JPH08144927A - Radial piston motor and radial piston - Google Patents

Abstract

PURPOSE: To simplify a motor and a pump in terms of structure by installing an energizing means, energizing a piston body inward to the radial direction of a turning shaft, in a cylinder. CONSTITUTION: When a high pressure fluid is fed to a high pressure fluid area H from a fluid inflow port 3A, pressing force or an energizing means energizing each of ball pistons(BP) 9b and 9c inward acts on them at each of cylinders 8b and 8c. On the other hand, the fluid is freely exhausted from a low pressure fluid area L via a fluid outflow port 3B, and at each of cylinders 8e and 8f, other ball pistons 9e and 9f become freed. Moreover, at other cylinders 8a and 8d being not yet interconnected to either of the high pressure fluid area H and the low pressure one L, other ball pistons 9a and 9d are maintained at the position intact. Accordingly, the ball pistons 9b and 9c is in a state of being shifted inward, and further the ball pistons 9e and 9f is in a state of being shifted outward, whereby the all piston 9a and 9d become almost the stopped state in the radial direction of a turning shaft. With this, this turning shaft 6 rotates counterclockwise to be shown in an arrow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radial piston motor and a radial piston pump.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Although a radial piston motor and a radial piston pump are used, further cost reduction and simplification of the structure therefor are desired.

It is an object of the present invention to realize the simplification and cost reduction of the structures of the radial piston motor and the radial piston pump by adopting a novel structure.

[0004]

According to the present invention, in order to achieve the above object, a rotary shaft is inserted in a casing, and a cam member capable of rotating together is attached to the rotary shaft. A fluid supply side valve plate member capable of rotating together with the rotating shaft is attached to one side of the cam member in the axial direction of the rotating shaft, and the other of the cam members in the axial direction of the rotating shaft. A fluid discharge side valve plate member capable of rotating together with the rotary shaft is attached to the side, and the fluid supply side valve plate member and the fluid discharge side valve are provided outside the cam member in the radial direction of the rotary shaft. A cylinder block is arranged between the plate member and the cylinder block is fixed to the casing,
The fluid supply side valve plate member and the fluid discharge side valve plate member are respectively slidable on both sides of the cylinder block in the radial direction of the rotation shaft, and the cylinder block has the rotation shaft A plurality of cylinders extending along the radial direction are arranged, and each of these cylinders accommodates at least a part of a piston body,
The piston body is capable of abutting an inner end in the radial direction of the rotary shaft on a cam surface formed on the outer periphery of the cam member within a reciprocating stroke range in the cylinder,
In the cylinder block, a fluid supply side flow extending from a portion outside the reciprocating stroke range of the piston body in each cylinder in the radial direction of the rotating shaft to a sliding surface with the fluid supply side valve plate member. A hole and a fluid discharge side flow hole extending to a sliding surface with the fluid discharge side valve plate member are formed, and the fluid supply side flow hole is formed in the fluid supply side valve plate member when rotating with the rotary shaft. A plurality of fluid supply side valve holes that can communicate with the holes are formed, and a plurality of fluid discharge side valves that can communicate with the fluid discharge side flow holes when rotating with the rotating shaft in the fluid discharge side valve plate member. A hole is formed, and the fluid supply side valve hole and the fluid discharge side valve hole are arranged at positions where they do not communicate with each other through the fluid supply side circulation hole, the cylinder and the fluid discharge side circulation hole. And The inclination of the cam surface along the circumferential direction of the rotary shaft is such that the fluid supply side valve hole has an angular region around the rotary shaft in which the rotation center of the rotary shaft is considered and the fluid discharge side valve hole has the rotary shaft. Is set so that one of them is an upward slope and the other is a downward slope in the angle region in which the center of rotation of the fluid supply side valve plate member and the inner wall of the casing are formed. Is formed, a low pressure fluid region is formed between the fluid discharge side valve plate member and the inner wall of the casing, and a fluid inlet port that is in communication with the high pressure fluid region is disposed in the casing. And a fluid outlet that is in communication with the low-pressure fluid region is disposed in the casing,
A radial piston motor is provided.

In one aspect of the present invention, all of the cam member, the fluid supply side valve plate member and the fluid discharge side valve plate member are splined to the rotary shaft.

[0006] In one aspect of the present invention, the cylinder block is formed with six cylinders, and the cylinders are adjacent to each other in a circumferential direction of the rotary shaft and form an angle of 60 degrees with each other. .

