A multi-speed transmission, comprising:
- a driving shaft that rotates as a rotational force is input;
- a plurality of driving gears which are coupled to the driving shaft and rotate by the rotation of the driving shaft;
- a plurality of transmission gears which are engaged with the driving gears;
- a transmission shaft which includes a plurality of pawl assemblies that are at least partially moved inward and outward on an outer peripheral surface, is coupled with the transmission gears, and is selectively coupled with at least a part of the transmission gears in accordance with the inward and outward movement of at least a part of the pawl assemblies;
- a transmission control means for selectively controlling the inward and outward movement of at least a part of the pawl assemblies;
- a plurality of driven gears which are engaged with at least a part of the transmission gears;
- and
- a driven shaft which is coupled with the plurality of driven gears and transmits rotational force to an object to be driven,
- wherein the transmission control means comprises:
- a plurality of guide members which are disposed in a hollow portion of the transmission shaft, moved along a longitudinal direction of the transmission shaft, and selectively come into contact with a part of the pawl assemblies to guide the inward and outward movement of a part of the pawl assemblies;
- a plurality of guide rods each connected to the plurality of guide members on one side;
- a wire for transmitting;
- and
- a transmission channel which is rotatable by the wire, and includes a transmission guide groove formed to have a predetermined radius and length,
- wherein the other sides of the plurality of guide rods each come into contact with the transmission channel, and are selectively inserted into the transmission guide grooves by rotation of the transmission channel to selectively move the guide member,
- wherein the guide member comprises a seating part including a seating slope configured so that a part of the pawl assemblies is able to seat, and
- wherein a plurality of first insertion holes and second insertion holes arranged along the longitudinal direction of the transmission shaft are formed on a peripheral surface of the transmission shaft, and
- the pawl assemblies comprise:
- a first pawl member which is rotatably provided in the first insertion hole and formed so that at least a part thereof is selectively exposed to the outside of the transmission shaft;
- an elastic member inserted into the second insertion hole;
- and
- a second pawl member which includes a first contact part that comes into contact with the first pawl member, a second contact part that comes into contact with the elastic member, and a seating protrusion that is formed to protrude in an inward direction between the first contact part and the second contact part, and formed to selectively come into contact with the seating slope in accordance with movement of the guide member,
- wherein when the seating protrusion is seated on the seating slope, as the first contact part exerts an external force to the first pawl member, at least a part of the first pawl member is exposed to the outside and locked to a locking groove formed on an inner side of the transmission gears.