Wanco AB Series, Owner'S Manual

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16 Owner’s Manual
Wanco Two-Bearing Belt-Drive Generators
Figure 3-3 Equation for calculating pulley size
■
Keep the pulley close to the engine. The outer edge of the pulley
should not extend more than 2 inches (50mm) past the end of the
crankshaft (see Figure 3-4). Greater distances will stress the shaft
and bearings.
■
If a belt tensioner is used, it should be installed on the slack side run
of the belt (see Figure 3-5). If the tensioner is used as a drive clutch,
you may need to install a brake at the driven pulley to prevent
driven pulley rotation while belt tension is released.
■
Avoid using an idler pulley whenever possible. If an idler must be
used, install it on the slack side of the belt (see Figure 3-5).
The equation for determining pulley diameter is:
The equation can be solved for any variable using simple algebra.
EXAMPLE: You want to operate an engine at 2400 RPM. You have an AR-Series
generator, which must always operate at 3600 RPM. You have a pulley on the
engine that is 7.0 inches in diameter. What diameter pulley should you use on
the generator?
Engine Speed
Generator Speed
-----------------------------------------
Generator Pulley Diameter
Engine Pulley Diameter
----------------------------------------------------------------
=
2400
3600
------------
Generator Pulley Diameter
7
----------------------------------------------------------------
=
2400 7

3600
---------------------
Generator Pulley Diameter =
16800
3600
--------------- 4.67 Generator Pulley Diameter = =