A DEVICE FOR CLEANING A CONTAMINATED CRANKCASE GAS

Abstract

A device for cleaning a contaminated crankcase gas generated during operation of an internal combustion engine is provided. An internal combustion engine including such a device is also provided. The device permits for an increased flexibility as to constructing the cleaning device while maintaining or possibly improving cleaning of the contaminated crankcase gas.

Claims

1. A device (200) for cleaning a contaminated crankcase gas generated during operation of an internal combustion engine (102) comprising a crankcase (210), the device (200) comprising: a housing (302) having a longitudinally extending side wall portion (215), the housing (302) comprising: an inlet (216) configured to receive the contaminated crankcase gas from the crankcase (210), and an outlet (218) configured to release a cleaned crankcase gas out from the housing (302), a fan (306; 310) configured to establishing a gas flow through the housing (302) between the inlet (216) and the outlet (218), and a cleaning arrangement (308, 308) for cleaning the contaminated crankcase gas, the cleaning arrangement (308, 308) being arranged inside of the housing (302), characterized in that the cleaning arrangement (308, 308) comprises: a traverse wall member (304) configured to cover a portion of a cross section of the housing (302), wherein the traverse wall (304) is configured to at least partly restrict the gas flow and/or affect a direction of the gas flow, and a rotatably arranged member (306) arranged downstream of the traverse wall member (304) in the direction of the gas flow, wherein the rotatably arranged member (306) comprises a plurality of wings (318) and by its rotation is configured to redirect contaminants comprised in the crankcase gas towards an inside surface of the longitudinally extending side wall portion of the housing (302).

2. The device (200) according to claim 1, wherein the rotatably arranged member (306) is arranged in parallel with the traverse wall member (304) in the direction of the gas flow.

3. The device (200) according to any preceding claim, wherein the rotatably arranged member (306) is arranged in close vicinity of the traverse wall member (304).

4. The device (200) according to any preceding claim, wherein the fan (306; 310) and the rotatably arranged member (306) are jointly constituted, forming a wing wheel.

5. The device (200) according to any preceding claim, wherein the traverse wall member (304) is constituted by a flat disc.

6. The device (200) according to any preceding claim, wherein the traverse wall member (304) is arranged to be stationary in the housing.

7. The device (200) according to any one of the preceding claims, wherein the traverse wall member (304) comprises a plurality of through holes (316) for restricting a cross sectional area of the gas flow.

8. The device (200) according to any one of the preceding claims, wherein the housing (302) presents a circular cross section.

9. The device (200) according to any one of claims 1-7, wherein the housing (302) presents a cross section having at least one of a tapered lower end (320) and a tapered upper end (322).

10. The device (200) according to any one of the preceding claims, wherein the housing (302) is elongated.

11. The device (200) according to any one of the preceding claims, wherein the device (200) is configured to recirculate the crankcase gas from a region downstream of the rotatably arranged member (306) to a region upstream of the traverse wall member (304).

12. The device (200) according to claim 11, further comprising a controllable valve mechanism (326) configured to adjust a level of crankcase gas recirculation based on a crankcase gas pressure.

13. The device (200) according to claim 12, wherein the valve mechanism (326) is configured to be controlled based on a crankcase gas pressure in the crankcase.

14. The device (200) according to any one of the preceding claims, wherein the rotatably arranged member (306) is configured to be connected to a transmission of and mechanically driven by the internal combustion engine (102).

15. The device (200) according to any one of claims 1-13, wherein the rotatably arranged member (306) is configured to be driven by an electric motor.

16. The device (200) according to any one of claims 1-13, wherein the rotatably arranged member (306) is configured to be driven by at least one of a hydraulic motor or turbine.

17. The device (200) according to any one of the preceding claims, further comprising a plurality of traverse wall members (304) and rotatably arranged members (306) arranged in a stack (308, 308).

18. The device (200) according to claim 17, wherein the plurality of traverse wall members (304) and rotatably arranged members (306) are alternatingly arranged in the stack (308, 308).

19. An internal combustion engine (102) including a crankcase (210) and further comprising a device (200) according to any one of the preceding claims.

20. A powertrain comprising an internal combustion engine (102) according to claim 19 and a transmission driven by the internal combustion engine (102), wherein the rotatably arranged member (306) is operatively connected to the transmission for being driven by the transmission.

