Types of Gears

Types of Gears

We can have various types of gears depending upon their axe’s position and can be classified into intersecting, non- intersecting shafts and parallel shafts.

Some types of gears are listed below:

  • Internal gear
  • Miter gear
  • Worm gear
  • Screw gear
  • Spiral bevel gear
  • Bevel gear
  • Gear rack
  • Spur gear
  • Helical gear

Internal gear

These type of gears have teeth cut on the inside part of cones and cylinders and is used to pair with external gears. These are used in shaft couplings which are of gear types and planetary gear drives. One limitation in this type of gears is the difference between number of external and internal gears which occurs due to trimming problems, and interference such as trochoid and involute.

Miter gear

Miter gears are one type of bevel gears with speed ratio 1. There are of two types such as straight and spiral. These are used to change the direction of power transmission without changing the speed.

Worm gear

It consists of two components which is a mating gear which is called worm wheel and a shaft which is screw shape cut called worm. A hard material is used for the worm and a soft material is used for the worm wheel in order to reduce friction due to sliding contact of the surfaces of gears.

Screw gear

It consists of same hand helical gears in an angle of 45 degrees on the non-intersecting and non- parallel shafts. It is used for small power transmission and when used, it requires attention on its lubrication.

Spiral bevel gear

These are bevel gears with curved lines of tooth. They have greater efficiency and strength but it produces more noise and vibration. And because the tooth contact ratio is high, it is little difficult to produce.

Bevel gear

It is of cone shape at its pitch surface and the teeths are cut along the cone. These are used to transmit force between two shafts. They are classified into helical bevel, straight bevel, angular bevel, zero bevel, miter and hypoid gears.

Gear rack

It is a cylindrical shaped gear with the radius of pitch as infinity. If it is meshed with a gear pinion which is of cylindrical shape, it can convert rotational motion into linear motion. There are two types of gear rack which are straight and helical tooth racks.

Spur gear

It is a cylindrical gear with tooth line straight and parallel to the shaft. It is easy to produce and has high accuracy.

Helical gear

These are cylindrical gear with winding tooth lines. It can transmit high loads and are very quiet. They are of two types namely right hand twist and left hand twist.

These were some types of gears, if you wish to know more, download BYJU’S The Learning App.


Practise This Question

An inverted tube barometer is kept in a lift moving vertical  upward with an acceleration 'a'. The density of mercury is ρ and acceleration due to gravity is g. If the atmospheric pressure be Po then