AU2021290446A1

AU2021290446A1 - A housing assembly

Info

Publication number: AU2021290446A1
Application number: AU2021290446A
Authority: AU
Inventors: Murray Sydney CURTI
Original assignee: Hc Atm Group Pty Ltd
Current assignee: Hc-Atm Group Pty Ltd
Priority date: 2020-06-15
Filing date: 2021-06-15
Publication date: 2023-02-16
Also published as: WO2021253076A1; JP2023530040A

Abstract

The present invention relates to a housing assembly for housing a turbine wheel or compressor wheel, the housing assembly comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct. The present invention, at least, alleviates problems associated with imperfections on an inner surface of the housing assembly.

Description

TITLE

A housing assembly

FIELD OF THE INVENTION [0001] The present invention relates to the field of housing. More particularly, the invention relates to housing assembly. Even more particularly, the invention relates to housing assembly for a turbine wheel or a compressor wheel.

BACKGROUND TO THE INVENTION [0002] Any reference to background art herein is not to be construed as an admission that such art constitutes common general knowledge in Australia or elsewhere.

[0003] Turbochargers are centrifugal compressors driven by an exhaust gas turbine. Turbochargers are employed in engines to boost the amount of air delivered to the engine. Turbocharger performance influences important engine parameters, such as fuel economy, power, and emissions.

[0004] A turbocharger generally comprises two housings: a turbine housing and a compressor housing. The compressor housing typically houses an impellor or compressor wheel, and the turbine housing typically houses a turbine wheel. Typically, exhaust gases from an internal combustion engine enters the turbine housing and this in turn drives the turbine wheel. The turbine wheel is coupled with the compressor wheel by a solid shaft and, as the turbine wheel is rotated, this rotates the compressor wheel. The compressor wheel is housed in a compressor housing and feeds air to the combustion chamber. As such, the exhaust gases rotate the compressor wheel which, in turn, increases the flow of air to the engine. This results in an increase in efficiency of an engine.

[0005] The operating principles of a turbocharger involve utilizing the energy contained in a stream of exhaust gas to increase the pressure in the intake tract of an internal combustion engine. This improves charging of the combustion chamber with oxygen (through increased air supply). This also makes it possible for more fuel to be converted per combustion process, and thus increases the power of the internal combustion engine. [0006] For a turbocharger to work efficiently, the turbine housing must be airtight, otherwise exhaust gases may escape therefrom and result in a loss of efficiency. Similarly, the compressor housing must also be airtight otherwise there may also be a loss of efficiency. As such, housing utilized in turbochargers are generally formed by metal casting. Metal casting involves heated liquid metal being delivered to a mould that contains a negative impression of the desired shape. Heated liquid metal is poured into the mould through a hollow channel, and allowed to cool. The cooled metal is then extracted to provide a turbine housing and/or a compressor housing.

[0007] However, a disadvantage to metal casting of the turbine housing and/or compressor housing is that the inner surface thereof may contain defects that cannot be easily accessed and corrected. These defects can affect the overall efficiency of the turbocharger. For instance, these defects may create friction with a fluid (such as air) flowing therethrough and lead to lower exhaust gas speed on the turbine wheel. This friction may also increase the temperature of the gas flowing therethrough which may also affect efficiency.

[0008] It would be advantageous to alleviate one or more of the above problems, or to at least provide the consumer with a commercial alternative to the presently available options. SUMMARY OF THE INVENTION

[0009] In a first aspect, although it need not be the only or indeed the broadest aspect, the invention resides in a housing assembly for housing a turbine wheel or compressor wheel, the housing assembly comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct. [0010] In one embodiment, the first body comprises a first partial spiral duct, and the second body comprises a second partial spiral duct, wherein the first partial spiral duct and the second partial spiral duct together define the spiral duct.

[0011] In embodiments, the first body comprises a first locking portion and the second body comprises a second locking portion. The second locking portion is complementary to the first locking portion.

[0012] In some embodiments, the first body is sealing engaged with the second body.

