US2472355A - Pump - Google Patents

Description

'2 Sheets-Sheet 1 w 2 E I 80 s am i June 7, 1949. D. J. WHITTINGHAM PUMP Filed Feb. 1. 1946 //A 6 7 M MN June 7, 1949. WHITHNGHAM I 2,472,355

Filed Feb. 1, 1 4

I Jmuwlvi David J-Whiifingham 3W r&

Patented June 7; 1949 David J. Whittingham, Watertown, N. Y., as-

signor to The New York Air Brake Company, a corporation of New Jersey Application February 1, 1946, Serial No. 644,820

This invention relates to radial cylinder pumps and will be described as embodied in an 18 cylinder pump having two groups each of 9 radial cylinders, the cylinders of the two sets being angularly displaced 20 of are so that an even Claims. (01.103-174) flow is assured. More groups or only one could be arranged in a single unit and still avail of most of the features of the invention.

The object of the invention is to simplify the construction and assembly of the parts, secure compactness wtih adequate bearings, and produce a pump which can readily be modified by 2 i parts fully retracted, so that the inlet as is open.

Fig. 4 is an elevation of the outer side of a discharge valve cage.

"Fig. 5 is a section through the cage shown in Fig. 4.

The pump housing comprising a cup-like shell 6 and a cover plate I centered thereon by circular shoulder 8 and held by machine screws, one of which appears at 9. A circular series of threaded holes, one of which appears at H, and the annular flange I2 are used toattach and interchange of cylinder bushings and pistons so as to operate with the same power-input at different volumetric outputs suited to difierent head pressures.

To change the pump over, all that is necessary is to release one cover plate, withdraw the shaft and cylinder body assembled as a unit, and substitute, in the body, cylinder units which are manually inserti'ble and each of which comprises a cylinder bushing, a plunger and return spring. Each cylinder bushing is held in place by the discharge valve assembly, which is unchanged and which is removable by unseating a snap ring. M

Ready removability of the cylinder bushings imples a rather free fit. This is made practicable by the use of crosshead sleeves each of which delivers thrust to its plunger while absorbing all side thrust.

The pump as illustrated is rated at 7.5 G. P. M. at 1200 R. P. M. against a head pressure of 3000 p. s. i. By substituting smaller cylinder bushings and plungers the same pump at 1200 R. P. M.

will deliver 4.5 G. P. M. against a head pressure of 5000 p. s. i. The maximum permissible speed for either setup is established at 1750 R. P. M. These figures are merely illustrative.

An important feature of the pump is that all separable parts 01" the cylinder, cylinder body Referring to the drawings, which illustrate a commercial embodimentof the invention:

Fig. 1 is an axial section of the complete pump taken on the line I -l of Fig. 2..

position any suitable supporting bracket (not shown).

A central hole in shell 6, opposite to cover plate I is closed by a'threaded plug l3.

7 Shell 6 is boredto afiord a cylindrical seat It leading to shoulder l5. Closely fitting seat I4 and mounted between shoulder l5 and cover ports all cylinder bushings and discharge valves and the bearings for the pump shaft, all as will hereafter be described.

In seat M at shoulder I5 is' an annular'groove which receives gasket l1. In body I 6 are two annular grooves which receive gaskets.l8 and I9. All three gaskets are toric inform and eaclf is formed of resilient rubber-like material which will deform under the' discharge pressure developed by the pump and thus develop a good seal. Gaskets nzand l8 seal the body l6 to the 'shell 6 on oppositesides of'a- ,relief,groove 2| which functions as an annulardischarge passage and leads to discharge port 22. Gasket l9 forms a double seal between the body 16 and shell 6 on the one hand and cap I on the other;

see Fig. 1, A port l0 vents the space between gaskets i8 and It! to space 25.,Apin 20 set. in body 16 and engaging a slot in cap 'I- determines the position of body IS in shell 6.

Inlet passage 23 leads'to space 24 within shell 6 and communicates with all shaft'and eccentric bearings vwith the cylinder inlet ports and with Fig. 1.

