Electric Motor and Spindle Bearing Grease

[Langanobob]

I don't know my way around here yet and I first posted this in the industrial oil forum and I think it should have gone here. My apologies for double posting.

I occasionally work on electric motors and spindle bearings on machine tools, all with some form of roller bearings, mostly angular contact. I've been using general purpose Mobil synthetic GL2 grease in the bearings and nothing bad has happened so far.

I see ads for specialty bearing greases, Kluber is the company I see a lot. I think their product is a polyurea base vs the Mobil lithium base. And I have been reading about polyethylene grease (?). Are there any measurable benefits to be gained from using the specialty motor and spindle bearing greases?

 

[Tempest]

Are these large or small motors?

 

[Langanobob]

The motors are small about 10 HP, both nominal 1750 and 3600 RPM.

Thanks,

Bob

 

[Tempest]

If you've not had any problems then I'd guess you probably wouldn't see any benefits from a special grease. High speed motors or those that operate in extreme conditions might see more benefit from a specialty grease, IMHO.

 

[IH8mush]

Is there any manufacture information ?

 

[tom slick]

Motor manufacturers often recommend a polyurea grease. Lithium may or may not be compatible with polyurea; there are charts of specific brand/formulations for compatibility.

Over-greasing can kill a motor by pushing grease into the windings and can even overheat the motor.

This is direct from Baldor's documentation on AC and DC motor installation and maintenance:

Lubrication Information
This is a ball or roller bearing motor. The bearings have been
lubricated at the factory. Motors that do not have regrease
capability are factory lubricated for the normal life of the
bearings. Washdown motors can not be lubricated.
Lubricant
Baldor motors are pregreased, normally with Mobil
Polyrex EM unless stated on nameplate. Do not mix
lubricants due to possible incompatibility. Look for signs of
lubricant incompatibility, such as extreme soupiness visible
from the grease relief area. If other greases are preferred,
check with local Baldor representative for recommendations.
Relubrication Intervals (For motors with regrease
capability)
New motors that have been stored for a year or more should
be relubricated. Lubrication is also recommended at these
intervals.
LUBRICATION INSTRUCTIONS
Cleanliness is important in lubrication. Any grease used to
lubricate anti friction bearings should be fresh and free from
contamination. Properly clean the grease inlet area of the
motor to prevent grease contamination.
1. Select service condition from Table 1.
2. Select lubrication frequency from Table 2.
LUBRICATION PROCEDURE
Bearings should be lubricated while stationary and the motor
is warm.
1. Locate the grease inlet, clean the area, and replace the
pipe plug with a grease fitting.
2. Locate and remove the grease drain plug, if provided.
3. Add the recommended volume of recommended lubricant
until clean grease appears at the grease drain, at the
grease relief, or along the shaft opening.
4. Replace the grease inlet plug and run the motor for two
hours.
5. Replace the grease drain plug.

http://www.baldor.com/support/literature_load.asp?ManNumber=MN416

 

[IH8mush]

Actually thats some good info,

Signs of incompatibility , soupy grease,

now the term "Anti Friction" bearing ?

is this another name for a ball bearing, or something else ? the term is rather odd, the [censored] radar is going off just a tad with that one,,,

 

[tom slick]

Anti-friction bearing is the long-hand terminology; we shorten it to "bearings" (of any type) in the machinery world. It could also be "load bearing" (structural), "bearing a course" (navigation), "Military bearing" (discipline), etc.

I also found "soupy" an interesting term for technical documentation.

 

[IH8mush]

Okay a general term, any bearing that reduces friction

Now a completely frictionless bearing,or means of support,

 

[tom slick]

Some homework:

http://www.machinerylubrication.com/Read/575/electric-motor-bearings

http://www.machinerylubrication.com/Read/798/grease-selection

http://www.machinerylubrication.com/Read/749/electric-motor-regreasing

http://www.energy-business-review.com/su...electric-motors

 

[Langanobob]

Originally Posted By: tom slick
Anti-friction bearing is the long-hand terminology; we shorten it to "bearings" (of any type) in the machinery world. It could also be "load bearing" (structural), "bearing a course" (navigation), "Military bearing" (discipline), etc.

I also found "soupy" an interesting term for technical documentation.


I'm the original question asker in this thread, and I hope I'm not stepping on anyone's toes. The term "anti-friction bearing" refers only to rolling element bearings, as opposed to sliding or journal type bearings. If it's being used in the machinery world to describe all types of bearings, it's being used incorrectly.

Bob

 

[IH8mush]

Originally Posted By: Langanobob
Originally Posted By: tom slick
Anti-friction bearing is the long-hand terminology; we shorten it to "bearings" (of any type) in the machinery world. It could also be "load bearing" (structural), "bearing a course" (navigation), "Military bearing" (discipline), etc.

I also found "soupy" an interesting term for technical documentation.


I'm the original question asker in this thread, and I hope I'm not stepping on anyone's toes. The term "anti-friction bearing" refers only to rolling element bearings, as opposed to sliding or journal type bearings. If it's being used in the machinery world to describe all types of bearings, it's being used incorrectly.

Bob


Thanks Bob,,It just didnt sound right to me, I agree, the way I seen it described is any bearing that reduced friction, or something like that,

The first time I seen that term was on a Quaker State tube of grease,,,

Its really important to get the technical meaning behind all these grease terms,