Electric pump

Abstract

An electric pump includes a housing 2 configured of a housing body 3 and a cover 4 , a stator 6 having a plurality of coils 15 , a rotor 7 configured of an inner side outer rotor 16 and an outer side rotor body 17 , a pump part 8 disposed on the inner circumferential side of the rotor 7 of an electric motor 5 , side plates 11 and 12 disposed on both side surfaces of the rotor 7 , an inner rotor 9 , and a plurality of connecting plates 10 interposed between the outer rotor 16 and the inner rotor 9 . The side plate 12 of the side plates 11 and 12 is pressed to the rotor 7 by a compression coil spring 28.

1 . An electric pump comprising:
 a housing having a sealed structure;   a stator including a plurality of coils arranged circumferentially, the stator which is accommodated in the housing;   a rotor disposed on an inner circumferential side of the stator;   a pump part disposed on an inner circumferential side of the rotor and driven by an electric motor, the rotor which also serves as an outer rotor of the pump part and forms the electric motor with the stator;   a pair of side plates disposed on both side surfaces of the rotor; and   an inner rotor disposed on the inner circumferential side of the rotor eccentrically, and forming a pump chamber of the pump part with the rotor and the pair of the side plates, the inner rotor which rotates with rotation of the rotor,   wherein at least one of the pair of the side plates is pressed to the rotor by an elastic member.   
     
     
         2 . The electric pump according to  claim 1 , wherein the rotor is configured of the outer rotor forming the pump chamber of the pump part with the pair of the side plates and the inner rotor, and of a rotor body provided with permanent magnets corresponding to the respective coils at a stator side, the rotor body which is fitted and fixed on an outer circumferential side of the outer rotor. 
     
     
         3 . The electric pump according to  claim 2 , wherein the pump part comprises, in addition to the outer rotor, the pair of the side plates and the inner rotor, plate members configured to divide the pump chamber formed between the outer rotor and the inner rotor into a plurality of regions, the plate members whose respective one ends are swingably supported on the outer rotor and the respective other ends are slidably fitted to the inner rotor. 
     
     
         4 . The electric pump according to  claim 3 , wherein the housing is divided into two parts in an axial center direction of the rotor, and configured of a housing body and a cover member, and
 wherein the outer rotor, the inner rotor and the pair of the side plates disposed on both side surfaces of each of the outer rotor and the inner rotor are press-held by the housing body and the cover member.   
     
     
         5 . The electric pump according to  claim 4 , wherein the outer rotor includes, on its outer circumferential edge portion, a rim portion whose length in the axial center direction is longer than that of the rotor body,
 wherein bearings are interposed in respective spaces between an inner circumferential surface at one end portion in a longitudinal direction of the rim portion and the cover and between the inner circumferential surface at the other end portion in the longitudinal direction of the rim portion and the housing body, and   wherein the rotor configured of the outer rotor and the rotor body is rotatably supported at both ends by the bearings.