Hysteresis brakes and clutches
OwnerJeffrey C. Peduinventor
Life of this patent
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Abstract
Improved hysteresis brakes and clutches are disclosed wherein a secondary magnet is so positioned as to establish a substantially unidirectional magnetic field in the annual gap through which the disk or drag cup rotates in order to reduce or eliminate the undesirable phenomenon of "cogging".
Claims20
A hysteresis brake or clutch apparatus comprising in combination:
- a rotatable shaft;
- a disk coupled to said shaft and projecting radially therefrom, said disk comprising a first portion comprising a magnetic material;
- a primary magnet comprising a plurality of north-south poles and defining an annular region between said poles, said primary magnet being disposed about said shaft so that said first portion of said disk rotates past said poles and through the magnetic field of said primary magnet when said shaft rotates;
- and
- a secondary magnet disposed about said shaft so that said first portion of said disk rotates past said secondary magnet and through the magnetic field of said secondary magnet when said shaft rotates.
In a brake or clutch apparatus comprising a shaft, a radially-extending disk affixed to said shaft, said disk comprising a first portion comprising a magnetic material, a primary magnet assembly surrounding said shaft and comprising north and south poles on opposite sides of said first portion of said disk, and means for rotatably supporting said shaft for rotation on its axis relative to said primary magnet assembly so that said first portion of said disk rotates past said poles and through the magnetic field of said primary magnet when said shaft rotates;
- the improvement which comprises a secondary magnet positioned about said shaft so that said first portion of said disk rotates past said secondary magnet and through the magnetic field of said secondary magnet when said shaft rotates.
A method for substantially eliminating cogging in a hysteresis brake and clutch apparatus of the sort which comprises a shaft, a radially-extending disk affixed to said shaft, said disk comprising a first portion comprising a magnetic material, a primary magnet assembly surrounding said shaft and comprising north and south poles on opposite sides of said first portion of said disk, and means for rotatably supporting said shaft for rotation on its axis relative to said primary magnet assembly so that said first portion of said disk rotates past said poles and through the magnetic field of said primary magnet when said shaft rotates,
- said method comprising:
- positioning a secondary magnet about said shaft so that said first portion of said disk rotates past said secondary magnet and through the magnetic field of said secondary magnet when said shaft rotates;
- and
- turning said disk at lest one complete revolution.
Dependencies are inferred from the claim text.