What grease for motor bearings

Since I am going through the Clausing lathe anyway, I decided to give some attention to the motor. The motor is a 40+ year old Reuland motor. The only problem with it that I observed is that it squeaks/squeals at 60 Hz. This is not the sound of the VFD frequency, either. It is irregular squeak/squeal.

I suspected the bearings.

This motor has regular 6306 bearings inside and I will get the replacements tomorrow. The ones in the motor were double shielded bearings and that is also the replacement that I will be getting.

My first question is regarding the grease. The motor has no grease fitting. The bearings were generously covered in grease. I would like to know if I need to do the same with the new bearings, or it is optional. Also, can I use white lithium grease.

My second question is about the dirt in the motor. The motor is quite dirty inside, windings being covered with black dried oil/grease/muck. I would like to remove that stuff, but safely, so I am concerned that chemicals like oven cleaner or carb cleaner could somehow deleteriously affect insulation. Has anyone successfully cleaned old motors like that, thanks.

i
Reply to
Ignoramus27020
Loading thread data ...

If they're double-shielded, they're greased from the factory, good for life(of the bearing). Apparently the shielding worked if the innards were that filthy. Usually, motors were dipped in varnish to impregnate the windings and then baked. The stuff is fairly resistant to solvents, I'd wipe, not dunk and check out a non-critical spot first. Caustic will probably turn the varnish to soap, I wouldn't use oven cleaner. VM&P naptha would be what I would try first, you might want to check with a motor rewind shop to see what they'd use. The naptha shouldn't dissolve the paint, either, it's supposed to be used for paint prep to remove grease and not leave a deposit.

Stan

Reply to
stans4

Remember the old motors had a varnish on the windings due to the thickness of a coat needed. The thin high voltage coatings we have on modern windings allow more copper turns and higher power in the same package.

Chemicals might dissolve the varnish and require the motor to be rewound. The best info is from a motor repair man.

They might not know as they 'burn' by oven cooking the winding to strip out the copper and clean the iron.

Mart> Since I am going through the Clausing lathe anyway, I decided to give

Reply to
Martin H. Eastburn

1st Q/ HMP grease.

2nd Q/ TOTALLY DISCONNECT from electrical supply :-) . We used to wash dirty armatures and windings in petrol ( I guess what you would call Gas) and a 1ins paint brush. I hope I don't have to remind you about the flammability of Gasoline, (otherwise forget it.) Dry thoroughly, preferably outside in the sun.

If you don't fancy doing that, wash the windings in water with some mild detergent e.g washing up liquid (safe for your Hands :-) ). rinse well with clean soft water, final rinse with distilled or deionised water, dry in well ventilated oven at about 50deg C for approx 2 days. I 've often done this with electrical items, and even Printed circuit boards carrying micro amps, they were OK providing they are well dried afterwards. Note!! pure water is a Non-conductor of electricity. Don

Reply to
Donwill

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.