Device for separating particles from a gas flow, particle separator and crankcase ventilation system

Abstract

A device separates particles such as oil particles from a gas flow, from a blow-by gas of a crankcase ventilation, in an internal combustion engine. The device includes a valve seat that defines a flow passage opening and a movable valve element that can be displaced between a closed position, in which the valve element is in abutting contact with the valve seat and the abutting contact defines an axial abutting point, and at least one open position, in which the valve element is moved from the axial abutting point in an axial actuating direction. The movable valve element has a rotationally symmetrical bowl upstream of the gas flow, and a base of the bowl axially protrudes past the abutting point opposite to the axial actuating direction.

Claims

1. A device for separating particles from a gas flow, with a blow-by gas of a crankcase ventilation in an internal combustion engine, the device comprising: a valve seat that defines a flow passage opening; and a valve element that can be displaced between a closed position, in which the valve element is in abutting contact with the valve seat and the abutting contact defines an axial abutting point, and at least one open position, in which the valve element is moved from the axial abutting point in an axial actuating direction (A), wherein the valve element has a rotationally symmetrical bowl upstream of the gas flow; wherein a base of the bowl axially protrudes past the abutting point opposite to the axial actuating direction (A) by at least 10% of the longitudinal extent of the valve element.

2. The device according to claim 1, wherein the bowl base supports a spring, which causes a displacement into the closed position, wherein the bowl base is realized in a disk-shaped manner and/or wherein the bowl has a shell, which extends from the bowl base in the actuating direction (A), or a guide pin, which extends centrally from the bowl base in the actuating direction (A) and serves for guiding the spring and/or the valve element, and wherein an annular space, which a becomes larger in the actuating direction (A), particularly is formed between the guide the pin and the shell.

3. The device according to claim 2, wherein the valve seat forms a rotationally symmetrical hollow body, which is shaped complementary to the bowl and tapered in a closing direction (S) extending opposite to the actuating direction (A), wherein the bowl can be telescopically displaced into the actuating position and the closed position inside the hollow body or wherein the hollow body guides the valve element during a displacement in the actuating direction and the closing direction (S) and/or wherein the hollow body defines the flow passage opening.

4. The device according to claim 1, wherein the valve element has a collar, which leads into the bowl and defines an annular space that is open in a closing direction (S) extending opposite to the actuating direction (A) together with the bowl.

5. The device according to claim 4, wherein the valve seat has a collar, which particularly leads into the hollow body and especially protrudes into the annular space between the bowl and the valve element collar, wherein the valve seat collar defines an annular space that is open in the closing direction (S) and particularly defines an annular space that is open in the closing direction (S) together with the hollow body.

6. The device according to claim 1, wherein the axial abutting point is formed by a radial web, which extends in a radial direction (R) that is oriented perpendicular to the actuating direction (A) and leads into the valve seat collar, further wherein the valve seat collar, the radial web and an axial web extending from the radial web in the actuating direction (A) particularly define an annular gap that is open in the actuating direction (A), and further wherein the annular gap particularly guides the valve element during a displacement in the actuating direction and in the closing direction (S).

7. The device according to claim 1, wherein at least one leakage opening is arranged in the valve element, in the bowl, wherein the leakage opening allows a fluid return such as a drainage, of separated particles, opposite to the actuating direction (A) and/or a fluid passage in the closed position.

8. A device for separating particles from a gas flow, with a blow-by gas of a crankcase ventilation in an internal combustion engine, the device comprising: a valve seat that defines a flow passage opening; a movable valve element that can be displaced between a closed position, in which the valve element is in abutting contact with the valve seat and the abutting contact defines an axial abutting point, and at least one open position, in which the valve element is moved from the axial abutting point in an axial actuating direction (A); and a spring, the spring comprising a coil spring, that is supported on the valve element and is configured to cause a displacement of the valve element into the closed position; wherein the supporting point of the spring on the valve element axially protrudes past the abutting point opposite to the axial actuating direction (A) in the closed position of the valve element.

9. The device according to claim 8, wherein the valve element has a guide pin, which extends from the supporting point in the actuating direction (A) and over which the spring is placed, wherein the guide pin particularly moves out of a housing that defines the device during the displacement of the valve element in the actuating direction (A) whereas the spring is supported on a housing wall lying opposite of the supporting point, and further wherein a passage opening for the guide pin in the housing particularly is dimensioned in such a way that it guides the valve element during a displacement in the actuating direction and in the closing direction (S).

10. The device according to claim 9, wherein the spring has a progressive spring characteristic and comprises a progressively coiled spring, wherein another spring is arranged in series with this spring, and the upstream spring near the valve element particularly has a lower spring constant than the downstream spring, and wherein the spring near the valve element particularly is supported on the valve element and the downstream spring is supported on the spring near the valve element.

11. The device according to claim 8, further comprising a multipart housing, wherein the housing particularly has an inflow housing part that contains the flow passage opening and a cover part that can be connected to the inflow housing part, and wherein the valve element and the spring particularly are supported in the housing or wherein the housing parts are connected to one another by means of a clip connection and/or wherein the housing, particularly the inflow housing part, can be connected to the crankcase by means of a tongue-and-groove connection.

12. The device according to claim 11, wherein the valve element has a rotationally symmetrical bowl upstream of the gas flow, wherein the supporting point for the spring is formed on the bowl base of the bowl.

