Magnetic couplings

A magnetic coupling is a coupling that transfers torque from one shaft to another, but using a magnetic field rather than a physical mechanical connection.
Magnetic couplings are of considerable interest for many industrial applications because they can transmit torque from a primary driver to a follower, without mechanical contact. In particular, as they allow torque to be transmitted across a separation wall, axial permanent magnetic couplings (APMCs) are well suited for use in isolated systems such as vacuums or high-pressure vessels.

Close up of magnetic couplings
Close up of magnetic couplings

Magnetic couplings are most often used for liquid pumps and propeller systems, since a static, physical barrier can be placed between the two shafts to separate the fluid from the motor operating in air.