Escalator

A fixed, electrically powered device with a circular motion that transports passengers upward or downward.

It must comply with the requirements of GB 16899-2011, "Safety Specification for the Manufacture and Installation of Escalators and Moving Walkways."

Features of escalators

Escalators are used in department stores, supermarkets, office buildings, hotels, airports, and urban transportation, offering the following advantages:

1) They have a greater capacity than elevators, allowing them to transport large numbers of people in a short period of time!

2) Because they operate continuously, passengers don't have to wait.

3) Because they operate in one direction, the direction of travel can be planned naturally.

4) They allow for easy boarding and alighting, eliminating the burden of climbing stairs.

5) They are aesthetically pleasing and serve as a decorative feature of buildings.

Escalator Classification Escalators can be classified based on the type of handrail, effective width, lifting height, and shape.

Railing Type Classification

a.Transparent Escalator: The railing is glass, allowing for viewing through the escalator. Available with or without lighting. (NL, N, EN)

b. Paneled Escalator: The railing's siding is primarily constructed of stainless steel or painted steel.

Application Classification:

a. General Escalator: A standard escalator. b. Public Transportation Escalator: An escalator designed for public transportation facilities such as stations, with adjustable speeds. To enhance transportation capacity and ensure passengers reach their destination as quickly as possible, the escalator's operating speed must be increased. Specific measures have been taken to ensure passenger safety and escalator durability. (This escalator is part of a public transportation system, including entrances and exits. It operates approximately 140 hours per week and must be continuously loaded for at least 0.5 hours within any 3-hour interval, at 100% of the braking load.)

c. Outdoor Escalator: An escalator designed to protect against the effects of outdoor rain and direct sunlight. The escalator's protection level, including rust prevention for all components, the main unit, and safety devices, is specifically designed for these applications Specially designed.

Effective Width Classification

Categories include 800, 1000, and 1200 types. This refers to the effective width between railings at a vertical height of 600mm from the step surface.

Lift Height Classification

Standard-height escalators: generally refer to escalators with a lift height of 6.5m or less.

High-height escalators: generally refer to escalators with a lift height between 6.5m and 13m (1200 model).

Ultra-high-height escalators: refer to escalators with a lift height exceeding 13m.

Shape Classification:

Standard Escalators: Transparent standard escalators are generally used in shopping malls, department stores, hotels, and other places where appearance is important. Paneled standard escalators are used in stations and transportation facilities where capacity is important.

b. Special Escalators: Intermediate Horizontal Escalators and Horizontal Extended Travel Escalators.

Escalator mechanical structure

The mechanical structure of the escalator includes trusses, three main machines (working brakes and additional brakes), ladder guide rail system, railings (aprons and apron anti-pinch devices, inner and outer covers, wall panels), handrails, step chains, steps, combs and support plates (front plates), inspection covers and floor plates (bed covers), etc.

Truss

The escalator's truss supports the entire structure's weight, exterior, and passenger loads, ensuring the fixed position of the drive unit, handrails, and guide rails, while maintaining their relative positions. The escalator's truss is constructed from welded angle steel. The load for escalator support structure design is: the weight of the escalator or moving walkway plus a load of 5000 N/m². The maximum deflection calculated or measured based on a load of 5000 N/m² should not exceed 1/750 of the support distance L1. For public transportation escalators and moving walkways, the maximum deflection calculated or measured based on a load of 5000 N/m² should not exceed 1/1000 of the support distance L1.

Escalator guide rail system

Escalator rail system

The rail system consists of upper and lower deflecting rails and an intermediate linear guide system. The geometric relationships between the guide rails and return rails in the upper and lower deflecting rail systems are complex. To accurately control the dimensions of each rail, the guide rails and return rails on the same side are fixed to a single side plate, forming a single assembly. The upper and lower deflecting rail systems are equipped with deflecting walls at their ends to allow the steps and step chains to rotate. The lower deflecting wall is movable and works with a tension adjuster to adjust the step chain tension.

The escalator rails ensure a regular movement of the steps to prevent them from deviating and withstand the loads transmitted from the main and secondary step pulleys. They feature a smooth, flat, and wear-resistant working surface. To reduce the pressure on the guide rails and extend the life of the step rollers, the upper and lower guide rail operating radii are 2000mm and 1500mm, respectively. The upper and lower turning guide rails are rolled from 10T, 8T, and 15T cold-drawn flat steel. The intermediate guide rails are made from 2.5T steel plates with a galvanized surface. Guide rail support plates are used to secure the metal structure.

Escalator railing

Interior panel

The panel located between the apron panel (or inner decking) and the handrail decking (or handrail rail).

Inner decking

The component connecting the apron panel and the handrail decking when they do not intersect.

Outer decking

The component connecting the outer decking and the handrail decking.

Skirting

The vertical portion of the handrail assembly adjacent to the steps, treads, or belts.

Skirt deflector

A device that reduces the risk of pinching between the steps and the apron panel.

If glass is used for the skirting, it should be tempered glass. The minimum thickness of single-layer glass should be 6mm. If multiple layers of glass are used, it should be laminated tempered glass, and at least one layer should have a thickness of 6mm. The thickness should not be less than 6mm.

