US1838799A

US1838799A - Shaft seal

Info

Publication number: US1838799A
Application number: US517531A
Authority: US
Inventors: Harry J Welch
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-02-21
Filing date: 1931-02-21
Publication date: 1931-12-29
Anticipated expiration: 1948-12-29

Description

Dec. 29, 1931. J, WELCH 1,838,799

SHAFT SEAL Filed Feb. 21, 1931 'j maar a. wams, or eRArToN, omo

'SMT 'SEAL `Application ledgFebi-uary 21, 1931. 'Serial No. 517,581. I

frais' inventibnxiaas a) Shaft seais; n has to do more particularly with an improved form of seal that is adapted to be` utilized in connection with theA water pump -"shaft of an internal combustion motor, although it is not' limited in its use to the specific instance noted above andmmay-v be employed in other` capacities if so desired.

l.li-leretofore much difficulty ha's been experience-d in providing a shaft seal that would be more or less `of a permanent-natureand would'operateffo'r the purposejjintended with'-V out breaking downlonleaking ln'some instances, the shaft has been surrounded with a packing material that was expanded by means of alpacking nut, quite difficult tofac'curatelyy .adjustjand maintain in adjustment. The'least over-'pressure on thematerial would resultin the glazing or hardenin thereof and the subsequent destruct-ion of t e seal, thus necessitating replacement which is both eX- pensive andtroubl'esomeh More in particular", this invention is directed to a pump shaft assembly that may' or may not mount a fan on one "end .thereof and that includes as a novel partof the com'-l bii'iationyaf` pair of co-operating seal" members, each yhaving a wedge `or ltapered engagement with the` other, one of such members being lixed and the other of said members being rotatablepwith relation thereto "and movf able axially," toward and. away ftherefrom.-

The movable member, in the preferred"formy of shaft assembly 'may be `forn'ied as apart ol'.i the shaft and is moved'thereby into seal'- ingeng'agement withthe first named memben. The shaft, in turn ,'is'urged Vby theresilient pressure of a springer the like'to maintain the engagement jbetween fthe"v 'cooperating members regardless offwear there-4V4 between. If the pump shaft mounts a: an,f the pull Vof the lfan is also effective' to tend.)`

to move theshaft axially inthe poper'direc-V tion to effecty and maintain theabovementionedseal. f

In addition to the objects thatv are appa-rent from a study of the preceding paragraph, it

is a further objectof this invention to providel a pump shaft assembly including such means as vwill permit ,o 'ffthey continued .and efficient operation ofsucli lapparatus forthe purpose intended -iwithout requiring Afirequent attention Vto placevthe ,parts in adjustment.l j A* y Another object4 of this invention consiste in the provisionof al pumpshaft assembly, per se, that vmay be manufactured Vat avrelatively low costwand may b e readilyinstalled as a replacement for worn oifit'orunsatisfactory types'` of pump devices, or,l on the other hand, may be installed as standard equipment in new motor's tothereby provide a leakproof assembly at the outset. -f

Other objects and advantageous features" of this invention will be notedin thejaccompanying drawing and the following description wherein'like figures of reference designate corresponding p'artsand wherein:

Fig'. i is a verticalv longitudinal section through the? preferred form' of my pump shaft assembly; y y

Fig. 2 is a horizontal longitudinal section of the assemblyshown in Fig.` l;

Figf is a detail in section of theresilient means for imparting a thrustto the pump shaft; f F ig. 4 is a modili'ed'sho'win'g ofthe shaft assemb1y.= 1 'f 1 with reference *ai the] drawing', I have shown in Figs. vl and 2 the preferred' formof my inventionasl comprisinga pump shaft assembly mounted' onthe water jacket l of an internal combustionmotor;` This assemfected bymeans of an end plate 3 formed:

as para f thabnaekec 4. that r'tfitably;Sup;-l

pprtsjtheoppo'sin'g end Qftl'ie'fshaft 21, invia,

ari'ng zllnf the showingiiinllig. l, a pro-A peller fan 6 is mounted at the end of the shaft for rotation therewith. The o posing end of the shaft lying within the jac et 1 carries an impeller 7 thatis also mounted for rotation therewith, the shaft being turned by means of the usual pulley 8 and belt 9 arrangement.

To prevent leakage of water from the wa- 'ter jacket, a tapered bushing 10 of bronze or other suitable material is secured in theend plate 3 vand is adapted to encompass a tapered enlar ement 11 formed asa part of the shaft l. T 'e tapered construction of the bushing 10 and enlargement 11 provides for a leakproof joint. The wedge-like engagement of these two members is maintained at all times,y

regardless of the amount of wear produced by the frictional engagement of 'such surfaces, by a means adaptedl to exert a force on whic serves as a thrust bearing so that the tension of the sprin 14 normallyvpresses the shaft outwardly; hus movement of the shaft in-the direction indicated would maintain the bearing surfaces in contact to take up wear therebetween and' provide a leakproof joint. As'the plug 12, lies within the water jacket Vthe contact surface between the cylinder head castingand the end of the plug will alwaysbe lubricated bythe water 1n t ejacket.

