US767580A - Blast-fan. - Google Patents

Description

PATBNTED AUG`..16,`190 4.

D. P. LEPLBY.. lBLAST PAN.v APPLIOATION FILEDBEPT. 4, .1903.

2 SHBETaS-BHEET 1.

Y No MODEL.

PATENTED AUG. 16,1904.l

YD. F. LBPLEY.

BLAST FAN. -APP'LIUATIVON FILED 3m14.190s.

2 SHEETS-SHEET 2.

'N0 MODEL;

Fig. 2 is a side elevation of the same.

UNITED STATES Patented August 16, 1904.

PATENT OEEicE.A

BLAST-FAN.

SPECIFICATION forming part of Letters Patent NO- 76'7,580, dated' August 16, 1904.

Application filed September 4:, 1903. Serial No. 171,993. (No model.)

To all whom, 2S wtay concern.'

Beit known that LDANIEL F. LEILEY, a citi zen of the United States, residing at Connellsville, in the county of Fayette and State of Pennsylvania, have invented a new and useful Blast-Fan, of which the following is a specification.

This invention relates to certain improvements in blast-fans, and particularly to that class of fans employed for the ventilation of mines and in heating plants for forcing air into contact with steam-coils or similar heating devices.

The principal object of the invention is to provide a fan in which the driving movement from the shaft is at a centralor intermediate point in the width of the fan, thereby lessening strain on both fan and its shaft.

A further object of the invention is to provide a fan construction in which danger of twisting or straining the shaft in assembling the various parts of the fan will be entirely' avoided,

A still further object of the invention is to 'provide a fan structure in which the weight of the fan is applied to the shaft at points near the bearings where it can be readily supported without causing vibration ofthe shaft,

provide improved means for securing the fan to its shaft in such manner as to permit the bearing-boxes to fit close to the sides of the fan.

With these and other objects in view the invention consists in the novel construction and arrangement of parts hereinafter described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, and minor details of construction may be made without departing from the spirit or sacrificing any of the advantages of the invention.

In'the accompanying drawings, Figurerl is a transverse sectional elevation of a fan constructed in accordance with the invention. Fig. 3

is a detail perspective View of a portion of the hub or casing by-which the fan is connected to the shaft. Fig. i is a sectional view illustrating a modified construction of hub or supporting-casing.

Similar numerals of reference are employed to indicate corresponding parts throughout the several figures of the drawings.

In the manufacture of large blast-fans, especially those in which a central driving-disk is employed, there is a tendency of the disk to warp or bend while the fan-blades are being secured in position, this being due to the fact that inA tho punching of the main driving-disk there is an unavoidable twisting or warping, which can be taken out only by straining the disk in the course of assembling the parts of the fan. Under ordinary circumstances the iiattening of this disk or the removal of the warp thereof results in a deflection of the hub or casing, which in turn is communicated to the shaft and strains or twists the latter to such an extent as to materially interfere with the true running of the shaft and fan. In carry-ing out the present invention this difiiculty is overcome by keying the hub or casing to the shaft only at the terminals of the former, and thus relieving the shaft of the pressure or contact of the hub or casing at the center of the shaft. A twist Vunder these circumstances in the hub or casing does not affect the shaft, and therefore does not destroy or impair the true running properties of the fan, with the result that the bearing-boxes in which the extremities of the 'shaft are mounted may be adjusted to take up lost motion and insure steady and even running of the fan. A further advantage resulting from this construction is that the entire weight of the fan is applied to the shaft at points near the bearings, so that there will be less vibration of the shaft,while the desired central driving veffect is accomplished by transmission of power from the hub or casing to the central disk of the fan.

Referring to the drawings, 1 indicates a suitable shaft mounted in bearings 2, that are indicated in dotted lines in Fig. l and may be of any suitable size and construction. On this shaft is mounted a hub or casing formed of a number of connected members 3, 1i, and

IOO

5, each of said members being providedwith annular bolting-iianges 6 and all rotating with the shaft. The end members 3 and 5 fit snugly to the shaft and are secured thereto by means of keys 7, which are passed through dri'fts 8 in the central member 4 and then forced outward to proper position. rIhis permits the bearing-boxes to lit snugly against the end portions of the hub or casing, a construction which would be impracticable if the locking-piece were inserted from the outer ends of the hub or casing, and permits the ready removal of said keys should it become necessary to adjust or dismantle the fan. The central hub member 4 has a bore considerably larger than the diameter of the shaft, so as to permit considerable bending without danger of coming into contact with the shaft, and when this bending occurs the shaft will not be moved out of alinement or distorted to an extent suflicient to prevent true running.

