JPH0575484U - Axial piston pump - Google Patents

Abstract

(57) [Summary] [Purpose] With regard to an axial pistol pump, the object is to be able to smoothly support the reciprocating motion of the swash plate, facilitate the processing and assembly work, and further reduce the size. To do. [Structure] The rear projection 10c of the swash plate 10 is reciprocally disposed in the recessed portion 21 of the swash plate guide member 1, and the swash plate 1 is provided.
While rotating the base end portion of the piston 11 with respect to the front inclined surface 10a of 0 while rotating with the cylinder block 7,
In an axial piston pump that reciprocates the piston 11 to discharge hydraulic oil, the swash plate guide member 1 is provided with support shafts 22 orthogonal to the reciprocating direction of the swash plate 10 at predetermined intervals. , The support shaft 22 is provided with a needle bearing 23, and the needle bearing 2
The rear projection 10c of the swash plate 10 is brought into contact with the sheet 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an axial piston pump, and more particularly to a support device for supporting a swash plate (cradle) of an axial piston pump.

[0002]

[Prior Art]

 Conventionally, an axial piston pump is driven by an engine, for example, in an industrial vehicle, and sends hydraulic oil whose discharge amount increases in proportion to the engine speed to a hydraulic motor for traveling to drive the vehicle through the motor. It is used to drive.

The axial piston pump is configured to rotate an inclined surface of a swash plate (cradle) while sliding a base end portion of a piston to reciprocate the piston to discharge hydraulic oil. .. Then, the discharge amount of the hydraulic oil is controlled by controlling the inclination angle of the swash plate and the stroke amount of the piston.

Therefore, a supporting device that supports the swash plate is desired to be smooth and have excellent durability. The supporting device for the swash plate is generally disclosed in Japanese Patent Publication No. 60-45313.

That is, in the supporting device, rollers are arranged between the swash plate and a swash plate guide member (a part of the machine casing) at a constant interval by a holding frame, and the swash plate smoothly reciprocates by the rollers. I am making it. Further, the supporting device is provided with a rod for restricting the movement of the holding frame within a certain range so that the holding frame does not pop out due to the reciprocating rotation motion.

[0006]

[Problems to be solved by the device]

 However, in the above supporting device, a bush is formed on the swash plate and the swash plate guide member for mounting the regulating rod for regulating the moving range, and the bush must be mounted on the bush and connected to the holding frame. The work was very troublesome. Further, in order to smoothly reciprocate the swash plate with respect to the swash plate guide member, a roller is interposed between the swash plate and the swash plate guide member. Therefore, there is a problem that the axial length becomes large and the axial piston pump becomes large.

The present invention has been made to solve the above problems, and its purpose is to be able to smoothly support the reciprocating motion of a swash plate and to facilitate processing and assembly work. Another object is to provide an axial piston pump that can be downsized.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention arranges a rear projection of a swash plate in a recess of a swash plate guide member so as to be able to reciprocate, and slides a base end portion of a piston on a front inclined surface of the swash plate. In an axial piston pump that rotates together with a cylinder block while moving, and reciprocates the piston to discharge hydraulic oil, the swash plate guide member includes a support shaft orthogonal to the reciprocating direction of the swash plate. The gist of the invention is to provide a rotary member on the support shaft at predetermined intervals, and to bring the back projection of the swash plate into contact with the rotary member.

[0009]

[Action]

 When the swash plate moves in one direction, the rear projection of the swash plate is smoothly guided while being supported by the rotation of the rotation member of the support shaft provided in the swash plate guide member in the direction orthogonal to the reciprocating direction of the swash plate. It At this time, since the rotating member only rotates on the spot, the holding member is not moved based on the movement of the swash plate. Since the supporting shaft provided with the rotating member is directly arranged with respect to the swash plate guide member, the total length of the axial piston pump is shortened.

