Patent ID: 12240003

DETAILED DESCRIPTION

Aspects of the present invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

FIG.1illustrates an example of a prior art centrifugal separator100mounted to an internal combustion engine112. The centrifugal separator100comprises a gas inlet102, a gas outlet104, a separator housing105and a turbine housing106. The turbine housing106comprises a flange108. The flange108of the turbine housing106is mounted to a flange interface110of the internal combustion engine112. The centrifugal separator100is configured to separate liquid and solid particles from a flow of crankcase gases generated by the internal combustion engine112using a centrifugal rotor arranged in the separator housing106. The centrifugal rotor of the centrifugal separator100is not illustrated inFIG.1for the reason of brevity and clarity. The gas inlet102may be connected to crankcase ventilation aperture of the internal combustion engine112and the gas outlet104may be connected to an air inlet of the internal combustion engine112or to the atmosphere.

FIG.2illustrates a cross section of the prior art centrifugal separator100and of the internal combustion engine112illustrated inFIG.1. InFIG.2, the cross section is made in a cross section plane PC indicated inFIG.1. The cross section plane PC extends through the turbine housing106and the flange108of the turbine housing106. Moreover, the cross section plane PC extends through the flange interface110of the internal combustion engine112.

As can be seen inFIG.2, the turbine housing106comprises a hydraulic drive arrangement116,118. The hydraulic drive arrangement116,118is configured to rotate the centrifugal rotor of the centrifugal separator100during operation of the centrifugal separator100. The hydraulic drive arrangement116,118comprises a turbine116connected to the centrifugal rotor and a nozzle118configured to eject oil onto the turbine116. As seen inFIG.2, the turbine housing106comprises a hydraulic connection120connecting the nozzle118of the hydraulic drive arrangement116,118to an engine oil circuit122of the internal combustion engine112.

Engine oil is fed to the nozzle118of the hydraulic drive arrangement116,118via the engine oil circuit122and the hydraulic connection120during operation of the internal combustion engine112. The engine oil is ejected from the nozzle118onto the turbine116and is returned to the internal combustion engine112via a return duct124connected to a return aperture126of the internal combustion engine112. The return aperture126of the internal combustion engine112is connected to an engine oil sump of the internal combustion engine112.

As understood from the above, the turbine housing106of the prior art centrifugal separator100has tree functions. Namely to function as a console for the centrifugal separator100, provide an interface for drive oil, and to return drained oil and drive oil to the engine oil sump of the internal combustion engine112. Combustion engines112comes in a variety of sizes and designs and usually, one type of turbine housing106is developed per type of internal combustion engine112. The design is usually complicated, and tooling and production costs are relatively high. For example, the flange108of the turbine housing106and the flange interface110of the internal combustion engine112require high tolerances for flatness. Moreover, the position of the hydraulic connection120of the turbine housing106and the position of an aperture122′ of the engine oil circuit122of the internal combustion engine112require high tolerances.

In summary, partly due to the above given reasons, the turbine housing106of a prior art centrifugal separator100constitutes a great proportion of the total cost of the centrifugal separator100. Moreover, the prior art centrifugal separator100requires manufacturers of internal combustion engines112to develop costly and complicated flange interfaces110for the connection of a centrifugal separator100.

FIG.3illustrates a perspective view of a centrifugal separator1according to some embodiments of the present disclosure mounted to a machine3. The centrifugal separator1is configured to separate liquid and solid particles from a flow of gas generated by the machine3. The centrifugal separator1comprises a separator housing6, a gas inlet10and a gas outlet12. The centrifugal separator1is configured to separate liquid and solid particles from a flow of gas flowing from the gas inlet10to the gas outlet12.

As is further explained herein, the machine3may be an internal combustion engine, wherein the centrifugal separator1is configured to separate liquid and solid particles from a flow of crankcase gases generated by the internal combustion engine. According to such embodiments, the gas inlet10of the centrifugal separator1may be connected to a crankcase ventilation aperture of the internal combustion engine and the gas outlet12may be connected to an air inlet of the internal combustion engine, or to the atmosphere, as is further explained herein.

FIG.4illustrates a cross section of the centrifugal separator1and the machine3illustrated inFIG.3. As can be seen inFIG.4, the centrifugal separator1comprises a centrifugal rotor5. The centrifugal rotor5is configured to rotate around a rotation axis ra during operation of the centrifugal separator1. InFIG.4, the cross section is made in a plane comprising the rotation axis ra. The centrifugal rotor5comprises a stack of frustoconical separation discs50configured to separate liquid and solid particles from the flow of gas generated by the machine3during rotation of the centrifugal rotor5. According to other embodiments, the centrifugal rotor5may, instead of comprising a stack of conical discs, comprise axial plates, a rotating filter, or a rotating coalescer. In yet another embodiment, the centrifugal rotor may comprise a rotating stack of centrifugal discs in combination with a rotating filter or a rotating coalesce.

