Patent ID: 8398384

Claim:
A rotary pump comprising: an electric motor having a wound claw pole stator; a plastic pump housing, with a first housing part that defines a pump space; a plastic intermediate housing part connected to the first housing part and which accommodates the electric motor, the intermediate housing part having a split core; means for mounting the wound claw pole stator of the electric motor on the split core; a permanent magnetic rotor mounted to rotate within the split core; and a plastic motor housing part, defining a motor space, wherein a) three axial and parallel split core ribs are provided between the split core and the claw pole stator, the ribs being distributed about the periphery of the split core at non-uniform angle distances between them; b) a return ring has first and second end sections, the return ring being connected to the wound claw pole stator, so that the first and second end sections are welded to each other; c) the stator is press-fit onto the split core via the ribs; d) more than three axial-parallel housing ribs protrude radially inward and are formed with the motor housing part, the axial-parallel housing ribs being distributed on the inside periphery of the motor housing part; and e) the stator is press-fit into the motor housing part via the housing ribs.