Patent ID: 7458792

Claim:
A method for producing a sintered metal rotor of a rotary piston pump, in particular a rotary piston pump for generating a vacuum of a vacuum brake booster of a motor vehicle, where the brake booster can be connected to a vacuum pump intake connection, with a pot-shaped base body ( 1 ) and a bearing journal element which protrudes centrally from the bottom of this base body ( 1 ) from a cylindrical foot area coming directly out of the bottom and a connecting claw section ( 2 ) to be connected to it for a coupling element to be attached, comprising the features the connecting claw section ( 2 ) is designed in the form of two protruding individual webs ( 3 ), the individual webs ( 3 ) are diametrically opposed in the outside circumferential area of the cylindrical base section in an area limited to max. 100° at the circumference and radially to max. 25% of the diameter of the cylindrical base section, and assigning separate rams to the individual webs ( 3 ) according to cross section of the web and providing each ram with a separate pressure acting on them in a sintering compression mold for producing the sintered rotor; and wherein the produced rotor has the structure of a one piece, press-sintered rotor with differently compressed regions, whereby the individual webs ( 3 ) are compressed to a sufficient degree for the material stability required in each region, and the sintering pressure is sufficient to achieve a material density of 6.8 to 7.4 g/cm 3 .