US2182654A - Split throw armature winding - Google Patents

Description

. 5, 1939. P. BOLLINGER SPLIT THROW ARMATURE WINDING Filed May 26, 1938 4 Sheets-Sheet l I INVENTOR Pau/ Bo/fingen BY ATTORN EY Dec. 5, 1939. P. BOLLINGER 2,182,654

SPLIT THROW ARMATURE WINDING Filed May 26, 1938 4 Sheets-Sheet? I II f1 1 1 v I 1 5'; 5 i W WITNESSES: INVENTOR Q Paul Bo/h'n'ger /3. a6 jam/M .BY a Z ATTORNEY Dec. 5, 1939 v BOLLINGER 2,182,654

SPLIT THROW ARMATURE WINDING Filed May 26, 1938 4 Sheets-Sheet 3 WITNESSES: INVENTOR 0% 6%. Paul Bow/yer.

BY 5. Z a 6 ATTORNEY Dec. 1939- BOLLINGER 2,182,654

SPLIT THROW ARMATURE WINDING Filed May 26, 1938 4 Sheets-Shet 4 WITNESSES: INVENTOR W 4 Pau/ 60/0/7991.

ATTORNEY Patented Dec. 5, 1939 UNITED STATES PATENT OFFICE SPLIT THROW ARMATURE WINDING sylvania.

Application May 26, 1938, Serial N0. 210,187

12 Claims.

My invention relates to an armature winding for dynamo-electric machines of the commutator type with particular emphasis on the connections and design of the winding for obtaining materially improved commutation.

One object of my invention is to provide for minimizing inductive disturbances of conductors and coils undergoing commutation by arranging the conductors of the coils in such order that the last conductor to be commutated has a self-inductance of a value approaching the minimum of that of any conductor of the coil.

It is a further object of my invention to provide a novel coil structure which may be assembled into the rotor of a machine in such a manner that a split throw coil winding may be obtained. The advantages of split throw coils are fully disclosed in Patent No. 1,298,705 granted April 1, 1919, to R. E. I-Iellmund. In a split throw armature, the conductors of the main turns of a coil usually are separated by the desired number of slots. However, one of the turns, preferably the last to be commutated, has a pitch slightly greater or slightly less than the slot pitch of the other turns of the coil. By such construction, all turns of an armature being commutated are made to be closely coupled for successive commutation. There is no abrupt change in mutual inductance between the turns being successively commutated. This construction has been found to be of great value in the minimizing of sparking during commutation. However, it has heretofore been the practice to design a split throw coil with three active portions, two of the portions embracing the conductors of the main turns whereas the third portion comprises that conductor which affects the split throw. The coil would necessarily be irregular in the portion which ordinarily would contain the split throw conductor. It was frequently necessary to increase the slot size in order to accommodate an irregular side portion of one coil with the split throw portion of the next coil.

It is a further object of my invention to design a coil which will have only two active portions but which can be connected to other coils to give the effect of a split throw armature winding.

It is a further object of my invention to design such a coil as mentioned in the previous paragraph so that the back end connections can be readily interconnected conductively.

It is still another object of my invention to design a coil which may be utilized in an armature ments combined with a commutating sequence of the conductors of the coil such as to minimize sparking during commutation.

Other novel features and objects of my invention, not specifically set forth above, but yet within the scope of my invention, will become more apparent from a study of the following specification when considered in conjunction with the accompanying drawings, showing my invention applied specifically to a coil having six conductors per side portion. However, I do not desire to be limited to the specific coil which I have chosen as the vehicle by which to describe my invention, since the principles of my invention are applicable to coils having more, and less, conductors per active side portion.

In the drawings:

Figure l is a developed symbolic showing of a coil in the slots of an armature rotor. This figure depicts the paths of current through the various conductors, their sequence of commuta- 5 tion and their back end connections by which I obtain a split coil elfect.

Figs. 2 through 8 show the separate turns and half turns comprising a. complete coil such as diagrammatically indicated in Fig. 1.

Fig. 9 is a perspective view of the back end of such a coil showing also how the back end connections and cross connections can be easily accomplished with adjacent turns and cross connections.

Fig. 10 is a. diagrammatic showing of the back end connections in one of my new coils and the adjacent ends of the adjacent coils.

Fig. 11 is a plan view of a coil indicating the conductor arrangement.

Fig. 12 is a view of the coil of Fig. 11 looking at it from the commutator or front end of the machine.

Fig. 13 is a view of the coil of Fig. 11 looking at it from the back or pinion end of the machine.

Fig. 14 is a View of the coil of Fig. 11 looking at a side thereof.

