CN102606378B - Full water lubrication pass shaft type water hydraulic piston motor - Google Patents

Abstract

The utility model relates to a through-axis water hydraulic plunger motor with full water lubrication, which belongs to the field of fluid machinery. There are an odd number of large holes and small holes parallel to the axis on the cylinder shaft, and the plungers in the plunger shoe assembly are respectively placed in the large holes to form a plunger pair; one end of the cylinder shaft is equipped with a floating disc, which is evenly distributed on the One end of the central spring in the small hole of the cylinder shaft presses the floating plate on the distribution plate, and the other end of the central spring presses the ejector rod on the central spherical hinge assembled on the cylinder shaft, and is set on the return plate outside the central spherical hinge. Press the sliding shoe in each plunger sliding shoe assembly on the inclined surface of the swash plate through the bottom of the sliding shoe; put one end of the floating sleeve into the corresponding cylinder hole of the cylinder shaft, and install the other end of the floating sleeve into the corresponding hole of the floating plate middle;. The invention adopts the cylinder shaft to avoid the circumferential movement of the distribution plate caused by the side clearance of the spline or the flat key, and avoids the high-stress corrosion of the contact part between the transmission key and the shaft. For an odd number of plungers, all the plungers use return springs for centralized return. , there is almost no fatigue damage, which is conducive to long-term work in seawater.

Description

Fully water-lubricated thru-axis water hydraulic plunger motor

Technical field

The invention relates to an energy conversion device and an actuator hydraulic motor in water hydraulic transmission, and belongs to the field of fluid machinery.

Background technique

With the progress of society and the development of science and technology, saving energy and resources, eco-friendly green manufacturing technology has become the primary goal of modern mechanical engineering. Water hydraulic transmission technology uses filtered natural water (including seawater and fresh water) as the working medium of hydraulic transmission to realize power transmission without any additives. It has the unique advantages of wide source, environment-friendly, clean and safe, and the water itself has resistance Combustibility and other advantages can satisfy people's desire for safety, economy and environmental protection to the greatest extent, and meet the needs of sustainable development of human beings. It has become one of the latest development directions in the field of international fluid transmission and control. Coupled with the application of new materials, the advancement of precision machining technology and the successful development of hydraulic components with new structures, water hydraulic transmission technology has made great progress. Developed countries including the United States, the United Kingdom, Germany, Finland, Denmark, and Japan began to develop it in the late 1970s or early 1980s. Now it has entered the stage of practical promotion and has been widely used in ocean development, nuclear energy industry, mining and other fields. Since the early 1990s, my country has started research on water hydraulic transmission technology, but the development speed is relatively slow. At present, there are no finalized products on the market, and the research and development of various water hydraulic components is still in its infancy.

The water hydraulic motor (pump) is a key component in the water hydraulic system, and its performance index directly determines the performance index of the entire water hydraulic system. So far, the sea and fresh water hydraulic motor (pump) structures that have been developed have the following characteristics:

Except for the earliest vane motors developed for underwater working tools in the United States, almost all sea and freshwater motors (pumps) use plunger structures.

The transmission shaft of the oblique shaft axial plunger structure is a cantilever structure and bears a large axial force, so more stringent requirements are put forward for the bearing. Rolling bearings (oil or grease lubrication) can meet the requirements when ceramic bearings are used or oil and water separation structures are used, but for plunger motors (pumps) that use water as the lubricating medium, sliding bearings are difficult to handle the oblique shaft structure. huge load. Therefore, most hydraulic plunger motors (pumps) adopt a swash plate structure.

In order to improve the anti-corrosion and wear ability of the friction pair and improve the anti-pollution ability of the seawater hydraulic motor, engineering ceramics, engineering plastics and corrosion-resistant alloys are widely used in the friction pairs of almost all sea and freshwater hydraulic motors (pumps).

Foreign axial plunger hydraulic pumps have both valve distribution type and end face distribution type. The valve distribution structure has good sealing performance and is used as the distribution mechanism of ultra-high pressure water pumps. The water hydraulic motor generally adopts the distribution plate structure, and the working speed is generally 1400-1800r/min.

