Worm gears lubricating

Compounded Oils. These are usually petroleum-based oik containing 3 to 5 percent fatty or synthetic fatty oik (usually animal fat or acidless tallow). They are usually used for worm-gear lubrication, where the fatty content helps reduce the friction generated nnder high-sliding conditions. 

One of the major advantages of the worm gear is low wear, which is due mostly to a full-fluid lubricant film. In addition, friction can be further reduced using metals having low coefficients of friction. For example, the wheel is typically made of bronze and the worm of highly finished hardened steel. 

An important point to remember with over-slung worm gears is that they are not immersed in the lubricant and the oil must be fed to the point of contact. The viscosity of the oil is important here, as it must not drain too quickly from the contact area. Manufacturers because of the particular lubrication problems involved with worm gears often prefer a mineral oil compounded with fatty oil. 

Worm gears of either type operating at speeds above 2400 rev/min or 610 m/min rubbing speed may require force-feed lubrication. In general, a lubricant of lower viscosity than recommended in the above the table may be used with a force-feed system. 

Several of the current synthetic semi-fluid lubricants for worm gears are based on a poly-alkaline glycol - which possesses slipperiness . Oxidation and rust-inhibitors are... 

Gear lubricants In addition to the usual oxidation and corrosion inhibitors, lubricants for heavily loaded gears almost always contain EP additives containing sulphur, chlorine or phosphorus. In order to function, these additives must react locally with the metal surfaces, and yet the extent of the reaction should not be such that it could be described as corrosive, or promote fatigue pitting . These EP additives may be quite safe with ferrous metal surfaces, but may cause severe corrosion on copper alloys, e.g. on bronze worm wheels if for any reason excessive temperatures arise. 

Defects in ball bear. ngs and worm gear may be due to poor lubrication (bad or too little oil). ... 

Smith, R.K. and Marshek, K.M., Lubricants Containing Dispersed Molybdenum Disulfide Improve Worm Gear Efficiency, NLGI Spokesman, 48, 47, (1984). 

For highly loaded spur, helical, worm and bevel gears, lubricants containing tribological additives such as sulphurized and phosphorus-containing additives are used. These provide excellent anti-wear and extreme pressure protection over a wide range of conditions. 

Thibault, R. (May 2001) Lubrication of worm gears. Machinery Lubrication Magazine. Lawrence, G.L., Jr. (January 2005) Lubrication selection for enclosed gear drives. Machinery Lubrication Magazine. 

API GL-2 Lubricants intended for automotive worm gear axles operating under such conditions of load, temperature and sliding velocity that lubricants satisfying API GL-1 service will not suffice. Products suited for this type of service contain anti-wear additives or film-strength improvers specifically designed to protect worm gears. 

Oil dip-lubricated, single-reduction worm gear, 1500 rpm input 78 11 5 6... 

Due to the high sliding contact encountered in enclosed worm and hypoid gears, lubricant selection for these should be considered separately from lubrication of other types of enclosed gears. 

Either splash lubrication or forced-feed oil lubrication is commonly used for rotating machinery such as turbines, pumps, compressors, reduction gears, and worm gears. Splash lubrication is used for relatively slow-speed machinery, while high-speed machinery always requires forced-feed lubrication. 

Lubricants not recommended. The following lubricants should never be used for worm gearing ... 

CC Highly refined mineral oils with 150 Heavily loaded gears and worms Pressure and bath lubrication of May also be used for manual or... 

Before assembling, clean the parts of the worm wheel shaft with kerosene and wipe the gear housing. Check the ball bearings for defects. Clean and Lubricate carefully before refitting. 

Fasten the worm wheel guard and fill lubricating oil into the gear housing.. 

Common Materials. Gears may be made of a wide range of materials that may be ferrons, nonferrous, and nonmetallic. For indnstrial applications of spnr, helical, and bevel gears, steel is most commonly used, with iron and other metals occasionally nsed. Wormgear pairs generally are made up of bronze or iron for the wormwheel and steel for the worm. Use of plastics is generally limited to light applications, particnlarly those in which minimal lubrication is available. 

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