To aid in the selection of the proper
belt for each application, manufacturers provide technical and
performance data about their belts.
In addition, the Rubber Manufacturers’
Association (RMA) and the Mechanical Power Transmission Association
(MPTA) have worked together to publish engineering standards and
bulletins for most types of belts and drive hardware (see
Bibliography).These publications contain information that supplements
design catalogs.
There are four basic questions that
need to be answered in the drive design:
1. What horsepower is required of the
drive?
2. What is the speed (rpm) of the
driver shaft?
3. What is the speed (rpm) of the
driven shaft?
4. What is the approximate desired
center distance?
In addition to the basic elements,
there are a number of special drive characteristics that may require
consideration. These might include:
● Special environmental conditions
such as abrasives, chemicals, and so on.
● Overhung load (OHL) considerations
for gear motors and reducers
● Driven pulley inertia (WR2)
requirements for equipment such as piston compressors, crushers, and
so on.
● Special drive characteristics such
as shock loads, inherent misalignment, clutching requirements, and so
on.
Also, while selecting and evaluating
the drive, consider the following points:
● Selecting larger diameter pulleys
will keep drive face width to a minimum.
● Selecting larger diameter pulleys
will keep drive tensions and shaft load at a minimum.
● Larger diameter pulleys will often
give a more economical drive, but should not be so large that
multiple V-belt capability is sacrificed.
● If space is limited, consider using
the smallest diameter drive. However, pulleys on electric motors must
be at least as large as the National Electric Manufacturers
Association (NEMA) minimum recommended standards.
● When the drive is between two belt
cross-section sizes, the larger section will usually be more
economical.
However, it is always recommended to
check drives in both cross sections. Selecting an optimum belt drive
involves many factors, but drive selection can be readily
accomplished using manufacturers’ design literature. Many
manufacturers also offer computer programs for drive design
selection.
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