How The Elevator Works By Joseph Mackay Plaxco The University of the South Sewanee, TN 37383
Why? • I find the elevator “cool.” • Phobia when younger • Gets people to destinations fast. • Large cities wouldn’t be the same.
Different Types • Freight Elevators • Stage Elevators
The Basic Design • The basic design is a compartment that is somehow lifted • Two Types of Elevators: • Hydraulic • Rope-Geared
The Hydraulic Elevator • The car is moved up and down using “a fluid piston mounted inside a cylinder” (Harris). • Consists of three parts: • Tank • Pump • Valve
Hydraulic ElevatorsA Closer Look • The car is placed on a piston. • Fluid Pumping System • A tank (off to the side) holds the fluid. • When the valve closes, the car is lifted. • When the valve opens, the car is lowered.
Diagram of Hydraulic Elevator • The following link is from the website “How Stuff Works” written by Tom Harris. • How Elevators Work - Hydraulic
Hydraulic Disadvantages • Two Disadvantages • Must Have Enough Room • Energy Inefficient
Rope-Geared Elevators • These are the most popular types of elevators. • Rather than being pushed from below, these types of elevators are moved using cables
Rope-Geared Design • Cables attach to the car and through a sheave. • The sheave is connected to an electric motor. • Motor turns one way, elevator moves up. Motor turns the other way, elevator moves down. • The ropes are connected to a counterweight. • The counterweight system serves as a means for conserving energy.
Rope-Geared Design (Cont’d) • Rails are used to guide the elevator • Keep elevator and counterweights steady. • Rope-geared elevators are much more efficient and safer.
Diagram of Rope-GearedElevator • The following link came from the “How Stuff Works” webpage written by Tom Harris • Rope-Geared Elevator Diagram
Safety Systems • More ropes than needed • Built-in brake systems • Governor prevents the elevator from falling to the bottom of the shaft. Centrifugal force causes a brake system to activate. • Also has an electromagnetic brake that is activated if the elevator loses power. • Automated Brake System at the top and bottom of the shaft.
Moving To Destinations • Modern elevators use computers. • Slows down • Only answer “up calls” as going up and the same for going down. • Modern “Smart” systems take into account the busiest parts of the day. • Press the floor you want in the lobby. • Load Sensor
Works Cited • Harris, Tom. “How Elevators Work”. www.howstuffworks.com/elevator 2002.