Bearing Load Calculations; Arc Of Contact Correction Factors G And R Table 3-3; Allowable Sheave Rim Speed* Table 3-4; Overhung Sheave Figure 3-3 - DSI Dynamatic AS-703 Instruction Manual

Arc of Contact Correction Factors G and R
Small Sheave
D-d
Arc of
C*
Contact
.00 180°
.10 174°
.20 169°
.30 163°
.40 157°
.50 151°
.60 145°
.70 139°
*D = diameter of large sheave; d = diameter of small sheave; C = center distance.

Bearing Load Calculations

To find actual bearing loads it is necessary to know
machine component weights and values of all other
forces contributing to the load. Sometimes it
becomes desirable to know the bearing load
imposed by the V-belt drive alone. This can be
done if you know bearing spacing with respect to
the sheave center and shaft load (see Figure 3-3)
and apply it to the following formulae:
Load at B, Lbs. = Shaft Load (a+b)
Load at A, Lbs. = Shaft Load (b)
Where: a and b = spacing, inches
Allowable Sheave Rim Speed*
Sheave Material
Cast iron
Ductile Iron
Steel
*These rim speed values are maximum for normal
considerations. In some cases, these values may
be exceeded. Consult factory and include complete
details of proposed application.
16
Factor Factor
G
1.00 1.000
.99 .999
.97 .995
.96 .989
.94 .980
.93 .968
.91 .964
.89 .937
A
a
Table 3-4
Rim speed in feet per
minute
6,500
8,000
10,000
Small Sheave
D-d
R C*
.80
.90
1.00
1.10
1.20
1.30
1.40
1.50
Overhung Sheave
Factor
Arc of
G
Contact
133° .87
127° .85
120° .82
113° .80
106° .77
99° .73
91° .70
83° .65
Table 3-3
Factor
R
.917
.893
.866
.835
.800
.760
.714
.661
Figure 3-3