A gear drive drive requires two gears for operation. Both gears are spur cut, and the drive equipment receives force from the power output. The drive equipment then transfers power to the driven gear.
Different Drive Systems
All drive systems need a drive gear. The drive gear is the main transfer from the energy source to the powered equipment. A belt from the drive gear to the driven gear is a “belt driven” system. Another option may be the “chain driven” system. The “chain driven” system runs on the chain from the drive gear to the driven gear. The “gear drive” program is immediate gear-drive. The drive equipment is straight meshed with the powered gear.
Common applications
Gear drives are found in transmissions, rear ends and transfer cases; at times the drive gear will be smaller than the driven gear. Different gear ratios allow the transmission to change to lower or more rpm speeds.
Automotive gear drive
Gear drives are applied to automotive engines. A “gear drive” usually refers to 
the timing drive; it replaces the common timing-chain with spur-cut gears. A equipment drive is well known for the “whining sound” it emits. One’s teeth of the gears mesh collectively as the gears switch with the rotation of the engine. This helps to keep the engine in time.