Four-wheel drive system for motor vehicles

摘要

A system is provided with a viscous coupling which is filled with a viscous material and adapted to transmit the output of a transmission through the viscous material. A first clutch and a second clutch are provided for selectively transmitting the output of the transmission to front and rear wheels. Each clutch is arranged to selectively transmit the output without interposing the viscous coupling and to selectively transmit the output through the viscous coupling.