Patent Publication Number: US-2022233988-A1

Title: Separating Apparatus for Separating Liquid from Gas, in Particular Air, and Separating System of a Machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of international application No. PCT/EP2020/079568 having an international filing date of 21 Oct. 2020 and designating the United States, the international application claiming a priority date of 21 Oct. 2019 based on prior filed German patent application No. 10 2019 128 397.3, the entire contents of the aforesaid international application and the aforesaid German patent application being incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention concerns a separating apparatus for separating liquid from gas, in particular air, with a housing which comprises
         a connection device with which the separating apparatus can be connected separably by means of a rotation and/or insertion movement in relation to a virtual connection axis to a connection head of a machine,   at least one gas inlet for the gas to be freed from liquid,   at least one gas outlet for the gas freed from liquid, which surrounds the connection axis circumferentially,   and at least one liquid drain for separated liquid,   wherein in the housing at least one separating medium through which the gas can flow is arranged which separates the at least one gas inlet in relation to the gas flow from the at least one gas outlet,   wherein the at least one gas outlet and the at least one liquid drain lead out of the housing at the side where the connection device is arranged,   wherein the at least one liquid drain leads out of a liquid collection chamber which is arranged at a clean gas side of the separating medium and which circumferentially surrounds the connection axis and the at least one gas outlet,   wherein in the housing interior of the housing a pipe section leads to the at least one gas outlet and surrounds circumferentially the connection axis and at least partially forms a radially inner boundary of the liquid collection chamber.       

     Moreover, the invention concerns a separating system of a machine
         with at least one separating apparatus for separating liquid from gas, in particular air, with a housing which comprises   a connection device with which the separating apparatus can be connected separably by means of a rotation and/or insertion movement in relation to a virtual connection axis to a connection head of a machine,   at least one gas inlet for the gas to be freed from liquid,   at least one gas outlet for the gas freed from liquid, which surrounds the connection axis circumferentially,   and at least one liquid drain for separated liquid,   wherein in the housing at least one separating medium through which the gas can flow is arranged which separates the at least one gas inlet in relation to the gas flow from the at least one gas outlet,   wherein the at least one gas outlet and the at least one liquid drain lead out of the housing at the side where the connection device is arranged, —wherein the at least one liquid drain leads out of a liquid collection chamber which is arranged at a clean gas side of the separating medium and which circumferentially surrounds the connection axis and the at least one gas outlet,   wherein in the housing interior of the housing a pipe section leads to the at least one gas outlet and surrounds circumferentially the connection axis and at least partially forms a radially inner boundary of the liquid collection chamber,   and with a connection head, at which a connection socket is arranged that is separably connected to the connection device of the separating apparatus, for connecting the at least one separating apparatus.       

     DE 10 2014 000 281 A1 discloses a device, for example, an oil separator or a fuel filter, for separating liquid from air. The device has a cup-shaped housing with a filter element arranged therein and embodied as an annular coalescer, for example, a so-called spin-on filter. For closing its open end face, the cup-shaped housing comprises a housing cover. This housing cover comprises an opening for discharging the filtered clean air. In the opening, a nipple is received which extends through the housing cover in the direction of the longitudinal axis of the cup-shaped housing. The housing cover is detachably connectable to the nipple. The region of the housing cover detachably connectable to the nipple is designed such that in the connected state of the housing cover with the nipple between housing cover and nipple at least one liquid drain, for example, an oil passage channel or connection channel, is arranged for discharging the separated liquid out of the interior of the cup-shaped housing. For supply of raw air into the cup-shaped housing, the housing cover comprises at least one raw air inlet arranged off-center. For discharging the clean air from the cup-shaped housing, the nipple comprises a central clean air outlet that is formed as one piece together with the nipple. 
     The invention has the object to configure a separating apparatus and a separating system of the aforementioned kind in which a connection between the separating apparatus and the connection head can be realized in a simpler way. In particular, a mounting and/or component-related expenditure during exchange of the separating apparatus is to be reduced. 
     SUMMARY OF THE INVENTION 
     This object is solved for the separating apparatus in that the pipe section is separated functionally from mechanical force-transmitting connection elements of the connection device. 
