The Braking and Gearing Systems of Elevators

As far as we know, the history of Elevator can be traced back to 19th century, and with the development of technology, though major improvements has been made in the motors, the principles remain the same. This article will give a brief understand of the braking system and gearing system in elevators.

Firstly, we will introduce the braking system. As time went by, regenerative braking technology is slowly becoming accepted in many different areas in industry. It is ubiquitous in electric cars, as well as hybrids. In general, using normal braking technology, the kinetic energy of a moving vehicle is converted to heat by the application of brake pads to a wheel, almost all of the kinetic energy is lost.

However, regenerative brakes recoup some of the kinetic energy by using it to turn a small generator, also known as a dynamo. The electricity produced by the brakes is stored in a battery and is available for the vehicle's use. And with time, regenerative braking technology is creating brakes that recoup more of the energy lost by the stopping of the vehicle.

Elevators are prime examples of vehicles where regenerative braking technology can produce excellent results. This is because the elevator's counterweights ensure that no more than 55% of the elevator's capacity must be moved or stopped by an input of energy. As a result, momentum can be built up at a relatively low energy cost. By recouping some of this energy in batteries, elevator efficiency is greatly increased.

Retrofitting elevators with regenerative braking technology is relatively simple, because almost all elevators use motors driven by DC power. The input of DC power from a battery becomes almost trivial. So only the braking mechanism requires replacement.

Then, let’s have a look at gearing system. The use of a continuously variable transmission (CVT) allows a motor's transmission to use a gear ratio that provides maximum efficiency. A CVT enables moving between gear ratios steplessly, providing for smooth acceleration.

As a matter of fact, CVTs are used in a variety of applications from tractors and snowmobiles to drill presses and milling machines. Many cars, including racing cars, use CVT to generate electrical power in aircraft.

As a result, the use of CVT in elevators can improve efficiency by using the gear ratio most appropriate to the weight differential between the current weight of the elevator and the weight of the counterweight.