IMPROVEMENTS IN COMPRESSORS WITH SKEWED DISC ROTOR

Description

TITLE INV. DES. PRIORITY CEM8RE 1978 GENERAL MOTORS CORPORATION IN DETROIT MICHIGAN USA IMPROVEMENTS IN COMPRESSORS WITH SKEWED DISC ROTOR BYRON LESTER BRUCKEN AND FRANK WILLIAM HODITS / JR. USA PATENT DOM.N.966067 OF 4 OF ϋ3ι -1 APR Rome, there. there' / Kx 509941 / 79 MINISTRY OF INDISTRIES, COMMERCE AND FRIENDSHIP PROVINCIAL OFFICE OF INDUSTRY, COMMERCE AND CRAFTS - ROME ...... Mod. V 1 MINUTES OF FILING FOR INDUSTRIAL INVENTION PATENT In the year 19...??.... on the day?®®??®®®............. of the month of ..........at .9...................and minutes ..©... toCtoUf........................................................................................ tocto^K tfaAto Stoto Sai àalwara resident .............eatrolt tMlchig»n,VSA............................ Via ................................................... n'..............................' a me2Z0 «nondatatario.................................................................. with domicile of choice........... for legal purposes at................................................. -................ of nationality....................' (fig. C. C ! '> a? ......... 1 < ...... Via................................................................................................................................. n..............................., at . has................................................presented to me, the undersigned: 1. - Application, on a 2000 L. stamp, for a PATENT FOR INDUSTRIAL INVENTION having as TITLE ..........**Mu^a«tonara«to iM»i ceifi^^^aaaorX cxMt ratora * dlaco ineiln*to.................. PBX(>BXrA»«V«>«A«4 9XCCl«ÌHIBl9?6-Bttr.R·...»66*96?.................................... ,,to,vwi^.»,...ey«mi....i«a.tor...mc«i^...* rraat. trills · · «o&xxs» ac* 2. - Description in duplicate of n.......2Λ.............. pages of writing. 3. - Drawings, tables n......2........................... in duplicate. wewùtKieitecfsu». lcttcra 5. - Priority document and Italian translation. 6. > Authorization or Deed of Assignment. (rlxry<) ] / 7. - Declaration of consent of the inventor to be mentioned in the patent. (ÌWg»to) 8. - Proof of payment (on postal account no. 668004, made out to the Registry Office for Government Taxes and Concessions - Rome) of lire ...AA?*???..................................................... issued by the Post Office, day «»*«*€>«......................................... on date..................i / tun 9. - Revenue stamp of L. 2000. n, me. The application, descriptions and drawings listed above have been signed by............................................. applicant and countersigned by me and stamped with the official seal. A copy of these minutes has been signed by me and delivered to the interested party. The Depositor U, Pinta * Rome THE OFFICIAL ROGANTE MINISTRY OF INDUSTRY, COMMERCE AND CRAFTS Τ' ............................................................................................................................................ ............................................................'.............................................' Central Patent Office ROME The undersigned Company: GENERAL MOTORS CORPORATION Presented ftlì-l · (,<· .....verbaie Delaware State Corporation at Grand Boulevard, Detroit, Michigan, USA, National USA INVENTORS: Byron Leater BRUCKEN and Frank William H0DITS,Jr. represented in Italy by ING, BARZANO' & ZANARDO SpA, Technical and Legal Consulting Company, in Rome, Via Piemonte 26. Request a PATENT CERTIFICATE 599(44 / 79 for INDUSTRIAL INVENTION, entitled: Improvements in compressors with rotor and back Inclined The undersigned hereby requests that the priority deriving from the application filed in the USA be recognized, in accordance with the International Convention. DECEMBER 19? Botto No. 966.067 dated LIST OF DOCUMENTS L,..........Letter of appointment........................................... ì. Description in duplicate ì. Drawings (Tables 2 ) in duplicate 4. Money order for the paid tax of 127,500 Lire >. A revenue stamp of 2,000 Lire >. Foreign priority document and Italian translation Authorization (reservation) ' ?*8. ACT OF DESIGNATION OF INVENTOR * «U<99 volume, on 23 NOVEMBER 1979 ϊ. p. GENERAL MOTORS CORPORATION NG. BARZANO' & ZANARDO SpA JLW / TK / 1303 Italy description accompanying a patent application for an invention entitled: Improvements in swashplate rotor compressors on behalf of GENERAL MOTORS CORPORATION Oesca izioi e rnodibcetfi Uri 49 DP R, η. 338 / 1979) stanza. I' 4.2- £*> _ 5o<ìoìì)ì SUMMARY ​A swashplate compressor has a cylinder block defining tubular cylinder bore portions that form, with its outer shell, an upper low-pressure gas inlet channel and a pair of lower low-pressure gas outlet channels. Port means are provided in one of the heads and the associated valve plate to allow direct axial flow communication from the compressor suction inlet to the upper inlet channel for a low-pressure gas-oil mixture. Port means are formed in the compressor heads and their associated valve plates, providing communication from the upper inlet