Contactless, high-efficiency, high-torque transmission with inherent overload protectionA magnetic gear uses permanent magnets to transmit torque between an input and output shaft without mechanical contact. Torque densities comparable with mechanical gears can be achieved with an efficiency >99% at full load and with much higher part load efficiencies than a mechanical gear. For higher power ratings a magnetic gear will be smaller, lighter and lower cost than a mechanical gear. Since there is no mechanical contact between the moving parts there is no wear and lubrication is not required. Magnetic gears inherently protect against overloads by harmlessly slipping if an overload torque is applied, and automatically and safely re-engaging when the fault torque is removed.Advantages over mechanical gears - Reduced maintenance and improved reliability - Lubrication free - Higher efficiency than conventional gears - Precise peak torque transmission and inherent overload protection - Physical isolation between input and output shafts - Inherent anti-jamming transmission - Significantly reduces harmful drivetrain pulsations - Allows for misalignment/vibration of shafts - Very low acoustic noise and vibration
Electrical machine with fully integrated magnetic gear offering unrivalled torque densityThe PDDŽ machine is a pioneering extension of the low ratio magnetic gear and was invented and demonstrated by Magnomatics personnel in 2005 and is widely regarded as the most significant advancement in electrical machine design for 20 years. This ground breaking technology combines the high torque density of the magnetic gear and the functionality and performance of a brushless permanent magnet machine to offer unparalleled torque output for direct drive applications.Advantages of PDDŽ Significant size reduction over conventional direct drive machine Ultra high efficiency removes the need for ancillary cooling Reduced maintenance and improved reliability over mechanically geared drives Inherent torque overload protection High power factor (typically >0.9) Employs standard power electronic controllers Possibility for two output shafts with different rotational speeds
Dunno what's the catch though ... there always is one? Discuss
Can this concept transmit thousands of horsepower?
Although I would love to play with some of these, I would guess that weight could be a prohibitive trade for rocket turbo pumps.
For higher power ratings a magnetic gear will be smaller, lighter and lower cost than a mechanical gear.
Quote from: Damon Hill on 04/12/2014 06:11 amCan this concept transmit thousands of horsepower?There will be limits based on the strength of magnets, but you can order really long magnets. I had some pretty large custom neodymium magnets made in China for an experiment a few years ago. I was limited to about 2x2x12 inches because the guy's currie-cure oven wasn't big enough for larger. But larger ovens exist and can certainly be built. So... Yes.
Quote from: go4mars on 04/12/2014 06:55 amAlthough I would love to play with some of these, I would guess that weight could be a prohibitive trade for rocket turbo pumps.Quote from: R7 on 04/10/2014 03:11 pmFor higher power ratings a magnetic gear will be smaller, lighter and lower cost than a mechanical gear.cheers, Martin
- Uses lots of rare earth metals.
It's not the refining per se that is uneconomical, it's the environmental protection equipment the EPA requires for US refineries that makes it uneconomical. If I remember correctly, quite of bit of thorium and other metals are "waste" from the process that must be handled per EPA rules, plus the usual air quality issues and employee safety. Part of the reason chinese rare earths are so cheap is they are skipping a lot of environmental and worker protections, at their peril. Though the increasing middle class in china will soon mean they will put stricter export limits to protect the resources for domestic use, so other countries will have no choice but to refine their own ore at additional cost. There is a major ore deposit and refinery complex in the US that is currently being warmed up from mothball status (shutdown due to chinese exports being so cheap), but completing the refinery improvements is a major capital cost so is proceeding slowly.
If I remember correctly, quite of bit of thorium and other metals are "waste" from the process ...
had my eyes on this tech and sad story for years. http://www.heritage.org/research/reports/2008/05/magnequench-cfius-and-chinas-thirst-for-us-defense-technology
Quote from: Prober on 04/15/2014 03:19 pmhad my eyes on this tech and sad story for years. http://www.heritage.org/research/reports/2008/05/magnequench-cfius-and-chinas-thirst-for-us-defense-technologyIs former Magnequench now Molycorp ?It seems they are again mining in Mountain Pass, CA.