How To Made Elevators
January 29, 2012 – 8:39 pmFor some of us, For some of us, elevator parts are such a part of our daily lives that we might never stop to think about what makes them work. Despite Hollywood portrayals of people falling down elevator shafts, or cables snapping and sending elevator cars plummeting hundreds of feet, we still just trust these machines to work, and with good reason. Elevators have been around for over a hundred years, and the safety measures in place make a fatal accident nearly impossible. There are two main types of elevator in service today, piston elevators and rope elevators.
Piston Elevators
Piston elevators are pushed up from below by a hydraulic piston. Underneath the building, a motor controls the pumping of hydraulic oil into a piston. When this fluid is pumped into the piston, the increase in pressure causes the elevator to rise. When the elevator needs to lower, the fluid is allowed to drain from the piston back into the reservoir. These elevators work well for smaller buildings. However, when the elevator parts is on the first floor, the piston must be entirely below the building. This means that the motor and piston must be buried as deep below ground as the building is high. This limitation makes the piston elevator less than ideal for larger structures.
Rope Elevators
Rope elevators use steel cables connected to a pulley system to move the elevator up and down the shaft. At the top of the shaft, in the elevator control room, the steel cables wrap around a large pulley. Below, one end of the cables is attached to the elevator, and the other end is attached to the counterweight. The counterweight weighs as much as the elevator with an average load in it. When the car goes up, the counterweight goes down. This setup greatly reduces the amount of energy that is required to lift the elevator by allowing gravity to do most of the work, similar to the way a teeter-totter works. A motor in the control room turns the pulley. When the pulley is turned one way the elevator parts goes up; when it is turned the other way the elevator goes down.
Control Systems