| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device reducing deviation of an engaging position of a worm wheel and a worm caused by a change of temperature and allowing easy assembly. SOLUTION: Since there is a ball bearing 34 as a supporting base of a pinion shaft 2 immediately below the worm wheel 51, relative deviation of the engaging position of the worm wheel 51 and the worm 53 to an axial direction of the pinion shaft 2 is slight in quantity even when the temperature on the periphery of the electric power steering device is changed. A bearing hole 47 into which an outer ring of a lower needle bearing 36 is pressed and a bearing hole 45 into which the outer ring of an upper ball bearing 34 is pressed are formed on the same lower gear box 41. Also, since through processing by a boring tool from a bearing hole 45 side can be carried out, processing time is shortened, and concentricity of the bearing holes is enhanced. Thus, oscillation of the worm wheel 51 is reduced, and noise in an engaging part or abrasion of a tooth surface can be suppressed. COPYRIGHT: (C)2005,JPO&NCIPI |
