Nonsinusoidal torque of permanent-magnet couplings

This paper presents new structures of permanent-magnet couplings and ways of calculating their characteristics. The analytical formulas of the force between two magnets are used to calculate the torque of the couplings. This allows optimization of the structures and easy comparison for several criteria. The presented structures are fitted with magnets on one rotor, which do not have the same angular width, and magnets on the other rotor, which are not necessarily jointive and do not necessarily have the same angular width. As a result, these structures appear to be very interesting in terms of maximum torque, torque-to-weight ratio, and magnet volume. Such devices are particularly interesting for applications such as screwing devices.