Patent Publication Number: US-11396877-B2

Title: Scroll compressor having axial guide support

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This patent application is a continuation of U.S. patent application Ser. No. 15/459,594, filed Mar. 15, 2017, which is a continuation of Application No. PCT/EP2015/070568, filed Sep. 9, 2015, and claims the benefit of German Application No. 10 2014 113 435.4, filed Sep. 17, 2014, the entire teachings and disclosure of which are incorporated herein by reference thereto. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to a compressor, including a compressor housing, a scroll compressor unit that is arranged in the compressor housing and has a first, stationary compressor body and a second compressor body that is movable in relation to the stationary compressor body, whereof first and second scroll vanes, in the shape of a circle involute, engage in one another to form compressor chambers when the second compressor body is moved in relation to the first compressor body on an orbital path, an axial guide that supports the movable compressor body to prevent movements in the direction parallel to a centre axis of the stationary compressor body and, in the event of movements, guides it in the direction transverse to the centre axis, a drive motor that drives an eccentric drive for the scroll compressor unit, wherein the eccentric drive has an entrainer that is driven by the drive motor, that revolves on a path about a centre axis of the drive shaft and that cooperates with an entrainer receptacle in the second compressor body, and a coupling that prevents the second compressor body from rotating freely. 
     Compressors of this kind are known from the prior art. 
     A requirement of these compressors is that they are constructed to be as lightweight and compact as possible, so that they can be used for example in automotive technology. 
     SUMMARY OF THE INVENTION 
     This object is achieved according to the invention in the case of a compressor of the type mentioned in the introduction in that the axial guide supports a compressor body base, which carries the scroll vane, of the second compressor body against an axial support face, in that the axial support face abuts a sliding body such that it is slidable transversely to the centre axis, the sliding body for its part being supported, such that it is slidable transversely to the centre axis, on a carrier element that is arranged in the compressor housing. 
     The advantage of the solution according to the invention can be seen in the fact that, as a result of the sliding body provided between the axial support face of the compressor body base and the carrier element on the compressor housing, it is possible to guide the second compressor body on the one hand with optimum support and on the other with little wear, since the sliding body that is arranged between the axial support face and the carrier element creates the possibility of providing an optimum supply of lubricant. 
     In theory, the sliding body could be movable in one dimension, either in relation to the compressor body base or in relation to the carrier element. 
     It is particularly favourable if the sliding body is movable in two dimensions, in relation to the compressor body base and in relation to the carrier element. 
     This makes sufficient lubrication of the support between the axial support face and the sliding body, and between the sliding body and the carrier element, achievable simply and reliably. 
     Particularly advantageously, movability of the sliding body can be achieved if the sliding body is guided in a two-dimensional guidance with play in relation to the compressor body base or in relation to the carrier element. 
     Here, guidance with play allows the two-dimensional movability of the sliding body to be achieved in a simple manner and for the permitted extent thereof to be established. 
     For example, guidance with play makes it possible to establish that the sliding body can perform a limited guiding orbital movement in relation to the compressor base or in relation to the carrier element. 
     Here, the orbital movement is advantageously defined by a guiding orbital radius that is smaller than the compressor orbital radius of the movable compressor body. For example, the values of the guiding orbital radius for the sliding body are equal to 0.5 that of the compressor orbital radius. It is better if the values of the guiding orbital radius are 0.3 that of the compressor orbital radius or less, and even better 0.2 that of the compressor orbital radius or less. 
     In order to obtain a minimum lubrication, the guiding orbital radius is 0.01 that of the compressor orbital radius or more, and, better, 0.05 that of the compressor orbital radius or more. 
     More detailed comments have not yet been made as regards the form taken by the guidance with play. 
     Here, an advantageous solution provides for the guide to have a first guiding element that is arranged on the sliding body and a second guiding element that is either connected to the compressor body base or to the carrier element. 
     The most diverse possibilities are conceivable for the form taken by the guiding elements. 
     It is particularly favourable if the guidance with play has, as the guiding elements, a guide pin and a guide recess that cooperates with the guide pin, and these are movable in two dimensions in relation to one another in that the guide pin engaging in the guide recess is movable within the guide recess as a result of its diameter, which is smaller than the diameter of the guide recess. 
