Timing Gear – Timing gears, since the name implies, are utilized for various timing purposes. Also called synchronous gears, they can be either spur or helical gears. They are generally used in automotive applications to control valve timing in engines.
Worm Equipment – A worm gear consists of a worm and a worm wheel working jointly. The worm Ground Helical Gear Racks resembles a screw and is sometimes known as a worm screw, as the worm wheel appears comparable to a spur gear or helical gear with a slight helix position. This set is sometimes also called a worm drive. Worm gears will be the most compact kind of gear and so are often used in applications where space is bound.
Spur Gear – Spur gears are the most typical kind of gear. They are accustomed to transmit motion between two parallel shafts and so are known for being highly efficient and making a lot of power. Spur gears are known by quite a few other names including straight gears, straight-cut gears, spur wheels, and spur gearing. All of these have the same basic definition and can be used interchangeably.
Pump Gear – A pump gear may be the name intended for a gear used in equipment pumps. They contain both a driver and powered gear and can be either spur or helical gears. Not to be confused, the term gear pump refers to the entire pump, while pump gears identifies the gears only. Gear pumps are positive displacement pumps, which means they pump a constant amount of liquid in each revolution. The volume of fluid in a revolution depends on the geometry of the pump gears (i.e. number of tooth, diametrical pitch, etc.).
Spline – Splines are the 
ridges or the teeth (external spline) on a drive shaft that mesh with an equal number of like ridges or tooth (internal spline) in a mating piece with the purpose of transferring torque from one member to the additional. The most typical splines are parallel important splines, involute splines (closely related to involute gears but with shorter the teeth, root to tip), and serrations. Splines could be produced by shaping, hobbing or broaching.
Sprocket – Sprockets, or sprocket wheels, are toothed wheels whose the teeth engage the links of chains or belts. Sprockets are distinguished from gears in that sprockets are never meshed together directly. There are several various kinds of sprockets, including silent chain, roller, and ladder sprockets.
Pinion Gear – A pinion may be the smaller sized of two meshed gears in an assembly. Pinions gears can be either spur or helical type gears, and become either the driving or driven gear, based on the application. Pinion gears are found in many different types of gearing systems such as ring and pinion or rack and pinion systems.