Patent ID: 7798282
Filing Date: 2010-09-21
Classification: B62D

Abstract:
1. A power steering assist system for an automotive vehicle including: an over-center variable displacement hydraulic pump having a central rotor for rotation in a direction about a relatively fixed center of rotation, an adjustable cam with an inner wall that surrounds said central pump rotor providing space between said inner cam wall and said rotor to define a pair of variable pump chambers to differentially pressurize fluid in said chambers communicated to a pair of outlet ports connected to a steering gear apparatus; an electrical torque motor connected to apply torque forces to said adjustable cam; a control circuit configured to react to vehicle driver input and other vehicle data to provide an electrical signal to energize said electrical torque motor; said electrical torque motor reacting to said electrical signal to apply a desired amount of torque force to said cam; and said pump being sensitive to said applied torque force to adjust its output of differentially pressurized fluid communicated to said steering gear apparatus by a predetermined amount.