Oil separator

1. An oil separator comprising a housing and a rotor having a drive element rotatably mounted within the housing, and an oil separating element and a shaft for driving the oil separating element of the rotor via the shaft of the rotor around the shaft axis wherein at least one of said elements of the rotor is configured to be displaceable via an actuator element axially from an inoperative position to an operating position when the separator is started up and from an operating position to an inoperative position when the separator is stopped, said actuator element comprising a flange defined on the shaft of the rotor, said actuator element further comprising a surface of a slide bush of the shaft forming a braking element having a braking surface, wherein in the inoperative position the braking surface of the braking element axially frictionally engages said flange, and wherein in the operating position the braking surface of the braking element is disengaged from said flange, and wherein the oil separating element has a stack of truncated cone-shaped disks which are arranged one above the other, extend coaxially to the shaft axis and are rotatably mounted in the middle by means of the shaft.

2. The oil separator as claimed in claim 1 , wherein the drive element, the oil separating element and the shaft are displaceable together in a rigidly coupled manner.

3. The oil separator as claimed in claim 1 , wherein the actuator element is a pressure face exposed to hydraulic pressure action, which pressure face is part of the rotor or is rigidly or flexibly coupled or connected to the rotor.

4. The oil separator as claimed in claim 1 , wherein the braking element is arranged in the flow of hydraulic fluid.

5. The oil separator as claimed in claim 1 , wherein the drive element and/or the shaft and/or a sliding bearing are comprised of aluminium, stainless steel and/or plastic.

6. The oil separator as claimed in claim 1 , wherein the shaft and a disk of the stack of truncated cone-shaped disks of the oil separating element which is arranged nearest to the drive element or one said disk which is arranged furthest away from the drive element are designed with material uniformity and/or in one piece.

7. The oil separator as claimed in claim 1 , wherein the shaft has a plastic liner which with the disk of the disk stack of the oil separating element which is arranged nearest to the drive element or the disk which is arranged furthest away from the drive element is designed with material uniformity and/or in one piece.

8. The oil separator as claimed in claim 1 , wherein the braking element with the disk which is arranged nearest to the drive element or the disk which is arranged furthest away from the drive element can enter into frictional engagement.

9. The oil separator as claimed in claim 1 , wherein the actuator element is arranged on or in the rotor and/or is designed as part of the rotor, including as part of the shaft.

10. The oil separator as claimed in claim 9 , wherein a partial flow of hydraulic fluid acts in the axial direction upon the actuator element which is formed in or on the shaft, and a second partial flow of the hydraulic fluid acts upon the drive element in the radial direction.

11. The oil separator as claimed in claim 1 , wherein the drive element is a hydraulically driven drive element.

12. The oil separator as claimed in claim 11 , wherein at least one rotatably seated element of the rotor is configured to be displaced via hydraulic pressure, including an operating pressure of hydraulic fluid, from the inoperative position to the operating position.

13. The oil separator as claimed in claim 12 , wherein the hydraulic fluid is conducted into the rotor in an interior space of the shaft in its axial direction and acts upon the actuator element.

14. The oil separator as claimed in claim 12 , wherein the hydraulic fluid is oil, including engine oil.