Abstract:
In order to improve a refrigerant compressor, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit, such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible, it is proposed that the connector terminals should be provided in a housing that is arranged on the drive housing, and that an electronic functional unit which performs at least one compressor function should be provided in the housing.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application is a continuation of International application number PCT/EP2015/073551 filed on Oct. 12, 2015. 
         [0002]    This patent application claims the benefit of International application No. PCT/EP2015/073551 of Oct. 12, 2015 and German application No. 10 2014 114 837.1 of Oct. 13, 2014, 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, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit. 
         [0004]    Refrigerant compressors of this kind are known from the prior art, and the electronic functional unit therein is conventionally provided as a separate unit independent of the refrigerant compressor, for example being part of a higher-level controller of a refrigeration unit, in which case making the connections between the refrigerant compressor and the electronic functional unit is a complex matter, since they cannot be taken into account by the manufacturer of the refrigerant compressor. 
         [0005]    It is thus the object of the invention to improve a refrigerant compressor of the generic type such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible. 
       SUMMARY OF THE INVENTION 
       [0006]    This object is achieved according to the invention in the case of a refrigerant compressor of the type described in the introduction in that the connector terminals are provided in a housing that is arranged on the drive housing, and in that the electronic functional unit which performs at least one compressor function is provided in the housing. 
         [0007]    The advantage of the solution according to the invention can thus be seen in the fact that it gives a compact solution that consists in integrating the electronic functional unit in the housing, which has in any case to be provided for the connector terminals, and thus making it possible for the electronic functional unit already to be connected to the refrigerant compressor by the manufacturer of the refrigerant compressor and delivered, fixedly installed, at the same time. 
         [0008]    In this context, the most diverse possibilities are possible for the form taken by the housing. 
         [0009]    Here, an advantageous solution provides for the housing to have a connector housing unit in which the connector terminals are arranged. 
         [0010]    Further, it is preferably provided for the housing to have a controller housing unit in which the electronic functional unit is arranged. 
         [0011]    Preferably in this case, it is provided for the connector housing unit and the controller housing unit to be individual modules of the housing, from which the housing can be assembled. 
         [0012]    A particularly favourable solution provides for the connector housing unit to be arranged on the drive housing and thus to be able to be mounted already fixed to the drive housing. 
         [0013]    Moreover, it is preferably provided for the controller housing unit to be arranged on the connector housing unit. 
         [0014]    This means that the connector housing unit carries the controller housing unit. 
         [0015]    A particularly favourable solution provides for the controller housing unit to be arranged on the connector housing unit on an opposite side thereof to the drive housing. 
         [0016]    This provides the possibility of mounting the connector housing unit on the drive housing first and then, after the connector housing unit has been mounted, additionally mounting the controller housing unit on the connector housing unit. 
         [0017]    In particular, this provides the possibility of arranging the connector housing unit and the controller housing unit above one another in the manner of stacking. 
         [0018]    A particularly favourable solution provides for the controller housing unit to cover the connector housing unit, that is to say that in this case the controller housing unit can serve to cover the connector housing unit and to close it on the opposite side thereof to the drive housing. 
         [0019]    It is particularly favourable if the controller housing unit is detachably connected to the connector housing unit. 
         [0020]    This provides the possibility of making the necessary connections first in the connector housing unit, in particular with the connector terminals, and then of mounting the controller housing unit and connecting it to the corresponding units and/or sensors. 
         [0021]    For example, the controller housing unit could be constructed such that it has its own cover. 
         [0022]    In order to enable particularly simple mounting and simple wiring of the electronic functional unit in the controller housing unit to be achieved, it is preferably provided for the controller housing unit to be covered by a housing cover on a side remote from the connector housing unit. 
         [0023]    More detailed statements have not been made in conjunction with the embodiments described hitherto as regards the compressor function to be performed by the electronic functional unit. 
         [0024]    Here, a solution that is advantageous as an alternative or in addition to the embodiments described hitherto provides for the compressor function to be a parameter determining function and, in particular for performing the parameter determining function, for at least one of the function parameters such as temperature of the electric motor, voltage across the electric motor, current consumption of the electric motor, lubricant temperature, lubricant differential pressure, lubricant level, incoming pressure of the refrigerant, incoming temperature of the refrigerant, outgoing pressure of the refrigerant and outgoing temperature of the refrigerant to be determined. 
         [0025]    A determination of the function parameters of this kind enables sufficient information on the respective operating state of the compressor to be obtained. 
