US3685923A

US3685923A - Automotive air conditioning compressor

Info

Publication number: US3685923A
Application number: US87410A
Authority: US
Inventors: Everett C Hutchins; Gary E Spencer; Marion K Tucker
Original assignee: General Motors Corp
Current assignee: Motors Liquidation Co
Priority date: 1970-11-06
Filing date: 1970-11-06
Publication date: 1972-08-22
Anticipated expiration: 1989-08-22

Abstract

In preferred form, a four cylinder radial compressor which is operated by an eccentric slider drive mechanism. Two pairs of cylinder bores are radially spaced 90* apart with the center lines of the cylinders lying in a common plane. Opposed pairs of pistons in the bores are linked together with sheet metal links that apply piston preload to an eccentric slider block for high speed continuous operation. The compressor is lubricated by oil that is carried by the refrigerant to the compressor. The refrigerant gas enters the compressor at the rear of the drive shaft and the suction return is diverted into the cylinder housing while the heavier oil enters an aligned hole in the shaft for distribution to the eccentric bearing and eccentric slider of the drive mechanism.

Description

United States Patent Hutchins et a]. [4 1 Aug. 22, 1972 [54] AUTOMOTIVE AIR CONDITIONING I 1,631,425 6/1927 Marcus et a1 ..417/273 COMPRESSOR 3,093,301 6/1963 Mitchell ..417/273 [72] Inventors: Everett C. Hutchins' Gary Spencer; Marion K. Tinker, an of Prlrnary Examtner-Carlton R. Croyle Dayton, Ohio Assistant Exarruner-John J. Vrablik Att0rney-W. S. Pettigrew and J. C. Evans [73] Ass1gnee: General Motors Corporation,

Detroit, Mich. I 57 ST [22] Filed: 1970 In preferred form, a four cylinder radial compressor 211 App} 7 410 which ,is operated by an eccentric slider drive mechanism. Two pairs of cylinder bores are radially spaced 90 apart with the center lines of the cylinders [52] US. Cl ..417/273, 417/523 lying in a Common plane. Opposed pairs of pistons in [51] P Cl F04b 27/04 F04b 21/04 the bores are linked together with sheet metal links [58] Fleld of Search ..417/273, 523, 534-537; that apply piston preload to an eccentric Slider block 92,138 for high speed continuous operation. The compressor is lubricated by oil that is carried by the refrigerant to [56] References cued the compressor. The refrigerant gas enters the com- UNITED STATES PATENTS pressor at the rear of the drive shaft and the suction return is diverted into the cylinder housing while the 3,174,436 3/1965 Wanner ..417/273 heavier oi] enters an aligned hole inthe Shaft for 2,450,248 9/1948 Morgan et "417/273 tribution to the eccentric bearing and eccentric slider 1,023,685 4/ 1912 Ruwell ..417/273 of the drive mechanism 1 3,456,874 7/1969 Graper ..417/534 2,529,996 11/1950 Browne ..417/273 4 Claims, 9 Drawing Figures Z5 8 i= 243246 zaz 5 n 24-? 5 g Q6 I: 7 g, 9x

T IL 10: w z.

4 I w w 1 121 as w w in a 7 ll 56 a /Z T- i I Z w mmtmuczzmz 3.685323 SHEET 2 0f 3 IN VEN TORS ivezef/ fluid/2:225, 5054/ a: James: 6:

AT TOR/VEY AUTOMOTIVE AIR CONDITIONING COMPRESSOR This invention relates to rotary machines and more particularly to compressors having radial bores and radially reciprocated pistons therein driven by a common drive mechanism.

In automotive air conditioning systems it is desirable to have a light weight compressor that can be connected to the engine block of the automobile and driven at a continuous high speed of operation by the belt that drives the engine cooling fan.

At such high speed operation it is desirable to have a built-in lubricant supply system in the compressor and additionally it is desirable that the radial piston units be operated by a drive mechanism that will prevent wear producing tipping movement of the reciprocating pistons in the cylinder bores.

Accordingly, an object of the present invention is to provide a high speed rotary machine which includes a plurality of radially located piston cylinder units driven by a common drive mechanism wherein means are provided to prevent each of a plurality of the pistons from being tipped with respect to the cylinder bores during compressor operation.

Yet another object of the present invention is to provide a compact high speed compressor by locating a plurality of radial piston and cylinder units in a common plane and driving them by a common slider drive mechanism that prevents the pistons from tipping with respect to the cylinder units during high speed operation and wherein the pistons are separate components in the assembly and tied together by means of separate preloading links that maintain a tight fitting, no tip, close tolerance relationship between the common drive mechanism and the pistons during high speed operation.