channel to the compressor's low-pressure gas suction chambers through the swashplate space and each of the lower outlet channels. The result - 2 is that lubrication is obtained by the introduction of low pressure gas and oil which enters the upper inlet channel and which flows in heat exchange relation with the upper tubular parts which separate a part of the oil from the gas by deposit on the upper tubular parts for subsequent gravitational flow to the working parts of the compressor. This invention relates to refrigerant compressors and more particularly to an improved compact swash plate compressor for air conditioning applications. In mobile air conditioning systems, there is an increasing need for improved compressors that are smaller and lighter to enable vehicles to achieve higher fuel efficiency. An example of such a compressor currently successfully used in automotive air conditioning systems is illustrated in U.S. Patent No. 3,057,545 to Ransom et al., issued October 10, 1962, and assigned to the assignee of this application. The Ransom et al. inclined-diaphragm compressor, which is referred to as a six-element axial compressor, - 3 because it has three double-acting axial reciprocating pistons, is a reliable and efficient device, and requires a separate oil pump for its lubrication system. Numerous attempts have been made to provide swashplate axial compressors with improved lubrication systems that eliminate the need for an oil pump. An example of such a compressor is illustrated in U.S. Patent 3,930,758, issued by Kwang H. Park on January 6, 1976, also assigned to General Motors Corporation. Accordingly, it is an object of the present invention to provide an improved small swash plate compressor suitable for use in automotive air conditioning systems having a minimum number of parts. Another object of the present invention is to provide an improved compact swash plate compressor having a lubrication system that does not require a separate oil pump. Yet another object of the present invention is to provide an improved open-plane swashplate compressor, i.e., open space between adjacent cylinder tubular portions, which achieves a substantial reduction in weight. - 4 Still another object of the present invention is to provide an improved axial swash plate compressor wherein lubrication is achieved by a refrigerant flow path wherein the total flow of low pressure refrigerant gas from the inlet line, containing a substantial amount of entrained oil, enters an axially disposed upper inlet channel means, so that the refrigerant gas and oil mixture are conveyed into heat exchange relationship with the upper cylinder block raised to gas temperature which causes sufficient separation of oil therefrom and deposition on the upper tubular portions for subsequent gravitational flow to lubricate portions of the compressor, and whereby the total flow of low pressure refrigerant gas is conveyed out of the upper inlet channel for delivery to the central space of the swash plate before being conveyed into lower outlet channels.allowing enough of the remaining oil mixed with the gas to strike and wet the surfaces of the swash plate mechanism to lubricate it during compressor operation. Further purposes and benefits of this t ί - 5 invention will become clear from the following description» by reference to the attached drawings in which a preferred embodiment of the present invention is clearly shown. In the drawings: Figure 1 is a vertical sectional view of the improved swash plate compressor of the present invention; Figure 2 is a vertical sectional view of the compressor taken substantially on line 2-2 of Figure 1 showing the rear face of the cylinder-piston block; Figure 3 is a vertical sectional view of the compressor taken substantially on line 3-3 of Figure 1 showing the notched portions of the rear cylinder block; Figure 4 is a vertical sectional view taken on line 4-4 of Figure 1 showing the rear valve plate and the suction outlet reed valve of the compressor; Figure 5 is a vertical sectional view taken substantially on line 5-5 of Figure 1 showing the interior of the rear head of the compressor; Figure 6 is a vertical sectional view taken substantially on line 6--6 of Figure 1, showing the discharge valve arrangement of the present compressor; and Figure 7 is an end elevational view taken on line 7--7 of Figure 1» showing the rear head of the compressor. Referring now to the drawings in which a preferred embodiment of the present invention has been illustrated, reference numeral 10 in FIG. 1 designates a swash plate axial compressor which is adapted to be driven by suitable actuating means, such as a magnetic clutch assembly (not shown) suitably shown on the neck portion 11. Reference numeral 12 designates an outer shell member which is cylindrical in shape and serves to support a pair of front and rear cylinder heads 14 and 16 respectively which cap opposite ends of shell 12, as shown. A swash plate 18 is fixedly mounted on a compressor drive shaft 20 which is rotatably supported by front 22 and rear 24 journal bearings mounted in front 26 and