 serving as oil inlet and outlet and communicating the plunger ball socket 58 and the plunger bore 81.

Specifically, the flow distribution pair comprises a cylinder end and a flow distribution plate 90 for supporting the rear end cover 33, wherein a cylinder static pressure bearing surface 83 is arranged on the end surface of the cylinder end opposite to the flow distribution plate 90, the cylinder static pressure bearing surface 83 is supported on the flow distribution plate 90 and keeps sliding fit with the flow distribution plate 90, and a static pressure bearing surface 91, a low-pressure flow distribution port 92, a high-pressure flow distribution port 93, an outer sealing band 94 and an inner sealing band 95 are also arranged on the flow distribution plate 90.

As shown in fig. 1 and 2, the pump body of the embodiment includes a housing 31, and a rear end cover 33 and a front end cover 32 connected to the housing 31. The housing 31 has a housing cavity 35 for accommodating the rotor assembly, the rear end cover 33 is used for closing one end opening of the housing 31, the front end cover 32 is used for closing the other end opening of the housing 31, the rear end cover 33 is provided with an oil inlet 33a and an oil outlet 33b of the pump, the rear end cover 33 is provided with a communication groove 37 for communicating the oil inlet 33a with the housing cavity 35, namely, when the pump absorbs oil, oil in the oil inlet 33a is divided into two parts, one part of oil flows into the plunger hole from a low-pressure distributing port of the distributing plate, the other part of oil enters the housing cavity 35 through the communication groove 37, and cold oil of the part cools friction pair components arranged in the housing cavity, so that thermal deformation of the friction pair components is reduced.

The main shaft 10 is cylindrical, penetrates through the housing 31 to the rear end cover 33, a first bearing support part 11 and a second bearing support part 12 are arranged on the main shaft 10, a first bearing 21 is clamped between the first bearing support part 11 and the housing 31, a second bearing 22 is clamped between the second bearing support part 12 and the rear end cover 33, one end of the main shaft 10 penetrates through the flow distribution disc pair and extends out of the housing 31 and is supported on the housing 31 through the first bearing 21, the end is used for being connected with an external prime mover (or load), the other end penetrates through the flow distribution pair, is supported on the rear end cover 33 through the second bearing 22 and is rotatable around the axis of the main shaft through the first bearing 21 and the second bearing 22 relative to the housing 31, a key connection structure for connecting the cylinder 80 is arranged on the circumferential surface of the middle area of the main shaft 10, and the main shaft 10 drives the cylinder 80 to synchronously rotate through the key connection structure.

The cylinder block 80 has a columnar configuration having a circular cross section in a radial direction and is accommodated in the housing cavity 35 of the housing 31, the cylinder block 80 has a plurality of plunger holes 81 uniformly distributed circumferentially about the cylinder block axis 80C and a main shaft fitting hole 82 for accommodating a main shaft at the center, and the cylinder block 80 has a plurality of plunger holes 81, preferably, the number of plunger holes is generally set to 7 or 9 as shown in fig. 6; the main shaft 10 is connected to the cylinder 80 by a connecting key provided on the outer circumferential surface of the shaft through a main shaft fitting hole 82 of the cylinder 80, and the cylinder 80 is supported on the main shaft 10 so as to move in synchronization with the main shaft 10.

The other end face of the cylinder 80 is abutted against the valve plate 90 to form a flow distribution pair, both end portions are supported in a hydrostatic manner, as shown in fig. 2 and 3, a cylinder hydrostatic bearing surface 83 is provided on the end face of the cylinder 80 opposite to the valve plate 90, the cylinder hydrostatic bearing surface 83 is supported on the valve plate 90 and is always in sliding fit with the valve plate 90, a plurality of cylinder kidney-shaped holes 85 in a kidney shape are provided on the cylinder hydrostatic bearing surface 83, preferably, the cylinder kidney-shaped holes 85 are uniformly distributed on the cylinder hydrostatic bearing surface 83 with the cylinder axis 80C as the center, and oil through holes 84 for communicating the plunger holes 81 with the cylinder kidney-shaped holes 85 are provided on the cylinder end portions.

