US2180883A - Fuel pump assembly - Google Patents

Description

Nov. 21, 1939. P. L. SCOTT FUEL PUMP ASSEMBLY Filed Nov. l2, 1936 Patented Nv. 21, 15939 PATENT- OFFICE FUEL rum ASSEMBLY Philip Lane Scott, Chicago, Ill., assignor to Super Diesel Tractor Corporation, La Porte, Ind.,'a corporation of New York Application November 12, 1936, Serial No. 110,485

6 Claims.

'Ihis invention relates to a means for making, sizing and maintaining the size of a barrel in which a member is mounted for reciprocation.. 'I'he invention relates, therefore, to a pump or analogous device and to the method of making it.

Oneobject of the invention is to provide a pump or similar combination of barrel and plunger in which the bore in the barrel ismade of approximately the right size, is corrected as to roundness and parallelism and is then finally reduced to the proper internal diameter by exertin'g pressure upon a liner which forms a part of the barrel. Another object of the invention is to provide means for re-sizing the barrel. A

i6 still further object is to provide means for taking up wear.

Other objects will appear from time to time in .the speciiication and claims.

e The invention is illustrated more or less diagrammatically in the accompanying drawing,

wherein:

Figure 1 is a longitudinal section through a pump, wherein portions of a pump and a pump barrel made in accordance with my invention are shown:

Figure 2 is a sectional detail of a modified form of barrel construction.

Like parts areA designated by like characters throughout the specification and drawing. lo 'Ihe numeral I designates a portion of a pump housing provided with a cylindrical bore or hollow 2 in the lower end oi which may be seated a spring 3 to prevent separation of the parts. The

member I is provided with lateral projections or ears 4 which are perforated as at 5 for attachment to a suitable base. At its opposite end the pump housing is partially closed in by the portion 6 which may be shouldered as at 1. 8 designates a further or additional part of the pump houso ing which is provided with a bore 9 generally axially aligned with the bore 2. The details of this sectionand of the pump in general, including the valves, the inlet and theoutlet form no essential part of the invention and are not cie-1 scribed in detail. The barrel construction of the present invention might be applied to a large variety of pumps whose details voi construction are independent of the barrel construction.

'I'he barrel is formed of two parts, a sleeve or jacket I0 provided at one end preferably with a laterally extending flange II which is seated against the shoulder 'I of the member I. 'I'he sleeve may be tapered interiorly as at I2. A liner E I3 exteriorlytapered to correspond to the taper 5 I2 of the sleeve I0 is provided and is inserted within'the sleeve.

Theliner has preferably'a cylindrical bore I4 which is ilared at one end as at I5 to receive a sealing member I6 a portion of which lies' in a o corresponding flared portion I'I of the bore 9 size and is then pressed into the sleeve.

(ci. asa-149.55

of the housing member 8. A piston I8 is mounted for reciprocation within the liner. It may be of any desired shape but in the formA here shown ,is pointed as at I9.

' 24 is mounted to reciprocate within the housing section I and also surrounds thebarrel assembly. A contact member maybe removably 'mounted in a perforation 26 in the closed bottom 21 of thecross head. This member 25 may be shouldered at 28 to be seated in a corresponding shoulder 29 in the cross head. Aspring or other member 30 holds the contact member 25v removably in place.

Figure 2 shows a modied barrel construction in which, instead ofthe interiorly tapered sleeve Ill, a cylindrical sleeve 3l is used. Its exterior contour is the same as that of the sleevel I0 and it is seated in the pump housing in the same manner. A liner 32 which corresponds on its exterior to the interior of the sleeve 3| is used. It is made cylindrical without exterior taper. It is made approximately to interior size and is then inserted within the sleeve which is shrunk or otherwise compressed on it to the desired degree to produce the proper internal size of the' liner bore.

In manufacture the sleeve. may be formed as shown with a tapered bore. 'I'he liner which maybe of cast iron or other suitable material isv made preferablywith a tapered exterior corresponding in taper with that of the sleeve. The sleeve is oi' a material of high tensile strength which, therefore, resists deformation. The borev or hole inthe lineris made approximately to The bore is normally made slightly larger than necessary and after being seated within the sleeve the liner is driven or pressed, further in to` close upthe bore to the desired diameter.. By this means absolutely. accurate sizing ofthe liner bore can be accomplished without the necessity of extremely accurate original work. The bore can be closed down to thedesired .size with great,

accuracyand with extreme simplicity by forcing the liner into the sleeve the necessary distance. Thus, since the sizing of the bore of the liner is simply accomplished, the manufacturing problem is simplied and in manufacture the attention may be concentrated upon making holes or bores of proper trueness and surface finish, and thenal sizing operation, instead of being accomplished as a machining or lapping or similar operation is carried out by forcing the liner into the sleeve until the proper degree of fit between sleeve and plunger is obtained.

