Induction hot plate as a cheaper solution for bearing mounting

[elinBG]

Hello,

Do you think that induction hot plate (

http://www.ebay.com/bhp/induction-hotplate

) can be used as a tool for heating the bearings instead of the expensive SKF tools (

http://www.skf.com/binary/12-35761/tih100m_datasheet_e.pdf

)?

If yes please tell me your pros and cons!

Next question is what is happaning with the grease of capsulated bearings (RS or ZZ), when heated?

Regards,
Teodor

http://www.eldvigateli.com

 

[crshears]

Hmmm...

I think it would depend a great deal on the sophistication of the hotplate...

If each and every induction coil is equipped with ferrodetection and the unit only excites those coils, it could very well work. If on the other hand ferrodetection is based only on zones or blocks, the hotplate could well refuse to function, especially if the circular bearing mass is not recognized in the same way that a cooking vessel would be.

If the foregoing is not a problem, using such a plate could well be ideal; this combined with the use of a hand-held infra-red temperature detector would allow for controlling the heating to a nicety.

As to the effects on sealed / encapsulated grease, I'm not sure...

 

[electricpete]

It seems that bearing induction heaters have some feature built into the deenergization that helps prevent magnetization of the bearing. I don't know if an induction hotplate has the same feature or not.

=====================================
(2B)+(2B)' ?

 

[squeeky]

Not a good idea. The heating will be uncontrolled and from one side unless you have it in an oven. Heating the lubrication beyond design may (will) lead to premature failure. At a company where money was tight, we found old transformers that had been used for control voltages. We modified the laminations so we could put on different size cross arms for different size bearings. We used a light dimming switch to control the power. It wasn't very efficient but it worked.

 

[redlinej]

hi,
try this tool, i have one and it's working great.

http://www.skf.com/group/products/m...ng-tools/bearing-fitting-tool-kits/index.html

 

[elinBG]

We already have it, but thank you for the reply.

Squeeky can you give me more information about the transformer which you used (power/size)?

Thanks

http://www.eldvigateli.com

 

[squeeky]

Hi, most of them were redundant control transformers so they would have been between 500 and 5000.VA. this FMCG company used to rewind small motors and coils for solenoids and then stopped as it was not their "core business." There was lots of free material around. A welding machine was never successful to any extent. I think it was too big. Your bearing is a single turn of the secondary so the turns ratio is very high. We had a variable transformer for the primary input that would push out about 5 amps. All very hit and miss but we had a few working models. This was when I was newly qualified and with equally nieve mates.

When we made the cross arm (yolk) we battled to cut the laminationsto size. Eventually we went at night and used the mechanical workshop gilitine. Drilling the holes for the binding is also time consuming and we went through a lot of drill bits. We ended up hand riveting them together as we could not get enough pressure from thin bolts and would strip the threads. We could not get small bearings over the heads so pinning it over with a ball pien hammer was the answer.

If you still want to peruse this I can make more technical enquiries on how to get better holes as I'wem sure the heat did not help the examinations and insulation.

 

[catserveng]

A quick check on ebay shows a number of decent bearing heaters from $250 to $3500 USD, including a couple of real nice Ludeca units around $1500.

Maybe before going to much further a good question to ask is what size bearings are you dealing with? Open/unsealed bearings and sealed bearings generally have slightly different limits for heating, depending on materials and factory installed lubricants.

http://www.timken.com/en-us/products/Documents/Industrial-Bearing-Maintenance-Manual.pdf

At about page 14 or 15 this manual shows some recommended methods and temperature limits.

http://www.ien.com/uploadedfiles/ien/Blog/SKFBearingInstallationAndMaintenance.pdf

Also at about page 14.

Not sure what your time is worth per hour but it seems like a suitable bearing heater for many applications can be had for the cost of a couple hours of your labor.

Hope that helps, Mike L.

 

[squeeky]

I agree with Mike L. If you have the money, it is better for quality purposes.

 

[dArsonval]

Bearing installation is no chance thing.
It must be Clean, and a "DE-Magnetized" process.

If you're heating a bearing; keep the process clean,
and never allow an opportunity for the item to become magnetized.

John

 

[elinBG]

Thank you for all your kind answers!

Last question, for a dummie like me:

Why the induction hot plate magnetize the bearing and why the SKF induction heater doesnt?

@electricpete mentioned "some built in feature for the deenergization that helps prevent magnetization of the bearing" ...
How do they do it?

http://www.eldvigateli.com