Motor-driven wheel small in size and improved in ride comfort and ease of assembly
A motor-driven wheel includes a wheel disc, a wheel hub, a knuckle, a hub bearing, a constant-velocity joint, an in-wheel motor, and a spring. The center of swing of the constant-velocity joint is placed closer to the outside of the vehicle relative to the hub bearing. Since such components of the constant-velocity joint as an inner race, balls and a cage are placed differently in position from the hub bearing, the hub bearing can be reduced in diameter. An outer race of the constant-velocity joint is integrated with the wheel hub into a single part and has an opening facing the outside of the vehicle. Since the opening is large and shallow, the work of installing the cage, balls and inner race and securing them with a snap ring is facilitated.
1. A motor-driven wheel comprising:
a motor supported swingably in up-and-down direction of a body of a vehicle and rotating a wheel unit;
a hub bearing rotatably supporting said wheel unit; and
a constant-velocity joint provided on a power transmission path extending from an output shaft of said motor to said wheel unit and having its center of swing located closer to outside of the vehicle relative to said hub bearing,
said constant-velocity joint including
an outer race integrated, with a wheel hub to which a wheel of said wheel unit is fixed, into a single part, and having a first opening facing the outside of the vehicle,
an inner race connected to the output shaft of said motor in a manner that allows motive power to be transmitted, and
a rolling body transmitting the motive power between said inner race and said outer race.
2. The motor-driven wheel according to claim 1 , further comprising a knuckle connected to a suspension arm attached to the body of the vehicle, wherein
said motor is connected through an elastic member to said knuckle.
3. The motor-driven wheel according to claim 2 , wherein
said hub bearing is fixed to said knuckle.
4. The motor-driven wheel according to claim 1 , wherein
said constant-velocity joint further includes a cage restraining position of said rolling body, and
said first opening is larger in diameter than an assembly into which said cage, said rolling body and said inner race are assembled.
5. The motor-driven wheel according to claim 1 , wherein
said outer race further has a second opening facing inside of the vehicle, and a rotational shaft connected to said inner race passes through said second opening,
said first opening is larger than said second opening, and
said hub bearing rotatably supports a portion where said rotational axis passes through of said outer race integrated with said wheel hub into the single part.
6. The motor-driven wheel according to claim 1 , further comprising a cap covering said first opening.