Abstract:
The invention relates to a hermetically enclosed refrigerant compressor having a hermetically tight compressor housing inside of which a piston/cylinder unit that compresses a refrigerant operates with a suction valve having a suction opening located in a valve plate of the unit. A suction sound damper having a filling volume is provided on the cylinder head of the piston/cylinder unit and refrigerant flows to the suction valve of the piston/cylinder unit via this suction sound damper. To this end, the suction sound damper has an entry cross-section via which refrigerant flows into the suction sound damper, and a compensation volume is provided, which is connected to the suction sound damper and to the interior of the compressor housing, and inside of which refrigerant oscillates. The compensation volume equals 0.5 to 3 times the displacement of the piston of the piston/cylinder unit.

Description:
TECHNICAL FIELD OF THE INVENTION  
       [0001]     The present invention relates to a hermetically encapsulated refrigerant compressor, comprising a hermetically sealed compressor housing, in the interior of which a piston-cylinder unit works which compresses a refrigerant, on the cylinder head of which a muffler is arranged through which the refrigerant flows to the intake valve of the piston-cylinder unit, according to the preamble of claim  1 .  
       STATE OF THE ART  
       [0002]     Such refrigerant compressors have long been known and are predominantly used in refrigerators and cooling shelves. The annually produced number is accordingly very high.  
         [0003]     Although the power consumption of an individual refrigerant compressor is only approximately between 50 and 150 watts, there is a very high power consumption when regarding all refrigerant compressors used worldwide, which consumption increases continuously as a result of the rapidly progressing development in poorer countries as well.  
         [0004]     Any technical improvement made to a refrigerant compressor and increasing the efficiency thus offers an enormous potential for saving energy when extrapolating the refrigerant compressors used worldwide.  
         [0005]     The refrigerant process as such has long been known. The refrigerant is heated in the compressor by taking up energy from the space to be cooled and finally overheats and is pumped by means of the refrigerant compressor to a higher pressure level where it emits heat via a condenser and is conveyed back to the evaporator via a throttle where there is a pressure reduction and a cooling of the refrigerant.  
         [0006]     The largest and most important potential for a possible improvement of efficiency lies in the lowering of the temperature of the refrigerant at the beginning of its compression process. Every lowering of the intake temperature of the refrigerant into the cylinder of the piston-cylinder unit leads to a reduction of the required technical work for the compression process, as does the lowering of the temperature during the compression process and, in connection with the same, the push-out temperature.  
         [0007]     In known hermetically encapsulated refrigerant compressors there is a strong heating of the refrigerant on its path from the compressor (cooling space) to the intake valve of the piston-cylinder unit as a result of the design.  
         [0008]     The intake of the refrigerant occurs via a suction pipe coming directly from the compressor during an intake stroke of the piston-cylinder unit. In known hermetically encapsulated refrigerant compressors, the suction pipe usually opens into the hermetically encapsulated compressor housing, mostly close to the inlet cross section into the muffler, from where the refrigerant flows into the muffler and from the same directly into the intake valve of the piston-cylinder unit. The muffler is used primarily to keep the noise level of the refrigerant compressor as low as possible during the intake process. Known mufflers usually consist of several volumes which are in connection with each other and an intake cross section through which the refrigerant is sucked from the hermetically encapsulated compressor housing volume into the interior of the muffler and an opening which lies close to the intake valve of the piston-cylinder unit.  
         [0009]     On the way between the entrance of the refrigerant into the compressor housing and the intake valve of the piston-cylinder unit there is (as already mentioned) an undesirable heating of the refrigerant. Measurements have shown that at a refrigerant temperature of 32° C. in the suction pipe (predetermined by standardized ASHRAE conditions) the refrigerant was heated already in the first muffler volume to a temperature of approx. 54° C. already shortly before entering the compressor housing. The cause for this undesirable heating of the refrigerant is the fact that the refrigerant freshly flowing from the suction pipe to the compressor housing is mixed with warmer refrigerant already situated in the compressor housing. The mixture is principally caused in such a way that the intake valve of the piston-cylinder unit is merely open over a crank angle range of approx. 180° per cycle and that refrigerant can be drawn into the cylinder of the refrigerant compressor merely within this time window. The intake valve is closed thereafter, during the compression cycle. The cold refrigerant has a virtually constant mass flow, even when the intake valve is closed, as a result of which it flows in from behind into the compressor housing and dwells there and cools the piston-cylinder unit in motion and its components, which again causes a heating of the refrigerant. As a result of the pressure oscillations during the compression phase, there are further flow processes from the compressor housing to the muffler and vice-versa, which thus causes an additional mixing.  
