Note: Descriptions are shown in the official language in which they were submitted.
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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
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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
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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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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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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,
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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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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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A plurality Or clrcularly dlsposed vanes 19 are lntegrally
rormed wlt;h end ring ll and extend generally parallcl with
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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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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
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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
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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
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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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