Page 367 - Intro Predictive Maintenance

358 An Introduction to Predictive Maintenance

Anything that is introduced onto or between moving surfaces in order to reduce
friction is called a lubricant. Oils and greases are the most commonly used substances,
although many other materials may be suitable. Other liquids and even gases are
being used as lubricants. Air bearings, for example, are used in gyroscopes and other
sensitive devices in which friction must be minimal. The functions of a lubricant
are to:

• Separate moving materials from each other in order to prevent wear, scoring,
and seizure.
• Reduce heat.
• Keep out contaminants.
• Protect against corrosion.
• Wash away worn materials.

Good lubrication requires two conditions: (1) sound technical design for lubrication
and (2) a management program to ensure that every item of equipment is properly
lubricated.

Lubrication Program Development. Information for developing lubrication specifi-
cations can come from four main sources:

• Equipment manufacturers
• Lubricant vendors
• Other equipment users
• Individuals’ own experience

Like most other preventive maintenance elements, initial guidance on lubrication
should come from manufacturers. They should have extensive experience with their
own equipment both in their test laboratories and in customer locations. They should
know what parts wear and are frequently replaced. Therein lies a caution: A manu-
facturer could in fact make short-term profits by selling large numbers of spare
parts to replace worn ones. Over the long term, however, that strategy will backfire
and other vendors, whose equipment is less prone to wear and failure, will replace
them.

Lubricant suppliers can be a valuable source of information. Most major oil compa-
nies will invest considerable time and effort in evaluating their customers’ equipment
to select the best lubricants and frequency or intervals for change. Figure 16–1 shows
a typical report. Naturally, the vendor hopes that the consumer will purchase its lubri-
cants, but the total result can be beneficial to everyone. Lubricant vendors perform a
valuable service of communicating and applying knowledge gained from many users
to their customers’ specific problems and opportunities.

Experience gained under similar operating conditions by other users or in your
own facility can be one of the best teachers. Personnel, including operators and
mechanics, have a major impact on lubrication programs. Table 16–1 shows typical