What grease to use?

[timberwolf]

True just about any non corosive lubricant that does not absorb moisture should do the job.

I have become a bit sold on synthetic grease, it is about the only way I can seem to keep front wheel berings, and u joints in my jeep. I think the synthetic tends to dry out less and absorb fewer contaminents and might even be a bit more sticky.

And if nothing else for the amount required on a chain saw it won't cost any more, and you will have the satisfaction and bragging rights to say you put synthetic grease on it.

TW

 

[fun_chopper]

I will tell you one thing, you people are very focused on one topic, or shred of a topic at once, the original thought came from my statement that a AUTOMOTIVE bearing because someone asked about AUTOMOTIVE grease, and my previous statement was about AUTOMOTIVE bearings!! please in the future read all of the posts, and then comment-Matt

 

[xander9727]

Originally posted by fun_chopper
Check it out, the bearing at the center if a wheel approx 1-2" is tremenously smaller than the outsife of the wheel. if you used a ratio here you would find that the brearing spins approx 49 times for every revolution of the wheel, now I know their travel is relative, but their speed is not, now a single roller inside the braing revolves 63 time for every revolution of the bearing race. so here it is 1 (tire revolution)=49 (bearing race revolution)+63 (single bearing revolutions)=112 rpm. Now 1 revolution of the wheel =112 revolutions of a bearing inside. 17,000/112=151.79ish now by my calculations a 265 60r 15 spins about 460ish rpm, at 60 MPH so my calculations of 17,000 where way off the actual bearing speed is 51,520 rpm!-lol this was just to prove a point with grease-Matt

Your looking at this a little wrong. First of all the size of the bearing doesn't matter when figuring the rpm of the wheel. There is no ratio to figure out here. The outside of the tire may be moving at an over land speed of 60 mph but the much smaller bearing is moving at an over land speed of 1/13 of that(26" diameter tire) (using your ratio of 1/49 would give you a tire with a diameter of 98 inches). You were correct when you stated that each roller is moving at a much greater speed than the outer bearing race. However, this speed is dependent on the inner diameter of the outer bearing race and the diameter of the roller. i.e. if the wheel is traveling at 460 rpm and the inner diameter of the outer race is 2 inches. 2(pi)(460)=2889 inches per minute. For sake of argument we'll say the diameter of the roller is .375"(3/8) and it is a non tapered roller. It's radius would be .375(pi)=1.178 inches. 2889/1.178=2453 rpm. This is no where near the 51,520 rpm figure you came up with. FYI machines that spin in excess of 25k rpm usually don't use grease as a lubricant. I know that as soon as I write this someone will give several examples that contradict this statement. That is why I said usually. I hope this helps.

 

[fun_chopper]

This is a stupid argument, and I will not continue this any further, and I will let anyone have the last word, but it is not beacuse I am wrong, or that I even belive that I am wrong, because all of the data, and numbers that were crunched here are from my friend a mechanical engineer for Boeing, and I would hope that he is right. Now down to the meat of this stupid departure from the actual topic.I USE VALVOLINE SYNTHETIC GREASE FOR EVERYTHING!!!!!!

 

[xander9727]

First, if it was your friend that made the error than why are you taking this personally? Second, what airlines fly boeing planes? I'll be taking a trip next month and I want to make sure I don't fly on one your friend designed.

 

[treeclimber165]

Originally posted by fun_chopper
Now down to the meat of this stupid departure from the actual topic.I USE VALVOLINE SYNTHETIC GREASE FOR EVERYTHING!!!!!!

Valvoline synthetic? On your meat?

 

[dbabcock]

Nice math rebuttal, Xander! I like it when people back up their opinions with cold, hard facts. This thread is getting good! Now where's that Porkuface when you need him!

 

[fun_chopper]

yes I have found that Valvoline on a nice porterhouse is the best...Matt

 

[mikek711]

Grease

Guys,
Thanks for all the replys.I didnt mean to heat anything up (no pun intended) Its just that I put a new bar and chain on a buddy of mines saw a few weeks ago and after pulling the clutch hub off of the crank to clean behind it,I noticed that the crank was really knarled up where the bearing rides.I just didnt want to start any pre-mature wear on my saw.I know that when the factory puts something together,they arent very generous with the lube.After pulling my hub off,I was right.Well anyway,the 55 is all clean,lubed and back together.
Thanks to all again,
Mike.

 

[fun_chopper]

xander, this is not personal however, I need to redo some math, but the point is he is right, the ratio is all that matters in this argument. Now this is personal, dont bad mouth my friend, he has worked to remedy design flaws that save people from becoming part of a smoking hole in the planet, so maybe the next time you are sitting in an airplane you might consider that! Do the math, and you might be shocked about what you find, a small wheel bearing travels at such great speed that you might not belive. And in response to the 25krpm thing..show me the money, and I will show you grease in a jet engine that travels much faster than 25k.