rear 27 center hub portions integrally formed with the front 28 and rear 30 cylinder blocks respectively. Rotation of the drive shaft 20 is transformed into the reciprocating motion of three double-acting pistons indicated at 31, 32 and 33 in FIG. 2.As seen from the double-acting lower piston 33 in FIG. 1, each of the pistons is arranged to reciprocate in a direction parallel to the axis of the drive shaft as a result of being slidably disposed in front piston cylinder bores 31', 32', 33' and rear piston cylinder bores 31; 32 and 33 of the front cylinder blocks 28 and rear cylinder blocks 30, respectively. The rotation of the drive shaft 20 is transformed into reciprocating motion of the double-acting pistons 31, 32 and 33 through sliding members which in the form illustrated are hemispherical bodies 36. As seen in Figure 1, for the piston 33, each of the pistons has a central portion of its first side cut away so as to rest on either side of the outer edge of the swash plate 18. Cup-shaped recesses 38 are formed on the cut away portions of the pistons with hemispherical sliding bodies 36 supported in the cup-shaped recesses 38 in opposite relation to the flat sides of the bodies which cooperate with the flat surfaces 39 of the swash plate. I ί - 8 intermediate 18. By virtue of the bearing construction shown in Figure 1, piston pumping loads are absorbed both by the front journal or radial needle bearings 22 and rear 24 and in the front needle thrust bearings 40 and rear 42. Individual front valve plates 44 and rear valve plates 46 are mounted between the front heads 14 and rear heads 16 and their associated front cylinder blocks 28 and rear cylinder blocks 30. As seen in FIGS. 1 and 4, the valve plates 44, 46 are formed with intake inlet and exhaust outlet ports 47 and 48, respectively, in registration with each front cylinder 31', 32', 33' and rear cylinder 31, 32, 33. Each valve plate is provided with an intake reed valve 50 on its inner face and exhaust reed valves 52 and 53 (FIG. 6) on its outer face as is well known in the prior art. Back-up valve retainers or stops 54 and 55 are provided for their associated exhaust reed valves 52 and 53, respectively, to prevent excessive deflection thereof.Each intake or outlet port 47 provides communication between its associated pumping cylinder bore and external cylindrical low pressure gas intake chambers in the front head 56 and rear head 58, as seen at 58 in FIG. 5 for the rear head outer intake chamber 16. Each intake or outlet port 48 provides communication between the cylinder bores 1. pumping and the internal high pressure gas exhaust chambers of the front head 60 and the rear head 62, as seen in Figure 5 for the rear head internal chamber 62. It will be noted that O-ring sealing elements 63 in the front and rear valve plates separate the external intake chambers 56, 58 from the internal exhaust chambers 60 and 62, respectively. The front and rear cylinder heads 16 each have intermediate and outer concentric closed annular loops or ribs 64, 65, and 66, respectively, defining the external low pressure intake chambers of the front head 56 and rear head 58, which communicate with their associated three intake gas inlet ports 47. As seen in FIG. 5, the rear head 16 has a circular shaped upper intake gas inlet port or aperture 70, symmetrical with the vertically extending plane defined by the construction line X of FIG. 5. The aperture 70 extends through an integral boss 72, which communicates first with a nearly rectangular shaped aperture 73 defined between the intermediate and outer annular ribs 66 and the vertical connecting partitions 74 and 75 positioned in equidistant parallel relationship on either side of the construction line X. The see plate 46.The rear valve includes an upper opening 76 shaped to align with the nearly rectangular shaped opening 73. Thus, the intake gas to be compressed is admitted through the aligned rear head inlet opening 70, the rear valve plate opening 76 and the opening 73 into an upper low pressure refrigerant gas inlet channel 77. As best seen in FIGS. 1 and 3, the front cylinder blocks 28 and the rear cylinder blocks 30 are positioned for flush-fitting alignment by a pair of alignment or locating pins (not shown) along a transverse partition surface indicated at 80 in FIG. 1. Similar pairs of alignment pins shown at 82 in FIGS. 2 and 4 and 5 properly position the valve plates and compressor heads by insertion into locating bores. Thus, the inlet channel 77 is formed by the upper tubular portions 1-F and 2-F of the front cylinder block 28, the corresponding abutting tubular portions 1-R and 2-R of the rear cylinder block (FIG. 3) terminating, with the outer shell 12, the upper inlet channel for the low pressure refrigerant gas 77.In a similar manner, the front 1-F and rear 1-R pair of upper tubular parts define, with the front 3-P and rear 3-R pair of lower tubular parts and the shell 12, a first lower outlet channel 78 for the low-pressure refrigerant gas. Finally, the front 2-F and rear 2-R pair of upper tubular parts define, with the front 3-P and rear 3-R pair of