Abstract:
In order to improve a refrigerant compressor system, comprising at least one low-pressure stage and at least one high-pressure stage, a suction duct leading from a suction connection for the refrigerant to the low-pressure stage, an intermediate-pressure duct leading from the low-pressure stage to the high-pressure stage, a high-pressure connection connected to the high-pressure stage, and a lubricant bath to which the intermediate pressure in the intermediate-pressure duct is applied, in such a way that there is always an adequate supply of lubricant for the low-pressure stage, it is proposed that a lubricant feed device draws lubricant from the lubricant reservoir and feeds said lubricant to the induced refrigerant flowing to the low-pressure stage in an intake path.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application is a continuation of International application No. PCT/EP2014/052212 filed on Feb. 5, 2014. 
         [0002]    This patent application claims the benefit of International application No. PCT/EP2014/052212 of Feb. 5, 2014 and German application No. 10 2013 203 268.4 of Feb. 27, 2013, the teachings and disclosure of which are hereby incorporated in their entirety by reference thereto. 
     
    
     BACKGROUND OF THE INVENTION 
       [0003]    The invention relates to a refrigerant compressor system, comprising at least one low-pressure stage and at least one high-pressure stage, a suction duct leading from a suction connection for the refrigerant to the low-pressure stage, an intermediate-pressure duct leading from the low-pressure stage to the high-pressure stage, a high-pressure connection connected to the high-pressure stage, and a lubricant bath to which the intermediate pressure in the intermediate-pressure duct is applied. 
         [0004]    Refrigerant compressor systems of this kind are known from the prior art. 
         [0005]    In these systems, the problem has arisen that damage occurs in the low-pressure stage, especially to valves of said stage, since insufficient lubricant is available, at least in some operating states. 
         [0006]    It is therefore the underlying object of the invention to improve a refrigerant compressor system of the type in question in such a way that an adequate supply of lubricant for the low-pressure stage is ensured at all times. 
       SUMMARY OF THE INVENTION 
       [0007]    According to the invention, this object is achieved in the case of a refrigerant compressor system of the type described at the outset by virtue of the fact that a lubricant feed device draws lubricant from the lubricant reservoir and feeds said lubricant to the induced refrigerant flowing to the low-pressure stage. 
         [0008]    The advantage of the solution according to the invention is to be regarded as the fact that there is the possibility, with the lubricant feed device according to the invention, of exploiting the pressure gradient between the intermediate pressure and the suction pressure of the refrigerant compressor system and thus of feeding lubricant from the lubricant reservoir to the induced refrigerant of the low-pressure stage and thereby of ensuring adequate lubrication, especially of valves of the low-pressure stage. 
         [0009]    In principle, feeding in lubricant at any desired points would be conceivable as long as lubricant was fed in to the induced refrigerant. 
         [0010]    However, in order to feed the lubricant into the low-pressure stage in as favorable a manner as possible, provision is preferably made for the lubricant feed device to feed the lubricant to an intake path of the low-pressure stage which extends in the system housing, in particular to an intake duct and/or to an intake manifold of the low-pressure stage, thus allowing the lubricant to be fed in without having to provide components outside the system housing. 
         [0011]    In particular, the intake duct or the intake manifold are also situated in the system housing. 
         [0012]    In order to prevent the quantity of lubricant fed to the induced refrigerant becoming too large and instead to keep it within reasonable limits at all times, provision is preferably made for the lubricant feed device to comprise a dispensing unit, which dispenses a lubricant quantity in accordance with the operating state, such that there is the possibility with the dispensing unit of adapting the quantity of lubricant in accordance with the operating state. 
         [0013]    For example, provision is made to define various operating states and/or operating state ranges and to dispense the lubricant quantity by means of the dispensing unit according to the operating state and/or operating state range. 
         [0014]    As regards dispensing in the individual operating states, it is advantageous if the supply of lubricant by the dispensing unit is stopped when the compressor is stationary in order thereby to avoid accumulation of lubricant in the intake path. 
