What safety hazards does escalator roller failure bring?- Ningbo Yinzhou Fukangda Elevator Parts Factory

1. Common types of roller failure

Mechanical failure

Bearing stuck: Insufficient lubrication or foreign matter intrusion causes damage to the rolling element and the roller cannot rotate.

Rim wear: Long-term friction causes the rim to become thinner or cracked, and loses its guiding function.

Aging of rubber/polyurethane: Surface cracking and hardening, and reduced shock absorption performance.

Functional failure

Eccentric operation: Wear of the bushing causes the roller to shake, causing the step to deviate.

Abnormal noise: Damage to the bearing or deformation of the wheel body produces a harsh friction sound.

Step derailment or sudden stop

Risk scenario:

When the guide wheel fails, the step may derail, causing passengers to fall.

The drive wheel slips or gets stuck, and the escalator stops suddenly, causing passengers to fall by inertia.

Step jitter and abnormal gap

Risk manifestation:

Worn rollers make the steps run unsteadily and produce obvious vibrations.

The gap between the steps increases (>4mm), which may pinch shoes or children's fingers.

Standard requirements:

GB 16899-2011 stipulates that the step gap must be ≤4mm and the vertical jitter must be ≤0.5mm.

Fire risk (rare but serious)

Causes:

The dry friction between the metal roller and the guide rail produces high-temperature sparks, which ignites grease or dust.

Polyurethane wheels overheat and carbonize, releasing toxic fumes.

Daily inspection points

Symptoms	Possible failure components	Emergency treatment measures
Abnormal noise (metal friction sound)	Bearing damage/wheel deformation	Stop for inspection, replace bearings or rollers
Steps swaying left and right	Guide wheel wear or eccentricity	Adjust wheel width or replace wheel set
Escalator running jams	Drive wheel slipping or insufficient lubrication	Clean the track and add grease

Professional testing tools

Vibration analyzer: detects the degree of bearing wear (replacement is required when the vibration value is greater than 7.1mm/s).

Infrared temperature gun: there is a risk of overheating when the wheel body temperature is greater than 70℃.

Inspection frequency

Daily (applicable to high-frequency use places, such as subways and shopping malls):

Observe whether the roller rotates flexibly and whether there is any abnormal noise.

Check whether the steps run smoothly and whether there is obvious shaking.

Weekly (applicable to ordinary commercial escalators):

Check whether there are cracks, deformation or abnormal wear on the roller surface.

Clean the dust and oil around the guide rails and rollers to prevent impurities from accelerating wear.

Key inspection areas

Roller type	Inspection content	Abnormal performance
Step wheel	Rim thickness, bearing rotation	Rim wear > 20%, rotation jam
Guide wheel	Contact surface between wheel body and guide rail	Surface peeling, eccentric shaking
Drive wheel	Tooth surface wear, lubrication status	Tooth deformation, grease drying

Lubricant selection

Bearing lubrication: high viscosity lithium-based grease (temperature range -30℃~120℃).

Guide lubrication: synthetic lubricant (low dust absorption, such as ISO VG 68).

Lubrication cycle and method

Lubrication parts	Frequency	Operation method
Roller bearings	Every 3 months	Remove the roller, clean the old grease and add new grease (the amount of grease added accounts for 60% of the bearing cavity)
Guide contact surface	Every month	Use a brush or automatic lubrication system to apply evenly
Drive sprocket	Every 6 months	Remove the old grease and apply high temperature resistant grease