TRANSMISSION FOR MOTOR

The present invention relates to a transmission for a motor, and more particularly, to a transmission for a motor, which optimizes a transmission for outputting a rotational force only in one direction at different shifting ratios according to forward/reverse rotation directions of a rotational shaft of the motor while enabling a reverse input, accurately transmits the rotational force without slippage and has durability even upon use thereof for a long period of time. The transmission receives a rotational force from a rotational shaft (12) of a motor (10) to perform an output to an output shaft through shifting, and outputs the rotational force only in one direction at different shifting ratios according to forward/reverse rotation directions of the rotational shaft (12) of the motor (10). The transmission includes a driving shaft (100) having one or more one-way clutch contact surfaces (110) formed on an outer periphery of a certain region of the driving shaft (100); a dual one-way clutch (200) including a carrier (210) for accommodating forward restrictors (211) and reverse restrictors (212) in both faces of the carrier (210), respectively, wherein the forward and reverse restrictors (211 and 212) are radially equidistantly arranged with a predetermined phase angle difference, and a forward output ring (220) and a reverse output ring (230) disposed outside the forward restrictors (211) and the reverse restrictors (212), respectively, to be selectively rotated according to a rotation direction of the driving shaft (100); and a low-speed rotational force transmitting means (300) and a high-speed rotational force transmitting means (400) including a plurality of gears engaged with one another, wherein the low-speed rotational force transmitting means (300) and the high-speed rotational force transmitting means (400) receive the rotational force independently from the forward output ring (220) and the reverse output ring (230) of the dual one-way clutch (200) so as to rotate the output shaft (500) with the shifting ratios though different paths, whereby the dual one-way clutch (200) allows a reverse input in a direction opposite to a rotation direction of an output of the output shaft (500). Accordingly, the transmission improves reliability and shifting accuracy and maximizes marketability and market competitiveness. Fig. 3