A total hydrostatic floating support slide pair and a slide-type piston pump incorporating the same structure

Abstract

This invention discloses a fully hydrostatic floating support slide plate pair, including a swashplate and a slide plate supported on the swashplate. The slide plate is an integral disc structure, and a fully hydrostatic floating support is formed between the slide plate and the swashplate. The fully hydrostatic floating support includes an axial support kinematic pair and a radial support kinematic pair. The axial support kinematic pair is formed by the corresponding fit between the axial end face of the slide plate and the axial end face of the swashplate. The radial support kinematic pair is formed by the corresponding fit between the radial support surface of the slide plate and the radial support surface of the swashplate. The floating support slide plate pair structure adopted in this invention features a fully hydrostatic floating support structure, with all kinematic pairs supported by a hydrostatic oil film. This allows most of the forces on the slide plate in all directions to be balanced through the hydrostatic oil film support, especially the lateral forces along the radial direction of the slide plate, which can significantly improve the working pressure, speed, and other performance characteristics of the slide plate piston pump.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic transmission and control technology, and specifically relates to a fully hydrostatic floating support slide pair and a slide piston pump incorporating the structure. Background Technology

[0002] Axial piston pumps and motors are among the most widely used hydraulic components in modern hydraulic transmission. Among them, swashplate pumps and sliding shoe pumps are currently the two most widely used and important types of axial piston pumps. Swashplate piston pumps and swashplate piston pumps each have their own advantages and characteristics: for example, swashplate piston pumps have a simpler and more compact structure, smaller size, lighter weight, and can achieve stepless displacement through swashplate oscillation. Displacement is convenient, has many displacement forms, low inertia, and a faster response speed. However, the swashplate piston pump's speed is limited due to the centrifugal force acting on the slipper, and the large overturning moment on the cylinder block caused by the lateral force acting on the piston limits the swashplate tilt angle, which is generally less than 20°. The swashplate pump is superior to the slipplate piston pump in terms of speed and efficiency, especially in terms of large tilt angles (maximum tilt angle can reach 40°) and significant reduction in lateral force. However, because the variable displacement of the swashplate piston pump relies on the oscillation of the cylinder block, it has high inertia, slow variable displacement response, large bidirectional variable displacement volume, and the bearings need to withstand huge axial forces, which places high demands on machining, assembly, and bearing technology, resulting in a high price.

[0003] Sliding disc piston pump technology represents a significant breakthrough in structural principles in recent years. This technology deeply integrates the advantages of existing swashplate and swashplate piston pump technologies while mitigating their respective shortcomings, resulting in a technology that combines the advantages of both. It transforms the traditional single slipper into an integral sliding disc structure, coupled with a conical piston structure. This fundamentally solves the key problems inherent in traditional slipper structures, such as centrifugal overturning torque, excessive lateral force, and the resulting slipper pair overturning wear and disc burning, distribution pair overturning wear and disc burning, and leakage. It also revolutionizes the three major friction pairs of traditional axial piston pumps, a technology that has been in use for nearly a century.

[0004] The invention patents with application numbers 201810494748X and 2018111057637 respectively propose a bearing external support slide plate pair structure and a bearing internal support slide plate pair structure. This bearing-supported slide plate pair structure constrains the radial movement or movement trend of the slide plate by the bearing, and balances the lateral component of the slide plate force. This eliminates or significantly reduces the lateral force of the slide plate acting on the cylinder through the plunger. It can avoid the overturning caused by the cylinder being subjected to the lateral force, which leads to a wedge gap between the cylinder and the distribution plate. It also avoids problems such as severe local wear, seal failure, and excessive oil leakage, thereby improving the working reliability, working pressure and working life of the slide plate plunger pump or motor.

[0005] To further optimize the technology of sliding disc piston pumps, enrich and expand the lateral force support technology system of sliding disc piston pumps, and improve the performance of sliding disc piston pumps, a new type of sliding disc pair and sliding disc piston pump or motor are proposed. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems by providing a total hydrostatic floating support slide pair and a slide-type piston pump incorporating this structure.

[0007] The technical solution of this invention is as follows: a total hydrostatic floating support slide plate pair, characterized in that: it includes a swashplate and a slide plate supported on the swashplate, the slide plate is an integral disc structure, and the slide plate and the swashplate are a total hydrostatic floating support;

[0008] The total hydrostatic floating support includes a sliding plate axial support kinematic pair and a sliding plate radial support kinematic pair;

[0009] The axial support kinematic pair of the slide is formed by the corresponding fit between the axial end face of the slide and the axial end face of the swashplate;

[0010] The radial support kinematic pair of the slide is formed by the corresponding and mating of the radial support surface of the slide and the radial support surface of the swashplate.

[0011] The hydrostatic floating support slide block assembly of the present invention includes a slide block end face and a swashplate end face supporting the slide block. The end faces of the slide block and the swashplate that are axially opposed are provided with a hydrostatic support surface. The hydrostatic support surface is provided with a slide block waist-shaped hole. The hydrostatic support surface and the swashplate are in sliding fit with a hydrostatic oil film support.

[0012] The sliding plate radial support kinematic pair includes a sliding plate radial support surface and a swashplate radial support surface. A high-pressure oil groove is provided on the sliding plate radial support surface or the swashplate radial support surface. A high-pressure oil hole is provided on the swashplate. The high-pressure oil hole introduces high-pressure oil into the high-pressure oil groove, so that a hydrostatic oil film support is formed between the sliding plate radial support surface and the swashplate radial support surface.

