JP2000205118A - Piston pump motor with swash plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swash plate type piston pump motor equipped with a leaf spring involving less dispersion in the spring force capable of hindering a load from acting on the leaf spring in its circumferential direction and reducing the spring force as much as possible. SOLUTION: Through a holder plate 51, a ring-shaped leaf spring 42 is installed between a retainer 40 mounted on an output shaft 22 and a shoe 31 to slide on the sliding surface of a swash plate 30. A leaf spring 42 is provided with a hole 57 to admit insertion of the mounting part 32 of the shoe 31, and its fitting part 59 at the inside surface is fitted on the retainer 40 and fixed, and at the periphery a pawl is provided whose second bend 66 abuts to the holder plate 51 to allow the spring force to act on the shoe 31, while the forefront 68 is fitted in a notch 53 provided in the holder plate 51 so as to hinder the shoe 31 and leaf spring 42 from making relative displacement in the circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type piston pump or motor having a plurality of pistons arranged in parallel with an output shaft and a swash plate inclined with respect to a plane perpendicular to the output shaft. .

[0002]

FIG. 6 is a sectional view showing a conventional swash plate type piston motor 1, and FIG. 7 is a front view showing a leaf spring 9 mounted on the swash plate type piston motor 1. As shown in FIG. Such a piston motor 1 is disclosed in Japanese Utility Model Laid-Open No. 50-82702. The swash plate type piston motor 1 includes an output shaft 10,
A cylinder block 2 coaxially connected to the output shaft 10,
A plurality of pistons 4 mounted on the cylinder block 2,
A swash plate 6, and piston chambers 3 are formed in the cylinder block 2 at equal intervals in the circumferential direction in parallel with the output shaft 10. The shoe 5 is rotatably mounted on the tip of the. The swash plate 6 is arranged to be inclined with respect to a plane perpendicular to the output shaft 10 and has a flat sliding surface facing the cylinder block 2. The shoe 5 has a sliding portion 16 that slides on the sliding surface of the swash plate 6 and a mounting portion 12 to which the tip of the piston 4 is mounted. An output shaft 10 between the swash plate 6 and the cylinder block 2 is provided with a retainer 8 serving as a plate spring support around the output shaft 10, and an annular plate spring 9 is provided between the retainer 8 and the shoe 5. Intervened.

The leaf spring 9 has a flat portion 17 and a fitting portion 18 which protrudes from the inner peripheral portion and is opened to fit into the retainer 8. The mounting portion 12 of the shoe 5 is inserted through the flat portion 17. A plurality of insertion portions 11 to be cut out from the outer periphery are formed at equal intervals in the circumferential direction. The leaf spring 9 is configured such that the flat portion 17 is provided on the sliding portion 1 of each shoe 5 while the fitting portion 18 is supported by the retainer 8.
The shoe 5 is pressed against the swash plate 6 by resiliently pressing the shoe 6.

[0004] A valve plate 7 is provided on the cylinder block 2 opposite to the side where the piston 4 is arranged. In the valve plate 7, a semi-circular supply hole 19 is formed on the near side in FIG. 6 around the output shaft 10, and a semi-circular discharge hole (not shown) is formed on the far side in FIG. Is done. When driving the swash plate type piston motor 1, hydraulic oil is supplied from the supply hole 19 of the valve plate 7 to the piston chamber 3 on the near side in FIG. 6 among the plurality of piston chambers 3 formed in the cylinder block 2,
Each piston 4 is extended and pressed rightward in FIG. This pressing force acts on the swash plate 6 via the shoe 5.
Since the swash plate 6 is arranged obliquely, the shoe 5 pressed against the swash plate 6 is rotated on the output shaft 10 clockwise as viewed from the left in FIG. To slide. The rotation of the shoe 5 rotates the output shaft 10 via the cylinder block 2. The piston 4 disposed on the back side with respect to the paper surface of FIG. 6 is guided by the swash plate 6 with the rotation of the cylinder block 2 and contracts to discharge the hydraulic oil in the piston chamber 3 to the valve plate 7. Drain through. Thus, the swash plate type piston motor 1 is driven to rotate.

