A full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation

Abstract

A full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation relates to the field of positive displacement pumps. The device is provided with a throttling damping hole on the distribution plate, and a cavity of set volume connected to the throttling damping hole is provided on the rear end cover, and an anti-shock valve assembly and a forced lubrication structure are added, wherein the anti-shock valve assembly is arranged on the cylinder rotating assembly, and the anti-shock valve assembly, plunger filler, pre-compression cavity and other structural arrangements are used to greatly reduce the operating noise of the water hydraulic pump and expand the application range of the water hydraulic axial piston pump; the set forced lubrication structure introduces the high-pressure water at the pump discharge port through the front and rear throttles into the friction surface of the pump away from the inlet for full lubrication, thereby avoiding cavitation, dry friction and burning of the disc.

Description

Technical Field

[0001] The invention relates to the field of positive displacement pumps, and in particular to a full-water-lubricated low-noise water hydraulic axial piston pump capable of operating under negative pressure. Background Art

[0002] In recent years, water hydraulic transmission and control technology, which directly uses water (filtered natural water, including seawater and fresh water) instead of mineral oil as the working medium, has made breakthrough progress. In a wide range of engineering applications, it has been proven to be environmentally friendly, clean, efficient, easy to use and maintain, and low in operating costs compared to traditional oil hydraulic transmission. Water hydraulic transmission and control technology has been widely used in high-pressure water atomization, seawater desalination, high-pressure water cleaning, stage drive and control, submersible buoyancy adjustment system, marine engineering and other transmission and control fields.

[0003] Water hydraulic axial piston pumps have become the most commonly used water hydraulic pumps in water hydraulic transmission and control systems due to their outstanding advantages such as high speed, high pressure, large flow, small flow pulsation, compact size and light weight. Limited by technological development, the water hydraulic axial piston pump products currently reported on the market are all fixed displacement pumps, such as the Danish Danfoss series of sea and fresh water pumps, the British WaterHydrulic series of sea and fresh water pumps, the axial piston pumps developed by Huazhong University of Science and Technology, the pure water pumps developed by Zhejiang University, the fresh water pumps of Hubei Renchuang Technology Co., Ltd., and the water hydraulic pumps of Wuxi Huaxin Kechuang Technology Co., Ltd.

[0004] When the axial piston pump uses the working medium as the lubricating medium and the suction port is under negative pressure, the lubricating medium in the pump cavity will be sucked out. Although the shaft outlet uses a mechanical seal, it still cannot avoid air inhalation. After the air enters the cavity, the friction surface will cavitate, and even dry friction sintering will suddenly fail, causing serious failures. In oil pressure axial piston pumps, this phenomenon is not very prominent due to the excellent lubrication performance of oil, but it is particularly prominent in water pumps that directly use water as the lubricating medium. Axial piston water pumps generally require a positive pressure at the inlet. For example, the Danish Danfoss company's series of seawater pumps clearly require an inlet pressure of 5 bar, and the water hydraulic pumps of Wuxi Huaxin Science and Technology Co., Ltd. require positive pressure water inlet. Under negative pressure conditions, an imported water supply pump is set to meet the pump inlet requirements, making the system application more complicated.

[0005] Noise is a manifestation of energy loss. Noise directly affects the surrounding working environment. The noise value of a water hydraulic pump using water as a lubricating medium is generally 85-90dB (A). It is difficult for people to bear this kind of noise for a long time under such working conditions. This noise has also become an obstacle that directly affects the development and application of water hydraulic technology. At the same time, if people are on duty for a long time in the pump room of a water hydraulic drive stage project, their hearing will be impaired and even other occupational diseases will occur. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation.

[0007] The technical solution adopted by the present invention is: a full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation, the technical key points of which are: comprising a rear end cover, a distribution plate, a cylinder rotating assembly, a housing, a sliding bearing, a plunger sliding shoe assembly, a return plate, a swash plate, a front end cover and a main shaft;

[0008] The rear end cover and the front end cover are respectively fixedly mounted on the two ends of the shell, and the distribution plate, the cylinder rotating assembly, the return plate and the swash plate are installed in the shell in sequence, wherein the distribution plate is fixedly mounted on the rear end cover, the distribution plate is provided with a throttling damping hole, and the rear end cover is provided with a cavity of a set volume, and the throttling damping hole is connected with the cavity; the cylinder rotating assembly is movably mounted on the inner wall of the shell, the plunger slipper assembly is movably mounted in the cylinder rotating assembly, and the spherical plunger end of the plunger slipper assembly is movably assembled on the swash plate, one end of the swash plate is connected to the front end cover, and the other end of the swash plate is connected to the return plate, the main shaft is movably assembled on the front end cover, and is transmission-connected to the cylinder rotating assembly.