Further, a protruding cylinder boss surface 83a extending toward the valve plate 90 along the cylinder axis 80C is provided on the end surface of the cylinder 80 facing the valve plate 90, the cylinder boss surface 83a is formed by a region surrounded by an inner diameter R1 and an outer diameter R2, the cylinder boss surface 83a and the valve plate 90 support surface slidably contact each other, a plurality of cylinder kidney-shaped holes 85 are provided on the cylinder boss surface 83a at positions corresponding to the plunger holes 81, and preferably, the cylinder kidney-shaped holes 85 are uniformly distributed on the cylinder boss surface 83a at intervals along a common circumference centered on the cylinder axis 80C.

The effective static pressure oil film support is formed between the cylinder boss surface 83a and the supporting surface of the port plate 90, the cylinder boss surface 83a is provided with a sealing part for sealing oil action, the sealing part is arranged on the inner periphery and the outer periphery of the cylinder boss surface 85 in a state of surrounding the cylinder boss surface 85, the sealing part comprises a cylinder inner sealing part 87, a cylinder outer sealing part 86 and a cylinder interval sealing part 88, the cylinder inner sealing part 87 is an area surrounded by the inner edge of the cylinder boss surface 85 and the inner diameter R1 of the cylinder boss surface 83a, the cylinder outer sealing part 86 is an area surrounded by the outer edge of the cylinder boss surface 85 and the outer diameter R2 of the cylinder boss surface 83a, the cylinder interval sealing part 88 is an interval boss surface area between the adjacent cylinder boss surface 85, and a certain reasonable clearance is always kept between the sealing part of the cylinder boss surface 83a and the supporting surface of the port plate 90 so that leakage is at a reasonable level.

In this embodiment, the flow distribution pair is a bidirectional high-low pressure flow distribution pair, the flow distribution pair comprises a cylinder end and a flow distribution plate 90 supported on the rear end cover 33, the cylinder end and the end surface of the flow distribution plate 90 form a static pressure oil film support in clearance fit, a low pressure flow distribution port 92 and a high pressure flow distribution port 93 are separately arranged on the flow distribution plate 90, and the low pressure flow distribution port 92 and the high pressure flow distribution port 93 are respectively communicated with an oil inlet 33a and an oil outlet 33b of the rear end cover, as shown in fig. 3. The flow distribution slide plate pair is a unidirectional low-pressure flow distribution slide plate pair, the flow distribution slide plate pair comprises a swash plate 40 and a slide plate 50 supported on the swash plate 40, the end surfaces of the swash plate 40 and the slide plate 50 form a clearance fit static pressure oil film support, the swash plate 40 and the slide plate 50 are in sliding fit, a low-pressure flow distribution window 43 is arranged on one side of the slide plate 50 opposite to the low-pressure plunger hole, the low-pressure plunger hole refers to a corresponding plunger hole into which low-pressure oil enters, conversely, the high-pressure plunger hole refers to a corresponding plunger hole into which high-pressure oil enters, and when the pump absorbs oil, low-pressure oil liquid in the shell cavity 35 flows through the low-pressure flow distribution window 43, the slide plate waist-shaped hole 53, the plunger center hole 72 and the cylinder body plunger hole 81 in sequence.

In operation, hydraulic pressure acts on the cylinder end and is further transferred to the port plate 90, and in general, the axial force of the hydraulic pressure acting on the cylinder end is greater than the supporting force of the port plate 90 acting on the cylinder end through the oil film reaction, so the cylinder end always slides against the port plate 90 through a layer of oil film.

Specifically, the plunger 70 includes a plunger ball 71 having one end supported by the plunger ball socket 58 of the slide 50 and fixed to an end surface of the slide via the pressing plate 60, a plunger center hole 72 for communicating the plunger hole 81 and the plunger ball socket 58, a tapered rod portion 73 having a conical outer peripheral surface, and a plunger portion 74 having clearance fit with a cylinder plunger hole wall and being reciprocable therein, the plunger ball 71 being spherically and slidably supported by the plunger ball socket 58 of the slide 50; the plunger central hole 72 is a large-aperture through hole structure and is used as a suction and/or discharge oil liquid channel; at least one seal ring is often disposed on the plunger portion 74 for sealing the liquid, and the tapered rod portion 73 is tapered to gradually increase from the ball end of the plunger toward the plunger portion 74, and when the plunger 70 moves to a certain position, the tapered rod portion 74 contacts the inner circumferential surface of the plunger hole 81 for force transmission. It should be noted that the plunger 70 is not limited to the conical plunger type, and may include a rod-plunger having a ball at both ends or a spherical plunger with a universal hinge.

