Variable Deceleration Mechanism Prevents Motor Overrun in Banknote Handling
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Solution Overview
Problem
Existing banknote handling devices face challenges in accurately preventing misalignment of opening/closing members due to inertial forces, leading to durability issues and prolonged processing times, especially when correcting for overrun during high-frequency operations.
Innovation Solution
An illegal-act detecting mechanism with an opening/closing member, a rotary member, and a drive transmission mechanism that includes driven and driving pieces with a buffer member to control the rotation posture and prevent overrun, ensuring accurate positioning and reducing the need for reverse rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the deceleration section is set evenly for all devices, then the device complexity is reduced, but the manufacturing precision deteriorates due to part accuracy errors causing misalignment
Solution Approach 1:
The gear is designed with a variable deceleration section where the circumferential gap between the driving piece and driven piece changes during rotation. The gap is larger at the initial rotation position to accommodate part accuracy errors and prevent overrun, while being smaller at other positions for precise control. This dynamic variation in the deceleration profile resolves the contradiction by adapting to manufacturing tolerances without requiring complex adjustment mechanisms.
2Manufacturing precision
If reverse rotation is performed to correct overrun, then the stop position accuracy is improved, but the productivity deteriorates due to prolonged processing time
Solution Approach 1:
The deceleration section is designed to proactively prevent overrun before it occurs by creating a larger circumferential gap at the initial rotation position. This preliminary design feature allows the driven piece to be reliably positioned without exceeding the target position, eliminating the need for corrective reverse rotation actions and maintaining high processing speed.
3Manufacturing precision
If reverse rotation is repeated frequently, then the stop position accuracy is maintained, but the reliability deteriorates due to motor durability degradation
Solution Approach 1:
The variable deceleration section design proactively prevents overrun by providing a larger circumferential gap at the initial rotation position, eliminating the need for repeated reverse rotation operations. This preliminary preventive measure protects the motor from frequent bidirectional operation, thereby maintaining system reliability and motor durability while achieving accurate stop positioning.
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
The solution effectively prevents misalignment and reduces motor durability deterioration, while enhancing processing speed and efficiency by ensuring a sufficient deceleration section is maintained, thus preventing overrun and jamming.
Implementation Method 1
a buffer member that biases the driven piece and the driving piece in a direction away from each other
Data Source
AI summary
In an illegal-act detecting mechanism including an opening/closing member for detecting an illegal act and preventing pullout, at the time of stopping the opening/closing member at an initial rotation position, it is prevented that a stop position is deviated due to overrun by an inertial force of a motor. The illegal-act detecting mechanism includes an opening/closing member 50 that permits passage of a paper sheet at the initial rotation position, and blocks passage of the paper sheet at a non-initial rotation position deviated from the initial rotation position, a rotary member 70 that integrally rotates with the opening/closing member, a driving member 90 pivotally supported so as to be able to rotate relative to the opening/closing member, and a drive transmission mechanism 100. The drive transmission mechanism includes at least one driven piece provided in the rotary member, at least one driving piece that is provided in the driving member and intermittently drives and rotates the rotary member, and a buffer member 101 that biases the driven piece and the driving piece in a direction away from each other.