US3536094A - Compressor valve - Google Patents

Description

l1ll3,536,094

United States Patent Patented Oct. 27, 1970 y 3,536,094

Sheet 1 of 2 F E. M/VLK Jl.' F IG. 2 A y y INVENTOR.

A TTORNEVS COMPRESSOR VALVE BACKGROUND OF THE INVENTION Piston type compressors commonly utilize freely moving intake and discharge valves, located in the cylinder head or between the cylinder and the cylinder head of the compressor for controlling the intake and discharge of fluids or gases by the compressor. Valves commonly employed in present compressors provide unidirectional flow into and out of the compressor cylinders and are known in the art. Conventional valves of this type that are generally provided have perforated flat circular plates of alloy sheet steel or a multiple series of concentric flat steel sealing rings biased toward the valve seat by coil springs or spring plates. These valves control fluid or gas flow by the reciprocal movement of the concentric sealing rings or the circular plates between a closed or sealed position with machined seating surfaces and an open position wherein the rings are displaced from sealing engagement with these surfaces to permit fluid or gas flow through the valve.

The efficiency of piston type compressors is largely dependent upon the characteristics of the flow valves through which intake and discharge of the fluid or gases take place. In the compressor valves commonly in use today. there is an appreciable velocity head loss occasioned by problems in moving the fluid through the valve at high velocity. The problems are largely caused by energy losses resulting from violent changes in flow direction. frictional interference and turbulence by the fluid as it passes through the compressor valve and around the sealing surfaces. Thesev problems are especially critical in attempting to obtain optimum efficiency and capacity in high speed compressors, operating in the range of 400 to 2000 strokes per minute. The optimum performance of the compressors, which by their nature have a very short stroke, requires valves which not only permit flow of the fluid or gases to and from the cylinder with a minimum of pressure loss and at a high velocity. but which will also seat rapidly and positively during the critical pressure reversals which take place at the beginning and end of the intake and discharge strokes. In such high speed compressors, the valves may be subjected to extremely high pressures and temperatures. At high compression speeds the reciprocal movement of the rings or plates against the seating and stopping surfaces within the valve case is extremely rapid and under high pressure` the rings slamming into the seating and stopping surfaces at high speed and with great force. Such rapid high velocity movementy and impact causes the valve seating surfaces to become pitted and rough, allowing fluid or gas leakage during the intake stroke. In addition, the noise level associated with such valves is very high and disagreeable for workmen who must work in proximity to the equipment.

The present invention remedies these problems by the use of sealing rings or plates of a synthetic resin having novel sealing and engaging surfaces.

SUMMARY OF THE INVENTION The instant invention provides a novel compressor valve utilizing concentric sealing rings or circular sealing plates constructed of a suitable synthetic resin. The basic configuration of the rings or plates is conventional, having a flat upper surface and a discrete thickness with rounded or straight vertical edges, but having a downwardly convex protruding sealing surface to engage recessed seating surfaces in the valve seat. The recessed seating surfaces are angularly disposed to the flat inner surface of the valve seat member and engage the convex sealing surfaces of the sealing rings or plates to interrupt fluid or gas flow through the compressor valve. The synthetic resin of which the sealing plate or rings are constructed is selected to include the following primary characteristics: generally nonresilient, high-impact and high-temperature resistant, and resistant to corrosive chemical action.

In addition, the valve case comprised of the valve seat and valve guard members is of a unitary design` This unitized construction utilizes interrupted screw threads for easy and time saving disassembling. This unitized construction feature eliminates all through bolting for the use of'setscrews which often are difficult to remove after the valve hasbeen installed and in use over long periods of' time. Further, after long periods of use, the tremendous forces and vibration acting on the valve often cause the bolts or other retaining means holding the valve guard and seat, members'together to fail and allow metallic pieces of such bolts or setscrews to fall into the valve and into the compressor cylinder which can cause extensive damage. The use of the interrupted screwthread unitized construction makes the task of maintenance and installation easier and simplifies the assembly of the valve after any field repair. The valve case has such symmetrical dimensions and is so constructed that the valve may be used as an intake or discharge valve without modification, simply by inverting the valve itself.

