TRANSMISSION RATIO VARIABLE STEERING DEVICE

摘要

A transmission ratio variable steering device capable of solving a problem in a conventional transmission ratio variable mechanism installed in a steering column wherein, since a spiral cable is required, an extra space is required and a trouble by the breakage of the cable may occur. A steering wheel shaft (11) and an output shaft (22) are supported on a housing (21) fitted to the steering column (13) rotatably on a same axis, a first sun gear (45) and a second sun gear (46) having the number of teeth slightly different from each other are formed at the opposed ends of the steering wheel shaft and the output shaft, and a first planetary gear (53) and a second planetary gear (54) meshed with these first and second sun gears are supported on a carrier (47). A worm shaft (58) meshed with a worm wheel (57) rotatingly connected to the carrier is rotated by a motor (43) disposed in the housing at right angle to the rotating axes of the steering wheel shaft and the output shaft. Thus, the space-saved transmission ratio variable steering device (10) without the spiral cable can be provided.