Housing for a centrifugal separator

Abstract

Disclosed herein is a housing (1) for a centrifugal separator (3), wherein the centrifugal separator (3) is configured to separate a liquid phase from a crankcase gas of an internal combustion engine using a rotor (5). The housing (1) includes a housing body (7) forming a separation chamber (9), an opening (11) in the housing body (7), a bearing holder (13) disposed at the opening (11), and a bearing (15) inserted into the bearing holder (13). The bearing (15) is configured to receive a rotor shaft (17) extending into the separation chamber (9). The bearing holder (13) comprises a bearing seat portion (19) provided with a plurality of plastic deformation zones (21) holding the bearings (15) in the bearing holder (13). The present disclosure also relates to a centrifugal separator (3) and a method of retaining a bearing (15) of a rotor shaft (17) in a housing (1) for a centrifugal separator (3).

Description

Technical Field

[0001] The present disclosure relates to a housing for a centrifugal separator configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor. The present disclosure also relates to a centrifugal separator configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor, and a method of retaining bearings of a rotor shaft in a housing for a centrifugal separator configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor. Background Art

[0002] Mixtures of fluids with different densities can be separated from each other using a centrifugal separator. A specific use of a centrifugal separator is to separate the liquid phase from the crankcase gases of an internal combustion engine. The crankcase gases of an internal combustion engine originate from gases that leak from the combustion chamber of the internal combustion engine through the piston rings into the crankcase of the engine. This continuous leakage of gas into the crankcase can lead to an undesirable increase in the pressure in the crankcase, and as a result, it is necessary to exhaust the gases from the housing. The crankcase gases typically carry a certain amount of engine oil (as droplets or fine mist) as well as other liquid hydrocarbons, soot, and other solid combustion residues. These substances can be harmful to the environment. Therefore, for certain types of internal combustion engines, regulations require that the crankcase gases be handled in an environmentally friendly manner.

[0003] In some internal combustion engines, crankcase gases are directed to the engine's intake. This prevents the crankcase gases from being discharged directly into the ambient air. However, the function of the internal combustion engine can be adversely affected by the presence of oil in the intake air, particularly in engines that include a turbocharger system, where the efficiency of the turbocharger's compressor can be adversely affected by the presence of oil. Therefore, it is advantageous to clean the crankcase gases to remove any oil carried by the gases before they are introduced into the intake system. This cleaning process can be performed by a centrifugal separator mounted on or adjacent to the crankcase, which directs the cleaned gases to the intake system and returns the separated oil to the crankcase. An example of such a separator is disclosed, for example, in US Pat. No. 8,657,908.

[0004] Internal combustion engines generate significant amounts of vibration and noise during startup, operation, and shutdown. This is due to the high pressure in the combustion chamber and the movement of the piston, connecting rod, and other engine components. Consequently, centrifugal separators mounted on or adjacent to the crankcase of an internal combustion engine are subject to considerable vibration during startup, operation, and shutdown of the engine.

[0005] When manufacturing components for centrifugal separators configured to separate a liquid phase from the crankcase gases of an internal combustion engine, it is advantageous to ensure that the components are durable enough to last the life of the engine.

[0006] Furthermore, in order to provide a competitive product, it would be advantageous if the components of the centrifugal separator could be obtained in a cost-effective manner. Summary of the Invention

[0007] It is an object of the present invention to provide a robust housing for a centrifugal separator which can be produced in a cost-effective manner.

[0008] According to an aspect of the present invention, an objective is achieved by a housing for a centrifugal separator configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor, wherein the housing includes a housing body forming a separation chamber, an opening in the housing body, a bearing retainer disposed at the opening, and a bearing inserted into the bearing retainer. The bearing is configured to accommodate a rotor shaft extending through the bearing and the opening into the separation chamber. The rotor shaft is configured to retain the rotor within the separation chamber. The bearing retainer includes a bearing seat portion having a plurality of plastic deformation zones for retaining the bearing in the bearing retainer. Because the bearing seat portion includes the plurality of plastic deformation zones for retaining the bearing in the bearing retainer, the bearing is securely retained in the bearing retainer, a manner that is less susceptible to vibration than, for example, when using a bearing retainer including fastening elements such as screws or bolts for retaining the bearing.

[0009] Furthermore, a less complex housing for the centrifugal separator is provided, as the need for fastening elements, such as screws or bolts for retaining the bearings, is circumvented.

[0010] Furthermore, a housing for a centrifugal separator is provided which can be manufactured in a cost-effective manner since the holding of the bearings in the bearing holder does not require the attachment of fastening elements such as screws or bolts, thereby saving time during the manufacturing process of the housing.

[0011] Furthermore, a housing for a centrifugal separator is provided, wherein the bearing is retained using fewer manufacturing tolerances (also referred to as engineering tolerances) for the alignment between the centrifugal separator rotor shaft and the bearing, compared to prior art solutions in which the bearing is retained using additional fastening elements, such as screws or bolts, which in turn require additional manufacturing tolerances and increase manufacturing costs. As a result, the bearing can be easily and accurately aligned with the centrifugal separator rotor shaft, which can also improve the durability of the bearing and the bearing retainer of the housing.