         [0026]    This solution is also particularly advantageous because, as a result, the pathways for determining the function parameters of the electric motor and also the further function parameters of the refrigerant compressor are very short. 
         [0027]    In particular, damage to the compressor can be avoided by performing one or more protective functions. 
         [0028]    In this case, it is preferably provided for the compression function to be a protective function that compares the at least one function parameter that has been determined in the parameter determining function with at least one reference parameter, and in the event of the at least one reference parameter being exceeded or not reached brings about a switch-off of the refrigerant compressor in order to avoid damage thereto. 
         [0029]    Moreover, as an alternative or in addition, preferably further compressor functions for operating the refrigerant compressor are advantageous. 
         [0030]    Here, a further advantageous solution provides for the compressor function to be a control function and, in particular for performing the control function, for at least one of the units such as a lubricant heater, a supplementary fan, a control element for the compressor output, an injection element for compressed refrigerant for supplementary cooling, in particular for injecting liquid refrigerant, preferably into an intake channel and/or on the high pressure side in the region of a valve plate or a high-pressure chamber, and/or a motor controller to be controlled. 
         [0031]    In the case of controlling the motor, for example a motor start-up controller and/or the motor itself are controlled in respect of its speed of rotation, for example if the electronic functional unit includes a frequency converter. 
         [0032]    These additional control functions provide the possibility of operating the refrigerant compressor in optimum manner within the given application limits. 
         [0033]    A further advantageous solution provides for the compressor function to be an operating state monitoring function and, in particular for performing the operating state monitoring function, for the performance of at least one parameter determining function and/or at least one protective function and/or at least one control function to be recorded. 
         [0034]    Recording such functions in this manner provides the possibility of monitoring the operating states of the refrigerant compressor according to the invention throughout operation thereof, and also detecting whether the respective permitted operating states are exceeded briefly or indeed detecting whether the respective application limits are exceeded in an operating diagram. 
         [0035]    Preferably, it is provided here for recording of the at least one function parameter and/or performing of at least one protective function and/or performing of the at least one control function to take place over time. 
         [0036]    In order, using the refrigerant compressor according to the invention, to enable communication also with further external devices, it is preferably provided for the electronic functional unit to be provided with a communication unit for exchanging data with external devices. 
         [0037]    A communication unit of this kind may take a form such that it exchanges data either in a hard-wired arrangement or wirelessly. 
         [0038]    Moreover, it is preferably provided for the electronic functional unit to be provided with at least one indicator element that indicates at least one performance state of a compressor function or the result thereof. 
         [0039]    Further features and advantages of the invention form the subject matter of the description below and the representation in the drawing of an exemplary embodiment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0040]      FIG. 1  shows a diagrammatic side view of a refrigerant compressor according to the invention; 
           [0041]      FIG. 2  shows a detail of a longitudinal section through a housing according to the invention and a drive unit carrying this housing; 
           [0042]      FIG. 3  shows a perspective exploded illustration of a housing of modular construction, including a connector housing unit and a controller housing unit and a cover; and 
           [0043]      FIG. 4  shows a plan view of the controller housing unit according to the invention with the cover removed, in the direction of the arrow A in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0044]    An exemplary embodiment of a refrigerant compressor according to the invention, which is designated  10  as a whole, illustrated in  FIG. 1 , includes a compressor unit  12  and a drive unit  14  for driving the compressor unit  12 . 
         [0045]    Here, the compressor unit  12  is arranged in a compressor housing  22  and includes at least one compressor element  24  for the refrigerant, for example taking the form of a piston-and-cylinder element. Moreover, the drive unit  14  is arranged in a drive housing  26 , wherein preferably the compressor housing  22  and the drive housing  26  form parts of an overall housing  28  of the compressor unit  10 . 
         [0046]    As illustrated schematically in  FIG. 2 , the drive unit  14  includes in particular an electric motor that is designated  32  as a whole and has a rotor  34  and a stator  36  surrounding the rotor  34 , wherein the stator  36  is arranged to be stationary in the drive housing  26 . 
         [0047]    As illustrated in  FIG. 2 , the stator  34  is provided with a set of connector terminals  42 ,  44 ,  46  that are guided out of the drive housing  26  and project into a connector housing unit  48  that is placed on the drive housing  26 . 
         [0048]    Within the connector housing unit  48  a connection is made between a motor feed cable that is designated  52  as a whole and has for example three phases  54 ,  56 ,  58 , wherein each of the phases  54 ,  56 ,  58  is connected to one of the connector terminals  42 ,  44 ,  46  within the connector housing unit  48 , and the motor feed cable  52  is guided out of the connector housing unit  48  by means of a cable lead-through  62 . 
