Multiple-stroke hydrostatic axial piston machine

1. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion,

wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body,

wherein the displacement body is in the form of a cage of the roller,

wherein the roller is a cylindrical or barrel roller, and

wherein the displacement body has a first piston segment that holds the roller and a second hydraulically pressurizable piston segment with a smaller diameter than that of the first piston segment.

2. The multiple-stroke hydrostatic axial piston machine as claimed in claim 1 , wherein the first and second piston segments of the displacement body are located one immediately behind the other.

3. The multiple-stroke hydrostatic axial piston machine as claimed in claim 1 , wherein the first piston segment is located in a first boring segment of an associated displacement chamber, which first boring segment is provided for the absorption of transverse forces, and the second piston segment projects into a second boring segment of the displacement chamber that contains hydraulic fluid.

4. The multiple-stroke hydrostatic axial piston machine as claimed in claim 3 , wherein the first boring segment of the displacement chamber is connected to an air vent.

5. The multiple-stroke hydrostatic axial piston machine as claimed in claim 3 , wherein an axis of rotation of the roller is located inside the first boring segment of the displacement chamber, at least when it is in contact with a camshaft of axial cams.

6. The multiple-stroke hydrostatic axial piston machine as claimed in claim 1 , wherein the first piston segment is located outside the displacement chamber.

7. The multiple-stroke hydrostatic axial piston machine as claimed in claim 1 , wherein the track is provided on a stator assembly and displacement chambers are provided in a cylinder drum of a rotor assembly that is in axial contact against a control surface of the stator assembly that is fixed to the housing.

8. The multiple-stroke hydrostatic axial piston machine as claimed in claim 1 , wherein the track is provided on an eccentric disc of a rotor assembly and displacement chambers are provided in a machine housing of a stator assembly.

9. The multiple-stroke hydrostatic axial piston machine as claimed in claim 8 , including a disc cam that rotates in synchronization with a drive shaft of the rotor assembly, and is located so that it can move axially in a disc cam receptacle that is connected with the drive shaft and is in contact against a surface of the stator assembly.

10. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion, wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body, and wherein the displacement body is in the form of a cage of the roller; and

a pressure device that is independent of the operating pressure and provided to generate a force that pushes at least one of the displacement bodies toward the track and holds the roller in engagement with the track.

11. The multiple-stroke hydrostatic axial piston machine as claimed in claim 10 , wherein the pressure device includes a compression spring that acts directly or indirectly on the displacement body.

12. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that that is provided with axial cams that generate a reciprocal motion, wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body, and wherein the displacement body is in the form of a cage of the roller; and

a securing device to limit rotation of the displacement body relative to an associated displacement chamber.

13. The multiple-stroke hydrostatic axial piston machine as claimed in claim 12 , wherein the securing device includes a radial pin which projects into an axial groove that is machined into an outer periphery of the displacement body.

14. The multiple-stroke hydrostatic axial piston machine as claimed in claim 13 , wherein the displacement body has a first piston segment that holds the roller and a second hydraulically pressurizable piston segment with a smaller diameter than that of the first piston segment, wherein the first piston segment is located in a first boring segment of an associated displacement chamber, which first boring segment is provided for the absorption of transverse forces, wherein the second piston segment projects into a second boring segment of the displacement chamber that contains hydraulic fluid, and wherein the axial groove is provided on the first piston segment of the displacement body.

15. The multiple-stroke hydrostatic axial piston machine as claimed in claim 12 , wherein the displacement body has a first piston segment that holds the roller and a second hydraulically pressurizable piston segment with a smaller diameter than that of the first piston segment, wherein the first piston segment is located in a first boring segment of an associated displacement chamber, which first boring segment is provided for the absorption of transverse forces, wherein the second piston segment projects into a second boring segment of the displacement chamber that contains hydraulic fluid, and wherein the second piston segment has an offset with respect to the first piston segment.

16. The multiple-stroke hydrostatic axial piston machine as claimed in claim 12 , wherein the displacement body has a first piston segment that holds the roller and a second hydraulically pressurizable piston segment with a smaller diameter than that of the first piston segment, wherein the first piston segment is located outside the displacement chamber, and wherein the first piston segment has contact areas in the peripheral direction that are in engagement with contact areas of the first piston segments of the neighboring displacement bodies and act together as a securing device to restrict the rotation of the displacement body relative to the displacement chamber.

17. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion,

wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body,

wherein the displacement body is in the form of a cage of the roller,

wherein the track is provided on a stator assembly and displacement chambers are provided in a cylinder drum of a rotor assembly that is in axial contact against a control surface of the stator assembly that is fixed to the housing, and

wherein the displacement body has a first piston segment that holds the roller and a second hydraulically pressurizable piston segment with a smaller diameter than that of the first piston segment, wherein the first piston segment is located in a first boring segment of an associated displacement chamber, which first boring segment is provided for the absorption of transverse forces, wherein the second piston segment projects into a second boring segment of the displacement chamber that contains hydraulic fluid, and wherein the second piston segment and the second boring segment are offset in relation to the first piston segment and the first piston segment respectively radially inwardly with respect to the axis of rotation of the cylinder drum.

18. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion, wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body, wherein the displacement body is in the form of a cage of the roller, and

wherein the track is provided on a stator assembly and displacement chambers are provided in a cylinder drum of a rotor assembly that is in axial contact against a control surface of the stator assembly that is fixed to the housing; and

a brake located radially between the cylinder drum and a surrounding machine housing.

19. The multiple-stroke hydrostatic axial piston machine as claimed in claim 18 , wherein the brake is a spring-loaded disc brake comprising at least two independent brake groups.

20. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion, wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body, wherein the displacement body is in the form of a cage of the roller, and

wherein the track is provided on an eccentric disc of a rotor assembly and displacement displacement chambers are provided in a machine housing of a stator assembly; and

a disc cam that rotates in synchronization with a drive shaft of the rotor assembly, and is located so that it can move axially in a disc cam receptacle that is connected with the drive shaft and is in contact against a surface of the stator assembly; and

a brake located radially between a disc cam receptacle and the machine housing.

21. The multiple-stroke hydrostatic axial piston machine as claimed in claim 20 , wherein the brake is a spring-loaded disc brake comprising at least two independent brake groups.

22. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion, wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body, wherein the displacement body is in the form of a cage of the roller, and

wherein the track is provided on an eccentric disc of a rotor assembly and displacement chambers are provided in a machine housing of a stator assembly;

a disc cam that rotates in synchronization with a drive shaft of the rotor assembly, and is located so that it can move axially in a disc cam receptacle that is connected with the drive shaft and is in contact against a surface of the stator assembly; and

a brake located radially between the drive shaft and the machine housing.

23. The multiple-stroke hydrostatic axial piston machine as claimed in claim 22 , wherein the brake is a spring-loaded disc brake comprising at least two independent brake groups.

24. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion,

wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body,

wherein the displacement body is in the form of a cage of the roller,

wherein the track is provided on a stator assembly and displacement chambers are provided in a cylinder drum of a rotor assembly that is in axial contact against a control surface of the stator assembly that is fixed to the housing, and

wherein the rotor assembly has a differential transmission.

25. A multiple-stroke hydrostatic axial piston machine comprising:

a plurality of piston-shaped displacement bodies each longitudinally movable in a displacement chamber, wherein the displacement bodies are supported by a roller body on a track that is provided with axial cams that generate a reciprocal motion,

wherein each of the roller bodies is a roller which is located in a recess of the displacement body that restricts radial and axial relative movements of the roller with respect to the displacement body.

wherein the displacement body is in the form of a cage of the roller,

wherein the track is provided on a stator assembly and displacement chambers are provided in a cylinder drum of a rotor assembly that is in axial contact against a control surface of the stator assembly that is fixed to the housing, and

wherein the rotor assembly is rotationally synchronously coupled with a rotor assembly of a second axial piston machine having a swashplate, and wherein the second axial piston machine has an adjustable stroke volume and is connected hydraulically in parallel.

26. The multiple-stroke hydrostatic axial piston machine as claimed in claim 25 , wherein eccentric discs of the two axial piston machines that form a module are located on opposite ends of the module, with a common control flange located between the two axial piston machines.