US3716199A

US3716199A - Stator winding machine

Info

Publication number: US3716199A
Application number: US00203816A
Authority: US
Inventors: G Ericson
Original assignee: Westinghouse Electric Corp
Current assignee: AO Smith Corp
Priority date: 1971-12-01
Filing date: 1971-12-01
Publication date: 1973-02-13
Anticipated expiration: 1990-02-13

Abstract

In a stator coil winding machine having a wire dispensing gun rotatable about the stator core axis, there is provided a moving form separately rotatable about the same axis as the gun and shaped to force wire radially outwardly about fingers corresponding to core slots. When the moving form is withdrawn and the gun axially reciprocated to the other core end, the wire is seated deeply in the core slot with minimum end turn length of the coils. The form may be configured so that it is versatile over a wide coil span and winding the various coils of a single stator may be accomplished with a single form.

Description

United? States Patent n 1 Ericson [s41 S TATOR WINDING MACHINE [75] Inventor: Gene S. Ericson, Cridersville, Ohio [73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: Dec. 1, 1971 [21] Appl. No.: 203,816

Related US. Application Data [63] Continuation of Ser. No. 842,648, July 17, 1969,

1/1966 Frederick ..242/l.l E 5/1966 Brown et al ..242/l.l E

Primary Examiner-Billy S. Taylor Attorney-A. T. Stratton et al.

[5 7] ABSTRACT In a stator coil winding machine having a wire dispensing gun rotatable about the stator core axis, there is provided a moving form separately rotatable about the same axis as the gun and shaped to force wire radially outwardly about fingers corresponding to core slots. When the moving form is withdrawn and the gun axially reciprocated to the other core end, the wire is seated deeply in the core slot with minimum end turn length of the coils. The form may be configured so that it is versatile over a wide coil span and winding the various coils of a single stator may be accomplished with a single form.

8 Claims, '11 Drawing Figures MOVEMENT AND CONTROL MEANS MOVEM ENT AND CONTROL MEANS ,22 40 i 2? I 1 I I l FIG]. l I l l l l I FIGZ.

WITNESSES INVENTOR 20m j %M 7 Gene S; Ericson I V ATTORNEY PATENIEDFEBIIB ms Iii/16199 sum 2 or a PATENIED FEB 13 ms sumanra 1 1 ST A'IORWINDING MACHINE RELATED APPLICATION This I is a continuation of application Ser. No. 842,648 filed July 17, I969 and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to coil winding machines for winding coils on stators of dynamoelectric machines.

2. Description of the Prior Art Stator coil winding machines are well known that use a moving wire dispensing gun for traversing a core slot from end to end, passing over the core end to an appropriate return slot, returning axially to the opposite core end and continuing this motion until the coil is completed. Two things are desirable for machine efficiency and conservation of costly materials. One is that the individual windings be packed together to result in a high slot filled factor. The other is that a minimum amount of conductor length occur in the end turns as they do not contribute to machine efficiency and merely waste material.

In the past, a stationary form has been used to act as a camming surface that guided the wire into the conductor slot as the wire was played out from the gun. The stationary form requires an excessive stroke of the gun to wrap the wire about the camming surface of the .form which directs the wire into the conductor slot.

This excess stroke causes long end turn length. Also, a different form is usually required for each coil span of the stator winding. This multiplicity of forms and their handling becomes costly particularly with the large number of coil spans found in some present day motor designs.

An alternative practice to that of the fixed camming surface forms just described has been to use a ring of hooks or fingers at the core end with the space between the adjacent hooks corresponding to that of the core slots. Typically such winding machines have a shuttle mounted on the gun head to place the wire behind the I fingers. This shuttle mechanism is difficult to build to operate through the smaller bores of two pole statorsv SUMMARY OF THE INVENTION Among the objects of this invention are to provide a stator coil winding-machine producing wound stators with a high slot fill factor and minimum end turn conductor length. Versatility as to coil span angle, speed,

v and reliability are also desired.

The invention achieves these and other objects through the provision in a winding machine with a wire gun of a moving form rotatable about the same axis as [the wire gun but separately controlled for initiation of I rotation prior to that of the gun and also for rotation at a. faster rate than that of the gun. The form may be tapered from a point (blunted) that first comes in contact with the wire outwardly to its maximum radial extent at its distal end. Since only the outer surface of the formcontacts the wire, the form may be variously constructed to define this surface besides the blunt tapered shoe just described.

