CN113898548B

CN113898548B - Self-lubricating connecting rod plunger type valve flow distribution hydraulic pump

Info

Publication number: CN113898548B
Application number: CN202111007114.5A
Authority: CN
Inventors: 尹方龙; 纪辉; 聂松林
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2023-03-31
Anticipated expiration: 2041-08-30
Also published as: CN113898548A

Abstract

The invention discloses a self-lubricating connecting rod plunger type valve flow distribution hydraulic pump, which adopts a cylinder rotary valve flow distribution working mode, and the rotary centrifugal force is favorable for opening radially arranged suction valves during working, so that the working pressure and the suction performance of the pump are improved. By adopting a compact structure of a non-spherical hinge type return stroke mechanism and an integral fixed connecting rod plunger, the sliding bearings are arranged on the connecting rod fixed disc and the excircle of the cylinder body, so that the lateral force of key components is effectively balanced. All friction pairs can realize self-lubrication, the key friction pair adopts the hard-hard material pairing of corrosion-resistant hard alloy and composite engineering ceramic, and the plane friction pair adopts the bionic texture to improve the lubricating and wear properties. The invention has the obvious technical advantages of high working pressure, large power-weight ratio, strong pollution resistance, high reliability and the like, and can be widely applied to ultrahigh pressure hydraulic systems which use hydraulic oil or pure water as transmission media.

Description

Self-lubricating connecting rod plunger type valve flow distribution hydraulic pump

Technical Field

The invention relates to a self-lubricating connecting rod plunger type valve flow distribution hydraulic pump which can be used as a power element applied to a hydraulic transmission system, is particularly suitable for hydraulic transmission systems with low-viscosity media (such as high water-based and pure water hydraulic transmission systems and the like), and belongs to the technical field of fluid transmission and control.

Background

The hydraulic technology is a basic transmission and control technology which takes liquid as a working medium to generate, control and transmit liquid energy, mainly utilizes a hydraulic pump to convert the mechanical energy of a prime motor into the pressure energy of the liquid, realizes energy transmission through the change of the liquid pressure energy, converts the pressure energy of the liquid into the mechanical energy by means of an actuating element (a cylinder or a motor) through various control valves and pipelines, and drives a working mechanism to do linear reciprocating motion or rotary motion. Hydraulic equipment is not available in various fields of national economy, including aerospace and deep sea equipment. The high pressure plunger pump is the core power element of the high end hydraulic equipment, called the "heart" of the hydraulic system.

Compared with foreign brands, the high-pressure plunger pump produced at present in China has larger differences in technical advancement, working reliability, service life and dynamic and static performance indexes, and the high-pressure swash plate type plunger pump with the rated working pressure of more than 35MPa depends on import by more than 90 percent. Particularly, for a pure water hydraulic swash plate type plunger pump, the bottleneck problem to be broken through is the need of how to improve the working pressure, the pollution resistance and the reliability of the pump because of low viscosity and poor lubricity of water and impurities in seawater. The swash plate type axial plunger pump mainly comprises two structural types of end face flow distribution and valve flow distribution, the flow distribution valve is good in sealing performance, high pressure is easy to obtain, and the swash plate type axial plunger pump has good pollution resistance, so that the swash plate type axial plunger pump is widely applied to high-pressure and ultrahigh-pressure hydraulic plunger pumps. However, the existing valve-distributing axial plunger pump has the following defects: 1) Most valve flow distribution axial plunger pumps still keep a sliding shoe-swash plate pair and a spherical hinge-return plate pair, and the two friction pairs are severe in stress working condition under the high-pressure condition and easy to wear and lose efficacy; 2) Most pumps still adopt the traditional plunger piston-slipper structure, the structure needs to adopt rolling or injection molding and other modes to realize the shoe wrapping, the forming process is very complex, the maintainability and the repairability are not available, once the slipper or the plunger is worn, only the plunger piston-slipper assembly can be integrally replaced; 3) Most pumps adopt a working mode of rotating a swash plate and keeping a distributing valve static, the problem of unbalanced rotating of the swash plate exists, the vibration noise of the pumps can be increased due to the alternating impact load generated by unbalanced rotating of the swash plate at high speed and high pressure, and the further improvement of the performance of the pumps is limited; 4) Most hydraulic valve flow distribution axial plunger pumps still adopt an oil-water separation structural style, namely parts with complex stress, such as a swash plate, a sliding shoe, a return ball hinge, a bearing and the like, are lubricated by hydraulic oil, water and a lubricating oil cavity in a plunger cavity are separated by a sealing ring, and once the sealing ring is degraded and damaged, the oil and the water are mutually connected to cause rapid wear failure of the pump.