[0009] In the above scheme, the plunger of the plunger shoe assembly is a hollow metal structure filled with nylon.

[0010] In the above scheme, the anti-shock valve assembly includes a guide rod, an anti-shock valve core, an anti-shock valve spring and an anti-shock valve throttling damper. The left chamber of the anti-shock valve and the right chamber of the anti-shock valve are located on both sides of the anti-shock valve core. The guide rod is fixedly installed in the flow channel of the cylinder rotating assembly. The anti-shock valve core slides on the guide rod and abuts against one end of the anti-shock valve spring. The other end of the anti-shock valve spring abuts against the inner wall of the cylinder hole of the cylinder rotating assembly. The anti-shock valve throttling damper is fixedly installed at the junction of the right chamber of the anti-shock valve and the inner chamber of the cylinder rotating assembly.

[0011] In the above scheme, the forced lubrication structure includes a first flow channel arranged on the rear end cover, a second flow channel arranged on the shell, a third flow channel arranged on the front end cover, a forced lubrication front throttle and a forced lubrication rear throttle, the forced lubrication front throttle is fixedly installed on the shell, and the forced lubrication rear throttle is installed on the front end cover, the first flow channel and the second flow channel are connected to the inner cavity of the cylinder rotating assembly through the forced lubrication front throttle, and the first flow channel and the second flow channel are sealed and connected to each other with the third flow channel through the forced lubrication rear throttle.

[0012] In the above scheme, the guide rod material is stainless steel, nickel-copper alloy or titanium alloy, and the impact-resistant valve core material is engineering plastic PEEK or engineering plastic PTFE.

[0013] In the above scheme, the left chamber of the anti-shock valve is connected to the plunger chamber of the plunger sliding shoe assembly.

[0014] In the above scheme, the number of the anti-shock valve assemblies is the same as the number of the plunger shoe assemblies, and the plunger cavity of the plunger shoe assembly is communicated with the corresponding anti-shock valve assembly.

[0015] In the above scheme, the number of plunger shoe assemblies is odd.

[0016] The beneficial effects of the present invention are as follows: the fully water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation is provided with a throttling damping hole on the distribution plate, and a cavity of a set volume connected to the throttling damping hole is provided on the rear end cover, and an anti-shock valve assembly and a forced lubrication structure are added, wherein the anti-shock valve assembly is arranged on the cylinder rotating assembly, and the anti-shock valve assembly, plunger filler, pre-compression cavity and other structural arrangements greatly reduce the operating noise of the water hydraulic pump, and expand the application range of the water hydraulic axial piston pump; the set forced lubrication structure introduces the high-pressure water at the pump discharge port into the friction surface of the pump away from the inlet through the front and rear throttles for sufficient lubrication, thereby avoiding cavitation, dry friction and disc burning. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a cross-sectional view of a full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation in an embodiment of the present invention;

[0019] Figure 2 Schematic diagram of the throttling damping hole structure in an embodiment of the present invention;

[0020] The serial numbers in the figure are explained as follows: 1 rear end cover, 1-1 flow passage, 2 distribution plate, 2-1 throttling damping hole, 3 cylinder rotating assembly, 3-1 flow passage, 4 housing, 4-1 flow passage, 5 sliding bearing, 6 plunger shoe assembly, 7 return plate, 8 inclined plate, 9 mechanical seal, 10 front end cover, 10-1 flow passage, 11 main shaft, 12 guide rod, 13 anti-shock valve core, 14 anti-shock valve spring, 15 anti-shock valve throttling damper, 16 forced lubrication front throttle, 17 forced lubrication rear throttle. DETAILED DESCRIPTION

[0021] To make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the following is a brief description of the present invention in conjunction with the attached Figure 1 and Figure 2The present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

