Abstract:
A compressor for refrigerant, comprising a housing and a scroll compressor including a first compressor body in a stationary position in the housing, and a second compressor body which can move relative to the first compressor body. A drive for the second compressor body has a drive motor. A rear-side cooling chamber is arranged between the rear side of the first compressor body and a partition of the housing, which runs at a spacing from the rear side. At least one aperture in the base of the first compressor body is configured to cool the first compressor body in the region of the rear side. The second compressor body is configured to enable the refrigerant to wash around the compressor body in the region of the rear side, remote from the scroll ribs, to cool the second compressor body.

Description:
The present disclosure relates to the subject matter disclosed in PCT application No. PCT/EP01/14918 of Dec. 18, 2001, which is incorporated herein by reference in its entirety and for all purposes. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a compressor for refrigerant, comprising a housing, a scroll compressor, which is disposed in the housing and has a first compressor body, which is disposed in a stationary position in the housing, and a second compressor body, which can move relative to the first compressor body, each of these bodies having a base and respective first and second scroll ribs, which are formed, for example, in the form of an involute to a circle and/or an arc of a circle, which rise above the respective base and engage in one another in such a way that, during compression of the refrigerant, the second compressor body can be moved along an orbital path about a center axis with respect to the first compressor body, and a drive for the second compressor body, having a drive motor. 
     Compressors of this type are known from the prior art, for example DE 100 99 10 460. 
     In compressors of this type, there is a need to achieve the highest possible efficiency, in particular the lowest possible leakage, during compression of the refrigerant. 
     SUMMARY OF THE INVENTION 
     In the case of a compressor of the type described in the introduction, this object is achieved, in accordance with the invention, by the fact that the refrigerant which is to be compressed by the scroll compressor can wash around the two compressor bodies in the region of their rear side, which is remote from the scroll ribs, so that the compressor bodies can be cooled. 
     The advantage of the inventive solution is considered to be that it makes it possible for both compressor bodies to be cooled in the same way and therefore for at least a similar temperature distribution to be achieved in both compressor bodies, so that both compressor bodies have a similar thermal expansion, and therefore the low but not insignificant leakage which can be achieved by means of high manufacturing precision is not adversely affected by uneven temperature distributions and therefore different levels of thermal expansion, so that overall the efficiency of the scroll compressor is reduced as a result. 
     In this context, it is particularly advantageous if the refrigerant which is to be compressed can wash around the second compressor body in the region of the rear side, which is disposed opposite the second scroll rib, radially outside its driver receiving part, since refrigerant washing around the compressor body on its rear side ensures that this body is effectively cooled, and in particular cooling is ensured as close as possible to the regions of the compressor body in which most heat is introduced. 
     Furthermore, it is particularly advantageous if the refrigerant which is to be compressed can wash around the first compressor body in the region of a rear side, which is remote from the first scroll rib. 
     In this case too, it is particularly advantageous for the compressor body to be cooled via its rear side, in order once again to provide cooling as close as possible to the regions of the compressor body in which considerable amounts of heat are introduced, in particular through heated compressed refrigerant. 
     In order also to enable the scroll ribs to be cooled as efficiently as possible via the rear side of the compressor body, it is preferably provided that the rear surface of the respective compressor body is formed directly by a base which carries the respective scroll rib, so that the scroll ribs which are connected to the respective base are also cooled as efficiently as possible. 
     In particular, with a view to the most efficient conduction of heat possible, it is particularly advantageous if the rear side of the compressor body forms the rear side of a unitary part which includes the base and the scroll rib and, in particular in the region of the rear side, does not have any elements which are incorporated in or connected to, for example fitted onto, this part. 
     To improve the cooling of the compressor bodies still further, it is preferably provided that both compressor bodies can be cooled by the refrigerant which is to be compressed in the region of a peripheral side which is on the outer side with respect to the center axis. 
     In connection with the explanation of the cooling of the first compressor body in the region of its rear side, it has not been defined in more detail whether cooling takes place substantially over the entire rear side or only in partial regions of the rear side. 
     In particular, it has also not been specified in further detail to what extent the first compressor body is still fixed via the rear side. 
