CA1056137A - Method of mounting a fan on a rotor - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A method of forming and mounting a fan for use in cooling an annular group of stator winding end turns in a dynamoeleatric machine. The method comprises the steps of forming in an annulus of a plurality of cooling means which remain disposed generally in the plane of the annulus, and the annulus is then secured to an end ring of a rotatable assembly for the dynamoelectric machine. Thereafter, the cooling means is deformed from the plane of the annulus to extend over the outer periphery of the stator end turns. The method of making a dynamo-electric machine and the method of effecting improved concentricity of a fan in the manufacture of a dynamo-electric machine are also disclosed.

Description

~S6~37 This application is a division Of Canadian Application Serial Number 207,066, filed August 14, 1974.
This invention relates to dynamoelectric machine and more particularly to methods of making them and of mounting and Eorming a component thereof.
As is well known in the dvnamoelectric machine art, most electric motors and generators comprise a stationary member, generally referred to as a stator, in ~hich a rotat-able assembly, generally referred to as a rotor, is rotatably mounted. Typically, the stator comprises a laminated mag-netic core having a cylindrical bore in which the rotor is received, and a plurality of winding receiving slots commun-icating longitudinally through the core between two core ;~ `~
faces. Electrically energizable windings pass through the ~, .
slots, which windings include end turns that pass between slots adjacent each of the two core faces to collectively ; ` ~-form two annular groupings of winding end turns. Normally, the stator also comprises two end frames or a housing secured `
to the core in spaced relation therewith and with the ~n annular grouping of winding end turns disposed therebetween.
A bearing is typically carried by each of the end shields through which bearing the rotor drive shaft is journalled. -During operation of dynamoelectric machines of the type just described, the temperature o~ the stator ~indings ma~ become sufficiently elevated to render the inclusion of air cooling means, such as fans, desirable for efficient mach-ine operation and longevity. ~eretofore, as exemplified by U.S.
Patent No. 3,243,617 to Cunningham, this has been accomplished ~ ; , ~C~56137 by provision of circularly disposed integral fan blades or vanes projecting from one end of the rotor ass~mbly concentrically wi-thin the annular grouping of winding end turns. Sets oE arcuate vanes are riveted or staked to the other end oE the rotor assembly, which vanes project out f~om within an annular grouping of end turns closely ad~acent the en~ of the grouping which end extends generally radially of the rotor shaft.
More recently a group of patents have issued, singularly and jointly to Lawrance W. Wightman, namely U.S. Patents No. 3,518,468, 3,518,471, 3,527,970, 3,538,598, 3,544,820, and 3,610,976. In these patents dynamoelectric machines are also shown having the aforementioned circularly disposed integral fan vanes projecting from the rotor ends coaxially of the rotor shaft. To two planar ends of these vanes, two annuluses are secured, respectively, by a set of screws, facing the ends of the annular grouping of end turns. Fan vanes are formed with concave surfaces provided in the annulus to rotate adjacent the ends of the end turns upon ~-rotation of the rotor.
As pointed out in Canadian Patent l,006,898 issued ; -March 15, 1977 to Baronc, while the above described means for cooling stator windings undoubtedly have at least some desirable features, there are also a number of disadvantages.
Typical of these disadvantages are individual mounting -~
of the fan blades to an annulus using screws and individually tapped holes in the annulus, an unnecessary axial elongation of the machine, and an inhibition of the free flow of air around the winding end turns.
Deployment in a particulate environment such as clothes