[0013] In certain embodiments, the first body and/or the second body are formed of steel. Suitably, the first body and/or the second body are formed of carbon steel. More suitably, the first body and/or second body are formed of medium carbon steel. In a preferred embodiment, the first body and/or the second body are formed of K1045.

[0014] In an embodiment, the housing assembly is adapted to house a turbine wheel and/or a compressor wheel. In an embodiment, the housing assembly is adapted to house a turbine wheel. In certain embodiments, the housing assembly is adapted to house a compressor wheel.

[0015] In one embodiment, the invention resides in a turbocharger for an internal combustion engine comprising a housing assembly of the first aspect.

[0016] In one embodiment, the invention resides in a body for housing a turbine wheel or compressor wheel, the body comprising: a partial spiral duct; and a locking portion located around a periphery of the body adapted to sealing engaging a complimentary locking portion of a complimentary body.

[0017] In an embodiment, the invention resides in a complementary body for housing a turbine wheel or compressor wheel, the body comprising: a partial spiral duct; and a complementary locking portion located around a periphery of the complementary body adapted to sealing engaging a locking portion of a body. [0018] In another aspect, the invention resides in a method of producing a housing assembly adapted to house a turbine wheel or a compressor wheel including the steps of: forming a first body; forming a second body, wherein the first body and second body define a spiral duct; sealing and engaging the first body to the second body, to thereby produce the housing assembly.

[0019] In an embodiment, the method further includes the step of correcting defects in the first body and/or the second body. In a further embodiment, the method includes the step of correcting defects in a partial spiral duct of the first body and/or the second body.

[0020] In certain embodiments, the correcting defects step includes the step of machining the first body and/or second body. [0021] In embodiments, the step of forming the first body and/or the step of forming the second body is by metal casting.

[0022] The various features and embodiments of the present invention referred to in the individual sections above and in the description which follows apply, as appropriate, to other sections, mutatis mutandis. Consequently, features specified in one section may be combined with features specified in other sections as appropriate.

[0023] Further features and advantages of the present invention will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, embodiments of the invention will be described by way of example only with reference to the accompanying drawings, in which: FIG 1 shows an assembled housing assembly for a turbine wheel;

FIG 2 shows various views of an embodiment of a first body;

FIG 2a shows a front view of the first body;

FIG 2b shows an under view of the first body; FIG 2c shows a rear view of the first body;

FIG 2d shows a flat view of the first body;

FIG 2e shows an alternate flat view of the first body.

FIG 3 shows various views of an embodiment of a second body;

FIG 3a shows a front view of the second body; FIG 3b shows an outer view of the second body;

FIG 3c shows a rear view of the second body;

FIG 3d shows a flat view of the second body.

FIG 4a shows an enlarged cross section of a first locking portion;

FIG 4b shows an enlarged cross section of a second locking portion; FIG 5 shows the alignment of a first body relative to the second body;

FIG 6 shows the Chassis Dyno Report of a standard turbocharger formed from casting;

FIG 7 shows the Chassis Dyno Report of the present housing assembly with minimal changes and slightly polished; and FIG 8 shows the Chassis Dyno Report of the present housing assembly with further polishing.

DETAILED DESCRIPTION OF THE INVENTION

[0025] Embodiments of the present invention reside primarily in a housing assembly. Accordingly, the housing, assembly and method steps have been illustrated in concise schematic form in the drawings, showing only those specific details that are necessary for understanding the embodiments of the present invention so as to not obscure the disclosure with excessive detail that will be readily apparent to those of ordinary skill in the art having the benefit of the present description.

[0026] In this specification, adjectives such as first and second, top and bottom, left and right, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order.

[0027] Words such as “comprises” or “includes” are intended to define a non exclusive inclusion, such that a housing, assembly or method that comprises a list of elements does not include only those elements but may include other elements not expressly listed, including elements that are inherent to such a housing, assembly or method.

[0028] As used herein, the term ‘about’ means the amount is nominally the number following the term ‘about’ but the actual amount may vary from this precise number to an unimportant degree.

