Gear lubricants open gears

Oil, used for lubricating the gears and bearings, is separated from the compressed airstream by labyrinth seals. Shown in Figure 3.31, the seals consist of two separate components, an air seal and an oil seal. In between the two, the seal is open to atmosphere. Any oil bypassing the oil seal leaks to atmosphere. The air seal is always at a higher pressure so that any leaks are always from air to atmosphere and oil cannot enter the process fluid. Oil is typically provided by a shaft-driven pump with a standby motor-driven pump available. 

Pyroshield. [Lubrication Engineers] Open gear lubricant... 

For this duty, the machines were powered with flat belts and speed adjustment was accomplished by means of pulleys and crude open gear reduction. Only one roller was driven and timing occurred by open ( naturally lubricated by coal dust) coupling gears... 

H 1 Bituminous lubricant with solvent content for use in open gears, chains and ropes By hand... 

The consumption of lubricants will depend to a great extent on whether the cement works is relatively old, with aging machinery, or is a modern one with up-to-date equipment. Whereas open gear systems are still found in some older works, modern practice is to use enclosed gear units, while kiln and mill drives are of almost completely encased design. 

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. 

Open gears operate under conditions of boundary lubrication. The lubricant can be applied by hand or via drip-feed cups, mechanical force-feed lubricators, or sprays. Heavybodied residual oils with good adhesive and fihn-strength properties are required to survive the relatively long, slow, heavy tooth pressure while maintaining some film between applications of lubricant. 

Lubrication of open gears is by means of a grease or very heavy oil. Operating conditions have to be considered for ... 

Where, the design of the machine is such that the parts to be lubricated can in no way retain the liquid lubricant, e.g., open gears. 

Open gears, such as those used in cement mills, have been lubricated with asphalt gear oils diluted with chlorinated solvent to help flow. Such gear lubricants adhere to the surface, which allows low feed rates while producing a relatively thick EHL film. Environmental concerns now limit the use of chlorinated solvents. Replacement organic solvents could be used but often their volatility created a fire hazard. As a result several replacement options have been investigated. 

In general, the lubricant for open or partly enclosed gears is used on a total loss basis - it is neither recirculated nor recovered. Rates of application must be minimal, both for economy and because the accumulation of used lubricant creates problems. A distinguishing feature of this category is that separate provision must be made for lubricating the bearings - by grease cups, oil bottles or mechanical lubricators. 

Industrial gearing may be enclosed, where the gears and the bearings that support them are operated off the same lubricant system or open, where the bearings are lubricated separately from the gears themselves. 

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