When the swash plate type piston motor 1 that is driven to rotate is stopped, the supply of hydraulic oil is stopped. When the supply of hydraulic oil is stopped, the rotation of the cylinder block 2 does not stop immediately, but due to inertia. Spin for a while and then stop. At this time, a force for separating the shoe 5 from the swash plate 6 by a pumping action acts on each piston 4 disposed on the near side in FIG. 6, but the shoe 5 is elastically moved toward the swash plate 6 by the leaf spring 9. Since the shoe 5 is pressed, the shoe 5 is prevented from separating from the swash plate 6.

[0006]

The leaf spring 9 is provided in the insertion portion 1.
1 with the mounting portion 12 of the shoe 5 inserted through the flat portion 1
7 is in contact with the sliding portion 16, the leaf spring 9 slides on the sliding portion 16 and the mounting portion 12 contacts the inner peripheral surface of the insertion portion 11 in the circumferential direction. The leaf spring may be deformed due to a pressing load acting in the direction. In the sliding part,
Wear occurs on the leaf spring. Also, the leaf spring 9 is formed by pressing a fitting portion 18 of an inner peripheral portion for applying a spring force, and the whole shape is formed radially as shown in FIG. , The spring force acting on the shoe 5 varies, which may damage the leaf spring 9.

[0007] When the distance between the fitting portion 18 fitted to the retainer 8 and the contact portion of the flat portion 17 with the shoe 5 is small, the spring force of the leaf spring 9 increases, and the pressing force increases. However, if the pressing force is too large, the resistance of the piston motor 1 will be high. Therefore, the spring force of the leaf spring 9 is desirably a weak spring force that does not separate the shoe 5 from the swash plate 6. When the distance between the fitting portion and the contact portion is small and the spring force is large, the variation in the spring force acting on each shoe also becomes large. Conventional techniques including a leaf spring having a small gap between the fitting portion and the contact portion are disclosed in Japanese Utility Model Laid-Open No. 62-3972 and Japanese Patent Laid-Open No. 8-26847.

An object of the present invention is to provide a swash plate type piston motor in which a relatively weak spring force is uniformly applied to each shoe and a load is not applied to a leaf spring in a circumferential direction.

[0009]

According to the first aspect of the present invention, there is provided a mounting portion in which tips of a plurality of pistons inserted into a cylinder block connected to an output shaft are rotatably mounted. A shoe that slides on the sliding surface of the plate around the output shaft, and an annular plate spring interposed between a plate spring support portion provided on the outer periphery of the output shaft, wherein the plate springs are arranged at equal intervals in the circumferential direction. A swash plate type piston pump motor in which a mounting portion of the shoe is inserted into the formed insertion portion, an inner peripheral portion is supported by the plate spring support portion, and the shoe is biased toward the swash plate by a spring. And the shoe is provided with engaging means for preventing circumferential displacement of the leaf spring and the shoe in a state where the inner peripheral surface of the leaf spring insertion portion and the shoe mounting portion are separated in the circumferential direction. And a swash plate type piston pump motor.

According to the present invention, the inner periphery of the leaf spring is pressed and supported by the swash plate side by the leaf spring supporting portion, and the outer peripheral side resiliently presses the shoe to place the shoe on the sliding surface of the swash plate. Pressing elastically. The leaf spring is cut out from the outer circumference,
Or an insertion portion formed as a hole to be inserted is formed,
The mounting portion of the shoe is inserted through the insertion portion.