13. The device according to claim 8, wherein the valve seat and the valve element are realized in a collar-shaped manner and particularly can be telescopically displaced inside one another in such a way that a continuous collar-shaped gap is formed in the circumferential direction (U) between the valve element and the valve seat in the open position or in the closed position.

14. The device according to claim 8, further comprising at least one separating nozzle, which has a constant through-flow cross section, is arranged downstream of the valve element for the nebulization and/or defined discharge of the gas flow, wherein a flow cross section between the valve element and the valve seat at the abutting point lies in the range between 90% and 200%, of a through-flow cross section of the separating nozzle in an open position.

15. A particle separator with at least two devices for separating particles from a gas flow, from a blow-by gas of a crankcase ventilation in an internal combustion engine, wherein the at least two devices respectively comprise: a valve seat that defines a flow passage opening; and a movable valve element; wherein the at least two devices particularly are fluidically connected to one another in such a way that a gas flow can be divided between the two devices upstream of the particle separator and a gas flow can flow from one device into the other device.

16. A crankcase ventilation system of an internal combustion engine comprising: a crankcase with a flow outlet opening, through which blow-by gas can exit the crankcase; and a device for separating particles from the blow-by gas, which is fluidically connected to the flow outlet opening and further comprises: a valve seat that defines a flow passage opening; and a valve element that can be displaced between a closed position, in which the valve element is in abutting contact with the valve seat and the abutting contact defines an axial abutting point, and at least one open position, in which the valve element is moved from the axial abutting point in an axial actuating direction (A), wherein the valve element has a rotationally symmetrical bowl upstream of the gas flow; wherein a base of the bowl axially protrudes past the abutting point opposite to the axial actuating direction (A) by at least 10% of the longitudinal extent of the valve element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other properties, advantages and characteristics of embodiments of the invention are described below with reference to the attached drawings, in which:

(2) FIG. 1 shows an inventive crankcase ventilation system in the form of a schematic diagram of an example of the formation of blow-by gases and of the installation position of inventive separating devices and particle separators;

(3) FIG. 2 shows a side view of a first embodiment of a valve element for a separating device;

(4) FIG. 3 shows a bottom view of the valve element according to FIG. 2;

(5) FIG. 4 shows a section through the valve element according to FIG. 2 along the line of section D-D in FIG. 3;

(6) FIG. 5 shows a side view of a second embodiment of a valve element for a separating device;

(7) FIG. 6 shows a bottom view of the valve element according to FIG. 5;

(8) FIG. 7 shows a section through the valve element according to FIG. 5 along the line of section E-E in FIG. 6;

(9) FIG. 8 shows a side view of a third embodiment of a valve element for a separating device;

(10) FIG. 9 shows a bottom view of the valve element according to FIG. 8;

(11) FIG. 10 shows a section through the valve element according to FIG. 8 along the line of section C-C in FIG. 9;

(12) FIG. 11 shows a sectional view of a first embodiment of a particle separator with two separating devices, wherein the left separating device is illustrated in the closed position and the right separating device is illustrated in the open position; and

(13) FIG. 12 shows a sectional view of a second embodiment of a particle separator with two separating devices, wherein the left separating device is illustrated in the closed position and the right separating device is illustrated in the open position.

DETAILED DESCRIPTION

(14) In the following description of exemplary embodiments, an inventive device for separating particles is also simply referred to as separating device and generally identified by the reference symbol 51. The separating device as a whole is described in detail with reference to FIGS. 11 and 12, which show an inventive particle separator that is generally identified by the reference symbol 53.

(15) FIG. 1 shows an embodiment of an inventive crankcase ventilation system of an internal combustion engine, which is identified by the reference symbol 29 below. The crankcase ventilation system 29 comprises a crankcase 15 with a flow outlet opening 25, through which blow-by gas can exit the crankcase 15, and an inventive separating device 51 that is fluidically connected to the flow outlet opening 25 and schematically indicated in FIG. 1. It should be clear that an inventive particle separator 53 may also be fluidically coupled to the outlet opening instead of the inventive separating device 51 in order to form an inventive crankcase ventilation system 29. According to FIG. 1, the fluidic connection between the separating device 51 and the flow outlet opening 25 may be realized by means of a pipeline system such as an outlet pipe 135, which fluidically connects the flow outlet opening 25 of the crankcase to the flow passage opening 27 of the separating device 51. In a (not-shown) alternative embodiment, the separating device 51 may be mounted on the crankcase 15 in such a way that the flow passage opening 27 of the separating device 51 corresponds to the flow outlet opening 25 of the crankcase 15.

(16) FIG. 1 furthermore shows an example of the formation of blow-by gas and of the general installation position of separating devices 51 and particle separators 53. This figure shows an internal combustion engine 1 that is fluidically coupled to a fresh air supply 3, an exhaust gas discharge 5 and a crankcase ventilation 7. The internal combustion engine 1 comprises a cylinder head cover 9, a cylinder head 11, a cylinder 13 and a crankcase 15. A piston 17 is guided in the cylinder and separates a swept volume 19 from a crankcase interior 21. Not-shown sealing rings are provided between the piston 17 and the cylinder 13 in order to seal the swept volume 19 relative to the crankcase interior 21. Nevertheless, combustion gases and/or unburnt gases flow from the swept volume 19 into the crankcase interior 21 between the piston 17 and the cylinder 13. The resulting gas flow 23 is also referred to as blow-by gas flow and not only contains air and oil, but also combustion gases and unburnt fuel components.