As soon as the wire gun passes the form on exit from the stator, the form oscillates toward the gun and, traveling faster than the speed of rotation of the gun, cams the wire behind the hooks to a radially outward position corresponding to the bottom of the core slots. The oscillation of the form is reversed as the oscillation of the wire nozzle is completed and the leading end of the form is withdrawn from the wire loop as the wire gun starts its return stroke through the stator core. The forms may be shaped so as to make them versatile over a particular range of coil span angles, including a wide range if desired.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1 and 2 are elevation views, in section, of certain features of a winding machine in accordance with this invention;

FIGS. 3, 4 and 5 are partial perspective views illustrating the manner of operation of a winding machine in accordance with this invention;

FIGS.,6 and 7 are partial plan and elevation views of an alternative embodiment of the moving form of this invention;

FIGS. 8 and 9 are partial plan and elevation views of an additional embodiment of the moving form of this invention; and

FIGS. 10 and 11 are partial plan and elevation views 'of additional features of apparatus in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. I, a stator core 10 is shown comprising a stack of punched laminations defining a hollow cylinder with axial coil retaining slots 11 extending radially out from the inner surface. The core 10 is mounted by suitable means, not shown, in a wire winding machine in accordance with this invention. A plurality of fingers or hooks 12 as have been used in prior gun type winding machines are positioned at the upper and lower ends of the stator core with the openings between adjacent fingers aligned with the core slots 11. Concentrically within the stator core 10 is a shaft 14 on which is mounted a wire dispensing gun or nozzle 16. In this example, a pair of diametrically opposed guns 16 are mounted on the same shaft 14 for simultaneously winding two coils. For convenience, operation of just one gun will be described herein.

The coil winding operating proceeds by the axial reciprocation and oscillation of the wire gun 16. The tip of the wire gun 16 from which a wire 18 extends follows a path extending through a pair of core slots and over each end surface of the core 10 between those slots. The basic motion is simple for the gun 16 itself to perform, but such movement does not impart to the wire 18 any radially directed force to pack it into the slots 1 1 with high density (called a high slot fill factor). The gun 16 must clear the inner circumference of the core 11 to permit its axial movement or else be designed so its tip fits within the opening of a core slot but, even so, cannot extend to the bottom of the slots and thus does not cause the wire to fill the slots densely. The fingers 12 merely retain the wire on the end face until winding is complete at which time the fingers are withdrawn. As was discussed previously herein, prior means for effecting slot fill almost necessarily resulted in excessive looping of the wire at the ends of the core or other disadvantages.

ln accordance with the improvement of this invention, the winding machine includes a moving form 20, one for each wire gun, at each core end. The form is rotatable about the same axis as the wire gun. Axial movement is not necessary for the form 20. At the upper core end, forms 20 are supported by arms 22 centrally joined to a shaft and bearing means 24 for rotation about the axis. FIG. 1 illustrates the head of the wire gun at its upward extreme. In FIG. 2 are shown the wire guns 16 in their lowermost position with additional moving forms 20 on arms 22 that are concentrically rotatable with the axis by a bearing means 25.

Each form 20 is shaped so that its passage on the radially inward side of the wire 18 between the tip of the wire gun l6 and the core imparts to the wire a radially outward force. The form 20 earns the wire in the radially outward direction. The rotation of the form 20 is separate from that of the wire gun 16 but is synchronized therewith as will be subsequently explained in connection with the subsequent figures.

Various means, represented by movement and control means 40, may be employed to control the axial movement and rotation of the shaft 14 supporting the wire gun 16 as well as the rotation of the forms 20 and their synchronism with the wire gun; such means will not be detailed herein. ln machines that have been made in accordance with this invention, the controlled movement of the wire gun 16 and forms 20 was achieved by a mechanical driven cam system designed to permit adjustment for different span angles. Reference to the Morey et al. Pat. No. 3,253,793 may be made, as well as to other prior art, for description of suitable mounting, drive and control means that may be adapted in accordance with the skill of the art for use in winding machines embodying the present invention. The invention may be employed in machines for winding coils on horizontally positioned cores as well as vertical cores, as shown in FIG. 1. A single machine may have a plurality of assemblages for simultaneously winding coils on a number of cores.

