Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: katieHaylor on 25/08/2017 11:42:23

Title: Could magnets be used to drive cogs or gears, instead of mechanical teeth?
Post by: katieHaylor on 25/08/2017 11:42:23
Bas says:

Is it possible to make cogs/gears with magnets instead of teeth? You could propel one of the gears to start a chain reaction because you set them in series, which causes gears to repel each other and thus making a great quantity of rotating magnetic fields out of where you might generate more energy because of coils than it costs to keep the installation running.

What do you think?
Title: Re: Could magnets be used to drive cogs or gears, instead of mechanical teeth?
Post by: chiralSPO on 25/08/2017 16:34:05
I think it would be possible to set up "gears" using magnetic fields, but I don't think there would be much benefit. There may also be problems associated with all the magnets interacting with one another (I would imagine that a gearbox would be such a mess of magnetic fields that the internal magnetic friction would be very significant). Magnets are also much more expensive than cogs...

There is no way to generate more energy than it costs to keep something running. This is a natural law that appears to be unbreakable. see: https://en.wikipedia.org/wiki/Perpetual_motion and https://en.wikipedia.org/wiki/First_law_of_thermodynamics
Title: Re: Could magnets be used to drive cogs or gears, instead of mechanical teeth?
Post by: teragram on 25/08/2017 17:51:20
Is it possible to make cogs/gears with magnets instead of teeth?

Yes, see http://www.magnomatics.com/pages/technology/low-ratio-magnetic-gears.htm
Can they be used to generate more power than is input? no, for the reasons stated above.
Title: Re: Could magnets be used to drive cogs or gears, instead of mechanical teeth?
Post by: BennettHi on 27/10/2017 17:55:58
I think it would be possible to set up "gears" using magnetic fields, but I don't think there would be much benefit. There may also be problems associated with all the magnets interacting with one another (I would imagine that a gearbox would be such a mess of magnetic fields that the internal magnetic friction would be very significant). Magnets are also much more expensive than cogs...

Yeah, a gear box would seem impossible to me. Plus it would probably be very expensive to engineer and produce so i doubt it would ever happen.
Title: Re: Could magnets be used to drive cogs or gears, instead of mechanical teeth?
Post by: PmbPhy on 28/10/2017 05:55:31
Is it possible to make cogs/gears with magnets instead of teeth?
Yup. In fact they've been in use for many years in a device called a stepper motor. See:
https://en.wikipedia.org/wiki/Stepper_motor

I used to work with equipment which contained them when I was an electronics technician. Otherwise I may never have heard of them.
Title: Re: Could magnets be used to drive cogs or gears, instead of mechanical teeth?
Post by: evan_au on 28/10/2017 10:12:47
Quote from: OP
Is it possible to make cogs/gears with magnets instead of teeth?
I have heard of them being used to transmit rotational force through a hermetically sealed wall. This doesn't require holes in the wall for an axle, with resultant sealing problems. The section of wall needs to be something non-magnetic such as glass or plastic (not steel).

It is mechanically simplest if you just want a 1:1 speed ratio - you can put all the mechanical gears and motors outside the sealed environment, where they are easier to service.
Title: Re: Could magnets be used to drive cogs or gears, instead of mechanical teeth?
Post by: teragram on 30/10/2017 20:55:03
Yeah, a gear box would seem impossible to me. Plus it would probably be very expensive to engineer and produce so i doubt it would ever happen.

Hello there,
Did you look at the link I posted?:-
 http://www.magnomatics.com/pages/technology/low-ratio-magnetic-gears
I know nothing about this company however