[0013] The hydrostatic floating support slide block assembly of the present invention has a swashplate support shaft extending axially in the middle of the swashplate, the outer periphery of the swashplate support shaft forming a radial support surface of the swashplate, a through-hole shaped central hole in the middle of the slide block, the inner wall of the central hole forming a radial support surface of the slide block, the swashplate support shaft being inserted into the central hole of the slide block and forming a clearance fit with the radial support surface of the slide block, and a high-pressure oil groove being disposed on the radial support surface of the swashplate.

[0014] The hydrostatic floating support slide block assembly of the present invention has a slide block support shaft extending axially in the middle of the slide block, the outer periphery of the slide block support shaft forming a radial support surface of the slide block, a groove-shaped swash plate center hole in the middle of the swash plate, the inner wall of the swash plate center hole forming a radial support surface of the swash plate, the slide block support shaft being inserted into the swash plate center hole and forming a clearance fit with the radial support surface of the swash plate, and a high-pressure oil groove being disposed on the radial support surface of the swash plate.

[0015] The hydrostatic floating support slide block assembly of the present invention has a high-pressure oil groove that is a full-circumferential annular oil groove. The high-pressure oil hole introduces high-pressure oil into the high-pressure oil groove, so that a hydrostatic oil film support is formed in the full circumference between the radial support surface of the slide block and the radial support surface of the swash plate.

[0016] The hydrostatic floating support slide block assembly of the present invention further includes a low-pressure oil groove on the radial support surface of the slide block or the radial support surface of the swash plate. The low-pressure oil groove and the high-pressure oil groove are separated by a spacer sealing part. The swash plate is provided with a low-pressure oil hole, which introduces low-pressure oil into the low-pressure oil groove.

[0017] The hydrostatic floating support slide block assembly of the present invention has O-rings and / or guide rings provided on both sides of the high-pressure oil groove or the low-pressure oil groove.

[0018] The hydrostatic floating support slide block assembly of the present invention has a plurality of plunger ball sockets provided on the end face of the slide block opposite the plunger ball head. The plunger ball head is partially enclosed in the plunger ball sockets and maintains free tilting within a certain tilt angle range.

[0019] The hydrostatic floating support slide block assembly of the present invention has a plane formed by connecting the centers of the ball sockets of each plunger intersecting the axis of the main shaft at point O. When the swash plate is in the zero displacement position, the high-pressure oil groove covers point O along the axial direction of the slide block.

[0020] The hydrostatic floating support slide plate assembly of the present invention has a plurality of slide plate waist-shaped holes on the hydrostatic support surface of the slide plate. The slide plate waist-shaped holes are distributed at intervals on the hydrostatic support surface with the spindle axis as the center. The slide plate waist-shaped holes are connected to the corresponding plunger ball sockets, so that the hydrostatic support surface and the swashplate end face form a clearance fit hydrostatic oil film support.

[0021] The hydrostatic floating support slide block assembly of the present invention can have its hydrostatic support surface configured as a planar or spherical structure.

[0022] The hydrostatic floating support slide block assembly of the present invention has a copper sleeve provided between the radial support surface of the slide block and the radial support surface of the swash plate.

[0023] A sliding piston pump comprising a total hydrostatic floating support sliding plate pair includes a main shaft, housing, first bearing, swashplate, sliding plate, pressure plate, piston, cylinder, distribution plate, and rear end cover. The sliding plate and swashplate form a total hydrostatic floating support. The main shaft axis coincides with the cylinder axis. One end of the main shaft extends through the distribution plate, out of the housing, and is supported on the first bearing. The other end cantilever supports the cylinder and is connected to the cylinder via a key. The main shaft and cylinder rotate synchronously. The piston reciprocates within the piston cavity of the cylinder to achieve the pump's suction and discharge operation. The sliding piston pump can be configured as a fixed displacement pump or a variable displacement pump.

[0024] Based on the above technical solution, the beneficial effects of the present invention are:

[0025] 1. The floating support slide plate pair structure adopted in this invention is a fully hydrostatic support floating structure. All kinematic pairs in each direction are supported by hydrostatic oil film. This allows the forces in each direction on the slide plate to be mostly balanced by the hydrostatic oil film support. In particular, the lateral forces along the radial direction of the slide plate can also be mostly balanced by the hydrostatic oil film support, which can significantly improve the working pressure, speed and other performance of the slide plate piston pump.

[0026] 2. The floating support sliding plate pair structure adopted in this invention eliminates or significantly reduces the lateral force of the plunger acting on the cylinder body, which can avoid the overturning caused by the cylinder body being subjected to lateral force, resulting in a wedge-shaped gap between the cylinder body and the distribution plate. This avoids problems such as severe local wear, seal failure, and excessive oil leakage, thereby further improving the working reliability, working pressure, and working life of the sliding plate plunger pump.

[0027] 3. The floating support slide plate pair structure adopted in this invention can avoid the adverse effects on the bearing structure caused by the alternating load of the plunger pump, the variable torque of the swashplate tilt, the pulsation of oil pressure, and the unbalanced torque of the traditional rigid bearing support slide plate structure.

[0028] 4. The floating support sliding plate pair structure adopted in this invention can significantly increase the variable tilt angle due to the greatly reduced lateral force. The maximum tilt angle can reach more than 30°, which is much greater than the tilt angle of the existing traditional swashplate piston pump (21°). Therefore, it can significantly improve the power density of the piston pump.

[0029] 5. This invention integrates flow distribution, variable tilt, and hydrostatic support functions into the swashplate pair. The pump's variable displacement is achieved by changing the tilt of the swashplate. Compared with existing swashplate piston pumps, the swashplate variable displacement has less inertia, is easier to adjust, and has a faster response speed. Therefore, this invention has a simpler and more compact structure, smaller size, and lighter weight, combining the characteristics of existing swashplate and swashplate piston pumps.