         [0015]    It is furthermore advantageous if the dispensing unit prevents pressure equalization between the output path and the lubricant bath via the lubricant feed device when or from the time when the compressor is stationary. 
         [0016]    It is thereby possible, by virtue of the maintenance of the pressure difference in the intake path, to feed lubricant that collects in said path back into the lubricant bath via leakage paths, e.g. in the region of the respective pressure stages, and thus to avoid oil surges, especially in the region of the working valves, when the refrigerant compressor system is restarted. 
         [0017]    Dispensing in a manner dependent on operating states could be accomplished by means of a separate control system provided for this purpose. 
         [0018]    Another, more advantageous solution envisages that the dispensing unit is controlled by the compressor power, with the result that there is the possibility of detecting the operating states by means of the compressor power and dispensing the lubricant quantity in accordance with the compressor power. 
         [0019]    In principle, the dispensing unit could be designed in many different ways in this case. 
         [0020]    For example, the dispensing unit could be controlled in many different ways in accordance with the compressor power. 
         [0021]    For example, there would be the possibility of controlling the compressor power by controlling a drive motor for the refrigerant compressor system and, in accordance with the control of the drive motor, also electronically controlling the dispensing unit by means of this control. 
         [0022]    However, a particularly simple solution envisages that the dispensing unit is controlled by a compressor shaft and dispenses the lubricant quantity in accordance with the speed of the compressor shaft. 
         [0023]    As regards the design of the dispensing unit itself, more precise details have not been given. 
         [0024]    Thus, for example, the dispensing unit could be designed as a slide or valve. 
         [0025]    A particularly simple solution envisages that the dispensing unit is designed as a dispensing pump. 
         [0026]    With a dispensing pump of this kind, there is a simple possibility of performing power-dependent dispensing. 
         [0027]    In particular, the dispensing pump is preferably designed in such a way that it has a speed-dependent delivery volume. 
         [0028]    This can be achieved in a particularly simple manner if the dispensing pump is controlled, in particular driven, by the compressor shaft. 
         [0029]    As regards the dispensing pump itself, more precise details have not yet been given. 
         [0030]    Thus, an advantageous solution envisages that the dispensing pump is a gear pump. 
         [0031]    As regards the lubricant mass flow fed to the induced refrigerant, provision is preferably made to prevent said mass flow from becoming too great since otherwise the compressor power and/or durability of the refrigerant compressor system is impaired since, for example, oil compression in the working chambers leads to an increased drive load. 
         [0032]    For this reason, provision is preferably made for a lubricant mass flow fed to the induced refrigerant to make up at most 5% of the total mass flow of refrigerant with lubricant drawn in by the low-pressure stage. 
         [0033]    As regards the arrangement of the dispensing unit, more precise details have not yet been given. 
         [0034]    Thus, provision is preferably made for the refrigerant compressor system to have a system housing on which the dispensing unit is arranged. 
         [0035]    In this case, the dispensing unit is preferably arranged in a cover of the system housing since, in this case, it can be installed easily in the system housing, wherein the dispensing unit is, in particular, integrated into the cover. 
         [0036]    In order to be able to design the lubricant feed device in as simple and protected a manner as possible, a delivery duct leading from the dispensing unit to the lubricant reservoir is provided on the system housing, preferably on the cover, in particular in the system housing, preferably in the cover, said delivery duct providing the possibility of delivering the lubricant from the lubricant reservoir to the dispensing unit. 
         [0037]    It is furthermore expedient if a delivery duct for the lubricant leading from the dispensing unit to the intake path is provided on the system housing, in particular in the system housing, thereby making possible simple production and assembly. 
         [0038]    In this case, the delivery duct can extend exclusively in the system housing, e.g. in a cover thereof. 
         [0039]    However, there is also the possibility of the delivery duct extending partially in the system housing and partially in a compressor component, e.g. in a compressor shaft. 
         [0040]    In the last-mentioned case, selective lubrication of bearings for the compressor shaft can also preferably be accomplished by means of the delivery duct. 