Yet another object of the present invention is to provide a compact compressor configuration for use in automotive air conditioning systems wherein a shaft bearing housing has a suction port therein in axial alignment with a large diameter opening in the end of the shaft to direct suction gas entrained oil between sliding surfaces in component parts of the drive mechanism and wherein the bearing housing includes means for diverting the refrigerant into a low pressure region in the center of the compressor and wherein the bearing housing includes discharge port means for communicating each of a plurality of radially located circum ferentially spaced cylinder bores for directing compressed refrigerant from the compact compressor arrangement.

These and other objects of the present invention are found in one working embodiment which includes a cylinder body having four cylinder bores radially spaced 90 apart. All of the cylinder bores have their center lines lying in a common plane. An iron plated die cast aluminum piston is located in each of the bores for sliding reciprocating movement therein during compressor operation. Each of the pistons are driven by a common eccentric slider block.

Opposing pairs of the pistons are linked together with sheet metal links that apply a piston preload to the eccentric slider block which is actuated by a common eccentric on a drive shaft. The drive shaft is supported by a rear bearing plate and a front bearing plate on the cylinder block. Suction gas enters the compressor through the rear plate where it is diverted into the cylinder body. Heavier oil in the returning refrigerant enters a hole in the shaft which is aligned with the suction port. Oil collected in the hole is distributed to an eccentric bearing which supports the eccentric slider block on the shaft eccentric.

Suction gas enters the compression chamber through suction ports in the top of the pistons. Suction reeds are attached to the top of the pistons. Refrigerant gas is discharged through a valve plate in each of the cylinder heads and is delivered to a manifold in the rear plate through a plurality of circumferentially spaced holes in the cylinder body, all located radially outwardly of the suction opening.

The arrangement enables the compressor to be operated at a high speed of operation in a range of 5500 continuous rpms to 8500 rpm a maximum instantaneous speed.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIG. 1 is a vertical sectional view taken along line 11 of FIG. 2 looking in the direction of the arrows;

FIG. 2 is a view in rear elevation of the compressor partly broken away and partly in section;

FIG. 3 is a horizontal sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a horizontal sectional view taken along the line 4-4 of FIG. 1 looking in the direction of the arrows;

FIG. 5 is an enlarged fragmentary vertical sectional view taken along the line 5-5 of FIG. 1 looking in the direction of the arrows;

FIG. 6 is a vertical sectional view taken along the line 6-6 of FIG. 1 looking in the direction of the arrows;

FIG. 7 is a horizontal sectional view taken along the line 77 of FIG. 6 looking in the direction of the arrows;

FIG. 8 is a vertical sectional view along the line 88 of FIG. 1 looking in the direction of the arrows; and

FIG. 9 is an elevational view of an eccentric slider block in the present invention.

Referring not to the drawings, in FIGS. 1 and 2, a compact compressor 10 is illustrated which includes a central block or cylinder body 12 having four radially spaced bores l4, 16, 18 and 20.

The bores 14 and 16 are formed coaxially of one another in the body and along an axis which is perpendicular to the axis of coaxially aligned bores 18 and 20.

In the illustrated arrangement the rear of the compressor body includes a central opening or suction space 22 therein which serves as the inlet to each of the cylinder bores 14 through 20.

As is best seen in FIG. 8, the rear of the body further includes a plurality of

arcuate openings

24, 26, 28 and 30 therein which are separated by partition members 32.

Each of the arcuate openings communicates with a discharge bore 36 in body 12 which is adapted to be communicated with an adjacent one of the cylinder bores at the discharge end thereof.

' port 50 that is adapted to be connected to a return conduit or suction hose of a refrigerant system of the type found in automotive air conditioning systems.

Between the bore 48 and suction opening 50 is a transition bore 52 which communicates with two spaced holes 54, 56 each of which intersects the, transition bore 52 at an acute angle A shown in FIG. 7. They also communicate with the suction opening 22 in the compressor body 12 on either side of the sleeve bore 48 therein.

Additionally, the rear bearing housing 44 includes an annular recess 58 formed in the inside face thereof continuously therearound to communicate each of the arcuate discharge openings in the compressor body with a discharge port 60 which is adapted to be connected to a'supply line from the compressor to a condenser unit in the refrigerant system.

In the illustrated arrangement, the arcuate recess 58 communicates with a plurality of

discharge muffler cavities

62, 64, 66, 68, 70, 72 and 74, each of which are separated by a reinforcing rib 76 formed as an integral part of the housing 44 as is best illustrated in FIG. 6.

Additionally, the housing includes an opening 78 which is adapted to communicate the low pressure side of the compressor with a pressure switch cavity 80 in which a diaphragm switch operated component can be located to control the operation of the refrigerant system. A pressure gauge tap 81 is also shown inFIG. 6.

The housing 44 includes a plurality of like circumferentially spaced connecting lugs 79 thereon which have connecting screws 83 directed therethrough into threaded engagement with tapped openings 82 in the housing at circumferential point at the outer periphery thereof as best seen in FIG. 8. g

A gasket seal 84 is fastened between the inside face of the bearing housing 44 at the outer periphery thereof around the lug 79 thereon and the peripheral surface of the body 12 to seal between the inlet and outlet passageways in the housing 44 and the body 12.

