Toyota Jidosha Kabushiki Kaisha

Hiroki Monji

Keita Imai

Shin Kurosaki

Kiichi Yokoyama

Tatsuya Sakai

Yusuke Ueta

A gear case of an in-wheel motor drive device houses first and second helical gears, has a first opening in its inner wall through which a motor main shaft passes, and has a second opening in its outer wall through which an axle passes. The in-wheel motor drive device further includes a first thrust bearing attached to the outer wall and supporting the first helical gear, and a second thrust bearing attached to the inner wall and supporting the second helical gear. The directions of helical teeth of the first and second helical gears are set so that when a motor vehicle travels forward, a thrust load directed outward in the vehicle width direction is applied to the first helical gear, and a thrust load directed toward the middle in the vehicle width direction is applied to the second helical gear.

In-wheel motor drive device mounted on motor vehicle

The power transmission device includes a speed reducer and a differential. The speed reducer includes a sun gear fixed to a hollow input shaft, stepped pinions, first and second ring gears. The stepped pinion has input and output gears, with the input gear engaging the sun gear. A first ring gear is fixed to a housing and engages the input gear. The second ring gear engages the output gear. The differential has a differential housing and first and second output shafts. The differential housing is fixed to the second ring gear. The first and second output shafts are arranged concentrically with the input shaft and extend in opposite directions from the differential housing. One of the first output shaft and the second output shaft passes through the inside of the input shaft. The differential housing is positioned to be surrounded by the output gears of the stepped pinions.

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Toyota, Japan

Hiroki Monji