lower tubular parts and the shell 12, a second outlet channel for the low-pressure refrigerant gas. 79. Each of the opposing front and rear tubular portions of the cylinder blocks has its own pair of front and rear cylinder bores separated axially in part by a radially facing notched opening in substantially one half of a cylinder or semi-cylinder. Thus, as seen in FIG. 1, the front upper tubular portion 2-F has an internal notched portion 92 in mirror image relationship to the notched portion 94 of the rear upper tubular portion 1-R. In this manner, the three semi-cylinder notched openings of the opposing tubular portions 1-F, 1-R; 2-P, 2-R; and 3-P, 3-R together with the opposing internal faces of the front hubs 26 and rear hubs 27 define a central space 100 for the swashplate. Thus, in operation, the total flow of low-temperature, relatively low-pressure suction gas entering the rear end of the upper intake channel, containing a substantial amount of suspended oil, flows axially in heat exchange relation over the heated upper surfaces 102 and 104 of the upper tubular portions 1-R, 1-F, 2-R, and 2-F. The increased temperature of the refrigerant gas causes some of the entrained oil to separate from the gas and settle by gravity onto the upper tubular portions. The lubricant or oil collected on the surfaces 102, 104 is subjected to the heat of the compressor cylinder blocks and the refrigerant dissolved therein is carried away or rapidly evaporates by this heat. The substantially refrigerant-free lubricant or oil so deposited subsequently moves by gravitational flow downward through slotted means 106 and 108 on the inner faces of the front and rear bearings to lubricate the front bearing means 22 and the rear bearing means 24, and the front thrust bearing means 40 and the rear thrust bearing means 42. Furthermore, the total flow of low pressure refrigerant gas is led out of the upper inlet channel 77 through the notched openings in the upper tubular portion 94, 96 (FIG. 3) for delivery or flow to the central space of swash plate 100 before being drawn or conveyed into the pair of lower outlet channels 78 and 79. The result is that sufficient of the remaining oil mixed with the gas impinges on and wets or mists the surfaces 39 of swash plate 18 to provide lubrication between the swash plate and the hemispherical pads or bodies 36 during the reciprocating motion of the double-acting pistons 31, 32 and 33. As best seen in FIGS. 4 and 3, lower channel outlet means are provided on the front valve plates 44 and rear valve plates 46. In the form illustrated the outlet means are pairs or groups of holes 112, 113 and 114, 115 in the front valve plate 44 and pairs or groups of holes 116, 117 and 118, 119 in the rear valve plate 46. Through these paired holes, aligned with their associated lower outlet channel, full-flow low-pressure gas flows from the swashplate space 100 and divides into the two lower outlet channels 78 and 79. As seen in FIG. 2 for the paired holes 116, 117 and 118, 119 for the rear valve plate, the holes route to both the external annular intake chambers 56 and 58 in the front and rear heads for gas introduction and their associated front and rear cylinder ports. The compressed gas is discharged into both the front and rear cylinder head center exhaust chambers 60 and 62. Thereafter, the exhaust chambers are connected by an exhaust gas crossover pipe 120, the forward end of which is telescoped into opening 122 in the front valve plate and sealed by an O-ring designated at 124. In a similar manner, the rear end of pipe 120 is telescoped into opening 126 in the rear valve plate and sealed by an O-ring 128. Thus, the compressed refrigerant gas moves from the front chamber 60 through pipe 120 into the rear chamber 72 and leaves the compressor through an outlet opening 130 in the rear head. In the form shown the compressor is assembled by forming the forward end of the outer shell with a rolled forward edge 132 so that the subassembly of compressor heads, blocks, valve plates, etc., is received telescopically into the open threaded end 134 of the shell. The assembly is then closed in a sealed manner by forward and aft head O-rings 136 and 138 and tightened together by an O-ring nut 140. Another achievement of applicant's unique compressor is in its substantial reduction in weight over prior art axial compressors. The arrangement provides cylinder heads 14 and 16 that partially form the pair of radially outer intake cavities or chambers 56, 58 and the pair of radially inner exhaust cavities or chambers 60, 62 that flank the compressor housing formed by the shell 12. The forward cylinder blocks 28 and the rear cylinder blocks 30 and their three associated composite tubular portions define a composite trifurcated cylinder block including three tubular portions disposed about an axis to provide space between adjacent pairs of the tubular portions, thereby reducing the weight of said cylinder block. While the embodiment of the present invention as illustrated herein constitutes a preferred form, it is to be understood that other forms could be adopted.

