Product Manual

CHAPTER IX
Gear Reducers and Gearmotors
A gear reducer, also called a speed reducer or gear box, consists of
a set of gears, shafts and bearings that are factory-mounted in an
enclosed, lubricated housing. Gear reducers are available in a broad
range of sizes, capacities and speed ratios. Their job is to convert
the input provided by a “prime mover” into output of lower RPM
and correspondingly higher torque. In industry, the prime mover is
most often an electric motor, though internal combustion engines or
hydraulic motors may also be used.
There are many types of gear reducers using various gear types to meet
application requirements as diverse as low first cost, extended life,
limited envelope size, quietness, maximum operating efficiency, and a
host of other factors. The discussion that follows is intended only as a
brief outline of the most common industrial gear reducer types, their
characteristics and uses.
Right-Angle Worm Gear Reducers
The most widely used industrial gear reducer type is the right-angle
worm reducer. Worm reducers offer long life, overload and shock load
tolerance, wide application flexibility, simplicity and relatively low cost.
In a worm gear set, a threaded input shaft, called the worm, meshes
with a worm gear that is mounted to the output shaft. Usually, the worm
shaft is steel and the worm gear is bronze. This material combination
-75-
Cutaway view shows key
components of an industrial-duty
worm gear reducer. Note steel
worm and bronze worm gear.
Seals on both input and output
shafts prevent lubricant leakage.