Page 18 - ThermoidPowerTransnmissionBeltsBrochure(HBDTHE-18770)

VARIABLE SPEED BELTS
For use on variable speed control drives, Thermoid Variable
Speed V-belts operate at low noise levels and are vibration­
free. Available in cut edge, molded cog constructions
that are oil and heat resistant. They are ideal for machine
tools and other equipment where changes in speed is a
requirement.
Number System
The numbering system for Variable Speed V-belts is based upon
the pulley groove dimensions and the pitch length of the belt.
For Example 1430V315.
Top width of groove in Groove Variable Belt pitch length in
closed position in angle speed 1/10-inch increments,
1/16-inch increments, Example Example 31.5:'
Example 14/16~' 30°
Variable Drive Systems
To change the speed of a belt-driven machine, split pulleys
permit one flange of a pulley to be moved in or out, varying the
pitch. This causes the variable speed V-belt to ride higher or
deeper in the groove, thereby changing its speed ratio.
Three basic variable speed pulley systems, are employed
which, together with our Variable Speed V-belts, form efficient
and economical variable speed drives.
Spring Loaded
Variable Pulley
Countershaft
Dual Variable
Pulley
Cross TOP WIDTH THICKNESS
Section (Inches) (Inches)
1422V 088 0.31
1922V 1 19 0.38
2322V 1.44 0.44
1926V 119 0.44
2926V 1.81 0.50
3226V 200 0.53
2530V 1.56 0.59
3230V 2.00 0.62
4430V 275 0.69
4036V 2.50 0.69
4436V 2.75 072
4836V 300 0.75
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