     The most diverse possibilities are conceivable for achieving the form taken by the axial support face. 
     For example, it is conceivable for the axial support face to be composed of individual partial faces that are arranged on the second compressor body. 
     These partial faces may then be arranged in different regions of the second compressor body. 
     In order to achieve optimum support, lubrication and guidance, however, it is preferably provided for the axial support face to take the form of an annular face surrounding the centre axis of the movable compressor body. 
     An annular face of this kind enables reliable, uniform and secure support of the second compressor body and at the same time the creation of a homogeneous film of lubricant, which is very important for the guidance properties and the resistance to wear. 
     In this case, the axial support face could be supported against individual face regions of the sliding body. 
     However, it is particularly favourable if the axial support face is supported on an annular face of the sliding body that surrounds the centre axis. 
     Preferably in this case, the annular face of the sliding body is dimensioned such that it is larger than the annular face of the axial support face, with the result that the axial support face is always supported over its full surface on the annular face of the sliding body as the second compressor body orbits. 
     In order to ensure optimum provision of lubricant for a lubricant film between the axial support face and the sliding body, it is preferably provided for the axial support face to be adjoined, radially outwardly and/or radially inwardly, by an edge face that is set back in relation to a plane in which the axial support face extends. 
     A particularly favourable solution provides for the edge face to directly adjoin the axial support face and thus also to reach as far as the plane in which the axial support face extends, and then to run at an increasing spacing from the plane in which the axial support face extends as its spacing from the axial support face increases. When the edge face has for example a step-shaped or wedge-shaped course of this kind, the supply of lubricant to the axial support face from the outside thereof is assisted. 
     The supply of lubricant between the axial support face and the sliding body may be further assisted if the axial support face and/or a sliding support face that carries the axial support face is provided with micro-recesses, for example micro-recesses that result from the material and/or are machined and/or stamped in, and that receive, retain and distribute lubricant. 
     More detailed comments have not yet been made as regards guidance of the sliding body in relation to the carrier element. 
     Here, an advantageous solution provides for the sliding body to be supported against the carrier element by means of a sliding bearing face. 
     The sliding bearing face could in this case likewise be formed by partial faces. 
     It is particularly favourable if the sliding bearing face takes the form of an annular face surrounding the centre axis of the stationary compressor body. 
     Furthermore, it is preferably provided for the carrier element to have a carrier face against which the sliding body is supported by means of the sliding bearing face. 
     This carrier face could also be formed by individual partial faces. 
     However, it is particularly advantageous if the carrier face takes the form of an annular face rotating about the centre axis of the stationary compressor body. 
     The supply of lubricant between the carrier element and the sliding body may be further assisted if the sliding bearing face and/or a carrier face that carries the sliding bearing face is provided with micro-recesses, for example micro-recesses that result from the material and/or are machined and/or stamped in, and that receive, retain and distribute lubricant. 
     Further, more detailed comments have not been made as regards the form taken by the sliding body. 
     In principle, the sliding body could take any desired shape. 
     For reasons of manufacturing engineering, it is particularly favourable if the sliding body takes a plate-like form, in particular as an annular disc. 
     Further, more detailed comments have not been made as regards the choice of materials in the compressor according to the invention. 
     Here, an advantageous solution provides for the first, stationary compressor body to be made from cast steel. 
     A first compressor body of this kind made from cast steel has optimum stability and fatigue strength. 
     Further, it is preferably provided for the second compressor body to be made from an aluminium alloy, in particular from cast aluminium alloy. 
     Manufacturing the second compressor body from an aluminium alloy has the advantage that this second compressor body has a small mass, which is advantageous in particular if the second compressor body is to move at high speed on the orbital path about the centre axis of the first compressor body. 
     Further, pairing the materials of an aluminium alloy and cast steel for the first and the second compressor body has the advantage of good running properties with high fatigue strength and long service life. 
     More detailed comments have not been made in conjunction with the description given above of the individual embodiments as regards the material for the sliding body. 
     In principle, the sliding body could be made from any desired material, although there should be an optimum pairing of materials for the second compressor body and the carrier element. 
