CN116123051B

CN116123051B - High-flow double-motion freedom degree water hydraulic piston pump

Info

Publication number: CN116123051B
Application number: CN202211711898.4A
Authority: CN
Inventors: 王灵锋; 潘成剑; 黄叶青; 孙健博; 郭明; 关成启
Original assignee: Beijing Aerospace Technology Institute
Current assignee: Beijing Aerospace Technology Institute
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2024-08-06
Anticipated expiration: 2042-12-29
Also published as: CN116123051A

Abstract

The invention provides a high-flow double-freedom-degree water hydraulic piston pump, which solves the problems of the existing water hydraulic piston pump and comprises a pump shell, a pump core assembly and a transmission through shaft, wherein the pump shell comprises a front end cover, a pump shell and a rear end cover which are sequentially and coaxially arranged along an axis, the transmission through shaft is arranged in the pump shell, the pump cores comprise a first pump core and a second pump core, the first pump core and the second pump core have the same structure and comprise baffle-type pistons, and the baffle-type pistons comprise: the hollow cylinder with two openings at the two ends, the baffle and the plunger shaft are arranged in the hollow cylinder and are connected with the inner wall of the hollow cylinder along the circumferential direction of the inner wall of the hollow cylinder, the baffle separates the inner cavity of the hollow cylinder into a first cavity and a second cavity along the axial direction of the hollow cylinder, the baffle is arranged on the plunger shaft in a penetrating mode, the plunger shaft is provided with an inner cavity, the axes of the baffle, the hollow cylinder and the plunger shaft are overlapped, and a plurality of water distribution ports are uniformly distributed in the circumferential direction of the hollow cylinder part a corresponding to the first cavity and the circumferential direction of the hollow cylinder part b corresponding to the second cavity.

Description

High-flow double-motion freedom degree water hydraulic piston pump

Technical Field

The invention belongs to the technical field of fluid machinery, relates to a high-flow double-motion-degree-of-freedom water hydraulic piston pump, in particular to a high-flow double-motion-degree-of-freedom baffle-type water hydraulic piston pump, and is suitable for high-flow working conditions with water as a working medium.

Background

A pump is an energy conversion device that converts mechanical energy into fluid pressure energy, and is typically used to output high pressure fluid. In the conventional pumps such as a common piston type pump, a vane type pump, a gear type pump and a screw type pump, the kinematic pair of the mechanical structure of the pump is mainly in a sliding friction mode in the working process, so that a large amount of friction energy loss is generated, the shape of parts is complex, and the processing cost is high.

The piston pump with double degrees of freedom of movement integrally designs the shaft and the piston, realizes continuous water suction and drainage by utilizing the principle of double degrees of freedom of motion of circumferential rotation and axial reciprocation of the piston, and omits a valve plate structure of the traditional piston pump. Meanwhile, a symmetric cam roller structure is adopted to replace a slipper swashplate structure, the original sliding friction pair is changed into rolling friction, and the symmetric stress structure ensures that the piston is not stressed in the radial direction, so that two friction pairs of the piston, a cylinder body and a valve plate are omitted, the pump efficiency is higher, and the restriction of the sliding friction pair on the pump performance and the like is broken through.

In the application occasions of large-flow water hydraulic pressure, a single-stage or multi-stage centrifugal pump is generally adopted, the centrifugal pump converts mechanical energy into kinetic potential energy of a working medium, the kinetic potential energy is converted into hydraulic energy, and the energy conversion rate is low. When the existing double-freedom-degree groove type piston pump is adopted, most of mechanical energy can be converted into hydraulic energy, but as the piston is positioned at the inner side of the cylinder body and rotates at a high speed, the flow resistance of the piston is larger, the centrifugal potential energy of liquid in the piston cavity hinders the suction process of working medium, the working medium can be sucked only by needing larger inlet pressure, and the hydraulic flow loss in the pump is serious; the existing structure has the problems of small flow distribution window, short flow distribution process time, overlarge flow velocity of working medium, easy occurrence of cavitation and the like.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art.

Therefore, the invention provides the high-flow double-freedom-degree water hydraulic piston pump.

The technical scheme of the invention is as follows: the utility model provides a high-flow two degree of freedom water hydraulic piston pump, this piston pump includes pump housing, pump core subassembly and transmission through axle, and the pump housing includes front end housing, pump housing and the rear end cap that sets gradually coaxial along the axis, and front end housing, pump housing and rear end cap link firmly and form the pump housing structure, the transmission through axle sets up in the pump housing, the pump core includes first pump core and second pump core, and first pump core and second pump core are according to certain phase angle, relative series connection install on the transmission through axle, wherein, first pump core and second pump core structure are the same, all include baffle type piston, baffle type piston includes: the hollow cylinder is arranged in the hollow cylinder, the baffle is connected with the inner wall of the hollow cylinder along the circumferential direction of the inner wall of the hollow cylinder, the inner cavity of the hollow cylinder is divided into a first cavity and a second cavity along the axial direction of the hollow cylinder by the baffle, the baffle is arranged on the plunger shaft in a penetrating way, the plunger shaft is provided with an inner cavity, the axes of the baffle, the hollow cylinder and the plunger shaft are coincided, and a plurality of water distribution ports are uniformly distributed along the circumferential direction of a hollow cylinder part a corresponding to the first cavity; the circumference of the hollow cylinder part b corresponding to the second cavity is also uniformly provided with a plurality of water distribution ports, and the transmission through shaft is also rotatably arranged in the inner cavity of the plunger shaft of the two baffle type pistons.

Further, the water distribution port on the hollow cylinder part a extends from one end of the hollow cylinder part a to the free end of the hollow cylinder part a; the water distribution opening on the hollow cylinder part b extends from one end of the hollow cylinder part b to the free end of the hollow cylinder part b.

Further, 2 water distribution ports are formed in the hollow cylinder part a, 2 water distribution ports are formed in the hollow cylinder part b, and two pairs of water distribution ports are orthogonally arranged.

Further, the end face of any water distribution port is designed to be a chamfer.

Further, the baffle has a radius greater than an inner diameter of the plunger shaft.

Further, the baffle is a circular baffle, and the hollow cylinder is a hollow cylinder.

