JPH1054344A - Adjustable axial piston machinery in swash plate type structure system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an optional structure member for guiding rotation of a turning plate by an operating device which is already built-in by forming the operating device as at least one of an operating piston capable of hydraulic pressure type operation, and connecting the operating device to the supporting side surface of the turning plate. SOLUTION: An operating piston 19 is slidably supported in the longitudinal direction hole 20 of a casing 4. An end part projected from the hole 20 of the operating piston 19 is formed, for example, in a ball shape. In a turning plate 16, a notch 21 which is suitably formed is arranged on a supporting side surface 23 positioned on the side opposite to a piston guide surface 15 for storing the operating piston 19. The turning plate 16 is loaded in a minimum displacement direction by force of a spring 22. In the case where the operating piston 19 is not loaded, the turning plate 16 is surely guided in every operating conditions since the supporting side surface 23 of the turning plate 16 is brought into contact with the lift part 24 of an casing inner wall in surface parallel. It is possible to prevent necessity for providing an optional structure member newly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjustable axial piston machine in a swash plate structure system, comprising a cylinder drum rotating in a casing about an axis of rotation. A plurality of pistons are arranged longitudinally movable, these pistons are operatively connected to a piston guide surface of a swivel plate non-rotatably arranged in the casing, and the swivel angle of the swivel plate is set by an actuator. It is variable with respect to the axis of rotation of the machine, in which case the swivel plate is supported on a support surface arranged on the casing at a support side opposite to the piston guide surface, wherein the swivel plate, when swiveling, The present invention relates to a type that performs a rolling motion relative to a support surface along a contour formed by the support side surface and the support surface.

[0002]

2. Description of the Prior Art An axial piston machine of this type is known from DE-A-373 33 08. In this axial piston machine, a minimum friction, that is, a rolling friction is generated when the revolving plate is turned. The advantage of this axial piston machine is that no additional components, such as rolling bearings or costly hydraulic relief devices, which increase the construction volume, are required for supporting the swivel plate. Such additional components are required in known axial piston machines with a cylindrical or spherical sliding path on the support side of the swivel plate. The axial piston machine can therefore be manufactured with very compact dimensions in the axial extension. Furthermore, the flat shape of the swivel plate can reduce the inertial force that is to be overcome for quick adjustment of the swivel plate.

In order to fix the position of the swivel plate and guide the movement of the swivel plate, the axial piston machine is provided with teeth on the support side surface of the swivel plate and the support surface of the casing of the machine. These teeth engage each other to prevent the swivel plate from sliding relative to the support surface. Thus, a precisely defined rolling movement of the swivel plate is obtained, and a sliding movement between the support side of the swivel plate and the support surface of the casing is avoided. In this way, the toothing eliminates slippage of the swivel plate relative to the casing and ensures rolling movement. This avoids the wear that occurs during the sliding movement. However, the production of such a tooth row is extremely laborious. Furthermore, when the swivel plate rolls on the support surface of the casing, a sliding portion occurs in the teeth. The sliding portion wears the teeth and impairs the rolling motion of the revolving plate.

[0004]

SUMMARY OF THE INVENTION The object of the invention is to improve an axial piston machine of the type mentioned at the outset, so that the rolling of the swivel plate without additional components for guiding the movement of the swivel plate is achieved. The object is to provide an axial piston machine which allows movement.

[0005]

SUMMARY OF THE INVENTION In order to achieve this object, in an embodiment of the invention, the actuating device pivots to guide the rolling movement caused by the contour formed by the supporting side and the supporting surface. It was operatively connected to the board.

[0006]

The idea underlying the present invention is that the actuating device already provided for swiveling the swivel plate further comprises
It is also provided to guide the rotational movement of the revolving plate. This makes it possible to omit additional components. The production of axial piston machines of this type is therefore simplified. Furthermore, the axial piston machine according to the invention does not have the space required for hydraulic load reduction or the space required for guiding the swivel plate by means of additional components. It can be made very compact with respect to radial and axial extension. At the same time, the swiveling of the swivel plate on the support surface of the casing can take place without a sliding movement at the bearing of the swivel plate.

In an advantageous embodiment of the invention, the actuating device is formed as at least one hydraulically operable actuating piston and is connected to the supporting side of the swivel plate.

