US1998264A - Compressor - Google Patents

Description

April 16, 1935. B. s. AIKMAN 1,998,264

COMPRESSOR Filed July 50, 1932 Fipl. 6 O 45 a H 46 INVENTOR BURTON S.AIKMAN A TTORNEY Patented Apr. 16, 1935 PATENT "OFFICE g V ooMrREsson l Burton S. Aikman, Milwaukee, Wisg assignor to The Westinghouse Air Brake Company, Wilmerding, Pa a corporation of Pennsylvania; Y 7 Application July30, 1932 SerialjNo. 6263501 14 mains; ci."230 z12)' This invention relates to fluid compressors and particularly to fluid compressors of the recipro cating piston type. v An object or" the invention is to provide'a fluid compressor of the reciprocating piston type wherein a single piston is utilized to'co'mpress fluid in two' stages during each cycle of operation or during a single revolutionof the crankshaft driving the piston. y I

A further objectof the invention is toprovide a compact twostage compressor which 'requires practically no more space or parts than is required for asingle stage compressor.

A further object of the invention is to provide a fluid compressor having theabove noted characteristics wherein provision is made for precooling the fluid entering the compressor and for adequately cooling the compressed fluid. during the progress of compression, thereby increasin the eificiencyof thefapparatus. These and other objects of. the invention tha will be made apparent throughout the further description thereof are attained bymeans of the fluid compressor hereinafter described and illustrated in the accompanying drawing; wherein,

.Fig. t is a vertical sectional view of a fluid compressor embodying features of the invention; and w i Fig. 2is'a transverse sectional view or the apparatus shown in Fig. 1, taken on the line 2I2 thereof. 7 l. H l Referring to the drawing; the compressor come prises a crank case section 3; a guidecylinder sec-c tion mounted thereon, a compressor cylinder section 5 mountedupon the guide-cylinder section, a head section 6 mounted on the compres-' sion cylinder section and an intake section '1' secured to the head section. 7

The crank case section 3 comprises a casing I 5;

part of which is shown, and which contains a crank chamber-J2.

V The casing also comprises an annular chamber i 3 for containing a, cooling fluid such as water which supplied to, the chamber in a manner to be hereinafter described.- The l chamber 5 3 surrounds a circular opening Milli the case through which the piston rod l5 projects and into which the lower end of a guide cylinder itextends; the guide'cylinder constitut ing an integral partof the casing H f-the guide cylinder section 4, which is secured to-theupper attaching face 53 of the casing H. p The guide cylinder casing I? is provided with a valve chamber 59 containing'an outlet'jcheck valve device 2! of the disc type, which comprises a seat disc 22 thatis inserted in an opening-23 in,

the valve disc 48 and the flange 5| of a retaining the casing l1 and which is retained 'inas'semled 7 position we vretainingcage z l, threaded in an opening 25 in the casing l1 an'd which is aligned with an opening Win the outer wall of the casing |1 -through which the cage maybe inserted. The 5 opening 20 is closed by a plate26 that may be secured to the casing ill bymeansof screws, not shown; I

yThe seat disc 2l2is' provided withfa series'of I ports 21 disposedin a circIe and which are adapted to be closed by a valve disc 28 thatis yieldingly held, in seated position by' ineansf-ofg'a spring129 that is disposedbetween'the valve disc 28 and the flange 3! of a retaining wa'sher 32 that is at tached'to'the'seat disc 22 by-means of a bolt 33. 15

Thevalve chamber l9 communicates withia discharge or outlet passage 34 thatis adapted to jbec'onnected to a" reservoir, not shown, for re:

'ceivingthe compressed fluid. The parts 21in the seat disc; 22 establish communication between the valveichamber. l9 and" a passage- 35, the purposeof'which will hereinafter appear. v

The compression cylinder-section 5 compr' es a casing 36 containing acylindrical bore 31 that is oflgreater diameter than the diameter of'the guide cylinder l6 and isadapted toreceive an enlarged head 38 of a piston 39'having a reduced cylindrical portion engaging the guidewall oi.

