US2980990A

US2980990A - Spiral blower wheel

Info

Publication number: US2980990A
Application number: US635388A
Authority: US
Inventors: Lowell E Sprouse
Original assignee: Vernco Corp
Current assignee: Vernco Corp
Priority date: 1957-01-22
Filing date: 1957-01-22
Publication date: 1961-04-25
Anticipated expiration: 1978-04-25

Description

April 25, 196] SPRQUSE 2,980,990

SPIRAL BLOWER WHEEL Filed Jan. 22, 1957 3 Sheets-Sheet 1 lK/vE/vmR- don 54 6. 529005:

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SPIRAL BLOWER WHEEL Filed Jan. 22, 1957 3 Sfieets-Sheet 2 lK/vE/v TUE- zon/izz E 529005:

driveway April 25, 1961 SPRQUSE 2,980,990

SPIRAL BLOWER WHEEL Filed Jan. 22, 1957 3 Sheets-Sheet 3 JNVENTUR don Eu 5 S aces! ly-wfm ArraEMs-v United States Patent SPIRAL BLOWER WHEEL Lowell E. Spronse, Columbus, Ind., assignor to Vernco Corporation, Columbus, Ind., a corporation of Indiana Filed Jan. 22, 1957, Ser. No. 635,388

3 Claims. (Cl. 29-156.8)

This invention relates to a blower wheel of a drum type wherein there are a plurality of spaced apart blades,

around the periphery of the wheel. One particular use of the blower wheel of the present invention is found in the customary automobile heater.

Normally in automobile construction, space is always at a premium for installation of blower wheels, and it becomes increasingly necessary through the years to try to increase the output of the blower wheel while not increasing its diameter or its axial length, or even to actually reduce the overall dimensions of the wheel.

The blower wheel involved in this invention is intended to operate within a scroll type housing wherein the air intake is directed axially of the wheel, and then discharged substantially tangentially of the wheel all in the usual and well known fashion.

Heretofore, all blower wheels within my knowledge, and particularly the blower wheels for the smaller diameters have been made with a plurality of blades axially aligned in parallel arrangement. There is a limit to the number of blades which can be utilized around the periphery of the wheel for any given diameter thereof, even by using narrow blades and a larger number of them as compared to wider blades and less numbers. It is to be remembered that the blades in the structure in mind are normally punched or pressed out of a strip of material or even the side wall of a cup of material so that all of the metal going into the blade in each instance has to be within the circumferential length of the blank or cup. Thus there becomes a limit in this construction to the number of wide or narrow blades, and correspondingly there comes a limit of the amount of air to be delivered by the blower wheel.

The structure forming the present invention differs from the wheel having the blades in parallel alignment with the axis of the wheel in that the invention employs blades of longer lengths than the parallel blades in the axial alignment by using spirally positioned blades which are in diagonal relationship to the axis of the wheel.

Thus by using a diagonally positioned blade across the periphery or circumferential wall of the wheel, a longer blade may be obtained in the same axial length of wheel in comparison to the parellelly aligned blade.

It is therefore a purpose of my invention to provide longer blades in a blower wheel construction than has heretofore been possible in the use of the parallel blades, in order to step up the delivery of air from the wheel.

Also it is a purpose of the present invention to provide these diagonally positioned blades with a delivery edge thereacross lying within a circumferential surface which would be defined by the travel of those edges in rotation of the wheel. This straight edge of each blade is maintained in spite of the fact that one end of the diagonal blade lies at one point on the circumference of such a defined surface whereas the other end of that edge would lie at a circumferentially spaced apart point.

A curvature of the edge of each blade makes it possible to stamp the blades out of a flat strip of metal and then form that strip subsequently into a cylindrical shape so as to bring the blades into positions circumferentially spaced apart, and at the same time have the exterior of the blade edges with all points along those edges traveling in a circumferential dimension of common radius.

