US3114326A

US3114326A - Plunger type pump especially for high pressure

Info

Publication number: US3114326A
Application number: US136621A
Authority: US
Inventors: Yaindl Charles
Original assignee: Aldrich Pump Co
Current assignee: Aldrich Pump Co
Priority date: 1961-09-07
Filing date: 1961-09-07
Publication date: 1963-12-17
Anticipated expiration: 1980-12-17

Description

C. YAINDL Dec. "17, 1963 Filed Sept. 7, 1961 Z W 9 4 0 2 4 4 J R m o m N W 4 m m w v 7 g A 6 M J Y W a d 1 B "W J a n W a M w 7 W 2 6 3 1 7 u m J m .NIJ E a a 75 U 7 0 United States Patent 3,114,326 PLUNGER TYPE PUMP ESPECEALLY Fill? HIGH PRESSURE Charles Yaindl, Allentown, 9a., assignor to The Aldrich Pump (Iompany, Allentown, Pa., a corporation of Pennsylvania Filed Sept. 7, 1961, er. No. 136,621 4 Claims. (Cl. 103-153) This invention relates to pumps, particularly pumps adaptedfor the development of pressure in liquids, for instance water, and the pump of the present invention is especially suited to the development of very high pressures, for instance pressures of the order of tens of thousands of pounds per square inch.

Various prior art pumps intended for hi h pressure work have been subiect to a number f disadvantages including brealtages or iailure due to excessively high stress concentration at certain points in the pump structure, leakage from the high pressure side of the pump system either to atmosphere or the low pressure side of the system, entrapment of air or gases during operation of the pump, with consequent loss of eiliciency and/ or violent hammering, etc.

More specifically, one of the problems encounteredwith many prior high pressure pumps arose because of the arran ement of the pump in such manner-as to utilize in the pump structure cavities or bores having their axes arranged in relatively angled relationship, for instance at right angles to each other. Thus, in certain prior high pressure pumps, a bore for the pump plunger was arranged at right angles to the bore for certain of the valve structures, as a result of which a corner of metal occurred between the two right angle bores. This resulted in excessive stress concentration at the corner, in consequence of which cracks developed in the metal and failures occurred from this cause, particularly where very high pressures were being handled.

Attempts to reduce this stress concentration included the rounding or chamiering of the corners where stress concentration occurred. At best this only partially eliminated the problem and at very high pressures became less and less practical because of the progressively smaller diameter of bores used for the high pressures, resulting in increased diiiiculty of access to the corners for the purpose of the necessary machining to eilect chamfering or rounding thereof.

According to the present invention, it is contemplated to avoid employment of relatively angled bores in the pump structure, by utilizing a type of construction in which the valve mechanisms are arranged generally coaxially or" and are mounted to move in directions generally parallel to the motion of the pump plunger in its operating cylinder. At the same time, the present invention contemplates certain special arrangement and special relative positioning of various pump and valve parts to substantially eliminate entrapment of air or gases, and also to provide a structure which will more readily withtand the stresses of high pressure operation.

The construction and arrangement or" various of the pump and valve parts, according to the present invention, also makes possible the use of parts of circular or cylindrical shape which, may be more readily and securely fastened and sealed together in the pump assembly, as compared with various prior arrangements.

The full nature of the foregoing advantages and obiects can best be understood from analysis of a specific embodiment of pump structure according to the invention, and there is therefore here given a detailed description of a preferred embodiment of the invention as illustrated in the accompanying drawing in which:

cavity in 3,lld,32li Patented Dec. 1?, 19%3 FEGURE 1 is a longitudinal sectional view through a vertical plunger pump constructed according to the present invention; and

FlGURE 2 is a fragmentary view on an enlarged scale of portions of the upper end of the structure shown in FIGURE 1 including the discharge and inlet valve mechanisms provided.

Referring to the drawing, the pump structure may conveniently be built up upon a base 3, and the pump includes a main body member 4 comprising a cylinder and a stuiiing box for the pump plunger 5. Within the cylinder is a. sleeve, for instance a bronze sleeve 6 fitting the plunger 5, and in which the plunger works. In the lower portion of the cavity in the cylinder 4 there is a stack of packing or sealing rings or elements 7 surrounding the plunger 5. A lubricant sleeve 3 is positioned intermediate two groups of sealing elements 7, and the parts 7 and d are adapted to be secured in place by means of the gland 9 and spacer sleeve 9a, the gland being threaded into a the bottom end of the main body 4 in the pump structure. The lower end of the body 4 is reduced as indicated at it) and this reduced part fits into a mounting cavity in the base structure 3. lust above the reduced part ll? the bodyd is externally threaded to cooperate with the ring ll, which ring is tapped at a plurality of circuinterentially spaced points to cooperate with the fastening bolts l2 by means of which the pump structure is secured to the base structure An inlet connection 13 is provided for introducing lubricant to the lubricant distributing sleeve 8, a lubricant outlet 14 also being provided so as to permit continual c rculation of lubricant and thus effect lubrication :of the plunger 5 in its reciprocating motion.