[0029] As used herein, the term ‘sealingly engagable’ refers to two distinct bodies which are formed such that they can be a sealed and engaged to one another. This seal results in an airtight seal therebetween.

[0030] For ease of description, the present invention has been described in relation to a turbine housing for housing a turbine wheel; specifically, a turbocharger for a combustion engine. However, the person skilled in the art will appreciate that the present invention may be utilized in other centrifugal compressor systems or at least in compression housing.

[0031] As mentioned above, imperfections or defects on the internal surface of turbine housing and/or compressor housing can lead to inefficiencies in turbochargers (in particular, imperfections in the spiral duct). The present invention is predicated on, at least, the finding that housing (either the turbine housing and/or compressor housing) can be formed in two parts, the internal surfaces thereof may be machined to remove imperfections or defects thereon, and assembled together to form the housing. The resultant housing has a reduction in friction with a fluid flowing therethrough (with respect to an unmachined housing), and this leads to improved efficiency. In one embodiment, the m (friction coefficient) is less than the m of a comparative un-machined housing assembly. In another embodiment, the m is less than the m of a housing assembly formed by casting in a unitary fashion.

[0032] In a first form, although it need not be the broadest or indeed the only form, the invention resides in a housing assembly for housing a turbine wheel or a compressor wheel, the housing assembly comprising a first body sealingly engagable with a second body. In one embodiment, the first body and the second body together (when assembled) define a spiral duct.

[0033] In one embodiment, the first body comprises a first partial spiral duct, and the second body comprises a second partial spiral duct. The partial spiral duct is formed as a recess in the respective body. It will be appreciated that the first partial spiral duct and the second partial spiral duct together define the spiral duct (when the first body is sealingly engaged with the second body).

[0034] As previously mentioned, imperfections or defects on an internal surface of a turbine housing or a compressor housing (such as the spiral duct) may be detrimental to the efficiency thereof. Typically, turbine housing and compressor housing utilized in turbochargers are formed by metal casting to provide a unitary structure to ensure that they are gastight and have sufficient integrity to be used for extended periods of time. However, there are imperfections on the internal surface of the housing associated with metal casting and these are extremely difficult to access and correct. As such, turbine and/or compressor housing are utilized with such imperfections. Whilst, there have been improvement in casting techniques, housing cast from these methods still have imperfections. It would be advantageous to be able to remove such imperfections from the internal surface of the housing.

[0035] The present inventors have surprisingly found that a housing assembly can be formed by combining two discrete bodies. These two bodies can be sealingly engaged to form a housing assembly for either a turbine wheel or a compressor wheel. An advantage of the presently claimed invention over the housing formed by prior art casting techniques is that the internal surface of the housing assembly can be easily accessed to correct the imperfections thereon. The easily accessible internal surface of the housing assembly also allows for more precise machining to occur. Furthermore, the internal surface of the housing being easily accessible allows for more complex spiral ducts to be accessed. In this regard, the dimensions of the spiral duct affects the overall efficiency of turbine. The more complex spiral ducts formed from casting may have more imperfections which detracts away from the efficiency of the housing assembly. In order to address this issue, more complex spiral ducts are avoided with casting techniques. This is a significant issue in the art. In this regard, the housing assembly comprises a first body that is sealingly engageable with a second body. The first body and second body together define the internal cavity of the housing assembly. For instance, the first body and second body together define a spiral duct. In this regard, the first body may define the top inner surface of the spiral duct and the second body may define the bottom inner surface of the spiral duct (as shown in the FIGs). In one embodiment, the first partial spiral duct is the top inner surface of the spiral duct. In an embodiment, the second partial spiral duct is the bottom inner surface of the spiral duct. In one embodiment, the spiral duct is split into the first partial spiral duct and a second partial spiral duct by a central plane through the spiral duct. The internal surface of the housing (such as the spiral duct) can be easily machined to correct imperfections thereon. The spiral duct suitably has a gradually reducing cross- section. Once the internal surface of the housing has been machined to correct or alleviate the imperfections thereon, the first body and second body can be sealingly engaged to form the housing assembly. The present inventors have found that the first body and second body can be sealingly engaged to form a substantially gastight housing. The resultant housing also has sufficient integrity to be utilized for extended periods of time. The resultant housing is also suitable for use with a turbine wheel or a compressor wheel and thus centrifugal compressor systems. The person skilled in the art will appreciate that either the turbine housing or the compressor housing can be formed utilizing this method.

