Patent attributes
A driving force transmitting device includes a case, an electric motor, and a gearbox. The electric motor includes an output shaft. The gearbox includes a spur gear that rotates coaxially with the output shaft. The case includes a partition wall, a first accommodating chamber accommodating the electric motor, and a second accommodating chamber that accommodates a second driven gear. The partition separates the first accommodating chamber and the second accommodating chamber from each other. The partition wall includes a connecting hole that connects the first accommodating chamber and the second accommodating chamber to each other. The connecting hole is located on one direction side in relation to the central axis of the output shaft. At least part of the connecting hole overlaps with the spur gear when viewed in a direction along the central axis.