It is particularly advantageous if the working piston is arranged in a cylindrical bore provided in the casing of the machine,
The longitudinal axis of the bore is inclined with respect to the axis of rotation of the machine.

In this case, the longitudinal axis of the cylindrical bore is inclined by a predetermined angle with respect to the axis of rotation of the machine. This angle corresponds as much as possible to the rolling characteristics of the swivel plate along the support surface of the casing. Therefore, when the operating piston is operated, the supporting side surface of the revolving plate performs a rolling motion relative to the supporting surface of the casing. The working piston is in this case mounted in a cylindrical bore in the housing.

Advantageously, the end of the working piston facing the swivel plate is formed in a spherical shape and is accommodated in a correspondingly formed notch in the swivel plate. Thereby, the working piston can introduce a force to be applied to guide the swivel plate to the swivel plate.

When the working piston is operated, a translational movement of the working piston is carried out through a cylindrical hole provided in the casing, so that the working piston guides the turning plate linearly. This results in a very small sliding movement of the swivel plate relative to the support surface of the casing during the rolling of the swivel plate, based on a predetermined angle of the longitudinal axis of the cylindrical bore with respect to the axis of rotation of the machine. A small component of movement occurs at the pivot axis of the pivot plate. The cause of this sliding motion is that when the supporting side surface of the revolving plate rolls along the supporting surface of the casing, the revolving axis of the revolving plate is not stationary but moves along a curved path defined by the contour geometry. Is to do. However, due to the linear guide of the swivel plate by the working piston and the frictional connection between the working piston and the swivel plate, such a movement of the swivel axis is not entirely possible. As a result, the above-described slip component occurs in the rolling motion of the turning plate.

[0012] In order to avoid such a sliding portion, in the main configuration of the present invention, at least one rolling element is arranged between the supporting side surface of the revolving plate and the supporting surface on the casing side. Has become. In this way, the turning axis of the turning plate is located on the rolling element that can perform a rolling motion along the support surface of the casing. Thus, any slippage remaining during the movement of the swivel plate is compensated by the slight rolling movement of the rolling elements along the support surface. As a result, when the revolving plate turns, a rolling motion occurs that overcomes only the rolling friction.

It is particularly advantageous if the support side and the support surface each have at least one concave notch. The notch provided on the support surface of the casing operatively connected to the rolling element may be formed, for example, in a partially cylindrical shape,
It may be arranged perpendicular to the axis of rotation of the machine. This concave cutout provided in the support surface is formed such that the force transmitted in the radial direction from the revolving plate to the rolling element is introduced and led out at the same angle as possible. This allows
In the recess, the rolling elements are guaranteed to roll without sliding movement. Furthermore, such a shape of the notch prevents sliding and tilting of the rolling element which may occur when the shape of the support surface of the casing is flat.

The notch provided on the supporting side surface of the revolving plate is also formed in a concave shape. With such a configuration, the rolling elements are arranged between the two concave notches such that the axial extension of the machine is reduced. In addition, such a configuration of the support surface and the support side surface provides a simple geometric characteristic that causes rolling motion when the swivel plate is turned.

It is particularly advantageous for the support side of the swivel plate to abut against the inner wall of the housing when the swivel plate is displaced at a minimum and at a maximum. Thereby, the displacement of the revolving plate can be easily limited.

It is particularly advantageous if the piston guide surface of the swivel plate is inclined at a minimum displacement with respect to a plane lying perpendicular to the axis of rotation. In this case, the minimum displacement of the swivel plate is set such that the piston guide surface is not perpendicular to the rotation axis of the machine but is inclined. Thus, the machine starts operating at a small swivel angle of the swivel plate. This always produces a force at the swivel plate caused by the fluid pressure on the piston of the cylinder drum, which guarantees the connection between the working piston and the swivel plate. The working piston therefore always acts on the swivel plate,
The motion of the revolving plate can be reliably performed in all driving states.

It is particularly advantageous if the spring is operatively connected to the pivoting plate and acts in the direction of the minimum displacement of the pivoting plate. As a result, during pressureless operation of the axial piston machine according to the invention, the swivel plate is pressed in order to fix its position in the direction of the minimum swivel angle.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention.