(17) In order to prevent a pressure increase in the crankcase 15, the gas flow 23 is discharged from the crankcase 15 by means of a crankcase ventilation 7 and fed to the fresh air supply 3. In this case, the crankcase ventilation 7 particularly comprises the fluidic coupling between the flow outlet opening 25 of the crankcase 15 and the flow passage opening 27 of the separating device 51. The separating device 29 furthermore is fluidically connected to the crankcase 15 by means of a return pipe 31 for returning separated particles such as oil. The return pipe 31 fluidically connects, in particular, a return outlet 33 of the separating device 29 to a return inlet 35 on the crankcase 15. Furthermore, a return pipe 37 fluidically connects the separating device 51 to the fresh air supply 3 upstream of the separating device 29 in order to feed a gas flow, from which particles such as oil have been separated, to the fresh air supply 3. The resulting fresh air flow 41 is compressed by means of a compressor wheel 39 and fed to the internal combustion engine 1 through the cylinder head 11 by means of a charge air cooler 43. Combustion gases that do not reach the crankcase 15 between the piston 17 and the cylinder 13 are fed to a turbocharger 47 in the form of exhaust gas 45 by means of an exhaust gas discharge, wherein said turbocharger drives the compressor wheel 39 in the fresh air supply 3 via a shaft 49.

(18) It should be clear that the installation position of the inventive separating device 51 is in an application as an oil separator in internal combustion engines not limited to the installation position illustrated in FIG. 1 and also not limited to the use in a crankcase ventilation system 29. For example, the separating device 51 could also be used for separating particles from gas flows that exit the internal combustion engine 1 between the cylinder 13 and the cylinder head 11 and/or between the cylinder head 11 and the cylinder head cover 9. Another potential field of application can be seen in the fresh air supply 3 and/or in the exhaust gas discharge 5, which particularly may be fluidically coupled to one another by means of the shaft 49 connecting the compressor wheel 39 and the turbine wheel 47.

(19) FIGS. 2 to 4 show a first embodiment of a valve element 55 for an inventive separating device 51 in the form of a side view (FIG. 1), a bottom view (FIG. 3) and a sectional view along the line of section D-D (FIG. 4). An axial actuating direction, in which the valve element 55 moves during a displacement from the closed position into the open position, is identified by the reference symbol A below. The radial direction extending perpendicular to the actuating direction A is identified by the reference symbol R below. The valve element 55 comprises a bowl 57 with a bowl base 59 that essentially extends in the radial direction R, particularly in a disk-shaped manner. A shell 61 essentially extends from the bowl base 59 in the actuating direction A. The shell 61 and the bowl base 59 form a bowl 57 that is open toward a side 58 in the actuating direction A. The shell 61 is tapered in a closing direction S extending opposite to the actuating direction A and leads into the disk-shaped bowl base 59. The bowl base 59 and the shell 61 are realized rotationally symmetrical, wherein the taper of the shell 61 is limited in such a way that the maximal inside diameter 63 of the shell 61 is no more than 30%, 50%, 70% or 110% greater than the minimal inside diameter 65 of the shell 61.

(20) A valve element collar 67 respectively borders on or leads into the shell 61, particularly the end of the shell 61 pointing in the actuating direction A. The valve element collar 67 is realized rotationally symmetrical and initially extends from the shell 61 essentially in the radial direction R, particularly in an arc-shaped manner, and then essentially in the closing direction S. The valve element collar 67 and the bowl 57, particularly the shell 61, define an annular space 69 of the valve element 55 that is open in the closing direction S.

(21) The end of the collar 67 in the closing direction S forms at least one essentially circumferential abutting contact surface 71 of the valve element 57 for the abutting contact between the valve element 57 and the valve seat 73. The circumferential direction is identified by the reference symbol U below. According to FIGS. 2 to 10, the abutting contact surface 71 of the valve element 57 may be contoured in order to allow a fluid passage in the closed position of the separating device 51. The contouring of the at least one abutting contact surface 71 may comprise at least one projection and/or at least one depression 75. In the exemplary embodiments shown, the contouring comprises multiple depressions 75 (recesses) in the abutting contact surface 71 of the valve element collar 67. The multiple depressions 75 are circumferentially distributed on the contouring, particularly on the valve seat collar, in an equidistant manner. In the present embodiment, the contouring comprises thirteen depressions 75. However, more or fewer depressions 75 may also be provided. In the examples shown, the depressions 75 are illustrated with an exemplary rectangular cross section. However, they may also have other cross-sectional shapes such as, for example, that of a circle, an ellipse, a triangle, a pentagon, etc. It proved advantageous to incline the depressions 75 downstream in the closing direction S starting from a plane extending in the radial direction R in order to direct the passage taking place through the contouring at the abutting contact surface 77 of the valve seat 73, wherein the separation rate, i.e. the efficiency of the separating device 51, can thereby be increased.

