US1920154A

US1920154A - Edgewise winding machine for stator cores

Info

Publication number: US1920154A
Application number: US639623A
Authority: US
Inventors: Helge E Carlson
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1932-10-26
Filing date: 1932-10-26
Publication date: 1933-07-25
Anticipated expiration: 1950-07-25
Also published as: GB412472A

Description

July 25, 1933. H. E. CARLSON 1,920,154

EDGEWISE WINDING MACHINE FOR STATOR CORVES Filed Oct. 26, 1932 2 Sheets-Sheet l Inventor Helge E.CaT|SOn,

by I ,His Attovney.

July 25, 1933. H. E. CARLSON EDGEWISE WINDING MACHINE FOR STATOR CORES Filed Oct. 26, '1952 2 Sheets-Sheet 2 )I ln lunl V I -lIlllIllllllllllllllllllllll Inventor: Helge ELCarlson,

W Mm

His Attorney.

Patented July 25, 1933 UNITED: STATES PATENT OFFICE HELGE E. CARLSON, 0F SAUGUS, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK 'EDGEWISE WINDING MACHINE FOR STATOR CORES Application filed October 26, 1932. Serial No. 639,623.

In the construction of dynamo electric machines, a large item of expense is the,

magnetic steel used in the construction of magnetic steel used in the construction of the stator and rotor cores. This is particularly true where silicon steel is used for the purpose. The established practice is to punch rings or round disks from sheet stock for the smaller size machine and to punch segments for the larger sizes. In both cases, each punching is provided with teeth between which are slots to receive the windings. In many cases, the punchings are also provided with external perforated lugs to receive clamping bolts. Punching round or segmental objects from rectangular sheet stock results in a large amount of scrap which substantially increases the cost of manufacture. Furthermore, commercial sheet steel as obtained from the manufacturers is not of exactly the same thickness throughout the sheet. Due to this, it is the custom in as sembling a core structure to pile a certain number of disks or pieces forming a set in place, then to pile a second set on top of the first but angularly advanced with respect thereto by a certain amount, then add more disks or pieces angularly advan'ced from the second and so on, the purpose being to average the inequalities in the total assemblage and avoid small spaces between adjacent laminations. Such a method of procedure increases the cost of assembly, and also results in a structure in,

which the grain of the steel instead of extending uniformly in one direction throughout the core, as it should to attain the best electrical results, extends in a number of different directions, depending principally upon'the number of laminations in each of the aforesaid sets.

My invention has for its object the provision of a machine of simple construction by means of which cores of dynamo electric machines may be accurately and expeditiously edgewise wound from strip stock in which the teeth and coil slots have previously been formed.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the drawings which are illustrative of my invention, Fig. 1 is a view in side elevation of my improved machine; Fig. 2 is a plan View of the notched or index plate which receives the core stock as it is formed; Fig. 3 is a perspective view-of a mandrel for receiving the stock from the notched index plate; Fig. 4 is a detail view showing the means for causing the bent stock to move from the plate on to the mandrel; Fig. 5 is an enlarged view, chiefly in side elevation of the head of the machine; and Fig. 6 is a plan view with the mandrel and other parts above the line 6-6 removed.

Briefly stated, in carrying out my invention, the strip stock which has previously been punched to form teeth and coil slots, is fed endwise into the machine where it is acted upon by a pair of slightly coned rolls which subject it to heavy pressure and bend it edgewise. These rolls cause the stock to form a helix, and for a part of a circle of predetermined diameter, one of the turns is held in a rotary notched index plate. During that portion of the operation where the plate acts on the stock, a stationary guide also acts thereon to size it. From the plate, ghelbent stock is fed on to a removable man- Referring now to the specific construction of the machine, 7 indicates a base of suit able construction mounted on suitable supports 8. On the base is mounted a head 9 which carries the forming rolls 10 and 11. The shafts of the rolls are driven in opposite directions by the gears '12 and 13. The gears are driven by the horizonntal shaft 14:, and between it'and one of the gear shafts is a sliding clutch 15. The clutch is actuated by a yoke 16, spindle l7 and handle 18. The shaft 14 is. driven by bevel or other gearing from the main shaft 19. 2O inrlicates a notched index plate which is mounted to turn freely on the support 21. Above the plate and mounted on a pivot. 22 inclined at an angle to the base is a removable mandrel 23 which receives the stock as it issues from between the rolls and retains it in helical or coiled form.