The axial piston machine according to the invention has a drive or driven shaft 1. The drive shaft or driven shaft 1 is supported on the casing 4 and the casing bottom 5 by rolling bearings 2 and 3. A cylinder drum 6 having a plurality of longitudinal holes 8 concentrically arranged with respect to a rotation axis 7 is non-rotatably connected to the shaft 1. In the longitudinal bores 8, one piston 9 can slide in the longitudinal direction. Longitudinal hole 8
Is connected to the control surface 11 and the liquid supply passage and the liquid discharge passage (not shown) through the hole 10. The cylinder drum 6 is pressed against the control surface 11 by the force of a spring 12 and, additionally, during operation, due to the high pressure of the fluid, which occurs in a part of the bore 8. The end 13 of the piston 9 projecting from the longitudinal bore 8 is formed in a spherical shape and is accommodated in a correspondingly formed cutout in the slide shoe 14. The hydrostatically reduced slide shoe 14 is supported on a piston guide surface 15 of a revolving plate 16 that is stationary with respect to the rotational movement of the cylinder drum 6 and the piston 9. The lower holding plate 17, which is loaded in the direction of the piston guide surface 15 by the lower holding device 18 and a spring (not shown), prevents the slide shoe 14 from separating from the revolving plate 16 during operation of the machine. You.

The swivel angle of the swivel plate 16 can be arbitrarily adjusted with respect to the rotation axis 7 by an actuator. For this purpose, according to the invention, a working piston 19 is provided. This working piston 19 is slidably supported in a longitudinal bore 20 of the casing 4. The end of the working piston 19 protruding from the hole 20 is formed, for example, in a spherical shape. The working piston 19 is provided on the revolving plate 16.
A correspondingly shaped notch 21 is provided in the support side 23, which is located opposite the piston guide surface 15, for accommodating the same.

The revolving plate 16 is loaded in the direction of the minimum displacement by the force of the spring 22. When the working piston 19 is not loaded, the supporting side surface 23 of the revolving plate 16 comes into contact with the raised portion 24 of the casing inner wall in a plane-parallel manner. In such a configuration, since the bearing position is located outside the center of rotation of the swivel plate, the working piston always acts on the swivel plate, so that the swivel plate is reliably guided in all operating conditions. Can be done.

The support side surface 23 of the revolving plate 16 is provided with one partially cylindrical notch 25 on each side of the rotation axis 7. The notch 25 is connected to a partially cylindrical notch 27 provided on the support surface 32 of the casing 4 by a rolling element 26. The support side 23 of the swivel plate 16 is thus mounted on a support surface 32, in which case an additional rolling element 26 is arranged between the support side 23 and the support surface 32.

If the working piston 19 is loaded by the working pressure, for example the high pressure of the machine, the working piston 19
Moves the swivel plate 16 in the direction of maximum displacement against the force of the spring 22 and the force generated by the swivel plate during operation (see FIG. 2).
The support side surface 23 is chamfered obliquely in a region located on the opposite side of the rotation axis 7 from the engagement point of the working piston 19. Therefore, there is a space between the turning plate 16 and the casing inner wall 28 that allows the turning plate 16 to turn.
When displaced to the maximum, the revolving plate 16 contacts the casing inner wall 28 in a plane-parallel manner at the oblique chamfer. This makes it possible to easily limit the turning angle.

The working piston 19 makes a linear movement along the longitudinal axis of the bore 20 when loaded by the working pressure. Due to the frictional connection between the working piston 19 and the swivel plate 16, the movement of the swivel plate 16 is guided by the working piston 19. In this case, the revolving plate 16 performs a rolling motion on the rolling element 26 by the support side surface 23 and the notch 25 provided in the support side surface 23. At the same time, the rolling elements 26 roll in the notches 27 provided in the support surface 32 of the casing 4. Due to such a movement of the rolling element 26 in the notch 27, the movement of the working piston 1
Sliding parts due to the linear guide of the swivel plate 16 due to 9 are avoided. Therefore, when turning, a pure rolling motion of the turning plate 16 is generated. Therefore, between the support side surface 23 of the swivel plate 16 and the support surface 32 of the casing 4, it is only necessary to overcome the rolling friction when the swivel plate 16 turns.