(22) A guide pin 79 extends from the bowl base 59 in order to guide a spring and/or the valve element in the actuating direction A. The guide pin 79 particularly extends along a rotational axis of symmetry of the bowl 57 and/or the collar 67, which is identified the reference symbol B, and beyond the collar 67 and the bowl 57 in the actuating direction A. In the closing direction S extending opposite to the actuating direction A, the guide pin 79 extends beyond the abutting contact surface 71 of the valve element 55, particularly the valve element collar 71. The guide pin 79 and the bowl 57, particularly the shell 61, define an annular space 81 that is open in the actuating direction A and particularly becomes larger in the actuating direction A. According to FIGS. 11 and 12, the annular space 81 between the guide pin 79 and the bowl 57 particularly serves for accommodating a spring 83 that is supported on the bowl 57, particularly on the bowl base 59, and causes a displacement in the closing direction S.

(23) An inventive device for separating particles such as oil particles from a gas flow, from a blow-by gas of a crankcase ventilation 7, in an internal combustion engine comprises a valve seat 73 that defines a flow passage opening 109 and a movable valve element 55 that can be displaced between a closed position, in which the valve element 55 is in abutting contact with the valve seat 73, and at least one open position, in which the valve element 55 is moved from the axial abutting point in an axial actuating direction A.

(24) According to the above-described first embodiment of the inventive separating device 51, the valve element 55 comprises a rotationally symmetrical bowl 57 upstream of the gas flow, particularly on an axial end 84 of the valve element 55. The bowl 57 furthermore has a bowl base 59, which according to one embodiment axially protrudes past the abutting point opposite to the axial actuating direction A, i.e. in the closing direction S, by at least 5 mm, particularly by at least 10 mm, such as by at least 10%, 20%, 30%, 40% or 50% of the longitudinal extent of the valve element. The abutting point particularly is defined by the common contact surfaces 71, 77 of the valve seat 73 and an abutting contact surface 71 of the valve element 55 in the closed position. In the embodiments illustrated in FIGS. 11 and 12, the abutting point is formed by the abutting contact surface 71 of the valve element 73. The bowl base 59 serves as a supporting point 117 for a spring, which is supported on the valve element 55 with an axial end in the closing direction S and on the housing 110, particularly on the cover part 113 of the housing 110, with the other axial end in the actuating direction A. Since the bowl base 59 axially protrudes past the abutting point, particularly the abutting contact surface 71 of the valve element 73, in the closing direction S, the supporting point 117 of the spring 82 may likewise protrude past the abutting point in the closing direction S. The available spring travel can thereby be increased without increasing the overall extent of the separating device 51 in the actuating direction A. In this way, the overall axial extent of the separating device 51 required for the desired actuating travel particularly is partially shifted in the closing direction S for the benefit of the axial extent in the actuating direction A.

(25) According to the above-described embodiment separating device 51, the valve element 55 does not necessarily comprise a bowl 57. In this embodiment, it is particularly important that the supporting point 117 of the spring 83 on the valve element 55 protrudes past the abutting point, particularly the abutting contact surface 71 of the valve element 73. Analogous to the prior described embodiment, the overall axial extent of the separating device 51 required for the actuating travel is thereby partially shifted in the closing direction S for the benefit of the axial extent in the actuating direction A.

(26) FIGS. 5 to 7 show a second embodiment of a valve element 55 for an inventive separating device 51 in the form of a side view (FIG. 5), a bottom view (FIG. 6) and a sectional view along the line of section E-E (FIG. 7). Corresponding characteristics are identified by the same reference symbols in order to improve the readability of the application. At least one leakage element 85 is formed in the valve element 55 in this second embodiment of the valve element 55 of an inventive separating device 51. According to FIG. 6, in particular, multiple leakage elements 85 are formed in the valve element 55 according to the second embodiment. The leakage elements 85 are realized in the form of bores that are tapered in the actuating direction A. Due to this taper, the gas flow is accelerated during its passage through the leakage elements 85 such that the separation of particles is promoted. In alternative embodiments, the leakage elements 85 could also be realized in the form of bores that widen in the actuating direction A or in the form of bores with constant cross section. It is likewise not mandatory that the bores have the round shape shown. The bores could also have an elliptical shape or be realized angularly. The leakage elements 85 are located in a reversal section 86 of the bowl 57, which protrudes farthest in the actuating direction A and into which the shell 61 and the collar 67 lead, and essentially extend in the actuating direction A. Leakage elements 85 may alternatively or additionally be formed, for example, in the shell 61 and essentially extend in the radial direction R (in a not-shown manner) or formed in the bowl base 59 and essentially extend in the actuating direction A (in a not-shown manner).

(27) In order to additionally improve the separation rate of separating devices, the inventive separating device 51 may comprise a fibrous web 87, which is arranged on the separating device 51 in such a way that the gas flow impinges upon and/or flows through the fibrous web 87. When a fibrous web 87 is used as illustrated, for example, in FIGS. 11 and 12, it proved advantageous to provide a ring 89 on the end of the collar 67 or the shell 61 in the actuating direction A, wherein the inside diameter 91 of said ring is greater than or equal to the maximal inside diameter 63 of the shell 61. In this case, the leakage elements 85 extend through the collar 67 and the ring 89 in the actuating direction A. It proved advantageous to provide between two and ten leakage elements 85, such as between two and eight leakage elements, particularly between two and six leakage elements, in the actuating element 57, wherein said leakage elements particularly are arranged equidistant from one another in the circumferential direction U.

