MXPA00004172A - Hermetic scroll compressor - Google Patents

Abstract

The flow, use, interaction and separation of lubricant and gas flowing through the suction pressure portion of a low-side refrigeration scroll compressor is managed by the use of a multi-ported frame in conjunction with separate suction gas supply and lubricant return passages cooperatively defined by the compressor shell and the stator of the motor which drives the compressor.

Description

HERMETIC SPIRAL COMPRESSOR Background of the Invention The present invention relates to spiral compressors. More specifically, the present invention relates to the controlled flow of lubricant and suction gas in and through a low side, hermetic, refrigerant spiral compressor. Low-side compressors are compressors in which the motor by means of which the compression mechanism of the compressor is driven is arranged in the suction pressure portion (low side) of the compressor shell. In the case of a scroll compressor, the motor drives more frequently one of the two spiral members comprising the compression mechanism of the compressor and which are restricted, by the use of a device such as an Oldham coupling, to relative movement so that one spiral member orbits with respect to the other. Said orbital movement, in the appropriate direction, causes the cyclic creation of cavities at the ends radially outward of the interleaved turns of the spiral members. During the operation of the compressor, these cavities fill with suction gas, close and move radially inward while decreasing in volume, compressing in this way the gas trapped therein. The compression cavities finally move towards communication with a discharge port, more frequently placed in the center of the spiral fire, and the compressed gas is expelled through it. In spiral compressors on the low side used in refrigeration applications, relatively all the oil-free refrigerant gas in the Suction pressure must be delivered to the vicinity of the suction cavities that are cyclically defined at the radially outer ends of the turns of the spiral members. At the same time, however, provision must be made for the lubrication of the bearings in which the arrow of drive and spiral driven member rotate as well as the lubrication of other components and surfaces in the suction pressure portion of the compressor shell As a result the delivery of lubricant to surfaces requiring lubrication on the underside of the shell of a spiral refrigeration compressor, its return to the lubricant sump therein and the interaction of said lubricant with the suction gas flowing to the compression mechanism therethrough, must be carefully managed and controlled in order to maximize the efficiency of the compressor while providing adequate lubrication where and when needed. An arrangement whereby the suction gas and the lubricant flow are controlled in a low-side scroll compressor is taught in the U.S. Patent. 5,533,875, assigned to the assignee of the present invention and incorporated herein by reference. In that arrangement, use is made of a sleeve mounted on the suction pressure portion of the compressor shell and wherein the compressor drive motor is mounted so as to control and isolate the lubricant and suction gas from each other. as they flow through the low side of the compressor. The USQ of this sleeve, even when effective, causes certain disadvantages and costs both in terms of the material cost of the compressor and in terms of the compressor assembly process.

