US2011780A - Valve mechanism - Google Patents

Description

Aug. 20, 1935. A. c. sTALEY VALVE MECHANISM 3 Sheets-Sheet 1 Filed July 28, 1952 f. .mYmrWvl mmv.

. INVENToR. Y ALLEN GQSTALEX 'fqoRNES/s.

Filed July 28, 1952 3 Sheets-Sheet 2 INVENTOR. LLEN CT :STA LEY j ATTORNEYS.

orrics VALVE MECHANISM Allen C. Staley, Birmingham, Mich., assigner to vChrysler Corporation, Detroit, Mich., aV corporation of Delaware Application July 28, 1932, Serial No. 625,449

16 Claims.

My inventionv relates,V to air or gas compressing and air or gas expanding mechanism of the rev ciprocating piston type and has particular relation to several novel types 4of valve mechanism, and several novel combinations of such types, for use in equipment of the character designated.

More particularly,l my invention relates to novel types of inlet and exhaust valve mechanism, and to novel combinations thereof for use in air compressors and in air or gas expanding mechanism for use in refrigerating systems.

By my invention, I have provided a mechanically operated valve of the poppet type for use as an intake valve in an air motor in which a cam of normal contour is employed to operate the valve and in which the valve is mechanically closed at the proper time. f l

One of the" objects of my invention consists in l providing a novel type of valve adapted for use as 2U an exhaust valve of a compressor of the reciprocating type which eliminates theobjections of both the mechanically operated and the pressure operated valve and retains the advantages of both types. Y y

A still further object of my invention consists in providing a novel type of valvevmechanism in which the effect of the inertia of the valve closing Y member is eliminated as a factor in the timing of operation of pneumatically operated valves. An additional object is to provide a novel combination for use in compressors and an additional novel ycomloination'of intake and exhaust valve mechanism for use in air motors or in expanding machines as used in refrigerator equipment. 35 For a more detailed understanding of my ino vention,`refe'rence may now be had tothe accompanying drawings, of Which: y p Fig. 1 is a longitudinal cross-sectional View of an air compressor constructed in accordance with 10 my invention. y

Fig. 2is a transverse cross-sectional View of the structure illustrated in Fig. 1, the section be- 4 ing taken along the line II-II thereof. v

Fig. 3 is a longitudinal cross-sectional View of a combined `compressor and expander, or airv kthe section being taken along the line` V-V thereof. Y

Figs. 6, 7, 8, and 9 are cross-sectional views of modified forms of valve constructions which embody my invention. 5i

lIn Fig. l I have illustrated a compressor of the reciprocating type consisting of a cylinder block IS, a crankcase I I, and a cylinder head I2. The cylinder block Ill is provided with four cylinders I3, all of which are identical, and each of which 10 is provided with a piston I 4. Each cylinder is provided with an intake valve mechanism I5 and an exhaust valve mechanism I t, both ofthe poppetvalve type. The pistons I4 are operated by'ay crankshaft I7 and the valve mechanisms I5 and 15` I6 are operatedby valve operating rods I8 and I9 which in turn are operated by a camshaft 2U provided with four inlet valve operating cams 2| and a similar number of exhaust valve operating cams 22. The camshaft is driven at half the 20 speed ofthe crankshaft by means of a gear 23 secured thereon which meshes with a smaller gear 24'mounted on the crankshaft.

In Fig. 2 is shown a cross-sectional view of the compressor inlet valve shown inrFig. l. In this 25 construction the valve mechanism is `of theusual type employed in internal combustion engines in which an intake manifold passageway communicates with the interior of the cylinder I3` through a valve port SI which is guarded by a 30 port closing member 32. v'I'he port closing member comprises a valve head 33 which seats in the valve port 3I andv an integral valve stem Se Which extends upwardly through a valve stem guide 35. The upper end of the valve stem Sli is 35 disposed in engagement with a laterally extending projection of a pivotally mounted rocker arm 3B.

A compression spring 31 surrounds the upper end of the valve stem 3Q, one end being disposed-in engagement with the upper surface of the cylinder head I2 and the other end in engagement with a disc or pin 38 mounted on the valve stem Se. The spring 3l thus tends to hold the valve head 33 in engagement with the seat of the valve port 3l. The rocker arm 36 is provided with a second laterally extendingv projection 39 v/hichV is engaged by the valve operating rod I8 in such manner that the cam 2I on the camshaft 2U raises the rod and thereby opens the valve twice during each revolution of the camshaft.