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;` :: ~, ~C~S6~37 dryers, has lead to the further problem of lint blocking the air flow.
The disadvantageous fea-tures of the past motor fans have been overcome by the apparatus and method disclosed in the aforementioned Canadian patent No.
1,006,898. Very briefly, the patent discloses a dynamoelectric machine having a rotor supported fan Eor cooling an annùlar group of stator winding end turns comprising an annular fan attached to rotor vanes and having an outer peripheral edge adjacent a set of fan vanes which are bent over to extend about the outer periphery of the annular grouping of end turns. Such an annular fan arrangement provides good cooling and .
air flow, is not particularly troubled by a particulate environment, and maintains the overall axial machine dimension within desired limits.
In addition to the foregoing, other dis-advantageous features were encountered in the production ~;
or manufacturing stages of the past motor fans. For example, in past production annular fans were produced by progressive dies which blank, punch, slit and form the fan from a strip of relatively thin sheet metal after ~;
which the fans are, for example, galvanized or given a ;
zinc coating and then stored for subsequent -:attachment to a motor rotor. During plating and storing, the already formed vanes or blades of the fan become entangled with other vanes and were difficult to untangle thus not only causing storage problems but also `~
wasting precious time at the production line. Further, the -above-mentioned entanglement along with other

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- 1056~37 handllng and productlon problem~ made lt difficult to malntain the desLred tolerances o~ inside and outside dlameter~ o~
~he past rans. Thu~, whe.n staked to the rotor, the concentrlcity o~ the past ~anes relatlve to the rotor were o~ten without tolerance llmits, and ln extreme sltuatlons, the vanes of the past fans struck the end turns or the motor houslng when turning.
A principle obJect Or the present invention ls to provlde a method Or ~ormlng and mountlng a fan for use ln coollng stator wlndlng end turns ln a dynamoelectrlc machlne, a method Or making a dynamoelectrlc machlne, and a method of e~fectlng 1mproved concentriclty o~ a fan in the manufacture Or a dynamoelectrlc machine which overcome the dlsadvantageous features Or the past methods, and thls, as well a~ other ob~ects `~
S and advantageous features of the present lnventlon, wlll be ~ :
~n part app~e~ and in part pointed out in the specl~icatlon :`
whlch rollow~.

Sum~a~y of the Invention In general, a method of thl~ lnventlon of formlng and mountlng a fan ror use in cooling an annular group of stator wlnding and turns ln a dynamoelectric machlne compriseA formlng ln an annulu~ ad~acent the outer edge thereof a plurality of coollng means whlch remaln dl~posed generally in the plane of the annulus~ The annulus ls secured to an end rlng of a rotatable assembly for the dynamoelectric machine, and the cooling mean~ are then deformed from the plane of the a~nulus : `

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to extend generally over the outer periphery of the annular group of stator winding end turns which may be disposed adjacent the fooling means.
In another method of this invention of making a dynamo- ;
electric machine, a c~enerally flat fan stamping is formed and mounted to one end of an at least partially completed rotatahle assembly with the axis thereof extending generally normal to the plane of the stamping, and portions of the stamping `
are thereafter bent away from the plane thereof. The rotatable :~
assembly with the fabricated fan.attached is then inserted onto :. :
a bore of a stator and supported for rotation therein.
In still another method of the invention for making a dynamoelectric machine, a generally planar member of sheet ~.
material is attached to a rotatable assembly for the dynamoelectric machine, and portions of the attached member are deformed ~ ~ ;
thereby to formfan vanes extending away from the plane of the member and disposed generally concentrically about the axis the rotatable assembly which is thereafter supported for rotation within a wound stator.
Thus, the invention in a preferred form is as follows: `-in the manufacture of a dynamoelectric machine having a fan attached to and rotatable with a rotatable assembly about its axis in the machine,.the axis being defined by a shaft with which the rotatable assem~ly rotates, the method of effecting improved concentricity of.the fan vanes about said axis of said rotatable assembly comprising the steps of: (a) placing a generally planar, annular fan member on an end of said rotatable .
: assembly in a located position which is generally concentric :~
with said axis of said rotatable assembly and which is -~
perpendicular thereto, (b) securing said fan member in said position on said end of said rotatable assembly., lc) locating -the fan and rotatable assembly.relative to a deforming means, B