Referring now to FIGS. 3' to 5, further description of the cooperative functioning of the wire gun 16 and the moving form 20 will be given. in H6. 3 the position of the elements is such as occurs when the wire gun 16 is at the end of its axial stroke and before its oscillation has begun. When the gun 16 is in this position the moving form 20, not yet bearing against the wire, initiates movement (in fact the form 20 may start to move, for time saving, before the wire gun 16 comes to rest).

Midway in rotation to form an end turn the position of the elements is as shown in FIG. 4. The form 20 moves faster than the wire gun 16. Thus the outward surface of the form 20, which operates as the camming surface, has come in contact with the wire 18 and has moved partially past the wire gun 16. In so doing, the form 20 pushes radially outward on the wire 18 deeply in the slot 11 from which it extends and outside the ring ofwire holding fingers 12.

FlG. 5 shows the position of the elements at the end of rotation. The gun 16 is in a fixed position. The form 20 is at its position of maximum rotational extent as determined by the desired coil span. At this point the form 20 reverses direction prior to movement of the wire gun 16. When the form 20 has withdrawn from contact with the wire, the gun makes its axial stroke to the other end of the core. Only during the brief period when the form 20 has withdrawn and before axial movement of the gun is there no tension on the wire. The wire therefore remains located radially well out at a location corresponding to the maximum depth of the core slots 11 so that when the gun makes its axial stroke the wire is deeply seated therein.

The form 20 shown in FIGS. 1 to 5 has a smoothly curving outward surface the centerline of which is in a plane substantially perpendicular to the axial direction. Such a shape is generally suitable but is not as effective in insuring deep seating of wire in the core slot where there is a log coil span and thus other form designs may be preferred as will be subsequently described.

General requirements for the moving form 20 include (i) that it extend radially inward sufficiently to catch the wire extending from the wire gun, (2) that it extend radially outward sufficiently to carry the wire to a location at least as deep as the core slot depth, and preferably deeper, (3) that it be axially located to provide sufficient clearance from the fingers 12, and (4) that it have enough surface for the maximum coil span to be wound.

A reason for preferring a radially outward extent greater than the depth of the core slots is so that end turns for larger coil spans are laid relatively flat on the core end face rather than bunching up on top of previously' wou'nd coils of shorter span or traversing the core bore.

FIGS. 6, 7, 8 and 9 show forms with a vertical offset (as seen in the elevation views of FIGS. 7 and 9) as has been found to be desirable for winding'larger span coils while still efficiently winding shortspan coils, effectively covering the range of at least about 45 to in coil span angle. Here the point or front end 31 of the forms is radially in enough to catch the wire. The wire gun 16 in this example extends just inside the core slot opening. Even with the form 20 as shown, the gun 16 could be entirely within the core bore because of some arcing of the wire from the gun. The front end 31 of the form 20 is also vertically positioned sufficiently to clear the fingers 12. The rear portion 32 of the form is located radially outward well beyond the maximum core slot depth to a distance from the inner core surface of roughly twice the slot depth. The portion of the fonn surface that contacts the wire when winding a coil with a 165 span (largest coil of a two pole machine) subtends an angle A at the axial center of about 45. Since the form 20 is not relied on for tangential force on the wire, it does not require a step or notch for holding the wire but such may be provided if desired. The rear portion 32 is vertically displaced from the front portion 31 to bring it closer to the core end face. Such configuration results in flat end turns as normally the shorter span coils (inner coils) are wound first and the longer span coils (outer coils) preferably go radially around the short coils as has previously been achieved in shuttle type winding machines by a special shuttle design (for two pole machines) that includes a gargoyle like tongue that leads the wire behind the appropriate hooks.

The form of FIGS. 6 and 7 and the form of FIGS. 8 and 9 have substantially the same configuration for the effective camming surface (the radially outward surface). A difference, however, is that in FIGS. 6 and 7 the form has a relatively large cross section (as also does arm 22) while in FIGS. 8 and 9 the form is made to conserve material and fabrication expense by having a small, substantially uniform cross section that may be formed readily by casting with the arm 22 integral therewith.

