In-wheel motor drive assembly

An in-wheel motor drive assembly comprising:

• a motor unit including a tubular motor rotary shaft extending in an axial direction;
• a wheel hub bearing unit including a tubular wheel hub, a cylindrical outer-ring-side member surrounding an outer circumferential surface of the wheel hub, and a wheel hub bearing provided in an annular space formed between the outer circumferential surface of the wheel hub and an inner circumferential surface of the outer-ring-side member and rotatably supporting the wheel hub;
• and
• a speed reduction unit adopting a speed reduction mechanism having an output shaft extending in one direction and an input shaft extending in the other direction to reduce the rotational speed of the input shaft and transmit the reduced rotation to the output shaft, the output shaft being fixedly inserted in the center of the tubular wheel hub, and the input shaft being fixedly inserted in an axial end of the tubular motor rotary shaft.