The invention is herein described in reference to the accompanying drawings, in which Fig. l is a view in side elevation of a blower wheel embodying the invention;

Fig. 2 is a view in intake end elevation of the blower wheel;

Fig. 3 is a view in top plan of a strip of metal blanked to define the separate blades;

Fig. 4 is a view in transverse section on an enlarged scale on the line 4-4 in Fig. 1;

Fig. 5 is a view on a reduced scale in side elevation and partial section of a housing carrying the blower Wheel;

Fig. 6 is a view in top plan and partial section of the housing and contained wheel;

Fig. 7 is a view in top plan of a strip of metal blanked to define the separate blades to be employed in a method differing from that wherein the blanked strip of Fig. 3 is employed; and

Fig. 8 is a view in side elevation of a blower wheel made from the strip of Fig. 7 in a form prior to being .twisted to the condition indicated by the dash lines.

Referring to Fig. 1, there is shown a completed wheel wherein there is a multiplicity of individual blades 10 diagonally positioned between end lands 11 and 12. These lands 11 and 12 are interconnected respectively by an outer ring 13 and a back plate 14. In making this interconnection, the land 11 is turned outwardly and radially of the wheel into the flange 15 which is encircled by the metal portion 16 being rolled around thereover all as indicated in Fig. 4. Likewise the land 12 has an outer radially outturned flange 13 which is encircled by a peripheral portion 19 of the back plate 14.

Attention is directed to the fact that each of the blades 10 has an outer end 20 at the land 11 which is circumferentially spaced from the opposite end 21 of that same blade.

Also, as indicated in Fig. 1, each blade, although diagonally positioned across the spacing between the ring metal portion 16 and the plate portion 19, presents an outer edge 22, all points of which will lie in a common cylindrical area between the

portions

16 and 19.

Referring to Fig. 5, wherein the blower wheel, generally designated by the numeral 23, is mounted within a scroll or housing 24, there is an edge line sometimes curved but herein shown as a straight line edge 25 extending across the housing 24 and therewithin, under which edge 25, all of the blades 10 must travel. It is desirable for the greatest efiiciency of the blower wheel that every point along the blade outer edge 22 in each instance be substantially equally spaced from that edge 25 as the blades travel thereunder.

In order to establish and maintain that relationship of the blade edges with the housing edge 25, referring to Fig. 3, the edge 22 in each instance is blanked from the flat strip 26 not in a straight line, but in an arcuate line 2211. Then when the blade 10 is formed into shape, that curved edge 22a will come into a line edge 22 that in the finished wheel all points along that edge 22, as above indicated, will be at the same radial distance from the axis of the wheel. The wheel 23 will have been formed in the usual manner by rolling the strip 26 into cylindrical shape after the blades are formed with the edges 22a being on the inside of that shape as indicated in Fig. 2.

3 To the ends of that shape are fixed the back plate 14 in the outer ring 13.

The back plate 14 will have a mounting hub 27 for driving purposes, and preferably is provided with some reinforcing means herein shown as rectilinear ribs 28, such reinforcing not being a part of the invention per se.

It is possible to form the blades directly from the flat strip 26, and then carry that strip around into a circumferential cylindrical shape, and have the blades 10 presented diagonally around the circumferential shape. The wheel may also be made as indicated in Fig. 7 by forming the blades in parallel alignment one with the other and also in parallel alignment with the axis of rotation of the wheel. However in this instance, the length of the wheel between the back plate portion 19 and the ring portion 16, Fig. 8, has to be made greater than the desired length of the finished wheel. The ring 13 and the back plate 14 are gripped individually by suitable members 30, such as aboutthe'ir

peripherial portions

16 and 19, and then one end of the blower wheel, herein indicated as the ring end, is circumferentially rotated around a cylindrical surface in relation to the back plate 14 which is held stationary to carry the blades 10a into the desired diagonal positions, as indicated by the dash lines, Fig. 8. In this method of forming the wheel, the blade edges 22b will be curved in order that they will come down into the conformation that cylindrical surface as previously indicated where every line along the outer blade edge will be at exactly the same radial distance from the axis of the wheel.

In the form of the blank strip 26 shown in Fig. 3, since the edges 22a are cut not only concave but also diagonally of the strip, the concave edges 22a, as the trailing edges, are already positioned to contact and fit diagonally around an imaginary cylinder, while the convex edges (leading edges) follow at equal distances throughout from that imaginary surface. In other words the blades spiral in relation to that surface.

