US1086818A - Dynamo-electric machine. - Google Patents

Description

A.M.GRA.

DYNAMO ELECTRIC MACHINE. APPLICATION HLBD 001227, 1910.

Patented Feb. 10, 1914 UNITED STATES PATENT CFFICE.

ALEXANDER M. GRAY, 0F MILVAUKEE, WISCONSIN, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO ALLIS-CHALMERS MANUFACTURING COMPANY, A CORPORATION 0F DELAWARE.

Specication of Letters Patent.

DYNAlIO-ELECTRIC MACHINE.

Patented Feb. 10, 19,14.

To all whom it may concern Be it known that I, ALEXANDER M. GRAY, a subject of the King of England,` residing at Milwaukee. in the county of Milwaukee and State of Wisconsin, have inventedcertain new and useful 'Improvements in Dynamo-Electric Machines, of which the following is a full, clear, and exact specification.

This invention relates to dynamo'electric machines, and more particularly to means whereby such machines can be kept in a cool and economical operating condition.

In order to keep 'the temperature of dyna1no-electric machines within vcertain. prescribed limits, 'it is customary to provide them with some means of Ventilating, such as a fan :blade construction by means of which a forced circulation or dow of air is created. It is found that the currents of air which are drawn into a machine have a great tendency 'to Aeddy and circle around the various parts, especially if these parts extend or lie in the paths of the cooling cur rents. `Great attention is given to the cooling of windings, in which a considerable degree of heat is developed. In order to convey away heat thus developed, cooling duid currents are directed on the windingsl of dynamo-electric machines, but. due to the fact that these currents of fluid eddy they become heated quite excessively after circling around a coil or winding a very few times.

It is the object of this invention to provide simple and inexpensive means whereby this eddying or circling ot cooling currents will be overcome so that the cooling {iuid will come in contact only once with the operating structure or parts to be cooled and then pass out of the machine.

lThis invention is illustrated on the accompanying sheet of drawings in which Figure 1 is a longitudinal elevation, partly in section, ot an induction motor equipped with my invention; and Fig. A2 is a fragmentary end elevation, made on a smaller scale, of that shown in Fig. 1.

I do not intend to limit my invention as applied to induction motors but intend to use it in connection with all different types of dynamo-electric machines.

The various novel features of my invention will be described in the specification and particularly set forth in the appended claims.

lMounted upon the shaft 10 of the induc-A tion motor illustrated is a spider 11 com-- prising mainly a hub 12 and radial arms 13 which support an integrally formed rim 14. This rim includes an annular portion 15 against which a laminated core 16 is forced when mounted upon the rim 14. The laminatcd core is held between the annular portion 15 and an end plate 17, which is retained in position by a split ring 18 adapted to be secured in a slot in the rim 14. vThe core 16 is provided with a winding 19 including conductors which project beyond the core and are secured to shortcircuiting rings 20, which are provided with integrally formed i'an blades 2l. The shaft 10 rotates in bearings which are mounted in the bearing housings 22 formed integrally with 'the end housings 23. The end housings are secured to the yoke 24 of this machine by bolts 25. Sccnred'in the usual way inthe yoke of the machine is a stationary laminated core 26, which is provided with a vwinding 27 having end turnsprojecting beyond the core.

Then the machine is set in operationc'iirrents of air are drawn in through openings 29 in the end housings 23 by the action of the. fans 21. The air, after being drawnin, is further forced into intimate contact with the projecting end portions of the rotor and stator conductor windings to convey away the heat developed in said windings. Reiter-ating, there is a great tendency for these cnrrents of' cooling air, after having once passed the fans and end portions of the rotor and stator windings, to againrcircle around and traverse precisely tue same paths which they have previously traversed within the. machine. the air naturally is somewhat more heated a ud its capacity 'for absorbing heat from the windings is materially decreasedand limited. It is seen readily that if these same currents of air only circulate around the rotor and stator windings avcomparatively few times the air will become extremely warm, the heat developed in the windings of the machine will cease to be absorbed by the circulating currents and the machine will heat up more and more, making its operation dangerous, less economical than de- This time, however,

sirable and possibly render the machine useless. In order to prevent this continual eddying or circling of air currents around the' fans and windings of a machine after the air has been drawn in by the fans, means has been provided for directing these ucurrents of air out of the machine in a d1rec' These cone-shaped balfles may, however,\`. e

removablyv secured in position and may be located in any convement place or places w1th1n the housing as long as they intercept the paths of the cooling currents which tendY to eddy.

As here shown the bafilcs are secured t0 lha" end housings adjacent to the end portioLs of the windings so that the baffles div( le the opening formed in said end herring-into inner and outer parts. The air is drawn in through the inner part and forced out through the outer partot the end housings after having absorbed heat-from thewindings. T he bailles or delectors, which extend substantially longitudinally of rthe machine, as stated before are coneshaped or somewhat funnel-shaped so that theire is a nozzle action, the velocity of the air being increased upon entering. The air used. for cooling.r in addition to being driven out over the batlles, may escape through the opening 32 formed in the stator yoke. By meains of this arrangement a maximum amount of heat is absorbed by the ventilating lema-ents and conveyed away, maintain ii the machine in a safe, cool, and economical operating condition.

llihat i claim asv new is:

l. ifn a dynamo-electric machine, means for causing circulation of a cooling lluid through a portion ofL said machine, an end member provided with openings, and a coollng fluid guiding end member attached to thelinner side of said member to insure theA havilg projecting end portions, a ventilating end member surrounding said end port-ions, means for drawing in a coolingl fluid through one portion of said end member past the end portions of said windings, and means engaging said end member for deflecting said fluid flow from an eddying path and out through another portion of said end member.

4. In a dynamo-electricmachine, the combination of rotor and stator windings, an end member provided with a Ventilating opening, means for causing the circulation of cooling fluid through said end member and past portions of said windings, and fluid guiding means for insuring the discharge of said fluid adjacent to said guiding member, and in a direction parallel to .or

awavfrom the axis of saidv machine, where` by the circulation of heated fluid in the immediate vicinity of the machine is prevented.

Milwaukee, Wis., Oct. 1Q, 1910. In testimony whereof I alixmy signature, in the presence of two witnesses.

ALEXANDER M. GRAY.

Witnesses:

Y CHAS. L. BYRON,

LAURA HUENNEKENS.

Abination of rotary and stationary windings l

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