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Practical Magnetic Levitating Transmission Gear System Loses Its Teeth
Zothecula writes: A new transmission device that uses magnetic levitation to almost completely eliminate friction and wear has been developed as part of the MAGDRIVE research project, a collaboration of seven European nations. The creation of the unit entailed the development of a magnetic gear reducer and corresponding frictionless magnetic axles. Aimed primarily for use in spacecraft due to its extended mechanical life, the system is also adaptable for use in automobiles, railways, and aircraft.
On 5-10 years back about classic cars from some museum in SoCal or something.
The 3 primary vehicles they discussed were:
A 1900s era Battery Powered car with a 25 mile range.
A Steam powered car capable of 'gas-like' performance, given ample 'warmup' time.
And a 1920s or 30s electrocoupled automatic transmission car that I believe used increasing rotational speed to more closely couple the engine to the output shaft (Can't remember if it also had gears or if the coupling mechanism doubled as the 'gears'.)
Point being: So they're finally getting back to R&D on 'non-mechanical' coupling mechisms in modern vehicles. Yay! Only took like 90 years.
It looks too bulky to provide a lot of gears in an automotive application, but if it could provide just two that you couldn't strip out no matter how much torque you put through them, it could be a really nice match for EVs. They would benefit from a transmission, but it's difficult for any transmission of a reasonable size to handle the output torque.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Way more efficient than gears for loads it's designed to handle - but it's not meant for heavy lifting; the "magnetic gears" will "slip" if the load is too high, and in this case "too high" is quite low (think force required to move two magnets oriented in "repulsing" way against each other).
It would be great for stuff like stabilizing flywheels - things that once set in motion stay in motion for years, and may take a long time to spin up or stop. It would work well for things that require very little force, like reorienting the solar panels or aiming the antenna.
OTOH, stuff like lander wheel bearings or drills for picking samples are better handled with normal bearings that can take much heavier loads.
It's not a cure-all solution, it's just a good new option for specific applications. You won't use it to build a better crane but gyroscope flywheels could immensely benefit from that!
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Way more efficient than gears for loads it's designed to handle - but it's not meant for heavy lifting; the "magnetic gears" will "slip" if the load is too high, and in this case "too high" is quite low (think force required to move two magnets oriented in "repulsing" way against each other).
If you couldn't move high forces with a transmission like this, then you also couldn't generate them with an electric motor, because you couldn't hope for the magnetic fields to turn the stator against high loads.
OTOH, stuff like lander wheel bearings or drills for picking samples are better handled with normal bearings that can take much heavier loads.
What happens when you put too much torque through a drill? You shatter your bit. What happens when you put too much torque through an axle? All kinds of exciting things can happen, check out some four wheeling videos. There's lots of reasons why some slip designed into the system is not an undesirable thing.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The question is, how much force can it handle? Large electro-mags can pick up entire cars. Sure, it's huge, but it's lifting up 2700 lbs+. Also the surface area is large because the objects surface area is large. If a really high powered small electro mag was used, it would just rip out that piece of metal.
How many pounds of force can the small one withstand? It's possible using two small unpowered magnets to easily make one that could crush a hand if a hand was implace and restraints were let go on the mags.
I imagine it could potentially with a little voltage withstand a lot of torque, and limited slip to prevent spin outs, it might be fantastic for rovers.
They're often in lower gravity environments to begin with.
The other point being that it could be designed only to replace the kinetic friction parts of a transmission, the parts that synchronize the system. The gearing itself can probably still be mechanical. Not having to replace clutch plates, for example, might be a nice and relatively easily doable thing.
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This should really be looked at by those producing Diesel engines for Airplanes.
The biggest problem tinker's face when trying to put a Diesel engine on an airplane is that the Diesel has very massive "power surges" each time a cylinder fires, and a nasty power "stall" when it's compressing a cylinder. This isn't a huge deal with the other applications of Diesel engines, they just add mass to the fly-wheel and transmission and that takes care of it. In Airplanes however, the mass costs too much (in terms of airplane weight) so they try to reduce it as much as possible, however if you reduce it too much the propeller is literally torn apart by the surges and stalls. Early tests had the propeller lasting only hours when running on a 4 or 6 cylinder diesel. If there is a reduction drive on it to bring the RPMs further down they too like to self destruct with a Diesel.
If they could use a low-weight magnetic coupler to absorb the surges and stalls and provide smooth power that would solve the biggest problem putting a diesel on an airplane and would really boost that market!
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