Its teeth are mainly carved on wheels, cylinders, or cones. Many devices that we use in our day-to-day lives are based on the working principle of a gear. The tooth and wheel are basic working parts of such devices.
Internal and External Gears
They are the most simplest form of gears, and are used to control locomotion of a mobile body. Their teeth, which are carved on the body's exterior, are interconnected with another gear.
These exterior gears are used mostly along with a chain, like in a bicycle or motorcycle. More complex combinations of such gears are used to manufacture gearboxes for vehicles.
The design of interior gears is similar to that of an exterior one. The only difference is that the teeth are carved inside the wheel, and they are mostly used for perpendicular transfer of energy. Their teeth, which are used to apply the effort, have a perpendicular or straight projection.
Another difference between these two types is the radial projection of teeth. The uppermost portion of this device is carved in such a manner, that it is always parallel to the axis of rotation.
Due to this, the teeth get the appearance of a helix. They were developed to replace spur gears that could not last the stressed out high-speed rotation and resolution.
They are especially useful for a perpendicular transfer of energy. They are further classified according to the angle, as per which the energy transfer takes place.
As the name suggests, they are shaped like a crown. Their teeth are pointed in an upward direction, and are perpendicularly carved on the wheel. These types are often considered to be an evolution of bevel gears.
All the gears that are presently used have the same principle of physics, and they form an integral part of the modern mechanisms. All have been modified and re-engineered to form different designs, and to execute different functions.