Page 132 - Rollingbearings

Operating temperature and speed

B.5 Operating temperature

and speed

Bearing operating
The relationships between the temperature
and power loss of components within an
application is complex and these factors, in temperature and
turn, have interdependencies with many heat low
others such as bearing sizes, loads and
lubrication conditions Temperature has a major inluence on many
They inluence many performance char- performance characteristics of an applica-
acteristics of an application and its parts, tion The heat low to, from and within an
Operating temperature and speed tions have been reached the steady-state temperature it attains when
application determines the temperature of
and do so in various ways depending on the
its parts
operational state, such as at start-up or in
The operating temperature of a bearing is
normal operation, when steady-state condi-
Estimating the operating temperature and
running and in thermal equilibrium with its
verifying speed limitations is a critical aspect
surrounding elements The operating tem-
of the analysis of an application
perature results from (diagram 1):
This section provides details of these pri-
mary relationships, and guidance on what to
• the heat generated by the bearing, as a
result of the combined bearing and seal
consider
frictional power loss
to the bearing via the shaft, housing, foun-
dation and other elements in its
B.5 • the heat from the application transferred
surroundings
• the heat dissipated from the bearing via
the shaft, housing, foundation, lubricant
cooling system (if used) and other cooling
devices

The bearing operating temperature depends
as much on the application design as on the
bearing generated friction Therefore, the
bearing, its adjacent parts and the applica-
tion should all be thermally analysed

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