The gear drive is a precision component that relies on solid design, quality components and precise assembly to achieve a reliable operating system. Proper gear drive application requires a selection based on many operating parameters, including input power, load demand, external loads, duty cycle, environment, system accessories and facility needs. Gear drive selection is then made based on a service factor that accounts for the non-uniformity of torque by the driving and driven machines.
In a car, the motor turns a shaft attached to gears that turn other gears, one of which is attached to the car's axle. The car's axle is attached to the wheels. When the gears are turned the car's axle move, which in turn moves the wheels of the car. It's the gear drive system that moves the car.