Electropermanent magnets let a magnetorheological clutch hold and vary torque with pulsed power instead of continuous current.
Blades remix settled magnetorheological fluid while combined permanent and electromagnetic fields raise clutch torque and stability.
Centrifugal and one-way valves keep the work chamber nearly empty at rest, reducing startup coupling, noise, and wasted energy.
A pre-positioned stop lets the wiper scrape rotor fluid efficiently, then limits contact after wear to reduce viscous coupling failure.
Thin low-permeability drums reduce MR clutch inertia while electromagnets sustain torque transmission for faster, more controllable response.
Passive pump and wiper stages use slip-driven centrifugal flow and an arc-shaped wall to limit fluid migration and improve clutch response.
An oil scraping mechanism on the drive disk boosts oil supply at low fan speed, speeding torque transfer and reducing overheating risk.
Active supply pump pre-fills working chamber via shear gap flow, reducing fluid quantity and response time compared to centrifugal filling.