Axial plunger pump capable of adaptively regulating and controlling thickness of lubricating film of flow distribution pair
The adaptive control technology combining permanent magnets and figure-8 coils solves the problem of unstable liquid film thickness in traditional axial piston pumps under high-speed and high-pressure conditions, realizes adaptive control of lubricating film thickness, reduces friction, wear and leakage, and improves service life and volumetric efficiency.
Patent Information
- Application Number
- CN202510931785.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-07
- Publication Date
- 2025-09-12
AI Technical Summary
Under high-speed and high-pressure conditions, the liquid film thickness of traditional axial piston pumps is significantly affected by temperature, speed, and load fluctuations, resulting in increased friction, wear, and leakage. Existing technologies are unable to adaptively control under wide-speed operating conditions, resulting in increased pressure pulsation.
By combining permanent magnets with figure-8 coils, Lenz's law is used to generate induced current and magnetic force, dynamically regulating the thickness of the lubricating film of the distribution pair, and combining the fluid dynamic pressure effect to achieve adaptive regulation.
It reduces friction, wear and leakage, extends the service life of the axial piston pump, and adaptively adjusts the posture when the cylinder body overturns, thereby improving volumetric efficiency.
Smart Images
Figure CN120626480A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of hydraulic transmission, and in particular to an axial piston pump capable of adaptively regulating the thickness of a lubricating film of a distribution pair. Background Art
[0002] As the core power element of the hydraulic system, the performance of the friction pair formed by the axial piston pump's valve plate and the cylinder end face directly affects the pump's volumetric efficiency, noise level, and service life. Traditional valve plate designs rely primarily on passive liquid film lubrication technology. By creating geometric structures such as triangular unloading grooves and damping holes on the valve plate surface, the fluid dynamic pressure effect is used to form a lubricating film to reduce friction. However, this type of design has significant drawbacks. Under high-speed and high-pressure conditions, the thickness of the liquid film is significantly affected by temperature, speed, and load fluctuations, leading to increased friction, wear, and leakage. At the same time, mechanical contact generates high-frequency noise, making it difficult to meet the requirements of the main engine. In addition, the fixed parameter design of the damping slot hole cannot adapt to the switching of wide-speed operating conditions, resulting in increased pressure pulsation.
[0003] To improve friction performance, existing technologies attempt to use coatings or ceramic composite materials to enhance the wear resistance of the distribution plate. Although such methods can extend the life of components, they cannot eliminate boundary friction and face technical bottlenecks such as high processing costs and the risk of coating peeling. In recent years, non-contact support technology has begun to be applied to the field of hydraulic pumps, such as magnetic levitation bearings, but its strong magnetic field interference, complex control algorithms and other problems have limited the industrialization process, and the suspension scheme based on electromagnetic force control still has defects such as insufficient suspension force and low response frequency. As the current hydraulic system is developing towards high speed, high pressure and low viscosity media, traditional distribution pair lubrication technology has become difficult to achieve the coordinated optimization of friction loss, noise and dynamic characteristics, and there is an urgent need to break through the technical limitations of traditional lubrication film. Summary of the Invention
[0004] In response to the problems existing in the prior art, the present invention provides an axial piston pump with adaptive control of the thickness of the lubricating film of the distribution pair. When the lubricating film thickness deviates from the ideal value or the cylinder body overturns, the radial horizontal center line of the permanent magnet and the radial horizontal center line of the 8-shaped coil are offset. At this time, the relative movement of the permanent magnet and the coil causes the magnetic flux in the coil to change. According to Lenz's law, an induced current is generated, and the magnetic force is generated by interacting with the magnetic field of the permanent magnet. Combined with the fluid dynamic pressure effect, the film thickness of the distribution plate and the cylinder liner end face is adaptively controlled, thereby effectively reducing wear and leakage and extending the life of the axial piston pump.
