Honda Motor Co., Ltd.

Satoshi Imamori

Kenji Niwata

Makoto Tsuchihashi

Tetsuya Otani

Eisuke Hosoda

Provided is a hydraulic power transmission device enabling to minimize a pressure loss in an oil passage downstream from a piston chamber of a hydraulic clutch, and to properly prevent reduction in transmission torque capacity in the hydraulic clutch. Left and right pressure regulating valves (L,R) regulating pressure of oil flowing out from piston chambers (L,R) of left and right clutch devices (L,R) are arranged adjacent to a downstream of the piston chamber (). This can shorten an oil passage from the piston chamber () to the pressure regulating valve () and minimize pressure loss in the oil passage. Due to better flexibility of arrangement of the pressing load receiving member () receiving a pressing force (thrust) of the piston member (), thrust efficiency of the hydraulic piston () improves to properly prevent reduction in transmission torque capacity in the hydraulic clutch ().

Hydraulic power transmission device

In a power transmission device for a vehicle, a boss portion of a clutch guide, which is an input-side rotation member of a clutch unit, includes: a spline portion spline-connected to a small-diameter portion at one end of a center shaft which is an input shaft; and a fitting portion that extends further from the spline portion in an axial direction to contact the outer circumference of a medium-diameter portion of the center shaft. A recess functioning as a torque fuse is formed in the medium-diameter portion of the center shaft corresponding to the fitting portion. When the center shaft is severed or disconnected at the recess, the medium-diameter portion of the severed cut center shaft can still remain within the fitting portion, so that appropriate centering can be secured and stable self-propulsion of the vehicle can be secured without unwanted misalignment of the axis of rotation of the clutch.

Growing community of inventors

Wako, Japan

Satoshi Imamori