US 2549208 A
Description (OCR text may contain errors)
April 17, 1951 M. s. KlCE, JR 2,549,208
April 17, 1951 M. S. KICE, JR
FAN AND METHOD OF ASSEMBLY AND DISASSEMBLY 2 Sheets-Sheet 2 Filed May 20, 1946 lNVEN MURRAY S. KICE JR. BY
MYOQZW Patented Apr. 17, 1951 UNITED STATES PATENT OFFIACE FAN AND METHOD OF ASSEMBLY AND DISASSEMBLY Murray S. Kice, Jr., Detroit, Mich., assignor to American Blower Corporation, Detroit, Mich., a corporation of Delaware Application May 20, 1946, Serial No. 671,022
3 Claims. 1 i
This invention relates to fans and blowers and particularly to fans of the Sirocco type and to methods of repairing the same.
The Sirocco type fan or blower is one in which the fan wheel comprises a plurality of circumferentially spaced and axially extending blades which transfer gas between an axial inlet openin in a fan hOllSlIlg to a peripheral outletopening. This type of fan is characterized by blades which are relatively narrow in the radial direction but of which there are a multiplicity spaced around the periphery of the fan rotor. The result of this blade arrangement is a highly efficient fan, especially well adapted to induced draft installations and which operates at relatively low speeds, and with little noise.
The construction of this type fan produces a V relatively low moment of inertia, which, together with the low operating speed, results in correspondingly low stresses in the fan parts during operation. This type fan has the further advantage of being relatively insensitive to vibration from conditions of slight out of balance which would be serious in blowers of other types.
Accordingly, the primary object of the present inventionris to provide an improved method for repairing the fan wheels of fans and blowers, especially of the Sirocco type.
Another object is to provide an improved type fan wheel for a Sirocco type fan which is so arranged that replacement of the fan wheel when it is desired to repair a blower is facilitated.
Still another object is to provide a Sirocco fan wheel and a method of assembling and disassembling same such that a fan or blower can be repaired in the field without dismantling the heavy drive shaft from the fan housing.
These and other objects and advantages will become more apparent upon reference to the followin specification taken together with the accompanying drawings in which:
Figure 1 is a perspective view of an induced draft fan having a fan wheel therein according to this invention;
Figure 2 is a fragmentary perspective view of the fan wheel of'Figure 1 showing the arrangement thereof more in detail;
Figure 3 is a cross section through a fan wheel constructed according to thi invention and is indicated by the line 3-3 on Figure 4;
' Figure 4 is a cross'section indicated by the line 44 on Figure 3;
Figure 5 is an enlarged view indicated by the line 5 -5 on Figure 3;
Figures 7 and 8 show how the fan wheel rim may be scarfed and welded when the fan wheel is General arrangement According to the present invention a fan or blower is provided which has a portion of the casing thereof removable so that access can be had to-the fan wheel. The removable portion of the casing is easily removed from the fan, or may be hinged so that it can be latched in an open position. The removable or hinged section of the casing is independent of the bearings which support the fan wheel shaft so that the casin may be readily opened at any time.
According to the present invention, it is proposed that the fan wheel within the fan be so constructed that it can be removed for replacement or repaired without removing the fan wheel shaft. This is accomplished by constructing the fan wheel from spaced end rings: or rims with the blades supported therebetween and" securing one of the said rings to a hub plate which is carried on the fan wheel shaft. Then, by detaching the blades and rings from the a'foremen-' tioned hub plate, the fan wheel proper may be' split by cutting through the end rings at dia than previous methods wherein the fan wheel" and fan wheel shaft were removed in their entirety from the fan casing and the wheel re-* moved from the shaft by slidin it axially over the end of the shaft.v
The fan is reassembled on the shaft in the same manner that it was disassembled by inserting the fan halves into the casing, securing them to the fan hub plate and welding the halves together along their line of separation at both places on both of the end rings. The as sembled fan is then balanced, if necessary, and I the unit is again ready for operation.