The central hub member 4 is provided with an annular flange 9, to which is secured the large central disk 10, that forms the main support of the fan and through which the driving movement is transmitted. This disk 10 is punched in tangential lines for the reception of the securing-rivets of angle-bars 11, the inner ends of which are deiected somewhat, as shown in Fig. 2, in order to increase the effective action of the fan-blades 12, said blades and the angle-bars extending inward to a point beyond the perimeter of the opening 13, by which air is fed to the fan. The outer edges ofthe fan-blades are connected by anglebars 14 to terminal rings 15, formed of sheet metal and serving as supports and guards for the opposite edges of the fan-blades.

To assist in the support of the fan, the outer ends of the hub members 3 and 5 are provided with radiating arms 16, having recesses or countersunk portions for the reception of the inner ends of radially-disposed bars 17, that extend inside the rings at points between adjacent blades, and may also form the connecting means between sheets of material of which the fan is made when the latter is of large diameter. The arms 17 serve as supports for a ring 2O of a diameter somewhat less than that of the air-supplying opening, and the inner ends of angle-bars 13 are extended to the line of the ring and secured thereto by bolts or rivets.

With a fan of this construction the straightoning of a central disk, while it may result in twisting or straining of the central hub member 4, cannot in any manner affect the shaft, and while the driving movement is effected from the center of the fan the greater part of the weight is disposed at the ends of the shaft adjacent to the bearing-boxes.

In some cases the hub or casing may be made of a single piece of metal, as indicated in Fig. 4, the central portion of said hub member being bored out in order to avoid contact with the shaft except at the end portions of the hub.

Having thus described the invention, what is claimed is 1. The combination in a fan, of a hub member having a bore of greater diameter at its center than at its ends, a disk secured to the central portion of the hub, end rings, spiderarms connecting the end rings to the end portions of the hub, and blades carried by the disk and rings, the connection between the central portion of the hub and the disk being such as to permit distortion ofl such central portion without distorting the shaft or affecting the positions of the end rings and spider-arms.

2. In a fan, a shaft, an elongated hub of which the central portion has a bore of greater diameter than the shaft to permit distortion of the hub without bending the shaft, a disk secured to the central portion of the hub, end rings, spider-arms connecting the end rings to the end portions of the hub, and blades carried by the disk and rings.

3. In a riveted fan structure, a shaft, a hub, the bore of which at a central point is greater than at its opposite ends, an annular iange projecting from the central portion of such hub, a disk formed of sections of sheet metal riveted to each other and secured to said flange, end rings formed of riveted sections of sheet metal, spider-arms connecting the rings to the end portions of the hub, and blades of sheet metal riveted to the central disk and to the end rings.

4. In a sheet-metal fan structure, a hub member, a central disk secured to the hub member, end rings, spider-arms connecting the end rings to the ends of the hub, and blades secured to the disk and rings, the disk being movable independently of the end rings to accommodate warp of the metal.

5. A center-driven fan including a main disk, end rings and blades, a hub secured to the main disk and having a central portion provided with a bore, of greater diameter than the end portions, the central portion of the hub being yieldable with the disk without coming into contact with the driving-shaft, the yielding movement being independent of the rings.

6. In afan structure, a hub formed of a plurality of connected sections, and blade-supporting members secured one to each of said sections, the connections between the hub-sections being independent of the blade portion of the fan.

7. A center-driven fan including a sectional hub of which the central section has a bore of greater diameter than the remaining sections, and means for securing said sections to each other.

8. In a blast-fan, a shaft, a hub member of which the intermediate portion is of greater internal diameter than the end portions, said end IOO ITO

portions having keyways, and the shaft being also provided with keyways, and keys for locking the shaft and hub together, the intermediate portion of the hub being provided with drifts through which the keys may be inserted and removed.

9. In a blast-fan, a hub member formed of a plurality of connected sections, the connections being independent of the fan-blades, a

main disk secured to the central section, end

rings, means for securing the rings to the end sections of the hub and blades supported by said disk and rings.

10. In a blast-fan, a hub member having a plurality of radially-disposed recessed arms,

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