     A particularly favorable solution provides that the refrigerant which is to be compressed can wash around the first compressor body in the region of its rear side which lies outside a high-pressure connection. 
     This provides a particularly large area, namely the area which lies radially outside the high-pressure connection, for cooling of the first compressor body, the high-pressure connection also contributing, in particular at least in part, to fixing the first compressor body in the housing. 
     A solution which is particularly advantageous in design terms provides that a rear-side cooling chamber, through which the refrigerant which is to be compressed can wash, lies between the rear side of the first compressor body and a partition of the housing, which runs at a spacing from this rear side. 
     The rear-side cooling chamber may be formed in a very wide variety of ways. A particularly favorable solution provides for the rear-side cooling chamber to surround a mounting receiving part for the first compressor body, so that substantially the rear side of the compressor body, with the exception of the regions in which the mounting receiving part is active, can be cooled via the rear-side cooling chamber. 
     It is preferable for the mounting receiving part to be formed in such a way that the rear-side cooling chamber runs in the form of a ring around the mounting receiving part for the first compressor body. 
     In this context, it is particularly suitable if the high-pressure connection for the first compressor body is integrated into the mounting receiving part and therefore passes through this mounting receiving part. 
     Particularly efficient cooling of the first compressor body is achieved if the mounting receiving part can also be cooled via the rear-side cooling chamber, so that if heat is introduced into the mounting receiving part by the refrigerant emerging under high pressure, the mounting receiving part itself can be directly cooled, in order for this heat to be dissipated. 
     In connection with the previous explanation of the individual exemplary embodiments, emphasis has been placed primarily on the cooling of the compressor bodies via the rear side. The cooling of the compressor bodies can be improved still further by the fact that the rear-side cooling chamber merges into a peripheral-side cooling chamber which surrounds an outer periphery of the first compressor body. 
     In this case, it is preferable for the peripheral-side cooling chamber to surround not only the outer periphery of the first compressor body but also the outer periphery of the second compressor body. 
     A solution which is particularly advantageous in mechanical terms provides that the first compressor body is supported by outer support elements which lie radially outside the scroll ribs with respect to the center axis. 
     In this case, it is particularly advantageous if the peripheral-side cooling chamber runs around the outer support elements, and therefore cools the first compressor body via the outer support elements, in particular if the outer support elements are formed integrally on the first compressor body. 
     Thus far, no further statement has been made in connection with the cooling action of the refrigerant which is to be compressed and washes through the rear-side cooling chamber. By way of example, a particularly advantageous exemplary embodiment provides that the temperature of the surface, which borders the refrigerant which is to be compressed in the rear-side cooling chamber, of the first compressor body within an annular region which lies between approximately 50% and approximately 80%, preferably approximately 60% and approximately 70%, of a maximum radius of the scroll ribs is at most 8° centigrade, preferably at most 5° centigrade, higher than the temperature of the refrigerant which is to be compressed and reaches the second compressor body. 
     This relation shows that sufficient cooling of the first compressor body is possible even if refrigerant which is to be compressed washes sufficient thoroughly through the rear-side cooling chamber; this washing action may take place as a result of pressure fluctuations, turbulence or convection and does not necessarily require the refrigerant which is to be compressed to flow through the rear-side cooling chamber. 
     In connection with the above description of the individual exemplary embodiments, no further statements have been made with regard to the order in which the compressor bodies are cooled. 
     By way of example, a particularly advantageous exemplary embodiment provides that the refrigerant which is to be compressed washes around the second compressor body first of all and then around the first compressor body. 
     In principle, the refrigerant which is to be compressed could originate from any desired section of a cooling installation. It is particularly advantageous if the refrigerant which is used to cool the compressor bodies is the refrigerant which is to be sucked in by the scroll compressor. 
     It could be refrigerant which, after it has cooled the compressor bodies, also cools further units. A particularly advantageous embodiment provides that the refrigerant which is to be sucked in cools the compressor bodies substantially immediately before it enters an intake region of the scroll compressor. 
     This solution is advantageous if only for the reason that the refrigerant which is to be compressed and is to be fed to the scroll compressor in any case, immediately before it enters the intake region, can be used to cool the compressor bodies. 