[0036] The present inventors have found that a substantially gastight seal can be formed between the first body and the second body. The first body and the second body are suitable formed of any housing material that forms a gastight seal therebetween. [0037] The housing material has an iron (Fe) content of suitably greater than 90%, more suitably greater than 95%, even more suitably greater that 97%, preferably greater than 98%, and most preferably 97.71% or 98.4%.

[0038] The housing material has a carbon (C) content of suitably between about 0.01% to about 1%, more suitably between about 0.25% to about 0.75%, preferably about 0.4% to about 0.6%, and most preferably between about 0.43% to about 0.50%.

[0039] The housing material has a silicon (Si) content of suitably between about 0.01% to about 1%, more suitably between about 0.01% and about 0.5%, and most preferably between about 0.1% to about 0.35%.

[0040] The housing material has a manganese (Mn) content of suitably between about 0.01% to about 2%, more suitably between about 0.5% to about 1.5%, preferably between about 0.5% to about 1%, and most preferably between about 0.6% to about 0.90%.

[0041] The housing material has a phosphorus (P) content of suitable less than about 0.1%, more suitably less than about 0.05%, and most preferably less than about 0.04%.

[0042] Suitably, the housing material has a sulphur (S) content of suitably between about 0.01% to about 1%, more suitably between about 0.25% to about 0.75%, preferably about 0.4% to about 0.6%, and most preferably between about 0.43% to about 0.50%.

[0043] In one embodiment, the first body and the second body are formed of steel. In a further embodiment, the first body and the second body are formed of carbon steel. In yet another embodiment, the first body and the second body are formed of medium carbon steel. A non-limiting example of the medium carbon steel is K1045. It will be appreciated that the above list are only exemplary materials in which the first body and second body can be formed. The person skilled in the art will appreciate that other materials can be utilized in forming the first body and/or second body. These materials include metallic and non-metallic materials. Non-limiting examples of metallic materials are steel and titanium. A non-limiting example of a non-metallic material is ceramic. [0044] In one embodiment, the housing material has a yield strength (Mpa) of suitably between about 100 to about 1000, or preferably between about 300 to about 900.

[0045] In one embodiment, the housing material has a tensile strength (Mpa) of suitably between about 100 to about 1000, more suitably between about 500 to about 1000, preferably between about 600 to about 700, and most preferably between about 600 to about 670.

[0046] In an embodiment, the housing material has an elongation measure in a specimen whose gage length is 5.65 times square root of it gauge area (Elong. On 5.65VS0 (%)) of suitably between 16-28.

[0047] In one embodiment, the first body and/or second body may further comprise a ceramic coating. The ceramic coating may be on the external surface of the first body and/or second body, or on the surface forming the spiral duct. The ceramic coating may reduce the thermal cycle and reduce surface temperatures. Furthermore, the ceramic coating can provide protection by keeping the heat internal to the assembly.

[0048] The discrete first body and discrete second body, and their associated partial spiral ducts make it particularly easy to apply a ceramic coating to the surfaces defining the spiral duct (when compared to a cast housing). This is particularly advantageous as the ceramic coating applied in this manner is postulated to have a more even coating and thus believed to confer further efficiency.

[0049] It is postulated that the reduced friction in the spiral duct of the present housing assembly will have advantageous features compared to housing assembly in which the internal spiral duct cannot be accessed for machining and polishing. The easy access to the partial spiral ducts alleviates this issue. In this regard, it is postulated that the efficiency and results from comparative testing will show that the present invention results in significant improvements. Additionally, the efficiency and improved results of the present invention also results in less emissions which makes the use of the present housing more environmentally friendly. Furthermore, the efficiency and improved results of the present invention is more economical for the consumer. That is, less fuel is required because of the efficiency gains.