Figz 2 is a transverse section taken on the line 2-2"of Fig. 1. x I

Fig. 3 is a fragmentaryview, similar to a portion of Fig. 1 but showing a plunger and related space 25, as will be readily understood from A fitting 26 with pipe threaded openings 21 and 28 ofi'ers connections to inlet passage 23 and discharge passage 22. Fitting 26 is held by countersunk machine screws, not visible in the drawing and each connection is sealed by a corresponding nipple 29 with soft toric gasket 3| of rubberlike material. v

The main pump shaft-has a portion 32 which turns in a central aperture in can I, a projecting outer end 33 with key and, a main portion 35 on which the bearings andecc'entrics are mounted. The portion 35 is of smaller diameter than portion 32 so that a shoulder 38 is formed at a 'point spaced inward from theinner face of cap 1. Portion I has two 'keyways diametrically opposed, as shown in dotted lines in Fig. 1 and is threaded at 31 to receive nut 38. A look washer 39 of known form retains the nut.

Clamped between nut II and shoulder 36 and in the order stated are the inner race 4| of a radial annular ball bearing (whose outer race is shown at 42), spacer 43. needle bearing guard 44, eccentric 45 (keyed to the shaft at 45) needle bearing guard 41, eccentric 44 (keyed to the shaft at 49), needle bearing guard 5i, spacer 52 and inner race 53 of a' second annular ball bearing (whose outer race appears at 54). The eccentrics 45 and 48 are not quite opposed. In a nine cylinder pump one trails the other at 160 so that the discharge strokes in the two circular series of cylinders alternates Mounted on eccentrics 45 and 48 are straps or rings 55 spaced therefrom by bearing needles 56. The guards 44, 41 and 5| are metal discs which prevent escape of the needles-and confine rings 55. The body or spider I6 is axially bored to fit the peripheries of outer races 42 and 54, so that ,the shaft is supported by and centered in body I 6.

Since the eccentrics are nearly diametrically opposed the pump is very nearly in running balance and the reaction of the eccentrics approximately neutralize one another so that the loads on the shaft bearings are moderate.

The outer face of race 53 is lapped and is engaged by the lapped face of a sealing ring 51. This encircles freely portion 32 of the shaft and is sustained by a flexible metal diaphragm 58 whose outer margin is clamped to cap I at 59. Ring 51 is held in sealing engagement by spring disc 6| Thus a running oil-seal is provided. An auxiliary seal 62 is also provided. To retain the shaft and bearing assembly against motion in the direction of the shaft axis, two snap rings 63 are mounted in grooves in body It, one at either side of outer race 42. The outer ring 63 has a wedging action in a V-shaped groove as shown in Fig. l.

Body l6 has two series of radial bores approximately centered respectively on eccentrics 45 and 48. There are nine bores in each series, the bores of the two series being staggered. In other words, the bores of each series radiate at 40 intervals and the two sets are ofi'set 20 with respect to one another.

Each bore has a guide portion 64 and at its outer enda larger counterbore i5 ending at an annular shoulder 68. Working in each guide ,portion 64 is a cup-like crosshead 61. Each has a slightly inclined thrust face 68 which engages the corresponding one of rings 55 and each is cut away at 69 (see Figs. 1 and 2) to permit the crossheads to clear each other at the low side of the eccentric (note how the four lower crossheads appear to overlap in 'Fig. 2). The cut-away at 69 affords a through port H (see Fig. 1) so that the crossheads never out off flow to the inlet ports of the cylinder bushings. The obliquity improves thethrust reaction as will readily be appreciated.

Seated in each counterbore 65 against shoulder 66 is an externally flanged cylinder bushing 12. Each has an external groove with toric, rubberlike sealing gasket 13 and each is provided with opposed inlet ports 14 which communicate with cross-bores I5 in body I6. These cross-bores connect spaces 24 and 25.

Each cylinder bushing 12 is held in place by a dischar e valve cage 18 held by a snap ring 11 (see Figs. 4 and 5). The discharge valve 18 is cup-shaped, is guided in cage 16 and is seated by a coil compression spring 19 against the outer open end of the cylinder bushing 12.

Reciprocable in the cylinder bushings and in thrust engagement with corresponding crossheads 61 are plungers 8i each with a flanged ring 82 against which a coil compression spring 83 reacts. Ring 82 is sustained by snap ring 80.