[0030] 6. The axial piston pump of the present invention integrates the inlet and outlet ports on the rear end cover, which greatly simplifies the structure, makes it smaller and more compact, and reduces the weight of the pump, thus improving its power density per unit mass. At the same time, the cylinder is closer to the bearing, which reduces the bending moment acting on the cantilever spindle, which is more beneficial to the spindle stress, extends the bearing life, and reduces mechanical noise during operation.

[0031] 7. In this invention, the functions of flow distribution, variable displacement tilting, and hydrostatic support are integrated into the slide plate pair. Since the plunger ball socket and plunger ball head on the slide plate can tilt relative to each other during operation, it can adapt to various tilting movements such as swashplate tilting and cylinder tilting, so that the slide plate can always be in close contact with the swashplate to complete the functions of flow distribution, variable displacement, and support, avoiding wedge-shaped clearance. At the same time, compared with replacing the cylinder block, replacing the slide plate or swashplate is easier and more economical.

[0032] 8. The swashplate structure in this invention is an integral structure, replacing the multiple independent slippers and the return plate structure in the prior art. The connection between the plunger and the swashplate, and between the swashplate and the pressure plate in this invention is more reliable, avoiding the wear, shearing damage, and cracking of the drilled part of the return plate that occur in the prior art, thereby improving the working reliability of the swashplate plunger pump. At the same time, the centrifugal force and friction force of each part of the swashplate cancel each other out, avoiding the overturning of a single slipper under the combined action of centrifugal torque caused by circumferential motion and friction torque generated by cylinder rotation during high-speed movement. The integral swashplate structure has uniform wear, eliminating or reducing the uneven wear phenomenon of the original slipper pair. Attached Figure Description

[0033] Figure 1 This is one embodiment of the sliding disc type axial piston pump in the present invention.

[0034] Figure 2 In this invention Figure 1 Sectional view of AA.

[0035] Figure 3 This is a cross-sectional view of the swashplate structure in this invention.

[0036] Figure 4 for Figure 3 Cross-sectional view of the middle section (BB).

[0037] Figure 5 This is a schematic diagram of the structure on the other side of the swashplate in this invention.

[0038] Figure 6 This is a schematic diagram of the slide end face structure in this invention.

[0039] Figure 7 for Figure 6 CC cross-section view.

[0040] Figure 8 This is a schematic diagram of the other end face structure of the slide in this invention.

[0041] Figure 9 This is a schematic diagram of the slide structure with auxiliary support in this invention.

[0042] Figure 10 This is a schematic diagram of the slide structure with a spherical support surface in this invention.

[0043] Figure 11 This is another embodiment of the sliding disc axial piston pump in this invention.

[0044] Figure 12 This is one embodiment of the sliding disc piston pump in this invention, which only has a high-pressure oil tank.

[0045] Figure 13 for Figure 12 One embodiment of the swashplate is described in the examples.

[0046] Figure 14 for Figure 12 Another embodiment of the swashplate in the examples.

[0047] Figure 15 This is an embodiment of a slid-type piston pump with a shaft extension structure in this invention.

[0048] Figure 16 for Figure 15 AA cross-sectional view in the embodiment.

[0049] Figure 17 This is another embodiment of the present invention in which the slide is a shaft extension structure.

[0050] Figure 18 This is one embodiment of the sliding piston pump with copper sleeve structure in this invention.

[0051] Figure 19 This is one embodiment of the quantitative sliding disc piston pump in this invention.

[0052] In the diagram, the markings are as follows: 10 is the main spindle, 10C is the main spindle axis, 21 is the bearing, 31 is the housing, 32 is the front end cover, 33 is the rear end cover, 33a is the oil inlet, 33b is the oil outlet, 34 is the first housing cavity, 35 is the second housing cavity, 40 is the swashplate, 41 is the swashplate support surface, 41a is the swashplate radial support surface, 41b is the swashplate center hole, 42 is the swashplate support shaft, 42a is the high-pressure oil groove, 42b is the low-pressure oil groove, 42c is the spacer seal, 43 is the low-pressure distribution groove, 44 is the high-pressure distribution groove, 45 is the distribution cylindrical surface, 46 is the sealing ring, 47 is the guide ring, 48a is the high-pressure oil hole, 48b is the low-pressure oil hole, 49 is the shaft pin, 50 is the sliding plate, 50C is the sliding plate axis, 51 is the hydrostatic support surface, 51a is the sliding plate radial support surface, 5 2 is the center hole of the slide plate, 53 is the waist-shaped hole of the slide plate, 54 is the outer sealing part of the slide plate, 55 is the inner sealing part of the slide plate, 56 is the spaced sealing part of the slide plate, 57 is the auxiliary support surface of the slide plate, 57a is the annular oil drain groove of the slide plate, 57b is the radial oil drain groove of the slide plate, 58 is the plunger ball socket, 59 is the slide plate support shaft, 60 is the pressure plate, 70 is the plunger, 71 is the plunger ball head, 72 is the center hole of the plunger, 73 is the tapered rod part, 74 is the plunger part, 80 is the cylinder block, 81 is the plunger hole, 82 is the main shaft assembly hole, 83 is the static pressure support surface of the cylinder block, 84 is the oil passage hole, 80C is the cylinder block shaft, 90 is the distributor plate, 91 is the static pressure support surface of the distributor plate, 92 is the low-pressure distributor window, 100 is the center spring, 101 is the steel ball, 102 is the sleeve, 103 is the outer sleeve, and 110 is the copper sleeve. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the accompanying drawings.

