US 11,732,761 B2
Power transmission device
Yoshihiko Ozawa, Hamamatsu (JP); Han Hiong Chen, Hamamatsu (JP); Makoto Kataoka, Hamamatsu (JP); and Masataka Murai, Hamamatsu (JP)
Assigned to Kabushiki Kaisha F.C.C., Hamamatsu (JP)
Filed by Kabushiki Kaisha F.C.C., Hamamatsu (JP)
Filed on Jul. 31, 2022, as Appl. No. 17/877,982.
Application 17/877,982 is a continuation of application No. 17/336,447, filed on Jun. 2, 2021, granted, now 11,460,077.
Application 17/336,447 is a continuation of application No. PCT/JP2019/047408, filed on Dec. 4, 2019.
Claims priority of application No. 2018-227995 (JP), filed on Dec. 5, 2018.
Prior Publication US 2022/0389974 A1, Dec. 8, 2022
Int. Cl. F16D 13/56 (2006.01); F16D 43/12 (2006.01)
CPC F16D 13/56 (2013.01) [F16D 43/12 (2013.01); F16D 2013/565 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A power transmission device comprising:
a clutch member includes a plurality of driven-side clutch plates that are alternately formed with a plurality of drive-side clutch plates of a clutch housing rotating together with an input member rotated by engine driving power of a vehicle, the clutch member coupled with an output member rotating a wheel of the vehicle;
a pressure member movable between an active position and an inactive position, in the active position, the pressure member presses the drive-side clutch plates and the driven-side clutch plates against each other to transmit the engine driving power to the wheel, and in the inactive position, the pressure member releases a press-contact force between the drive-side clutch plates and the driven-side clutch plates to stop transmitting the engine driving power to the wheel;
a weight member movable from a radially-inner position to a radially-outer position due to a centrifugal force generated as the clutch housing rotates;
an interlocking member switching the drive-side clutch plates and the driven-side clutch plates from a non-operating state, where the press-contact force between the drive-side clutch plates and the driven-side clutch plates is released, to an operating state, where the driving power of the engine is able to be transmitted to the wheel by pressing the drive-side clutch plates and the driven-side clutch plates against each other as the weight member moves from the radially-inner position to the radially-outer position;
the clutch member includes
a first clutch member coupled to the output member,
a second clutch member attached to the driven-side clutch plates;
a plurality of clutch side first cam portions, each of the plurality of clutch side first cam portions including a clutch side assist cam surface and a clutch side slippery cam surface, the clutch side assist cam surface generating a force in a direction that the pressure member approaches the clutch member to increase the press-contact force between the drive-side clutch plates and the driven-side clutch plates when rotating relative to the pressure member, and the clutch side slippery cam surface separating the pressure member from the clutch member to reduce the press-contact force between the drive-side clutch plates and the driven-side clutch plates when rotating relative to the pressure member,
the plurality of clutch side first cam portions are provided with the first clutch member,
the pressure member includes
a plurality of a pressure side cam portions, each of the plurality of pressure side cam portions including a pressure side assist cam surface and a pressure side slippery cam surface, the pressure side assist cam surface being contactable with the clutch side assist cam surface and generating the force in the direction that the pressure member approaches the clutch member to increase the press-contact force between the drive-side clutch plates and the driven-side clutch plates when rotating relative to the clutch member, and the pressure side slippery cam surface being contactable with the clutch side slippery cam surface and separating the pressure member from the clutch member to reduce the press-contact force between the drive-side clutch plates and the driven-side clutch plates when rotating relative to the clutch member.