Each crosshead 61 has a long bearing surface, as compared to its overhang and so is well adapted to absorb lateral thrust. The effect is to protect plungers 8| from lateral thrust. Hence the cylinder bushings can be held aligned by the simple arrangement shown and can be rather freely fitted. Since the outer end of the cylinder bushhead pressure, rings H can be quite light. The hydraulic pressure holds the bushings seated on shoulders 66.

To interchange bushings and plungers, cap 1 is removed and body I5 is withdrawn. Removal of plug i3 permits body IE to be pushed out, if necessary. Removal of the valve cages I6 permits withdrawal of the bushings, plungers and crossheads while the shaft assembly remains undisturbed. To set the pump for rotation in the opposite direction, the crossheads 6] may be reversed. To change pump capacity differently dimensioned cylinder bushings and plungers may be substituted.

The operation of the pump will be obvious from the description above given. The pump may be constructed with different numbers of cylinders and the specific form of the parts may be considerably varied within the scope of the invention. Hence, the embodiment above described in detail is meant to be illustrative.

What is claimed is:

1. A radial multicylinder pump comprising in combination, a two part closed hollow shell having means for connecting an inlet line and a discharge line and having a shouldered seat; a body mounted in said seat and clamped between the parts of said shell, said body having radial bores and means forming with the shell an annular passage surrounding the body and connecting the outer ends of said bores with said discharge connecting means, said body also having passages connecting other portions of said bores with said inlet connecting means; at least two resilient annular sealing rings compressed between the body and shell along the opposite margins of said annular passage and serving to isolate the inlet and discharge spaces within the shell; a radial pump mechanism comprising shaft, shaft bearings, eccentric cam, plungers, cylinders and valves, all sustained by said body, said shaft extending through an opening in the shell, and the body being removable" from the shell upon separation of the parts thereof, while all the body-sustained parts remain in assembled relation; and a seal between said shaft and the shell around said opening.

2. The combination defined in claim 1, in which each radial bore has a guide portion at its inner end and has at its outer end a counterbored seat; and each bore contains a pump assembly comprising a removablecylinder bushing open at both ends positioned by said .counterbore, a valve cage releasably fixed in said counterbore and serving to retain the bushing, a discharge valve in the cage,-a plunger reciprocable in the cylinder bushing, a cup-like crosshead guided in said guide' portion reciprocable by said eccentric cam and in thrust engagement with the plunger and a spring biasing said plunger toward said crosshead.

3. In a pump, the combination of a body having a bore formed at one of its ends as a guide-way and provided with inlet ports and formed at the other of its ends with a counterbore leading to a shoulder; means connecting said counterbore with a discharge passage; a cylinder bushing smaller than said bore removably mounted in said bore and having a flange seated against said shoulder, said flange fitting said counterbore and serving to center and aline the bushing, said bushing being open at both ends and having lateral inlet ports; a resilient annular gasket sealing said bushing to said body; a valve cage releasably fixed in said counterbore and serving to hold said flange against said shoulder; a discharge valve arranged to seat. against one end of said bushin and guided by said cage; a spring for seating said valve; a plunger reciprocable in said bushing and projecting through the other end thereof; a cuplike crcsshead reciprocable in aid guide-way surrounding and in thrust engagement with the pro- Jecting end of said plunger; means biasing said plunger toward said crcsshead; and means for reciprocating the crosshead.

4. The combination defined in claim 3 in which the means for reciprocating the crcsshead com-' prises a rotatable eccentric and a ring freely rotatable thereon, and the crosshad has an oblique plunger therein, a spring urging the plunger toward the crosshead, a valve cage releasably locked in the outer end of the bore and confining the bushing and a discharge valve in the cage; a multi-part hollow shell clamped around the body and forming therewith inlet and discharge passages for the pump assemblies, said shell having an opening through which said shaft projects; and a seal between the shaft and shell.

DAVID J. WHI'ITINGHAM.

REFERENCES crrnn 'I .he following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 622,704 McPherson et a]. Apr. 11, 1899 2,265,997 Bremser Oct. 6, 1938 2,345,125

Huber 0-..... Mar. 28, 1944

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