Whew... summer 2005 was a hot 1 around here. over 40 bearings stayed in alarm during the day & 6 bearings were thought of as "very critical" & management requested air horns blowing on the housing 24/7. That's alot of "air" energy & most of the time operations hit the thermal coupling pretty good, so I'm not sure of the real help it was doing.

Naturally synthetic oils are my thoughts for 2006. We have real examples of being able to remove coolers after changing the min. oil out for syn. oil.

I'm new to this CBM world - see log in name. There is a lot of good information on this board. Here are the Q's.

Q - Anyone experienced good results getting rid of hot bearings in the summer time? I've heard you can have temp reductions of 10-30F.

Q - Who's the best vendor? Where can I find the cheap stuff?

Thx
Stan Dalziel

Stan,

How hot is hot? I see you are from VA and I do not see it getting much hotter there than a papermill in central Florida. First, I would make sure you are using the correct product for the applications. Often the wrong viscosity can cause bearings to overheat or they can be overfilled with the same results. I have shyed away from synthetics as best as I can. I have a hard time justyfing 3+ times the price when I don't feel I am getting 3 times the value.

Check with your lube supplier for what they have to offer. Chevron is our lube supplier, but their list of synthetics is small. Exxon/Mobil has a good line as well as Royal Purple, but be prepared to pay a premium.

Just my 2 cents,

Gary B

We've been using alot of synthetic grease and oils on bearings for shakers that convey hot sand in a foundry (sand temp of 140-180 degrees along with an still air temp around 110+ in the summer).
What we found is the bearings do run cooler because the grease/oil is not breaking down due to a synthetics ability to resist heat better than a mineral based lubricant.
Also in machine tool aplications we were able to extend the length of time between oil changes on spindle oils for the same reason. We would sample the oils and with the mineral based oils they would break down after 2 months, and we would get 6 months of life out of the same viscosity oil but synthetic.
We personally use Amsoil lubricants in all of our critical equipment.
If you have any questions on Amsoil lubericants let me know.
Thanks Chad.
performances@sbcglobal.net

What kind of bearings on what kind of equipment?

It could be that the cause is not the oil, but something else entirely.

Good Luck

Danny Harvey
(also in VA)

Stan,

I had an experience replacing mineral grease with synthetic one on a high speed bearing fan.

We could reduce the bearing temperature from 175˚C to 60˚C.

We are using Mollub Alloy 860-2/ES from BP/Castrol. Perhaps you can ask the supplier there to get some advise.

Regards,
Helmy F

I know that all of you know the L.E.T.S is a good way to decide what type base and techonolgy to use. I would like what Danny Harvey says! Guys what about the application???see the attached paper on Syn vs. Mineral base stock's and oils..Don't get me wrong they both have a place.In many cases it comes down to additives! Many companies such as mine used the best base for the application.We try not to shoot with a shoot gun approch, but with a long rifle aproch . In the end if you build the best product for the application you will have a better chance to win. And guys remember that price is nothing, however relibility is everything. How much does a $6.50 tube of grease cost you when it can lower bearing temps temps 18 degrees and extend the life of a $200.00 bearing by 2oo%. What if that bearing took 2 guys 4 hours to R&R?
See the artical below. I would love feed back at ackleyj@lubricationengineers.com
Beyond Synthetic vs. Mineral Basestock
Or
What Happened to the Application?

As lubricant manufacturers search to improve their profitability, a trend has been emerging from the major oil lubricant manufacturers and independent commodity oil blenders. This trend is to emphasize synthetic lubricants, an issue that appears to be coming up frequently in sales presentations to lubricant end users. While the trend is for improved lubrication from the users standpoint, they can be led down the wrong path that a synthetic based lubricant will always provide superior performance. To help the end user choose the right path they must be provided with some basic knowledge of how the different types of lubricants are formulated with respect to performance in the application.

Lubricant Types

There are four principal types of finished lubricants being produced today. The first and oldest is mineral oils with no additives. These oils are typically seen in the limited applications where no enhancement to the base oil is needed. Applications of this type are API SA engine oil, barrier oils, seal oils, technical oils, etc.

