Patent ID: 6363833
Filing Date: 2002-04-02
Classification: B62D,F15B,F16J

Abstract:
A hydraulic power assist steering system for a vehicle having steerable wheels, said system comprising:a housing and a rack movable in said housing to effect turning movement of the steerable wheels of the vehicle; a fluid motor for moving said rack, said fluid motor including a piston fixedly connected to said rack and a pump; said piston having first and second opposite end faces against which hydraulic fluid is directed by said pump to effect movement of said piston, and thereby said rack, relative to said housing; said piston having a wall including a first end portion connected with said rack at a first axial location along said rack, a second end portion connected with said rack at a second axial location along said rack, and a central portion extending between and interconnecting said first and second end portions of said wall; said central portion of said wall having an outer peripheral groove for receiving a seal ring for engagement with said housing; said first end portion and said second end portion and said central portion of said piston defining a cavity in said piston; said cavity having an annular configuration extending around said rack inside of said wall.