[0050] In one embodiment, the invention resides in the housing assembly for use in a turbocharger. In another embodiment, invention resides in the housing assembly when used in a turbocharger. In an embodiment, the invention resides in a turbocharger comprising the housing assembly.

[0051] In one embodiment, the invention resides in the first body as described substantially hereinabove. In this regard, the invention resides in a body for housing a turbine wheel or compressor wheel, the body comprising: a partial spiral duct; and a locking portion located around a periphery of the body adapted to sealing engaging a complimentary locking portion of a complimentary body.

[0052] In embodiments, the body comprises a first partial spiral duct. In one embodiment, the second partial spiral duct is a top inner surface of the spiral duct.

[0053] In an embodiment, the invention resides in the second body described substantially hereinabove. In this regard, the invention resides in a complementary body for housing a turbine wheel or compressor wheel, the body comprising: a partial spiral duct; and a complementary locking portion located around a periphery of the complementary body adapted to sealing engaging a locking portion of a body.

[0054] In certain embodiments, the complementary body comprises a second partial spiral duct. In one embodiment, the second partial spiral duct is a bottom inner surface of the spiral duct. The first partial spiral duct and the second partial spiral duct together define a spiral duct.

[0055] In one embodiment, the complementary body is the first body, and the locking portion is the locking portion of the first body.

[0056] In another form, the invention resides in a method of producing a housing assembly adapted to house a turbine wheel or a compressor wheel including the steps of: forming a first body; forming a second body; sealingly engaging the first body to the second body; to thereby produce the housing assembly.

[0057] In one embodiment, the first and the second body define a spiral duct

[0058] The housing assembly is as substantially described hereinabove for the first form.

[0059] In one embodiment, the first body may comprise a first partial spiral duct, and the second body may comprise a second partial spiral duct.

[0060] In one embodiment, the method further includes the step of correcting defects in the first body and/or the second body. In an embodiment, the method further includes the step of correcting defects in the first partial spiral duct and/or the second partial spiral duct. In a further embodiment, the method includes the step of correcting defects in a partial spiral duct of the first body and/or the second body. The step of correcting defects occurs before the sealing engagement of the first body to the second body. In one embodiment, the step of correcting defects is achieved by machining the first body and/or the second body. In one embodiment, the step of correcting defects includes buffing the spiral duct. In another embodiment, the step of correcting defects includes sanding, polishing and/or honing the spiral duct

[0061] In one embodiment, the first body is formed by casting. In an embodiment, the second body is formed by casting. In certain embodiments, the first body is integrally formed. In embodiments, the second body is integrally formed. The term ‘integrally formed’ as used herein refers to being formed of a single unitary piece of material.

[0062] In one embodiment, the first body and second body are sealingly engaged by cold pressing. In this regard, the first body and the second body are sealing engaged at roughly about room temperature. [0063] In an embodiment, the method further includes the step of welding the first body and the second body. The weld can provide a further deterrent to any leaks between the first body and the second body. The weld also provides a final product with a cosmetically appealing appearance.

[0064] FIG 1 shows an embodiment of an assembled housing for a turbine wheel. The assembled housing 100 comprises a first body 110 sealingly engaged to a second body 120. The assembled housing 100 comprises aperture 160 that accommodates or houses a turbine wheel (not shown). Furthermore, the assembled housing 100 further comprises an exhaust gas inlet 150.

[0065] The exhaust gas inlet 150 may sealingly engage an exhaust outlet of an internal combustion engine. In this regard, the exhaust gas inlet 150 may suitable comprise a number of securing portions 151 which can be utilized to secure to the exhaust outlet of an internal combustion engine. The assembled housing 100 may also comprise a number of securing portions 101 which can be utilized to attach to a vehicle.

