Switching characteristics of torque transmission utilizing movement of magnetic fluid

This paper describes the switching characteristics of torque transmission and their improvement by modifying a rotating disk and tank in a magnetic fluid coupling, as was discussed in the authors' previous report. Whenever a magnetic field is applied to a fluid coupling, the magnetic fluid shifts to the outer area of the rotating disk, and a torque is transmitted via the viscous friction of the magnetic fluid between the disk and the case. In order to enhance rapid and smooth movement of the magnetic fluid, slits were cut in the rotating disk. A channel for magnetic fluid was cut at the bottom of a tank to cancel the output torque under a nonmagnetic field. As a result of these modifications, a large torque difference was obtained whether a magnetic field is applied or not. The response of the output torque was also improved whether the input signal is turned on or off.