Page 138 - Rollingbearings

B.5 Operating temperature and speed
Speeds above the
reference or limiting

speed

It is possible to operate a bearing at speeds
above its reference speed, its adjusted refer-
ence speed, or even the limiting speed
Before doing so, irst make a detailed ther-
mal analysis, and take whatever further
measures may be required, such as use of
special cage executions, or consider using
high precision bearings Regarding manage-
ment of the effects of increased speed, con-
sider the following options:

• Control the resulting increase in bearing
temperature by additional cooling
• Compensate for any reduction in bearing
clearance resulting from increased bear-
ing temperature
• Revise the housing itting tolerance choice
to ensure that the inluence of increased
Operating temperature and speed • Revise the bearing tolerance class,
bearing temperature does not impair the
axial displaceability of non-locating bear-
ing outer rings
together with the geometrical precision of
the shaft and housing seats, to ensure
these are suficient to avoid excessive
vibration
• Consider using an alternative cage execu-
tion that is suitable for higher speed oper-
ation, in particular when approaching or
exceeding the limiting speed

B.5 • Ensure that the lubricant and lubrication
method used are compatible with the
higher operating temperature and the
cage execution
• Check that the relubrication interval is still
acceptable, particularly for grease lubri-
cated bearings Oil lubrication may be
required

136