Referring more particularly to Fig. 1, I have shown diagrammatically an armature coil comprising active side portions A and B. Electrically, the armature coil is to have six complete turns, five of which are in the desired slot pitch, while the sixth is to be a split throw turn. In this description, by coil or armature coil I mean the structural unit, whereas by split throw coil 5 I mean the electrical efifect of the assembly of the coils in the armature, since my split-throw coil electrically embraces five and one-half turns of one coil and a half turn of an adjacent coil.

The side A is disposed in the bottom of slot C and comprises the bottom side portion of my coil. The side B is disposed in the top of slot D and forms the top coil side portion. The slots and D are preferably separated by desired slot pitch. The conductors within the side portions are of rectangular shape with the long sides b disposed generally radially, or parallel to the rotor teeth in the bottom side portion, and at right angles to the radial or parallel with the bottom of the slot in the top side portion and the short sides a, of course, perpendicular to the sides I). For the particular coil shown, the bottom side portion has conductors i, 2, 3, i, and 6 arranged in files of two with three ranks in the direction of the height of the slot. As is common in the construction of coils, each conductor of a coil side is insulated from the others, and the entire side portion is wrapped in appropriate insulation. It may be observed that the active conductors of each coil side form a quadrilateral in cross section, more specifically, of rectangular form.

The numerals 29, 3|, 33, 35, 39, ii and 33 represent risers from commutator bars Zil, 22, 2d, 26, 28, 30, 32 and 34, respectively. Conductor l is connected to riser M by an integral end connection I. Conductors 2, 3, 3, 5 and 6 are similarly connected by integral connectors 2, 3', d, 5 and 6', respectively, to the risers 39, 3?, 35, 33 and 3!, respectively.

The top side portion of the coil has conductors 1, 8, 9, iii, ii and i2 having integral end connections I, 8, 9, Iii, ii and i2 connected, respectively, to the risers ii, 3Q, 37?, 35, 33 and iii. The conductors 2 and i are integral with a back end connection 2'5. In the same way connectors 3 and 8; 4 and 9; 5 and it; 3 and ii are part of the same turns connected integrally by end connectors 38, 49, Elli and ti i, respectively. However, the conductors l and i2 do not have any integral and continuous connection between themselves. The conductor i has an integral end connection i" while the conductor has an integral connection 52'. The end connection 5" is connected conductively to the end connection !2"b of a coductor in the slot E adjacent to that of slot D but following it.

The end connection 52" is connected conductively to the end connection la of the conductor la in the slot F adjacent to the slot A but preceding it.

The conductors in slots E and F having reference characters composed of numbers and small letters combined correspond in position to the conductors of the coil side portions A and B with the different small letters representing different coils positioned in difierent slots. Thus, conductor la is in a bottom side portion of a sec 0nd coil, while conductor i222 is in the top side portion of a third coil. Reference may be had to Fig. 10 to more clearly indicate the relationship of these conductors.

The turns during commutation may be traced in Fig. 1 ii the commutator bar segments are assumed to move in the direction of the arrow shown and the brush t? spans two bar segments 32 and 34. The turn being shorted with the brush 45 spanning segments 32 and 36 may be traced as follows: bar 35, riser 33 to conductor 12b, end connection i2"b, end connection i, conductor i, end connection i, through riser M, to bar 32, and back to the brush 415. When the commutator moves so that brush i5 is over bar segments 323 and 32, it will be found that a turn comprising conductors 'l and 2 will be shorted, and as the rotor rotates the turns successively shorted comprise the conductors 8 and 3; 9 and d; it and 5; and ii and ii. The last conductor i2, however, is part of a turn embracing la. This split turn is the last to be commutated.

I-Ieretofore it has been the practice to preform the armature coil with the conductors i2 and la with an integral and continuous end connection joining them, while the conductor i formed part of a similar preceding coil B. In such instance the bottom side portion A would comprise five conductors, 2 through respectively, and a void later filled by the addition of the conductor 1 from an adjacent coil. The prior coils, therefore, were each made with three active side portions, one side having, as applied to the instant coil, six conductors, a second side, five conductors, and the third side, one conductor. 1e diificulty of making such coils, and assembling them in a rotor is at once apparent. By having the conductors i and E2 or" the coil with open back end connections properly disposed, I am able to effect conductive connection at the back end of the rotor to give the electrical effect of a split-throw coil, while mechanically being able to preform the coil with the entire number of conductor bars therein. In the example described, each side of the new coil has six conductors with two conductors, i and i2, having separate back end connections, as shown more clearly in Fig. 9, and which are conductively secured to half turns of other coils, as shown diagrammatically in Fig. 10. My new structure avoids the awkward, to say the least, insulating and assembling steps employed in the manufacture of the complete rotor with coils of prior design. My new coil enables the customary insulating and assembling steps ordinarily employed with the usual coils of two side portions only, the splitthrow being effected by suitable operations at the back end of the rotor after the coils are in place.