In Figs is illustrated in detail an exhaust valve of the type employed in the structure illustrated in Fig. 1. In this construction the cylv inder I3 communicates with a passageway Ali 55 Y engagement a sleeve t2.

vided with a centrally disposed-valve openingA or connected to thevexhaust manifold throughia passageway'lii in which is disposed in threaded port-.liSand with a valve seat lid. The valve seat ad is adapted to be engaged by aV vport closing member l5 which is provided witha cen# trally disposed recess 13.5 the r walls of vwhich are substantially straight. and concentrically with .the valve port 123 'is a vhollow valve stem guide 46e rigidly secured `in f the rcylinder head i2.: A valvestem lillois slid-f' ably niountd within the guidewiia and isprovidedV at its lowerend with an enlarged portionf pro-L vided with straight sides," and similar in lshape.

to the recess 66 in the port closing member 45.

The valve stem 4l is also provided with a coilar i9 and a coiled spring 5U which surrounds the lowerrend of the valve stem and engages at.. one vvend the collar 49 and on the other end'the'i" port closing member firrg'lhe spring 56 serves# to resiliently urge the port closing member away from the collar 49 andtheenlarged portion i8 serves to guide the movement of the port closing member l5 as vit slides thereon when the valve stem-lil is in other than its lowermost position and Serves to rigidlyhold the port rclosing member-ll5 on the seat M when the valve'Y member Eiland a-portionof the cylinder head i2' isa'relatively large coiled compr'ession'spring iifll and a smallerinteriorly disposed coiledcompression springv-, The springs 58 and 59, are so designedthat whenno pressure is exertedon the top of the valvestem-'M the valve stem is raised thereby,I thus serving to eliminate the inertiarof.V

the valve stem as av factorin the time of opening thevalve. y f' The valve stem'i is provided at its upper end with fa khemispherical Vsurfaceillgon.v which is ymounted Va cap'` 6i having a. hemispherical depres sion -thereinadapted to yfit over andfengage the surface till.,Y A rocker arm BZis pivotally mount- .jed on a pin 63 which in turn Yis mounted ,on the cylinder Ahead The rocker arm is provided' with three outwardly projecting arms '645, 675, and- The arm ,54 is provided with a downwardly 6G. projecting portion'l provided with a hemispheri- ,cal end'portion over whichis tted a cap G8 Vprovidedwith a hemispherical depression therein..

A coiledcompression spring'e is mounted intermediate fthe caps @il and and is of such rigidity that when thelarm 66 ofthe rocker armii moves downwardly the valve stem 4l is resiliently forced' downwardly. toclose the valve. ,The arm 'of thev rock-er`- member 62 serves 'as means for zn'o'untingY a coiled compression spring it betweenthe rocker member 62 and thetopf of vthe cylinder head i2,

which tends to. hold .the arm @dof the rocker arm 52 in its uppermost position.

The rocker arm isactuated by means of a cam v(not` shown in Figi@ which operates the tappet ing of the tappetrod i9 exerts a pressure onthe valvev stemlii throughr the 'spring 69, serving `to,4 move theport lclosing member into positive v engagement with the valve seat' 44, thusv closing' The sleeve L32 is pro-v Dispos'edvertically above l pressing the light spring 5o.

, the valve. Whenvthe cam has passed rfromengagement with the tappet rod i9 the spring le immediately raises the arm 6d, thus removing the 'force by which thevalve stemv lil was moved downwardly. When this occurs, the springs 58 and 59 immediately raisethe valve stem il until the member 48 is raised partially out of the recess it ,inY the portv closing member 4,5. The spring 5i), having been unloaded by raising the valve stem lll, now exerts no force on the port closing member 45 except that due to its weight. Thepressure inthe'chamber daholds the mem- "ber fi'onits seat until'suchftime as the pres-4 sure within thev cylinder I3 becomes greater than the pressure within rthe passageway iii land the 'force' ofthe spring. When this occurs the relatively Vlight closing member a5 risesirom the yseat fis guided bygthe rmember 48,. again coin- Y The spring 5d thus serves as a shock absorber forY the member i5 Vduring openingof the` valve.