Further, the baffle, the hollow cylinder and the plunger shaft are of an integrated structure.

Further, the first and second pump cores also each include a cam rail, a support bushing, a cylinder, a seal bushing, and a roller frame assembly, wherein, for any pump core:

The cam guide rail is arranged at one end of the plunger shaft, and the cam guide rail and the baffle type piston form a guide rail piston assembly;

The support bushing, the cylinder body and the sealing bushing are sequentially and fixedly connected, a through hole is formed in the support bushing, a support arm assembly is further arranged on the end face, far away from the cylinder body, of the support bushing, and the plunger shaft is arranged in the through hole in a penetrating mode and is in clearance fit with the through hole; the inner part of the cylinder body is provided with an inner cavity, the hollow cylinder body and the baffle part of the baffle type piston are also positioned in the inner cavity to divide the inner cavity into a left sealing cavity and a right sealing cavity, and the other end of the plunger shaft is also rotatably connected with the sealing bushing;

The roller frame component is connected with the supporting arm component and is attached to the cam guide rail surface, wherein under the cooperation of the transmission through shaft, the roller frame component and the cam guide rail, the guide rail piston assembly simultaneously and axially reciprocates relative to the supporting bush, the cylinder body and the sealing bush in a rotating manner;

the support bushing of the first pump core, the front end cover and the pump shell also form a closed lubrication cavity, and the cam guide rail and the roller frame component of the first pump core are both positioned in the corresponding lubrication cavity; the supporting bush of the second pump core, the rear end cover and the pump shell also form a closed lubrication cavity, the cam guide rail and the roller frame component of the second pump core are both positioned in the corresponding lubrication cavity, and lubricating oil is filled in the lubricating oil.

Further, the cylinder body is in a round table shape, the cylinder body is provided with a pair of water suction ports and a pair of water discharge ports which are orthogonally arranged, the pair of water suction ports and the pair of water discharge ports are symmetrically arranged along the circumferential direction of the cylinder body, a water suction port a is arranged on the end face of one end of the round table, which is connected with the supporting bushing, the inner wall of the cylinder body is provided with a water suction port b, the water suction port a is communicated with the water suction port b, the water suction port a and the water suction port b are L-shaped and form one of the pair of water suction ports, and the water suction port a is also communicated with the pump shell cavity; the circular truncated cone is characterized in that an annular groove is formed in the circumferential side wall of the circular truncated cone, the water outlet is located on the annular groove and communicated with the inner cavity of the cylinder body, a high-pressure cavity is formed between the annular groove and the pump shell, and when the guide rail piston assembly rotates and axially reciprocates, the water distribution port on the baffle type plunger is matched with the water suction port and the water outlet, so that water suction and water discharge are realized.

Further, first annular leakage groove and second annular leakage groove are circumferentially arranged on the inner wall of the through hole of the support bushing, the first annular leakage groove is close to the corresponding lubricating cavity, the second annular leakage groove is close to the inner cavity of the cylinder body, leaked lubricating oil is enriched at the first annular leakage groove and used for lubricating the baffle-type piston, a first external leakage port is further formed in the support bushing, the second annular leakage groove is communicated with the first external leakage port, and leaked working medium in the inner cavity of the cylinder body is discharged out of the pump through the first external leakage port through the second annular leakage groove.

Further, the center of the sealing bush is provided with a through hole, the circumference of the inner wall of the through hole is provided with a third annular leakage groove and a fourth annular leakage groove, the sealing bush is internally provided with a second external leakage port, the fourth annular leakage groove is communicated with the second external leakage port, the shell is internally provided with a leakage pipe which is respectively communicated with the second external leakage port and the outside, and liquid leaked from the inner cavity of the cylinder body and the lubricating cavity is discharged out of the pump through the second external leakage port and the leakage pipe.

Further, the cam guide rail is a double-sided cam, and the curved surface of the cam guide rail is provided with wave crests and wave troughs.

Further, the support arm includes first support arm and second support arm, and the interval sets up on the support bush terminal surface, roller carrier assembly includes first roller carrier assembly and second roller carrier assembly, and first roller carrier assembly and second roller carrier assembly all include annular roller carrier and a plurality of gyro wheel, annular roller carrier and respectively with first support arm and second support arm rotationally be connected, two annular roller carriers set up along the length direction interval of support arm, a plurality of gyro wheels set up on the inner wall of annular roller carrier along the circumference interval of corresponding annular roller carrier, cam guide is held by a plurality of gyro wheels of first roller carrier assembly and a plurality of gyro wheels centre gripping of second roller carrier assembly.

Further, the transmission through shaft is provided with two groups of linear ball channels parallel to the axis along the axial direction, the linear ball channels are used for arranging balls, the inner cavity of the plunger shaft of the baffle piston of the first pump core is provided with a linear ball channel matched with one group of linear ball channels, the inner cavity of the plunger shaft of the baffle piston of the second pump core is provided with a linear ball channel matched with the other group of linear ball channels, wherein the balls have a clearance delta L=h/pi in the linear ball channels, h is a cam guide rail stroke, the length of the linear ball channels is L=nD+h/pi, D is the diameter of the balls, and n is the number of the balls.

Further, the piston pump further comprises a first support bearing, a second support bearing, a third support bearing and a pump core connecting piece, wherein the first support bearing and the second support bearing are respectively arranged on the front end cover and the rear end cover, the transmission through shaft is respectively and rotatably connected with the first support bearing and the second support bearing, the pump core connecting piece is respectively and fixedly connected with a sealing bush of the first pump core and a sealing bush of the second pump core, the third support bearing is arranged in the pump core connecting piece, the transmission through shaft is further rotatably connected with the third support bearing, and the baffle type piston is in non-contact with the corresponding cylinder body under the cooperation of the first support bearing, the second support bearing, the third support bearing and the transmission through shaft.

Further, the baffle type piston and the cylinder body are made of the same corrosion-resistant material.

