Transmission

A transmission, comprising:

• an input shaft;
• an output shaft receiving power from the input shaft;
• and
• a transmission device changing torque and speed transmitted from the input shaft to the output shaft, the transmission device comprising:
• a ring gear;
• an input member including an input gear which internally contacts one portion of the ring gear and rotates the ring gear while being rotated by the power transmitted from the input shaft, and a guide bar passing through a center point A of the input gear located at a center of the input gear in a direction along a diameter of the input gear and a center point B of the ring gear located at a center of the ring gear in a direction along a diameter of the ring gear;
• a gear shifting slider which has one end coupled to the guide bar to be movable to the center point A of the input gear and the center point B of the ring gear, and another end coupled to the input shaft and which changes a rotation center of the input gear to change a torque of the ring gear;
• and
• an output gear internally contacting another portion of the ring gear which is not contacted with the input gear, and transmitting changed torque and speed to the output shaft while being rotated by the ring gear.