Medium Feeding Device Torque Limiting Mechanism
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Solution Overview
Problem
Conventional medium feeding devices face challenges in reliably separating media at high conveying speeds due to the inertia of electromagnetic brakes, leading to potential paper feed failures and double feeds when handling media with varying friction characteristics.
Innovation Solution
A medium feeding device with a rotational load generating unit comprising a first torque limiter and a second torque limiter in series, connected to a brake roller, and an electromagnetic clutch that switches between the power transmission path and a bypass route, allowing for rapid adjustment of rotational load to prevent double feeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electromagnetic brake with large inertia is used to change the rotational load, then the rotational load can be controlled to prevent double feeds, but the response time deteriorates at high medium conveying speeds
Solution Approach 1:
The power transmission path is segmented into multiple stages with two torque limiters (first and second) arranged in series. The switching unit can selectively connect or disconnect the second torque limiter from the power transmission path, creating distinct operational modes: a first rotational load mode when the second torque limiter is connected, and a second rotational load mode when it is disconnected. This segmentation allows rapid switching between different torque characteristics without the inertia limitations of electromagnetic brakes.
Solution Approach 2:
The system dynamically adjusts the rotational load characteristics by switching between two predetermined torque values (first predetermined torque and second predetermined torque) based on operational requirements. The switching unit enables real-time reconfiguration of the power transmission path, allowing the brake roller to generate appropriate rotational load promptly at high conveying speeds without being constrained by electromagnetic brake inertia.
2Productivity
If the medium conveying speed is increased to improve productivity, then business efficiency increases, but the separation performance deteriorates due to insufficient rotational load response
Solution Approach 1:
The system pre-configures two distinct rotational load characteristics through the two torque limiters, allowing the brake roller to immediately assume the appropriate torque level when switching is required. This preliminary preparation of torque settings eliminates the response delay that would otherwise occur at high conveying speeds, ensuring separation performance is maintained even as productivity increases through higher medium conveying speeds.
3Device complexity
If a single torque value is used for the brake roller, then the device structure is simplified, but it cannot adapt to different media with varying friction characteristics
Solution Approach 1:
The brake roller is designed with multi-functionality through the switching unit that can connect to either the first torque limiter or the second torque limiter. This allows a single brake roller to serve multiple functions: generating a first rotational load for media requiring higher separation force, and generating a second rotational load for media requiring lower separation force. The switching unit enables this versatility without requiring multiple separate brake mechanisms, thus maintaining relatively simple device structure while achieving broad media adaptability.
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 enables reliable separation of media at higher conveying speeds by reducing the influence of inertia, ensuring effective separation of the target medium from others, even when using media with different friction characteristics, thus enhancing operational efficiency and preventing paper feed failures.
Implementation Method 1
a first torque limiter that is directly connected to the brake roller and generates a load of a first predetermined torque based on driving power generated by a driving source
Implementation Method 2
a second torque limiter that is arranged in series with the first torque limiter on a power transmission path along which the rotational load is transmitted to the brake roller, and that generates a load of a second torque smaller than the first torque
Implementation Method 3
The rotational load generating unit further includes a switching unit that is connected to the first torque limiter side rather than the second torque limiter side on the power transmission path and switches between connection and disconnection between the power transmission path and a bypass route which bypasses the second torque limiter
Implementation Method 4
a brake roller arranged to be in pressure contact with the feeding roller, and a rotational load generating unit that is connected to the brake roller and causes the brake roller to generate a rotational load in a direction counter to the conveying direction
Data Source
AI summary
A medium feeding device 1 includes a separating power generating device 7 which causes a brake roller 4 to generate a rotational load in a direction counter to a conveying direction. The device 7 includes a torque limiter 17 which generates a load of a predetermined upper limit torque T1, a torque limiter 18 which is arranged in series with the torque limiter 17 on a power transmission path to the brake roller 4 and generates a load of an upper limit torque T2 smaller than the torque T1, and an electromagnetic clutch 22 which switches between connection and disconnection between the power transmission path and a bypass route which bypasses the torque limiter 18. The device 7 can change the rotational load of the brake roller 4 to the torque T1 or the torque T2 by the switching of the electromagnetic clutch 22.