[0005] Specifically, the present invention provides an axial piston pump with adaptive control of the thickness of the lubricating film of the distribution pair, which includes a housing, a cylinder body located in the housing, a cylinder liner, a permanent magnet, a coil ring, a plunger slipper assembly and a drive shaft. The first end of the housing is provided with a swash plate, the second end of the housing is provided with a distribution plate, the plunger slipper assembly is provided on the cylinder body, and the cylinder body is supported on the distribution plate through the cylinder liner; a plurality of groups of permanent magnets are provided on the cylinder liner, and the plurality of groups of permanent magnets are arranged in an array on the cylinder liner, and the permanent magnets are provided on the cylinder liner through permanent magnet end covers, the coil ring is provided at the second end of the housing and is located on the outside of the cylinder liner, a plurality of groups of coil winding brackets are evenly distributed around the inner side of the coil ring, a coil is wound on the coil winding bracket, and the coil is a single coil structure in the shape of an 8. When the lubricating film thickness between the distribution plate and the cylinder liner is at an ideal value, the radial horizontal center line of the coil is aligned with the radial horizontal center line of the permanent magnet. At this time, the upper coil part and the lower coil part in the coil generate induced electromotive forces of equal magnitude and opposite directions, and then the induced current generated on the coil is zero; the first end of the transmission shaft is supported on the upper end cover of the shell, and the second end of the transmission shaft passes through the upper end cover and the inclined plate and is threadedly connected to the cylinder body. The transmission shaft drives the cylinder body to rotate, and the cylinder body drives the cylinder liner and the permanent magnet to rotate, generating a periodically changing spatial magnetic field in the circumferential direction of the coil. When the lubricating film thickness between the distribution plate and the cylinder liner deviates from the ideal value, the radial horizontal center line of the permanent magnet is offset relative to the radial horizontal center line of the coil. At this time, the coil generates an induced current due to the change in magnetic flux under the periodic changing spatial magnetic field. The induced current generates an induced magnetic field and interacts with the spatial magnetic field generated by the permanent magnet to generate magnetic force. The axial component generated by the magnetic force acts on the suspended cylinder liner, thereby dynamically adjusting the lubricating film thickness of the distribution pair.
[0006] Furthermore, when the thickness of the lubricating film between the distribution plate and the cylinder liner becomes smaller, the radial horizontal center line of the permanent magnet is below the radial horizontal center line of the coil, the spatial magnetic field distribution of the coil is in an asymmetric state, and the magnetic flux of the lower coil part of the coil is greater than the magnetic flux of the upper coil part of the coil, thereby generating an induced current. At this time, the lower coil part generates a repulsive force on the permanent magnet, and the upper coil part generates an attractive force on the permanent magnet. The axial combined force of the repulsive force and the attractive force increases the thickness of the lubricating film between the distribution plate and the cylinder liner.
[0007] Furthermore, when the thickness of the lubricating film between the distribution plate and the cylinder liner increases, the radial horizontal center line of the permanent magnet is above the radial horizontal center line of the coil, and the spatial magnetic field distribution of the coil is in an asymmetric state. The magnetic flux of the lower coil part of the coil is smaller than the magnetic flux of the upper coil part of the coil, thereby generating an induced current. At this time, the lower coil part generates an attractive force on the permanent magnet, and the upper coil part generates a repulsive force on the permanent magnet. The axial combined force of the attractive and repulsive forces reduces the thickness of the lubricating film between the distribution plate and the cylinder liner.
[0008] Preferably, when the cylinder body overturns inside the shell, the thickness of the lubricating film on the first side between the distribution plate and the cylinder body liner increases, and the thickness of the lubricating film on the second side corresponding to the first side decreases. At this time, the thickness of the lubricating film on the first side decreases under the action of the axial resultant force of the coil magnetic force, and the thickness of the lubricating film on the second side increases under the action of the axial resultant force of the coil magnetic force.
