Adjustable torque hysteresis clutch

An adjustable torque hysteresis for the releasably coupling an output shaft of a motor to a mechanical load, the clutch comprising:

• a housing;
• a first rotor rotatably mounted within said housing and driven by the output shaft of the motor;
• a second rotor rotatably mounted within said housing, adapted to rotate with, and relative to, said first rotor;
• an annular hysteresis sleeve secured to the first rotor, and an annular permanent magnet secured to the second rotor, said magnet and hysteresis sleeve forming concentric overlapping rings whereby magnetic flux from said magnet enters said hysteresis sleeve, and magnetic hysteresis within said hysteresis sleeve generates a torque acting against the second rotor when the first rotor is rotated, such that the first rotor imparts rotation to the second rotor;
• and
• an axially adjustable magnetic shunt mounted external to the housing and comprising an annular ring of soft magnetic material threadedly mounted to said housing whereby the axial position of the shunt relative to the hysteresis sleeve may be engaged by spinning the shunt relative to the housing, said axially adjustable magnetic shunt being positionable to alter the magnetic flux density within said hysteresis sleeve, thereby altering the maximum magnitude of the torque transferred to the second rotor.

A hysteresis slip clutch having an adjustable stall torque comprising:

• a first rotor and a second rotor, and a housing at least partially enclosing the first and second rotors;
• an annular permanent magnet rigidly mounted on said first rotor and an annular hysteresis sleeve rigidly mounted to said second rotor,
• said first and second rotors mounted such that said magnet and hysteresis sleeve are concentrically located and axially aligned so that magnetic flux from said magnet penetrates said hysteresis sleeve and magnetic hysteresis developed within said hysteresis sleeve opposes relative angular motion between said first and second rotors;
• an annular magnetic shunt adjustably mounted relative to hysteresis sleeve and permanent magnet, said shunt being movable between a first position remote from said hysteresis sleeve and magnet wherein said magnetic flux is substantially unaffected by said shunt, and a second position wherein a substantial amount of magnetic flux is diverted from said hysteresis sleeve to said shunt;
• and
• an end plate mounted on an output end of said housing, an output bearing mounted within said endplate, and an output shaft segment extending from said first rotor supported by said output bearings and extending through said endplate.

A hysteresis slip clutch having an adjustable stall torque comprising:

• a first rotor and a second rotor;
• and a housing at least partially enclosing the first and second rotors;
• an annular permanent magnet rigidly mounted on said first rotor and an annular hysteresis sleeve rigidly mounted to said second rotor,
• said first and second rotors mounted such that said magnet and hysteresis sleeve are concentrically located and axially aligned so that magnetic flux from said magnet penetrates said hysteresis sleeve and magnetic hysteresis developed within said hysteresis sleeve opposes relative angular motion between said first and second rotors;
• an annular magnetic shunt adjustably mounted relative to hysteresis sleeve and permanent magnet, said shunt being movable between a first position remote from said hysteresis sleeve and magnet wherein said magnetic flux is substantially unaffected by said shunt, and a second position wherein a substantial amount of magnetic flux is diverted from said hysteresis sleeve to said shunt;
• and
• a threaded connection between said shunt and said housing whereby rotation of said shunt relative to said housing changes the axial position of said shunt relative to said hysteresis sleeve and magnet, said threaded connection comprising a first threaded surface formed on an internal surface of said housing, and a second threaded surface formed on an outer diameter surface of said annular magnetic shunt.