SUMMARY OF THE INVENTION An object of the present invention is to control and manage the flow of refrigerant gas in the suction pressure portion of a spiral, low side refrigeration compressor. A further object of the present invention is to control and administer the lubricant flow in the suction pressure portion of the low side scroll spiral compressor. A still further object of the present invention is to control and administer the flow, use, interaction and separation of lubricant and suction gas in a spiral compressor of low side refrigerant in a manner that improves the efficiency of the compressor, however, ensures that adequate lubrication is provided for where and when needed in the suction pressure portion of the compressor shell. Another object of the present invention is to take advantage of the pressure differentials that develop in the suction pressure portion of the low side scroll compressor, when the compressor is in operation, to assist in the delivery of lubricant to surfaces within that portion of the compressor that require lubrication. Still another object of the present invention is to provide a spiral refrigeration compressor in which the compressor drive motor is directly supported by the compressor shell and in which flow, use, interaction and separation of lubricant and suction gas are administered. effectively through the use of a multi-porthole frame in order to prevent the flow of excessive amounts of lubricant out of the compressor into the discharge gas stream and reduce the cost of such compressors in terms of both their constituent parts and the complexity and expense of its manufacture and assembly. These and other objects of the present invention, which will be observed when considering the following Description of the Preferred Modality and the figures of the attached drawing, are achieved in a spiral compressor having a driving motor, whose stator is mounted directly to the shell of the compressor. The compressor employs a multiple porthole frame that, in conjunction with passages defined cooperatively by the compressor shell and drive motor stator, effectively manages the flow, use and interaction of lubricant and suction gas in and through of the suction pressure portion of the compressor. The motor stator and the compressor shell cooperate in the definition of a suction gas supply passage to and through which the vast majority of the suction gas entering the suction pressure portion of the compressor shell is directed and restricts flow. The primary suction gas stream, which remains relatively oil-free, is forced to diverge and flow around the upper portion of the drive motor stator after leaving the supply passage, cooling that portion of the motor in the process. The divergent portions of the gas stream then enter the opposite raised portholes defined by the multi-porthole frame that opens toward the vicinity of the opposite pair of suction cavities that are defined by the spiral members and their turns. The oil is initially pumped up from a sump into the suction pressure portion of the compressor shell through a gallery defined in the compressor drive shaft. The oil flowing through that gallery is carried to a lower drive shaft bearing, an upper drive shaft bearing and to the surface of a short end shaft at the upper end of the drive shaft that drives the spiral member driven. 'The delivery of the oil to the bearing surfaces and the short arrow is assisted by venting the drive arrow oil gallery to a location in the suction pressure portion of the compressor shell which, when the compressor is in operation, it is at a reduced pressure compared to the oil sump pressure. The multiple-port frame is configured to pick up said lubricant, once used, in an internally defined cavity and return it to the oil sump of the compressor through an essentially discrete oil return path that is effectively isolated from the flow path of the compressor. primary suction gas through the suction pressure portion of the compressor leading to the spiral set. In this regard, the oil collected in the cavity defined by the multi-porthole frame flows from the cavity through a port that is configured to direct said return oil away from the suction gas stream flowing outside of and partially around. of the multiple-port frame and around the upper end of the drive motor stator en route to the high suction gas openings, defined by the frame. Said oil is directed towards an oil return passage which is at least partially defined by the stator of the compressor drive motor and the compressor shell. The geometry of the multiple-port frame and the location of the suction gas and oil return gas supply openings defined therein, together with the opposed locations of the separate suction gas and oil return gas passages that They are cooperatively defined by the compressor shell and the drive motor stator, they serve to keep the suction gas flowing to the spiral set essentially separate from the oil that is used in the suction pressure portion of the compressor • shell. which reaches the cooling of the drive motor by the suction gas.

DESCRIPTION OF THE DRAWINGS OF THE DRAWING Figure 1 is a cross-sectional view of the side-down coolant scroll compressor of the present invention that best illustrates the opposing flow paths of suction gas and oil return in the pressure portion. suction of the compressor shell. Figure 2 is also a cross-sectional view of the compressor of the present invention, but taken at an angle of 90a from the cross-sectional view of Figure 1 and illustrating the divergent suction gas flow path leading to the Spiral set in the upper portion of the compressor shell. Figure 3 is a view taken along line 3-3 of Figure 1. Figure 4 is a view taken along line 4-4 of Figure 1.