     Here, it has proved particularly advantageous if the sliding body is made from spring steel. 
     Forming the sliding body from spring steel has the advantage on the one hand that it provides a favourable pairing of materials with the second compressor body, made from aluminium, and on the other hand that it also allows an optimum pairing of materials with the carrier element. 
     Moreover, forming the second sliding body from spring steel also has major advantages for cost reasons, since spring steel is an inexpensive material from which the shape suitable for the sliding body can be made in simple manner by cutting or punching. 
     More detailed comments have not yet been made as regards the carrier element. 
     In the simplest case, the carrier element could be made from steel or indeed from the material of the compressor housing. 
     In order to achieve a very sturdy construction, however, it is preferably provided for the carrier element to be made from sintered material, for example sintered metal. 
     A particularly favourable solution provides for the carrier element to have a carrier face formed by an open-pored sintered material, on which the sliding body is supported by means of its sliding bearing face. 
     An open-pored sintered material of this kind for forming the carrier face has the major advantage that it can advantageously take up lubricant and then also discharge it for the purpose of lubrication between the carrier face and the sliding bearing face. 
     In this case, the lubricant may be held in particular in the open pores of the sintered material such that a film of lubricant can be permanently maintained between the carrier face and the sliding bearing face in a simple manner. 
     The use of sintered material that is softer than the spring steel of the sliding element has proved favourable, such that a pairing of the materials of the carrier element and the sliding body that is advantageous for sliding guidance is produced. 
     As an alternative or in addition to the solution described above to the object mentioned in the introduction, in the case of a further compressor of the type described in the introduction it is provided for the axial guide to support the second compressor body against an axial support face that is formed by the latter such that it is slidable transversely in relation to the centre axis, and for the axial support face to be formed by a compressor body base that carries the scroll vane. 
     A solution of this kind may be produced in a manner that is in particular advantageous for production engineering, since there is no need for a separate part for forming the support face, but rather the support face may itself be formed by the compressor body base. 
     In particular, in this case it is favourable if the entrainer receptacle is integrated in the compressor body base such that there is no need for a further part for this either. 
     Preferably in this case, the entrainer receptacle is arranged on the compressor body base such that it does not project beyond the support face in the direction parallel to the centre axis of the movable compressor body, with the result that the forces acting on the entrainer receptacle when the second compressor body is driven, as seen in the direction parallel to the centre axis, act on the second compressor body between the support face and the scroll vanes and hence the tilting moments that act on the second compressor body during operation of the scroll compressor unit are kept small. 
     As an alternative or in addition to the exemplary embodiments described above, for the purpose of solving the object mentioned in the introduction it is provided, in the case of a further compressor, for the coupling that prevents free rotation to have at least two coupling element sets that include at least two coupling elements. 
     A coupling of this kind may be achieved in the most diverse ways. In order to achieve advantageous support of the second compressor body in relation to the compressor housing with a coupling of this kind, it is preferably provided for one of the coupling elements to be held on the compressor body base. 
     Further, it is preferably provided for one of the coupling elements to be held on the carrier unit. 
     In this case, the coupling element sets are thus arranged and take a form such that they act directly between the carrier unit and the compressor body base of the second compressor body, with the result that a compact construction may be achieved. 
     In order to improve guidance of the second compressor body in relation to the compressor housing by the coupling, it is preferably provided for the coupling that prevents free rotation to have more than two coupling element sets. 
     More detailed comments have not yet been made as regards the coupling element sets. 
     Here, an advantageous solution provides for the coupling element sets to be arranged at equal angular spacings around the centre axis of the orbital path. 
     More detailed comments have not yet been made as regards the form taken by the coupling elements themselves. 
     Here, an advantageous solution provides for one of the coupling elements to be formed by a pin body. 
     Moreover, it is advantageously provided for one of the coupling elements to take the form of a cylindrical receptacle. 
     A further advantageous solution provides for one of the coupling elements to take the form of an annular body arranged in the cylindrical receptacle. 
     Preferably, it is provided here for the annular body to be seated in the cylindrical receptacle loosely, that is to say with play, and thus to be able to move in relation to the cylindrical receptacle. 
