Thoughts on New SRM Design?

Joined
Sep 21, 2010
Messages
309
I was recently sent a white paper on a design for a new SRM that is coming to market and am hoping to get your thoughts about the magnetic design. They are claiming specific torques far higher than any other motor currently available. I don't know enough about motor design to know if this is reasonable or not. What are y'all's thoughts?

US07663283-20100216-D00004.png
US07663283-20100216-D00006.png

 
Last edited:
Hard to tell from just the diagram.
Is this a variable reluctance motor?

High specific torque would be good for a direct drive motor.
 
Switched reluctance motors (SRM)

I don't know what reluctance is, or why switching it is better somehow...Since this is a new thing, anyone who makes these will charge a premium price. However, it looks like it "might" be easy to wind the coils onto he parts that hold the coils. If the other parts could be laser-cut, this might be a good design to look at...
 
spinningmagnets said:
I don't know what reluctance is,
I don't pretend to understand it, but:
https://en.wikipedia.org/wiki/Magnetic_reluctance

or why switching it is better somehow...Since this is a new thing,
It's not new, just easier to control these days with MCUs and such:
https://en.wikipedia.org/wiki/Reluctance_motor
https://en.wikipedia.org/wiki/Switched_reluctance_motor

Stepper motors (used for at least decades in printers, plotters, disk drives, tape drives, CNC machines, and other machinery that moves in incremental steps) are SRMs, and I've heard of generators made from SRMs that are driven by their shafts from high speed power sources (though I don't think I've ever seen one in person).
 
SRM has an amazing array of positive traits. I also think that geometry looks clever for maximizing reluctance swing on a wide radius.

SRM has no permanent magnet material, giving it extreme temperature capability and ruggedness and low cost with very good efficiency if done right.
 
switched reluctance motors are the future, that for sure, mechanically more robust, so you don't need to worry that your neo-magnets will break, more heat resistant, no demagnetization, easier to construct, they can built to be fast with little torque or slow with high torque, can be very high efficient, if you are clever and use an absolute position shaft encoder (it is really not big of a deal) then the torque will be very smooth even with close to zero speeds, can work with regenerative breaking, even, because it is more robust, can break like crazy (no magnets to come off), more like a mechanical breaking, and the biggest advance (at least in my eyes) is, there is absolutely no magnet dragging, so can coast nicely, all off these things are yelling for the ev usage :D
 
there is absolutely no magnet dragging

One of the issues with mounting a motor to a swingarm (instead of a common hubmotor)is what freewheel to use, and whether to mount it on the motor-sprocket or the wheel-hub sprocket. Motors that don't use permanent magnets can use a "live" chain that is always spinning with the wheel, but cogging was the biggest issue with that configuration. I'm not saying a live chain is a good idea, but once you eliminate all cogging, a left-side-drive becomes simpler and much more attractive.
 
Back
Top