         [0010]     In order to prevent this thorough mixture of warm refrigerant from the interior of the compressor housing with refrigerant freshly coming from the evaporator, the outlet of the suction pipe for the refrigerant is placed in known refrigerant compressors close to the inlet cross section of the muffler. This ensures that a relatively low amount of cold refrigerant can escape from the evaporator into the interior of the compressor housing. Subsequently, the suction pipe end was configured in such a way that an intermediate pipe could be inserted into the same. At the same time, the intermediate pipe was enclosed by a spiral spring which rests on the one hand on the entrance of the suction pipe into the housing and on the other hand on the intermediate pipe in order to achieve a linkage of the suction pipe to the muffler. All these known efforts to prevent a mixture of the cold refrigerant from the evaporator with the heated refrigerant in the interior of the compressor housing have merely caused a reduction in this mixing, but not a complete prevention.  
         [0011]     It is known from WO 03/038280 to directly connect the inlet cross section of the muffler with the outlet of the suction pipe, so that refrigerant coming from the evaporator is guided directly into the muffler without reaching the interior of the compressor housing and without being heated there. As a result of the already mentioned fact that the cold refrigerant has a nearly constant mass flow even when the intake valve is closed and flows into the muffler (now via the direct connection), it is then necessary however to provide a compensating volume in the muffler in order to compensate a pressure rise in the muffler as a result of the refrigerant that is continuously flowing in and through which refrigerant contained in the muffler can flow out of the same again into the compressor housing. During the next intake stroke, the refrigerant situated in the muffler or flowing from the suction pipe into the muffler is drawn into the piston-cylinder unit via the intake valve on the one hand, and refrigerant situated in the interior of the compressor housing is drawn into the compensating volume for pressure compensation (as a result of leakage from the piston-cylinder unit and by the mentioned flow-out from the muffler) on the other hand.  
         [0012]     The flow conditions occurring thereby, especially during the overflow into the compensating volume which would not occur without a direct connection of the suction pipe with the muffler, lead to the likelihood of increased flow losses.  
       SUMMARY  0 F THE INVENTION  
       [0013]     It is therefore the object of the present invention to avoid this disadvantage and to provide a refrigerant compressor of the kind mentioned above in which the refrigerant temperature is kept as low as possible at the beginning of the compression process and thus necessarily also during the intake into the cylinder of the piston-cylinder unit, with flow losses during the intake being avoided to the highest possible extent. It is a further object of the invention that the pressure fluctuations occurring in the interior of the compressor housing and in the muffler and the noise level during the overflow into compensating volume are kept as low as possible.  
         [0014]     This is achieved in accordance with the invention by the characterizing features of claim  1 .  
         [0015]     By creating a compensating volume with a volume which amounts to 0.5 to 3 times the displacement of the piston of the piston-cylinder unit, it is guaranteed that the refrigerant coming from the suction pipe will not reach the compressor housing even when the intake valve is closed and will mix there with already heated refrigerant. It is guaranteed at the same time that during the intake process no refrigerant is drawn from the compressor housing via the compensating volume into the muffler or into the cylinder.  
         [0016]     In addition, the noise development can be minimized which is caused with the creation of the compensating volume by the flow processes into the compensating volume and into the compressor housing, so that there will not be any disturbing noise for the operator, which is an especially important feature for household refrigerators. Furthermore, a slightly larger compensating volume can be produced more easily during manufacturing.  
         [0017]     In accordance with the characterizing features of claim  2  it is provided that the smallest cross section in the compensating volume has a cross-sectional surface area which corresponds to ¼ to ¾ of the cross-sectional surface area of the intake opening. This ensures that the pressure difference will become small, the flow losses will decrease and the noise damping increases to the outside.  
         [0018]     According to the characterizing feature of claim  3 , the cross section of the compensating volume can correspond at most to 1.5 times the piston head surface area. This ensures that on the one hand the need for space for the compensating volume will not become too high and it is ensured on the other hand that cold and hot suction gas will not mix or form the boundary layer as described below.  
         [0019]     The characterizing features of claim  4 , according to which the compensating volume has a circular cross section and the ratio of the length of the compensating volume to its diameter is higher than 10, describe a preferred embodiment which leads to especially low flow losses.  
