Patent ID: 7364004
Filing Date: 2008-04-29
Classification: B62D

Abstract:
1. An apparatus for use in turning steerable vehicle wheels during operation of an engine of a vehicle, said apparatus comprising: a hydraulic power steering motor connected with the steerable vehicle wheels and operable to turn the steerable vehicle wheels, a pump connected in fluid communication with said hydraulic power steering motor and operable to supply hydraulic fluid to said hydraulic power steering motor during turning of the steerable vehicle wheels, and a gearset connected with the engine of the vehicle and with said pump, said gearset being operable under the influence of force transmitted from the engine of the vehicle to drive said pump at a first speed during turning of the steerable vehicle wheels at relatively low vehicle speeds, said gearset being operable under the influence of force transmitted from the engine to drive said pump at a second speed during turning of the steerable vehicle wheels at relatively high vehicle speeds, said first speed at which said pump is driven by said gearset during a vehicle steering operation at relatively low vehicle speeds is greater than said second speed at which said pump is driven by said gearset during a vehicle steering operation at relatively high vehicle speeds.