Compared with the prior art, the invention has the beneficial effects that:

(1) The piston pump adopts a baffle type piston structure, can be suitable for high-flow occasions, almost eliminates the rotary motion of a working medium in the flow distribution process, reduces the kinetic energy loss of the working medium, and improves the energy conversion rate and the working efficiency of the piston pump; the piston pump adopts a baffle type piston structure, so that working medium only flows at low speed along the radial direction and the axial direction, the working medium can rapidly and timely fill a piston cavity, cavitation and cavitation erosion are avoided, and the cavitation erosion resistance of the hydraulic piston pump is improved;

(2) According to the invention, an independent lubrication structure of the rolling friction pair is adopted, the lubrication cavity is separated from the piston cavity, the cam guide rail and the roller needle bearing are sealed in the lubrication cavity, lubricating oil is adopted for lubrication, the problems of corrosion and the like caused by contact with water are avoided, the small influence of the change of working environment and working condition on the pump is ensured, and the efficiency and reliability of the pump are effectively improved;

(3) According to the invention, the oil-water separation structure is designed on the bushing, so that leaked lubricating medium and working medium are leaked, oil-water compatibility is avoided, and the working medium is polluted;

(4) According to the scheme of the hydraulic piston pump with double degrees of freedom of movement, the piston has no lateral force, and the piston and the cylinder body are in no contact under the support of the through shaft. Therefore, the piston and the cylinder body can be made of the same anti-corrosion material, and the restriction of the pv value of the friction pair material under the large size is broken through.

Drawings

The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is evident that the drawings in the following description are only some embodiments of the present invention and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic diagram of a high-flow two-degree-of-freedom baffle type hydraulic piston pump according to the present invention;

FIG. 2 is a schematic diagram of a pump core assembly according to the present invention;

FIG. 3 is a schematic diagram of the assembly of the roller assembly with the cam and flapper piston of the present invention;

FIG. 4 is a schematic view of an assembly of a cam track and a flapper piston of the present invention;

FIG. 5 is a schematic diagram of a phase difference between the first and second pump cores according to the present invention;

FIG. 6 is a schematic view of the structure of the roller frame of the present invention;

FIG. 7 is a schematic view of a support bushing of the present invention;

FIG. 8 is a schematic view (front view and cross-sectional view) of a support bushing of the present invention;

FIG. 9 is a schematic diagram of the cylinder structure of the present invention;

FIG. 10 is a schematic view of a seal bushing of the present invention;

FIG. 11 is a schematic view of a rotary reciprocating drive structure of the present invention;

FIG. 12 is a schematic view of a drive through shaft according to the present invention;

Fig. 13 is a schematic view of the structure of the housing of the present invention.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

As shown in fig. 1-13, in one embodiment of the present invention, there is provided a high-flow dual-freedom-of-motion hydraulic piston pump, which includes a pump housing, a pump core assembly, and a transmission through shaft, the pump housing including a front end cover 1, a pump housing 7, and a rear end cover 11 coaxially disposed in order along an axis, the front end cover 1, the pump housing 7, and the rear end cover 11 being fixedly connected to form a pump housing structure, the transmission through shaft 13 being disposed in the pump housing structure, the pump core including a first pump core and a second pump core, the first pump core and the second pump core being mounted on the transmission through shaft 13 in series with respect to each other at a certain phase angle, wherein the first pump core and the second pump core are identical in structure and each include a barrier piston, the barrier piston including: the hollow cylinder is arranged in the hollow cylinder, the baffle is connected with the inner wall of the hollow cylinder along the circumferential direction of the inner wall of the hollow cylinder, the inner cavity of the hollow cylinder is divided into a first cavity and a second cavity along the axial direction of the hollow cylinder by the baffle, the baffle is arranged on the plunger shaft in a penetrating way (the plunger shaft part is also arranged in the hollow cylinder), the plunger shaft is provided with an inner cavity, the axes of the baffle, the hollow cylinder and the plunger shaft are overlapped, and a plurality of water distribution ports are uniformly distributed in the circumferential direction of the hollow cylinder part a corresponding to the first cavity; the circumference of the hollow cylinder part b corresponding to the second cavity is also uniformly provided with a plurality of water distribution ports, and the transmission through shaft 13 is also rotatably arranged in the inner cavity of the plunger shaft of the two baffle type pistons.

That is, as shown in fig. 1, the pump housing includes a front end cover 1, a pump housing 7, and a rear end cover 11 coaxially disposed in this order along an axis, and the front end cover 1, the pump housing 7, and the rear end cover 11 may be fastened by bolts to form a pump housing structure.

In the embodiment of the invention, the water distribution ports on the hollow cylinder part a can be used as a water inlet and a water outlet, and the water distribution ports on the hollow cylinder b can be used as a water inlet and a water outlet. Therefore, this embodiment is collectively called a water distribution port.

In addition, for convenience of understanding and description, the baffle piston of the first pump core may be referred to as a first baffle piston 15, and the baffle piston of the second pump core may be referred to as a second baffle piston 19, and since the two structures are identical, a first baffle piston 15 is, for example, as shown in fig. 4, and includes a first hollow cylinder 152 with two open ends, a first baffle 154, and a first plunger shaft 151, where a plurality of first linear ball channels 153 are uniformly distributed in the inner circumference of the inner cavity of the first plunger shaft 151. Specific structures can be described in the above embodiments, and will not be described in detail herein.

It should be understood by those skilled in the art that the "first" and "second" in this embodiment do not limit the scope of the present invention, but are merely distinguished as descriptions of the first pump core and the second pump core.

It is obvious that, unlike the existing piston, the piston pump of this embodiment adopts a novel baffle type piston structure, and the water distribution port of the piston is arranged on the hollow cylinder, wherein, the water distribution port is communicated with the inner cavity of the hollow cylinder, the hollow cylinder is not contacted with the plunger shaft under the action of the baffle, and the plunger shaft is directly arranged on the baffle in the hollow cylinder in a penetrating way, thus, the wall surface for separating the high pressure cavity from the low pressure cavity is not arranged in the circumferential direction in the piston cavity, and the hydraulic loss generated when the fluid in the piston cavity rotates along with the wall surface of the piston can be effectively reduced.

In the above embodiment, in order to better achieve the flow distribution, the water distribution port on the hollow cylinder part a extends from one end of the hollow cylinder part a to the free end thereof; the water distribution opening on the hollow cylinder part b extends from one end of the hollow cylinder part b to the free end of the hollow cylinder part b.

That is, the depth of the water distribution port is consistent with the depth of the corresponding first cavity or second cavity.

