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Publication numberUS3627440 A
Publication typeGrant
Publication dateDec 14, 1971
Filing dateApr 7, 1970
Priority dateApr 7, 1970
Publication numberUS 3627440 A, US 3627440A, US-A-3627440, US3627440 A, US3627440A
InventorsCarl O Wood
Original AssigneeWestinghouse Electric Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Centrifugal fan
US 3627440 A
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Description  (OCR text may contain errors)

United States Patent 72] Inventor Carl 0. Wood Needham Heights, Mass. [21 Appl. No. 26,234 [22] Filed Apr. 7, 1970 [45] Patented Dec. 14, 1971 [73] Assignee Westinghouse Electric Corporation Pittsburgh, Pa.

[54] CENTRIFUGAL FAN 2 Claims, 3 Drawing Figs.

[52] US. Cl 415/53, 415/204, 415/219, 4l5/D1G. 1 [51 Int. Cl ..F04d 17/08, F04d 29/40 [50) Field 01 Search 415/204, 206, 53, 219, DIG. l

156] Relerences Cited UNITED STATES PATENTS 1,787,656 1/1931 Anderson 415/53 1,862,523 6/1932 Anderson 415/53 3,285,501 11/1966 McDonald 415/116 FOREIGN PATENTS 565,188 3/1958 Belgium 415/157 Primary Examiner- Henry F. Raduazo Attorneys-F. H. Henson and F. E. Blake ABSTRACT: An axial inlet for acentrifugal fan is provided with an inlet cone-shaped to converge at a distance in front of the inlet opening of the wheel sideplate to a diameter less than the diameter of the wheel inlet opening and then reversely curved to terminate adjacent the edge of the wheel sideplate opening. A seal plate may extend from around the exterior of the reversely curved portion of the inlet cone in a manner to overlap the front of the wheel sideplate and an inside edge of the sideplate opening wall may be chamfered towards the interior of the wheel in the direction of the periphery of the wheel.

FIG. 3

FIG. 2

INVENTOR 0. Wood EK/W/ ATTORNEY Curl FIG.

PATENTEU DEC! 4:971

\\\\\\ \\\\\\\\\N\\\\\\NI S E S S E N h W CENTRIFUGAL FAN BACKGROUND OF THE INVENTION It is known that the performance of an axial inlet centrifugal fan is related to the effectiveness with which the fan blades are loaded or in other words the effectiveness with which the inlet air is distributed uniformly over the full extent of the nose portions of the fan blades. The problem with an axial inlet fan is that the inlet air must be turned into the fan blades in a manner to uniformly distribute the air over the fan blading and there also must be a minimum of air leakage at the side plate inlet opening of the fan wheel.

PRIOR ART Reference may be made to the US. Pat. No. 3,285,501 issued to McDonald on Nov. 15, 1966 which discloses a prior arrangement of inlet cone for an axial inlet centrifugal fan that is however more complex and difficult to manufacture than the arrangement of the subject invention.

SUMMARY In accordance with the invention, the inlet cone for an axial inlet centrifugal fan is shaped to provide an effective boundary layer control for turning the inlet air to thereby uniformly load the fan blading. In addition, a seal plate together with a specified shaping of the wheel sideplate opening surface is provided to obtain an effective inlet air seal at the wheel sideplate. The centrifugal fan of the invention is of the type mounted in a casing and having a sideplate axial inlet opening for the fan wheel within the casing. One wall of the casing is formed as an inlet cone-shaped to converge at a distance in front of the inlet opening of the wheel sideplate to a diameter less than the diameter of the wheel inlet opening and then reversely curved to terminate adjacent the edge of the sideplate opening. In order to minimize leakage of air from around the inlet opening of the wheel sideplate, a seal plate is positioned to extend from around the exterior of the reversely curved portion of the inlet cone in a manner to overlap the front surface of the wheel sideplate. In order to further define a boundary layer control, an inside edge of the sideplate opening of the wheel may be chamfered toward the interior of the wheel in the direction of the nose portions of the fan blade and the periphery of the wheel.

Further features and advantages of the invention will be apparent with reference to the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view in section of a centrifugal fan embodying this invention;

FIG. 2 is an end view of the fan of FIG. 1 looking at its inlet end; and

FIG. 3 is an enlarged fragmentary view in section of the curved portions of the inlet cone showing details of the seal plate and chamfered edge of the radial sideplate opening of the wheel.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2 of the drawings it will be seen that the centrifugal fan of the invention is comprised of the fan casing generally shown at 10 within which is journaled a fan wheel generally shown at 11 mounted for rotation on the shaft 12. The casing 10 is provided with the inlet wall 13 and the outlet from the fan issues through the opening 14 of the casing 10. The fan wheel generally shown at 11 is provided with a back plate 15 and a front sideplate 16 between which are fastened a plurality of blades such as shown at 17 and 18. The front sideplate 16 is provided with an axial inlet opening shown at 20 and the inlet cone 13 of the housing 10 is generally coaxial with the fan wheel inlet opening 20.

