Magnetic gear

A magnetic gear resembles in part, the traditional mechanical gear. All cogs of each gear component of magnetic gears act as a magnet with periodic alternation of opposite magnetic poles on mating surfaces. Gear components are mounted with a "cushioned" backlash capability similar to other mechanical gearings with no cushioning effect. Although they can exert as much force as a traditional gear, such gears work without touching and so are immune to wear of mating surfaces, have very low noise and can slip without damage making them very reliable. They can be used in configurations that are not possible for gears that must be physically touching and can operate with a barrier completely separating the driving force from the load. The magnetically coupled gear can transmit force into a hermetically sealed enclosure without using a radial shaft seal, which may leak. Hermetically sealed processes are not contaminated or chemically affected by the magnetic gear. This can be an advantage in explosive or otherwise hazardous environments where leaks constitute a real danger.

Magnetic gears advantages:

The magnetic gear is a magnetic coupling device that renders a mechanical ratio between two magnetically-coupled devices such that:

A magnetic gear is composed of magnets of the type permanent, electromagnetic or otherwise magnetically induced fields. It consists of two or more elements that are usually rotating but can be linear or curve linear in nature.

The classical gear is defined as a ratio of pole pairs. Where the Pole pairs are magnets N-S and S-N in nature. For the ratio to be affected there must be at least two elements. with Magnetic pole pair pieces.

Such devices were invented Armstrong, C. G., 1901, “Power Transmitting Device”, U.S. Pat. No. 0,687,292 and developed further from the 1940s

There are four basic magnetic gearing modes.

A defined ratio of magnets on one driving element and one driven element. This mode One device such as patented by Andrew French of MGT Australia near Port Stephens NSW and Hungarian Arpad Kasler with his Magnemot can be implemented at angles, and through walls. MGT devices are claimed to be 99.9 % efficient which translated to near zero maintenance and roughly a 22% reduction in power losses.

Generally a rotational device. A ratio of magnetic pole pairs, where the least number rotates at a higher rate than the higher number pole pair. An intermediate ferromagnetic pole "stator" is usually held stationary and used to effect the concentration of the magnetic lines of force between the high speed rotor and the low speed rotor. The ratio of High speed to Low Speed is the number of magnetic pole pairs on the high speed rotor to the number of magnetic pole pairs on the low speed rotor. This implies an even number of magnets on both rotors. The Ferromagnetic stator has two alternative solutions. The first being the sum of the number of pole pairs of the two rotors, giving the opposite direction of rotation, and the second having pole pieces numbering the difference between the pole pairs of the rotors, which results in the direction of rotation being the same.

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