FIG. 3 clearly shows the position of the rolling elements 26 arranged on both sides of the machine axis of rotation and perpendicular to this axis of rotation. The rolling element 26 has a cylindrical shape, but may be formed in a spherical or barrel shape. The notch 27 provided in the casing 4 is formed as a semi-cylindrical hole. This hole can be made without significant
It can be formed as a transverse bore directly in the casing of the machine. At the outlet opening of the transverse bore provided in the housing, in this case, for example, a closing screw 28 is provided, which serves simultaneously to guide the rolling element 26 in the axial direction. The swivel plate 16 has a through hole 29 for the shaft 1. The fixing of the rolling element 26 in the axial direction is performed by the stopper 3
Performed by 0. This stop 30 can be formed integrally with the casing or with the swivel plate 16 as in this embodiment.

The torque acting on the swivel plate during operation of the machine is, on the one hand, received by the spherical receiving part of the working piston 19 and, on the other hand, on the casing 4 by the lateral contact surface 31 of the swivel plate with the casing 4. It is captured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an axial piston machine at the time of a minimum displacement of a revolving plate.

FIG. 2 is a longitudinal sectional view of the axial piston machine at the time of a maximum displacement of the revolving plate.

3 is a longitudinal sectional view of the axial piston machine shown perpendicular to FIG. 1;

[Description of Signs] 1 drive shaft, 2, 3 rolling bearing, 4 casing, 5 casing bottom, 6 cylinder drum,
7 axis of rotation, 8 longitudinal bore, 9 piston,
Reference Signs List 10 hole, 11 control surface, 12 spring, 13 end, 14 slide shoe, 15 piston guide surface, 16 turning plate, 17 lower holding plate, 18 lower holding device, 19 working piston, 20 hole, 2
1 notch, 22 spring, 23 supporting side surface, 24 ridge, 25 notch, 26 rolling element, 27 notch,
28 closing screw, 29 through hole, 30 stopper, 31 contact surface, 32 support surface

Claims (9)

[Claims] An adjustable axial piston machine in a swash plate configuration, comprising a cylinder drum rotating in a casing about an axis of rotation, in which a plurality of pistons are disposed in a longitudinal direction. Arranged movably, these pistons are non-rotatably operatively connected to a piston guide surface of a swivel plate arranged in the casing, the swivel angle of the swivel plate being variable with respect to the axis of rotation of the machine by means of an actuator. In this case, the revolving plate is supported on a support surface disposed on the casing at a support side surface opposite to the piston guide surface,
In the form in which the swivel plate performs a rolling movement relative to the support surface along a contour formed by the support side surface and the support surface when turning, an actuator (19) is generated by the contour. An adjustable axial piston machine in a swash plate configuration, characterized in that it is operatively connected to a swivel plate (16) for guiding the rolling motion to be set. 2. The actuating device according to claim 1, wherein the actuating device is formed as at least one hydraulically operable actuating piston (19) and is connected to the support side (23) of the swivel plate (16). Axial piston machine. 3. An actuating piston (19) is arranged in a cylindrical bore (20) provided in a casing (4) of the machine, the longitudinal axis of which (20) being the axis of rotation of the machine. 3. The axial piston machine according to claim 2, which is inclined with respect to (7). 4. The swivel plate (1) of the working piston (19).
6) is formed in a spherical shape at the end facing the rotating plate (1).
4. The axial piston machine according to claim 3, wherein the axial piston machine is accommodated in a notch (21) corresponding to (6). 5. A support side surface (23) of the revolving plate (16),
5. The axial piston machine according to claim 1, wherein at least one rolling element (26) is arranged between the bearing surface (27) on the casing side. 6. The support side (23) and the support surface (32) each have at least one concave notch (25, 2).
7. The axial piston machine according to claim 5, comprising (7). 7. The support side (23) of the revolving plate (16)
7. The axial piston machine according to claim 4, wherein the pivoting plate (16) comes into contact with the inner wall of the casing at the time of the minimum displacement and the maximum displacement. 8. A piston guide surface (1) of a revolving plate (16).
8. The axial piston machine according to claim 1, wherein 5) is inclined at a minimum displacement with respect to a plane lying perpendicular to the axis of rotation (7). 9. The axial piston machine according to claim 8, wherein the spring (22) is operatively connected to the swivel plate (16) and acts in the direction of the minimum displacement of the swivel plate (16).