The leaf spring and the shoe are provided with engaging means for preventing the relative displacement of the leaf spring and the shoe in the circumferential direction when the mounting portion of the shoe and the inner peripheral surface of the insertion portion are separated in the circumferential direction. When each shoe rotates around the output shaft, the rotation of the shoe is transmitted to the leaf spring by the engaging means, and the shoe mounting portion and the inner peripheral surface of the insertion portion are separated from each other. The spring will rotate about the output shaft with the shoe. Therefore, it is possible to prevent the shoe from coming into contact with the insertion portion of the leaf spring during rotation and exerting a pressing load on the leaf spring in the circumferential direction as in the prior art described above.
Further, since the relative displacement in the circumferential direction between the leaf spring and the shoe is prevented by the engagement means, the leaf spring is prevented from sliding at the contact portion that resiliently presses the shoe,
This prevents the contact portion from being worn.
Thus, the load acting on the leaf spring is reduced, the leaf spring is not easily broken, and the durability is improved.

[0012] The leaf spring according to claim 2 is characterized in that the outer peripheral portion is continuous over the entire circumference.

According to the present invention, the outer periphery of the leaf spring is continuous over the entire circumference. That is, the insertion portion through which the mounting portion of the shoe is inserted is formed as a hole. Even if the spring force acting on each shoe varies, the variation is reduced because the outer peripheral portion is continuous over the entire peripheral portion, and the spring force acting on each shoe becomes uniform.

According to a third aspect of the present invention, the leaf spring is characterized in that an outer peripheral portion resiliently presses each shoe.

According to the present invention, the annular leaf spring has an inner peripheral portion supported by a leaf spring supporting portion provided on the output shaft, and an outer peripheral portion furthest away from the output shaft in the radial direction resiliently connects each shoe. Is pressed. Therefore, the distance between the support portion supported by the leaf spring support portion and the acting portion that acts on the spring force can be made as long as possible, whereby the spring force acting on the shoe can be reduced, and the mechanical force of the piston motor can be reduced. Efficiency can be improved, and the strength of the leaf spring itself can be improved.

The inner peripheral portion of the plate spring according to the fourth aspect is formed with a fitting portion which projects to the swash plate side and is opened to fit into the leaf spring support portion, and a plurality of insertion portions are formed. The angle between the flat portion and the direction perpendicular to the sliding surface of the swash plate is 9 in the natural state of the leaf spring where no shoe is attached and no external force acts.
It is characterized in that it is selected to be at least 0 degree and at most 120 degrees.

According to the present invention, the annular plate spring is bent so that the inner peripheral portion protrudes toward the swash plate to form a fitting portion, and this fitting portion is fitted into the leaf spring support portion. The leaf spring is supported by the leaf spring support. An insertion portion is formed in a flat portion extending outward from the fitting portion. If the angle formed between the flat portion where the insertion portion is formed and the fitting portion is small, the spring constant of the leaf spring increases, whereby the pressing force of the shoe pressing against the swash plate becomes excessive, and the mechanical efficiency of the motor increases. However, in the present invention, the angle between the direction perpendicular to the sliding surface of the swash plate and the flat portion of the leaf spring is selected to be 90 degrees or more and 120 degrees or less in the natural state of the leaf spring. By setting the angle to 90 degrees or more, the spring force acting on the shoe can be reduced, and the mechanical efficiency of the motor can be improved. On the other hand, if the angle is larger than 120 degrees, it becomes difficult to press the shoe on the outer periphery of the leaf spring.

According to a fifth aspect of the present invention, the connecting portion where the fitting portion and the flat portion are connected to each other is provided with a groove-shaped reinforcing portion which is recessed on the side opposite to the swash plate and extends in the circumferential direction. Features.

According to the present invention, the fitting portion and the flat portion are not directly connected to each other, but are connected to each other via a groove-shaped reinforcing portion which is recessed on the side opposite to the swash plate and extends in the circumferential direction. If the reinforcing portion is not formed at the connecting portion where the fitting portion and the flat portion are connected, stress will be concentrated on the connecting portion when bending, but the stress concentration is reduced by interposing the groove-shaped reinforcing portion. Thus, fatigue due to repeated bending can be reduced, and the durability of the leaf spring is improved. Also, by changing the concave shape of the groove-shaped reinforcing portion, a desired spring constant can be obtained.