[0054] While the invention is permissible in various forms, this specification and drawings only disclose certain specific forms as exemplified by the invention. However, the invention is not intended to be limited to the described embodiments. The scope of the invention is set forth in the appended claims.

[0055] For ease of description, embodiments of the present invention are shown in a typical orientation such that when the central axis of the spindle of the axial piston pump is horizontally positioned, with the coupling end of the spindle on the left and the rear end cover on the right, the terms “longitudinal,” “transverse,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “horizontal,” “bottom,” “inner,” and “outer” used in the description are all used with reference to this position and are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or a specific orientation construction and operation. It should be understood that the present invention can be manufactured, stored, transported, used, and sold in orientations other than those described.

[0056] Example 1:

[0057] like Figures 1 to 9 The diagram shows an embodiment of the sliding disc piston pump of the present invention. In the illustrated embodiment, the piston pump is a non-through-shaft piston pump, comprising a main shaft 10, a housing 31, a first bearing 21, a swashplate 40, a sliding disc 50, a pressure plate 60, a piston 70, a cylinder 80, a distribution plate 90, and a rear end cover 33. The main shaft axis 10C of the main shaft 10 coincides with the cylinder axis of the cylinder 80. One end of the main shaft 10 extends through the distribution plate, protrudes from the housing 31, and is supported on the first bearing 21. The other end cantilever supports the cylinder 80 and is connected to the cylinder 80 via a key. The main shaft 10 and the cylinder 80 rotate synchronously. The piston 70 reciprocates within the piston cavity of the cylinder 80, thereby realizing the pump's oil suction and discharge operation.

[0058] The pump body includes a hollow housing 31 with openings at both ends, and a front cover 32 and a rear cover 33 connected to the housing 31. The housing 31 has a first cavity 34 for accommodating a first bearing 21 and a second housing cavity 35 for accommodating a cylinder block 80 and a sliding plate assembly. The housing 31 is bolted to the front cover 32 and the rear cover 33, respectively. The rear cover 33 is provided with an oil inlet 33a and an oil outlet 33b of the pump. When the plunger pump is a variable displacement pump, a variable displacement mechanism for variable oscillation can be provided on the rear cover 33. The variable displacement mechanism includes a slide valve 33c that can slide within an end seat. The shaft pin 49 of the swashplate 40 is connected to the slide valve 33c in a relatively tiltable state. Under the action of the variable displacement mechanism, the swashplate 40 together with the sliding plate 50 can rotate within the second housing cavity 35 via the shaft pin 49.

[0059] The swash plate pair is a key core component of the swash plate piston pump, including a swash plate 40 and a swash plate 50 supported on the swash plate 40. In this embodiment, the swash plate 50 is an integral disc structure, and the swash plate 50 and the swash plate 40 are connected by a hydrostatic floating support. The hydrostatic floating support structure includes a first floating support kinematic pair and a second floating support kinematic pair, the structure of which is described in detail below.

[0060] The first floating support kinematic pair is a sliding disk axial support kinematic pair, including the end face of the sliding disk 50 and the end face of the swashplate 40 supporting the end face of the sliding disk 50. The end faces of the sliding disk 50 and the swashplate 40 opposite each other are provided with a hydrostatic support surface 51. The hydrostatic support surface 51 is provided with a sliding disk waist-shaped hole 53. The hydrostatic support surface 51 and the swashplate 40 maintain a sliding fit and form a clearance fit hydrostatic oil film support.

[0061] Furthermore, a hydrostatic support surface 51 is provided on the end face of the sliding plate 50 opposite to the swashplate 40. The sliding plate axis 50C is at a certain angle to the main shaft axis 10C. The hydrostatic support surface 51 is supported on the swashplate 40 and always maintains a sliding fit with the swashplate 40. The hydrostatic support surface 51 is provided with a plurality of waist-shaped sliding plate holes 53. Preferably, the waist-shaped sliding plate holes 53 are evenly distributed on the hydrostatic support surface 51 with the sliding plate axis 50C as the center. The waist-shaped sliding plate holes 53 communicate with the plunger ball socket 58. Figure 6 , Figure 7 , Figure 8 As shown.

[0062] An effective hydrostatic oil film support is formed between the hydrostatic support surface 51 and the swashplate 40 support surface. The hydrostatic support surface 51 is provided with a sealing portion for sealing the oil. This sealing portion is positioned around the inner and outer circumferences of the swashplate's oblong hole 53. The sealing portion includes an inner sealing portion 55 and an outer sealing portion 54 distributed radially inside and outside the oblong hole 53, and a swashplate spacing sealing portion 56 distributed between adjacent oblong holes 53. The inner sealing portion 55 is the area enclosed by the inner edge of the oblong hole 53 and the inner diameter R1 of the hydrostatic support surface 51. The outer sealing portion 54 is the area enclosed by the outer edge of the oblong hole 53 and the outer diameter R2 of the hydrostatic support surface 51. The swashplate spacing sealing portion 56 is the area of ​​the spacer boss between adjacent oblong holes 53. A certain reasonable gap is maintained between the sealing portion of the hydrostatic support surface 51 and the swashplate 40 support surface to keep oil film leakage at a reasonable level.

[0063] Furthermore, the hydrostatic support surface 51 of the slide 50 can be configured as a planar or spherical structure, as shown in the figures below. Figure 7 and Figure 10 As shown. Planar hydrostatic bearing surfaces are easy to process and have a relatively low cost, while spherical hydrostatic bearing surfaces have a more complex process and higher cost, but better self-stability and sealing performance. The oil film between the sliding plate 50 and the swashplate 40 is more stable, which can significantly improve volumetric efficiency and service life.

