Centrifugal Fan Housing

Abstract

The centrifugal fan housing consists of not more than five parts, two of which are duplicate parts, which may be assembled with the inlet bell at either end of the housing and with the scroll located to provide for clockwise rotation or counterclockwise rotation of the fan. This arrangement provides a universal fan housing which is assembled from identical parts to suit any installation.

Description

BACKGROUND OF THE INVENTION

Conventionally, centrifugal fan housings embody a fixed design and structure whereby the fan must be oriented in a particular manner when it is installed for use; and the fan must be rotated in either a clockwise or a counterclockwise direction according to the design and structure embodied in the fan housing. This necessitates the manufacture and stocking of a large number of different parts in order that a fan of a certain capacity and arrangement is available for a particular installation.

SUMMARY OF THE INVENTION

This invention has as an object a centrifugal fan housing consisting only of duplicate end members formed with openings and two closures, one of which is formed with an inlet bell, and the other with a small opening to receive the motor shaft on which the fan is mounted. The fan housing also includes a scroll forming member formed of sheet material and preferably including a cutoff. The scroll member is mounted between the end members with the cutoff positioned at either side of the center of the fan housing, whereby the fan may be operated in either a clockwise or counterclockwise direction.

The duplicate end members may be formed at their periphery with flanges of substantial width with the flanges arranged in abutting relation to form the intermediate portion of the fan housing. Preferably, the end members are formed with narrow flanges and the scroll member is formed of substantial width, being fixed at its ends to the end member and forming the intermediate portion of the housing. The arrangement includes means for attaching the closures to the end members with the inlet bell located in registration with the axis of the scroll and, accordingly, the axis of the fan regardless of which way the scroll is assembled with the end pieces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a centrifugal fan housing embodying my invention;

FIG. 2 is a top plan view;

FIG. 3 is an end elevational view looking to the left of FIG. 1;

FIG. 4 is an end elevational view looking to the right of FIG. 1;

FIG. 5 is an exploded view of the components embodied in the fan housing;

FIG. 6 is a sectional view taken on a line corresponding to line 6--6 of FIG. 4 illustrating a double-ended fan mounted in the housing;

FIG. 7 is an enlarged sectional view taken on line 7--7 of FIG. 1;

FIG. 8 is a view similar to FIG. 4 with the housing components assembled for clockwise rotation of the fan;

FIG. 9 is a view similar to FIG. 5 illustrating a modified form of end members; and

FIG. 10 is a view taken on line 10--10 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The housing includes a pair of end members 10 complemental in form and dimension. The end members include a flat wall 11 having a linear edge defined by an outwardly bent flange 12. The sides of the end members extend downwardly from the ends of the flange 12 and merge with a semicircular bottom edge 13. The end members 10 are formed with identical and symmetrical openings 15, enlarged in a direction transversely of the end member. The peripheral edge portion of each end member extending from the ends of the flange 12 is bent inwardly to form a flange 20. The marginal portion 21, of uniform width, of the sidewall 11 about the opening 15 is offset inwardly as at 23 (FIG. 6).

Closures 25,26 are provided for the openings 15 in the end walls. These closures are in the form of flat plates symmetrically dimensioned and shaped to be received on the inwardly offset marginal surfaces 23. The closure 25 is formed with an inlet bell 27 and the closure 26 is formed with a relatively small opening 28. The inlet bell 27 and the opening 28 are located in an end area of the closures for a purpose herein later referred to. The plates 25,26 are formed with apertures 30, and the end walls 11 of the end members 20 are formed with like apertures 31. The apertures 30,31 are located symmetrically, whereby the end plates 25,26 may be rotated 180.degree. in either direction and affixed to the inwardly offset margins 21 of the end members as by fasteners 32 extending through the apertures 30,31. The closures 25,26 may be affixed to the end members by other means, as by being secured to the end members by adhesive, especially if these parts are formed of plastic material. Also, it will be apparent that other means may be employed for symmetrically positioning the closures 25,26 with their openings arranged in registration with the axis of the scroll by symmetrically arranged means other than the symmetrically arranged fasteners 32. Actually, the shoulder formed by the inwardly offset portion 21 of each end member is dimensioned and shaped comparable to the periphery of the plates 25,26 and accordingly provides means for symmetrically positioning the end plates.