[0009] Preferably, the first end surface of the cylinder liner contacts the first end surface of the distribution plate, and the second end surface of the cylinder liner is provided with a permanent magnet slot, in which the permanent magnet is provided.
[0010] Furthermore, each group of permanent magnets includes a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet. The magnetization directions of two adjacent permanent magnets in each group of permanent magnets differ by 90°. The magnetization direction of the first permanent magnet is radially from the center of the cylinder liner to its circumferential direction, the magnetization direction of the second permanent magnet is radially from the second permanent magnet to the first permanent magnet along the circumferential direction of the cylinder liner, the magnetization direction of the third permanent magnet is from the circumferential direction of the cylinder liner to the center of the cylinder liner, and the magnetization direction of the fourth permanent magnet is radially from the third permanent magnet to the fourth permanent magnet along the circumferential direction of the cylinder liner.
[0011] Preferably, a coil ring positioning pin is provided on the outside of the coil ring, and a positioning hole corresponding to the coil ring positioning pin is provided on the inner surface of the shell. The coil ring is circumferentially fixed through the positioning hole on the shell. The length of the coil ring positioning pin on the coil ring is the same as the depth of the positioning hole on the shell. The first end face of the coil ring contacts the end face of the positioning hole of the shell, and the second end face of the coil ring contacts the lower end cover.
[0012] Preferably, each set of coil winding brackets includes an upper bracket and a lower bracket, and the upper bracket and the lower bracket are spaced apart on the inner side of the coil ring in the vertical direction. The upper bracket, the lower bracket and the coil ring together constitute a coil accommodating groove, and the coil is accommodated in the coil accommodating groove.
[0013] Preferably, the ideal value range of the lubricating film thickness between the valve plate and the cylinder liner is 10~20 .
[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The axial piston pump with adaptive control of the lubricating film thickness of the distribution pair provided by the present invention does not require an additional power source and relies only on the movement characteristics of the piston pump itself, that is, the rotation of the drive shaft drives the permanent magnet in the cylinder liner to rotate, and the coil arranged on the inner surface of the shell cuts the spatial magnetic field generated by the permanent magnet in the array. According to Lenz's law, when the lubricating film thickness deviates from the ideal value, the axial horizontal center line of the coil and the permanent magnet is offset, and an induced current is generated in the coil, thereby generating an induced magnetic field and interacting with the magnetic field of the permanent magnet to generate magnetic force. The axial component of the magnetic force can be used to dynamically adjust the liquid film thickness of the distribution pair.
[0015] 2. The axial piston pump provided by the present invention has the function of adaptively controlling the thickness of the lubricating film of the distribution pair. When the cylinder body overturns, the side with excessively large and insufficient film thickness can be subjected to axial components that reduce and increase the film thickness respectively, thereby adaptively controlling the cylinder body to return to the equilibrium position.
[0016] 3. The axial piston pump with adaptive control of the lubricating film thickness of the distribution pair provided by the present invention combines the electric suspension principle with the movement characteristics of the axial piston pump. It has the characteristics of simple structure, high energy utilization efficiency, no additional energy consumption when the film thickness is reasonable, adaptive control of film thickness and adaptive adjustment of cylinder posture, etc., which reduces the friction, wear and leakage between the distribution plate and the cylinder liner and extends the service life. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 Schematic diagram of the assembly of the permanent magnet, coil ring and coil of the present invention; Figure 2 Schematic diagram of the overall structure of the axial piston pump of the present invention; Figure 3 Schematic diagram of the arrangement of the permanent magnets of the present invention; Figure 4 It is a structural schematic diagram of the coil support of the present invention; Figure 5 It is a structural schematic diagram of the housing of the present invention; Figure 6 This is a schematic diagram of the alignment state of the permanent magnet and the coil of the present invention; Figure 7 Schematic diagram of the upward displacement of the permanent magnet relative to the coil of the present invention; Figure 8 Schematic diagram of the permanent magnet of the present invention being deflected downward relative to the coil; Figure 9 It is a schematic diagram of the cylinder body of the present invention overturning in the shell.