[0064] Furthermore, to reduce the supporting force on the slide plate support surface and reduce wear, multiple auxiliary support surfaces 57 can be added radially on the outer circumference of the slide plate 50, based on the slide plate waist-shaped hole 53 provided on the hydrostatic support surface 51. Figure 9 As shown, a radial oil drain groove 57b is provided between the auxiliary support surfaces 57, and an annular oil drain groove 57a is also provided between the auxiliary support surface 57 and the outer sealing part 54. The radial oil drain groove 57b and the annular oil drain groove 57a are interconnected.

[0065] like Figure 3As shown, the swashplate 40 has a swashplate support surface 41 that matches the hydrostatic support surface 51 of the swashplate. On the swashplate support surface 41, there are waist-shaped low-pressure distribution channels 43 and high-pressure distribution channels 44. The low-pressure distribution channels 43 and high-pressure distribution channels 44 are divided into two sides by the central axis of the swashplate. The low-pressure distribution channels 43 and high-pressure distribution channels 44 can be configured as symmetrical or asymmetrical structures relative to the central axis. For example, the high-pressure distribution channels 44 can be configured as multiple waist-shaped windows. This allows the swashplate to have… It has a certain pre-pressurization and pre-depressurization function, which can rotate the low-pressure distribution channel 43 and the high-pressure distribution channel 44 by a certain angle along the central axis of the swashplate; or, specifically, a throttling channel or hole (not shown) can be provided at the end of the low-pressure distribution channel 43 in the direction of transition from the low-pressure distribution channel 43 to the high-pressure distribution channel 44, and at the end of the high-pressure distribution channel 44 in the direction of transition from the high-pressure distribution channel 44 to the low-pressure distribution channel 43, so as to play the role of pre-depressurization and pre-pressurization from high pressure to low pressure or from low pressure to high pressure.

[0066] like Figure 5 As shown, the support surface of the swashplate 40 opposite the end cap 33 is configured with a cylindrical distribution surface 45. The end cap 33 has a sliding arc surface (not shown) with the same radius as the distribution cylindrical surface 45 of the swashplate 40, so that the distribution cylindrical surface 45 of the swashplate 40 always remains in close contact when sliding on the sliding arc surface of the end cap 33. The distribution cylindrical surface 45 of the swashplate 40 has slots that communicate with the low-pressure distribution slot 43 and the high-pressure distribution slot 44.

[0067] The second floating support kinematic pair is a sliding plate radial support kinematic pair, including a sliding plate radial support surface 51a and a swashplate radial support surface 41a. A high-pressure oil groove 42a is provided on the sliding plate radial support surface 51a or the swashplate radial support surface 41a, and a high-pressure oil hole 48a is provided on the swashplate 40. The high-pressure oil hole 48a introduces high-pressure oil into the high-pressure oil groove 42a, so that a hydrostatic oil film support is formed between the sliding plate radial support surface 51a and the swashplate radial support surface 41a.

[0068] Furthermore, the swash plate 40 has a swash plate support shaft 42 extending axially in the middle, and the outer periphery of the swash plate support shaft 42 forms a swash plate radial support surface 41a. The slide plate 50 has a through-hole-shaped slide plate center hole 52 in the middle, and the inner wall of the slide plate center hole 52 forms a slide plate radial support surface (51a). The swash plate support shaft 42 is inserted into the slide plate center hole 52 and forms a clearance fit with the slide plate radial support surface 51a. The high-pressure oil groove 42a is provided on the swash plate radial support surface 41a. The swash plate 40 is provided with a high-pressure oil hole 48a. One end of the high-pressure oil hole 48a is connected to the high-pressure distribution groove 44 on the swash plate 40, and the other end is connected to the high-pressure oil groove 42a. The high-pressure oil hole 48a introduces high-pressure oil into the high-pressure oil groove 42a, so that a hydrostatic oil film support is formed between the slide plate radial support surface 51a and the swash plate support shaft 42. Furthermore, a low-pressure oil groove 42b is provided on the radial support surface 51a of the sliding plate or the radial support surface 41a of the swashplate. The low-pressure oil groove 42b and the high-pressure oil groove 42a are separated by a spacer sealing part 42c. A low-pressure oil hole 48b is also provided on the swashplate 40. One end of the low-pressure oil hole 48b is connected to the low-pressure distribution groove 43a, and the other end is connected to the low-pressure oil groove 42b. The low-pressure oil hole 48b introduces low-pressure oil into the low-pressure oil groove 42b.

[0069] Furthermore, O-rings 46 are provided on both sides of the high-pressure oil tank 42a and the low-pressure oil tank 42b. These O-rings 46 can further prevent oil leakage and prevent loss of volumetric efficiency. At the same time, in order to prevent the unbalanced torque from affecting the radial support clearance of the slide plate and swashplate, and thus affecting the oil film thickness, a guide ring 47 can be further provided on the outside of the O-rings 46.

[0070] Furthermore, the end face of the slide plate 50 facing the cylinder body has multiple plunger ball sockets 58 arranged circumferentially opposite to the plunger 70, such as... Figure 7 , Figure 8 As shown, the plunger ball socket 58 forms a roughly hemispherical recess on the end face of the slide plate 50. The plunger ball socket 58 supports the plunger in a manner that is evenly spaced around the common circumference of the slide plate axis 50C. After the plunger 70 is installed in the plunger ball socket 58, it is fixed to the end face of the slide plate 50 by a pressure plate 60, thereby restricting the movement of the plunger 70 away from the end face of the slide plate 50. In particular, the method of fixing the plunger 70 to the end face of the slide plate 50 is not limited to using a pressure plate. For example, a shape-locking clamping device (not shown) can also be provided on the slide plate 50, which can fix the plunger ball head 71 by covering it with a greater than 180-degree angle.

