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Publication numberUS3832085 A
Publication typeGrant
Publication dateAug 27, 1974
Filing dateOct 4, 1972
Priority dateOct 4, 1972
Also published asCA996080A1, DE2345506A1
Publication numberUS 3832085 A, US 3832085A, US-A-3832085, US3832085 A, US3832085A
InventorsFauw R De, R Murley
Original AssigneeFord Motor Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Automotive fan shroud
US 3832085 A
Abstract
A shroud enclosing an automotive type fan has ridges projecting from the internal surface equally spaced circumferentially to provide a circumferentially undulating pattern to the axial flow of air forced through the space between the shroud and the fan to reduce the noise level of the shroud-fan combination.
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Description  (OCR text may contain errors)

United States Patent [191 DeFauw et a1.

AUTOMOTIVE FAN SHROUD Inventors: Raymond Henry DeFauw,

Dearborn; Raymond G. Murley, Dearborn Heights, both of Mich.

Ford Motor Company, Dearbom, Mich.

Filed: Oct. 4, 1972 Appl. No.: 295,048

Assignee:

US. Cl 415/119, 415/185, 415/DIG. 1 Int. Cl. F01d 25/04 Field of Search 415/182, 183, 184, 185,

415/186, 209, DIG. 1; 181/33 HA, 33 HB References Cited UNITED STATES PATENTS 11/1928 Schmidt 415/209 3/1935 Funk 415/209 5/1940 Forrest 415/209 1 Aug. 27, 1974 2,558,816 7/1951 Bruynes 415/D1G. 1 2,650,752 9/1953 Hoadley.... 415/D1G. 1 2,844,001 7/1958 Alford 415/D1G. 1 2,944,623 7/1960 Dodine, Jr 181/33 HB 3,610,262 10/1971 Wise 181/33 HA FOREIGN PATENTS OR APPLICATIONS 1,161,481 1/1964 Germany 415/D1G. 1

Primary ExaminerHenry F. Raduazo Attorney, Agent, or FirmKeith L. Zerschling; Robert E. McCollum [57] ABSTRACT A shroud enclosing an automotive type fan has ridges projecting from the internal surface equally spaced circumferentially to provide a circumferentially undulating pattern to the axial flow of air forced through the space between the shroud and the fan to reduce the noise level of the shroud-fan combination.

3 Clains, 3 Drawing Figures PAIENIEDmszmm FlG.3

FIG.&

AUTOMOTIVE FAN SHROUD This invention relates, in general, to an automotive type fan shroud. More particularly, it relates to a construction to reduce the noise level of a fan shroud combination.

The use of a shroud to surround an automotive type fan to increase the efficiency of airflow through the engine compartment invariably also increases the noise level of the combination. Devices have been suggested for reducing the noise level, such as, for example, changing the curvature in an axial direction of the shroud. Such is shown, for example, in US. Pat. No. 3,334,807, Fan, K. D. McMahan. Another suggestion is to decrease the turbulence of flow through the shroud to decrease noise level, as shown, for example, in US. Pat. No. 3,433,403, Fan Inlet Shroud, Gerlitz. It will be noted, however, that, in both of the above instances, the circumferential pattern of air as it flows axially through the shroud is the same as other constructions, the airflow pattern in an axial direction being changed but not'circumferentially.

The invention provides a construction to reduce noise level in which the circumferential pattern to the flow of air past the shroud and fan blades is undulating and provided by ridges located on the internal surface of the shroud equally spaced circumferentially around the shroud.

it is a primary object of the invention, therefore, to provide an automotive type fan shroud construction with a reduced noise level.

It is a further object of the invention to provide a fan shroud with internal ridges equally spaced circumferentially and projecting into the path of axial flow of air through the shroud so as to provide an overall circumferential undulating flow pattern to the air to reduce the noise level of the fan-shroud combination.

Other objects, features and advantages of the invention will become more apparent upon reference to the succeeding detailed description thereof, and to the drawings illustrating a preferred embodiment thereof, wherein;

FIG. 1 is an end elevational view of a fan shroud embodying the invention;

FIG. 2 is a side elevational view of the fan shroud of HO. 1, with parts broken away and in section, and,

HG. 3 shows a modification.

As stated previously, the fan shroud of the invention is adapted to cooperate with a fan of the automotive type, such as, for example, that indicated at in phantom in FIGS. 1' and 2. The fan would be mounted in a conventional manner on the engine, and would generally be of a stamped steel or similar design having a number (4 in this case) of circumferentially spaced fan blades 12. It will be understood of course that the number and spacing and construction of the fan play no part in the present invention and is optional insofar as the fan shroud construction is concerned.