Figure 5 is a perspective view of the multiple-port frame in which the drive arrow of the compressor drive motor rotates and which, together with other compressor components, define discrete paths of gas and lubricant flow within the compressor. suction pressure portion of the compressor shell. Figure 6 is a bottom view of the multiple-door frame of Figure 5. Figure 7 is a side view of the multiple-port frame of Figure 3 illustrating the openings through which the suction gas is delivered to the set of spiral. Figure 8 is a cross-sectional view of the multi-porthole frame of Figure 6 taken along line 8-8 thereof, line 8-8 bisecting the openings through which gas is delivered to the set of spiral. Figure 9 is a cross-sectional view of the multiple-gate frame of Figure 6 taken along line 9-9 thereof, line 9-9 bisecting the opening through which the oil is returned to sink on the low side of the compressor. Figure 10 is a perspective view of the suction gas baffle of the compressor of the present invention, DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to Figures 1, 2, 3 and 4 of the Drawing, it is noted that Figures 1 and 2 are cross-sectional views of the scroll compressor 10 of the present invention taken 90s apart with Figure 1. illustrating better the opposite relationship of the suction gas delivery and oil return paths beyond the motor stator in the compressor of the present invention. The solid arrows illustrated within the figures of the drawing generally denote the flow of lubricant and some of the examples of these arrows are numbered 300. It should be understood that even though the preferred embodiment of the present invention is directed to a spiral compressor of the type fi Orbiter, the present invention also has application to scroll compressors of other types. The compressor 10 has an airtight shell 11 consisting of a lid 12, a shell 14 medium, and a base plate 16. The mid-shell 14 has a portion 15a of reduced diameter and a lower portion 15b of greater diameter. The shell 11 is divided to a low side or suction pressure portion 18 and a raised side or discharge pressure portion 20, in the preferred embodiment, by the end plate 27 of the fixed spiral member 24. The fixed spiral member 24 has a spiral turn 26 extending from its end plate 22 which is intermeshed with the spiral turn 28 extending from the end plate 29 of the orbiting spiral member 30. Together, the scroll members 24 and 30 comprise the spiral set and the compression mechanism of the compressor. The Oldham coupling 32 restricts the spiral member 30 to orbit with respect to the fixed scroll member 24 when the compressor is in operation. The orbiting scroll member 30 is driven by the drive arrow 34 on which the motor rotor 36 is mounted. In the preferred mode, a protrusion 38 depends from the orbiting scroll member 30 on the opposite side of the end plate 29 of the spiral turn 28 while the drive arrow 34 is supported for rotation within the multi-porthole frame 40 and the lower frame 42, both of which are fixedly mounted inside or to the shell of the compressor. As will be described more fully below, the surface 41 of the frame 40 cooperates with the reduced diameter portion 15a of the mid-shell 14 in creating a boundary / barrier between the relatively free current of suction gas oil that is delivered to the set of spirals and the flow path by which the oil is returned to the sump of the compressor 10 after being used for lubrication in the suction pressure portion of the compressor shell. The motor stator 44 is fixedly supported, preferably by interference fit, in the mid-shell 14. In this respect, the average shell 14 preferably will shrink thermally towards the stator 44 even though the stator 44 could alternatively be pressed towards it. The mid shroud 14 and the motor stator 44 cooperate in defining a suction gas supply passage 46 that is formed therebetween as a result of a recess in the motor stator 44. The suction gas baffle 48, in the preferred embodiment, is fixed to the inner surface 50 of the lower portion 15b of the middle shell 14 and, as will be described subsequently, cooperates with the supply passage 46 and the multiple frame 40 Portlights in the delivery of relatively oil-free suction gas to the spiral set. The suction gas is initially delivered to the suction pressure portion 18 of the compressor 10 through a suction fitting 52 with the suction gas baffle 48 being positioned in opposition to it. An oil sump 54 is defined at the bottom of the shell 11 and a lubricant pump 56 depends thereon. The lubricant pump 56 is fixed to the drive shaft 34 and the rotation of the pump 56, which results from the rotation of the drive shaft 34, causes the oil in the sump to travel upwards through the drive shaft as shown in FIG. will describe subsequently. In the preferred embodiment, the pump 56 is of the centrifugal type even when the use of pumping mechanisms of other types, including those of the positive displacement type, is contemplated. Garbage carried in the oil pumped out of the sump 54 by the pump 56 is centrifuged to an annular garbage collection area 58 within the lower frame 42. This garbage is returned to the sump through a drainage hole, not shown. The oil centrifuged to the collection area 58 is fed end to the bearing surface 60 of the lower frame 42 in which the lower end of the compression drive shaft rotates. Another portion of the oil introduced to the discharge arrow 34 by means of the pump operation 56 continues upwards through the oil gallery 62. in the preferred embodiment, it is an inclined passage A ventilation passage 64 connects the oil gallery 62 with the outside of the drive shaft in the region 65 of the suction pressure portion 18 of the compressor shell. The region 65 is located in the vicinity of the upper ends of the motor rotor 36 and the motor stator 44 and the dependent portion of the frame 40 The ventilation passage 64 is significant due to two reasons First allows degassing of the refrigerant trapped in the oil running through the gallery 62 before said oil is delivered to the upper bearing surface 66 in the second frame, it induces the flow of oil upwardly within the arrow through the gallery 62, in both cases due to the reason that the region 65 is at a relatively lower pressure than the pressure that exists in the oil sump 54 when the compressor is in operation In this respect, the location of the ventilation passage 64 and the reduced pressure in the vicinity of its exit in the region 65 results in the existence of a pressure drop in the oil that flows upwards through the gallery 62 that effectively raises said hard oil of the sump 54 This, in turn, reduces the lifting that must be achieved by the oil pump 56 itself, or in another direction, increases the pump output. The creation of relatively lower pressure in the region 65 in the vicinity of the ventilation 64 results from the high-speed rotation of the drive shaft and the drive motor rotor in the vicinity of the upper end of the stator 44 and in the vicinity of the dependent portion of the frame 40 of multiple ports. The upper bearing surface 66, on which the short arrow portion 68 of the drive shaft 34 is rotatably supported, is fed through a transversely drilled lubrication passage 70 communicating between the gallery 62 and the support surface 66 . The passage 70 opens towards an upper portion of the bearing surface 66. A second or upper oil gallery 72 is defined by the lower side of the end plate 29 of the orbiting spiral member 30, the protrusion 38 and the upper end face 74 of the short arrow 68. The oil communicated to the upper gallery 72 from the drive shaft gallery 62 makes its way down from the drive surface 76 which is in interface between the short arrow 34 and the inner surface of the protrusion 38.

