Bel-Ray Specialty Lubricants: Tech Notes, Vol 2, Issue 2
Inspecting Large Open Gear Drives
It is generally thought that with the operation and maintenance of large open gears, the lubricant is totally responsible for the condition of the gears. While proper lubrication is essential to the life of these gear sets, there are many other factors that can contribute to early wear, fatigue and failure of a customer’s gear sets. If there are deficiencies in the “drive system”, these deficiencies must be discovered by a thorough inspection of the complete system.
The Tribological System below links the 3 main components that must all work together to ensure maximum life of the gears;
- Drive System = dimensions, materials, surfaces, forces, speeds.
- Lubricant = quantity, Extreme Pressure properties, film formation, adhesion, cohesion, anti-wear properties, rheological properties (flow of fluids and deformation of solids under applied stresses or strains).
- Automatic Lubricant System = control of lubricant spray application intervals, nozzles and air supply.
Inspecting the complete Drive System includes; electric motor bearings, couplings, shafts, enclosed gear case/gearbox, fixed and free pinion bearings, the pinion and girth (bull) gear. Most of the time, inspecting alignment of just the pinion and girth gear is performed. However, to insure maximum life of the gearing, the total drive system must be properly aligned. Before any adjustments are made to the gears, adjustments (if needed) must be made from the electric motor through to the pinion.
The key to determining if adjustments are needed requires inspecting/checking the vertical, horizontal and axial vibration of all components in the drive system. These include 4 areas on the electric motor shaft through the gearbox, the gearbox shaft prior to the pinion gear drive coupling and the fixed and free end bearings located on either side of the pinion gear. If vibration readings are outside of normal parameters, a more complicated inspection method using precision indicators is required. Loosening and moving main components, etc. will need to be performed and additional critical alignment procedures will be needed. This type of repair must be left strictly to a very few industry expert mechanical engineers that have years of training and experience.
Temperature readings at points mentioned above (as well as bull and pinion gear tooth profile) are also needed. As no complete drive system can be or stay perfectly aligned, the drive system can be slightly out of alignment and temperatures can indicate the need for re-alignment or allow for sufficient operation until the next scheduled inspection.
Lubrication of Cement Plants — Clinker Cooling
In this third of four articles discussing the lubrication of cement plant equipment the topic is clinker cooling.
The cement manufacturing process consists of four well-defined steps; raw material grinding and cooking, already discussed in the two previous articles, cooling and cement grinding. Cement grinding equipment is similar to and often the same as that used for raw material grinding.
The material formed in the dehydration and reaction processes of the cement raw materials that occur in the kiln is called clinker. During the cooking stage, the raw materials are heated to the point at which the fine particles fuse with one another into much larger particles. Cement, the finished product, is clinker ground into a very fine powder. However, before clinker can be ground it must be cooled. There are two common clinker cooling methods.
The planetary system consists of tubular cooling chambers mounted around the circumference of the discharge end of the kiln. Cooling air is pumped through the cooling chambers. Hot discharge air is often used as hot combustion air. Cooled clinker is discharged to the cement grinding step. Lubrication of this system is negligible.
The other common cooling system, the reciprocating grate cooler, receives hot clinker discharged from the kiln onto a heavy grating. As the grating travels forward cooling air is blown up through the clinker. The hot air is directed to other uses such as combustion air. Primary lubrication of this cooling system includes gear cases, cooling fans and chain drives.
Often gear cases are located in hot areas. Mineral oil-based gear oils such as Bel-Ray 100 Gear Oil or Bel-Ray Raylene EP Lubricant will work well. Our primary recommendation for these gear cases is Bel-Ray Synthetic Gear Oil. The synthetic base fluids of the Bel-Ray Synthetic Gear Oil and its additive package can handle the temperature for extended periods of time. In addition to this performance benefit, Bel-Ray Synthetic Gear Oil is highly filterable extending its useful service life. Oil change intervals can be significantly extended over those for mineral based-gear oil.
Cooling fan bearings are usually located far enough from the cooling grate to prevent exposure to high temperature. Where this is true, Bel-Ray Termalene EP Grease, a 180 centistoke mineral oil-based Extreme Pressure grease, based on an aluminum complex thickener, will work very well. However, if fan bearings are operating at an elevated temperature, we recommend Bel-Ray SC2500 EP Grease. This is an ISO VG 460 mineral oil-based sodium complex Extreme Pressure grease. The unique sodium complex thickener leaves no residues at elevated temperatures.
If the cement plant lubricates the cooling grate drivechain and sprockets, we recommend a good solvent-free mineral oil or syntheticchain lubricant. Bel-Ray Waterproof Chain Lubricant is an excellent mineral oil-based chain lube. It penetrates the chain to the pins and bushings. It resists water washout and it protects outdoor chains from rust and corrosion. Bel-Ray’s synthetic chain lubricant recommendation for a grate drivechain and sprockets is Bel-Ray EPO 900. This is an ISO VG 220 ester-based chain lubricant. In addition to excellent high temperature resistance, penetration and rust and corrosion protection, the ester-based Bel-Ray EPO 900 will keep chains residue-free. Residue formation is negligible and old residues will be slowly cleaned from the chain and sprockets.
The Little Things
Have you ever stopped to think just how many moving parts a motorcycle, quad or scooter has? In the power sports industry it is incredible how much can be taken for granted. A brand new 1000cc sport bike has over 160 hp that is transferred from a crank to three small pieces of equipment, a chain and two sprockets. Most riders will roll on the throttle and experience that exhilarating sense of speed without a thought that it’s all riding on a chain made up of rivets, links, bushings and rollers.
Bel-Ray has certainly not forgotten how crucial your drivetrain is. For 2011 we are offering a number of products designed to clean, lubricate and look after your chain and sprockets. Our scientists and researchers use 5 basic tests to make certain your chain is in good hands; fling-off testing, falex testing, penetration testing, corrosion testing and the water washout test. In our fling-off testing we will use a specially built machine that will simulate drivetrain speeds of 186mph. The device is enclosed in a fiberglass case so any chain lube that doesn’t remain in place will be displayed on the fiberglass. Our chain lubes are world renowned for keeping the glass clean, this translates to more lubrication on the chain, and less on undesirable places like your riding boots, swing arm or expensive leathers. Falex testing re-creates the Extreme Pressure load put on the chain when the aforementioned 160hp is transferred to the drivetrain. We want to be 100 percent sure that when our lubricant is applied, a chain can withstand this extreme and drastic change in force. During penetration testing we test the ability of each lubricant to successfully penetrate the chain as desired. A corroded chain can lead to a catastrophic failure. A chain breaking while under power can lead to injury and severe damage to a machine’s engine cases. Corrosion is the cause of many of these types of failures; our corrosion testing addresses these issues. We ensure that our products meet the highest standards of corrosion protection and prevention. Many riders will often come in contact with wet or rainy weather, especially when riding off-road; in our water washout test we simulate these conditions by subjecting the lubricated chain to a jet of water. It is imperative that the lubrication stays in place, even when hit with water.
Bel-Ray Super Clean Chain Lube has been an industry standard for years and will continue to be the choice of industry professionals and consumers in 2011. This year we are also introducing a new product, Bel-Ray Blue Tac Chain Lube, specifically developed with professional race teams, that applies clear in finish and maintains adhesion to the chain in the most extreme conditions. Look for these products at a dealer near you and be sure to try both of them out. Remember - it’s the little things that count.