The preceding description has assumed the use of a ring of identical wire holding fingers 12. Such fingers, as shown in FIG. 1, include a terminal portion that extends axially. One or more of the fingers may, if desired, curve radially outward for helping retain coils. When fingers are shaped to curve outward there may be difficulty in placing the wire behind the finger by the form 20 when the span is small and the engagement of the form with the wire is small. However, in accordance with another aspect of this invention an outwardly curving finger may be advantageously used. FIG. 10 shows a form 20 (that may be like that of any of the previous description) in use in a machine with the previously described axially extending hooks 12 except in a portion of the ring where the shortest span coil is to be wound, particularly in a two pole application. A hook 34 extends nearly across the entire desired span of the smallest coil. its curved outer surface 35 (shown in side elevation in FIG. 1 1) provides a complementary cam surface with the form 20 so that a scissors like action forces the wire behind hook 34. This is to ensure a satisfactory winding action over the extreme range of coil spans as found in a two pole motor (45to 165).

While the invention has been shown and described in a few forms only it is apparent that various additional modifications may be made.

I claim as my invention:

1. in a stator coil winding machine: a wire dispensing gun mounted on a shaft having an axis, said shaft being movable along said axis and rotatable about said axis; a wire directing form, rigidly attached to an arm, to force wire from said gun radially outward a distance greater than the radial extent of said gun, means for rotating said arm separately from said gun about a center aligned with said shaft axis with said form rotating with said arm, said form having a curved outer surface ineluding a front portion radially inward of the normal radial extent of wire from said gun, the remainder of said surface curving radially outward therefrom to a distance desired for the position of said wire, said curved outer surface contacting said wire upon rotation of said arm to carry wire on said curved outer surface to the desired radially outward position.

2. The subject matter of claim 1 wherein: said outer surface extends radially outward to an extent substantially beyond the maximum depth of core slots in which wire is to be wound.

3. The subject matter of claim 2 wherein: a plurality of wire holding fingers are positioned concentrically about said shaft and define gapscorres onding to core slots of a stator to be woun said fron portion of said form being offset axially from said fingers to permit clearance from said fingers in the rotation of said form.

4. The subject matter of claim 3 wherein: a rear portion of said form is in a plane transverse to said axis that intersects said fingers.

5. The subject matter of claim 3 wherein: said fingers include a plurality of wire like fingers spaced for location of each said finger between two adjacent core slots, said wire like fingers having substantially straight axially extending extremities, and a curved hook positioned in said ring and spanning the location of the shortest span coil to be wound, said hook having an extremity with an outer surface curving radially outward for cooperation with said form in a scissors like camming action.

6. The subject matter of claim 1 wherein: said form has a uniform, round cross-section.

7. In a stator coil winding machine: an adjustably rotatable and axially reciprocable wire gun for carrying a wire, in a plurality of coil turns of a given coil span angle, through a first stator core slot, over a core end face, back through another core slot, and over another core end face, to wind a first coil and then, with differing extent of rotation, a second coil of differing span angle; an adjustably rotatable, axially fixed, wire camming form near each axial extreme of said wire gun, said form having a curved outer surface including a front portion extending radially inside the normal radial extent of wire from said gun and a rear portion extending radially outside the radial extent of core slots within which wire is to be wound; movement and control means for bringing said gun axially through a first core slot, initiating rotation of said form prior to rotation of said gun, rotating said gun to a second core slot, said form rotating faster than said gun during rotation and camming wire radially outward, oppositely rotating said form prior to axial movement of said gun, and bringing said gun axially through said second core slot.

8. Thelsubject matter of claim 7 wherein: said form outer surface subtends angles at the axial center for camming wire of coils of different span angles in the range of from about 45 to about a a: a:

Claims

1. In a stator coil winding machine: a wire dispensing gun mounted on a shaft having an axis, said shaft being movable along said axis and rotatable about said axis; a wire directing form, rigidly attached to an arm, to force wire from said gun radially outward a distance greater than the radial extent of said gun, means for rotating said arm separately from said gun about a center aligned with said shaft axis with said form rotating with said arm, said form having a curved outer surface including a front portion radially inward of the normal radial extent of wire from said gun, the remainder of said surface curving radially outward therefrom to a distance desired for the position of said wire, said curved outer surface contacting said wire upon rotation of said arm to carry wire on said curved outer surface to the desired radially outward position.

3. The subject matter of claim 2 wherein: a plurality of wire holding fingers are positioned concentrically about said shaft and define gaps corresponding to core slots of a stator to be wound; said front portion of said form being offset axially from said fingers to permit clearance from said fingers in the rotation of said form.