In one aspect of the present invention, the fluid supply side valve plate member and the fluid discharge side valve plate member are formed with five fluid supply side valve holes and five fluid discharge side valve holes, respectively. Each of these valve holes is an elongated hole elongated in the circumferential direction of the rotary shaft.

In one aspect of the present invention, the cam surface has a columnar shape along the axial direction of the rotary shaft.

In one aspect of the present invention, the piston body includes a ball portion and a piston portion that receives the ball portion, and the ball portion is capable of contacting the cam surface.

In one aspect of the present invention, the piston body comprises a columnar portion having a convex columnar shape along the axial direction of the rotating shaft and a piston portion connected to the columnar portion,
The columnar portion is not housed in the cylinder but can come into contact with the cam surface, and the piston portion is housed in the cylinder.

Further, according to the present invention, in order to achieve the above object, a biasing force for biasing the piston body inward in the radial direction of the rotary shaft is provided in the cylinder of the radial piston motor as described above. A radial piston pump, characterized in that the means are arranged.

In one aspect of the present invention, the urging means comprises a compression coil spring arranged in a portion outside the piston body in the radial direction of the rotary shaft in the cylinder.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing a first embodiment of a radial piston motor according to the present invention, and FIGS. 2 and 3 are sectional views thereof.

In these figures, 2 is a casing main body portion, 4 is a casing lid body portion, which are joined by bolts and integrated to form a casing. A substantially cylindrical cavity 5 is formed in the casing body 2 so as to be rotationally symmetrical about the XY direction. A rotary shaft 6 in the XY direction is arranged in the cavity 5. The rotary shaft 6 is rotatably supported at the Y direction end by the casing main body 2 through a bearing, and is rotatably supported at the X direction end by the casing lid 4 through the bearing. It is supported and extends out of the casing. The rotary shaft 6 has a spline 6A in a portion inside the casing.

An annular cylinder block 8 is disposed in the casing body cavity 5. The cylinder block 8 is fixed to the casing body 2 with bolts. The cylinder block 8 has a cylindrical outer peripheral surface adapted to the inner peripheral surface of the cavity 5, and further has a cylindrical inner peripheral surface. The cylinder block 8 has six cylinders 8a, 8 radially along the radial direction of the rotary shaft 6.
b, 8c, 8d, 8e and 8f are formed. These cylinders are evenly arranged in the circumferential direction of the rotary shaft 6, that is, adjacent cylinders form an angle of 60 degrees with each other. Each of these cylinders is formed so as to penetrate from the inner peripheral surface to the outer peripheral surface of the cylinder block 8. In the cylinder block 8, fluid supply side circulation holes 20a, 20b, 20c, 20d, 20e, which penetrate through the cylinder block 8 to the surface on the X side at positions corresponding to the cylinders,
20f are formed, and similarly, fluid discharge side circulation holes 22a, 22b, 22c, 22d, 22 which penetrate through the cylinder to the surface on the Y side at positions corresponding to the cylinders.
e, 22f are formed. These flow holes extend in the XY direction.

Then, each of the cylinders 8a, 8b, 8
c, 8d, 8e, and 8f have ball pistons 9a and 9f.
b, 9c, 9d, 9e and 9f are arranged. The ball piston 9a, as shown in FIG.
8 and a piston portion 29, and a spherical ball portion 28 is housed in a concave spherical surface formed on the end surface of the piston portion 29. The side surface of the piston portion 29 has a cylindrical shape adapted to the inner surface of the cylinder. A fluid passage 30 having a small cross-sectional area is formed in the piston portion 29 so as to extend therethrough between both end faces thereof. As shown in the drawing, the ball piston 9a is arranged such that the ball portion is located inside and the piston portion is located outside in the radial direction of the rotary shaft 6. Other ball piston 9
b, 9c, 9d, 9e and 9f are also the ball piston 9
It has the same configuration and arrangement as a.

A cam member 10 is arranged further inward of the inner peripheral surface of the cylinder block 8. The cam member 1
Reference numeral 0 has a spline hole in the center that engages with the spline 6A of the rotary shaft 6, and the outer peripheral surface is a cam surface 10A having a star-shaped cross-section in the plane orthogonal to the XY direction.

