In calculating for pulleys, multiply or divide by their diameter in
inches.
In calculating for gears, multiply or divide by the number of teeth
required.
The driving wheel is called the “driver,” and the driven wheel the
“driven.”
PROBLEM 1.—To find the diameter of the driver when the revolutions of
the driver and driven and the diameter of the driven are given.
RULE.—Multiply the diameter of driven by its number of revolutions, and
divide by the number of revolutions of the driver.
PROBLEM 2.—To find the diameter of the driven to make the same number
of revolutions in the same time as the driver, when the diameter and
revolutions of driver are given.
RULE.—Multiply the diameter of the driver by its number of revolutions,
and divide the product by the required number of revolutions.
PROBLEM 3.—To find the number of revolutions of the driven when the
diameter or number of teeth and number of revolutions of the driver and
the diameter or number of teeth of the driven are given.
RULE.—Multiply the diameter or number of teeth of the driver by its
number of revolutions, and divide by the diameter or number of teeth of
the driven.
PROBLEM 4.—To find the number of revolutions of the driver when the
diameter of the driven and the number or revolutions of driven are
given.
RULE.—Multiply the diameter of driven by its number of revolutions, and
divide by the diameter of the driver.