Accordingly, it is a primary feature of the present invention toprovide a compressor valve that minimizes the velocity and pressure loss through the valve and increases compressor efficiency and capacity.

Another primary feature of the present invention is to provide a compressor valve that may be used either as an intake or.1discharge valve without modification.

vAnother primary feature of the present invention is to provide a compressor lvalve assembly utilizing sealing rings or plates constructed of a synthetic resin that will not damage the compressor cylinder or cylinder walls in thc event that the sealing rings or plates fail during operation.

Another feature of the present invention is to provide recessed seating surfaces having a geometrically symmetrical cross section that self-center geometrically symmetrical crosssectioned sealing surfaces of a sealing plate or concentric sealing rings or annular projecting surfaces engaging the seating surfaces.

Itis yet another feature of thc present invention to provide a compressor valve assembly of unitized construction utilizing interrupted screw threads for easy and simplified assembly' and disassembly.

Itis yet another feature ofthe present invention to provide a compressor valve assembly utilizing sealing rings or plates ofa synthetic polymeric material that dramatically reduces the noise level of the compressor valves during operation.

"Another feature of the present invention is to provide a compressor valve wherein the valve ring or plate movement during opening and closing of the valve may be varied by utilizing synthetic resin rings or plates of different thicknesses.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which the above-recited advantages and features of the invention are attained, as well as others which will become apparent, can be understood in detail, a more particular description of the invention may be had by reference to specific embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and therefore are not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

In the drawings:

FIG. 1 is a perspective view, partly in cross section, of a compressor valve assembly accordingto the present invention utilizing concentric sealing rings` FIG. 2 is a detailed vertical cross-sectional view of the compressor valve according to this invention taken along lines 2-2 of FIG. l.

FIG. 3 is a detailed horizontal cross-sectional view of the compressor valve assembly shown in FIG. l as taken along lines 3-3 of FIG. 2.

FIG, 4 is a detailed partial vertical cross-sectional view of a portion of the compressor valve assembly shown in FIG. l with the valve shown in its closed condition.

, FIG. 5 is a detailed partalvertical cross-sectional view of a portion of the compressor `assembly shown in FIG. 1 with the valve shown in its open position.-

FIG. `6v is a detailed` horizontal cross-sectional view of a compressor valve assembly according to the present invention utilizing a circular plate having concentric sealing surfaces.

FIG. 7 is a detailed partial vertical cross-sectional view of the valveV seat recessed `seating surfaces and the sealing,k

` member of another' embodiment ofthe compressor valve. t

DESCRIPTION OF THE PREFERREDEMBODIMENTS Referring now to the ldrawings and first to FIG. l, a perspective view, partially in cross section, of afcompressor valve 10 i according tothe present invention is shown comprising a valve `guard 11, a valve seat member 16, concentric annular sealing;

' rings 30 and coil springs 28.

Cylindrical valve guard 1l has an internal interrupted screw I t thread surface 12 aboutits inner periphery of projecting rim 13 that mates with outer interrupted screw thread segments 14 of cylindrical valve seat` 16 to hold the inner surfaces of the guard and seat in a desired parallel spaced-apart relationship.

gages the concave valve seating surfaces 32 to close the annul larand semicircularapertures 34 and 36respectively.