Disclosure of Invention

The invention aims to provide a self-lubricating connecting rod plunger type valve flow distribution hydraulic pump, which overcomes the defects that the friction pair of the existing swash plate type axial plunger pump is bad in stress, low in service life, large in leakage at high pressure, large in vibration noise, large in volume and weight, incapable of self-lubricating the water hydraulic valve flow distribution axial plunger pump and the like; the novel return mechanism is adopted, so that a return spherical hinge friction pair which is easy to wear and lose efficacy is eliminated; the integrated connecting rod fixing disc and the wear-resisting disc are adopted for opposite grinding, the wear-resisting disc is convenient to replace, and the surface of the wear-resisting disc is provided with the bionic pits, so that the maintainability and the lubricating property are improved; when the friction pair is in work, the low-pressure fluid is filled in the shell, and all friction pairs can realize self-lubrication. Through the core technical points, the volume efficiency, the service life, the lubricating performance and the power-weight ratio of the swash plate type axial plunger pump are improved, and the practicability is very strong.

The invention adopts the following technical means that a front end cover (3) is connected with a shell (9) through a screw, and the shell (9) is connected with a rear end cover (19) through a screw. The sealing gland (40) is arranged on the front end cover (3) through a screw and a positioning spigot, the mechanical seal (2) is arranged in the sealing gland (40), the swash plate (4) is fixed on the front end cover (3) through the positioning spigot and a positioning pin, and the wear-resistant disc (39) is arranged in the swash plate (4) in an interference manner; the surface of the wear-resisting disc (39) is provided with a bionic cylindrical pit, the right side surface of the wear-resisting disc (39) is connected with a connecting rod fixing disc (6), the excircle of the connecting rod fixing disc (6) is connected with a swash plate sliding bearing (5), left ball sockets (38) are uniformly distributed on the inner circumference of the connecting rod fixing disc (6), the left ball sockets (38) are connected with a connecting rod (35), a left ball socket fixing ring (37) is installed on the outer side of the left ball socket (38), the left side of a pressing ring (36) is tightly attached to the left ball socket fixing ring (37), the right side of the pressing ring (36) is tightly attached to an inclined block (7), a return wave spring (8) is installed on the right side of the inclined block (7), and the other end of the return wave spring is connected with a step of a shell (9); a right ball socket (34) is arranged on the right side of the connecting rod (35), the right ball socket (34) is connected with the ball head of the plunger (31), a right ball socket fixing ring (33) is arranged on the right side of the ball head of the plunger (31), a connecting rod gland (32) is arranged on the connecting rod (35) in an interference fit mode, and the connecting rod gland (32) is tightly attached to the right ball socket fixing ring (33); the main shaft (1) penetrates through the sealing gland (40), the mechanical seal (2) and the swash plate (4), the main shaft (1) is connected with the cylinder body (13) into a whole through keys, cylinder holes are uniformly distributed in the inner circumference of the cylinder body (13), the cylinder sleeve (30) is installed in the cylinder holes in an interference mode, and the plunger (31) is coaxially installed in the cylinder sleeve (30). A cylinder body gland (10) is installed on the left side of a cylinder body (13), a sliding bearing inner ring (12) is installed on the excircle of the cylinder body (13), and the cylinder sleeve (30) and the sliding bearing inner ring (12) are limited by the cylinder body gland (10). A sliding bearing outer ring (11) is arranged on the excircle of the sliding bearing inner ring (12), and the sliding bearing outer ring (11) is arranged in an inner hole of the shell (9) in an interference manner; the rotary valve disc (15) is fixedly connected with the cylinder body (13) through screws, cylindrical holes with the same number as the plungers (31) are uniformly formed in the radial direction of the rotary valve disc (15), an intake valve seat (29), an intake valve core (28), an intake valve spring (26) and an intake valve guide rod (27) are installed in each cylindrical hole, an intake valve fixing ring (14) is installed on the outer side of the intake valve guide rod (27), and the intake valve fixing ring (14) is installed on the rotary valve disc (15) through screws; cylindrical holes with the same number as the plungers (31) are uniformly formed in the axial circumference of the rotary valve disc (15), and an extrusion valve seat (25), an extrusion valve core (24), an extrusion valve spring (23) and an extrusion valve guide rod (22) are arranged in each cylindrical hole; the rotary valve disc (15) is connected with a rotary valve disc end cover (16) on the right side through a screw, an O-shaped sealing ring (17) is installed in the rotary valve disc (15) and the rotary valve disc end cover (16), the right side of the rotary valve disc end cover (16) is connected with a thrust disc (18), and the thrust disc (18) is installed on a rear end cover (19) through a screw. Two valve disc rotary seals (20) are arranged between the rotary valve disc (15) and the rear end cover (19), and two valve disc end cover rotary dynamic seals (21) are arranged between the rotary valve disc end cover (16) and the rear end cover (19).

