Патент USA US2406202код для вставки
Patented Aug. 20, 1946 i 2,406,202 UNITED STATES PATENT> OFFICE j f y K ` AIR Y COMPRESSOR 2,406,262 ` Phil-ip L. Crittenden, Edgewood, Pa., assìgnor to4 The Westinghouse Air Brake Company, Wil merding, Pa., a corporation of Pennsylvania Application December 28, 1943, Serial No. A515,92€) 1o claims. This invention relates to fiuid compressors and more particularly to: the reciprocating piston type. ` l y 4(o1. 23o-184) ` ' Y \ 2v e - y , - g c. bottom surface of thehead IIJ', the Wall of the cylinder 4 and the top surface of the piston. 5. In a similar manner a, ñuid compressing-cham In compressors of the conventional type,v it has ber I2 isv definedV at the left hand endv of the cas been found necessary _to have a. certain amount ing by another portion of the bottom surface of dead space for clearance between the piston of the head I0, the wall of the cylinder 'If and and the cylinder head and in the valve chambers. the top surface of the piston 8. This space retains a quantity of fluid at a pressure Formed in the bottom face of the cylinder substantially above-they fluid pressure of a storage head I IJ and located between the two portions> just reservoir or receiver, whichV iiuid must expand 10 mentioned is a recess I 3 which communicates with during the intakestroke until the pressure in the Y the compressing chamber II'by way of a valve cylinder is substantially below atmospheric pres controlled passage I4Í in the head and with the sure before the inlet valve will open to supply compressing chamber I2 by way of a Valve con ñuid to» the cylinder for the. inlet stroke. This trolled passage I5V in the head. This recess is cond-ition results' in lowered volumetric eiiiciency open at theV bottom toA a vertical bore IB formed because of the unproductive piston movement in the wall between the cylinders 4 and ‘I’ of the and thediminished quantity of fluid delivered by casing I. ‘ the compressor to the receiver. Slidably mounted in the bore I 6 is a piston valve It is an object of this invention, therefore, to provide an improved compressor of the recipro 20 member I'I, the> upper end` of which is provided with a frusto-conically shaped valve I8. This cating piston type so designed that thev inlet valve is arranged to engage a corresponding valve and discharge valves will be positioned promptly seat I9 which defines a portion of the recess I3` for the intake movement of each piston and and to thereby close communication between pas thereby to increase the volumetric efficiency of sages I4 and I 5.> Interposed between and oper the compressor. 25 atively engaging the bottom of the» bore I6 and Another object is to provide a "compressor hav the lower end of the valve member I"I is a» helical ing a plurality of fluid compressing cylinders in spring 2Q which constantly exerts an upwardlyl which one cylinder will be supercharged with a certain amount of iiuid under pressure from an other cylinder before the beginning ofv the intake stroke of the piston in the first' mentioned cylin der. ' . ‘ In the accompanying drawing the single' figure isa vertical sectional view of a fluid compressor directed force on the valve member. - ~ Thel lower end of the valve member I'I is pro vided with an actuating stem 2| which is slid ably carried in a vertical> bore 22 in the casing I and extends through bore 23 in the crankcase 2 into> the crankcase chamber 24. Securedto the ` lower’end of the stem 2| by a nut 25 is a cross' constructed in accordance with this invention. 35 member 26 which projects into the paths of travel As shown in the drawing, the compressor may of both pistons so as to be engaged> and moved comprise a casing, designated by the numeral I„ downwardly by either piston against the oppas# having secured to the bottom surface thereof in ' ing pressure of spring 2U. a suitable manner a crankcase 2 in which there Atthe extreme right-hand end of the cylinder' is rotatably mounted the usual driven crankshaftv head I0 there is formed a discharge chamber 2`I3. The right-hand end of the casing I, as illus which extends vertically through the' head andy trated, is provided with a cylinder 4 in which a is in constant open communication with a ñuid piston 5 is slidably mounted toy be reciprocated by discharge pipe 28. Y This chamber is closed at the thecrankshaft 3-through the medium of the con necting rod 6. The left-hand end of the casing i) top by a hollow nut member 29 which has screw threaded engagement withr the cylinder head I-U. I is provided with, a cylinder 1 in which a- pistony The nut member is providedA with a vertically cy 8 issimilarly mounted and reciprocated