Twisting Device Grooves and Stiffened Extraction Bars
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Solution Overview
Problem
Existing twisting devices for electric machine stator or rotor windings face issues with extraction bar bending due to uneven stress, particularly as the length of extraction bars increases, leading to production stoppages and component damage.
Innovation Solution
A twisting device with radially offset grooves in its channels and an extractor assembly featuring stiffened extraction bars with reinforcement ribs, which reduce the likelihood of bending during the extraction process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the length of extraction bars is increased to accommodate larger stator/rotor cores, then the axial extension capability is improved, but the likelihood of extraction bar bending increases
Solution Approach 1:
The patent applies local quality by providing reinforcement ribs at specific locations on the extraction bars - particularly at the upper end portions and in regions subject to higher stress during extraction. This allows the bars to maintain adequate length for large cores while having localized structural reinforcement where bending is most likely to occur, thus improving reliability without compromising the length requirement.
Solution Approach 2:
The extraction bars are designed as composite structures combining base material with added reinforcement ribs. This composite approach allows the bars to achieve both the required length and the necessary bending resistance by integrating reinforcing elements that enhance structural integrity without requiring a complete redesign of the entire bar.
2Length of stationary object
If the channels are deepened to accommodate longer bar conductors, then the axial extension of winding conductors is improved, but the stress unevenness on extraction bars increases
Solution Approach 1:
The patent addresses stress distribution by providing reinforcement ribs at specific locations on the extraction bars - particularly at the upper end portions and in regions subject to higher stress during extraction. This allows the bars to maintain adequate length for large cores while having localized structural reinforcement where bending is most likely to occur, thus improving reliability without compromising the length requirement.
3Productivity
If extraction bars are made longer to extract longer winding conductors, then the extraction capability is improved, but the production stoppages due to bar damage increase
Solution Approach 1:
The patent applies local quality by providing reinforcement ribs at specific locations on the extraction bars - particularly at the upper end portions and in regions subject to higher stress during extraction. This allows the bars to maintain adequate length for large cores while having localized structural reinforcement where bending is most likely to occur, thus improving reliability without compromising the length requirement.
Solution Approach 2:
The reinforcement ribs serve as a preventive measure against extraction bar bending and damage. By incorporating these reinforcing elements in advance into the extraction bar design, the patent prevents potential failures before they occur, thereby avoiding production stoppages and component replacements.
Data Source
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AI summary
A twisting device (10) is described adapted to simultaneously twist a plurality of bar electric conductors (11) for making a stator or rotor winding for an electric machine, comprising: at least one first body (12) extending around a twisting axis (Z-Z) and comprising a first circular array of channels (15) having centre on such an axis (Z-Z); and - at least one second body (13), extending around and coaxial with the first body (12), comprising a second circular array of channels (16) with centre on the twisting axis (Z-Z); associated with each of the channels (15) of at least one of said first and second arrays, a channel extension groove (15A) extending longitudinally in a direction parallel to the twisting axis (Z-Z) and projecting from the respective channel (15) in a direction (CC) circumferential with respect to said axis (Z-Z).