Patent ID: 8298112

Claim:
A device for switching between normal and reverse drive force, comprising an input gear ( 11 ), an output gear ( 12 ) and a switch mechanism ( 13 ) that selectively switches drive torque applied to said input gear ( 11 ) and transmitted to said output gear ( 12 ), wherein said switch mechanism ( 13 ) comprises a planetary gear mechanism ( 14 ), a control mechanism ( 15 ) and a clutch mechanism ( 16 ), wherein said planetary gear mechanism ( 14 ) comprises a rotation transmission shaft ( 18 ) supported by a fixed shaft ( 17 ), a sun gear ( 19 ) coaxially integrated with said rotation transmission shaft ( 18 ), an internal gear ( 21 ) coaxially provided around said sun gear ( 19 ) and integrated with said output gear ( 12 ), planetary gears ( 22 ) provided between said sun gear ( 19 ) and said internal gear ( 21 ), and a carrier ( 23 ) for said planetary gears ( 22 ) provided coaxially with said rotation transmission shaft ( 18 ), wherein said control mechanism ( 15 ) comprises a control gear ( 25 ) provided rotatably and coaxially on said fixed shaft ( 17 ) and capable of being selectively locked and unlocked by an external actuator ( 24 ), said control gear ( 25 ) being integrated with said carrier ( 23 ), wherein said clutch mechanism ( 16 ) comprises a unidirectional roller clutch ( 26 ) provided between radially opposed surfaces of said rotation transmission shaft ( 18 ) and a clutch-mounting portion ( 34 ) provided in said carrier ( 23 ), wherein lock release pins ( 28 ) formed on said control gear ( 25 ) are provided at ends to which wedge angle (θ) narrows in said roller clutch ( 26 ), leaving predetermined clearances to adjacent rollers ( 27 ), and wherein said input gear ( 11 ) is integrated with said rotation transmission shaft ( 18 ).