Anti-false brinelling and tribocorrosion metrics as a function of oil viscosity

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Hello,

after searching among the products of various brands of industrial lubricants, I could not find a grease that is formulated against false brinelling and its base oil is >300-350 Cst at 40°C.
Most of them are around 130 Cst @ 40°C.
Maybe I did not search at the right place, but the fact that the majority of products do not contain very thick oil, maybe shows something. So could somebody assume that the 'cushioning factor' of oil hits the point of diminishing return if greater of 300-350Cst?

thank you for sharing your thoughts

Regards,
 
Hello Imp4,

actually the applications are two

1. swing arm needle bearings (suspension). The rotational movement is in the single digit area of degrees. Most of the operation is around the balanced position once the vehicle travels, with limited rotational movement around the balance position. The swingarm is directly mounted on the engine (i.e. vibrations) without elastic mounts, in order to gain stiffness of the construction (the engine in also mounted stiff on the frame of the motorcycle, playing a vital role of the total stiffness of the frame). Operating temp is ~90°C (194°F) hence the need for a higher viscosity base oil. 2 wheel vehicle = constructed with weight reduction in mind = many parts are undersized.

2. Steering head bearings. Similar situation as above, the only difference is that the rolling elements are spherical not needles.
 
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I think that would be a call for a similar hi-moly 5% grease like on backhoe pins....its still low temp for grease but extreme pressure.....
 
Berlyn,

The key to controlling false brinelling is not cushioning from the grease but adequate flowback to ensure rolling elements and races are coated. False brinelling occurs when the limited motion of the rolling elements against the races or against each other in full compliment bearings, forces the grease out of the contact area, eventually leaving it starved. Then the false brinelling occurs. The low base oil viscosity promotes flowback into the roller path. The false brinelling can also lead to fretting wear which is similar to lapping.

Do you have pictures of the effected bearings?
 
RDMgr,

This is great input. Greatly appreciated.
Unfortunately I do not have yet disassembled the faulty bearing due to high office workload but once I do I will post the pictures.

So this might be the reason why not only the viscosity of the base oil of the greases formulated against false brinelling is low, but their consistency is in most cases NLGI 1 or 2. Never seen one of an NLGI 3 class.
Furthermore, depending on the dn factor perhaps it would be meaningful to completely fill the bearing with grease in order to avoid starvation. I must search about the correct qty
 
SKF has an ant-false brinelling grease. Check with your local SKF dealer (reference SKF publication 10/P8 17032). I believe this is a modified LGWA-2 product. Normally for auto/truck wheel bearings.
 
Thank you for your feedback. I first thought it could be an SKF LGBB 2 modified product due to ASTM D4170 results, same thickener with LGWA 2 but SKF LGBB 2 has a very lower base oil viscosity..
 
Thank you. Seems like a product used only in OEM and not commercially available.
 
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