In foreign countries, the U.S. Patent (Patent No.: 6000316) discloses an axial piston pump, which is a fully water-lubricated half-shaft front swash plate structure. limit. At present, there is no finalized commercial pure water hydraulic motor (pump) in China. Chinese patent (patent number: ZL03118632.7) discloses an axial plunger type water hydraulic pump, which adopts a full water lubricating valve flow distribution structure, the main shaft drives the swash plate to rotate, while the cylinder body is stationary, and the structure is relatively complicated. Processing is more difficult. Chinese patent (Application No.: 200310108538.6) discloses a pure water hydraulic axial plunger pump/motor with full water lubrication. The body is an interference fit with a floating end face flow distribution structure of a floating thrust plate, which has a compact structure, high specific power, and relatively difficult processing, but the actual effect has not been reported.

Contents of the invention

The technical problem to be solved by the present invention is to provide a fully water-lubricated through-axis water hydraulic plunger motor with flow distribution on the end face, which uses filtered natural water (including fresh water and sea water) as the working medium, and does not need any other lubrication agent.

In order to solve the above problems, the all-water-lubricated thru-axis water hydraulic plunger motor of the present invention includes: the large end cover is fixedly connected with the housing through threads, the small end cover and the large end cover are fixedly connected with screws, the large end cover, the shell The body and the small end cap constitute the shell; the ball head of the plunger is inserted into the semicircular ball socket of the shoe, the shoulder gasket is inlaid on the shoe, the bottom of the shoe is pressed into the inner hole of the shoe, and the interference fit A plunger slide shoe assembly is formed by a slide shoe, a slide shoe sole, a boot shoulder spacer and a plunger.

The through-shaft structure is adopted, the cylinder shaft is inserted into the inner hole of the housing, and is respectively supported by the front sliding bearing in the housing and the rear sliding bearing in the large end cover; there are an odd number of shafts parallel to the axis on the cylinder shaft Large holes and small holes, the plungers in the plunger shoe assembly are respectively placed in the large holes to form a plunger pair; one end of the cylinder shaft is equipped with a floating disc, which is evenly distributed in the small holes of the cylinder shaft. One end presses the floating plate on the distribution plate, the floating plate and the distribution plate form a flow distribution pair, the other end of the central spring presses the ejector rod on the central spherical hinge assembled on the cylinder shaft, and the return plate set outside the central spherical hinge will The sliding shoe in each plunger sliding shoe assembly is pressed against the inclined surface of the swash plate through the bottom of the sliding shoe to form a pair of sliding shoes; one end of the floating sleeve is installed in the corresponding cylinder hole of the cylinder shaft, and the other end of the floating sleeve is installed in the floating In the corresponding hole of the disc, the floating disc floats relative to the axis of the cylinder body; a positioning ring is installed in the center of the large end cover, and the positioning ring and positioning pin fix the distribution plate on the large end cover, and the positioning ring fixes the swash plate on the shell , There are water guide grooves on the shell, cylinder shaft and swash plate.

The plunger is provided with a plunger center hole, the ball head is provided with a plunger ball head center hole, and the slide shoe is provided with a slide shoe center hole, the plunger center hole, the plunger ball head center hole, and the slide shoe center hole , the bottom hole of the sliding shoe and the contact surface between the bottom of the sliding shoe and the swash plate communicate in sequence.

A water inlet hole and a water outlet hole are respectively arranged on the big end cover, and a water absorption waist groove and a water drainage waist groove are respectively opened in the flow distribution plate. When absorbing water, high-pressure water flows from the water inlet hole of the large end cover into the water absorption waist groove of the distribution plate connected with it, and then flows into the connecting hole of the floating plate and floating sleeve connected with it and enters the cylinder hole; when draining, the cylinder hole The low-pressure water in the tank is discharged from the water outlet hole of the large end cover through the floating sleeve, the floating plate, and the drainage waist groove on the distribution plate that are connected to it.

The large end cover and the shell are connected through a damping hole, through which high-pressure water is introduced into the shell to provide static pressure support for the forward sliding bearing, and pressure relief in the shell is realized through the leakage port of the shell.

The beneficial effects that the present invention has are:

1. The shaft of the cylinder block is directly processed into one part of the drive shaft and the cylinder block to avoid the circumferential movement of the valve plate caused by the side clearance of the spline or flat key, and also to avoid high stress corrosion at the contact part between the drive key and the shaft.

2. The hydraulic motor has an odd number of plungers, and all plungers use return springs for centralized return. The return spring has almost no fatigue damage, which is beneficial to long-term work in seawater.