21. A vehicle (100) comprising a powertrain according to claim 20.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

[0028] FIG. 1 illustrates a vehicle equipped with an internal combustion engine according to the invention;

[0029] FIG. 2 conceptually illustrates an internal combustion engine equipped with a cleaning device;

[0030] FIGS. 3a-3d conceptually illustrates preferred embodiments of the inventive cleaning device; and

[0031] FIG. 4 illustrates alternative embodiment for redirecting/restricting a gas flow though the cleaning device.

DETAILED DESCRIPTION

[0032] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout.

[0033] Referring now to the drawings and to FIG. 1 in particular, there is depicted an exemplary vehicle, here illustrated as a truck 100. The truck 100 is provided with a source of motive power 102 for propelling the truck via a driveline connecting the power source to the wheels. The power source 102 is constituted by an internal combustion engine (ICE) in the form of a diesel engine. It will in the following for ease of presentation be referred to as an internal combustion engine 102.

[0034] FIG. 2 shows the internal combustion engine 102 equipped with a cleaning device 200 according to the invention.

[0035] During use of the ICE 102, ambient air will be drawn though an air filter 202, pass a turbo 204 and into an upper part of a cylinder 206, above a piston 208, where it will be mixed with a fuel, such as for example diesel or petrol. As the air/fuel mixture in the cylinder 206 is ignited, portions of the combustion gases will leak past the sides of the piston 208 (past piston ring(s) of the piston) and into a crankcase 210 comprised with the ICE 102.

[0036] The combustion gases entering the crankcase 210 comprise contaminants, such as for example soot particles. The combustion gases will further come in contact with and be partly mixed with further contaminants comprised in the crankcase 210, such as oil, forming a contaminated crankcase gas. A pressure formed by the combustion gases entering the crankcase 210 needs to be vented in a controlled manner, in accordance to the invention through the cleaning device 200. The crankcase gas is allowed to exit the crankcase 210 through an outlet 212, for example arranged at an upper portion of the ICE 102, other placements of such an outlet is of course possible and within the scope of the invention.

[0037] A first conduit 214 is provided for transporting the crankcase gas from the outlet 212 of the ICE 102 to an inlet 216 of the cleaning device 200. The crankcase gas is cleaned inside of the cleaning device 200, as will be further discussed below, and a cleaned crankcase gas will be released through a first outlet 218 of the cleaning device 200. A fan function may be provided inside of and/or outside of the cleaning device 200 for assisting the transportation of the crankcase gas through the cleaning device 200. The cleaned crankcase gas may for example, as illustrated in FIG. 2, be mixed with ambient air before entering the turbo 204. A second conduit 220 may be provided for connecting the first outlet 218 of the cleaning device 200 to the turbo 204. Alternatively, the cleaned crankcase gas may be allowed to enter the atmosphere, possibly passing through further filters members before doing so.

[0038] The contaminants/particles having been removed from the contaminated crankcase gas are preferably passed back to the crankcase 210 through a second outlet 222 of the cleaning device 200 and by a third conduit 224. The cleaning device 200 is preferably arranged such that the contaminants passed back to the crankcase 210 from the cleaning device 200 is allowed to do so by means of gravitation acting on the contaminants, i.e. by arranging the cleaning device 200 in a slightly elevated position as compared to the crankcase 210. Furthermore, it should be noted that it is desirable to arrange some form of check valve (one-way valve) functionality between the second outlet 222 of the cleaning device 200 and the crankcase 210, thereby only allowing contaminants to be passed back to the crankcase 210 and not allowing contaminated crankcase gases to be sucked backwards into the cleaning device 200.

[0039] Turning now to FIG. 3a, which illustrates an example of a currently preferred embodiment of a cleaning device 200 that may be used together with the internal combustion engine 102. In the illustrated embodiment, the cleaning device 200 is comprised of a housing 302 having a longitudinally extending side wall portion 215 and arranged to have an essentially circular cross section. The housing 302 further comprises the inlet 216, the first outlet 218 and the second outlet 222 as discussed in relation to FIG. 2. In addition, the cleaning device 200 comprises a plurality of traverse wall members 304 and rotatably arranged members 306 arranged in a parallel and in close vicinity to each other in a stack 308. In a preferred embodiment and as is illustrated in FIG. 3a, the stack 308 is organized in such a manner that the traverse wall members 304 and the rotatably arranged members 306 are alternatingly arranged in the stack 308. In any case, it is desirable to position a rotatably arranged member 306 downstream of a traverse wall member 304. The stack 308 is arranged inside of the housing 302 of the cleaning device 200. The number of elements of the stack 308 may depend on the implementation in mind.

