Design of a safety escape device based on magnetorheological fluid and permanent magnet

In this research, a novel safety escape device based on magnetorheological fluid and permanent magnet is designed, manufactured, and tested. The safety escape device with magnetorheological fluid and permanent magnet can provide an increasing braking torque for a falling object by increasing the magnetic field intensity at the magnetorheological fluid. Such increase is realized by mechanically altering the magnetic circuit of the device when the object is falling. As a result, the falling object accelerates first and then decelerates to stop in the end. Finite element analysis is used to determine some of the specifications of the safety escape device for larger braking torque and smaller size. Finite element analysis results are also used for theoretical study and establishment of the dynamic model of the safety escape device. A prototype is realized and tested finally. The experimental test results show that the operation of the prototype conforms to the prediction by the dynamic model and validates the feasible application of magnetorheological fluids in developing falling devices.