The lower end of the plunger 5 projects out of the pump structure as indicated at 15 and this end of the plunger is adapted to be connected with the driving or operating mechanism which may be of known type and which is therefore not illustrated or described herein, as it forms no part of the present invention per se. The plunger 5 is shown in FIGURES l and 2 at the upper end of its stroke, and in FlGURE 1 there is a dotted indication at 5a illustrating the lower end of the plunger structure.

It is here pointed out that as illustrated and described above, the body member 4 of the pump is provided with a cavity or cylinder which is arranged at least in a generally upright position and preferably substantially vertically. The valve mechanisms, including both the discharge-valve and the suction or inlet valve, are disposed at the upper end of the plunger chamber, and this is of importance in providing against entrapment of air or gases in the pump. This end is also served by certain special arrangements of the discharge valve structure which will be brought out below in connection with the description of the valve mechanisms, which is now presented.

Toward the upper end of the main body 4 of the pump the body 4- is externally threaded to cooperate with a ring or stuffing box head 16. This member 16 is provided with a cylindrical cavity in which is received a valve seat body member 17 which, in turn, has a central cavity in which is located the valve seat member 18.

The member 16 is provided with a radial bore 19 comprising an inlet port with which the inlet or suction connection Zll is associated. The valve seat body member 17 {is provided with an external peripheral groove Zll with which the port 19 communicates. This part 17 also has a series of radial ports 22 interconnecting the groove M with the internal groove 23. Inlet passages or ports are also provided in the valve seat 13, including the radial bores 24 and the interconnected axially extending bores 25 which terminate at their lower ends in an annular groove 26 formed in the lower face of the valve seat member 18. The intake valve itself comprises a simple annular ring 27 adapted to move vertically or work in a cylindrical chamber formed in the lower portion of the valve seat body member 17, a spring 28 serving to urge the valve 27 upwardly to fit against the lower face of the valve seat member 18 and thereby close the groove member 25 and thus close Oil the inlet or suction passages. The spring 28 is arranged within a cylindrical spring retains 2?, the lower portion of which is adapted to abut against a snap ring 51 which is seated in a groove machined in the lower portion of valve seat body 17.

The discharge from the pump is eilected through the discharge passage or port 30 which is centrally arranged and extended axially of the cylindrical cavity of the body 4 and thus centrally and axially of the plunger 5. The upper end of the plunger is provided with an extension of reduced diameter indicated at 33 which projects into the central opening in the suction valve 27 and fills up a large part of that opening when the plunger is in its uppermost position. This extension 31 also has a tapered or cone portion at its top which extends into a correspondingly flared inlet opening provided in the lower end of the discharge port 3t). Because of these arrangements, when the plunger 5 reaches the upper end of its stroke, which is the position shown in full lines in FIGURES 1 and 2, the plunger and its extension 31 occupy or fill up most of the volume of the space and passages at the end of the plunger chamber, leavin only little more than the volume of the discharge port 36 as free space. This is of importance, especially in very high pressure pumps, as it is desirable in such pumps to reduce the free space ahead of the discharge valve to an absolute minimum when the plunger reaches the end of the pressure stroke.

The discharge valve which may be either a ball or a plug type valve is here shown as a ball 32 seated in the upper end of the port 39 against the upper side of the valve seat 18. This ball 32 is adapted to be urged to its closed position by means of a spring 33 working against a valve guide 3- having a lower conical surface adapted to engage the ball 32. The spring 33 and guide are vertically movable within the retainer or cup member 35, this motion being guided by vertical guide elements 36, three or more of which are provided around the periphery of the valve guide member, the spaces in between these guides 36 constituting the discharge passages for the pumped fluid. From the interior of the upper end of the cup member 35 the discharge flow takes place through ports 37 into the central chamber 38 from which the discharge port 39 extends upwardly for association with a discharge connection 49 shown in FIGURE 1.

The chamber 38 and the passage 39 are provided in the discharge or upper end member 41 arranged at the top of the pump structure and connected with the valve seat body member 17 by means of a shouldered securing ring 42 and a series of bolts 43. These bolts 43 thus serve to clamp various of the parts together at the upper end of the pump structure and it is here pointed out that an annular seal 44 is provided between the member 41 and the valve seat body member 17. A similar seal 45 is provided between the valve seat body member 17 and the upper end of the main body 4 of the pump. Tightening the bolts 43 tightens both of these seals, and since these two seals lie at opposite sides of the

suction portage

23, 22 and 21, the high pressure is eiiectively isolated from the suction side of the system.

