Chain Drive

The advantages of chain drive systems are as follows:

1. Shaft center distances are

relatively unrestricted. Whereas

gear drive center-to-center

distances are restricted to

specific dimensions for a given

set of gears, the center distances

between two chained sprockets

can vary anywhere from 50% to

300% or more of their pitch

diameters.

2. Chain Drive are relatively easy

to install. Assembly tolerances

are not as restrictive as those for

gear drives. Chain drives are a

better choice for less experienced builders working with a minimum of machine tools.

3. Chain drives can be readily redesigned and reconfigured in comparison to gear drive

systems.

4. Chains perform better than gears under shock loading conditions.

5. Chain drives spread operating loads over many teeth whereas the operating loads acting

on gear drives are concentrated on one or two teeth.

6. Chain drives do not require tension on the slack side (Belt drives do) thus bearing loading

is reduced.

7. Chain drives require less space for a given loading and speed condition than pulleys and

belts.

8. Chain drives systems are (usually) less costly to build and maintain than an equivalent

gear drive.

While chain drives offer many advantages, there are good reasons to choose a gear drive system,

particularly when:

1. Compact drive requirements

demand the shortest possible

distance between shaft

centers.

2. High speed ratios are

required.

3. High rotating speeds (RPM)

are required.

4. High horsepower AND high

speed loading is required.

Belt and pulley systems also offer design advantages with respect to either chain or gear drives.

These advantages include:

1. Belts slip, chain and gears drives do not. This is a useful advantage for drive systems that

do not require positive speed

ratios to be maintained.

Momentary overloading

loading conditions may cause

a belt to slip over the pulleys

whereas a chain may break or

a gear tooth may shear. Belts

offer built in “Clutching”. Of

course sustained overloading

will cause premature wear and

“Burned out” belts.

2. Belt drives are not as noisy as

chain or gear drive systems.

3. Belt drives can operate over

longer center distances than

chain drives.

Belts are better suited to extremely high-speed ratios.