The centrifugal separator1comprises a hydraulic drive arrangement7,9. The hydraulic drive arrangement7,9is configured to rotate the centrifugal rotor5. According to the illustrated embodiments, the hydraulic drive arrangement7,9comprises a turbine7connected to the centrifugal rotor5and a first nozzle9configured to eject a liquid onto the turbine7. According to further embodiments, the centrifugal separator1may comprise another type of hydraulic drive arrangement for rotating the centrifugal rotor5, such as a reaction drive arrangement where a liquid jet is discharged from a rotor in a tangential direction, at a position offset from the rotational axis of the rotor, thereby providing the rotational force of the rotor. Moreover, the centrifugal rotor5of the centrifugal separator1may be provided with a central inlet for pressurised liquid, and at least one liquid outlet radially spaced from the rotational axis of the centrifugal rotor5, said outlet(s) being directed in an at least partly tangential direction to accomplish a reaction drive of the centrifugal rotor5. One example of such a reaction drive arrangement is disclosed in U.S. Patent Application No. 2005/0198932.

According to the illustrated embodiments, the centrifugal separator1comprises a turbine housing8connected to the separator housing6, wherein the hydraulic drive arrangement7,9is arranged in the turbine housing8. The centrifugal separator1comprises a hydraulic connection11for connecting the hydraulic drive arrangement7,9to a hydraulic circuit13of the machine3. A portion of the hydraulic circuit13of the machine3is also indicated inFIG.3. In embodiments where the machine3is an internal combustion engine, the hydraulic circuit13may be an engine oil circuit of the internal combustion engine. The centrifugal separator1comprises a connecting portion15for connecting the centrifugal separator1to the machine3. According to the illustrated embodiments, the connecting portion15is arranged on the turbine housing8. Moreover, according to the illustrated embodiments, the connecting portion15form part of a mounting section15′ of the centrifugal separator1. The mounting section15′ of the centrifugal separator1is also indicated inFIG.3. As indicated inFIG.3, the mounting section15′ comprises a number of through holes16. The through holes16are configured to receive a fastening element, such as a screw or bolt, to fasten the centrifugal separator1to the machine3.

As seen inFIG.4, the hydraulic connection11is arranged on the connecting portion15. Moreover, as seen inFIG.4, the connecting portion15is configured to be inserted into a connecting aperture19of the machine3. As indicated inFIG.4, the hydraulic circuit13of the machine3is connected to the connecting aperture19and the hydraulic connection11connects the hydraulic drive arrangement7,9to the hydraulic circuit13of the machine3. Since the hydraulic connection11is arranged on the connecting portion15and the connecting portion15is configured to be inserted into a connecting aperture19of the machine3, a centrifugal separator is provided circumventing the need for a costly and complex turbine housing8and a costly and complex flange interface on the machine3, as is further explained herein.

According to the illustrated embodiments, a centre axis ca of the connecting portion15is substantially parallel to the rotation axis ra of the centrifugal rotor5. Moreover, according to the illustrated embodiments, the centre axis ca of the connecting portion15is substantially coaxial with the rotation axis ra of the centrifugal rotor5. Due to these features, a compact centrifugal separator1is provided having conditions and characteristics suitable for being manufactured and assembled in a cost-efficient manner. According to the illustrated embodiments, the centrifugal separator1is configured to be connected to the machine3such that a rotation axis ra of the centrifugal rotor5is substantially parallel to a horizontal plane hp when the machine3is oriented in an upright use position. According to further embodiments, the centrifugal separator1is configured to be connected to the machine3such that a rotation axis ra of the centrifugal rotor5is transversal to a horizontal plane hp, such as for example substantially perpendicular to the horizontal plane hp, when the machine3is oriented in an upright use position.

The connecting aperture19of the machine3and the connecting portion15of the centrifugal separator1together form a connection interface20. The connection interface20comprises a groove21, wherein the hydraulic connection11is fluidly connected to the groove21. In this manner, hydraulic fluid from the hydraulic circuit13of the machine3can flow into the hydraulic connection11via the groove21during operation of the machine3. According to the illustrated embodiments, the connection interface20comprises at least one sealing23,23′ on each side of the groove21. In this manner, leakage of hydraulic fluid is avoided.

As seen inFIG.4, according to the illustrated embodiments, the connecting portion15of the centrifugal separator1comprises the groove21, wherein the hydraulic connection11is arranged in the groove21. Moreover, the hydraulic circuit13of the machine3is configured to superimpose the groove21when the connecting portion15of the centrifugal separator1is inserted into the connecting aperture19of the machine3. Furthermore, as is indicated inFIG.4, the connecting portion15comprises the least one sealing23,23′ on each side of the groove21.