         [0041]    In particular, it is advantageous for the feeding of the lubricant to the induced refrigerant flow if a nozzle for the lubricant to be fed to the intake path is associated with said intake path. 
         [0042]    As regards the type of compression of the refrigerant in the refrigerant compressor system, no further details have been given in connection with the illustrative embodiments thus far. 
         [0043]    Thus, it would be conceivable in principle to provide any kind of compressor, e.g. a scroll compressor or a screw compressor. 
         [0044]    However, the solution according to the invention has particular advantages if the refrigerant compressor comprises a reciprocating piston compressor since a reciprocating piston compressor has intake valves which are particularly sensitive to wear. 
         [0045]    It has furthermore proven advantageous in the design of a low-pressure stage and of a high-pressure stage if the piston compressor comprises a first cylinder bank to form the low-pressure stage and a second cylinder bank to form the high-pressure stage, thus allowing both the low-pressure stage and the high-pressure stage to be separated in a simple manner by the fact that they are formed by different cylinder banks of a compressor. 
         [0046]    Moreover, more precise details as regards the arrangement of the lubricant reservoir have not yet been given. 
         [0047]    For example, the lubricant reservoir could be an external reservoir. 
         [0048]    However, a particularly simple solution envisages that lubricant reservoir is arranged in a drive space of the system housing, wherein the drive for the low-pressure stage and the high-pressure stage is arranged in the drive space. 
         [0049]    In particular, provision is made here for the lubricant reservoir to be arranged at the bottom of the drive space. 
         [0050]    Further features and advantages of the invention form the subject matter of the following description and of the graphical representation of a number of illustrative embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0051]      FIG. 1  shows a side view of a refrigerant compressor system according to the invention; 
           [0052]      FIG. 2  shows an elevation of the refrigerant compressor system in the direction of arrow A in  FIG. 1 ; 
           [0053]      FIG. 3  shows a section along the line  3 - 3  in  FIG. 2 ; 
           [0054]      FIG. 4  shows a section along the line  4 - 4  in  FIG. 3 ; 
           [0055]      FIG. 5  shows a section along the line  5 - 5  in  FIG. 2 ; 
           [0056]      FIG. 6  shows a section along the line  6 - 6  in  FIG. 2 ; 
           [0057]      FIG. 7  shows a section along the line  7 - 7  in  FIG. 6  with a cutaway illustration of the cylinder head, of the valve plate and of the cylinder liners of a cylinder bank; 
           [0058]      FIG. 8  shows an enlarged illustration of the section in  FIG. 6  in the region of the valve plate and of the intake valve; 
           [0059]      FIG. 9  shows a plan view in the direction of arrow A in  FIG. 3 ; 
           [0060]      FIG. 10  shows a section along the line  10 - 10  in  FIG. 9 ; 
           [0061]      FIG. 11  shows an elevation corresponding to  FIG. 9  with a plan view of a dispensing pump according to the first illustrative embodiment; 
           [0062]      FIG. 12  shows a longitudinal section similar to  FIG. 3  through a second illustrative embodiment of a refrigerant compressor system according to the invention, and; 
           [0063]      FIG. 13  shows a section similar to  FIG. 10  through the second illustrative embodiment of the refrigerant compressor system according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0064]    An illustrative embodiment of a refrigerant compressor system  10 , which is shown in  FIGS. 1 and 2 , comprises a system housing, denoted overall by  12 , which extends in a longitudinal direction  14 . 
         [0065]    In this case, the system housing  12  comprises a central housing body  16 , which likewise extends in the longitudinal direction  14  and, on a first end, carries a first end cover  22  and, on a second end, a second end cover  24 , which is, for example, furthermore provided on its side facing away from the central housing body  16  with a flange surface  26  for mounting a converter. 
         [0066]    As shown in  FIG. 3 , the central housing body  16  comprises a drive housing section  32  of a piston compressor  40 , which encloses a drive space  34 , wherein the drive space  34  extends between the first end cover  22  and a partition wall  36  of the central housing body  16 , said wall being situated between the drive housing section  32  and a motor housing section  42  of the central housing body  16 . 