(28) An axial extent 93 between the abutting surface 71 of the valve element 57 and the bowl base 59 in the actuating direction A of the guide pin 79 can be adapted in relation to an overall axial extent 95 in the actuating direction A of the valve element 55, particularly shifted in the closing direction S extending opposite to the actuating direction A, in order to reduce the required structural space in the actuating direction A. It proved advantageous to realize an axial extent 93 of the guide pin 79 between the abutting surface 71 of the valve element 57 and the bowl base 59 such that it corresponds to at least 10%, 20%, 30%, 40% or 50% of the overall axial extent 95 of the valve element 55. The axial extent 93 of the guide pin 79 between the abutting surface 71 of the valve element 57 and the bowl base 59 amounts to approximately 12.5% of the overall axial extent of the valve element 57 in the embodiment according to FIGS. 2 to 4 and to approximately 20% in the embodiment according to FIGS. 5 to 7. In this way, the axial extent of the valve element and the separating device, into which the valve element is inserted, can be shifted in the closing direction S in order to thereby reduce the axial extent in the actuating direction A. According to FIG. 7, the guide pin 79 is tapered in the actuating direction A. The taper begins approximately at the axial height of the valve element collar 67 and extends over a short section in the actuating direction A, e.g. over approximately 10% of the overall axial extent 95 of the guide pin 79, wherein the guide pin 79 then continues to extend in the actuating direction A with constant cross section. Viewed in the actuating direction A, at least one guide lug 97 particularly extends in the radial direction R on an upper end 80 of the guide pin 79 in the actuating direction A, wherein multiple guide lugs 97 are provided as an example and essentially distributed on the guide pin 79 in the circumferential direction U. The guide lugs 97 particularly serve for guiding the guide pin 79, in a housing of the separating device 51, wherein the guide lugs 97 particularly may engage into (not-shown) guide grooves provided for this purpose.

(29) The valve elements 55 illustrated in FIGS. 2 to 12 comprise flow guide surfaces 99 for deflecting the gas flow such that particles are separated from the gas flow due to the impact of the particles on the flow guide surfaces 99. In this context, the surfaces of the valve element 55, which come in contact with the gas flow and deflect and/or guide this gas flow, are referred to as flow guide surfaces 99. The flow guide surfaces 99 particularly are formed on an outer surface 100 of the valve element 55, which faces away from the axial actuating direction A. The flow guide surfaces 99 are formed by the bowl 57, particularly the shell 61, and the valve element collar 67. The flow guide surfaces 99 of the valve element 55 define the annular space 69, which is open in the closing direction S, such that a gas flow flowing toward the valve element 55 in the actuating direction A is deflected and/or guided.

(30) FIGS. 8 to 10 show a third embodiment of a valve element 55 for an inventive separating device 51 in the form of a side view (FIG. 8), a bottom view (FIG. 9) and a sectional view along the line of section C-C (FIG. 10). Corresponding characteristics are identified by the same reference symbols in order to improve the readability of the application.

(31) The flow guide surfaces 99 of the valve element 55 comprise at least one turbine blade-like guide projection 101 that transforms the gas flow into a swirling flow in order to increase the separation rate of the separating device 51, wherein at least one turbine blade-like guide depression may alternatively or additionally be provided for this purpose. According to the embodiment in FIGS. 8 to 10, multiple guide projections 101 are provided in order to improve the effect thereof. The turbine blade-like guide projections 101 extend along the bowl 57 of the valve element 55, particularly along the shell 61. It proved advantageous to form the guide projections 101 on the shell 61 of the bowl 57. The guide projections 101 may alternatively or additionally also be provided on the valve element collar 67 and/or on the bowl base 59 of the valve element 55. It is furthermore possible to arrange additional or alternative guide projections 101 and/or guide depressions on flow guide surfaces of the valve seat 73 (in a not-shown manner) in order to additionally increase the separation rate.

(32) The guide projections 101 according to the exemplary embodiment are realized helically. In this case, the guide projections 101 particularly are realized in the form of continuously extending material webs that helically extend about a rotational axis of symmetry B of the valve element 55. The guide projections 101 respectively comprise an inflow profile lug 103 and an inflow profile rear edge 105, wherein the gas flow impinging upon the valve element 55 initially comes in contact with the inflow profile lug 103, is then guided along the flow guide surfaces 99 by means of the guide projections 101 in order to form a swirling flow and ultimately exits the guide projections 101 along the inflow profile rear edge 105. A connecting line between the inflow profile lug 103 and the inflow profile rear edge 105 forms a profile chord that is indicated with a reference line 107 and extends askew with respect to a main flow direction, particularly the actuating direction A. In an embodiment, in which the guide projections 101 are helically realized on the shell 61, the profile chord 107 can starting from the profile lug 103 be described as a vector that has a component in the radial direction R, a component in the axial actuating direction A, as well as a component in the circumferential direction U, particularly an angular offset in the circumferential direction U. However, a vector describing the profile chord 107 does not have to have each of these directional components. For example, profile chords that only have components in the radial direction R and in the circumferential direction U, in the radial direction R and in the actuating direction A or in the circumferential direction U and in the actuating direction A would also be conceivable. Eight rotationally symmetrical guide projections 101 are provided in the example illustrated in FIGS. 8 to 10. The guide projections 101 are arranged on the respective flow guide surfaces 99 of the valve element 55 such that they are uniformly distributed in the circumferential direction U.