     A construction of this kind of the coupling element sets has the major advantage on the one hand that they ensure optimum lubrication and on the other that they enable low-noise movement of the second compressor body in relation to the first compressor body, since in each of the coupling element sets there are two films of lubricant with a damping action, namely on the one hand a film of lubricant between the pin body and the annular body and on the other a film of lubricant between the annular body and the cylindrical receptacle in which the annular body is arranged. 
     More detailed comments have not yet been made as regards the arrangement of the coupling element sets in relation to the sliding body. 
     In principle, the sliding body and the coupling element sets could be arranged separately from one another. 
     For example, the sliding body could extend peripherally around the outside of the coupling element sets, or vice versa. 
     It is advantageous if the coupling element sets pass through the sliding body such that lubricant can be transported between the sliding body and the coupling element sets, in particular if the coupling element sets pass through openings in the sliding body. 
     In order in particular also to lubricate the coupling element sets to the optimum, it is preferably provided for the compressor body base of the second compressor body to be provided with pockets that have openings facing the cylindrical receptacles of the coupling element sets. 
     Pockets of this kind, with openings facing the cylindrical receptacles, have the advantage that lubricant is entrained thereby as the second compressor body base orbits, and so lubricant can always be transported to the cylindrical receptacles. 
     The action of the pockets is particularly favourable if the openings in the pockets are positionable to overlap in each case with two cylindrical receptacles that are arranged succeeding one another in the peripheral direction, that is to say that in this case the openings in the pockets have an angular extent such that, as the compressor body base orbits, they can in each case connect two pockets to one another in individual angular positions and so lubricant can advantageously be transported from one cylindrical receptacle to the next cylindrical receptacle. 
     The features of the solution according to the invention that have been described in conjunction with the embodiments above are particularly advantageous if the centre axis of the stationary compressor body extends in a level position. 
     Here, an extent in the level position of the centre axis of the stationary compressor body means that during operation of the compressor according to the invention the centre axis extends approximately parallel to the horizontal, wherein the term “approximately parallel” should be understood to mean that the angle between the centre axis and the horizontal when the compressor according to the invention is used in a normal operating mode is at most 30°, or better at most 20°. 
     Further, in the solution according to the invention it is likewise advantageously provided for the drive shaft of the drive motor to extend substantially in a level position, wherein the same conditions apply to the angle between the centre axis of the drive shaft and the horizontal as for the alignment of the centre axis of the stationary compressor body in relation to the horizontal. 
     Moreover, it is advantageous for the object stated in the introduction if the compressor housing is also made from an aluminium alloy, so that the compressor according to the invention can be constructed with as low a weight as possible. 
     Moreover, this also gives the compressor better resistance to the influence of external weather conditions. 
     Further features and advantages of the invention form the subject matter of the description below and the representation in the drawing of some exemplary embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective illustration of a compressor according to the invention; 
         FIG. 2  shows a longitudinal section through the compressor according to the invention, in a plane of section extending through a centre axis of a stationary compressor body; 
         FIG. 3  shows a cross section through a scroll compressor unit, in the region of the mutually engaging scroll vanes, and an illustration of an orbital path of the movable scroll vane in relation to the stationary scroll vane; 
         FIG. 4  shows a longitudinal section according to  FIG. 2  on a larger scale, in the region of the movable compressor body and an axial guide for the movable compressor body; 
         FIG. 5  shows a section on an even larger scale, through a partial region of the axial guide, in the region of guidance with play for a sliding body of the axial guide; 
         FIG. 6  shows a plan view of the axial guide, with the sliding body and a carrier element that carries the latter; 
         FIG. 7  shows a perspective illustration of the axial guide, together with coupling elements of a coupling for preventing it from rotating freely, including a plurality of coupling element sets; 
         FIG. 8  shows a plan view of a flat side of the movable compressor body, opposite the scroll vane; 
         FIG. 9  to  FIG. 14  show a schematic illustration of the cooperation between the coupling element sets of the coupling that prevents free rotation; 
         FIG. 15  shows a section along the line  15 - 15  in  FIG. 4 ; and 
         FIG. 16  shows a section along the line  16 - 16  in  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An exemplary embodiment illustrated in  FIG. 1 , of a compressor according to the invention which is designated  10  as a whole, and is for a gaseous medium, in particular a refrigerant, includes a compressor housing which is designated  12  as a whole and has a first end housing portion  14 , a second end housing portion  16  and an intermediate portion  18  arranged between the end housing portions  14  and  16 . 
