US2662686A

US2662686A - Fan wheel

Info

Publication number: US2662686A
Application number: US283044A
Authority: US
Inventors: Donald F Wuerfel
Original assignee: EDMUND E HANS
Current assignee: EDMUND E HANS
Priority date: 1952-04-18
Filing date: 1952-04-18
Publication date: 1953-12-15
Anticipated expiration: 1970-12-15

Description

Dec. 15, 1953 D. F. WUERFEL 2,662,686

FAN WHEEL Filed April 18, 1952 2 Sheets-Sheet l INVENTOR.

a g/vnw A ll/l/ERFEL A TTOP/VEY Dec. 15, 1953 D. F. WUERFEL FAN WHEEL 2 Sheets-Sheet 2 Filed April 18, 1952 INVENTOR. DOA/0L0 F. LUUERE L BY M&

A 77' OE/VE Y Patented Dec. 15, 1953 UNITED STATES PATENT OFFICE FAN WHEEL Donald F. Wuerfel, Detroit, Mich., assignor to Edmund E. Hans, Detroit, Mich.

2 Claims.

This invention relates to improvements in fan wheels or impellers, and refers particularly to a fan wheel or impeller including a disc having blades extending at right angles from its periphery and parallel with its axis.

It is an object of the invention to provide a fan wheel or impeller of the type above stated wherein the blades are all integral with a single disc, and their number and width are such as to provide maximum efficiency and air output, thereby rendering it unnecessary to utilize a plurality of superimposed concentric blade-equipped discs in order to obtain efiicient operation; and wherein the disc and all its blades are blanked and formed in two simple operations.

Another object of the invention is to provide such a fan wheel or impeller wherein the disc and blades are so reinforced and strengthened by their formation and relative arrangement that no appreciable distortion or deformation occurs when the fan is rotated at relative high speed and the blades are of normal length. Moreover I also provide supplemental means which may be employed for reinforcing the blades and preventing them from spreading when they are unusually long or the fan is intended to be rotated at very high speed.

A further object of the invention is to provide such a fan wheel or impeller wherein the inner face of the disc is of irregular form so that no air flowing into the fan for discharge by the blades can remain stationary adjacent the said inner face but is retained in motion for immediate discharge. It will also be noted that the blades are so formed relative to the disc that they are effective throughout their entire length from the said disc to their outer extremities for discharging air.

Figure 1 is a plan view showing the blank out of which the fan wheel is made, and

Figure 2 is a side view thereof, partly in section.

Figure 3 is a perspective view of the fan wheel, and

Figure 4 is a side elevation thereof.

Figure 5 is a plan view looking into the fan wheel, and onto the inner face of the disc.

Figure 6 is an inverted plan view looking onto the outer face of the disc.

Figure 7 is an enlarged section on the line 1--l of Figure 5, and also includes an annular reinforcing member to prevent the blades from spreading at very high speeds.

Figure 8 is an enlarged sectional view on line 88 of Figure 6.

Referring to the drawings, l designates a blank 2 stamped out of a single sheet of material, usually aluminum. This blank consists of an annular disc 2 centrally apertured at 2a and having a plurality of identical, uniformly spaced fingers 3 extending outwardly therefrom. These fingers, which are of uniform width throughout their length, consist of inner portions 3a which are radial to the axis of the disc 2; intermediate portions 31) which are curved; and outer portions which are disposed at substantially degrees to imaginary lines extending radially from the axis of the disc and passing centrally through the inner portions 3a. The opposite corners of the fingers 3 are usually rounded at their outer extremities as shown at 30!, and the adjacent inner margins of each adjacent pair of fingers 3 are connected by substantially semi-circular peripheral portions 2b of the disc 2 so that the inner ends of the fingers 3 are slightly spaced from one another, and also to strengthen the fingers at their roots.

When the blank I is formed the fingers 3 are folded to constitute blades 4 having their outer portions 4a extending longitudinally substantially parallel with the axis of the disc 2 and transversely substantially radial to the said axis. During this folding operation the blades 4 are also bent transversely throughout their length to add strength and rigidity, the formation of their outer portions 411 being such that their leading faces 41) are transversely somewhat concave to increase their operating efficiency, and this concavity at the inner extremities, as illustrated in Figure 8, provides means for strengthening the junctures between the blades and the disc. When the blades 4 are formed their inner extremities 40 remain substantially radial to the disc axis and their intermediate elbow portions ad, which are formed out of the curved intermediate portions 3b of the fingers, are so folded that the inner and outer edge faces of the outer portions 4a of the blades lie substantially in radial alignment relative to the axis of the disc 2. Moreover the folding is such that the outer ends of the inner blade portions 40 and the adjacent extremities of the elbow portions 4d not only provide very strong rigid connections to support the outer portions to but also constitute emcient operating parts of the blades so that air is discharged by the blades throughout their entire length for immediately adjacent the disc 2 to their outer extremities.