[0020]

FIG. 1 is a sectional view showing a swash plate type piston motor 20 according to an embodiment of the present invention. The swash plate type piston motor 20 includes an output shaft 22 and an output shaft 2.
2 includes a cylinder block 25 coaxially connected to the housing 2, a hollow housing 21 that houses the cylinder block 25, and a cover 35 that closes an opening of the housing 21. The output shaft 22 is attached to a front wall 49 of the housing 21. The bearing 23 mounted on the cover 35 and the bearing 24 mounted on the cover 35 rotatably support the axis L1. The cylinder block 25 is spline-coupled to the output shaft 22 and coupled to the output shaft 22 in a state where displacement about the axis L1 is prevented. A plurality of piston chambers 26 parallel to the axis L1 are provided in the cylinder block 25 at equal intervals around the axis L1.
In the present embodiment, nine are formed. A piston 27 is attached to each piston chamber 26 so as to be able to expand and contract in the direction of the axis L1.
An annular swash plate 30 that is inclined with respect to a plane perpendicular to the axis L1 is fixed to the front wall 48 of the housing 21. Swash plate 3
Reference numeral 0 denotes a sliding surface 48 which is disposed so as to be inclined rightward as it goes upward in FIG.

The piston 27 mounted on the cylinder block 25 has a tip 41 protruding from the cylinder block 25.
Is formed in a spherical shape, and the shoe 31 is
Are rotatably mounted. The shoe 31 has a disk-shaped sliding portion 39 slidably in contact with the sliding surface 48 of the swash plate 30;
A cylindrical mounting portion 32 protruding from the sliding portion 39 and having a spherical mounting recess in which the spherical tip portion 41 of the piston 27 is fitted is formed integrally. Each shoe 31 is mounted on an annular holding plate 51. A retainer 40 that protrudes toward the front wall 49 of the housing 21 and functions as a leaf spring supporting portion is formed on the inner peripheral portion of the cylinder block 25, and an annular leaf spring 42 is provided between the retainer 40 and the pressing plate 51. Is interposed.

FIG. 2 is a sectional view showing the vicinity of the shoe 31, FIG. 3 is a front view showing the pressing plate 51, and FIG. As shown in FIG. 2, the center of the cylinder block 25 is
1 is formed integrally with the cylinder block 25 so as to protrude toward the front wall 49, and the outer peripheral surface 53 is formed so as to constitute the surface of a sphere centered on the center point P on the axis L1.

As shown in FIG. 3, the holding plate 51 has insertion holes 52 through which the mounting portions 32 of the respective shoes 31 are inserted at equal intervals in the circumferential direction, and a shaft insertion hole through which the output shaft 22 is inserted at the center. 55 are formed. The inner diameter D1 of the insertion hole 52 is larger than the outer diameter of the mounting part 32, and the mounting part is loose. A rectangular notch 53 is formed in the outer peripheral portion between the insertion holes 52.

As shown in FIG. 2 and FIG.
Reference numeral 2 denotes an annular thin metal plate having an inner peripheral portion which projects toward the swash plate 30 and is opened to form a fitting portion 59 which fits into the outer peripheral surface 53 of the retainer 40. In the flat portion 60 extending outward from the fitting portion 59, insertion holes 57 through which the mounting portion 32 of each shoe 31 is inserted are formed at equal intervals in the circumferential direction. The mounting portion 32 of the shoe 31 passes through the insertion hole 57, and the inner diameter D2
Is slightly larger than the inner diameter D1 of the insertion hole 52 of the holding plate 51. Claws 56 projecting radially outward from the flat portion 60 are provided in the outer peripheral portion corresponding to the space between the insertion holes 57. As shown in FIG. 2, the claw 56 is bent at the first bent portion 65 from the flat portion to the swash plate side, and the second portion is radially outward at the middle portion.
It is bent at the bent portion 66 and further bent at the third bent portion 67 toward the swash plate 30 between the distal end portion and the second bent portion. Leaf spring 42
The second bent portion 66 of the claw 56 resiliently contacts the holding plate 51 in a state where the fitting portion 59 of the inner peripheral portion is fitted and fixed to the outer peripheral surface 53 of the retainer 40, The notch 5 of the holding plate 51 is located at the tip 68 of the claw ahead of the third bent portion 67.
Fit into 3. At this time, both circumferential ends 68a, 68b of the distal end portion 68 of the claw 56 are fitted or abutted on the circumferential side walls 53a, 53b of the notch 53 of the holding plate 51 with a slight gap. .