Claims

1. CLAIMS: axial piston cylinder of the type having a swash plate 18 (41) rotatably supported and contained axially between a pair of cylinder blocks 28, 30 (12, 16) joined at the ends by journal bearings 22, 24 (50 F, R) and thrust bearings 40, 42 (52 P, R) on opposite sides of the swash plate and wherein the sides 39 of the swash plate are in sliding guide fit with pistons 31, 32, 33 (36) mounted in cylinders 33 (32) in the cylinder blocks and wherein a cylinder head 14, 16 (10, 20) is provided. in gui_at least one passage_ ( ! suction 78 0 79 (101) extends longitudinally within the compressor between ciUndrl ad.adjacent in each cylinder block and directly connects a suction inlet 70 (80) into the compressor rlcg; sells gaseous refrigerant and entrained oil in both compression chambers, meanwhile exposing a portion of the sides of the swash plate between these adjacent cylinders, and in which gaseous refrigerant and entrained oil from the suction inlet flows over one side and the sides of the swash plate is shielded from the heat of these walls and distributed by gravity to the journal bearing and the swash plate bearing, characterised in that the suction chamber 70 (80) is 5£ 4 58 (98, lQ. 2kAi. cylinder head 77(90) of each cylinder block is located around its periphery, cavity 77(90) of each cylinder block is located adjacent to the periphery of the compressor, suction inlet 70(80) is located in one of the cylinder heads longitudinally aligned with said cavities, the package 77(90) of each cylinder block is located adjacent to the periphery of the compressor, the ...the sides of the inclined disc away from the suction inlet, and the cylinder blocks each have a hollow opening 92" 94 (35) at their junctions which together form within the compressor, an accommodating space for the inclined disc opening directly to the cavities and the longitudinally extending suction passage, and further form a transversely extending suction passage A1 extending to the periphery of the compressor and along both sides of the inclined disc and across its axis joining the suction inlet to the longitudinally extending suction passage whereby the weight of the cylinder block is substantially reduced and furthermore the sliding guide surfaces of both sides of the inclined disc are directly exposed to and completely surrounded by the gaseous refrigerant.and entrained oil as it passes from the suction inlet to the longitudinally extending suction passage causing a sufficient quantity of entrained oil to be separated as films on the sides of the swash plate.

2. An axial piston swash plate compressor according to claim 1, characterized in that the longitudinally extending suction passage is defined in the form of a chamber by walls of thickness just sufficient to form adjacent cylinders in each cylinder block so that the weight of the cylinder block is substantially further reduced.

3. Axial piston swash plate compressor according to claim 1 or 2, characterized in that the cavities are defined in the shape of adjacent cylinders in each cylinder block so that the weight of the cylinder block is substantially further reduced. ' Rome, pp.: GENERAL MOTORS CORPORATION ING. BARZANÒ & ZANARDO ROMA SpA AN AUTHORIZED REPRESENTATIVE (Enrico Toschi) ì ET / CJ / gg-507O 50901A / 79 50901A / 79 Ing. BARZANÒ & ZANARDO «pa. ROME - MILAN TURIN