Segmented Pole Cover Structure for Stress-Absorbing Rotor Windings
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Solution Overview
Problem
Existing pole covers for electric motors face challenges with mechanical load capacity and shape stability due to the use of thermosetting plastics, which are brittle and require spring-loaded regions that occupy design space and are sensitive during assembly.
Innovation Solution
A pole cover design featuring segments made of a shape-stable thermosetting plastic material and decoupling regions made of a more elastic thermoplastic material, allowing for stress absorption without increasing design space, ensuring improved mechanical load capacity and shape stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If spring-loaded regions are used between segments to absorb stresses, then the pole cover can withstand tensile and flexural stresses, but the design space increases and shape stability decreases
Solution Approach 1:
The patent changes the material parameter from uniform thermosetting plastic to a composite of thermoplastic and thermosetting plastic. The thermoplastic regions provide elasticity for stress absorption, while the thermosetting plastic regions provide shape stability. This material parameter change resolves the contradiction by allowing both stress absorption and shape stability to coexist.
Solution Approach 2:
The patent applies different material qualities to different regions of the pole cover. Elastic thermoplastic material is used in stress-prone areas between segments, while rigid thermosetting plastic is used in regions requiring shape stability. This local differentiation allows each region to perform its specific function optimally without compromising the overall structure.
2Stress or pressure
If spring-loaded regions with reduced wall thickness are used, then tensile stresses are reduced, but the pole cover becomes sensitive during assembly and easily damaged
Solution Approach 1:
The patent uses a composite material system where thermoplastic and thermosetting plastic are combined. The thermoplastic provides stress relief through elastic deformation, while the thermosetting plastic provides structural integrity and damage resistance during assembly. This composite approach maintains adequate wall thickness while achieving both stress reduction and assembly reliability.
3Temperature
If thermosetting plastics are used for pole covers, then heat resistance and compressive strength are improved, but tensile and flexural stress resistance decreases
Solution Approach 1:
The patent combines thermoplastic and thermosetting plastic materials to create a composite pole cover. The thermosetting plastic provides heat resistance and compressive strength, while the thermoplastic contributes to tensile and flexural strength through its elastic properties. This composite material system resolves the contradiction by leveraging the complementary strengths of both materials.
Solution Approach 2:
The patent applies different materials locally based on stress requirements. Thermosetting plastic is used in regions requiring heat and compression resistance, while thermoplastic is used in regions requiring tensile and flexural strength. This local material differentiation optimizes the pole cover's performance across different loading conditions.
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 design enhances mechanical load capacity and shape stability, facilitating easy installation and preventing damage during assembly, while maintaining precise winding guidance and stress absorption.
Implementation Method 1
the decoupling regions are designed to absorb mechanical stresses between the segments in the operating state
Data Source
AI summary
A pole cover is provided for receiving and guiding a winding on a rotor of an electric motor, comprising multiple segments which extend in a radial direction to a center axis of the pole cover, wherein the segments receive a partial region of the winding of the electric motor, and wherein each of the segments includes a winding region to receive the winding and a segment connection region for connecting to other segments, wherein the winding region and the segment connection region border on each other and the segment connection region is situated closer to the center axis than the winding region. The segment connection regions extend at least partially in the circumferential direction about the center axis and each segment connection region protrudes, in the circumferential direction about the center axis, beyond the adjoining winding region. Multiple decoupling regions are also provided, each being situated between two segment connection regions in the circumferential direction about the center axis. An electric motor having such a pole cover and a method for producing a pole cover are also provided.