Non-clearance double-gear output transmission method and transmission device

The invention discloses gapless two-gear driving output method and device, which comprises the following steps: setting two helical gears of different rotary directions on the output shaft; transforming the transmission force to two output gears through two driving circuits separately; transmitting torque separately when two output gears are activated by positive and negative direction. The device comprises the following parts: gear box, input-and-output shaft of the same axle, gear I, II shaft on two sides of input shaft, first, second helical gears of different rotary direction on the input shaft, first driven helical gear and first driving gear engaged to the first helical gear on the gear I shaft, second driven helical gear and second driving gear engaged to the second helical gear on the gear II shaft, third driving gear and first output gear engaged to the first driving gear on the output shaft, forth driving gear and second output gear engaged to the second driving gear on output shaft through the bearing case. The invention accomplishes the gapless driving of high precision.