Waist-shaped through flow grooves (6.1) with the same number as the connecting rods (35) are formed in the bottom of the connecting rod fixing disc (6), damping holes (6.2) are formed in the middles of the waist-shaped through flow grooves (6.1), bionic cylindrical pits are formed in the surfaces of the wear-resistant disc (39) and the thrust disc (18), the diameter of each pit is 0.3mm, the depth of each pit is 0.5mm, and the coverage rate of each pit is 10.48%. A plurality of water through holes (9.1) are uniformly distributed on the circumference of the shell (9), and a plurality of radial water through holes are arranged on the main shaft (1), so that communication, cooling circulation and lubrication of friction pairs of fluids in the hydraulic pump are realized.

The bottom and the excircle of the connecting rod fixing disc (6) are coated with nickel-based hard alloy, and the swash plate sliding bearing (5) and the wear-resistant disc (39) are both made of composite silicon-based engineering ceramics; the material of the inner ring (12) of the sliding bearing is integral nickel-based hard alloy, and the material of the outer ring (11) of the sliding bearing is composite silicon-based engineering ceramic; the bottom of the end cover (16) of the rotary valve disc, the excircle of the plunger (31), the ball head of the connecting rod (35) and the ball head of the plunger (31) are all coated with nickel-based hard alloy, and the thrust disc (18), the cylinder sleeve (30), the right ball socket (34) and the left ball socket (38) are all made of composite silicon-based engineering ceramic.

Compared with the prior art, the invention has the following beneficial effects.

1. The working mode of the rotary cylinder body valve flow distribution plunger pump is adopted, the problem of unbalanced swash plate movement caused by the existing swash plate rotary valve flow distribution plunger pump is avoided, and alternating impact load and vibration noise caused by unbalanced swash plate rotation are eliminated. The valve flow distribution mode is easy to realize high-pressure, the leakage of the flow distribution valve is small, and the pollution resistance of the flow distribution pair is greatly improved.

2. By adopting the novel return mechanism, a return spherical hinge friction pair which is easy to wear out and lose efficacy is cancelled, and the wave spring is adopted to ensure that the inclined block and the pressing ring are attached to the connecting rod fixing disc, thereby realizing the reliable return of the plunger. And through the reasonable design of the structural dimensions of the connecting rod fixing disc, the wear-resisting disc and the rotating valve disc end cover, the thrust disc, the axial thrust of the pump is balanced, the working load of the novel return mechanism is reduced, and the service life of the pump is prolonged.