Fig. 4 shows an alternative arrangement of bushing wherein the numeral 20 indicates a hardened steel tapered bushing that is mounted for rotation with the shaft 2 by be# ing keyed to or pressed thereon and is adapted to bear within the bronze bushing 10, the only difference between this arrangement and the one shown in Fig.` l residing in the in-l `tegral nature of the bushing 11 with respect to the shaft 2.

Fig. 4 also shows an alternative arrange- I ment for providing a thrust bearing for the .a lubricant reservoir 26 concentric with the shaft 2 that communicates with the frictionally engaging surfaces by means of conduits 27 forme in the bushing 10. j

Although I preferably intend to construct these pump assemblies for installation on the forward end of the water jacket, it will be seen that such may be mounted at other points on the vehicle and may, if desired, be chain driven from the engine cam shaft. However, in the preferred form shown in Fig. 1, the apparatus` is adapted to carry the air fan on one end of the shaft. and it may be stated at this point that such fan operates as an aux iii-ary means, in addition to the resilient force of the spring 14 to move the shaft 2 outwardlyl to thereby effect a leakproof joint between t e bushing 10 and enlargement 11. The rasp of the blades on the moving column of air flowing thereover during rotation is sov .sucient to set up a pull on the shaft 2 that aids in producing an efficient leakproof en'- gagement between the sealing surfaces.

A shaft seal of my novel constructionis both simple and highly efficient in operation and will remain in operative condition for an indefinite period due to the arrangement of parts wherein the seal members are al- 'vays biased toward firm eflicient co-operaion.

It is believed that the .sealing action of devices embodying the present invention is largely due to the arrangement of the conical or tapered surfaces. When one of such surfac'es is fixed and the other is rotated and lwhen the larger ends of such surfaces are exposed .to liquid' a pumping action takes place between the two surfaces which causes or tends to cause liquid between the surfaces to flow toward the larger ends ofthe latter. This action is suiiiciently great to overcome any tendency of liquid to flow in the' opposite direction and out at the smaller ends of -the tapered or conical surfaces and hence the device effectively seals itself against liquid leakage. This pumping action is sufficient in itself in many instances to make it unnecessary to apply sprin force to urge lthe shaft axially and bring t e conical surfaces into closer engagement with each other. For example the force of gravity in the case of a vertical-axis shaft or the flowing head of water axially against the impeller'niay be sufficient without force such. as spring pressure to maintain the conical surfaces in liquid sealing cooperation.

'It is obvious that modifications and variations in the construction and arrangements of parts of my pump shaft assembly may be made without de artingfrom the spirit ofA my invention an I do not, therefore, limit myself to the precise details shown .and described but claim as my invention all embodiments thereof coming within the scope of the appended claims'. l

I claim is:

Having thus' described my invention, what i' nasspoof ysaid bushing and provided with a conical surface rotatable with the shaft, said conical surface being adapted to have bearing and liquid pumping engagement thruout substantially the full length of the said conical bore.

2. A liquid sealing shaft assembly includlng a portion of the Wall of a liquid containing chamber, a bushing secured in an opening thru said Wall, said bushing having an elongated conical bore substantially coextensive therewith and converging from the inner or liquid contacting end toward the outer end of the bushing, a shaftextending thru said bushing and provided with a conical surface rotatable with the shaft, said conical `surface being adapted to have bearing and liquid pumping engagement thruout substantially the full length of the said conical bore and a liquid impeller on the shaft at the chamber side of said Wall near the larger end ofthe conical surface.

3. A liquid sealing shaft assembly including a portion of the Wall of a liquid containing chamber, a bushing secured in an opening thru said Wall, said bushing having an elongated conical bore substantially coextensive therewith and converging from the inner or liquid contacting end toward the outer end of the bushing, a shaft extending thru said bushing and provided with a conical surface rotatable with the shaft, said conical surface being adapted to have bearing and liquid pumping engagement thruout substantially the full length of the said conical bore, and Ifneans to lubricate the bore and conical surace.

4. A liquid sealing shaft assembly including a portion of the Wall of a liquid containing chamber, a bushing secured in an opening thru said Wall, saidbushing having an elongated conical bore substantially coextensive therewith and converging :from the inner or liquid contacting end toward the outer` end of the bushing, bushing and provided with a conical surface rotatable with the shaft, said conical-surface being adapted to have bearing and liquid pumping engagement thruout substantially the full length of the said conical bore, and means to urge the shaft axially toward the smaller end of said bore.

5. A liquid sealing shaft assembly including a portion of the Wall of a liquid containing chamber, a bushing secured in an opening thru said wall, said bushing having an elongated conical bore substantially coextena shaft extending thru saidv sive therewith and conver 'ng from the inner or li uid contacting en toward the outer end of t e bushing, a shaft extending thru said bushing and provided with a conical surface rotatable with the shaft, said conicalr surface being adapted to have bearin and liquid pumpin engagement thruout sustantially the full ength of the said conical bore a second bearing for the shaft axially s aced from the smaller end of the bore of the hushing and fixed against axial movement.

HARRY J. WELCH.

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