CA1056892A - Ventilating air baffle and deflector for a dynamoelectric machine - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A combination baffle and deflector for guiding ventilating air in and around a dynamoelectric machine is characterized by incorporating an annulus having in-tegrally formed base, leg and rim portions that enable the baffle and deflector member to be mounted on one end of a dynamoelectric machine to provide optimum air flow control while also providing means for blocking entry of rodents, snakes, and other similar foreign objects into the machine. In a combined form of the invention the unique baffle and deflector member is assembled with an electric motor that has plurality of axially extending, radially projecting cooling ribs on an exterior surface of its housing. Fin portions integrally formed with the baffle and deflector member are disposed to cooperate with the cooling ribs on the motor housing to provide an efficient and inexpensive screen over on portion of the ventilating passagew ys through the motor.

Description

21-VM_232 ~L~561 3~Z
The invention relate-R to v~ntilation m~an~ for dynamo-electric machines and more particularly to a co~bination baffle and deflector that embodie~ ve~tilating air guiding means integrally formed with screen and fin structure~ that ar~ operable to protect the interivr of a dynamoelectri~
machine on which the combination ba~fle and deflector is mounted ~rom injury due to entry therein of rodents, snakes ox similar hazardous intruders.
In the design and manu~acture of dynamoelectric machines it ha~ become customary to utilize various forms of air ba~1es and deflectors to guide ventilating air through and around heated components of the machines to optimize the ventilation of such parts. In ~eneral, such bafle and de-flector members are conventionally arranged in or adjacent to the end turn cavities of a motor or generator housing to direct ~treams o~ incoming cooling air onto the end turns of the motor stator and rotor and thence ~hrough exhaust ports to the exterior of the machine, Frequently, such ventilating arrangementq force the exhau~t air over the ex- :
terior sur~ce of the machine housing to help remove heat conductor to the housing from the stator lamination~ of the machine, Many examples of such prior art ventilation ar-range~nt~ for electric motors are available. One example of uch a conve~tional air inlet baffle and defle~tor arrangement is shown in U.S. Patent ~o. 2,725~706 - hukens which issued April 3, 1973 and is assigned to the assignee o the prssent invention, TypicalIy, such prior art ventilating arrangements for dynamoelectric machines either do not utilize screens or '~``, 30 other means to protect the interior o~ the machine from damage by intruding small animals or other foreign objects9 : -~
. or i~ su~h screen arrangements are u~ed ~hey are simply ', :, s ~S~ 21-VM-232 added as a separate component at a point in the air ~low stream spaced from the air baffle and deflector elements.
Also, in ~uch prior art structures it has been normal practice to provide separate air ba~fle member~ and air deflector members, For example, in the afore-mentioned Luken~ patent an air baffle member 23 is used to force cooling air inward toward the motor shaft while separate air deflectors are mounted adjacent the tips of a cooling fan 22 and on the circumference of end caps 18 to direct the exhaust air axially along heat radiating ribs 21 on the ~otor. In additic~n to being relatively expensive to manu-facture~ particularly in a vertical motor design where similar air ~low paths would normally be formed by goring operations on the end caps~ such articulated ventilating arrang2ments are ~airly complex to install and may be subject to increased maintenance ~xpense normally associated with a multipart machine in which the pal~ts are vibrated con-tînuously against one another or relative to other com-ponent~ o~ the machine. ~his proble~ is compounded in elec~ric motors where magnetic flux adds to the causes of vibration. As will be apparent from the following des-cription of the inventîon, tu the extent that compone~ts o~ :
such machines can be made o~ a non-magnetic material such ~c.
as moldable plastic~ this additional source of vibration can be mini~ized. ~hus it can be ssen that it w~uld be desirable to provide a ventilation means for a dynamoelectric , machine that would overcome these drawbacks o~ known prior ~;": ?
~ axt ventilatin~ arrang~ments.