According to further embodiments of the present disclosure, the connecting aperture19of the machine3may comprise a groove, wherein the hydraulic connection11of the centrifugal separator1is configured to superimpose the groove when the connecting portion15of the centrifugal separator1is inserted into the connecting aperture19of the machine3. Moreover, according to some embodiments of the present disclosure, the connecting aperture19of the machine3may comprise one or more sealings configured to seal the connection interface20.

FIG.5illustrates a perspective view of the centrifugal separator1illustrated inFIG.3andFIG.4. As best seen inFIG.5, according to the embodiments illustrated inFIG.3-FIG.5, the connecting portion15of the centrifugal separator1is cylindrical. According to further embodiments, the connecting portion15of the centrifugal separator1may be substantially cylindrical. The connecting aperture19of the machine3may also be cylindrical or substantially cylindrical. The wording “substantially cylindrical”, as used herein, may encompass that the object referred to deviates less than 5% geometrically from the shape of a cylinder.

According to the illustrated embodiments, the groove21extends along the entire circumference of the connecting portion15. According to further embodiments, the groove21may extend along more than 50% of the circumference of the connecting portion15. In this manner, a fluid connection between the hydraulic connection11and the hydraulic circuit of the machine can be obtained in a simpler and more reliable manner. That is, due to these features, a greater freedom is provided in the rotational position of the centrifugal separator1relative to the machine. Moreover, a greater freedom is provided in the positioning of the hydraulic circuit of the machine, which potentially reduces manufacturing and assembling costs of the centrifugal separator1and of the machine.

FIG.6illustrates a cross section of a centrifugal separator1according to some further embodiments of the present disclosure mounted to a machine3. The centrifugal separator1according to the embodiments illustrated inFIG.6may comprise the same features, functions, and advantages, as the centrifugal separator1explained with reference toFIG.3-FIG.5, with some differences explained below. According to the embodiments illustrated inFIG.6, the connecting portion15of the centrifugal separator1is conical with the narrow portion facing the machine3. According to further embodiments, the connecting portion15of the centrifugal separator1may be substantially conical.

As can be seen inFIG.6, according to these embodiments, the connecting aperture19of the machine3may also be conical, or substantially conical, with the wider portion facing the centrifugal separator1. Due to these features, the connecting portion15of the centrifugal separator1may be inserted into the connecting aperture19of the machine3in a simpler manner. The wording “substantially conical”, as used herein, may encompass that the object referred to deviates less than 5% geometrically from the shape of a cone.

FIG.7illustrates a centrifugal separator1according to some further embodiments of the present disclosure. The centrifugal separator1according to the embodiments illustrated inFIG.7may comprise the same features, functions, and advantages, as the centrifugal separator1explained with reference toFIG.3-FIG.6, with some differences explained below. According to the embodiments illustrated inFIG.7, the hydraulic drive arrangement7,9comprises three nozzles9,9′,9″, namely a first, a second, and a third nozzle9,9′,9″ each configured to eject a liquid onto the turbine7. According to further embodiments, the hydraulic drive arrangement7,9may comprise two or more nozzles9,9′,9″. Thereby, a more reliable hydraulic drive arrangement7,9is provided because the hydraulic drive arrangement7,9can continue to function even in case of a malfunction of one or more of the nozzles9,9′,9″. A malfunction of a nozzle9,9′,9″may for example occur if a nozzle9,9′,9″ becomes clogged.

According to the illustrated embodiments, the connecting portion15of the centrifugal separator1comprises a groove21extending along the entire circumference of the connecting portion15. Each nozzle9,9′,9″ is fluidly connected to the groove21which allows for a simple and efficient design in which the nozzles9,9′,9″ are fed with a liquid from a hydraulic circuit of a machine.

FIG.8illustrates a cross section of a centrifugal separator1according to some further embodiments of the present disclosure mounted to a machine3. The centrifugal separator1according to the embodiments illustrated inFIG.8may comprise the same features, functions, and advantages, as the centrifugal separator1explained with reference toFIG.3-FIG.7, with some differences explained below. According to the embodiments illustrated inFIG.8, the centrifugal separator1comprises a return conduit25. The return conduit25is configured to return liquid and solid particles separated by the centrifugal rotor5of the centrifugal separator1to the hydraulic circuit13of the machine3. According to the illustrated embodiments, the centrifugal separator1is configured to be connected to the machine3such that a rotation axis ra of the centrifugal rotor5is substantially parallel to a horizontal plane hp when the machine3is oriented in an upright use position. As can be seen inFIG.8, the return conduit25is arranged below the rotation axis ra of the centrifugal rotor5when the centrifugal separator1is oriented in an intended use position. InFIG.8, the centrifugal separator1is oriented in the intended use position. Moreover, the return conduit25is arranged below an outer periphery5′ of the centrifugal rotor5when the centrifugal separator1is oriented in the intended use position. In this manner, liquid and solid particles separated by the centrifugal rotor5can be returned to the hydraulic circuit13of the machine3in an efficient manner by gravity.