[0012] Thus, a strong and durable housing for a centrifugal separator is provided, which can be manufactured in a cost-effective manner.As a result, the above mentioned objects are achieved.

[0013] Optionally, the bearing includes an outer ring configured to remain stationary relative to the housing during rotation of the rotor shaft, wherein the plurality of plastically deformed zones abut the outer ring of the bearing. As a result, the bearing is securely retained in the bearing holder without requiring any fastening elements (such as screws or bolts). The inner ring of the bearing can still rotate freely when the rotor shaft rotates.

[0014] Optionally, the bearing retainer includes a wall surrounding an outer surface of the bearing, wherein the bearing seat portion further includes a stop portion extending into the bearing seat portion, wherein the outer ring includes a first surface abutting the stop portion of the bearing seat portion and a second surface opposite the first surface, wherein the plurality of plastically deformed regions abut the second surface of the outer ring of the bearing. As a result, the bearing is more securely retained in the bearing retainer and is less susceptible to vibration.

[0015] Optionally, the plurality of plastically deformed zones abut the second surface at at least three locations. Plastically deformed zones abutting the second surface at at least three locations have been shown to achieve sufficient and secure retention of the bearing in the bearing holder. This allows for a simple and secure retention of the bearing in the bearing holder, for example, by using a punching tool.

[0016] Optionally, the plurality of plastically deformed zones surround the second surface of the bearing. This allows the bearing to be more securely held in the bearing holder and less susceptible to vibration. Furthermore, the second surface of the bearing is protected by the plurality of plastically deformed zones.

[0017] Optionally, the outer ring of the bearing has a rounded edge between the second surface and the outer surface, wherein the plurality of plastically deformed regions abut the rounded edge. The abutment of the rounded edge against the bearing provides for secure retention of the bearing. Furthermore, the abutment of the rounded edge against the bearing may help maintain alignment of the bearing with the rotor shaft of the centrifugal separator.

[0018] Optionally, the bearing further comprises an inner ring and a rotatable body arranged between the inner ring and the outer ring.Thereby, a strong and durable bearing is provided.

[0019] Optionally, multiple plastic deformation zones cover the area between the inner and outer rings of the bearing. Thus, the area between the inner and outer rings is protected by the multiple plastic deformation zones. This reduces the risk of dirt or other unwanted matter entering the area between the inner and outer rings, thereby improving the life of the bearing.

[0020] Optionally, the bearing further comprises a sealing gasket covering the area between the inner ring and the outer ring, wherein the plurality of plastic deformation zones abut the sealing gasket. The sealing gasket may be made of metal and / or plastic material and is arranged to seal the area between the inner ring and the outer ring of the bearing. This further protects the area between the inner ring and the outer ring. The plurality of plastic deformation zones abutting the sealing gasket may help to keep the sealing gasket in place. As a result, the risk of any dirt or other unwanted matter entering the area between the inner ring and the outer ring is further reduced. Thus, the life of the bearing can be further improved.

[0021] Optionally, a plurality of plastic deformation zones surround the sealing washer.Thus, the sealing washer is protected by a plurality of plastic deformation zones, which can further improve the durability of the sealing washer and therefore also the bearing.

[0022] Optionally, a plurality of plastic deformation zones are formed by roll forming. Thus, the bearing is firmly held in the bearing retainer in a simple, firm and effective manner.

[0023] Optionally, the housing body and the bearing holder are made of a metal material, preferably aluminum. This allows the housing body and the bearing holder to be constructed from a single, durable, lightweight piece of material. Providing the housing body and the bearing holder as one piece further reduces manufacturing tolerances on the alignment between the centrifugal separator's rotor shaft and the bearings. Furthermore, it improves the robustness and durability of the housing.

[0024] Optionally, the housing body is made of a polymeric material, and the bearing retainer is made of a metal material, preferably aluminum. Polymeric materials are lightweight, inexpensive, resistant to vibration, and resistant to crack formation. Metallic materials (such as aluminum) are harder than polymeric materials. Therefore, by making the housing body of a polymeric material and the bearing retainer of a metal material (such as aluminum), a lightweight, inexpensive, and strong housing is provided, in which the bearing is securely retained.

[0025] Optionally, at least a portion of the bearing retainer is embedded in the housing body. The feature of at least a portion of the bearing retainer being embedded in the housing body may include at least a portion of the bearing retainer extending into the material of the housing body, such that the material of the housing body surrounds at least a portion of the bearing retainer. Because at least a portion of the bearing retainer is embedded in the housing body, a simple and secure attachment of the bearing retainer to the housing body is achieved using a small number of manufacturing tolerances for alignment between the centrifugal separator rotor shaft and the bearing.

[0026] A further object of the present invention is to provide a robust centrifugal separator configured to separate a liquid phase from crankcase gases of an internal combustion engine using a rotor, which centrifugal separator can be manufactured in a cost-effective manner.