     According to the invention, the pipe section in relation to a mechanical force transmission is realized separate from the actual connection device. In this way, the function of delimiting the liquid collection chamber relative to the at least one gas outlet can be functionally separated from the holding function of the connection device for holding the separating apparatus at the connection head. In contrast thereto, in the device known from the prior art, the respective nipple is provided as a pipe piece within the container interior for separating the gas outlet from the liquid collection chamber and outside of the container for screwing into the connection head of the machine. By means of the separation of these two functions according to the invention, a connection socket on the part of the connection head can also be designed to be correspondingly shorter. The head-side connection element must only extend into a connection receptacle on the part of the housing of the separating apparatus according to the invention. The required installation space on the part of the connection head can thus be reduced. In this way, the separating apparatus can be more easily mounted. 
     The at least one gas outlet surrounds the connection axis circumferentially. In this manner, the at least one gas outlet can be centrally arranged in relation to the connection axis. 
     The pipe section surrounds the connection axis circumferentially and forms a radially inner boundary of the liquid collection chamber at least partially. By means of the pipe section, it can be prevented that separated liquid that collects in the liquid collection chamber can flow into the at least one gas outlet and contaminate again in this way the clean gas that has already been freed from liquid. 
     The at least one gas outlet and the at least one liquid drain lead out of the housing at the side at which the connection device is arranged. In this manner, the at least one gas outlet and the at least one liquid drain can be connected by means of the connection device more easily with a corresponding gas discharge channel or a corresponding oil drain channel on the part of the connection head. 
     Advantageously, the housing can comprise an in particular cup-shaped housing pot. The open side of the housing pot can be closed with a housing cover. The housing cover, after installation of the at least one separating medium, can be connected to the housing pot so as to be separable only destructively. Preferably, housing and housing cover are of metal, preferably sheet steel. 
     Advantageously, the housing cover can be connected by means of a crimp connection, in particular by means of a connection plate, to the housing pot. In this manner, a simple, fluid-tight, and stable connection between the housing cover and the housing pot can be realized. Instead of a crimp connection, a weld connection can be used. 
     Advantageously, at least one part of the connection device can be realized at the housing cover. In this manner, corresponding mechanical forces when connecting the separating apparatus with a connection head can be absorbed substantially by the housing cover. The housing pot and the at least one separating medium contained therein can thus be relieved of the corresponding mechanical forces which act between the separating apparatus and the connection head. In this manner, the requirements in regard to the mechanical stability of the housing pot and of the at least one separating medium can be reduced accordingly. 
     Advantageously, at least one sealing device for sealing of fluid-conducting regions in the housing and between the housing and the connection head can be arranged at the housing, in particular the housing cover. The at least one sealing device can be activated automatically upon connecting the separating apparatus to the connection head. 
     The separating apparatus can be separably connected by means of a rotation and/or insertion movement in relation to a virtual connection axis to the connection head of a machine. In this context, this can be a pure rotation movement, a pure insertion movement or a combined rotation/insertion movement. Combined rotation/insertion movements are carried out in particular in screw connections or bayonet closure-type connections. In screw connections, an insertion movement is realized by the rotation of the participating threads relative to each other. 
     The connection device can advantageously comprise at least one connection element, in particular a thread, a rotation and/or insertion connection, in particular a screw connection or a bayonet closure-type connection. 
     Advantageously, the separating apparatus can be embodied as a so-called spin-on device, in particular spin-on filter, also known as an exchangeable screw-on filter. In this manner, it can be simply screwed on the connection head and correspondingly removed therefrom by unscrewing. 
     Advantageously, the at least one separating medium can comprise at least one coalescence medium. The at least one separating medium can be part of a separating insert, in particular coalescence insert. 
     Advantageously, the at least one separating medium can surround circumferentially an interior and/or the connection axis. The at least one separating medium, in particular the separating insert, can be realized advantageously in connection with a so-called round filter element. 
     Advantageously, the separating apparatus can be used in connection with machines in which gas, in particular air, is contaminated with oil, wherein the gas is to be freed again from the oil with the separating apparatus. Advantageously, the separating apparatus can be used in connection with in particular oil-lubricated compressors, internal combustion engines, air/oil separator boxes and the like. 
     In an advantageous embodiment, the pipe section can extend exclusively in the housing interior of the housing. In this manner, a corresponding space requirement at the outer side of the housing can be reduced. In contrast thereto, the nipple known from the prior art extends also outside of the container interior. The connection socket on the part of the connection head can be designed according to the invention significantly shorter than the nipple known from the prior art. In this manner, material, in particular metal, can be saved. 