[0022] The fully water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation adopted in this embodiment comprises a rear end cover 1, a distributor plate 2, a cylinder rotating assembly 3, a housing 4, a sliding bearing 5, an odd number of plunger shoe assemblies 6, a return plate 7, a swash plate 8, a mechanical seal 9, a front end cover 10, a main shaft, an anti-shock valve assembly and a forced lubrication structure. The rear end cover 1 and the front end cover 10 are respectively fixedly mounted on both ends of the housing 4, the distributor plate 2 is mounted on the rear end cover 1 and is located in the housing 4. One end of the return plate 7 is mounted on the front end cover 10, and the swash plate 8 is mounted on the other end of the return plate 7. The cylinder rotating assembly 3 is movably mounted on the inner wall of the housing 4 through the sliding bearing 5 and is located between the distributor plate 2 and the swash plate 8. The plunger shoe assembly 6 is movably mounted in the cylinder rotating assembly 3, and the spherical plunger end of the plunger shoe assembly 6 is movably assembled on the swash plate 8. The main shaft is movably assembled on the front end cover 10 and is transmission-connected with the cylinder rotating assembly 3. In this embodiment, the plunger of the plunger shoe assembly 6 is a hollow metal structure, filled with nylon or other similar engineering plastics, and provided with a flow hole. The distribution plate 2 is provided with a throttling damping hole 2-1, and the rear end cover 1 is provided with a chamber A of a set volume, and the throttling damping hole 2-1 is connected to the chamber A.

[0023] The anti-shock valve assembly also includes a guide rod 12, an anti-shock valve core 13, an anti-shock valve spring 14, and an anti-shock valve throttle damper 15, wherein the guide rod 12 is made of reinforced stainless steel, nickel-copper alloy or titanium alloy, and the anti-shock valve core 13 is made of engineering plastic PEEK or engineering plastic PTFE. A flow passage 3-1 is provided on the cylinder rotating assembly 3, and the plunger cavity and the left cavity of the anti-shock valve are connected through the flow passage 3-1. The right cavity of the anti-shock valve is connected to the inner cavity of the pump body through the anti-shock valve throttle damper 15.

[0024] The guide rod 12 of the anti-shock valve assembly is fixedly mounted on the cylinder rotating assembly 3 by means of threads, the anti-shock valve core 13 is sleeved and slid on the guide rod 12 and abuts against one end of the anti-shock valve spring 14, and the other end of the anti-shock valve spring 14 abuts against the inner wall of the cylinder rotating assembly 3. The anti-shock valve throttling damper 15 is fixedly mounted on the cylinder rotating assembly 3 by means of threads.

[0025] The forced lubrication structure mainly comprises a flow passage 1-1 arranged on the rear end cover, a flow passage 4-1 arranged on the housing, a flow passage 10-1 arranged on the front end cover, a forced lubrication front throttle 16 and a forced lubrication rear throttle 17. The forced lubrication front throttle 16 is fixedly installed on the housing 4 by threads, and the forced lubrication rear throttle 17 is installed on the front end cover 10 by a tight fit.

[0026] The pump drain port is connected through the flow channel 1-1 on the rear end cover 1, the flow channel 4-1 on the housing 4, the forced lubrication front throttle 16, the plunger slipper assembly 6 in the pump chamber and the chamber near the friction surface of the swash plate 8; the pump drain port is connected through the flow channel 1-1 on the rear end cover 1, the flow channel 4-1 on the housing 4, the forced lubrication rear throttle 17 and the flow channel 10-1 installed on the front end cover 10.

[0027] The number of the anti-shock valve assemblies arranged on the cylinder rotating assembly 3 is the same as the number of the plungers of the plunger sliding shoe assembly, and is 5, 7 or 9, and each plunger chamber is communicated with the corresponding anti-shock valve assembly.

[0028] The working process of the full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation provided by the present invention is as follows:

[0029] In the initial working state, the main shaft 11 rotates, driving the cylinder rotating assembly 3 and the plunger sliding shoe assembly 6 to rotate. The plunger sliding shoe assembly 6 reciprocates in the cylinder hole of the cylinder rotating assembly 3 through the interaction with the swash plate 8. For each rotation of the cylinder rotating assembly 3, the plunger reciprocates in the cylinder hole once. Through the interaction between the cylinder rotating assembly 3 and the port plate 2, each group of plunger sliding shoe assemblies 6 completes a water absorption and drainage process.

[0030] The fluid noise of the plunger pump mainly comes from the backflow of flow during the high-low pressure switching process. When the pump is working normally, the plunger cavity is filled with high-pressure water and negative-pressure water with alternating pressure changes.

[0031] During the plunger drainage and pressurization process, high-pressure water flows to the left chamber of the anti-shock valve assembly through 3-1, and the anti-shock valve core 13 compresses the anti-shock valve spring 14 under the action of high-pressure water. The water in the right chamber of the anti-shock valve flows to the inner chamber of the pump body through the anti-shock valve throttling damper 15 until the maximum pressure is reached; during the plunger water absorption process, the plunger chamber is under negative pressure, and the anti-shock valve core 13, under the action of the spring, pushes the water in the left chamber of the anti-shock valve to the plunger chamber, thereby compensating the plunger chamber and reducing noise.