likewise lindrical sleeve portion 3U which extends intol through the medium of a connecting rod' 9. Y the chamber 21 andv which servesl as a guide l Secured to the top` surface of the casing I byA and a stop for the discharge valve 3 I .v ‘I'his valve; bolts or other suitable means is a cylinder head preferably of the tapered poppet type is operably I0- which provides valve controlled inlet and dis mounted in vthe chamber 21. and controls com» charge passages for the iîiuidr compressed in a munication between compressing cl‘iamber> I land manner hereinafter more fully described.V A fluid chamber 21. compressing chamber I I is thus defined at'thev right hand end' of the casingby a portion of the 55 Projecting fromV the upper surface ofthe 'valve SI is a vertical guide stem 32 which is slid 2,406,202 unseated position fluid under pressure may flow from compressing chamber I2 to compressing chamber II by way of passage I5, recess I3 andY passage I4 for reasons which will hereinafterV ably guided in the sleeve portion 30 of the nut member 21. VInterposed between and operatively ' engaging the nut member 21 and the back sur face of the valve 3I is a helical spring 3‘3 which, With the piston positioned ' more fully appear. when the piston 5 substantially completes its as just described the inlet and discharge valves will be in their seating positions as shown. upwardrstroke, urges the valve downward into Y sealing engagement with an annular tapered seat _HUpon rotation of the crankshaft 3„,c0nnect 34 formed in the bottom of thel chamber 21'as> ing".v rod'B and' thereby ¿piston 5 will'. be moved illustrat‘ed,` to interrupt the flow of fluid under upwardly. In response tothe upward travel of 10 pressure'from the compressing chamber II. Vthe piston the compressed spring 20 will act to To the left of the chamber 21 there is formed ’ move the valve member I1 upwardly until valve I8 again engages valve seat I9 and closes com- l ingthe cylinder head I0 an inlet chamber 35` which is in constant communication with a fluid inlet passage 36 which is in open communication . munication between chambers II and I2. It is preferred that the piston movement re with an inlet pipe 31. This chamberl is closed 15. quired to permit the valve memberV I1 to -seat be at the top by a nut member '38 which has screwe ‘ relatively small so 'that there will be little reverse threaded engagement Iwith the headv I6. The 'fluid flow after'the pressures of fluid Vin the communication between the bottom of the cham- , , two rcompressing chambers have equalized. ber 35 and the compressing chamber lIl may bev The piston 5 as it moves upwardly compresses closed,vas illustrated,"by a valve 39, preferably therfluid in the chamber II until the Yupwardly of the poppet type, which is arranged to seat on directed'force exertedïfbythe fluid V0n the dis* a. valve seat> 48 formed »in thelower side of the charge 'valve 3l un'seats> the VvalveÍaga'inst the combined downwardly directedrforce exertedwb'y 'vr-Above the valve 39Ãthe ` head _ I 0 is provided with the spring 33 and the fluid Vpressure vwhich may fa; wall: 4I which defines the bottom ofthe cham 25 be in the discharge pipe 28. With valve'3I'un herr-.35 andwhich’is provided with an' upwardly fluid will flow from chamber II into dis extending Vsleeve portion 4Ia `in which »there is Y seated, charge-chamber 21and thence into discharge ' slidably mounted the guide vste'm’42 of the lvalve pipe 28 anda suitable fluid receiver, notV shown. under pressure will continue to flow in this ,The stem 42 »is preferably formed integrally 30 Fluid manner until the piston-5 nearly'reachesrtheend with the valve 39 and is iluted to permit the pas of its upward stroke when,V with the ñuid pres sage of fluid through the sleeve portion 14|. sures in the discharge pipe 28Íand the chamber Pinned to the upper end of the stem is a spring 5 substantially'equal, the force of the s'pring33- Y seatY 43, Vupon- which an upwardly directed force will prevail and the valve 3I"'Wil1 again be seated. Y Y 35 is exertedby `a spring 44 interposed> between the At the same time 4aspiston 5 is making its up- Y spring seat and the upper surface of the wall 4Ia', ward stroke, piston 8-will be'making its down 'thereby urging the' valve 39 into sealing engage ward stroke. At the startY of the stroke the inlet ment with the Valve seat 4I). and discharge valves are positioned as shown in -'Attention‘ is here directed to the fact that the members employed for imparting resiliencyv to 40 the accompanying drawing. After a slight down' ward movement ofthe piston, pressure> of fluid the movement of the valves are disposed in the in chamber l2 will be'sufñciently below atmos cylinder head and not Vin the compressing cham phere to allow the pressure of fluid inthe inlet ber, thereby keeping rthe necessary clearance chamber 35’ to move valve 39’ against the 'pres space between the piston and the head at a min sure of‘spring 44’ and away from the valve seat,Y imum and thereby'adding to the volumetric efñ 49'. Fluid will flow' through inlet vpipe 31 and ciencyîofthe compressor. ' Í ' È' passage 36 to inlet chamber 35’ and thence past ¿At the left-hand .end of the compressor, the the valve-seat ‘49’ to compressing chamber I2. >head'IILí 39. , Y Y, Y head I_ß is provided with an‘inlet and discharge valve construction for cooperating with cylinder The pressure" of ' inñowfing fluid will- hold valve 39' unseat‘eduntil the piston Y8 nears the end of 1 similar‘to that described above for cylinder 4. 50 its downwardV movement. ` As the' piston'nears At the extreme left-hand end of the cylinder the end of its stroke'the --valve W'ill `aga'inwbe . head I0, forV controlling the ñow of fluid to and seated by spring 44’. from the .compression chamber I2, thereis pro . ‘Shortly after the inlet valve is seated, thevbot-- ~ vided a; discharge valve mechanism and an inlet tom yof the piston 8 will engage the cross-member valve'mechanism, each of which Yis identicalwith 26 andv move it downward which will likewise thercorresponding mechanism mounted in the move'the ¿valve member Vl1 downward thereby right-hand end of theA cylinder head. In view of the similarity; the >several parts of thesemech moving the valve I8 away from valve seat I9. ' The discharge valve 3I will also- have been anisms will be indicated by the same reference numerals a's applied tothe mechanisms atthe 60 right handend of the casing with the exception that the prime sign is added. ' , 1 kIn operation, when the crank shaft 3 is lturned by any suitable source of power, pistons 5 and 8 will be actuated by the connecting rods 6 and 9, respectively. Each piston completes an inletïand a discharge stroke for each revolution of the crankshaft. . ` y '.In» the accompanying drawing, piston 6 is shown in its upper'dead center position and piston 5 is shown in its lower dead center position. ‘TheA piston 5 in this position acts through the medium seated before the piston 8 engages the cross-.Í member 26. Fluid under pressure will now flow from compressing chamber IIV to compressing chamber I2 by way of passage I4, recess I3,l and passage I5. ' ' , " The piston 8 will now be at bottom dead center while the piston 5‘will beat top dead center. f'ïr‘lgleV ` Y valves will be in the position as illustrated@`>> ~ ; The same operation will follow as previously described except that the function performed by piston 5 will now bel performed4 _bypiston 8 andviceversa» ' ' 1 ' At the completion of each compression v_stroke or inlet stroke, valve member'. l1. will operate to of the memberl26 and stem 2| of the valve mem open communication between the two compresse. ber to hold valve I8 out of engagement with valve ' seat'ßI9. Upon movement of the valve I8 to its 75 ing chambers. /Thu'sthe pressure of Yfluid ina. 5 2,408,202 compression chamber is reduced before the begin ning of an inlet stroke of its piston and is in creased before the beginning of a compression stroke. Having now described my invention, what I claim as new and desire to secure by Letters Pat ent is: therein while ñuid is being compressed in another chamber and comprising two fluid compressing chambers and two pistons for reciprocating in the respective chambers, in combination, means for supercharging each of said chambers with iiuid under pressure, the supercharging means comprising means rendering the supercharging l. In a íluid compressor of the type comprising means ineffective until either piston is substan two pistons and means connected to said pistons tially at the end of its inlet stroke and operative for actuating íirst one and then the other to 10 by the piston as it approaches the end of its compress fluid, in combination, a communica inlet stroke to render said supercharging means tion for permitting fluid to flow between the eifective. pressure sides of said pistons, a valve for open 7. A iluid compressor of the type arranged to ing and closing said communication, means for draw fluid into one chamber for compression effecting the operation of said valve to open said 15 while fluid is being compressed in another cham communication as an incident to either piston ber and comprising two pistons for reciprocating reaching substantially the end of its inlet stroke, in the respective chambers, in combination, means and means for effecting the operation of the for preloading the pressure side of a piston, com valve to close said communication at all other pleting its inlet stroke, with fluid under pressure times. 