The fan housing further includes a scroll 35 formed of sheet material. In the arrangement shown in FIGS. 1-7, the scroll 35 is formed at one end with a relatively narrow flange 37, and terminates at its opposite end in a cutoff 40 which may be provided by bending the sheet material, forming a plate 41, extending from the cutoff 40 to like ends of the flanges 12 (see FIGS. 5 and 7). The upper ends of the peripheral flanges 20 of the end members are bent outwardly to form relatively short flanges 48,49 which are offset downwardly from the plane of the flanges 12 a distance equal to the thickness of the sheet stock from which the scroll 35 is formed. The flange 37 and the cutoff plate 41 are positioned on these flanges 48,49 and secured thereto by screw fasteners or the like.

Also, in the arrangement shown in FIGS. 1-7, the side edges of the scroll member 35 are positioned on the inner surfaces of the peripheral flanges 20 of the end members. The latter are provided with holes 50 and the scroll member with holes 51 spaced complemental to the holes 50 for the reception of fasteners to secure the end members 20 to the side edges of the scroll 35. In this arrangement, the scroll forms the intermediate member of the fan housing.

Referring to FIGS. 2, 3, 4, and 7, the scroll forming member 35 is positioned with the cutoff plate 41 extending from the cutoff 40 to the flanges 49 to which the plate is secured. Accordingly, the scroll flange 37 is positioned and fixed to the short flanges 48. In order that the cutoff 40 be properly located and supported, the walls 11 of the end members 10 are formed with inwardly extending beads 60. Each end member is formed with a bead 60 positioned each side of the plane indicated by line 62 of FIG. 7 extending perpendicular to the flanges 12, this plane being located intermediate the ends of the flanges 12. There is also a circular bead 61 merging with the upper bead 60. It will be apparent, making reference to FIG. 7 particularly, that these beads 60,61 serve to locate the cutoff 40 and afford a support therefor together with the plate 41. The outer ends of beads 60,61 terminate in spaced relation to the adjacent portion of the flange 20, whereby the opposite end of the scroll member 35 can extend upwardly along the inner surface of the flanges 20 with the flange 37 overlapping the flanges 48.

With the scroll positioned as in FIGS. 3, 4, and 7, the closure 25 will be affixed to the end member 10 with the inlet bell 27 arranged in registration with the axis 63 of FIG. 7 of the scroll 35. In like manner, the closure 26 will be affixed to the opposite end member 20 with the opening 28 therein also located in registration with the axis of the scroll to accept a motor shaft 65 on which the fan 67 is mounted. Referring to FIG. 4, the fan will operate in a counterclockwise direction as indicated by the arrow 67. In FIG. 8, the enclosure 25 has been reversed to locate the inlet bell in the right-hand portion of the end member, in which event the fan will rotate in a clockwise direction as indicated by arrow 70 in that figure. It will be understood that the closure 26 will likewise be reversed to position the fan in the axis of the scroll.

In the arrangement shown in FIG. 9, the end members 10 are formed with elongated flanges 120, rather than the short flanges 20 as shown in FIGS. 1-7. The flanges 120 are secured together in abutting relation by any suitable means and form the intermediate portion of the housing rather than the scroll 35. With this arrangement, the scroll 135 curves downwardly only a short distance from the cutoff 40 inasmuch as the remainder of the scroll compartment is formed by the end member flanges 120. The scroll 135 is of sufficient width to extend to the walls 11 of the end members. The flanges 112 correspond to the flanges 12 in FIGS. 1-7. In the arrangement shown in FIGS. 1-7, the end members may be economically produced by being drawn from sheet metal. In the arrangement shown in FIG. 9, the end members with the flanges 120 may be molded from plastic material. In FIG. 9, the flanges 148,149 are comparable to the flanges 48,49 in FIGS. 1-7. The walls 11 of the end members may be formed with holes 80 to receive fasteners 81 to secure mounting legs 83 to the end members. In FIG. 6, a double-ended fan is mounted in the housing and, accordingly, a closure 25 is affixed to each end member to provide an inlet bell at each end of the fan.