[0027] According to aspects of the present invention, further objectives are achieved by a centrifugal separator configured to separate a liquid phase from crankcase gases of an internal combustion engine using a rotor, wherein the centrifugal separator includes a housing according to some embodiments. Because the centrifugal separator includes the housing according to some embodiments, a robust, durable, and uncomplicated centrifugal separator is provided that can be manufactured in a cost-effective manner. Consequently, the further objectives mentioned above are achieved.

[0028] Optionally, the centrifugal separator further comprises a bearing plate having an additional opening, an additional bearing holder arranged at the additional opening, and an additional bearing inserted into the additional bearing holder, wherein the additional bearing is configured to accommodate a rotor shaft extending through the additional bearing and the additional opening into the separation chamber, wherein the additional bearing holder comprises a bearing seat portion having a plurality of plastic deformation zones for retaining the additional bearing in the additional bearing holder. This provides a centrifugal separator in which the additional bearing is retained in a secure manner that is less susceptible to vibrations. Furthermore, since the need for fastening elements, such as screws or bolts, for retaining the additional bearing is avoided, a less complex centrifugal separator is provided. Furthermore, fewer manufacturing tolerances are employed for retaining the additional bearing, which improves the durability and robustness of the housing and, therefore, the centrifugal separator comprising the housing.

[0029] Furthermore, a centrifugal separator is provided that can be manufactured more cost-effectively, since the additional bearing can be retained without the use of fastening elements (such as screws or bolts), which saves time during the manufacture of the centrifugal separator. The carrier plate provided with the additional bearing holder that retains the additional bearing can be located below the rotor and, therefore, also below the separation elements and / or separation discs of the rotor. Thus, the additional bearing can constitute a lower bearing located below the rotor and the separation elements and / or separation discs of the rotor, and the bearing in the bearing holder can constitute an upper bearing located above the rotor and the separation elements and / or separation discs of the rotor.

[0030] A further object of the present invention is to provide a method of retaining a bearing of a rotor shaft in a housing for a centrifugal separator, which provides a robust housing in a cost-effective manner.

[0031] According to aspects of the present invention, a further object is achieved by a method of retaining a bearing of a rotor shaft in a housing for a centrifugal separator, wherein the centrifugal separator is configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor, wherein the housing includes a housing body forming a separation chamber, an opening in the housing body, a bearing retainer arranged at the opening, and a bearing configured to receive a rotor shaft extending through the bearing and the opening into the separation chamber, the rotor shaft configured to retain the rotor within the separation chamber, wherein the bearing retainer includes a bearing seat portion for inserting the bearing, wherein the bearing seat portion is provided with a wall configured to surround the bearing, and wherein the bearing seat portion includes at least one protrusion arranged at the wall of the bearing seat portion and protruding therefrom, wherein the method comprises: - inserting the bearing into the bearing seat portion of the bearing retainer, and - Plastic deformation of the at least one protrusion towards the bearing is performed so that a plurality of plastic deformation zones are formed to retain the bearing in the bearing holder.

[0032] Because the method includes performing plastic deformation of at least one protrusion toward the bearing so that a plurality of plastic deformation zones are formed to hold the bearing in the bearing holder, the bearing is held in the bearing holder in a secure manner that is less susceptible to vibrations than, for example, when using a bearing holder that includes fastening elements (such as screws or bolts) for holding the bearing.

[0033] Furthermore, a less complicated method of retaining the bearings of a rotor shaft in a housing for a centrifugal separator is provided, since the need for fastening elements, such as screws or bolts, for retaining the bearings is avoided.

[0034] Furthermore, a cost-effective method is provided, since the holding of the bearing in the bearing holder does not require the attachment of fastening elements such as screws or bolts, thereby saving time.

[0035] In addition, a method is provided that reduces manufacturing tolerances for the alignment between the centrifugal separator rotor shaft and the bearing. As a result, the bearing can be easily and accurately aligned with the centrifugal separator rotor shaft, which can also improve the durability of the bearing and the bearing holder of the housing.

[0036] Hence, a method of retaining a bearing of a rotor shaft in a housing for a centrifugal separator is provided, which provides a robust housing in a cost-effective manner.As a result, the above mentioned further objects are achieved.

[0037] Plastic deformation is a process in which a force is applied to an object to deform the object or part of it, and due to the size, geometry, and material of the object and the magnitude of the applied force, the object does not return to its original shape once the force is no longer applied. Plastic deformation may also be referred to as permanent deformation.

[0038] Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Various aspects of the present invention, including its particular features and advantages, will be readily understood from the exemplary embodiments discussed in the following detailed description and accompanying drawings, in which: Figure 1 shows a centrifugal separator configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor, Figure 2 shows the bearing retainer, Figure 3 Shown Figure 2 The bearing retainer shown in FIG, wherein the bearing is retained in the bearing retainer, Figure 4 shows a bearing retainer in which a plurality of plastically deformed zones covers the area between the inner and outer rings of the bearing, Figure 5 A bearing retainer is shown, wherein the bearing further comprises a sealing gasket covering the area between the inner and outer rings of the bearing, Figure 6 shows a further bearing holder arranged at a further opening of a carrier plate of a centrifugal separator, Figure 7 A method of retaining a bearing of a rotor shaft in a housing for a centrifugal separator is shown. DETAILED DESCRIPTION

[0040] Aspects of the present invention will now be described more fully. Like reference numerals denote like elements throughout. For the sake of brevity and / or clarity, well-known functions or constructions are not necessarily described in detail.

