METHOD OF WINDING A STATOR CORE TO PREVENT BREAKAGE OF WIRE BETWEEN PIN AND WINDING GROOVE

Abstract

To prevent breakage of the segment of an enameled wire that extends between a pin and a winding groove on an insulating stator base, a tension servo of an automatic wire-winding machine in controlled to first wind the enameled wire tightly around the pin of the insulating stator base and then to loosely wind the enameled wire around the pin to form at least one loose winding with a gap between the enameled wire and the pin. The enameled wire is then drawn into the winding groove of the stator base and tightly wound around the stator core within the winding groove. Optionally at least one first loose winding with a gap between the enameled wire and a bottom of the winding groove may initially be formed before tightly winding additional windings within the winding groove.

Claims

1. A method for preventing enameled wire extending between a pin and a winding groove on an insulating stator base from breakage, comprising controlling a tension servo of an automatic wire-winding machine to: first winding the enameled wire tightly around the pin of the insulating stator base; after first winding the enameled wire tightly around the pin of the insulating stator base, loosely winding the enameled wire around the pin to form at least one loose winding with a gap between the loose winding and the pin; after loosely winding the enameled wire around the pin, drawing the enameled wire into the winding groove of the insulating stator base to form windings that tightly encircle the stator base within the winding groove.

2. A method for preventing enameled wire between a pin and a winding groove on an insulating stator base from breakage, comprising controlling a tension servo of an automatic wire-winding machine to: first winding the enameled wire tightly around the pin of the insulating stator base; after first winding the enameled wire tightly around the pin of the insulating stator base, loosely winding the enameled wire around the pin to form at least one loose winding with a gap between the enameled wire and the pin; after loosely winding the enameled wire around the pin, drawing the enameled wire into the winding groove of the stator base and loosely winding the enameled wire around the stator base within the winding groove to form at least one loose winding with a second gap between the enameled wire and a bottom of the winding groove; after loosely winding the enameled wire around the stator base within the winding groove to form the first loose winding, tightly winding the enameled wire around the stator base within the winding groove to form subsequent tightly-wound windings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a perspective view of a conventional stator winding.

[0010] FIG. 2 is a cross-sectional view taken along Line 2-2 of FIG. 1.

[0011] FIG. 3 is an enlarged view of Part A of FIG. 2.

[0012] FIG. 4 schematically shows bends of the enameled wire segment between the pin and the winding groove on the insulating base of FIG. 3.

[0013] FIG. 5 is a cutaway view of the conventional stator winding and a Hall sensor's PCB.

[0014] FIG. 6 is cross-sectional view of the assembled stator winding and PCB of FIG. 5.

[0015] FIG. 7 is a schematic drawing illustrating a first embodiment of the present invention.

[0016] FIG. 8 is a schematic drawing illustrating a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] FIG. 7 shows a first embodiment of a method for preventing enameled wire between a pin and a winding groove on an insulating stator base from breakage. The method comprises controlling a tension servo of an automatic wire-winding machine to first wind the enameled wire W tightly around the pin 13 of the insulating stator base 11, then to wind the enameled wire W around the pin 13 to form at least one winding that loosely encircles the pin 13 so that the loose winding forms a gap G with the pin 13, and afterward to draw the enameled wire W into the winding groove 12 of the insulating stator base 11 to form windings that tightly encircle the insulating stator base 11 within the groove 12. Consequently, in the process where the enameled wire W forms layers of windings in the winding groove 12, the enameled wire segment W2 between the pin 13 and the winding groove 12 with the gap G formed by the at least one loose winding provides a margin that compensates for the compression that would otherwise be caused by bending of the enameled wire W as it enters the winding groove 12, so that the enameled wire segment W2 between the pin 13 and the winding groove 12 is not over-tensioned at all, and eliminating the risk of breakage.

[0018] FIG. 8 shows a second embodiment of a method for preventing enameled wire between a pin and a winding groove on an insulating stator base from breakage. The method comprises controlling a tension servo of an automatic wire-winding machine to first wind the enameled wire W tightly around the pin 13 of the insulating stator base 11, and then wind the enameled wire W around the pin 13 to form at least one winding that loosely encircles the pin 13 to form a gap G between the enameled wire W and the pin 13. After forming the loose winding, the enameled wire W is drawn into the winding groove 12 of the insulating stator base 11 to form a first loose winding that forms a gap G1 with a bottom of the winding groove 12, and then to successively form windings that tightly encircle the insulating stator base 11. As a result, in the process where the enameled wire W forms layers of windings in the winding groove 12, the enameled wire segment W2 between the pin 13 and the winding groove 12, which extends between the gap G formed by the at least one winding around the pin 13 and the gap G1 formed by the at least one loose winding around the winding groove 12, provides a margin that compensates for the compression that would otherwise be caused by bending of the enameled wire W as it enters the winding groove 12, so that the enameled wire segment W2 between the pin 13 and the winding groove 12 is not over-tensioned at all, eliminating the risk of breakage.

[0019] To sum up, the present invention can eliminate the bends in the enameled wire segment between the pin and the winding groove that are seen in the conventional insulating base, and achieve a defect-free rate as high as 100%, in contrast to the 0.5% defect rate of stator winding products made by existing mass manufacturing processes, making the present industrially usable and practical.