Hysteresis clutches and brakes
Among the hysteresis clutches and brakes produced by us, each non-magnetised hysteresis material e.g. AlNiCo 8/4 has, as an opposite, a magnetised permanent magnet material e.g. HF 24/20. The material combinations are varied according to application and required moment.
The torque or brake moment of the hysteresis combination is largely independent of the relative speed (rpm) and is present even on very small rpm. Fig.10 shows a plan of this dependence for 2 different air gaps between drive and driven side. In practice, however, it is shown that at high relative speeds there is a slight increase in the moment because of a superimposed eddy current moment. Maximum temperature of the AlNiCo 8/4 disc may not exceed 400°C, as otherwise irreversible losses occur due to structural changes. Hysteresis clutches or brakes are generally useful where a constant moment is to be transferred over a large rpm. range.
If necessary, slight control of the torque is possible through axial displacement, that is by altering the air gap and thus the effective flux. It must be ensured, that there is no iron placed behind the AlNiCo 8/4 hysteresis disc, otherwise the transferable torque is considerably reduced. The distance between hysteresis disc and iron parts must be at least 15 mm.
Please find below an extract of our product range Further types on request. We also develop solutions according to your special requirements.
Hysteresis clutches and brakes HF 24/20, SmCo and AlNiCo
Diagrammatic representation of torque of hysteresis and eddy current clutches dependent on relative speed
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