3. The integral connecting rod fixing disc and the wear-resisting disc are adopted for opposite grinding, the wear-resisting disc is convenient to replace, the bionic pits are formed in the surface of the wear-resisting disc, the maintainability and the lubrication characteristics are improved, the swash plate-slipper pair of the traditional plunger pump is improved, the sliding bearing is arranged on the outer circle of the connecting rod fixing disc, the support of the connecting rod fixing disc and the swash plate is realized, the swash plate lateral force borne by the connecting rod fixing disc during working is effectively balanced, and the problems that the slipper pair is prone to overturning and wearing failure under high pressure in the traditional plunger pump are solved.

4. The novel connecting rod plunger structure is adopted, the ball head and the inner ball socket are respectively arranged at two ends of the connecting rod, open installation of the ball head structure is realized through the ball socket fixing ring and the connecting rod gland respectively, the processing technology is simplified, and the maintainability of the connecting rod plunger is improved; the ball head of the plunger is arranged outside the cylinder body, so that the lateral force of the plunger during working is effectively reduced, the problems of cylinder body overturning and plunger pair abrasion caused by overlarge lateral force of the plunger are avoided, and the overall structure is more compact.

5. The novel distribution valve arrangement mode is adopted, the suction valves are uniformly arranged along the radial direction of the rotary valve disc, the rotary centrifugal force can promote the opening of the suction valves during working, and the problem that the working medium is not sucked enough due to the rotation of the distribution valve is effectively avoided.

6. When the plunger type hydraulic pump works, low-pressure fluid is filled in the shell, all friction pairs can realize self-lubrication, key friction pairs are formed by matching and combining hard-hard materials of nickel-based hard alloy and composite silicon-based engineering ceramic, and the friction surfaces of the wear-resistant disc and the thrust disc are provided with bionic textures, so that the lubrication characteristic, the wear resistance, the corrosion resistance and the pollution resistance of the friction pairs under a high-pressure working condition are improved, the working pressure and the working reliability of the plunger type hydraulic pump are favorably improved, and the plunger type hydraulic pump is particularly suitable for deep-sea open seawater hydraulic systems.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the present invention;

FIG. 2 is a schematic front view of an integrated connecting rod holding pan and connecting rod plunger;

FIG. 3 is a schematic view of the reverse side of the integrated connecting rod fixing disk and connecting rod plunger;

fig. 4 is a schematic structural diagram of a bionic cylindrical pit on the surfaces of a wear-resistant disc and a thrust disc.

In the figure: 1. the main shaft, 2, a mechanical seal, 3, a front end cover, 4, a swash plate, 5, a swash plate sliding bearing, 6, a connecting rod fixing disc, 7, a swash block, 8, a return wave spring, 9, a housing, 10, a cylinder gland, 11, a sliding bearing outer ring, 12, a sliding bearing inner ring, 13, a cylinder, 14, a suction valve fixing ring, 15, a rotary valve disc, 16, a rotary valve disc end cover, 17, an O-shaped seal ring, 18, a thrust disc, 19, a rear end cover, 20, a valve disc rotary seal, 21, a valve disc end cover rotary seal, 22, a pressing valve guide rod, 23, a pressing valve spring, 24, a valve core pressing out, 25, a pressing valve seat, 26, a suction valve spring, 27, a suction valve guide rod, 28, a suction valve core, 29, a suction valve seat, 30, a cylinder sleeve, 31, a plunger, 32, a connecting rod gland, 33, a right ball socket fixing ring, 34, a right ball socket, 35, a connecting rod, 36, a pressing ring, 37, a left ball socket fixing ring, 38, a left ball socket, 39, a wear-resistant disc, 40, and a sealing gland.

Detailed Description

Embodiments of the present invention will now be described in more detail with reference to the accompanying figures 1-4 in some embodiments of the invention. It is obvious that the described embodiments are only a part of all embodiments of the invention. Other embodiments, which can be directly derived from or derived from the disclosure of the present invention, are within the scope of the present invention and are considered by those skilled in the art without inventive faculty.

