Gear lubricants lubrication methods

Provision must be made for adequate lubrication of open, semienclosed, or enclosed gears. See Chap. 5.12, Lubricants, for information on gear lubrication. ANSI/AGMA 9005-D94, Industrial Gear Lubrication, also provides information on lubricant types and methods of lubrication. 

With the development of gears made from synthetics such as Bakelite, Nylon, Celoron, Micarta, and others, special lubricating methods may be needed. The ability of a nonmetaUic gear to withstand petroleum lubricants should be identified and known before a selection is made. 

The lubrication of gears is not a simple matter, because of their shape and variability of motion. Fundamental factors which affect their lubrication are gear characteristics, materials, temperature, speed, loading, method of applying the lubricant and environment. 

Incorrect lubrication can take many forms. One example is the use of oil that is too thick or too thin, or is incompatible with the metal of the gears. Others include unsuitable methods of application, bad filtration, inadequate maintenance, filling to the wrong level, and poor standards of storage and handling. 

Federal Test Method Standard No 791C. Lubricants, Liquid Fuels, and Related Products Methods of Testing. Method 6508, Load Carrying Capacity of Lubricating Oils (Ryder Gear Machine). 

MethodIP166. Determination of Ixtad-Carrying Capacity of Lubricants -1AE Gear Machine Method. IP Standard Methods for Analysis and Testing of Petroleum and Related Products and British Standard 2000 Parts. Energy Institute. 

The IR spectra of the most common machinery lubricants are shown in Fig. 16.7. As can be seen, petroleum, polyol ester and phosphate ester fluids have different spectra. In addition, petroleum oils are broken down into detergent (crankcase) and non-detergent (bearing and gear) oils, which exhibit different responses to IR analysis. Thus, modern IR oil analysers and sensors will use multiple analysis methods to cover all required oil measurements for the lubricant types encountered. 

Gear tests check the internal cohesion and pressure withstanding properties of lubricants on real gears. Various methods are used depending on the type of gear and test conditions. 

The authors micro ehl solution technique derives from their earlier solution method for heavily-loaded spherical contacts (3) and the elongated elliptical contacts found in high conformity gears of the Wildhaber-Novlkov type (4), (5). The solution method, which utilises the inverse solution of the Reynolds equation, is as described in the above publications except that the elastic deformation calculation must take account of the deformation produced by pressures acting on adjacent asperities, as mentioned above, and in the solution of the lubrication equations the side boundary condition is one of zero transverse pressure gradient rather than zero pressure. 

Erdemir A., Method to improve lubricity of low sulfur diesel and gasoline fuels, U.S. Patent 6,783,651 (2004). Komvopoulos, K., Chiaro, V., Pakter, B., Yamaguchi, E. S., and Ryason, P. R., Antiwear tribofilm formation on steel surfaces lubricated with gear oil containing borate, phosphoms, and sulfur additives, Tribol. Trans., 45 (2002) 568-575. 

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