Patent Description:
A turbocharger can include a rotating group that includes a turbine wheel and a compressor wheel that are connected to one another by a shaft. For example, a turbine wheel can be welded or otherwise connected to a shaft to form a shaft and wheel assembly (SWA) and a compressor wheel can be fit to the free end of the shaft. As an example, a shaft that is attached to one or more bladed wheels may be supported by one or more bearings disposed in a bearing housing, which may form a center housing rotating assembly (CHRA). During operation of a turbocharger, depending on factors such as size of various components, a SWA may be expected to rotate at speeds in excess of <NUM>,<NUM> rpm.

A turbine wheel can be positioned in a turbine housing where the turbine housing can include one or more volutes that are shaped and sized to direct flow of exhaust to the turbine wheel. For example, a turbine housing can include an inlet and an outlet where exhaust is directed from the inlet to one or more volutes to a turbine wheel space and then from the turbine wheel space to the outlet. Exhaust from the outlet may be directed to one or more components for exhaust treatment, which may include treatment as to one or more of chemical composition, heat content and noise. A prior art turbine housing and turbocharger featuring a double turbine housing defined between the volute wall and the turbine exit housing in axial direction is disclosed in <CIT>.

The present invention relates to a turbine housing according to claim <NUM> and a turbocharger according to claim11.

A more complete understanding of the various methods, devices, assemblies, systems, arrangements, etc., described herein, and equivalents thereof, may be had by reference to the following detailed description when taken in conjunction with examples shown in the accompanying drawings where:.

Below, an example of a turbocharged engine system is described followed by various examples of components, assemblies, methods, etc..

Turbochargers are frequently utilized to increase output of an internal combustion engine. Referring to <FIG>, as an example, a system <NUM> can include an internal combustion engine <NUM> and a turbocharger <NUM>. As shown in <FIG>, the system <NUM> may be part of a vehicle <NUM> where the system <NUM> is disposed in an engine compartment and connected to an exhaust conduit <NUM> that directs exhaust to an exhaust outlet <NUM>, for example, located behind a passenger compartment <NUM>. In the example of <FIG>, a treatment unit <NUM> may be provided to treat exhaust (e.g., to reduce emissions via catalytic conversion of molecules, etc.). As an example, a silencer such as a muffler may be included that aims to reduce sound emissions. As an example, a combined treatment unit and silencer may be utilized along an exhaust flow path or exhaust flow paths.

As shown in <FIG>, the internal combustion engine <NUM> includes an engine block <NUM> housing one or more combustion chambers that operatively drive a shaft <NUM> (e.g., via pistons) as well as an intake port <NUM> that provides a flow path for air to the engine block <NUM> and an exhaust port <NUM> that provides a flow path for exhaust from the engine block <NUM>.

The turbocharger <NUM> can act to extract energy from the exhaust and to provide energy to intake air, which may be combined with fuel to form combustion gas. As shown in <FIG>, the turbocharger <NUM> includes an air inlet <NUM>, a shaft <NUM>, a compressor housing assembly <NUM> for a compressor wheel <NUM>, a turbine housing assembly <NUM> for a turbine wheel <NUM>, another housing assembly <NUM> and an exhaust outlet <NUM>. The housing assembly <NUM> may be referred to as a center housing assembly as it is disposed between the compressor housing assembly <NUM> and the turbine housing assembly <NUM>.

In the turbocharger <NUM> of <FIG>, the shaft <NUM> may be a shaft assembly that includes a variety of components (e.g., consider a shaft and wheel assembly (SWA) where the turbine wheel <NUM> is welded to the shaft <NUM>, etc.). As an example, the shaft <NUM> may be rotatably supported by a bearing system (e.g., journal bearing(s), rolling element bearing(s), etc.) disposed in the housing assembly <NUM> (e.g., in a bore defined by one or more bore walls) such that rotation of the turbine wheel <NUM> causes rotation of the compressor wheel <NUM> (e.g., as rotatably coupled by the shaft <NUM>). As an example a center housing rotating assembly (CHRA) can include the compressor wheel <NUM>, the turbine wheel <NUM>, the shaft <NUM>, the housing assembly <NUM> and various other components (e.g., a compressor side plate disposed at an axial location between the compressor wheel <NUM> and the housing assembly <NUM>).