[0010]

【Example】

 An embodiment embodying the present invention will be described below with reference to FIGS. As shown in FIG. 1, a drive shaft 3 is rotatably supported between a swash plate guide member 1 also serving as a casing and an end cover 2 via a pair of bearings 4 and 5. A cylinder block 7 which is in sliding contact with the end cover 2 is fixed to the spline portion 6 of the drive shaft 3 and is provided so as to be rotatable integrally with the drive shaft 3.

A plurality of cylinder bores 8 are formed in the cylinder block 7 so as to extend in parallel with the drive shaft 3 and the centers thereof are located on the same circumference with the drive shaft 3 as the center. .. A piston 11, which is constantly pressed by a swash plate 10 via a shoe 9, is accommodated in the cylinder bore 8 so as to be capable of reciprocating.

An accommodation hole 12 is formed in the front side of the central portion of the cylinder block 7, and a pressing member 13 is inserted into the accommodation hole 12 so as to be integrally rotatable with the cylinder block 7 and slidable in the axial direction. Has been done. The pressing member 13 is biased toward the swash plate 10 side by the spring 14 arranged in the accommodation hole 12, and the shoe 9 is attached to the swash plate 10 via the shoe retainer 15 that contacts the spherical surface portion 13a of the pressing member 13. It is adapted to be pressed by the front inclined surface 10a.

The shoe retainer 15 is configured such that when the shoe 9 receives a force in a direction in which the shoe 9 is pulled away from the front inclined surface 10 a due to a line resistance on the suction side of hydraulic oil in the intake stroke of the piston 11, the shoe 9 is inclined to the front It plays the role of suppressing separation from the surface 10a.

A position corresponding to the rotation locus of the cylinder bore 8 during the suction stroke (movement to the right in FIG. 1) of the piston 11 and the discharge stroke of the piston 11 are provided on the rear side surface of the end cover 2. An intake port 16 and a discharge port 17 are respectively provided at positions corresponding to the rotation locus of the cylinder bore 8.

As shown in FIGS. 2 and 4, the swash plate 10 is formed in a substantially semi-cylindrical shape, and the swash plate 10 is provided in the front inclined surface 10a serving as a flat surface portion and in the approximate center of the curved surface side. The cutout recess 10b and the curved back surface protrusions 10c provided on both sides of the cutout recess 10b. Further, a rod 18 is projectingly provided in parallel with the front sloped surface 10a at the lower center of the curved surface of the swash plate 10 so as to project to the outside of the end cover 2. Further, a through hole 10d through which the drive shaft 3 is inserted is formed at the center of the front inclined surface 10a.

Then, as shown in FIG. 5, the swash plate guide member 1 is formed in a planar U-shape by the main body 1a and the support pieces 1b provided on both sides thereof. A through hole 20 is formed in the center of the side surface of the main body 1a, and a rotary shaft 3 is rotatably inserted and supported in the through hole 20 via a bearing 5.

Further, a concave portion 21 as an arc-shaped concave portion is formed on the inner side surface of the support piece 1b, and a rear projection 10c of the swash plate 10 is arranged. The swash plate 10 is adapted to reciprocate along the recessed portion 21. Further, a pair of support shafts 22 are provided between the support pieces 1b above and below the recessed portion 21 so as to be orthogonal to the reciprocating direction of the swash plate 10. Each of the support shafts 22 is rotatably provided with a needle bearing 23 as a pair of rotating members.

The needle bearing 23 is provided so as to project from the curved surface of the recess 21. Therefore, when the rear projection 10c of the swash plate 10 is disposed in the recess 21, the needle bearing 23 is contacted by the rear projection 10c of the swash plate 10. Therefore, the swash plate 10 smoothly reciprocates along the recessed portion 21 by the needle bearing 23 with which the back projection 10c abuts.

The rod 18 is connected to an angle control mechanism (not shown), and when the rod 18 is operated, the swash plate 10 rotates along the recess 21. Therefore, the angle of the front slope 10a can be controlled, and the amount of movement of the piston 11 moving in the cylinder bore 8 can be adjusted.

