Escalator Drive Chains and Step Chains
At the heart of every public transportation system in shopping malls, metro stations, and train stations is the transmission system. To ensure continuous operation and handle multi-passenger loads without leading to sudden failures and downtime, it is essential to use reliable components. In our wholesale offer for lift companies, we provide top-quality escalator drive chains and traction ropes without which the movement of platforms would be impossible. Each certified step chain for escalators available at MPPR guarantees maximum resistance to static and dynamic stretching, while meeting stringent standards set by the Office of Technical Inspection (UDT).
Escalator Chains - FAQ
The main drive chain is a transmission component that transfers torque from the engine and reducer to the main shaft of the machine. In turn, the step chain of movable stairs is the central load-bearing element of the entire belt - the steps are directly attached to it, allowing them to move cyclically from platform to platform along the track.
Replacement is necessary when the total elongation of the chain exceeds the limit values specified in the manufacturer's DTR (usually around 1-2% of the nominal length). Additionally, every step chain of movable stairs must be replaced in case of pin damage, detection of micro-cracks on side plates, or complete wear of interacting rollers.
Lubrication should be done regularly, preferably using automatic lubrication systems, with the use of dedicated oils of appropriate viscosity that penetrate the gaps between the pin and the bushing. Proper lubrication significantly extends the life of the system and prevents uneven and premature stretching of the tendons.
Definitely not. For safety and mechanical reasons, both multi-row drive chains for escalators and the left and right step chains for escalators must always be replaced in pairs and form a set from the same production batch. Installing one new chain and one used chain will immediately cause steps to skew and machine destruction.
To precisely select a step chain for escalators or a drive chain, you need to provide the pitch (distance between pin centers), roller diameter (if applicable), inner width between link plates, and the total number of links required to close the circuit in the specific device. It is also safest to provide the manufacturer's catalog number for the particular elevator.
Construction Differences: Drive Chains vs. Escalator Step Chains
For engineers and service technicians, distinguishing between these two key systems is fundamental for correctly diagnosing the equipment. From a technical standpoint, the machine is based on two separate closed circuits of steel cables:
- Main Drive Chains for Escalators: This is a short, robust, often two- or three-row chain (Duplex / Triplex type), whose task is to directly transmit a huge torque from the electric motor shaft and the gearbox to the main drive shaft of the escalators. Its breakage poses an immediate risk of either the belt stopping or an uncontrolled descent (in case of auxiliary brake failure).
- Escalator Step Chain: This is a load-bearing system of immense length, running along both sides of the entire track (from the entrance comb plate to the upper machine room). The bodies of individual steps are rigidly attached to this chain. It supports the weight of all transported persons.
Why is the quality of the Escalator Step Chain important?
The primary issue in the operation of continuous drives is the phenomenon of cable elongation due to the wearing of pins and bushings inside the links. Cheap, uncertified steel used in low-quality substitutes accelerates this process. When the Escalator Step Chain undergoes excessive stretching (beyond critical 1-2% of its length), it begins to damage the gear wheels of the main shaft and the steps lose their ideal geometry relative to the comb plates, posing a risk of catastrophic body collisions and comb breakages. Therefore, we supply only specially hardened drive chains for escalators with chrome-plated pins or subjected to carbonitriding, significantly reducing internal friction.
When should the service replace the chain system?
UDT inspectors and DTR procedures clearly define wear limits. It should be noted that both drive chains for escalators and each new escalator step chain must always be replaced simultaneously in pairs (left and right simultaneously, from the same production batch). Leaving one old chain and installing one new chain immediately causes the step to be set diagonally on the track, leading to loud operation, vibrations, and guide damage.
Order Precision Parts at MPPR
As a reliable B2B component supplier, we provide tailor-made solutions. We have a range fully compliant (O.E.M) with the requirements of market giants such as Otis, Schindler, Kone, ThyssenKrupp (TK Elevator), and O&K. Before ordering, prepare key parameters: chain pitch, roller diameter (if applicable), inner link width, pin diameter, and desired working length. We will help you select the perfect escalator step chain and gears for the repaired installation, ensuring the lowest rolling resistance and many years of trouble-free operation.