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

In addition to the problem of torque and space optimization, the heat of magneto-rheological brake generated by friction during vehicle cruising is also a major problem. Because magneto-rheological fluids are normally immersed in the rotating disc or discs and electromagnetic casing, there is still friction between the magneto-rheological fluids and discs even without applying a magnetic field during vehicle cruising. The heat generated by friction during vehicle cruising may seriously affect the braking capacity of magneto-rheological brake. The magneto-rheological brake friction during vehicle 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 magneto-rheological brake mechanism consists of three parts. They are two-way overrunning clutch, electromagnetic clutch and conventional magneto-rheological brake, respectively. These three parts work together to achieve the function of low frictional torque during vehicle cruising and controllable braking torque during braking. The function of low frictional torque during vehicle cruising is achieved by adjusting the work state of two-way overrunning clutch. It is able to disengage the conventional magneto-rheological brake from the drive shaft during vehicle cruising. Then there is no magneto-rheological brake friction and no heat generated by friction during vehicle cruising. It is also able to achieve a controllable braking torque during the vehicle braking by coordinated control of two-way overrunning clutch, electromagnetic clutch and the magnetic field applied to the conventional magneto-rheological brake. The design details and prototypes are presented in the paper