         [0020]     In order to achieve the most compact configuration of the muffler despite the additional compensating volume, the characterizing features of claim  5  are provided, according to which the compensating volume is formed by a compensating pipe which has a substantially U-shaped cross section and wraps around the muffler at least partly.  
         [0021]     The characterizing features of claims  6  to  9  describe a preferred embodiment of the connection of suction pipe and inlet cross section into the muffler.  
         [0022]     The characterizing features of claims  10  and  11  describe two different embodiments of a hermetically encapsulated refrigerant compressor, in which the inlet cross section into the muffler and the transition from muffler to compensating volume is arranged once separately and. once coincidentally. Depending on the need for space in the interior of the compressor housing, the most advantageous embodiment must be chosen. In the case where the inlet cross section into the muffler and the transition from muffler to compensating volume coincide, a further preferred embodiment according to the characterizing features of claims  12  to  14  are provided. This embodiment comes with the advantage that a tight connection between suction pipe and muffler is not necessary.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
    
    
       [0023]     The invention will now be explained in closer detail by reference to the drawings, wherein:  
         [0024]      FIG. 1  shows a front view of a hermetically encapsulated refrigerant compressor in accordance with the invention with a compressor housing in a sectional view;  
         [0025]      FIG. 2  shows a sectional side view of a refrigerant compressor hermetically encapsulated in accordance with the invention;  
         [0026]      FIG. 3  shows a front view of a refrigerant compressor hermetically encapsulated in accordance with the invention;  
         [0027]      FIG. 4  shows a sectional view of a muffler in accordance with the state of the art;  
         [0028]      FIG. 5  shows a further sectional view of a known muffler;  
         [0029]      FIG. 6  shows a sectional view of a muffler in accordance with the invention with a closed intake valve;  
         [0030]      FIG. 7  shows a sectional view of a muffler in accordance with the invention with an opened intake valve;  
         [0031]      FIG. 8  shows an oblique view of the muffler in accordance with the invention in the compressor housing;  
         [0032]      FIG. 9  shows an alternative embodiment of a muffler in accordance with the invention;  
         [0033]      FIG. 9   a  shows a further alternative embodiment of a muffler in accordance with the invention;  
         [0034]      FIG. 10  shows an additional alternative embodiment of a muffler in accordance with the invention;  
         [0035]      FIG. 11  shows a detailed view of a hermetically sealed connection between muffler and suction pipe;  
         [0036]      FIG. 12  shows a detailed view of an alternative embodiment of a hermetically sealed connection between muffler and suction pipe;  
         [0037]      FIG. 13  shows a detailed view of a further alternative embodiment of a hermetically sealed connection between muffler and suction pipe;  
         [0038]      FIG. 14  shows a detailed view of a connection between a plastic hose with a suction pipe;  
         [0039]      FIG. 15  shows a detailed view of a connection of a plastic hose with a suction pipe;  
         [0040]      FIG. 16  shows a detailed view of a connection of a plastic hose with a suction pipe;  
         [0041]      FIG. 17  shows a detailed view of a connection of a plastic hose with a suction pipe;  
         [0042]      FIG. 18  shows a detailed view of a connection of a plastic hose with a suction pipe;  
         [0043]      FIG. 19  shows an oblique view of an alternative muffler in accordance with the invention;  
         [0044]      FIG. 20  shows a further oblique view of the muffler of  FIG. 19  in accordance with the invention;  
         [0045]      FIG. 21  shows a sectional view of the muffler of  FIG. 19  in accordance with the invention;  
         [0046]      FIG. 22  shows a further sectional view of the muffler of  FIG. 19  in accordance with the invention. 
     
    
       [0047]      FIGS. 1, 2  and  3  each show a sectional view through a hermetically encapsulated refrigerant compressor, with  FIGS. 1 and 3  each showing a view in the direction of arrow A of  FIG. 2 . A piston-cylinder motor unit is elastically held by means of springs  2  in the interior of a hermetically sealing compressor housing  1 .  