(33) FIG. 11 and FIG. 12 respectively show an embodiment of an inventive particle separator 53. As an example, the particle separator 53 comprises two inventive separating devices 51 that are fluidically connected to one another, wherein the left separating device 51 is illustrated in the closed position and the right separating device 51 is illustrated in the open position. The valve elements 55 of the separating device 51 illustrated in FIG. 11 approximate the valve element 55 illustrated in FIGS. 2 to 4 and particularly can be distinguished by a larger annular space 69 between the valve element collar 67 and the bowl 57. The valve elements 57 illustrated in FIG. 12 correspond to the valve element illustrated in FIGS. 8 to 10. Corresponding characteristics are identified by the same reference symbols in order to improve the readability of the application.

(34) The separating devices 51 of the particle separator 53 are arranged parallel to one another and fluidically connected to one another. In this context, the term arranged parallel to one another refers to the separating devices 51 being arranged in such a way that a gas flow impinging upon the particle separator 53 can simultaneously flow into both separating devices 51 or be divided between the two separating devices 51, respectively. Each separating device 51 has a flow passage opening 109, by means of which a gas flow impinging upon the particle separator 53 can be divided between both separating devices 51. Although FIGS. 11 and 12 merely show the coupling of two separating devices 51 in the form of a particle separator 53, it should be clear that the preceding and following description of the separating devices 51 applies to a particle separator 53 with two separating devices 51, as well as to an individual separating device 53 and to a particle separator 53 with more than two parallel separating devices 51.

(35) The separating device 51 particularly comprises a two-part housing 110. The housing comprises an inflow housing part 111 and a cover part 113 that respectively is or can be connected thereto. The inflow housing part 111 and the cover part 113 particularly may be separably connected to one another by means of a (not-shown) clip connection. The inflow housing part 111 particularly may be connected to the crankcase by means of a (not-shown) tongue-and-groove connection. In one embodiment, the inflow housing part 111 can be connected to the crankcase by means of a tongue-and-groove connection. The separating device 51 comprises a valve seat 73 that defines the flow passage opening 109. The valve seat 73 forms part of the housing 110, particularly the inflow housing part 111. The valve seat 73 and the inflow housing part 111 are made of one piece. In the particle separator 53 shown, the valve seats 73 of the two separating devices 51 and the inflow housing parts 111 are made of one piece. The cover parts 113 of the two separating devices 51 are likewise made of one piece. For example, die casting methods may be used for this purpose.

(36) The housing 110 defines a separation space 115 for separating particles from the gas flow and for accommodating and guiding the valve element 55. The valve element 55 is mounted in the separation space 115. In the closed position, the valve element 55 is in abutting contact with the valve seat 73. During this abutting contact, the abutting contact surface 71 of the valve element 55 and the abutting contact surface 77 of the valve seat 73 contact one another. In this case, the valve element 55 is pressed against the valve seat 73 by means of a spring 83 that is supported on the valve element 55 with an axial end 84. An axial end 82 of the spring 83 lying opposite of the axial end 84 is supported on the cover part 113 of the housing. When the valve element 55 is acted upon by a gas flow with sufficient pressure, it is moved from the closed position into an open position in the actuating direction A. In this case, the gas flow acts against the spring force of the spring 83, wherein it would also be possible, for example, to provide a multi-spring arrangement such as a serial arrangement of at least two springs 83. The spring 83 supported between the valve element 55 and the housing cover 113 is compressed during a displacement of the valve element 55 in the actuating direction A. The spring force acting against the displacement motions of the valve element 55 increases as the displacement of the valve element 55 progresses in the actuating direction A. The spring characteristic can be adapted to a desired response characteristic of the valve element 55 by using springs with progressively coiled spring characteristic and/or by using a serial arrangement of multiple springs.

(37) The spring 83 is placed over the guide pin 79 that extends from the bowl 57, particularly from the bowl base 59, in the actuating direction A. A passage opening 131 for the guide pin 79, into or through which the guide pin 79 respectively protrudes, is provided in a part of the housing, particularly the cover part 113, which lies opposite of the bowl base 59 in the actuating direction A. The passage opening 131 is dimensioned in such a way that it guides the valve element 55 during a displacement in the actuating direction and/or the closing direction A, S.

(38) The space requirement of the spring 83, particularly in the actuating direction A, is reduced in that the spring 83 is supported on the bowl 57, especially on the bowl base 59, wherein a supporting point 117 is viewed in the actuating direction A formed at a lowest point on a bowl side pointing in the actuating direction A. The space requirement for the spring 83 is alternatively or additionally reduced in that the supporting point 117 of the spring 83 and/or the bowl base 59 axially protrudes past the abutting point 71, 77 opposite to the actuating direction A in the closed position of the valve element 55. In this way, the overall extent of the separating device 51 required for the actuating travel of the spring 83 particularly can be partially shifted in the closing direction S in favor of the extent in the actuating direction A. This also makes it possible, in particular, to reduce the overall axial extent of an arrangement, particularly a crankcase ventilation system 29, which comprises a separating device 51 and a gas flow source that is connected to the separating device 51 upstream and particularly may be realized in the form of a crankcase, from which blow-by gas flows into the separating device. In this case, the invention utilizes the fact that the extent, which is shifted in the closing direction S in favor of the axial extent in the actuating direction A, protrudes into an already available structural space of the gas flow source such that the actuating travel of the spring 83 can be increased without reducing the overall axial extent of the arrangement.

