US2890428A

US2890428A - Lamination stacking arrangements

Info

Publication number: US2890428A
Application number: US430194A
Authority: US
Inventors: Daniel J Sikorra
Original assignee: Honeywell Inc
Current assignee: Honeywell Inc
Priority date: 1954-05-17
Filing date: 1954-05-17
Publication date: 1959-06-09
Anticipated expiration: 1976-06-09

Description

LAMINATION smcxmc ARRANGEMENTS Filed May 17.1954

mmvron DANIEL J. SIKORRA ATTORNEY United States Patent LAMINATION STACKING ARRANGEMENTS Daniel J. Sikorra, Champlain, Minn., assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application May 17, 1954, Serial No. 430,194 4 Claims. (Cl. 336-217) The present invention relates to laminated, magnetic core structures and more particularly to improvements in their ease of magnetization by the arrangement or stacking of the laminations and by the relation of the laminations to the oriented grain structure of the material from which they are fabricated.

In core constructions currently in use, for such devices as magnetic amplifiers or very high primary reactance transformers, undesirable effects have been caused by the air gaps between abutted laminations and by the inefficient use of the oriented grain structure of the lamination material. The improved structure herein disclosed provides a core which overcomes the use of abutted air gaps in its magnetic circuit and allows greater ease of magnetization of the oriented grain structure of the core. The magnetic core is formed of a novel stacking of conventionalE and I or E and square laminations, where square refers to any lamination of a square or rectangular shape with an open center or window area. The members of the laminations may be of any desired proportions and are not restricted to those shown.

It is an object of this invention to provide a laminated core formed of conventional laminations, and having a greater ease of magnetization than conventional cores.

It is another object of this invention so provide an improved, laminated,'magnetic core structure in'which the oriented grain structure and magnetic circuit are gen erally in the same direction.

It is also the object of this invention to provide an improved core stacking to permit a magnetic circuit to be formed which, for practical purposes, eliminates the necessity of the flux crossing through an abutted air gap.

These and other objects of this invention will become apparent from the reading of the attached specification together with the drawing wherein:

Figure 1 is an exploded view of an arrangement of E and I laminations:

Figure 2 is an exploded view of an arrangement of E and square shaped laminations;

Figure 3 is a side view of a core formed of laminations shown in Figure 1 and having a coil on the center leg of the core.

The laminated, magnetic core structure of the subject invention, as is shown in one form in Figure 1, is made of laminations in the form of an E 10 and laminations in the form of an I 11. The E 10 and I 11 laminations are formed of a magnetic material which is produced to have an oriented grain structure in the direction of the arrow 13. The I laminations 11 are abutted to the heels 14 of the E laminations 10 so that the oriented grain structure indicated by arrows 13 in the E laminations 10 are at right angles to the oriented grain structure in the I laminations 11. The combination of E 10 and I 11 laminations are alternately stacked so that the I laminations 11 of a layer overlay the ends of the

legs

15 and 16 of the E laminations 10 in adjacent layers.

In the core structure disclosed above, a typical magnetic circuit follows two paths and neither path crosses through the air gaps between the heels 14 of the E laminations 10 and the associated I laminations 11. The two paths followed by the flux in the improved core construction, for example, would be as follows:

The first path for flux originating in the center leg 16 of an E lamination 10 would be to follow the oriented grain structure in the direction of arrow 13 in leg 16 until it reached the heel 14 which is integral with its leg 16, then divide and move crossgrain in the integral heel 14 until reaching legs 15. At legs 15 the flux would again flow along the legs 15 in the direction of the oriented grain structure indicated by the arrow 13 until reaching the end area of legs 15. From the end area of legs 15 the flux flows to adjacent I laminations 11 through lapped joints, then in the adjacent I laminations 11 in the direction of the oriented grain structure indicated by arrow 13. When the flux reaches the lapped area between the I lamination 11 and the leg 16 in which it originated, it returns through the lapped area between them to complete its circuit.

The second path for flux originating in the center leg 16 of the E lamination 10 would follow the oriented grain structure in the direction of the arrow 13 in leg 16 until it reached the heel 14 which is integral with its leg 16, then flow through lapped joints to the legs 16 adjacent to it, through the lapped joints to the I lamination 11 in its original level. Upon reaching the I lamination 11 the flux would flow in the oriented grain structure in the direction of arrow 13 and return to legs 15 through lapped joints and complete its circuit as described above.

From the above description of fiux paths, it can be seen that at no time is the flux required to flow through the abutted air gaps between E 10 and I 11 laminations, and that flux flow is generally in the direction of the oriented grain structure of the core.