' as soon; as 'the pressure'in the cylinder-exceeds the pressure inthe passageway ,139, and without any delay incident to r overcoming the inertia of "the relatively heavy valverstem or to over-y corningthe forceof a relatively st ififvalve closingspring. Y Also, by; reason of very small mass. oitheemember i5v and the light force of theA spring 5o', the valve will immediately open Vto its wide Vopen position, and, altwtheendV of lits movement, Vwill be cushioned by the springT 59.

In addition, the valve is'mechanic'ally closed at` the 'correcty point with` respectto the position" of the piston,whichV eliminates any delay in Y closing the valve incident. to Y.overcomingv the inertia of the relatively heavy valve stem. Thus, this valve enjoysall y,of the' advantages of both the pressure operated and themecha'nically op-V erated valves but` suffers `fro if 'noneV offthe objections thereto. v *y A A, @In Fig. 3r is .illustratedA a combination gas `or air compressing and expanding machine adapted particularly for use in a refrigerating system. In

thislcon'struction, a crankshaft 'lefoperates two compressorjpistons' and hasconnected there- 'totwo` expanding vmachine or air motor pistons lil. v, The two pistons 'i6 move within compressor cylinders irwhichfare of larger diameter than the expander or air motor cylinder 'i9 Vwithin which the pistons 'il operate. The compressor cylindersl are each provided with an intake valve'mechanism,Biisimiiar to that `illustrated in Fig. 2, and an exhaust valve mechanism Si, simillustrated infFig. 5, and an exhaust valve mechanism 83,r similar toY thatillustrated in Fig. 2.-`

In refrigerating systems of this typeV it is cus- Atomary to employ a compressor or compressor cylinder which serves to compress air or other gas, preferably the former, which compressed gas is then carried to an air coo-ling means, such as' a water orair cooled radiator orfthe like. The

compressed gas, now cooled, is Vin turn" admitted vto tlf'le'expander or 'air motor which reduces theVVV ,pressure thereof, and the cold air at the reduced rod i3 which engages a ball joint li vadjustably L mounted' on the arm ii of the rocker member 52,7 l It will be apparentjfrorn this description that rais-` `With Fig. 1.

In Fig. 5 Vislillustrated a valve mechanism which f exhaust valvemechanism of a compressor.

may be employed either as the intake valve mechanism' of` an air motor orY expander, or as the Inv this .ligure I have illustrated the usual cylinder i3 pro-vided with the cylinder head `i2 lin which is disposed a passageway 9B communicatingwith the cylinder 'I3 through alvalve port 9i which is guarded by a valve head 92, thel latter being provided with lan integral valve stem 93. The valve stem 93 moves Within any suitable arrangement oiv valve guides Sli. The upper end of the Vvalve stem 9311s provided vwith a groove 95 in whichv is `atted a two-part locking collar Sii provided with a conical exterior surface and 'l fserves asia seat for va spring collar member 91,'

similar to that described in connection with Fig.

4., 'The valve stern is surroundedbyftwo Acoiled compression springs 93 and S9, which together serve to raise the valve head 92 from its seat when no pressure is exerted thereon by the rocker mounted an adjustable member i which in turn valve head 92 and serves to hold the valve closed.

As thepiston approaches the upper end oi its stroke, there being but comparatively little clearance between the cylinder head and the piston,

' the pressure created `thereby is sufficient, to-

gether-with `the aid of the springs S8 and S9,

to Vraise the valve head @E from its seat against the pressure inthe chamber Si). When this occurs, the `pressure is immediately equalized on ".both sides of 'the valve'head and the springs 58 and 95 open the valve wide instantly. The upwardly moving valve stem 93 engages the resilient arm 02 and is cushioned thereby, so as to prevent any sharp blows to any part of the valve mechanism, thus eliminating any slowness of movement resulting from the inertia of the valve head and valve stem. It will be apparent that,

'f by reason of theforce of the springs 98 and SS being additive tothe pressure within the cylinder, the valve will start to open before the pressure in the cylinder equals that in the chamber 98. This small interval of time is suiiicient for overcoming the inertia oi the valve closing member and its stem so that the valve actually opens at the time when the pressure in theV cylinder is equal'to that inthe passagewayv. When the cam engages the tappetrod l 9 it moves the rocker arm l e2 downwardly, thus promptly and positively closing the valve through a resilient connection. The rocker arm maybe raised immediately thereafter but the Valve remains closed because of the pressure in the passageway 99 on the upper side of the valve head being greater than the pressure exerted thereon by vthe springs 98 and S9, rand the valve will remain closed until the piston again reaches theupper portion of its stroke and pneumatically` raises the valve, as previously described.