' Coil spring members 28 are disposed within spring retaining apertures 26 drilled into the inner vface of valve guard in a predetermined spaced-apart configuration. Semicircular apertures 22 are disposed between ring stopping surfaces 18 and `20 and provide open communication between `the top surface ofthe guard 1l and the interior` of valve 10. An axial rcircular openin`g24 through guard l1 and regularly spaced circular i `apertures 23`disposed radially about guard ll and adjacent its outer edge also provide communication with `theginterior of valvel0. l

A detailed vertical cross-sectional viewof thecompressor valve shown in FIG. 1 is provided in FIG. 2..Va|ve guard I1 is shown threadably attached to valve scat member 16 to maintain the inner surface of guard 1l in a spaced-apart relation to compressor. Y

Concentric rings 30 are shown with their convex lower surfaces 3lsealingly engaging theconcave seating surfaces 32 of seat 16.` Rings 30 are biased in their sealed position by coil springs 28 recessed in retaining apertures `26'within the interior face of guard 11. Ring stopping surfaces 18 `and 20'of guard 11 are shown in their spaced-apart relationship directly above rings 30. With rings 30 in sealing contact with vsurface 32 of Rings30 have` a lower convex surface 3l` that .tsealingly cn- Referring now to FIG. 3, a horizontal `cross section'of the compressor valve l0,shown in FIGS. land 2 is illustrated. An outer section of rim` 13 of guard `ll is shown threadably attached to valve seat `I6 and a semicireularportioit of rings 30 areshown in their sealing engagement with seat 16."The lower coil of springs 28 is shown engaging rings 30 and urging the rings downward intosealing engagement withthe seating surl faces 32 of seatmember 16, thereby closing apertures 34 and 36. The sealing rings of the present invention and shown in i FIGS. 1-3 aremade of a synthetic polymeric material which is resistant to high temperatures and the high-impact stresses normally occurring in compressor valves of this class. `The use of such materials appreciably` decreases `the noise, ,level generally associated with automatic ring ]valves of this type and' providesa more positive "seal as `will be hereinafter described. Further, rings 30 constructed of suchmaterials are lighter and require springs 28 of a lighter-spring rate than `would be necessary if the rings were of metal. Another factor `in utilizing such syntheticV polymeric materials is the tremen` dously reduced cost at which the rings may be manufactured over presentlyused metal sealing rings. t

Referring now to `FIGS.4 and 5, detailed vertical `partial cross-sectional views of the valve are illustrated and show the rvalve ring `seating and liftingaction during' operation. Valve guard 1I is shown in its parallel spaced-'apart relationship to w valve seat 16. Ring 30 is shown disposed in the space between guard Il andseat In FIG. 4;.rin`g30fis shown in sealing contact with recessed concave seating surfaces 32, while in FIG. 5. ring 30 is shown engaging ring stopping surfaces 20 of guard 1l. Spring 28 is shown disposed` within recessed aperture 26 in theinside face of'guard Il. Apertures 22 and 23 are valve seat 16, apertures 22, 23f and 24 are sealed to fluid or gas passage in the directionindicated by the iarrow A in FIG. 2,

thus closing the valve. Springs28 make contact with the top surface of their respective concentricV rings` urging them into sealing engagement with seating surfaces 32 of valve seat'16.4 When'fluid or gas pressure' is directedthroughapertures v34 i and 36 of seat 16 in a direction as indicated by the arrow B an 3l. Springs 28 resistthis upward force exerted bythe fluid or gaspressure against theopposite convex ring face 31, until the .1 fluid or gas pressure overcomes the springforce and moves or. "lifts the rings 30 to the open position against stopping'surfaces 18 and20 of guard l1. Rings 30 lift until they make Vcontact with stoppingsurfaces 18`and 20and compress the springs 28 within thespring retaining apertures26. The lift" of the valve is defined as `the distance that rings 30 travel from sealing engagement with seating surface 32 to the full open position in contact withfstopping Vsurfaces 18 and 20,"as indicated bythe interval FIG. 2.

shoiwn in guard llfand a portion of aperture. 34 is shown disposed through seat 16.` o

Referringnow to FIG. 4, ring `30 is shown having a convex lowersurface 31 in sealing engagement withza concave seating surface 32 of seat member 16. Ring 30 is urged into this sealed position by the action of coil spring 28 togprevent fluid or gas passage throughapertures 22and 23 indicated by the arrows A y p fWhen fluid or gas flow reverses andfis inthe direction ini, `dicatedby the arrow B.\an upward pressureis applied against surface 3l of rings 30 throughfaperturcs 34 and 36 (see F IG. 2), while spring 28 is resisting the upward movement or liftf of the rings through the interval indicated at X as hereinbefore l -4 defined. In FIG; 5,`ri ng 30 is shown in its lifted position with its upper surface in contact with ring stopping ,surface 20 and` i having compressed spring 28 within its retaining aperture 26. With rings 3 0 lifted against ring stoppingi surfaces 20'and I8 (see FIG. 2) ofguard l1,.fluid 'or gas flow 1in the direction indicated by the arrow B through apertures 34 and 36 (see FIG.