The commutator end connections and the back end connections of the integral turns are preferably made in accordance with the teachings of the patent to M. F. Jones No. 2,085,099 granted June 29, 1937. The commutator ends oi the turns are flattened and twisted as fully described in this patent. The end connections are twisted to change the position of the rectangles of each conductor in accordance with whether they lie in the bottom or top side portions of the coil, all in accordance with the general principles of the aforesaid patent. However, I have found that I may twist the back end connections of the coil in such manner as to occupy a minimum of space and also to provide spacing between the turns for effective and efficient ventilation.

Figs. 2 through 8 show more particularly the side view of the construction of the bends of the conductors forming my coil. Fig. 2 shows the conductor 6 having integral commutator end connection i and back end connection i. It will be observed that this conductor I, together with its end connections, comprises in effect only a half turn. Fig. 3 shows conductors 2 and 'E with their commutator end connections 2 and 'l and the back connection 27. The entire turn is a single piece of copper. In the same way Figs. 4, 5, 6, '7, 8 and 9 show the various turns ofthe integral conductors with their end connections, Fig. 8 showing the half turn comprising the conductor l2.

The arrangement of the back end connections are more clearly shown in the perspective view of the coil. The end bend 49 is small and is approximately at the center line of the coil. End bend 38 nests within end bend 27 and both are taped and lie to oneside of end bend 49. In the same way end bend 5H] nests within end bend 6H and both are taped and lie to the side of bend 49 opposite that at which the bends 38 and 2'! lie. Bends I" and I2" lie at what may be said diagonally opposed corners and are essentially in the same plane with those of the adjacent nested bends but spaced therefrom. This construction provides excellent ventilation.

The extremities of bends I and I2" are left bare and project in opposite directions, as shown, to facilitate connection to the proper half turn of the adjacent coils. The extremity of the half turn in the bottom side portion projects upward while the extremity of the half turn in the top side portion projects downward. When adjacent coils are assembled an extremity of an end connection such as I2" is substantially juxtaposed to an extremity such as la. of a-half turn of an adjacent coil. These extremities being bare, it is a simple matter to braze or otherwise conductively fasten them together and follow this operation by insulating the bare portions, the spacing of the turns facilitating the last operation. If desired, a cross connection can be formed to have its end terminate in proximity to the bare extremities of the half turns and all three may be conductively secured together as shown diagrammatically in Fig. 9.

It may be observed in Fig. 1 that with the movement of the commutator bars in the direction shown, the last conductor of the coil side portion B to be commutated is conductor 12. This conductor, together with conductor Ia of the adjacent coil forms a split-throw coil turn for coupling the inductance of the turns of the coils in slots 0 and D to the conductors in the adjacent slots of which F is one. With the direction of movement of the commutator bars reversed, the split throw is effected by conductors I and [2b. In other words, the specific embodiment described effects a split throw for a reversible dynamo-electric machine, such as, for for example, a motor adapted for railway traction. It should also be observed that conductors l and I2 are spaced from the bottom of slot C so that self-inductance of these conductors is at a minimum since of the coil side conductors, they are the furthest removed form the bottom magnetic portion of the slot. By this arrangement of the conductors, I obtain marked advantages of commutation as disclosed in the aforementioned patent to Jones and to Hellmund.

My new coil has the advantage of having only two active side portions insofar as its structural features are concerned, but can be connected to other similar coils to give the effect of a split throw coil having three side portions, the third including, of course, a conductor in the adjacent slot equivalent to conductors la or I 2b. Moreover, with my construction, I am able to obtain the effects of split throw coils for a reversible machine without the necessity of additional side portions to the coil. It is obvious that any number of turns may be included in the split throw by merely increasing the number of half turns in the two side portions of my new coil and properly connecting them together at their back ends.

While I have illustrated my invention in the form which I now believe to give the best mode of application thereof, it is obvious that many changes may be made within the spirit and scope of the novel invention which I have introduced. It is desired, therefore, that the appended claims be given the broadest construction consistent with their language, limited only by prior art.

I claim as my invention:

1. An an independent article of manufacture, an armature coil of two side portions comprising a complete turns and at least one additional onehalf turn, where n is any integer, said half turn having a back end and commutator end tip bared for electrical connections.

2. A split throw armature winding for electric dynamo machines having individual armature coils which before and after assembly on the armature each have two active side portions each having conductors symmetrically arranged in a regular quadrilateral section, integral and continuous end connections between conductors in said side portions and insulation binding each of said side portions and maintaining said form in total section, one of said side portions including a conductor having bared end tips at each of the front and back extremities.

