Patent ID: 6112583
Filing Date: 2000-09-05
Classification: F16D,G01D

Abstract:
A position detector for a motor for detecting a specified moving position of a moving body in forward and reverse directions, said detector comprising:a cover plate;a planetary gear train unit including a ring gear rotatably held in said cover plate, planetary gears engaged with said ring gear, and a sun gear engaged with said planetary gears, said unit being operatively linked with said moving body through a moving force transmitted from said moving body when said moving body moves;a switch portion including a moving contact formed integrally with said ring gear for rotating together with said ring gear and a fixed contact fixed in said cover plate and formed to contact said moving contact, said switch portion being for detecting a specified moving position of said moving body through operation of contacts that turn ON and OFF;a clutch mechanism operatively linked to said planetary gear train unit to stop a revolution of said planetary gears until said switch portion is actuated so that the moving force of said moving body is transmitted from said planetary gears to said ring gear to rotate said ring gear and, to shut off transmission of said moving force in a forward direction from said moving body to said ring gear by the revolution of said planetary gears after said switch portion is actuated;a pulse plate for generating pulse signal with an operation of said planetary gear train unit, said pulse plate having a through hole and a fitting portion for fixing said pulse plate to said sun gear of said planetary gear train unit; andpulse signal detection unit for detecting a pulse signal generated in said pulse plate, wherein:said sun gear includes:a shaft portion having a contacting surface for contacting said pulse plate;an insertion portion extending from said shaft portion in a rotation axial direction at a center portion of said shaft portion, and being inserted into said through hole of said pulse plate; anda protrusion portion protruding from said contacting surface of said shaft portion in said rotation axial direction around said insertion portion, said protrusion portion being engaged with said fitting portion of said pulse plate.