On the opposite end of the body a front bearing housing 86 has a peripheral shoulder 88 formed thereon which fits within an; end opening 90 on the body 12.

The front bearing housing 86 includes a seal cavity 92 therein which is formed by an axially outwardly directed tubular extension 94. The outer periphery of the housing 86 includes a plurality of connecting lugs 96 thereon which have screws 98 directed therethrough into threaded engagement with the central body 12 to hold an annular gasket seal 100 in sealing engagement between the body 12 and the bearing housing at the opening 90 therein.

A drive shaft 102 is directed through the body 12. It includes an outboard end extension 104 thereon which is adapted to be connected to a drive source for high speed operation. A rear end 106 of theshaft is supportingly received by a bearing assembly 108 seated within the sleeve bore 48 in the rear housing 44.

As is best seen in FIG. 5, the shaft includes a large diameter opening 110 on the front end thereof which is aligned coaxially of the suction port 50 and the transition bore 52. The opening 1 10 in turn is in cornmunicar I tion with an oil feed passageway 1 12 formed longitu-,

dinally through shaft 102 that is intersected by a bore 114 extending radially outwardly of the passageway 112 to intersect the outer surface 116 of an eccentric 118 integrally formed on the shaft 102. In the illustrated arrangement the eccentric 118 has three

holes

120, 122, 124 formed therethrough to balance the shaft 102.

Additionally, the shaft 102 has a second bearing surface 126 thereon which is supportingly received in a bearing assembly 128 that is fitted within a sleeve bore 130 in housing 86. Bore 130 is aligned coaxially with the bore 48 thereby to support the shaft 102 for rota-.

tion with respect to the central compressor body 12 so as to move the eccentric 118 therein with respect to each of the cylinder bores.

The eccentric 118 forms partof an improved high speed compressor slider drive mechanism 132.

The eccentric slider drive mechanism 132 more par: ticularly includes a needle bearing assembly 131 which has the inner race thereof fit on the outer'periphery 116 of the eccentric 118 in the outer race thereof fit with one another and slidably received within the cylinder bores 12, 14 for opposite reciprocation therein during operation of the compressor. l

' Additionally, the eccentric slider block 134 includes a second pair of flat spaced parallel surfaces 152, 154 I thereon which are supportingly received in grooves 156, 158 located in opposed pistons 160, 162, respectively.

The opposed pistons 160, 162 are slidably supportingly received for reciprocation in the coaxially aligned cylinders 18, 20 which are located on an axis perpendicular to that of the axis formed through the Y coaxially aligned cylinders 14, 16.

In accordance with one principle of the present invention, all of the piston cylinder units are located in a common plane and driven by a common drivemechanism to produce a reduced outer dimensional compactness compared to the total volumetric output thereof.

One important aspect of the present invention is the manner in which the opposed pistons are'tied together and balanced with respect to the eccentric compressor drive mechanism 132 to produce an improved high speed range of operation of the device.

To accomplish such operation, the shaft is maintained in its supported relationship with respect to the sleeve bearings 108,128 by means of a first bearing thrust washer 160 at one end of the shaft which is located between a hub extension 162 and a shaft counterweight 164 which seats against a shaft shoulder 166.

The opposed pistons 148, are coaxially aligned On the opposite end of the shaft a Belleville type thrust washer 168 is located between a hub extension 170 on the front bearing housing 86 and a counterweight 172 which seats against a shaft shoulder 174.

The counterweights and drilled eccentric serve to carefully balance the high speed shaft 102 and the bearing arrangement define a stable platform.

Additionally, in order to further enhance the dynamic stability of the mechanism while operating at high speed operation, in accordance with certain principles of the invention the opposed parallel surfaces 142, 143 are maintained in a close tolerance relationship with the slider grooves 144, 146 on the pistons 148, 150 be a pair of spaced connector links 176, 178 of sheet metal material.

The link 176 includes a central portion 180 which is bent to one side of the drive shaft 126 is best illustrated in FIG. 2. It is joined to offset ends 182, 184 that are fastened to the end of a cross pin 186 through piston 148 and a cross pin 188 through piston 150, respectively.

The connecting link 178 includes a central portion 190 which is bulged to one side of the shaft 126 in the opposite direction to the central portion 180 of link 176. It includes opposite ends 192, 194 thereon which are press fit over the opposite end of the cross pin 186 and the cross pin 188.

Together the links 176, 178 are prestressed during the assembly of the compressor to cause the slider grooves 144, 146 on the pistons 148, 150 to be held in close sliding fit relationship with the parallel surfaces 142, 143 on the slider block.

One feature of the slider surfaces 142, 143 and the grooves 144, 146 is that they are formed fiat with respect to one another and together define a moving, sliding flat surface that enables the supported piston thereon to reciprocate within its cylinder bore without being tipped with respect thereto on opposite reciprocation of the piston within the unit.