         [0049]    As illustrated in  FIGS. 1, 2 and 3 , the connector housing unit  48  is seated with one mounting side  64  directly on a mounting surface  66  formed by the drive housing  26 , and is connected to the drive housing  26 . 
         [0050]    The connector housing unit  48  further has an access side  68 , opposite the mounting side  64 , through which the connections between the connector terminals  42 ,  44 ,  46  and the phases  54 ,  56 ,  58  are accessible, as illustrated in  FIGS. 2 and 3 . 
         [0051]    In particular, the connector housing unit  48  includes for example four housing outer walls  72 ,  74 ,  76  and  78  that rise above the mounting side  64 , wherein the housing outer walls  72  and  74  and the housing outer walls  76  and  78  in each case extend parallel to one another such that they form a housing frame that is designated  82  as a whole, has a preferably rectangular external contour  84 , rises between the mounting side  64  and the access side  68  and is accessible in particular from the access side  68 . 
         [0052]    Preferably, the mounting side  64  and the access side  68  extend in mutually parallel planes, with the result that the housing frame  82  rises above the mounting side  64  to the access side  68  by an extent that is the same on all sides. 
         [0053]    A controller housing unit that is designated  88  as a whole is placeable on the connector housing unit  48 . 
         [0054]    The controller housing unit  88  includes an electronic functional unit  92  for performing one or more different compressor functions, such as protective, monitoring, controlling, diagnostic, communication and regulating functions, which will be described in more detail below by way of example. 
         [0055]    The controller housing unit  88  itself has a mounting side  94  and extends as far as an access side  98 , wherein a carrier base  96  is arranged between the mounting side  94  and the access side  98 , preferably lies close to the mounting side  94  and carries the electronic functional unit  92 . 
         [0056]    The controller housing unit  88  also includes housing outer walls  102 ,  104 ,  106  and  108 , wherein preferably the housing outer walls  102  and  104 , and the housing outer walls  106  and  108 , extend parallel to one another and thus form a rectangular housing frame  112 . 
         [0057]    Preferably, the housing frame  112  of the controller housing unit  88  takes a form such that its external contour  114 , which is for example rectangular, is identical with the external contour  84  of the housing frame  82 , with the result that the housing frame  112  is placeable with the mounting side  94  congruently on the housing frame  82 , wherein the mounting side  94  entirely covers the access side  68  of the connector housing unit  48 . 
         [0058]    Preferably, the access side  68  of the connector housing unit  48  and the mounting side  94  of the controller housing unit  88  are also provided with positively-locking elements, with the result that the housing frame  112  of the controller housing unit  88  is fixable on the housing frame  82  of the connector housing unit  48  in the placed-on position with positive engagement, to prevent movements in the plane defined by the access side  68 . 
         [0059]    In the case of the controller housing unit  88  as well, the mounting side  94  and the access side  98  preferably lie in mutually parallel planes, with the result that the housing frame  112  rises from the mounting side  94  to the access side  98  by an extent that is the same on all sides. 
         [0060]    Further, the controller housing unit  88  is also closable on its access side  98  by a cover  118  that extends over the entire access side  98  of the controller housing unit  88  and preferably has an external contour  122  that corresponds to the external contour  114  of the controller housing unit  88 . 
         [0061]    In the solution according to the invention, when the controller housing unit  88  is in the state placed on the connector housing unit  48 , it is detachably fixable thereto, and moreover the cover  118  is detachably fixable at least to the controller housing unit  88 . 
         [0062]    This is achieved for example in that the cover  118  has screw holes  132   a,    132   b,    132   c  and  132   d  which are arranged coaxially with screw channels  134   a,    134   b,    134   c  and  134   d  in the controller housing unit  88 , and these screw channels  134  are in turn arranged coaxially with threaded bores  136   a,    136   b ,  136   c  and  136   d.    
         [0063]    In this way, screws  138   a,    138   b,    138   c  and  138   d  may be passed through the screw holes  132  and the screw channels  134  and screwed into the threaded bores  136 , with the result that the cover  118  is fixable on the controller housing unit  88  by the screws  138  and at the same time the controller housing unit  88  is in turn fixable, together with the cover  118 , on the connector housing unit  48 . 
         [0064]    In the refrigerant compressor  10  according to the invention, the connector housing unit  48 , the controller housing unit  88  and the cover  118  form a housing unit  142  of modular construction, wherein the connector housing unit  48  and the controller housing unit  88  and the cover  118  each represent a module of this housing unit  142 . 
