Development of a Rotary Tri-Blade Coupling for Four-Wheel Drive Cars

A new type of torque transmit coupling has recently been developed for 4WD cars, that provides a better match to ABS, is of lighter weight, and uses a simpler operating mechanism. This coupling transmits torque with a multi-disc clutch that is engaged by the pressure of high viscosity silicone oil. The rotary blade generates variably the silicone oil pressure, according to both differential speed and direction of rotation between the front and rear wheels.

This coupling provides a good match between 4WD performance and four wheel Anti-lock Braking System (ABS) by a modification of the rotary blade shape. No additional devices are needed.

This paper describes the characteristics of this coupling and the in-vehicle performance.