Specifically, a plurality of plunger sockets 58 are provided at positions facing the plunger 70 in the circumferential direction of the end surface of the slide plate 50 facing the cylinder, and as shown in fig. 7, 8 and 9, the plunger sockets 58 are formed with recesses having substantially hemispherical openings in the end surface of the slide plate 50, and the plunger sockets 58 support the plunger ball heads 71 in a state in which the common circumferences of the slide plate axes 50C are uniformly spaced apart, and after the plunger 70 is mounted on the plunger sockets 58, they are fixed to the end surface of the slide plate 50 by the pressing plate 60, so that the plunger 70 is restricted from moving away from the end surface of the slide plate 50. In particular, the manner for fixing the plunger 70 to the end face of the slide plate 50 is not limited to the manner using a pressure plate, and for example, a form-locking pressing device (not shown) which can fix the plunger ball 71 by a coating of more than 180 ° may be provided on the slide plate 50.

The end surface of the slide plate 50 opposite to the swash plate 40 is provided with a slide plate static pressure bearing surface 51, as shown in fig. 7, the slide plate axle center 50C forms a certain angle with the spindle axle center 10C, the slide plate static pressure bearing surface 51 is supported on the swash plate 40 and keeps sliding fit with the swash plate 40 all the time, the slide plate static pressure bearing surface 51 is provided with a plurality of slide plate waist-shaped holes 53 with waist-shaped configuration, preferably, the slide plate waist-shaped holes 53 are uniformly distributed on the slide plate static pressure bearing surface 51 with the slide plate axle center 50C as the center, and the slide plate waist-shaped holes 53 are communicated with the plunger ball socket 58.

Further, a protruding disc boss surface 52 extending toward the swash plate 40 along the disc shaft center 50C is provided on the end surface of the disc 50 facing the swash plate 40, the disc boss surface 52 is formed by a region surrounded by the inner diameter R1 and the outer diameter R2, the disc boss surface 52 and the swash plate 40 support surface slidably contact each other, a plurality of disc kidney-shaped holes 53 are provided on the disc boss surface 52 at positions corresponding to the plunger ball sockets 58, and preferably, the disc kidney-shaped holes 53 are uniformly distributed on the disc boss surface 52 at intervals in a common circumference centered on the disc shaft center 50C.

The effective static pressure oil film bearing is formed between the disc boss surface 52 and the bearing surface of the swash plate 40, a sealing part for sealing oil is arranged on the disc boss surface 52, the sealing part is arranged on the inner periphery and the outer periphery of the disc boss surface 53 in a state of surrounding the disc boss surface 53, the sealing part comprises a disc inner sealing part 55, a disc outer sealing part 54 and a disc interval sealing part 56, the disc inner sealing part 55 is an area surrounded by the inner edge of the disc boss surface 53 and the inner diameter R1 of the disc boss surface 52, the disc outer sealing part 54 is an area surrounded by the outer edge of the disc boss surface 53 and the outer diameter R2 of the disc boss surface 52, the disc interval sealing part 56 is an interval boss surface area between the adjacent disc boss surface 53, and a certain reasonable clearance is always kept between the sealing part of the disc boss surface 52 and the bearing surface of the swash plate 40 so that the oil film is leaked reasonably.

In operation, hydraulic pressure acts on the plunger 70 and is further transferred to the slide plate 50, and in general, the axial force of the plunger 70 acting on the slide plate 50 is greater than the sum of the supporting force of the swash plate 40 acting on the slide plate 50 through the oil film reaction and the return force of the plunger 70, so that the slide plate 50 always slides against the swash plate 40 through a layer of oil film.

Considering that the initial seal between the slide plate and the sloping cam plate is still needed when the plunger pump is started to build oil pressure as soon as possible, an initial sealing device is needed to be arranged on one side of the flow distribution slide plate pair.

Preferably, as shown in fig. 12, a spring pre-tightening device is provided between the slide plate 50 and the cylinder 80, and the spring pre-tightening device enables a certain initial contact force between the flow distribution slide plate pair and the flow distribution pair. The spring pre-tightening device comprises a central spring 100, a check ring 101 and a spherical hinge 102, wherein one end of the pre-tightening spring force of the central spring 100 acts on the pressure plate 60 through the spherical hinge 102 and is further transmitted to the sliding disc 50, and the other end acts on the end of the cylinder body and the valve plate 90 through the check ring 101.

