公开(公告)号：US3614494A

公开(公告)日：1971-10-19

申请号：US3614494D

申请日：1970-05-18

Applicant: DANFOSS AS

Inventor： BORCHERS ALWIN ,  SJOTUN KYRRE GUTTORM ,  HANSEN GUNNAR LYSHOJ ,  CLAUSEN JORGEN RONO

IPC: H02K7/08 ,  H02K17/04 ,  H02K17/00

CPC classification number: H02K16/02 ,  H02K7/085 ,  H02K17/04

Abstract: The invention relates to a single-phase electric motor assembly for installations such as oil burners. The motor has two oppositely rotatable rotors with one rotor adapted to drive a blower and the other adapted to drive an oil pump. The stator has main and secondary windings offset from each other which are switchable on and off together. The current phase in the secondary winding leads by up to 20* upon startup and remains above 0* at the highest operating voltage. There is a time lag during which the blower rotor builds up speed and it is only thereafter that its rotary field acts on the pump rotor to drive it in the opposite direction. Alternate hydraulic and mechanical means are provided for making the pump effective in only one operating direction.