Escalator apron anti-pinch devices

Composed of rigid and flexible components (e.g., brushes, rubber profiles), the protrusion from the vertical surface of the apron should be a minimum of 33mm and a maximum of 50mm. A force of 900N applied perpendicular to the rigid component's connection line and uniformly applied over a 6cm² rectangular area should not cause detachment or permanent deformation.

The rigid component should have a horizontal protrusion of 18mm to 25mm and meet specified strength requirements. The horizontal protrusion of the flexible component should be a minimum of 15mm and a maximum of 30mm.

On inclined sections, the vertical distance between the lowest edge of the rigid component of the apron anti-pinch device and the line connecting the leading edge of the step should be between 25mm and 30mm.

Handrails

Handrails are components on both sides of escalators and moving walkways that provide passenger safety and provide a convenient place for passengers to stand and hold onto. Handrails should not have any areas where people can stand normally. Handrails are powered moving handrails for passengers to hold onto while using escalators or moving walkways. The handrails' movement is controlled by handrail guide rails fixed to the handrails. The handrails' guidance and tensioning should prevent them from dislodging from the handrail guide rails during normal operation.

The handrails' driving force is provided by the main drive shaft, which rotates the handrail drive shaft. The handrails on both sides are pressed against the handrail friction wheels by the handrail pressure pulley assembly. The friction between the handrail friction wheels and the handrails allows the handrails to move at a high degree of synchronization with the step speed in the same direction. The handrail cross-section and the formed assembly of the handrail guide rails should be designed to prevent fingers or hands from being pinched. The distance between the handrail opening and the guide rail or handrail support should not exceed 8 mm in any case. The handrail width b2 should be between 70 mm and 100 mm.

Step Chain

The step chain primarily consists of a step pulley, inner and outer chain plates, a special-shaped cylindrical pin, and a sleeve. One chain is installed on each side of the step, connected by the step shaft, and together they pull the steps. The step chain is tensioned by a tensioner at the turning wall of the lower turning guide system to absorb any elongation of the step chain due to wear and other factors.

Escalator steps should be driven by at least two chains, one on each side.

The steps are a special four-wheeled carriage with two main wheels and two secondary wheels. The main wheels are hinged to the step chain, while the secondary wheels are fixed to the steps. All steps run on a regularly arranged guide rail. On the upper branch of the escalator, the steps remain horizontal, while on the lower branch, they can be inverted.

Steps

Lower turning section guide rail system with turning wall opening

The steps are fixed to the step shaft and can be easily removed from the lower machinery compartment without removing the step shaft or railing. This provides excellent interchangeability and facilitates maintenance. Furthermore, the escalator can be operated and maintained even without the steps installed.

Clearance between steps, treads, and apron panels: The apron panels of an escalator or moving walkway are located on both sides of the steps, treads, or conveyor belt. The horizontal gap on any one side should not exceed 4mm, and the total gap measured symmetrically on both sides should not exceed 7mm. If the apron panels of a moving walkway are located above the treads or conveyor belt, the vertical gap between the tread and the bottom of the apron panel should not exceed 4mm. Lateral movement of the treads or conveyor belt should not create a gap between the side edge of the treads or conveyor belt and the vertical projection of the apron panel.

Drive Unit

A single drive unit should not drive more than one escalator or moving walkway. Service Brake

Escalators and moving walkways should be equipped with a braking system that brings the escalator or moving walkway to a near-uniform stop and maintains the vehicle in that stopped state (service brake). The braking system should operate without intentional delay. After the escalator or moving walkway is started, a device should monitor the release of the brake system.

Escalator safety device

Step Chain Break Protection Device: If the step chain overextends or breaks, the escalator stops. The safety switch is manually reset after the fault is corrected.

The handrail entrance protection device stops the escalator when an object is caught in the handrail entrance. The safety switch automatically resets when the fault is eliminated.

Emergency Stop Button

The emergency stop button on the control box at the escalator entrance can immediately stop the escalator in an emergency.

Skirt Guard

If an object becomes trapped between the step and the skirt, the escalator stops. The safety switch automatically resets when the fault is resolved.

The step safety device stops the escalator if a step sinks, deforms, or breaks. The safety switch is manually reset after the fault is eliminated.

The comb protection device stops the escalator if a foreign object carried by the steps enters the comb teeth and may damage them. The safety switch automatically resets when the fault is eliminated.

The non-operational reversal protection device stops the escalator when it suddenly reverses direction without human intervention (power grid phase reversal, overload, drive chain break, etc.).

When the escalator speed exceeds or falls below the rated speed, the escalator stops running.

Drive chain break protection device stops the escalator when the drive chain is overstretched or broken. The safety switch is manually reset after the fault is eliminated.

The motor brake detection switch is installed on the brake support plate to prevent the motor from starting before the brake is fully released.

Maintenance and repair stop switches should be installed at both the drive station and the turn station. Actuation of the stop switch should disconnect the power supply to the drive unit, apply the service brake, and effectively stop the escalator or moving walkway. Actuation of the stop switch should prevent the escalator or moving walkway from starting. The stop switch should have clear and permanent markings for the on and off positions. The emergency stop device should be red and labeled "Stop" on or adjacent to the device.