Classification of Gears
Today there are a number of Gears that are available commercially used for
different purposes. There is a system to classify them according to
different criteria. Some of the popular classification methods are listed
below.
Gear Types Based upon the Shaft
Arrangement
| Parallel Shafts |
Intersecting Shafts |
Non-intersecting (Non-parallel) Axes |
Rotary To Translation |
| Spur Gears |
Miter Gears |
Spiral Gear |
Rack and Pinion |
| Helical Gears |
Face Gears |
Hypoid Gears |
|
| Herringbone Gears |
Zero Bevel Gears |
Worm Gears |
|
| Double Helical Gears |
Straight Bevel Gear |
Screw Gear |
|
Parallel Shafts
These are the class of gears that best describes those that mesh in the
same plane. They are typically applied for transmission of rotary motion in
between parallel shafts. The advantages includes good transmission of power
and very high efficiency. They are ideal for high horsepower applications,
where importance is given to long-term operational efficiency. The following
image shows Parallel shaft class of the Gears.
Intersecting Shafts
These class of gears are specifically designed for smooth transmission of
power and motion between angular intersecting shafts. They are most suitable
for applications that need high load capacity. They are also less costly
than parallel shaft gears. They are typically used for applications
requiring speed, and strength. The following is the image of Intersecting
Shaft Gears.
Non Intersecting Shafts
These gears are best suited for power transmission applications that
necessitates for a high-ratio speed reduction in a space that is limited.
However, they can operate with only restricted load capacity. Their
efficiencies can be increased by lowering ratios. These gears are the least
expensive among all the gears.
Gear Types Grouped upon the Number of Steps
This particular system of classification segregates the gears, depending on
the number of steps:
- One Step Gears
- Two Step Gears
- Three Step Gears, so on and so forth
Gear Types Based upon Housing
Design
In this particular type of classification there can be two classes. Namely
- Open Drives: The gear drive is bereft of a casing. This means they
are prone to the action of grime and dust.
- Closed Drives: Here the gear Drives are found enclosed in protective
casings that offers good protection against dirt and dust.
Gear Types Depending upon the
Peripheral Velocity
The following classification can be done:
- Low Velocity: V is less than 3 m/s.
- Medium Velocity: V equals 3 to 15 m/s.
- High Velocity: where V is above 15 m/s.
Gear Types Based upon
Manufacturing Precision
According to International Standards there could be around 12 degrees of
manufacturing accuracy.
Gear Types Based upon Pitch Diameter
- Coarse Pitch Gear
- Fine Pitch Gear
- Medium Pitch Gear