In the example of <FIG>, a variable geometry assembly <NUM> is shown as being, in part, disposed between the housing assembly <NUM> and the housing assembly <NUM>. Such a variable geometry assembly may include vanes or other components to vary geometry of passages that lead to a turbine wheel space in the turbine housing assembly <NUM>. As an example, a variable geometry compressor assembly may be provided.

In the example of <FIG>, a wastegate valve (or simply wastegate) <NUM> is positioned proximate to an exhaust inlet of the turbine housing assembly <NUM>. The wastegate valve <NUM> can be controlled to allow at least some exhaust from the exhaust port <NUM> to bypass the turbine wheel <NUM>. Various wastegates, wastegate components, etc., may be applied to a conventional fixed nozzle turbine, a fixed-vaned nozzle turbine, a variable nozzle turbine, a twin scroll turbocharger, etc. As an example, a wastegate may be an internal wastegate (e.g., at least partially internal to a turbine housing). As an example, a wastegate may be an external wastegate (e.g., operatively coupled to a conduit in fluid communication with a turbine housing).

In the example of <FIG>, an exhaust gas recirculation (EGR) conduit <NUM> is also shown, which may be provided, optionally with one or more valves <NUM>, for example, to allow exhaust to flow to a position upstream the compressor wheel <NUM>.

<FIG> also shows an example arrangement <NUM> for flow of exhaust to an exhaust turbine housing assembly <NUM> and another example arrangement <NUM> for flow of exhaust to an exhaust turbine housing assembly <NUM>. In the arrangement <NUM>, a cylinder head <NUM> includes passages <NUM> within to direct exhaust from cylinders to the turbine housing assembly <NUM> while in the arrangement <NUM>, a manifold <NUM> provides for mounting of the turbine housing assembly <NUM>, for example, without any separate, intermediate length of exhaust piping. In the example arrangements <NUM> and <NUM>, the turbine housing assemblies <NUM> and <NUM> may be configured for use with a wastegate, variable geometry assembly, etc..

In <FIG>, an example of a controller <NUM> is shown as including one or more processors <NUM>, memory <NUM> and one or more interfaces <NUM>. Such a controller may include circuitry such as circuitry of an engine control unit (ECU). As described herein, various methods or techniques may optionally be implemented in conjunction with a controller, for example, through control logic. Control logic may depend on one or more engine operating conditions (e.g., turbo rpm, engine rpm, temperature, load, lubricant, cooling, etc.). For example, sensors may transmit information to the controller <NUM> via the one or more interfaces <NUM>. Control logic may rely on such information and, in turn, the controller <NUM> may output control signals to control engine operation. The controller <NUM> may be configured to control lubricant flow, temperature, a variable geometry assembly (e.g., variable geometry compressor or turbine), a wastegate (e.g., via an actuator), an electric motor, or one or more other components associated with an engine, a turbocharger (or turbochargers), etc. As an example, the turbocharger <NUM> may include one or more actuators and/or one or more sensors <NUM> that may be, for example, coupled to an interface or interfaces <NUM> of the controller <NUM>. As an example, the wastegate <NUM> may be controlled by a controller that includes an actuator responsive to an electrical signal, a pressure signal, etc. As an example, an actuator for a wastegate may be a mechanical actuator, for example, that may operate without a need for electrical power (e.g., consider a mechanical actuator configured to respond to a pressure signal supplied via a conduit).

<FIG> shows an example of a turbocharger <NUM> that includes a turbine assembly <NUM>, a compressor assembly <NUM> and a center housing <NUM>. The turbine assembly <NUM> includes a turbine housing <NUM> that is shaped to accommodate a turbine wheel <NUM> and the compressor assembly <NUM> includes a compressor housing <NUM> that is shaped to accommodate a compressor wheel <NUM>. As shown, a shaft <NUM> operatively couples the turbine wheel <NUM> and the compressor wheel <NUM> as supported by one or more bearings <NUM> and <NUM> in a through bore of the center housing <NUM>.

