Machinery Lubrication

Machinery Lubrication March April 2014

Machinery Lubrication magazine published by Noria Corporation

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ML 16 | March - April 2014 | lUbe -tiPs How Titanium Gets in Oil The presence of titanium in used oil analysis is generally a result of contamination from paint. This is often expected from new or rebuilt components such as gearboxes. Titanium can also result from wear of high-alloy bearings or high-quality steel in gears. For example, recent oil analysis results for a gearbox that had been in service for some time showed increasing levels of titanium, copper, nickel and iron. Upon inspection, it was discovered that one of the gears had been painted. The oil had a high level of acid, the gearbox was running hot, and the paint was melting and curdling off the gear. Cleaner Oil Sampling Bottles Sometimes it is hard to justify using sterile oil sample bottles, especially when the ISO cleanliness targets are not very low. To ensure that low-cost bottles are as clean and partic- ulate free as possible, some plants use canned air (computer/keyboard cleaner) to clean the bottles. A few blasts to the bottle and lid take only a couple of seconds and have proven to work very well, resulting in consistently clean bottles. Keep an Eye on Makeup Oil When evaluating diesel engine oil analysis, makeup oil is an important trend to consider. Excessive makeup oil can signal problems with the engine that otherwise may go unno- ticed for an unacceptable period of time. It can also mask warning signals in the oil anal- ysis such as abnormal base number depletion, additive depletion and increases or decreases in viscosity. Excessive makeup oil also dilutes high wear metal trends and contamina- tion levels (e.g., soot, fuel, dirt and coolant). Contact the equipment manufacturer for typical makeup oil rates. The concept of trending makeup oil complements other information gathered by reliability and predictive maintenance- focused personnel. The Importance of 'Running in' New Gears In gear contacts, low surface roughness and thin oil films produce much less wear than high surface roughness and thick oil films. Properly "running in" a new gear unit can play a critical role in reducing surface roughness. Regrease During Machine Operation When adding grease to bearings through grease fittings or other ports, it is usually best to add grease while machinery is in opera- tion if safety permits. Depending on the application, this allows excessive grease, with the aid of the moving bearing elements, to be pushed out of the bearing track to an adjacent cavity, vent port or other exit pathway. Check Spin-on Filter Head Bypass If you notice that your filters are lasting longer than usual or particle counts have risen and changing filters doesn't help, check to see if the filter head has a spring-loaded bypass valve. Vibration can cause the spring, plunger or bypass plate to quickly wear through, putting the filter in continuous bypass or at least partial bypass, sometimes with little or no indication in pressure. Coolant Contamination Causes Bearing Failures A piece of equipment in service for 10 years had problems with axis-thrust bearing failure due to coolant contamination, and the failure occurred every two years. The bearings sat in the housing with only the end-cap side sealed. The ball-screw side had a rubber bumper attached to the housing where the pitch of the ball screw would sling coolant into the bearing. This washed away the packed grease and caused contamination. A pneumatic circle-flow nozzle that wrapped around the ball screw was added, forcing the coolant to blow off the ball screw before it reached the bearing housing. This solution, along with installing an automatic shut-off to the system, has greatly reduced maintenance and production costs. The "Lube-Tips" section of Machinery Lubrication maga- zine features innovative ideas submitted by our readers. Additional tips can be found in our Lube-Tips email news- letter. If you have a tip to share, email it to us at editor@noria. com. To receive the Lube-Tips newsletter, subscribe now at

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