To enhance reliability of an in-wheel motor driving device that lubricates a planetary gear reduction gear mechanism with oil stored in a casing including an electric motor and planetary gear reduction gear mechanism.
A casing 10 includes: an electric motor 30; and a planetary gear speed reduction device 40 which reduces the speed of rotation of a rotor shaft 33 in the electric motor 30 to be output from an output shaft 41 arranged coaxially with the rotor shaft 33. An oil container 25 having an opening at the top and an oil discharge path 26 formed at the bottom is provided on an inner surface of a cover 12 serves as a sidewall of the casing 10. Oil stored at the bottom in the casing 10 is scraped up by rotation of the rotor 32 in the electric motor 30. The oil flowing from the opening at the top of the oil container 25 to the inside thereof is filtrated by a filter 27 included in the oil container 25 to capture contamination such as abrasive powder of a wheel contained in the oil, thereby reducing the amount of contamination contained in the oil.
Naoya Kamata
Yaichiro Nakatani
Takashi Shimizu