Design and testing of a novel two-way controllable overrunning clutch based magneto-rheological brake

In addition to the problem of torque and space optimisation, the heat of magneto-rheological(MR)brake generated by friction during vehicle cruising is also a major problem. Because MRfluids are normally immersed in the rotating disc or discs and electromagnetic casing, there isstill friction between the MRfluids and discs even without applying a magneticfield duringvehicle cruising. The heat generated by friction during vehicle cruising may seriously affect thebraking capacity of magneto-rheological brake. The magneto-rheological brake friction duringvehicle cruising also leads to the consumption of vehicle fuel. In order to overcome this problem,a new magneto-rheological brake mechanism is designed in this paper. The new MR brakemechanism consists of three parts. They are two-way overrunning clutch, electromagnetic clutchand conventional MR brake, respectively. These three parts work together to achieve thefunction of low frictional torque during vehicle cruising and controllable braking torque duringbraking. The function of low frictional torque during vehicle cruising is achieved by adjustingthe work state of two-way overrunning clutch. It is able to disengage the conventional MR brakefrom the drive shaft during vehicle cruising. Then there is no MR brake friction and no heatgenerated by friction during vehicle cruising. It is also able to achieve a controllable brakingtorque during the vehicle braking by coordinated control of two-way overrunning clutch,electromagnetic clutch and the magneticfield applied to the conventional MR brake. The designdetails and prototypes are presented in the paper