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~05~37 the deforming means having a working axis bearing a fixed relation to said axis of said rotatable assembly, and (d) deforming a plurality of fan vanes from the plane of said fan member adjacent to its outer peripheral edge to positions extendiny generally perpendicular to said member whereby the deEormed fan vanes are deormed at places equally spaced from said axis of said rotatable assembly as defined by said shaft to provide concentricity of said vanes with respect to said axis oE said rotatable assembly.
FIGUR~ 1 is a cross-sectional view of a dynamoelectric machine embodied in this invention.
FIGURE la is an enlarged, exploded perspective view of the rotatable assembly of FIGURE l;
FIGURE 2 is a functional flow diagram of a process of assembling the rotatable assembly of FI5URE 1 emphasizing the steps relating to the fan; thereof embodied in the present invention; `
FIGURE 3 is a plan view of an annulus or fan component for the rotatable assembly of FIGURE l;
FIGURE 4 is a plan view of the fan of FIGURE 3 at a later stage of formation;
FIGURE 5 is a plan view of the fan of FIGURE 4 attached to the rotatable assembly;
FIGURE 6 is a plan view of the fan of FIGURE 5 after formation of a plurality of vanes;
FIGURE 7 is a functional flow diagram illustrating a -~
variation on the assembly process of FIGURE 2 and which is -also embodied in the present invention; and i~ FIGURE 8 is a perspective view of a completed rotatable assembly with the fan vanes formed and centrifugal switch in place. ~ -',. ~,' `.

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~056137 Referring now to the FIGURES 1 and la, there is shown generally at 1 a dynamo~lectric machine, such as an electric motor, having a stator 2 of stacked metal laminations, and windings 3 are disposed in the stator ~`
having an annular grouping of end turns ~ adjacent the opposite ends of faces of the stator. ~ plurality of beams 5 are contained in stator 2, and the opposite ends o the beam are connected by suitable means, such as disclosed in aforementioned Canadian Patent No. 1,Q06,898, with opposite end frames 6 having bearing means 7 therein. A rotatable assembly 8 generally comprises a squirrel-cage rotor 9 having end or short circuiting rings 10, 11 integrally cast or molded on opposite ends of the rotor, as well known in the art, and the mid-portions of a shat 12 is fixedly disposed in the rotor by suitable means, such as a press or shrink it or the like. Other components, such as a fan 13 and centrifugal switch 14, may also constitute components of rotatable assembly 8. Rotor 9 is rotatably received in stator 2, and opposite ends of shaft 12 are journaled in bearing means 7 of end frames 6 thereby to rotatably support rotatable asse~ly 8 in dynamoelectric machine 1 in predetermined spaced relation with the end frames. A
pair of retaining clips 15, 16 are predeterminately spaced apart on shaft 12, and thrust washers 17, 18 are adapted to bear against the clips and a part of end frames 6 to ;~
maintain the predetermined spaced relation of rotatable assembly 8 with end frames 6. Of course/ stator 2, rotatable assembly 8 and end frames 6 may also be disposed in the usual motor housing, as well known in the art.

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1056~L37 A plurality Or clrcularly dlsposed vanes 19 are lntegrally rormed wlt;h end ring ll and extend generally parallcl with ,, the axis o~ rotatable assembly ~. A mountlng or locating mean~, such as a de~ormable stud 21, is provided on the ends Or integral vane~ l9 ex~ending thererrom in a dlrection generally parallel to the axi~ Or rotatable assembly 8, and the ~tud~ are predeterminately located generally concentrically about sald axis. Seating or locatlng means, such a~ a plurallty of sur~aces or abutments 22, are also provlded on the ends Or vane~ l9 and are predeterminately formed generally perpendlcular to the axis Or rotatable assembly ll. I~ de~lred, each ~tud 21 may be provided wlth a conic recession 23 in the dlstal end thereo~ which aids derormatlon of the stud causlng it to extrude laterally when force 1~ applled thereto ln a direction generally parallel to the rotor axls, as discussed ~hereinarter.
A generally planar annulu~, such as an a~nular member or ~ -fan stamping 37 in the stage of manu~acture shown in FIGURE 4, i8 Pormed ~rom ~heet me~al materlal, ~u~h as steèl or the like, and may be coa~ed or plated, if desired. Stamplng 37 lq provided with lugs 39 extending ~nerally radially inwardly ad~acent ~ e inner peripheral portion or edgc 40 thereor, and each lug 1 provided with a locating or posltioning means, such a~ an opening, aperture, slot or indenture 41 or the like, whlch are also adJacent to the inner peripheral edge. Openings 41 are predeterminately formed and po~ltioned ~o a~ to mate with alternate ones Or studs 21J and the portion of lugs 39 ad~acent each opening 41 are di~po~ed ln seatIng or locatlng engagement ''`

