Passenger Conveyor Support Reinforcement for Earthquake Moment Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional passenger conveyor systems are prone to cracking and deformation due to increased building shake amplitudes caused by earthquakes, as the additional frame receives support reaction forces beyond the conventional support angle, leading to higher moments around the base corner of the support angle.
Innovation Solution
A passenger conveyor system with a support reinforcement part that includes a connection portion fixed to the support angle, a building-side extension portion along the floor face, and a main-frame-side extension portion along the upper face of the main frame, where the main-frame-side extension portion is not fixed to the main frame, allowing it to touch the upper face in case of increased support reaction forces, thereby reducing the moment around the base corner of the support angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the disposition margin length of the support angle is increased to comply with post-revision earthquake standards, then the reliability of the passenger conveyor is improved, but the moment acting around the base corner of the support angle becomes larger, causing the main frame to crack or deform
Solution Approach 1:
The support reinforcement part is divided into three functional segments: a connection portion fixed to the support angle, a building-side extension portion that contacts the building structure, and a main-frame-side extension portion that contacts the main frame. This segmentation allows each part to perform its specific function independently, distributing the earthquake loads and reducing the moment on the support angle base corner.
Solution Approach 2:
The support reinforcement part acts as an intermediary structure between the support angle and the main frame. It transfers and distributes the support reaction forces from the building structure through its extension portions, preventing these forces from creating excessive moments at the support angle base corner that would otherwise crack or deform the main frame.
2Reliability
If an additional frame is added to extend the support angle to comply with post-revision earthquake standards, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The support reinforcement part merges multiple functions into a single integrated component: it provides structural extension to achieve the required disposition margin, offers fixed connection to the support angle for force transfer, and creates contact with the main frame for moment reduction. This consolidation achieves the same reliability improvement as an additional frame but with simpler overall structure.
Solution Approach 2:
The support reinforcement part serves multiple functions simultaneously: it extends the effective support length to meet earthquake code requirements, transfers loads from the building structure, and reduces moments at the support angle base corner. This multi-functionality eliminates the need for separate additional frames while achieving the same reliability improvement.
3Strength
If the main-frame-side extension portion is not fixed to the main frame, then the moment around the base corner of the support angle is reduced, but the stability of the connection is worsened
Solution Approach 1:
The connection between the main-frame-side extension portion and the main frame transitions from a fixed rigid connection to a dynamic contact connection. This allows the extension portion to move relative to the main frame during earthquakes, enabling the contact mechanism to function properly in reducing moments while maintaining connection stability through controlled interaction.
Solution Approach 2:
The non-fixed contact design provides a cushioning effect by allowing controlled movement and contact between the extension portion and the main frame. This prevents rigid force transmission that would create excessive moments, while the contact itself provides stability when needed, effectively cushioning the system against harmful dynamic loads.
Data Source
AI summary
A passenger conveyor includes a main frame, a support angle at an end in a longitudinal direction of the main frame and which is to be disposed on a building structure; and a support reinforcement part. The support reinforcement part includes a connection portion which is fixed to the support angle, a building-side extension portion which is extended from the connection portion along a floor face of the building structure, and a main-frame-side extension portion which is extended from the connection portion along an upper face of the main frame. In a case where the building-side extension portion of the support reinforcement part is in contact with the building structure, and the support angle is not in contact with the building structure, at least one portion of the main-frame-side extension portion is able to touch the upper face of the main frame.