Referring back to FIG. Cylinder block 2
A valve plate 33 is interposed between the cover 5 and the cover 35. The valve plate 33 is attached to the cover 35 in a state where rotation about the axis L1 is prevented. The supply hole 34 is formed in a semicircular shape on the near side in FIG. The cover 35 has a discharge hole (not shown) formed in a semicircular shape on the back side, and the cover 35 has a hydraulic oil supply port 43 connected to a supply hole of the valve plate 33 and a discharge hole of the valve plate 33. A hydraulic oil outlet 44 is formed.

When the swash plate type piston motor 20 is driven, hydraulic oil is supplied from a hydraulic oil supply port 43 formed in the cover 35. Then, hydraulic oil is supplied to the respective piston chambers 26 of the cylinder block 25 disposed on the near side with respect to the paper surface of FIG. 1 through the supply holes 34 of the valve plate 33. Then, the piston 27 extends and presses the swash plate 30. As shown in FIG. 1, the swash plate 30 is arranged to be inclined leftward as it goes downward,
Shoe 3 pressed against swash plate 30 by piston 27
1 acts downwardly. Therefore, the piston 27 disposed on the near side in FIG. 1 is displaced downward while extending, and the cylinder block 25 and the output shaft 22 connected to the cylinder block 25 rotate clockwise when viewed from the left in FIG. Will be driven.

Each piston 27 disposed on the back side with respect to the plane of FIG. 1 is pushed upward from the swash plate 30 while being moved upward with the rotation of the cylinder block 25 and contracts. Then, the hydraulic oil in the piston chamber 26 is supplied to the valve plate 33.
And the hydraulic oil discharge port 44 of the cover 35 is discharged to the outside. Thus, the output shaft 22 is rotationally driven.

Further, the cylinder block 2 is supplied from the supply hole 34.
The hydraulic oil supplied to the piston chamber 26 of the piston 5
The oil is supplied between the shoe 31 and the sliding surface of the swash plate 30 via oil holes 45 and 47 formed in the shoe 31 and functions as a lubricant. It can slide smoothly.

When the output shaft 22 is stopped, the rotation of the cylinder block 25 is stopped by stopping the supply of the hydraulic oil from the hydraulic oil supply hole 43 and closing the passage communicating with the discharge hole 44. At this time, the cylinder block 25 rotates for a while due to inertial force after the supply of the hydraulic oil is stopped, and then stops. At this time, the swash plate 30 is attached to the shoe 31 to perform the pumping action.
Force acts in the direction away from The shoe 31 is connected to the swash plate 3 via the holding plate 51 by the spring force of the leaf spring 42 interposed between the retainer 40 and the holding plate 51.
Since the shoe 31 is pressed against the second side, the shoe 31 is prevented from separating from the sliding surface 48 of the swash plate 30.