[0066] Referring to FIGs 2a-2e, there is shown a number of views of the first body 110. FIG 2a shows a front view of the first body. FIG 2b shows an under view of the first body 110. FIG 2c shows a rear view of the first body 110. FIG 2d shows a flat view of the first body 110. FIG 2e shows an alternate flat view of the first body 110.

[0067] Referring to FIG 2b, the first body 110 comprises a first partial exhaust gas inlet 150a. The first partial exhaust gas inlet 150a and a second partial exhaust gas inlet 150b of the second body 120 (mentioned in more detail hereinafter) form the exhaust gas inlet 150. The first body 110 further comprises a partial spiral duct 155a. Shown in FIG 2b is partial spiral duct 155a and a non limiting example of the contour thereof. The person skilled in the art will appreciate that different contours may be utilized, and these can be easily achieved because the partial spiral ducts of both the first body and the second body are easily accessible. As shown, the first partial exhaust gas inlet 150a is in fluid communication with a first partial spiral duct 155a. The first partial spiral duct 155a and a second partial spiral duct 155b of the second body 120 (mentioned in more detail hereinafter) form the spiral duct 155. The first body 110 further comprises a first aperture 160a. The first aperture 160a and a second aperture 160b of the second body 120 align to form the aperture 160.

[0068] Referring to FIGs 3a-3d, there is shown a number of views of the second body 120. Shown in FIG 3a is a front view of the second body 120. Shown in FIG 3b is an outer view of the second body 120. Shown in FIG 3c is a rear view of the second body. Shown in FIG 3d is a flat view of the second body 120.

[0069] The second body 120 comprises a second aperture 160b. The second aperture 160b, as mentioned above, aligns with the first aperture 160a to form aperture 160. The second body 120 comprises the second partial exhaust gas inlet 150b. The first partial exhaust gas inlet 150a forms the exhaust gas inlet 150 when combined with the second body 120 which comprises a second partial exhaust gas inlet 150b. In other words, the first partial exhaust gas inlet 150a and the second partial gas exhaust inlet 150b align to form the exhaust gas inlet 150. The second body 120 further comprises the second partial spiral duct 155b (not shown). The second partial spiral duct 155b forms the spiral duct 155 when combined with the first body 110 which comprises a first partial spiral duct 155a. The formed spiral duct 155 receives the exhaust gas from the exhaust gas inlet 150.

[0070] In use, the assembled housing 100 comprises an exhaust gas inlet 150 in fluid communication with a spiral duct 155. As exhaust gas is produced from a combustion engine, the exhaust gas enters the assembled housing 100 through the exhaust gas inlet 150. The exhaust gas then enters the spiral duct 150. The spiral duct 150 is in the form of a tightening curve around a turbine wheel.

[0071] It will be appreciated that the turbine wheel is in direct contact with the exhaust gas and is driven thereby. The turbine wheel and compressor wheel are fastened rotationally and joined by a shaft. As such, as the turbine wheel is driven, the compressor wheel is also driven. The compressor wheel is housed in a compressor housing (which can similarly be formed of a first body and a second body), and is in fluid communication with a combustion chamber of a combustion engine. As the compressor wheel is rotated, additional air is drawn into the combustion chamber and thus improving efficiency.

[0072] As mentioned hereinabove, the first body 110 is sealingly engagable to the second body 120. In this regard, the first body 110 comprises first locking portion 112 which is complementary to a second locking portion 122. The second body 120 comprises the second locking portion 122. The first locking portion 112 is located around the periphery of the first body 110. The second locking portion 122 is located around the periphery of the second body 120. The first locking portion 112 and the second locking portion 122 together form a gas tight seal. The first locking portion 112 and the second locking portion 122 preferable form an interference fit. The junction of the first body 110 and the second body 120 may be welded.

