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