Heat dissipation mechanism of the thermosyphon electric knitting needle

Compared with the traditional mechanical knitting needle, the tubular magnetic suspension knitting needle has the advantages of no friction and flexible control. But the highspeed reciprocating motion of the needle needs to consume a lot of power. The winding temperature is difficult to suppress. The heat dissipation performance becomes the main obstacle restricting the power improvement. In this paper, an integral tubular electric knitting needle is proposed and studied. The heat dissipation area of the needle is increased by the annular thermosyphon in the motor housing. The heat dissipation performance is carefully studied by experiments, and the results show that the heat dissipation performance is obviously improved compared with the original design. Under the power of 17 W, after the annulus thermosyphon is started, the maximum temperature of the winding can be suppressed at about 107 °C. Boiling occurs only at certain points on the surface of the winding, which is related to the structural asymmetry in the winding manufacturing and epoxy injection processes. The heat dissipation performance is best when the winding is located at the bottom of the motor. The axial temperature difference is within 15 °C while the circumferential temperature difference is within 4 °C.