[0073] Shown in FIG 4a is an enlarged view of a cross section of the first locking portion 112, and shown in FIG 4b is an enlarged view of a cross section of the second locking portion 122. The first locking portion 112 comprises a recess 115. The recess 115 is defined by a substantially flat portion 112a, inclined surface 112b and wall 112d. In the embodiment shown, the wall 112d is substantially parallel to the substantially plat portion 112a. In one embodiment, the inclined surface 112b is sloping downardly towards the distal end. As shown, the inclined surface 112b forms a shelf with the substantially flat portion 112a. In this regard, the inclined surface 112b and the substantially flat portion 112a are connected by an intermediate surface 112c. At least a portion of the intermediate surface 112c is above the plane of the substantially flat surface 112a. The intermediate surface 112c is a substantially perpendicular surface relative to the substantially flat portion 112a. The length of the inclined surface does not exceed the length of the substantially flat portion 112a.

[0074] The substantially flat portion 112a defines a plane. The inclined surface 112b is inclined such that a proximal end thereof is above said plane and a distal end thereof is below said plane. The inclined surface is substantially planar.

[0075] The second locking portion 122 has a complementary structure to the first locking portion 112. The second locking portion 122 comprises a recess 125. The recess 125 is defined by an elongate portion 122a, a head portion 122b and wall 122d. In the embodiment shown, the wall 122d is substantially parallel to the substantially flat portion 122a. The head portion 122b is located at a distal end of the first locking portion 122. In one embodiment, the elongate portion 122a is substantially flat, as shown in FIG 4b. In one embodiment, the head portion 122b is in the form of an inclined surface, as shown in FIG 4b. In this regard, the inclined surface is sloping downwardly from the elongate portion 122a to the distal end. As shown, the inclined surface forms a shelf with the elongate portion 122a. The elongate portion 122a and the head portion 122b are connected by an intermediate surface 122c. At least a portion of the intermediate surface 122c is above the plane of the elongate portion 122a. The intermediate surface 122c is a substantially perpendicular surface 122c relative to the elongate portion 122a. In one embodiment, the length of the head 122b portion does not exceed the length of the elongate portion 122a.

[0076] Similar to the first locking portion 112, the elongate portion 122a defines a plane. The head portion 122b is inclined such that a proximal end thereof is above said plane and a distal end thereof is below said plane. The elongate portion 122a is substantially planar.

[0077] In use, the inclined surface 112b engages the head portion 122b. As force is applied to the first body 110 and/or second body 120, the inclined surface 112b is pushed along the head portion 122b until the shelf of one of the locking portions engages the substantially flat portion or the elongate portion. This engages the first locking portion to the second locking portion and sealingly secures the first body to the second body. The shelf also prevents the first body and second body from being disassembled.

[0078] FIG 5 shows an example of the alignment of the first body 110 and the second body 120. As shown, the first locking portion 112 and the second locking portion 122 are aligned and sealingly engageable to each other. As shown, the first locking portion 112 is located along a periphery of the first body 110. The second locking portion 122 is similarly located along a periphery of the second body 120. The first locking portion 112 and the second lick lock portion 122 are substantially aligned with one another. The junction of the first body 110 and the second body 120 may be welded. [0079] Please note that FIGs 2a-2e, 3a-3d, 4a and 4b show exemplary and non-limiting dimensions (in mm) of certain features of the housing assembly.

Testing

[0080] A turbocharger comprising the present housing assembly (comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct) was fitted to a vehicle(FORD FG XR6). The vehicle was then field tested.

[0081] No issues were observed with the turbocharger comprising the present housing assembly. After approximately twelve (12) months, no failures were observed with the turbocharger and this demonstrates that an airtight seal was formed between the first body and the second body. This suggests that the present housing assembly has longevity in a turbocharger despite the temperature fluctuations that the housing assembly is subjected to.

[0082] The tester of the vehicle noticed that the use of the turbocharger comprising the present housing assembly appeared to provide a quicker response (less turbo lag) and had superior power compared to the previously fitted turbocharger (one where the turbine housing was formed from casting). This suggests that an improvement was observed from the removal of imperfections.

