ThyssenKrupp Magnettechnik Permanent magnetic couplings and brakes for drive applications

ThyssenKrupp Magnettechnik

ThyssenKrupp Magnettechnik Classification and principle of design Permanent magnetic couplings and brakes can be divided into three basic types: • Synchronous couplings, which include the disc and concentric ring couplings • Hysteresis clutches and brakes • Eddy current clutches and brakes For all types of coupling and brake the relevant efficiency equation¹) is P1 – Pv – P2 = 0. P1 is the influx power from the drive side. P2 is the transmitted power from the driven side and Pv is the power loss which occurs through the transmission mechanism in coupling and brake. In synchronous couplings Pv...

ThyssenKrupp Magnettechnik Synchronous couplings disc and concentric couplings Design and types The disc and concentric ring couplings developed by us are manufactured and offered – according to application, capacity and required performance – in the following materials: • • • Ceramic materials, hard ferrite (HF): HF 8/22, HF 24/20 Metallic materials, AlNiCo: AlNiCo 18/10, AlNiCo 36/14, AlNiCo 40/5 Rare Earth materials: SmCo, NdFeB In practice these elements have proved themselves in numerous applications. With relatively small magnet sizes they allow the transmission of great torques in closed...

ThyssenKrupp Magnettechnik If concentric ring couplings in HF 8/22 are used without soft iron mountings the given torque and rigidity are reduced by approx. 10%. HF-materials are extensively resistant to chemicals. In special cases metal protection by using non-magnetic chrome-nickel steels and plastic is possible. Linear torque increase is possible through a stringing together of individual rings or systems, but then the whole unit must be completely magnetised. Temperature behaviour of the magnets The working range of HF-couplings is between –30°C and +150°C. If the working temperature is raised...

ThyssenKrupp Magnettechnik Disc couplings Resin Magnet Iron Mounting Please find below an extract of our product range. Any other types are available on demand. Disc couplings in HF 24/20 and SmCo Torque in Ncm*) with air gap LL in mm Axial force in N with air gap LL in mm Outer Bore in the iron mounting Sizes magnet with iron mounting Magnet sizes Inner *) 1 Ncm =100 cmp=0.00738 ft lbs ¹) Special type in Hartferrit ²) Special type in SmCo Special type cannot be delivered from stock.

ThyssenKrupp Magnettechnik Concentric ring couplings in HF 8/22 Please find below an extract of our product range. Any other types are available on demand. Concentric ring couplings in HF 8/22 with air gap ≤ 3mm Inner magnet Outer magnet Wall thickness of iron mountings Concentric ring couplings in HF 8/22 with air gap ≥ 3 mm Inner magnet Wall thickness of iron mounting Outer magnet Height mm

ThyssenKrupp Magnettechnik Concentric ring coupling in SmCo Concentric ring couplings in SmCo are advantageous to use, if rotational energy is to be transmitted through partitions. The utilisation of an electrically conductive partition walls induces eddy currents in the wall. This leads to eddy-current looses which, depending on the rpm., diminish the maximum torque. Furthermore, the eddy currents cause heat losses in the cylindrical partition wall in the air gap, so that cooling has possibly to be provided. The drive system must compensate for the additional eddy-current losses, meaning that...

ThyssenKrupp Magnettechnik Hysteresis clutches and brakes Among the hysteresis clutches and brakes produced by us, each nonmagnetised 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. Resin Magnet Iron Mountíng The torque or brake moment of the Hysteresis Material 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...

ThyssenKrupp Magnettechnik Figure 10 Diagrammatic representation of torque of hysteresis and eddy current clutches dependent on relative speed Eddy current clutches and brakes In contrast to the drive and brake elements described previously, the torque in eddy current clutches and brakes (fig.4) is only produced by a relative speed between drive and driven sides. Resin Magnet Iron Mounting Thus the transferable moment increases with the relative rpm. Fig. 10 shows the torque gradient for two Soft Iron Copper different air gaps. In practice rings or segments in permanent magnet material e.g. HF...

ThyssenKrupp Magnettechnik Please find below an extract of our product range. Any other types are available on demand. Eddy current clutches and brakes in HF 24/20, SmCo and Cu/Fe Torque in Ncm*) with air gap LL in mm With relative speed n Sizes magnet with iron mounting Magnet sizes Outer Eddy current unit Bore in the iron mounting *) 1 Ncm =100 cmp=0.00738 ft lbs ¹) Special type in Hartferrit ²) Special type in SmCo Special type cannot be delivered from stock.

ThyssenKrupp Magnettechnik Technical advice and supply of samples Normally every mass production of permanent magnetic clutches is preceded by the testing of a trial model. For eddy current and hysteresis clutches and brakes this is advisable in every case as the moment curves can alter according to application e.g. through heating. Magnet rings and segments of disc couplings, eddy current and hysteresis clutches and brakes are stuck with special adhesive to the iron parts or to the cup filled with special resin. If high chemical and thermal resistance is necessary, we would like to obtain details...