         [0065]    This provides the possibility for example that a refrigerant compressor  10  that is equipped only with a connector housing unit  48  covered by the cover  118  on its access side  68  may in addition be retrofitted with an electronic functional unit  92  that is arranged in the controller housing unit  88 , by removing the cover  118 , and that this controller housing unit  88  may itself be closed on its access side  98  by the cover  118  that has been removed from the connector housing unit  48 . 
         [0066]    For the purpose of explaining the various possible compressor functions that may be determined and/or monitored and/or controlled by the electronic functional unit  92 , various possibilities are illustrated by way of example in  FIGS. 1, 2 and 4 , wherein the exemplary illustration of various compressor functions is given merely by way of example, so not all such compressor functions have necessarily to be embodied in the construction of the control unit according to the invention, and the compressor functions that are illustrated may also be supplemented by further compressor functions. 
         [0067]    The electronic functional unit  92  performs by way of example, as a compressor function, a parameter determining function in which at least one function parameter, preferably a plurality of function parameters, are determined. 
         [0068]    Here, for example, the electronic functional unit  92  is to be provided on a connector side  152  with inputs  154 ,  156  and  158  for determining the voltages across the connector terminals  42 ,  44 ,  46 , with the result that corresponding lines lead from the inputs  154 ,  156  and  158  to the connector terminals  42 ,  44 ,  46  in order to determine the voltages UM across these connector terminals  42 ,  44 ,  46  as a function parameter. 
         [0069]    Further, the connector side  152  is also provided with an input  162  for a current signal from which a line  164  leads to a current sensor  166  that surrounds for example one of the connector terminals  42 ,  44 ,  46  and determines a magnetic field generated by the current IM that flows through the surrounded connector terminal  42  and, depending on the magnetic field, transmits a signal representing the current through this connector terminal  42  to the input  162  of the electronic functional unit  92 . 
         [0070]    Further, the electronic functional unit  92  is for example also provided at the connector side  152  with an input  172  for an item of information on the motor temperature TM, with the result that a line  174  leads from the input  172  to a temperature sensor  176  that is associated for example with the stator  36  in order to determine a temperature of the stator  36  and to transmit to the input  172  of the electronic functional unit  92  a value for the temperature or merely a signal representing a permitted or impermissible, in particular excessively high, motor temperature. 
         [0071]    All the lines leading to the inputs  154 ,  156 ,  158  and the inputs  162  and  172  are guided through an aperture  182  in the carrier base  96 , directly from the controller housing unit  88  into the connector housing unit  48 , and there are either connected to the connector terminals  42 ,  44 ,  46  or, in the case of the temperature sensor  176 , are guided through the connector housing unit  48  directly to a current lead-through element or to the stator  36 . 
         [0072]    Further, it is possible to guide through the aperture  182  a line for any required heating for the purpose of preventing condensation. 
         [0073]    On the basis of the signals present at the inputs  154 ,  156  and  158  and  162  and  172 , the electronic functional unit  92  is thus able to determine and monitor the function of the electric motor  32  and where appropriate to respond to overload states. 
         [0074]    Moreover, as illustrated in  FIG. 4 , the electronic functional unit  92  is also provided with an input  192  for a lubricant temperature TS as a function parameter, from which a line  194  leads to a temperature sensor  196  that determines a temperature of a lubricant, in particular a lubricant bath, in the compressor housing  22 . 
         [0075]    Further, the electronic functional unit  92  is provided with an input  202  from which a line  204  leads to a sensor  206  for the lubricant level NS as a function parameter, in order to determine whether there is sufficient lubricant in a lubricant supply and/or in the lubricant bath. 
         [0076]    Moreover, the electronic functional unit  92  is also provided with an input  212  from which a line  214  leads to a pressure difference sensor  216  in order to determine a lubricant pressure PS as a function parameter, preferably by measuring a pressure differential, for example at a lubricant pumping unit. 
         [0077]    Further, the electronic functional unit  92  is also provided with an input  222  for a value of an input pressure PE of the refrigerant, from which a line  224  leads to a pressure sensor  226  that is associated with an intake connector  228  of the refrigerant compressor  10  and thus determines the pressure in the intake connector  228 . 
         [0078]    Further, the electronic functional unit  92  is also provided with an input  232  for determining an incoming temperature TE of the refrigerant, wherein a line  234  leads from the input  232  to a temperature sensor  336  that is likewise associated with the intake connector  228  of the refrigerant compressor. 