Preferably, as shown in fig. 1 and 2, another initial sealing device may also be provided on the slide plate 50 and/or the cylinder block 80 with a restriction device that restricts the movement of the slide plate 50 of the flow distributing slide plate pair away from the swash plate 40 and the movement of the cylinder block 80 of the flow distributing pair away from the flow distributing plate 90.

Further, the restraining means includes a swash plate stopper portion protruding outward on the side of the slide plate 50 close to the slide plate static pressure bearing surface 51, and an engaging means 140 provided on the swash plate bearing stopper portion 41 a. The stopper 57 is used to restrict the movement of the third bearing 23, and the engagement means includes an engagement circumferential groove provided on the support stopper 41a adjacent to the third bearing 23, and a snap spring (not shown) provided on the engagement inner circumferential groove, which restricts the slide plate from moving outwardly away from the end surface of the swash plate 40 in such a manner as to restrict the movement of the third bearing 23.

It is conceivable that elastic shims (not shown) may also be provided between the stop and the third bearing 23 or between the clamping spring and the third bearing 23, so that the restraint assembly, in addition to limiting the slide plate away from the end face of the swash plate, also has a certain initial pretension to maintain the pretension state of the slide plate and the swash plate. Similarly, the restraining manner of the restraining device 140 may be further realized by interference fit between the third bearing 23 and the swash plate support block 41a, and the swash plate support block 41a is provided with an engagement circumferential groove adjacent to the third bearing 23 and a snap spring engaged with the engagement circumferential groove to perform a further restraining function. On one side of the cylinder, the restraining means further comprises a clamping spring 141 for restraining the movement of the end of the cylinder away from the thrust disc.

As shown in fig. 10, the swash plate 40 has a swash plate bearing surface 41 that mates with a swash plate slide plate static pressure bearing surface 51, and in this embodiment, a kidney-shaped low pressure distribution window 43 is provided on the swash plate bearing surface 41, and the low pressure distribution window 43 may be provided as a plurality of windows having a kidney shape. In order to make the swash plate 40 have a certain pre-pressure increasing and pre-pressure decreasing function, a throttle groove or orifice 43a may be provided at the end of the low-pressure distribution window 43. Meanwhile, the swash plate 40 is provided with an oil inlet groove 48, and the oil inlet groove is communicated with the housing cavity 35 and the low-pressure distributing window 43 of the swash plate 40.

As shown in fig. 11, the other side of the swash plate 40 is provided with a cylindrical sliding arc surface 45 shaped as a cylinder. The casing 31 has a sliding arc surface (not shown) with the same radius as the sliding arc surface 45 of the swash plate cylinder, so that the sliding arc surface 45 of the swash plate cylinder always maintains a close-contact state when sliding on the sliding arc surface of the casing 31. The cylindrical sliding arc surface 45 on the high pressure side of the swash plate 40 is provided with a groove-shaped oil chamber 47a and a swash plate oil through hole 39, and the swash plate oil through hole 39 introduces high pressure oil into the groove-shaped oil chamber 47a to form an oil film support.

When the pump works, the oil flow is as follows: when oil is absorbed, one path of low-pressure oil entering from the oil inlet 33a of the rear end cover 33 enters the plunger hole 81 from the low-pressure distributing port 92 of the distributing plate 90, and the other path enters from the oil inlet groove 48 of the swash plate and sequentially passes through the low-pressure distributing window 43 of the swash plate, the waist-shaped hole 53 of the sliding plate, the central large hole of the conical plunger and the plunger hole; when the oil is discharged, the slide plate waist-shaped hole 53 on the side of the swash plate 40 is closed by the swash plate supporting surface, and the high-pressure oil can only flow out from the side of the plunger hole 81 of the cylinder body, through the high-pressure distributing port of the distributing plate 90, and finally is discharged from the oil outlet 33b of the rear end cover 33.

Example 2:

As shown in fig. 13, another embodiment of the present invention is shown, which is different from embodiment 1 in that the outer periphery of the cylinder 80 is provided with an impeller 150, and other structures can be referred to as embodiment 1.

