REDUCTION GEAR MECHANISM AND MOTOR-DRIVEN POWER STEERING DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To reduce sounds caused when a worm is moved in radial direction by engagement reaction or the like. SOLUTION: This reduction gear mechanism includes a pressing body 6 capable of moving in the direction to support the shank 1a of a worm 1 and press the worm 1 against a worm wheel 2; a coil spring 8 for energizing the pressing body 6; and a guide part 32 for guiding the movement of the pressing body 6. A closing part 36 is provided on the side of the guide hole 32 opposite to the coil spring 8 across the pressing body 6, and an air reservoir part 37 controlling the movement of the pressing body 6 caused by the coil spring 8 is provided between the closing part 36 and the pressing body 6. The speed, amount and number of oscillations of the pressing body 6 when the pressing body 6 is moved by the dynamics between the engagement reaction and the coil spring 8 in such a way as to increase or decrease the distance H between the rotation axes of the worm 1 and the worm wheel 2 are reduced. COPYRIGHT: (C)2003,JPO