`2) of valve seat 16 is allowed to` flow between the'convex ring face 31 and the concave seating surface 32.as indicated by the arrows C, thereby allowing the fluid or gas topass upwardly through apertures 22 and 23 in guardllas `indicated by the arrows D. With rings30 in their lifted position, valve 10 is in its open position andwith rings 30 in their seated position,

` upward force will be exerted against theconvex ring surface `valve 10 is in its closed position.

The concave seating surfaces 32employed inv valve seat member 16 provide fora more s'treamlinedfflow of fluid or` gases through thevalve resultingin a smallerpressure drop and increasing compressor efficien'cyand capacity. `An appreciable velocity head` loss through .a compressor valve is generally occasioned by problems in moving the fluid or gases Vthroughthe valve at high velocity, the problems largely being `caused by energy losses resulting from `violent changes in flow direction, fricitonal interference and turbulence. If the seating surface 32 communicating with aperture 134 Alin valve seat 16 had al square shoulder, as is commonly usedwin present compressor valvesrthe fluid or gas lflow as indicated by arrow B in' FIG. 5 would have to make two 90 reversals in direction in moving from aperture 34 to aperture 23 of `valve guard 1l in the direction shown by the arrows-B and D These, abrupt changes in the fluid or gases around the sealing ring and its seat cause frictional interference and turbulence in the flow stream at each such direction change increasing the energy loss and contributing to the total velocity and pressure transfer loss through the compressor valve.

As may be seen in FIG. 5, the fluid or gas flow through aperture 34 and between convex surface 31 of sealing ring 30 and the recessed concave seating surface 32 curvilinearly alters the direction of the flow of the fluid as indicated by the arrows C and directs the fluid or gases in a circular upward path around sealing ring 30 and toward apertures 22 and 23 of guard 1I. There are no abrupt reversals or changes in direction of the fluid or gas flow; thus, frictional interference and turbulence are minimized and energy losses are decreased, resulting in a smaller pressure drop through the compressor valve and correspondingly increasing compressor efficiency and capacity.

The use of a geometrically symmetrical cross-sectional sealing surface 3l on sealing ring 30 and a geometrically symmetrical cross-sectioned seating surface 32 eliminates the need for ring guides commonly employed to guide the rings 30 vertically during the lifting and downward seating movement. Such ring guides trap foreign material which falls on the valve seating surface causing abrasive wear to the sealing surfaces of the conventional disc sealing rings. The convex ring sealing surface 31 eliminates the need for such ring guides since the rings 30 will be self-centering when closed, asshown in FIG. 4, and convex ring sealing surface 31 engages the concave seating surface 32 of valve seat member I6.

Utilizing concave seating surfaces, as herein disclosed, will further reduce -the wear occasioned by the high velocity impact between the rings 30 and seat member I6, since the actual area of the engaged seating surfaces of concave cross section will be greater than the areas of thc planar seating surfaces presently utilized in valves of the'same class. With the high velocity impacting forces spread over a greater surface area of the sealing rings 30 and seating surfaces 32, wear on these surfaces is significantly decreased. Further, as may be seen, the downward slope of the seating surfaces 32 into apertures 34 and 36 produces a self-scavenging action, since foreign material falling on the seating surfaces 23 will be pushed into apertures 34 and 36 by the seating action of rings 30, thereby cleaning seating surfaces 32 and preventing a buildup of foreign material that may abrade the surfaces and interfere with positive sealing.