         [0067]    The motor housing section  42  for holding an electric motor  50  comprises a motor space  44  which, for its part, is situated in turn between the partition wall  36  and the second end cover  24 , wherein the motor space  44  also furthermore extends from the motor housing section  42  into the second end cover  24 . 
         [0068]    Seated in the motor space  44  is the electric motor, which is denoted overall by  50  and which comprises a stator  52  arranged in the motor space  44  and a rotor  54  surrounded by the stator  52 , wherein the rotor  54  is rotatable about an axis of rotation  56 . 
         [0069]    For this purpose, the rotor  54  is seated on a compressor shaft of the piston compressor  40 , said shaft being denoted overall by  60 , carrying the rotor  54  by means of a rotor carrier section  62  extending in the motor space  44 , and supporting said rotor in a manner which allows it to rotate about the axis of rotation  56 . However, the compressor shaft also extends into the drive space  34  and has a drive section  64 , which passes through the drive space  34  and carries a plurality of eccentrics  66 . 
         [0070]    For its part, the compressor shaft  60  is mounted in the system housing  12  in a bearing receptacle  72 , which is provided on the partition wall  36 , and in a bearing receptacle  74 , which is provided on the first end cover  22 , with the result that the drive section  64  is situated with the eccentrics  66  between the bearing receptacles  72  and  74 , while the rotor carrier section  62  starts from bearing receptacle  72  and extends with a free end in the motor space  44 . 
         [0071]    As shown in  FIG. 3 , the eccentrics  66  of the drive section  64  of the compressor shaft  60  are used to drive a plurality of cylinders  82  of the piston compressor  40 , these being arranged in the form of two cylinder banks  84  and  86  in the drive housing section  32 , for example, wherein each of the cylinders  82  has a cylinder space  92 , in which a piston  94  can be moved in a stroke direction  96 , wherein each cylinder space  92  is surrounded, for example, by a cylinder liner  98  seated in the drive section. 
         [0072]    For its part, each piston  94  is driven by a connecting rod  102 , which is mounted in an articulated fashion on the piston  94  at one end and surrounds one of the eccentrics  66  at the other end. 
         [0073]    The cylinder spaces  92  of each of the cylinder banks  84  and  86  are closed off by a valve plate  104  and  106 , respectively, wherein the respective valve plate  104  or  106  carries a cylinder head  112  or  114 , respectively, on its side facing away from the respective cylinder liner  98 . 
         [0074]    Cylinder head  112  is associated with the first cylinder bank  84 , and cylinder head  114  is associated with the second cylinder bank  86 . 
         [0075]    For example, each of the valve plates  104 ,  106  and each of the cylinder heads  112  and  114  fits over all of the cylinder spaces  92  of the cylinders  82  of the respective cylinder banks  84  and  86 . 
         [0076]    As shown in  FIGS. 1 and 5 , a suction shutoff valve  122  is provided, for example, in the refrigerant compressor system  10  according to the invention, said valve being provided, for its part, with a suction connection  124 , being mounted on the first end cover  22 , for example, and feeding refrigerant to be drawn in to a suction duct  126 , which is provided in the first end cover  22  and the drive housing section  32  and which extends from the suction shutoff valve  122  to the first cylinder bank  84 , wherein the suction duct  126  passes through an aperture  128  in the drive housing section  32 , said aperture being in alignment with an aperture  132  in valve plate  104 , with the result that the induced refrigerant can flow out of the drive housing section  32 , pass through valve plate  104  and enter a suction chamber  134  of cylinder head  112 , as shown in  FIGS. 3 ,  6  and  7 . 
         [0077]    In particular, the suction duct  126  and the suction chamber  134  form an intake path  130 , provided in the system housing  12 , for the induced refrigerant. 
         [0078]    However, it is also possible to provide a simple suction line connection instead of the suction shutoff valve  122 , whether by means of a screwed joint or a fitted joint. 
