What happened to this motor???

[Shadowdog500]

My drillpress picked up a vibration and a hum even with the belts off of the motor so I thought I would check out the bearings. Turns out that the bottom bearing was shot.


While I was in there I noticed two things that seemed odd. First was that the motor was not wired as shown on the motor plate and had two leads reversed (5 and 6), second was that the internal fins were all twisted to hell. I've had this drill press since new about 30 years and I know that the motor has never been apart before.


Is this bent fin thing something that happens to old motors?

im wondering if the wires being reversed set up a vibration or or strange field that slowly bent the fins?


Thanks,


Chris

 

[12bolts]

Ive never seen an armature that bad before! You 100% positive youve had that motor since new?
The reversed wires are possibly just to make it run in the correct direction for its application.

Cheers Phil

 

[JimDawson]

If you have had that motor since new, then it must have been put together that way in the factory. The fins may have been bent over to provide clearance for something internal. Not the best manufacturing practice but what ever works I guess.

Pretty sure that there is no possibility of weird fields causing this. I agree with 12bolts the interchanged wires are probably for changing the direction.

 

[Shadowdog500]

Ive never seen an armature that bad before! You 100% positive youve had that motor since new?
The reversed wires are possibly just to make it run in the correct direction for its application.

Cheers Phil

Thanks for the response!


Yes, I bought this drill press brand new from a Farm and Family center in 1984. I took it out of the box and set it up. It has run beautifully for the last 30 years until the bottom bearing dried up and started a vibration and hum last month. I was wondering if the magnetic fields in the motor could cause this, or the vibration from the bad bearing could cause this. If not, maybe someone at the Toyang motor factory was having a bad day and took it out on this motor.


I just re read the data plate and found that you switch lead 5 and 6 to reverse direction to counter clock wise rotation, so the switched 5 and 6 wires are OK.

If there is room in the case, I may try to straighten the fins back out.

Thanks,

Chris

 

[12bolts]

If you try to straighten those fins they will most likely snap off and you run the risk of breaking some of the windings.
If its run fine like that for 30 years just replace the bearing and be done with it.

Cheers Phil

 

[chuckorlando]

Being the fins are bent in 2 directions, assuming you have only run it in one direction, I would say it came to you bent like that. I would think that if it bent while you were using it, you would have known instantly to shut it down as that would make a racket and a half

 

[Ebel440]

Just out of curiosity would it fit in the housing if the fins were straight? Maybe they made a smaller motor and used an existing armature scary to think they built more like that

 

[Shadowdog500]

If you try to straighten those fins they will most likely snap off and you run the risk of breaking some of the windings.
If its run fine like that for 30 years just replace the bearing and be done with it.

Cheers Phil

Thanks for the recommendation. I was thinking of straightening them but I agree this would cause them to break either now or later on. I'm going to put another set of bearings in it and see what happens. The fins actually have oxidation on them and no obvious signs of being banged over.

Cheers,

Chris

 

[John Hasler]

If you try to straighten those fins they will most likely snap off and you run the risk of breaking some of the windings.
If its run fine like that for 30 years just replace the bearing and be done with it.

Cheers Phil

That's an induction motor armature. There are no windings: just bars embedded in the steel. I agree with not trying to straighten the fins, though.

 

[middle.road]

OK, I've taken a lot of motors apart and seen a plethora disassembled, but I have never seen fins like that - strange design.