[0018] Main reference numerals: Lower end cover 1; distribution plate support 2; distribution plate 3; liquid outlet channel 31; liquid inlet channel 32; coil ring 4; coil ring locating pin 41; coil winding bracket 42; upper bracket 421; lower bracket 422; coil 5; upper coil portion 51; lower coil portion 52; cylinder liner 6; permanent magnet 7; first permanent magnet 71; second permanent magnet 72; third permanent magnet 73; fourth permanent magnet 74; permanent magnet end cover 8; cylinder liner 9; cylinder body 10; housing 11; locating hole 111; plunger 12; sliding shoe 13; swash plate 14; upper end cover 15; transmission shaft 16; liquid outlet valve 17; liquid inlet valve 18; compression spring seat 19; compression spring 20; sealing ring 21; return plate pressure head 22; return plate 23. DETAILED DESCRIPTION
[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0020] The present invention provides an axial piston pump with adaptive control of the lubricating film thickness of the distribution pair, such as Figure 1 and Figure 2 As shown, it includes a housing 11, a cylinder block 10 located in the housing 11, a cylinder block liner 6, a permanent magnet 7, a coil ring 4, a plunger and a sliding shoe assembly and a transmission shaft 16. A swash plate 14 is provided at the first end of the housing 11, an upper end cover 15 is provided on the swash plate 14, a distribution plate 3 is provided at the second end of the housing, a lower end cover 1 is provided on the distribution plate 3, and a liquid outlet valve 17 and a liquid inlet valve 18 are provided on the lower end cover 1, a distribution plate support 2 is provided at the center of the distribution plate 3, and a liquid outlet channel 31 and a liquid inlet channel 32 are provided on both sides of the distribution plate 3 and are connected to the liquid outlet valve 17 and the liquid inlet valve 18, a cylinder block 10 is provided inside the housing 11, a plunger and a sliding shoe assembly is provided on the cylinder block 10, and the plunger and a sliding shoe assembly includes a cylinder liner 9, a plunger 12, a sliding shoe 13 and a return plate 23, a plurality of through holes around the central axis of the cylinder block are provided on the cylinder block 10, a cylinder liner 9 is provided in each through hole of the cylinder block, and a cylinder liner 9 is provided in each through hole of the cylinder block. The first end of the tube 9 is connected to the cylinder liner 6, and the second end of the cylinder liner 9 is connected to the through hole in the cylinder 10 through the sealing ring 21. A compression spring seat 19 is provided inside the cylinder 10, and the first end face of the compression spring seat 19 contacts the first end of the compression spring 20, and the second end face of the compression spring seat 19 contacts the cylinder liner 6. The second end of the compression spring 20 contacts the first end of the cylinder 10, and the through hole on the cylinder 10 is in sliding contact with the plunger 12. The second end of the cylinder 10 is provided with a return plate pressure head 22, and the return plate pressure head 22 is connected to the return plate 23 by a ball joint. The plunger 12 is connected to the slip shoe 13 by a ball joint. The first end of the slip shoe 13 contacts the return plate 23, and the second end of the slip shoe 13 is in sliding contact with the inclined plate 14.
[0021] like Figure 1 、 Figure 3 and Figure 6As shown, the cylinder body 10 is supported on the distribution plate 3 through the cylinder body liner 6. The cylinder body liner 6 is provided with multiple groups of permanent magnets 7. The multiple groups of permanent magnets 7 are arranged in an array on the cylinder body liner 6. In a preferred embodiment, they are arranged in a Halbach array. A permanent magnet end cover 8 is provided below the permanent magnet 7. The permanent magnet 7 is set on the cylinder body liner 6 through the permanent magnet end cover 8. The coil ring 4 is provided at the second end of the shell and is located on the outside of the cylinder body liner 6. Multiple groups of coil winding brackets 42 are evenly distributed around the inner side of the coil ring 4. The coil 5 is wound on the coil winding bracket 42. The coil 5 is a single coil structure in the shape of an 8. When the lubricating film thickness between the distribution plate 3 and the cylinder body liner 6 is at an ideal value, the radial horizontal center line of the coil 5 is aligned with the radial horizontal center line of the permanent magnet 7. At this time, the upper coil part 51 and the lower coil part 52 in the coil 5 generate induced electromotive forces of equal magnitude and opposite directions, and then the induced current generated on the coil 5 is zero. In a preferred embodiment of the present invention, the specific structure of the coil 5 is an 8-shaped coil.