         [0079]    The suction chamber  134  is situated on a side of the respective valve plate  104 ,  106  facing away from the cylinder space  92  and above suction openings  136  for all the cylinders  82  of the respective cylinder bank  84 ,  86 , said openings being arranged in the respective valve plate  104 ,  106 , wherein a working valve or suction valve  138  is associated with each suction opening  136  on a side facing the cylinder space  92 , said valve being arranged, for example, on valve plate  104  and comprising a suction flap or valve tongue  140 , which closes the suction opening  136  in the closed position depicted in solid lines in  FIGS. 7 and 8 , in which it rests on valve plate  104 , and exposes the suction opening  136  in an open position, which is depicted in dashed lines in  FIGS. 7 and 8 , allowing refrigerant to be drawn into the cylinder space  92  through said opening. 
         [0080]    To define the mobility of the valve tongue  140 , use is made, on the one hand, of valve plate  104  in the closed position of said tongue and, on the other hand, a guide recess  142  is provided in a cylinder liner collar  144  of the cylinder liner  98 , for example, into which recess the respective valve tongue  140  engages by means of a tongue tip  146 , ensuring that the tongue tip  146  is guided in the guide recess  142  during its movement between its closed position and its open position. 
         [0081]    To define the position of maximum opening of the valve tongue  140 , the guide recess  142  is provided with a stop surface  148 , which is depicted, in particular, in  FIG. 8  and which defines the position of maximum opening of the valve tongue  140 , that is to say the position furthest away from valve plate  104 , the guide recess  142  thus forming with the stop surface  148  a stroke limiter. 
         [0082]    In the respective cylinder head, in cylinder head  112  in  FIGS. 7 and 8 , the suction chamber  134  is furthermore associated with an oppositely situated pressure chamber  152 , which is likewise formed in cylinder head  112 , wherein a row of outlet valves  154  is arranged in the pressure chamber  152 , said outlet valves being seated on valve plate  104 , for example, and likewise being capable of exposing outlet openings, thus allowing compressed refrigerant to enter the pressure chamber  152  from the cylinder space  92 . 
         [0083]    The cylinders  82  of cylinder bank  86  are also formed in the same way as the cylinders  82  of cylinder bank  84  with the valve plate  104  and  106 , wherein, in particular, valve plate  106  and cylinder head  114  are designed in a corresponding way. 
         [0084]    As shown particularly in  FIGS. 4 and 5 , the refrigerant compressor system with the two cylinder banks  84  and  86  operates as a two-stage compressor, that is to say that refrigerant drawn in at suction pressure PS by the cylinders  82  of the first cylinder bank  84 , which form a low-pressure stage  156 , is initially compressed to an intermediate pressure PZ, then flows into the motor space  44 , flows through the motor space  44  and flows from the latter into an intermediate-pressure duct  162  of the drive housing section  32 , with the result that the refrigerant at intermediate pressure PZ can enter the suction chamber  134  of cylinder head  114  of cylinder bank  86  and is finally compressed to high pressure PH by the cylinders  82  of the second cylinder bank  86 , which form a high-pressure stage  158 , wherein the refrigerant at high pressure PH can then emerge from the high-pressure connection  164 . 
         [0085]    In order to avoid damage to the suction valves  138 , as evidenced, for example, by the valve tongues  140  exhibiting spalling over the course of time, especially in the region of their tongue tips  146 , caused at least in part by impacts by the valve tongues  140  and/or the tongue tip  146  on valve plate  104  and/or the stop surfaces  148 , a lubricant feed device denoted overall by  170  is provided, which takes lubricant from a lubricant bath  174  formed above a bottom region  172  of the drive space  34  by means of a first delivery duct  176  provided in the first end cover  22 , for example, and by means of a filter  178  arranged ahead of said duct and feeds said oil to a dispensing unit  180  via delivery duct  176  ( FIGS. 3 and 9  to  11 ). 