As described above, the leaf spring 42 is
0 is provided to prevent the shoe 31 from separating from the swash plate 30 when the rotation of the piston motor 20 is stopped. If the spring force is too large, the resistance between the shoe 31 and the swash plate 30 increases, and the mechanical force of the piston motor 20 is increased. Efficiency will be reduced. Further, in order to reduce the increase / decrease of the spring force due to the variation in the axial dimension of each part, it is preferable that the spring constant of the leaf spring 42 is low. In the present embodiment, as described above, the leaf spring 42 has the inner peripheral portion fitted and supported by the retainer 40, and the second bent portion 66 of the claw 56 formed on the outer peripheral portion abuts on the peripheral edge portion of the holding plate 51. To apply a spring force to the shoe 31,
The width W (see FIG. 4) from the fitting portion 59 fitted into the retainer to the second bent portion 66 that acts on the spring force can be made as large as possible, and the spring force can be reduced.

The mounting portion 32 of the shoe 31 is loosely inserted into the insertion hole 52 of the holding plate 51 and the insertion hole 57 of the leaf spring 42, and the claw 56 of the leaf spring 42 is engaged with the engaging portion 68 at the tip. 51 is fitted into and engaged with the notch 53, and the holding plate 5
1 and the leaf spring 42 are prevented from relative displacement in the circumferential direction. Further, since the outer diameter D1 of the insertion hole 52 of the holding plate 51 is formed slightly smaller than the outer diameter D2 of the insertion hole 57 of the leaf spring 42, even if the holding plate 51 moves in the circumferential direction, The mounting portion 3 for the shoe 31 is provided on the inner peripheral surface of the insertion hole 57.
2 comes into contact, and the mounting portion 32 of the shoe 31 comes into contact with the inner peripheral surface of the insertion hole 57 of the leaf spring 58, thereby preventing a load from acting on the leaf spring 42 in the circumferential direction. The pressing plate 51 and the claws 56 of the leaf spring 42 function as engagement means for preventing relative displacement between the leaf spring 42 and the shoe 31 in the circumferential direction.

FIG. 5 is an enlarged sectional view showing the leaf spring 42 when the shoe 31 and the holding plate 51 are not mounted. As shown in FIG. 5, the leaf spring 42 is
The connecting portion where the fitting portion 59 that fits into the flat portion 60 in which the insertion hole 57 is formed is recessed in the opposite side to the swash plate 30,
A groove-shaped reinforcing portion 70 extending over the entire inner peripheral portion is formed. As described above, since the fitting portion 59 and the flat portion 60 are not directly connected but are connected via the reinforcing portion 70 which is once recessed on the side opposite to the swash plate 30, concentration of stress to bending is prevented, and The durability is improved. Further, as shown in FIG. 5, the leaf spring 42
Leaf spring 4 in which no external force acts on flat portion 60 without mounting 1
2, a straight line L perpendicular to the sliding surface 48 of the swash plate 30.
2 and the flat portion 60 have an angle θ of 90 degrees or more and 12
It is formed in a substantially conical shape by press working so as to be selected at 0 degrees or less. By selecting the angle θ in this manner, the angle formed between the fitting portion 59 and the flat portion 60 can be increased, and thereby the spring constant of the leaf spring 42 can be reduced. If the angle θ is less than 90 degrees, the spring constant of the leaf spring 42 becomes too large, and if the angle θ exceeds 120 degrees, it is provided on the outer peripheral portion of the leaf spring 42 and further extends the claw 56 that contacts the pressing plate 51. You have to do it. When the presser plate 51 and the shoe 31 are attached to the leaf spring 42 in such a state and the piston motor 20 is assembled, the claws 56 of the leaf spring 42 abut on the presser plate 51, and the outer periphery of the leaf spring 42 has the swash plate 30. , And a spring force acts to press the shoe 31 against the swash plate 30. Since the outer peripheral portion of the leaf spring 42 is continuous over the entire circumference, the spring force acting on each shoe 31 is constant.
The difference in spring force is reduced. The leaf spring 42 and the shoe 3
The variation in the spring force is also absorbed by the pressing plate 51 interposed between the spring 1 and the pressing plate 51.