     In a further advantageous embodiment, the pipe section can be connected with a fastening end directly or indirectly, in particular fixedly, to the housing. In this manner, the pipe section can be separable only destructively from the separating apparatus. The separating apparatus including the pipe section can be produced, mounted, and exchanged more easily. 
     Alternatively or additionally, the pipe section can be directly or indirectly, in particular fixedly, connected to a separating insert of the separating apparatus which is arranged in the housing. In this manner, the pipe section can be produced and/or mounted together with the separating insert. 
     In a further advantageous embodiment, the free end of the pipe section can project past a radially outer circumferential wall of the liquid collection chamber in axial direction in relation to the connection axis. In this manner, for stronger gas flows, it can be prevented that liquid collected in the liquid collection chamber can splash across the free rim of the pipe section and flow into the at least one gas outlet. 
     In a further advantageous embodiment, the at least one gas outlet can be designed as a connection receptacle for a connection socket, wherein the connection socket is connected or can be connected fixedly or separably to the connection head. In this manner, in a space-saving way the flow-through function and the holding function can be combined with each other. In the connection receptacle, the connection socket can be introduced with a rotation and/or insertion movement. 
     In a further advantageous embodiment, an inner diameter of the pipe section, at least in the region of its fastening end, can be larger than an inner diameter of the at least one gas outlet. In this manner, turbulences of the gas flow can be reduced, in particular avoided, at the transition location between the pipe section and the gas outlet. 
     Advantageously, an inner diameter of the pipe section at least in the region of its fastening end can be larger than an inner diameter of a connection socket. In this manner, turbulences can be further reduced. 
     In a further advantageous embodiment, the pipe section can be of plastic material. In this manner, the pipe section can be realized simpler, less expensively, and/or with a reduced weight than in case of pipe sections of metal. The use of plastic material is possible because significantly smaller mechanical forces are acting at the pipe section than at the nipple that is known from the prior art. 
     In a further advantageous embodiment, the at least one gas outlet can be arranged coaxially to the connection axis. In this manner, a connection socket on the part of the connection head can be introduced with the rotation and/or insertion movement about the connection axis into the at least one gas outlet, which then can act as a connection receptacle. 
     Advantageously, the at least one gas outlet can be designed of a circular shape. In this manner, the at least one gas outlet is of rotational symmetry, which is particularly advantageous for a screw connection. 
     In a further advantageous embodiment, a part of the housing surrounding the at least one gas outlet can comprise a mechanical connection element of the connection device. In this manner, the mechanical connection element can be realized simply and, in a space-saving manner. The mechanical connection element can be connected in this way force-transmittingly directly to the housing. In this manner, the pipe section can be kept free of connection forces between the housing and the connection head. The functional separation between the pipe section and the mechanical connection element can thus be ensured. 
     Advantageously, the mechanical connection element can be a thread or a part of a bayonet closure-type connection. 
     Advantageously, the at least one gas outlet can be surrounded by an inner thread. The inner thread can interact in a simple manner with a corresponding outer thread on the part of the connection head, in particular at a connection socket on the part of the connection head. 
     In a further advantageous embodiment, at least one gas inlet can lead on the same side into the housing at which the liquid drain and the at least one gas outlet lead out of the housing. In this manner, all fluid connections can be arranged at the same side of the housing. This simplifies the connection of the separating apparatus to the connection head. 
     Advantageously, the at least one liquid drain can be arranged between the at least one gas outlet and the at least one gas inlet. In this manner, the liquid drain can be arranged in a space-saving manner in the vicinity of the at least one gas outlet. In this way, the corresponding fluid channels on the part of the connection head can be realized in a more space-saving way. 
     In a further advantageous embodiment, the at least one gas outlet and the at least one liquid drain can be surrounded by at least one annular seal device. In this manner, the at least one gas outlet and the at least one liquid drain can be sealed in outward direction and/or toward the at least one gas inlet. 
     In a further advantageous embodiment, at least one seal device can be arranged between the at least one liquid drain and the at least one gas inlet. In this manner, the at least one liquid drain can be separated fluid-tightly from the at least one gas outlet. In this way, it can be prevented that separated liquid can flow back into the purified gas. 
     The object is solved for the separating system according to the invention in that the pipe section is separated functionally from the mechanical force-transmitting connection elements of the connection device. 
