Cable Transport Variable Gear Drive for Rapid Braking
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Solution Overview
Problem
Cable transportation systems face challenges in increasing passenger-carrying capacity due to the risk of collision at turnaround stations, where the existing mechanical drives fail to rapidly stop transportation units, leading to long braking distances and limited capacity enhancement.
Innovation Solution
A cable transportation system with a mechanical gear drive having two degrees of freedom, controlled by a variable velocity ratio signal from a control device, allows for rapid braking and repositioning of transportation units, utilizing an epicyclic gear train and electric motor to manage the motion along curved paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a mechanical drive with clutch is used to move transportation units along the second path, then the transportation units can be accelerated and decelerated, but the braking distance becomes long and collision risk increases
Solution Approach 1:
The patent applies a variable velocity ratio mechanism that dynamically adjusts the speed ratio between the first and second portions based on real-time distance measurements. When transportation units are close together, the system automatically reduces the velocity ratio to slow down the second portion, preventing collision. This dynamic adjustment transforms the static mechanical drive into an adaptive system that responds to changing operational conditions.
Solution Approach 2:
The patent implements a feedback control system where the control device continuously monitors the distance between transportation units and adjusts the velocity ratio of the mechanical drive accordingly. The feedback loop closes when the distance falls below a threshold, automatically reducing the velocity ratio to prevent collision. This feedback mechanism ensures safe operation without requiring manual intervention.
2Reliability
If the velocity ratio is fixed in the mechanical drive, then the structure is simple, but the system cannot rapidly stop the transportation units to prevent collision
Solution Approach 1:
The patent transforms the fixed velocity ratio mechanism into a variable one, allowing the speed ratio between portions to be dynamically adjusted based on operational needs. This enables rapid stopping capability when collision risk is detected, while maintaining mechanical simplicity through the use of a single motor driving both portions through the variable ratio mechanism.
Solution Approach 2:
The patent changes the velocity ratio parameter of the mechanical drive from a fixed value to a variable value that can be adjusted in real-time. By modifying this key parameter based on distance measurements, the system achieves rapid stopping capability without adding multiple motors or complex control systems, thus balancing reliability improvement with structural simplicity.
3Speed
If multiple motors are used to drive the first and second portions separately, then the braking performance improves, but the cost and complexity increase significantly
Solution Approach 1:
The patent makes a single motor serve multiple functions by using it to drive both the first portion (acceleration) and the second portion (deceleration) through a variable velocity ratio mechanism. This multi-functional approach eliminates the need for separate motors for each function, reducing system complexity and cost while maintaining effective braking performance through the dynamic adjustment of the velocity ratio.
Solution Approach 2:
The patent merges the driving functions of the first and second portions into a single motor system. Instead of using separate motors for acceleration and deceleration, the invention combines these functions into one integrated drive system with a variable velocity ratio mechanism, thereby reducing the number of components, lowering costs, and simplifying the overall system architecture while preserving braking performance.
4Productivity
If the distance between transportation units is reduced to increase passenger-carrying capacity, then productivity improves, but the risk of collision at the turnaround station increases
Solution Approach 1:
The patent uses a feedback control system that continuously monitors the distance between transportation units and automatically adjusts the velocity ratio of the mechanical drive to prevent collision. This feedback mechanism allows the system to operate with reduced spacing between units (increasing productivity) while automatically maintaining safety through real-time distance-based control adjustments.
Solution Approach 2:
The patent applies a dynamic velocity ratio adjustment mechanism that responds in real-time to the spacing between transportation units. When units are positioned closer together (to increase capacity), the system automatically reduces the velocity ratio of the second portion to prevent collision. This dynamic adaptation enables higher productivity through closer spacing while maintaining safety through automated speed control.
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 enables rapid stopping and precise positioning of transportation units, reducing the distance between them and enhancing passenger-carrying capacity without the high costs associated with multiple motors or inefficient clutch systems.
Implementation Method 1
a mechanical gear drive with two degrees of freedom having a velocity ratio selectively variable as a function of a signal emitted by the control device and correlated to the distance between the transportation units
Implementation Method 2
The mechanical drive comprises a mechanical gear drive with two degrees of freedom
Implementation Method 3
Being driven frictionally by the rollers, the distance between the transportation units may vary
Data Source
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AI summary
A cable transportation system (1) having a cable (2) moved along a first path (P1); a number of transportation units (3) connectable selectively to the cable (2); a turnaround station (4) having a transportation device (5), which is equipped with positively-driven rollers (16) extending along a second path (P2) at the turnaround station (4) to move the transportation units (3) detached from the cable (2), and has a first portion (10; 13) for accelerating or decelerating the transportation units (3), and a second portion (11; 12) adjacent to the first portion (10; 13) and driven by the first portion (10; 13) via a mechanical drive (15) having a velocity ratio selectively variable as a function of a signal emitted by a control device (6) for monitoring the distance between the transportation units (3).