The impeller 150 is fixed to the cylinder 80 and rotates synchronously with the cylinder. Under the action of the impeller, the oil in the casing forms a certain oil pressure and moves in a directional manner, namely, the oil is driven to the oil inlet groove 48 of the swash plate 40. The structure has the advantages that: firstly, the flow of hot oil in the cavity 35 of the shell is quickened, so that the hot oil leaves the vicinity of the friction pair as soon as possible, and the influence of high temperature on the friction pair is reduced; secondly, the oil absorption flow of the side of the slide disc is improved, and the oil absorption performance is enhanced.

Example 3:

as shown in fig. 14 to 18, another embodiment of the present invention is different from embodiment 1 in the point of opposing abutment with the port plate slider pair and the port plate pair, and the port flow path is different therefrom, and the other configurations described in reference to embodiment 1 are described.

The flow distribution pair comprises a cylinder body 80 and a flow distribution plate 90 which is abutted on the shell 31, the cylinder body 80 and the flow distribution plate 90 are supported in a hydrostatic mode and transmit axial force to the shell, the flow distribution pair is a unidirectional low-pressure flow distribution pair, the flow distribution pair comprises a cylinder body end and the flow distribution plate 90 supported on the shell 31, the cylinder body end and the end face of the flow distribution plate 90 form clearance fit static pressure oil film support, the cylinder body end and the end face of the flow distribution plate are in sliding fit, a low-pressure flow distribution port 92 is arranged on one side of the flow distribution plate opposite to the low-pressure plunger hole, and when the pump absorbs oil, low-pressure oil enters the cylinder body plunger hole 81 from the pump housing cavity 35 through the low-pressure flow distribution port 92.

The flow distribution slide plate pair is a bidirectional high-low pressure flow distribution slide plate pair, the flow distribution slide plate pair comprises a swash plate 40 and a slide plate 50 supported on the swash plate 40, the swash plate 40 and the end face of the flow distribution plate 90 form a clearance fit static pressure oil film support, the two are in sliding fit, a support surface of the swash plate 40 opposite to the rear end cover 33 is provided with a cylindrical slide cambered surface 45 which is formed into a cylinder shape, the cylindrical slide cambered surface 45 of the swash plate 40 is provided with a groove-shaped low pressure port 46 and a groove-shaped high pressure port 47 which are formed into a groove shape, and the groove-shaped low pressure port 46 and the groove-shaped high pressure port 47 are respectively correspondingly communicated with an oil inlet 33a and an oil outlet 33b of the rear end cover 33.

When the pump works, the oil flow is as follows: when oil is absorbed, one path of low-pressure oil entering from the oil inlet 33a of the rear end cover 33 enters the plunger hole from the low-pressure distributing window 43 of the swash plate 40, the waist-shaped hole 53 of the slide plate and the central large hole of the conical plunger, and the other path enters the plunger hole 81 from the low-pressure distributing port 92 of the distributing plate 90; when the oil is discharged, the cylinder plunger hole is closed by the supporting surface of the valve plate, high-pressure oil can only flow out from one side of the plunger hole 81 of the cylinder through the conical plunger central hole 72, the sliding plate waist-shaped hole 53 and the groove-shaped high-pressure port 47 of the swash plate, and finally is discharged from the oil outlet 33b of the rear end cover.

Example 4:

As shown in fig. 19, the main difference from the other embodiments is that this embodiment is a non-through shaft type axial plunger pump. The spindle axis 10C of the spindle 10 coincides with the cylinder axis 80C of the cylinder 80, one end of the spindle 10 extends out of the housing 31 and is supported by the first bearing 21, and the other end is cantilever-supported in the cylinder 80 and is connected to the cylinder 80 by a key.

At this time, if a variable mechanism for variable oscillation is provided on the rear end cap 33 when the plunger pump is a variable pump, the variable mechanism includes a spool 33c slidable in an end seat, a shaft pin 49 of the swash plate 40 is connected to the spool 33c in a relatively tiltable state, and the swash plate 40 together with a slide plate 50 is rotatable in the housing cavity 35 via the shaft pin 49 by the variable mechanism.

Example 5:

As shown in fig. 19, the main difference from the other embodiments is that in the sliding disc pair, a thrust disc 24 is clamped between a sliding disc 50 and a swash plate 40, the sliding disc 51 is supported on the thrust disc 24 and keeps sliding fit with the thrust disc 24, the valve plate 90 is fixed on the swash plate 40 by a pin or the like, a high-pressure distributing port and a low-pressure distributing port (not shown) are arranged on the thrust disc 24, the high-pressure distributing port and the low-pressure distributing port are respectively communicated with a low-pressure distributing window 43 and a high-pressure distributing window 44 on the swash plate 40, and the clamping of the thrust disc 24 between the sliding disc 50 and the swash plate 40 has the advantage that the later replacement of the thrust disc 24 is easier and more cost-effective than the replacement of the swash plate 40.

