No. 4, 1998 - Tribology in Industry

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C*ntemporary Lubricanfs: Rcle and
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Sr;i"',ing of tibologica! problems in moving parts of nnchhtes and devices inevitably includes tlrc application
cf the apitrcpiate ry*pes o! lubicants. Their clmracteristics are detennilrcd by eEipment marutfactttrerc and
enr:ironme ntal protectiott legislatiott.. The object of this paper i.g to nnal,r,se the state and tendencies of the
rnodcnt. iubicgt:ts developmetil itt the light of tlie reEirements rneriliotrcd.
Key words:.Lubicittts, Basic properlics, Reqttiremenls
I.INTRODUCTION
Lubricirnts are vital components in transportation, as
rveil :rs with most of industnal equipment. A proper
selcciicn of the lulrricant end lubricating methods increirse
the lifetime of machinery and decrease operation
anci maintenance costs, These effects manifest themselves
in a decre:rse of energSl consumption, lower working
iemDeiiitrtres and sliorter clown times.
Histcrically. :ire iirst applicetion of lubricants coincides
ri'ith the beginni ;rgs of civilization, while the first research
v,'iis canied out during the industrial revolution. Fr'->m
that tir're till today, lubricants have played an important
rolr in the developrneni of industrial society [1].
The gcnera.l technical progress, requirements for high
crnfonniry of all parameters of machine operations and
cver stricter regulations over environmental protection
ha."'e in the last several years resulted in a series of
soiutions thai should cnsure highly productive and also
environmcntally friencity iubricants.
2. R{}LE O! I,UBRICAI\ITS IN
TzuR OF'I ECIIINI OlL SYSTENI S
Thousailds of products nowaCays cover all the aspects of
!ubricatiru iechnokrgy. This will undoubtedly remain so
in the fl:ture. .Aiarge nunrber of different types of lubricauts
rirrl producis iras been brought about by tlsks ihat
iubnianis have to perforrn iir different constructions,
;intl unricr dilfercrtt rvcrkinu and environmental conditioris.
Apciicatinn oi'!ubricanis is inevitable in solving tribological
oroblems in the majority of b:rsic macirinelements
(gears, siiding anC ro!iing hearings. joints, ropes, chains,
P:,t.f. dr,llcksaridar Rac, di;tl. ing.
F n c t : !ry c,{ I'f e t' l t a : i t a I Er ryi t t e ei t ry, B eo gra d
etc.), aswell as in different machines (IC engines, pumps,
turbines, compressors, etc.), and technological processes
of metal machining.
Effectiveness of iLrbricants depends on numerous interrelated
factors that are determining the influence of a
lubricant on fdction and wear of the vital machine parts
and equipment. They include the properties of Iubricants
and changes that occur in the properties during exploitation,
character!stics of frictional surfaces, character of
interactions of the lubricant components and surface
material, speed, lcad, temperature, and other parameters
of the workjng regime [2].
Tiris points to the mutual dependence of the development
of machues, their components and lubricants,
which is one of the characteristic features of modern
mechanical systerus. Thus, for instance, the solutions
realized in the area of lubrication theory and lubricant
production technology enabled the designing of hydrodynamic
sliding bearings of high reliability and efficiency
[3], they helped to achieve high performances and long
life of rolling bearings and gears [4], they contributed to
the decreasing of fuel consumption and improvement of
the IC engines pertonnances [5], etc.
As far as thr:ii'history is concerned, lubricants were the
subject of intense develcpment during the fifties and the
sixties of thrs century.
'fhe multigrade oils were introduced,
as well as highly refined mineral base oils, nerv
additives, synthetic lubricants, etc.
In the mid-seventies, which were witness to crude oil
crises, ihe trend shifted towards the saving ofenergy and
other resources, and tc the solving of accumulated pro-
Lrlems related to environrnental prolection. During that
period economic aspects of lubricants application, especially
their irtfluence on energy saving in machinery,
l'lec;rrng ltrore Drominent.
7'riLrcicp itt itulrtsiry', i'ciunre 20, No. 4, 1998,
137