Patent ID: 6705830
Filing Date: 2004-03-16
Classification: F04D

Abstract:
A vacuum pump comprising:a pump case having an inlet port at an end portion thereof and a flange portion extending from a periphery of the end portion, the flange portion having a first main surface, a second main surface disposed opposite the first main surface, a first bolt insertion hole extending through the first and second main surfaces, and a second bolt insertion hole extending through the first and second main surfaces; a rotor disposed in the pump case for undergoing rotation; a plurality of rotor blades integrally connected to an outer circumferential surface of the rotor; a stator having a plurality of stator blades disposed between the rotor blades; a driving motor for rotationally driving the rotor; an auxiliary ring connected to the first main surface of the flange portion of the pump case, the auxiliary ring having a first main surface, a second main surface disposed opposite the first main surface, and a third bolt insertion hole extending through the first and second main surfaces of the auxiliary ring; an auxiliary ring attaching bolt extending through the third bolt insertion hole for connecting the auxiliary ring to a chamber housing disposed opposite the end portion of the pump case; a pump case supporting bolt extending through the second bolt insertion hole of the flange portion of the pump case and connected to the auxiliary ring; and a pump case fastening bolt extending through the first bolt insertion hole of the flange portion of the pump case and connected to the auxiliary ring, a shaft portion of the pump case fastening bolt having a diameter smaller than a shaft portion of each of the auxiliary ring attaching bolt and the pump case supporting bolt.