Direct electrical drive

1. A direct electrical drive for a wheel set of a vehicle, comprising:

a stator;

a rotor interacting with the stator and having a rotor hub coupled mechanically with a wheel set shaft of the wheel set, said wheel set shaft defining an axis;

a cooling device constructed to cool the rotor and including a fan for drawing in air through an air inlet and conducting the air through a cooling channel inside the rotor; and

a barrier located in an area within the rotor in close proximity adjacent to the wheel set shaft to protect the wheel set shaft against ingress of foreign matter via the air inlet when the fan draws in air, said barrier including a catch device extending in a direction of the axis in parallel relationship to the wheel set shaft, and a dirt guide device connected to the rotor hub at a distance to and in alignment with the catch device.

2. The direct electrical drive according to claim 1 , wherein stator and the rotor are part of an electric machine, wherein the wheel set has two wheels mounted to the wheel set shaft, said wheel set shaft being completely enveloped in an area between the wheels by the electric machine.

3. The direct electrical drive according to claim 2 , wherein the wheel set shaft has a continuous jacket between the wheels of the wheel set.

4. The direct electrical drive according to claim 1 , wherein the rotor hub is connected via at least one rotor web with a support for a rotor reaction part.

5. The direct electrical drive according to claim 1 , wherein the catch device has a first section forming part of the fan and disposed in close proximity of an air outlet of the cooling channel.

6. The direct electrical drive according to claim 5 , wherein the catch device has a second section in close proximity of the air inlet.

7. The direct electrical drive according to claim 6 , wherein the first and second sections of the catch device have an inwardly turned nose.

8. The direct electrical drive according to claim 1 , wherein the barrier includes a baffle wall disposed in the air inlet for deflecting foreign matter.

9. The direct electrical drive according to claim 8 , wherein the baffle wall has a slanted configuration.

10. The direct electrical drive according to claim 1 , wherein the rotor has a dirt-binding surface.

11. The direct electrical drive according to claim 10 , wherein the surface is sticky.

12. The direct electrical drive according to claim 1 , wherein the cooling channel has an inside wall formed with a dirt-binding surface.

13. The direct electrical drive according to claim 1 , wherein the dirt guide device is part of an air guiding device of stepped configuration.