The above is a further detailed description of the invention in connection with specific preferred embodiments, and it is not to be construed as limiting the practice of the invention to these descriptions. It will be apparent to those skilled in the art that several simple deductions or substitutions can be made without departing from the spirit and scope of the invention, and all such modifications and variations are intended to be included within the scope of the appended claims.

Claims

1. A slide disc type axial plunger pump is characterized in that: comprises a flow distribution slide plate pair, a plunger pair and a flow distribution pair, wherein the flow distribution slide plate pair comprises a swash plate (40) and a slide plate (50) supported on the swash plate (40), the slide plate (50) is of an integral structure, a slide plate waist-shaped hole (53) communicated with a plunger center hole (72) of the plunger pair is arranged on the slide plate (50), a low-pressure flow distribution window (43) serving as an oil inlet channel is arranged on a supporting surface of the swash plate (40) opposite to a low-pressure plunger hole, a static pressure support is formed between the supporting surface of the swash plate (40) opposite to a high-pressure plunger hole and the slide plate waist-shaped hole (53), the low-pressure distributing window (43) is communicated with the shell cavity (35) through an oil inlet groove (48) arranged on the swash plate (40), when the plunger pump works, the main shaft drives the cylinder body to synchronously rotate, and drives the sliding plate (50) to slide on the swash plate (40) through the plunger, low-pressure oil enters the cylinder body plunger hole (81) of the cylinder body (80) from a low-pressure distributing port (92) of the distributing plate (90) and the oil inlet groove (48) or the groove-shaped low-pressure port (46) of the swash plate (40) in a double-way, high-pressure oil is discharged from a high-pressure distributing port (93) of the distributing plate (90) or the groove-shaped high-pressure port (47) of the swash plate (40) in a single-way, so that the suction and the discharge of hydraulic oil are realized, the end of the cylinder body and the end face of the valve plate (90) form a clearance fit static pressure oil film support, and the end face and the static pressure oil film support are in sliding fit.

2. The slide-on axial plunger pump of claim 1 wherein: a slide disc boss surface (52) extending to one side of a swash plate (40) along the axis of the slide disc is arranged on the slide disc (50), a plurality of slide disc kidney-shaped holes (53) and sealing parts for sealing oil are arranged on the slide disc boss surface (52), the sealing parts are arranged on the inner periphery and the outer periphery of the slide disc kidney-shaped holes (53) in a state of surrounding the slide disc kidney-shaped holes (53), and each sealing part comprises a slide disc inner sealing part (55), a slide disc outer sealing part (54) and a slide disc interval sealing part (56) arranged between the adjacent slide disc kidney-shaped holes (53).

3. The slide-on axial plunger pump of claim 1 wherein: the flow distribution pair is a bidirectional high-low pressure flow distribution pair, the flow distribution pair comprises a cylinder body end part and a flow distribution plate (90) supported on a rear end cover (33), a low-pressure flow distribution port (92) and a high-pressure flow distribution port (93) which are separated are arranged on the flow distribution plate (90), and the low-pressure flow distribution port (92) and the high-pressure flow distribution port (93) are respectively communicated with an oil inlet (33 a) and an oil outlet (33 b) of the rear end cover.

4. A slide-on axial plunger pump as set forth in claim 3 wherein: the valve slide plate pair is a unidirectional low-pressure valve slide plate pair, a static pressure oil film support in clearance fit is formed between the swash plate (40) and the end face of the slide plate (50), the swash plate and the static pressure oil film support are in sliding fit, a low-pressure valve window (43) is arranged on one side of the slide plate (50) opposite to the low-pressure plunger hole, and when the pump absorbs oil, low-pressure oil liquid in the shell cavity (35) sequentially flows through the low-pressure valve window (43), the slide plate kidney-shaped hole (53), the plunger center hole (72) and the cylinder plunger hole (81).