Preferably, the hollow cylinder part a is provided with 2 water distribution ports, the hollow cylinder part b is also provided with 2 water distribution ports, and two pairs of water distribution ports are orthogonally arranged.

That is, 2 water distribution ports on the hollow cylinder part a constitute one pair of water distribution ports, 2 water distribution ports on the hollow cylinder part b constitute another pair of water distribution ports, and the two pairs of water distribution ports are orthogonally arranged so as to absorb and discharge water during operation.

In the above embodiments, the end face of any of the water distribution ports is designed as a chamfer.

According to the embodiment of the invention, the end face of the water inlet and outlet of the piston is designed with the chamfer surface, so that the hydraulic loss caused by the outer diameter end face can be effectively reduced when the piston rotates, and the working efficiency of the large-flow double-freedom-degree water hydraulic piston pump can be effectively improved.

In the above embodiment, the radius of the baffle is larger than the inner diameter of the plunger shaft in order to better reduce the hydraulic loss caused by the outer diameter end surface.

Preferably, the baffle is a circular baffle, and the hollow cylinder is a hollow cylinder.

Preferably, the baffle, the hollow cylinder and the plunger shaft are of an integrated structure.

Therefore, the baffle type piston provided by the embodiment of the invention integrates the functions of water suction, water discharge, flow distribution and transmission, and is designed in a mode of large outer diameter, small inner diameter and no inner wall surface as shown in fig. 3 and 4. The outside cylindrical surface is a drainage surface, two symmetrical pairs of water inlets and outlets are respectively distributed on two sides, the end faces of the water inlets and outlets of the piston are designed with chamfer surfaces, and hydraulic loss caused by the end faces of the outer diameter can be effectively reduced when the piston rotates.

Specifically, the piston of the embodiment of the invention is in a design form of large outer diameter, small inner diameter and no inner wall surface (namely, the outer diameter of a large hollow cylinder and the outer diameter of a small plunger shaft, the hollow cylinder is not contacted with the plunger shaft), the circumferential direction in the piston cavity is not provided with a wall surface for separating a high pressure cavity from a low pressure cavity, the middle cylindrical surface is a drainage surface, two symmetrical pairs of water distribution ports are respectively distributed on two sides, the end surface of the water distribution port is provided with an inclined surface design, the hydraulic loss generated when the fluid in the piston cavity rotates along with the wall surface of the piston can be effectively reduced, the rotation motion of a working medium in the flow distribution process is almost eliminated, the kinetic energy loss of the working medium is reduced, the energy conversion rate and the working efficiency of the piston pump are improved, and the piston pump can be suitable for a large-flow occasion. In addition, the baffle type piston structure can enable the working medium to flow only at a low speed along the radial direction and the axial direction, the working medium can rapidly and timely fill the piston cavity, cavitation and cavitation erosion are avoided, and the cavitation erosion resistance of the hydraulic piston pump is improved.

In the above embodiment, as shown in fig. 1-2, a first pump core and a second pump core are arranged in the pump casing along the axial through shaft, the structures of the first pump core and the second pump core are identical, the first pump core and the second pump core also comprise a cam guide rail, a supporting bush, a cylinder body, a sealing bush and a roller frame assembly, for any pump core, the cam guide rail is arranged at one end of the plunger shaft, and the cam guide rail and the baffle type piston form a guide rail piston assembly; the support bushing, the cylinder body and the sealing bushing are sequentially and fixedly connected, a through hole is formed in the support bushing, a support arm assembly is further arranged on the end face, far away from the cylinder body, of the support bushing, and the plunger shaft is arranged in the through hole in a penetrating mode and is in clearance fit with the through hole; the inner part of the cylinder body is provided with an inner cavity, the hollow cylinder body and the baffle part of the baffle type piston are also positioned in the inner cavity to divide the inner cavity into a left sealing cavity and a right sealing cavity, and the other end of the plunger shaft is also rotatably connected with the sealing bushing; the roller frame component is connected with the supporting arm component and is attached to the cam guide rail surface, wherein under the cooperation of the transmission through shaft, the roller frame component and the cam guide rail, the guide rail piston assembly simultaneously and axially reciprocates relative to the supporting bush, the cylinder body and the sealing bush in a rotating manner; the support bushing of the first pump core, the front end cover and the pump shell also form a closed lubrication cavity, and the cam guide rail and the roller frame component of the first pump core are both positioned in the corresponding lubrication cavity; the supporting bush of the second pump core, the rear end cover and the pump shell also form a closed lubrication cavity, the cam guide rail and the roller frame component of the second pump core are both positioned in the corresponding lubrication cavity, and lubricating oil is filled in the lubricating oil.

For example, the invention can drive the guide rail piston assembly to rotate relative to the supporting bush, the cylinder body and the sealing bush through the rotation of the transmission through shaft, and simultaneously, the guide rail piston assembly axially reciprocates under the cooperation of the roller frame assembly and the cam guide rail so as to complete the water sucking and draining work.

Specifically, as shown in fig. 1-2, the first pump core includes a cam rail, a support bushing, a cylinder, a seal bushing, and a roller frame assembly referred to as a first cam rail 3, a first support bushing 5, a first cylinder 6, and a first seal bushing 8, and the second pump core includes a second cam rail 21, a second cylinder 10, and a second support bushing 10, respectively. Taking the first pump core as an example, the roller frame assembly and the first cam guide rail 3 of the first pump core are enclosed in an enclosed lubrication cavity formed by connecting the front end cover 1 with the first support bush 5, and are lubricated by adopting lubricating oil. The first baffle piston 15 is enclosed in a working chamber formed by the connection of the first support bush 5, the first cylinder block 6 and the first sealing bush 8. The transmission through shaft can drive the first cam guide rail 3 and the first baffle piston 15 to rotate through the balls 14, and meanwhile, the first baffle piston 15 axially reciprocates under the guidance of the curved surface of the first cam guide rail 3.