A counterweight is mounted on the drive arrow 34 for rotation therewith. The lubricant exiting from the upper portion of the bearing surface 66 in the vicinity of the bottom of the counterweight 78 is intermixed with the lubricant exiting the lower portion of the driving surface 76 and centrifugally pulled outward into the cavity 80 of collecting lubricant from frame 40 of multiple ports by rotating at high speed the drive shaft and the counterweight therein. It should be noted that a portion of said oil is driven both centrifugally outwards and upwards along the inner radius of the counterweight 78 through the space 79 which is defined between the counterweight and the protuberance 38. Said oil provides for the lubrication of the side lower portion of the coil member 30 in contact with the pushing surface 81 which is an upward facing surface of the multi-porthole frame 40. Once used for lubrication purposes, the oil is directed out of the cavity 80 through the oil return opening 82 of the multiple-port frame 40 towards the vicinity of the inlet 884 of the oil return passage 86, whose opening 82 is in alignment. The oil return passage 86, like the suction gas supply passage 46, is cooperatively defined by the motor stator 44 and the mid shell 14. The inlet 84 to the oil return passage 86 is preferably located 180a around the shell of the compressor 10 from the outlet 88 of the suction gas supply passage 46. The oil entering the inlet 84 of the passage 86 is trickled through it back into the sump 54. Focusing now on the flow of suction gas and with reference to all the figures in the drawing, the vast majority of the suction gas entering to the compressor shell through the suction fitting 52 impinges on the suction baffle 48 and is directed upwardly thereto towards the suction gas supply passage 46. A relatively minor portion of the suction gas flows or "spills" into the lower interior portion of the compressor shell around the suction gas baffle 48. The arrangement of the suction gas deflector 48 as opposed to the suction fit 52, together with its physical geometry including a solid base portion 90, protects the oil sump 54 from the primary suction gas flow stream, maintaining advantageously in this way the oil in the sump 54 in a still state while causing the essentially oil-free suction gas to be directed towards a relatively discrete flow path, near the drive motor, to promote its cooling by the gas of suction en route to the spiral game. Most of the suction gas entering the shell 11 travels up through the suction gas supply passage 46 and issues out of the outlet 88 thereof. The suction gas flow stream leaving the outlet 88 diverges and flows in two directions partially around the outside of the multiple-port frame 40 in the vicinity of the upper end of the motor stator 44. The upward flow of a smaller portion of suction gas through the rotor-stator space 92 together with the relatively much larger and substantially free flow of oil flow flowing through the suction gas passage 46 and around the upper portion of the motor stator 44 proactively causes the cooling of the compressor drive motor while the compressor is in operation, which improves the reliability of the compressor. The divergence of the suction gas flow stream leaving out of outlet 88 results from the existence of opposing suction gas openings 94 and 96 in the multi-porthole frame 40. The openings 94 and 96 are positioned above and 90s around the interior of the mid-shell 14 from the outlet 88, of the suction gas supply passage 46. The suction gas is attracted through the openings 94 and 96 towards the suction cavities formed by the relative orbital movement of the spiral members when the compressor is in operation after passing through the region 98 which is placed outside the interengaged turns of the coil members. As noted above, the circumferential surface 41 of the frame 40 and its arrangement near the bottom surface of the recessed portion 15a of the mid-shell 11 creates a barrier between the relatively oil-free region 98 in the compressor and the area below that. region through which the oil is returned out of the cavity 80 through the opening 82 en route to the sump 54. It should be noted that the suction gas flowing into the 98 region, even though relatively very oil-free, will carry with it a small and controlled amount of trapped lubricant. The existence of this lubricant in the region 98 is beneficial in that it provides means for lubricating the Oldham coupling and for sealing and lubricating the tips and turns of the spiral members in juxtaposition to the end plate of the limb member. opposite spiral. Above all, the suction gas that flows into the 98 region, however, is the oil! essentially free as a result of the protection of the primary suction gas flow stream from the sump 54 of! oil as it enters the shell 11, as a result I of the definition of the oil deflection trajectory below and circumferentially further around the frame 40 from the path through which the suction gas stream I it actively flows to the engaged turns of the spiral members and as a result of the relatively high speed at which the suction gas is attracted out of the suction passage 46 towards the openings 94 and 96 of the frame 40 which maintains the current of cohesive and discrete gas from those locations in the suction pressure portion I of the compressor shell where the oil content is relatively higher. The net result is to provide means for the lubrication of those bearings and surfaces in the suction pressure portion 18 of the compressor 10 which require lubrication in suitable quantities I to meet its lubrication needs while providing means for delivery of the lubricant. Relatively, the suction gas comes from the oil to the compression mechanism and the proactive operation of the compressor drive motor. Although the present invention has been described in terms of a preferred embodiment, it will be noted that modifications thereto and departures thereof which fall within the scope of the invention are contemplated and embraced by the language of the following claims. .