         [0048]     The piston-cylinder-motor unit substantially consists of a cylinder housing  3  and the piston  4  performing a lifting movement therein, and a crankshaft bearing  5  which is arranged perpendicular to the cylinder axis  6 . The crankshaft bearing  5  receives a crankshaft  7  and protrudes into a centric bore  8  of rotor  9  of an electromotor  10 . A connecting rod bearing  12  is situated at the upper end of crankshaft  7 , through which the connecting rod and consequently the piston  4  are driven. The crankshaft  7  comprises a lubricating oil bore  13  and is fixed to rotor  9  in the area  14 . The muffler  16  is arranged on the cylinder head  15 , which muffler is to reduce noise development to a minimum during the intake process of the refrigerant.  
         [0049]      FIG. 4  shows a sectional view of a muffler  16  according to the state of the art. As is already shown in  FIGS. 1, 2  and  3 , the muffler  16  is arranged on the cylinder head  15  in the interior of the hermetically sealed compressor housing  1 . The refrigerant coming from the evaporator, which refrigerant is cold in comparison with the warm refrigerant situated in the compressor housing  1 , flows via a suction pipe  17  into the interior of the compressor housing  1  close to the inlet cross section  18  of the muffler  16  when such a known muffler  16  is used, where it mixes with the warm refrigerant already situated in the compressor housing  1  and is heated up and is drawn into the piston-cylinder unit via the muffler  16 .  
         [0050]     Mufflers  16  according to the state of the art usually consist of several successively connected and/or parallel connected volumes V 1 , V 2 , V n  which are connected via pipes with each other, and of an oil separator opening  31  at the lowest point. The cold refrigerant flows via suction pipe  17  into the interior of the compressor housing  1  where as a result of its configuration a first thorough mixing with the warm refrigerant occurs which is already situated in the compressor housing  1 . The already mixed and heated refrigerant then flows through the inlet cross section  18  into the first volume V 1  and then into the second volume V 2  of the muffler  16  and mixes again with the warm refrigerant already situated both in V 1  as well as V 2 , as a result of which there is a renewed heating of the refrigerant. In these known mufflers, the heating between the outlet from suction pipe  17  and shortly before the intake opening  24  in the muffler  16  is between 30K and 40K, depending on the output of the refrigerant compressor.  
         [0051]      FIG. 5  shows a muffler  16  which is also known from the state of the art, namely from WO03/038280, whose inlet cross section  18  is tightly connected with the suction pipe  17 . The cold refrigerant coming from the suction pipe  17  is unable to mix with the warm refrigerant situated in compressor housing  1  before it is drawn into the muffler  16 . A compensating volume  21  is connected to the muffler  16 , through which the pressure compensation can occur which is required as a result of the direct connection of the muffler  16  with the suction pipe  17 , such that a connection exists both to the muffler  16  as well as into the interior of the compressor housing. The required pressure compensation leads to flow states of the refrigerant which can lead to the flow losses which offset the gain in energy which is achieved by the reduction of the refrigerant temperature at the beginning of the compression phase.  
         [0052]     In order to avoid or minimize these flow losses, it is necessary to arrange the compensating volume  21  in such a way that the energy loss caused by the additionally occurring flow losses is lower than the energy gain achieved by the improved suction. An embodiment of a muffler in accordance with the invention is shown in  FIG. 6 . Muffler  16  is shown in  FIG. 6  in a sectional view.  FIGS. 1, 2  and  3  also show refrigerant compressors with such a muffler  16  in accordance with the invention. The inlet cross section  18  of muffler  16  is connected with the suction pipe  17  via a schematically shown, hermetically sealed connection  19 . A tight connection  19  can principally be any preferably elastic connection as known to the person skilled in the art, such as a simple rubber tube which needs to be connected in a tight manner with the muffler  16  and the suction pipe  17 . Examples for such connections are shown in  FIG. 11  to  FIG. 18 . The muffler  16  in accordance with the invention delimits a filling volume  20  (with the arrangement of several filling volumes being possible and done). Adjacent to the muffler  16 , a compensating volume  21  is arranged which is formed by a U-shaped compensating pipe  34 . The illustrated U-shaped compensating pipe  34  offers the advantage of limiting a sufficient compensating volume  21  and of requiring only little additional space, and of producing the required flow conditions which minimize the mentioned losses. The compensating volume  21  and the compensating pipe  34  are in connection via a compensating opening  23  with the interior of the compressor housing  1  and with the filling volume  20  of the muffler  16  via the transition opening  26 .  
         [0053]      FIG. 6  shows the flow progress of the refrigerant with closed intake valve by means of arrows, which valve is situated behind the intake opening  24  of the muffler  16  on the side of the valve plate facing the piston.  