.~ ~ A primary object of the invention i~ to provide a ', 30 combination cooling air baffle and d~flector ~or d~namo-.~ :
~lectric machin~s that overcomes the abov~-~entioned dis-advantage~ of prior art ventilating arrangements ~or su~h ~
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21-VM-~32 machines.
A further object of the invention is to provide a com-bination baffle and de~lector having integrally formed air-guiding vanes, rodent-blocking screens and fins that protect the air flow passagew~ys of the machines from penetration by such animals.
Another o~j~ct of the invention is to provide an im-proved dynamoelectric machine having a combination baffle and air de~lector that efficiently and inexpensiYely opti- -mizes the ventilating characteristics of a coolant air -: :
~tream while preYenting wildlife ~rom entering the machin~
Additional objects and advantages of the invention will be apparent to those .killed in the art ~rom the description of it that follows considered in combination with the at-tached drawings. .;
In one preerrad embodiment of the invention a com-bination air ba~fle and de1ector is provided with integral : base~ leg and rim portions that cooperats to deflect and : guide cooling air in an efficientp optimum manner due to the characteristics features of th~ structure, Moreover, in a combined ~orm of the invention the baffle and de~ -~lector i~ assembled with a dynamoelectric machin~ such as an el~ctric motor to ~orm part o the ventilating means o~
the machine, As thus assembled~ the combinatlon baffle and deflector i9 operable to guide inlet air around the end turns o~ a motor s~a~or and to exhau~t ~he air axially along th~ -exterior of the mo~or housing. Also5 the combination baffle and de~lector includes unique screen and fin arrangements - that operate effectively to block the entry of rodents and , ~ 30 othex ~mall wildli~e from ths intsrior of the motor housing.
Figure 1 is an axial cross sectional view o~ a dyna- :~
moelectric machine having mounted therein a combi~ation ~, .' .
~ ; - 3 -i6892 baffle and de~lector constructed pursu~nt to the lt~aching of ~he preserlt invention, Figure 2 i~ a ~ragmentary3 top plan view of a segment of the combination baffle and deflector illustrated in its as~en~bled position in Figure 1.
Figure 3 is a cross sectional view through one side of the combination baffle and de~lector taken along the plane 3-3 illustrated in Figuxe 2.
Figure 4 is an ~xial cross section, in recluce~ scale~
of the combination baffle and deflector shown in Figure 1.
- Figure 5 is a fragmentary, pexspective view o~ the : combination baffle and ~eflector shown in Figures 1-4.
; R~ferring now to Figure 15 it will be seen that there ~:
is shown a dynamoelectric machine 1 having a laminated ~tator 2 provided with a conventional stator winding 3 mounted thereon, a ,uitable 4 moun1ted ~or rotation on a ~ :
~haft 5 ~hat is journaled in housing end caps 6 and 7 and rotatably supported on guide bearin~ 8 and thrust bearing 9, respectively, mounted at tha bottom and upper ends o -:~.
the machine, ~he hou~ing for machine 1 i~ completed with a cen~ral ~ylindrical hou~ing portion 10 that i8 shrunk fit or otherwise suitably clamped around the laminated ~tator

2 in any conventional ~a~ner. To optimize the dissipating ; ch~racteristics o~ ~he machine, the ~entral portlon of the housing 10 i~ prvvided with integral, axially extending ribs lQA projecting radially outward thexe~rom.
Cooling air i~ drawn into the hou~ing of machine~
by a pair of fans 11 and 12 mounted, re~pectively, on the opposite end o~ rotor 4. Acces~ for the cooling air is provided by wall mean~ 6A in end cap 6 which operate~ in combinat~on with the upper end of the central housing portion :~ 10 to de~ina a plurality o~ air inlet passageways around ~he ' _ 4 --,, ,:

. 21-VM-~32 ~156)39~' end cap-supporting struts 6B and 6C~ etc, that are used ~o space the main body portion of end cap 6 fxom the upper end of the central housing poxtion 10. In this form of the invention thP end cap 6 is se~ured to the central housing ~ :
portion 10 by a plurality o~ bolts, such as the bolt 13 illustrated in Figure 1 to the left side of end cap 6.
From the descr iption o~ the invention ~hat follows, it will be appreciated that although the components of dynamoelectric machine 1 described above are exemplary o~ :
lQ s~ne type of machine with whie::h the colribination baffle and de1e~tor o* the invention will operate, okher types of dynamoelectric machines ars equally suitable for use in practicing the in~rention described hexein. ~hu~, various .
conventionally available dynamoelectric machine6 ox various co~inations o component parts thereo can be used in lieu of the particular structures and a~angemen~s ill_ .:
ustxated in Figure 1 and describedl generally above.
Pursuant to one aspect o~ ~hel present invention, there is shown assenibled in con~ination with th~3 motor 1 a com-bination baffle and deflector 14 ~hat will now be described in detail with re~er~n~e to Figures ~93,4 and 5 o~ the dxawing. Subsequan~ly~ the optimum operating characteri~tics of the cooling and wild~ife-blocking features o~ the com- -bi~tio~ baffle and de~lector 14, as used in a~sociation with a dynamoele¢tri~ machine such a~ machine 1, will be discussed in more detail with reference to Figure 1.
A~ ~hown best in Fig~res 3 and 4, the combination ba~i~le and dei~lec~or 14 u6ed :Eor guiding ventilating air in ~ .
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and arou~d dynamoelectric machi~e 1, compri~es an integral annulu~ (de~ignated 14~ that i5 formed o~ a thermo~etting : :
pla~tic material that is molded into rigid form in the pre-, . ~erred embodiment of the invention, but that ~ay be ~ormed ~ S _ ~
,:

6~2 21-VM 2~2 o~ any ~uitable moldable material in alternative ~mbodiments o the i~vention~ The annulus 1~ ha~ a generally U-shaped configuration as seen in cross section on the radial plane

3-3 through its central axis and one side thereo9 as de-picted in ~igure 3. Thi~ ganerally U-shaped configuration : :
consists of a base portio~ 14A that is ger~erally flat3 as shvwn, in this embodiment. Integrally formed with the base ~
portion 14A is one outer leg portion 14~ and an inner leg ~ : :
portiorl 14C that iæ sloped toward ~e center of~ the annulus 14, away from the base portion 14A, Finally, an inte~ral rim portion 14D extends outward from the junction of the outer leg portion 14B and the base portion 14A, In order ~:
to perform the desired air baflin~ and deflecting functions :
of ~he inventionl, the base portion 14A and the inner and outer leg po~tions 14B and 14C are made substantially im-pervious to air. On the other hanld~ the rim portion 14D
i3 provided with suitable wall means that define apertures through the rim portion ~o enable air to pass through it.
Sev~ral o~ these apertures are designated by the ~u~ber 15 in Figures 2, 3 and 5. In the preferred embodiment of the invention described hereirl the apertures 15 are de:Eined `. by a plurality o~ radially extendin~ spokes 16, 16A, 16B
etc. (Figs. 2 and 5) that are respectively disposed in a plane that extends sub~tantially perpendicularly outward ~ro~ the outer leg portion 14B of annulus 14 as clearly s~en in Figure 3. Cooperating with ~he spokes 16 is a ~irst outer ring portion 17 ~upported on the outer ends of the spokes 16, 16A etc. and a s2cond ring portion 18 that is supported on the spoke~ intermediate their respective ends to define the aperturss 15 in the form they are arranged as :~

a grid structure on ~.im portions 14D.
Pursuant to the present invention7 the aperture~ 15 a~

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~56~9Z 21_VM_232 defined by the spokes and supported rings 17 and 18 are made suf~iciently small ef~ctively to block the pas~age these obj~ctionable intruders are preYented from passing the rim portion when it is mounted in an air inlet pas~age-way, such as the passagew3y defined by w~ll means 6A of motor end cap 6 illustrated in Figure 1, Thus, it will be understood ~hat variou6 other suitable co~figurations or grid structures may be formed in the rim portion 14D
to afford this desirable ob~ective of the invention in alternative embodiments thereo~
A further unigue ~eature o~ the present invention is the pxovi~ion of a plurality of generally flat-sided fins 19~ 20, 21 etc. disposed between 1:he outer leg portion l~A
of the a~nulus 14, with ths flat ~;ide o~ each ~in being substantially perpendicular to $he base portion as ill-ustrated by the phantom Vi2W in ~:igure 2, ~he side elevation views in ~igures 3 and 4 and the perspective view I of Figure 5. The purpose of the :Eins lg is to provide a .~ mean~ for efectively blocking the entry o undesirable wildlif~ thxough the ~xhaust air passageways defined by the combination baf~le and deflector when it is mounted on a motor~ such as the motor 1 shown in Figure 1. mu~, it will ~e appre{!iated that a variety of sui~able con~igura- .
tions or tbe :eins lgD 209 21 etc. may be used in alternata em~bGdiments of ~he invention. However ~ in the preferred ~odiment being di~closed her~ the maximum length o~ -:
eac~h of l~he ~ins 19_21 etc. i~ at least 25 percent of th~
width o:E the base portion 14A of tha annulu3 and preferably :~:
is about one hal~ the radial width of the ba~e portion~
as hown. Likewise~ the width o:E each of thase fins, ; ~ . .
measured parallel to tha outer le~ portion 14B, is at least 2 5 percent of ~he length s:~f the outer leg portior~ and ~ .
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105689Z 21 -~M_232 preferably at least one half as long as outer leg portion 14B It has be~ found preferably~ as disclosed in this embodiment of the invention, to support each of the fins 19-21 etc. on both the base portion 14A and the outer leg portion 14B so that the fins are rigidly held in po~ition to resist forces that may be exerted on them by ~ :
animals attempting to destroy or de~lect the fins To accomplish such a ~upport in the disclosed form o~ the invention, ths fins are molded integrally with the other portions o~ the annulus 14, but i~ will be undlerstood that ot~er suitable support means can be used to afford this func:tion.
Now, re~erring again to Figuxe 1, an embodiment of the invention will be described in which the combination baffle and deflector annulus 14 i~ a~sembled in combination with a motor 1. In this preferred a~sembly, the base portion 14A of the annulus i8 po~ltioned ,adjacent to the upper end of the central housing portion 10 of the motor At the ~ame time the outer leg portion 14B ~f the annulus is dis-posed around the outer edges of one end of the cooling ribs lQ~ on the central hou~ing portion 109 as shown, and each of ths fins 19-21 etc, is positioned~ respectively, in- ~:
termediate the ends o two o~ the ribs (lOA) on central housing poxtion 10. Actually~ in order to most effectively ;
prevent the entry of animals into the motor 11, the ~ins should each be placed approximate~y the midpoint of the ` channel defined by the two ribs adjacent to it thereby to ;
; divide the cross se~tional area o~ the potential entry tunnels in half. To best a~sure the e~fect~veness o~ this ~:
~reening arrange~ent, ~h~ ~ins 19-21 eto. are formed 80 that each of them is approximately equal i~ radial length . to the radial width of the ribs lQ~ of a motor~ such as ~.