As shown in <FIG>, the turbine housing <NUM> can include an exhaust inlet <NUM> and an exhaust outlet <NUM> where a volute <NUM> is defined at least in part by the turbine housing <NUM>. The volute <NUM> can be referred to as a scroll that decreases in its cross-sectional diameter as it spirals inwardly toward a turbine wheel space that accommodates the turbine wheel <NUM>.

As shown in <FIG>, the compressor housing <NUM> can include an air inlet <NUM> and an air outlet <NUM> where a volute <NUM> is defined at least in part by the compressor housing <NUM>. The volute <NUM> can be referred to as a scroll that increases in its cross-sectional diameter as it spirals outwardly from a compressor wheel space that accommodates the compressor wheel <NUM>.

Disposed between the compressor housing <NUM> and the center housing <NUM> is a backplate <NUM>, which includes a bore <NUM> that can receive a thrust collar <NUM>, which can abut against a base end <NUM> of the compressor wheel <NUM>. As shown, the thrust collar <NUM> can include a lubricant slinger <NUM> that extends radially outward, which can help to reduce undesirable flow of lubricant (e.g., to the compressor wheel space, etc.).

The center housing <NUM> includes various lubricant features such as a lubricant inlet <NUM>, a lubricant bore <NUM>, lubricant jets <NUM>, and a lubricant drain <NUM>. As shown, lubricant can be provided at the lubricant inlet <NUM> to flow to the lubricant bore <NUM> and to the lubricant jets <NUM>, which include a compressor side jet for directing lubricant to the bearing <NUM> and a turbine side jet for directing lubricant to the bearing <NUM>. Lubricant can carry heat energy away from the bearings <NUM> and <NUM> as they rotatably support the shaft <NUM> as the turbine wheel <NUM> is driven by flow of exhaust through the turbine housing <NUM>.

As shown in the example of <FIG>, the compressor housing <NUM> can be clipped to the backplate <NUM> via a clip <NUM>, the backplate <NUM> can be bolted to the center housing <NUM> via bolt or bolts <NUM> and the center housing <NUM> can be bolted to the turbine housing <NUM> via a bolt or bolts <NUM>; noting that various other techniques may be utilized to couple the components to form a turbocharger.

In the example of <FIG>, one or more of the housings <NUM>, <NUM> and <NUM> may be cast. For example, the turbine housing <NUM> may be cast from iron, steel, nickel alloy, etc. As an example, consider a Ni-Resist cast iron alloy with a sufficient amount of nickel to produce an austenitic structure. For example, consider nickel being present from approximately <NUM> percent by weight to approximately <NUM> percent by weight. As an example, an increased amount of nickel can provide for a reduced coefficient of thermal expansion (e.g., consider a minimum at approximately <NUM> percent by weight). However, increased nickel content can increase cost of an Ni-Resist material; noting that density tends to be relatively constant over a large range of nickel content (e.g., approximately <NUM> to <NUM> grams per cubic centimeter). The density of Ni-Resist material tends to be approximately <NUM> percent higher than for gray cast iron and approximately <NUM> percent lower than cast bronze alloys. As to machinability, Ni-Resist materials tend to be better than cast steels; noting that increased chromium content tends to decrease machinability due to increasing amounts of hard carbides. When compared to stainless steel (e.g., density of approximately <NUM> grams per cubic centimeter), Ni-Resist materials can be less costly and of lesser mass (e.g., lesser density).

Ni-Resist materials tend to exhibit suitable high temperature properties, which may be at rated to over <NUM> degrees C (<NUM> degrees F). Ni-Resist materials can be suitable for turbocharges for diesel and gasoline internal combustion engines. As an example, a diesel engine can have exhaust that may be at about <NUM> degrees C and, as an example, a gasoline engine can have exhaust that may be at about <NUM> degrees C. Such exhaust can be received by a turbine assembly that includes a turbine housing made of a suitable material.

As shown, the turbine housing <NUM> may be a relatively large component when compared to the compressor housing <NUM> and the center housing <NUM> such that the mass of the turbine housing <NUM> contributes significantly to the mass of the turbocharger <NUM>.