The second type is mineral base oils with additives. These lubricants make up the majority of the commercially available lubricants in the marketplace today. Applications of this type of lubricant are engine oil, hydraulic oil, turbine oil, gear oil, air compressor oil, etc. These types of lubricants are applicable with the exception of high or low temperature or where a hostile environment is affecting the lubricant.

The third type is synthetic base oils with additives. These oils make up a small part of the overall lubricant marketplace but are increasing due to their popularity with many lubricant end users. For the past decade the end user has been told, in passenger car motor oil advertising campaigns from the majors, that these lubricants perform better than mineral based oils. Due to the strategic advertising directed at the general public for passenger car motor oil, most lubricant end users believe that synthetic equals superior performance over any other type of lubricant regardless of the application.

Synthetic base oils can be many different types of compounds with many being limited to one specific application. The majors push synthetic base oil lubricants because the primary synthetic is PAO (poly-alpha-olefin). PAO is a primary product produced by two of the major oil companies in the United States. They heavily market these synthetic lubricants because the PAO base oil provides them with improved profitability over mineral base oil lubricants. One only needs to compare pricing of a mineral oil based passenger car motor oil to that of a synthetic base to see that the pricing would improve the marketer's profitability. Independent commodity oil blenders have also jumped on the synthetic bandwagon because it helps them improve profitability.

A limited number of high performance lubricant manufacturers go beyond the synthetic vs. mineral oil argument to truly formulating a superior enhanced lubricant. These lubricants are formulated for superior performance in a specific range of applications without limitations to the base oil type or performance additives used. If the high performance lubricant manufacturer believes that synthetic base oil with additives is needed for the application then this is how the lubricant is formulated. In most cases however, these manufactures know that mineral base oil with properly selected and balanced conventional and proprietary additives can be formulated with a robust treat level to provide superior application performance. Thus, the lubricant end user is given a lubricant that provides superior performance at the most economical cost for the application. This is why the lubricant end-users are looking at a synthetic in the first place, because of their desire for a superior performance lubricant.

Enhanced Lubricants

To describe the concept of formulating an enhanced lubricant that is application specific we must first look at the strengths and weaknesses of both the mineral and synthetic base oils. Strengths of the synthetic base lubricants are applications where high or low temperatures are expected or a hostile environment would be detrimental to mineral oil based lubricant. A source that explains this more in detail is the Shell lubricants website at shell-lubricants.com/syntheticlubricants/synthetic_descriptions.pdf. Strengths of the mineral oil are improved additive solubility, natural oxidation resistance characteristics, better seal compatibility and lower base oil cost.
Weaknesses of the synthetic based lubricants are: limited additive solubility, reversal of ester based synthetic base oil to an acid, seal incompatibility with some seal materials, and a significantly higher per gallon cost compared to most mineral based oil. Mineral base oils have limitations in high and low temperature applications and certain atmospheres.

Mission of the Enhanced Lubricant Formulator

The high performance lubricant manufacturer must educate lubricant end users that lubricants are formulated beyond the base oil, whether it is mineral or synthetic base oil. Enhanced lubricants that are formulated and manufactured by a high performance lubricant manufacturer are designed to provide the highest level of performance in a specific application. This performance is proven in both laboratory tests and actual field applications. What the lubricant end user seeks is improved performance in their particular application. By seeking a synthetic lubricant, they perceive they are asking for a lubricant that will give them superior performance when compared to the commercial grade lubricant they have been using with limited success.
Enhanced lubricants are designed significantly beyond the minimal formulating done for commercial grade mineral or synthetic base oil lubricants. When formulating these enhanced lubricants, research staff looks for synergistic combinations between the base oil (synthetic or mineral), conventional additives and proprietary additives. This synergy is what allows the product to provide the maximum performance for the application.

Formulation of Enhanced Lubricants

As we have discussed earlier, the first step in formulating is to decide if the application needs mineral or synthetic base oil. Determine which one will provide the superior application performance. Should the research person use a synthetic base oil which limits additive choice and concentration or a mineral base oil which allows a wider range of additive chemistries at a higher, more robust treatment concentration?