Claims (30)

1. A spiral compressor comprising: a shell, the shell having a discharge pressure portion and a suction pressure portion, the suction pressure portion defining a lubricant sump; a first spiral member having a spiral turn; a second spiral member having a spiral turn, the turns of the first and second spiral members being interleaved; and a motor, the motor having a rotor and a stator, the stator being mounted to the shell at the suction pressure portion thereof, the stator cooperating with the shell to define a clamping gas supply passage and a passage of lubricant return, the rotation of the motor rotor driving one of the first and the second spiral members.

2. The spiral compressor according to claim 1, further comprising a frame, the frame defining at least one opening through which the suction gas flows to the interleaved turns of the first and second spiral members and at least one opening through which leaves the lubricant of the frame for return to the lubricant sump.

3. The scroll compressor according to claim 2, further comprising a drive shaft, the motor rotor being mounted thereon, the drive shaft defining a gallery through which the lubricant flows out of the sump of lubricant when the compressor is in operation, the driving arrow penetrating the frame and being in drive coupling with one of the first and the spiral members, a portion of the lubricant flowing into the drive shaft gallery being delivered through the same to a surface inside the compressor that requires lubrication and from there to a lubricant collection cavity defined by the frame.

4. The scroll compressor according to claim 3, wherein the lubricant return opening defined by the frame is in flow communication with the lubricant collection cavity and in general alignment with the defined oil return passage. cooperatively by the motor stator and the shell.

5. The spiral compressor according to claim 4, wherein the suction gas supply passage cooperatively defined by the stator and the shell and the lubricant return passage cooperatively defined by the stator and the shell are generally placed on opposite sides of the stator inside the heart.

