Ring electromagnet flux path

[strokersix]

First of all, I am a mechanical engineer with very limited electrical or magnetic knowledge so please forgive my basic question.

I wish to build a ring electromagnet as part of a proof-of-concept prototype. The device I'm building is a clutch similar to an automotive AC compressor clutch. I have an idea what the geometry needs to be but would like some confirmation. I think the windings should be cylindrical, like a voice coil only more layers, then inserted into an annular pocket in solid steel with the open side toward what I'm trying to attract. Can someone point me toward reference material or images of similar designs please? Thanks in advance.

 

[IRstuff]

Why don't you just take one apart?

TTFN

FAQ731-376

 

[strokersix]

I've done that, that's how I got to the geometry I described above. Because my application has some unique additional geometry requirements, I need to better understand the magnetic characteristics involved.

 

[TStaples]

Strokersix,

I have designed an electromagnetic clutch for a major OEM A/C supplier. What you are designing is basically still a solenoid actuator, with some really unusual geometry. It is not a trivial design task. To make a functional unit, you could easily do the calulations using a simple sum of the reluctances approximation (i.e. Roter's method) in a spreadhseet. To do a highly optimized design (lowest mass vs. inexpensive to fabricate components) will require FEA analysis.

Here is a good place to start. Specifically check out Chapter 11:

http://www.consult-g2.com/

Most of these concepts are covered in the EE curriculum, not the ME, but are relatively straightforward. Many of the electromagnetic design specialists that I know have a Mechanical instead of Electrical Engineering education. Design is design.

-Tony Staples

http://www.tscombustion.com

 

[TStaples]

Oops. I left off that you need to select the "Course" link on the left hand column once you go to G2 Consulting's home page.


-Tony Staples

http://www.tscombustion.com

 

[strokersix]

TStaples,

Thank you! That's what I needed.

I figured this was not going to be a trivial design task. I'm at proof-of-concept stage at this point and just need to understand enough to build a functional prototype. Detail design, analysis, and optimization will of course follow if we decide to proceed.