3. The floating plate on the end face of the cylinder floats through the floating sleeve in the cylinder hole, and is pressed on the distribution plate by the return spring. The floating distribution structure is used for distribution, and the gap of the distribution plate is small, which can ensure the contact and sealing of the distribution surface, and can avoid the failure of the eccentric grinding disc between the cylinder body and the distribution plate.

4. The return spring adopts a dispersed multi-spring combination. When there is a wedge-shaped gap between the distribution plate and the floating disk, the springs will generate a deviation correction torque due to uneven compression, so that the distribution plate and the floating disk are closely attached.

5. The main friction pair is designed by the static pressure balance method or the residual pressing force method to reduce the PV (contact specific pressure) value of the water-lubricated friction pair, improve mechanical efficiency, and prolong the life of the motor.

6. Most of the friction pairs adopt the friction plate or friction sleeve structure inlaid with wear-resistant materials to reduce wear, prolong life, and create conditions for the replacement of wearing parts.

7. The through-shaft structure is adopted, the structure is simple, the number of parts is small, and the reliability is good. It is similar to the oil hydraulic axial plunger structure, which is convenient for professional plunger motor manufacturers to quickly mass produce.

8. All parts of the motor can be submerged in water, and the water depth pressure can be automatically compensated when working underwater, avoiding the energy consumption caused by the water depth pressure.

Description of drawings

The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the left view of structural representation of the present invention;

Fig. 3 is a structural schematic diagram of a distribution plate of the present invention;

Fig. 4 is an enlarged view of the plunger shoe assembly of the present invention.

In the figure: 1 key; 2 cylinder shaft; 3 shaft seal; 4 small end cap; 5 screws; 6 large end cap; 6.1 large end cap water inlet; 6.2 large end cap water outlet; 7, 8, 9 O Sealing ring; 10 positioning pin; 11 distribution plate; 11.1 drainage waist groove; 11.2 water absorption waist groove; 12 center spring; 13 ejector rod; 14 center ball hinge; 15 return plate; 18 plastic gasket; 19 front sliding bearing; 20 positioning ring; 21 swash plate; 22 screw; 23 pressure plate; 24 plunger sliding shoe assembly; 24.1 sliding shoe bottom; Center hole; 24.3 boot shoulder gasket, 24.4 plunger; 24.41 plunger ball head center hole; 24.42 plunger center hole 25 floating sleeve; 26O type sealing ring; 27 sealing retaining ring; 28 floating disc; 29 positioning ring; 30 rear plain bearings.

Detailed ways

Implementation Figures 1 to 4 combine to provide a fully water-lubricated through-axis water hydraulic plunger motor, which is mainly composed of a housing (mainly composed of a large end cover 6, a small end cover 4, and a housing 16), installed in the housing The cylinder shaft 2 rotatable in the body 16, the swash plate 21 fixed in the housing 16, the plunger shoe assembly 24 and the distribution device (including the distribution plate 11, the floating plate 28, and the floating sleeve 25) are composed.

The large end cap 6 is fixedly connected with the housing 16 through threads, the small end cap 4 and the large end cap 6 are fixedly connected through the screws 5, and the large end cap 6, the housing 16 and the small end cap 4 form a shell.

The through-shaft structure is adopted, and the inner hole of the housing 16 is equipped with a plastic gasket 18. The cylinder shaft 2 is inserted into the inner hole of the housing 16 and directly contacts with the plastic gasket 18. The plastic gasket 18 can effectively reduce the rotation of the cylinder shaft 2. When wear and vibration between housing 16, pressure plate 23 is fixed with cylinder shaft 2 left end cylinder body by screw 22, thereby guarantees that plunger 24.4 does not move out from cylinder bore.