     The solutions which have been described thus far have not provided any further details as to how the refrigerant which is to be compressed enters the scroll compressor. A particularly favorable solution provides that the refrigerant which is to be sucked in flows into the intake region of the scroll compressor at least in part from a peripheral side of the scroll compressor between the base of the first compressor body and the base of the second compressor body. 
     In particular, it is possible for the refrigerant which is to be sucked in to be guided in such a way that it flows into the intake region of the scroll compressor at least partially radially with respect to the center axis between the bases of the compressor bodies. 
     To achieve particularly efficient cooling of the rear-side cooling chamber, it has proven advantageous if the refrigerant which is to be compressed, at least in the form of a part-stream, flows with forced guidance through the rear-side cooling chamber, so that, as a result of the forced guidance of the part stream, sufficiently intensive washing through the rear-side cooling chamber is ensured under all operating conditions. 
     This can advantageously be achieved by the fact that the refrigerant which is to be sucked in flows into the intake region of the scroll compressor at least in part from the rear-side cooling chamber through at least one aperture in the base of the first compressor body. 
     The inevitable result of this is that at least a part stream of the refrigerant which is to be sucked in flows through at least a partial region of the rear-side cooling chamber and therefore the refrigerant which is to be compressed washes with sufficient intensity any regions of the rear-side cooling chamber through which there is no direct flow, as a result of turbulence, pressure fluctuations and/or convection, in order for these regions to be cooled. 
     An embodiment of the solution according to the invention which is particularly advantageous and in particular operates stably in all operating regions provides that all the refrigerant which is to be sucked in flows into the intake region of the scroll compressor through the rear-side cooling chamber and then through at least one aperture in the base of the first compressor body, so that this forced guidance of the refrigerant which is to be compressed ensures sufficiently intensive washing of the rear-side cooling chamber even at low volumetric flows. 
     Furthermore, if the refrigerant which is to be compressed is guided in this manner, there is a reduced risk of liquid refrigerant entering the intake region if the first compressor body is disposed above the second compressor body and in particular also above the drive. 
     In the compressor according to the invention, the drive motor usually also needs to be cooled. It could be cooled separately. However, an advantageous embodiment provides for the refrigerant which is to be compressed to cool the drive motor and the scroll compressor. 
     In order, in particular, to ensure that no liquid refrigerant enters the scroll compressor itself, in particular when the compressor is being started up, it is preferably provided that the refrigerant which is to be compressed cools the drive motor first of all and then cools the scroll compressor. As a result, it is easy to achieve sufficiently intensive heating of the refrigerant which is to be compressed before it enters the scroll compressor, in order to avoid liquid refrigerant in the scroll compressor. 
     No more detailed statements have been made concerning the flow through the drive motor. By way of example, an advantageous solution provides for the refrigerant which is to be compressed to cool the drive motor on the rotor side. 
     In addition or as an alternative to this, there is provision for the refrigerant which is to be compressed to cool the drive motor on the peripheral side. 
     Furthermore, the compressor according to the invention can be made particularly simple if the refrigerant which is to be compressed first of all flows around the second compressor body in the region of the rear side of the base thereof, in particular radially outside the support body, and then enters the intake region of the scroll compressor, since as a result the refrigerant which flows through the drive motor can be used to cool the second compressor body immediately after the drive motor. 
     Furthermore, it is preferably provided that the refrigerant which is to be compressed, before entering the intake region, flows around support elements of the scroll compressor which are on the radially outer side with respect to the center axis of the first scroll rib. 
     In connection with the description given thus far of the individual exemplary embodiments, no further statements have been made as to the sealing of the scroll rib. By way of example, an advantageous embodiment provides for the scroll ribs of one compressor body, on end sides which face the base of the other compressor body, to carry end-side seals which are fitted into grooves. 
     These end-side seals could be disposed immovably in the grooves. It is particularly advantageous if the end-side seals can move in the grooves, in the direction of the base of the other compressor body. 
     A particularly suitable embodiment provides that the end-side seals, under the action of the higher pressure in each case in the scroll compressor, can be moved in the direction of the base of in each case the other compressor body. 