Next, the operation of the axial piston pump configured as described above will be described. When the axial piston pump is operated, the drive shaft 3 is rotated at a constant speed by a drive source such as a motor, and the cylinder block 7 is also rotated integrally. Then, since the piston 11 is constantly pressed against the front inclined surface 10a of the swash plate 10 through the shoe 9, the piston 11 reciprocates in the cylinder bore 8 as the cylinder block 7 rotates, and the piston 11 rotates around the drive shaft 3. Revolve around.

When the cylinder bore 8 moves to a position corresponding to the suction port 16, the piston 11 moves to the right while being rotationally moved from the lower position to the upper position in FIG. It is sucked into the cylinder bore 8. Further, when the piston 11 moves to a position corresponding to the discharge port 17, the piston 11 moves leftward while being rotationally moved from the upper position to the lower position in FIG. 1, and the hydraulic oil sucked into the cylinder bore 8 is removed. It is discharged from the discharge passage through the discharge port 17.

When the stroke of the piston 11 is adjusted to adjust the suction amount and the discharge amount of the hydraulic oil, the rod 18 is driven by an angle control mechanism (not shown). Then, the swash plate 10 rotates, and the suction amount and the discharge amount can be increased as the value of the inclination angle increases. At this time, since the back projection 10c of the swash plate 10 is in contact with the needle bearing 23 of the support shaft 22 provided between the support pieces 1b of the swash plate guide member 1, the back projection 10c of the swash plate 10 is While rotating the needle bearing 23, the needle bearing 23 smoothly reciprocates along the concave portion 21.

Further, at this time, the needle bearing 23 only rotates on the spot, and therefore is not moved based on the movement of the rear surface protrusion 10c of the swash plate 10. Further, the support shaft 22 is surely supported by the support piece 1b, so that the movement due to the movement of the swash plate 10 can be surely prevented. As a result, unlike the prior art, there is no need to provide a bush on the swash plate guide member 1 and the swash plate 10 or to use a regulating rod, so that the assembly and processing work can be facilitated.

Further, since the support shaft 22 provided with the needle bearing 23 is directly provided to the swash plate guide member 1, there is no large member between the swash plate 10 and the swash plate guide member 1, so that the rotation is prevented. The axial size of the shaft 3 can be shortened, and the axial piston pump can be made compact.

Further, since the rear surface protrusion 10c does not directly contact the recessed portion 21 of the swash plate guide member 1, it is not necessary to improve the accuracy of the surface finish of the recessed portion 21, and the working operation is facilitated. be able to.

The present invention is not limited to the above embodiment, and it is possible to provide a plurality of support shafts 22 provided with needle bearings 23. In addition to the needle bearing 23, it is possible to use another bearing or a rotating member composed of rollers.

[0027]

[Effect of the device]

 As described above in detail, according to the present invention, it is possible to smoothly support the reciprocating motion of the swash plate, facilitate the working and assembling work, and further reduce the size. Have.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an axial piston pump according to the present invention.

FIG. 2 is a partial plan sectional view of a swash plate guide member.

FIG. 3 is a partial cross-sectional view of a swash plate guide member and a swash plate.

FIG. 4 is a perspective view showing the shape of a swash plate.

FIG. 5 is a perspective view showing the shape of a swash plate guide member.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Swash plate guide member, 21 ... Recessed part as a recessed part, 10
... swash plate, 10c ... rear projection, 10a ... front inclined surface, 11
... piston, 7 ... cylinder block, 22 ... support shaft, 2
3 ... Needle bearing as rotating member

Claims (1)

[Scope of utility model registration request] 1. A swash plate guide member is provided with a rear projection of the swash plate so as to be capable of reciprocating in a concave portion of the swash plate, and a base end portion of a piston is slid relative to a front inclined surface of the swash plate together with a cylinder block. In an axial piston pump that rotates and reciprocates the piston to discharge hydraulic oil, the swash plate guide member is provided with a support shaft orthogonal to the reciprocating direction of the swash plate at predetermined intervals. An axial piston pump in which a rotary member is arranged on the support shaft, and the rear projection of the swash plate is brought into contact with the rotary member.