Rotary Shaft Vibration Damping via Speed-Adaptive Movable Ring
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Solution Overview
Problem
Existing damping devices for shafts face challenges in effectively damping flexural vibration at critical speeds while minimizing friction and reducing response time, especially when rotation speeds differ from critical speeds.
Innovation Solution
A damping device with a movable ring and elastic means, including springs, that adjusts its position based on rotation speed, allowing minimal contact and friction at non-critical speeds and maximizing damping at critical speeds through sliding friction and oscillation, while quickly returning to a low-friction state when speeds decrease.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the shaft fits loosely through the ring opening when rotating outside critical speed, then friction between shaft and ring is minimized, but the damping effect at critical speed is reduced
Solution Approach 1:
The ring is made movable relative to the shaft, allowing it to dynamically adjust its position. When the shaft rotates outside critical speed, the ring moves to a first position where it does not contact the shaft, minimizing friction. When the shaft reaches critical speed, the ring moves to a second position where it contacts the shaft, providing damping effect. This dynamic adjustment resolves the contradiction between minimizing friction and maximizing damping.
2Reliability
If the ring contacts the shaft at critical speed to provide damping, then flexural vibration is reduced, but friction and energy loss increase at non-critical speeds
Solution Approach 1:
The ring alternates between two positions based on the rotation speed of the shaft. At non-critical speeds, the ring is in the first position (no contact). At critical speeds, the ring moves to the second position (contact). This periodic switching ensures damping is applied only when necessary, minimizing energy loss during normal operation while maintaining reliability when needed.
3Device complexity
If a fixed ring structure is used, then the structure is simple, but the response time to damping vibrations is slow
Solution Approach 1:
The ring is designed to be movable rather than fixed, allowing it to quickly respond to changes in shaft rotation speed. The ring can rapidly transition between the first and second positions as the shaft enters or exits the critical speed range, significantly reducing response time compared to a fixed structure.
4Loss of energy
If the ring is made movable to reduce friction at non-critical speeds, then energy loss is minimized, but device complexity increases
Solution Approach 1:
The ring automatically adjusts its position based on the shaft's rotation speed without requiring external control systems. The movable ring self-regulates by moving to the appropriate position (first or second) according to the vibration conditions, minimizing friction loss while avoiding the need for complex control mechanisms.
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 device effectively dampens flexural vibrations at critical speeds with reduced friction and rapid response time, ensuring stable shaft operation and easy maintenance due to its modular design.
Implementation Method 1
Device 1 comprises elastic means 18 interposed between supporting body 6 and ring 11
Implementation Method 2
sliding friction between the shaft and the damping device ring; which sliding friction opposes rotation and flexural vibration
Data Source
Figure 1
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AI summary
A damping device (1) for damping flexural vibration of a shaft (2) rotating about a first axis (A), the device having : a supporting body (6); and a member (11), which defines an annular opening (12) fitted through with the shaft (2), and is movable, with respect to the supporting body (6) and radially with respect to the first axis (A), between a first and a second position when the shaft (2) flexes radially with respect to the first axis (A). The member (11) is set to the first position, and the opening (12) is traversed loosely by the shaft (2) when the rotation speed of the shaft (2) is within a first range; the member (11) is set to the second position, and the opening (12) cooperates with the shaft (2), when the rotation speed of the shaft (2) is within a second range differing from the first range and including at least one critical speed of the shaft (2); and the damping device (1) has elastic means (18; 35, 36) interposed between the supporting body (6) and the member (11).