US2333200A - Rotor assembly - Google Patents

Description

, Nov. 2, 1.943 H, ROE 2,333,200

} ROTOR ASSEMBLIES Filed Nov. 8, 1941 IN VENTOR.

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Patented Nov. 2, 1943 ROTOR ASSEMBLY Howard A. Roe, Elyria, Ohio, assignor to The General Industries Company, Elyria, Ohio, a

corporation of Ohio Application November 8, 1941, Serial No. 418,378

4 Claims.

My invention relates to rotor assemblies for induction motors and relates more particularly for such rotor assemblies as are utilized in connection with small induction motors.

In certain prior assemblies with which I am familiar straight conductor bars of copper are inserted in the rotor core and copper end plates are provided on either side of a plurality of laminae making up the rotor core, the ends of the rotor bars being bent over, thus anchoring the conductor ends of such copper rods together and also binding the core laminae together.

It is an object of the present invention to so construct the rotor assembly of my invention as to eliminate the use of copper end plates.

Another object of my invention is to so construct the improved rotor assembly of my invention as to enable the same to be conveniently and quickly assembled, a minimum of parts being utilized therein, such assembly being inexpensive to manufacture and highly efficient in use.

A further object of my invention is to provide an improved rotor assembly wherein the contactlng end portions form a solid ring of contacting material.

Other objects of my invention and the invention itself will become apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of my invention is illustrated, wherein:

Fig. 1 is a top plan view of the rotor assembly of my invention;

Fig. 2 is a side elevational view of the rotor of my invention;

I Fig. 3 is a sectional view of the rotor assembly of Fig. 2;

Fig. 4 is a sectional view taken on the line AA of Fig, 1, the rotor shaft of Fig. 1 being omitted from this figure;

Fig. 5 is a fragmentary plan view of the conductor bars of Figs. 1 to 4 inclusive showing the.

same after an intermediate crimping operation; Fig. 6 is a top plan view of the conductor bars of Fig. 5 showing the same in their final position, as more completely illustrated in Fig. i and Fig. 7 is a sectional view of the rotor assembl similar to Fig. 4.

Referring to the figures of drawing, l0 represents a rotor shaft upon which is mounted a core II which is preferably composed of a plurality of laminations l2 superimposed upon each other, preferably formed of iron or alloy steel discs, the said discs being disposed in a pile, as stated, superposed one upon the other.

A plurality of equidistant perforations l3 adjacent the outer periphery of each of said discs II are suitably aligned whereby rotor conductors ll preferably constructed of copper or equally good conductive material may be projected therethrough. Saidconductor bars I! are straight throughout the greater part of their length and have tapered end portions I5 and i6 and said.

bars, after being-projected through the stack of core laminations so that equal lengths thereof project from both core ends, are then bent or crimped, as shown in Fig. 5, thus compressing the core laminations tightly together and then the tapered ends l5 and iii of said bars are bent simultaneously to high pressure in order to securely bind the same together whereby an emcient conducting ring is formed.

1 am aware that numerous and extensive departures may be made from the embodiment herein illustrated and described without however departing from the spirit of my invention and the scope of the appended claims.

I claim:

1. A squirrel-cage type rotor for a dynamoelectric machine comprising a stack of magnetizable discs, relatively spaced bars threaded intra peripherally through the discs and having 'outwardly projecting ends, said ends abruptly bent toward the stack axis and swedged against the stack end surface whereby said bar ends are flattened and broadened to eifect lateral pressure engagement between the adjacent side surfaces of adjacent bar ends and to firmly hold said discs in operative stacked relationship.

2. A squirrel-cage type motor rotor comprising a co-axial stack of magnetizable discs, a plurality of substantially parallel conductor bars threaded intraperipherally therethrough, and having end tips projecting beyond the flat end surfaces of the stack, said tips at each end of the stack, abruptly bent axially inwardly of the stack in relatively converging directions, and deformed by flattening pressure against said stack end surfaces to so increase the width of the converged tips, whereby the laterally expanded tips each exert such lateral pressure against adjacent tips as to effect a low resistance to electrical currents traversing the annular circuit of said contacting tips.

8. A squirrel-cage rotor for a dynamoelectric machine comprising a stack of magnetizable discs, and a plurality of substantially parallel electrical conductor bars threaded through said discs and having end portions projecting beyond the stack at both ends thereof, the portions of said bars located in the region of emergence from the stack being in relatively substantially spaced circular arrangement concentric with the stack axis, each projecting bar portion being abruptly bent in said region to deflect its tip laterally inwardly towards and against a portion of the end surface of the stack which is disposed between the stack axis, and the aggregated widths of said tips being slightly greater than the circular dimensions of the annular space into which said tip is moved by said bending as to effect wedging compressive stresses to be exerted by each tip against contiguous engaged sides of the adjacent tips, whereby good electrical conducting contacts are effected between the ring of engaged tips.

4. A squirrel-cage type rotor for a dynamoelectric machine comprising a stack of axially aligned magnetizable discs, all provided with a series of spaced intraperipheral openings, and a plurality of electrical conducting bars each threaded through corresponding openings of all said discs, each of said bars being generally of U-form, the yoke of each bar enclosed with the stack and the end arms being abruptly turned from said yoke inwardly along the adjacent end surface of the stack in the general direction of the stack axis, and the lateral confronting surfaces of corresponding arms of adjacent bars, progressively converging proceeding toward said stack axis, whereby said confronting surfaces, in the regions of the arm tips, are caused to contact, the radially inwardly disposed tip portions of all of said arms being additionally flattened against the adjacent stack end, to increase the contact pressure exerted laterally between said adjacent contacting arm tip surfaces to provide an annular electrical conducting circuit comprising the interengaged arm tips.

HOWARD A. ROE.

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