Radial piston compressor with transmission element and piston guide ring

Patent metadata

Field	Value
Publication number	US-12286965-B2
Application number	US-202118026957-A
Country	US
Kind code	B2
Filing date	Sep 14, 2021
Priority date	Sep 17, 2020
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

The present invention relates to a piston-cylinder assembly for a radial piston compressor. The piston-cylinder assembly comprises a drive shaft with a cylindrical eccentric for guiding the movement of the piston to a top dead center position. A cylindrical piston guide ring guides the movement of the piston to a bottom dead center. Both the cylindrical eccentric and the piston guide ring are connected to the piston by means of respective concave/convex contact surfaces for the positive transmission of the forces.

First claim

What is claimed is:

1. A piston-cylinder assembly for a radial piston compressor, comprising:
a piston;
a cylinder bore, in which the piston is arranged displaceably along a center line of the cylinder bore;
a drive shaft with an axis of rotation and with a cylindrical eccentric, a center point of which is spaced apart from the axis of rotation of the drive shaft, wherein, during rotational movement of the drive shaft, the piston is movable by the cylindrical eccentric in the cylinder bore in a manner directed outward in a radial direction away from the drive shaft as far as a top dead center; and
a transmission element, which transmits movement of the cylindrical eccentric to the piston for generating movement of the piston outward in the cylinder bore in a manner directed away from the drive shaft, wherein the transmission element has a first supporting surface with which the transmission element is supported on a cylinder surface of the cylindrical eccentric;
wherein the piston has a concavely shaped, first operative surface facing the transmission element, and the transmission element has a convexly shaped, second supporting surface facing the first operative surface, wherein the first operative surface and the second supporting surface form a form-fitting connection which is effective in a circumferential direction of the cylindrical eccentric, and wherein a cylindrical piston guide ring is provided, through which the piston is movable in the cylinder bore in a manner directed inward toward the drive shaft in the radial direction from the top dead center (TDC) as far as a bottom dead center (BDC), wherein the piston has a convexly shaped, second operative surface which faces an inner shell surface of the piston guide ring and which, together with the inner shell surface of the piston guide ring, forms a form-fitting connection which is effective in a direction of the center line of the cylinder bore;
wherein the second operative surface of the piston is a cylinder shell section with a second operative surface radius, wherein a radius of the second supporting surface and the second operative surface radius have the same center point, wherein the center point is on a cylindrical surface of the cylindrical eccentric and is the point at which the center line of the cylinder bore penetrates the cylindrical surface of the cylindrical eccentric, and wherein the sum of a radius of the cylindrical surface of the cylindrical eccentric and the second operative surface radius of the piston corresponds to a radius of the inner shell surface of the piston guide ring.

2. The piston-cylinder assembly as claimed in claim 1 , wherein the first supporting surface of the transmission element is one of a flat surface and a concavely shaped cylinder shell section with a first supporting surface radius, the first supporting surface radius corresponding to the radius of the cylindrical surface of the cylindrical eccentric.

3. The piston-cylinder assembly as claimed in claim 2 , wherein the second supporting surface of the transmission element and the first operative surface of the piston are cylinder shell sections with a second supporting surface radius, or wherein the second supporting surface of the transmission element is a spherical surface section and the first operative surface of the piston is a ball socket with a second supporting surface radius.

4. The piston-cylinder assembly as claimed in claim 1 , wherein a contact zone between the second supporting surface of the transmission element and the first operative surface of the piston and/or between the cylindrical surface of the cylindrical eccentric and the first supporting surface of the transmission element is slightly convex in a direction transversely with respect to the radii of curvature of said surfaces.

5. The piston-cylinder assembly as claimed in claim 4 , wherein two piston guide rings are provided which are arranged spaced apart from each other in an axial direction of the eccentric, wherein two second operative surfaces are formed on the piston, with one second operative surface being assigned to an inner shell surface of each respective piston guide ring.

6. The piston-cylinder assembly as claimed in claim 5 , wherein at least part of the second operative surface formed on the piston or parts of the second operative surfaces formed on the piston is or are arranged offset outward in a direction perpendicular to a center line of the piston in relation to the first operative surface of the piston interacting with the transmission element and spaced apart radially outward in a direction of the center line of the piston.

7. The piston-cylinder assembly as claimed in claim 1 , wherein the transmission element is manufactured from a metal with a small coefficient of sliding friction or a metal alloy with a small coefficient of sliding friction.

8. The piston-cylinder assembly as claimed in claim 1 , wherein at least one of the first supporting surface of the transmission element and the first operative surface of the piston has a recess forming a lubricant reservoir.

9. A radial piston compressor with a plurality of piston-cylinder assemblies, which are arranged distributed uniformly in a circumferential direction, as claimed in claim 1 , wherein the cylinder bores are provided in a cylinder block and the individual pistons are driven by the cylindrical eccentric via a single drive shaft.

10. The piston-cylinder assembly as claimed in claim 1 , wherein the transmission element is manufactured from copper, bronze or a brass alloy.

11. A piston-cylinder assembly for a radial piston compressor, comprising:
a piston;
a cylinder bore, in which the piston is arranged displaceably along a center line of the cylinder bore;
a drive shaft with an axis of rotation and with a cylindrical eccentric, a center point of which is spaced apart from the axis of rotation of the drive shaft, wherein, during rotational movement of the drive shaft, the piston is movable by the cylindrical eccentric in the cylinder bore in a manner directed outward in a radial direction away from the drive shaft as far as a top dead center; and
a transmission element, which transmits movement of the cylindrical eccentric to the piston for generating movement of the piston outward in the cylinder bore in a manner directed away from the drive shaft, wherein the transmission element has a first supporting surface with which the transmission element is supported on a cylinder surface of the cylindrical eccentric;
wherein the piston has a concavely shaped, first operative surface facing the transmission element, and the transmission element has a convexly shaped, second supporting surface facing the first operative surface, wherein the first operative surface and the second supporting surface form a form-fitting connection which is effective in a circumferential direction of the cylindrical eccentric, wherein two cylindrical piston guide rings are provided, through which the piston is movable in the cylinder bore in a manner directed inward toward the drive shaft in the radial direction from the top dead center (TDC) as far as a bottom dead center (BDC), wherein the piston has two convexly shaped, second operative surfaces which each face a respective inner shell surface of a respective piston guide ring and which, together with the inner shell surfaces of the piston guide rings, form a form-fitting connection which is effective in a direction of the center line of the cylinder bore;
wherein the two piston guide rings are arranged spaced apart from each other in the axial direction of the eccentric.

12. The piston-cylinder assembly as claimed in claim 11 , wherein the first suppor

Assignees

• Thyssenkrupp Dynamic Components Gmbh
• Thyssenkrupp Ag

Inventors

• Mueller Ulf
• Dietel Uwe
• Krause Sebastian
• Reichelt Robert

Classifications

• F04B27/0409

  Pistons · CPC title

• F04B27/0423

  Cylinders · CPC title

• F04B37/12

  to obtain high pressure · CPC title

• F04B27/0414 Primary

  Cams · CPC title

• F04B27/0531 Primary

  with cam-actuated distribution members · CPC title