the guide cylinder l6, and which is pivotally con- 7 nected to the piston rod l5 by means-of awrist 0 pin. 7 V The head section. 6 comprises a casing 4| which serves. toclose 'the end'fof the cylindrical bore 3'! and which is provided with-avalv'e chamber 30 containing an inlet disc valvedevice 42, which comprises a seat disc 43 mounted within an openingddinrthe casing 45 andwhich is retained in operative position by means of a cage45 that is threaded into an opening 45 in the outer wall of the casing 4|. The seatvdisc 431s provided 40 with 'aseries of ports that are adapted to be closed by means'ofa valve disc 48 thatis yieldinglyheld in engagement'with the seat disc43 by means of a spring 49 that is disposed between washer 52, that issecured to the seat disc 43 by means of a bolt 53; The valve chamber 30 communicates with an inlet passage 54, communicating withthe inletpassage 55in the inlet section 'l. The passage 55 may beconnected to a conduit, I 1

not-shown, through which air at atmospheric pressure is'supplied to the compressor. Thecports 47 establish-communication between the valve chamber 39 and the bore 31 of thecompression cylinder section 5. l r 7 The enlarged head 38 of the piston 39 serves to divide the bore v3'1 into a compression chamber 56 on the upper side of the piston head and an annular compression chamber 51 on the under side of the piston head 38, the maximum volumetric capacity of which is considerably smaller than the maximum volumetric capacity of the compression chamber 56. The volumetric capacity of the chamber 5'! is maximum when the piston 39 is in its uppermost position and the volumetric capacity of the chamber 55 is maximum when the piston 39 is in its lowermost posi' tion as shown in Fig. l. I

The passage 35 opens into the annular co pression chamber 5? as indicated in Fig. l, and

the head 38 of the piston is provided with a ring type check valve device 58 which comprises a split piston ring 58 that is disposed within an ansealing faces 52 and 53 of the groove 6| as the piston is moved downwardly and upwardly. A series of perforations 64 establish communication between the groove 5! and the compression chamber Slat the lower side of the piston head 38.,

The operating cycle of a two stage compression operation of the compressor is as follows. Assuming the, piston 38 to be in the uppermost position, the initial downward movement of the piston moves the sealing seat E2 of the groove 5| into sealing engagement with the valve ring 59. Further downward movement of the piston creates suction within the chamber 56 andcauses air at atmospheric pressure to be drawn into the compression chamber 56 on the upperside of the piston. During the downward movement of the piston, the compressed fluid within the annular compression chamber 5'! at the under side of the piston head 38, which has been previously forced into the chamber 51in a manner to be hereinafter described, is compressed within the chamber 51 until the pressure therein overcomes the tension of the spring 29 of the discharge check valve device 2| and the pressure'within the valve chamber l9 and forces the valve disc 28 to open position. With the valve disc 28 open, fluid under pressure within the compression chamber 51 flows into the valve chamber 119 and thence to; the reservoir, not shown, through the passage 34.

Upon completion of the downward stroke of the piston 39, the spring 48 ofthe intake check valve device 42 forces-the valve disc 48 into closed position and prevents a reflux of the fluid drawn into the chamber 55 through the ports 'l'pf the check valve device 52. Upon the upward stroke of the piston 38, the sealing seat 62 of the piston groove 6! is moved away from the valve ring 59 which is frictionally retained at rest against the cylinder wall during the initial movement'of the piston, thereby opening communicationirom the compression chamber 56 to the compression chamber 5'! through the ports B4 in the piston head '38. Accordingly, as the piston is moved upward the fluid'within the compression chamber 55 is forced into the relatively smaller compression chamber 5'! through the ports 54, thereby increasing the pressure of the fluid within the chamber'5lih accordance .with the difierence in maximum volumetric capacity of the two chambers, it being understood that the maximum volumetric'c'apacity of the chamber 51 is considerably less than the maximum volumetric capacity of the chamber 56.

As before stated, upon the down stroke of the piston, when the pressure of the fluid Within the chamber 51 exceeds thatof the pressure within the valve chamber l9 and the reservoir associated therewith sufliciently to overcome the tension of the spring 29, the compressed fluid is forced into the valve chamber l9 and into the reservoir, not shown. Upon termination of the down stroke, the valve disc 28 is closed by the spring 29 and upon the succeeding up stroke of the piston, the fluid drawn into the chamber 56 during the down stroke of the piston will be forced into the annular compression chamber 5'! and the compression operation is then repeated in the manner above described.

