Magnetic drive centrifugal pump having ceramic bearings, ceramic thrust washers, and a water cooling channel

摘要

A ceramic bearing system for a centrifugal pump includes two substantially identical circular ceramic shafts, two substantially identical non-circular ceramic washers and two substantially identical non-circular ceramic bearing members. The centrifugal pump incorporating the bearing system includes an impeller shaft having one of the circular ceramic shafts mounted in each end and a non-circular recess in a rear end thereof for receiving one of the non-circular ceramic washers. The impeller is provided with a non-circular recess in a front end thereof for receiving the other non-circular ceramic washer. One of the non-circular ceramic bearing members is mounted in a non-circular hole or recess in the pump volute and the other non-circular ceramic bearing member is mounted in a non-circular hole or recess in the rear of the motor. When assembled, the circular ceramic shafts are rotatably mounted in the respective non-circular ceramic bearing members and the non-circular ceramic washers act as thrust bearings between the impeller and the bearing in the volute and between the impeller shaft and the bearing in the motor. According to the presently preferred embodiment, a fluid channel is provided along the length and around the back of the impeller shaft such that fluid being pumped by the pump circulates around the shaft and the bearings thereby cooling the assembly.