US1953297A

US1953297A - Blower wheel

Info

Publication number: US1953297A
Application number: US438067A
Authority: US
Inventors: Paul E Good
Original assignee: Elliott Co
Current assignee: Elliott Co
Priority date: 1930-03-22
Filing date: 1930-03-22
Publication date: 1934-04-03
Anticipated expiration: 1951-04-03

Description

April 3, 1934. p, E GOOD 1,953,297

BLOWER WHEEL Filed Marh 22, 1930 ill/IA i Patented Apr. 3, 1934 PATENT oFFic BLOWER WHEEL Paul E. Good, Riverton, N. J., assignor to Elliott Company, Pittsburgh, Pa., a corporation of Pennsylvania Application March 22,

5 Claims.

This invention relates to means for securing a rotor to a shaft in such fashion that the rotor may be readily removed from the shaft. One object of my invention is to provide an improved mounting for a rotor, whereby the same may be securely mounted on a shaft and yet readily removed when desired. A further object of my invention is to improve the construction of the mounting for a rotor on a shaft, this improved construction permitting the removal of the rotor with facility from the shaft. Further objects of my invention will appear inthe course of the ensuing description, and will be more clearly pointed out in the claims.

For purposes of illustration, I have illustrated my invention as embodied in a blower wheel forming a part of a centrifugal blower construction; and accordingly, in the drawing,

Figure 1 is a longitudinal sectional view taken through one end of a shaft and through a blower wheel mounted thereon, the section being taken on line I-I of Figure 3;

Figure 2 is a transverse section on the line II-II of Figure 1;

Figure 3 is an end elevation of the mechanism shown in Figure 1;

Figure 4 is an end view similar to Figure 3, but

with the securing nut removed and replaced by a removing device;

Figure 5'is a view similar to Figure 1,\but on a reduced scale, with an alternative device in position for removing the blower wheel from the shaft; and

Figure 6 is a view similar to Figure l, with a modied device in position for removing the blower wheel from the shaft.

My invention is broadly applicable to various types of rotors which are mounted on shafts in such fashion as to prevent relative rotation between the two. Diiiiculty is often encountered in removing the rotor when repairs, or some necessity for taking the machine apart requires that the rotor be slid off the shaft. My invention is particularly useful in connection with avblower wheel forming part of a centrifugal blower. Furthermore, if the blower wheel be cast of aluminum alloy or other metal which has a relatively low structural strength it is obviously not desirable to drill holes in the wheel for the attachment of devices which may be used as anchors in drawing the wheel from the shaft. In other Words, it is undesirable t-o in any way decrease the strength of the hub of the blower wheel. Another 'difficulty encountered in removing a blower wheel may result from the construction 1930, Serial No. 438,067 (ci. 287-53) of the centrifugal blower itself, in that the shaft on which the blower wheel is mounted may project through an -opening in a solid casting, making it impossible to use hammers from behind the wheel to force the same oif the shaft. In my improved mounting for a rotor, the parts are so assembled that the blower wheel may be readily removed from its shaft when desired.

In the illustrative embodiment shown herein,

the rotor consists of a blower wheel 7, the form and shape of this wheel being unimportant and, therefore, not shown. The blower wheel 7 surrounds and 'is mounted on a reduced portion 10 of a shaft 8, a shoulder 9 being accordingly formed between the reduced portion 10 and the main body -of the shaft 8. The portion l0 is somewhat tapered so that the diameter of the' shaft gradually decreases from the shoulder 9 toward the end of the portion 10.

Between the wheel 7 and the reduced shaft portion 10 is a tapered bushing or sleeve 1l whose bore is'proportioned to nt the reduced portion 10 of the shaft 8. The outside of the bushing 11 is substantially cylindrical, and fits the cylindrical bore 12 in the blower wheel 7. The bushing 11 therefore serves as wedging means to tighten the rotor 7 on its shaft. This friction between the bushing, the rotor, and the shaft portion l0 would, with ordinary loads, be sulficient to prevent slipping of the rotor. If desired, however, additional security against slippage may easily be afforded. In such case, a keyway 13 may soA be cut in both the shaft portion 10 and the f wheel 7, the sleeve 1l being slotted throughout its entire length to complete the opening for a key 14, which, when inserted in position, prevents relatively rotation between the shaft 8 and blower wheel 7.

The outer end 16 ofthe shaft portion 10 is still further reduced in diameter, and is threaded. to receive a nut 17 having an inwardly directed peripheral fiange 18. This flange surrounds the outer end of the sleeve 11; and in order to force the blower wheel 7 into position against the shoulder 9, the nut 17 may be screwed inwardly on the threaded portion 16. A hardened washer 20 may be interposed between the fiange 18 and the hub of the blower wheel 7. The outer end of the hub of the blower wheel 7 is formed with a machined surface'Zl which is engageable by the hardened washer 20, when, as above described, the nut 17 is tightened. As is shown in Figures 1 and 3, one or more set screws 22 are arranged within the nut 17, the set screws projecting inwardly and bearing against the outer end of the sleeve 11. These set screws act as locking means to prevent relative rotation between the nut 17 and the shaft portion 10. A cotter pin 15 may additionally be passed through the nut 17 and shaft portion 10 for the same purpose (see Figure 3). A

In Figure 4 is shown a device which may be employed for removing the wheel 7 from the shaft 8. To use this device, the nut 17 is first removed.

Y As shown in Figure 4, this device takes the form of an acorn nut 23 which is adapted to cooperate with screw threads 24 on the outer end of the sleeve 11.

