Bearing grease power increase

[oil pan 4]

The grease in bearings causes more resistance than you think.

I never had a good way to measure the difference in a bearing that was worn in versus one freshly filled with grease. Until now...

Where I work now we have hundreds of motors, many of which run 24/7, all motors have amp draw closely monitored, the amp draw is even recorded an its trend can be viewed on demand. Some of the motors have vibration monitors installed too.

On the high speed blower motors that run pretty much at the same speed all the time at high speed I have found that when I pump grease into these bearing the motor amp draw can go up by as much as 15%.
Even the large 500 horse power turbo fan motors that run around 3400rpm see a 5% increase in amp draw.
They stay like this for several hours after greasing. I guess they continue to draw more power till the extra grease works it way out.

Next step will be to go to the motor control room and see what the voltage is and determine the actual horse power draw that increase.
At the same time I will be looking for motors that like to run around 600 to 900 RPM (about the same speed as your cars tires on the highway) and see the effect of a load of grease on the bearings.

[some_other_dave]

The effects of having no grease in the bearings also cause significant resistance.... Especially when the moving bits weld themselves to each other.

So, what should we do? Perhaps a thinner synthetic grease? Make sure to use just the right amount of grease and no more? Use different bearings that require a different type of lubrication? (And what kind of lubrication? What resistances do they impose, and what lifespans and costs are associated with them?)

-soD

[oil pan 4]

The bearing on my Camaro and suburban are cheap and I hand pack them.
When I hand pack them I don't spare any grease. I don't plan on using any less grease.
Just putting it out there.

Only alternative I can think of is wet bearings.

[Frank Lee]

I modded the dust cap and ran one of the rear wheel bearings on my Tempo in gear oil for several years. It worked fine until my mod let the oil out. Prior to that the wheel would really spin- better than the other side. Can't say if the effect of fe was measurable. Replaced the bearing and packed it with grease. :/

[oil pan 4]

That seems to be the main draw back for wet bearings.
Grease will stick around until you scrub or dissolve it away, oil is gone the first chance it gets.

I was really surprised how much motor power consumption went up when more grease was added.

[ToddT58]

My father was a lube/corrosion engineer years ago. He was a real fan of greases with Moly (molybdenum disulfide). I still remember some of his experiences with large industrial equipment. Big difference and worth investigating.

[Gasoline Fumes]

What about something like this?
Wheel Bearing Grease [#870] - $12.95 : Lamb Components Inc., The Drag Racing Specialist!


No endorsement of the product or vendor intended!

[oil pan 4]

I think in this aspect grease is grease.
I don't think lower friction grease is going to make much difference. If the grease is thick enough to hang on and stay around its going to increase bearing drag.

[Gasoline Fumes]

Originally Posted by oil pan 4

I think in this aspect grease is grease.
I don't think lower friction grease is going to make much difference. If the grease is thick enough to hang on and stay around its going to increase bearing drag.

You're probably right. 20 years ago when I played around with R/C cars, I remember noticing that even a drop of thin oil in a ball bearing made a huge difference in how long it would spin. Drier spun much longer.

[Frank Lee]

Pinewood Derby cars use graphite.