Drive system for hydraulically driven working mechanisms of a working machine

1. A drive system for hydraulically driven working mechanisms of a working machine, comprising:

an axial piston pump having a pump capacity and flow direction that is varied by changing a pivot angle of the axial piston pump;

a hydraulic motor connected via a line to the axial piston pump and drivably connected to the driven working mechanisms;

a control unit that is operated to set the pump capacity of the axial piston pump to zero via actuation of a solenoid valve; and

an actuator system that is actuated by the control unit to actuate a limiting device to enable mechanically setting the pivot angle of the axial piston pump to zero degrees)(0°);

wherein the actuator system is a control valve arrangement that comprises a valve assembly and a first and a second control valve; and

wherein the limiting device comprises a piston-shaped element, at least one side of which is acted upon with hydraulic pressure.

2. The drive system according to claim 1 , wherein the limiting device is integrated into the axial piston pump.

3. The drive system according to claim 1 , wherein the valve assembly comprises a valve assembly housing, in which a delivery valve and a return valve and the limiting device are disposed.

4. The drive system according to claim 1 , wherein the limiting device is actuated by the first control valve.

5. The drive system according to claim 1 , wherein the second control valve actuates a delivery valve and a return valve, which control the inflow and the outflow of hydraulic oil to or from the axial piston pump, respectively.

6. The drive system according to claim 1 , wherein the limiting device is displaced such that the flow direction of the axial piston pump can be reversed.

7. The drive system according to claim 1 , wherein the control unit is set up to detect an operating state of the working machine that is representative of a foreign body entering the working mechanism of the working machine or is representative of a triggering of a reversing operation of a working mechanism.

8. A method for operating a drive system for hydraulically driven working mechanisms of a working machine, comprising axial piston pump having a pump capacity and flow direction which are varied by changing a pivot angle of the axial piston pump, a hydraulic motor connected via a line to the axial piston pump and drivably connected to the working mechanisms, an actuator system embodying a control valve arrangement that comprises a valve assembly and a first and a second control valve and a control unit operatable to set a pump capacity of the axial piston pump to zero, comprising steps of:

detecting a presence of an operating state representative of a foreign body entering a working mechanism of the working machine or of a triggering of a reversing operation of a working mechanism; and

actuating the actuator system embodying the control valve arrangement, by the control unit, to control a limiting device to mechanically set a pivot angle of the axial piston pump, depending on the operating state that is detected;

wherein the limiting device comprises a piston-shaped element, at least one side of which is acted upon with hydraulic pressure in the step of actuating.

9. The method according to claim 8 , wherein the step of actuating includes the control unit actuating the first control valve of the control valve assembly to transfer the limiting device into a position in which the pivot angle of the axial piston pump is set to zero by the limiting device.

10. The method according to claim 9 , wherein, upon detection of the triggering of a reversing operation, the first control valve of the control valve assembly is actuated such that the limiting device is transferred into a position in which the axial piston pump is operated in a reversing manner.

11. The method according to claim 9 , wherein, upon detection of a foreign body in a working mechanism, the control unit actuates a second control valve such that the flow direction of the axial piston pump is reversed.

12. A drive system for hydraulically driven working mechanisms of a working machine, comprising:

an axial piston pump having a pump capacity and flow direction that is varied by changing a pivot angle of the axial piston pump;

a hydraulic motor connected via a line to the axial piston pump and drivably connected to the driven working mechanisms;

a control unit that is operated to set the pump capacity of the axial piston pump to zero via actuation of a solenoid valve; and

an actuator system that is actuated by the control unit to actuate a limiting device to enable mechanically setting the pivot angle of the axial piston pump to zero degrees)(0°);

wherein the actuator system is a control valve arrangement comprising a valve assembly and a first and a second control valve.

13. A method for operating a drive system for hydraulically driven working mechanisms of a working machine, comprising axial piston pump having a pump capacity and flow direction which are varied by changing a pivot angle of the axial piston pump, a hydraulic motor connected via a line to the axial piston pump and drivably connected to the working mechanisms, an actuator system embodying a control valve arrangement that comprises a valve assembly and a first and a second control valve and a control unit operatable to set a pump capacity of the axial piston pump to zero, comprising steps of:

detecting a presence of an operating state representative of a foreign body entering a working mechanism of the working machine or of a triggering of a reversing operation of a working mechanism; and

actuating the actuator system embodying the control valve arrangement, by the control unit, to control a limiting device to mechanically set a pivot angle of the axial piston pump, depending on the operating state that is detected.