[0041] Figure 1 A centrifugal separator 3 is shown, configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor 5. The centrifugal separator 3 includes a housing 1, which includes a housing body 7 forming a separation chamber 9, an opening 11 in the housing body 7, a bearing retainer 13 disposed at the opening 11, and a bearing 15 inserted into the bearing retainer 13. The housing 1 is a stationary housing 1, meaning that it is arranged to remain stationary relative to the internal combustion engine during operation. The bearing 15 is configured to accommodate a rotor shaft 17 extending through the bearing 15 and the opening 11 into the separation chamber 9. The rotor shaft 17 is configured to retain the rotor 5 within the separation chamber 9.

[0042] Figure 1The centrifugal separator 3 shown in FIG. 1 includes an oil nozzle 18 connected to the engine oil circuit of the internal combustion engine. During operation of the internal combustion engine, oil is pumped through the oil nozzle 18 to a wheel 20 connected to the rotor shaft 17, thereby rotating the rotor shaft 17 and the rotor 5. Alternatively, the centrifugal separator 3 may include an electric motor arranged to rotate the rotor shaft 17 and the rotor 5. As a further alternative, the centrifugal separator 3 may include a turbine wheel connected to the rotor shaft 17, wherein the turbine wheel is arranged to be driven by exhaust gas from the internal combustion engine to rotate the rotor shaft 17 and the rotor 5. Figure 1 The centrifugal separator 3 shown in FIG comprises an inlet for crankcase gas through the rotor shaft 17. However, the centrifugal separator 3 may comprise a separate inlet for crankcase gas in the upper region of the housing 1. The crankcase gas is ducted from the inlet into the rotor. The rotor comprises separation elements and / or separation discs, such as a stack of frustoconical separation discs. For reasons of clarity, Figure 1 Such separation components and / or separation discs are not shown. During the rotation of the rotor 5, oil and other particles and / or matter from the crankcase gas are separated from the gas. The separated oil and other particles and / or matter are directed to an oil outlet 22.1 of the centrifugal separator 3. This oil and other particles and / or matter are directed back to the engine oil circuit of the internal combustion engine, along with the oil from the oil nozzle 18 used to drive the wheel 20. The centrifugal separator 3 also includes a clean crankcase gas outlet 22.2, where the clean crankcase gas is directed to the inlet of the internal combustion engine or discharged to the ambient air.

[0043] Figure 2 A bearing retainer 13 according to some embodiments is shown. The bearing retainer 13 includes a bearing seat portion 19 for inserting a bearing 15. The bearing seat portion 19 is provided with a wall 24 configured to surround the bearing 15 when the bearing 15 is inserted into the bearing seat portion 19. The bearing seat portion 19 includes at least one protrusion 25 arranged at the wall 24 of the bearing seat portion 19 and protruding therefrom, and the at least one protrusion 25 is arranged to undergo plastic deformation toward the bearing 15, so as to form a plurality of plastic deformation zones 21 that retain the bearing 15 in the bearing retainer 13.

[0044] Plastic deformation is a process in which a force is applied to an object to deform at least a portion of the object, and due to the size, geometry, and material of the object and the magnitude of the force applied, once the force is no longer applied, the object or portion of the object does not recover its original shape. In order to plastically deform, the yield strength or yield stress of the material must be exceeded. For example, many metallic materials (such as, for example, aluminum, steel, and brass) have a significantly distinguishable yield strength. When subjected to plastic deformation, the material from which the object is made undergoes a lasting change in its microstructure, such as, for example, by forming dislocations. Therefore, it is possible to determine whether a material has been plastically deformed. In contrast to elastic deformation (wherein due to the size, geometry, and material of the object and the magnitude of the force applied, once the force is no longer applied, the object recovers its original shape), plastic deformation can be referred to as permanent deformation.

[0045] Therefore, each of the plastically deformed regions 21 of the bearing holder 13 can be distinguished from a non-deformed region of the bearing holder 13. Thus, the plurality of plastically deformable regions 21 form a structural feature of the bearing holder 13, the housing 1, and the centrifugal separator 3. The plastically deformed regions 21 are portions of the material from which the bearing holder 13 is made, in which the yield stress of the material has been exceeded.

[0046] according to Figure 2 In the embodiment of the bearing retainer 13 shown in FIG, the wall 24 of the bearing seat portion 19 is substantially cylindrical and has a height h in the direction of the cylinder axis A of the substantially cylindrical wall 24. The height h of the wall 24 is equal to the height h of the bearing 15 to be retained. The wall 24 and the at least one projection 25 together have an extension e in the direction of the cylinder axis A of the substantially cylindrical wall 24 that exceeds the height h of the bearing 15 to be retained. The projection 25 arranged on the wall 24 of the bearing seat portion 19 also includes a cylindrical wall, which, as shown, may constitute a continuation of the wall 24 of the bearing seat portion 19 configured to enclose the bearing 15. Therefore, according to some embodiments, the wall 24 of the bearing seat portion 19 and the at least one projection 25 may be embodied by a coherent cylinder having an extension e in the direction of the cylinder axis A of the bearing seat portion 19 that exceeds the height h of the bearing 15 to be retained. According to further embodiments, the bearing retainer 13 includes a plurality of interspaced protrusions 25 circumferentially arranged at the wall 24 of the bearing seat portion 19. By way of example only, according to such embodiments, the bearing retainer 13 may include 2-8 interspaced protrusions 25 circumferentially arranged at the wall 24 of the bearing seat portion 19.