In using the form of the blank shown in Fig. 7, where the edges 22b of the blades are not diagonally cut in the strip, but still are concave, then the blower wheel has to be twisted as between the plate and ring about some instrument such as a mandrel to carry the edges 22b diagonally into contact with that surface.

The blades 10 seem to operate to the best advantage in respect to power input and cubic feet of air delivered when those blades are disposed between twelve and fifteen degrees from the line parallel with the wheel axis. In thus positioning the blades 10, there is a decided reduction in the noise level as compared to wheels made with blades parallel to the axis, in addition to the reduction in power input and in an increase in the rate of air delivery.

For example, in a comparative test for two wheels each of exactly the same diameters, same blade lengths, same blade conformations, but with one wheel having the blades parallel to the axis and the other wheel having the blades diagonally positioned within the angle range of from twelve to fifteen degrees, using a driving motor operating at fourteen volts which is the normal voltage of the pres ent day late model automobiles, with a wattage input of one hundred and fifty-five, the blower wheel with the diagonally positioned blades operated at a decibel level of ninety-one and delivered thirty-eight and one tenth cubic feet of air per minute at two thousand six hundred and twenty revolutions per minute. The parallel bladed wheel, that is the wheel with the blades parallel to the axis, operating at the same speed of two thousand six hundred and twenty revolutions per minute at fourteen volts, required a power input of one hundred fifty-eight watts, had a decibel level of ninety-six and delivered zero cubic feet of air per minute. Now this is at the extreme high speed operation with high static pressure conditions, but even at lower speeds with lower static pressure, the diagonal blade wheel turning at one thousand nine hundred and seventy revolutions per minute with a voltage input of fourteen requiring two hundred and thirty-two watts at a decibel level of ninety-two gives an air delivery of two hundred ninety-seven and one tenth cubic feet per minute. The other wheel having the parallel blades operating at exactly the same speed of one thousand nine hundred and seventy revolutions per minute had a decibel level of ninety-three with an air delivery of one hundred ninety-eight and three tenths cubic feet per minute.

In other words, the diagonally positioned blades offer a decided increase in air delivery and a very noticeable decrease in noise as compared to the blades being positioned parallel to the axis at the same speed and with the same dimensions. This is highly important as has been indicated where the space is limited, and furthermore it is particularly important in view of the fact that the electrical system of the average automobile carries an extremely high load, and the engineers want to reduce that load or at least keep it within a minimum amount in order not to use up too much horsepower of the engine itself in driving the generator, and to conserve storage battery ampere ho'urs.

Therefore while I have described my invention in the one particular form, it is obvious that structural variations may be made in the structure such as in the curvature radially across the blades, the degrees of diagonal twist, the method of mounting the blades, and dimensions of the various parts, all without departing from the spirit of the invention, and I therefore do not desire to be limited to that precise form beyond the limitations which may be imposed by the following claims.

I claim:

1. The method of forming a high efliciency blower wheel which comprises slitting a strip on concave lines thereacross between land portions along the strip edges and forming concave blades out of the strip portion lying between the slits, each blade being concave along one slit edge and convex along its other slit edge with a constant distance between said edges linearly of the strip; rolling the strip into cylindrical wheel shape with the blade concave edges inside and the convex edges outside.

2. The method of claim 1 in which said slitting is diagonally made across the strip.

3. The method of claim 1 in which said wheel shape is circumferentially twisted by one end in relation to the other end bringing the respective edges of the blades into spiral form.

References Cited in the file of this patent UNITED STATES PATENTS 1,017,215 Ilg Feb. 13, 1912 1,075,120 Rogers Oct. 7, 1913 1,156,118 Warg Oct. 12, 1915 2,242,586 Marbach May 20, 1941 2,684,521 Morrison July 27, 1954 2,724,547 Abbott et a1. Nov. 22, 1955 2,779,424 Lyon Jan. 29, 1957 2,785,850 Sprouse Mar. 19, 1957 2,878,989 Sprouse Mar. 24, 1959 2,915,239 Borkat Dec. 1, 1959 FOREIGN PATENTS 212,108 Germany July 23, 1909