Fiber-Wound Rotor Protection Ring With Slit for Delamination Control
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Solution Overview
Problem
Existing rotating electrical machines face issues with delamination and reduced strength in the rotor protection ring due to high-speed rotation, leading to potential damage and loss of the permanent magnet.
Innovation Solution
A rotating electrical machine protection ring constructed by winding a tape-like or sheet-like material made of reinforcing fibers impregnated with resin several times in a circular manner to form a cylindrical laminate, with at least one slit formed in the winding end region of the outermost layer to prevent delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the rotating electrical machine is rotated at a high speed, then the performance of the rotating electrical machine is improved, but the permanent magnet may fall off the rotor due to centrifugal force or the rotor itself may be damaged
Solution Approach 1:
A protection ring is pre-installed on the rotor before operation to prevent permanent magnet detachment and rotor damage during high-speed rotation. The protection ring serves as a preventive measure that is already in place before the harmful effects of high-speed rotation can occur.
Solution Approach 2:
The protection ring is constructed using fiber-reinforced composite materials (such as carbon fiber, glass fiber, or aramid fiber) impregnated with resin. These composite materials provide high strength-to-weight ratio, enabling the protection ring to withstand centrifugal forces at high rotation speeds while maintaining lightweight characteristics.
2Reliability
If a sleeve or rotor sleeve is placed on the outer periphery of the permanent magnet to prevent destruction, then the rotor integrity is improved, but the material constituting the winding end portion delaminates from other portions resulting in reduced strength
Solution Approach 1:
The protection ring is constructed by winding fiber-reinforced composite material in multiple layers to form a segmented cylindrical structure. This layered segmentation allows for better stress distribution and prevents delamination by creating distinct bonding interfaces between layers, each contributing to overall structural integrity.
Solution Approach 2:
The protection ring design incorporates varying fiber orientation and layering patterns at different locations. The winding end portion receives special attention with optimized fiber arrangement and resin impregnation to prevent delamination, while other portions maintain standard construction for overall protection.
3Reliability
If the fiber tow is cut at a winding end in a substantially V shape to prevent delamination, then the delamination prevention is attempted, but stress is concentrated in the distal end portion resulting in unsatisfactory effect
Solution Approach 1:
Instead of symmetric V-shaped cutting, the invention uses asymmetric overhang configurations where the fiber tow extends beyond the winding end by a controlled amount. This asymmetric extension distributes stress more evenly and prevents both delamination and stress concentration by creating a gradual transition zone.
Solution Approach 2:
Rather than cutting the fiber tow to prevent delamination (which creates stress concentration), the invention inverts the approach by leaving the fiber tow uncut or with minimal cutting, allowing it to naturally anchor and distribute stress. The resin impregnation and layering structure provide delamination prevention without requiring aggressive cutting.
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 delamination in the winding end portion of the rotating electrical machine protection ring, allowing the machine to operate at higher speeds with improved strength and durability.
Implementation Method 1
When the rotating electrical machine is rotated at a high speed, the permanent magnet disposed on the outer circumference may fall off the rotor due to centrifugal force
Data Source
Figure 1~3[E]
AI summary
A rotating electrical machine protection ring constructed by winding a tape-like or sheet-like material made of reinforcing fibers impregnated with resin several times in a circular manner to form a cylindrical laminate and molding the cylindrical laminate, wherein at least one slit is formed in a winding end region of an outermost layer of the laminate. There is provided a rotating electrical machine protection ring and a manufacturing method of the rotating electrical machine protection ring, the rotating electrical machine protection ring being constructed by molding a fiber-reinforced composite material that has been wound on an outside of a rotor in a rotating electrical machine, wherein the rotating electrical machine protection ring is given improved strength by preventing occurrence of delamination in a winding end portion of the rotating electrical machine protection ring while the rotating electrical machine is operating, thus enabling the rotating electrical machine to rotate at a higher speed.