Ball and Roller Bearings - Ntn-snr.com

Bearing Load Calculation
4.1.2 Chain / belt shaft load
The tangential loads on sprockets or pulleys when
power (load) is transmitted by means of chains or belts
can be calculated by formula (4.7).
Kt 19.1 106 H
N
Dpn
4.7
1.95106 H kgf
Dpn
where,
KtSprocket/pulley tangential load, N
H Transmitted force, kW
DpSprocket/pulley pitch diameter,mm
For belt drives, an initial tension is applied to give
sufficient constant operating tension on the belt and
pulley. Taking this tension into account, the radial loads
acting on the pulley are expressed by formula (4.8). For
chain drives, the same formula can also be used if
vibrations and shock loads are taken into consideration.
4.2 Bearing load distribution
For shafting, the static tension is considered to be
supported by the bearings, and any loads acting on the
shafts are distributed to the bearings.
For example, in the gear shaft assembly depicted in
Fig. 4.7, the applied bearing loads can be found by using
formulas (4.10) and (4.11).
FrA ab F1 d F2 4.10
b cd
FrB a F1 c F2 4.11
b cd
where,
FrARadial load on bearing A, N
FrBRadial load on bearing B, N
F1, F2Radial load on shaft, N
Krf bKt4.8
where,
KrSprocket or pulley radial load, N
f bChain or belt factor (Table 4.3)
a
b
Bearing A
Bearing B
Table. 4.4 chain or belt factor f b
Chain or belt type
f b
F
F
Chain (single)
1.21.5
F! F@
V-belt
1.52.0
c
d
Timing belt
1.11.3
Flat belt (w / tension pulley)
2.53.0
Fig. 4.7 Gear shaft
Flat belt
3.04.0
F1
Loose side
Dp
Kr
F2
Tension side
Fig. 4.6 Chain / belt loads
A-21