[0022] Specifically, the ideal value range of the lubricating film thickness between the valve plate 3 and the cylinder liner 6 is 10~20 .
[0023] In a preferred embodiment, the first end surface of the cylinder liner 6 contacts the first end surface of the distribution plate 3 , and the second end surface of the cylinder liner 6 is provided with a permanent magnet slot, in which the permanent magnet 7 is disposed.
[0024] like Figure 1 、 Figure 2 and Figure 6 As shown, the first end of the transmission shaft 16 is supported on the upper end cover 15, and the second end of the transmission shaft 16 passes through the upper end cover 15 and the swash plate 14 and is threadedly connected to the cylinder body 10. The transmission shaft 16 drives the cylinder body 10 to rotate, and the cylinder body 10 drives the cylinder liner 6 and the permanent magnet 7 to rotate, thereby generating a periodically changing spatial magnetic field in the circumferential direction of the coil 5. When the lubricating film thickness between the distribution plate 3 and the cylinder liner 6 deviates from the ideal value, the radial horizontal center line of the permanent magnet 7 is offset relative to the radial horizontal center line of the coil 5. At this time, the coil 5 generates an induced current due to the change in magnetic flux under the periodically changing spatial magnetic field. The induced current further generates an induced magnetic field and interacts with the spatial magnetic field generated by the permanent magnet to generate a magnetic force. The axial component generated by the magnetic force acts on the suspended cylinder liner 6, and then the lubricating film thickness of the distribution pair can be dynamically adjusted.
[0025] like Figure 3As shown, each group of permanent magnets includes a first permanent magnet 71, a second permanent magnet 72, a third permanent magnet 73 and a fourth permanent magnet 74. The magnetization directions of two adjacent permanent magnets in each group of permanent magnets 7 differ by 90°. The magnetization direction of the first permanent magnet 71 is radially from the center of the cylinder liner 6 to its circumferential direction, the magnetization direction of the second permanent magnet 72 is radially from the second permanent magnet 72 to the first permanent magnet 71 along the circumferential direction of the cylinder liner 6, the magnetization direction of the third permanent magnet 73 is from the circumferential direction of the cylinder liner 6 to the center of the cylinder liner 6, and the magnetization direction of the fourth permanent magnet 74 is radially from the third permanent magnet 73 to the fourth permanent magnet 74 along the circumferential direction of the cylinder liner 6.
[0026] like Figure 4 As shown, each set of coil winding brackets 42 includes an upper bracket 421 and a lower bracket 422. The upper bracket 421 and the lower bracket 422 are spaced apart on the inner side of the coil ring 4 in the vertical direction. The upper bracket 421, the lower bracket 422 and the coil ring 4 together constitute a coil accommodating groove, and the coil 5 is arranged in the coil accommodating groove.
[0027] like Figure 4 and Figure 5 As shown, a coil ring locating pin 41 is provided on the outside of the coil ring 4, and a positioning hole 111 corresponding to the coil ring locating pin 41 is provided on the inner surface of the shell 11. The coil ring 4 is circumferentially fixed by the positioning hole 111 on the shell 11. The length of the coil ring locating pin 41 on the coil ring 4 is the same as the depth of the positioning hole 111 on the shell 11. The first end face of the coil ring 4 contacts the end face of the positioning hole 111 of the shell 11, and the second end face of the coil ring 4 contacts the lower end cover 1.
