| 摘要 |
An electric power steering apparatus comprising: an electric motor; a ball screw mechanism connected to said electric motor via a gear train containing an idler gear and used for driving a rack shaft; and a steering gear case incorporating said rack shaft and said ball screw mechanism, wherein said idler gear is rotatably supported by an idler gear shaft fixed at its two side ends to said steering gear case, and a couple of bearings pre-loaded by pre-loading members is interposed between said idler gear shaft and said idler gear. In a second embdiment, a ball nut is rotationally driven by an electric motor through a gear train containing an idler gear and having a female thread groove formed in its inner periphery; a rack shaft is disposed on an axis of said ball nut and having a male thread groove so formed in its outer periphery as to face to said female thread groove; and a plurality of circulation balls is interposed between said female thread groove and said male thread groove, an axis of said electric motor, an axis of said idler gear and an axis of said ball nut being disposed substantially on the same plane. <IMAGE> |