 

[xander9727]

I thought you were done with this thread? You said anyone could get the last work.....as long as it's you? The main bearings and most of the ancillary devices on a gas turbine (jet engines are gas turbines) use synthetic lube oil. They are dry sumps that are pressure fed and have scavenge pumps to remove the oil. The high speed of gas turbines require lubrication that can withstand high heat and pressure. Most of the vital seals are pressurized use compressor bleed air to prevent leaks and in the combustor section coking. I sure you could probably lecture for hours on radial drive assemblies, variable stator vanes, fuel scheduling and the Brayton cycle. However, your not very well versed on calculating speeds of rotating masses. If you want to get the actual velocity of the bearings I would be more than willing to pass on the formulas. From there we could calculate the masses and find the centripetal force the bearing exerts on the race and with the weight of the vehicle we could find out at what rpm we have calculated equalibrium (disregarding friction to keep it simple). I know that this has nothing to do with grease but I thought it might be fun.......and you started it. Now if your friend designs the wheel bearings on planes than obviously I have stepped into water that is way above my head and I apologize. Something tells me that he probably knows what he is talking about but then again he isn't on this thread is he.
I'm sure you'll have plenty to say to this but don't wait to long, I don't want to miss dateline.

 

[stihltech]

grease

Sprocket bearing, grease it. With grease. ANY kind.

 

[Stumper]

Fun chopper, I don't want to pick a fight or fuss with you about a math mistake but you have a more fundamental error in your calculations. Please bear with me. The boo boo is that no rpm ratio exists at the wheel bearing other than 1/1. If there were a belt or chain drive between the big wheel and the little wheel (bearing)then a big RPM ratio would exist BUT the wheel bearing is simply the center of the large wheel- they turn at the same revolution rate.
Stand with your arms extended and start spinning around in place. Your fingertips will travel much further than the tip of your nose each revolution. The finger tips have a much higher velocity BUT both finger tips and nose are making the same number of Revolutions Per Minute.

 

[Beavergirl]

Originally posted by Stumper
Stand with your arms extended and start spinning around in place.

I wonder if this is how Sikorsky started.

Automotive wheel bearing/rotor/tire assemblies can have either the outer or inner race stationary. However in no case should there be slippage between the outside diameter of the tire and the respective rotating race of the bearing assy. Mcpherson strut assy's allow inner race rotation. Upper/ lower A frame front suspensions generally use a spindle and the outer race is in motion with the tire.

After conducting some experiments and looking at bearing data. 90% of all bearing assemblies have inner and outer races with dimensional ratios which result in the rollers or balls completing about 3-5 revolutions for each revolution of either the inner or outer race. Kaydon brand slim line bearings would be an obvious exception. The roller or ball orbit rpm is generally about 1/3 to 1/2 the velocity of either race in motion. This can be viewed by looking at the roller or ball cage position after each revolution of the outer or inner race.

C-

 

[daveb]

Good post Beav, You explained what the others were trying to say a little clearer, so hopefully this will be the end of this off topic discussion.

 

[fun_chopper]

WOW xander looks like you have a book on jet engines! AGD main shaft bearings into the RGB....lubed with...you guess it grease, now you are correct in saying that the N1, and N2 shafts are dry sump lubrication....


BTW XANDER, DON'T EVEN TRY AND BE SMUG ABOUT THE LAST WORD THING, YOU ARE JUST AS STUBBORN AS I

Now I did make a mathematical mistake, you must divide the total number by 2 so the actual rpm is 25,000 ish


NOW CHECK OUT THE DIAGRAM, BECAUSE I MUST HAVE MISLEAD YOU PEOPLE SOMEWHERE ALONG THE WAY, HERE IS WHAT I AM TALKING ABOUT!!!!!

 

[xander9727]

First you had better be specific about which gas turbine you are talking about! I can name several gas turbines that use lube oil on the radial drive shafts for the accessory gear boxes (AGD). Second not all gas turbines have a rear gear box (RGB). Third and most important NEVER assume anything. You obviously think that I know very little about gas turbines. I know that you only have as much information as your "friend/partner" is feeding you. Your diagram while colorful and entertaining in a third grade kind of a way doesn't prove your point! What is the inside diameter of the outer bearing race? What is the diameter of the bearing? Without these critical measurements you cannot calculate the relative velocities of the masses. Do yourself and everyone following this thread a favor. Stop talking about something you obviously know very little about. Have your "friend" email me once he has read my post and tell me where I went wrong in my calculations. I will not continue to argue with you anymore. I could write until next week and you probably wouldn't comprehend the concepts that you are trying to prove. Unless YOU can do the calculations and SHOW where I am wrong don't bother responding.

BTW I don't need a book on jet engines, I get the information from my brain. I worked on gas turbines for several years.

 

[Fish]

As Russ, and others have pointed out, the sprocket bearing only
serves duty when the saw is idling. These rarely fail, which is
the main reason this thread is very silly. If everyone stops and
considers this, they may just put the calculators away.
Look back at the many posts that say any grease, spit , or whatever will work, as these bearings seldom fail, and this
topic is a non-issue.
Darin just needs to start a jet engine/turbine forum.

 

[Gypo Logger]

I sprayed some liquid tar on the clutch bearing of my 385KD, but I still cant make that darn bearing fail. Am I to reduce myself to trying some crazy glue?
Anyone have any suggestions other than trying a 50/50 salt brine solution?
I think Otto is out there trying to see what it takes to cook the bearing on his 372 Huskybarny.
John

 

[Gypo Logger]

How's it goin Eh!
Just in case you folks thought I was conceited or otherwise stuck on myself, I just wanted to dispell all notions.
Gypo