High Precision Ball Bearings - Kraftmek

Limiting speed for deep groove bearings
The speeds listed in the tables are attainable speeds for
a single spring-preloaded bearing operating under normal
conditions such as
• Good heat dissipation
• Low external load
• Rotating inner ring
• Grease lubrication
• Good form accuracy
• Good balancing of rotating parts
If the operating conditions deviate from the conditions
mentioned these must be taken into account by correction
factors.
Correction factors and speed values are only for guidance.
Permissible speed = Speed value · f n1 · f n2 · f n3 · f n4 · f n5
Correction factors
f n1 : Lubrication Grease lubrication (note n · dm factor of grease) 1.0
Oil-mist lubrication 1.25
f n2 : Cages Y/J (n · dm < 625 000) 1.0
T9H (n · dm < 1 400 000) 1.6
TBH (n · dm < 1 000 000) 1.2
TA (n · dm < 1 600 000) 1.8
MA (n · dm < 1 350 000) 1.5
TB (n · dm < 1 400 000) 1.6
MB (n · dm < 1 200 000) 1.4
f n3 : Kinematics Rotating inner ring 1.0
Rotating outer ring 0.6
f n4 : Bearing arrangement Single bearing with spring preloading 1.0
bearing pairs Pairs in DF, DB, DT, DUA, DUO, DUV 0.8
f n5 : Ball material Steel 1.0
Ceramic (Si 3 N 4 ) 1.25
... for bearing calculation
Radial clearance as per DIN 620/Part 4
Nominal bore size
Radial clearance in micron
d C2 CN C3 C4
mm
over to min max min max min max min max
11.5 6 0 7 2 13 8 23 – –
16,5 10 0 7 2 13 8 23 14 29
10,5 18 0 9 3 18 11 25 18 33
18,5 24 0 10 5 20 13 28 20 36
24,5 30 1 11 5 20 13 28 23 41
30,5 40 1 11 6 20 15 33 28 46
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