The front and rear necks of the cylinder shaft 2 are respectively connected in rotation with the front sliding bearing 19 located in the housing 16 and the rear sliding bearing 30 located in the large end cover 6, and the cylinder shaft 2 is evenly distributed on the same circumference and is parallel to the axis of the cylinder shaft 2 There are an odd number of large holes and small holes, the plunger 24.4 of the plunger shoe assembly is placed in the large hole of the cylinder shaft 2, and reinforced plastic is embedded in the large hole, and it forms a plunger pair with the plunger 24.4 made of stainless steel. , plunger 24.4 ball head outsourcing engineering plastics, and slide shoe 24.2 ball socket form a ball socket pair; the right side of the cylinder shaft 2 is a floating disc 28, which is placed in the central spring 12 in the odd number of small holes evenly distributed on the cylinder shaft 2 The right end of the right end presses the floating plate 28 on the distribution plate 11, the floating plate 28 and the distribution plate 11 form a distribution pair, the left end of the center spring 12 passes through the cylinder shaft 2, the center spherical hinge 14 outside the cylinder shaft 2, the center spring 12 through the ejector rod 13 The return plate 15 outside the ball joint 14 presses the shoe 24.2 in each plunger shoe assembly 24 on the swash plate 21 via the shoe sole 24.1 to form a shoe pair. The outer spherical surface of the center ball joint 14 and the return plate 15 The inner ball-and-socket surface constitutes a central spherical hinge pair.

The floating end surface flow distribution method is adopted, the left end of the floating sleeve 25 is installed into the large hole of the corresponding cylinder shaft 2, and the right end of the floating sleeve 25 is installed into the corresponding hole of the floating plate 28, and the interference fit makes the floating plate 28 relative to the cylinder. The body shaft 2 floats and rotates with the cylinder shaft 2 . There are O-shaped rubber sealing rings 26 and O-shaped sealing retaining rings 27 in the distribution sleeve 25 for sealing, ensuring that high-pressure water does not leak from the radial gap of the distribution sleeve 25, and compensating for processing and installation errors, which can ensure the contact seal of the distribution surface .

A positioning ring 29 is installed in the center of the large end cover 6 , and the positioning ring 29 and the positioning pin 10 fix the distribution plate 11 on the large end cover 6 . The positioning ring 20 fixes the swash plate 21 on the housing 16 . The swash plate 21 , the cylinder shaft 2 , and the housing 16 are all provided with water guide grooves, and drain and release pressure through the leakage port on the housing 16 .

The shaft end of the cylinder shaft 2 is sealed by the shaft seal 3, the large end cover 6 is fixed with the small end cover by the screw 5, and is sealed with the O-ring 7 and the large end cover 6, and the large end cover 6 is connected with the cylinder shaft 2 The O-ring 9 is used for sealing, and the big end cover 6 and the housing damping hole 16.1 are sealed by an O-ring 8 .

Working process of the present invention is:

The center spring 12 applies force to the center spherical hinge 14 via the pressing rod 13, and applies force to each plunger shoe assembly 24 on average through the return plate 15, so as to ensure that the shoe sole 24.1 is always in close contact with the swash plate 21 Swipe on an incline. The high-pressure water flows into the water-absorbing waist groove 11.2 on the flow distribution plate 11 connected to it through the water inlet hole 6.1 on the large end cover 6 of the motor, and then flows into the communication hole of the floating plate 28 and the floating sleeve 25 connected thereto and enters the cylinder shaft 2 In the big hole, make the plunger 24.4 in the plunger shoe assembly 24 that is positioned at the water inlet side stretch out under the effect of high-pressure water. The swash plate 21 gives the plunger shoe assembly a reaction force perpendicular to the slope of the swash plate 21. The horizontal component force of the reaction force is balanced with the hydraulic pressure in the horizontal direction of the plunger assembly 24. The vertical component force of the reaction force makes the plunger slide. The shoe assembly 24 generates torque on the cylinder shaft 2 . The plunger shoe assembly 24 located on the return water side of the motor is forced to retract, and the water in the cylinder hole passes through the communication hole of the floating sleeve 25 and the floating plate 28, and the drainage waist groove 11.1 on the distribution plate 11, and flows from the motor to the main body. The water outlet hole 6.2 of the end cover 6 is discharged. The force of the plunger shoe assembly 24 on the drain side is the same as that of the plunger shoe assembly 24 on the water inlet side, but because the pressure of the water in and out is different, the torque to the cylinder shaft 2 is different, so the plunger Under the combined torque of the sliding shoe assembly 24 on the cylinder shaft 2, the cylinder shaft 2 drives the plunger sliding shoe assembly 24, the floating sleeve 25, and the floating plate 28 to rotate, outputting torque and rotational speed outward, thereby realizing the plunger 24.4 Continuous reciprocating motion in the cylinder bore.

