Hysteresis Magnetic Coupling

Hysteresis Magnetic Coupling, Permanent Magnetic Couplings, Hysterisis Face to Face Coupling, Hysterisis Linear Coaxial Coupling, Hysterisis Linear Planar Coupling Side by Side, Magnetic Hysterisis Coaxial Coupling

Hysteresis Magnetic Coupling – As a hybrid of the Class 1 and Class 2 technologies, this coupling is typically used in an asynchronous fashion as a force limiter, but can be utilized in a synchronous state. An array of alternating pole permanent magnets (N-S-N-S) is placed on either the driver or follower, and an easily magnetized/demagnetized material known as Hysterloy is placed on the mating component. At rest, the permanent magnet array is designed to magnetize the Hysterloy, resulting in a synchronously coupled magnetic circuit*. Should these forces suffice for the application, this coupling will operate in a synchronous state.

*The volumetric force density can be orders of magnitude lower than the Class 1 coupling due to the magnetic characteristics of the Hysterloy.

However, should the prime mover induce forces in excess of this synchronized operating state, the driver decouples from and begins to move with respect to the follower. This motion causes the Hysterloy to cycle through its magnetization loop (magnetize-demagnetize-magnetize) via the permanent magnets on the mating component which are now translating with respect to it. Like the Class 2 eddy current coupling, the magnetic field from the permanent magnets is being utilized and converted. However, unlike the eddy current coupling where the energy from the magnetic field is converted to a flowing electrical current (and heat), the cyclical progression around the Hysterloy’s magnetization loop (hysteresis loop) utilizes the magnetic energy to convert the magnetization state of the Hysterloy material from a North pole to a South pole. As a result of this variant on the energy conversion mechanism, hysteresis coupling are much less prone to (although not completely excluded from) Ohmic heating.