Efficiency Testing

[0083] Preliminary testing of the present housing assembly was completed. In this regard, a turbocharger comprising the present housing assembly (comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct) was tested. The partial spiral ducts of the first body and the second body were polished in their entirety as they were easily accessible.

[0084] Preliminary testing appeared to suggest that a rough initial polish was able to achieve at least a 1% to 2% increase in output. It is postulated that further improvement may be observed with additional refining. Furthermore, no leakage was observed between the first body and the second body.

Dvnolog Chassis Testing [0085] A standard turbocharger (formed from casting); a turbocharger comprising the present housing assembly (comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct) with minimal changes and slightly polished; and another turbocharger comprising the present housing assembly (comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct) with further polishing were provided. Each of the turbochargers were installed into a FORD FG XR6 Turbo and tested with a Dynomometer.

[0086] Shown in FIG 6 is the Chassis Dyno Report of the standard turbo charger (formed from casting), shown in FIG 7 is the Chassis Dyno Report of the present housing assembly (comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct) with minimal changes and slightly polished; and shown in FIG 8 is the Chassis Dyno Report of another turbocharger comprising the present housing assembly (comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct) with further polishing.

[0087] It should be noted that the Chassis Dyno Report shown in FIG 8 was terminated at >3500 rpm as a fault was found in the relief valve. However, in any event, the Chassis Dyno Report shown in FIG 8 appears to, at least, suggest that the present housing assembly improves the results in the low revolution range. It is postulated that further testing and refinement will show further improvements. [0088] FIG 7 demonstrates that a housing assembly of the present invention can be utilized in a vehicle despite it being formed of two parts. Furthermore, FIG 7 shows a marginal improvement.

[0089] The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this invention is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims

1. A housing assembly for housing a turbine wheel or compressor wheel, the housing assembly comprising a first body sealingly engagable with a second body, wherein the first body and second body define a spiral duct.

2. The housing assembly of claim 1, wherein the first body comprises a first partial spiral duct, and the second body comprises a second partial spiral duct, wherein the first partial spiral duct and the second partial spiral duct together define the spiral duct.

3. The housing assembly of any one of the preceding claims, wherein the first body comprises a first locking portion and the second body comprises a second locking portion that is complementary to the first locking portion.

4. The housing assembly of any one of the preceding claims, wherein the first body is sealing engaged with the second body.

5. The housing assembly of claim any one of the preceding claims, wherein the first body and second body sealing engaging to form a substantially gas-tight housing assembly.

6. The housing assembly of any one of the preceding claims, wherein the first body and/or the second body are formed of steel.

7. The housing assembly of any one of the preceding claims, wherein the first body and/or the second body are formed of carbon steel.

8. The housing assembly of any one of the preceding claims, wherein the first body and/or the second body are formed of K1045.

9. The housing assembly of any of one claims 1 to 8, wherein the housing assembly is adapted to house a turbine wheel.

10. The housing assembly of any one of claim 1 to 8, wherein the housing assembly adapted to house a compressor wheel.

11. A turbocharger for an internal combustion engine comprising a housing assembly of any one of the preceding claims.

12. A method of producing a housing assembly for housing a turbine wheel and/or a compressor wheel including the steps of: forming a first body; forming a second body, wherein the first body and second body define a spiral duct; sealingly engaging the first body to the second body, to thereby produce the housing assembly.

13. The method of claim 12 further including the step of correcting defects in the first body and/or the second body.

14. The method of claim 13, wherein the correcting defects step includes the step of machining the first body and/or second body.

15. The method of any one of claim 12 to 14, wherein the step of forming the first body and/or the step of forming the second body is by metal casting.

16. A body for housing a turbine wheel or compressor wheel, the body comprising: a partial spiral duct; and a locking portion located around a periphery of the body adapted to sealing engaging a complimentary locking portion of a complimentary body.

17. A complementary body for housing a turbine wheel or compressor wheel, the body comprising: a partial spiral duct; and a complementary locking portion located around a periphery of the complementary body adapted to sealing engaging a locking portion of a body.