Gear Types

There are many kinds of gear, below are the common gear we use normally.

Spur Gear
When two spur gears of different sizes mesh together, the larger gear is called a wheel, and the smaller gear is called a pinion. In a simple gear train of two spur gears, the input motion and force are applied to the driver gear. The output motion and force are transmitted by the driven gear. The driver gear rotates the driven gear without slipping.






Bevel Gear
Bevel gears have teeth cut on a cone instead of a cylinder blank. They are used in pairs to transmit rotary motion and torque where the bevel gear shafts are at right angles (90 degrees) to each other.

Worm Gear
A gear which has one toothe is called a worm. The tooth is in the form of a screw thread. A wormwheel meshes with the worm. The wormwheel is a helical gear with teeth inclined so that they can engage with the thread-like worm. The wormwheel transmits torque and rotary motion through a right angle. The worm always drives the wormwheel and never the other way round. Worm mechanisms are very quiet running.

Rack Gear and Pinion Gear
A rack and pinion mechanism is used to transform rotary motion into linear motion and vice versa. A round spur gear, the pinion, meshes with a spur gear which has teeth set in a straight line, the rack.








Internal Gear
Internal gears have better load-carrying capacity than external spur gears. They are safer in use because the teeth are guarded.