4 / 60
Table 1 Groove Dimensions
Drive Design Factors (in.)
Cross
Section Datum Diameter Range
Minimum
Recommended
Datum Diameter
2a
A, AX
Up through 5.40
Over 5.40
A: 3.0
AX: 2.2
0.250
B, BX
Up through 7.00
Over 7.00
B: 5.4
BX: 4.0
0.350
A, AX & B, BX
Combination
A,
AX
Up through 7.40 (1)
Over 7.40
A: 3.6 (1)
AX: 2.8
0.620 (2)
B,
BX
Up through 7.40 (1)
Over 7.40
A: 5.7 (1)
BX: 4.3
0.280 (2)
C, CX
Up through 7.99
Over 7.99 to and including 12.00
Over 12.00
C: 9.0
CX: 6.8
0.400
D
Up through 12.99
Over 12.99 to and including 17.00
Over 17.00
D: 13.0
0.600
E
Up through 24.00
Over 24.00
E: 21.0
0.800
Table 1 Groove Dimensions
Deep Groove Dimensions (in.)
Cross
Section Outside Diameter Range
Groove
Angle
±
0.33
b
g
b
g
hg
Min.
2a
Sg
±
0.025
S
e
S
e
B, BX
Up through 7.71
Over 7.71
34
38
0.747
0.774
±
0.006
0.730 0.710 0.875 0.562
+0.120
-0.065
C, CX
Up through 9.00
Over 9.00 to and including 13.01
Over 13.01
34
36
38
1.066
1.085
1.105
±
0.007
1.055 1.010 1.250 0.812
+0.160
-0.070
D
Up through 14.42
Over 14.42 to and including 18.43
Over 18.43
34
36
38
1.513
1.541
1.569
±
0.008
1.435 1.430 1.750 1.062
+0.220
-0.080
E
Up through 25.69
Over 25.69
36
38
1.816
1.849
±
0.010
1.715 1.690 2.062 1.312
+0.280
-0.090
ୋ
(1) Diameters shown for combination grooves are outside diameters.
A specific datum diameter does not exist for either A or B belts in
combination grooves.
(2) The “A” values shown for the A/B combination sheaves are the
geometrically-derived values. These values may be different than those
shown in manufacturer’s catalogs.
Summation of the deviations from “S g ” for all grooves in any one sheave
shall not exceed
±
0.050 in.
The variation in datum diameter between the grooves in any one sheave
must be within the following limits: Up through 19.9 in. outside diameter
and up through 6 grooves: 0.010 in. (add 0.0005 in. for each
additional groove).
20.0 in. and over on outside diameter and up through 10 grooves: 0.015 in.
(add 0.0005 in. for each additional groove).
This variation can be obtained easily by measuring the distance across
two measuring balls or rods placed diametrically opposite each other in a
groove. Comparing this “diameter over balls or rods” measurement between
grooves will give the variation in datum diameter.
Deep groove sheaves are intended for drives with belt offset such as
quarter-turn or vertical shaft drives. (See RMA Power Transmission Belt
Technical Information Bulletin IP-3-10, V-Belt Drives with Twist).
Joined belts will not operate in deep groove sheaves.
Also, A and AX joined belts will not operate in A/AX and B/BX
combination grooves.
Other Sheave Tolerances
Outside Diameter
Up through 8.0 in.
Outside diameter:
±
0.020 in.
For each additional inch of outside diameter add...
±
0.005 in.
Radial Runout*
Up through 10.0 in.
Outside diameter:
±
0.010 in.
For each additional inch of outside diameter add...
±
0.0005 in.
Axial Runout*
Up through 5.0 in.
Outside diameter:
±
0.005 in.
For each additional inch of outside diameter add...
±
0.001 in.
*Total Indicator Reading
4
V-Belts
Installation Guide