In the example of <FIG>, various components of the turbocharger <NUM> may be defined with respect to a cylindrical coordinately system that includes a z-axis centered on a through bore of the center housing <NUM>, which can coincide with the rotational axis of a rotating assembly that includes the turbine wheel <NUM>, the compressor wheel <NUM> and the shaft <NUM>. As mentioned, a turbine wheel may be welded to a shaft to form a shaft and wheel assembly (SWA) and a compressor wheel may be threaded onto an end of a shaft (e.g., a "boreless" compressor wheel) or have a through bore that receives a free end of the shaft where a nut or other suitable component is used to secure the compressor wheel to the shaft. In the example of <FIG>, the turbine wheel <NUM> is welded to the shaft <NUM> and a nut <NUM> is used to secure the compressor wheel <NUM> to the shaft <NUM> and, hence, the turbine wheel <NUM>.

In the example of <FIG>, a clearance exists between blades <NUM> that extend from a hub <NUM> of the turbine wheel <NUM> and a shroud portion <NUM> of the turbine housing <NUM>. As shown, the shroud portion <NUM>, in the cross-sectional view is "J" shaped, which can define a body of rotation that has an annular ridge portion <NUM> and a cylindrical portion <NUM>. As shown, the annular ridge portion <NUM> can define a nozzle for exhaust that flows from the volute <NUM> to the turbine wheel space at an inducer portion of the turbine wheel <NUM>, which can be defined by leading edges where each of the blades <NUM> includes a leading edge (L. As shown, the turbine wheel <NUM> also includes an exducer portion where each of the blades <NUM> includes a trailing edge (T. During operation, exhaust flows from the volute <NUM> via the nozzle defined in part by the annular ridge portion <NUM> of the shroud portion <NUM> to the leading edges of the blades <NUM>, along channels defined by adjacent blades <NUM> of the turbine wheel <NUM> as confined between the hub <NUM> and the cylindrical portion <NUM> of the shroud portion <NUM> and then to the trailing edges of the blades <NUM> where the exhaust is confined by a larger diameter cylindrical wall <NUM>, a slightly conical wall <NUM> and a yet larger diameter cylindrical wall <NUM>. As shown in <FIG>, the cylindrical wall <NUM> can be defined by a portion of the turbine housing <NUM> that includes a fitting such as an annular ridge <NUM> that can be utilized to secure an exhaust conduit to the turbine housing <NUM>. Such an exhaust conduit may be in fluid communication with one or more other components such as an exhaust treatment unit, a muffler, another turbocharger, etc. As to the exhaust inlet <NUM> of the turbine housing <NUM>, it too may be shaped to couple to one or more exhaust conduits such as, for example, an exhaust header, an exhaust manifold, another turbine housing (e.g., for a multi-stage turbocharger arrangement), etc..

As shown in <FIG>, the turbine housing <NUM> severs various functions through its structural features and shapes thereof; however, such structural features can contribute to mass of the turbocharger.

As an example, a turbocharger may weigh from approximately <NUM> kilograms (e.g., <NUM> lbs) to approximately <NUM> kilograms (e.g., <NUM> lbs) or more.

As mentioned, a turbocharger can be defined with respect to a cylindrical coordinate system where a z-axis may be along a length. In the example of <FIG>, the length of the turbine housing <NUM> is over <NUM> percent of the total length. The overall length or size of a turbocharger can be a factor when installing in an engine compartment of a vehicle as it presents design constraints.

The turbocharger <NUM> of <FIG> can be cooled via one or more media, such as lubricant (e.g., oil), water (e.g., radiator fluid, etc.), and air (e.g., via an environment with ambient air or vehicle engine compartment air).