     The end-side seals may be made from different materials. By way of example, it is known from the prior art to form the end-side seals from metal lamellae. A particularly advantageous solution provides for the end-side seals to be made from plastics. 
     It has proven particularly suitable for the end-side seals to be made from Teflon. 
     It is preferable to use a TefleR Teflon® compound comprising approximately 5% to approximately 20% of carbon and other strength-promoting additives. 
     Furthermore, in the compressor according to the invention it is preferable for a nonreturn valve, which prevents the refrigerant which is under high pressure from flowing back into the scroll compressor, to be associated with the high-pressure outlet. 
     In this case, it is preferable for the nonreturn valve to be formed in such a way that it has a seal seat which lies in the first compressor body. 
     An alternative solution provides that the nonreturn valve is disposed in a high-pressure chamber on a side of the partition which lies opposite the first compressor body. 
     Further features of the invention form the subject matter of the following description and of the drawing illustrating some exemplary embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a longitudinal section through a first exemplary embodiment of a compressor according to the invention; 
     FIG. 2 shows a section on line  2 — 2  in FIG. 1; 
     FIG. 3 shows a longitudinal section similar to that shown in FIG. 1 through a second exemplary embodiment; 
     FIG. 4 shows a section on line  4 — 4  in FIG. 3; 
     FIG. 5 shows a section similar to that shown in FIG. 3 through a third exemplary embodiment, and 
     FIG. 6 shows an enlarged illustration of region A in FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A first exemplary embodiment of a scroll compressor according to the invention, illustrated in FIG. 1, comprises a housing, which is denoted overall by  10  and in which an electric drive motor, denoted overall by  12 , and a scroll compressor, denoted overall by  14 , are disposed. 
     The scroll compressor  14  comprises a first compressor body  16  and a second compressor body  18 , the first compressor body  16  having a first scroll rib  22 , which rises above a base  20  thereof and is formed in the shape of an involute to a circle, and the second compressor body  18  having a second scroll rib  26 , which rises above a base  24  and is formed in the shape of an involute to a circle, the scroll ribs  22 ,  26  engaging in one another and in each case bearing in a sealing manner against the base  24  or  20 , respectively, of in each case the other compressor body  18 ,  16 , so that chambers  28  are formed between the scroll ribs  22 ,  26  and the base surfaces  20 ,  24  in which chambers a refrigerant, which flows in at an initial pressure via an intake region  30  which surrounds the scroll ribs  22 ,  26  on the radially outer side and, after compression in the chambers  28 , emerges having been compressed to high pressure via an outlet  32  provided in the first compressor body  16 , is compressed. 
     In the first exemplary embodiment described, the first compressor body  16  is held in a fixed position in the compressor housing  10 , while the second compressor body  18  can be moved on an orbital path, around a center axis  34 , relative to the first compressor body  16 , the scroll ribs  22  and  26  theoretically bearing against one another along a contact line and the contact line likewise revolving around the center axis  34  during the movement of the second compressor body  18  along the orbital path. 
     The drive motor  12  for driving the second compressor body  18  comprises a stator  40 , which is arranged in a fixed position in the housing  10 , and a rotor  42 , which sits on a drive shaft  44 , which for its part is mounted rotatably, specifically about the center axis  34 , in the housing  10 . 
     To couple the rotary movement of the drive shaft  44  to the second compressor body  18 , there is a driver unit, which is denoted overall by  50  and comprises an eccentric  52  which is formed as a driver and is disposed with an offset, specifically in the radial direction, with respect to the center axis  34 . 
     The driver  52  engages in a driver receiving part  54 , which is formed, for example, as a sleeve and is disposed at the base  24  of the second compressor  18 , specifically on a side thereof which lies opposite the scroll rib  26 , and faces toward the drive motor  12 . 
     As illustrated in FIG. 2, the driver receiving part  54 , which is formed as a sleeve, has an inner cylinder surface  60 , the cylinder axis of which on the one hand intersects the theoretically circular orbital path and on the other hand runs parallel to the center axis  34  but is arranged offset by the radius of the orbital path with respect to the center axis  34 . 