On the other hand, a fluid supply side valve plate member 12 is arranged adjacent to the X-direction end surface of the cylinder block 8. The valve plate member 12 has the rotary shaft spline 6 at the center.
The cylinder block 8 has a spline hole that engages with A.
b, 20c, 20d, 20e, and 20f, the fluid supply side valve hole 12-1, which is an arc-shaped elongated hole extending over an appropriate length in the circumferential direction at a radial position equivalent to that of the rotating shaft.
12-2, 12-3, 12-4, 12-5 are formed. The fluid supply side valve holes are evenly arranged in the circumferential direction, that is, the adjacent fluid supply side valve holes are arranged at positions displaced from each other by an angle of 72 degrees.

A fluid discharge side valve plate member 14 is disposed adjacent to the end surface of the cylinder block 8 in the Y direction. The valve plate member 14 has the rotary shaft spline 6 at the center.
It has a spline hole for engaging with A, and the fluid discharge side circulation holes 22a, 22 of the cylinder block 8 are provided in the outer peripheral portion.
b, 22c, 22d, 22e, and 22f, the fluid discharge side valve hole 14-1, which is an arc-shaped elongated hole extending over an appropriate length in the circumferential direction at the radial position of the rotary shaft,
14-2, 14-3, 14-4, 14-5 are formed. The fluid discharge side valve holes are evenly arranged in the circumferential direction, that is, the adjacent fluid discharge side valve holes are arranged at positions offset from each other by an angle of 72 degrees.

As can be seen from the figure, the fluid supply side valve hole and the fluid discharge side valve hole are arranged so as to be offset by an angle of 36 degrees with respect to the circumferential direction. As can be seen from FIG. 3, the fluid supply side valve hole and the fluid discharge side valve hole are arranged in the circumferential direction, and the fluid discharge side circulation holes 22a, 22d and the like (the fluid supply side circulation holes 20a, 20d and the like are also provided between them). ) Are separated as much as possible so that they do not overlap.

In the casing, a high pressure fluid region H is formed on the X side of the fluid supply side valve plate member 12, and a low pressure fluid region L is formed on the Y side of the fluid discharge side valve plate member 14. Has been done. A high pressure fluid inlet 3A is formed in the casing body 2 so as to communicate with the high pressure fluid region H, and a fluid outlet 3B is connected so as to communicate with the low pressure fluid region L. There is.

The relationship between the shape of the cam surface 10A of the cam member 10 and the circumferential positions of the fluid supply side valve hole and the fluid discharge side valve hole is as shown in FIG. In FIG. 5, O indicates the center of rotation of the rotary shaft 6. That is, FIG.
It is the schematic seen in the rotating shaft direction similarly to FIG. Draw two straight lines connecting both circumferential ends of the fluid supply side valve hole 12-1 and the rotation center O, and draw two straight lines connecting both circumferential ends of the fluid discharge side valve hole 14-1 and the rotation center O. When pulled, the cam surface 10A ′ of the cam member makes an upward gradient in the counterclockwise direction in the angular region around the rotation axis O sandwiched by the two straight lines relating to the fluid supply side valve hole 12-1, and the fluid is discharged. Rotation axis O sandwiched by two straight lines relating to the side valve hole 14-1
The shape of the cam surface 10A is set so that the cam surface 10A ″ of the cam member has a downward slope in the counterclockwise direction in the angular region around the arrow. Other fluid supply side valve holes and fluid discharge side valve holes Is also the same.

As a result, when each cylinder communicates with the high pressure fluid region H through the fluid supply side circulation hole and the fluid supply side valve hole, a counterclockwise rotational force is always applied to the cam member 10 by the ball piston. To be done. At that time, the ball piston in the cylinder communicating with the low-pressure fluid region L can freely move outward in the radial direction of the rotation axis. Therefore, the rotary shaft 6 that is splined with the cam member 10 is rotated counterclockwise. With the rotation of the rotary shaft 6, the fluid supply side valve plate member 12 and the fluid discharge side valve plate member 14 which are splined with the rotary shaft 6 are rotated counterclockwise.

In the apparatus of this embodiment, the circumferential positional relationship between the shape of the cam surface 10A of the cam member 10 and the fluid supply side valve hole 12 and the fluid discharge side valve hole is as shown in FIG. Has become.

That is, in the cylinder 8a, the ball piston 9a is located on the innermost side of the range of reciprocating movement within the cylinder, and the ball portion is located on the star-shaped first trough of the cam surface 10A. . The flow holes 22a and 20a corresponding to the cylinder 8a do not communicate with the fluid discharge side valve hole and the fluid supply side valve hole, respectively.

