US2037127A - Fluid pump - Google Patents

Description

H. FORD FLUID PUMP April 14, 1936.

Filed May 1, 1935 Patented Apr.-

FLUID PUMP Henry Fora, Dearborn, Mioh., signor to Fora` Motor Company, Dearborn, Mich., a corporation of Delaware Appuoanoo Mayr, 193s, sei-iol No. ssa'lo s claiois. (c1. 10c-10s) 'TheK object of my invention is to provide a uid pump of simple, durable, and inexpensive construction. The specific pump shown is designed for use on an internal combustion engineto cir-- culate the cooling water from the engine and through the radiator; however, the novel features incorporated in my pump may be readily adapted for use in pumps of other design and for other purposes without departing from my invention.

More specifically, the object of my invention is to provide a centrifugal pump having an im peller rotor therein characterized in Athat the ordinary fibrous packing material is eliminated and a metal to metal seal substituted therefor which '15 prevents the iluid from flowing around the impeller'and out through the pump shaft bearing, This seal is disk-'shapedand is provided with `means for supplying just enough oil to the coaotingsurfaces to lubricate same. This restriction in the ow oi oil to the seal surfaces is necessary in order that the centrifugal action of the seal does not throw out large amounts of oil into thev fluid stream thereby diminishing the oil supply and contaminating the uid circulated 1 25 by the pump.

A further feature of my improved pump is that the impeller is rotatably mounted within the iiuid chamber independently of the pump shaft, the rear face of the impeller forming one surface 0f the water seal and which impeller is resiliently urged against the fluid seal by means of a spiral spring which is anchored in the pump housing. A universal joint connects the impeller with the pump shaft so that axial deflections of the shaft.

in no way tend to afect the functioning of the 'water seal, as invariably results Where the impeller is fixedy to or mounted upon the pump shaft.

. With these 4and other objects in view, my in- 40 vention consists in they arrangement, constructionxand combination of the various parts comprising my improved device, as described inthe specification, claimedin my claims, and illustrated in the accompanying drawing, in which:

Figure 1 shows ,a central cross-sectional View through my improved pump, illustrating the sevyeral elements comprising same.

Figure 2 shows anv end view of my pump im. peller. and

Figure 3 shows an end view 'of the spring which resiliently urgesv the impeller axially,y to form the fluid seal. o 4

Referring to the accompanying drawing, I have used the reference numeral I0 to indicate genera ally a pump housing which is provided withv a ange II Vcast integrally therewith and which flange is adapted to'be bolted to the cylinder head I2 of an internal-combustion engine. It will be noted that the flanged wall of the housing Ill is provided with a central opening I3 which -5 is' aligned with a corresponding opening in the cylinder head I2. 'Ihe uid circulatedv is thus drawn from the vcylinder=head into the pump housing through these openings.

In position'axially aligned' with the opening 10` I3, but in the opposite'wall of the housing, I have machined a cylindrical impeller bearing I5.

'- This bearing does not extend through the adjacent wall of the housing but is closed by a diskshaped impellenseat I4 which is formed integrally 15 with `the housing and which forms one element of the pumps uid seal. My impeller is a diskshaped casting I6; one face of which is machined' smooth and iiat to coact with the seat III and the edge of which is machined cylindrical whereby 20 the impeller is rotatably mounted in the bearing I5.

This impeller is installed in position on the seat I4 by inserting it through the opening I3. l A pair of diametrically opposed impeller blades 25 Il extend axially from the back of the impeller into the chamber formed-within the housing II), which blades are cast integrally with a hub memn l ber I8. 'Ihe path described by the blades I'I is shown by dotted lines I9 in Figure 1, from which 3-0 it may be seen that rotation of the impeller will draw fluid in through the opening I3 and force it outwardly through an opening 36 formed in the upper portion of the housing. It will be noted that the hub ca is not bored through and that 5 any uid escaping by other than the openings vI3 and 36 must pass through the bearing IEfand fluid seal I4. o *fff i In order that this seal may be iiuid'tight, the impeller is resiliently urged against the seatl 4 yby 40l a spring 20. This spring, as shown in `Figure-3, is of spiral or conical shape; however, the periph ery of the spring is truly circular and has a free diameter considerably larger than the opening I3'. An internal grooveZI is machined in the edge 45 of the opening I3 intowhich theouter coilgof my spring is anchored. A very important feature of this device is that when the spring yis snapped into position in the groove 2l almost thel whole outer coil of the spring rests against the bottom 50 of the groove thereby firmly anchoring the spring into position. This'is made possible because, as will be noted in Figure 3, the spring is given an' abrupt bend, as shown at- 22, the spiral portion l of the 'spring starting at this bend. The center v5| ter of the flat impeller face, this slot being cut with a standard Woodruff keyway cutter. The

y'slot/does not extend through the impeller, as there is no passageway whatever between the blade side of the impeller and the slot 24 except along the joint formed by the bearing I5 and seat I4. The

slot 24 is provided to form a drive for the, impeller. i

It will be noted that an oil chamber 25 is cast integrally with the housing I0 and that a pair of openings 21 and 26 extend through the center of the seat I4 and through the outer wall of the oil chamber 25, respectively. 4These openings are aligned with each other and extend, perpendicular to the seat I4. A porous graphite bronze bushing 28 is pressed into the openings and 21 and extends therebetween leaving the intermediate portion of the bushing exposed to the lubri'- cant in the oil chamber 25, which chamber is provided with a suitable tting 30 which permits of ready'replenishment of the oil in the chamber.