That is, in the embodiment of the present invention, the working chamber is formed by connecting the support bush, the cylinder body and the seal bush, and it can be seen that the water distribution port portion of the baffle piston is disposed in the working chamber (all for the same pump core). The working chamber and the lubrication chamber of the embodiments of the present invention are separate. The cam guide rail and the roller frame assembly are sealed in the lubrication cavity, lubrication is performed by adopting lubricating oil, and the independent lubrication structure of the rolling friction pair is adopted, so that the problems of corrosion and the like caused by contact with water are avoided, the small influence of the change of working environment and working condition on the pump is ensured, and the efficiency and reliability of the pump are effectively improved.

Preferably, the lubricating oil in the lubricating chamber may be poured when the lubricating oil is insufficient.

Preferably, the first pump core and the second pump core are arranged in a staggered 45-degree manner, that is, in order to ensure that the phase angles of the two pump cores are different accurately and are easy to operate during installation, the circumferential positions of the cam guide rails in the two pump cores are staggered by a required phase angle, as shown in fig. 5, the phase angles of the two pump cores are different by 45 degrees, and the theoretical flow of the outlet of the hydraulic piston pump is ensured to be free from pulsation.

As shown in fig. 9, the cylinder body is in a shape of a circular truncated cone, the cylinder body is provided with a pair of water suction ports and a pair of water discharge ports which are orthogonally arranged, the pair of water suction ports and the pair of water discharge ports are symmetrically arranged along the circumferential direction of the cylinder body, wherein a water suction port a is arranged on the end surface of one end of the circular truncated cone, which is connected with the supporting bushing, a water suction port b is arranged on the inner wall of the cylinder body, the water suction port a is communicated with the water suction port b, the water suction port a and the water suction port b are L-shaped and form a water suction port (one of the pair of water suction ports), and the water suction port a is also communicated with the pump shell cavity; the circular truncated cone is characterized in that an annular groove is formed in the circumferential side wall of the circular truncated cone, the water outlet is located on the annular groove and communicated with the inner cavity of the cylinder body, a high-pressure cavity is formed between the annular groove and the pump shell, and when the guide rail piston assembly rotates and axially reciprocates, the water distribution port on the baffle type plunger is matched with the water suction port and the water outlet, so that water suction and water discharge are realized.

In the embodiment of the invention, in order to ensure that a high-pressure cavity is formed between the annular groove and the pump shell, sealing rings are respectively arranged between the two ends of the annular groove and the pump shell.

Specifically, taking the first cylinder body 6 as an example, as shown in fig. 9, the first cylinder body 6 is in a shape of a circular table, water sucking and discharging ports which are orthogonally distributed are circumferentially arranged, the first water sucking port a63 is communicated with the first water sucking port b64, the first water sucking port a63 is also communicated with a pump shell cavity, a first annular groove 66 is formed in the circumferential side wall of the circular table of the first cylinder body 6, the first water discharging port 65 is positioned on the first annular groove 66 and communicated with the first cylinder body cavity 62, the first cylinder body cavity 62 is formed in the middle of the first cylinder body 6, the first baffle piston 15 is arranged in the first cylinder body cavity 62 (namely a piston cavity), the cavity is divided into a left sealing cavity and a right sealing cavity, and working mediums in the two sealing cavities are alternately sucked and discharged under the action of the rotation and reciprocation of the first baffle piston 15.

In the embodiment of the invention, the baffle type pistons of the first pump core and the second pump core have the same water sucking and draining, flow distributing and transmission principles, so that the water sucking and draining, flow distributing and transmission principles of one baffle type piston are described below by taking one baffle type piston as an example.

When the transmission through shaft drives the baffle type piston to rotate, the baffle type piston axially reciprocates under the guide of the curved surface of the guide rail, a closed cavity, namely a working cavity, can be formed by the baffle type piston, the corresponding supporting bushing and the cylinder body, the baffle type piston is in a drainage stroke in the process of moving the baffle type piston from the highest point to the lowest point, the volume of the piston cavity is reduced, working medium (namely water) is compressed, and the working medium in the piston cavity flows into a drainage port at a high-pressure cavity through a drainage port on a baffle of the cylinder body baffle type piston to finish drainage; in the process that the guide rail piston moves from the lowest point to the highest point, the baffle piston is in a water absorption stroke, the volume of a piston cavity is enlarged, vacuum is formed, working medium in a shell enters the piston cavity through a water absorption port a and a water absorption port b to finish water absorption, water absorption and drainage of the left piston cavity and the right piston cavity of the baffle piston are alternately performed (namely, when the transmission through shaft 13 drives the first baffle piston 15 to rotate through the ball 14 as an example, the first baffle piston 15 axially reciprocates under the guide of a guide rail curved surface, and a closed cavity can be formed by the first baffle piston 15, the first support bushing 5 and the first cylinder body 6; in the process that the guide rail piston 15 moves from the lowest point to the highest point, the first baffle piston 15 is in a water suction stroke, the volume of a piston cavity is enlarged, vacuum is formed, working medium in a shell enters the piston cavity through the first water suction port a63 and the first water suction port b64, water suction is completed, and oil suction and discharge operations of the left piston cavity and the right piston cavity of the first baffle piston 15 are alternately performed.

Therefore, the embodiment of the invention adopts the baffle type piston structure, the working medium enters the piston cavity and does not generate rotary motion, and the working medium can quickly follow the axial motion of the baffle type piston to timely fill the piston cavity. The baffle type piston structure enhances the cavitation resistance of the pump while reducing the stirring loss. Meanwhile, the baffle type piston structure is adopted, the area of the distributing port is larger, and the self-priming performance of the pump is improved. Meanwhile, as the baffle type piston is adopted, the working medium enters the piston cavity and is not influenced by the rotary motion of the baffle type piston, the working medium does not generate rotary motion, the kinetic energy generated by the working medium is small, and the conversion rate of the piston pump from mechanical energy to hydraulic energy is high.

In order to ensure that the phase angles of the two pump cores are accurate in phase difference and easy to operate during installation, the circumferential positions of the cam guide rails in the two pump cores are staggered by a required phase angle, as shown in fig. 5, the phase angles of the two pump cores are 45 degrees, and the theoretical flow of the outlet of the hydraulic piston pump is ensured to be free from pulsation.