         [0086]    From the dispensing unit  180 , the lubricant is fed via a second delivery duct  182 , which is shown in  FIG. 6  and  FIGS. 9 to 11  and is provided in the first end cover  22 , and via a filter  184 , which is also arranged in said duct, to a nozzle  186 , which is directed into the suction duct  126  and by means of which the lubricant can be injected into the suction duct  126 , through which induced refrigerant flows, with the result that the lubricant injected into the suction duct  126  is taken along by the induced refrigerant and is fed at least to the suction valves  138  in order to lubricate the latter. 
         [0087]    The pressure difference for the delivery of the lubricant by the lubricant feed device  170  is already given by the fact that a pressure corresponding to the intermediate pressure PZ is present in the drive space  34 , this pressure being higher than the suction pressure PS, with the result that this pressure difference is already sufficient to deliver the lubricant from the lubricant bath  174  to the nozzle  186 . 
         [0088]    Thus, the dispensing unit  180  does not necessarily have to produce a pressure difference but serves primarily to achieve dispensing of the lubricant in accordance with a power of the lubricant compressor system, in the simplest case in accordance with a speed of the compressor shaft  60 . 
         [0089]    This fed in lubricant forms a lubricant coating, especially in the region of valve plate  104  and of the stop surfaces  148  of the guide recesses  142 , by means of which coating impact of the valve tongues  140  and of the tongue tips  146  of the valve tongues  140  on valve plate  104  and/or on the stop surfaces  148  is damped in order thereby to avoid spalling in the region of the tongue tips  146  and/or of the valve tongues  140 . 
         [0090]    To make the dispensing unit  180  as simple as possible, said unit could be a volume-controlling valve. 
         [0091]    In particular, the dispensing unit  180  is designed as a dispensing pump  190  with a speed-dependent, in particular speed-proportional, delivery volume, which pump is coupled to the compressor shaft  60  and is thus driven in synchronism with the compressor shaft  60  in order to make the dispensing of the lubricant injected into the suction duct  126  via the nozzle  148  proportional to the speed of the compressor shaft  60 . 
         [0092]    As shown in  FIG. 11 , the dispensing pump  190  is designed as a gear pump, which has an internally toothed outer body  192  and a corresponding externally toothed inner body  194 , which, on the one hand, is rotatable about an axis  196  of an eccentric journal  198 , wherein the eccentric journal, for its part, is arranged eccentrically with respect to the axis of rotation  56  of the compressor shaft  60  and is formed integrally on the compressor shaft  60 , with the result that the inner body  194  of the gear pump  190  is driven directly by the compressor shaft  60 . 
         [0093]    In this case, the outer body  192  and the inner body  194  are formed in such a way relative to one another that the eccentric revolution of the eccentric journal  198  between the outer body  192  and the inner body  194  leads to the formation of free spaces  202  which are moved in a circulating fashion around the axis of rotation  56  of the compressor shaft  60  through the eccentric movement of the eccentric journal  198 , with the result that lubricant fed in through delivery duct  176  via an inlet pocket  204  enters the free spaces  202  which form and is delivered, by the movement of the free spaces  202  around the axis of rotation  56 , to an outlet pocket  206 , which is connected to delivery duct  182 , thus allowing the lubricant to be fed through the latter to the nozzle  186  directed into the suction duct  126 . 
         [0094]    In this case, the gear pump  190  is constructed in such a way that, when the eccentric journal  198  is no longer moving around the axis of rotation  56  and the inner body  194  is therefore stationary, lubricant delivery by the lubricant feed device  170  is blocked, and thus feeding of lubricant to the suction duct  126  is blocked when the compressor shaft  60  is stationary. 
         [0095]    This has the advantage that, when the drive of the compressor shaft  60  is stationary and thus also when the piston  94  is stationary, no more lubricant can flow into the suction duct  126  from the lubricant bath  174  since the dispensing pump  190  prevents this. 
         [0096]    However, the dispensing pump  190  furthermore also blocks a buildup of the pressure in the suction duct  126  when the compressor shaft  60  is stationary and the inner body  194  is thus stationary, with the result that lubricant which is still present in the suction duct  126  flows back to the lubricant bath  174  via different paths, e.g. leaks in the region of the pistons  94  of the cylinder banks  84 ,  86 . 