The provision of separate pistons and connecting links has a further advantage in that it enables four piston units to be driven by a common slider block eccentric at high speeds. This is in contrast to arrangements where a slider block mechanism is located within a double-ended unitary piston which is reciprocated within opposed cylinder units as for example of the type shown in US. Pat. No. 2,031,940 to Drysdale. In this arrangement, the inclusion of a double-ended piston prevents location of an additional pair of opposed piston cylinder units at 90 with respect to a, first air. v p In this arrangement, the-opposed pistons 160, 162 are interconnected by a second pair of connecting links 196, 198 which are located axially of the shaft between the outer connecting links 176, 178 and the axial end surfaces on the eccentric l 18 as is best seen in FIG. 1.

The connecting link 196 includes a central portion 200 thereon bulged outwardly of the shaft 126 to the same extent as are central portions 180, 190. Offset ends 202, 204 on the link 198 are press fit over cross pins 206, 208 directed through the ends of pistons 160, 162, respectively.

The connecting link 198 is located between the eccentric 118 and the link 178. It includes a central portion 212 and end portions 214,216 which are connected to the opposite ends of the cross pins 206, 208. As in the case of the pistons 148, 150, the connecting links 198, 210 are preloaded to draw the axially aligned piston 161, 162 together so as to hold them in a close tolerance sliding fit relationship with the grooves 156, 158 therein and the opposed parallel surfaces 152, 154 on the slider block 134. The respective sliding surfaces thus serve as a stable platform during compressor operation to prevent tipping of the pistons with respect to their cylinder bores.

In addition to the dynamic stability the compressor includes features to maintain a uniform suction and discharge action through the discharge port 60 and the suction port 50 of the rear bearing housing 44. Such refrigerant flow is accomplished through a flow path which separates the lubricant from the circulating refrigerant gas. Furthermore, the high speed shaft 102 has the extension 104 thereon sealed by a rotary seal assembly 218 which is operative to prevent gas leakage through the shaft bore 92 during such operation. More particularly, the rotary seal assembly includes a rotary seal element 220 which is connected for rotation with the shaft 102 through a seal retainer 222 that is secured on a shoulder 224 of the shaft. The rotary spring is spring biased outwardly of the retainer 222 coaxially along the shaft 102 by coil spring 226. The biased element 220 bears against a sealing surface 228 constituted by an annular ring that is held in place by a snap ring 230 within the housing 178.

The refrigerant circuit for all of the piston cylinder units is identical. For purposes of this description, reference will be only had to that through the piston unit 148.

The component parts of the refrigerant circuit are the'same for each of the piston cylinder bore units. It includes an annular seal 232 in the periphery of each of the pistons which is biased radially outwardly to seal against the inside surface of the cylinder bore to prevent bypassing of the piston.

Additionally, each of the pistons includes a plurality of suction ports 234 formed in the head thereof at uniformly spaced circumferential points therealong.

A suction reed valve 236 includes a center segment 238 thereon secured to the top of the piston by a screw retainer 240. It further includes an outwardly located continuously formed peripheral ring 242 which covers each of the suction ports 234.

The upper open end of each of the bores is closed by a discharge valve plate 244.

It is sealed with respect to the housing or compressor body 12 of the bore therein by a valve plate gasket 245.

The valve plate includes a plurality of discharge ports 246 therein which are best illustrated in FIG. 3, as being formed continuously around the plate 244 at equally spaced circumferential points thereon.

These discharge ports are covered by a discharge reed valve 248 that has a center portion 250 thereon secured to the center of the plate 244 by a rivet 252 having the head thereof 254 upset against the underside of the plate 244.

The discharge reed valve 248 further includes an outer peripheral ring 256 thereon which covers the ports when the valve is closed. A back-up plate 257 is fastened by rivet 252 toplate 244.

A cylinder head 258 is located on each of the plates 244 in covering relationship therewith. Each of the heads 258 includes a plurality of openings 260 therethrough which receive connecting screws 262 that are directed through like openings 263 in the discharge plate into tapped holes in the compressor body 12 around the bore therein.

Additionally, the cylinder head 258 includes a recess 265 thereon which includes a side segment 264 that overlies a crossover passageway 266 in the discharge plate which leads to a discharge bore 36 in the body 12.

The cylinder head is sealed with respect to the upper surface of the discharge plate by a head gasket 270.