3. A split throw armature winding for electric dynamo machines comprising two separate and complete armature coils of two side portions each and end connections between a conductor of one of the coils and a conductor of a second coil for obtaining the split throw coil efiect.

4. An armature coil for an electric dynamo machine, said coil having a bottom side portion and a top side portion, each portion having 12 conductors; the bottom portion conductors being identified by numerals l to 12, inclusive, in their order of commutation; the top portion conductors being identified by numerals n+l to 2n, inclusive, the conductors on both portions which are connected to a common commutator bar being separated by the numeral 11; the conductors on both portions separated by the numeral 71-! being integral with end connections; the first and 212th conductors having independent integral end connections adapted to be secured to the proper independent integral end connections of a second similar coil.

5. In a commutating electric dynamo machine comprising an armature coil for an electric dynamo machine, said coil having a bottom side portion and a top side portion, each portion having it conductors; the bottom portion conductors being identified by numerals I to n, inclusive, in their order of commutation; the top portion conductors being identified by numerals n+l to Zn, inclusive, the conductors on both portions which are connected to a common commutator bar being separated by the numeral n; the conductors on both portions separated by the numeral nl being integral with end connections; the first and 272th conductors having independent integral end connections adapted to be secured to the proper independent integral end connections of a second similar coil, the commutator bar connections to the conductors being such that the first or 211th conductors are commutated first or last depending on the direction of rotation followed or preceded in sequence by the others of the associated side portion.

6. An armature coil for an electric dynamo machine, said coil having a bottom side portion and a top side portion, each portion having it conductors; the bottom portion conductors being identified by numerals i to 72, inclusive, in their order of commutation; the top portion conductors being identified by numerals n+l to in, inclusive, the conductors on both portions which are connected to a common commutator bar being separated by the numeral 7!; the conductors on both portions separated by the numeral "rt-i being integral with end connections; the first and 2nth conductors having independent integr 'id connections adapted to be secured to the pi cper independent integral end connections oi a second similar coil, the integral end connections being such that there is a small central loop in the connection between two inner conductos of said side portions, with nested larger loops formed in the connections between other end connections of conductors in the side of portions, said larger loops being spaced from said smaller central loop, and said independent end connections in the plane of said larger loops and spaced therefrom whereby said end connections have ventilating spaces, and ready access may had for operations on said independent end connections.

7. The coil of claim l wherein said conductors are rectangular in section with sides a and and said integral end connections serve to twist the conductors so as to lie with sides a of side portion towards the bottom of an armature slot and sides b of the other side portion towards the bottom of an armature slot, said conductors with independent end connections preferably arranged to correspond.

8. The coil of claim 6 wherein said conductor are rectangular in section with sides a and b, and said integral end connections serve to twist the conductors so as to lie with sides a of or side portion towards the bottom of an armi-iture slot and sides 2) of the other side portion towards the bottom of an armature slot, said conductors with independent end connections preferably arranged to correspond.

9. In an electric dynamo machine armature having commutator bars, comprising an armatnc coil having a bottom side portion and a top portioneach portion having six conductors; the bottom portion conductors being identified by side r numerals 1 through 6 in their order of com mutation; the top portion conductors being identified by numerals 7 through (2 the conductors on both portions which are connected to a common commutator bar being separated by the numeral ii; the conductors on both portions separated by the numeral 5 being integral with end connections, the first and last conductors having independent end connections adapted to be secured to the proper independent integral end connections of a second similar coil, said side portions being arranged in three ranks of two conductors each, the integral end connections being such that there is a small central loop joining two conductors, with two nested larger loops on each side of said smaller loop and spaced therefrom and said independent connectors have oppositely projecting parts at diagonal corners, whereby said end connections have ventilating spaces, and ready access may be had for operations on said independent end connections.

10. In an electric dynamo machine armature having commutator bars, an armature coil having complete turns and a half turn terminating in a bared back end, an adjacent armature coil having complete turns and a half turn terminating in a bared back end, certain of said ends being arranged to lie in proximity to each other whereby the ends may be readily conductively secured and then insulated.

11. In an electric dynamo machine armature having commutator bars, an armature coil comprising complete integral turns and a half turn terminating in a bared back end, an adjacent armature coil comprising complete integral turns and a half turn turning in a bared back end, said ends being at relatively opposite diagonal corners oi their respective coils, and projecting towards each other.

12. In an electric dynamo machine armature having commutator bars, an armature coil having a half turn terminating in a back end, an adjacent armature coil having a half turn turning in a back end, said ends being at relatively opposite diagonal corners of their respective coils, and projecting towards each other, an end of a cross connection, and means conductively securing all said ends together.

PAUL BOLLINGER.

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