     The driver  52 , which is formed as an eccentric, is for its part likewise preferably formed as a cylindrical body with a cylindrical lateral surface  64 , the cylinder axis of which likewise runs parallel to the center axis  34  and, furthermore, is at a radial distance therefrom which approximately corresponds to the radius of the orbital path. 
     According to the invention, the driver  52  is formed in such a way that, by means of a driver surface, it bears against the inner cylinder surface  60 , which acts as a driver surface, of the driver receiving part  54  in a partial section, but otherwise runs without contact with respect to the driver surface  60 , as described in DE 199 10 460, to the entire content of which reference is expressly made with regard to the structure and function of the driver unit. 
     To allow advantageous cooling of the compressor according to the invention, an inlet  70  for refrigerant which is to be compressed is provided in the housing  10 , and specifically in the region of the driver motor  12 , through which inlet the refrigerant which is to be compressed flows into an outer motor cooling chamber  72  which lies between an outer housing wall  74  and a shielding sleeve  76  which surrounds the drive motor  12 . 
     From the outer motor cooling chamber  72 , the refrigerant which is to be compressed flows in the direction  78  to a housing base  80  which is remote from the scroll compressor  14 , but before it reaches the housing base  80  it is diverted radially inward by an intermediate base  81  and passes through passages  82  in the shielding sleeve  76  and then flows in direction  83  through the rotor  78 , approximately parallel to the axis  34 , until it reaches a carrying element  84 , which on one side has a bearing sleeve  86  for the drive shaft  44  and on the other side has carrying surfaces  88 , on which the second compressor element  18  rests by means of a rear side  90 , which is on the opposite side from the second scroll rib  26 , of the base  24  and is thereby supported in such a way that the second compressor body  18  is as a result prevented from moving away from the first compressor body  16 . 
     The refrigerant which is to be sucked in preferably flows around the carrying element  84 , during which process some of the refrigerant may also flow through the carrying element  84 , and thus reaches the rear side  90  of the base  24  and is diverted radially outward thereby into an outer cooling chamber  100 , which on one side is surrounded by the outer housing wall  74  and on the other side surrounds the scroll compressor  14  on the radially outer side. 
     This outer cooling chamber  100  is adjoined by a rear-side cooling chamber  110  which lies between a rear side  112  of the base  20  of the first compressor body  16  and a partition  114  fixed in the housing  10 , the partition  114  carrying a mounting receiving part  116 , by means of which a seal is produced between the pressure side and the suction side with respect to the first compressor body  16  in the region of the outlet  32  and by means of which the first compressor body  16  is also mounted, for example, on the partition  114 . 
     For its part, the partition  114  extends transversely through the housing  10  and delimits a high-pressure chamber  120  which lies between a housing cover  122  and the partition  114 , compressed refrigerant from the outlet  32  entering the high-pressure chamber  120  through the mounting receiving part  116 , preferably by means of a flow in the direction of the axis  34 . 
     Furthermore, the high-pressure chamber  120  is also provided with a high-pressure outlet  124 , through which compressed refrigerant emerges from the high-pressure chamber  120 . 
     The rear-side cooling chamber  110  surrounds the mounting receiving part  16  in the shape of a ring and, moreover is delimited on one side by the partition  14  and on the other side by the base  20  of the first compressor body  16 , more than half the area of the rear side  112  of the base  20  bordering the rear-side cooling chamber  110 , which runs radially outward with respect to the axis  34 , all the way to the outer cooling chamber  100 , and merges into the latter. 
     In the first exemplary embodiment, the refrigerant which is to be compressed enters the intake region  30  from the outer cooling chamber  100  by flowing in the radial direction from the outer cooling chamber  100 , between an outer region  128  of the base  20  and an outer region  130  of the base  24 , into the intake region  30 , which lies between the base  20  and the base  24  and, moreover, borders radially outer ends of the scroll ribs  22  and  24 . 
     The first compressor body  16  is preferably supported on the carrying element  84  via outer support elements  132 , which preferably engage on the base  20 , apertures  134  being provided between the support elements  132 , which apertures allow the refrigerant which is to be compressed to pass from the outer cooling chamber  100  into the intake region  30  in the radial direction with respect to the axis  34 . 
