Transmission with 1 axis shift mechanism

A transmission including a shift mechanism in which a shift fork is slidably coupled to a shift rail, and the shift fork includes a sleeve that allows the shift fork to be meshed with a gear portion coupled to an input shaft, the transmission comprising:

• a motor;
• a first shift gear which is connected to the motor and moves according to rotation of the motor;
• a second shift gear arranged at one end of the shift rail and secured to the first shift gear;
• and
• a sliding pin arranged at the other end of the shift rail and configured to slide the shift fork by contacting a sliding protrusion arranged around an insertion hole of the shift fork, into which the shift rail is inserted,
• wherein the sliding protrusion protrudes from a bottom surface arranged around the insertion hole, and
• the sliding pin rotates according to rotation of the second shift gear and comes into contact with an upper surface of the sliding protrusion to slide the shift fork in a longitudinal direction, and
• wherein the shift fork includes the bottom surface on which the sliding protrusion is arranged and a support wall extending along edges of the bottom surface to surround the sliding protrusion, and
• the sliding pin is arranged within the support wall and extends from the other end of the shift rail by a length shorter than an inner diameter of the support wall, and selectively comes into contact with the bottom surface or the upper surface of the sliding protrusion according to rotation of the second shift gear to move the shift fork by a height difference between the bottom surface and the sliding protrusion.