It will be apparent from the foregoing that this invention provides for a very rapid and simple means of effecting repairs to blowers without the necessity of removing the fan wheel shaft from the fan casing, and that the efficiency of the fan unit is substantially unimpaired by the operator.
Structural arrangement Referring more particularly to the drawings,
- there is, illustrated a fan having a casing H] v I which, may comprise a pair of inlet openings at iEWhich communicate with the fan rotor 141 from the opposite ends thereof.- The fan rotor id is adapted for discharging gas peripherally into a central scroll passage H in the fan casing which communicates with a discharge conduit at 18. The fan wheel I4 is carried on a fan wheel shaft 20 which is journalle'd'in the bearing blocks 22 at each end of the fan.
I For facilitating the inspection and repair of the fan wheel, the fan casing it] comprises a portion 2 which is removable from the casing or 30. For securing the fan wheels on the fan H wheel shaft 28, the latter mounts a hub 32 and a hub plate 34. The hub plate 36 has substantially the same diameter as the rims 26 and 23 andis apertured to receive mounting bolts which also pass through the rims 28. In general, four 0 bolts as indicated at 36 will be sufficient to secure the fan wheels to the hub plate 34, but it will be understood that any number desired may be employed. ,7 The plate 34 may be bolted,
riveted or welded to the hub 32, and preferably one of the last 'tWo means is employed.
Inasmuch as the blades to are relatively closely spaced, it may be necessary to delete one of the blades at each mounting bolt in order to accommodate the said bolt but the efficiency of the fan is substantially unimpairedby this omission of blades.
The blades may be secured between the rings in any suitable manner, such as by riveting, and if riveted, at least the rivets passing through the rims 28 are required tohave counter-sunk heads as indicated at 3B in Figure 5. This enables the rimsZB to fit closely against the hub plate 3% so that the maximum amount of support is given the fan wheels to insure greater rigidity and freedom from vibration.
Returning to Figures 1 and 2, should it become necessary to repair or replace one or both of the portions of the fan wheel Hi, this may be accomplished by unbolting the said portions from the hub plate 34, cutting them in half by splitting the rims 2t and 28, and removing the resulting halves from thefan casing. I e
Since any wear on the wheeldue to abrasion thereof by particles carried'in the gas stream occurs'at the heel of the blades 36 at the center of the wheel,- or opposite the hub 32, the removed shells can be reversed and replaced. In this case the rims may be split in any convenient place but it is preferred that they be split along diametrically opposite lines and between a pair of adjacent blades, substantially midway between two of the attaching bolts 36. By dividing the Wheel into substantially identical halves th e balancing of the wheel, upon re-assembly, is facilitated because noi great amount of unbalance results from the Welding necessary during the l e-assembly.
In this case'of re-using the present wheel, the rims are "scarfed after being torched through. The outer rim 26 is scarfed as indicated in Figure 4 7, as re-assembly welding can be done on both sides. The center rims 28 are scarfed as shown in Figure 8, to afford all Welding being done from one side.
In the case of the installation of new wheel parts on the present hub plate 34, the halves of the portion or portions are placed within the fan casing and bolted in place on the hubplate 34.
The wheel halves are then bolted, centered, and
welded, the scarfing of the rims having been done at the factory. Preferably, the outer rim ,26 is scarfed and welded on both sides as indicated at 40 in Figure 7 while the inside rims 28 are scarfed and Welded only on the side opposite the plate 34 as is indicated at .42V in Figure 8. The line along which the rims are split is substantially radial but may be somewhat inclined in order to accommodate for the position occupiedbythe blades 30. A representative cutting line is indicated at 44 in Figure 6.
'After the new or repaired wheel halves'fhave been rewelded and secured to the back plate'ii l; it is preferable that the fan rotor be balanced, if necessary, by welding weights around the periphery of the wheels. This is preferably accom-' plished by arc welding weights -on the outside of V the outside portion.
