ELECTRIC POWER STEERING SYSTEM

摘要

In an electric power steering system according to the present invention, a housing member for bearings, which supports at least one rolling bearing, is formed of resin. It is preferable that the resin: can be used continuously in an environment of -40 to 85ºC; comprises a resin composition that contains a fibrous filler at 30-55 mass%; has a linear expansion coefficient in the range of 1.2x10-5-5.5x10-5(1/ºC) in both the fiber direction and the direction orthogonal thereto at temperatures in the range of 23 to 80ºC; and has a water absorption rate of equal to or less than 4% when left in 23ºC water for 24 hours.