It will be noted, however, that many of the advantages and features exhibited by the sealing rings 30 having a projecting convex sealing surface 3l and constructed of a suitable synthetic polymeric material may be obtained by utilizing steel or other metal rings having the same seating surface contiguration. Of course, it will be seen that the use of metal rings will not effect the same decrease in noise level as would be obtained by the use of synthetic polymeric materials.

Although symmetrical cross-sectioned seating andsealing surfaces have been found to be particularly advantageous in eliminating fluid or gas flow turbulence and providing a positive sealing means that is self-centering, it may be seen that other surfaces have a geometrically symmetrical cross section may be advantageously employed. For example, the sealing surfaces of the rings and plates may be of a convex configuration for seating with angular planar seating surfaces 32, sloping towards the passage part, as shown in FIG. 7. Of course, other sealing and seating surfaces having protruding curved or planar surfaces or combinations of differing such surfaces may be employed to achieve the features and advantages of the present invention.

Valve lift as indicated at X in FIG. 4 may be easily controlled in the compressor valve shown in the present invention by varying the thickness of the sealing rings 30. This would allow the use of a standard size valve guard 1l and valve seat 16 to be used in various compressors operating over variable ranges of speed and capacity without having to modify the' design of the guard or seat members to vary the space between their respective internal surfaces, as indicated by the interval at Y in FIG. 5. Thus, one valve case employing a standard size valve guard l1 and seat 16 may be employed utilizing sealing rings 30 of one thickness for use in one compressor, and the same size valve case utilizing sealing rings 30 of a second thickness may be used in another compressor. The rings would be easily interchangeable between standard size valve assemblies.

Of course, it may be seen that various coil spring assemblies 28, having different spring rates to control lifting and closure speed of the sealing rings 30, may be necessary with different thicknesses of rings. Spring cavities 26, of course, are capable of different arrangements as to size and location; they may be oblong or square in cross section. The springs 28 may also be changed as to size, their cross section may be of a square or flat` material. In addition, it should be understood that although the specific embodiment herein illustrated shows the use of regularly wound helical coil springs, other springs, such as Belleville springs, radial disc springs, or spring plates and other spring members, may also be employed.

Referring now to FIG. 6, a horizontal cross-sectional view of the; compressor valve according to this invention is shown wherein a circular sealing disc instead of several discrete rings is employed to perform the sealing function. Valve l0 is comprised of a guard member 11 and a base seat member 16 as hereinbefore described. Seat member 16 has arcuate and semicircualr openings 34 and 36 for allowing fluid passage through the seat member 16. Seating surface 32 has a recessed cross section identical to that hereinbefore described.

Sealing plate 40 is a thin circular disc having concentric surfaces projecting from its lower face to form concentric projecting rings, indicated at 44. These projecting ring surfaces 44 have a projecting convex surface to sealingly engage the recessed cross-sectioned seating surfaces 32 of seat I6. Between rings 44 are curved slotted ports 50, separated by a web 48, for allowing fluid flow through the disc. Fluid or gas flow will also be directed around the outer edge of the disc in the space 52 between the outer edge of the di'sc 5l and the inside cylindrical surface 52 of guard ll. Springs 28 areshown disposed in a circular arrangement to bias plate 40 and its con- Vexv seating surfaces 44 toward scat member 16.

Plate 40 may conveniently be constructed of a synthetic polymeric material as hereinbefore described for sealing rings 30 and would, of course, enjoy the same advantages and features as hereinbefore detailed. As may be readily seen, a disc plate 40 could be constructed of any suitable material such as steel.

