A high efficiency, alignment and vibration tolerant, coupler using high energy-product permanent magnets

Industrial processes invariable require the connection of motors to the loads that they drive. The difficulties that exist in the connection are frequently overcome by the use of flexible couplings, which allow a limited degree of misalignment. A coupling is proposed which employs the Foucault (eddy current) principle of torque transmission by the controlled use of high energy-product, permanent magnets. The replacement of electromagnets by neodymium-iron-boron (Nd-Fe-B) permanent magnets has the potential to greatly simplify the eddy-current coupling (no electrical supply, electrical contacts, or controls are required). Hence, it is possible that a robust coupler can be produced with a good tolerance for both misalignment and shock loads. The cost of such a unit will depend on the judicious use of the expensive Ne-Fe-B magnets. This paper describes the construction and testing of the proposed permanent magnet coupler and makes recommendations for future developments and applications.