Flexible Neutral Ring for Rotating Electrical Machines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing neutral rings in rotating electrical machines suffer from fatigue damage due to stress caused by deformation differences between the neutral ring and coils under centrifugal force, leading to reduced service life.
Innovation Solution
A flexible neutral ring is formed by connecting multiple arc-shaped members with low rigidity, allowing them to follow coil deformation and reducing stress at junctions, instead of a rigid ring shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid ring-shaped neutral ring is used, then the structural strength is improved, but the stress at junctions with coils increases due to deformation difference under centrifugal force
Solution Approach 1:
The neutral ring is divided into multiple arc-shaped members (first, second, third arc-shaped members) that are connected together. This segmentation allows each member to independently deform with the coils, reducing stress concentration at junctions while maintaining overall structural strength through the interconnected arrangement.
Solution Approach 2:
The neutral ring transitions from a rigid structure to a flexible structure where the arc-shaped members can dynamically adjust their positions to follow coil deformation. The overlapping arrangement of arc-shaped members enables the neutral ring to flexibly accommodate centrifugal force-induced deformations, reducing stress at connection points.
2Reliability
If a rigid ring-shaped neutral ring is used, then the electrical connectivity is maintained, but fatigue damage accumulates at junctions due to repeated stress from coil deformation
Solution Approach 1:
By segmenting the neutral ring into multiple arc-shaped members connected together, the structure can flexibly deform with the coils during operation, reducing repeated stress at junctions. This segmentation maintains electrical connectivity through the interconnected members while significantly reducing fatigue damage accumulation, thereby extending service life.
Solution Approach 2:
The neutral ring adopts a flexible structure composed of overlapping arc-shaped members that can elastically deform to follow coil movements. This flexibility allows the neutral ring to accommodate dynamic loads without generating excessive stress, preventing fatigue damage while maintaining continuous electrical connectivity across the rotor windings.
3Stress or pressure
If the neutral ring is made flexible with overlapping arc-shaped members, then the stress at junctions is reduced, but the structural rigidity decreases
Solution Approach 1:
The neutral ring is segmented into multiple arc-shaped members that are connected and overlap with each other. This segmentation provides flexibility to reduce stress at junctions while the interconnected and overlapping arrangement of multiple members collectively maintains sufficient structural rigidity to support the electrical and mechanical loads in the rotor.
Solution Approach 2:
The neutral ring employs a composite structure formed by multiple arc-shaped members made of conductive material (such as copper or aluminum alloy) that are connected and overlap. This composite arrangement combines the flexibility needed to reduce junction stress with the collective structural integrity required to maintain adequate rigidity for rotor operation.
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 flexible structure reduces fatigue damage and extends the service life of the neutral ring by minimizing stress at junctions between the neutral ring and coils.
Implementation Method 1
When the rotor rotates, the neutral ring receives stress due to centrifugal force by rotation. In addition, junctions between the coils and the neutral ring also receive stress due to deformation of respective phase coils.
Implementation Method 2
the deformation difference between the neutral ring and the coils due to centrifugal force caused by rotation of the rotor increases, the stress at the junctions between the neutral ring and the coils becomes larger
Data Source
AI summary
A method for manufacturing a neutral ring includes connecting a cut-off neutral ring to an arc-shaped connection element. The method also includes filling an insulator between the cut-off neutral ring and a connection element. The neutral ring shunts the rotor coil in three phases.