US1901478A - Compressor and valve therefor - Google Patents

Description

March 14, 19331 G C SUTT N Er AL 1,901,478

COMPRESSOR AND VALVE THEREFOR Filed Marc h 29, 1952 2 Sheets- Sheet 1 INVENTORS Gro r' G Sutton ZEZEr/K mYIs'C J ATTORNEY March 1933- G. c. SUTTON T AL COMPRESSOR AND VALVE THEREFOR Filed March 29, 1952 2Sheets-Sheet 2 INVENTORS era l aztale TiienIfi'toc/kye V ATTORNEY Patented Mar. 14, 1933, i

UNITED'STATES PATENI. OFFICE.

GROVER C. SUTTON AND PETER H. WITSCHGE, OF SPOKANE, WASHINGTON, ASSIGNORS 'I'O GENERAL MACHINERY COMPANY, OF SPOKANE, WASHINGTON, A. CORPORATION OF WASHDQ'GTON oouranssoa mm vALvE rmm-on Application filed larch 29, 1982. Serial No. 601,748.

This invention relates broadly to improvements in compressors and more particularly to an improvement in closed circuit compressors such as are used on ammonia machines. The invention also resides in an improved non-return passage valve structure for such machines.

One of the objects of this invention is to provide a valve structure of such reduced inertia that the speed, and hence the capacity of such machines, may be greatly increased without any accompanying or resulting noise of operation.

A further feature of the invention .is to provide a valve structure with a quickly responsive escape or safety feature whereby release of pressure from they cylinder is automatic when such pressure becomes abnormal.

.An object of the invention is to interpose between the low and high pressure sides of the compressor a valve structure that is slidably mounted in a hearing or bearinggland so that the entire valve structure can recede under spring control or resistance away from the end of the cylinder responsive to abnormal pressure.

It is a further feature to provide the compressor with a removable head and to so 9 construct the valve structure that it can readily be removed in one assemblage, and replaced as such.

The invention 7 features which will be more fully described in connection with the accompanying drawings and will be more particularly pointed out in and by the appended claims.

Inthe drawings Fig. 1 is a sectional view of aportion of a twin cylinder ammonia compressor showing the device of this invention with the parts in normal operation.

Fig. 2 is asimilar view of the left hand unlt of Fig. 1, showing the position of the parts when abnormal-pressure has been generated.

Fig. 3 is a sectional view on line of Fig. 2.

Fig. 4 is a sectional view on line H of I Fig. 2.

has many other objects and" bridge or web 16 is centrally dis Like characters of reference designate similar parts throughout the different figures of the drawings.

The housing 1, of the ammonia machine, is provided with cylinders 2 and 3 in which pistons 4 and 5, respectively, are alternately reciprocated. The piston '5, is shown in a receding or suction position and the piston 4, is shown in a projected or-compression position and when the latter has fully attained such position, its end will be flush with the end of its cylinder so as to express therefrom practically all of the gaseous body compressed therein, as will later appear. The pistons at and 5 are drivenby an suitable means not shown The housing'l is provided with a permanent head generally indicated at A, and a removable head generally designated at B,

the two constituting what will hereinafter be generically referred to as the head structure. The head A is walled at 6 and is provided with an annular shoulder 7 that is recessed from the face 8, of the head A. The central portions of the shoulders 7 may be formed on a bridge 9, as clearly shown. The shoulders 7 have centering walls 10 for centering certain parts that will presently be described.

The removable'head B has a flange 11 that is secured to the face 8, of the head A, by

bolts 12, with suitable interposed acking 13. The head B is domed at 14' to orm an ingress chamber C for the gas that is to be compressed. An intake 15 leads from a low pressure source of supply of the gas. A osed and forms a partof the,lower face 0 the head B, such face being indicated at 17. The packing or gasket 13, is shaped to fit between the faces 8 and 17 and has a central portion 18.

Each unit of the machine is provided with bearing-gland rings and as said rings are identical in structure and function, one 96.- thereof being designated at 19 and the other at 20, only one need be described in detail.