6. The scroll compressor according to claim 5, further comprising a baffle for directing a majority of the suction gas entering the shell to the suction gas supply passage cooperatively defined by the engine stator and the breastplate

7. The scroll compressor according to claim 6, wherein the frame defines at least two openings through which the suction gas flows to the interleaved turns of the first and second coil members, the at least two apertures being circumferentially arranged around the frame within the shell so that the flow of suction gas out of the suction gas supply passage cooperatively defined by the motor stator and the shell becomes diverged, a first portion of the suction gas which leaves the supply passage and flows to the interleaved turns of the first and second coil members through one of the openings and a second portion of the suction gas that leaves the supply passage and flows to the interleaved loops of the first and second spiral members through a second of the at least two openings.

8. The scroll compressor according to claim 7, wherein the frame defines a generally circumferential surface, the surface being juxtaposed to the inner surface of the shell so that the suction gas flows to the interleaved turns of the cores. first and second spiral members, after having passed through the at least two gas flow openings defined by the frame, is protected from the oil flowing out of the oil return opening defined by the frame, 9.- The spiral compressor in accordance with claim 1, wherein the shell is generally cylindrical and has a portion of reduced diameter and a portion of larger diameter, the sump being defined in the larger diameter portion of the shell and the engine being mounted to the portion of reduced diameter of the breastplate 10. The scroll compressor according to claim 9, wherein the suction gas flow stream flowing out of the suction gas supply passage defined cooperatively by the motor stator and shell is diverged after exit the suction gas supply passage and flow at least partially around in the upper portion of the engine in order to cool the engine. 11. The scroll compressor according to claim 10, further comprising a frame, the frame defining first and second openings through which the suction gas flows to the interleaved turns of the first and second spiral members and when less a lubricant return opening through which the lubricant leaves the frame for return to the sump, most of the lubricant leaving the opening in the frame entering the oil return passage defined by. the motor stator and the shell. 12. The scroll compressor according to claim 11, wherein the frame defines a cavity in which the lubricant is collected, the divergent suction gas streams flowing out of the outside, through the upper portion of the stator. of the engine and to the first and second gas flow openings defined by the frame, the frame defining a barrier between the suction gas that has passed through the first and second gas flow openings in the frame and the lubricant which leaves the cavity defined by the frame through the lubricant return opening. 13. The scroll compressor according to claim 12, further comprising a baffle to direct a majority of the suction gas entering the shell to the suction gas supply passage defined cooperatively by the motor stator. and the shell and where the suction gas enters the shell in the larger diameter portion of the shell. 14. The scroll compressor according to claim 13, further comprising a drive shaft, the rotor of the drive motor being mounted on the drive shaft and the drive shaft defining a gallery through which the fluid flows. lubricant from the lubricant sump to a surface in the compressor that requires lubrication when the compressor is in operation, the drive shaft penetrating the frame and being in drive coupling with one of the first and second coil members. 15. A spiral compressor comprising: a shell, the shell having a discharge pressure portion, a suction pressure portion and defining a sump, the shell also having a reduced diameter portion and a larger diameter portion, the sink being defined in the larger diameter portion; a first spiral member having a spiral turn; a second spiral member having a spiral turn, the turns of the first and second spiral members being interspersed; an engine, the motor having a rotor and a stator, the stator being supported fixedly and directly by the shell in the reduced diameter portion thereof, the stator cooperating with the shell to define a passage of suction gas supply and a lubricant return passage; and a frame, the frame defining a lubricant collection cavity, at least one opening through which the lubricant passes out of the cavity before entering the lubricant return passage and at least one opening through which it flows the suction gas to the interleaved turns of the first and second coil members after leaving the suction gas supply passage defined by the motor stator in the shell. 16. The scroll compressor according to claim 15, further comprising a drive shaft, the rotor of the motor being mounted thereon, the drive shaft defining a gallery a - '2! Through which the lubricant flows from the lubricant sump to a surface inside the cavity defined by the frame that requires lubrication when the compressor is in operation, the impulse arrow penetrating the frame and being in drive coupling with one of the first and second coil members, the lubricant flowing through the gallery being delivered to the cavity defined by the frame after its use in lubricating the surface. 17. The scroll compressor according to claim 16, wherein the suction gas enters the shell in the larger diameter portion thereof, the majority of the suction gas flowing upward to the flow passage of the suction gas. suction gas defined cooperatively by the motor stator and the shell. 18. The scroll compressor according to claim 17, wherein the suction gas supply passage defined by the motor stator and the shell and the lubricant return passage defined by the motor stator and the shell are placed on generally opposite sides of the stator inside the shell. 1