The second step is to determine what conventional additives and what quality levels are available to build the core of the lubricant around. While commercial grade lubricants are formulated only to a minimal performance level, an enhanced lubricant is formulated well beyond this point. This is accomplished by looking for synergy with high quality component additives, which "enhance" the performance of the lubricant. Additional additive components are then added at optimum treat levels to assure the enhanced lubricant will deliver maximum performance for the specific application. If the formulation requires synthetic base oil, the main issue is still the additive concentration needed for superior performance. Many times synthetic base oil will not hold enough additive in solution to deliver the needed performance for the application.

The third and final step of formulating an enhanced lubricant is choosing which proprietary additives should be used? Through basic research and proven field performance, high performance lubricant manufacturers will have a number of proprietary additives that work in specific applications and have proven will enhance the performance of the lubricant. One or more of these additives will be used to fine-tune the enhanced lubricant.

The Educated End User

Once a lubricant end user understands what is involved in formulating an enhanced lubricant it becomes easy to see where a synthetic lubricant might not be the superior product for the particular application. Also, the price of the enhanced lubricant is now more justified because the customer understands that there is a technology and performance level beyond that of the lubricant that has been used in the specific application.

Sure, the synthetic lubricant manufacturer recommends a synthetic. He recommends a synthetic because it brings him better profitability than the commodity mineral base oil lubricant that he is also selling. An article discussing synthetics in the June 2003 edition of Lubricants World covers how the public has embraced the synthetic concept and how they do not understand what they are really receiving for the extra money they spend. The article indicates that consumers were "becoming more acquainted with the word "synthetic" and the impression was favorable in terms of better performance than was perceived as available from conventional motor oil." The article goes on to state that "the public is enraptured by the concept and so the market is growing, despite a higher price."

In the continuing debate about synthetic versus mineral oils, the end user is really only interested in protecting the investment they have in their equipment. High performance lubricant manufacturers have lubricants to provide this protection beyond that offered by major oil lubricant manufacturers and commodity oil blenders.

quote:

Originally posted by Helmy Ferdiansyah:

I had an experience replacing mineral grease with synthetic one on a high speed bearing fan.

We could reduce the bearing temperature from 175˚C to 60˚C.

Helmy,

First, you probably meant from 75C down to 60C reduction?
Secondly, was something else changed, other then grease type, which may have caused temperature reduction. By changing just grease type (same consistency)it is hard to expect IMO such a drastic effect.

I have once just improved alignment that lowered pillow block bearing temperature by 25F.

David had a thread "someone changed viscosity...." which touched on a lot of related issues:
http://maintenanceforums.com/eve/forums/a/tpc/f/319...761067241#1761067241

My thoughts
- If you want to decrease temeprature you should consider decreasing viscosity, but only with a careful check that you will still be above minimum viscosity under all conditions.
- In the thread linked above, I reported results of testing under carefully controlled conditions VG68 oil of synthetic and plain-old r&o mineral oil in the upper bearing of a large vertical motor. There was no difference in temperature in this particular application. There was a difference when viscosity was changed.
- I have heard several different people claim that they have decreased temperature using synthetic oils. I don't understand the exact mechanism, but I also don't discount that they are seeing something I just haven't run into.

[QUOTE]Originally posted by David_G:
First, you probably meant from 75C down to 60C reduction?
Secondly, was something else changed, other then grease type, which may have caused temperature reduction. By changing just grease type (same consistency)it is hard to expect IMO such a drastic effect.
/QUOTE]

David,
1st. Thank you for correction, yes you are correct. It was 75˚C not 175˚C.
2nd. We found that the bearing used on that fan (3000 RPM) was Y-Bearing. Compare to the other fans, the bearing used on fan shaft is Spherical Roller Bearing. So we replaced the bearings too.

Question:
Is there anybody know about the correct bearing shoud be used for a fan. We have many fans here such as belt drive, direct mounts and also direct coupled fans. Is it Ball Bearing or Spherical Roller Bearing? Really appreciated if you can share any experiences and documents with me.

Thanks.
Helmy

Hello Helmy,
A good choice for fans would be torroidal bearings these will help alot with minor missalignments and unbalancing, they are almost the same price as sphercal roller bearings. Another alternative would be hybrid bearings but they are still very expensive (Cost differential is justifiable though). I would also suggest you check hot and cold alignment and fan balancing.