Magnetic gear

As a result magnetic gears are able to apply pressure no matter the relative angle.

A magnetically coupled gear can be used in a vacuum without lubrication, or operations involving hermetically sealed barriers.

This can be an advantage in explosive or otherwise hazardous environments where leaks constitute a real danger.

A stationary intermediate ferromagnetic cylinder allows a motion ratio due to the harmonic relationship between the number of poles input compared to output.

First order gears can be implemented at angles, and through non-magnetic barriers, because they do not require a coupler component.

The table below shows the relationship between magnets in the rotors, the number of pairs, the number of iron stator rods, the gear ratio and the output direction for a pair of imaginary motors.

This type of gear consumes approximately 25% of its input power in the process, causing current in the external coils.

The lower maintenance and the torque limiting characteristics may find suitability in some applications, however.

Illustration of the interior and exterior rotors of second-order gears with the ferromagnetic stator in between the rotors.
Drawings of patent US687292, showing a first-order motor with electromagnets on one of the gears.