As shown in fig. 4, 6, 7 and 8, the supporting arm comprises a first supporting arm and a second supporting arm, the supporting arms are arranged on the end face of the supporting bushing at intervals, the roller frame assembly comprises a first roller frame assembly and a second roller frame assembly, the first roller frame assembly and the second roller frame assembly both comprise annular roller frames and a plurality of rollers, the annular roller frames are rotatably connected with the first supporting arm and the second supporting arm respectively, the two annular roller frames are arranged at intervals along the length direction of the supporting arm, the plurality of rollers are arranged on the inner wall of the annular roller frames along the circumferential intervals of the corresponding annular roller frames, and the cam guide rail is clamped by the plurality of rollers of the first roller frame assembly and the plurality of rollers of the second roller frame assembly.

As shown in fig. 7, two support arms 51 are provided on the end face 52 of the first support bush 5.

In an embodiment of the present invention, mounting holes 53 may be machined into each support arm for mounting an annular roller frame.

In the embodiment of the invention, the number of the plurality of rollers is preferably 2.

Further preferably, the rollers are bolt type roller needle bearings, are uniformly distributed circumferentially and are fixed on the positioning holes of the corresponding roller frames by bolts. The first roller frame component and the second roller frame component can be installed on the installation holes of the first support arm and the second support arm through pins, rollers are tightly attached to the cam guide rail through a zero-clearance assembly method, the roller frame component can rotate around the pins, the contact of the two rollers on one side with the cam guide rail is ensured at any time, and the axial force borne by the baffle type piston is equally divided.

As shown in fig. 4 and 6, taking the first roller frame assembly as an example, the first roller frame assembly includes a first annular roller frame 4 and first rollers 2, preferably 2 first rollers 2, more preferably, the rollers adopt bolt type roller needle bearings, and are circumferentially uniformly distributed and fixed on the positioning holes 42 of the first annular roller frame 4 by bolts. The first roller frame components are fixedly installed on the installation holes 53 of the first support bushing supporting arms 51 (corresponding to the pin holes 41 on the first annular roller frame 4) in pairs through the pins 21, the first rollers 2 are tightly attached to the first cam guide rail 3 through a zero-clearance assembly method, the roller frame components can rotate around the pins 21, the contact of the two rollers on one side with the guide rail is ensured at any time, and the axial force borne by the baffle type piston is equally divided.

Further, the cam guide rail is clamped by two groups of roller assemblies, preferably, the cam guide rail is a double-sided cam, and the curved surface of the cam guide rail is provided with a crest and a trough, and more preferably, the crest and the trough are two in each. The cam guide rail and the roller component form a conjugate cam mechanism, so that the baffle type piston can realize reciprocating motion according to a rule.

As shown in fig. 7 and 8, a first annular leakage groove and a second annular leakage groove are circumferentially formed in the inner wall of the through hole of the support bushing, the first annular leakage groove is close to the lubrication cavity, the second annular leakage groove is close to the inner cavity of the cylinder body, leaked lubricating oil is enriched at the first annular leakage groove and used for lubricating a corresponding baffle-type piston, a first external leakage port is further formed in the support bushing, the second annular leakage groove is communicated with the first external leakage port, and leaked working medium in the inner cavity of the cylinder body is directly discharged out of the pump through the first external leakage port through the second annular leakage groove.

Therefore, the so-called oil-water separation structure formed by gap sealing between the baffle type piston and the corresponding supporting bushing realizes the sealing effect of rotation and reciprocating motion through the simple two annular leakage grooves and the outer leakage holes, and avoids the mixing of working medium and lubricating medium and the influence on the lubricating effect.

Specifically, taking the first support bushing 5 as an example, as shown in fig. 7 and 8, the first support bushing 5 has a hole in the middle of the first support bushing 52, and two annular leakage grooves a54 (i.e., a first annular leakage groove and a second annular leakage groove) are formed in the hole. The leaked lubrication oil is enriched in the annular leakage groove near the lubrication chamber and can be used for lubricating the first barrier piston 15. The annular leakage groove near the working chamber is directly communicated with the outer leakage port a55, and leaked working medium can directly flow out of the pump through the outer leakage port a 55. The so-called oil-water separation structure formed by the clearance seal between the first baffle piston 15 and the first support bush 5 realizes the sealing effect of rotation and reciprocating motion through the simple two annular leakage grooves and the outer leakage holes, and avoids the mixing of working medium and lubricating medium to influence the lubricating effect.

The sealing bush 8 is shown in fig. 10, a through hole is formed in the center of the sealing bush, a third annular leakage groove and a fourth annular leakage groove are formed in the circumferential direction of the inner wall of the through hole, a second external leakage port is formed in the sealing bush, the fourth annular leakage groove is communicated with the second external leakage port, a leakage pipe which is respectively communicated with the second external leakage port and the outside is arranged in the shell, and liquid leaked from the inner cavity of the cylinder body and the lubricating cavity is discharged out of the pump through the second external leakage port and the leakage pipe.

Specifically, taking the first seal bushing 8 as an example, as shown in fig. 10, the center of the first seal bushing 8 is perforated, two annular leakage grooves b82 (i.e., a third annular leakage groove and a fourth annular leakage groove) are provided in the hole, the leakage grooves b82 are communicated with an external leakage port b81, and liquid leaked from the working chamber and the lubrication chamber is led out of the pump through the external leakage port b81 via the leakage pipe 16.

That is, the annular drain groove of the sealing bush also forms an oil-water separation structure, and the oil-water separation principle is similar to that of the supporting bush.

As shown in fig. 1, the piston pump further comprises a first support bearing 12, a second support bearing 12a, a third support bearing 17 and a pump core connecting piece 9, the first support bearing 12 and the second support bearing 12a are respectively arranged on the front end cover 1 and the rear end cover 11, the transmission through shaft 13 is respectively and rotatably connected with the first support bearing 12 and the second support bearing 12a, the pump core connecting piece 9 is respectively and fixedly connected with a sealing bush of the first pump core and a sealing bush of the second pump core, the third support bearing 17 is arranged in the pump core connecting piece 9, the transmission through shaft 13 is also rotatably connected with the third support bearing 17, and the baffle type piston and the corresponding cylinder body are not contacted under the cooperation of the first support bearing 12, the second support bearing 12a, the third support bearing 17 and the transmission through shaft 13.

That is, the transmission through shaft is sequentially arranged in the first support bearing, the inner cavity of the plunger shaft of the first pump core, the third support bearing, the inner cavity of the plunger shaft of the second pump core and the second support bearing in a penetrating manner.