It will be apparent from the foregoing that a compressor having a single piston is so constructed that fluid is compressed in two stages by the single piston during a single cycle of operation of the piston and consequently the compressor may be of relatively compact construction.

Theefiiciency of the compressor is further enhanced by reason of an improved means for extracting the heat from the compressed fluid during the compression operation, which means comprises a system of conduits and chambers through which cooling fluid such as water is advantageously circulated for obtaining maximum cooling results. The conduit systemior the cooling fluid includes passages 65 and 68 within the casing H of the cylinder section 4, which register respectively with passages El and 58 leading from the chamber [3 disposed within the upper wall 69 of the casing I [of the crank case section 3. The

casing 11 is also provided with two arcuate cham-- bers H on opposite sides of the guide cylinder and which communicate with the chamber [3 through-openings 72 which extend through the flange 13 of the casing l'l and'are aligned with openings 14 in the wall of the casing as indicated in Figs. 1 and 2.

The compression cylinder casing of the compression cylinder sectioni is provided with a chamber, 15 that extends partially around the bore 31 and which communicates with the cham- 1 here H in the casing I! through aligned passages 16 in the lower wall of the chamber 15 and the upper wall of the chambers H. The casing 35 is also provided with a passage H which registers with the passage 65 in the casing 11.

. The headcasing 4| of the head section it is provided with an annular chamber 18 that is disposed over the end of the chamber 53 as indicated in Fig. l and communicates with the charm ber 15'through passages 19 in the inner wall of J.

the casing 4| and the upper wall of the chamber T5. The head casing 41 is-also provided with a passage 8! which registers with the passage '5? in the casing 36 and with a passage 82 opening into a chamber 83 in the casing of the inlet section 1 which'surrounds a portion of the passage as indicated in Fig. l.

The passage 66 in the casing l? opens into a chamber 84 which surrounds the valve chamber 7 I9. The chamber 84 opens into an outlet passage air entering the compressor through the passage 55. The cooling fluid then flows through passage BI, tothe passages 17 and B5 in the casings 31 and H respectively, and thence :into the annular chamber l3 in the casing, l'l, where-the cooling fluid serves to cool'a portion of-the-crank caseand maintain the lubricant in the crank case .at a

- proper operating temperature; 7

Cooling fluid flows from the chamber 13 into the chambers 1| through the openings 12 and thence flows through openings 16 into the chamber surrounding the cylinder bore S'L-of the casing 35. Fluid compressed by thepiston inv the compression chambers and 51 is thus cooled during the act of compression by reason of the,

through the pipe til-before it is again returned to the compresso'rthrough the pipe 89, or the compressor maybe supplied with cooling fluid from-a water supply system, not shown, in which case the cooling fluid passing through the pipe 88 is dischargedto a drain; 7 I g From the foregoing it is apparent that a compact and highly efficientcomp'ressor is provided wherein the fluid is compressed in two stages by asingle piston and wherein the air is pre cooled before entering the compression chamber of the compressor and'cooled during the compression 'ope'rationfsince thewalls of the piston guide cylinder are, cooled, the temperature of the piston is maintained relatively low and tends to further cool the fluid both in the first and second stages of compression. Since the'temperature or-me crank case chamber 12 is maintained relatively low due to the large bodyof cooling fluid circulated through the chamber 13 in the upper part of the casing I I, the interior of thepiston is not subjected to relatively hot gases as would be the case where'no provision is made. for'cooling the lubricant within the crank case chamber.