5. The slide-on axial plunger pump of claim 1 wherein: the flow distribution pair is a unidirectional low-pressure flow distribution pair, the flow distribution pair comprises a cylinder end and a flow distribution plate (90) supported on a shell (31), a low-pressure flow distribution port (92) is arranged on one side of the flow distribution plate (90) opposite to the low-pressure plunger hole, and low-pressure oil enters the cylinder plunger hole (81) from a pump housing cavity (35) through the low-pressure flow distribution port (92) when oil is pumped.

6. The slide-on axial plunger pump of claim 5 wherein: the two-way high-low pressure flow distribution slide plate pair is characterized in that the flow distribution slide plate pair is a two-way high-low pressure flow distribution slide plate pair, a static pressure oil film support in clearance fit is formed between the inclined plate (40) and the end face of the flow distribution plate (90), the two are in sliding fit, a cylindrical sliding arc surface (45) formed into a cylinder shape is arranged on a support surface of the inclined plate (40) opposite to the rear end cover (33), a groove-shaped low-pressure port (46) and a groove-shaped high-pressure port (47) formed into a groove shape are formed in the cylindrical sliding arc surface (45) of the inclined plate (40), and the groove-shaped low-pressure port (46) and the groove-shaped high-pressure port (47) are correspondingly communicated with an oil inlet (33 a) and an oil outlet (33 b) on the rear end cover respectively.

7. The slide-on axial plunger pump of claim 1 wherein: a thrust disc (24) is clamped between the slide disc (50) and the swash plate (40), the slide disc (50) is supported on the thrust disc (24) and is in sliding fit with the thrust disc (24), a low-pressure distributing port and/or a high-pressure distributing port are arranged on the thrust disc (24), and the distributing port of the thrust disc (24) is communicated with a distributing oil groove (42) of the swash plate (40) and a slide disc waist-shaped hole (53) of the slide disc (50).

8. The slide-on axial plunger pump of claim 1 wherein: a spring pre-tightening device is arranged between the slide disc (50) and the cylinder body (80), and a certain initial contact force is formed between the flow distribution slide disc pair and the slide disc pair through the spring pre-tightening device;

Or a restraining device is arranged on the sliding plate (50) and/or the cylinder body (80), and the restraining device is provided with a function of limiting the sliding plate (50) of the flow distribution sliding plate pair to move away from the sloping cam plate (40) and limiting the cylinder body (80) of the flow distribution pair to move away from the flow distribution plate (90).

9. The slide-on axial plunger pump of claim 1 wherein: an impeller device is provided on the cylinder (80) and oriented to drive low pressure oil from the housing cavity (35) into the plunger bore (81).

10. The slide-on axial plunger pump according to any one of claims 1 to 9, wherein: the sliding disc type axial plunger pump is of a through shaft type structure and comprises a main shaft (10), a shell (31), a first bearing (21), a second bearing (22), a plunger (70), a cylinder body (80), a valve plate (90) and a rear end cover (33), wherein a communicating groove (37) communicated with a cavity (35) of the shell is formed in the rear end cover (33), a main shaft axis (10C) of the main shaft (10) coincides with a cylinder body axis (80C) of the cylinder body (80), one end of the main shaft (10) penetrates through the valve plate pair to extend out of the shell (31) and is supported on the first bearing (21), the other end penetrates through the valve plate pair and is supported on the second bearing (22), the cylinder body (80) is supported on the main shaft (10) and is connected with the main shaft through a key to realize synchronous rotation, and the plunger (70) reciprocates in a plunger cavity of the cylinder body (80) to realize sucking and discharging of the pump.

11. The slide-on axial plunger pump according to any one of claims 1 to 9, wherein: the sliding disc type axial plunger pump is of a non-through shaft type structure and comprises a main shaft (10), a shell (31), a first bearing (21), a plunger (70), a cylinder body (80), a sliding disc (50) and a rear end cover (33), a communicating groove (37) communicated with a shell cavity (35) is formed in the rear end cover (33), a main shaft axis (10C) of the main shaft (10) coincides with a cylinder body axis (80C) of the cylinder body (80), one end of the main shaft (10) penetrates through a flow distribution pair to extend out of the shell (31) and is supported on the first bearing (21), the other end of the main shaft is supported in the cylinder body (80) in a cantilever mode and is connected with the cylinder body (80) through a key, the main shaft (10) and the cylinder body (80) synchronously rotate, and the plunger (70) reciprocates in a plunger cavity of the cylinder body (80) to realize oil sucking and discharging work of the pump.