Said'ring 19 is provided with a relative:

l elon ted bearing portion 21, of cylin:

,'ca.l 01111, and below or inside of said I which' is shown in the form of a cylinder agains't'the shoulder 7, and be centered inposition by the cylindrical centering wall 10.

. readil .1 portion the ring is off-set and threaded at 22, to form one member of a packing gland. The remaining member of said gland is indicated at 23, and is threaded into 22 to com ress an interposed packing 24. The peripli ery of the ring 19, as indi: cated at 25,1s suitably shoulderedto seat- A suitable packin or gasket is'shown interpose'das indicate at 26. 1

It will be noted that the gasket 13 and the face 17, overhang the rings 19 and 20 so as firml to hold the latter against the shoulders .and the interposed packing or gasket 26. It will also be clear that when the head B 'isremoved, the rings 19 and 20 may be withdrawn.

Re erence will next be made to the improved valve structure and to the manner in which it coacts with the mechanism thus far described.

As all the valves are identical in structure and operation, only one need be described in detail, and the same reference numerals are applied to both, but for convenience in the description of the operation, I will designate oneEvalve unitas a whole at D, and the other at Each valve unit includes a .shell 27 and which is longitudinally and slidably fitted in the bearing-gland to move along and be guided by the bearing wall 21, the land 22 andv 23, making a gas tight fit. hus, whatever movement the shell 27 has in the bearing-gland willrequire a very con-' siderable thrust to bring it about. Internally T a glurality of ingress ports 29 is formed' of said shell, and preferably formed integral therewith, is a port diaphragm 28, in. which disposed concentrically about the center of said diaphragm. A flat rin closure 30, which is of relatively thin and material, functions to seat against or be unseated from said ports 29, as will presently appear. Spring means is provided for seat-.

ing said closure and ma consist of a spring ring 31, having a plura ity of spring fingers 32 which normally act to seat said closure ring 30, against said ports 29, to close the latter, as shown in unit D of Fig. 1.

Aretainer is rovided whose function it is to hold said rings 30 and 31 in concentric relation with said ports 29 and to support said closure and spring ring.

- Said retainer includes a central shank 33 about which said closure and spring rings are disposed, and said retainer has a supporting flange 34 that extends abreast of said rings, as clearly shown. A bolt 35 extends through and has threaded engagement with said diaphragm 28 and said shank 33, and is shown provided with a head 36 countersunk in said retainer. A nut 37 is adapted light weight.

morass and. outwardly to wall 38, which de ects the gas and changes its course so that it must pass through the space between wall 38 and the edge 39, as will now be clear.

Wall 38 extends outwardly from said shell and forms a shoulder 40, the purpose of which will presently appear. Said wall 38 also extends outwardly and terminates in a port flange 41in WhlCll there is formed a plurality of egress ports'42. This flange 41 is adapted to seat against the end of the cylinder, as indicated at, 43, and it will be clear that this flange 41, and diaphragm 28,

together form a cylinder head or valve plate closing the end of the cylinder 2, against which said flange is shown seated.

. Itwill now be clear that with the closure for the ports 42, about to be described, that the valve unit heretofore described, partitions oil or divides the low pressure ingress chamber C, from. the high pressure egress chamber, which I will designate at F. In' the low pressure chamber C, the pressure] may be as low as fifteen pounds to the square inch while in the highpressure chamber F, it may be one hundred and fifty pounds to the square inch, this diflerential serving to illustrate, as an example, the function which the device is intended to perform, which is that of a relatively heavy duty function.

The outlet for the egress or high pressure chamber is designatedat 44. Thus, itwill be clear that the egress chamber F extends throughout the entire area below rings 19 and 20 and above the cylinders 2 and 3, and

within the walls 6 of the housing.

