| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving force transmission device for four-wheel drive vehicles which has a simple configuration with the number of components reduced and being capable of appropriate torque transmission to sub-driving wheels according to the running state of a vehicle.SOLUTION: In a driving force transmission device for four-wheel drive vehicles, a lubricating oil introduced into bearings (38, 39) supporting a pinion shaft (36) of a rear differential (30) is introduced into a storage chamber (63) of a torque transmission switching mechanism (60) by a discharge pressure produced by the rotation of the bearings (38, 39) and then returned from the storage chamber (63) to a casing (41). When a spool valve (65) moves within the storage chamber (63) in response to the inertia force of the vehicle, the fluid pressure acting on a piston (61) changes, and engagement and non-engagement between a dog tooth (61a) of the piston (61) and a dog tooth (17a) of a rotary member (17) are thereby switched mutually, leading to switching between presence and absence of torque transmission to the rear wheels (W3, W4) by a viscous coupling (10). |