The-strip stock comprises a thin body of steel 24 which has previously been punched to form teeth 25 with overhanging ends and f ited amount of the metal of the stock to flow tangentially, to the end that the thickness of the stock shall be maintained substantially uniform throughout and without wrinkles in the flat side surfaces. Such an arrangement of rolls produces a trapezoidal section of the body portion of strip stock but the difierence in thickness of the inner and outer edges is so small as to be negligible where the stock is initially thin, as experience has amply demonstrated.

The pressure exerted by the rolls causes the stock to curl or curve into circular form, the diameter of which circle is predetermined and which is or maybe slightly larger than the finished core.- The pressure exerted by the rolls, the taper thereof and the thickness of the stock are determining factors in the formation of the cores: The proper relation and construction of the parts may be closely determined by calculation,

' but one or more trials are desirable as a check. The stock after leaving the rolls passes on to the notched index plate 20, the latter being mounted on the support 21 and adapted to freely turn about the cylindrical part or pivot 30, Fig. 5, as an axis. The pivot is made of large diameter to reduce the tendency to error due to wear, and the portion of the support directly underneath the plate is of sufficientarea to afford an adequate support. Rotary movement is imparted to the plate by the stock as it moves into and through the machine. Partly enclosing the notched plate is a guide 31, Fig.

' 6, having a flat horizontal surface 32 and a shoulder 33 rising above it by an amount substantially equal to the thickness of, strip stock. The shoulder engages the back or outer edge of the bent strip stock and exerts some further bending action thereon if the outside diameter is not exactly correct. In other words, the guide serves as a sizing means. At or about the point where the stock leaves the guide and'moves on to the mandrel, the flat horizontal surface is depressed as indicated by the shade lines at 34.

The notched index plate performs an important function in the formation of the core. In addition to conveying the stock to the mandrel, it also insures the correct radial space of the teeth, bending them slightly where necessary to cause exact alignment in the finished core or helix. As the stock is bent by the rolls, the enlarged ends of the teeth move from parallel positions toward each other to radial positions having a common axis, and unless suitable means are provided to prevent it, there would be a tendency of the teeth to fail to align themselves properly with the final result that the spaces for the wire forming the coils would be less than they should be. It follows from the above statement that the pitch spacing of the notches should correspond accurately with that of the teeth and therefore of the coil slots. The notches in the plate are divided by the groove 35, Fig. 2, into two sets, an outer and an inner. In order that the teeth may be directed into the notches the instant the stock is passed through the rolls, the successive teeth must also seat themselves in the bottoms of the notches to obtain the desired bending action. Because the level of the space between the rolls is slightly below the top surface of the notched plate, it is necessary to provide means to cause the teeth to enter the notches without injury. At their bases, the teeth will ride over the top surfaces 36 between the outer row or set of notches 37 without difliculty by slightly cutting away the corners 38. The inner row or set of notches 39 are differently constructed, having three surfaces located at difierent levels. The top surface 40 of each part between notches is at the same level as the top surfaces 36 of the outer row, the surfaces 41 having one straight and one diagonal wall are slightly lower, and the third or bottom wall 42 of each notch is at the same level as the bottoms of the notches in the outer row. When the teeth finally seat themselves in the bottom walls of the notches, they occupy the positions shown in Fig. 2 beginning with the tooth directly above the axis of the plate.