Moreover, according to the illustrated embodiments, the return conduit25comprises a one-way valve27configured to allow flow of fluid from the return conduit25to the hydraulic circuit13of the machine3and is configured to hinder flow of fluid from the hydraulic circuit13of the machine3to the return conduit25of the centrifugal separator1. According to the illustrated embodiments, the return conduit25is formed in the separator housing6of the centrifugal separator1.

FIG.9illustrates a perspective view of the separator housing6of the centrifugal separator1illustrated inFIG.8. As best seen inFIG.9, the return conduit25is formed as a narrow slot. In this manner, interference between internal gas flow and separated liquid and solid particles can be avoided. Moreover, as can be seen inFIG.9, as well as inFIG.8, an opening25′ of the return conduit25in the separator housing6is provided with a considerable length measured in a direction of the rotation axis ra of the centrifugal rotor5. In this manner, a flow of separated liquid and solid particles can be ensured from the separator housing6even when the centrifugal separator1is inclined relative to the horizontal plane hp.

The following is explained with reference toFIG.8. According to the illustrated embodiments, the length of the opening25′ of the return conduit25is approximately 100% of the length of the centrifugal rotor5measured in the direction of the rotation axis ra of the centrifugal rotor5. According to further embodiments, the length of the opening25′ of the return conduit25may be within the range of 30%-150%, or 50%-135% of the length of the centrifugal rotor5measured in the direction of the rotation axis ra of the centrifugal rotor5.

As indicated inFIG.8andFIG.9, the separator housing6of the centrifugal separator1comprises a flange30for connecting an outlet portion25″ of the return conduit to the hydraulic circuit13of the machine3.

FIG.10schematically illustrates a machine3according to some embodiments of the present disclosure. According to the illustrated embodiments, the machine3is an internal combustion engine3′. The internal combustion engine3′ may for example be a compression ignition engine, such as a diesel engine, or an Otto engine with a spark-ignition device, wherein the Otto engine may be configured to run on gas, petrol, alcohol, similar volatile fuels, or combinations thereof. The internal combustion engine3′ may be configured to provide motive power to a vehicle comprising the internal combustion engine3′. The vehicle may be a truck or another type of manned or unmanned vehicle for land or water based propulsion such as a lorry, a bus, a construction vehicle, a tractor, a car, a ship, a boat, or the like.

The internal combustion engine3′ comprises a centrifugal separator1. The centrifugal separator1may be a centrifugal separator1according to any one of the embodiments explained with reference toFIG.3-FIG.9. The centrifugal separator1is configured to separate liquid and solid particles from a flow of crankcase gases generated by the internal combustion engine3′. As can be seen inFIG.10, the gas inlet10of the centrifugal separator1is connected to a crankcase venting aperture35of the internal combustion engine3′. The gas outlet12of the internal combustion engine3′ is connected to an air inlet system37of the internal combustion engine3′. In this manner, the centrifugal separator1can separate liquid and solid particles from a flow of crankcase gases generated by the internal combustion engine3′ and cleaned air can be returned to the air inlet system37. Thereby, the emission of liquid and solid particles from the crankcase is avoided. According to further embodiments, the gas outlet12of the internal combustion engine3′ may be connected to the atmosphere.

According to the embodiments illustrated inFIG.10, the centrifugal separator1is connected to the machine3such that a rotation axis ra of the centrifugal rotor of the centrifugal separator1is substantially parallel to a horizontal plane hp when the machine3is oriented in an upright use position. InFIG.10, the machine3is oriented in the upright use position. In this manner, less space is required for the centrifugal separator1in the vertical direction vd of the machine3, and more freedom is provided in the positioning of the centrifugal separator1onto the machine3.

However, according to further embodiments of the present disclosure, the centrifugal separator1may be connected to the machine3such that a rotation axis ra of the centrifugal rotor of the centrifugal separator1is transversal to the horizontal plane hp when the machine3is oriented in the upright use position. As an example, the centrifugal separator1may be connected to the machine3such that a rotation axis ra of the centrifugal rotor of the centrifugal separator1is substantially parallel to the vertical direction vd when the machine3is oriented in the upright use position.

The wording “substantially parallel to”, as used herein, may encompass that the angle between the objects referred to is less than 7 degrees.

It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, without departing from the scope of the present invention, as defined by the appended claims.

As used herein, the term “comprising” or “comprises” is open-ended, and includes one or more stated features, elements, steps, components, or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions, or groups thereof.