Annular sealing rings

46 and 47 are also provided between the

members

16 and 17, one of these rings lying above and the other below the peripheral groove 21. Although the structure of the

members

16 and 17 may be incorporated in a single member or part, it is preferred to provide two separate parts as is illustrated.

The valve seat is and the valve seat body member 17 are machined to provide a drive taper fit of the valve seat 13 in the cavity in the valve seat body member 17. The tightness of this fit is important in isolating the 4 high pressure side of the system from the suction side and also in avoiding leakage from the high pressure side to a point exteriorly of the pump.

.One reason for forming the valve seat member 13 separately from the valve seat body member 17, as is preferred, is that. the various passages and ports can more readily be drilled and machined in two separate parts than in a single part. In addition, according to the invention it is preferred to form these members separately so that one of them, namely the valve seat member proper (18) can be made of very strong and wear resistant metal, such as certain formulations of stainless steel, without requiring formation of the valve seat body member 17 of this same material. At the same time, because of the drive taper t of the member or part 18 into the cavity in the valve seat body member 17, the valve seat body member acts as a reinforcement for the valve seat member itself. This is of particular importance in very high pressure pumps, because of the fact that the valve seat member in such a pump is subjected to very high stresses.

If desired a cooling jacket 48 is arranged around the main body 4 of the pump, eing provided with cooling medium or refrigerant inlet 49 and outlet 59.

Various of the structural features and arrangements as above described have distinctive advantages especially for high pressure pumping purposes. For example it will be noted that no angled bores are used in the pump structure where stress concentration because of exposure to high pressure would result. The arrangement of both of the valve mechanisms at the upper end of the pump structure, and the arrangement of the pump so that the discharge or p'essure stroke is the upward stroke of the plunger results in a natural tendency for any gases present in the liquid being pumped to rise directly into the discharge passage and thus avoid entrapment of gases in the system. To this same end, the location of the discharge passage centrally of the plunger and its operating cylinder and at the extreme upper end thereof further serves to assure free and immediate egress of any gases which may enter or be developed in the system.

It is also of importance that the discharge valve is centrally located and the suction or inlet valve is of annular construction, surrounding the discharge passage. The em loyment of a central discharge passage and valve and an annular surrounding suction or inlet valve has the advantage of enabling the use of small size parts on the discharge or high pressure side or" the system. Also the relatively large suction port passages allow for low intake velocities which enables the pump to breathe easily. The location of the suction and discharge valves on top of the extreme upward position of the plunger leaves very little volume of fluid to expand on the suction stroke. Any such volume cuts down on the volumetric elficiency of the pump.

if the surrounding annular valve were to be used for discharge, this would require the employment of larger parts in order to withstand the high pressures and at the same time the suction valve port area would have to be increased for ease of breathing, which in turn would increase the internal liquid volume subject to expansion on the suction stroke, thus again cutting down on the pump volumetric efiiciency.

By arranging both of the valve mechanisms axially of the stroke of the pump plunger the invention has further made possible the construction of the various par-ts of the pump and valve mechanisms of annular or cylindrical form which lend themselves readily to construction to withstand high pressures without resorting to excessive size or wall thickness. The annular or cylindrical shape of the parts, including for example the main body member 4, the ring 16, the valve seat body member 17, the valve seat member 13, the tubular upper end member 41 and the ring 42., is still further of advantage as it is entirely practical even for very high pressure operation, to effectively fasten together and to seal the annular or cylindrical parts. In contrast, with parts of various other shapes high pressure sealing is exceedingly diflicult.

I claim:

1. A reciprocating plunger pump comprising a body member having a cylindrical plunger chamber, a pump plunger adapted to work in said plunger chamber, a valve seat structure at one end of the body member having a discharge passage communicating with the plunger chamber and located centrally and extended axially of the plunger chamber with its end remote from the plunger chamber provided with a valve seat, a discharge valve associated with said valve seat, the valve seat structure further having inlet passage means communicating with the plunger chamber radially outwardly of the centrally located discharge passage and provided with a valve seat at its end communicating with the plunger chamber, an inlet valve structure associated with said last mentioned valve seat, said valve seat structure comprising a valve seat body member in which is formed a.- portion of said inlet passage means mounted at the end of the plunger body member, and a unitary valve seat member in which portions of both said discharge passage means and inlet passage means are formed and on which both the discharge and the inlet valve seats are formed, said valve seat body member having a cavity dimensioned to tightly receive said unitary valve seat member with the portion of the inlet passage means in the latter in register with the portion of the inlet passage means formed in the valve seat body member.

-2. A construction according to claim 1 in which said cavity and said valve seat member are of circular cross section and are tapered to provide a drive taper fit between said valve seat member and said valve body member.