The fan housing of my invention is particularly advantageous in that the need for separate inventories of parts for right- and left-hand fan rotation is eliminated. The production cost is materially reduced in that the end members are of identical symmetrical form; and in the arrangement shown in FIGS. 1-7, the capacity of the fan is increased by simply using a wider scroll forming member. The fan housings may be installed in back-to-back relation with a common motor mounted between the housings for driving both fans, the arrangement still permitting a choice of right-hand or left-hand fan rotation.

Claims

I claim:

1. A centrifugal fan housing for either left- or right-hand discharge from the fan housing comprising a pair of end members complemental in form and dimension, each of said end members including a wall having a lineal edge surface and being formed with an elongated opening extending in a direction parallel to said lineal edge surface in areas of the wall at opposite sides of a plane extending perpendicular to said lineal surface medial of the ends thereof, a scroll member terminating at one end at a cutoff, means for reversibly mounting said scroll member intermediate said end members with said cutoff having a downstream extending surface substantially coplanar with said lineal edge surface, with the cutoff extending inwardly from a selected end of said lineal edge surface and terminating in spaced relation to the opposite end thereof to provide a discharge opening in one direction, a closure for the opening in the wall of each end member, one of said closures being formed with an inlet opening in one end area thereof, the wall of said one end member and said one closure having symmetrically arranged means cooperable to fix said one end closure to said one end member with the axis of the inlet opening in said one closure arranged in registration with the axis of said scroll is in said one direction and said closure being adapted in the opposite end area of said elongated opening to fix the axis of the inlet opening in registration with the axis of the scroll in the opposite direction.

2. A centrifugal fan housing having means for adapting the fan housing for discharging in opposite directions, said fan housing comprising a pair of end members complemental in form and dimension and including a wall having a curved perimeter merging at its ends with a lineal surface, a scroll member mounted intermediate said end members, said scroll member terminating at one end at a cutoff, means for reversibly mounting said cutoff substantially coplanar with said lineal surface at a selected side of a plane extending perpendicular to said lineal surface medial of the ends thereof, the wall of one of said end members being formed with an elongated opening, extending in the area of said wall at opposite sides of said plane, a closure for said opening dimensioned comparable thereto, said closure being formed with an inlet opening, the wall of said one end member and said closure having symmetrically arranged means cooperable to fix said closure to said end member with the inlet opening in said closure in registration with the axis of said scroll in one direction of discharge and the wall of said end member and the closure member having means to fix said inlet opening in registration with the axis of said scroll when the discharge therefrom is in the opposite direction.

3. A centrifugal fan housing as set forth in claim 2 wherein the marginal area about said opening in said one end member is offset inwardly, and the perimeter of said closure being of complemental shape and dimension and overlapping said inwardly offset marginal portion of said wall.

4. A centrifugal fan housing as set forth in claim 2 wherein said opening is noncircular and the walls of said end members are formed on their inner surfaces with cutoff supporting beads at opposite sides of said plane, said beads extending in close parallel adjacency with said lineal surfaces, whereby said scroll and said cutoff may be mounted at either side of said medial plane.

5. A centrifugal fan housing as set forth in claim 1 wherein the closure for the opening in the wall of said other end member is formed with an opening to receive a fan supporting shaft, the wall of said other end member and said other closure having symmetrically arranged means cooperable to fix said other end closure to said other end member with said shaft receiving opening in registration with the axis of said scroll.