The leaked lubricating oil at the third support bearing 17 can be discharged out of the pump through the oil-water separation structure at the sealing bush.

In the embodiment of the invention, the baffle type piston and the cylinder body are made of the same corrosion-resistant material.

Therefore, the piston of the embodiment of the invention has no lateral force, and the piston and the cylinder body are not contacted under the support of the through shaft. Therefore, the piston and the cylinder body can be made of the same anti-corrosion material, and the restriction of the pv value of the friction pair material under the large size is broken through.

As shown in fig. 1, 11 and 12, the transmission through shaft is provided with two groups of linear ball channels 134 parallel to the axis along the axial direction, the linear ball channels 134 are used for arranging the balls 14, the inner cavity of the plunger shaft of the baffle piston of the first pump core is provided with a linear ball channel matched with one group of linear ball channels, and the inner cavity of the plunger shaft of the baffle piston of the second pump core is provided with a linear ball channel matched with the other group of linear ball channels.

Specifically, as shown in fig. 12, the transmission shaft has a first support bearing mounting end 131 and a second support bearing mounting end 132 at two ends, and an optical axis 133 in the middle, on which a linear ball channel 134 is formed.

The transmission through shaft, the two cam guide rails and the two baffle type pistons form a rotary reciprocating transmission structure, and particularly, 8 groups of linear ball grooves are formed in the transmission through shaft and correspond to the ball grooves on the inner cavity of the plunger shaft of the baffle type piston, balls are placed in the ball grooves, the transmission through shaft drives the baffle type pistons of the first pump core and the second pump core to rotate through the balls, and meanwhile, the baffle type pistons of the first pump core and the second pump core axially reciprocate under the guidance of curved surfaces of the corresponding cam guide rails.

Further, the linear ball grooves 134 on the transmission shaft are divided into two groups, which correspond to the ball grooves in the center of the baffle piston of the first pump core and the baffle piston of the second pump core respectively, and each group of ball grooves is uniformly distributed on the transmission shaft in the circumferential direction, preferably four, and all the linear ball grooves have the same length and depth.

Preferably, the ball clearance Δl=h/pi in the linear ball channel 134, where h is the cam track travel, and further preferably, the linear ball channel 134 has a length l=nd+h/pi, where D is the ball diameter, n is the number of balls, and the number of balls is determined according to the bearing capacity of the balls and the torque to be transmitted, which is specifically set as known in the art.

Because the linear ball grooves 134 are not fully filled with balls, the initial positions of the balls on the grooves are inconsistent, which results in a tilting moment of the balls on the drive shaft and the blind piston, which moment can be balanced by the first support bearing 12, the second support bearing 12a and the third support bearing 17. Under the support of the transmission through shaft, the baffle type piston is in non-contact with the cylinder body, the baffle type piston is hardly worn in the working process of the hydraulic pump, and the reliability and the service life of the hydraulic piston pump are greatly enhanced.

As shown in fig. 13, the pump casing 7 is provided with a water passage 74, and a water suction port 76 and a water discharge port 72 are provided outside the pump casing, and are supported by a plurality of legs 73, preferably 4 legs. Two leakage pipes 16 are arranged on the lower side of the housing and are respectively communicated with the outer leakage ports of the two sealing bushes.

In summary, the embodiment of the invention provides a large-flow double-freedom-degree baffle type hydraulic piston pump, which comprises a front end cover, a rear end cover, a bushing, a pump shell, a cylinder body, a baffle type piston, a cam guide rail, a roller frame, rollers, a transmission through shaft, balls, bearings (which can contain bearing seats), sealing rings and the like. The front end cover, the pump shell and the rear end cover are connected through screws to form a closed lubrication cavity and a working cavity, parts such as a cam guide rail, a roller frame, a bearing, a supporting arm and the like are closed in the lubrication cavity, and lubrication is performed by adopting lubricating oil; the working cavity is internally provided with a cylinder body, a bushing, a baffle type piston and other parts. The transmission through shaft is connected with the front/rear end cover through a bearing and a shaft seal, and torque is transmitted between the ball and the pump core assembly. According to the invention, through the baffle type piston structure, the flow loss under the high-flow working condition is effectively reduced, and the self-priming capability, the cavitation resistance and the working efficiency of the hydraulic piston pump under the high-flow occasion are improved; by adopting the independent lubrication cavity structure, the problem that the working medium corrodes parts such as cam guide rails is solved, and the working life and efficiency are improved.

In the description of the present invention, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present invention; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface on … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present invention.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a high-flow two degree of freedom water hydraulic piston pumps, the piston pump includes pump housing, pump core subassembly and transmission through axle, and the pump housing includes front end housing, pump housing and the rear end cap that sets gradually coaxial along the axis, and front end housing, pump housing and rear end cap link firmly and form the pump housing structure, the transmission through axle sets up in the pump housing, its characterized in that, the pump core includes first pump core and second pump core, and first pump core and second pump core are installed according to certain phase angle, relative series connection on the transmission through axle, wherein, first pump core and second pump core structure are the same, all include baffle type piston, baffle type piston includes: the hollow cylinder is arranged in the hollow cylinder, the baffle is connected with the inner wall of the hollow cylinder along the circumferential direction of the inner wall of the hollow cylinder, the inner cavity of the hollow cylinder is divided into a first cavity and a second cavity along the axial direction of the hollow cylinder by the baffle, the baffle is arranged on the plunger shaft in a penetrating way, the plunger shaft is provided with an inner cavity, the axes of the baffle, the hollow cylinder and the plunger shaft are coincided, and a plurality of water distribution ports are uniformly distributed along the circumferential direction of a hollow cylinder part a corresponding to the first cavity; the circumference of the hollow cylinder part b corresponding to the second cavity is also uniformly provided with a plurality of water distribution ports, and the transmission through shaft is also rotatably arranged in the inner cavity of the plunger shaft of the two baffle type pistons.

2. A high flow dual freedom of movement water hydraulic piston pump of claim 1 wherein the water distribution port on the hollow cylinder portion a extends from one end of the hollow cylinder portion a to a free end thereof; the water distribution opening on the hollow cylinder part b extends from one end of the hollow cylinder part b to the free end of the hollow cylinder part b.

