Page 1028 - Rollingbearings

19 Solid Oil bearings
Loads Speed limits Calculation example
A deep groove ball bearing 6208/W64 is to
operate at an ambient temperature of 50 °C
Load carrying The recommended speed values for bear- (120 °F) What is the reduced speed limit?
capacity ings and bearing units with Solid Oil
(table 2), operating in an ambient tempera-
ture of 20 °C (70 °F), are limited by the max- 1 Recommended speed limit for 20 °C
The basic dynamic and static load ratings for imum continuous operating temperature of (70 °F) ambient temperature
bearings with Solid Oil are the same as for 85 °C (185 °F). Ambient temperature is the – From table 2: speed value
corresponding SKF standard bearings temperature closest to the bearing position, nd = 300 000 mm/min (single row
m
not necessarily room temperature. deep groove ball bearing with a
For bearing types or variants not listed in stamped metal cage)
table 2, contact the SKF application engin- – Dimensions: d = 40 mm, D = 80 mm
Temperature eering service. n = 300 000 / d
m
= 300 000 / (0,5 (40 + 80))
For ambient temperatures above 20 °C
limits (70 °F), the speed limit should be reduced = 5 000 r/min
using the reduction factor f (diagram 1)
T
2 Reduction for 50 °C (120 °F) ambient
The permissible operating temperature for temperature
bearings with Solid Oil can be limited by: – From diagram 1: speed reduction factor
f ≈ 0,53
T
• the dimensional stability of the bearing n reduced = 5 000 f
T
rings and rolling elements = 5 000 × 0,53
• the cage(s) = 2 650 r/min
• the seals
19 • the Solid Oil Table 2
Recommended limits for the speed value of bearings and bearing units with Solid Oil
For limits of bearing rings, rolling elements,
cage(s) and seals, refer to Temperature limits Bearing type Speed value nd m
of the relevant product section of the stand- – mm/min
ard bearing
The relevant limits for Solid Oil are listed Deep groove ball bearings
in table 1, page 1025 – single row with a stamped metal cage 300 000
Where temperatures outside the permis- – single row with a polymer cage 40 000
– double row 40 000
sible range are expected, contact SKF
Angular contact ball bearings
– with a stamped metal cage 150 000
– with a polymer cage 40 000
Self-aligning ball bearings
– with a stamped metal cage 150 000
– with a polymer cage 40 000
Cylindrical roller bearings
– with a stamped metal cage 150 000
– with a polymer cage 40 000

Tapered roller bearings 45 000
Spherical roller bearings
– E design 42 500
– CC design 85 000
Insert bearings, ball bearing units 40 000

n = rotational speed [r/min]
d m = bearing mean diameter [mm]
= 0,5 (d + D)

For bearings with integral seals, use 80% of the quoted speed limits

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