The fan shroud in this case consists of a narrow section 14 of a thin cylinder that circumferentially surrounds and axially encloses the fan blades. It has a generally smooth exterior surface 16 that is welded or otherwise suitably secured to a generally rectangular supporting structure 18. The latter would be secured in a known manner adjacent the radiator of the motor vehicle for cooperation of the fan therewith to pull airflow through the radiator into the engine compartment.

As best seen in FIG. 2, the upper portion of the leading edge of the fan shroud 16 is formed with a cover forcontrol purposes, for example, to control the total flow of air and provide proper restriction, as is common in an automotive fan shroud installation.

Attached to the inner surface 22 of shroud 14 are a plurality of ridges or projections 24 that extend axially for approximately an inch, for example, and are oriented with an axis parallel to the axis of the shroud. The ridges have a finger-like appearance, and are equally spaced circumferentially around the shroud inner surface, for example, in this case, approximately four inches apart. The ridges have a generally hat-shaped or square-like cross-section, I although FIG. 3 indicates that the ridges 24' could have a half-round crosssection with a radius of approximately 0.25 inches. The radial projection of the ridges defines an annular clearance space between the ridges and fan blades, as shown. It will be obvious, of course, that other crosssectional configurations could be used without departing from the scope of the invention. As best seen in FIG. 2, each of the ridges 24 is tapered axially at its leading edge for a nonturbulent entrance of the air past the ridges.

From the above, it will be seen that the airflow past the interior of the shroud as a whole will have a smoothly undulating pattern in a circumferential direction, but that otherwise the axial flow of air is essentially in parallel streamlines except forthat portion of air blocked by the cover or baffle 20.

The above construction provides for the smooth entrance of air into the shroud, with the circumferentially undulating pattern reducing the shroud fan combination noise level.

While the invention has been described and illustrated in its preferred embodiments in the drawings, it will be clear to those skilled in the arts to which it pertains that many changes and modifications may be made thereto without departing from the scope of the invention.

We claim:

1. An automotive type fan shroud including a generally cylindrical section adapted to surround and axially enclose a fan and having circumferentially spaced projections from the internal surface to provide a circumferentially undulating pattern to the axial. flow of air past the shroud thereby reducing fan-shroud combination noise level the fan having blades enclosed by the shroud, a radial clearance space being provided between the inner extremities of the projections and the outer radial extent of the fan blades.

2. A fan shroud as in claim 1, the projections each having a finger like appearance oriented parallel to the shroud axis and the projections together being equally spaced circumferentially around the shroud internal surface.

3. A fan shroud as in claim 2, the projections having an axially extending taper at the air entrance end.

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4061188 *Mar 19, 1976Dec 6, 1977International Harvester CompanyFan shroud structure
US4152094 *Oct 18, 1976May 1, 1979Hitachi, Ltd.Axial fan
US4662818 *Jan 15, 1986May 5, 1987International Standard Electric CorporationTangential blower
US4927328 *Nov 1, 1989May 22, 1990Scoates William DShroud assembly for axial flow fans
US5277541 *Dec 23, 1991Jan 11, 1994Allied-Signal Inc.Vaned shroud for centrifugal compressor
US5507703 *Jul 15, 1993Apr 16, 1996Gkn Viscodrive GmbhDifferential drive
US5518364 *Mar 25, 1994May 21, 1996Deutsche Forschungsanstalt For Luft-Und Raumfahrt E.V.Method for the reduction of sound emission as well as for the improvement of the air output and the efficiency in an axial flow machine, and flow machine
US6123051 *Nov 3, 1998Sep 26, 2000Chrysler CorporationShroud for an engine cooling fan
US6264427Feb 10, 1999Jul 24, 2001Shop-Vac CorporationVaneless impeller housing for a vacuum cleaner
US6358005Sep 7, 2000Mar 19, 2002Shop Vac CorporationVaneless impeller housing for a vacuum cleaner
US6375416Jul 15, 1993Apr 23, 2002Kevin J. FarrellTechnique for reducing acoustic radiation in turbomachinery
US6485259Jul 24, 2001Nov 26, 2002Shop Vac CorporationVaneless impeller housing for a vacuum cleaner
US6746391 *Nov 7, 2002Jun 8, 2004Eppendorf AgSwing-out-rotor laboratory centrifuge with noise abatement system
US8777560Jun 23, 2010Jul 15, 2014Socpra—Sciences et Genie, S.E.C.Method and apparatus for controlling tonal noise from subsonic fans
Classifications
U.S. Classification415/119, 123/41.49, 165/135, 415/185, 165/122, 415/914
International ClassificationF01P11/10, F04D29/54
Cooperative ClassificationF04D29/545, Y10S415/914
European ClassificationF04D29/54C3