     As illustrated in  FIG. 2 , provided in the first housing portion  14  is a scroll compressor unit which is designated  22  as a whole and has a first compressor body  24 , which is arranged to be stationary in the compressor housing  12 , in particular in the first housing portion  14 , and a second compressor body  26 , which is movable in relation to the stationary compressor body  24 . 
     The first compressor body  24  includes a compressor body base  32  surmounted by a first scroll vane  34 , and the second compressor body  26  likewise includes a compressor body base  36  surmounted by a second scroll vane  38 . 
     The compressor bodies  24  and  26  are arranged in relation to one another such that the scroll vanes  34 ,  38  engage in one another in order to form between them, as illustrated in  FIG. 3 , at least one and preferably a plurality of compressor chambers  42  in which the gaseous medium, for example refrigerant, is compressed in that the second compressor body  26  moves with its centre axis  46  about a centre axis  44  of the first compressor body  24  on an orbital path  48  having a compressor orbital path radius VOR, wherein the volume of the compressor chambers  42  decreases and ultimately compressed gaseous medium emerges through a central outlet  52 , while gaseous medium to be drawn in is drawn in on the radially outer side in relation to the centre axis  44 , through peripherally opening compressor chambers. 
     The compressor chambers  42  are also sealed off from one another in particular in that the scroll vanes  34 ,  38  are provided on their end side with axial sealing elements  54  and  58  respectively, which abut sealingly against the respective bottom face  62 ,  64  of the respectively other compressor body  26 ,  24 , wherein the bottom faces  62 ,  64  are formed by the respective compressor body base  36  and  32  respectively and lie in a plane extending perpendicular to the centre axis  46 . 
     The scroll compressor unit  22  is received as a whole in a first housing body  72  of the compressor housing  12 , wherein this housing body  72  has an end cover portion  74  and a cylindrical annular portion  76  that is integrally formed in one piece with the end cover portion  74  and for its part engages by means of an annular projection  78  in an end bushing  82  of a central housing body  84  that forms the intermediate portion  18 , wherein the central housing body  84  is terminated at a side opposite the first housing body  72  by a second housing body  86  that forms an inlet chamber  88  for the gaseous medium. 
     Here, by means of the cylindrical annular portion  76 , the first housing body  72  surrounds a receptacle  92  for the scroll compressor unit  22 , and this receptacle has a bearing face  94  for the compressor body base  32  of the first compressor body  24 . 
     In particular, the first compressor body  24  is immovably fixed in the receptacle  92  in a manner preventing any movement parallel to the bearing face  94 . 
     In this way, the first compressor body  24  is fixed within the first housing body  72  and thus also within the compressor housing  12  such that it is stationary in a precisely defined position. 
     The second, movable compressor body  26 , which has to move on the orbital path  48  about the centre axis  44  in relation to the first compressor body  24 , is guided in relation to the centre axis  44  in the axial direction by an axial guide, which is designated  96  as a whole and supports and guides the compressor body base  36  at a flat side  98  remote from the scroll vane  38 , in the region of an axial support face  102 , such that the compressor body base  36  of the second compressor body  26  is supported, in relation to the first compressor body  24  that is positioned stationary in the compressor housing  12 , and in the direction parallel to the centre axis  44 , such that the axial sealing elements  58  remain against the bottom face  64  and do not lift away therefrom, wherein at the same time the compressor body base  36  can move with the axial support face  102  such that it can slide transversely to the centre axis  44  in relation to the axial guide  96 . 
