Bobbin Holder Balancing at Resonance Nodes
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Solution Overview
Problem
Existing balancing methods for rotation members in textile machines, such as yarn winding devices, are laborious and can increase vibration due to the addition of weights for balancing, especially in resonance modes where the member behaves as a flexible rotor, leading to inefficiencies in vibration reduction across various speed ranges.
Innovation Solution
A balancing method that identifies node positions in the rotation member's resonance mode and adds or removes mass within a specific axial range near these nodes, reducing the displacement and centrifugal force of the added mass, thereby minimizing vibration during resonance modes, and allows for two-plane balancing to simplify the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If three-plane balancing is performed over a wide speed range, then unbalance correction is improved, but the balancing process becomes extremely laborious and time-consuming
Solution Approach 1:
The invention segments the balancing process into two distinct parts: (1) rigid rotor balancing at low speed to correct unbalance in the non-resonant state, and (2) flexible rotor balancing at high speed to correct unbalance in the resonant state. This segmentation allows each part to be optimized independently, reducing the overall complexity and time required compared to performing full three-plane balancing across the entire speed range.
Solution Approach 2:
The invention performs preliminary rigid rotor balancing at low speed before the rotation member enters the resonance speed range. This preliminary action corrects the majority of unbalance when the member behaves as a rigid rotor, reducing the amount of unbalance that needs to be addressed later when the member becomes flexible at higher speeds.
2Ease of operation
If two-plane balancing is performed by treating the rotation member as a rigid rotor, then the balancing process is simplified, but vibration increases in resonance modes where the member behaves as a flexible rotor
Solution Approach 1:
The invention transitions from a static rigid rotor model to a dynamic flexible rotor model by performing balancing at two different speed ranges. At low speed, the member is treated as rigid for simplified two-plane balancing. At high speed, the member's flexibility is accounted for by performing additional balancing corrections when it operates in resonance modes, thus adapting the balancing approach to the dynamic behavior of the rotation member.
Solution Approach 2:
The invention changes the operational parameter (rotation speed) to alter the mechanical behavior of the rotation member. By performing balancing at low speed where the member behaves as a rigid rotor and then again at high speed where it behaves as a flexible rotor, the invention adapts the balancing corrections to match the changing physical parameters of the member across different operating conditions.
3Ease of manufacture
If weights are added at positions far from node positions, then unbalance correction is easier to implement, but centrifugal force increases and vibration worsens in resonance modes
Solution Approach 1:
The invention applies local quality by placing balancing weights specifically at or near the node positions of the flexible rotor mode shapes. At these locations, the displacement is minimal, which reduces the centrifugal force generated by the added weights while still providing effective unbalance correction. This localized placement strategy optimizes the balance between correction effectiveness and force minimization.
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 approach effectively reduces vibration in resonance modes, including high-speed ranges, while making the balancing process less laborious and enabling the formation of high-quality packages by targeting specific node positions for unbalance correction, even at lower correction speeds.
Implementation Method 1
the total sum of centrifugal forces acting at the time of rotation of the rotation member does not become zero, which increases vibration
Implementation Method 2
resonance occurs at a predetermined rotation speed
Data Source
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AI summary
In a resonance mode in which bending occurs at a bobbin holding portion 20, an increase in vibration by a mass for balancing is prevented or lessened. Positions of nodes N1 and N2 of the bobbin holding portion 20 in a predetermined resonance mode of a bobbin holder 9, in which bending occurs at the bobbin holding portion 20, are obtained. An unbalance corrector 25 for adding or removing a mass for balancing is provided at or around each node N1, N2, within a range of 10% of the length of the bobbin holding portion 20, the range being defined by taking the position of the node N1, N2 as the midpoint of the range.