The embodiment of the invention provides a self-lubricating connecting rod plunger type valve flow distribution hydraulic pump. As shown in fig. 1, the front cover 3 is connected to the housing 9 by screws, and the housing 9 is connected to the rear cover 19 by screws. The sealing gland 40 is arranged on the front end cover 3 through a screw and a positioning spigot, the mechanical seal 2 is arranged in the sealing gland 40, the swash plate 4 is fixed on the front end cover 3 through the positioning spigot and a positioning pin, and the wear-resistant plate 39 is arranged in the swash plate 4 in an interference fit manner; the surface of the wear-resisting disc 39 is provided with a bionic cylindrical pit, the right side surface of the wear-resisting disc 39 is connected with a connecting rod fixing disc 6, the excircle of the connecting rod fixing disc 6 is connected with a swash plate sliding bearing 5, left ball sockets 38 are uniformly distributed on the inner circumference of the connecting rod fixing disc 6, the left ball sockets 38 are connected with a connecting rod 35, a left ball socket fixing ring 37 is installed on the outer side of the left ball socket 38, the left side of a pressure ring 36 is tightly attached to the left ball socket fixing ring 37, the right side of the pressure ring 36 is tightly attached to an inclined block 7, the right side of the inclined block 7 is provided with a return wave spring 8, and the other end of the return wave spring is connected with a step of a shell 9; a right ball socket 34 is arranged on the right side of the connecting rod 35, the right ball socket 34 is connected with the ball head of the plunger 31, a right ball socket fixing ring 33 is arranged on the right side of the ball head of the plunger 31, a connecting rod gland 32 is arranged on the connecting rod 35 in an interference fit mode, and the connecting rod gland 32 is tightly attached to the right ball socket fixing ring 33; the main shaft 1 penetrates through the sealing gland 40, the mechanical seal 2 and the swash plate 4, the main shaft 1 is connected with the cylinder body 13 into a whole through keys, cylinder holes are uniformly distributed in the inner circumference of the cylinder body 13, the cylinder sleeve 30 is installed in the cylinder holes in an interference mode, and the plunger 31 is coaxially installed in the cylinder sleeve 30. The left side of cylinder body 13 is installed with cylinder body gland 10, and the excircle of cylinder body 13 is installed with slide bearing inner ring 12, and cylinder liner 30 and slide bearing inner ring 12 are spacing with cylinder body gland 10. A sliding bearing outer ring 11 is arranged on the excircle of the sliding bearing inner ring 12, and the sliding bearing outer ring 11 is arranged in the inner hole of the shell 9 in an interference manner; the rotary valve disc 15 is fixedly connected with the cylinder body 13 through a screw, cylindrical holes with the same number as the plungers 31 are uniformly formed in the radial direction of the rotary valve disc 15, an intake valve seat 29, an intake valve core 28, an intake valve spring 26 and an intake valve guide rod 27 are installed in each cylindrical hole, an intake valve fixing ring 14 is installed on the outer side of the intake valve guide rod 27, and the intake valve fixing ring 14 is installed on the rotary valve disc 15 through a screw; cylindrical holes with the same number as the plungers 31 are formed in the axial uniform circumference of the rotary valve disc 15, and a pressing valve seat 25, a pressing valve core 24, a pressing valve spring 23 and a pressing valve guide rod 22 are installed in each cylindrical hole; the rotary valve disc 15 is connected with a rotary valve disc end cover 16 on the right side through screws, an O-shaped sealing ring 17 is installed inside the rotary valve disc 15 and the rotary valve disc end cover 16, the right side of the rotary valve disc end cover 16 is connected with a thrust disc 18, and the thrust disc 18 is installed on a rear end cover 19 through screws. Two valve disc rotary seals 20 are arranged between the rotary valve disc 15 and the rear end cover 19, and two valve disc end cover rotary seals 21 are arranged between the rotary valve disc end cover 16 and the rear end cover 19. The bottom of the connecting rod fixing disc 6 is provided with waist-shaped through flow grooves 6.1 the number of which is the same as that of the connecting rods 35, the middle of each waist-shaped through flow groove 6.1 is provided with a damping hole 6.2, the surfaces of the wear-resisting disc 39 and the thrust disc 18 are provided with bionic cylindrical pits, the diameter of each pit is 0.3mm, the depth of each pit is 0.5mm, and the coverage rate of each pit is 10.48%.