     In other respects, the features and advantages which have been explained in connection with the separating apparatus according to the invention and the separating system according to the invention and their respective advantageous embodiments apply correspondingly mutually and vice versa. The individual features and advantages can, of course, be combined among each other, wherein further advantageous effects may result that go beyond the sum of the individual effects. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages, features, and details of the invention result from the following description in which embodiments of the invention will be explained in more detail with the aid of the drawing. A person of skill in the art will consider the features disclosed in combination in the drawing, the description, and the claims expediently also individually and combine them to expedient further combinations. The Figures show schematically embodiments of the invention. 
         FIG. 1  shows a longitudinal section of a separating apparatus for separating liquid from gas according to a first embodiment, which is arranged separably at a connection head of a machine. 
         FIG. 2  shows a detail illustration of the longitudinal section of  FIG. 1  in the region of a housing cover of the separating apparatus. 
         FIG. 3  shows an isometric illustration of the sectioned separating apparatus at the connection head of  FIG. 1 . 
         FIG. 4  shows a longitudinal section of a separating apparatus for separating liquid from gas according to a second embodiment. 
         FIG. 5  shows a longitudinal section of a separating apparatus for separating liquid from gas according to a third embodiment. 
     
    
    
     In the Figures, same components are identified with same reference characters. 
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In  FIGS. 1 to 3 , a separating apparatus  10  for liquid, for example, oil  12 , from gas  14 , for example, air, according to a first embodiment is illustrated in longitudinal section, in a detail view, and in an isometric illustration. The separating apparatus  10  is detachably connected, for example, to a connection head  16  of a machine that is not illustrated otherwise, in particular an oil-lubricated compressor. With the separating apparatus  10 , the compressor gas  14  is freed from oil  12 . In the normal operating position, the separating apparatus  10  is arranged spatially in accordance with  FIG. 1 . In this context, the separating apparatus  10  is located spatially at the top in the normal operating position and the connection head  16  spatially at the bottom. 
     The separating apparatus  10  comprises a housing  18 . The housing  18  comprises a cup-shaped housing pot  20  having an open side which in normal operating position is located spatially at the bottom and is closed by a housing cover  22 . The housing cover  22  is connected by means of a crimp connection, not of interest here, seal-tightly to the housing pot  20 . 
     The housing cover  22  comprises a central opening which serves as a gas outlet  24  for gas  14  freed from oil  12 . The gas outlet  24  is circular and coaxial to a virtual connection axis  26 . 
     When in the description “radial”, “coaxial”, “axial”, “tangential”, “circumferential”, “concentric”, “eccentric” or the like is referred to, this relates to the connection axis  26  if nothing else is mentioned. 
     A radially inner section of the housing cover  22  which surrounds the gas outlet  24  is of a circular cylindrical shape and extends coaxially in a housing interior  32  of the housing  18 . The radially inner circumferential side of the housing cover  22 , respectively of the circular cylindrical radially inner section, comprises an inner thread  28 . The gas outlet  24  serves additionally as a connection receptacle for a connection socket  30  which is fastened on the part of the connection head  16 . 
     Radially outwardly, the gas outlet  24  is surrounded by a plurality of oil drains  34 . The oil drains  34  are arranged circumferentially distributed. The oil drains  34  lead through the housing cover  22 , respectively. 
     Moreover, a plurality of gas inlets  36  leads through the housing cover  22 . In  FIG. 3 , one of the gas inlets  36  can be seen in an exemplary fashion. The gas inlets  36  are located in a ring section of the housing cover  22  which surrounds radially outwardly the oil drains  34 . 
     In the housing  18 , an oil separating insert  38  is arranged. The oil separating insert  38  as a whole is of a circular cylindrical configuration in an exemplary fashion and coaxially arranged. The oil separating insert  38  comprises a separating medium  40  for the oil  12 . The oil separating medium  40  can be designed, for example, as a so-called coalescence medium. In this way, the oil separating insert  38  as a whole can be realized as a coalescence insert. The separating medium  40  surrounds circumferentially continuously an insert interior  42  of the oil separating insert  38 . 
     At the side which is axially facing away from the housing cover  22 , the oil separating insert  38  is provided with an upper end disk  44  with which the insert interior  42  is closed off thereat. 
     At the axially oppositely positioned side which is facing the housing cover  22 , the oil separating insert  38  comprises a connection end disk  46 . The connection end disk  46  comprises a coaxial opening which is larger than the gas outlet  24 . 
