Motor Winding Machine: Which Is More Wire-Efficient for Hollow-Cup Motors—Needle Winding or Flying Fork Winding? — Jiuju Motor Automatic Assembly Line

The winding method for hollow-cup motors affects copper losses and slot fill factor; both needle-type and flying-fork winding methods have their respective applications.

Q: What is the key difference between needle winding and fork winding?

Needle winding involves using a hollow needle to guide enameled wire through the cup opening, arranging it in successive layers; this method is suitable for products with wire diameters of 0.05–0.3 mm, high turn counts, and small cup diameters; Flying fork winding, on the other hand, involves the flying fork rotating the wire cup, resulting in a faster wire speed. This method is suitable for hollow cups with slightly larger outer diameters and wider slots. We conducted a comparison: for the same φ22 mm hollow cup with 36 turns, the needle winding cycle time was approximately 12 seconds, while the flying fork method could reduce it to 7 seconds; however, the end height with the flying fork method was about 0.5 mm higher.

Q: Which method uses less copper wire and results in lower copper losses?

In terms of wire usage, needle-wound coils have neater ends and can save an average of 8%–12% of copper wire; however, if fly-fork winding is combined with automatic wire laying, a higher slot fill rate can be achieved. Taking a wire diameter of 0.15 mm as an example, the slot fill rate for needle-style winding is typically 55%–62%, while fork-style winding can achieve 65%–70%. In terms of copper loss, for every 5% increase in slot fill rate, the temperature rise of the winding under the same load decreases by approximately 3–5°C; therefore, we recommend the fork-winding solution for high-power-density applications.

Q: Which option should be prioritized for small-batch prototyping?

Needle winding is the preferred method during the prototyping phase. During changeovers, only the guide pins and fixtures need to be replaced, with setup time taking approximately 30 minutes; for fly-spool changeovers, the fly-spool head, tension wheel, and yarn nozzle must be replaced, and setup typically takes more than one hour. If monthly production is less than 5,000 units, the overall cost of needle winding is lower; consider dedicated fly-spool machines only when production exceeds 20,000 units.