US2411816A - Centrifugal blower - Google Patents

Description

Nov. 26, 1946. JR 2,411,816

CENTRIFUGAL- BLOWER Filed Bay 16, 1944 2 Sheets-Sheet 1 i 21 90. a 1 11% Q INVENTOR. h i Wall'erD- A TTDRNE Y 1946- w. D. TEAGUE, JR

CENTRIFUGAL BLOWER Filed May 16, 1944 2 Sheets-Sheet 2 Q I mmvron Walk 1. BY, er uq AT TORNE Y PatentedNov. 26, 1946 l 2,41 1,s 1e CENTRIFUGAL BLOWER Walter- D. Teaguc, J12, Alpine,

Bendix Aviation Corporation,

N. J., assignon'to Teterboro, N. J

' a corporation of Delaware Application May 16, 1944, Serial No. 535,868 2 Claims. (Cl. 230-127) I My present invention relates to centrifugal blowers or pumps, novel blower for obtaining a low air flow output with high efliciency. v

An object of my invention is to provide a novel impeller means.

Another object of my invention is toprovide 'a blower having a shrouded impeller of novel design and rotatable in a housing with a scroll type diffuser.

Another object of my invention is to provide a novel self -contained motor driven unit for providing proper airflow for supplying combustion air for gasoline heater operation, or similar applications, where a low air flow output is desired at high driving motor efliciency.

Another object of my invention is to provide a compact blower unit of vgreat efiiciency in comparison to its size and of such simplicity in construction as to adapt it for manufacture and installation at low cost.

The above and further objects and novel features of this invention will more fully appear fdom the following detailed description and the accompanying drawings wherein like reference characters refer to It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawings: a

Figure 1 is a side view of a blower embodying my invention.

Figure 2 is a perspective view of my novel rotary impeller.

Figure 3 is a plan view of a blower embodying my invention with part of the casing broken away so as to better illustrate the structure of my novelimpeller means.

Figure 4 is a sectional view of Figure 3 taken along the lines B---% and looking in the direction of the arrows. 1

Referring to the drawings, there is provided a casing i in which is mounted an electric motor indicated generally by the numeral 2. The motor 2 is of conventional structure and includes a stator 3 and rotor i having a commutator 5 on which rides suitable brushes, one of which is shown at Figure 4 in dotted lines and indicated by the numeral 6. The motor 2 has provided electrical connections leadingfrom it to a plug a mounted on the casing l and arranged for connecting the motor terminals to a suitable source of electrical energy. 4

As shown in Figure 4 the rotor 4 has a shaft 8 projecting axially from one end thereof and rotatably mounted in a suitable anti-friction bearing 8 supported at the closed end of the easing 8, A second shaft Iii projects axially irom and more particularly to a g trio therewith.

like parts in the several views.

, gether by suitable bolts the opposite end .of the rotor 6 and through the opposite end of the casing i The opposite end of the casing i has provided around the outer edge thereof an annular shoulder portion H adapted to fit within an annular flange i2 of a casting indicated generally by the numeral i3. Suitablefastening means, as indicated at H, are provided for securing the motor casing I to the casting i3.

The casting i3 includes an annular platemember I5 having provided at one side thereof the annular flange i2 and a sleeve member i6 positioned within the annular flange i2 and concen- Positioned within suitable anti-friction bearing ii held in place in the sleeve it by an annular plate i8 fastened to the free end of the sleeve-it by bolts IS. The shaft i0 projects through the bearing ll and sleeve i6 and is rotatably mounted in the antiiriction bearing ll.

The plate it of casting It forms with a second plate 20 a housing indicated generally by the numeral 2!. The plates i5 and 2c are bolted to- 22. The plates l5 and 20 are formed with suitable cooperating recesses so as to provide within the housing 2! a rotor chamber 23 surrounded by a scroll type diffusion chamber it open to the rotor chamber through a radial channel 25. The difiusion chamber M has provided an outlet opening 26 as will be explained.

Rotatably mounted in the rotor chamber 23 is my novel-shroud type impeller indicated generally by the numeral 2i and formed by two annular plates 25 and 29 which are fastened together by suitable rivets til.

. The plate 29 has provided a irusto-conical shaped, hub 3| which projects through an annular orifice 32 formed in the plate 28 and in spaced relation to the orifice defining surface of the plate 28.

The hub 3! is keyed at 33 to the end of the shaft H1 and held in place by a nut 34 which engages suitable screw threads at the end of the shaft it.

Cooperating with the annular opening 32 provided in the plate 2815 a similar formed annular recess 35 surrounding in spaced relation the hub 3! of plate'ZS. v

Radiating from the annular opening or pocket thus formed in the impeller 21 are annular shaped air impeller conduits or passages 31 formed by suitable cooperating recesses provided in the opposite halves 28 and 29 of the impeller rotor 21.