In the cylinder 8b, the ball piston 9b is displaced outward from the innermost side in the radial direction of the rotation axis, and the ball portion is adjacent to the star-shaped first valley portion of the cam surface. It is located over the mountainous area of. The circulation hole 22b corresponding to the cylinder 8b does not communicate with the fluid discharge side valve hole, but the circulation hole 20b corresponding to the cylinder 8b communicates with the fluid supply side valve hole 12-2.

In the cylinder 8c, the ball piston 9c is further displaced outward in the radial direction of the rotating shaft, and the ball portion is in the second trough adjacent to the star-shaped first peak portion of the cam surface. It is located beyond the second mountain adjacent to the section. Then, the circulation hole 22c corresponding to the cylinder 8c
Does not communicate with the fluid discharge side valve hole, but the flow hole 20c corresponding to the cylinder 8c communicates with the fluid supply side valve hole 12-3.

In the cylinder 8d, the ball piston 9d is located on the outermost side, and the ball portion is the third mountain adjacent to the third valley portion adjacent to the star-shaped second mountain portion of the cam surface 10A. Located in the department. The flow holes 22d and 20d corresponding to the cylinder 8d do not communicate with the fluid discharge side valve hole and the fluid supply side valve hole, respectively.

In the cylinder 8e, the ball piston 9e is displaced inward in the radial direction from the outermost side, and the ball portion is in the fourth valley adjacent to the star-shaped third peak portion of the cam surface. It is located in front of the fourth mountain portion adjacent to the section.
The circulation hole 22e corresponding to the cylinder 8e communicates with the fluid discharge side valve hole 14-4, but the circulation hole 20e corresponding to the cylinder 8e does not communicate with the fluid supply side valve hole.

In the cylinder 8f, the ball piston 9f is further displaced inward in the radial direction, and the ball portion forms a fifth valley portion adjacent to the star-shaped fourth peak portion of the cam surface. It is located beyond. And cylinder 8
The flow hole 22f corresponding to f communicates with the fluid discharge side valve hole 14-5, but the flow hole 20f corresponding to the cylinder 8f.
Does not communicate with the valve hole on the fluid supply side.

In this embodiment, when a high-pressure fluid (for example, oil) is supplied from the fluid inlet 3A to the high-pressure fluid region H, a cylinder communicating with the high-pressure fluid region H (8b in FIG. 3). , 8c), a pressing force acts inwardly on the ball pistons (9b, 9c in FIG. 3). On the other hand, since the fluid is freely discharged from the low-pressure fluid region L via the fluid outlet 3B, the cylinder communicating with the low-pressure fluid region L (see FIG. 3).
8e, 8f), the ball pistons (9e, 9f in FIG. 3) are free. Further, in the cylinders (8a, 8d in FIG. 3) that are not in communication with either the high pressure fluid region H or the low pressure fluid region L, the ball pistons (9a, 9d in FIG. 3) are maintained at that position. However, here, since the radial movement of the ball piston due to the rotation of the cam member 10 per unit angle is extremely small, the resistance force against the rotation of the cam member 10 is extremely small.

Therefore, in FIG. 3, the ball piston 9
b and 9c are in the inward moving state as shown by the arrows, the ball pistons 9e and 9f are in the outward moving state as shown by the arrows, and the ball pistons 9a and 9d are substantially in the radial direction of the rotating shaft. It is in a stopped state. As a result, the rotary shaft 6 is rotated counterclockwise in FIG. 3 as indicated by the arrow. Then, along with the rotation of the rotating shaft, the fluid supply side valve plate member 12
And the fluid discharge side valve plate member 14 also rotates at the same time.

In the present embodiment, the fluid (oil) is filled in the inter-structure member regions other than the high pressure fluid region H and the low pressure fluid region L in the casing. And
Through the fluid passage 30 of the piston portion 29 of the ball piston shown in FIG. 4, fluid flow based on the fluid pressure difference is performed, and thereby a lubricating function is realized.

FIG. 6 is a partial sectional view showing an embodiment of the radial piston pump according to the present invention. This figure is shown in FIG.
The same part as is shown. In this figure, the same members as those in FIG. 3 are designated by the same reference numerals.

In the present embodiment, structurally, a compression coil spring, which is a biasing means for biasing the ball piston (9a, etc.) inward in the radial direction of the rotary shaft 6, is provided inside each cylinder (8a, etc.). 40 is arranged only in the above first
This is different from the radial piston motor of the embodiment. As shown in the figure, the compression coil spring 40 is arranged at a portion outside the ball piston in the radial direction of the rotation axis in the cylinder.