         [0054]     The cold refrigerant flowing from the suction pipe  17  flows via the tight connection  19  to the muffler volume  20  and from there into the compensating volume  21 , as a result of which the warmer refrigerant situated there is pressed from the compensating pipe  34  via the compensating opening  23  into the interior of the compressor housing  1 . The line indicated with reference numeral  25  symbolizes the boundary layer which forms between the cold and warm refrigerant.  
         [0055]      FIG. 7  shows the same muffler  16  in accordance with the invention, plus flow progress with opened intake valve. In this case, the refrigerant is drawn in both from the compensating volume  21  and from the filling volume  20  and the suction pipe  17 . Since the refrigerant in the compensating volume  21  has a lower temperature than the warm refrigerant situated in the interior of the compressor housing  1 , the mixing temperature of the refrigerants from the mentioned intake regions is lower than the mixing temperature of the refrigerants when using mufflers known from the state of the art, as a result of which the aforementioned undesirable temperature increase is prevented. As a result of the inventive feature that the compensating volume  21  has 0.5 to 3 times the lifting volume of the piston of the piston-cylinder unit, warm refrigerant is unable to flow from the interior of the compressor housing into the muffler, which in this embodiment is volume  20 . Due to the fact that the smallest flow cross section  32  has a cross-sectional surface area in the compensating volume  21  which corresponds to ¼ to ¾ of the cross-sectional surface area of the intake opening  24 , it is ensured that the pressure difference between muffler  16  and the interior of the compressor housing  1  is low and at the same time the noise damping in the interior of the compressor housing is high. An enlargement of the compensating volume also contributes to this, with the same being at least half, preferably 0.5 to 3 times the displacement of the piston of the piston-cylinder unit.  
         [0056]     At the same time, the flow losses are minimized by the muffler in accordance with the invention and the refrigerant can easily flow into the compensating volume or from the same without negatively influencing the refrigerant process.  
         [0057]     For the purpose of better clarity,  FIG. 8  shows an oblique view of the muffler  16  in accordance with the invention in the compressor housing  1  without the piston-cylinder motor unit.  
         [0058]      FIG. 9  shows an alternative embodiment of a muffler  16  in accordance with the invention, plus compensating volume  21 . The compensating volume  21  and the muffler  16  are formed by an encasing pipe  34  which encases the intake opening  24  on the one hand and opens into the same, and encases an end section of the suction pipe  17  along a section on the other hand. The cold refrigerant flowing from the suction pipe  17  flows during the entire intake cycle into the section of the encasing pipe  34  forming the filling volume  20  of the muffler  16 . In the subsequent compression cycle, the filling volume  20  of the muffler  16  can no longer receive any further refrigerant from the suction pipe  17  as a result of the closed intake valve, which is why the refrigerant flows back into the compensating volume  21  which is also formed by a section of the encasing pipe  34  and displaces the warm refrigerant contained therein via the compensating opening  23  into the interior of the compression housing  1 .  
         [0059]     As already described in  FIGS. 5 and 6 , this leads to the formation a boundary layer  25  between warm and cold refrigerant, which layer is movable depending on the intake cycle. During the next intake cycle, cold refrigerant can be drawn into the cylinder both from the suction pipe  17  as well as from the compensating volume  21  of the encasing pipe  34 . The relevant aspect is that the boundary layer does not exceed the line designated with reference numeral  33 , which in this embodiment simultaneously forms the inlet cross section  18  into the muffler  16  and the transitional opening  26 , in the direction of intake opening  24  in order to prevent a thorough mixture of warm and cold refrigerant prior to the intake process.  
         [0060]     At the same time, no cold refrigerant is allowed to be displaced from the suction pipe  17  from the compensating volume  21  into the compressor housing  1 . The boundary layer  25  must thus not be displaced behind the line marked in  FIG. 9  with reference numeral  23  (compensating opening). Irrespective of the embodiment, a precise adjustment of the volume of the compensating volume  21  to the refrigerating output and thus to the displacement of the piston-cylinder unit is necessary.  
         [0061]      FIG. 9   a  shows a further alternative embodiment of a muffler  16  plus compensating volume  21 , in which the muffler  16  is provided with an additional volume  20  in comparison with that of  FIG. 9 . In all other respects this variant is identical to the one shown in  FIG. 9 .  
