SYNCHROMESH SPEED REDUCING DEVICE

PURPOSE:To enhance the transmission efficiency by interposing rolling elements between an inner ring and an externally cogged gear, and thereby eliminating frictional loss due to slip to be generated between externally cogged gear and outer ring. CONSTITUTION:An externally cogged gear 4 is provided at its inner face with a groove of raceway 12 for running of rolling elements 7 of a bearing 3, to serve as an outer ring of the bearing 3. Thus the rolling elements 7 roll in the gap between this externally cogged gear 4 and inner ring 6. The inner ring 6 is pressure fitted on a rotor 2, and the rolling elements 7 are held by the inner ring 6 so that they are not movable in the axial direction. Accordingly the externally cogged gear 4 is consolidated with the inner ring 6 through rolling elements 7, that eliminates frictional loss due to slip otherwise generated between outer ring and externally cogged gear 4 to lead to enhancement of the power transmission efficiency.