Hydrostatic axial piston machine

Patent metadata

Field	Value
Publication number	US-11619203-B2
Application number	US-202117489002-A
Country	US
Kind code	B2
Filing date	Sep 29, 2021
Priority date	Oct 7, 2020
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A hydrostatic axial piston machine includes a cylinder drum that rotates during operation and has a plurality of cylinder bores in which displacement pistons are arranged, each of which opens out in a control opening in one end face of the cylinder drum, and having a control part against which the cylinder drum bears with the end face and on which two kidney-shaped control ports in the form of circular arcs are provided. Between the two kidney-shaped control ports, a first changeover web and a second changeover web are formed, wherein two sets of compensating openings that are able to be overlapped by control openings are located in the changeover webs with one compensating opening of each set located in each changeover web, and the compensating openings in the two sets of compensating openings are connected together via respective compensating fluid paths.

First claim

What is claimed is:

1. A hydrostatic axial piston machine, comprising:
a cylinder drum configured to rotate during operation and including a plurality of cylinder bores in which respective displacement pistons that carry out a stroke movement during operation are arranged, each of the plurality of cylinder bores opening out in a respective control opening in an end face of the cylinder drum;
a control part against which the cylinder drum bears with the end face and on which a first kidney-shaped control port in the form of a circular arc and a second kidney-shaped control port in the form of a circular arc and, between the two kidney-shaped control ports, a first changeover web and a second changeover web are formed, wherein a first compensating opening configured to be overlapped by the respective control openings is located in each changeover web, and the first compensating openings are connected together via a first compensating fluid path, wherein
the first compensating openings are arranged adjacent to the first kidney-shaped control port;
a second compensating opening configured to be overlapped by the respective control openings is located in each changeover web, said second compensating opening arranged adjacent to the second kidney-shaped control port;
the two second compensating openings are connected together via a second compensating fluid path; and
an angular spacing between the first and second compensating openings arranged in the same changeover web is greater than an angular width of a control opening.

2. The hydrostatic axial piston machine according to claim 1 , wherein the first compensating openings have the same angular spacing from the first kidney-shaped control port.

3. The hydrostatic axial piston machine according to claim 2 , wherein the first compensating openings have the same angular spacing from the first kidney-shaped control port as the second compensating openings that are adjacent to the second kidney-shaped control port have from the second kidney-shaped control port.

4. The hydrostatic axial piston machine according to claim 2 , wherein the angular spacing of the first compensating openings from the first kidney-shaped control port is substantially the same as the angular width of the first and second compensating openings.

5. The hydrostatic axial piston machine according to claim 1 , wherein the number of cylinder bores that are present, and thus also the number of displacement pistons, is an odd number.

6. The hydrostatic axial piston machine according to claim 1 , wherein each of the first and second compensating fluid paths are formed by a respective plurality of bores that meet one another.

7. The hydrostatic axial piston machine according to claim 1 , wherein, at the start of a compensating flow between two control openings ( 39 ) that overlap the first compensating openings, there is still a passage cross section between a control opening ( 39 ) leaving the first kidney-shaped control port and the first kidney-shaped control port.

8. The hydrostatic axial piston machine according to claim 1 , wherein the first compensating openings and the first kidney-shaped control port are configured such that toward the end of a compensating flow between two control openings that overlap the first compensating openings, the control opening of the two control openings that has left the first kidney-shaped control port only comes out of overlap with the corresponding first compensating opening when the other control opening of the two control openings is still overlapping the other first compensating opening and there is already a passage cross section between the other control opening of the two control openings and the first kidney-shaped control port.

9. The hydrostatic axial piston machine according to claim 6 , wherein the first compensating openings and the first kidney-shaped control port are configured such that in a position of two control openings in which a first of the two control openings overlaps a first of the first compensating openings and a second of the two control openings overlaps a second of the first compensating openings, and the first of the two control openings and the first kidney-shaped control port and the second of the two control openings and the first kidney-shaped control port overlap with overlapping areas of the same size, the ratio of the cross-sectional area of the first of the first compensating opening to the cross-sectional area of the overlapping area is greater than two.

10. The hydrostatic axial piston machine according to claim 1 , wherein:
a displacement volume of the hydrostatic axial piston machine is variable between a minimum displacement volume and a maximum displacement volume; and
at the minimum displacement volume, the volume of the first compensating fluid path is less than one tenth of a free volume of a cylinder bore at an inner dead center position of the displacement piston.

11. The hydrostatic axial piston machine according to claim 1 , wherein the first and second kidney-shaped control ports, the first and second compensating openings, and the first and second compensating fluid paths are located in a control plate which is supported on a housing part.

12. The hydrostatic axial piston machine according to claim 10 , wherein:
the hydrostatic axial piston machine is a variable-displacement bent axis machine with a control lens which is adjustable together with the cylinder drum; and
the first and second compensating fluid paths are partially formed in the control lens.

13. The hydrostatic axial piston machine according to claim 1 , wherein the hydrostatic axial piston machine is configured such that the first and second kidney-shaped control ports are subjectable to high pressure and to low pressure.

Assignees

• Bosch Gmbh Robert

Inventors

• Wustmann Walther

Classifications

• F04B1/2064

  Housings · CPC title

• F04B1/2042

  Valves · CPC title

• F01B3/0055

  Valve means, e.g. valve plate · CPC title

• F04B1/303

  by turning the valve plate · CPC title

• F03C1/0694 Primary

  by changing the inclination of the axis of the cylinder barrel in relation to the axis of the actuated element · CPC title