     For this purpose, as illustrated in  FIG. 4 , the axial guide  96  is formed by a carrier element  112 , which is made in particular from an open-pored sintered material and has a carrier face  114  that faces the axial support face  102  but on which the compressor body base  36  does not lie by means of the axial support face  102 , but rather on which there lies a sliding body  116 , in particular plate-like and designated  116  as a whole, having a sliding bearing face  118 , wherein the sliding body  116  guides the axial support face  102  in a manner supported by means of a sliding support face  122  opposing the sliding bearing face  118 , to prevent movements parallel to the centre axis  44 , but supported such that it is slidable in respect of movements transverse to the centre axis  44 . 
     In this way, an axial movement of the second compressor body  26  in the direction of the centre axis  44  is prevented, but a movement in a plane transverse, in particular perpendicular, to the centre axis  44  is made possible. 
     Here, the axial guide  96  according to the present invention provides, in the event of a movement of the second compressor body  26  on the orbital path  48  about the centre axis  44  of the first compressor body  24 , on the one hand for the second compressor body  26  to move with the compressor body base  36  and the axial support face  102  thereof in relation to the sliding body  116 , and on the other hand for the sliding body  116  itself to move in relation to the carrier element  112 . 
     In this way, sliding takes place between the compressor body base  36  and the sliding body  116  as a result of a movement of the axial support face  102  in relation to the sliding support face  122  of the sliding body  116 , and moreover the sliding bearing face  118  of the sliding body  116  slides in relation to the carrier face  114  of the carrier element  112 . 
     To improve lubrication, for example the sliding support face  122  and the sliding bearing face  118  of the sliding body  116  are provided with recesses  123 , in particular micro-recesses, which form receptacles for a lubricant and contribute to distribution of the lubricant, as illustrated by way of example in  FIG. 6  in conjunction with the sliding support face  122 . 
     In order to predetermine the limited two-dimensional movability of the sliding body  116  in relation to the carrier element  112  and parallel to a plane E perpendicular to the centre axis  44 , the sliding body  116  is guided in relation to the carrier element  112  by a guidance with play which is designated  132  as a whole, wherein the guidance with play  132  includes a guide cutout  134  that is provided in the sliding body  116  and has a diameter DF, and also includes a guide pin  136  that is anchored in the carrier element  112  and whereof the diameter DS is smaller than the diameter DF, with the result that half of the difference DF-DS defines a guide orbital radius FOR by means of which the sliding body  116  can perform an orbital movement in relation to the carrier element  112 . 
     In order to ensure that a sufficient film of lubricant is formed between the axial support face  102  of the compressor body base  36  and the sliding support face  122  of the sliding body  116 , and between the carrier face  114  and the sliding bearing face  118 , the carrier element  112  is provided with radially outward pockets  142  that extend below an outer edge region  144  of the sliding body  116  and thus facilitate the access of lubricant into an intermediate space  146  between the carrier face  114  and the sliding bearing face  118 . 
     Further, because of the movement of the sliding body  116  with the guide orbital radius FOR in relation to the carrier element  112 , the intermediate space  146  is filled with a film of lubricant  147  in a manner similar to the mode of operation of a hydrodynamic bearing. 
     For a stable film of lubricant  147 , it is sufficient if the guide orbital radius FOR is 0.01 times the compressor orbital radius VOR or more, in particular 0.05 times the compressor orbital radius VOR or more. 
     In particular, the guide orbital radius FOR is 0.3 times the compressor orbital radius VOR or less, or, better, 0.2 times the compressor orbital radius VOR or less. 
     Further, as a result of the fact that the carrier element  112  is made, at least in the region of the carrier face  114 , from an open-pored sintered material, in addition improved lubrication is ensured in that lubricant enters the pores of the carrier element  112  and is thus retained in the region of the carrier face  114  for the purpose of forming the film of lubricant  147  in the intermediate space  146 , by way of the pores of the carrier element  112 . 
     The formation of the film of lubricant  147  in the intermediate space is additionally assisted by the fact that the sliding body  116  itself takes the form of a plate-like annular part and made of spring steel, and so the sliding bearing face  118  facing the carrier face  114  creates a smooth surface of spring steel. 
     Further, the pairing of materials made from open-pored sintered material, which is softer in the region of the carrier face  114  than spring steel, and the spring steel in the region of the sliding bearing face  118  has advantageous properties when used over the long term, because of the resistance to wear. 
