https://www.gwinsys.com/hairpin-vs-traditional-winding.html
As electric motor technology advances—especially in the era of high-efficiency EV powertrains—manufacturers are increasingly shifting from conventional round-wire windings to hairpin winding technology. A modern hairpin stator production line enables highly automated, repeatable, and high-precision manufacturing, making hairpin stators a preferred solution for next-generation traction motors. Understanding the technical differences between hairpin winding and traditional winding methods helps illustrate why this new approach is rapidly becoming an industry standard.
1. Conductor Shape: Rectangular vs. Round Wire
Hairpin Winding
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Uses rectangular (flat) copper wire, which provides superior slot fill and lower electrical resistance.
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Larger cross-section improves current-carrying capability and reduces heat generation.
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Consistent geometry allows automated forming, insertion, and welding.
Traditional Winding
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Uses round copper wire wound continuously into the stator slots.
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Slot fill factor is limited by the circular geometry.
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Electrical efficiency is lower due to increased copper losses.
Technical Impact: Hairpin conductors significantly reduce copper loss, improving motor efficiency and thermal performance.
2. Manufacturing Process and Automation Level
Hairpin Winding
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Highly compatible with automation.
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Production steps—cutting, bending, insertion, twisting, laser welding, and insulation—are performed by a fully automated hairpin stator production line.
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Ensures tight tolerances and consistent quality.
Traditional Winding
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Relies more on manual or semi-automated coil winding processes.
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Quality can vary with operator skill.
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More difficult to guarantee precise conductor placement.
Technical Impact: Hairpin technology enables mass production with better repeatability, fewer defects, and higher efficiency.
3. Slot Fill Factor and Power Density
Hairpin Winding
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Rectangular wire packs more efficiently, achieving up to 70–80% slot fill.
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Better electromagnetic performance increases torque density and motor output.
Traditional Winding
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Slot fill typically ranges 40–55% depending on wire diameter and winding method.
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Lower fill results in reduced performance potential.
Technical Impact: Higher slot fill equals higher torque density, making hairpin stators ideal for EV traction motors.
4. End-Turn Geometry and Thermal Behavior
Hairpin Winding
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Short, uniform end turns reduce copper usage and minimize I²R losses.
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Excellent thermal conduction between conductors and stator core.
Traditional Winding
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Long, irregular end turns reduce efficiency.
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More hotspots due to uneven conductor distribution.
Technical Impact: Hairpin stators support higher continuous power and improved thermal stability.
5. Electrical Performance and NVH Characteristics
Hairpin Winding
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Lower resistance and more uniform electromagnetic fields.
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Reduced motor noise and vibration due to consistent geometry.
Traditional Winding
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Higher AC losses, less predictable electromagnetic distribution.
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NVH performance depends strongly on winding quality.
Technical Impact: Hairpin windings often deliver smoother, quieter motor operation—critical for EVs.
6. Flexibility and Application Scope
Hairpin Winding
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Best suited for high-power, high-efficiency motors:
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EV traction motors
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Hybrid motors
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High-performance industrial drives
Traditional Winding
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More flexible for motors requiring:
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Lower cost
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Smaller scale
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Irregular slot geometries
Technical Impact: Hairpin technology excels in applications where efficiency, density, and durability matter most.
Hairpin winding technology represents a major leap forward in electric motor manufacturing. With superior slot fill, lower losses, improved thermal characteristics, and high automation potential, hairpin stators deliver performance levels unmatched by traditional round-wire windings. A fully automated hairpin stator production line enables manufacturers to reduce labor costs, increase production throughput, and achieve consistent high-precision results—making it the ideal solution for next-generation electric motor production.
https://www.gwinsys.com/Hairpin-Stator-Assembly-Line.html
https://www.gwinsys.com/hairpin-vs-traditional-winding.html
Jieyun Intelligent Equipment (Suzhou) Co., Ltd.