As to lubricant cooling (e.g., oil, whether natural, synthetic, etc.), some tradeoffs exists. For example, if a carbonaceous lubricant reaches too high of a temperature for too long of a time (e.g., consider a time-temperature dependence), carbonization (e.g., also known as coke formation or "coking"), may occur. Coking can exasperate heat generation and heat retention by any of a variety of mechanisms and, over time, coke deposits can shorten the lifetime of a lubricated bearing system. As an example, coke deposits may cause a reduction in heat transfer and an increase heat generation, which may lead to failure of the bearing system. To overcome coking, a turbocharger may be configured to improve lubricant flow. For example, a pump may pressurize lubricant to increase flow rates to reduce residence time of lubricant in high temperature regions. However, an increase in lubricant pressure can exasperate various types of lubricant leakage issues. For example, an increase in lubricant pressure of a bearing system can result in leakage of lubricant to an exhaust turbine, to an air compressor or both. Escape via an exhaust turbine can lead to observable levels of smoke while escape via an air compressor can lead to lubricant entering an intercooler, combustion chambers (e.g., combustion cylinders), etc..

As to temperatures experienced during operation, they can depend on temperature of exhaust flowing to an exhaust turbine of a turbocharger, which can depend on whether an internal combustion engine is gasoline or diesel fueled (e.g., as mentioned, a diesel engine may have exhaust at about <NUM> degrees C and a gasoline engine may have exhaust at about <NUM> degrees C). Also, as to temperature, consider the example arrangements <NUM> and <NUM> of <FIG> where the turbine housing assemblies <NUM> and <NUM> are in close proximity to combustion cylinders, which may result in the turbine housing assemblies <NUM> and <NUM> experiencing higher exhaust temperatures and/or higher ambient temperatures.

<FIG> shows an example of a turbocharger <NUM> that includes a compressor assembly <NUM> with a compressor housing for a compressor wheel, a turbine assembly <NUM> with a turbine housing for a turbine wheel, a center housing <NUM> for a bearing, bearings or a bearing assembly to rotatably support a shaft of a shaft and wheel assembly (SWA), and an actuator <NUM> with a linkage <NUM> to a control arm assembly <NUM> for a wastegate of the turbine assembly <NUM>. The turbocharger <NUM> can include one or more of the components shown in <FIG>. In the view of <FIG>, the exhaust inlet of the turbine assembly <NUM> is not visible because it is on the opposite side. General directions of flow of air or exhaust are indicated by arrows. The actuator <NUM> is shown as being mounted to the compressor assembly <NUM>, which can help to reduce temperatures experienced by the actuator <NUM> (e.g., compared to having the actuator mounted on a turbine housing). The turbocharger <NUM> can be part of a vehicle such as, for example, the vehicle <NUM> of <FIG>. As an example, the turbine assembly <NUM> may optionally be arranged such as in one of the example arrangements <NUM> or <NUM> of <FIG>.

<FIG> show views of an example of a portion of a system that includes a manifold <NUM>, a turbine housing <NUM> and a treatment unit <NUM>. As shown, the turbine housing <NUM> can be integral to the manifold <NUM> and can include a flange <NUM> for coupling to the treatment unit <NUM>, for example, via a flange <NUM> of the treatment unit <NUM>. The treatment unit <NUM> can include flared pipe <NUM> that increases in diameter from the flange <NUM> to a catalyst housing <NUM> where the flared pipe <NUM> may include one or more fittings <NUM> for equipment coupling (e.g., one or more sensors, one or more conduits, etc.). As shown, the treatment unit <NUM> can include the flange <NUM> as a proximal flange and another flange <NUM> as a distal flange where exhaust flows generally in a direction from the flange <NUM> to the flange <NUM>. The flange <NUM> can include features <NUM> for coupling to the flange <NUM> of the turbine housing <NUM>, which may be via bolts, etc. As an example, a band may be utilized, threads, a bayonet, etc., to couple a turbine housing to a treatment unit.

As shown in <FIG>, the flange <NUM> can include an opening <NUM> that leads to the flared pipe <NUM>, which leads to an opening <NUM> of the catalyst housing <NUM>. As shown, a catalyst assembly <NUM> may be disposed in the catalyst housing <NUM> where, for example, the catalyst assembly <NUM> can include support material that supports one or more catalysts.

