TYPES OF GEARS

According to the position of axes of the shafts.

a.Parallel

1.Spur Gear

2.Helical Gear

3.Rack and Pinion

b.Intersecting

Bevel Gear

c. Non-intersecting and Non-parallel

worm and worm gears

SPUR GEAR

• Teeth is parallel to axis of rotation
• Transmit power from one shaft to another parallel shaft
• 

Helical Gear

• The teeth on helical gears are cut at an angle to the face of the gear
• This gradual engagement makes helical gears operate much more smoothly and quietly than spur gears
• One interesting thing about helical gears is that if the angles of the gear teeth are correct, they can be mounted on perpendicular shafts, adjusting the rotation angle by 90 degrees

Rack and pinion

A rack is a toothed bar or rod that can be thought of as a sector gear with an infinitely large radius of curvature.

Torque can be converted to linear force by meshing a rack with a pinion: the pinion turns; the rack moves in a straight line. Such a mechanism is used in automobiles to convert the rotation of the steering wheel into the left-to-right motion of the tie rod.