[0047] Figure 3 Shown Figure 2, wherein the bearing 15 has been inserted into the bearing seat portion 19 of the bearing holder 13. In addition, plastic deformation of at least one protrusion 25 toward the bearing 15 has been performed so that a plurality of plastic deformation zones 21 are formed to hold the bearing 15 in the bearing holder 13. Thus, as Figure 3 As shown in FIG, the bearing retainer 13 includes a bearing seat portion 19, which is provided with a plurality of plastic deformation zones 21 for retaining the bearing 15 in the bearing retainer 13. Therefore, when plastically deformed, at least one protrusion 25 forms a plurality of plastic deformation zones 21. At least part of the plurality of plastic deformation zones 21 may extend in the radial direction of the cylindrical axis A of the bearing seat portion 19 to retain the bearing 15 in the bearing retainer 13. In the embodiment shown, before plastic deformation, as shown in FIG. Figure 2 As shown in FIG, at least one protrusion 25 extends in the axial direction of the cylindrical axis A, and after plastic deformation, at least one protrusion 25 (now forming a plurality of plastic deformation zones 21) extends in the radial direction of the cylindrical axis A. Thus, the bearing 15 is securely held in the bearing retainer 13. By way of example only, the bearing retainer 13 may include one to eight plastic deformation zones 21 that retain the bearing 15 in the bearing retainer 13. The plurality of plastic deformation zones 21 may be discrete regions of the bearing retainer 13 arranged at regular or irregular intervals around the bearing 15, i.e., each of the plastic deformation zones 21 may be isolated from one another, for example, by a circumferential gap between each of the plastic deformation zones 21, or by a region between the plastic deformation zones 21 that is not plastically deformed. Alternatively, the plurality of plastic deformation zones 21 may form one continuous region of plastically deformable material, i.e., the plastic deformation zones 21 extend into one another, for example, forming a band of plastic deformation material adjacent to the bearing 15 in the bearing retainer 13. The plurality of plastically deformed regions 21 may be formed using a forming process such as roll forming or stamping.

[0048] The bearing 15 includes an outer ring 23 that is configured to remain stationary relative to the housing during rotation of the rotor shaft. A plurality of plastically deformed zones 21 adjoin the outer ring 23 of the bearing 15 .

[0049] As in Figure 2As best seen in FIG, the bearing retainer 13 is provided with a wall 24 which is configured to surround an outer surface 26 of the bearing 15. The bearing seat portion 19 further comprises a stop portion 27 which extends into the bearing seat portion 19 in a radial direction of the cylindrical axis A of the bearing seat portion 19. Thereby, when the bearing 15 is fully inserted into the bearing seat portion 19, the stop portion 27 prevents further displacement of the bearing 15 in the insertion direction. The bearing 15 comprises an inner ring 39 and a rotatable body 41 arranged between the inner ring 39 and the outer ring 23. The outer ring 23 comprises a first surface 31 and a second surface 35 opposite to the first surface 31. When the bearing 15 is inserted into the bearing seat portion 19, the first surface 31 of the outer ring 23 abuts the stop portion 27 of the bearing seat portion 19. Furthermore, as shown in FIG. Figure 3 As can be seen in FIG, a plurality of plastically deformed regions 21 abut against a second surface 35 of the outer ring 23 of the bearing 15. As a result, the bearing 15 is securely held in the bearing holder 13 without requiring any fastening elements (such as screws or bolts). The inner ring 39 of the bearing 15 can still rotate freely when the rotor shaft rotates.

[0050] The plurality of plastically deformed zones 21 may abut the second surface 35 in at least three locations. Furthermore, the outer ring 23 of the bearing 15 is provided with a circular edge 37 between the second surface 35 and the outer surface 26, wherein the plurality of plastically deformed zones 21 abut the circular edge 37. According to some embodiments, the plastically deformed zones 21 are arranged so as to surround at least 25%, such as at least 50%, or at least 75%, of the circular edge 37 between the second surface 35 and the outer surface 26 of the bearing 15. This provides for a secure hold of the bearing 15, and the circular edge 37 surrounding the bearing 15 may also help maintain alignment of the bearing 15 with the rotor shaft of the centrifugal separator.

[0051] according to Figure 3 In the embodiment shown in FIG, a plurality of plastically deformed zones 21 surround the second surface 35 of the bearing 15. According to another embodiment, the plastically deformed zones 21 are arranged so as to surround at least 25%, such as at least 50%, or at least 75%, of the second surface 35 of the bearing 15. As a result, the bearing 15 is securely held in the bearing holder 13.

