Gears are broadly classified into three types,
- Parallel shaft gears
- Intersecting shaft gears
- Non parallel non intersecting shaft gears
1.Parallel shaft gears
- Spur gear
- Helical gear
- Rack and pinion
2.Intersecting shaft gears
- Bevel gear-Straight bevel, Spiral bevel, Hypoid bevel
3.Non parallel non intersecting shaft gears
- Spiral gear
- Worm gear