Segment Coil End Bending for Restricted Stator End Spaces
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Solution Overview
Problem
Existing methods for producing segment coils for electric machines with restricted end spaces are not entirely satisfactory, as they require bending of stator windings which can be complex and inefficient, especially in large electric machines.
Innovation Solution
A method involving the production of a stack of coil loops from a continuous electrical conductor with staggered end portions, where the end portions are bent to a predetermined angle using a bending press with a first roll device and a second roll device, ensuring the outer end of the stack remains substantially straight, facilitating the accommodation of stator windings in limited spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional methods are used to bend end portions of stator coils to fit restricted end spaces, then the coils can be accommodated in limited spaces, but the manufacturing process becomes complex and inefficient
Solution Approach 1:
The end portions of the coil loops are pre-staggered during production before the bending operation. This preliminary arrangement of the coil loops with different lengths ensures that when the stack is bent to the predetermined angle, the outer end portions align substantially straight, simplifying the fitting process in restricted end spaces
Solution Approach 2:
The invention changes the length parameter of individual coil loops in the stack, creating a progression where each successive coil loop has a slightly different length. This parameter variation allows the stack to be bent to a predetermined angle while maintaining a substantially straight outer end, resolving the contradiction between fitting ease and process complexity
2Manufacturing precision
If the outer end of the stack of coil loops is kept substantially straight after bending, then the coils fit better in restricted end spaces, but the manufacturing process becomes more complex
Solution Approach 1:
The bending press employs a dynamic mechanism where the swing frame can rotate around the first shaft, and the second roll device rotates on the second surface of the stack of coil loops. This dynamic system allows the stack to be bent to a predetermined angle while maintaining control over the outer end alignment, achieving precision without excessive complexity
Solution Approach 2:
The coil loops are pre-configured with staggered end portions during the production phase, before bending. This preliminary preparation ensures that when the bending operation is performed using the roll devices, the outer end portions naturally align substantially straight, reducing the complexity of the bending press itself while achieving the desired precision
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 method provides a simple and effective way to produce segment coils for large electric machines, ensuring proper fitting of stator windings in restricted end spaces, enhancing the efficiency and ease of production.
Implementation Method 1
a bending press comprising a first roll device being supported via a first shaft on a stationary frame and a second roll device being rotatably supported via a second shaft on a swing frame
Data Source
Figure 1
Figure 2~4
Figure 5A~5E
AI summary
The method comprises producing a stack (400) of coil loops (300) from a continuous electrical conductor, the coil loops having two parallel straight side portions and two opposite curved end portions connecting the ends of the side portions. A length of each coil loop in the stack of coil loops decreases, whereby a staggered end portion is formed at each end of the stack of coil elements. The end portion of the stack of coil loops is bent into a predetermined bending angle, whereby the staggering has been determined so that an outer end of the end portion of the stack of coil loops is substantially straight when the stack of coil loops is bent into the predetermined bending angle.