| 摘要 |
<p>PURPOSE:To improve the torque transmission efficiency, by forming at least one roller separated from a magnetic body in the axial direction, and making the separated member to be absorbed and combined by magnetism, in a planetary roller type decelerating mechanism consisting of a set of rollers with approximately V shape friction surfaces. CONSTITUTION:This electric-powered steering device decelerates the rotation of a rotor 37 of a motor 33 through a decelerating mechanism 50 and transmits the rotation to an output shaft 7 through carrier member 54 and 64. The decelerating mechanism 50 consists of two-stage planetary systems 51 and 52, each of which consists of a ring roller 53, sun rollers 56 and 62, planetary rollers 54 and 63, and the like. In this case, at least the ring roller 53 of those set of rollers is formed of a magnetic body. And the rollers 53, 54, and 63 are separated in the axial direction at the top of the V shape grooves of the friction surfaces 53b...,54b.... At one side of the axial direction of the ring roller 53 is formed an electromagnetic coil 70, and the each separated member 53a... is made to be absorbed and combined by the excitation of the coil 70.</p> |