Prior to completion of the forming operation the inner annular portions 20 of the disc 2 is dished or laterally offset in the same direction as that in which the blades 4 extend; and formed in the disc 2 and extending the entire distance from the annular dished portion 20 to the inner extremity 4c of each blade is a rib or corrugation 2d which projects laterally from the outer face of the disc 2, is radial to the disc axis, and is in radial alignment with the said inner extremity of one of the blades. It will thus be noted that these ribs 2d project from the opposite face of the disc to the dished annular portion 20. On the inner face of the disc 2 radial grooves or flutes 2e are formed which constitute the inner sides of the said ribs or corrugations 2d and because of the circularly irregular surface thus formed, air entering the fan wheel for dis charge thereby cannot lie dormant against the inner face of the disc.

The ribs 2d materially strengthen the disc and this strengthening is partly attributable to the fact that the ribs project on one side of the disc and the dished portion 20 projects on the other side. Again due to the fact that the ribs 2d are in radial alignment with, and form inward concave continuations of the concave inner extremities of the blades, further stiffening both of the disc 2 and the blades 4' results. Though the blades are transversely somewhat folded throughout their length their surface width is uniform throughout their length, and again by shaping the. blank as shown and described herein the required number of blades of the proper width to. affordmaximum efficiency are all formed integral with a single disc.

The central aperture 2a of the disc 2 is usually enlarged after the forming operation has been completed to insure absolute concentricity of the disc 2-, and it, is: then mounted upon a tubular hub 5. In the present instance the hub 5 is of reduced diameter from one end as shown at 5:2. This reduced hub portion is inserted through the aperture 2a, preferably with a washer E. lying againstv each side of the disc, and the outer extremity of. the reduced hub end is then riveted over asshown at Bbto; hold the. disc'2 and washers 6 immovable on the hubfor rotation therewith.

Due. to the reinforcement of the disc 2 and blades 4" above, described it is found that my fan Wheels. are so rigid that they will not show any perceptible distortion when made, of relatively thin. metal provided the blades. are of normal length-and the fan wheel is rotated at normal speeds. If fans having exceptionally long. blades are to be rotated at very high speeds an annular reinforcing member may be utilized to prevent the blades: from, spreading. Figure '7 shows an annular reinforcing member consisting of a wire ring 1. engaging grooves 8' formed", in the pres.- ent instance, in: the outer peripheries of the blades 4 adjacent their outer ends.

While in the foregoing: the preferred embodiment. of the invention ha been described and shown iti'ss understood. that. alterations: and modifications may be'made thereto. provided the said alterations and modifications fall within the scope of theappended claims.

What I claim is:

l. A fan wheel comprising an annular sheet metal disc having its inner annular portion dished or laterally offset relative to the outer peripheral portion of the disc, blades integral with and projecting from the disc, ribs or corrugations in the disc and projecting laterally outward from the side of the disc remote from its offset annular portion, said side constituting the outer face of the disc, each rib being substantially in radial alignment with one blade, each blade being folded from adjacent its inner extremity so that the outer portion of the blade extends longitudinally substantially parallel with the axis of the disc and transversely substantially radially to the disc axis, and said blades having said outer portions transversely curved whereby their leading faces are somewhat concave, each rib extending into an adjacent blade and terminating at the outer end of the blade between the side edges of the blade toform said transverse curvature, and the inner face of'said" disc having radial grooves therein extending outwardly from said laterally offset portion to said blades whereby air cannot lie dormant against the inner face thereof.

2. A fan wheel comprising an annular sheet metal disc having its inner annular portion dished or laterally offset relative to the outer peripheral portion of said disc, blades of uniform surface width throughout their length integral with and projecting from said disc, the inner extremities of the blades being radial to the disc axis, ribs or corrugations formed in said disc and projecting from the side thereof remote from the offset annular portion, said side constituting the outer face of the disc, each rib being in substantial radial alignment with both the inner extremity and the outer portion of one. blade and extending from said offset annular portion into and forming an integral part of the inner end 01" that blade, each blade being folded adjacent its inner extremity so that its outer portion extends longitudinally substantially parallel with the axis of the disc and transversely substantially radially to said axis, and the inner face of said disc having radial grooves therein extending outwardly from said laterally offset portion to said blades whereby air cannot lie dormant against the inner face'thereof.