3. The high-flow double-freedom-degree water hydraulic piston pump of claim 1 or 2, wherein the hollow cylinder part a is provided with 2 water distribution ports, the hollow cylinder part b is also provided with 2 water distribution ports, and two pairs of water distribution ports are orthogonally arranged.

4. A high flow two degree of freedom water hydraulic piston pump according to claim 1 or 2, wherein the end face of any of said water distribution openings is designed as a chamfer.

5. The high flow, dual freedom of movement water hydraulic piston pump of claim 1 wherein the baffle has a radius greater than an inner diameter of the plunger shaft.

6. The high flow dual freedom of motion hydraulic piston pump of claim 1 wherein the baffle is a circular baffle and the hollow cylinder is a hollow cylinder.

7. A high flow two degree of freedom water hydraulic piston pump according to claim 5 or 6 wherein the baffle, hollow cylinder and plunger shaft are of unitary construction.

8. The high flow dual freedom of motion hydraulic piston pump of claim 1 wherein the first and second pump cores each further comprise cam tracks, support bushings, cylinders, seal bushings, and roller frame assemblies for any pump core:

The support bushing of the first pump core, the front end cover and the pump shell also form a closed lubrication cavity, and the cam guide rail and the roller frame component of the first pump core are both positioned in the corresponding lubrication cavity; the supporting bush of the second pump core, the rear end cover and the pump shell also form a closed lubrication cavity, the cam guide rail and the roller frame component of the second pump core are both positioned in the corresponding lubrication cavity, and the lubrication cavity is filled with lubricating oil.

9. The high-flow double-freedom-degree water hydraulic piston pump of claim 8, wherein the cylinder body is in a shape of a circular table, the cylinder body is provided with a pair of water suction ports and a pair of water discharge ports which are arranged in an orthogonal mode, the water suction ports and the water discharge ports are symmetrically arranged along the circumferential direction of the cylinder body, a water suction port a is arranged on the end face of one end face of the circular table, which is connected with the supporting bushing, a water suction port b is arranged on the inner wall of the cylinder body, the water suction port a is communicated with the water suction port b, the water suction port a is L-shaped and forms one of the water suction ports, and the water suction port a is communicated with the pump shell cavity; the circular truncated cone is characterized in that an annular groove is formed in the circumferential side wall of the circular truncated cone, the water outlet is located on the annular groove and communicated with the inner cavity of the cylinder body, a high-pressure cavity is formed between the annular groove and the pump shell, and when the guide rail piston assembly rotates and axially reciprocates, the water distribution port on the baffle type plunger is matched with the water suction port and the water outlet, so that water suction and water discharge are realized.

10. The large-flow double-freedom-degree water hydraulic piston pump of claim 8 or 9, wherein a first annular leakage groove and a second annular leakage groove are circumferentially formed in the inner wall of the through hole of the support bushing, the first annular leakage groove is close to the corresponding lubricating cavity, the second annular leakage groove is close to the inner cavity of the cylinder body, leaked lubricating oil is enriched at the first annular leakage groove and used for lubricating the baffle-type piston, a first outer leakage port is further formed in the support bushing, the second annular leakage groove is communicated with the first outer leakage port, and leaked working medium in the inner cavity of the cylinder body is discharged out of the pump through the first outer leakage port through the second annular leakage groove.

11. The high-flow double-freedom-degree water hydraulic piston pump of claim 10, wherein the center of the sealing bush is provided with a through hole, a third annular leakage groove and a fourth annular leakage groove are circumferentially formed in the inner wall of the through hole, a second external leakage port is further formed in the sealing bush, the fourth annular leakage groove is communicated with the second external leakage port, a leakage pipe which is respectively communicated with the second external leakage port and the outside is formed in the shell, and liquid leaked from the inner cavity of the cylinder body and the lubrication cavity is discharged out of the pump through the second external leakage port and the leakage pipe.

12. The high flow dual freedom of movement hydraulic piston pump of claim 8 wherein the cam track is a double sided cam having peaks and valleys on a curved surface.

13. The high-flow double-freedom-degree water hydraulic piston pump of claim 8, wherein the support arm comprises a first support arm and a second support arm which are arranged on the end face of the support bushing at intervals, the roller frame assembly comprises a first roller frame assembly and a second roller frame assembly, each of the first roller frame assembly and the second roller frame assembly comprises an annular roller frame and a plurality of rollers, the annular roller frames are respectively and rotatably connected with the first support arm and the second support arm, the two annular roller frames are arranged at intervals along the length direction of the support arm, the plurality of rollers are arranged on the inner wall of the annular roller frame at intervals along the circumferential direction of the corresponding annular roller frame, and the cam guide rail is clamped by the plurality of rollers of the first roller frame assembly and the plurality of rollers of the second roller frame assembly.

14. The high-flow double-freedom-degree hydraulic piston pump of claim 1, wherein the transmission through shaft is provided with two groups of linear ball channels parallel to the axis along the axial direction, the linear ball channels are used for arranging balls, the inner cavity of the plunger shaft of the baffle piston of the first pump core is provided with a linear ball channel matched with one group of linear ball channels, the inner cavity of the plunger shaft of the baffle piston of the second pump core is provided with a linear ball channel matched with the other group of linear ball channels, wherein the balls have a clearance delta l=h/pi in the linear ball channels, h is a cam guide rail stroke, the length of the linear ball channels is l=nd+h/pi, D is a ball diameter, and n is the number of balls.

15. The high flow dual freedom water hydraulic piston pump of claim 8 further including first, second, third and core connectors, the first and second support bearings being disposed on the front and rear end caps, respectively, the drive through shaft being rotatably connected to the first and second support bearings, respectively, the core connector being fixedly connected to the seal bushing of the first core and the seal bushing of the second core, respectively, the third support bearing being disposed within the core connector, the drive through shaft being rotatably connected to the third support bearing, wherein, in cooperation with the first, second, third support bearings and the drive through shaft, there is no contact between the barrier piston and the corresponding cylinder.

16. The high flow, dual freedom of motion hydraulic piston pump of claim 8 wherein the flapper piston and cylinder are made of the same corrosion resistant material.