[0032] When the pump is in motion and distributing flow, the highest point of the swash plate is the high-low pressure switching area, which is the theoretical dead point of the flow distribution and the highest pressure point in the plunger chamber. During the switching process to the lowest point, the area with the largest flow backflow is located here. When switching between high and low pressures, a pre-compression chamber A with a set volume is set on the rear cover 1 of the pump, and each plunger chamber is pre-compressed. Practice has proved that this scheme can effectively reduce the operating noise of the pump.

[0033] The hollow design of the plunger cavity reduces weight, reduces motion inertia, and reduces noise. At the same time, in order to reduce the volume of the alternating chamber, nylon or similar lightweight plastic materials are set inside to further reduce the operating noise of the pump body.

[0034] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation, characterized in that: It comprises a rear end cover (1), a valve plate (2), a cylinder body rotating assembly (3), a housing (4), a sliding bearing (5), a plunger sliding shoe assembly (6), a return plate (7), a swash plate (8), a front end cover (10) and a main shaft (11); The rear end cover (1) and the front end cover (10) are respectively fixedly mounted on the two ends of the housing (4), and the housing (4) is provided with a distribution plate (2), a cylinder rotating assembly (3), a return plate (7) and a swash plate (8) in sequence, wherein the distribution plate (2) is fixedly mounted on the rear end cover (1), a throttling damping hole (2-1) is provided on the distribution plate (2), and a chamber (A) of a set volume is provided on the rear end cover (1), and the throttling damping hole (2-1) is communicated with the chamber (A). The cylinder rotating assembly (3) is movably mounted on the inner wall of the housing (4); the plunger sliding shoe assembly (6) is movably mounted in the cylinder rotating assembly (3); and the spherical plunger end of the plunger sliding shoe assembly (6) is movably mounted on the swash plate (8); one end of the swash plate (8) is connected to the front end cover (10); the other end of the swash plate (8) is connected to the return plate (7); the main shaft (11) is movably mounted on the front end cover (10) and is drivingly connected to the cylinder rotating assembly (3); The plunger of the plunger shoe assembly (6) is a hollow metal structure filled with nylon; The invention also includes an anti-shock valve assembly, the anti-shock valve assembly including a guide rod (12), an anti-shock valve core (13), an anti-shock valve spring (14) and an anti-shock valve throttling damper (15), the left anti-shock valve chamber and the right anti-shock valve chamber being located on both sides of the anti-shock valve core (13), the guide rod (12) being fixedly mounted in a flow passage (3-1) of a cylinder rotating assembly (3), the anti-shock valve core (13) being sleeved and slidably mounted on the guide rod (12) and abutting against one end of the anti-shock valve spring (14), the other end of the anti-shock valve spring (14) abutting against the inner wall of the cylinder hole of the cylinder rotating assembly (3), and the anti-shock valve throttling damper (15) being fixedly mounted at the junction of the right anti-shock valve chamber and the inner chamber of the cylinder rotating assembly (3).

2. The full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation as claimed in claim 1, characterized in that: The forced lubrication structure comprises a first flow passage (1-1) arranged on the rear end cover (1), a second flow passage (4-1) arranged on the housing (4), a third flow passage (10-1) arranged on the front end cover (10), a forced lubrication front throttle (16) and a forced lubrication rear throttle (17), wherein the forced lubrication front throttle (16) is fixedly mounted on the housing (4), and the forced lubrication rear throttle (17) is mounted on the front end cover (10), the first flow passage (1-1) and the second flow passage (4-1) are connected to the inner cavity of the cylinder rotating component (3) through the forced lubrication front throttle (16), and the first flow passage (1-1) and the second flow passage (4-1) are sealed and connected to the third flow passage (10-1) through the forced lubrication rear throttle (17).

3. The full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation as claimed in claim 1 or 2, characterized in that: The guide rod (12) is made of stainless steel, nickel-copper alloy or titanium alloy, and the impact-resistant valve core (13) is made of engineering plastic PEEK or engineering plastic PTFE.

4. The full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation as claimed in claim 1 or 2, characterized in that: The left chamber of the anti-shock valve is in communication with the plunger chamber of the plunger sliding shoe assembly (6).

5. The full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation as claimed in claim 1 or 2, characterized in that: The number of the anti-shock valve assemblies is the same as the number of the plunger sliding shoe assemblies (6), and the plunger cavity of the plunger sliding shoe assembly (6) is in communication with the corresponding anti-shock valve assembly.

6. The full water-lubricated low-noise water hydraulic axial piston pump capable of negative pressure operation as claimed in claim 5, characterized in that: The plunger sliding shoe assemblies (6) are an odd number.

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