US2473814A

US2473814A - High-temperature fan

Info

Publication number: US2473814A
Application number: US743515A
Authority: US
Inventors: Nygren Carl
Original assignee: MICHIANA PRODUCTS CORP
Current assignee: MICHIANA PRODUCTS Corp
Priority date: 1947-04-24
Filing date: 1947-04-24
Publication date: 1949-06-21
Anticipated expiration: 1966-06-21

Description

C. NYGREN HIGH- .Fune 21, 1949.

TEMPERATURE FAN 3 Sheets-Sheet 1 Filed April 24, 1947 June 21, 1949. c. NYGREN HIGH-TEMPERATURE FAN 3 Sheets-Sheet 2 Filed April 24, 1947 June 21, 1949. V c, NYGREN 2,473,814

HIGH-TEMPERATURE FAN I Filed April 24, 1947 3 Shets-Sheet s Patented June 21, 1949 Carl: Nygremtluichigan City,-

Ind.,- assignor to Mich-iana Products/Corporation,. a corporation oflIndiana Application Airril 24, 1 94 3; Serial No. 7 43 515 41*Claims (Cl. 230-434) This: invention relates to centrifugal fansor:

blowers for handling gases anhigln temperatures,- and has for itsprincip'al object:- to' provide an improved, low cost assembly ofIsidemembers and blades that will. preserve dynamic'balance while allowing free relativemoyement: of. the router:- portions in expanding and contracting.

Generally speaking, this is accomplished by fasteningthe-co'nverging inner portions of a plurality of blades to hub members of side pieces in circular serie'sl'a'n'dinterlocking the outer portions of. the blades with, shroudv portions of. the side pieces, allowing'freedo'm to move. Thus, the

- fixed relation of the blades andsid'e pieces is established and maintained" by fastenings in a circle connecting the inner portions of the. blades with the hub portions of the SidBFpiBCBS and-leaving the parts otherwise free to expand andcon tract.

Specifically, this invention is an improvement over the construction disclosed in the Williams Patent No. 2,147,005, February 14, 1939.

Fig. 1 is a front elevation of a single inlet fan embodying the invention, the upper portion being shown in vertical section;

Fig. 2 is a perspective view of one of the fan blades;

Fig. 3 is a side elevation of the fan shown in Fig. 1, a portion of one of the side pieces being broken away and two of the blades being removed;

Fig. 4 is a perspective View of the plate for closing one side of the fan;

Fig. 5 is a perspective view of one of the pins by which the inner portions of the blades are made fast to the hub portions of the side pieces;

Fig. 6 is a front elevation of a double inlet fan similar to that shown in Fig. 1, the upper portion being in section.

In the drawings, 10 indicates a hollow water cooled shaft upon which the fan portions are assembled and by which they are driven.

The fans include two side members generally indicated by A and B, each having a hub portion- H, spokes l2, and a rim portion or shroud l3, here shown as cast in one piece. The hub portions are secured in driving relation to the shaft by three keys l4 equally spaced about the circumference.

In this particular embodiment, each shroud I 3 is provided with a series of radial grooves l5 spaced equldistantly to receive the corresponding edges l 6 of twelve blades H, which are slightly thickened and finished along the edges l 6 in order to fit closely within the grooves 15.

Each hub: portion H- has a circular flange I 8 finished: onits inner side [9 to cooperate with. th'efinishededges- Not the blades. Adjacent to those edges the blades are thickened at 2| and provided-with-pin holes 22 provided'with countersunk outer! portions-23, both of which correspond to similar pin openings and counter-bored. por-- tions 2- and 25' in the flanges l8. These openings and-counter-bores receive the pins 26 having, large intermediate portions 21 by which the inner endportions of the blades are made fast to the flanges l8 of thehub portions ll.

Thehub portion ll of the side piece B rests against a shoulder 28 on the shaft [Hand is held against that shoulder by a nut 29- threaded on the right end of the shaft Ill and locked by a l'ocknut- 3b and a lock washer 3 I.