         [0079]    The electronic functional unit  92  is further also provided with an input  242  for determining an outgoing pressure PA of the refrigerant, wherein a line  244  leads from this input  242  to a pressure sensor  246  that is associated for example with a pressure connector  248  of the refrigerant compressor  10 . 
         [0080]    As an alternative or in addition to the pressure sensor  246  for the outgoing pressure PA, it is also possible to provide a high-pressure switch which, in the event of a predetermined pressure being exceeded, causes the electronic functional unit  92  to switch off the refrigerant compressor  10  for the purpose of protection. 
         [0081]    Moreover, the electronic functional unit  92  is provided with an input  252  for an outgoing temperature TA of the refrigerant at the pressure connector  248 , wherein a line  254  leads from this input  252  to a temperature sensor  256  that is associated with the pressure connector  248  and determines the temperature of the refrigerant for example at the pressure connector  248 . 
         [0082]    Thus, as a result of the signals applied across the inputs  222 ,  232 ,  242  and  252 , the electronic functional unit  92  is able to determine as function parameters the pressure and temperature of the refrigerant, as the latter enters the compressor unit, for example by way of the intake connector  228 , and as it leaves the refrigerant compressor, for example by way of the pressure connector  248 . 
         [0083]    This provides the possibility, within the scope of performing a protective function, of comparing the respective function parameters with reference values and thus, in the event that the reference values are exceeded or not reached, of intervening using control measures or where appropriate, in an extreme case, of switching off the refrigerant compressor. 
         [0084]    The electronic functional unit  92  is, however, also provided with a plurality of outputs for performing control functions as compressor functions. 
         [0085]    For example, an output  262  is provided from which a line  264  leads to a lubricant heater  266  that is arranged in the compressor housing  22 , in order to heat up the lubricant provided therein by suitable control of the lubricant heater  266  by means of one of the control functions. 
         [0086]    A further output  272  serves to control, by way of a line  274  and by means of one of the control functions, a supplementary fan  276  that serves to supplement cooling of a refrigerant circuit at one or more points and/or of the refrigerant compressor. 
         [0087]    An output  282  serves to control, by way of a line  284  and by means of one of the control functions, at least one control element for the compressor output, for example a power regulating valve  286 , in order to control the compressor output. 
         [0088]    Further, an output  292  serves to control, by way of a line  294  and by means of one of the control functions, an injection element  296  that serves to inject refrigerant under high pressure into the refrigerant compressor, in order either to achieve a supplementary cooling effect in the region of the compressor element or of the electric motor  32  for cooling in the region thereof. 
         [0089]    Preferably, in addition application limits of the specific refrigerant compressor  10  and parameters of the refrigerant are also predetermined for the electronic functional unit  92  for the purpose of performing an operation monitoring function, with the result that, taking into account function parameters that are determined at the inputs  154 ,  156 ,  158 ,  162 ,  172 ,  182 ,  192 ,  202 ,  212 ,  222 ,  232 ,  242  and  252  of whether the refrigerant compressor is operating in a permitted operating state or outside a permitted operating state of this kind and as a result of the units controlled by way of the outputs  262 ,  272 ,  282  and  292 , where appropriate these ensure observation of the application limits. 
         [0090]    Further, the electronic functional unit is provided with an output  302  by way of which it is controllable, as one of the control functions, by means of a line  304  to a motor controller  306  that serves to control the electric motor  32  in a suitable manner during start-up and/or in the respective operating states, depending on the construction thereof. 
         [0091]    The motor controller  306  may also at the same time be used for switching off the electric motor  32  in the event of at least one reference parameter being exceeded or not reached, in which case a protective function is performed. 
         [0092]    Moreover, the electronic functional unit  92  is also provided with a communication unit  312  that is provided for the purpose of communicating with the external devices  316 , for example higher-level unit controllers. 
         [0093]    Here, communication with a unit controller  316  may either be hard-wired, by way of a line  314  such as a Modbus, or wireless over conventional communications protocols such as Bluetooth or W-LAN. 
         [0094]    Moreover, the electronic functional unit  92  is also provided with an indicator element  322  that is able to indicate at least one status or the result of a compressor function. 
         [0095]    A status of this kind of a compressor function may be for example the indication of function parameters and/or of permitted operating states and/or the indication of a triggered protective function and/or the indication of a control function and/or the indication of a malfunction, in particular in combination with the type of malfunction, and/or a combination thereof. 
         [0096]    The indication may take place by way of an indicator element  322  that is provided on the housing, or indeed by way of a hard-wired or wireless communication path to a fixed or portable indicator unit such as a computer or a portable communication device.