Lubrication

Types of Lubricant The recommended types of oil for use in gear units are either straight mineral oil or extreme-pressure (EP) oil. In general, the straight mineral oil should be a high grade, well-refined petroleum oil within the recommended viscosity range. It must be neutral in reaction and not corrosive to gears and ball or roller bear ings. It should have good defoaming properties and good resistance to oxidation for high operating temperatures.

Gear drives that are subject to heavy shock, impact loading, or extremely heavy duty should use an EP lubricant. EP gear lubricants are petroleum-based lubricants containing special chemical additives. The ones most recommended contain sulfur-phosphorous additives. Sulfur-phosphorous EP oils may be used to a maximum sump temperature of 180°F (82°C).

In general, if units are subjected to unusually high ambient temperatures (100°F, 38°C or higher), extreme humidity, or atmospheric contaminants, use the straight mineral oil recommended.

Grease Lubrication The lubricant should be high-grade, nonseparating, ball bearing grease suitable for operating temperatures to 180°F (82°C). Grease should be NLGI No. 2 consistency.

The grease lubricant must be noncorrosive to ball or roller bearings and must be neutral in reaction. It should contain no grit, abrasive, or fillers; it should not precipitate sediment; it should not separate at temperatures up to 300°F (149°C); and it should have moisture-resistant characteristics and good resistance to oxidation.

Grease Lubrication of Bearings Pressure fittings are often supplied in gear units for the application of grease to bearings that are shielded from the oil. Although a film or grease over the rollers and races of the bearing is sufficient lubrication, drives are generally designed with ample reservoirs at each grease point.

Greased bearings should be lubricated at definite intervals. Usually one-month intervals are satisfactory unless experience indicates that regreasing should occur at shorter or longer intervals.

Oil Seals Oil seals require a small amount of lubricant to prevent frictional heat and subsequent destruction when the shaft is rotating. Normally when a single seal is utilized, sufficient lubricant is provided by spray or splash. Certain design or application requirements dictate that double seals be used at some sealing points. When this is the case, a grease fitting and relief plug are located in the seal retainer to provide lubricant to the outer seal. Grease must periodically be applied between the seals by pumping through the fitting until overflow is noted by the relief plug. The greases recommended for bearings may also be used for seals.

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Survival Treasure

This is a collection of 3 guides all about survival. Within this collection you find the following titles: Outdoor Survival Skills, Survival Basics and The Wilderness Survival Guide.

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