Adjustment device for an axial piston machine and hydraulic machine having such an adjustment device

Patent metadata

Field	Value
Publication number	US-9518569-B2
Application number	US-201314075338-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	Nov 13, 2012
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

An adjustment device for a pivoting cradle of a hydraulic machine, in particular of an axial piston machine, is disclosed. Said adjustment device has an actuating piston to which pressure medium for pivoting the pivoting cradle about a pivoting axis is applied via an actuating pressure space. In order to control the feeding in of pressure medium and the relieving of the actuating pressure space, a control valve is provided. Said control valve has a control piston configured to be adjusted by an electric actuator, wherein the electric actuator is controlled by a control device. In this context, the control device controls the electric actuator as a function of a control difference formed from a setpoint pivoting angle and an actual pivoting angle of the pivoting cradle. The actual pivoting angle of the pivoting cradle is fed back electrically to the control device here.

First claim

What is claimed is:

1. An adjustment device for an adjustable pivoting cradle of a hydraulic machine, the adjustment device comprising:
an actuating piston to which pressure medium is applied via an actuating pressure space to pivot the pivoting cradle about a pivoting axis; and
a control valve configured to control a feeding of the pressure medium to the actuating pressure space and a relieving of the pressure medium from the actuating pressure space, the control valve having a control piston configured to be controlled by an electric actuator,
wherein an actual value of a controlled variable is fed back electrically to a control device to control the electric actuator, and
wherein the control piston and the actuating piston are mechanically decoupled, such that the control piston is independently movable relative to the actuating piston by the electric actuator.

2. The adjustment device according to claim 1 , further comprising a pivoting angle sensor configured to detect an actual pivoting angle of the pivoting cradle.

3. The adjustment device according to claim 2 , wherein the pivoting angle sensor is a Hall sensor.

4. The adjustment device according to claim 1 , wherein:
the control piston is configured to be shifted by the electric actuator in a direction of first control positions in which a pressure medium connection between the actuating pressure space and a high pressure side of the axial piston machine can be controlled, and
the control piston is configured to be shifted, by an opposing spring supported on a valve housing of the control valve, in a direction of second control positions in which a pressure medium connection between the actuating pressure space and a low pressure side of the axial piston machine can be controlled.

5. The adjustment device according to claim 1 , wherein the control device is configured to control further adjustment devices of further hydraulic machines.

6. The adjustment device according to claim 1 , wherein the control device is configured to determine an actual control current as a manipulated variable for the actuator as a function of a setpoint pivoting angle and of an actual pivoting angle.

7. The adjustment device according to claim 6 , wherein the control device is configured to form a setpoint control current with a controller as a function of a control difference formed from a setpoint value and the actual value of the variable to be controlled.

8. The adjustment device according to claim 7 , wherein the control device is configured to control an actual control current with a current controller as a function of a control difference formed from a setpoint control current and the actual control current.

9. A hydraulic machine, comprising:
a pivoting cradle; and
an adjustment device for the pivoting cradle, the adjustment device including:
an actuating piston to which pressure medium is applied via an actuating pressure space to pivot the pivoting cradle about a pivoting axis; and
a control valve configured to control a feeding of the pressure medium to the actuating pressure space and a relieving of the pressure medium from the actuating pressure space, the control valve having a control piston configured to be controlled by an electric actuator,

wherein an actual value of a controlled variable is fed back electrically to a control device to control the electric actuator, and
wherein the control piston and the actuating piston are mechanically decoupled, such that the control piston is independently movable relative to the actuating piston by the electric actuator.

10. The adjustment device according to claim 1 , wherein the actual value of the controlled variable is an actual pivoting angle of the pivoting cradle.

11. The adjustment device according to claim 7 , wherein the controller is a pivoting angle controller.

12. The adjustment device according to claim 11 , wherein the pivoting angle controller is a PID controller.

13. The adjustment device according to claim 8 , wherein the current controller is a PID controller.

Assignees

• Bosch Gmbh Robert

Inventors

• Howind Joern
• Diebold Carola
• Springmann Rolf

Classifications

• F04B49/123

  by changing the eccentricity of one element relative to another element · CPC title

• F04B1/324 Primary

  by changing the inclination of the swash plate · CPC title

• F04B1/2078

  Swash plates · CPC title