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l~S6~37 on locating surfaces 22 or the ends of vanes 19 when stamping 37 is assembled onto rotatable assembly 8. As previously mentioned, studs 21 are predeterminately disposed on vanes 19 generally in concentric relations with the axis of rotatable assembly 8, and openings 41 are precleterminately formed to be received on or mate with the stucls ln locating engagement therewith; therefore, it may be noted that the concentricities of the inner ~:
peripheral portions and inner peripheral edge 40 are accurately maintained Further, since lugs 39 seat on surfaces 22 which are predeterminately perpendicular to the axis of rotatable assembly 8, it may also be noted that the general plane of stamping 37 is normal to said axis upon deformation of studs 21 into displacement preventing or locating engagement with a portion of 39 about openings 41 therein, as discussed in detail hereinafter.
Centrifugal switch device 14, which functions to electrically disengage start windings within stator 2 according to well-known techniques, may be provided with :
apertures 43 which, in conjunction with studs extending from end ring 10 and not visible in FIGURE la, allow a centrifugal mechanism 45 to be staked to end ring 10. A
flat or key slot 47 is also typically provided on one or both ends of rotor shaft 12 to aid in the attachment of pulleys or other devices. The precise sequence of fabrication and the forming fan 13 will be better understood by considering FIGURE 1 in conjunction with a sequence of other FIGURES.
Considering FIGURES 3, 4, 5 and 6 sequentially in con- ~-junction with the functional block diagram of FIGURE 2, blanking 49 and punching 51 indicate that a sheet of relatively thin _ g _ : :

10~6137 strip material is passed through one or more presses having sequential dies or a single complex die to blank out a fan blank, punch arcuate or annularly disposed ~ ;
apertures or vents 53 and remove the central portion so as to ;Eorm annulus or fan stamping 37 having lugs or protrusions 39 and inden-tur~s 41. When blanked, an outer peripheral po~tion or edge 54 of stamping 37 is provided with a plurality of serrations 54a. Slitting operation 55 oE
FIGURE 2 iS another (perhaps simultaneous) press operation and indicates that slits 57 of FIGURE 4 lying generally :in a tangential position about stamping 37 and intersecting with serrations 5~a are to be provided to aid in subsequent forming operations. At this point stamping 37 of FIGURE 4 is placed on the free ends of vanes 19, as illustrated in FIGURE 5, and studs 21 are deformed by staking, as well known in the art, to firmly attach or secure the stamping in locating and displacement preventing engagement to vanes.l9, as illustrated. As previously mentioned the coactions between the predeterminately `~
located studs 21 and lug openings 41 and between lu~s 39 and vane surfaces 22 is effective to predeterminately maintain a general concentricity of the inner portions of -. .-- ` `
stamping 37 relative to the axis..of rotatable assembly 8.
The exact degree to which rotatable assembly 8 is assembled prior to or subsequent to staking operation ::
59 is variable as will be more clearly seen in considering FIGUR~ 7; however, for the purposes of the process illustrated in FIGURE 2, it is assumed that all of the parts illustrated in FIGURE 1 have been assembled prior to the staking operation, as indicated by block 61.
The output product from the assemble and staking operation -10 - ;~

