| 摘要 |
<p>A preprogrammed magnetorheological fluid device (20 etc.) which exhibits excursion (stroke or rotation) dependent resistance (force or torque) which is obtained passively. Linear and rotary embodiments are described. The device includes various ways for passively varying magnetic circuit reluctance to accomplish the stroke or rotation dependent (preprogrammed) characteristic. The devices (20 etc.) include a first component (22 etc.) with an internal cavity (24 etc.), a second component (26 etc.) received in the cavity and moveable relative to the first component, a working zone (36 etc.) created between the first and second component, a magnetorheological fluid (34 etc.) contained therein, at least one permanent magnet (32 etc.) for producing a magnetic field, a magnetic circuit (38 etc.) for directing a magnetic flux created by the permanent magnet (32 etc.) toward the magnetorheological fluid (34 etc.) in the working zone (36 etc.), and passively varying a magnetic circuit reluctance (such as by changing a thickness (tr etc.) of the magnetic return (42 etc.), by changing a gap thickness (tg etc.), by changing the material reluctance, by interacting multiple magnetic fields, or combinations thereof) as a function of excursion. This changes the magnetic field strength acting upon the magnetorheological fluid (34 etc.) in the working zone (36 etc.) and produces a force/torque which varies as a function of excursion (x or υ).</p> |