     The connection end disk  46  is bent multiple times in a radially inner section in which it is overlapping the insert interior  42  so that it forms a radially outer circumferential wall  48  for an oil collection chamber  50 . In the oil collection chamber  50 , separated oil  12  that sinks downwardly following the force of gravity can be collected. Through openings  52  are arranged in the bottom of the oil collection chamber  50 . With installed oil separating insert  38 , the through openings  52  correspond with the corresponding oil drains  34 . Through the through openings  52 , the oil  12  can flow out of the oil collection chamber  50  into the oil drains  34 . 
     The oil separating insert  38  as a whole is arranged in the housing  18  such that the separating medium  40  separates the gas inlets  36  from the gas outlet  24 . In this manner, the gas  14  must flow through the separating medium  40  and is freed thereby from the oil  12 . 
     The insert interior  42 , the oil collection chamber  50 , the through openings  52 , and the oil drains  34  are arranged at the clean gas side of the oil separating insert  38 . 
     A pipe section  54  extends coaxially in the housing interior  32 , respectively, the insert interior  42 . The pipe section  54  is of a circular cylindrical shape in an exemplary fashion. The pipe section  54  comprises a connection end  56  with which it is fastened at a radially outer circumferential side of the radially inner section of the housing cover  22  that is of a circular cylindrical shape. A seal, not illustrated, is arranged between the connection end  56  and the radially inner section of the housing cover  22 . 
     The pipe section  54  extends in axial direction approximately across half of the axial height of the insert interior  42 . It projects thus past the circumferential wall  48  of the oil collection chamber  50  in the axial direction. By means of the pipe section  54 , it is prevented that the oil  12  collected in the oil collection chamber  50  can flow into the gas outlet  24 . 
     The connection end  56  is arranged in this context radially between the radially inner section which surrounds the gas outlet  24 , on the one hand, and the through openings  52  and the oil drains  34 , on the other hand. 
     An inner diameter  58  of the pipe section  54  is larger than an inner diameter  60  of the gas outlet  24  and larger than an inner diameter of the connection receptacle for the connection socket  30 . Moreover, the inner diameter  58  of the pipe section  54  is larger than the inner diameter of the connection socket  30 . In this manner, turbulences can be avoided as the gas  14  freed from oil  12  flows out. 
     On the outer side of the housing cover  22  that is axially facing away from the housing interior  32 , a first seal  62  extends circumferentially about the oil drains  34 . In this context, the first seal  62  comprises in the region of the oil drains  34  a hollow cylinder section, respectively, which extends through the respective oil drain  34 . On the side that is axially facing away from the housing cover  22 , the first seal  62  is provided radially outwardly with a hollow cylinder section which extends in axial direction away from the housing cover  22 . 
     With the first seal  62 , the clean gas side is sealed against the oil drains  34  and the oil collection chamber  50  in the region of the gas outlet  24 . The seal  62  is oriented in the direction toward the connection head  16  and, for obtaining the sealing function, contacts preferably radially or even axially seal-tightly the connection head, preferably, as illustrated, the connection socket  30 . Moreover, when the separating apparatus  10  is mounted, the first seal  62  seals the oil drains  34  against a raw gas-side gas supply channel  64  in the connection head  16 . 
     The gas supply channel  64  corresponds, when the separating apparatus  10  is mounted, with the gas inlets  36  of the separating apparatus  10 . The oil drains  34  correspond, when the separating apparatus  10  is mounted, with an oil drain channel system  66  of the connection head  16 . The connection socket  30  is hollow inside and forms thus a part of a gas discharge channel  68  of the connection head  16 . 
     An annular second seal  70  is arranged moreover in the housing interior  32  between the connection end disk  46  and the housing cover  22 . The second seal  70  surrounds radially outwardly the oil collection chamber  50 , the through openings  52 , and the oil drains  34 . The second seal  70  separates the raw gas side of the oil separating insert  38  from the oil drains  34  and from the clean gas side. In operation, oil drains  34  and clean gas side comprise the same or a similar pressure level, which is lower compared to the raw gas side. The second seal  70  is positioned with its radially inner circumferential side at the hollow cylindrical sections of the first seal  62 . 
     The gas outlet  24  with the inner thread  28 , designed as a connection receptacle, forms a connection device  72  with which the separating apparatus  10  can be connected to the connection head  16 . 