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~L056~37 59 appears as illustrated in FIGURE 5.
After staking fan stamping 37 to rotor end ring 11, vanes 63, which are portions of the stamping defined by slits 57, are deformed or bent out of the plane of the stamping generally along imaginary lines emanating radially from ~he center of the stamping so as to lie gen~ally perpendiaular to the plane of the stamping, as illustrated in FI~UR~ 6 and better seen in FIGURE 8. ~s previously noted, fan stamping 37 is predeterminately located on studs 21 of vanes 19 in a manner to obviate or substantially elimina-te the need for mounting the stamping with relatively exact concentricity between the inner portion or inner peripheral edge 40 of the stamping and the axis of rotatable assembly 8. It should also be noted that with the rotatable assembly located, -vanes 63 can be accurately bent away from the plane of the stamping by utili~ing the axis of the rotatable assembly as a reference location.
In other words, the vanes are bent with respect to the axis, i.e. to the shaft 12 which defines the axis, so that the vanes as bent are concentric to the axis. In this manner, each of the vanes are spaced equi-distantly from the axis of rotatable assembly 8 along the aforementioned imaginary lines emanating radially from the center of stamping 37 through which the axis of rotatable assembly 8 passes. Therefore the need which existed in the prior art for a relatively high degree of accuracy in making the fan stamping and in forming studs 21 is no longer necessary to achieve final bent vanes whiah are concentric to the axis. As the vanes are bent after mounting on the rotatable assembly, they can be accurately bent with -~
respect to the axis to make the bent blades concentric to the axis even with reduced accuracy in making the fan stamping. In other words, the predeter-mined location of the inner edge or margin 40 about the axis of rotatable assembly 8 and the deformation of vanes 63 from stamping 37 while it is so mounted on rotatable assembly 8 permits the substantial elimination of the need for substantially exact concentricity between the inner and outer edges 40, 54 of completed fan 13 and rotatable assembly 8. This deformation preferably is a simultaneous action :;

~OS6~7 on all Or vanes 63, and whlle the bend llne is lllustrated as lylng along a radial, thk~J reature, as well as the perpendioularlty o~ the vanes to the membcr, 1s eixemplary only. After- formlng of va.n~ 63, as l:llustrated by step 65 Or FIGURE 2, which correspond~
to th~ ~ra.nsit10n from the configuratlon illustrated ln FIGURE 5 to ~hat illustrated in FIGURE 6, rotor 9 Or rotatable a~sembly 8 i9 inserted or passed into the bore o~ stator 2 which has previously had stator windings 3 placed in the slots thereof, as depicted by step 67. In the flnal assembly of rota~able assembly 8, the ends of shaft 12 are disposed in bearings 7 o~ end rrame~ 6 thereby rotatably supporting rotor 9 relatlve to stator 2, as illustrated by step 69 in FIGURE 2.
FIGURE 7 illustrates a varlation on the process lllustrated in FIaURE 2 whereln like re~erence numerals illustrate slmllar steps. In the process of FIGURE 7, the fan stamping 37 ~s staked :
to an incomplete rotatable assembly 8. For example, end rings l~ ll and/or shart 12 may be assembled ln the partial rotor assembly step 71, and this incomplete rotor then receives fan stamping 37 during the assemble and ~take process 73 after which centr~fugal switch 14 is ttaked to end ring lO, ~`
retalnlng clips 15, 16 attached to the shaft, and thrust collars 17J 1~ paæsed over the shaft. This completion of rotatable assembly 8 is lllustrated by block 75, after which ran vanes 63 are formed, as ln the prevlously descrlbed process. The degree of completion of rotor assembly 8 prlor to the step of staki~ fan stamping 37 thereto ls .not crltical~ nor for that matter, is lt critical whether rotor 9 l~ completely assembled prior to the step of forming vanes 63. For example, vanes 63 :
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mlght be formed prlor to the placement of thrust collars 17, 18 on sha~t 12.
FI~URE ~ lllustrate~ completed rotatable assembly 8 ready to be rotatably supported wlthin stator 2 l.n the ma.nner 5 illu~trated ln FIGURE 8. In FIGURE 8, de~ormed studs 77 which ~unction to ~take centri~ugal swltch 14 to end rin~ 10 are now visible, as 13 the annular area or chamber between vanes 63 and va.nes 19, which annular region accepts stator wlndlng end turns 4 when rotatable assembly 8 ls placed within stator 2. ~:
Upon rotation o~ rotatable assembly 8, vanes 19J 63 blow alr over end turns 4 providi.ng a de3irable cooli.ng erfect thereo~.
I.n vlew of the roregoing, :It ls apparent that a novel method o~ maklng a dynamoelectrlc machine, a novel method o~
~orming and mounting a fan in a dynamoelectric machine, and a 15 . novel method of effecting improved concentricity of a ran in ;: the manu~acture of a dynamoelectric machlne are provided meeting ; all o~ the ob~ects a.nd advantageous ~eatures sst out hereinbe~ore, as well as othersJ and that the arrangeme.nt, shapes and details o~ components embraced by such novel methods, as well as mlnor .
variations~in the steps thereo~ may be made without departing ~rom the spirlt a.nd scope of the i.nventio:n, as set out in the clalms whlch follow.

