| abstract |
The present invention relates to a variable-torque magnetorheologically actuated prosthetic knee (110, 210) which utilizes a plurality of interspersed and alternating rotors (120, 220) and stators (130, 230) to shear magnetorheological fluid (130) in gaps formed therebetween. Advantageously, by operating in the 'shear mode' there is substantially no or negligible fluid pressure buildup or change. Moreover, the multiple MR fluid gaps or flux interfaces desirably allow for the production of a large torque at low speed without the use of a transmission and also for a wide dynamic torque range to be achieved and add to the versatility of the invention. One embodiment of the invention allows the rotors (120, 220) and/or stators (130, 230) to close the gaps therebetween to create a frictional torque component, thereby forming a 'hybrid' braking system which provides a total torque or damping which is a combination of viscous torque and frictional torque. |