Assuming the rolls 10 and 11 to be rolling the stock to circular form, the next thing to be considered is how to transfer the stock from the plate to the mandrel, bearing in mind that the teeth are held by the side walls of the notches and furtherthat they are the relatively delicate parts of the core. For this purpose, a stationary disk 43 is provided, Figs. 2 and 5, which is secured in place by screws 44 that enter the support 21, said disk holding the notched plate in its proper position. Secured to the disk is a tapered shoe or cam 45 which remains stationary in the position best shown in Figs. 3 and 4. As the stock advances, it rides up on the tapered shoe and is delivered to the mandrel 23. In addition to the shoe a pair of stationary guides 46 and 47 is provided both of which are of semicircular form and secured by bolts 48 to the stationary disk 43. The under surface of the guide 46 cooperates with the shoe 45 to direct the bent stock on to the mandrel and the upper surfaces of the guides 46 and 47 serv to compel the stock to move upwardly on the mandrel as fast as it is received. On the mandrel are axially extending splines 49 which are of a pitch and width to enter the spaces between the ends of the teeth and thus hold the helically wound core in place. The axis of the mandrel coincides with the axis of the notched plate but is inclined thereto. By reason of the inclined arrangement, the lower front edge of the mandrel .for the fixed supporting is brought into close proximity to the notched plate and the lowermost turn of the helix therein with the result that very little bending of the stock takes place in passing from one to the other. Moreover, the inclined arrangement affords the necessary space at the rear of the mandrel for the means for vibrating or agitating the coil to prevent it from clamping or binding on the mandrel, as will appear later. The groove 35 permits of the insertion of a tool to spring'the stock upwardly out of the notches at the start and get it on to the shoe 45. The tool may be a permanent part of the machine if desired. Just enough stock may be wound on the mandrel to form a single core or a greater amount may be wound and afterwards cut to the desired length.

The mandrel comprises a cylindrical body. .50, Fig. 5, having heads 51 which center the body and also form bearing surfaces thereon s indle 22, the latter being secured in the fisk 43. After the core is formed, it is annealed. During the annealing operation, it is desirable to confine the core or helix in its proper shape on a spindle 53 carried by the block 54," thelatter having a transverse pivot 55 shown in dotted lines in Fig. 6 on which it is free to oscillate. -On the upper forming roll 10 are two tapered projections or pins 56 which are positioned slightly eccentric to the axis of the roll so that as the roll rotates, they alternately engage the exposed end of the spindle 53 and raise and lower the roller 52 by a slight amount. The vibratory'movement of the roller causes it to alternately enage and release the coiled stock on the man- Srel with the result that the stock freely moves up the mandrel as the stock is fed thereto at the bottom. A limited amount of lubricant may also be used if desired.

In some cases due to electrical characteristics of the machine in which the edgewise wound core is to be used or to the character of the metal used in making the core, it is desirable to slightly thicken the peripheral edge of each turn of the'core so that it is exactly the same as the body ad'acent the base of the teeth as 'distinguis ed from closely approximating the same. Where such thickness is necessary or desirable, it may be brought about by the employment of a grooved roller 57, Figs. 1 and 6, located in a position to act on the strip stock after it passes between the rolls 10 and 11. It is pivotally supported on a lever 58 carried by the head. 59 indicates the pivot for the lever which is located in a slot therein. Carried by thelever are two adjusting screws 60 by means of which the lever can be adjusted endwise to change the region of contact of the grooved roller 57 with the bent stock. The pressure exerted by said roller may be adjusted by the adjusting screw 61. The strip stock on leaving the forming rolls enters the guide 31 and the teeth enter the slots in index plate 20, the projections on the periphery of the plate entering the coil slots and engaging the bottoms thereon. These projectionsprevent inward movement of the strip when heavy pressure is applied thereto by the roll 57. As a result of this pressure, the outer edge of the strip stock is slightly thickened. The space between the flanges on the roll is enough greater than the normal thickness of the stock to permit this thickening to take place.

The fact that the stock after passing through the machine rotates the notched index plate and also the coil receiving mandrel greatly simplifies the apparatus because it does away with all driving means and also i with equalizing means which would be necessary if both plate and mandrel were independently driven. Moreover, the use of freely moving parts tends to decrease the wear on their bearing surfaces and avoid troubles incident to lack of exact positionin and adjustment. j

at I claim as new and desire to secure by Letters Patent of the United States is:

1. In a machine of the character described, the combination of rolls for rolling toothed strip stock to form a helix with cdgewise disposed turns, a notched plate re ceiving the stock after it is rolled, a mandrel receiving the stock from the plate, means for guiding the stock from the plate to the malndrel, and power means for rotating the r0 s.

2. in a machine of the character described, the combination of rolls for rolling toothed strip stock to form a helix with edgewise disposed turns, a guide acting on the stock after it leaves the rolls to insure the proper diameter of the finished coil, a notched plate inside of the guide for'receiving stock from the rolls, a mandrel receiving coiled stock from the guide and plate, means for guiding the stock from the plate to the mandrel, and power means for rotating the rolls.

