Can someone please direct me to any web site or article that recommends types and/or quantities of lubricants for large rotary driers (bull gears and tires/trunnions)
We are currently using an asphalt type grease sprayed on the bull gear/pinion and soda grease blocks on the tires/trunnions.
A consultant has told us: "we are over lubricating the tires and trunions on all of our drums. Over lubrication has a tendency to create pitting of the surfaces due to the hydraulic impregnation of the lubricant into the fissures of the steel and subsequent popping of the tire/trunion surface"
Is it possible to over lubricate an open gear or trunnion and cause damage? How can you over lubricate with grease blocks?
Schaeffer, Castrol, Exxon/Mobil, Kluber among others make high viscosity/high shear lubricants for open face gears. Yes it's possible to over lubricate, especially with asphaltics. It will pack in the root and cause bearing/vibration issues.
Yeas all of them are right - you can go to a discussion on open gears in this if you search for it in this web site and alternatively there are articles published by Noria on open gear Lubrication - you Can have dip lubrication, spray Lubrication and in your tire depending on the temp you can use a lubricant either a paste or anti friction coatings if you want to have specific brands let me know and I can guide you
Arupanjan Mukherji
Posts: 105 | Location: Kolkata, WB India | Registered: Sat March 20 2004
yes all of them are right. You can over lubricate the open gears. Asphalt is an old concept You can use a Spray or dip system for open gear Lubricants and you can use a paste or oil or Antifriction coatings in tire Lubrication if you require a particular brand let me understand
Arupanjan Mukherji
Posts: 105 | Location: Kolkata, WB India | Registered: Sat March 20 2004
Over lubrication has a tendency to create pitting of the surfaces due to the hydraulic impregnation of the lubricant into the fissures of the steel and subsequent popping of the tire/trunion surface"
Never heard this one "normally" pitting is from micro cracks forming from stress cracks from Impact of hard debris (dirt) into the metal surface then causeing micro pits which grow into a larger pit or spall.
Perhpas this is what was told to you, oil or grease alone will not impregnate and cause pits unless it is very dirty with hard debris then yes it will cuase pits perhaps you should try to stay cleaner with more frequent lube intervals or shelding from debris.
bruce
Posts: 172 | Location: SF Bay Area | Registered: Fri July 15 2005
Thank you all for your replies I have searched this forum, noria publications and the web but I have not found a lot of detailed info about open gears or tires&trunnions, probably because there are too many factors that affect lubricant choice and quantity(speed, load, atmosphere, etc.)
Lets see if there is any concensus on the best lubricant for tires& trunnions
The granulated fertilizer drier drums at my plant are inside buildings, dust is low to moderate, some use grease blocks that keep the surfaces wetted, some use to have grease/air sprayed on them but were replaced with dry graphite blocks What do you recommend for tires/trunnions?
This message has been edited. Last edited by: Badnewsbare,
Of all of the options I've ever seen, the dry graphite block was the best so far providing you can get it to work. Some folks have trouble keeping the blocks functioning as a lubricant, though I believe it has something to do with graphite needing water to lubricate well. see http://www.tribology-abc.com/abc/solidlub.htm fpr details about that.
Of all of the tire/trunnion lubrication methods I have seen, the graphite block is the best if you use it properly. Far less problems with the lubricating equipment. Some people have issues with it, but I would attribute this more to a lack of understanding of the lubricant. See http://www.tribology-abc.com/abc/solidlub.htm for details on graphite.
Out of all tire/trunnion lubrication methods I've seen, graphite looks the best with far less problems and safety concerns. You just need to make sure it is used properly or there will be issues. See http://www.tribology-abc.com/abc/solidlub.htm for details on graphite solid lubricants.
As I known, Asphaltic grease is very old, Exxon mobil Mobilgear OGL007 is a typical Asphaltic grease, Which is not very good on sprayed lubricating system. The pipe is very easy to be blocked and jamed.
In my opinion, NLGI 00# grease with viscosity(40℃) of base oil from 2000cst to 4000cst is very suitable for this kind of open gear. Such as Kluber GRAFLOSCON_A_G_1 ultra, LE 5180. Synthetic oil, in most case, Poly Easter with viscosity(40℃) from 1600cst to 46000cst is also a good choice, such as ExxonMobil Mobiltac 325NC, 375NC, SHC3200, SHC6800, SHC46M, Kluber Klueberfluid CF 3 ULTRA.
NLGI oo# grease with base oil mixture of miniral oil and poly easter, viscosity 40℃ 2000~3000cst is very suitable for open gear with injection system. Such as LE 5180
Another choice is synthetic oil with viscosity 40℃ 1600~46000cst, in most case the poly Easter. such as ExxonMobil Mobiltac 325NC, 375NC, SHC3200, SHC6800, SHC46M, Kluber Klueberfluid CF 3 ULTRA.
