Bicycle mid-drive motor assembly structure

A bicycle mid-drive motor assembly structure, which is applicable to a vehicle frame of a bicycle, wherein the vehicle frame includes an axle through-tube in which a crank axle is mounted for driving the bicycle by actuating a front chainwheel mounted on the crank axle, the mid-drive motor assembly structure comprising a motor that is selectively mounted to the vehicle frame and a clutch set arranged at one end of the crank axle, wherein the clutch set comprises:

• a crank axle sleeve, of which an inner surface of one end corresponding to the crank axle is formed with first straight teeth, and the crank axle comprises second straight teeth corresponding thereto and engageable therewith, a protruding axle portion protruding from an opposite side of the crank axle sleeve to sleeve on the crank axle, a middle portion of the protruding axle portion of the crank axle sleeve being provided with a first engagement tooth section, a portion of the protruding axle portion that is located inward of the first engagement tooth section being provided with a first bearing seat section for mounting a first bearing;
• a support sleeve, which comprises a threading protruding collar corresponding to the axle through-tube, and the axle through-tube includes a threading section for being meshed therewith, the support sleeve comprising includes a first inner bearing seat corresponding to the first bearing;
• a clutch wheel, which is provided, in a center thereof, with a second engagement tooth section corresponding to the first engagement tooth section of the crank axle sleeve, one side of the clutch wheel that is opposite to the vehicle frame being formed with a second bearing seat section for mounting a second bearing, clutch pawls being provided on an outer circumference of the clutch wheel;
• a cover cap, which is provided, on a one side thereof opposite to the vehicle frame, with a protruding axle collar arranged in a center thereof to sleeve on the support sleeve, the protruding axle collar being formed with a third bearing seat section, a ring cover being attached to a circumference of the cover cap;
• and
• a transmission wheel, of which an outer circumference is formed with engagement teeth meshed with the motor, the transmission wheel being provided, in a center thereof, with a third inner bearing seat corresponding to the cover cap for mounting, in combination with the third bearing seat section of the cover cap, a third bearing, one side of the transmission wheel that corresponds to the front chainwheel being formed with a second inner bearing seat for mounting, in combination with the second bearing seat section of the clutch wheel, the second bearing, the transmission wheel being formed, in an inner circumference thereof, with clutching teeth to correspond to the clutch pawls of the clutch wheel, the front chainwheel being coaxially mounted to an outside surface of the transmission wheel.