[0052] Figure 4 A bearing retainer 13 is shown in which a plurality of plastically deformed zones 21 cover an area 43 between the inner ring 39 and the outer ring 23 of the bearing 15. Thus, the area 43 between the inner ring 39 and the outer ring 23 is protected from the environment within the separation chamber by the plurality of plastically deformed zones 21, which may also improve the life of the bearing 15.

[0053] Figure 5A bearing retainer 13 is shown, wherein the bearing 15 further comprises a sealing gasket 45 covering the area 43 between the inner ring 39 and the outer ring 23, and wherein the plurality of plastic deformation zones 21 adjoin the sealing gasket 45. The sealing gasket 45 can be made of metal and / or plastic material and is arranged to seal the area 43 between the inner ring 39 and the outer ring 23. As a result, the area 43 between the inner ring 39 and the outer ring 23 is further protected from environmental influences within the separation chamber. In addition, the plurality of plastic deformation zones 21 adjoining the sealing gasket 45 can help to hold the sealing gasket 45 in place. Furthermore, in the illustrated embodiment, the plurality of plastic deformation zones 21 surround the sealing gasket 45. As a result, the sealing gasket 45 is also protected from environmental influences within the separation chamber by the plurality of plastic deformation zones 21, which can further improve the life of the sealing gasket 45 and, therefore, the bearing 15.

[0054] Reference Figure 1 The housing body 7 and the bearing holder 13 can be made of a metallic material, preferably aluminum. In other embodiments, the housing body 7 is made of a polymeric material, and the bearing holder 13 is made of a metallic material, preferably aluminum. In all of these embodiments, the bearing holder 13 can be an integral part of the housing body 7, without any additional bearing retaining means (such as screws or bolts) for retaining the bearing 15 in the bearing holder 13. Thus, the bearing 15 is securely retained in the bearing holder 13 in a manner that is less complex and less susceptible to vibrations than when using a bearing holder 13 that includes fastening elements (such as screws or bolts) for retaining the bearing 15. Furthermore, a housing 1 for a centrifugal separator 3 is provided in which the bearing 15 is retained with fewer tolerances regarding the alignment between the rotor shaft 17 of the centrifugal separator 3 and the bearing 15, compared to prior art solutions in which the bearing 15 is retained using fastening elements (such as screws or bolts).

[0055] According to other embodiments, the bearing retainer 13 is a separate part from the housing body. In these embodiments, the insertion of the bearing 15 into the bearing seat portion 19 of the bearing retainer 13 and the plastic deformation of the at least one protrusion 25 toward the bearing 15 to retain the bearing 15 in the bearing retainer 13 can be performed before the bearing retainer 13 is mounted to the housing body 7. In such embodiments, the bearing retainer 13 and the housing body 7 may include mounting elements or mounting portions (such as holes) for mounting the bearing retainer 13 to the housing body 7, for example, by using screws or nuts and bolts.

[0056] As an alternative or in addition, if Figure 1-6, at least a portion 44 of the bearing holder 13 can be embedded in the housing body 7. According to the embodiment of these figures, at least a portion 44 of the bearing holder 13 extends into the material of the housing body 7 in the region of the opening 11 in the housing body 7, so that the material of the housing body 7 surrounds at least a portion 44 of the bearing holder 13. The bearing holder 13 can be attached to the housing body 7 during the molding process of the housing body 7, so that the material of the housing body surrounds at least a portion 44 of the bearing holder 13. As a result, the bearing holder 13 can be made an integral part of the housing body 7 in a simple and secure manner.

[0057] like Figure 1 As shown in FIG, the centrifugal separator 3 further comprises a carrier plate 46, which is provided with a further opening 47 and a further bearing holder 49 arranged at the further opening 47. The further bearing is inserted into the further bearing holder 49, and the further bearing is configured to accommodate the rotor shaft 17 extending through the further bearing and the further opening 47 into the separation chamber 9. Figure 1 In the embodiment shown in , the bearing 15 in the bearing holder 13 constitutes an upper bearing, which is located above the rotor 5 and therefore also above the separation disks and / or separation elements of the rotor 5, and the further bearing in the further bearing holder 49 constitutes a lower bearing, which is located below the rotor 5 and therefore also below the separation disks and / or separation elements of the rotor 5.

[0058] Figure 6 An additional bearing retainer 49 is shown arranged at an additional opening 47 of the carrier plate 46. An additional bearing 51 is inserted into the additional bearing retainer 49. The additional bearing retainer 49 includes a bearing seat portion 53, which is provided with a plurality of plastic deformation zones 54 that retain the additional bearing 51 in the additional bearing retainer 49. The additional bearing retainer 49 may include corresponding features as described above for the bearing retainer 13. For example, the plurality of plastic deformation zones 54 may be formed using a forming process (such as roll forming or stamping). The plurality of plastic deformation zones 54 may be adjacent to the second surface of the additional bearing 51 in at least three locations, and may be adjacent to a circular edge between the outer surface and the second surface of the additional bearing 51. In addition, the plurality of plastic deformation zones 54 may surround the second surface of the additional bearing 51. The plurality of plastic deformation zones 54 may cover the area between the inner ring and the outer ring of the additional bearing 51. The further bearing 51 may comprise a sealing gasket covering the area between the inner ring and the outer ring, wherein the plurality of plastically deformed zones 54 may adjoin the sealing gasket and / or cover the sealing gasket and / or surround the sealing gasket.

