The objective of this project is to design and build a harmonic drive able to work under cryogenic conditions, with an extremely low friction, long life time and no wear. This harmonic drive will achieve a great reduction ratio, being able to function at cryogenic temperatures and based on a non-contact interaction between magnets, soft magnetic materials and superconductors. The drive will not use any lubrication and will be free of wearing. It is based on magnetic teeth. This project includes significant technological improvements: 1. The use of superconductors as diamagnetic spacers between the teeth. 2. The use of magnetic-superconductor bearings very suitable for cryogenic conditions. 3. The use of the last generation of magnetic and superconducting materials. 4. The use of thin film techniques to make a set of microteeth and to enhance the capability for torque transmission with respect to the total volume and weight of the drive.
The consortium has 7 partners from 5 countries, including Universities, Research Centres and SMEs with a good complementarity and able to make a prototype to test the technology, to validate a Technology Readiness Level TRL5 and to exploit the results.
The main goal will be to build a prototype and test a technology that fulfils the critical technology need as it is expressed by the "EC-ESA-EDA LIST OF URGENT ACTIONS FOR 2009, Join Task Force Final Report".
Contactless transmission gear
Friction and wear are the main cause of energy losses in machinery and vehicles, they limit their life and generate most of their breakdowns. What if the gear parts do not touch so that they never wear out?
Power transmission systems are, as their name suggests, devices used to transmit power or forces. Gears are elements of mechanical power transmission systems. These toothed wheels can alter the speed of driven parts (for example, the wheels of a car) relative to the speed of their driving mechanism (in the case of a car, its engine).
EU-funded researchers have developed a new transmission gear system based on magnetic forces that prevent friction and wear; and with no touching parts, it makes lubrication unnecessary. They substituted the gear teeth with magnets that repel and attract each other so that the transmission of forces between moving parts is achieved without contact.
This breakthrough technology is the result of the EU-funded 'Magnetic-superconductor cryogenic non-contact harmonic drive' (http://www.magdrive.eu/ (MAGDRIVE)) project. The development of the new transmission gear system entailed the design of magnetic gear reducer and corresponding frictionless magnetic input and output axles.
Specifically, it has levitating superconductor bearings that generate stable attraction and repulsion forces into the system's structure. These allow the axles to float and ensure stability by mitigating oscillatory movements and possible imbalances. With both the input and output axles floating without any contact, they can keep spinning at up to 3,000 revolutions per minute.
To demonstrate the applications for contactless transmission, MAGDRIVE researchers created two prototypes. The first was designed for space travel and planetary exploration missions, and is a cryogenic model that keeps axles floating at temperatures as low as –210 degrees Celsius in vacuum. The second prototype may be used in machinery for rail, oil and aircraft industries.
Presented at conferences organised by the European Space Agency (ESA), the National Aeronautics and Space Administration (NASA), and the American Society of Mechanical Engineers (ASME), project results have been published in the Journal of Engineering Tribology. The spin-off company http://www.magsoar.com/ (MAG SOAR) has been created to explore commercial exploitation of the technology developed during MAGDRIVE.