[0071] Furthermore, the plunger 70 includes a plunger ball head 71 supported at one end on the plunger ball socket 58 of the slide plate 50 and fixed to the end face of the slide plate via the pressure plate 60, a plunger center hole 72 for connecting the plunger hole 81 and the plunger ball socket 58, a tapered rod portion 73 with a conical outer circumference, and a plunger portion 74 that is clearance-fitted with the cylinder plunger hole wall and can reciprocate therein. The plunger ball head 71 is spherical and can slide freely supported on the plunger ball socket 58 of the slide plate 50. The plunger center hole 72 is a large-diameter through-hole structure, serving as a channel for sucking in and / or discharging oil. At least one sealing ring is often provided on the plunger portion 74 for sealing the liquid. The tapered rod portion 73 is a tapered shape that gradually increases from the plunger ball end to the plunger portion 74. When the plunger 70 moves to a certain position, the inner circumferential surface of the tapered rod portion 73 contacts the plunger hole 81, playing a force transmission role. However, it should be noted that the plunger 70 is not limited to the conical plunger type, but may also include a connecting rod-plunger with ball ends or a spherical plunger with universal joints.

[0072] The cylinder body 80 has a cylindrical configuration with a circular radial cross-section and is housed within the second housing cavity 35 of the housing 31. The cylinder body 80 has a plurality of plunger holes 81 evenly distributed around the cylinder body axis and a spindle mounting hole 82 at the center for accommodating the spindle 10. The cylinder body 80 has a plurality of plunger holes 81, preferably, the number of plunger holes is generally set to 7 or 9. The spindle 10 passes through the spindle mounting hole 82 of the cylinder body 80 and is connected to the cylinder body 80 by means of a connecting key on the outer peripheral surface of its shaft. The cylinder body 80 is supported on the spindle 10 in a manner that moves synchronously with the spindle 10.

[0073] The other end face of the cylinder body 80 abuts against the hydrostatic support surface 91 of the distribution plate 90. A low-pressure distribution window 92 is provided on the hydrostatic support surface 91, opening into the second housing cavity 35. A cylinder body hydrostatic support surface 83 is provided on the end face of the cylinder body 80 opposite to the distribution plate 90. The cylinder body hydrostatic support surface 83 is supported on the distribution plate 90 and maintains a sliding fit with the distribution plate 90. Multiple waist-shaped cylinder body holes 85 are provided on the cylinder body hydrostatic support surface 83. Preferably, the cylinder body waist-shaped holes 85 are evenly distributed on the cylinder body hydrostatic support surface 83 with the cylinder body axis 80C as the center. An oil passage hole 84 is provided at the end of the cylinder body 80, connecting the plunger hole 81 and the cylinder body waist-shaped holes 85. The cylinder body 80 and the distribution plate 90 form a low-pressure distribution pair, with their ends supported by hydrostatic pressure.

[0074] From a force analysis perspective, during the operation of the sliding disc piston pump, the high-pressure zone piston 70 is subjected to high-pressure hydraulic pressure from the cylinder piston bore 81. This pressure, transmitted through the piston ball head 71, applies a near-horizontal hydraulic pressure to the sliding disc 50, pushing it towards the swashplate 40 and ensuring close contact with its end face. This hydraulic piston force at the center of the piston ball socket can be decomposed into a vertical force along the axial direction of the sliding disc (50C) and a radial force perpendicular to the axis of the sliding disc (50C). The vertical force along the axial direction is largely balanced by the oil film support force on the hydrostatic support surface of the sliding disc, while the radial component is largely balanced by the high-pressure oil grooves and the surrounding hydrostatic oil film support force. Therefore, the sliding disc exhibits characteristics of a fully hydrostatic floating support.

[0075] This structure, employing a fully hydrostatic floating support slide plate pair, has the following characteristics: the hydrostatic oil film support force balances most of the axial and radial hydraulic components of the hydraulic piston force acting on the slide plate 50, thus eliminating or significantly reducing the lateral force exerted by the slide plate 50 on the cylinder 80 via the piston 70, improving the working reliability, working pressure, and service life of the axial piston pump or motor. During operation, through reasonable design, the axial force of the hydraulic piston force acting on the slide plate 50 is always greater than the sum of the slide plate support forces reacted by the swashplate 40 on the slide plate 50 through the oil film. Therefore, the slide plate 50 always slides against the swashplate 40 through a layer of oil film, exhibiting a self-returning characteristic.

[0076] Considering that an initial seal is still needed between the sliding plate and the swashplate when the plunger pump is started in order to establish oil pressure as soon as possible, an initial sealing device must be installed on one side of the sliding plate pair.

[0077] Preferably, one of the initial sealing devices, such as Figure 1 , Figure 2 As shown, a spring preload device is provided between the slide plate 50 and the cylinder 80. This spring preload device provides a certain initial contact force between the slide plate pair and the distribution pair. The spring preload device includes a central spring 100, a steel ball 101, a sleeve 102, and an outer sleeve 103. One end of the preload spring force of the central spring 100 acts on the pressure plate 60 through the steel ball 101 and is further transmitted to the slide plate 50. The other end acts on the cylinder end and the distribution plate 90 through the outer sleeve 103.