A closure retainer ring 45 is slidably mounted on shell 27 andis adapted to rest against shoulder 40, thereof. Said retainer 7 ring is provided with a plurality of cavities or sockets 46 in which springs 47 are disposed. A flat ring closure 48,'extends abreast of said springs 47 and is adapted to be engaged thereby to force the closure ring 48 against ports 42, to close the same. This ring closure 48, like closure 30, is made of very light weight material and is very thin and hence these closures have very little inertia and are capable of high speed and noiseless operation.

vReference will next be made to a further function of the retainer ring 45, and tea means whereby this ring may participate in an abnormal pressure release or escape feature together with the remainder of the valve unit, which will next be described.

A valve release spring 49 is interposed between the retainer ring 45 and the lower face of bearing ring 19 and this release spring 49, acts against the retainer 45, to hold the latter against said shoulder 40, and thereby hold the valve plate flange 41 in engagement with the end 43 of the cylinder 2, with suflicient pressure so that when piston 4 attains its full compression stroke, the flange 41 will not be unseated. While no adjustment is shown to increase or decrease the tension of spring 49, such adjustment is clearly within the province of mechanical skill if it is needed. However, it is preferred to employ release springs proportionate to the maximum normal pressure generated by compression strokes of the pistons.

The operation will now be described in detail. a

During normal operation when no excessive pressure is generated, and referring to Fig. 1, suction stroke of piston 5, will open closure 30 against the action of spring fingers 32, and gas will be drawn into cylinder 3 from the ingress chamber 0. The suction stroke of piston 5, will actto close or seat closure 48 against egress ports 42. In each instance, the springs actuating the closures are mainly for overcoming such inertia as these closures may have, which is very slight, and to obtain practically instantaneous closing action of said closures. Theoretically, no

springs would be required. Further, there is always sufficient pressure in the egress chamber F, to seat closure 48 against ports 42, irrespective of suction action by the pistons. It will be noted that when the closures 30 are unseated, they are not only arrested beyond a further opening movement but are also supported by the flanges 34.

On the compression stroke, in which the tandem piston 4 is shown, the pressure generated willseat closure 30 against ingress ports 29. However, as a matter of fact, and in practice, when the spring fingers 32' are employed, the latter will seat closure 30 instantly upon the piston attaining its full suction stroke, at which time suction is at zero, and theoretically before the piston reverses its movement toward a compression stroke. Thus, it will be celar, particularly with spring fingers 32, that they could be omitted and the compressor would still be highly eficient.

As the piston 4 is approaching the full compression position shown in Fig. 1, and when a pressure has been generated in advance of said pistion slightly greater than the pressure existant in the egress chamber F, the closure 48 will be unseated from ports 42, against the action of springs 47, and the closure will usually be forced into the position shown against the abutment ring 45,,

which thereby functions to limit opening movement of closure 48. This is what is referred to as normal operating pressure and it will be understood that the release spring it strong enough to hold the valve plate in gas tight engagement against the cylinder end 43, during such compression'stroke irrespective of the fact that the pressure geneerated on such compression stroke is sustained by the full area of the valve plate, which includes that portion of flange 41, insidethe cylinder outline, and'the port diaphragm 28.

At this point it is informative and desirable to state that in practically all compressors of the suction and compression type as shown, it is very essential that the pistons be advanced to a full compression stroke or in the device shown, into practically actual engagement with the valve plate.

It will be clear that if on completion of the compression stroke a clearance space of one eighth of an inch, for example, were left between the end of the piston and the valve plate, this compressed gas would of course expand on the intake stroke of the piston and fill the cylinder and practically no new gas would be drawn in, as the pressure in the'cylinder would be greater than in the ingress chamber 0, and the closure 30 would therefore remain seated.-

However, in any compressor where the piston approaches actual contact with the,

which contemplates and compensates for such an emergency will next be described.

Referring to Fig. 2, it will be seen that piston 4 is approaching a full compression stroke and it will be assumed that slugs of liquid ammonia have entered the cylinder and are being expressed through egress ports 42. Of course the gas will first be expressed but as the piston end 4 nearly reaches the valve plate, the ports 42 do not and cannot offer suflicient capacity for the practically instant passage of this liquid ammonia, and because the'latter is incompressible, something would have to yield or damage would result. In this invention, the release spring 49 yields under this abnormal pressure and permits the shell 27 to slide lengthwise in the bearing-gland 19, away from the cylinder.