The operation ofthe valve as seen in FIG. 6, in opening and v closing and the fluid or gas flow through the valve is identical As hereinbefore discussed in describing the operation of sealing rings 30, the sealing surfaces of the rings and the seating surfaces of the valve seat member are not limited to the symmetrical cross section herein described, but such sealing and seating surfaces having other geometrically symmetrical or projecting curved or planar cross sections may advantageously. be employed as hereinbefore described. y Numerous variations and modifications may obviously be made in the structure herein described without departing from the present invention. Accordingly, it should be clearly understood that the forms of the invention herein described and shown in the FIGS. of the accompanying drawings are illustrative only and are not intended to limit the scope of the invention. 4

I'claim: l. A compressor valve, comprising: an annular valve guard member having a rim circumferentially projecting from the face of said guard member, the inner surface of said rim having disposed thereon interrupted screw threads;

an annular valveseating member having arcuate passage` ports therethrough and recessed seating surfaces commuy nicating with said arcuate passage ports, said vseating member having interruptedscrew threads disposed about the outer edge offsaid seating member for cooperatively Y mating with said interrupted screw threads of said guard membenfor removably attaching'said guard and seating members together and, spacing said recessedseating sur faces from said guard member;

sealing means of synthetic resin disposed within said space Y between said guard member-and Saidrecessed seating surfaces and adapted for movement therebetween.' said` sealing means having projecting-convex sealing surfaces for engaging said recessed seating surfaces to seal said arcuate passage portsfand v- Y 1 means disposed between said guard memberand said sealing means to urge said sealing means into sealing engagement with said recessed seating surfaces.V

2. The compressor valvedescribed in claim; l. wherein said sealing means comprises aty least `one annular sealing ring having azconvex sealing surface engageable with'said recessed seating surfaces of said arcuate passage ports. i

.with said seatingsurfaces comprises a4 plurality of springs.

7. The compressor valve described in claim l, wherein said 'recessed seating surfaces communicating@ with said arcuate `passage ports have a concave configuration..

8. The-compressor valve described in cla'im 1,"wheren 'said recessed seating surfacescommunicating with said arcuate vpassage ports have anangledplanar` configuration sloping "toward said passage ports- 3. The compressor valve as described in claim 2..whc'rein A.

said at least one annular sealing Aring may bc constructed of varying thicknesses to control the lift of said sealing ring "dur-` ing valve operation.,

4. Thecompressorvalve described in claim 1,1.wherein saidA sealing means comprises an apertured sealing plate one side of p which has at least one annular convex sealing surface projectt ing ,therefromVsaid convex sealingv surface engageablc with said recessed seating surfaces of said arcuate passage ports.

5. The compressor valve as described in claim 4` wherein f said apertured sealing plate may be constructed of varying y thicknesses to control the lift of said sealing plate during valve operation. y

6.\\The compressor valve describedin claim '1. wherein said means for urging said sealing means into sealing engagement prising:

with said-interrupted screw threads of said guard member g for removably attaching said guardand seating members said guard member; v l a plurality of concentric annular sealing rings of a synthetic together` and spacing said recessed `seating surfaces from resin having convexrsealing surfaces for engaging said r recessed seating surfacesto seal said plurality of arcuate passage ports; andV a plurality of springs disposed between saidK guard member and each4 of said concentric annular sealing` rings to urge said sealingV rings into sealing engagement with said Y recessed seating surfaces. y

l0; The compressor valve deseribedin claim 9. `wherein said recessed seating surfacescommunicating-with said` arcuate passage ports have a concave configuration.

11. The compressor valve described in claim 9, wherein'said recessed lseating surfaces communicating with said arcuate passage ports have an angled planar toward said passage ports.

sofl

9.. A valve suitable for'use in a" high' speed compressor, com-y l configuration sloping gygo UNlTED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,536,0911 hated october 2l, 1970 Invent01`($0 Flavious E. Ma'nlev. Jr.

It is certified that error appears in the above-identified patent and that: said Letters Patent are hereby corrected as shown below:

Col. 8, line ll, insert the following paragraph: 'an annular guard member having a rim circumferentially projecting from the face of said guard member, the inner surface of said rim having disposed thereon interrupted screw threads,

sumen um sEAu-:n

FEE 21W! (SEM.) Annu Edward M. Fletcher, Ir.

WILLIAM E. SGHUYLER, JR. Amunt! 0mm Gomissiom or Patent!

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