The impeller conduits 31 extend radially from the annular orifice surrounding the hub 3i at the center of the impeller rotor 27 and suchcon-' .duits 31.0pen at the circumferential edge of the impeller rotor 21. The conduits 3i are'pre fei the sleeve member I6 is a s ably formed of equal dimeter throughout their length and open directly into the diffusion cham= ber 24, through the passage 25.

Provided in the plate iii of the housing it is an annular opening 38 which is arranged to cooperate with the annular opening 32 of the rotor 21, as an air inlet.

The surfaces defining the openings 32, $5, and 38 are so formed that the area normal to the air stream progressively decreases so as to smoothly accelerate the air flow into the passages 3i radi A flange 33 formed integral with the plate i is provided for mounting the mechanism while a second flange 543 is provided for fastening the outlet 28 to a suitable conductor.

In operation it will be readily seen that .the electric motor l will drive the impeller rotor 2F,

' combination, a two piece circular shaped impeller through the driving shaft it in a clockwise direc tion as shown in Figure 3, causing air to be drawn into the rotating impeller rotor 21 through the annular orifice or pocket 82, t5 and Sit, where-= 'upon the air stream under centrifugal force will be radially directed outward through the annular passages 3'? into the scroll-like passage 2% and out the outlet opening 2%.

It will be readily seen that such annular shaped conduits approach the ideal shape for emclent passages 37 remain equal andthere is not efi'ected an expansion in one direction and acontractlon in an opposite direction of the fluid medium due to one dimension diverg ng while another dimension converges, as in prior art devices.

It will be readily seen that for the same compression ratio and driving speed, the heretofore known impellers of the same diameter in order to accomplish equally low air flows would have to have impeller blades extremely thin in width, since the area of the passages at the impeller periphery is the main factor governing the emcient fiow rate for any particular impeller. The width of such impellers would in fact be so small that frictional losses would be prohibitive. However,

through use of my novel impeller rotor such fric tional losses may be avoided.

Although only one embodiment of the invention has been illustrated and described, various changes in the form andrelative arrangement of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention. Reference is, therefore, to be had to the appended claims for a defi nition of the limits of the invention.

What is claimed is:

1. A device of the character described, comprising, in combination, a two part circular rotor, a hub portion formed on one of said parts, said hub portion surrounded by an annular pocket formed in said one part, an annular orifice formed in the other part of said two part rotor, said hub portion projecting-through said annular orifice, said first and second parts of said rotor having recessed portions cooperating to form a plurality of passages radially extending from said pocket and annular orifice, the passages opening at the circumferential edge of said circular rotor, means fastening the parts of said two part rotor together, a housing having a first and a second part for enclosing said operation. since all the dimensions of the air flow rotor, said first and second housing parts having recessed portions forming a scroll type diffusion chamber into which the passages of said rotor open, means for fastening said first and second housing parts together, a driving-shaft amxed to said hub portion for rotatably mounting said rotor within said housing, and an annular air inlet opening passing through one part of said housing into said rotor opening, the surfaces defining the inlet and rotor openings being so formed that the area normal to the air stream progressively decreases so as to smoothly accelerate the air fiow to said impeller passages through said air inlet, an annular flange projecting outwardly from the one part of said housing and surrounding said annuar air inlet opening, and a screen mounted in' said flange through which the air may be drawn directly from the atmosphere.

2. A centrifugal blower unit comprising, in

formed of first and second circular shaped plates, a hub projecting from the first plate, an annular pocket surrounding said hub and provided in the first plate, the second of said plates having an annular orifice through which said hub projects, said first and second plates having recessed portions provided therein cooperating to form a plurality of passages radially extending from said pocket and annular orifice, each of said passages having an inner surface defining the same of circular shape and equal diameter throughout the length of said passage, means fastening said first and second impeller plates together, the passages opening at the circumferential edge of said circular impeller, a housing having provided; therein first cooperating recessesfor receiving the impeller, second cooperating recesses for providing a scroll type dif- .fusion chamber and third cooperatingrecesses for opening saldscroll type diffusion chamber to the openings from said impeller passages, said first and second housing plates having formed therein an outlet opening for said diffusion chamber, means for fastening said, first and secondv housing plates together, the first of said housing plates having an air inlet opening provided therein for cooperating with the annular orifice and pocket provided in said impeller so as to supply air to said impeller, the surfaces defining the inlet opening, annular orifice and pocket being so formed that the area normal to the air stream progressively decreases so as to smoothly accelerate the air flow to said impeller passages through said air inlet, an annular flange projecting outwardly from the first housing plate and surrounding said air inlet opening, and a screen mounted in said flange through which the air may be drawn directly from the atmosphere, a bearing provided in said second housing plate, an annular fiange projecting from said WALTER D. TEAGUE, JR.

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