The invention relates to a connecting rod-plunger implementation mode: as shown in fig. 1-3, the left side of the connecting rod 35 is a ball head, the connecting rod ball head is matched with the left ball socket 38, the left ball socket fixing ring 37 is pressed against the connecting rod ball head and the left ball socket 38 under the action of the pressing ring 36, the right side of the connecting rod 35 is a cylindrical hole, the right ball socket 34 is arranged in the cylindrical hole, the plunger ball head is arranged in the right ball socket 34, and the plunger ball head is tightly attached to the right ball socket 34 under the limit of the right ball socket fixing ring 33 and the connecting rod pressing cover 32. The connecting rod plunger is installed in an open mode during assembling, processes such as rolling, ball wrapping and the like are omitted, all related parts can be detached when the pump is overhauled, parts are abraded, then the parts are convenient to replace, and maintainability is greatly improved.

The friction pair material of the invention has the following matching mode: the bottom and the excircle of the connecting rod fixing disc 6 are coated with nickel-based hard alloy, and the swash plate sliding bearing 5 and the wear-resistant disc 39 are both made of composite silicon-based engineering ceramics; the material of the inner ring 12 of the sliding bearing is integral nickel-based hard alloy, and the material of the outer ring 11 of the sliding bearing is composite silicon-based engineering ceramic; the bottom of the end cover 16 of the rotary valve disc, the excircle of the plunger 31, the ball head of the connecting rod 35 and the ball head of the plunger 31 are all coated with nickel-based hard alloy, and the thrust disc 18, the cylinder sleeve 30, the right ball socket 34 and the left ball socket 38 are all made of composite silicon-based engineering ceramics. If the spraying process is changed into a forming process or a technical means such as surfacing, embedding and the like, the method belongs to the protection scope of the invention.

The friction pair self-lubricating realization mode of the invention is as follows: as shown in fig. 1 and 2, the housing 9 has a plurality of axial through holes formed in a step thereof, and the main shaft 1 has a plurality of radial through holes formed therein. When the pump is operated, fluid flows into the pump from the suction port, so that the inside of the cavity of the entire housing 9 is filled with the fluid. When the plunger 31 moves from the bottom dead center to the top dead center of the swash plate, the volume of the plunger cavity is changed from small to large, negative pressure is formed in the plunger cavity, the suction valve core 28 is opened, so that fluid in the pump shell 9 enters the plunger cavity, and the suction process of the fluid is started; when the plunger 31 moves from the top dead center to the bottom dead center of the swash plate, the volume of the plunger cavity is reduced, the fluid in the plunger cavity is compressed and the pressure is increased, the extruding valve core 24 is opened, and the fluid discharging process is started. When the pump works, low-pressure fluid in the shell 9 enters the plunger cavity through the suction valve and is discharged through the extrusion valve, and the low-pressure fluid is continuously supplemented from the suction port of the pump, so that a flowing circulation effect of the fluid in the shell 9 is formed, heat generated when each friction pair works is taken away, and self-lubrication and cooling of the friction pairs are facilitated.

The invention relates to a realization mode of a cylinder body rotation-valve flow distribution working mode, which comprises the following steps: as shown in fig. 1, the suction valve is arranged on the rotary valve disc 16 in the radial direction, the cylinder 13 and the rotary valve disc 16 are driven by the main shaft 1 to rotate, and the centrifugal force generated by the rotation of the suction valve core 28 is consistent with the opening direction of the valve core by controlling the steering direction of the main shaft 1, so that the suction performance of the suction valve is improved. The same number of extrusion valves are vertically arranged near the suction valve and are arranged along the central circumference of the rotary valve disc 16, and after the extrusion valve core 24 is opened by high-pressure fluid in the plunger cavity, the high-pressure fluid is converged to an extrusion opening of the rear end cover through an internal flow passage of the rotary valve disc 16 and is discharged out of the pump, so that the liquid discharging process is completed. Therefore, the valve flow distribution hydraulic pump works in the cylinder body rotation mode, and the liquid suction performance of the pump cannot be influenced. The problem of dynamic unbalance of the traditional valve flow distribution axial plunger pump caused by the rotation of the swash plate is avoided.