Emissions from an internal combustion engine can include constituents such as carbon monoxide, unburnt hydrocarbons and nitrogen oxides. Catalytic converters (e.g., treatment units) can reduce emissions; however, they introduce some losses such as increased engine back pressure. As an example, a catalytic converter can include one or more types of catalyst assemblies. For example, consider a concentric approach, a spiral approach, etc., which may provide relatively straight passages along a length of a catalytic converters. As an example, consider a cordierite ceramic monolith that may be formed into a honeycomb-like structure with straight channels. In various instances, straight channels may help to reduce pressure losses and provide for higher conversion efficiency of pollutants due to better flow distribution.

While treatment unit configuration can impact flow distribution, as explained herein, so can a turbine assembly. For example, if exhaust flow is maldistributed upon exiting a turbine housing, then it may be maldistributed upon entry to a treatment unit. In such an example, the features of the treatment unit that aim to provide for better flow distribution may help to retain the maldistribution of entering exhaust.

An article by <NPL>) is incorporated by reference herein. The article by Ibrahim et al. presents computational fluid dynamics (CFD) model results for flow behavior through a catalytic converter using a model with a straight vertical inlet pipe with an inlet diameter of <NUM> and length of <NUM> along with a <NUM> diameter and <NUM> long monolith container coupled to an exit pipe <NUM> long and <NUM> in diameter where both inlet and exit diffusers had a cone angle of <NUM>° and a length of <NUM>. As indicated, the inlet flow profile to the monolith container benefits from over ten diameters of axial length of a straight pipe (i.e., diameter of <NUM> with a length of <NUM>) along with the inlet diffuser (flared pipe). The article by Ibrahim et al. does not mention turbochargers.

<FIG> shows various diagrams that indicate general results of the CFD modeling of the article by Ibrahim et al. , including a diagram of a catalytic converter <NUM> with an inlet <NUM>, an inlet diffuser <NUM>, an outlet diffuser <NUM> and an outlet <NUM> where a catalyst assembly <NUM> is contained within the catalytic converter. As shown, exhaust velocity is relatively uniform upon entry to the inlet diffuser <NUM> where the velocity decreases. As indicated, pressure contours represent decreasing pressure as exhaust flows through the catalytic converter <NUM>.

The article by Ibrahim et al. noted that flow uniformity was increased by utilizing higher cell density monoliths with smaller hydraulic diameter and by splitting the monolith into two parts separated by a gap and that lower flow uniformity was observed in 3D steady state and transient numerical simulations in systems with higher monolith-to-inlet diameter ratios. The article by Ibrahim et al. also noted that the monolith acts as a flow resistance zone creating a high pressure area in the center of the catalytic converter that forces flow redistribution to the sides and that "the design of the inlet diffuser was found to play an important role in the converter design".

Referring again to the example of <FIG>, space for a <NUM> diameter long axial length of pipe may not be available in an engine compartment and, for example, a turbine housing may be integrally cast with an exhaust manifold. In various applications, preservation of heat energy can improve turbine performance and can improve catalyst performance. Preservation of heat energy can be accomplished by reducing flow path lengths, which may also reduce wall losses of exhaust flow.

In the example of <FIG>, the outlet of the turbine housing <NUM> directs exhaust into the treatment unit <NUM> where a relatively short distance from a turbine wheel space to the outlet can help to reduce spread (e.g., help to aim gas into the catalyst and ensure stable function). A metric as to exhaust flowing out of a turbine housing can be uniformity index, which may also be a specification of a treatment unit. For example, a higher uniformity index of a turbine housing can help to provide a specified catalyst inflow uniformity index and pressure gradient, which tend to be factors that define and ensure proper catalyst functionality. Proper function of a catalyst assembly tends to depend on proper heat distribution at the inlet of the catalyst assembly. Flow uniformity index can dictate catalyst reaction efficiency.

Another potential design factor that can impact functionality is, as shown in the example of <FIG>, the axis of the turbine housing <NUM> (e.g., turbine wheel rotational axis) being shifted with respect to the axis of the catalyst assembly <NUM> of the treatment unit <NUM>. Such a shift can result in a maldistribution of heat at catalyst inlet area where, for example, flow may not be in a perpendicular direction to a frontal surface of the catalyst assembly <NUM>. Such a factor can have an impact on catalyst reaction efficiency and in connection with it on stability of gas conversion.