Referring now more particularly to FIG. 3 of the drawing it will be seen that the inlet cone I3 converges to a point 24 which is of less diameter than the diameter of the sideplate opening 20 at a position in front of the wheel sideplate 16. From the point 24 the inlet cone is reversely curved as shown to terminate at25 adjacent the wheel inlet opening 20. In the preferred embodiment of the invention the point 25 at the inner end of the inlet cone 13 is curved to extend generally in alignment with the plane of the sideplate 16,

A seal plate 30 is secured by any suitable means such as welding to the exterior of the reversely curved portion of the inlet cone at the point 31 in a manner to overlap the front side of the wheel sideplate 16.

In the preferred form of the invention the inlet opening wall 20 of the sideplate 16 of the wheel is chamfered as shown at 35 to be angled inwardly toward the blade nose 36 and the periphery of the fan wheel.

As previously mentioned the provision of the smoothly curving surfaces of the inlet cone as shown from the point 24 to the point 25 provides a boundary layer effect to aid in turning the inlet air in a manner to uniformly load the noses of the fan blading. The combination of the overlapping seal sideplate 30 and the chamfered edge 35 of the sideplate opening also provides for an effective sealing of the air around the wheel inlet opening and assist in the boundary layer action to distribute the inlet air uniformly over the fan blade nosing.

Various modifications will occur to those Skilled in the art.

Iclaim:

l. A centrifugal fan comprising a casing, a fan wheel supported for rotation within said casing, said wheel having a radial sideplate with an opening forming an axial circular wheel inlet, the inside edge of said sideplate opening being chamfered towards the interior of the wheel in the direction of the periphery of the wheel, said casing having a wall forming an inlet cone concentric with said wheel inlet opening, said cone being shaped to converge at a distance in front of the wheel inlet opening to a diameter less than the diameter of said wheel inlet opening and then reversely curved to terminate adjacent the edge of the wheel sideplate opening substantially wholly within the confines of those radial planes defining the inner and outer axial limits of the chamfered portion of the sideplate opening for improving boundary layer control through said inlet.

2. The invention of claim 1 in which a seal plate extends from around the exterior of the reversely curved portion of said inlet cone in a manner to overlap the front of the wheel sideplate.

l i i l i

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1787656 *Sep 21, 1929Jan 6, 1931American Blower CorpInduction flow inlet fan
US1862523 *Oct 28, 1929Jun 14, 1932American Blower CorpInduction flow inlet fan
US3285501 *Dec 7, 1964Nov 15, 1966John E McdonaldCentrifugal fans
BE565188A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3887295 *Dec 3, 1973Jun 3, 1975Gen Motors CorpCompressor inlet control ring
US4915583 *Mar 17, 1987Apr 10, 1990Aciers Et Outillage PeugeotRadial-flow fan in particular for the air-conditioning of a motor vehicle
US4917572 *May 23, 1988Apr 17, 1990Airflow Research And Manufacturing CorporationCentrifugal blower with axial clearance
US5297931 *Apr 28, 1993Mar 29, 1994Airflow Research And Manufacturing CorporationForward skew fan with rake and chordwise camber corrections
US5489186 *Feb 15, 1995Feb 6, 1996Airflow Research And Manufacturing Corp.Housing with recirculation control for use with banded axial-flow fans
US5551838 *Sep 24, 1993Sep 3, 1996Abb Flakt AbInlet bell for centrifugal fans
US5735018 *Oct 2, 1996Apr 7, 1998Schiller-Pfeiffer, IncorporatedBlower for moving debris
US5855469 *Jul 17, 1997Jan 5, 1999Iowa State University Research Foundation, Inc.End seal design for blower
US6717114Dec 14, 2001Apr 6, 2004Maytag CorporationConvection fan assembly for a cooking appliance
US7186080Aug 11, 2004Mar 6, 2007American Standard International Inc.Fan inlet and housing for a centrifugal blower whose impeller has forward curved fan blades
US7261008 *Jul 30, 2002Aug 28, 2007Research International, Inc.Air sampler
US7476076 *Mar 30, 2006Jan 13, 2009Nidec Servo CorporationCentrifugal fan
US7591633 *Sep 13, 2005Sep 22, 2009Trane International, Inc.Centrifugal blower for air handling equipment
EP1039142A2 *Mar 21, 2000Sep 27, 2000Abb Flškt OyFan diffuser
WO1994008143A1 *Oct 6, 1993Apr 14, 1994Univ AlabamaInlet clearance gap seal
Classifications
U.S. Classification415/58.3, 415/914, 415/206, 415/204
International ClassificationF04D29/42
Cooperative ClassificationY10S415/914, F04D29/4226
European ClassificationF04D29/42C4
Legal Events
DateCodeEventDescription
Apr 1, 1985ASAssignment
Owner name: AMERICAN DAVIDSON, INC., 8111 TIREMAN AVENUE, DEAR
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION A CORP OF PA;REEL/FRAME:004386/0282
Effective date: 19841219