[0028] like Figure 7 As shown, when the thickness of the lubricating film between the distribution plate 3 and the cylinder liner 6 becomes smaller, the radial horizontal center line of the permanent magnet 7 is below the radial horizontal center line of the coil 5, and the spatial magnetic field distribution of the coil 5 is in an asymmetric state. The magnetic flux of the lower coil part 52 in the coil 5 is greater than the magnetic flux of the upper coil part 51 in the coil 5, and then an induced current is generated. At this time, the lower coil part 52 generates a repulsive force on the permanent magnet 7, and the upper coil part 51 generates an attractive force on the permanent magnet 7. The axial combined force of the two increases the thickness of the lubricating film between the distribution plate 3 and the cylinder liner 6.
[0029] like Figure 8As shown, when the thickness of the lubricating film between the distribution plate 3 and the cylinder liner 6 increases, the radial horizontal center line of the permanent magnet 7 is above the radial horizontal center line of the coil 5, and the spatial magnetic field distribution of the coil 5 is in an asymmetric state. The magnetic flux of the lower coil part 52 in the coil 5 is less than the magnetic flux of the upper coil part 51 in the coil 5, and then an induced current is generated. At this time, the lower coil part 52 generates an attractive force on the permanent magnet 7, and the upper coil part 51 generates a repulsive force on the permanent magnet 7. The axial combined force of the two reduces the thickness of the lubricating film between the distribution plate 3 and the cylinder liner 6.
[0030] like Figure 9 As shown, when the cylinder body 10 overturns inside the shell 11, the thickness of the lubricating film on the first side between the distribution plate 3 and the cylinder body liner 6 increases, and the thickness of the lubricating film on the second side corresponding to the first side decreases. At this time, the thickness of the lubricating film on the first side decreases under the action of the axial resultant force of the magnetic force of the coil 5, and the thickness of the lubricating film on the second side increases under the action of the axial resultant force of the magnetic force of the coil 5.
[0031] Specifically, the induced current expression of a single coil 5 is: ; Where, represents the total loop resistance of the coil, represents the induced electromotive force, Indicates the number of coil turns, Represents magnetic flux.
[0032] The specific operation steps of the present invention are as follows: like Figures 1 to 9 As shown, when the axial piston pump with adaptive control of the lubricating film thickness of the distribution pair of the present invention is regulated, when the external motor drives the transmission shaft 16 to rotate, the transmission shaft 16 drives the cylinder body 10 to rotate, and the cylinder body 10 drives the plunger 12 and the sliding shoe 13 to rotate. The compression spring 20 installed in the cylinder body 10 is always in a compressed state, and the first end of the compression spring 20 is in contact with the compression spring seat 19, and the second end of the compression spring 20 is in contact with the cylinder body 10, which makes the cylinder body 10 close to the return stroke. The disc pressure head 22 provides a pressing force. At the same time, the return disc pressure head 22 is connected to the return disc 23 by a ball joint, and the return disc 23 is in contact with the slipper 13. Since the plunger 12 is connected to the slipper 13 by a ball joint, the surface of the swash plate 14 and the plunger 12 form a certain angle. Therefore, the plunger 12 performs reciprocating linear motion in the cylinder body 10 while performing rotational motion. As a result, there will be a high-pressure area of 0~180°, namely the liquid outlet channel 31, and a low-pressure area of 180°~360°, namely the liquid inlet channel 32, on the surface of the distribution disc 23.