3. In' a machine of the character described, the combination of rolls for rolling toothed strip stock to form a helix with edgewise disposed turns, a plate having notches into which the teeth successively enter, a mandrel arranged to receive stock from the plate, splines on the mandrel having the same pitch distance as the notches in the plate, means for guiding the stock from the plate to the mandrel, and power means for rotating the rolls.

4. In a machine of the character de scribed, the combination of rolls for rolling toothed strip stock to form a helix, a stationary sizing guide through which the stock is forced by the rolls, a plate having notches to successively receive the teeth of the strip as it is coiled, a mandrel arranged to receive the stock as it is formed and retain it in helical form, means for delivering coiled stock from the plate to one end of the mandrel as it is formed, and power means for rotating the rolls.

5. In a machine of the character described, the combination of rolls for rolling toothed stock edgewise to form a helix, a stationary sizing guide receiving bent stock from the rolls, a notched plate partly enclosed by the guide and rotated by the stock, said notches being spaced to receive the teeth 011 the strip, a mandrel arranged to receive the bent stock from the plate, means for guiding the stock from the plate to the mandrel, splines on the mandrel having the same pitch relation as the notches in the plate to engage the ends of the teeth on the stock, said mandrel being rotated by the bent stock, and power means for rotating the rolls.

6. In a machine of the character described, the combination of means for winding a strip of sheet material edgewise to form a helix, a mandrel mounted to receive the coiled material, and an intermittently operating means acting on the coil to vibrate it and thus prevent it from clamping the mandrel as successive turns of the material are applied thereto.

.7. In a machine of the character described, the combination of means for bending a strip of toothed sheet metal to form a helix with edgewise disposed turns, a notched plate receiving the material as it is wound, a mandrel for receiving coiled stock. from the plate, a tapered guide over which the stock passes prior to its reception on the mandrel, and other guides which largely surround the mandrel and over which the turns at one end of the helix move in succession.

8. In a machine of the character described, the combination of means for bending a toothed strip of stock edgewise to form a helix, a means for successively bending the teeth to their respective radial positions as the stock moves through the machine, a means receiving the turns of the helix as they are successively formed, and a driving shaft for the bending means.

9. In a machine of the character described,

the combination of means for bending a toothed strip of stock edgewise to form a helix, a stationary sizing guide for the strip after it leaves the bending means, a rotary means for successively engaging the teeth on the strip and bending them to their respective radial positions as the stock moves through the-machine, a mandrel receiving the stock from the rotary means and rotated by it, and a driving means for the bending means.

10. In a machine of the chalracter described, the combination of means for bending a toothed strip stock edgewise to form a helix, a plate having a set of notches for receiving the base portions of the teeth of the strip after they have been moved to radial positions, a second set of notches for receiving the outer end portions of the teeth, said second set of notches increasing in depth by steps, and means for receiving the stock from the plate and retaining it in helical form.

11. In' a machine of the character described, the combination of rolls for bending a toothed strip of stock edgewise to form a helix, a horizontal plate for receiving the stock after it is bent, said plate having notches into which the teeth enter and are properly aligned thereby, a mandrel mounted above the plate to receive the stock, said mandrel being inclined to the face of the plate, a spindle for the mandrel, means for guiding the stock from the plate to the mandrel, a device for agitating the turns of the helix on the mandrel, and a power means for driving the rolls.

12. In a machineof the character described, the combination of a pair of slightly tapered rolls for bending a toothed strip of stock edgewise to form a helix, a sizing guide acting on the stock after it leaves the rolls, a notched plate partly enclosed by the guide which receives the stock from the guide and positions the teeth thereof, a mandrel for receiving the successive turns of the helix as they are discharged by the notched plate, splines on the mandrel engaging the inner ends of the teeth for holding them in position, means for guiding the stock from the plate to the mandrel, a device for agitating the helix on the mandrel, and a driving means for the rolls.

13. In a machine of the character described, the combination of a pair of rolls for bending a toothed strip of stock edgewise to form a helix, a notched plate receiving the stock from the rolls, a means acting on the peripheral surface of each turn of the helix for slightly thickening it, said means acting on the strip after it leaves the rolls, and a driving means for the rolls.

HELGE E. CARLSON.