     In this case, the refrigerant which is to be sucked in washes through the entire outer cooling chamber  100  and the rear-side cooling chamber  110  as a result of convection of the refrigerant which is to be sucked in assisted by pressure oscillations caused by the driven second compressor body  18 , which is moving on an orbital path and which is bordered by the intake region  30  which is in communication with the outer cooling chamber  100  via the apertures  134 . 
     As a result of this washing through the entire outer cooling chamber  100  and the rear-side cooling chamber  110 , while the compressor is operating, a mean temperature which is at most 8° centigrade, preferably at most 5° centigrade, above a temperature of the refrigerant which reaches the second compressor body  18  is established in a region  111  of the rear side  112  which borders the rear-side cooling chamber  110  and lies within an annular region RB which extends over a radius from approximately 50% to approximately 80%, preferably approximately 60% to approximately 70%, of the maximum radius R of the scroll rib  22  of the first compressor body  16 , so that the heat which is introduced into the first compressor body  16  can be dissipated via the rear side  112  thereof. 
     In this way, the first compressor body  16  can be held at a temperature which substantially corresponds to the temperature of the second compressor body  18 , so that the thermal expansion of the respective base  20  or  24  and of the scroll ribs  22  or  26 , respectively, is substantially identical and therefore the two compressor bodies  16  and  18  do not have any significant temperature differences which lead to uneven thermal expansion and therefore to a reduction in the seal in the region of the scroll ribs  22  and  26  and between the scroll ribs  22  and  26  and the respective bases  24  and  20 . 
     Furthermore, in the first exemplary embodiment it is provided that the outlet  32  is disposed in the first compressor body  16 , approximately coaxially with respect to the axis  34 , and opens out into outlet passages  136  which pass through the mounting receiving part  116 . The fact that the mounting receiving part  116  directly borders the rear-side cooling chamber  110  means that it is also possible for heat to be discharged directly from the mounting receiving part  116  into the refrigerant which is washing through the rear-side cooling chamber  110 . 
     Furthermore, the mounting receiving part  116  is covered by a valve plate  138 , which is disposed in the high-pressure chamber  120  in order to prevent the refrigerant which is under a high pressure, is flowing through the mounting receiving part  116  and enters the high-pressure chamber  120 , from flowing back into the scroll compressor  14  at all times at which the pressure at the high-pressure outlet  124  is lower than in the high-pressure chamber  120 . 
     Furthermore, in the compressor according to the invention, as illustrated in FIGS. 1 and 2, the axis  34  is located in such a way that it runs eccentrically with respect to a cylinder axis  144  of the housing  10 , in order, in the region of electrical connections  137  for supplying power to the electric drive motor  12 , to create a greater distance between the outer wall  74  of the housing  10  and the shield  76 . 
     In a second exemplary embodiment of the compressor according to the invention, illustrated in FIG. 3, those parts which are identical to those of the first exemplary embodiment of the compressor according to the invention are provided with the same reference numerals, and consequently for a description of these parts reference can be made entirely to the statements made in connection with the first exemplary embodiment. 
     In the second exemplary embodiment, illustrated in FIG. 3, unlike in the first exemplary embodiment, the base  20  of the first compressor body  16  is provided, in a sector which borders the intake region  30 , with apertures  150  which, as illustrated in FIG. 4, are used to allow refrigerant which is to be compressed to flow from the rear-side cooling chamber  110  into the intake region  30  between the bases  22  and  26  and thereby to allow the refrigerant which is entering to flow with forced guidance through the rear-side cooling chamber  110  and in this way to ensure that, in the region of the rear side  112  of the base  20 , optimum washing through the rear-side cooling chamber  110  and thereby optimum cooling of the first compressor body  16  is obtained. 
     The apertures  150  are preferably disposed in such a way that the refrigerant which is to be compressed flows from the rear-side cooling chamber  110  directly into the intake region  30  between the bases  20  and  24 . 