Operation of the compressor includes a continuous suction intake and discharge of refrigerant ga's to produce a relatively constant torque on the drive shaft clockwise direction as viewed in FIG. 2, the eccentric- 118 as shown in FIGS. 1 and 2 locates the opposed pistons 148 and 150 at the beginning of a discharge strokeand at the end of the discharge stroke, respectively. Simultaneously, the opposed pistons 160, 162 are located at intermediate positions within the bores through an intermediate point of a suction stroke and an intermediate point of a discharge stroke respectively. Further, clockwise movement will cause the following to occur:

The piston 148 will move upwardly within the bore 12 to discharge refrigerant between the top of the piston 148 and the discharge plate thence through the opening or recess of the cylinder head and out the discharge bore 36 into the arcuate recess 58 thence to the discharge port 60. At the same time, refrigerant gas is drawn through the suction port 48 and the central opening 22 into theinside of'the body 12 where it passes across the suction reed valve on the piston 150 into the increasing volume formed between the piston 150 and the bore 16. v 7

When the eccentric is moved 90 from the positio shown in FIG. 2 in a clockwise direction, the opposed parallel surfaces 142, 143 on the slider block 134 are positioned equidistantly with respect to the center line of the shaft thereby to position the piston unit 148, 146 at midpoint within their bores. At the same time the eccentric has moved the slider block 134 to cause the opposed parallel surfaces 152, 154 thereon to position the piston 160 at the end of its discharge stroke and the piston 162 at the end of its suction stroke. Further counterclockwise movement of 90 will move the piston 148 to the end of its discharge stroke and the piston 150 to the beginning of its suction stroke.

A further clockwise movement of 90 will cause the eccentric to be aligned with the piston 162 moving it to the end of its discharge stroke and the piston 160 to the end of its suction stroke leaving the'pistons 148, 150 at their intermediate position. Then the eccentric will be located in alignment with the piston 150 through a further clockwise movement of 90 to return the pistons to their positions shown in FIGS. 1 and 2.

Thus, the location of the eccentric will produce a continuous and progressive shifting movement of the pairs of parallel surfaces to cause each of the pistons to move completely upwardly within its bore and then reciprocate back to a suction position wherein the low point on the eccentric is in alignment with that piston. The motion is harmonic in nature and continuous to maintain a uniform torque on the shah.

pression strokes and discharge strokes each rotation of the shaft.

During this movement the respective sliding surfaces between the slider block and the pistons are moved through a sliding transverse movement with respect to each other thereby to define a continuous flat surface during the suction return. Refrigerant gases passing 7 through the suction port 50 enters the transition bore 52 .and then pass through the angularly formed holes 54, 56 and are thence directed into the interior of the compressor body 12 through the central end opening 22 therein. The light gas freely flows through the angular openings 54, 56.

Heavier oil particles, however, continue to-flow in the same direction through the suction port 50 and the transition bore 52 thereby to be collected by the large diameter opening 110 for flow through the previously described oil distribution system thereby to completely lubricate the friction surfaces between the outer surface 116 of the eccentric; the component parts of the eccentric bearing 131 and the grooves in each of the pistons. y

In one working embodiment of the present invention the compressor has a capacity of 8.5 cubic inches of displacement. This is produced by four cylinder bores cylinder head Part Material cylinder body 12 rear bearing housing 44 front bearing housing 86 pistons 148, 150, 160, 162 eccentric slider block 134 shaft 102 die cast aluminum die cast aluminum die cast aluminum iron plated die cast aluminum hardened steel I localized induction hardened I q ssi sl Also in addition to having extreme compactness the overall weight of the compressor is low which makes it especially suitable for connection'to small displacement internal combustion engines.

. While the embodiments of the present invention as herein disclosed constitute a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

l. A rotary machine comprising a cylinder block having four cylinder bores formed therein, each of said cylinder bores having their centerline located in a common plane, a first pair of said cylinder bores being located coaxially with one another and at a perpendicular relationship with a second pair of said bores, a rear bearing housing on said cylinder block, a front bearing housing on said block, a rotary shaft directed through said block having the opposite ends thereon supported by said front and rear bearing housings, said shaft having an extension thereon adapted to extend outwardly of said front bearing housing for connection to a drive source, an eccentric throw on said shaft, said eccentric throw having an outer peripheral surface thereon located in said common plane of the centerlines of said cylinder bores, an annular needle bearing on said eccentric, a slider block slidably supported by said annular needle bearing, said slider block having a first pair of parallel sides thereon located coaxially of said first pair of bores and a second set of parallel sides thereon located in coaxial alignment with said second pair of bores, a piston in each of said bores, each of said pistons having a base portion thereon with a groove therein in which is supportingly received one of said parallel surfaces on said slider block, said eccentric throw being rotated by said shaft within said needle bearing to cause axial movement of said slider block with respect to each of said cylinder bores to cause each of said pistons to reciprocate within one of said cylinder bores, said slider block being moved by rotation of said eccentric laterally with respect to the groove in each of said pistons to provide a full-bearing support for said piston during reciprocation thereof within said bore thereby to prevent tilting movement of said pistons during reciprocable movement thereof within said bores, and means to preload each of said piston base portions against one of said parallel sides of said slider block including a first pair of spaced apart flat sheet metal links located on opposite sides of said slider block, each of said links having a central portion offset from said shaft and opposite ends colinear with each other and with the axis of said shaft, means joining said opposite ends to said first pair of pistons together, each of said links being pre-stressed to a predetermined length between its opposite ends to locate said pistons to hold the grooved base portions of said first pistons in close sliding fit engagement with said first pair of parallel sides of said slider block, said preloading means including a second pair of flat sheet metal links located on opposite sides of said slider block, each of said links having a central portion offset from said shaft andopposite ends colinear with each other and with the axis of said shaft, means joining said opposite ends of said second pair of links to said second pair of pistons, each of said links being pre-stressed to a predetermined length between its opposite ends to locate said pistons to hold the grooved base portions of said second pair of pistons in close sliding fit engagement with said second pair of parallel sides on said slider block there to maintain said slider block and the grooves in said piston continuously in close sliding engagement upon opposite reciprocation of said pistons within said cylinder bores.

