Patent ID: 8579757

Claim:
A roller frictional transmission unit comprising: a first roller; a second roller having an outer circumference surface arranged to be pressed and contacted with an outer circumference surface of the first roller to transmit a power between the first roller and the second roller by a friction; an input shaft connected with a driving system of main driving wheels of a four wheel drive vehicle, and connected with one of the first roller and the second roller; an output shaft connected with a driving system of auxiliary driving wheels of the four wheel drive vehicle, and connected with the other of the first roller and the second roller; a thrust bearing arranged to position an input shaft side rotation section including the one of the first roller and the second roller and the input shaft, or an output shaft side rotation section including the other of the first roller and the second roller and the output shaft, with respect to a unit housing in an axial direction; and a low rigidity structure disposed in a thrust transmission path to the thrust bearing, and arranged to buffer a thrust.