Therefore, in this embodiment, by rotating the rotary shaft 6 from the outside, the fluid is sucked into the casing through the fluid inlet 3A and discharged from the casing through the fluid outlet 3B. Then, the pump action can be performed.

FIG. 7 is an exploded perspective view showing a second embodiment of the radial piston motor according to the present invention, and FIG. 8 is a sectional view thereof. In these drawings, members having the same functions as those in FIGS. 1 to 6 are designated by the same reference numerals.

In this embodiment, three members 1A, 1B and 1C are used as members constituting the casing, and the inside of each of these members has a substantially cylindrical cavity of rotational symmetry about the XY direction. 5A, 5B and 5C (not shown in the figure) are formed. Further, in this embodiment, both ends of the rotary shaft 6 extend to the outside of the casing.
These constituent members 1A, 1B and 1C are joined by bolts and integrated to form a casing.

The shapes of the cam member 10, the fluid supply side valve plate member 12 and the fluid discharge side valve plate member 14 are the same as those of the first embodiment, but the shape of the cylinder block 8 is slightly different from that of the first embodiment. ing. That is, the inner peripheral surface of the cylinder block 8 is not a simple cylindrical shape, and the key grooves 11A and 11B in the XY directions are formed on the outer peripheral surface. The key grooves 11A, 11B fix the cylinder block 8 to the casing by interposing the keys 15A, 15B between the key grooves 13A, 13B formed on the inner peripheral surface of the casing component 1B. It is used for

Further, a characteristic of this embodiment is that
A piston body (for example, 9f ') having a function corresponding to the ball pistons 9a to 9f of the first embodiment is shown in FIG.
As shown in, the axial direction of the rotary shaft 6 (X-Y direction)
A columnar portion 32 having a convex columnar shape along with a piston portion 33 connected to the columnar portion, the columnar portion 32 is not housed in the cylinder and is capable of contacting the cam surface 10A, That is, the piston portion 33 is housed in the cylinder. Therefore, in this embodiment, since the columnar portion 32 and the cam surface 10A are in line contact with each other, the sliding contact pressure is reduced and wear can be reduced.

[0042]

As described above, according to the present invention, there is provided a radial piston motor and a radial piston pump having a novel structure for fixing the cylinder block and rotating the valve plate member together with the cam member, whereby the radial piston is provided. The simplification of the structure of the motor and the radial piston pump and the cost reduction are realized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a radial piston motor according to the present invention.

FIG. 2 is a sectional view showing a first embodiment of a radial piston motor according to the present invention.

FIG. 3 is a sectional view showing a first embodiment of a radial piston motor according to the present invention.

FIG. 4 is an exploded perspective view of a ball piston in the first embodiment of the radial piston motor according to the present invention.

FIG. 5 is a diagram showing the relationship between the arrangement of fluid supply holes of the fluid supply side valve plate member and the fluid discharge holes of the fluid discharge side valve plate member and the shape of the cam surface of the cam member in the first embodiment of the radial piston motor according to the present invention. It is a schematic explanatory drawing which shows.

FIG. 6 is a partial sectional view showing an embodiment of the radial piston pump according to the present invention.

FIG. 7 is an exploded perspective view showing a second embodiment of the radial piston motor according to the present invention.

FIG. 8 is a sectional view showing a second embodiment of the radial piston motor according to the present invention.

FIG. 9 is an exploded perspective view of a piston body in a second embodiment of the radial piston motor according to the present invention.

[Explanation of symbols]

1A, 1B, 1C Casing component 2 Casing body 3A Fluid inlet 3B Fluid outlet 4 Casing lid 5,5A, 5B, 5C Cavity 6 Rotating shaft 6A Spline 8 Cylinder block 8a, 8b, 8c, 8d, 8e , 8f Cylinder 9a, 9b, 9c, 9d, 9e, 9f Ball piston 9f 'Piston body 10 Cam member 10A, 10A', 10A "Cam surface 11A, 11B, 13A, 13B Key groove 12 Fluid supply side valve plate member 12- 1, 12-2, 12-3, 12-4, 12-5
Fluid supply side valve hole 14 Fluid discharge side valve plate member 14-1, 14-2, 14-3, 14-4, 14-5
Fluid discharge side valve hole 15A, 15B key 20a, 20b, 20c, 20d, 20e, 20f
Fluid supply side circulation holes 22a, 22b, 22c, 22d, 22e, 22f
Fluid discharge side circulation hole 28 Ball portion 29 Piston portion 30 Fluid passage 32 Columnar portion 33 Piston portion 40 Compression coil spring H High pressure fluid region L Low pressure fluid region O Rotation axis rotation center