     The separating apparatus  10  comprises moreover an outer annular seal  74  which is located at the outer side of the housing  18  that is facing the connection head  16 . The annular seal  74  is arranged in a corresponding seal groove at a connection plate  76 . With the outer annular seal  74 , the oil drains  34 , the gas inlets  36 , and the gas outlet  24  are sealed in relation to the environment. The outer annular seal  74  is positioned for this purpose in axial direction seal-tightly at a corresponding seal surface on the part of the connection head  16 . 
     The connection plate  76  is located at the outer side of the housing cover  22  which is axially facing away from the housing interior  32 . With the connection plate  76 , the crimp connection of the housing cover  22  with the housing pot  20  is realized. The housing cover  22  is fixed with tabs—not of interest in this context—of the connection plate  76 . 
     For connecting the separating apparatus  10  to the connection head  16 , the separating apparatus  10  is screwed, with the housing cover  22  leading, onto the connection socket  30  of the connection head  16 . In this context, a corresponding outer thread on the part of the connection socket  30  engages the inner thread  28  on the part of the gas outlet  24 . Upon screwing, the first seal  62  and the outer annular seal  74  are automatically brought into engagement with corresponding seal surfaces on the part of the connection head  16 . A separation of the separating apparatus  10  from the connection head  16  is realized by unscrewing in reverse rotational direction. 
     In operation of the separating apparatus  10 , gas  14  contaminated with oil  12  is guided through the gas supply channel  64  of the connection head  16  and the gas inlets  36  into the housing interior  32  to the raw side of the oil separating insert  38 . The gas  14  that is to be freed from oil  12  flows through filter media, not of interest here and surrounding the separating medium  40  circumferentially continuously, and the separating medium  40  from the exterior to the interior in radial direction and reaches the insert interior  42 . In doing so, gas  14  is freed from oil  12 . The separated oil  12  sinks downwardly, following the force of gravity, in the insert interior  42  into the oil collection chamber  50 . The collected oil  12  flows through the oil drains  34  out of the separating apparatus  10  and is supplied to the oil drain channel  66  of the connection head  16 . The gas  14  that has been freed from oil  12  flows into the pipe section  54  and from there through the gas outlet  24  into the gas discharge channel  68  of the connection head  16 . 
     In  FIG. 4 , a second embodiment of the separating apparatus  10  is illustrated. Those elements that are similar to those of the first embodiment of  FIGS. 1 to 3  are provided with the same reference characters. The second embodiment differs from the first embodiment in that the pipe section  54  is connected with its connection end  56  as one piece with the circumferential wall  48  of the oil collection chamber  50 . In this context, the connection end  56  delimits the oil collection chamber  50  radially inwardly. The pipe section  54  is connected through the circumferential wall  48  as one piece with the connection end disk  46 . In this manner, the pipe section  54  is connected to the oil separating insert  38 . Moreover, the connection socket  30  extends into the housing interior  32  of the housing  18 . In this context, the pipe section  54  projects past the connection socket  30  in axial direction. An annular seal  78  is arranged between the radially outer circumferential side of the connection socket  30  and the radially inner circumferential side of the pipe section  54 . 
     Moreover, a drainage line that is hidden in  FIG. 4  and therefore not illustrated extends adjacent to the radially outer circumferential side of the connection socket  30 . The drainage line extends in axial direction and connects the raw gas side to the oil drain channel  66 . 
     In  FIG. 5 , a third embodiment of the separating apparatus  10  is illustrated. Those elements that are similar to those of the first embodiment of  FIGS. 1 to 3  are provided with the same reference characters. The third embodiment differs from the first embodiment in that the pipe section  54  with its connection end  56  is pushed onto the connection socket  30 . In this context, the connection socket  30  extends into the housing interior  32  of the housing  18 . The pipe section  54  is connected by connection socket  32  to the housing  18 . An annular seal  78  is arranged between the radially outer circumferential side of the connection socket  30  and the radially inner circumferential side of the pipe section  54 . 
     Moreover, the pipe section  54  extends to the upper end disk  44  of the oil separating insert  38 . With its end thereat, the pipe section  54  is connected as one piece to the upper end disk  44  and connected in this way to the oil separating insert  38 . The axial end face of the pipe section  54  on the side of the upper end disk  44  is closed. At its circumferential wall below the end disk  44 , the pipe section  54  comprises a plurality of through openings  80  for gas. 
     Moreover, a drainage line which is hidden in  FIG. 5  and therefore not illustrated extends adjacent to the radially outer circumferential side of the connection socket  30 . The drainage line extends in axial direction and connects the clean gas side to the oil drain channel  66 .