While this inventionhas been shownandde scribedinconnection with a double inlet type fan, it will be obvious that it is equally well adapted to fans of the single inlet type wherein it is inconvenientto remove the fan wheel in its entirety from the fan wheel shaft. v V
t will be apparenttha't'tihe Sirocco type fan is particularly well adapted for being dismantledand reassembled according to this "invention. This is'due to the fact that the Sirocco fan wheels operate at substantially lower speeds than other type fan wheels, have considerably smaller dead weight and have the parts thereof under considerably lower stresses duringoperation. 'Ac-' cordingly, this type of fan wheel canbe manufactured from a mild and easily welded steel rather than from'a special alloy steel and hence, can be welded without the weakening thereof at any part. However, it will be understood that in. many instances other types .of fan wheels canadvantageously be repaired int-he-field by practicing the methods of the present invention.
Itwill be understood thatthis *inventionis susceptible to modification in order to adopt it, to different usages and conditions and, accordingly, it isdesiredto comprehend such modifications within this invention as may fall wit-hinthe scope of the appended claims.
1. A fan wheel consisting-of, a pair of annular ring end rims, and a plurality of blades extending between said rims disposed axially thereofand fixedly connected thereto, each of said blades having afoot at each end thereof fixedly 'con-' lar sequence thereof between adjacent blades substantially greater than the space between the blades in the regular sequence thereof, and means in each rim of the pair in the saidgreater space for receivingan attachingj "means whereby to mount said wheel on a support.
2. In a fan, a drive shaft, 2; hub-en said shaft rotatable thereby, a radially extending flange carried by said hub, a fan wheel unit positioned on said flange, said fan wheel unit consisting of a pair of like individual fan wheels one of which is positioned at each side of said hub, each of said fan wheels consisting of a pair of annular ring end rims, and a plurality of blades extending between said rims disposed axially thereof and fixedly connected thereto, said blades of each of said wheels being positioned equidistantly from each other in a regular occurring sequence, said sequence of said blades in each of said wheels being broken at periodic intervals equidistantly positioned about said rims with a space between adjacent blades substantially greater than the space between the blades in the regular sequence thereof, said fan wheels positioned at each side of said flange each having one open end whereby each of said wheels receives air axially thereof and discharges air radially through said blades, and attachin means extending through said flange and one of said pairs of rims positioned against said flange in the rim portion thereof in the said greater space to detachably attach said wheels to said flange.
3. A method of disassembling and reassembling for reuse a fan wheel unit from a shaft supporting the same Without disturbing the position of the shaft, which unit consists of a pair of connected like cooperating individual fan wheels each consisting of a pair of unitary annular ring end rims connected by a plurality of blades extending therebetween and positioned axially thereof in which air moves into the individual wheels axially thereof and discharges therefrom radially through the blades which results in greater wear on the blades at the end portions remote from the inlet side of the wheels, the said fan wheels being detachably connected together and to a hub mounting carried on the shaft by one of the rims of each of the fan wheels,
which consists of, severing each of the unitary end rims of the wheels in at least two places spaced apart a distance greater than the diameter of the shaft that supports the wheels to divide said wheels into independent sectors, detaching the wheel sectors from the hub mounting and removing the sectors from around the supporting shaft, reassembling the cooperating sectors of each wheel around the shaft with the wheels formed thereby in reverse order of their initial position on the shaft whereby the worn portions of the blades are positioned at the inlet side of the wheels, detachably mounting the sectors on the hub mounting, and reuniting the rims into unitary annular rings.
MURRAY S. KICE, JR.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 919,623 McDuifee Apr. 27, 1909 1,143,082 Shepherd et al June 15, 1915 1,484,579 Still Feb. 19, 1924 1,704,123 Feinberg Mar. 5, 1929 1,928,075 Replogue Sept. 26,1933 1,985,705 Whiton Dec. 25, 1934 2,065,716 Leonard Dec. 29, 1936 2,115,367 Levy et a1. Apr. 26, 1938 2,155,231 Hubbard Apr. 18, 1939 2,392,113 Anderson Jan. 1, 1946