Patent ID: 7413424
Filing Date: 2008-08-19
Classification: F04C

Abstract:
1. A gear pump comprising a pump cover, an internal rotor disposed rotatably in a recess of the pump cover and formed in a rotationally fixed manner on a drivable plug-in shaft, and an external rotor rotatably disposed in the recess of the pump cover in such an eccentric manner relative to the axis of rotation (A) of the internal rotor that the external rotor is in mesh with the internal rotor only in a first angle-of-rotation range (α) and in a second angle-of-rotation range (β) lying opposite the first angle-of-rotation range (α) is in contact with an inner surface of a web, which is disposed in the recess and is in turn in contact at its outer surface with the external rotor, so that after closing of the recess by a cover plate there is formed in the recess an admission pressure chamber and a low-pressure chamber, wherein a holding element, which is held in the pump cover, in the initial assembled state of the gear pump holds the cover plate at a fixed angle of rotation on the pump cover; said holding element being held in a first recess formed in the pump cover and in the initial assembled state of the gear pump holding the cover plate by a second recess formed in the cover plate at a fixed angle of rotation on the pump cover; said holding element comprising a cylindrical partial body having outside diameter which is slightly larger than the inside diameter of the first recess, so that during the course of insertion of the holding element into the first recess, the cylindrical partial body is imparted a specific radial bias causing a force-locking connection between the holding element and the pump cover; and said cylindrical partial body of the holding element for receiving a screw having an inner bore with an inside diameter which approximately corresponds to the outside diameter of the screw.