A magnetic levitating gear system for zero friction and wear

December 2, 2014

A magnetic transmission that doesn’t wear out (credit: UC3M)

Researchers from Universidad Carlos III de Madrid (UC3M) are developing a new gear transmission mechanism with no touching parts, based on magnetic forces that prevent friction and wear and make lubrication unnecessary.

The device has potential applications in railroad and aircraft industries, as well as in space travel and exploration.

The design uses a magnetic gear reducer, that is, a mechanism that transforms speed from an input axle to another in an output axle (as in a bicycle chain mechanism or the gearbox of an automobile). But unlike a conventional gear reducer, this transmission is produced without contact between the pieces thanks to the use of magnetism.

One of its chief advantages is the absence of wear among the pieces, which makes lubrication unnecessary. “The operating life of these devices can be much longer than the life of a conventional gear reducer with teeth, and can even work in cryogenic temperatures” and at at 3,000 revolutions per minute, notes one of the researchers, Efrén Díez Jiménez, from the UC3M Department of Mechanical Engineering.

It can even continue to function after an event of overload. If the axle is blocked, “the parts simply slide among themselves, but nothing breaks.” It also produces less noise and vibration, and it is even capable of through-wall transmission.

Prototypes for space and industry

The researchers have developed two prototypes. One is for applications in outer space, including robot arms or antenna positioners, where high-precision movements are needed or when contamination from lubricants is undesired, and vehicles such as Mars Rover wheels, where temperature or extreme conditions shorten the life of conventional mechanisms.

The second prototype can be used at room temperature. The magnetic reducer “substitutes the gear teeth with permanent magnets that repel and attract each other” so that “the transmission of couples and forces between the moving parts with contact is achieved,” explains Jiménez.

Its applications are cases where conventional mechanical reducers are used, such as the railroad sector, the oil industry, or in mechanics and manufacturing in general, the researchers say. Thanks to the absence of lubrication and oils, it can also be applied in the pharmaceutical, biomedical, and food industries, where cleanliness requirements are strict.

This research is part of MAGDRIVE, a European project from the Space area of the European Union’s Seventh Framework Programme coordinated by Universidad Carlos III de Madrid, with the participation of the National Research Council of Genoa and the University of Cassino (both in Italy), the Foundation of the Faculty of Sciences at the University of Lisbon, in Portugal, and three companies: BPE from Germany, LIDAX from Spain and CAN Superconductors from the Czech Republic. Spin-off company MAG SOAR has been created from this project.

UC3M | Desarrollan un engranaje magnético levitante


  • J. Perez-Diaz, E. Diez-Jimenez, and E. Al. Performance of magnetic-superconductor non-contact harmonic drive for cryogenic space applications. Aerosp. Sci. Technol., 2014.