Patent ID: 7857092
Filing Date: 2010-12-28
Classification: B62D,F04C

Abstract:
1. A hydraulic power steering device comprising: a hydraulic power cylinder having first and second hydraulic chambers for assisting a steering force of a steering mechanism adapted to be linked to steered road wheels; a first fluid line connected to the first hydraulic chamber; a second fluid line connected to the second hydraulic chamber; a reversible pump comprising a drive shaft, a plurality of pumping chambers configured to pressurize working fluid by way of normal-rotation and reverse-rotation of the drive shaft, a first suction-and-discharge port interconnecting the pumping chambers and the first fluid line, and a second suction-and-discharge port interconnecting the pumping chambers and the second fluid line, for selectively supplying the working fluid from the pumping chambers into either one of the first and second fluid lines, and an electric motor connected to the drive shaft for rotating the reversible pump in a selected one of a normal-rotational direction and a reverse-rotational direction, the reversible pump comprising: wherein an inner peripheral surface of the outer-rotor housing portion is formed into a substantially elliptic shape that the first axis is a minor axis and the second axis through the center of the minor axis and perpendicular to the first axis is a major axis whose length is longer than the minor axis.