permanent magnet in DC Motor

[SebCestBien]

Hello all,

I'm restoring a old dc motor from a wheelchair, I'had to re-glue permanent magnet because it was un-sealed probably caused by overheat or oldness.
but I'm not sure that the sens and order was respected when I reguled it...

Is permanent magnet have sens ?

TRhanks a lot
Regards
Sébastien

P.S : I very appologies if my english is not conventional.. I'm try to do my best....

 

[GregLocock]

Yes they do have polarity,easily checked with a magnetic compass. You may be able to figure out the layout by looking at the commutator.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[waross]

The field magnets will have one that is North on the outside, South on the inside. The other will be South on the outside and North on the inside. If the original magnet is being glued back in place you should be OK.
If you have magnets from several motors, you will have to match a North outside with a South outside.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[SebCestBien]

Thanks a lot for your Help
I'm able to identify magnet polarity with another toy magnet and have found two identical pair of magnets.

Now I want to re-glue them together to the case, but a doubt arises...

when I couple 2 same magnets, I have a relatively strong force that repulse the two magnet...

It is normal ?

Thanks a lot
Regards
Sébastien

 

[waross]

The two magnets shown should be the same polarity.
The two magnets that are not shown in the picture should be the opposite polarity.
That is unless the armature is somehow non-standard.

Bill
--------------------
"Why not the best?"
Jimmy Carter