2. In a reciprocating compressor the combination of a body with a plurality of cylindrical bores therein, a suction space in said body, a plurality of discharge l 0 passageways formed in said body radially outwardly of said suction space' in spaced circumferential relationship therearound, a rear bearing housing secured to said body for closing said suction space therein, a front bearing housing secured to said housing, a rotary drive shaft, bearing means in said front bearing housing and said rear bearing housing for supporting said shaft within said body for rotation with respect thereto, an eccentric throw secured to said shaft for rotation therewith, said throw being located within said suction space, a bearing supported on the outer surface of said throw rotatable therewith, a slider block having a central opening receiving said bearing, said bearing and throw driving said block through oscillating movement with respect to the longitudinal axis of said drive shaft, said block including a plurality of flat surfaces on the outer periphery thereof, a piston in each of said cylinder "bores having a base portion thereon formed 'as a flat surface, each of said base portion surfaces engaging one of said slider surfaces on said slider block for sliding movement therebetween upon oscillatory movement of said slider block about the longitudinal axis of said drive shaft, a pin directed through each of said pistons, a link member having one end thereof connected to one end of a pin in one of said pistons and having the opposite end thereof connected to the end of a pin in another one of said pistons, a second link member having one end thereof connected to the op posite end of the pin in the one piston and the opposite end thereof connected to the opposite end of the pin in the another one of said pistons, said first and second links having a central portion thereon offset from the connected ends of each of said links on either side of said shaft, each of said links prestressed between its connected ends to a length to hold said first and second pistons against said slider block to maintain a close sliding fit therebetween upon rotation of the shaft, said slider block surfaces moving axially of and laterally of each of said bores during oscillation of said slider block about said drive shaft during rotation thereof to produce reciprocation of said first piston into and out of its cylinder bore in a direction opposite to the reciprocation of said second piston within its cylinder bore and serving to define a flat surface support for said pistons at the base thereof to prevent tipping movement of said pistons with respect to said cylinder bores during opposite reciprocation of said pistons within said bores.

3. In a reciprocating compressor the combination of, a central body, a plurality of radially outwardly directed cylinder bores in said body spaced apart, the centerline of each of said cylinder bores lying in a common plane, a separate piston in each of said cylinder bores, a rotary drive shaft for said pistons, means for supporting said drive shaft for rotation with respect to said body, a common eccentric on said shaft for actuating each of said pistons, a slider block operated by said common eccentric, a flat surface on said slider block in alignment with each of said pistons, means forming a flat follower surface on each of said pistons supportingly engaged by said flat surface on said slider block, a first pair of said pistons located coaxially of one another, a first pair of flat sheet metal connecting links located on each side of said second pair of pistons, each of said links having a center porspaced circumferential I means for communicating said suction space and said discharge openings with said bores, a rear bearing tion offset from said shaft and ends secured to said first pair of pistons, each of said links being prestressed to a predetermined length between its opposite ends, to locate said pistons together against said slider block, a second pair of said pistons located coaxially of one another and at right angles to said first pair, a second pair of flat sheet metal connecting links located on each side of said second pair of pistons, each of said links having a center portion offset from said shaft and ends secured to said second pair of pistons, each of said links being prestressed to a predetermined length between its opposite ends to locate said second pair of pistons together against said slider block, said first and second pairs of sheet metal connecting links maintaining the follower surface on each of said pistons in close sliding fit relationship with the flat surfaces on said said shafts for causing opposite reciprocation of each of said'pistons within one of said radial bores during rotation of said shaft, said drive means including an eccentric throw on said shaft, a bearing on the outer periphery of said throw, a slider block supportingly received on the bearing havinga portion thereon slidably engaging said pistons at an interface for caus-- housing formed coaxially of the end of said shaft supported by said rear bearing housing, said rear bearing housing having a transition bore aligned with said suction port for reducing velocity of inlet gas from said suction port, a largediameter opening in the supported slider block to produce opposite reciprocation of each of said pistons within its cylinder bore upon rotation of said shaft, said slider block flat surface moving laterally and axially of said piston during reciprocationthereof to define a stable supporting surface for said piston to prevent tipping movements thereof with respect to the cylinder bore during opposite reciprocation of said first and second piston pairs.