A further advantage of this device is that after wear occurs and the bore becomes oversize, the linercan be brought again to the proper size. It is necessary merely to force the liner further along the taper within the sleeve and it is resized to the desired dimension.

While there is shown a tapered bore and tapered liner andwhile with this form of the invention the sizing is accomplished by forcing the liner the necessary distance into the sleeve after it has been made true and given proper roundness and parallelism, it is obvious that the sleeve might be shrunk or otherwise tightened upon the liner to giveit the necessary size. Whichever form of the invention is used, the liner can be finished by what may be considered general shop work, in which it can be readily heldl to a very few ten-thousandths of an inch. A frequent condition will be that when the bore is properly nished and the plunger inserted there will be a slight clearance between the plunger and the bore, this clearance being of the order of a very few ten-thousandths of an inch, and this clearance is then taken up by exerting pressure on the liner either by forcing it into the tapered bore of the sleeve or by otherwise compressing it within the sleeve.

The liner, Whether in the form of Figure 1 or Figure 2, may be initially seated within the lsleeve before the liner bore is formed and after that bore has been formed, in the case of the tapered arrangement of Figure 1, the linermaybe further driven in to complete the sizing operation or, in the form of- Figure 2, the shrinking or other operation necessary to compress the liner to proper size may be carried out.

Heretofore an accurate mating between a plunger and barrel in a packingless pump, that is to say, in which the main sealing effect is obtained by the nicety of fit between a plunger and barrel of relatively hard materials rather than by soft and easily compressible materials, has proved a very serious problem. General practice has involved hand lapping operations to extreme accuracies which has proved both costly and required excessive amounts of time. This is because no way has previously been known to handle these hard materials except by some form of cutting or abrasion. My invention overcomes this difliculty in that even though the materials are hard they do have slight elasticity and I am taking advantage of this slight elasticity to change the size a mirute amount which, however, is sufficient to produce the desired fit.

In forming the pump and in adjusting the relative position of the liner and sleeve to accomplish the final size ofthe bore of the pump,'or to readjust it for Wear after use, it is to be understood that the adjustment ofthe liner and sleeve may be such as to produce first too tight f a t and movement of the parts may, when this occurs, be reversed to permit sufficient expansion on the part of the liner to produce the proper size of bore. The pump barrel as an article of manufacture is claimed in my co-pending application, Serial No. 110,484, filed November 12, 1936. The method of making and assembling the pump .barrel and associated parts.is. claimed herewith.

I claim:

1. The method of sizing a liner in a multi-part pump barrel, which includes the steps of forming a hollow liner with tapered exterior, forming a hollow sleeve with correspondingly tapered interior, forcing the two together axially and thereby decreasing the internal size of the liner to the desired final size.

2. The method of sizing a liner in a multi-part pump barrel, which includes the steps of forming a hollow liner with tapered exterior, leaving the interior size thereof 'greater than' that nally necessary, forming a hollow sleeve with correspondingly tapered interior, forcing the two together axially and vthereby substantially uniformly decreasing the internal size of the liner to the desired final substantially uniform size.

3. The methodof sizing a liner in a multi-part p ump barrel and guiding assembly which includes the following steps: making a hollow liner, forming through said liner a round, straight hole to a slightly variable, over-sized diameter, making a cooperating compression member, placing said compression member about said liner, moving the compression member with respect to the said liner, and thereby compressing the liner and reducing by said compression the outside diameter of the liner to a minute amount and, also, thereby reducing the diameter of the bore of said liner uniformly, and holding the stresses set up within both the liner and the compression member well within the elastic limits of the materials, and maintaining the inner walls of the liner bore straight during such compressive step.

4. The method of making and sizing a liner in a multi-part pump barrel assembly which includes the steps of making a liner, boring a round, straight hole axially through said liner, making and placing about said liner a co-operating compression member, moving the compression .member axially with respect to said liner and thereby exerting compression upon said liner and decreasing the internal diameter of the liner.

5. The method of making and of sizing a liner in a multi-part pump barrel assembly which includes the following steps: lmaking a liner, making a round, straight-sided, slightly over-sized hole from end to end of said liner, making a compression member, placing said compression member about said liner in contact therewith, moving thecompression member with respect to said liner and exerting as a result of such movement I a uniform compression upon said liner and thereby reducing uniformly the internal dimension of the liner, and simultaneously maintaining the inner walls of the liner straight.

6. The method of sizing the bore of a liner in a multi-part pump barrel assembly, having a liner, a jacket therefor, and a plunger return, and adapted to be reciprocated therein, which method includes the following steps: machining a bore in the liner to be slightly over-'size with respect to the said plunger, machining a tapered exterior wall on the liner, machining a mating tapered interior wall on the jacket, forcing the jacket and the liner together'by relative longitudinal movement along the axis of the tapers, and compressing the liner by means of the jacket uniformly along radial lines, and reducing the radial dimensions of the liner uniformly, and continuing the said movement until a predetermined running fit between bore and plunger is reached.

PHILIP LANE SCO'I'I.

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