In Figure 5 is shown an alternative device which may be employed for removing the wheel 7 from the shaft 8. The nut 17 having first been removed, a nut 26 formed with threads for cooperating with the threads 24 on the sleeve 11 is screwed onto the sleeve; and by bringing this nut 26 to bear on the surface 21 of the hub of the rotor 7, the sleeve 11 is withdrawn.

In Figure 6 is shown another modication of a device which may be Vemployed for removing the wheel 7 from the shaft 8. Similarly, as in the form shown in Figure 4, a device 27 replaces the nut 17, except that it is provided with threads 28 adaptedto engage the screw threads 24 on the sleeve l1 instead of the screw threads on the outer end 16 of the shaft. A cap screw 30V eX- tends inwardly through the device 27 to engage the outer end portion 16, this cap screw being adjustable in an obvious manner.

Two methods of assembling the rotor and shaft may be employed. In the first method, the sleeve 11 is rst assembled in the bore of the huhof the blower, wheel 7. It will be noted that the sleeve is tapered, so that the blower wheel and sleeve may be slipped onto the shaft portion 10, the sleeve sliding on the shaft portion 10 without substantial frictional resistance until the hub approaches fairly close to the shoulder 9. The washer 20 is temporarily omitted; andthe nut 17 is employed for forcing the sleeve 11 and Wheel 7 into position as 'shownin Figure 1. It should be noted in this connection that the nut 17 has a substantial bearing surface 25 for engaging the end of the sleeve 11. the set screws 22 being slightly withdrawn at this timek so that this flat recess 25 of the nut 17 will engage the end of the sleeve.

When the hub has been drawn into position by the nut, the latter is removed, the washer 20 placed in position against the machined surface 21, and the nut 17 is replaced and drawn up tight. The set screws 22 may then be tightehed to lock the nut 17 inJposition. Care should be taken in drawing up the nut'17 not to position the threaded opening for either set screw 22 to overlie the end of the keyway 13. Y

The other method of assembling has as a first step the placing of the sleeve 11 in position. The hub of the wheel 7 is next pushed inwardly over the tapered sleeve as far as it will go. The washer 20 is then placed in position loosely surrounding the threads 24. The nut 17 is then engaged with the threads 16 on the end of the shaft 8 and drawn up tight, the iiange 18 bearing against the hardened washer 20 to force the hub into position against the shoulder 9.

In removing the blower wheel from the shaft 8, the set screw 22 are loosened and the nut 17 is removed. The nut 26, the acorn nut 23 or the threaded device 27 is then screwed on to the projecting end of the sleeve 1l. If the device 27 is employed, it will be noted that the amount Lesage? which the cap screw 30 projects inwardly may be adjusted. This makes it possible to take care of slight differences in the amount of projection of the sleeve 11, or in the length of the shaft portion 16, etc. This modification is for this purpose to be preferred over the acorn nut 23. By turning the nut 23 or the device 27, as the oase may be, the same cooperates with the threads 24 to slide the sleeve 11 longitudinally of the shaft portion 10 so as to loosen its t on the shaft portion.

`Should the alternative form of device shown in Figure 5 be employed, the sleeve 11 moves outwardly relative to the wheel 7, when the nut 26 is turned in the proper direction on the threads 24. For certain purposes, as, for example, in case should be found desirable to taper the bore in the rotor 7 instead of the shaft portion 10, it is preferable to thus'move the sleeve 11 relative to therotor 7 rather than to move the sleeve and rotor together relative to the shaft portion 10. When the sleeve 11has been loosened by turning the acorn nut 23, the nut 26 or the device 27, as the case may be, the entire blower wheel assembly may be easily moved.

Although my invention has been described as being particularly useful in connection with a blower wheel such as illustrated in the drawing, it is to be understod that its utility is not limited to such a form of rotor, but that it is broadly applicable to rotors carried upon rotatable elements, myinvention having provided a simple and efficient means for withdrawing rotors from the elements on which they are mounted. It will be apparent moreover that I have provided a simple and highly advantageous arrangement for drawing a blower wheel olf the end of a shaft without interfering with the strength of the blowerl wheel o r necessitating reconstructionjof the blower apparatus itself.

While I have illustrated and described the present preferred form of my invention, itis to be understood that it may be otherwise embodied within the scope of the following claims:

I claim:

1. In combination, a shaft, a member mounted thereon and including a hub surrounding the shaft, a wedge bushing interposed between the hub and shaft, means independent of the bushing, mounted on the shaft and directly engaging the hub to secure the latter against displacement, and means movably mounted onl the securing means and engaging the bushing for moving the bushing with respect to said securing means.

2. In combination with a shaft, a member mounted thereon andincluding a hub surrounding the shaft, a bushing interposed between the shaft and hub and having means at one end for engagement by a removing device, said shaft projecting beyond said end, and a hub retaining device mounted on said projecting shaft end, extending over the said end of the bushing and engaging the hub to secure the same in place.

3. In combination with a shaft, a member mounted thereon and including a hub surrounding the shaft, a bushing interposed between the shaft and hub and having its outer end projecting beyond the hub and threaded to engage a removing device, said shaft projecting beyond said threaded end and itself being threaded, and a nut threaded on the projecting end of the shaft and enclosing the threaded end of the bushing, said nut having a bearing against the adjacent end of the hub around the end of the bushing.

4. In combination a shaft, a member mounthub and shaft, said shaft projecting beyond the bushing and said bushing projecting beyond the hub and having means for the attachment thereto of a removing device, a nut threaded on the projecting end of the shaft and extending over the projecting end of the bushing to bear against the hub, and a screw threaded in the nut and having a bearing against the projecting end of the bushing.

PAUL E. GOOD.