A self-lubricating connecting rod plunger type valve distribution hydraulic pump is shown in figures 1-4, and the complete working process is as follows: before the pump is started, low-pressure fluid flows into the cavity of the rotary valve disc 15 from the suction inlet, and uniformly fills the cavity of the shell through an axial water through hole 9.1 of the shell 9 and a radial water through hole on the main shaft 1; when the main shaft 1 of the pump is driven by an external motor to rotate at a high speed, the main shaft 1 drives the cylinder body 13, the rotary valve disc 15 and the rotary valve disc end cover 16 to rotate, and the centrifugal force generated when the suction valve core 28 rotates is consistent with the opening direction of the valve core. Under the action of the return wave spring 8, the inclined block 7 and the pressing ring 36 tightly press the connecting rod fixing disc 6, so that the connecting rod fixing disc 6 is tightly attached to the wear-resisting disc 39, and the return stroke of the plunger 31 is realized; high-pressure fluid in the plunger cavity flows into the bionic cylindrical pits on the surface of the wear-resistant disc through the damping holes 6.2 and the waist-shaped through flow grooves 6.1 on the connecting rod fixing disc to form static pressure support, so that the lubricating property of the connecting rod fixing disc-wear-resistant disc friction pair is improved. When the plunger 31 moves from the bottom dead center to the top dead center of the swash plate, the volume of the plunger cavity is changed from small to large, negative pressure is formed in the plunger cavity, the suction valve core 28 is opened under the combined action of the negative pressure and centrifugal force, fluid in the pump shell enters the plunger cavity, the suction process of the fluid is started until the plunger 31 moves to the top dead center, and the liquid suction process is finished; when the plunger 31 moves from the top dead center to the bottom dead center of the swash plate, the volume of the plunger cavity is reduced, the fluid in the plunger cavity is compressed and the pressure is increased, the extruding valve core 24 is opened, the fluid discharging process is started until the plunger 31 moves to the bottom dead center, and the fluid discharging process is finished.

Claims

1. A self-lubricating connecting rod plunger type valve flow distribution hydraulic pump is characterized in that: a wear-resistant disc (39) is arranged in the swash plate (4) in an interference manner;

the surface of the wear-resisting disc (39) is provided with a bionic cylindrical pit, the right side surface of the wear-resisting disc (39) is connected with a connecting rod fixing disc (6), the excircle of the connecting rod fixing disc (6) is connected with a swash plate sliding bearing (5), left ball sockets (38) are uniformly distributed on the inner circumference of the connecting rod fixing disc (6), the left ball sockets (38) are connected with a connecting rod (35), a left ball socket fixing ring (37) is installed on the outer side of the left ball socket (38), the left side of a pressing ring (36) is tightly attached to the left ball socket fixing ring (37), the right side of the pressing ring (36) is tightly attached to an inclined block (7), a return wave spring (8) is installed on the right side of the inclined block (7), and the other end of the return wave spring is connected with a step of a shell (9);

a right ball socket (34) is arranged on the right side of the connecting rod (35), the right ball socket (34) is connected with the ball head of the plunger (31), a right ball socket fixing ring (33) is arranged on the right side of the ball head of the plunger (31), a connecting rod gland (32) is arranged on the connecting rod (35) in an interference fit mode, and the connecting rod gland (32) is tightly attached to the right ball socket fixing ring (33); the rotary valve disc (15) is fixedly connected with the cylinder body (13) through screws, cylindrical holes with the same number as the plungers (31) are uniformly formed in the radial direction of the rotary valve disc (15), an intake valve seat (29), an intake valve core (28), an intake valve spring (26) and an intake valve guide rod (27) are installed in each cylindrical hole, an intake valve fixing ring (14) is installed on the outer side of the intake valve guide rod (27), and the intake valve fixing ring (14) is installed on the rotary valve disc (15) through screws; cylindrical holes with the same number as the plungers (31) are uniformly formed in the axial circumference of the rotary valve disc (15), and a pressing valve seat (25), a pressing valve core (24), a pressing valve spring (23) and a pressing valve guide rod (22) are installed in each cylindrical hole;