     In order furthermore to ensure that a film  149  of lubricant is formed in an intermediate space  148  between the sliding support face  122  and the axial support face  102 , the compressor body base  36  is provided, in a radially outward and a radially inward region  152 , with an edge surface  154  that extends inclined to the axial support face  102 , is set back in relation to the axial support face  102  and, together with the sliding bearing face  122 , results in an intermediate space  158  that opens radially outwardly or radially inwardly in the shape of a wedge and facilitates the access of lubricant to the intermediate space  148 . 
     As illustrated in  FIGS. 4, 6, 7 and 8 , the axial support face  102  and the sliding support face  122  cooperating therewith and the carrier face  114  and the sliding bearing face  118  cooperating therewith are all arranged radially outwardly of a plurality of coupling element sets  162 , which are arranged at the same radial spacings from the centre axis  44  and at the same angular spacings peripherally around the centre axis  44 , and together form a coupling  164  that prevents the second, movable compressor body  26  from rotating freely. 
     Each of these coupling element sets  162  includes, as illustrated in  FIGS. 4 and 6 to 8 , as the first coupling element  172  a pin body  174  that has a cylindrical surface  176  and, by means of this cylindrical surface  176 , engages in a second coupling element  182 . 
     The second coupling element  182  is formed by an annular body  184  that has a cylindrical internal face  186  and a cylindrical external face  188 , which are arranged coaxially to one another. 
     This second coupling element  182  is guided in a third coupling element  192 , which takes the form of a receptacle  194 , provided in the carrier element  112 , for the annular body  184  and has a cylindrical internal wall surface  196 . As shown in  FIG. 9 , the second coupling element  182  defines an internal hole  183 , wherein a central axis  185  of the cylindrical receptacle  194  intersects and passes axially through the internal hole  183 . 
     Here, in particular a diameter DI of the internal wall surface  196  is greater than a diameter DRA of the cylindrical external face  188  of the annular body  184 , and a diameter DRI of the cylindrical internal face  186  is necessarily smaller than the diameter DRA of the cylindrical external face  188  of the annular body  184 , wherein moreover the diameter DRI of the cylindrical internal face  186  is greater than a diameter DSK of the cylindrical superficial face  176  of the pin body  174 . 
     In this way, each coupling element set  162  forms a separate orbital guide, whereof the maximum orbital radius OR for the orbital movement corresponds to DI/2-(DRA-DRI)-DSK/2. 
     By dimensioning the orbital radius OR of the coupling element sets  162  such that it is slightly greater than the compressor orbital radius VOR, defined by the compressor bodies  24  and  26  of the scroll compressor unit  22 , the movable compressor body  26  is guided in relation to the stationary compressor body  24  by the coupling  164  such that, as illustrated in  FIGS. 9 to 14 , in each case one of the coupling element sets  162  acts to prevent free rotation of the second, movable compressor body  26 , wherein, for example if there are six coupling element sets  162 , after an angular range of 60° has been covered, the action of each coupling element set  162  changes from one coupling element set  162  to the succeeding coupling element set  162  in the direction of rotation. 
     Because each coupling element set  162  has three coupling elements  172 ,  182  and  192 , and in particular an annular body  184  acts between the respective pin body  174  and the respective receptacle  194 , on the one hand the resistance to wear of the coupling element sets  162  is improved and on the other the lubrication in the region thereof is improved, and moreover the development of noise in the coupling element sets  162 , produced by the change in action from one coupling element set  162  to the next coupling element set  162 , is also reduced. 
     Here, it is in particular essential that the coupling element sets  162  are given sufficient lubrication, in particular lubrication between the cylindrical superficial face  176  of the pin body  174  and the cylindrical internal face  186  of the annular body  184 , and lubrication between the cylindrical external face  188  of the annular body  184  and the cylindrical internal wall surface  196  of the receptacle  194 . 
     One possibility provides for the coupling element sets  162  to pass through the sliding body  116 , in particular for the pin bodies  174  to pass through openings  198  ( FIG. 7 ) in the sliding body  116 , as a result of which lubricant from the lubricant films  147  and  149  can be supplied to the coupling element sets  162 . 