9. The scroll compressor according to claim 18, further comprising a deflector for directing a majority of the suction gas entering the shell to the suction gas supply passage cooperatively defined by the motor stator and the breastplate 20. The scroll compressor according to claim 19, wherein the lubricant return opening defined by the frame is in general alignment with the lubricant return passage defined by the motor stator and the shell. 21. The scroll compressor according to claim 20, wherein the frame defines at least two openings through which the suction gas flows to the interleaved turns of the first and second coil members, the at least two apertures being arranged circumferentially around the frame in the shell so that the suction gas flow stream out of the suction gas supply passage defined by the motor stator and the shell is diverged, a first portion of the suction gas flowing to the interleaved turns of the first and second coil members through one of the openings and a second portion of the suction gas flowing to the interleaved turns of the first and second coil members through another of the at least two openings 22. The spiral compressor according to claim 21, wherein the frame defines a generally circumferential surface, the surface being juxtaposed to the interior surface of the reduced diameter portion of the shell, so that the lubricant flowing out of the lubricant return opening defined by the frame is insulated from the suction gas flowing to the interleaved turns of the first and second coil members after the passage of the suction gas through the at least two openings. 23.- A method to control the flow and. the interaction of lubricant and refrigerant gas in a refrigeration scroll compressor, comprising the steps of: mounting the stator of the motor that drives the compressor directly to the shell of the compressor; defining a flow passage of suction gas between the stator of the motor that drives the compressor and the shell of the compressor; define a lubricant return passage between the stator of the motor that drives the compressor and the compressor shell; directing most of the suction gas entering the compressor shell to the suction gas supply passage; and directing lubricant, after its use for lubrication purposes inside the compressor, to the lubricant return passage. < 24 - The method according to claim 23, comprising the additional step of placing the suction gas flow passage and the lubricant return passage on generally opposite sides of the compressor shell. 25. The method according to claim 24, comprising the additional steps of defining a lubricant sump in the shell of the compressor; pump lubricant from the sump to a surface that requires lubrication inside the compressor through a gallery defined in the compressor drive shaft; and, define a cavity in which the lubricant is collected after its use in the lubrication of the surface inside the compressor. 26. The method according to claim 25, comprising the additional step of defining an outlet of the cavity that is in general alignment with the lubricant return passage. 27. The method according to claim 26, comprising the additional steps of defining a flow path for suction gas from the suction gas supply passage to the interleaved turns of the compressor spiral members, the path being outside the cavity, the suction gas being restricted from flowing through a plurality of openings before reaching the interleaved turns of the scroll members of the compressor; and defining a barrier to the interaction of the lubricant flowing out of the cavity with the suction gas flowing through the portion of the flow path that is downstream of the plurality of openings. 28. The method according to claim 23, comprising the additional steps of providing a portion of reduced diameter of the shell of the compressor in which the engine is directly mounted; providing a larger diameter portion of the compressor shell in which an oil sump is defined; and, delivering the suction gas to the compressor shell in the larger diameter portion of the compressor shell. 29. The method according to claim 28, comprising the additional step of interposing a barrier in the larger diameter portion of the compressor between the flow of suction gas entering the larger diameter portion of the compressor and the sump of the compressor. lubricant defined in it. The method according to claim 29, comprising the additional steps of causing the majority of the suction gas entering the shell to flow upwardly into the shell beyond the stator of the engine; and, causing the suction gas flow stream to diverge in a region above the engine and flow partially around it out of the cavity defined by the frame so as to cool the engine before being delivered to the turns intercalated from the spiral members of the compressor.