Transmission structure of hub motor

Transmission structure comprising:

• a hub shell;
• an axle disposed through two opposite surfaces of the hub shell, and an extending direction of the axle defined as a first direction;
• a motor unit disposed in the hub shell and mounted on the axle, a rotating direction driven by the motor unit defined as a first rotating direction;
• a clutch assembly mounted in the hub shell, and the clutch assembly connecting the hub shell and the motor unit;
• the clutch assembly including:
• a driving ring connected to and driven by the motor unit, and the driving ring capable of rotating along the first rotating direction;
• the driving ring having a first surrounding teeth portion;
• an output disc rotatably connected to the hub shell and capable of driving the hub shell to rotate;
• the output disc including:
• multiple first toothed engaging portions formed on a surface of the output disc which faces towards the motor unit, and the first toothed engaging portions surrounding a rotating axis of the output disc;
• the first toothed engaging portions connected to each other;
• a fixing base disposed between the output disc and the motor unit, and the fixing base being magnetic and having
• a first pressing surface facing towards the output disc;
• and
• a first sliding portion formed on the first pressing surface;
• a clutch disc being magnetically attractable and being moveable between the fixing base and the output disc along the first direction;
• the clutch disc having:
• a second surrounding teeth portion engaging with the first surrounding teeth portion, thereby the driving ring being capable of driving the clutch disc to rotate;
• multiple second toothed engaging portions formed on a surface of the clutch disc which faces towards the output disc, and the second toothed engaging portions selectively engaging with the first toothed engaging portions, and the second toothed engaging portions connected to each other;
• and
• a first abutting portion formed on another surface of the clutch disc which is away from the output disc;
• a pressing ring disposed between the first pressing surface and the clutch disc, and the pressing ring capable of moving along the first direction;
• the pressing ring detachably contacting the clutch disc and having:
• a second abutting portion formed on a surface of the pressing ring which faces towards the clutch disc, and the second abutting portion selectively abutting the first abutting portion, thereby the clutch disc being capable of driving the pressing ring to rotate;
• and
• a second sliding portion contacting the first sliding portion and capable of sliding with respect to the first sliding portion, thereby the pressing ring moving toward the output disc;
• and
• an elastic unit disposed between the fixing base and the surface of the pressing ring which faces towards the clutch disc, and the elastic unit abutting the fixing base and configured to push the pressing ring.