[0078] Example 2:

[0079] like Figures 12-14 as well as Figure 17 As shown, another embodiment of the present invention is illustrated, which differs from Embodiment 1 in that the structure of the high-pressure oil tank 42a is different in this embodiment, while the other structures can be referred to in Embodiment 1.

[0080] One embodiment, such as Figure 13 As shown, the high-pressure oil groove 42a is a through annular oil groove, and the swash plate 40 is only provided with a high-pressure oil hole 48a. One end of the high-pressure oil hole 48a is connected to the high-pressure distribution groove 44, and the other end is connected to the high-pressure oil groove 42a. The high-pressure oil hole 48a introduces high-pressure oil into the high-pressure oil groove 42a, so that a hydrostatic oil film support is formed in the entire circumference between the radial support surface 51a of the swash plate and the radial support surface 41a of the swash plate.

[0081] Another embodiment, such as Figure 14 As shown, the high-pressure oil groove 42a is a partial annular oil groove, that is, only a portion of the circumference of the swashplate support shaft 42 is provided with the high-pressure oil groove 42a, and the portion where the high-pressure oil groove 42a is provided is in the direction of resisting the radial force of the slide plate.

[0082] Example 3:

[0083] like Figure 15 and 16 As shown, another embodiment of the present invention is illustrated, which differs from Embodiment 1 in that: in this embodiment, the slide 50 is an extended structure, the swashplate 40 is a slotted structure, and other structures can be referred to the structure described in Embodiment 1.

[0084] Specifically, the slide plate 50 has a slide plate support shaft 59 extending axially in the middle, and the outer periphery of the slide plate support shaft 59 forms a slide plate radial support surface 51a. The swash plate 40 has a groove-shaped swash plate central hole 41b in the middle, and the inner wall of the swash plate central hole 41b forms the swash plate radial support surface 41a. The slide plate support shaft 59 is inserted into the swash plate central hole 41b and forms a clearance fit with the swash plate radial support surface 41a. The high-pressure oil groove 42a is provided on the swash plate radial support surface 41a. The swash plate 40 is also provided with a high-pressure oil hole 48a. One end of the high-pressure oil hole 48a is connected to the high-pressure distribution groove 44, and the other end is connected to the high-pressure oil groove 42a. The high-pressure oil hole 48a introduces high-pressure oil into the high-pressure oil groove 42a, so that a static pressure oil film support is formed between the slide plate support shaft 59 and the swash plate radial support surface 41a.

[0085] Similarly, O-rings 46 can be provided on both sides of the high-pressure oil tank 42a and the low-pressure oil tank 42b. These O-rings 46 can further prevent oil leakage and prevent loss of volumetric efficiency. At the same time, in order to prevent the unbalanced torque from affecting the radial support clearance of the slide plate and swashplate, and thus affecting the oil film thickness, a guide ring 47 can be further provided on the outside of the O-rings 46.

[0086] Example 4:

[0087] like Figure 11As shown, another embodiment of the present invention is illustrated, which differs from Embodiment 1 in that the location of the high-pressure oil tank 42a in this embodiment is limited, while other aspects can be referred to the structure described in Embodiment 1.

[0088] Specifically, such as Figure 11 As shown, when the swashplate 40 is in the zero displacement position, the plane formed by the centers of the plunger ball sockets 58 intersects the spindle axis 10C at point O. The high-pressure oil groove 42a covers point O along the axial direction of the swashplate 50. More specifically, the central axis of the high-pressure oil groove 42a passes through point O. The advantage of this embodiment is that the point of application of the resultant radial force of the swashplate 50 is always within the range of the high-pressure oil groove 42a, the unbalanced torque acting periodically is small, and the impact on the stability of the oil film of the radial support is small.

[0089] Example 5:

[0090] like Figure 18 and 19 As shown, another embodiment of the present invention is illustrated. The difference from embodiment 1 is that a copper sleeve 110 is also provided at the radial engagement point between the slide plate 50 and the swashplate 40 in this embodiment. Other aspects can be referred to the structure described in embodiment 1.

[0091] Specifically, such as Figure 18 As shown, a copper sleeve 110 is provided on the center hole 52 of the slide plate. The copper sleeve 110 is nested in the wall of the center hole 52 of the slide plate 50 with an interference fit. The copper sleeve 110 and the swashplate support shaft 42 form a hydrostatic oil film support. This bimetallic structure is beneficial for metal pairing and reduces friction. If referring to embodiment 3, the copper sleeve 110 is nested on the slide plate support shaft 59, and the copper sleeve 110 and the slide plate support shaft 59 are interference fit.

[0092] Example 6:

[0093] like Figure 19 As shown, another embodiment of the present invention is illustrated, which differs from Embodiment 1 in that the sliding piston pump in this embodiment is a metering pump, and the other structures can be referred to in Embodiment 1.