All friction pairs used in the present invention are directly lubricated and cooled by water, including cylinder bore and plunger, plunger ball head and shoe ball socket, shoe bottom and swash plate, floating plate and distribution plate, cylinder shaft and front and rear sliding bearings, Ball hinge and return plate, etc. The specific implementation process is:

There is a certain gap between the big hole of the cylinder shaft 2 and the plunger 24.4, and the gap is realized by this gap. During the water absorption process, the cylinder bore is filled with high-pressure water, and a high-low pressure difference is formed at both ends of the seal gap between the cylinder bore and the plunger 24.4, so that the high-pressure water in the cylinder bore leaks into the housing 16 through the seal gap, and this part of the leaked water is in the gap The pressure decreases successively, and has a considerable bearing capacity. For the cylinder bore and the plunger 24.4, it plays the role of supporting, lubricating, and cooling.

The high-pressure water in the cylinder hole also passes through the center hole 24.42 of the plunger, the center hole 24.41 of the plunger ball head, and the center hole 24.21 of the shoe to reach between the ball head of the plunger and the socket of the shoe for lubrication; and then passes through the center hole of the shoe 24.21, the shoe bottom 24.11 arrives at the shoe bottom 24.1 and the swash plate 21 to form a friction pair, form a static pressure bearing, and play the role of lubrication and cooling.

The high-pressure water enters the damping hole 16.1 inside the casing 16 through the small hole connected to the water inlet hole 6.1 of the large end cover 6 and the casing 16, and is introduced into the front sliding bearing 19 and the casing through the built-in valve nozzle 17 of the casing 16. Between 16, front slide bearing 19 is formed hydrostatic bearing, also played the effect of lubrication, cooling. In addition, a plurality of water guiding grooves are formed between the front sliding bearing 19 and the cylinder shaft 2 to introduce the water in the housing 16 into them to lubricate and cool the friction pairs.

The main friction pairs of this device are made of stainless steel and engineering plastics. This matching has the characteristics of corrosion resistance, wear resistance and self-lubrication, which can effectively ensure sufficient reliability and service life under water lubrication conditions. Details are as follows:

Bearing pair has two: front sliding bearing 19 and cylinder shaft 2, rear sliding bearing 30 and cylinder shaft 2, two bearings all adopt engineering plastics, and cylinder shaft 2 adopts stainless steel. The ball joint pair is the center ball joint 14 and the return disc 15, wherein the center ball joint 14 is made of stainless steel, and the return disc 15 consists of two parts, the first part is the matrix of stainless steel material, and the second part is an engineering plastic injection molded in the matrix. A ball socket, which cooperates with the central spherical hinge 14 to form a spherical hinge pair. Cylinder body axis 2 also comprises two parts, and the first part is the base body of stainless steel material, and the second part is the engineering plastics of injection molding in the cylinder hole of cylinder base body, and it forms plunger pair with the plunger 24.4 of stainless steel material. Plunger 24.4 is divided into two parts, and a part is the substrate of stainless steel material, and the second part is the engineering plastics of plunger ball head injection molding, and it forms ball-and-socket pair with slide shoe 24.2 ball-and-socket. Sliding shoe bottom 24.1 is engineering plastics, constitutes sliding shoe pair with the swash plate 21 of stainless steel material.

In a word, the matching materials of the main friction pairs used in the present invention are stainless steel materials and engineering plastics, which not only ensure the corrosion resistance, strength, toughness and rigidity of the components in the pure water hydraulic axial motor, but also ensure the self-sufficiency of each friction pair. Lubrication, wear resistance, vibration reduction and other tribological properties can effectively avoid the phenomenon of adhesive wear, corrosion wear and seizure of the friction pair under the condition of high speed, heavy load and water lubrication, and effectively improve the working reliability and service life. life.

Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above implementations, and many variations are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention are considered to be within the protection scope of the present invention.

