Explain Escalator

Explain Escalator

To explain escalator components one must understand the purpose of handrails, step, handrail drive, electric motor, drive gear, chain guide, return wheel and inner rail.

An escalator which travels at a speed of 145 feet per minute will transport up to 10,000 people an hour. Escalator speed can vary from 90 feet per minute to as high as 180 feet per minute.

An escalator system consists of a pair of chains which drive two pairs of gears which is driven by an electric motor which turns the drive gears at the top which rotate the chain loops. A normal escalator makes use of a 100 horsepower to move the gears.

The motor and chain system are contained what is known as a truss which is a metal structure which extends between the lower and upper floors served by the escalator.

The escalator chain loops drive a number of steps on an incline unlike a conveyor belt which operates in a flat plain. It is advantageous that the steps as they move always stay levels and at the top and bottom the steps collapse creating a flat platform which makes it easier to access on and off the escalator.

There are two sets of wheels for each step which move along two separate tracks. The upper set (the wheels near the top of the step) are connected to the rotating chains, and so are pulled by the drive gear at the top of the escalator. The other set of wheels simply glides along its track, following behind the first set.

The spacing of the tracks ensures that each step will always remain level. At the top and bottom of the escalator, the tracks level off to a horizontal position, flattening the stairway. Each step has a series of grooves in it, so it will fit together with the steps behind it and in front of it during this flattening.

The electric motor in an escalator rotates the main chain loops and as well causes the hand rails to move. The handrails consist of a rubber conveyor belt that is looped around a series of wheels.

The belt is designed that it moves at equal speed as the steps and this provides stability for the riders.

An escalator will move many people short distances much more effectively than will elevators and this is known as a high loading rate. Also the continuous loading of people allow for the much increased loading rate.

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