From this description it will be apparent that the air motor intake valve is positively mechanically closed at the desired predetermined point and is pneumatically opened during its normal operation. It will also be apparent that the compressor exhaustjmechanism islikewise mechanicallypositively closed and is pneumatically opened by the direrential in pressure on the two sides thereof. f- In each instance the valve opens Without any retardation caused by the inertia of the valvemember andinstantly opens widely. Also, in each instance, the valve closing member moving upwardly engages at the uppermost portion of its movement aresilient cushioning member which serves to eliminate shocks to the mechanism.

- In Fig. S'Ihave illustrated another form of exhaust, valve mechanism in which a valve stem i I@ is provided at its lower end with a hemispherical surface HI, The valve stem is adapted to move within a valve guide i l2 and Lis disposed in alignment with an annular member l i3, which is provided with a valve seat l lll. The valve closing member consists of an annular disc l I5 provided with a centrally depressed portion having a contour similar to that of the portion HI of the valve stem HB. A coiled compression spring it extends between a stationary portion of the cylinder head and the valve closing member l l5. The upper end of the valve stem is provided with a plurality of springs, similar to those shown in Fig. 4, which tend to raise the Valve stem as soon .as thepressure from the cooperating rocker arm vis releasedthereirom. When the valve stem HB has been raised the spring I I6 serves to retain the valve closing member H5 on the seat H4,

thus keeping the valve closed until such time as I the pressure within the cylinder is suinciently great to raise the Valve closing member l i5 from its seat. It thereupon moves upwardly,l guided by themember III, and is cushioned by the spring H6. The valve closing member is subsei.

quentlyg' returned to engagement with the valve seat bymeans of the usual rocker arm engaging the upper end of the valve stem l I il. This structure differs from that illustrated in Fig. 4 primarily in that the spring i i5 extends between the valve closing member and a stationary part. or seat rather than between the valve closing member and valve stem.

In Fig. 7 I have illustrated a valve stem l2@ provided at its lower end with a disc l2| on the lower side of which is mounted a hemispherical member 422, rI'he valve stem 12B slides Within a valve stem guide H43 disposed in alignment with an annular member i251 provided with a valve seat l 25. l The valve port is closed by means of a circular member E26 which is provided with a hemispherical depression in its central portion, which conforms in contour with the member 22, and with an outwardly projecting flange E21 which engages the seat i25 of the valve. On the upper side'of the disc 2! is loosely mounted an annular collar 52S. A coiled compression spring 29 is mounted lintermediate a stationary seatand the collar t28. When the pressure of the rocker arm on the upper end of the valve stem IZB is released the springs mounted on the upper end of the valve stem immediately raise thevalve stem to its uppermost position, carrying with it the collar IES' and compressing the spring 29. The valve closing member |26 remains in engagement with the -f-lfl seat |25 until? the pressure within the cylinderL becomes greater than the pressure ,within the communicating passageway, whereupon it immediate'- ly. rises, guided in 'its path of movement bythe' ,member |22 yon the endof the valve stem.: .As

the valve closing member |26`reaches` the upper end of .its movement it engages, the lcollar |28 yso that Athe spring |291serves to cushiontheengagement of the valveclosing member-,|25.with the rvalve stem |29. In practice, Ihave found that Vby properly proportioning themassof the members |26 and |28, anydesiredportionfof theinertiaof the member -ii may be dissipatedfin striking the member |28, after which the remainder of the yinertia is dissipated, first by compressingthe springY l 2S and finally by engaging the member IZL; vAs the area ofgengagementpf.the members |25` and V`| 2S is relatively large, the unit stresses may be controlled at Will by varying the mass of the members |28 and 23 and nthe strength of thespring |29 so as to absorbany desiredportion of the inertiaoi the member V|25 in z infyone of the three stages of stopping thenfiovement of the member |26. -At

. present it.-V appears desirablelthat the mass ofthe member l 28 ,shouldqbe `approximately sixtypercent of the masser vthe member` |25 for good' performance. v c Y In the structureshown in Fig. 8, I have illustrated avalve stem ldprovided at its lower end with a flat discy i3 l.. `The valve stem moves within a guide |32 whichis disposed in alignment with an annular member |33kprovided with avalve seat |34. f The valve port is closed by'y means ora valve closing member lprovided with a substantiallyV flatk uppersurface `which' conforms with the lower surface of the disc |3`l.

shoulder l 36 and anl outer 'annular upper projecting ilangell. A coiled compression spring |38 is mounted intermediate the valvestemV guide` l 32 and the hat surface 38 of the valve closing mcmbei |35.

When the pressure on the valve stem exerted by the frockerarm' is removed the springs mounted on the upper end immediately raise the valvegstem-lh The valve closing member |35v remains on its seat',khowever, untilthe pressure Withinthe cylinder is greater than that inithe ex- ;haust passageway, whereupon it moves upwardly againstthe action of the 'relatively' light spring |331.' 'Ihe spring |38, byvreason of the flange |31, serves to guide the .upward movement of the memf bery |35.' The walls ofthe shoulder |38 aid in 'guiding the valve closing member With respect -toy the valve stem. The spring |38 also serves'to cushion the valve closing member atk the upper end of its movement. v f

Inthe structure illustrated lin Fig.V 9, I have shown a valve stem ME? which moves withina valve stem guidel |4|which,in turn is provided with a central recess |42. The valve stemguide Mil is disposedin` alignment with an annular The member H53 provided with-a valve seat Mii. valve is closed by means of a valve closing member. |45 which engages the seat Md.' Secured to the valveclosing member |45 by means of a rivet M is a circulary disc '|41 composedof resilient material, such as springr steel. Disposed intermediate the valve guide l! and the udisc litil is a relatively light coiled compressiony spring/MS.

When the pressure on the upper end of thevalveV stem MD exerted by the rocker arm rislreleased the springs secured to the upper end of the valve stem Mil immediately raise it out of contactwith theN resilient member |41. The .valve closing member |45 remains in engagement with thel seat ment.

The valve closingmeml ber. |35 is likewiseprovided Witlran annular ilaty 2,011,7eoy

plications thereof, it will be apparent to .those skilled in the art that my invention is not so limited butfthat various changesv and modificationsmay bemadetherein without departing from the -spirit thereof or from the scope ofthe appended claims. Y Y

1. In combination, a cylinden-a movable piston, an intake and an exhaust valve, each constructed to be moved between an open and a closed position, one of said valves being constructed to be moved fromkone position to the other by positively actuated mechanical meansrand to be returned to the first positionby gas pressure.

2. In combination, a cylinder, amovable piston, an'v intake and an exhaust valve, eachfcony structed to be moved ,betweenanopen and a closed position, one of said valvesbeing constructed to `be moved from one positionto the other by a pressure ldifferential on oppositewsides thereof Vand Y to be returned to the rst position by engagement with positively actuated mechanical means associated with said vmovable piston.-

*3.v -In combination, ,a cylinder, amovablepiston, an intake and an exhaustv valveeach constructed to be moved between an-open and a closed position,one of said valves being constructed to be closedby positively* actuated mechanical means; to be temporarily held closed pneumatically, and to be opened pneumatically. l., j

y e. In a compressor, a cylinder, a movable piston, an intake valvel and an exhaust Valve of the poppet type, each constructed to be opened and closed,v said exhaust valve being constructed to Vbe opened by apressure differential on opposite sidesV .thereof and to be closed by positively actuated mechanical means. y v.

y 5. In acompressor, a cylinder, a'movable piston, an intake and an exhaust valve,1 said exhaust valve beinggof the poppet type, each of said valves being constructed to be openedrand closed, positively actuated mechanical .means constructed tov closeftheexhaust va1ve-and to "retain itin its Yclosed positionduring a predetermined portion of the ,piston movement, said valve being, adapted to be opened by a pressure differential on opposite A sides thereof during other portions of the pistonv movement. f

6. In a compressor, a cylinder, a movable piston,'an intake and an exhaust valve of the poppet type, eachconstructed to be opened and closed, positively actuated mechanical means constructed to openk and close the'intake valve and toclose theexhaust valve at predetermined points in the travel ofthe piston and to hold said exhaust valve closed during a predetermined portion of the piston travel, said exhaust Valve being adapted to be opened by a pressure differential on opposite sides thereof during other portions of the piston travel.

' '7. In combination, a cylinder, a movable piston,

a uid passageway Vdisposed exteriorly of said'cylinder, a valve port interconnecting said cylinder and said passageway; a valve memberof the poppet type adapted to close said port, resilient means associated with said valve member and adapted ot exert a pressurethereon, said resilientv means being so disposed that the `fluid pressure e within the cylinder `and the pressure of the resilient member each tend to move said valve membertoits open position and the fluid pressure in the passageway tends to hold said valve member in its closed position.v i

8. In combinationfa cylinder, a movable piston, a iluid passageway disposed exteriorly of said cylinder, a valve port interconnecting said cylinder and said passageway, a valve member of the poppet type adapted to close said port, means associated with said valve` member adapted to resiliently hold said valve member in its open position, and positively actuated means adapted to move saidvalve member to its closed position.

9. In combination, a cylinder, a movable piston,

a fiuid"passageway disposed exteriorly of said cylinder, a Vvalve ,port interconnecting said cylin- 4 yder and said passageway, a valve member of the poppet type adapted to close said port, means associated with said valve member adapted to resiliently hold said valve member in its open position, and mechanically actuated means adapted to intermittently resiliently urge said valve member towards its closed position.

li). lIn combination, a cylinder, a movable piston,'a fluid passagewayidisposed exteriorly of said cylinder, a valve port interconnecting said cyl- 'ind-er and said passageway, a valve member of the poppet type adapted to close said port and pro- Y vided with a stem, aspring surrounding said stem and exerting a pressure thereon tending to move said valve memberraway from said port, a rocker arm adapted to engage said valve stem, and means adapted .to actuate said rocker arm once during each complete cycle of movement oi'the piston to move said valve member to its closed position said valve stem, a spring disposed between saidV portion and said valve stem, and means for mechanically actuating said rocker arm to resiliently move said valve toward the valve port against the action of the first mentioned spring.

,12. In combination, a cylinder, a movable piston, a fluid passageway disposed exteriorly of said cylinder, a valveport interconnecting said cylinder and said passageway, a valve member of the poppet type adapted to close said port and provided with a stem, a spring surrounding said stem and exerting a pressure thereon tending to move said valve member away from said port, a rocker arm `having a portion Yadapted toengage said stem to move said valve to its closed position, and means adapted to actuate said rocker arm to move said valve member to its closed position and to retain said valve member in its closed position during a predetermined portion of a cycle of movement of the piston, said valve member being under the combined control of said spring, the fluid pressure within the cylinder and the fluid pressure within the passageway during the remaining portion of the movement ofthe piston.

13. In combination, a cylinder, a movable piston and a valve port, means for closing said valve port comprising a valve port closing member, a

valve stem disposed in alignment therewith and movable relative thereto, a resilient member interconnecting said member and a stationary seat, and means adapted to guideany movement of said member in,` alignment with` said Valve port.

14. In combination, a cylinder, a movable piston and a valve port, means for closing said valve port comprising a metallic disc having a depressed central portion, a valve stem having an end portion projecting into said depressed portion of said disc and movable with respect thereto, and a. coiled compression spring surrounding said end portion and resiliently urging said valve stem and said disc apart.

l5. In combination, a cylinder, a movable piston and a valve port, means for closing said valve port comprising a valve port closing member, a valve stem disposed in alignment therewithA and movable relative thereto,resilient means tending to move said valve stem away from said valve port closing member, a resilient member adapted to cushion the opening movement of the valve port closing member, and means for positively mechanically seating said valve port closing member in said Valve port during a predetermined portion of the movement of said piston.

16. In combination, a cylinder, a movable piston and a valve port, means for closing said valve port comprising a valve port closing member, a valve stem disposed in alignment therewith and movable relative thereto, a coiled spring interposed between said valve port closing member `and an adjacent portion of said valve stem, a coiled spring interposed between the opposite end of said valve stem and a stationary spring seat, and a mechanically actuated rocker arm adapted to move said stem positively towards said valve port closing member.

ALLEN C. STALEY.

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