         [0097]    This furthermore has the advantage that there is thus the possibility of preventing flooding of the suction duct  126  with lubricant when the refrigerant compressor system according to the invention is stationary and furthermore also of maintaining the pressure in the suction duct  126  in order to feed the lubricant in the suction duct  126  back to the lubricant bath  104  via leaks, e.g. in the region of the cylinder banks  84 ,  86 , and thus of avoiding oil surges when the refrigerant compressor system restarts. 
         [0098]    In the first illustrative embodiment of the solution according to the invention, the lubricant feed device  170  is integrated into the first end cover  22 , with the result that delivery duct  176  and delivery duct  182  with the nozzle  184 , in particular, are situated in the first end cover  22 , and the filters  178  and  184  too are preferably likewise seated in the first end cover  22 . 
         [0099]    Moreover, the first cover  22  advantageously also comprises a receptacle  212  for the outer body  192  of the dispensing pump  190 , wherein the inlet pocket  204  and the outlet pocket  206  also open into this receptacle  212  at the end, in particular between the bearing receptacle  74  and receptacle  212 . 
         [0100]    The outer body  192  can be inserted non-rotatably into receptacle  212 , and the inner body  194  is then seated in said outer body, is mounted on the eccentric journal  198  in the manner described in such a way as to be rotatable about the axis  196  and thus revolves about the axis of rotation  56  with the eccentric journal  198 . 
         [0101]    In a second illustrative embodiment of a refrigerant compressor system according to the invention, shown in  FIGS. 12 and 13 , features which are identical with those of the first illustrative embodiment are provided with the same reference signs, and therefore in this regard reference can also be made in full to the statements relating to the first illustrative embodiment. 
         [0102]    In particular, the lubricant bath  174  is provided in the drive space  34  in the same way as in the first illustrative embodiment, from which bath the lubricant feed device  170 ′ takes lubricant, likewise through the delivery duct  176  provided in the first end cover  22 . 
         [0103]    The dispensing unit  180 , formed by the dispensing pump  190 , is furthermore likewise provided in the first end cover  22  in the same way as in the first illustrative embodiment and is designed in the same way as described in connection with the first illustrative embodiment. 
         [0104]    However, the dispensing pump  190  does not deliver the lubricant to a delivery duct extending onward in the first end cover  22  but delivers it into a compressor shaft duct  222 , which preferably extends coaxially with the axis of rotation  56  in the compressor shaft  60 ′, wherein a transverse duct  224  in the partition wall  36 ′ in the region of bearing receptacle  72 ′ leads from the compressor shaft duct  222  to a receiving groove  226 , which is provided in bearing receptacle  72 , which surrounds the compressor shaft  60 ′ and from which, in turn, a delivery duct  228  in the partition wall  36 ′ and in the drive housing section  32 ′ extends as far as a nozzle  232 , which opens into the suction duct  126 ′ in the drive housing section  32 ′. 
         [0105]    The compressor shaft duct  222  is furthermore provided with further transverse ducts, wherein a transverse duct  242  is used for lubricating a sliding bearing  244  between the compressor shaft  60 ′ and bearing receptacle  74 , transverse ducts  246  are used for lubricating sliding bearings  248  between the eccentrics  66  and the connecting rods  102 , and transverse ducts  252  are used for lubricating sliding bearings  254  between the compressor shaft  60 ′ and bearing receptacle  72 ′, for example. 
         [0106]    The lubricant feed device  170 ′ according to the invention thus serves not only to feed lubricant to the suction duct  126 ′ in order to achieve the effects in the region of the suction valves  138  which have been described in connection with the first illustrative embodiment but also to supply bearings  244 ,  248 ,  254  in the region of the compressor shaft  60 ′ with lubricant. 
         [0107]    Apart from the lubrication of the various sliding bearings, the same advantages are achieved in the second illustrative embodiment as have been described in detail in connection with the first illustrative embodiment.