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
- Mitre gear
- Worm gear
- Screw gear
- Spiral bevel gear
- Bevel gear
- Gear rack
- Spur gear
- Helical 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 a number of external and internal gears which occurs due to trimming problems and interference such as trochoid and involute.
Mitre 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.
It consists of two components which are 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 soft material is used for the worm wheel in order to reduce friction due to sliding contact of the surfaces of gears.
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 a tooth. They have greater efficiency and strength but it produces more noise and vibration. And because the tooth contact ratio is high, it is a little difficult to produce.
It is of cone shape at its pitch surface and the teeth 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, mitre and hypoid gears.
It is a cylindrical shaped gear with the radius of the pitch as infinity. If it meshes 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.
It is a cylindrical gear with tooth line straight and parallel to the shaft. It is easy to produce and has high accuracy.
These are a 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.