Drive device for a machine with a traction drive system and a hydraulic work system

1. A fork lift truck drive device, the drive device comprising:

a traction drive system having a drive axle with at least one drive wheel located on each end of the drive axle, wherein the drive axle has an axle housing that is substantially closed on all sides and is provided for connection with a vehicle frame; and

a hydraulic work system comprising at least one of a hoisting cylinder, a tilting cylinder, or a hydraulic steering system, the hydraulic work system comprising at least one electric motor and at least one pump driven by the electric motor,

wherein at least one of the electric motor and the pump of the hydraulic work system is located inside the axle housing.

2. The drive device as claimed in claim 1 , wherein the drive axle has two traction motors.

3. The drive device as claimed in claim 1 , wherein the drive axle has a single traction motor.

4. The drive device as claimed in claim 1 , wherein the drive axle includes at least one traction motor, wherein at least one of the electric motor of the hydraulic work system and the traction motor of the traction drive system is an oil-cooled electric motor and is connected with an oil circuit of the hydraulic work system.

5. The drive device as claimed in claim 1 , wherein a control of at least one electric motor or traction motor is fastened to the outside of the axle housing.

6. The drive device as claimed in claim 1 , including a valve control device installed on the pump of the hydraulic work system, which valve control device is integrated into the drive axle or is fastened to the outside of an axle housing in the vicinity of the pump.

7. The drive device as claimed in claim 1 , including an oil tank connected to the hydraulic work system and integrated into the drive axle or located immediately next to the drive axle.

8. The drive device as claimed in claim 1 , wherein the fork lift truck is powered by an electric storage battery or by an electric fuel cell.

9. The drive device as claimed in claim 2 , wherein the traction motors are located on the ends of the drive axle and at least one of the electric motor and the pump of the hydraulic work system is located axially between the traction motors inside the axle housing.

10. The drive device as claimed in claim 2 , wherein the traction motors are electric motors.

11. The drive device as claimed in claim 2 , wherein the traction motors are hydraulic motors having secondary regulation systems.

12. The drive device as claimed in claim 2 , including a reducing transmission installed downstream of each traction motor.

13. The drive device as claimed in claim 3 , wherein the electric motor of the hydraulic work system is provided as the traction motor of the traction drive system.

14. The drive device as claimed in claim 5 , wherein the control is oil-cooled.

15. The drive device as claimed in claim 10 , wherein the traction motors are electric disc rotor motors.

16. The drive device as claimed in claim 11 , wherein an installed delivery capacity of the pump is designed to deliver a volume of fluid required by the hydraulic work system.

17. The drive device as claimed in claim 12 , wherein the reducing transmissions are planetary gear trains.

18. A drive device for a machine, the drive device comprising:

a traction drive system having a drive axle; and

a hydraulic work system comprising at least one of a hoisting cylinder, a tilting cylinder, or a hydraulic steering system comprising at least one electric motor and at least one pump driven by the electric motor,

wherein at least one of the electric motor and the pump are integrated into the drive axle or are located directly on the drive axle,

wherein the drive axle has two traction motors,

wherein the traction motors are hydraulic motors having secondary regulation systems, and

wherein the traction motors are connected to the pump of the hydraulic work system, and the installed delivery capacity of the pump is in excess of a maximum amount required by the hydraulic work system.

19. A drive device for a machine, the drive device comprising:

a traction drive system having a drive axle; and

a hydraulic work system having at least one electric motor and at least one pump driven by the electric motor,

wherein at least one of the electric motor and the pump are integrated into the drive axle or are located directly on the drive axle,

wherein the drive axle has an axle housing that is substantially closed on all sides and is provided for connection with a vehicle frame, and wherein at least one of the electric motor and the pump of the hydraulic work system are located inside the housing, and

wherein the axle housing has a housing middle segment and two housing end segments that are detachably fastened to the middle segment.

20. The drive device as claimed in claim 19 , wherein at least one of the electric motor and the pump of the hydraulic work system are located in the housing middle segment.

21. The drive device as claimed in claim 19 , wherein the drive axle has two traction motors and the traction motors are located in the housing middle segment.

22. The drive device as claimed in claim 19 , including reducing transmissions located in the housing end segments.

23. The drive device as claimed in claim 19 , wherein when the drive axle is installed, at least one housing end segment can be removed from the housing middle segment without removing the drive axle from the vehicle frame, whereby an interior of the housing middle segment is accessible after removal of the housing end segment.