[0094] The above description, in conjunction with specific preferred technical solutions, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention. All technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A fully hydrostatic floating support slide pair, characterized in that: It includes a swashplate (40) and a slide plate (50) supported on the swashplate (40). The slide plate (50) is an integral disc structure, and the slide plate (50) and the swashplate (40) are connected by a hydrostatic floating support. The total hydrostatic floating support includes a sliding plate axial support kinematic pair and a sliding plate radial support kinematic pair; The axial support kinematic pair of the slide includes the end face of the slide (50) and the end face of the swashplate (40) supporting the slide (50). The axial support kinematic pair of the slide is formed by the corresponding fit between the axial end face of the slide (50) and the axial end face of the swashplate (40). The end faces of the slide (50) and the swashplate (40) that are axially opposed are provided with a hydrostatic support surface (51). The hydrostatic support surface (51) of the slide (50) can be set as a planar or spherical structure. The hydrostatic support surface (51) is provided with a slide waist-shaped hole (53). The hydrostatic support surface (51) and the swashplate (40) maintain a hydrostatic oil film support that slides in fit. The sliding disk radial support kinematic pair includes a sliding disk radial support surface (51a) and a swashplate radial support surface (41a). The sliding disk radial support kinematic pair is formed by the corresponding and matching of the radial support surface of the sliding disk (50) and the radial support surface of the swashplate (40). A high-pressure oil groove (42a) is provided on the sliding disk radial support surface (51a) or the swashplate radial support surface (41a). A high-pressure oil hole (48a) is provided on the swashplate (40). The high-pressure oil hole (48a) introduces high-pressure oil into the high-pressure oil groove (42a), so that a hydrostatic oil film support is formed between the sliding disk radial support surface (51a) and the swashplate radial support surface (41a). The high-pressure oil groove (42a) is a full-circumferential annular oil groove. The high-pressure oil hole (48a) introduces high-pressure oil into the high-pressure oil groove (42a), so that a static pressure oil film support is formed in the full circumferential direction between the radial support surface (51a) of the slide plate and the radial support surface (41a) of the swash plate. Alternatively, a low-pressure oil groove (42b) may be provided on the radial support surface (51a) of the slide plate or the radial support surface (41a) of the swash plate. The low-pressure oil groove (42b) and the high-pressure oil groove (42a) are separated by a spacer sealing part (42c). A low-pressure oil hole (48b) is provided on the swash plate (40), and the low-pressure oil hole (48b) introduces low-pressure oil into the low-pressure oil groove (42b).

2. The hydrostatic floating support slide pair according to claim 1, characterized in that: The swash plate (40) has a swash plate support shaft (42) extending along its axial direction in the middle. The outer periphery of the swash plate support shaft (42) forms a swash plate radial support surface (41a). The slide plate (50) has a through hole-shaped slide plate center hole (52) in the middle. The inner wall of the slide plate center hole (52) forms a slide plate radial support surface (51a). The swash plate support shaft (42) is inserted into the slide plate center hole (52) and forms a clearance fit with the slide plate radial support surface (51a). The high-pressure oil groove (42a) is provided on the swash plate radial support surface (41a).

3. The hydrostatic floating support slide pair according to claim 1, characterized in that: The slide (50) has a slide support shaft (59) extending axially in the middle, and the outer periphery of the slide support shaft (59) forms a slide radial support surface (51a). The swashplate (40) has a groove-shaped swashplate center hole (41b) in the middle, and the inner wall of the swashplate center hole (41b) forms a swashplate radial support surface (41a). The slide support shaft (59) is inserted into the swashplate center hole (41b) and forms a clearance fit with the swashplate radial support surface (41a). The high-pressure oil groove (42a) is provided on the swashplate radial support surface (41a).

4. The hydrostatic floating support slide pair according to claim 1, characterized in that: O-rings (46) and / or guide rings (47) are provided on both sides of the high-pressure oil tank (42a) or the low-pressure oil tank (42b).

5. The hydrostatic floating support slide pair according to claim 1, characterized in that: The slide plate (50) is provided with a plurality of plunger ball sockets (58) on the end face opposite to the plunger ball head (71). The plunger ball head (71) is partially enclosed in the plunger ball sockets (58) and keeps freely tilting with the plunger ball sockets (58) within a certain tilt angle range.

6. The hydrostatic floating support slide pair according to claim 5, characterized in that: The plane formed by connecting the centers of each plunger ball socket (58) intersects the spindle axis (10C) at point O. When the swashplate (40) is in the zero displacement position, the high pressure oil groove (42a) covers point O along the axial direction of the slide plate (50).

7. The hydrostatic floating support slide pair according to claim 5, characterized in that: The hydrostatic support surface (51) of the slide plate (50) is provided with a plurality of slide plate waist-shaped holes (53). The slide plate waist-shaped holes (53) are distributed at intervals on the hydrostatic support surface (51) with the spindle axis (10C) as the center. The slide plate waist-shaped holes (53) are connected to the corresponding plunger ball sockets (58), so that the hydrostatic support surface (51) and the end face of the swashplate (40) form a clearance fit hydrostatic oil film support.

8. The hydrostatic floating support slide pair according to claim 1, characterized in that: A copper sleeve (110) is provided between the radial support surface of the slide (50) and the radial support surface of the swashplate (40).

9. A sliding piston pump comprising a total hydrostatic floating support sliding plate pair as described in any one of claims 1 to 8, characterized in that: The sliding disc plunger pump includes a main shaft (10), a housing (31), a first bearing (21), a swashplate (40), a sliding disc (50), a pressure plate (60), a plunger (70), a cylinder (80), a distribution plate (90), and a rear end cover (33). The sliding disc (50) and the swashplate (40) are supported by a hydrostatic floating support. The main shaft axis (10C) of the main shaft (10) coincides with the cylinder axis of the cylinder (80). One end of the main shaft (10) extends through the distribution pair, protrudes from the housing (31), and is supported on the first bearing (21). The other end cantilever supports the cylinder (80) and is connected to the cylinder (80) by a key. The main shaft (10) and the cylinder (80) rotate synchronously. The plunger (70) reciprocates in the plunger cavity of the cylinder (80) to realize the pump's oil suction and discharge operation. The sliding disc plunger pump can be configured as a fixed displacement pump or a variable displacement pump.

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