Switched Reluctance Motor Coils With Variable Twist Rate
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Solution Overview
Problem
Manufacturing and assembling electric motors with twisted wire coils is challenging due to misshaping issues, which complicates coil placement on the stator and increases manufacturing difficulties.
Innovation Solution
The method involves winding electrically conductive wires into multiple turns with only the wire turns closer to the rotor end being twisted, while those closer to the base end remain untwisted, facilitating easier coil disposition on the stator poles and improving manufacturing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If wire turns of the coil are twisted to reduce losses and improve performance, then motor efficiency is improved, but the coils misshape and become difficult to manufacture and assemble
Solution Approach 1:
The coil is segmented into two distinct zones: a first zone with twisted wire turns and a second zone with untwisted wire turns. This segmentation allows the coil to benefit from twisted wire performance improvements in the critical rotor-end region while maintaining manufacturing ease in the base-end region.
Solution Approach 2:
Different portions of the coil have different wire configurations - the first zone near the rotor end has twisted wires to reduce losses where it matters most for performance, while the second zone near the base end has untwisted wires for easier manufacturing and assembly. This local differentiation resolves the contradiction between performance and manufacturability.
2Use of energy by moving object
If wire turns closer to the rotor end are twisted to improve performance, then efficiency is improved, but coil leg thickness increases and manufacturing becomes more difficult
Solution Approach 1:
Instead of twisting all wire turns throughout the entire coil, the invention applies twisting only partially - specifically to wire turns in the first zone closer to the rotor end. This partial action provides the necessary performance improvement while avoiding the excessive complexity that would result from twisting the entire coil.
3Loss of energy
If all wire turns are twisted to maximize efficiency benefits, then energy losses are reduced, but coil shape deteriorates and placement on stator becomes difficult
Solution Approach 1:
The coil structure implements local quality by having twisted wire turns in the first zone near the rotor end and untwisted wire turns in the second zone near the base end. This local differentiation preserves the beneficial energy loss reduction where it matters most while maintaining good coil shape and ease of placement in the base-end region.
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 reduces coil leg thickness and strand-to-strand contact stress, enhances coil shape, and improves cooling, while maintaining efficiency benefits of twisted wire coils.
Implementation Method 1
The wire turns of the coils are twisted to reduce these losses
Implementation Method 2
The wire turns of the coils are twisted to reduce these losses
Data Source
AI summary
An assembly for an electric motor includes a stator including a plurality of stator poles, each stator pole including a base end and a rotor end opposite the base end, and an electromagnetic coil around each stator pole. The coil around each stator pole includes at least two electrically conductive wires wound into multiple wire turns around the stator pole that extend from the base end of the stator pole to the rotor end of the stator pole. Wire turns of the coil closer to the rotor end of the stator pole are twisted and wire turns of the coil closer to the base end of the stator pole are not twisted.