Thus, the valve plate moves away from .cylinder head on its compression stroke,

mined position with respect to the cylinder bore so that when it returns thereto, the

egress ports 42, which are necessarily disposed outwardly, will all be in full registry with the bore. It is equally important to have an effective bearing so that the shell 27 will not wedge either on its outward or inward movement.

After the slugs have been expressed and abnormal pressure no lon er exists, then the release spring 49 instant y restores the whole valve unit, as an assemblage, from the Fig. 2, or releasing position, back to the Fig. 1, or normal position, and of course the releasing and restoring functions are all automatically performed.

It will be clear that in making replacements or repairs, id is merely necessary to take off the removable head, C, whereupon the release springs perform the highly useful and advantageous function of expanding and forcing the bearing-gland rings outwardly from the frame or housing of the machine thereby greatly facilitating its removal, apart from the valve unit, because the springs 49 serve to hold the valve unit against the cylinder while they are forcing the bearing-gland rings outwardly. Then, after the bearing-gland rings have been removed, the valve units can be removed, as unit assemblages. It is because of this construction, that the gland of said bearing ring can be disposed in the advantageous position shown,

In some cases, where a close, precision, or if desired, a ground fit is provided, be-

. tween the shell 27 and the bearing 21,.the

gland parts 22 and 23 may be omitted, and the'resulting structure would still be within the province of the invention, as claimed. This is especially true when the differential of pressure in the ingress and egress chamhers is not so great as'in the average 'am- J monia. compressor.

. It is believed that the invention will be clearly understood from the foregoing description, and while only one form thereof has been shownand described, it is under- ,stood that the invention is' not to be limited to the specific form shown except for such limitations as the claims may import.

We claim: p 1. In s an? ammonia compressor, a head structure having a bearing gland and provided with an ingress chamber" for thefigas said port diaphragm an port flange formas from said 3 of said shell and ing-a valve plate for the end of said cylinder and coacting with said shell to divide said ingress chamber from said egress chamber, said diaphragm having a plurality of ingress ports 0 ening through said shell to said ingress c amber and to said cylinder, a ring closure for said ports adapted to be unseated on suction movement of said piston and seated on compression movement thereof, said port flange having a plurality of egress ports communicating with said egress chamber and with said cylinder, a ring clo sure for said egress ports adapted to be'seated thereon'by pressure in said egress chamber and suction movement of said piston and u'nseated on compression movement of said piston, springs normallyacting to seat said egress port closure, an abutment ring for said egress closure spring slidably mounted on said shell and having shouldered engagement with said shell to'limit movement of said abutment ring toward said cylinder, and a safety spring acting against said abutment ring to hold said valve plate against said cylinder and adapted to yield under abnormal pressure to per= mit, said valve plate to' recede from said cylinder.

2. In a non-return passage valve struc ture for compressors, a valve shell having an outwardly projecting port flange provided with a plurality of egress ports, and said shell having a peripherally disposed stop shoulder, a ring closure adapted to seat against and close said ports, an abutment ring slidable onsaid shell and extending abreast of said closure to limit opening movement of the latter and having springs normally seating said closure against said ports, and a release'spring adapted normally to hold said abutment ring against said shoulder.

