How The Elevator WorksHow The Elevator Works

By Joseph Mackay PlaxcoBy Joseph Mackay Plaxco

The University of the SouthThe University of the South

Sewanee, TN 37383Sewanee, TN 37383

Why?Why?

I find the elevator “cool.”I find the elevator “cool.” Phobia when youngerPhobia when younger Gets people to destinations fast.Gets people to destinations fast. Large cities wouldn’t be the same.Large cities wouldn’t be the same.

Different TypesDifferent Types

Freight ElevatorsFreight Elevators Stage ElevatorsStage Elevators

The Basic DesignThe Basic Design

The basic design is a compartment The basic design is a compartment that is somehow liftedthat is somehow lifted

Two Types of Elevators:Two Types of Elevators:• HydraulicHydraulic• Rope-GearedRope-Geared

The Hydraulic ElevatorThe Hydraulic Elevator The car is moved up and The car is moved up and

down using “a fluid piston down using “a fluid piston mounted inside a cylinder” mounted inside a cylinder” (Harris).(Harris).

Consists of three parts:Consists of three parts:• Tank Tank • PumpPump• ValveValve

Hydraulic ElevatorsHydraulic ElevatorsA Closer LookA Closer Look

The car is placed on a piston.The car is placed on a piston. Fluid Pumping SystemFluid Pumping System A tank (off to the side) holds the fluid. A tank (off to the side) holds the fluid. When the valve closes, the car is lifted. When the valve closes, the car is lifted. When the valve opens, the car is lowered. When the valve opens, the car is lowered.

Diagram of Hydraulic ElevatorDiagram of Hydraulic Elevator

The following link is from the website The following link is from the website “How Stuff Works” written by Tom “How Stuff Works” written by Tom Harris.Harris.• How Elevators Work - HydraulicHow Elevators Work - Hydraulic

Hydraulic DisadvantagesHydraulic Disadvantages

Two DisadvantagesTwo Disadvantages• Must Have Enough RoomMust Have Enough Room• Energy InefficientEnergy Inefficient

Rope-Geared ElevatorsRope-Geared Elevators

These are the most popular types of These are the most popular types of elevators. elevators.

Rather than being pushed from Rather than being pushed from below, these types of elevators are below, these types of elevators are moved using cablesmoved using cables

Rope-Geared DesignRope-Geared Design

Cables attach to the car and through a sheave. Cables attach to the car and through a sheave. The sheave is connected to an electric motor.The sheave is connected to an electric motor. Motor turns one way, elevator moves up. Motor Motor turns one way, elevator moves up. Motor

turns the other way, elevator moves down.turns the other way, elevator moves down. The ropes are connected to a counterweight. The ropes are connected to a counterweight. The counterweight system serves as a means for The counterweight system serves as a means for

conserving energy.conserving energy.

Rope-Geared Design (Cont’d)Rope-Geared Design (Cont’d)

Rails are used to guide the elevatorRails are used to guide the elevator Keep elevator and counterweights steady.Keep elevator and counterweights steady. Rope-geared elevators are much more efficient Rope-geared elevators are much more efficient

and safer.and safer.

Diagram of Rope-GearedDiagram of Rope-GearedElevatorElevator

The following link came from the The following link came from the “How Stuff Works” webpage written “How Stuff Works” webpage written by Tom Harrisby Tom Harris• Rope-Geared Elevator DiagramRope-Geared Elevator Diagram

Safety SystemsSafety Systems More ropes than neededMore ropes than needed Built-in brake systemsBuilt-in brake systems Governor prevents the elevator from falling to the Governor prevents the elevator from falling to the

bottom of the shaft.bottom of the shaft.Centrifugal force causes a brake system to Centrifugal force causes a brake system to

activate.activate. Also has an electromagnetic brake that is activated if Also has an electromagnetic brake that is activated if

the elevator loses power.the elevator loses power. Automated Brake System at the top and bottom of the Automated Brake System at the top and bottom of the

shaft.shaft.

Moving To DestinationsMoving To Destinations

Modern elevators use computers.Modern elevators use computers. Slows downSlows down Only answer “up calls” as going up and the same Only answer “up calls” as going up and the same

for going down.for going down. Modern “Smart” systems take into account the Modern “Smart” systems take into account the

busiest parts of the day.busiest parts of the day. Press the floor you want in the lobby.Press the floor you want in the lobby. Load SensorLoad Sensor

Works CitedWorks Cited

Harris, Tom. “How Elevators Work”.Harris, Tom. “How Elevators Work”.

www.howstuffworks.com/elevatorwww.howstuffworks.com/elevator

2002.2002.