In this embodiment, the leaf spring 42 and the shoe 31
The engagement means for preventing the relative displacement in the circumferential direction with the plate spring 4
2 and a holding plate 42. As another embodiment of the present invention, a holding plate is not provided, a plate spring is directly mounted on each shoe, and a claw provided on the plate spring. Is engaged with the engaging recess formed in the shoe, thereby preventing relative displacement of the leaf spring and the shoe in the circumferential direction. The shoe comes into contact with the insertion portion of the leaf spring, and a load acts on the leaf spring in the circumferential direction. It may be configured to prevent the user from doing so.

Although the present embodiment has been described as a piston motor, the configuration of the present invention may be provided in a piston pump.

[0035]

According to the first aspect of the present invention, since the engaging means for preventing the relative displacement between the leaf spring and the shoe in the circumferential direction is provided, the mounting portion of the shoe is arranged in the circumferential direction with respect to the leaf spring. To prevent the pressing load from acting on the contact.

According to the second aspect of the present invention, since the outer peripheral portion of the leaf spring continues over the entire circumference, it is possible to reduce the variation in the spring force acting on each shoe.

According to the third aspect of the present invention, since the outer peripheral portion of the leaf spring resiliently presses each shoe, the spring force acting on the shoe can be reduced as much as possible.

According to the present invention, the angle between the flat portion of the leaf spring and the direction perpendicular to the sliding surface of the swash plate is 90 degrees.
Since it is selected to be not less than 120 degrees and not more than 120 degrees, the spring force can be effectively reduced.

According to the present invention, since the groove-shaped reinforcing portion is formed between the fitting portion and the flat portion, the spring constant can be adjusted and the durability of the leaf spring can be improved. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a swash plate type piston motor 20 according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing the vicinity of a shoe 31;

FIG. 3 is a front view showing a holding plate 51;

4 is a front view showing the leaf spring 42. FIG.

FIG. 5 is a view showing a cross section of the leaf spring 42 in a natural state.

FIG. 6 is a sectional view showing a conventional swash plate type piston motor 1.

FIG. 7 is a front view showing the leaf spring 9;

[Explanation of symbols]

 Reference Signs List 20 swash plate piston motor 21 housing 30 swash plate 31 shoe 32 mounting part 40 retainer 48 sliding surface 51 holding plate 52 insertion hole 56 pawl

Claims (5)

[Claims] 1. A shoe which has a mounting portion to which a plurality of pistons inserted into a cylinder block connected to an output shaft are rotatably mounted, and which slides on a sliding surface of a swash plate around the output shaft. And an annular leaf spring interposed between a leaf spring supporting portion provided on the outer periphery of the output shaft, wherein the mounting portion of the shoe is inserted through insertion portions formed at equal intervals in the circumferential direction. A swash plate type piston pump motor whose inner peripheral portion is supported by the leaf spring supporting portion and biases the shoe toward the swash plate by pressing the spring. A swash plate type piston pump motor, further comprising an engagement means for preventing circumferential displacement of the leaf spring and the shoe in a state where the surface and the mounting portion of the shoe are separated from each other in the circumferential direction. 2. The swash plate type piston pump motor according to claim 1, wherein an outer peripheral portion of said leaf spring is continuous over the entire circumference. 3. The swash plate type piston pump motor according to claim 2, wherein an outer peripheral portion of said leaf spring resiliently presses each shoe. 4. A flat portion having an inner peripheral portion of the leaf spring, which protrudes and opens to the swash plate side and is fitted into the leaf spring support portion, and a plurality of insertion portions are formed. The angle between the swash plate and the direction perpendicular to the sliding surface is 90 degrees or more and 120 degrees or more in a natural state of the leaf spring where no shoe is attached and no external force acts.
The swash plate type piston pump motor according to any one of claims 1 to 3, wherein the swash plate type piston pump motor is selected to be equal to or less than a degree. 5. A connecting portion where the fitting portion and the flat portion are continuous with each other, a groove-shaped reinforcing portion which is recessed on the side opposite to the swash plate and extends in the circumferential direction is formed. The swash plate type piston pump motor according to the above.