0568~2 the motor 1~ with which they are designed to be associated, Alternative relative radial widths of the ribs and axial lengths of associated fins of the baffle and deflector annulus may be used in alternate ~mbodimants of ~he in-vention, as determined desirable by the particular natuxe of screening size needed in given circum6tancQs.

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Claims (11)

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

1. A combination baffle and deflector for guiding ventilating air in and around an electric machine, comprising an annulus formed of moldable material, said annulus having a generally U-shaped configuration in cross-section on a radial plane through the central axis and one side thereof, said generally U-shaped configuration consisting of a base portion, an outer leg portion substantially vertically disposed relative to the base portion, an inner leg portion sloped toward the center of the annulus away from said base, a rim portion comprising a plurality of spokes disposed in a plane extending substantially perpendicularly outward from said outer leg portion from an area thereof closely adjacent the junc-tion of the outer leg portion and said base portion, said base portion and said inner and outer leg portions being formed as an integral unit and being substantially impervious to air, and wall means defining apertures through said rim portion to enable air to pass therethrough.

2. An invention as defined in claim 1 wherein said rim portion includes a ring portion supported on the outer ends of said spokes.

3. An invention as defined in claim 2 wherein said rim portion includes at least one additional ring portion supported by said spokes intermediate their respective ends whereby a grid structure is defined by the rings and spokes of said rim portion.

4. An invention as defined in claim 1 including a plurality of generally flat-sided fins disposed between said outer leg portion and said base portion with the flat sides of said fins extending substantially perpendicular to said base portion.

5. An invention as defined in claim 4 wherein the maximum length of each of said fins measured perpendicular to said outer leg portion is at least 25 percent of the radial width of said base portion.

6. An invention as defined in claim 5 wherein the width of each of said fins, measured parallel to said outer leg portion, is at least 25 percent of the axial length of said outer leg portion.

7. An invention as defined in claim 6 wherein each of said fins is supported by both said base portion and said outer leg portion.

8. An invention as defined in claim 4 in combination with a dynamoelectric machine having a housing comprising a central portion with axially extending ribs projecting radially outward therefrom, said base portion being positioned adjacent one end of said central portion of the housing, said outer leg portion being disposed around the outer edges of one end of said ribs, and each of said fins being positioned, respectively, intermediate and axially outward from the ends of two of said ribs.

9. An invention as defined in claim 8 wherein each of said fins is approximately equal in radial length to the radial width of said ribs.

10. An invention as defined in claim 8 including holding means for holding said fins in a fixed position relative to said ribs, said fixed position being effective to place one of said ribs respectively at the approximate mid-point between each pair of immediately adjacent ribs.
11. A combination baffle and deflector for guiding ventilating air in and around an electric machine, comprising an annulus formed of moldable material, said annulus having a generally U-shaped configuration in cross-section on a radial

Claim 11 continued:
plane through the central axis and one side thereof, said generally U-shaped configuration consisting of a base portion, an outer leg portion substantially vertically disposed relative to the base portion, an inner leg portion sloped toward the center of the annulus away from said base portion, and a rim having its radially inner end mounted closely adjacent the junction of the outer leg portion and said base portion with said rim extending outward from said junction in an axial direction to an extent that positions the outer peripheral area of the rim closer than the outer ends of either of said legs to said junction, said base portion and said inner and outer leg portions being formed as an integral unit and being substantially impervious to air, and wall means defining apertures through said rim portion to enable air to pass therethrough.