         [0062]      FIG. 10  shows an additional alternative embodiment of a muffler  16  in accordance with the invention. The reference numerals were maintained accordingly. As can be seen on the basis of the large number of different designs, the configuration of the compensating volume can principally be chosen freely as long as the features of compensating volume  21  in accordance with the invention which is situated upstream of the outlet opening of suction pipe  17  are maintained concerning its volume and the smallest flow cross section  32 . Only then will optimal energy savings be achieved and the efficiency of the refrigerant compressor will be improved accordingly.  
         [0063]     The question as to how the different compensating volumes  21  and the mufflers  16  are arranged is of lower importance as long as the features in accordance with the invention are realized and the gas column and the boundary layer  25  is allowed to oscillate in the compensating volume.  
         [0064]     The muffler  16  in the embodiment according to  FIG. 9  merely consists of a filling volume  20  which extends in a substantially conical manner, and in the embodiment according to  FIG. 9   a  of a filling volume  20   a  extending in a substantially conical manner and of the filling volume  20 , and in the embodiment according to  FIG. 10  of the volumes V 2  and V 1 . It is understood that the parallel or serial arrangement of additional volumes of the muffler  16  is possible at any time and leads to improved sound-damping properties of the muffler  16 .  
         [0065]     In the embodiment according to  FIG. 9 , the compensating volume  21  consists of a cylindrical volume. In the embodiment according to  FIG. 9   a,  it also consists of a cylindrical volume and in the embodiment according to  FIG. 10  of the volumes  21   a  and  21   b  . The further arrangement of the compensating volumes, whether parallel or serial, is obviously possible, with the same contributing to sound damping, like  21 b for example. The smallest flow cross section  32  in accordance with the invention can be realized either by a baffle as in  FIG. 9, 9   a  and  10 , or by a spatial constriction as shown in  FIG. 3 . Alternatively, the entire compensating volume  21  can have a constant cross section with the features in accordance with the invention.  
         [0066]     FIGS.  11  to  18  show different embodiments of the hermetically sealed connection from suction pipe  17  to muffler  16  in accordance with the invention. Only when this connection is actually tight, which means in other words that no warm refrigerant is drawn from the compressor housing  1  into the muffler  16 , the compensating volume  21  will show its optimal effect, if it concerns an embodiment as described in  FIG. 6  and  FIG. 7 .  
         [0067]     The simplest connection is shown in  FIG. 11 . In this case, the elastic bellows  19  is merely pushed over the suction pipe  17  without any additional fixing, but preferably glued.  
         [0068]      FIGS. 12 and 13  show a more complex but stable connection.  
         [0069]     In  FIG. 12 , the wall of the compressor housing  1  comprises an inwardly facing nose  28  over which the elastic plastic hose  19  is pushed, which nose simultaneously protrudes into the inlet cross section  18  of the muffler  16 . The plastic hose  19  which can also be arranged as an elastic pipe is enclosed by a spiral spring  27  which ensures required stability and fixing. An  0 -ring  29  is each arranged both in the area of the nose  28  as well as in the area of the inlet cross section  18 , which ring ensures the required tightness.  
         [0070]     In  FIG. 13 , the muffler  16  also comprises a respective nose protruding into the interior of the compressor housing  1 .  
         [0071]     FIGS.  14  to  18  show different fastening possibilities  30  between elastic connecting means  19  and suction pipe  17  which can be arranged either as a toothing ( FIG. 17 ,  FIG. 18 ) or as barbs ( FIG. 16 ) arranged on the elastic connecting means, or as simple shoulders ( FIG. 14 ,  FIG. 15 ).  
         [0072]     In an embodiment of the compensating volume  21  including muffler  1  as described in  FIGS. 9, 9   a  and  10 , lacks the requirement of such a tight connection between muffler  16  and suction pipe  17  for the reasons as described above.  
         [0073]      FIG. 19 ,  FIG. 20 ,  FIG. 21  and  FIG. 22  show a further embodiment of a muffler  16  plus compensating volume  21  as already schematically described in  FIGS. 9, 9   a  and  10 . The suction pipe  17  is guided close to the inlet cross section  18  of the muffler  16 . The inlet cross section  18  is connected by means of a plastic hose  19  tightly with the suction pipe  17 .  
         [0074]     The remaining parts of the refrigerant compressor were not drawn for reasons of clarity in  FIG. 19 ,  FIG. 20 ,  FIG. 21  and  FIG. 22 .