MR fluid viscous coupling and its torque delivery control

A torque controllable viscous coupling is presented. The coupling consists of two types of discs with slits. One is connected to a housing (follower discs) and the other is connected to a shaft (driving discs). The driving discs and follower discs are arranged by turns and they are sandwiched. MR fluid is filled in the housing. Magnetic fields freeze the fluid, so that the shear torque is generated between the diving discs and follower discs due to shears between the slits in the discs under the magnetic fields. The torque is controlled by electromagnets. In order to have large torque with small electric power, coil turns have to be large, so that response delays due to inductance of the coil. A controller which improves response is presented. A method of control is presented which controls distribution of torque of rear wheel and front wheel.