[0040] The rotatably arranged members 306 of the stack 308 are connected to an axis 310, at least partly extending to an outside of the housing 302. The part of the axis 310 extending outside of the housing 302 is provided with means for allowing rotation of the axis 310, and thus rotation of the rotatably arranged members 306. It may for example be possible, and as indicated in FIG. 3a, to provide one or a set of cog wheels, 312, 314, to be further connected to a rotating member of the ICE 102 for rotating the axis 310. It may alternatively be possible to rotate the axis 310 using either of an electrical motor, a hydraulic motor or a turbine. The set of cog wheels, 312, 314 may be used for adjusting a rotational speed of the axis 310 (e.g. forming a gear functionality).

[0041] The traverse wall members 304 of the stack 308 are preferably fixed to the inside of the housing 302. The traverse wall members 304 may for example be press fitted to the inside of the housing 302, or otherwise affixed to the inside of the housing (e.g. by welding). In a possible embodiment it may however be possible to allow for a slight rotation also of the traverse wall member 304, typically being a slow rotation in comparison to the rotational speed of the rotatably arranged member 306 during operation, possibly having a low friction based connection to the inside of the housing 302.

[0042] In the illustrated embodiment, the traverse wall member 304 is constituted by a flat disc comprises a plurality of through holes 316 for restricting a cross sectional area of a flow of the contaminated crankcase gas from the inlet 216 to the first outlet 218 of the cleaning device 200. The restriction provided by means of the plurality of through holes 316 will result in a change in the main direction of the gas flow. That is, the direction of the gas flow will be affected upstream of and in close vicinity of the traverse wall member 304 before passing the plurality of through holes 316 to the downstream side of the traverse wall member 304. Other possibilities exist for restricting and/or affect a direction of the gas flow, as for example will be further discussed in relation to FIG. 4.

[0043] As mentioned, downstream of the traverse wall member 304 there is provided a rotatably arranged member 306. The rotatably arranged member 306 comprises a plurality of wings 318 extending from a center of the rotatably arranged member 306 towards its periphery, where the periphery of the rotatably arranged member 306 preferably is provided with open portions. In a preferred embodiment and as is illustrated in FIG. 3a, the wings 318 are slightly angled, thereby efficiently acting as a fan for transporting the crankcase gas from the inlet 216 to the first outlet 218 of the cleaning device 200. The rotatably arranged member 306 may in such a case be defined as a wing wheel. It may however be possible, as indicated above, to provide the fan and the rotatably arranged member 306 as separate elements. In such a case the wings of the rotatably arranged member 306 may be angled essentially perpendicular to the traverse wall member 304. The fan may be provided inside of the housing or as a separate element outside of the housing. As understood, the angle of the wings will control the suction force provided by the wing wheels.

[0044] During operation of the cleaning device 200, the contaminated crankcase gas will be sucked from the crankcase, by the outlet 212, through the first conduit 214, by the inlet 216 and into the housing 302 by the rotation of the rotatably arranged members 306. The contaminated crankcase gas will then be forced to pass the plurality of through holes of the traverse wall member 304. Once having passed the traverse wall member 304, contaminants in the crankcase gas will come in contact with the wings 318 of the rotatably arranged member 306. Contaminants will cluster at the wings 318 and once the cluster of contaminants is large enough it will, by the rotation of the rotatably arranged member 306, be released from the wings 318, at least partly through the open portions of the periphery of the rotatably arranged member 306, and be forced towards an inside surface of the housing 302. Gravitation will then force the clustered contaminants towards a bottom of the inside of the housing 302 where the second outlet 222 is arranged. The third conduit 224 will release the contaminants back into the crankcase 210.

[0045] In some implementations it may be desirable to provide a housing of the cleaning device 200 to have an alternative cross section. For example, as is illustrated in FIG. 3b, the cleaning device 200 may be provided with a tapered lower end 320 for aggregating the contaminants before being passed back to the crankcase 210. As compared to an essentially circular cross section housing, the slight angled tapered lower end 320 will further improve runoff of contaminants from the inside of the housing towards its bottom end.

[0046] Alternatively, or also, the housing of the cleaning device 200 may be provided with a tapered upper end 322, as is shown in FIG. 3c. In a similar manner, such a tapered upper end 322 may provide improvements as to the runoff of contaminants from the inside of the housing such that contaminants does not fall directly back onto the rotatably arranged members 306, but rather runs along the inside surface of the housing towards the bottom of the housing. As understood from the above, it may of course be possible to provide the housing with a tapered lower end 320 and an upper tapered end 322, essentially forming an elliptic cross section of the housing. Similar functionality may be provided with similarly angular forms of the circular cross section of the housing. The shape of the traverse wall members 304 may, as an alternative to the illustrations provided in FIGS. 3b and 3c, be arranged to essentially correspond to the (inside) circular cross section of the housing.

