Gear Trains

Gear trains are a group of gears that can provide rotary motion of the desired direction, speed, torque, and angle of shaft, within a compact space that is desirable in most applications. Hence, they are an integral part of machines in many practical applications. Some well-known applications are automobiles (gearbox and differential), manufacturing machines, airplanes, helicopters, etc. Although all types of gears are used in gear trains (spur, helical, bevel, worm, etc.), we shall, however, focus on spur gears only in this chapter.