Patent attributes
Provided is a driving force transmission device that can achieve further reduction in drag torque when it is not in operation and thus is not transmitting a driving force. A driving force transmission device includes: a clutch hub and a clutch drum; inner clutch plates spline-fitted on the clutch hub; outer clutch plates spline-fitted in the clutch drum; and a housing having a second accommodating chamber accommodating the clutch hub and the clutch drum. The inner clutch plates and the outer clutch plates are lubricated by lubricant. The driving force transmission device further includes a fin plate. The fin plate rotates with the clutch hub. By this rotation, the fin plate scoops up the lubricant in the second accommodating chamber to feed the lubricant to a reservoir chamber formed in the housing.