Ebara Corporation

Genichi Sato

Yoshinori Ojima

Katsuaki Usui

Kozo Matake

Yasushi Hisabe

Masami Nagayama

Hiroaki Ogamino

A multishaft electric motor has a plurality of juxtaposed rotors having respective permanent magnets disposed therearound, and a plurality of sets of armature elements disposed fully circumferentially around the rotors, respectively, the permanent magnets of adjacent two of the rotors having a plurality of pairs of unlike magnetic poles for magnetically coupling the rotors through the armature elements between the permanent magnets. A positive-displacement vacuum pump includes a casing, a pair of pump rotors rotatably disposed in the casing in confronting relation to each other, and a two-shaft electric motor coupled to the pump rotors for rotating the pump rotors in opposite directions. The two-shaft electric motor may comprise a pair of juxtaposed rotors and a pair of sets of armature elements disposed fully circumferentially around the rotors, respectively.

Multishaft electric motor and positive-displacement pump combined with such multishaft electric motor

Multishaft electric motor and positive-displacement pump combined with

A vacuum pump has a pump casing having a suction side where a suction port is located and a discharge side where a discharge port is located, a pump assembly housed in the pump casing and comprising a pair of pump rotors rotatable in synchronism with each other and having respective shafts, and a brushless direct-current motor mounted on the pump casing at a suction side of the pump casing. The motor has a pair of motor rotors comprising respective sets of permanent magnets which are mounted respectively on the shafts, a pair of cans surrounding outer circumferential and end surfaces of the motor rotors in sealing relation to the pump assembly, a motor stator mounted on the cans and housed in a water-cooled motor frame.

Vacuum pump motor arrangement having reduced heat generation

Growing community of inventors

Chigasaki, Japan

Genichi Sato