Modular Roller Chain Newel for Escalator Handrail Tensioning
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Solution Overview
Problem
The existing solutions for maintaining tension in moving handrails over curved newels on passenger conveyors, such as escalators, are inefficient and costly due to the complexity of manufacturing and the limited lifetime of roller bearing and newel guide assemblies, which require frequent replacement.
Innovation Solution
A handrail assembly using a roller chain with interlinked chain units, each equipped with a frame, roller bearings, and hook-and-loop connectors, along with a spring to maintain tension, allowing for modular assembly and repair by replacing individual chain units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If roller bearings are retained in a newel guide that matches the profile of the curved newel, then the handrail can move over the curved newel, but the manufacturing complexity increases and the assembly cannot be easily repaired
Solution Approach 1:
The roller bearing assembly is divided into modular chain units that can be independently manufactured and assembled. Each chain unit contains roller bearings that can be separately replaced, eliminating the need to manufacture and replace the entire newel guide assembly. This segmentation resolves the contradiction by maintaining operational functionality while reducing manufacturing complexity and improving repairability.
Solution Approach 2:
The roller bearings are designed to be movable within the chain units, allowing them to dynamically adjust to the curved newel profile during operation. This dynamic design enables the handrail to move smoothly over the curved newel while the roller bearings self-adjust, reducing the need for complex fixed-profile newel guides.
2Reliability
If roller bearings are pinned into holes drilled into the newel guide, then the bearings are retained in position, but the manufacturing process becomes more difficult and quality suffers
Solution Approach 1:
The assembly is segmented into chain units with integrated bearing retention mechanisms. Instead of drilling holes into a complex newel guide, each chain unit has simple holes that are easier to manufacture with consistent quality. The modular design allows these simple components to be assembled into the complete retention system.
Solution Approach 2:
Multiple identical chain units are used instead of a single complex newel guide. Each chain unit is a simplified copy that performs the same bearing retention function, making manufacturing easier and quality more consistent while maintaining reliable bearing retention through the distributed modular system.
3Reliability
If the entire roller bearing and newel guide assembly is replaced when bearings wear out, then reliable operation is restored, but replacement cost and downtime increase
Solution Approach 1:
The roller bearing assembly is segmented into replaceable chain units. When bearings wear out, only the affected chain units need to be replaced rather than the entire assembly. This segmentation dramatically improves replacement efficiency and reduces downtime while maintaining operational reliability through targeted replacement of worn components.
Solution Approach 2:
The modular chain unit design enables selective discarding of only the worn bearing components within specific chain units, while recovering and retaining the rest of the assembly. This approach improves productivity by avoiding unnecessary replacement of functional components and reducing overall replacement costs.
4Reliability
If a spring is used to provide tension to the roller chain, then contact between the roller and handrail belt is maintained, but the system becomes more complex
Solution Approach 1:
The spring provides automatic self-tensioning to the roller chain, maintaining reliable contact between the roller and handrail belt without requiring external tensioning mechanisms or complex adjustment systems. The spring's elastic properties enable it to self-adjust and maintain optimal tension, resolving the contradiction by improving reliability through a simple, self-regulating mechanism.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution simplifies the assembly and repair of the handrail system, reducing manufacturing complexity and replacement costs by enabling the replacement of only damaged chain units, thus extending the lifespan of the assembly.
Implementation Method 1
a spring connected between a first end of the roller chain and the newel guide to provide tension to the roller chain
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A roller bearing and newel guide assembly (30) for a newel (24) in an escalator (10) has a newel guide (32), a roller chain (34), and a spring (40) connected between the roller chain (34) and the newel guide (32) to provide tension to the roller chain (34). The roller chain (34) comprises a series of interlinked chain units (36). Each chain unit (36) includes a frame (78), at least one roller bearing (72), and a pin (76) for connecting the roller bearing (72) to the frame (78). Each chain unit (36) has a female connector (62) and a male connector (64), which allow each chain unit (36) to connect to an adjacent chain unit (36) to form the roller chain (34).