     In order to assist lubrication, as illustrated in  FIGS. 8 and 15 , there are provided in the compressor body base  36 , between the bores  202  receiving the first coupling elements  172 , pockets  204  which have, in the flat side  98  that delimits the compressor body base  36 , an opening  206  which has an angular extent in relation to the centre axis  46  of the compressor body base  36  such that, as illustrated in  FIG. 15 , they can overlap in individual rotational positions with two receptacles  194  of the coupling element sets  162  that succeed one another in the direction of rotation, with the result that the pockets  204  are in a position to perform an exchange of lubricant between successive coupling element sets  162  and thus to enable a uniform supply of lubricant to all the coupling element sets  162 . 
     Preferably, the pockets  204  are arranged such that they extend on either side of a geometric arc  208  about the centre axis  46  which bisects the bores  202  in order always to achieve optimum overlap with the receptacles  194 . 
     The concept according to the invention, of lubrication of the axial guide  96  and the coupling element sets  162 , is particularly advantageous if in the normal case the centre axes  44  and  46  of the compressor bodies  24  and  26  extend in a level position, that is to say at an angle of at most 30° to the horizontal, in which case there is formed in the compressor housing  12 , in particular in the region of the first housing body  72 , at the lowest point with respect to the direction of gravity, a bath  210  of lubricant out of which lubricant swirls up during operation and in so doing is received and distributed in the manner described. 
     The movable compressor body  24  is driven by a drive motor which is designated  212  as a whole and which has in particular a stator  214  that is held in the central housing body  84  and a rotor  216  that is arranged within the stator  214  and is arranged on a drive shaft  218  that extends coaxially in relation to the centre axis  44  of the stationary compressor body  24 . 
     The drive shaft  218  is mounted on the one hand in a bearing unit  222  that is arranged between the drive motor  212  and the scroll compressor unit  22  and in the central housing body  84 , and on the other in a bearing unit  224  that is arranged on an opposite side of the drive motor  212  to the bearing unit  222 . 
     Here, the bearing unit  224  is mounted for example in the second housing body  86 , which closes off the central housing body  84  on an opposite side to the first housing body  72 . 
     Medium that is drawn in here, in particular the refrigerant, flows from the inlet chamber  88  formed by the second housing body  86  and through the electric motor  212  in the direction of the bearing unit  222 , flows around the latter and then flows in the direction of the scroll compressor unit  22 . 
     By way of an eccentric drive which is designated  232  as a whole, the drive shaft  218  drives the movable compressor body  26 , which moves in an orbit around the centre axis  44  of the stationary compressor body  24 . 
     The eccentric drive  232  in particular includes an eccentric pin  234  that is held in the drive shaft  218  and moves an entrainer  236  on an orbital path around the centre axis  44 , the entrainer  236  being mounted rotatably on the eccentric pin  234  and itself being mounted rotatably in a pivot bearing  238 , wherein the pivot bearing  238  allows the entrainer  236  to rotate in relation to the movable compressor body  26 . 
     The entrainer  236  is rotatable to a limited extent in relation to the eccentric pin  234  and in relation to the entrainer receptacle  242 , and enables the radius of the orbital movement of the movable compressor body  26  to be adapted so that the scroll vanes  34  and  38  are kept bearing against one another. 
     For receiving the pivot bearing  238 , as illustrated in  FIGS. 2, 4 and 16 , the second compressor body  26  is provided with an entrainer receptacle  242  that receives the pivot bearing  238 . 
     The entrainer receptacle  242  is in this case set back in relation to the flat side  98  of the compressor body base  36  and is thus arranged in a manner integrated within the compressor body base  36 , with the result that the drive forces acting on the movable compressor body  26  act on a side of the flat side  98  of the compressor body base  36  facing the scroll vane  38  and thus drive the movable compressor body  26  with a small moment of tilt, the movable compressor body  26  being supported axially against the axial support face  102  by the axial guide  96 , between the entrainer receptacle  242  and the electric motor  212  as seen in the direction of the centre axis  44 , and guided movably in a direction transverse to the centre axis  44 .