[0047] In a possible embodiment of the invention, it may be possible to equip the cleaning device 200 with means for recirculation the crankcase gas from a region downstream of the rotatably arranged member 306 to a region upstream of the traverse wall member 304. FIG. 3d provides an example of such an implementation, where a conduit 324 provides a path for a cleaned crankcase gas to again be forced through the stack 308. The flow through the conduit may in one embodiment be controlled using a valve 326. The valve may in turn be, e.g. automatically, operated based on an amount of contaminants being present in the crankcase gas being passed back to the crankcase (though further combustion as is illustrated in relation to FIG. 2). It may for example be possible to use a sensor to measure the amount of contaminants at the first outlet 218 and electrically control the valve 326 based on sensor data, for example using a control unit (not shown) provided with the ICE 102.

[0048] Alternatively, or also, it may be possible to control the recirculation based on a pressure level within the crankcase. That is, in case of for example the fan functionality of the rotatably arranged members 306 provides a larger suction force that what is desirable, it may be possible to allow a portion to the crankcase gas to be recirculated for lowering the suction force. In such an implementation the valve 326 may be mechanically operated based on a gas pressure inside of the crankcase 210. The recirculation means may not necessarily be implemented as external of the housing. Rather, it may be possible to provide a similar functionality integrated inside of the housing, for example by forming a recess on the inside of the housing.

[0049] Turning finally to FIG. 4 which illustrates a cleaning device 200 according to the invention provided with slightly alternative traverse wall members 402. In the alternative embodiment, rather than providing traverse wall members comprising a plurality of through holes 316, it may be possible to provide the traverse wall members 402 where a segment of the traverse wall member has been removed. The gas flow will in such an implementation be forced to pass through the cross sectional opening provided by the removed segment. The traverse wall members 402 may be slightly rotated in relation to each other such that the gas flow is forced to change direction for each traverse wall member 402 of the stack 308. In a possible embodiment of the invention the traverse wall members 402 of the stack 308 are rotated between 10-45 degrees for each traverse wall member 402. As understood from the above, different types of implementations of the traverse wall members may be provided for at least partly restrict the gas flow and/or affect a direction of the gas flow.

[0050] In summary, the present invention relates to a device for cleaning a contaminated crankcase gas generated during operation of an internal combustion engine comprising a crankcase, the device comprising a housing having a longitudinally extending side wall portion, the housing comprising, an inlet configured to receive the contaminated crankcase gas from the crankcase, and an outlet configured to release a cleaned crankcase gas out from the housing, a fan configured to establishing a gas flow through the housing between the inlet and the outlet, and a cleaning arrangement for cleaning the contaminated crankcase gas, the cleaning arrangement being arranged inside of the housing, wherein the cleaning arrangement comprises a traverse wall member configured to cover a portion of a cross section of the housing, wherein the traverse wall is configured to at least partly restrict the gas flow and/or affect a direction of the gas flow, and a rotatably arranged member arranged downstream of the traverse wall in the direction of the gas flow, wherein the rotatably arranged member comprises a plurality of wings and by its rotation is configured to redirect contaminants comprised in the crankcase gas towards an inside surface of the longitudinally extending side wall portion of the housing.

[0051] By means of the invention, the use of the traverse wall member combined with the rotatably arranged member will advantageously allow for an increased flexibility as to constructing the cleaning device while maintaining or possibly improving cleaning of the contaminated crankcase gas.

[0052] Even though the invention has been described with reference to specific exemplifying embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. For example, the above described cleaning devices have been illustrated to comprise a plurality of traverse wall members and rotatably arranged members arranged in a stack. It may be possible and within the scope of the invention, to limit the number of elements of the stack, for example providing a plurality of traverse wall members but only a single rotatably arranged member. Further similar embodiments are possible and within the scope of the invention.

[0053] In the description above, all the rotatably arranged members in the stack have the same configuration (design and shape). It may however be feasible and within the scope of the invention that the rotatably arranged members are of different configurations. Further, in the description above, all the traverse wall members in the stack have the same configuration (design, shape, and through hole pattern). It may however be feasible and within the scope of the invention that the traverse wall members are of different configurations.

[0054] In addition, in the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality.