US1871238A - Dynamo electric machine - Google Patents

Description

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6 6M411. J? A I A'TTORNEY Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE MALCOLM D. ROSS, OF PITTSBURGH, AND BENNIE A. ROSE, OF WILKINSBURG, PENNSYL- VANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY,

A CORPORATION OF PENNSYLVANIA DYNAMO ELECTRIC MACHINE Application filed December 19, 1930. Serial No. 503,446.

This invention relates to dynamo-electric machines and particularly to fabricated frames for turbo-generators.

Prior to our invention, fabricated frames for dynamo-electric machines have followed very closely the well established designs for east frames, in that the frame usually consisted of a heavy outer shell or frame inside of which strengthening ribs or ring members were welded. This construction was not only unnecessarily heavy but involved an unnecessarily large amount of tedious interior welding, because it was necessary to place the ribs or ring members in place inside of the shell member and then weld the ribs in place from the interior of the machine.

According to our invention, the heavy external shell, usually embodied in both fabricated and cast frames, has been dispensed with, and the reinforcing ribs held in place by spacing members extending directly through openings in the ribs and welded thereto. Our construction eliminates the necessity of internal welding and permits all welding to be done at the greatest advantage, while, at the same time, eliminating a considerable portion of the welding.

A further advantage lies in the fact that the spacing members may be tubular, so that they may be utilized to conduct ventilating fluid into certain portions of the machine.

It is an object of our invention to provide an improved fabricated frame for a dynamoelectric machine.

It is a further object of our invention to provide an improved ventilating system for such machines.

Other objects and advantages of our invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings in which:

Figure 1 is a perspective view of a skeleton frame;

Fig. 2 is a fragmentary view of our spacing member, and

Fig. 3 is an end view, partially in section, of our improved frame.

The apparatus disclosed in the drawings comprises a plurality of spaced rolled steel ribs 1 of so-called sheet steel, but may be special forms or ordinary rolled shapes bent and welded. The ribs may be of any suitable thickness, depending upon the overall size of the machine or any other circumstance of their use or installation. Preferably, the ribs 1 are constructed by cutting or burning out from rolled sheet metal plates. Each of the rib members 1 is provided with a plurality of alined openings 3 through which are inserted tubular spacer members 5. The spacing members 5 are connected to each of the ribs 1 by filet-welds 6 between the walls of the tubing and the side of the rib.

The ribs are also provided with offset footreceiving recesses or stops 8 to which are secured, preferably by Welding, mounting feet 10 which, in this instance, are composed of bars welded in the recesses in the ribs. For the purpose of securing light Weight and a minimum amount of material, the foot-receiving recesses 8 are so placed that the foot bars 10 eliminate two of the tubular spacing members 5.

Each of the spacing members 5 is provided with a plurality of lugs 12 extending inwardly of the machine and of such height that the tops of the lugs extend beyond the inner circumference of the ribs members. Also at the points where the spacing members 5 have been displaced by the feet members 10, suitable lugs 14 are welded directly to the rib members.

To complete the frame, end plates 15 are keyed into the end ribs. The end plates are provided with a plurality of openings 18 adapted to receive dove-tail bolts 20 on which the stator laminations 25 are stacked.

The preferred method of constructing our frame comprises burning out a plurality of ribs from sheet material of the desired thickness, and providing the ribs with a plurality of aliued openings 3, after which the rib members are assembled in spaced relation, and the preformed tubular spacing elements 5 are inserted through the openings and welded in place. After the spacing members have been welded in place, the foot members are then likewise welded in place. The bolt-supporting lugs 12 are then welded to the spacing members or to the ribs, as occaray-'1.-

sion may require. When this skeleton-like framework has been completed, a preformed end plate 25 is keyed in position by the keys 27, and the dove-tail bolts 20 are inserted, so that they lie adjacent to the bolt-supporting lugs 12. The laminated segments 25 of the stator are then assembled against any suitable jig (not shown) with suitable dovetails 32 engaging the dove-tail bolts 20.

When sufficient laminations 25 have been applied to pass one of the supporting lugs, the dove-tail bolts 20 are filet-welded to the lugs 12 as at 30, after which a further section of core is applied in like manner, and the dove-tail bolts are welded to the next succeeding lug in like manner. The operation is repeated until the entire core has been assembled, after which the second end plate is keyed in position, and the major portion of the frame is complete.

A light sheet-metal shell 35 is secured to the exterior of the ribs in any desired manner, as by tack welding or by screws.

WVe have found it desirable to provide our frame with one or more longitudinally extending support members 36, as an added convenience in applying the sheet-metal shell. By the employment of these longitudinal supports, it is possible to utilize comparatively small sizes of sheet-metal lagging and still maintain an air-tight covering by welding the sheets together at the longitudinal support, or even by securing the ends of the sheet directly to it.

In the preferred design, we desire to introduce ventilating fluid into one of the channels, usually the center channel, formed between the frame ribs 1. To accomplish this, We have provided our spacing members 5 with a plurality of small spirally arranged openings 40 having a total opening equal to at least twice the total cross-sectional area of the tubular members. The object of arranging these small openings in spiral formation is to retain the greatest possible strength in the tubular member, but, at the same time, permit sufficient outlet area.

We do not desire to restrict ourselves to the specific embodiment of our invention herein shown and described, since it is evident that it may be changed and modified without departing from the spirit and scope of our invention, as defined in the appended claims.

We claim as our invention:

1. A fabricated frame for a dynamo-electric machine comprising a plurality of spaced-apart rib members to provide a plurality of ventilating ducts about the machine, seats on each of said ribs for receiving feet members, and feet members secured to said seats, said ribs having alined openings therein, tubular spacing members extending through said openings and secured to each of said ribs, said tubular spacing members being provided with openings communicating with one of said ventilating ducts.

2. A fabricated frame for a dynamo-electric machine comprising a plurality of spaced-apart rib members to provide a plurality of ventilating ducts about the machine, seats on each of said ribs for receiving feet members, and feet members secured to said seats, said ribs having alined openings therein, tubular spacing members extending through said openings and secured to each of said ribs, said tubular spacing members being provided with openings communicating with one of said ventilating ducts, lugs secured to the spacing members and adapted to support core bolts, dove-tail bolts secured to said lugs, and a laminated core secured on said bolts.

3. A fabricated frame for a dynamo-electric machine comprising a plurality of ribs defining a plurality of annular ventilating ducts, said ribs having a plurality of alined openings therein, tubular spacing members extending through the openings and welded to the ribs, said tubular members being provided with openings for discharging ventilating fluid into one of said ventilating ducts.

4. A fabricated frame for a dynamo-electric machine comprising a plurality of ribs defining a plurality of annular ventilating ducts, said ribs having a plurality of alined openings therein, tubular spacing members extending through the openings and welded to the ribs, said tubular members being provided with openings for discharging ventilating fluid into one of said ventilating ducts, bolt means for receiving the laminated core, a laminated core held by said bolt mleans, and a cover secured exteriorly of said r1 s.

5. A fabricated frame for aturbo-alternator comprising a plurality of ribs cut from sheet material and having an annular opening adapted to receive the stator core of the alternator, said ribs having also a plurality of alined holes bored therein, spacing members assembled through the bored holes and welded to said ribs, bolt-supporting lugs welded to said spaced members, end plates secured to the end-most of saidribs, dovetail bolts supported by said end plates, and a core supported in predetermined relation to said ribs by said bolts.

In testimony whereof, We have hereunto subscribed our names this 12th day of December, 1930.

MALCOLM D. ROSS. BENNIE A. ROSE.

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