20 from the pressure side of a, piston completing its 2. In a fluid compressor of the type compris compression stroke, and means actuable by either ing two pistons and means connected to said piston at substantially the end of its inlet stroke pistons for actuating ñrst one and then the other to render said preloading means operative, and to compress fluid, in combination, a communi means separate from said piston for actuating cation for permitting fluid to flow between the 25 the second mentioned means to render the pre pressure sides of said pistons, a valve for open loading means ineifective. ing and closing said communication, resilient 8. A fluid compressor of the type arranged to means for actuating said valve to close said com draw ñuid into one chamber for compression munication, and means operative by either of said while fluid is being compressed in another cham pistons at substantially the end of its inlet stroke 30 ber and comprising two pistons for reciprocating to actuate said valve to open said communica in the respective chambers, in combination, means tion. for preloading the pressure side of a piston, com 3. In a ñuid compressor of the `type compris pleting its inlet stroke, with fluid under pres ing two pistons, and means connected to said pis sure from the pressure side of a piston complet tons and operable to actuate first one and then 35 ing its compression stroke, and means condition the other to compress fluid, in combination, a able upon the movement of either piston to sub communication connecting the pressure sides of stantially the end of its stroke for rendering said the two pistons, valve means controlling said preloading means operative. communication, and means conditionable upon 9. A ñuid compressor of the type arranged to the movement of either piston to substantially draw iluid into a chamber for compression vthere the end of its inlet stroke to actuate said valve in while fluid is being compressed in another means to open said communication, and means chamber and comprising two fluid compressing operative to actuate said valve means to close said chambers and two reciprocating pistons for com communication at all other times. pressing ñuid in said chambers, in combination, 4. A fluid compressor comprising two pistons, means for venting fluid under pressure from one means connected to said pistons to actuate first chamber, valve means operative to start and stop one and then the other of said pistons to com said venting action, means conditionable upon press fluid, a communication connecting the the movement of either piston to substantially chambers on the pressure sides of the two pis the end of its inlet stroke to actuate said Valve tons, valve means controlling said communica 50 means to start said venting action, and means tion, means for actuating said valve means to operative to actuate said valve means to sus close said communication, and means operative pend said venting action at all other times. by each piston at substantially the end of its 10. In a fluid compressor of the type compris inlet stroke to actuate said valve means to open ing two pistons and actuating means connected said communication. 55 to said pistons for compressing fluid with first 5. A ñuid compressor comprising two pistons, one piston and then the other, in combination, a means connected to said pistons to actuate first . passage in open communication with the pres one and then the other of said pistons to com sure side of` one of said pistons, a passage in press fluid, a communication connecting the open communication with the pressure side of chambers on the pressure sides of the two pis the other of said pistons a communication for tons, valve means controlling said communica permitting fluid to flow from one of said pas tion, means conditionable upon movement of sages to the other, valve means for controlling either piston to substantially the end of its in said communication, resilient means actuating let stroke to actuate said valve means to open said valve means to close said communication, said communication, and means operative to ac and means operable by either of said pistons at tuate said valve means to close said communi 65 substantially the end of its inlet stroke to cause cation at all other times. said valve means to open said communication. 6. A ñuid compressor of the type arranged to draw ñuid into one chamber for compression PHILIP L. CRI'I'TE-NDEN.