While 'but one embodiment of the invention is disclosed herein andshowing a single piston two stage compressor, it isobvious thatamultiple piston compressor having more stages of compression may be embodied in a single compressor unit and that many changes, additions and omissions may be made to the compressor construction dis"- closed without departing from the spirit of the invention. a 'Having now described my invention, what'I claim as new and desire to'secure by Letters Patent, is: 7

l. The combination with a compressor having a chamber a movable abutment dividing said chamber into, compression chambers on opposite sides respectivelyof said abutment having unequalmaximum volumetric capacities and connected by a communication between the chamber'wall and the abutment through which fluid compressed by said abutment movingto reduce the volumetric capacity of the compression cham--.' her having the larger maximum volumetric capacity is forced tothe chamber having the lesser maximum volumetric capacity, ofra ring type check valvecooperatingwith said abutment and Cooling fluid flows from the chamber said chamber ,wall for controlling said communication and for preventing av reflux of the fluid flowingihrough said communication.

2. The, c,ombination with a compressor having a chambenja movable abutment dividing said chamber into compression chambers on opposite sides respectively of saidabutment having unequal maximum volumetric, capacities and cone nected by a'communication' through which fluid compressed by said abutment'moving in one directionto reduce the volumetric capacity of the compression chamber having the larger maximum-volumetric capacity is forced to the cham I ber'having the lesser maximum volumetric capac ity, of a valve-means cooperating with a Wall of said chamber land's-aid; abutment I for controlling said-communication operative upon movement of said piston in the opposite; direction for preventing a reflux of the fluid flowing through said communication, an intake check valve for controlling the ingress of fluid to said compression chamber'having the larger maximum volumetric capacity and an outletcheck valve for controlling the egress of, fluid fromsaidccmpression chamber having'the lesser volumetriccapacity; f

3. The-combinati'on with a compressor having a chamber,, a movable abutment "dividing said chamber into compression chambers on'opposite sides respectively of saidabutment having unequal maximum volumetric capacitieswhichcapacities are varied upon movement of the'abutment in one direction so that as the capacity of one compression chamber is reduced, the capacity of the other compression chamber is increased, saidfcompression chambers being connected bya communication through which fluid compressed by Isaidabutment moving toreduce the volumetric capacity of the compressionchamber: having the larger maximum volumetricicapacity is forced into ,thexchamber having the lesser maximum volumetric capacity,o-f a valve imeans cooperat ring with a wall ,of said chamber and said abut ment for controlling said communication opera tive upon movement of said piston in the. oppositedirection forpreventing a reflux of the fluid flowing'through said communication a i 4'. The combination with a compressor having I a chamber, a movable abutment dividing said chamber into compression chambers on opposite sides respectively of said abutment havingunequalmaximum volumetric capacities, which ca pacities arellvaried upon movement of the abutment in one direction so that as the capacity of onev compression chamber'is reduced, the capacity of the other compression chamber is increased, said compressionchambers beingcon nected by a communication through which fluid compressed by said abutmentmoving to reduce the volumetric capacity of the compression chamher having .thelarger maximum volumetric capacity is .forcedinto the chamber having the lessor maximum volumetric capacity, of a valve means ecooperating with a wall of-sa-id chamber andsaid abutment for controlling saidccmmuni cation operative upon movement of said piston in the opposite direction for'preventing a reflux of the fluid flowing through said'communication, anintakecheck valve for wcontrollingthe ingress of fluid to said compressionchamber having the larger maximum volumetric capacity and an out-. let check valve for controlling the egress of fluid fromsaid compressionchamber having the lesser volumetric capacity.

5. The) combination with acompressor having a Piston; cylinder, a piston working within said cylinder and .dividing it into chambers on opposite sides respectively of said piston, having unequal maximum volumetric capacity and connected by a communication through which fluid compressed by said piston moving in one direction in the chamber having the larger maximum volumetric capacity is forced to the chamber having the lesser maximum volumetric capacity, of a valve means cooperating with a wall of said cylinder and said piston for controlling said communication and operative upon movement of said piston in the opposite direction for preventing a reflux of the fluid flowing through said communication.

6. The combination with a compressor having a piston cylinder, a piston working within said cylinder and dividing it into chambers on opposite sides r spectively of said piston, having unequal maximum volumetric capacity and connected by a communication between the cylinder wall of said cylinder and said piston through which fluid compressed by said piston moving in one direction in the chamber having the larger maximum volumetric capacity is forced to the chamber having the lesser maximum volumetric capacity, of a valve means cooperating with a wall of said cylinder and said piston for controlling said communication and operative upon movemerit of said piston in the opposite direction for preventing a reflux of the fluidflowing through said communication. 7 r I 7. The combination with a compressor having a piston cylinder, a piston working within said cylinder and dividing it into chambers on opposite sides respectively'of said piston, having unequal maximum volumetric capacity and connected by a communication between the cylinder wall and the piston, the chamber having the larger maximum" volumetric capacity having an inlet passageand the other chamber having an outlet passage, of an intake valve for controlling the flow of fluid through the inlet passage and preventing the flow of fluid from the: associated chamber through said passage, an outletvalve for controlling the flow of fluid through the outletpassage and permitting the flow of fluid therethrough from its associated chamber, and a ring type check valve cooperating with said cylinder wall and said piston for permitting the flow of fluid through said communication between said chambers only from the chamber having the inlet passage to-the chamber having the outlet passage.

8. The combination with a compressor having a piston cylinder, a pistonworking within said cylinder and dividing it into a'flrst stage compression chamber on one side of said piston and having an inlet port and a second stage compression chamber on the other side of said piston and having an outlet port, of an inlet check valve controlling the inlet port, an outlet check valve controlling the outlet port, the said piston having a passage through which fluid in the first stage compression chamber may flow to the second stage compression chamber, and a ring type check valve for controlling said passage in the piston for permitting fluid under pressure to flow from the first stage compression chamber to the second stage compression chamber and operative upon movement of the piston in one direction for preventing fluid under "pressure from flowing from the second stage compression chamber to the first stage compression chamber. g

9. A fluid compressor'comprising a casing hav ing a crank chamber, a guide cylinder, a comp-ression cylinder and a cylinder head, and a jacket covering walls of each of said element's-and divided into separate chambers, one adjacent each element and connected for providing a conduit through-which cooling fluidmay be forced for progressively contacting with the casing for said elementsin the order defined. Y

10. A fluid compressor comprising a casing having a fluid intake passage, a compression cylinder, a guide cylinder, a crank chamber and an outlet passage, and a jacket covering walls of 'each of said elements and passages and divided into separate chambers, one adjacent each element and connected for providing a conduit through which coolingfluid maybe forced for progressively contacting with the casing for said elements and passages in the order defined.

A fluid compressor comprising .a sectional casing having a crank chamber, a guide cylinder, a compression cylinder and a cylinder head, each of said elements having an integral jacket for providing a conduit, the said sections being connected together to constitute a compressor casing and with their respective conduits in registry whereby a continuous conduit is formed through which cooling fluidmay be forced for progressively contacting with the casing sections of said elements.

12. A compressor comprising a sectional casing having a compression chamber section, a head section cooperating with one end of said. chamber section, a crank case section; and a compressor piston guide section interposed in cooperating relation between the opposite end of said chamber section and said crankcase section, the walls of said casingsectionshaving passageways therein respectively cooperating to direct the flow of cooling fluid in succession through said chamber "section, said guide section, said crank case section, said guide section, said chamber section, and said head section.

l3. A compressor comprising a sectional casing having a compression chamber section, a head section cooperating with one end of said chamber section, an intake passage section" cooperating with said head section, a crank case section, and a compressor piston'guide sectioninterposed in cooperating relation between the opposite end of said chamber section and said crank case section, the walls of said casing sections having passageways therein respectively cooperating to direct the flow of cooling fluid in succession through said intake section, said head section, said chamber section, said guide section, said crank case section, said guidesection, said chamber section, and said head section.

14. .A compressor comprising a sectional casing having a section containing a compression chamber adapted to have a compressor piston operate therein, a head-section cooperating with one end of the chamber section for closing the compression chamber and having an intake valve mechanism therein, a crank case section, and a section for guiding the compressor piston, said guiding section being interposed in cooperating relation between the opposite end of said chamber section and said crankcase section and having a discharge valve mechanism therein, said casing sections having passageways therein respectively cooperating to direct the flow of cooling fluid in succession through said chamber section, said guiding section, said crank case section, said guiding section and said head section past said intake Valve mechanism, and also to direct the flow of cooling fluid from said crank case section through said guide section past the said discharge valve mechanism.

. BURTON S. AIKMAN.

Images