4. A compressor having a central body with a plurality of radially outwardly directed cylinder bores therein, a piston in each of said bores slidably reciprocable with respect thereto, said body including a suction space located centrally thereof and radially inwardly of ,said bores, a plurality of discharge openings in said body located radially outwardly of said suction space in relationship therearound,

housing secured to said body including means thereon closing said suction space in said body, a front bearing housing on said body, a rotary shaft having the opposite ends thereof supportingly received in said rear and front bearing housings, drive means for operatively connecting each of said pistons in said radial bores to end of said rotary shaft coaxially aligned with said suction port and transition bore and facing'in the direction of inlet gas flow through said suction port to separate and intercept lubricants suspended therein, a longitudinal passageway in said shaft for receiving separated lubricant from the large diameter opening, a transverse passageway in said shaft receiving oil from the longitudinal passageway to said bearing, and being rotated by sh to distribute oil in a ra 'al di ection, s 'd s 1 er b ock including a p uralrty o radial y outwar y directed openings therein for directing oil from said bearing to the sliding interface between said slider block and each of said pistons and into said suction at an angle with respect to the longitudinal axis of said transition bore on either side thereof for receiving gas from the suction port and directing it to the suction space in said body, and suction valve means in each of said pistons for passage of gas and lubricant from-the

Claims

1. A rotary machine comprising a cylinder block having four cylinder bores formed therein, each of said cylinder bores having their centerline located in a common plane, a first pair of said cylinder bores being located coaxially with one another and at a perpendicular relationship with a second pair of said bores, a rear bearing housing on said cylinder block, a front bearing housing on said block, a rotary shaft directed through said block having the opposite ends thereon supported by said front and rear bearing housings, said shaft having an extension thereon adapted to extend outwardly of said front bearing housing for connection to a drive source, an eccentric throw on said shaft, said eccentric throw having an outer peripheral surface thereon located in said common plane of the centerlines of said cylinder bores, an annular needle bearing on said eccentric, a slider block slidably supported by said annular needle bearing, said slider block having a first pair of parallel sides thereon located coaxially of said first pair of bores and a second set of parallel sides thereon located in coaxial alignment with said second pair of bores, a piston in each of said bores, each of said pistons having a base portion thereon with a groove therein in which is supportingly received one of said parallel surfaces on said slider block, said eccentric throw being rotated by said shaft within said needle bearing to cause axial movement of said slider block with respect to each of said cylinder bores to cause each of said pistons to reciprocate within one of said cylinder bores, said slider block being moved by rotation of said eccentric laterally with respect to the groove in each of said pistons to provide a full-bearing support for said piston during reciprocation thereof within said bore thereby to prevent tilting movement of said pistons during reciprocable movement thereof within said bores, and means to preload each of said piston base portions against one of said parallel sides of said slider block including a first pair of spaced apart flat sheet metal links located on opposite sides of said slider block, each of said links having a central portion offset from said shaft and opposite ends colinear with each other and with the axis of said shaft, means joining said opposite ends to said first pair of pistons together, each of said links being pre-stressed to a predetermined length between its opposite ends to locate said pistons to hold the grooved base portions of said first pistons in close sliding fit engagement with said first pair of parallel sides of said slider block, said preloading means including a second pair of flat sheet metal links located on opposite sides of said slider block, each of said links having a central portion offset from said shaft and opposite ends colinear with each other and with the axis of said shaft, means joining said opposite ends of said second pair of links to said second pair of pistons, each of said links being pre-stressed to a predetermined length between its opposite ends to locate said pistons to hold the grooved base portions of said second pair of pistons in close sliding fit engagement with said second pair of parallel sides on said slider block there to maintain said slider block and the grooves in said piston continuously in close sliding engagement upon opposite reciprocation of said pistons within said cylinder bores.