[0059] Figure 7A method 100 is shown of retaining a bearing of a rotor shaft in a housing for a centrifugal separator, wherein the centrifugal separator is configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor, wherein the housing includes a housing body forming a separation chamber, an opening in the housing body, a bearing retainer disposed at the opening, and a bearing configured to receive a rotor shaft extending through the bearing and the opening into the separation chamber, the rotor shaft configured to retain the rotor within the separation chamber, wherein the bearing retainer includes a bearing seat portion for inserting the bearing, wherein the bearing seat portion includes a wall configured to surround the bearing, and wherein the bearing seat portion includes at least one protrusion disposed at the wall of the bearing seat portion and protruding therefrom, wherein the method 100 includes: - inserting 101 the bearing into the bearing seat portion of the bearing retainer, and - performing 102 plastic deformation of the at least one protrusion towards the bearing such that a plurality of plastic deformation zones are formed to retain the bearing in the bearing holder.

[0060] According to some embodiments, the bearing includes an outer ring configured to remain stationary relative to the housing during rotation of the rotor shaft, wherein method 100 further comprises: - performing 103 plastic deformation of the at least one protrusion towards the bearing such that a plurality of plastically deformed zones adjoining the outer ring of the bearing are formed.

[0061] According to some embodiments, the bearing retainer includes a wall surrounding an outer surface of the bearing, wherein the bearing seat portion further includes a stop portion extending into the bearing seat portion, wherein the outer ring includes a first surface abutting the stop portion of the bearing seat portion and a second surface opposite the first surface, wherein method 100 further includes: - performing 104 plastic deformation of the at least one protrusion towards the bearing such that a plurality of plastically deformed zones are formed adjoining the second surface of the outer ring of the bearing.

[0062] According to some embodiments, the method 100 may further include: - performing 105 plastic deformation of the at least one protrusion towards the bearing such that a plurality of plastically deformed zones adjoining the second surface are formed in at least three locations.

[0063] According to some embodiments, the method 100 may further include: - performing 106 plastic deformation of the at least one protrusion towards the bearing such that a plurality of plastically deformed zones surround the second surface of the bearing.

[0064] According to some embodiments, the outer ring of the bearing has a rounded edge between the second surface and the outer surface, and wherein the method 100 further comprises: - performing 107 plastic deformation of the at least one protrusion towards the bearing such that a plurality of plastically deformed zones adjoin the circular edge.

[0065] According to some embodiments, the bearing comprises an inner ring and a rotatable body arranged between the inner ring and the outer ring, and wherein the method 100 further comprises: - performing 108 plastic deformation of the at least one protrusion towards the bearing such that a plurality of plastically deformed zones covers the area between the inner ring and the outer ring of the bearing.

[0066] According to some embodiments, the bearing further comprises a sealing gasket covering an area between the inner ring and the outer ring, and wherein the method 100 further comprises: - performing 109 plastic deformation of the at least one protrusion towards the bearing such that the plurality of plastically deformed zones abuts the sealing gasket.

[0067] According to some embodiments, the method 100 further comprises: - performing 110 plastic deformation of at least one protrusion towards the bearing, such that a plurality of plastically deformed zones surround the sealing gasket.

[0068] According to some embodiments, the method 100 further comprises: - Use roll forming to perform 111 plastic deformation.

[0069] According to some embodiments, the method 100 further comprises: - Using stamping to perform 112 plastic deformation.

[0070] It is to be understood that the foregoing is a description of various exemplary embodiments, and that the present invention is limited only by the appended claims. Those skilled in the art will recognize that the exemplary embodiments may be modified, and that different features of the exemplary embodiments may be combined to produce embodiments other than those described herein, without departing from the scope of the present invention as defined by the appended claims.

[0071] As used herein, the terms "comprising" or "including" are open-ended and include one or more stated features, elements, steps, components or functions, but do not preclude the presence or addition of one or more other features, elements, steps, components, functions or combinations thereof.

Claims

1. A housing (1) for a centrifugal separator (3), wherein the centrifugal separator (3) is configured to separate a liquid phase from crankcase gases of an internal combustion engine using a rotor (5), wherein the housing (1) comprises: - a housing body (7) forming a separation chamber (9), - an opening (11) in the housing body (7), - a bearing retainer (13) arranged at said opening (11), and - a bearing (15) inserted into said bearing holder (13), wherein the bearing (15) is configured to receive a rotor shaft (17) extending through the bearing (15) and the opening (11) into the separation chamber (9), the rotor shaft (17) being configured to retain the rotor (5) within the separation chamber (9), The invention is characterized in that the bearing retainer (13) includes a bearing seat portion (19) provided with a plurality of plastic deformation zones (21) for retaining the bearing (15) in the bearing retainer (13); the bearing (15) includes an outer ring (23) configured to remain stationary relative to the housing (1) during rotation of the rotor shaft (17), wherein the plurality of plastic deformation zones (21) abut the outer ring (23) of the bearing (15); the bearing retainer (13) is provided with a wall (24) surrounding an outer surface (26) of the bearing (15), wherein the bearing seat portion (19) further includes a stop extending into the bearing seat portion (19) portion (27), wherein the outer ring (23) includes a first surface (31) adjacent to the stop portion (27) of the bearing seat portion (19) and a second surface (35) opposite to the first surface (31), wherein the plurality of plastic deformation zones (21) are adjacent to the second surface (35) of the outer ring (23) of the bearing (15), wherein the plurality of plastic deformation zones (21) cover an area (43) between the inner ring (39) and the outer ring (23) of the bearing (15), wherein the plurality of plastic deformation zones (21) are a plurality of gap-formed protrusions (25) circumferentially arranged at the wall (24) of the bearing seat portion (19).