This invention is not limited to the specific configuration shown in Figure 1. Figure 2 shows another core construction utilizing this invention, and which contains alternately stacked E laminations 10 and square laminations 12, where square refers to any lamination of square or rectangular shape with'an open center or window area. In this combination a typical flux path is through the center leg 16 of the E lamination 10, lapped joints from leg 16 to leg 21 of the square lamination 12, through leg 21 and lapped joints to legs 15 of the E lamination 10 of its original layer, through lapped joints from legs 15 to leg 20 of the square lamination 12 and back through lapped joints between leg 20 and leg 16 of the E lamination 10. It can be readily seen from Figure 2 that this path follows the oriented grain structure indicated by arrows 13 in all legs and that no abutted air gaps are present. The stacking disclosed in Figure 2 provides for a core which contains only 50 percent as many laminations in the center leg 16 as in the outside legs 15 in combination with the square laminations 12. This arrangement is advantageous in certain core applications.

As shown in Figure 3 the laminations can be stacked with relation to a prewound coil or coils 22, with leads 23, in a conventional manner. It is understood that coils may be arranged on the core structure on any leg or in any number desired. The laminations may be held in place by any convenient means such as a clamp, nuts and bolts, or such means familiar to those versed in the art. Since the abutted air gaps between E laminations 10 and I laminations 11 do not enter the magnetic circuit, their spacing is less critical than in conventional types of stackmg.

In general, the arrangements of laminations in Figures 1 and 2 can be fabricated rapidly, economically, rigidly 3 and have a greater ease of magnetization than conven tional cores using the same core material.

In considering this invention it should be kept in mind that this disclosure isintended to be illustrative only and the scope of the invention is to be determined by the appended claims.

I claim as my invention:

1. In a magnetic core, a plurality of layers of laminations with oriented grain structure, each alternate layer having at least a first type of member and each other alternate layer having at least a second type of member, the first type of member having a plurality of legs integral at one end only with a transversely extending heel portion joining said legs at said one end, said legs being unconnected at their opposite ends and the oriented grain structure being parallel to said legs, the second type member including a rectangular portion of the same length as said heel portion and having the grain structure extending longitudinally thereof, said layers being stacked with the rectangular portion of said second member over- 0 lapping the unconnected ends of the legs of the members of said first type in adjacent layers to provide a magnetic circuit between said legs through said rectangular portions in the direction of grain orientation.

2. In a magnetic core, a plurality of layers of laminations with oriented grain structure, each layer comprising a first type of member and a second type of member, the first type of member having a plurality of parallel legs integral at one end only with a transversely extending heel portion joining said legs at said one end, said legs being unconnected at their opposite ends and the oriented grain structure being parallel to said legs, the second type of member being I-shaped and having the grain structure extending longitudinally thereof, said second type of member being disposed in each layer adjacent to and parallel With the heel member of said first type of member, said layers of laminations being so stacked that the legs of said members of the second type overlap the unconnected ends of the members of said first type in adjacent layers to provide a magnetic circuit between said legs through said members of the second type in the direction of grain orientation.

3. In a magnetic core, a plurality of layers of laminations with oriented grain structure, each layer comprising an E-shaped member and an I-shaped member, the

E-shaped member having three parallel legs integral at one end only with a transversely extending heel portion joining said legs at said one end, said legs being unconnected at their opposite ends and the oriented grain structure being parallel to said legs, said I-shaped member having the grain structure extending longitudinally thereof, said I-shaped member being disposed in each layer adjacent to and parallel with the heel member of said E-shaped member, said layers of laminations being so stacked that the I-shaped members overlap the unconnected end of the legs of said E-shaped members in adjacent layers to provide a magnetic circuit between said legs through said I-shaped members in the direction of grain orientation.

4. In a magnetic core, a plurality of layers of laminations with oriented grain structure, each alternate layer having at least a first type of member and each other alternate layer having at least a second type of member, the first type of member having a plurality of legs integral at one end only With a transversely extending heel portion joining said legs at said one end, said legs being unconnected at their opposite ends and the oriented grain structure being parallel to said legs, the second type of member being in the form of a frame having opposite rectangular portions of the same length as said heel portion and having the grain structure extending longitudinally of said rectangular portions, said layers being stacked with one of the rectangular portions of each of said second members overlapping the unconnected ends of the legs of said members of said first type in adjacent layers to provide a magnetic circuit between said legs through said one of said rectangular portions in the direction of grain orientation.

References Cited in the file of this patent UNITED STATES PATENTS 428,575 Stanley May 20, 1890 FOREIGN PATENTS 618,114 Great Britain Feb. 16, 1949 151,310 Australia July 26, 1951 693,288 Great Britain June 24, 1953 291,922 Switzerland Oct. 1, 1953 1,054,551 France Feb. 11, 1954