'3. A reciprocating plunger pump comprising a body member having a cylindrical plunger chamber, a pump plunger adapted to work in said plunger chamber, discharge and inlet valve mechanism at one end of the body member including a valve seat member and a valve seat body member having first inlet passage means extending radially therein, said valve seat body member having a cavity therein dimensioned to tightly receive therein said valve seat member, said valve seat member having a centrally disposed discharge passage means therein communicating axially with the adjacent end of the plunger chamber and second inlet passage means disposed in communication with the adjacent end of the plunger chamber and extending first axially from the latter and thence radially outwardly into register with said first inlet passage means, said valve seat member having a discharge valve seat formed thereon adjacent the end of the discharge passage means remote from the plunger chamber, a discharge valve associated with said discharge valve seat to control flow of discharge fiuid through said discharge passage means, an inlet valve associated with the end of the said second inlet passage means communicating with the plunger chamber, a head member overlying said discharge valve and having a discharge con nection adapted to communicate with said discharge passage means when the discharge valve is open, first annular sealing means interposed between said valve body member and said body member, second annular sealing means between said valve body member and said head member, an inlet connection communicating with [the first inlet passage means at a point intermediate said first and second annular sealing means, and mechanism for fastening said head member, valve seat body member, valve seat member, and body member together in the relationship described.

4. A reciprocating plunger pump comprising a body member having a cylindrical plunger chamber, a pump plunger disposed for reciprocation within said plunger chamber, discharge and inlet valve mechanism at one end of the body member including an annular valve seat body member arranged end-to-end with the body member having the plunger chamber therein, an annular valve seat member having a center opening serving as a discharge passageway, said annular valve seat body member having a center opening therein adapted to receive said annular valve seat member and to define an inlet valve chamber, an annular head member having a center opening serving as a discharge connection and arranged endto-end with the valve seat body member, annular seals disposed between the valve seat body member and the plunger chamber body member and between the valve seat body member and the head member, said valve seat member and the valve seat body member being provided with inlet passageways communicating with the plunger chamber and extending within the valve seat body member radially outwardly to a suriace lying between said seals, an inlet valve disposed in said inlet valve chamber for axial movement to control flow of fluid through said inlet passageways into the plunger chamber, said center opening in said head member being adapted to receive a portion of a discharge valve structure, and a discharge valve structure disposed with a portion thereof axially movable within said center opening in the head member.

References Cited in the file of this patent UNITED STATES PATENTS 677,137 Leavitt June 25, 1901 1,476,794 Berry Dec. 11, 1923 1,719,572 Stoll July 2, 1929 1,871,285 Tursky Aug. 9, 1932 FOREIGN PATENTS 768,172 France May 14, 1934

Claims

1. A RECIPROCATING PLUNGER PUMP COMPRISING A BODY MEMBER HAVING A CYLINDRICAL PLUNGER CHAMBER, A PUMP PLUNGER ADAPTED TO WORK IN SAID PLUNGER CHAMBER, A VALVE SEAT STRUCTURE AT ONE END OF THE BODY MEMBER HAVING A DISCHARGE PASSAGE COMMUNICATING WITH THE PLUNGER CHAMBER AND LOCATED CENTRALLY AND EXTENDED AXIALLY OF THE PLUNGER CHAMBER WITH ITS END REMOTE FROM THE PLUNGER CHAMBER PROVIDED WITH A VALVE SEAT, A DISCHARGE VALVE ASSOCIATED WITH SAID VALVE SEAT, THE VALVE SEAT STRUCTURE FURTHER HAVING INLET PASSAGE MEANS COMMUNICATING WITH THE PLUNGER CHAMBER RADIALLY OUTWARDLY OF THE CENTRALLY LOCATED DISCHARGE PASSAGE AND PROVIDED WITH A VALVE SEAT AT ITS END COMMUNICATING WITH THE PLUNGER CHAMBER, AN INLET VALVE STRUCTURE ASSOCIATED WITH SAID LAST MENTIONED VALVE SEAT, SAID VALVE SEAT STRUCTURE COMPRISING A VALVE SEAT BODY MEMBER IN WHICH IS FORMED A PORTION OF SAID INLET PASSAGE MEANS MOUNTED AT THE END OF THE PLUNGER BODY MEMBER, AND A UNITARY VALVE SEAT MEMBER IN WHICH PORTIONS OF BOTH SAID DISCHARGE PASSAGE MEANS AND INLET PASSAGE MEANS ARE FORMED AND ON WHICH BOTH THE DISCHARGE AND THE INLET VALVE SEATS ARE FORMED, SAID VALVE SEAT BODY MEMBER HAVING A CAVITY DIMENSIONED TO TIGHTLY RECEIVE SAID UNITARY VALVE SEAT MEMBER WITH THE PORTION OF THE INLET PASSAGE MEANS IN THE LATTER IN REGISTER WITH THE PORTION OF THE INLET PASSAGE MEANS FORMED IN THE VALVE SEAT BODY MEMBER.