(39) The valve seat 73 is realized rotationally symmetrical. The valve seat 73 particularly comprises a hollow body 119 that is shaped complementary to the bowl 57 of the valve element 55. The bowl 57 and/or the hollow body 119 is tapered in the closing direction S. In this case, the bowl 57 and the hollow body 119 particularly are shaped complementary to one another. The bowl 59 can be telescopically displaced into the hollow body 119 in order to displace the valve element 55 into the closed position and/or open position. Due to the complementary design of the bowl 57 and the hollow body 119, the valve element 55 is guided in the actuating/closing direction A, S by the valve seat 73, particularly the hollow body 119, during a displacement in the actuating direction and the closing direction A, S. It should be clear that a certain relative motion of the guided valve element 55 is possible in a direction extending transverse, especially perpendicular, to the actuating/closing direction A, S. In fact, the term guided respectively refers to the motion of the guided part, i.e. the valve element 55, at least being restricted in other directions or to centering of the part, i.e. the valve element 55, taking place due to the guidance.

(40) The term guidance is elucidated below with reference to the example illustrated in FIGS. 11 and 12. According to FIG. 11, a clearance s in the radial direction R exists between the bowl 57 and the hollow body 119 in the present guidance such that the guidance of the hollow body 119 allows a certain motion in the radial direction R. According to FIG. 12, in contrast, no clearance or hardly any clearance exists between the bowl 57 and the hollow body 119 in the closed position and only a slight clearance s in the radial direction R exists between the bowl 57 and the hollow body 119 in the maximal open position, which is illustrated in the right portion of FIG. 12. This clearly shows that the turbine blade-like guide projections 101 on the shell 61 may also fulfill a guiding function in addition to the function of transforming the gas flow into a swirling flow. Due to the arrangement of guide projections 110 or guide depressions on the bowl 57, this bowl may be in physical contact with the hollow body 119 and at the same time allow a through-flow between the bowl 57 and the hollow body 119.

(41) The valve seat 73 furthermore comprises a valve seat collar 121 that leads into the hollow body 119. In this case, the valve seat collar 121 initially extends in the radial direction A in an arc-shaped manner from an end 122 of the hollow body 19 in the actuating direction A and then essentially in the closing direction S. The hollow body 119 and the valve seat collar 121 define an annular space 123 that is opened in the closing direction S. The hollow body 119 and the valve seat collar 121 protrude into the annular space 115 defined by the valve element 55. In the closed position, the hollow body 119 and the valve seat collar 121 particularly are enclosed by the valve element 55 in the radial direction R.

(42) The axial abutting point 77 (abutting contact surface of the valve seat 73) is formed by a radial web 125, into which the valve seat collar 121 leads. An axial web 127, which essentially extends in the actuating direction and the closing direction A, S, borders on the radial web 125 in the radial direction R. The valve seat collar 121, the radial web 125 and the axial web 127 define an annular gap 126 that is open in the actuating direction A and particularly guides the valve element 55 during a displacement in the actuating direction and in the closing direction S.

(43) The valve elements 55 and valve seats 73 illustrated in FIG. 11 are realized in a collar-shaped manner and particularly can be telescopically displaced inside one another such that a collar-shaped gap 128 is formed between the valve element 55 and the valve seat 73, particularly in the closed position. The collar-shaped gap 128 particularly is formed between flow guide surfaces 129 of the valve seat 73 and flow guide surfaces 99 of the valve element 55. The flow guide surfaces 129 of the valve seat 73 particularly are formed by the inner surfaces of the hollow body 119 referred to the radial direction R, which come in contact with the gas flow, and by the outer surface of the valve seat collar 121 referred to the radial direction R. The collar-shaped gap 128 causes a deflection of the gas flow by at least 130°, 140°, 150°, 160°, 170° or 180°, wherein the gas flow flows between the flow guide surfaces 99, 129 of the valve element 55 and the valve seat 73.

(44) In the separating devices 51 illustrated in FIG. 12, multiple helical gaps 137 (see particularly FIGS. 8 and 9) extending in the actuating direction A are formed between the actuating element 55 and the valve seat 73 by the turbine blade-like guide projections 101, which are in physical contact with the hollow body 119. In this case, the helical gaps 137 are defined by flow guide surfaces 99 of the valve element 55 on the shell 61 and on the turbine blade-like guide projections 101, as well as by flow guide surfaces 129 of the hollow body 119. The helical gaps 137 transform into a rotationally symmetrical gap 139 (see particularly FIG. 9), which is defined by flow guide surfaces between the valve element collar 67 and the valve seat collar 121, downstream of these helical gaps.