I have provided a shaft II which is rotatably mounted in the bushing 28, this shaft having the end adjacent tothe impeller IB atted at 32 to therebyA form a` tongue which coacts with the slot 24 and rotatably drives the impeller. A collar 33 is formed integrally with the shaft 3| adjacent to the outer end of the oil chamber and a cap 34 is screwed down over this collar to thereby prevent-axial movement of the shaft in the bushing 28. The shaft 3l projects beyond the collar 33' and a driving pulley l5 is fastened on thisrprojecting portion of the shaft. -The preferred method of forming this shaft is bychill mold die casting with only a subsequent grinding operation.

From the foregoing it will be noted that rotation of the pulley 35 drives the shaft 3l which A rotates the impeller I6 by means of the tongue l32. It will also be noted that the impeller I8 is rotatably mounted independently of the shaft 3| so that a considerable axial misalignment of these two elements is permissible without affecting the iluid seal.

It is highly important that the impeller be rotatably mounted independently of the shaft II -asN it is believed impossible to maintain a fluid tight seal with the impeller if the latter i's fixed to the driving shaft, the reason being that should one end of the shaft bearing wear slightly more than the other end, due to the side-thrust resulting from the driving belt, the shaft then is not truly perpendicular to the seat I4. In this case the impeller wears to a conical shape and bears only upon one point on the seat I 4 thereby allowing `iiuid to seep through the joint with the rest of the seat surface and thus destroythe purpose of the joint. It is absolutely essential thaty truly complementary surfaces be maintained at all times between the impeller and the seat I4, as even a clearance of only a fraction of a thousandth of an inch at any point around the 'seat will allow fluid to seep through the seal. Another feature of great importance in this device comprises the lubrication system. It is well .known .that whemthe impeller is rotating acenimpeller and discharges it into the fluid chamber. If the keyway slot 24 were kept filled with oil from the chamber 25 while the pump was rotating a steady stream of oilv would be thrown of! theperiphery of the impeller. and not only soon deplete the oil supply but also this action would contaminate the fluid being pumped. To avoid this a novel means is provided whereby a denite but very limited amount of oil is supplied to the fluid'seal surfaces.

As has been stated, the bushing 28 is formed of porous material whichfhas a comparatively low elasticity. Consequently, when the bushing is installed in the pump it is essential that it be pressed first through the opening 21 and then into the opening 26 in the direction shown by arrow 29 so that a tight press fit will be secured in the opening 21 although the joint between the opening 26 and the bushing may be somewhat looser.

The tight t with the opening 21 is essential 'in order that oil may not be drawn by centrifugal action along the exterior of then bushing and through this opening.

' All lubrication for both the shaft and the'impeller must iilterthrough the bushing as there is no oil hole or other direct passageway 'from the oil chamber to the shaft. This feature of the device is highly important in that the amount of oil supplied to the shaft and impeller is regulated bythe wall thickness and porosity of the bearing. For this reason, even should the bushing wear an' appreciable amount, still* only suilicient oil will be supplied to the impeller to maintain an oil film on the seat I4. The advantage of this function may be better appreciated by contrasting it with the conventional pump bushing which supplies oil in an unlimited quantity to the bushing. Consequently, wear-in such a bushing would permit the impellerto draw out all the oil in the reservoir in only a very short time.

Refening to tl e' shouldered end of the shaft 2 I, it will be noted that oil which may seep out between the bushing 28 and opening 26 or along the adjacent bearing surfaces serves to lubricate the collar 33, and while this collar centrifugally throws the oil out to some extent, still the outer side of the collar also acts to centrifugally retain the oil in the cap 34, so that the effect is neutralized. For this vreason very little oll escapes from the pulley end of theshaft.

Among the many advantages arising use of my improved device, it might be well to mention that this pump is simple and durable and that the quantity of lubricant used is independent of the age or condition of the pump shaft bearing.

Another important advantage results from rotatably mounting the impeller independently of the pump shaft, as such structure maintains the fluid seal even should the bearing wear an excessive amount.

It may be thought that the friction of the button 23 on the end of the impeller would cause excessive wear, .due to the absence loi? oil lubricaous parts of my improved device without depart-.-y

ing from the spiritof my i`vention,'"and it is"`my `intention to cover by my claims such changes as from the' amara? mayreasonably be included within the scope thereof.

I claim as my 'lnventionz' l. A centrifugal pump construction comprising, a pump hosing, a drive shaft rotatably mounted in said housing, an impeller rotatably mounted in said housing independently of said drive shaft but in substantial axial alignment therewith, a universal driving connection disposed between said impeller and drive shaft, said impeller having a disc-shaped surface .which coacts with one wall oi' said housing to form a water seal therebetween, with said housing having an annular inlet passageway in substantial axial alignment with said impeller, said inlet passageway having an internal groove therein, and a conical shaped spiral spring, the base of which is secured in said internal groove with the apex oi' said spring abutting the centerof said impeller, whereby said impellery is resiliently urged against said housing to form the water seal.

, 2. A device, as 'claimed in claim 1, said universal driving connection comprising a Woodrufb' of said shaft is provided with a tongue which engages said slot to form a universal driving connection therebetween.

v3. A watery pump construction comprising, a

face thereon which coacts with an adjacent wall of the housing to form a water seal therebetween, said impeller having' its periphery between its disc shaped surface and said impeller blades tween said impeller and said shaft, said housing having a fluid inlet opening therein axially aligned with the impeller, and a spring extending across said inlet opening tothe central portion of said impeller, the iiuid being pumped circulating around said spring.

. HENRY FORD.

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