Page 303 - The Tribology Handbook

CI Selection of lubricant type

Table 7.2 Examples of specific mechanisms and possible lubricants and systems

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Lubricating Maintenance Inuestment Rate of heat
Lubricant system cost cost removal ty lubricant Remarks
Journal bearings Oil By hand High Low Small Only for light duty
Circulating Low High High Necessary oil flow must be ensured
system
Ring Low Low Moderate Only for moderate circumferential speeds
lubrication
Porous Low Low Small Only for moderate circumferential speeds and
bearings low specific pressures
Grease By hand High Low Nil Only for light duty
Centralised Low High Nil Good pumpahility of grease required if long
system lines to bearings

Rolling hearings Oil Oil mist Low High Small If compressed air in necessary quantity and
cleanliness available, investment costs are
moderate
Circulating Low High High Oil feed jets must be properly designed and
system positioned to ensure optimum lubrication
and heat removal
Bath Low Low Small Careful design and filling required to avoid
excessive churning
Splash Low Low Moderate Careful design of housing and other
components (e.g. gears) necessary to ensure
adequate oil supply
Greas Packed Low Low Nil Overfilling must be avoided. Maintenance
costs are only low if re-lubrication period
not too short
Centralised Low High Nil Possibility for used grease to escape must be
system provided. Shield delivery lines from heat

Gears Oil Bath Low Low Moderate Careful design of housing required to ensure
adequate oil supply to all gears and to avoid
excessive churning
Circulating Low High High Jets have to be properly designed and placed
system to ensure even oil distribution and heat
removal
Grease By hand High Low Nil Only for light duty
Housing Low Low Nil Principally for small, low-speed gears,
filled otherwise, use stiffer greases to avoid
slumping and overheating

C1.4