Stator Hairpin Reshaping for Precise Bending and Springback Control
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Solution Overview
Problem
The existing methods for forming conductor pieces in a stator core, particularly in hairpin technology, are not efficient in terms of speed and precision, especially when bending radially outer hairpins, which can lead to suboptimal alignment and increased material springback due to the limitations of current bending techniques.
Innovation Solution
A device and method that utilize a bending unit with a positioning unit and a contact section, allowing for controlled bending in multiple directions to compensate for material springback, ensuring precise alignment and efficient formation of conductor pieces by using a combination of translational and pivoting movements to achieve desired angles and prevent material deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional bending techniques are used for radially outer hairpins, then the forming process can be completed, but the alignment precision deteriorates and material springback increases
Solution Approach 1:
The bending unit incorporates dynamic control capabilities with actuators that can adjust bending force and position in real-time. The system includes movable components such as the positioning unit with adjustable rollers and the bending roller assembly that can be dynamically positioned to accommodate different hairpin positions and compensate for material springback during the forming process.
Solution Approach 2:
The invention changes key process parameters including bending force magnitude, bending speed, and roller position to optimize both precision and productivity. The control unit adjusts these parameters dynamically during operation, modifying the bending characteristics to minimize springback while maintaining high forming speed for radially outer hairpins.
2Manufacturing precision
If conventional bending techniques are used for radially outer hairpins, then the forming process can be completed, but the alignment precision deteriorates
Solution Approach 1:
The system incorporates feedback mechanisms where sensors detect the actual position and deformation state of hairpins during bending. The control unit receives this feedback and automatically adjusts bending parameters to compensate for deviations, ensuring consistent alignment precision and reducing material springback across all formed hairpins.
Solution Approach 2:
The positioning unit performs preliminary positioning of hairpins before the actual bending operation. Rollers and guides pre-align the radially outer hairpins in precise positions, and the system performs preliminary force application to pre-compress the material, reducing subsequent springback and improving forming consistency.
3Manufacturing precision
If a complex bending mechanism is implemented to improve precision, then alignment precision improves, but device complexity increases
Solution Approach 1:
The bending mechanism is segmented into modular functional units: a positioning unit with independent rollers, a bending roller assembly with controllable force application, and a control unit. Each module performs a specific function and can be independently adjusted or replaced, achieving high precision without requiring an overly complex integrated mechanism.
Solution Approach 2:
The bending unit is designed as a multi-functional device that can handle different hairpin positions (radially outer and inner), adjust to various bending requirements, and accommodate different material properties. This universal design achieves high precision across multiple operations without proportionally increasing device complexity.
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 enables faster and more precise formation of conductor pieces, minimizing material springback and ensuring accurate alignment, which is crucial for the efficient assembly of stator cores, particularly in hairpin configurations.
Implementation Method 1
compensate for material springback
Data Source
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AI summary
The invention relates to an apparatus (10) and a method for reshaping one or more conductor pieces (14) arranged in a stator core (12), in which the conductor piece (14) is preferably a hairpin having two longitudinally extended members and a connecting portion which connects these two members, a plurality of conductor pieces (14) being arranged in the stator core (12), said conductor pieces being arranged on a plurality of circular paths (17) running in a circumferential direction (16) in rows (19) which extend in a radial direction (18), and the reshaping taking place in a free end of the conductor piece (14) projecting out of the stator core (12).