Hydrostatic axial piston machine having a cylinder barrel with a working piston which is mounted obliquely with respect to its axial direction and with a planar control plate

Patent metadata

Field	Value
Publication number	US-9638180-B2
Application number	US-201414273531-A
Country	US
Kind code	B2
Filing date	May 8, 2014
Priority date	May 8, 2013
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

An axial piston machine of swash plate design includes cylinder bores with respective longitudinal axes that are arranged at an acute angle with the rotational axis and that approach the rotational axis radially in the direction of their control plate-side ends. For each cylinder bore, a point of action of a resulting hydrostatic relieving force, which acts on the cylinder barrel, of the hydrostatic sliding bearing is spaced apart radially with regard to the rotational axis of the cylinder barrel further than a point of intersection of the longitudinal axis of the cylinder bore with the cylinder barrel-side bearing face of the hydrostatic sliding bearing.

First claim

What is claimed is:

1. A hydrostatic axial piston machine of swash plate design, comprising:
a cylinder barrel mounted so as to rotate about a rotational axis, the cylinder barrel defining a multiplicity of cylinder bores, each of which is delimited in sections by one respective working piston and, during rotation of the cylinder barrel, is connected to high pressure or low pressure via a planar control plate having a first planar surface that bears against a first end side of the cylinder barrel via a first bearing face and a second bearing face of a hydrostatic sliding bearing;
a swash plate mounted pivotably in a pivoting bearing and on which piston shoes arranged at a swash plate-side end region of each of the respective working pistons slide during the rotation of the cylinder barrel,
wherein each cylinder bore has a central longitudinal axis arranged at an acute angle with respect to the rotational axis and which is radially closer to the rotational axis at the first end side of the cylinder barrel,
wherein, during operation of the hydrostatic axial piston machine, the hydrostatic sliding bearing is configured so as to produce a hydrostatic relieving force acting on the cylinder barrel which, for each cylinder bore, acts at a first point of action, the first point of action being spaced apart radially from the rotational axis of the cylinder barrel by a first distance, which is greater than a second distance between the rotational axis and a first point of intersection of the central longitudinal axis of the cylinder bore with the first bearing face, which is on a cylinder-barrel side of the hydrostatic sliding bearing.

2. The axial piston machine according to claim 1 , wherein the first distance is equal to or greater than a third distance between the rotational axis and a second point of action of a resulting relieving force, which, during operation of the axial piston machine, acts on the cylinder barrel, for each respective working piston, at a bearing face of the piston shoe of the respective working piston bearing on the swash plate.

3. The axial piston machine according to claim 1 , wherein:
the cylinder barrel defines a multiplicity of passage slots, each of which is assigned to a respective cylinder bore of the multiplicity of cylinder bores, extends from a distal end of the respective cylinder bore to the first bearing face of the hydrostatic sliding bearing, and has a cross-sectional area defined in a plane normal to a longitudinal axis of the passage slot that is less than a cross-sectional area of the respective cylinder bore defined in a plane normal to the central longitudinal axis of the respective cylinder bore; and
the longitudinal axes of the passage slots are arranged substantially parallel to the rotational axis of the cylinder barrel.

4. The axial piston machine according to claim 3 , wherein the longitudinal axis of the passage slot assigned to each working piston, at a control-plate side end of the passage slot, is spaced apart radially for each said working piston from the rotational axis of the cylinder barrel by a third distance, which is equal to or greater than a fourth distance between the rotational axis and a second point of action of a relieving force that acts on a swash plate end of the piston shoe of the respective working piston on a bearing face of the piston shoe in an axial direction of the respective working piston.

5. The axial piston machine according to claim 1 , wherein:
the hydrostatic sliding bearing is of annular configuration, and has an inner circular boundary and an outer circular boundary;
the control plate is of substantially annular configuration and has at least two control openings which penetrate the control plate in an axial direction of the control plate and which have an inner and an outer circularly arcuate boundary line at an opening to the second bearing face; and
passage openings open into the first bearing face so as to be aligned in the axial direction with the inner and outer boundary lines of the control openings.

6. The axial piston machine according to claim 5 , wherein a radial spacing between the inner boundary line of the control opening and the inner boundary of the hydrostatic sliding bearing is substantially the same size as a radial spacing between the outer boundary line of the control opening and the outer boundary of the hydrostatic sliding bearing.

7. The axial piston machine according to claim 5 , wherein a radial spacing between the inner boundary line of the control opening and the inner boundary of the hydrostatic sliding bearing is smaller than a radial spacing between the outer boundary line of the control opening and the outer boundary of the hydrostatic sliding bearing.

8. The axial piston machine according to claim 7 , wherein:
the inner boundary line of the control opening is assigned an inner arc length which is measured along the inner boundary of the hydrostatic sliding bearing and defines substantially the same arc angle as the inner boundary line;
the outer boundary line of the control opening is assigned an outer arc length which is measured along the outer boundary of the hydrostatic sliding bearing and defines substantially the same arc angle as the outer boundary line; and
a ratio between a radial spacing from the inner boundary line to the inner boundary and the inner arc length is substantially identical to a ratio between the radial spacing from the outer boundary line to the outer boundary and the outer arc length.

9. The axial piston machine according to claim 5 , wherein the control openings are configured as substantially kidney-shaped control openings.

10. A hydrostatic axial piston machine of swash plate design, comprising:
a cylinder barrel mounted so as to rotate about a rotational axis, the cylinder barrel defining a multiplicity of cylinder bores, each of which is delimited in sections by one respective working piston and, during rotation of the cylinder barrel, is connected to high pressure or low pressure via a planar control plate that bears against a first end side of the cylinder barrel via bearing faces of a hydrostatic sliding bearing;
a swash plate mounted pivotably in a pivoting bearing and on which piston shoes arranged at a swash plate-side end region of each of the respective working pistons slide during the rotation of the cylinder barrel,
wherein each cylinder bore has a longitudinal axis arranged at an acute angle with respect to the rotational axis and which is radially closer to the rotational axis at the first end side of the cylinder barrel,
wherein the cylinder barrel defines a multiplicity of passage slots, each of which is assigned to a respective cylinder bore of the multiplicity of cylinder bores and extends from a distal end of the respective cylinder bore to a cylinder-barrel side bearing face of the hydrostatic sliding bearing,
wherein longitudinal axes of the passage slots are arranged substantially parallel to the rotational axis of the cylinder barrel, and
wherein the longitudinal axes of the passage slots are spaced apart radially from the rotational axis of the cylinder barrel further than points of intersection of the longitudinal axes of the cylinder bores with a plane which is arranged perpendicularly with respect to the rotational axis and contains cylinder bore-side ends of the passage slots.

11. The axial piston machine according to claim 10 , wherein the longitudinal axes of the passage slots are spaced apart radially from the rotational axis of the cylinder barrel at the cylinder bore-side ends of the passage slots further than the points of intersection of the longitudinal axes of the cylinder bores with the plane which is arranged

Assignees

• Bosch Gmbh Robert

Inventors

• Sell Manuel
• Zehnder Frank
• Breuer David

Classifications

• F04B1/2078 Primary

  Swash plates · CPC title

• F04B1/2035

  Cylinder barrels · CPC title

• F04B1/2021 Primary

  characterised by the contact area between cylinder barrel and valve plate · CPC title

• F04B1/2092

  Means for connecting rotating cylinder barrels and rotating inclined swash plates · CPC title