     Nevertheless, in the second exemplary embodiment, refrigerant which is still to be compressed flows directly from the outer cooling chamber  100 , between the bases  20  and  24 , into the intake regions  30 , so that only some of the refrigerant which is to be compressed enters the rear-side cooling chamber  110  with forced guidance and flows at least in part through this chamber. 
     In a third exemplary embodiment, illustrated in FIGS. 5 and 6, those parts which are identical to the exemplary embodiments above are provided with the same reference numerals, and consequently, for explanations of these parts, reference can be made entirely to the statements which have been made in connection with the previous exemplary embodiments. 
     Unlike in the second exemplary embodiment, the possibility of refrigerant which is to be compressed passing from the outer cooling chamber  100  into the intake region  30  is substantially suppressed by a collar  152  which surrounds the scroll compressor  14 , so that the refrigerant which is to be compressed, on its way from washing around the second compressor body  18  to washing around the first compressor body  16 , flows through the outer cooling chamber  100  substantially parallel to the axis  34  and in the process cools the scroll compressor  14  on the peripheral side via the collar  152 , then flows into the rear-side cooling chamber  110 , flows at least partially through the latter and then enters the intake region  30  of the scroll compressor  14  via the apertures  150 . 
     Substantially the entire stream of the refrigerant which is to be sucked in is introduced into the rear-side cooling chamber  110  and, through turbulence and/or diffusion of the refrigerant which is to be compressed, leads to the rear side  112  of the base  20  being washed around. 
     Therefore, the entire stream of refrigerant which is to be sucked in which flows into the intake region  30  passes at least in part through the rear-side cooling chamber  110  before this stream enters the intake region  30  through the apertures  150 , so that optimum washing through the rear-side cooling chamber  110  and therefore optimum cooling of the first compressor body  16  and also of the mounting receiving part  116  takes place in the same way as for the second compressor body  18  through additional diffusion or also turbulent flows which form, so that both compressor bodies  16  and  18  preferably form the same temperature profile and therefore it is possible to optimize the temperature control of the two compressor bodies  16  and  18 , which contributes to improving the sealing of the scroll compressor  14  during operation. 
     In the third exemplary embodiment, moreover, a nonreturn valve  160  with a valve body  162  is disposed in the first compressor body  16 . For this purpose, a valve seat face  164  directly borders the outlet  32  as ring face on which the valve body  162  can be fitted in a tightly sealing fashion. 
     Furthermore, the valve body  162  is loaded toward the valve seat face  164  by means of a spring  166  and is therefore only lifted off the valve seat face  164  by the compressed refrigerant flowing out of the outlet  32 . 
     The advantage of this nonreturn valve  160  is that it can be arranged as close as possible to the outlet  32  without a large harmful volume. 
     Furthermore, in the third exemplary embodiment, as illustrated in FIG. 6, each of the scroll ribs, illustrated by way of example for scroll rib  26 , is provided with an end-side seal  170  which is inserted into a groove  174  which has been machined into an end side  172  of the respective scroll rib  26  and comprises two lateral groove walls  176  and  178  and a groove base  180 , the dimensions of the end-side seal  170  being such that it can move inside the groove  174  and therefore can be acted on in the direction of a base surface  182  of the base  20  of in each case the other compressor body. 
     It is therefore possible, starting from the chamber  28   a  which is under higher pressure, for the refrigerant which is to be compressed to act upon the end-side seal in such a way that the seal comes off the side wall  176  which faces the chamber  28   a  which is under a higher pressure and comes to bear against the side wall  178  which faces the chamber  28   b  which is under a lower pressure. The refrigerant which is under a higher pressure flows onward to the groove base  180  and therefore leads to the end-side seal  170  lifting off the groove base  180  and being moved toward the base surface  182  by the refrigerant which is under higher pressure, thereby being held in contact therewith. 
     In this way, it is advantageously possible to improve the seal between the individual scroll ribs  26  and the base surfaces  182  of in each case the other compressor body  20 , and thereby, moreover, to additionally increase the efficiency of the scroll compressor  14 . 
     It is particularly advantageous if the end-side seals  170  are produced from a plastics material like flouropolymer resins preferably Teflon®, in particular a Teflon® compound containing 5% to 20% of carbon or other strength-improving additives.