[0033] During the rotation of the cylinder body 10, the cylinder body liner 6 rotates synchronously through the connection of the cylinder body liner tube 9, and the Halbach permanent magnet array in the cylinder body liner 6 also rotates. The Halbach permanent magnet array forms a sinusoidally distributed rotating magnetic field in the circumferential direction. When the lubricating film thickness is at an ideal value, the axial horizontal center line of the coil 5 is aligned with the axial horizontal center line of the permanent magnet 7. At this time, the induced current in the coil 5 is 0; when the liquid film thickness becomes smaller, the center lines of the two shift downward, and the distribution of the magnetic field is in an asymmetric state. The magnetic flux of the lower coil part 52 of the coil 5 is greater than that of the upper coil part 51, and an induced current is generated. At this time, the lower coil part 52 generates a repulsive force on the permanent magnet 7, and the upper coil part 51 generates an attractive force. The axial combined force of the two increases the film thickness. Similarly, when the liquid film thickness increases, the center lines of the two shift upward, and the generated magnetic force can reduce the film thickness. When the cylinder body 10 overturns, the film thickness of the cylinder body liner 6 and the distribution plate 3 is too large on one side and too small on the other side. On the side with too small thickness, the permanent magnet 7 is subjected to the axial resultant force of the magnetic force of the coil 5, causing the film thickness to increase. On the side with too large thickness, the permanent magnet 7 is subjected to the axial resultant force of the magnetic force of the coil, causing the film thickness to decrease.
[0034] The present invention embeds a Halbach array of permanent magnets in the cylinder liner and installs a coil on the inner surface of the shell, utilizing the movement characteristics of the plunger pump itself. When the transmission shaft rotates, the cylinder, cylinder liner and permanent magnet are driven to rotate together. When the film thickness of the distribution pair deviates from the ideal value or the cylinder overturns, the magnetic flux in the coil changes. According to Lenz's law, an induced current is generated in the coil and further forms an induced magnetic field, which then interacts with the magnetic field of the permanent magnet to generate a magnetic force. The axial component of this magnetic force is used to adaptively control the film thickness of the distribution pair and the posture of the cylinder, thereby reducing the wear rate of the workpiece, improving the volumetric efficiency of the pump, and extending the service life. Since the above structure does not require additional energy input, the film thickness can be controlled only by relying on the rotation of the pump itself, and the energy utilization efficiency is high. In addition, the present invention broadens the technical field for improving the lubrication and wear performance of the distribution pair and other friction pairs.
[0035] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.
Claims
1. An axial piston pump with adaptive control of lubricating film thickness of a distribution pair, characterized by: It includes a shell, a cylinder block located in the shell, a cylinder block liner, a permanent magnet, a coil ring, a plunger sliding shoe assembly and a transmission shaft. A swash plate is provided at the first end of the housing, a port plate is provided at the second end of the housing, a plunger shoe assembly is provided on the cylinder body, and the cylinder body is supported on the port plate through a cylinder body liner; A plurality of groups of permanent magnets are provided on the cylinder liner, and the plurality of groups of permanent magnets are arranged in an array on the cylinder liner. The permanent magnets are provided on the cylinder liner through permanent magnet end covers. The coil ring is provided at the second end of the shell and is located on the outside of the cylinder liner. A plurality of groups of coil winding brackets are evenly distributed around the inner side of the coil ring. The coil winding brackets are wound with coils. The coils are single coil structures in the shape of a figure 8. When the lubricating film thickness between the port plate and the cylinder liner is at an ideal value, the radial horizontal center line of the coil is aligned with the radial horizontal center line of the permanent magnet. At this time, the upper coil portion and the lower coil portion in the coil generate induced electromotive forces of equal magnitude and opposite directions, and the induced current generated in the coil is zero. The first end of the transmission shaft is supported on the upper end cover of the shell, and the second end of the transmission shaft passes through the upper end cover and the swash plate and is threadedly connected to the cylinder body. The transmission shaft drives the cylinder body to rotate, and the cylinder body drives the cylinder liner and the permanent magnet to rotate, generating a periodically changing spatial magnetic field in the circumferential direction of the coil. When the thickness of the lubricating film between the distribution plate and the cylinder liner deviates from the ideal value, the radial horizontal center line of the permanent magnet is offset relative to the radial horizontal center line of the coil. At this time, the coil generates an induced current due to the change in magnetic flux under the periodically changing spatial magnetic field. The induced current generates an induced magnetic field and interacts with the spatial magnetic field generated by the permanent magnet to generate magnetic force. The axial component generated by the magnetic force acts on the suspended cylinder liner, thereby dynamically adjusting the thickness of the lubricating film of the distribution pair.
2. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 1, characterized in that: When the thickness of the lubricating film between the distribution plate and the cylinder liner becomes smaller, the radial horizontal center line of the permanent magnet is below the radial horizontal center line of the coil, the spatial magnetic field distribution of the coil is in an asymmetric state, and the magnetic flux of the lower coil part of the coil is greater than the magnetic flux of the upper coil part of the coil, thereby generating an induced current. At this time, the lower coil part generates a repulsive force on the permanent magnet, and the upper coil part generates an attractive force on the permanent magnet. The axial resultant force of the repulsive force and the attractive force increases the thickness of the lubricating film between the distribution plate and the cylinder liner.
3. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 2, characterized in that: When the thickness of the lubricating film between the distribution plate and the cylinder liner increases, the radial horizontal center line of the permanent magnet is above the radial horizontal center line of the coil, and the spatial magnetic field distribution of the coil is in an asymmetric state. The magnetic flux of the lower coil part of the coil is smaller than the magnetic flux of the upper coil part of the coil, and then an induced current is generated. At this time, the lower coil part generates an attractive force on the permanent magnet, and the upper coil part generates a repulsive force on the permanent magnet. The axial combined force of the attractive and repulsive forces reduces the thickness of the lubricating film between the distribution plate and the cylinder liner.
4. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 3, characterized in that: When the cylinder body overturns inside the shell, the thickness of the lubricating film on the first side between the distribution plate and the cylinder body liner increases, and the thickness of the lubricating film on the second side corresponding to the first side decreases. At this time, the thickness of the lubricating film on the first side decreases under the action of the axial resultant force of the coil magnetic force, and the thickness of the lubricating film on the second side increases under the action of the axial resultant force of the coil magnetic force.
5. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 1, characterized in that: The first end surface of the cylinder lining plate contacts the first end surface of the distribution plate, and the second end surface of the cylinder lining plate is provided with a permanent magnet slot, in which the permanent magnet is arranged.
6. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 1, characterized in that: Each group of permanent magnets includes a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet. The magnetization directions of two adjacent permanent magnets in each group of permanent magnets differ by 90°. The magnetization direction of the first permanent magnet is from the center of the cylinder liner along the radial direction to the circumferential direction thereof, the magnetization direction of the second permanent magnet is from the second permanent magnet along the circumferential direction of the cylinder liner to the first permanent magnet, the magnetization direction of the third permanent magnet is from the circumferential direction of the cylinder liner to the center of the cylinder liner, and the magnetization direction of the fourth permanent magnet is from the third permanent magnet along the circumferential direction of the cylinder liner to the fourth permanent magnet.
7. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 1, characterized in that: A coil ring locating pin is provided on the outside of the coil ring, and a locating hole corresponding to the coil ring locating pin is provided on the inner surface of the shell. The coil ring is circumferentially fixed through the locating hole on the shell. The length of the coil ring locating pin on the coil ring is the same as the depth of the locating hole on the shell. The first end face of the coil ring contacts the end face of the locating hole of the shell, and the second end face of the coil ring contacts the lower end cover.
8. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 7, characterized in that: Each set of coil winding brackets includes an upper bracket and a lower bracket, which are spaced apart on the inner side of the coil ring in the vertical direction. The upper bracket, the lower bracket and the coil ring together constitute a coil accommodating groove, and the coil is accommodated in the coil accommodating groove.
9. The axial piston pump with adaptive control of lubricating film thickness of the distribution pair according to claim 1, characterized in that: The ideal value range of the lubricating film thickness between the valve plate and the cylinder liner is 10~20 .