Article 47 -Lubrication of Escalators and Moving Walks

The Importance of Lubricating Escalators and moving walks

In this article, we intend to talk about escalator lubrication and its advantages in detail.

It is necessary to lubricate the mechanical parts of the escalators and moving walks. Lubrication helps the motion of components that are in contact and reduces the abrasion, heat, friction, wear, and noise. Without lubrication, the components would need more frequent maintenance, the risk of fire increase, and the lifecycle of components decrease.

Lubricants can be in different forms such as solid, liquid, grease, or gas. The lubricants used for escalators and moving walks are oil and grease. The viscosity of the lubricants is one of the important factors effective in lubrication. Viscosity refers to the internal friction of the liquid which causes its resistance against the flow.

Where and How to Lubricate Escalator and Moving Walks?

The parts of the escalators and moving walks that need to be lubricated are as below:

1. Main drive shaft bearing
2. Handrail drive shaft bearing
3. Tension carriage bearing
4. Drive chain
5. Handrail drive chain
6. Step chain
7. Worm gearbox
8. Motor brake Pin
9. There are two common ways to lubricate escalator parts:
10. Manual Lubrication
11. Automatic Lubrication

Manual lubrication is done by the technicians during the maintenance. In this type of lubrication, the technician applies lubricant to the parts of the escalator with appropriate tools. Manual lubrication is used for the parts lubricated by grease as well as gearbox and motor brake pin. The discharge amount and period of manual lubrication must comply with the factory instruction manual.

Today, most of the lubrication systems used for industrial applications are automatic and are programmed to lubricate components in periodic intervals without involving humans. Automatic lubrication, as the term implies, is lubricating the escalator components automatically through setting lubrication systems consisted of oil pumps that pump the oil through lubrication pipes to the brushes located on parts of the device which must be lubricated, and subsequently lubricating those parts. The drive chain, handrail drive chain, and step chain are the main parts of escalators and moving walks that should be lubricated automatically.

In addition, the lubrication pump must be able to operate at different temperatures from -20 °C to +60 °C and the capacity of the lubricant tank must be proportionate. The automatic lubrication pumps are equipped with a button used for manual lubrication. During the maintenance, the technicians must check the actuator button of the oil pump to make sure it works properly as well as checking the level of the oil in the tank.

Over-Lubrication and Under-Lubrication of Escalators and Moving Walks

One of the common problems concerning the lubrication of escalators and moving walks is applying a proper amount of lubricants to the components. Over-lubricating causes contamination in the escalator and makes the step surfaces dirty and slippery. Therefore, passengers might slip, fall, and get injured. Under-lubricating the escalator and moving walk leads to the friction and wear of the components and consequently a noisy operation.

To avoid over-lubrication and under-lubrication, the amount of discharged lubricant must be based on the standard and the requirements of the device. The discharge period is another effective factor in applying the right amount of lubricant. The discharge period of the automatic lubrication system for the device chains is controlled either by a PLC or a sensor.

To collect the dripping oils in the internal space of the escalator some drip pans must be considered to collect the excessive oil in the direction of movement. Also, the fully-outdoor escalator can be equipped with a water-oil separator device at the lower machine room that separates the excess oil and water room which enables the technician to clean the machine room from oil easily.

*In every inspection the oil tone must be checked and if the oil tone is light and same as that the normal oil tone no action is required, but if its tone is darker than the normal tone it must be changed.