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F04B 1/047 1/053

Claims (9)

[Claims] 1. A rotating shaft is inserted in a casing, and a cam member capable of rotating together is attached to the rotating shaft, and the cam member is provided on one side of the cam member in the axial direction of the rotating shaft. A fluid supply side valve plate member capable of rotating together with the rotating shaft is attached, and a fluid discharge side valve plate member capable of rotating together with the rotating shaft is provided on the other side of the cam member in the axial direction of the rotating shaft. A cylinder block is disposed between the fluid supply side valve plate member and the fluid discharge side valve plate member outside the cam member in the radial direction of the rotating shaft. The fluid supply side valve plate member and the fluid discharge side valve plate member are fixed to the casing, and can slide on both sides of the cylinder block in the radial direction of the rotating shaft. The cylinder block is provided with a plurality of cylinders extending in the radial direction of the rotary shaft, and each of the cylinders accommodates at least a part of a piston body. Has an inner end in the radial direction of the rotary shaft that can contact a cam surface formed on the outer periphery of the cam member within the range of reciprocating movement in the cylinder. A fluid supply side circulation hole extending from a portion outside the reciprocating stroke range of the piston body in the cylinder in the radial direction of the rotation shaft to a sliding surface with the fluid supply side valve plate member, and the fluid discharge side A fluid discharge side circulation hole extending up to a sliding surface with the valve plate member is formed, and the fluid supply side valve plate member is provided with the fluid supply side circulation hole when rotating with the rotation shaft. A plurality of fluid supply side valve holes that can pass through are formed, and a plurality of fluid discharge side valve holes that can communicate with the fluid discharge side flow hole when rotating with the rotating shaft are formed in the fluid discharge side valve plate member. The fluid supply side valve hole and the fluid discharge side valve hole are arranged at positions that do not communicate with each other through the fluid supply side circulation hole, the cylinder and the fluid discharge side circulation hole, The gradient of the cam surface along the circumferential direction of the rotary shaft is such that the fluid supply side valve hole has an angular region around the rotary shaft in which the rotation center of the rotary shaft is considered and the fluid discharge side valve hole is the rotary shaft. Is set so that one is an uphill slope and the other is a downhill slope with respect to the angle region in which a rotation center of the high pressure fluid region is provided between the fluid supply side valve plate member and the inner wall of the casing. Is formed, and the fluid drainage A low-pressure fluid region is formed between the outlet valve plate member and the inner wall of the casing, and a fluid inlet port that is in communication with the high-pressure fluid region is disposed in the casing, and the casing has the A radial piston motor, wherein a fluid outlet that is in communication with the low-pressure fluid region is arranged. 2. The radial according to claim 1, wherein the cam member, the fluid supply side valve plate member and the fluid discharge side valve plate member are all spline-coupled to the rotation shaft. Piston motor. 3. The cylinder block is formed with six of the cylinders, the cylinders being adjacent to each other in the circumferential direction of the rotary shaft, forming an angle of 60 degrees with each other. The radial piston motor according to claim 1 or 2. 4. The fluid supply side valve plate member and the fluid discharge side valve plate member are respectively formed with five fluid supply side valve holes and five fluid discharge side valve holes. The radial piston motor according to any one of claims 1 to 3, wherein the radial piston motor has an elongated hole elongated in the circumferential direction of the rotary shaft. 5. The radial piston motor according to claim 1, wherein the cam surface has a columnar shape along the axial direction of the rotary shaft. 6. The piston body comprises a ball portion and a piston portion that receives the ball portion, and the ball portion can contact the cam surface. 5. The radial piston motor according to any one of 5 above. 7. The piston body includes a columnar portion having a convex columnar shape along the axial direction of the rotating shaft and a piston portion connected to the columnar portion, and the columnar portion extends into the cylinder. It is not housed and can contact the cam surface,
The radial piston motor according to claim 5, wherein the piston portion is housed in the cylinder. 8. The radial piston motor according to any one of claims 1 to 7, wherein a biasing means for biasing the piston body inward in a radial direction of the rotary shaft is arranged in the cylinder. A radial piston pump characterized by the following. 9. The radial piston according to claim 8, wherein the biasing means comprises a compression coil spring arranged in a portion outside the piston body in the radial direction of the rotary shaft in the cylinder. pump.