2. The housing (1) according to claim 1, characterized in that The plurality of plastically deformed regions (21) abut the second surface (35) in at least three locations.

3. The housing (1) according to claim 1, characterized in that The plurality of plastically deformed zones (21) surround the second surface (35) of the bearing (15).

4. The housing (1) according to any one of claims 1 to 3, characterized in that The outer ring (23) of the bearing (15) is provided with a circular edge (37) between the second surface (35) and the outer surface (26), wherein the plurality of plastic deformation zones (21) are adjacent to the circular edge (37).

5. The housing (1) according to any one of claims 1 to 3, characterized in that The bearing (15) further comprises an inner ring (39) and a rotatable body (41) arranged between the inner ring (39) and the outer ring (23).

6. The housing (1) according to claim 5, characterized in that The bearing (15) further comprises a sealing gasket (45) covering the area (43) between the inner ring (39) and the outer ring (23), and wherein the plurality of plastically deformed zones (21) are adjacent to the sealing gasket (45).

7. The housing (1) according to claim 6, characterized in that The plurality of plastically deformed zones (21) surround the sealing gasket (45).

8. The housing (1) according to any one of claims 1 to 3, characterized in that The plurality of plastic deformation zones (21) are formed by roll forming.

9. The housing (1) according to any one of claims 1 to 3, characterized in that The housing body (7) and the bearing retainer (13) are made of metal material.

10. The housing (1) according to claim 9, characterized in that The housing body (7) and the bearing retainer (13) are made of aluminum material.

11. The housing (1) according to any one of claims 1 to 3, characterized in that The housing body (7) is made of a polymer material, and wherein the bearing retainer (13) is made of a metallic material.

12. The housing (1) according to claim 11, characterized in that The bearing retainer (13) is made of aluminum material.

13. The housing (1) according to any one of claims 1 to 3, characterized in that At least a portion (44) of the bearing retainer (13) is embedded in the housing body (7).

14. The housing (1) according to any one of claims 1 to 3, characterized in that The housing (1) is a stationary housing (1).

15. A centrifugal separator (3) configured to separate a liquid phase from crankcase gases of an internal combustion engine using a rotor (5), wherein the centrifugal separator (3) comprises a housing (1) according to any one of claims 1 to 14.

16. The centrifugal separator (3) according to claim 15, characterized in that The centrifugal separator (3) further comprises a carrier plate (46) provided with a further opening (47) and a further bearing holder (49) arranged at the further opening (47), and a further bearing (51) inserted into the further bearing holder (49), wherein the further bearing (51) is configured to accommodate the rotor shaft (17) extending through the further bearing (51) and the further opening (47) into the separation chamber (9), wherein the further bearing holder (49) comprises a bearing seat portion (53) provided with a plurality of plastic deformation zones (54) for holding the further bearing (51) in the further bearing holder (49).

17. A method (100) of retaining a bearing (15) of a rotor shaft (17) in a housing (1) for a centrifugal separator (3), wherein the centrifugal separator (3) is configured to separate a liquid phase from crankcase gas of an internal combustion engine using a rotor (5), wherein the housing (1) comprises a housing body (7) forming a separation chamber (9), an opening (11) in the housing body (7), a bearing retainer (13) arranged at the opening (11), and a bearing (15) configured to accommodate a rotor shaft (17) extending through the bearing (15) and the opening (11) into the separation chamber (9), the rotor shaft (17) being configured to retain the rotor (5) within the separation chamber (9), wherein the bearing retainer (13) comprises a bearing seat portion (19) for inserting the bearing (15), wherein the bearing seat portion (19) is provided with a wall (24) configured to surround the bearing (15), wherein the method (100) comprises: - inserting (101) the bearing (15) into the bearing seat portion (19) of the bearing holder (13), and - performing (102) plastic deformation of the at least one protrusion (25) toward the bearing (15) so as to form a plurality of plastic deformation zones (21) for retaining the bearing (15) in the bearing retainer (13), wherein the plurality of plastic deformation zones (21) cover the area (43) between the inner ring (39) and the outer ring (23) of the bearing (15), wherein the plurality of plastic deformation zones (21) are a plurality of protrusions (25) with gaps arranged circumferentially at the wall (24) of the bearing seat portion (19).

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