2. In a reciprocating compressor the combination of a body with a plurality of cylindrical bores therein, a suction space in said body, a plurality of discharge passageways formed in said body radially outwardly of said suction space in spaced circumferential relationship therearound, a rear bearing housing secured to said body for closing said suction space therein, a front bearing housing secured to said housing, a rotary drive shaft, bearing means in said front bearing housing and said rear bearing housing for supporting said shaft within said body for rotation with respect thereto, an eccentric throw secured to said shaft for rotation therewith, said throw being located within said suction space, a bearing supported on the outer surface of said throw rotatable therewith, a slider block having a central opening receiving said bearing, said bearing and throw driving said block through oscillating movement with respect to the longitudinal axis of said drive shaft, said block including a plurality of flat surfaces on the outer periphery thereof, a piston in each of said cylinder bores having a base portion thereon formed aS a flat surface, each of said base portion surfaces engaging one of said slider surfaces on said slider block for sliding movement therebetween upon oscillatory movement of said slider block about the longitudinal axis of said drive shaft, a pin directed through each of said pistons, a link member having one end thereof connected to one end of a pin in one of said pistons and having the opposite end thereof connected to the end of a pin in another one of said pistons, a second link member having one end thereof connected to the opposite end of the pin in the one piston and the opposite end thereof connected to the opposite end of the pin in the another one of said pistons, said first and second links having a central portion thereon offset from the connected ends of each of said links on either side of said shaft, each of said links prestressed between its connected ends to a length to hold said first and second pistons against said slider block to maintain a close sliding fit therebetween upon rotation of the shaft, said slider block surfaces moving axially of and laterally of each of said bores during oscillation of said slider block about said drive shaft during rotation thereof to produce reciprocation of said first piston into and out of its cylinder bore in a direction opposite to the reciprocation of said second piston within its cylinder bore and serving to define a flat surface support for said pistons at the base thereof to prevent tipping movement of said pistons with respect to said cylinder bores during opposite reciprocation of said pistons within said bores.

3. In a reciprocating compressor the combination of, a central body, a plurality of radially outwardly directed cylinder bores in said body spaced 90* apart, the centerline of each of said cylinder bores lying in a common plane, a separate piston in each of said cylinder bores, a rotary drive shaft for said pistons, means for supporting said drive shaft for rotation with respect to said body, a common eccentric on said shaft for actuating each of said pistons, a slider block operated by said common eccentric, a flat surface on said slider block in alignment with each of said pistons, means forming a flat follower surface on each of said pistons supportingly engaged by said flat surface on said slider block, a first pair of said pistons located coaxially of one another, a first pair of flat sheet metal connecting links located on each side of said second pair of pistons, each of said links having a center portion offset from said shaft and ends secured to said first pair of pistons, each of said links being prestressed to a predetermined length between its opposite ends to locate said pistons together against said slider block, a second pair of said pistons located coaxially of one another and at right angles to said first pair, a second pair of flat sheet metal connecting links located on each side of said second pair of pistons, each of said links having a center portion offset from said shaft and ends secured to said second pair of pistons, each of said links being prestressed to a predetermined length between its opposite ends to locate said second pair of pistons together against said slider block, said first and second pairs of sheet metal connecting links maintaining the follower surface on each of said pistons in close sliding fit relationship with the flat surfaces on said slider block to produce opposite reciprocation of each of said pistons within its cylinder bore upon rotation of said shaft, said slider block flat surface moving laterally and axially of said piston during reciprocation thereof to define a stable supporting surface for said piston to prevent tipping movements thereof with respect to the cylinder bore during opposite reciprocation of said first and second piston pairs.

4. A compressor having a central body with a plurality of radially outwardly directed cylinder bores therein, a piston in each of said bores slidably reciprocable with respect thereto, said body includinG a suction space located centrally thereof and radially inwardly of said bores, a plurality of discharge openings in said body located radially outwardly of said suction space in spaced circumferential relationship therearound, means for communicating said suction space and said discharge openings with said bores, a rear bearing housing secured to said body including means thereon closing said suction space in said body, a front bearing housing on said body, a rotary shaft having the opposite ends thereof supportingly received in said rear and front bearing housings, drive means for operatively connecting each of said pistons in said radial bores to said shafts for causing opposite reciprocation of each of said pistons within one of said radial bores during rotation of said shaft, said drive means including an eccentric throw on said shaft, a bearing on the outer periphery of said throw, a slider block supportingly received on the bearing having a portion thereon slidably engaging said pistons at an interface for causing the opposite reciprocation thereof, means for lubricating said bearing and a sliding interface between said slider block and each of said pistons, said lubricating means including a suction port in said rear bearing housing formed coaxially of the end of said shaft supported by said rear bearing housing, said rear bearing housing having a transition bore aligned with said suction port for reducing velocity of inlet gas from said suction port, a large diameter opening in the supported end of said rotary shaft coaxially aligned with said suction port and transition bore and facing in the direction of inlet gas flow through said suction port to separate and intercept lubricants suspended therein, a longitudinal passageway in said shaft for receiving separated lubricant from the large diameter opening, a transverse passageway in said shaft receiving oil from the longitudinal passageway to said bearing, and being rotated by said shaft to distribute oil in a radial direction, said slider block including a plurality of radially outwardly directed openings therein for directing oil from said bearing to the sliding interface between said slider block and each of said pistons and into said suction space for lubricating the surface during rotation of said shaft, said rear bearing housing including a pair of side ports intersected and communicated with said transition bore and said suction space, said side ports formed at an angle with respect to the longitudinal axis of said transition bore on either side thereof for receiving gas from the suction port and directing it to the suction space in said body, and suction valve means in each of said pistons for passage of gas and lubricant from the suction space of said body into each of said radial bores.