Patent ID: 8303184

Claim:
A motor pump comprising: a pump housing; a motor housing; a ceramic pump shaft supported in the motor housing and including an impeller extending into the pump housing; a rotor-stator structure in the motor housing for driving the shaft; a front bearing and a rear bearing for supporting the shaft; an annular bearing support member to which the front bearing is mounted; a tubular sleeve into which the annular bearing support member is inserted; and an interface surface defined between the annular bearing support member and the tubular sleeve and having an undulating surface with separate but multiple contact peak locations disposed between the bearing support member and the tubular sleeve; said undulating surface constructed and arranged so as to change from a less flattened out state before the annular bearing support member is inserted into the tubular sleeve to a more flattened out state when the annular bearing support member is inserted into the tubular sleeve to thus provide a spring force between the annular bearing support member and the tubular sleeve; said annular bearing support member including an inner annular portion for supporting the front bearing, and an outer annular portion with the undulation surface disposed between the outer annular portion of the annular bearing support member and the tubular sleeve; said outer annular portion having a diameter greater than the diameter of the inner annular portion; said undulating surface formed integrally with one of the tubular sleeve and annular bearing support member; wherein each bearing is constructed of a bronze material, and each bearing has added thereto a small amount of graphite.