Pump device, especially for mobile means of transport

1. A mobile pump device for use on mobile transport vehicle selected from the group of semi-trailers, tank trailers, tank semitrailers tank trucks and lorries comprising:

a drive motor and a rotary piston pump, wherein the drive motor has a motor housing and a motor shaft for driving the rotary piston pump,

wherein the rotary piston pump comprises a housing and two pump openings formed thereon, one of which serves as pump inlet and the other as pump outlet,

and wherein the rotary piston pump comprises two rotor units rotatably accommodated in the housing in a pump chamber for delivering a fluid from the pump inlet to the pump outlet,

wherein the two rotor units are received on rotatably mounted rotor shafts, and each rotor shaft being equipped with a rotor gear wheel arranged outside the pump chamber,

wherein a drive pinion connected to a drive shaft of the rotary piston pump is coupled to one of the rotor gears,

and the motor shaft of the drive motor has a recess at a front end, into which an end of the drive shaft of the rotary piston pump is received therein and the front end of the motor shaft and the drive shaft extends from the drive motor to the drive pinion;

wherein the drive motor is connected to the housing via a unitary connecting flange forming a U cross sectional shape providing a rear of a gear housing part assisting in retaining the rotor gear wheels in the gear housing part and a front of the motor housing with an intermediate space between the rear of the gear housing part and the front providing the U cross sectional shape as taken along the motor shaft.

2. The pump device according to claim 1 , wherein the motor shaft comprises a coupling portion at the front end of the motor shaft on which the recess is formed.

3. The pump device of claim 1 , wherein the recess forms a substantially cylindrical cavity.

4. The primp device of claim 1 , wherein said recess having at least one longitudinal groove.

5. The pump device of claim 1 , wherein the recess has a non-circular inner contour.

6. The pump device of claim 1 , wherein an internal soothing is formed on the recess.

7. The pump device of claim 1 , wherein external teeth formed or the drive shaft cooperate with internal teeth of the recess.

8. The pump device of claim 1 , wherein at least one coupling unit is provided, the at least one coupling unit connected to one of the drive shaft and the motor shaft.

9. The pump device of claim 1 , wherein at least one extending transverse opening is formed in the drive shaft and the motor shaft, at which opening a rotationally fixed coupling of the drive shaft and the motor shaft is achieved via a coupling unit arranged therein.

10. The pump device of claim 1 , wherein the drive motor is formed as an electric motor and driven via three-phase current with a power range between 1 kW and 15 kW.

11. The pump device of claim 1 , wherein the housing comprises a pump housing part and the gear housing part, wherein the rotor gears and the drive pinion are arranged in the gear housing part and the pump chamber with the rotor units is arranged in the pump housing part, wherein the pump housing part and the gear housing part are separated from each other by two separate partitions and a gap, and wherein bearing units for supporting the drive shaft and the rotor shafts are arranged in a transmission housing part.

12. The pump device of claim 11 , wherein at least one disc part is arranged between the separate partitions.

13. The pump device of claim 1 , wherein the housing comprises a cover which closes the pump chamber and wherein after disassembly of the cover the rotor units are accessible, and/or wherein the rotary piston pump comprises two rotor units each having a plurality of at least two rotor elements, wherein in the rotor units are plugged onto the rotor shafts and are fastened frontally to the rotor shafts.

14. The pump device of claim 1 , further comprising two hearing units of a each rotor shaft arranged axially between the rotor unit and the rotor gear Wheel.

15. The pump device of claim 1 , wherein the connecting flange forms a closure of the housing and the motor housing.

16. The pump device of claim 1 wherein the drive motor of the rotary piston pump is designed as an electric Motor and connected to a stationary power connection via a connecting cable.

17. The pump device of claim 1 having a foot unit extending below the pump housing in a direction away from the pump openings to a location directly below a portion of the motor.