3. In an ammonia compressor, a housing having a cylinder and provided with a permanent head forming a high pressure egress' chamber and pnovided with a centering seat,

a bearing-gland ring adapted. to be mounted in said seat and having a bearing-gland bore, a removable head mounted on said permanent head and forming a low pressure ingress chamber, a non-return passage valve having a shell slidably mounted in said bearing gland bore and having an internal diaphragm provided with a lurality of ingress ports and an external ange provided with a plurality of egress ports and engaging the end of said cylinder and said diaphragm and port flange forming a valve plate for the end of said cylinder and coacting with said shell to .divide said ingress chamber from said egress chamber, a piston in said cylinder for drawing gas through said ingress ports into said cylinder on the induction stroke of said piston and compressing and expressing said gas into said egress chamber on the compression stroke of said piston, closure means for said ingress ports adapted to open on suction and close on compression strokes of said piston, respectively, and closure means for said egress ports adapted to close on pressure from said egress chamber and open on compression stroke of said piston, an abutment ring slidable on said shell and having shouldered abutment therewith to limit movement of said abutment ring toward said cylinder, and a safety spring surrounding said shell and interposed between said bearing-gland ring and said abutment ring to hold said valve plate against said cylinder and adapted to yield under abnormal pressure to per- 't 'd l l 1 d f 'dm1 Sal Va V8 p rece 8 mm Sal I gress valve into said cylinder to be comcylinder.

4. In an ammonia compressor, a housing having a cylinder and provided with a permanent head forming a high pressure egress chamber and having a centering seat, a bearing ring adapted to be mounted in said seat and having a valve bearing bore, a removable head mounted on said fixed head and engaging said bearing ring to hold the latter seated and forming a low pressure ingress chamber, a valve structure dividing said high pressure and low pressure chambers and engaging said cylinder and having a shell slidably mounted in said bearing bore, and a spring interposed between said bearing ring and a portion of said valve structure for normally holding the latter against said cylinder and adapted when said removable head is withdrawn to move said bearing ring out of engagement with said centering seat.

5. In an ammonia compressor, a housinghaving ingress and egress chambers and provided with a cylinder, a bearing ring mounted in said housing, a valve structure slidable in said bearing ring and closing the end of said cylinder and dividing said chambers,

said valve structure having port means af-- fording communication between said cylinder and each of said chambers, and a release spring interposed between a portion of said valve structure and said bearing ring for holding said valve structure in engagement with said cylinder under normal pressure or permitting said structure to recede from said cylinder during abnormal pressure.

6. In a non-return passage valve structure for compressors, a hollow valve shell having ingress and egress ports, closures therefor, and said shell having a stop shoulder, an abutment ring slidable along said shell, and a safety release spring adapted normally to gold said abutment ring against said shoul- 7 In an ammonia compressor, a housing having ingress and egress chambers and provided with a cylinder, a bearing ring mounted in said housing, a non-return passage valve structure having a valve plate for closing said cylinder and provided with a cylindrical shell in gas tight engagement in said bearing ring and lengthwise slidable therein toward or away from said cylinder to cause said valve plate to close or open the latter respectively,'said valve plate having a non-return ingress valve opening through the interior of said shell into said cylinder from said ingress chamber, and

said valve plate having a non-return egress valveopenlng from said cyllnder exteriorly pressed and then delivered by said pistonthrough said egress valve into said egress chamber, and safety spring means coacting with said non-return passage valve structure and adapted to yield to permit said structure to recede from said cylinder upon abnormal pressure to permit liquid ammonia to pass into said egress chamber and then restore said valve structure with thevalve plate in closing engagement with the end of said cylinder.

8. In an ammonia compressor, a housing having a gas ingress and a gas egress chamber and provided with a cylinder with an annular valve seat about its open end, a gland bearing mounted in said housing, a

non-return passage valve structure having a said gland bearing, said valve structure having a valve plate adapted to engage said annular valve seat and present a flat plane surface to the interior of said cylinder, safety'spring means normally holding said valve plate in engagement with said seat to close said cylinder, safety spring means normally holding said valve plate against said seat and permitting said structure to recede from said seat under abnormal pressure, said valve structure having a non-return ingress valve opening to said cylinder through said shell tosaid ingress chamber and a nonreturn egress valve opemng from said cylinder to said egress chamber exteriorly of said shell, and apiston in said cylinder having a flat and adapted for precision close engag ment with said valve plate when in a, gas compression position.

G. c. SUTTQN. PETER H- vm'sm-zam

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