When the fan isassembledthe nut 292186917 up hard, and then backed off an amount corresponding to the expansion expected from the temperature at which the fan is to give service. Then the lock washer 3| and the lock 30 are applied.

The double inlet fan shown in Fig. 6 corresponds almost exactly to the fan shown in Figs. 1, 2, and 3 except that the blades 32 are wider and the shaft portion In between the side pieces is longer.

The side pieces are duplicates and may be used in both the single inlet fan and the double inlet fan. In the former, it is necessary to provide for closure of one of the side pieces, and this may be done by machining a seat 34 on the inner side of the appropriate piece to receive the circular plate or disc 35. Of course, such a disc can be made in one piece with the side piece when that seems appropriate.

The fan shown in Fig. 3 of the Williams Patent No. 2,147,005 includes spacers 2c and 25, which must be machined all over, and in many instances the cost of that work will be approximately $240.00 for each spacer. By eliminating those costly parts, changing the form of the inner portions of the blades, and providing for the fastening of those inner portions to the flanges IS on the hubs, a very much less costly and more practical fan construction is obtained. The machine work on both the hub portions and the blades is made very much simpler and less costly.

By changing the inner portions of the blades 29 of the Williams patent to the form shown in Figs. 1, 2, and 6, they are made much simpler to produce and much more rugged and durable in the rigorous service at high temperatures.

The construction here illustrated is for 24-inch the double fan being 12 wide at the cirfans,

6%," wide cumference and the single fan being at the circumference.

I claim:

1. In a centrifugal fan, a shaft, side pieces spaced apart lengthwise on the shaft and having hub portions and shrouds integrally connected by radiating spokes, a plurality of blades in circular arrangement about the axis of the shaft with their outer portions diverging outwardly and the side edges of their outer portions interlocked with the shrouds for normal rotation but capable of freedom of expansion and contraction and with their inner portions converging inwardly, and means in circular series about the shaft making the inner portions of the blades fast to the hub portions of the side pieces to hold the blades against individual bodily movement outwardly due to centrifugal force.

2. In a centrifugal fan, a shaft, side pieces spaced apart lengthwise on the shaft and having hub portions and shrouds integrally connected by radiating spokes, a plurality of blades in circular arrangement about the axis of the shaft with their outer portions diverging outwardly and the side edges of their outer portions interlocked with the shrouds for normal rotation but capable of freedom of expansion and contraction and with their inner portions converging inwardly, and pins in circular series about the shaft making the inner portions of the blades fast to the hub portions of the side pieces to hold the blades against individual bodily movement outwardly due to centrifugal force.

3. In a centrifugal fan, a shaft, side pieces spaced apart lengthwise on the shaft and having hub portions and shrouds integrally connected by radiating spokes, a plurality of blades in circular arrangement about the aris of the shaft with their outer portions diverging outwardly and the side edges of their outer portions interlocked with the shrouds for normal rotation but capable of freedom of expansion and contraction and with their inner portions converging inwardly and grasped between the hub portions, and means carried by at least one of the hub portions in circular series engaging said inner portions and holding the blades against bodily movement outwardly due to centrifugal force.

4. In a centrifugal fan, a shaft, a pair of side pieces spaced apart lengthwise on the shaft, at least one of said side pieces having a hub portion and a shroud integrally connected by radiating spokes, thereby providing inlet openings in the spaces between the spokes, a plurality of blades in circular arrangement about the axis of the shaft with their outer portions diverging outwardly and the edges at one side of each outer portion interlocked with the shroud for normal rotation but capable of freedom of expansion and contraction and with their inner portions converging inwardly, and means in circular series about the shaft making the inner portions of the blades fast to the hub portion of the named side piece to hold the blades against individual bodily movement outwardly due to centrifugal force.

CARL NYGREN.

REFERENCES CITED The following references are of record in the f le of this patent:

UNITED STATES PATENTS Number Name Date 2,147,005 Williams Feb. 14, 1939 2,385,838 Nygren Oct. 2, 1945