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Claims (9)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. In the manufacture of a dynamoelectric machine having a fan attached to and rotatable with a rotatable assembly about its axis in the machine, the axis being defined by a shaft with which the rotatable assembly rotates, the method of effecting improved concentricity of the fan vanes about said axis of said rotatable assembly comprising the steps of:
(a) placing a generally planar, annular fan member on an end of said rotatable assembly in a located position which is generally concentric with said axis of said rotatable assembly and which is perpendicular thereto, (b) securing said fan member in said position on said end of said rotatable assembly, (c) locating the fan and rotatable assembly relative to a deforming means, the deforming means having a working axis bearing a fixed relation to said axis of said rotatable assembly, and (d) deforming a plurality of fan vanes from the plane of said fan member adjacent to its outer peripheral edge to positions extending generally perpendicular to said member whereby the deformed fan vanes are deformed at places equally spaced from said axis of said rotatable assembly as defined by said shaft to provide concentricity of said vanes with respect to said axis of said rotatable assembly.

2. The method as set forth in claim 1 comprising the preliminary step of predetermining the position for the placing of said member by disposing on said end of said rotatable assembly a set-of locating means generally concentric with said axis of said rotatable assembly and a set of locating surfaces generally perpendicular to said axis.

3. The method as set forth in claim 2, wherein the step (a) comprises passing a portion of said member over said locating means into locating engagement therewith and into seating engagement with said locating surfaces.

4. The method as set forth in claim 2, comprising the preliminary step of forming said fan member with a set of openings adjacent the inner peripheral edge of said member for locating engagement with said locating means.

5. The method as set forth in claim 4, wherein step (a) comprises, passing said set of openings over said set of locating means into locating engagement therewith and wherein said securing step comprises securing said member in said set of locating surfaces thereby disposing said member in its located position.

6. The method as set forth in claim 5, wherein said securing step comprises deforming at least some. of said locating means of said set thereof into engagement with said member about at least some of the openings of said set thereof to seat said member on said set of locating surfaces and prevent displacement of said member from said rotatable assembly.

7. The method as set forth in claim 6, wherein said securing step further comprises staking said some of said locating means into engagement with said member.

8. The method as set forth in claim 4, wherein said securing step comprises deforming at least some of said locating means into engagement with said portion of said member thereby to locate said member perpendicularly of said axis.

9. The method as set forth in claim 1, comprising the preliminary step of forming said vanes in said member adjacents its outer peripheral edge with said vanes remaining substantially in the plane of said member.