Claims (5)

1. A fully water-lubricated thru-axis water hydraulic plunger motor, characterized in that it comprises: the large end cap (6) is fixedly connected with the housing (16) through threads, the small end cap (4) and the large end cap (6) Fixed connection, big end cap (6), housing (16) and small end cap (4) constitute the shell; the ball head of plunger (24.4) is inserted into the semicircular ball socket of slide shoe (24.2) Among them, the boot shoulder spacer (24.3) is inlaid on the slide shoe (24.2), and the slide shoe sole (24.1) is pressed into the inner hole of the slide shoe (24.2) for an interference fit. The slide shoe (24.2), the slide shoe sole ( 24.1), boot shoulder spacer (24.3), plunger (24.4) constitute plunger slipper assembly (24); The through-shaft structure is adopted, the cylinder shaft (2) is directly processed into a part of the transmission shaft and the cylinder body, the cylinder shaft (2) is inserted into the inner hole of the housing (16), and the The front sliding bearing (19) inside and the rear sliding bearing (30) located in the big end cover (6) are supported; an odd number of large holes and small holes parallel to the axis are opened on the cylinder shaft (2), and the plunger slides The plungers (24.4) in the shoe assembly (24) are respectively placed in the large holes to form a plunger pair; one end of the cylinder shaft (2) is equipped with a floating disc (28), which is evenly distributed in the small holes of the cylinder shaft (2) One end of an odd number of central springs (12) presses the floating plate (28) on the distribution plate (11), the floating plate (28) and the distribution plate (11) form a distribution pair, and the other end of the center spring (12) presses the push rod (13) Press on the central spherical hinge (14) assembled on the cylinder shaft, and the return disc (15) set outside the central spherical hinge (14) pushes the sliding shoe in each plunger sliding shoe assembly (24) (24.2) is pressed on the inclined surface of the swash plate (21) through the shoe bottom (24.1) to form a shoe pair; one end of the floating sleeve (25) is put into the corresponding cylinder hole of the cylinder shaft (2), and the floating sleeve (25 ) into the corresponding hole of the floating disc (28), the floating disc (28) floats relative to the cylinder shaft (2); a positioning ring (29) is installed at the center of the large end cover (6), and the positioning ring ( 29) and positioning pins (10) fix the distribution plate (11) on the large end cover (6), the positioning ring (20) fixes the swash plate (21) on the housing (16), the housing (16), Both the cylinder shaft (2) and the swash plate (21) are provided with water guide grooves; The plunger (24.4) is provided with a plunger center hole (24.42), the ball head is provided with a plunger ball head center hole (24.41), and the slide shoe (24.2) is provided with a slide shoe center hole (24.21). The center hole of the plug (24.42), the center hole of the plunger ball head (24.41), the center hole of the shoe (24.21), the bottom hole of the shoe (24.11), and the contact surface of the bottom of the shoe (24.1) and the swash plate (21) are communicated in sequence ; A water inlet (6.1) and a water outlet (6.2) are respectively provided on the large end cover (6), and a water absorption waist groove (11.2) and a drainage waist groove (11.1) are respectively opened in the flow distribution plate (11); Water flows into the water-absorbing waist groove (11.2) of the distribution plate (11) connected with it from the water inlet hole (6.1) of the large end cover (6), and then flows into the floating plate (28) and the floating sleeve (25) connected therewith. The connecting hole of the cylinder enters the cylinder hole; when draining, the low-pressure water in the cylinder hole passes through the floating sleeve (25), the floating plate (28) and the drainage waist groove (11.1) on the distribution plate (11) connected therewith, Discharge from the outlet hole (6.2) of the large end cap (6); The large end cover (6) and the housing (16) are connected through the damping hole (16.1), and high-pressure water is introduced into the housing (16) through the damping hole (16.1) to provide static pressure support for the forward sliding bearing (19), and Realize pressure relief in the housing (16) through the leakage port of the housing (16); The cylinder bore of the cylinder shaft (2) is inlaid with injection molding engineering plastics, and the plunger (24.4) of the built-in stainless steel material. 2. A fully water-lubricated thru-axis water hydraulic plunger motor according to claim 1, characterized in that: the cylinder shaft (2) is fixed to the casing through the rear sliding bearing (30) and the front sliding bearing (19) in the shaft hole on the 3. A fully water-lubricated thru-axis water hydraulic plunger motor according to claim 1, characterized in that: the sliding shoe (24.2) is made of metal material, and the sliding shoe bottom (24.1) is made of Made of engineering plastics, the boot shoulder gasket (24.3) is made of engineering plastics; 4. A fully water-lubricated thru-axis water hydraulic plunger motor according to claim 1, characterized in that: the inclination angle of the swash plate (21) is 15-20 degrees. 5. A fully water-lubricated thru-axis water hydraulic plunger motor according to claim 1, characterized in that: the front sliding bearing (19), the swash plate (21) and the cylinder shaft (2) are all open There are water guide grooves for lubrication and cooling.