Patent ID: 8322997

Claim:
A pump comprising a frame, a pump shaft which can be driven using a driving device and is mounted to be rotatable about a main axis that is stationary relative to the frame, an eccentric sleeve which is mounted in an axially movable manner on a pump shaft section, an anti-rotation element which is effective between the pump shaft section and the eccentric sleeve, several pump devices which are stationary relative to the frame and are provided with displacement elements that can be moved in a radial direction relative to the main axis, act upon a fluid contained in swept volumes of the pump devices, and are moved against a fluid pressure by an external surface of the eccentric sleeve, and at least one spring element which acts upon the eccentric sleeve in an axial direction and is formed by a compression spring or tension spring supported on the pump shaft, wherein the pump shaft section is designed as an inclined eccentric pin that has an eccentric pin axis which extends at an oblique angle from the main axis and the eccentric sleeve that is guided on the eccentric pin has a cylindrical external surface, the generatrices of which extend parallel to the main axis wherein the axial displaceability of the eccentric sleeve on the eccentric pin is restricted at least in one direction by an axially fixed stop element and a start position is defined thereby and the eccentric sleeve is pretensioned in the start position by the spring element against the stop element and the external surface of the eccentric sleeve in the start position has a maximum eccentricity with respect to the main axis.