Gears are mechanical transmission elements used to transfer motion and power between machine components. Gears, working in pairs, engage their teeth with the teeth of another corresponding gear or gear component, which prevents slippage during transmission operation. Each gear or threaded component is connected to a machine shaft or basic component. Therefore, when the driven gear rotates with its shaft component, the driven gear rotates or turns the shaft component. Depending on the design and construction of the gear pair, the transfer of motion between the drive shaft and the driven shaft can cause a change in rotation or movement direction. Additionally, if the gears are not of equal size, the machine or system gains a mechanical advantage that allows for a change in output speed and torque (i.e. the force that causes an object to rotate).
Gear manufacturing and its mechanical properties are widely used throughout industry to transmit motion and power in various mechanical devices such as clocks, instrumentation and equipment, and to reduce or increase speed and torque in a variety of motorized devices, including automobiles, motorcycles. Other design features, including construction material, gear shape, tooth structure and design, and gear pair configuration, help classify and categorize the various gear types available. Each of these gears offers different behaviors and advantages, but the requirements and characteristics required by a particular motion or power transmission application will determine the most suitable gear type for use.
Gears are available in a variety of designs, constructions and configurations to suit a wide variety of industries and applications. These various features are classified in several different ways gears include:
Most gear types are circular; that is, the gear teeth are arranged around a cylindrical gear body with a circular face. However, some non-circular gears are also available. These gears can have elliptical, triangular and square shaped faces.
One of the most common ways gears are applied is through transmissions, which are devices consisting of gearbox contained within a housing. These devices are available in a wide variety of gear types, including worm gears, bevel gears, helical gears, and spur gears, and are designed to perform a specific motion or power transmission task within the machine system, from changing speed and torque to varying output. Similar to most gear systems, gearbox has a variety of uses, such as in automobiles and other motor vehicles.