the rotary valve disc (15) is connected with a rotary valve disc end cover (16) on the right side through a screw, an O-shaped sealing ring (17) is installed in the rotary valve disc (15) and the rotary valve disc end cover (16), the right side of the rotary valve disc end cover (16) is connected with a thrust disc (18), and the thrust disc (18) is installed on a rear end cover (19) through a screw; two valve disc rotary seal (20) are arranged between the rotary valve disc (15) and the rear end cover (19), and two valve disc end cover rotary seal (21) are arranged between the rotary valve disc end cover (16) and the rear end cover (19); a plurality of water through holes (9.1) are uniformly distributed on the upper circumference of the shell (9), and a plurality of radial water through holes are arranged on the main shaft (1), so that communication and cooling circulation of fluid in the hydraulic pump are realized.

2. The self-lubricating connecting rod plunger type valve port hydraulic pump as set forth in claim 1, wherein: the front end cover (3) is connected with the shell (9) through a screw, and the shell (9) is connected with the rear end cover (19) through a screw; the sealing gland (40) is arranged on the front end cover (3) through a screw and a positioning spigot, the mechanical seal (2) is arranged in the sealing gland (40), and the swash plate (4) is fixed on the front end cover (3) through the positioning spigot and a positioning pin; the main shaft (1) penetrates through the sealing gland (40), the mechanical seal (2) and the swash plate (4), the main shaft (1) is connected with the cylinder body (13) into a whole through keys, cylinder holes are uniformly distributed on the inner circumference of the cylinder body (13), the cylinder sleeve (30) is installed in the cylinder holes in an interference mode, and the plunger (31) is coaxially installed in the cylinder sleeve (30); a cylinder body gland (10) is installed on the left side of the cylinder body (13), a sliding bearing inner ring (12) is installed on the excircle of the cylinder body (13), and the cylinder sleeve (30) and the sliding bearing inner ring (12) are limited by the cylinder body gland (10); the outer circle of the sliding bearing inner ring (12) is provided with a sliding bearing outer ring (11), and the sliding bearing outer ring (11) is arranged in the inner hole of the shell (9) in an interference manner.

3. The self-lubricating connecting rod plunger type valve port hydraulic pump as set forth in claim 1, wherein:

the bottom of the connecting rod fixing disc (6) is provided with waist-shaped through flow grooves (6.1) with the same number as the connecting rods (35), the middle of each waist-shaped through flow groove (6.1) is provided with a damping hole (6.2), the surfaces of the wear-resistant disc (39) and the thrust disc (18) are provided with bionic cylindrical pits, the diameter of each pit is 0.3mm, the depth of each pit is 0.5mm, and the coverage rate of each pit is 10.48%.

4. The self-lubricating connecting rod plunger type valve port hydraulic pump as set forth in claim 1, wherein: the bottom and the excircle of the connecting rod fixing disc (6) are coated with nickel-based hard alloy, and the swash plate sliding bearing (5) and the wear-resistant disc (39) are both made of composite silicon-based engineering ceramics; the material of the inner ring (12) of the sliding bearing is integral nickel-based hard alloy, and the material of the outer ring (11) of the sliding bearing is composite silicon-based engineering ceramic; the bottom of the end cover (16) of the rotary valve disc, the excircle of the plunger (31), the ball head of the connecting rod (35) and the ball head of the plunger (31) are all coated with nickel-based hard alloy, and the thrust disc (18), the cylinder sleeve (30), the right ball socket (34) and the left ball socket (38) are all made of composite silicon-based engineering ceramic.