(45) The valve element 55 divides the separation space 115 defined by the housing 110 into a flow space between the valve element 55 and the valve seat 73 and a bypass space 141 between the valve element 55 and the cover part 113. The gas flow flows through the flow space along the flow guide surfaces 99, 129 between the valve seat 73 and the valve element 55. The gas flow can reach the bypass space 141, in which particles can also be separated, through leakage elements 85 in the valve element 55, e.g. leakage elements of the type illustrated in the embodiment according to FIGS. 5 to 7. In the separating devices 51 illustrated in FIGS. 11 and 12, a fibrous web 87, on which particles can be separated, is provided in the bypass space 141. In this case, the gas flow does not have to flow through the fibrous web 87. It suffices if the gas flow impinges upon the fibrous web 87 in order to separate particles thereon. The fibrous web 87 is realized in a disk-shaped manner, especially annularly, and fastened on the cover part 113 of the housing 110.

(46) A separating nozzle 133 with constant through-flow cross section is arranged downstream of the valve element 55 for the nebulization and/or defined discharge of the gas flow. The separating nozzle particularly forms at least one gap between the housing cover 113 and the inflow housing part 111 in the installed state. Since the housing cover 113 and the inflow housing part 111 essentially are fastened to one another in an immovable manner, the cross section of the gap and therefore the through-flow cross section of the separating nozzle 133 essentially remain constant regardless of the position of the valve element 55. Due to this constant through-flow cross section, a minimal particle separation by means of the at least one separating nozzle 133 can also be ensured when the valve element 55 is completely opened. The separating nozzle 133 is arranged downstream of the abutting contact between the valve element 55 and the valve seat 73. An annular gap between the abutting contact surface 71 of the valve element 55 and the abutting contact surface 77 of the valve seat 73 is formed in the maximal open position. The through-flow cross section of this annular gap, particularly a clearance between the abutting contact surfaces 71, 77 of the valve element 50 and the valve seat 73 in the actuating direction A, is greater, especially at least 20%, 40%, 60%, 80% or 100% greater, than the maximal through-flow cross section of the separating nozzle 133, particularly than the axial extent of the gap between the housing cover 113 and the inflow housing part 111.

(47) According to FIGS. 11 and 12, at least two separating devices 51 can be fluidically connected to one another into a particle separator 53 in such a way that a gas flow can flow from one separating device 51 into the other separating device 51. The separating devices 51 particularly are fluidically connected to one another downstream of the separating nozzle 133. An exemplary embodiment of such a fluidic connection is illustrated in FIGS. 11 and 12. In this case, a gas flow can exit the separation space 115 of one separating device 51 through its separating nozzle 133 and enter the separation space 115 of the other separating device 51 through its separating nozzle 133.

(48) A separation space connecting gap 143 is provided between the valve element 55 and the separating nozzle 133, particularly between the separating nozzle 133 and the valve element collar 67, wherein the gas flow can flow from the flow space into the bypass space 141 and vice versa through said connecting gap. Contouring of the abutting surfaces 71, 77 also enables a gas flow to flow from one separating device 51 into the other separating device and vice versa in the closed position of both valve elements 57. Contouring of the abutting surfaces 71, 77 furthermore enables a gas flow to flow from the flow space into the bypass space 141 and vice versa in the closed position when valve elements 79 without leakage elements 85 are used.

(49) The characteristics disclosed in the preceding description, the figures and the claims may be important for realizing the different embodiments of the invention individually, as well as in arbitrary combinations.

LIST OF REFERENCE SYMBOLS

(50) 1 Internal combustion engine 3 Fresh air supply 5 Exhaust gas discharge 7 Crankcase ventilation 9 Cylinder head cover 11 Cylinder head 13 Cylinder 15 Crankcase 17 Piston 19 Swept volume 21 Crankcase interior 23 Gas flow 25 Flow outlet opening 27 Flow passage opening 29 Crankcase ventilation system 31 Return pipe 33 Return outlet 35 Return inlet 37 Return pipe 39 Compressor wheel 41 Fresh air flow 43 Charge air cooler 45 Exhaust gas 47 Turbocharger 49 Shaft 51 Separating device/device 53 Particle separator 55 Valve element 57 Bowl 58 Bowl side 59 Bowl base 61 Shell 63 Maximal inside diameter of shell 65 Minimal inside diameter of shell 67 Valve element collar 69 Annular space between bowl and valve element collar 71 Abutting contact surface of valve element 73 Valve seat 75 Contouring depression 77 Abutting contact surface of valve seat 79 Guide pin 80 End 81 Annular space between guide pin and bowl 83 Spring 82, 84 Axial end 85 Leakage element 86 Reversal section 87 Fibrous web 89 Ring 91 Inside diameter of ring 93 Axial extent of guide pin 95 Overall axial extent of valve element 97 Guide lug 99 Flow guide surface of valve element 100 Outer surface 101 Guide projection 103 Inflow profile lug 105 Inflow profile rear edge 107 Profile chord 109 Flow passage opening 110 Housing 111 Inflow housing part 113 Cover part 115 Separation space 117 Supporting point of spring on valve element 119 Hollow body of valve element 121 Valve seat collar 122 End 123 Annular space between hollow body and valve element collar 125 Radial web 126 Radial gap 127 Axial web 128 Gap 129 Flow guide surfaces of valve seat 131 Passage opening for guide pin 133 Separating nozzle 135 Outlet pipe 137 Gap 139 Gap 141 Bypass space 143 Separation space connecting gap A Actuating direction S Closing direction R Radial direction U Circumferential direction B Rotational axis of symmetry s Clearance