<FIG> shows example plots <NUM> and <NUM> of exhaust flow of a turbine housing <NUM>, which is shown in a cross-sectional view. As shown, the turbine housing <NUM> includes opposing ends <NUM> and <NUM>, a volute wall <NUM>, a nozzle space <NUM>, a turbine wheel space <NUM> and an outlet space <NUM> where the turbine space <NUM> and the outlet space <NUM> are defined by a wall <NUM>. Dimensions can include a shroud diameter Ds of the turbine wheel space <NUM> and an outlet diameter Dout of the outlet space <NUM>, along with an axial dimension Δz of the wall <NUM>. As explained, a relatively short axial distance between the turbine wheel space <NUM> and the end <NUM> may be utilized.

In <FIG>, the turbine housing <NUM> has a contiguous wall <NUM> that increases in its cross-sectional area from an axial position corresponding to Ds to an axial position corresponding to Dout, except for a relatively small portion near the end <NUM>, which may be of a constant cross-sectional area (e.g., a cylindrical portion of the wall <NUM>).

In the example of <FIG>, the uniformity index of the axial velocity is <NUM> where Dout is approximately <NUM> percent of Ds and approximately <NUM> percent of Δz. As shown in the plots <NUM> and <NUM>, the axial velocity tends to be higher near the wall <NUM> and lesser near the center (see, e.g., contours for <NUM> near wall and <NUM> near the center). The difference in contour values and positions of the contours lead to the uniformity index being substantially less than unity (e.g., <NUM> less than unity).

<FIG> shows example plots <NUM> and <NUM> of exhaust flow of a turbine housing <NUM>, which is shown in a cross-sectional view. As shown, the turbine housing <NUM> includes opposing ends <NUM> and <NUM>, a volute wall <NUM>, a nozzle space <NUM>, a turbine wheel space <NUM>, an extended space <NUM> and an outlet space <NUM> where the extended space <NUM> is disposed between the turbine wheel space <NUM> and the outlet space <NUM>. As shown, a wall <NUM> defines the turbine wheel space <NUM> and the extended space <NUM> where the wall <NUM> transitions to a wall <NUM> that defines the outlet space <NUM>. As shown, the wall <NUM> reaches an annular axial peak <NUM> where it descends axially along a substantially cylindrical portion <NUM> to an annular axial valley <NUM>. The wall <NUM> then extends from the annular axial valley <NUM> to the end <NUM>.

In the example of <FIG>, the turbine housing <NUM> includes a transition region where the wall <NUM> transitions to the wall <NUM>. As shown, a single wall of increasing cross-sectional area is not present; rather, the wall <NUM> can be set within the wall <NUM> where a transition region may connect the wall <NUM> and the wall <NUM>. In the example of <FIG>, the turbine housing <NUM> includes a double wall for various axial positions. For example, consider a cutting plane at an axial position just above the annular axial valley <NUM> where the wall <NUM> forms a passage bounded by the wall <NUM>. As an example, the annular axial peak <NUM> of the wall <NUM> may extend axially higher than shown in the example of <FIG>. For example, consider the annular axial peak <NUM> extending toward the end <NUM> and/or past the end <NUM> (e.g., to define an overall axial length of the turbine housing <NUM>).

As shown in <FIG>, dimensions can include a shroud diameter Ds of the turbine wheel space <NUM> and an outlet dimension Dout of the outlet space <NUM>, along with an axial dimension Δz. The outlet dimension Dout may be a diameter of a circular outlet or a dimension of a non-circular outlet (e.g., an oval outlet, an ellipsoidal outlet, etc.). As explained, a relatively short axial distance between the turbine wheel space <NUM> and the end <NUM> may be utilized. Additionally, dimensions can include an extended axial dimension Δze and a dimension of an intermediate outlet, De, being the outlet of the extended space <NUM>, which may be a diameter of a circular outlet or a dimension of a non-circular outlet (e.g., an oval outlet, an ellipsoidal outlet, etc.).

In the example of <FIG>, the uniformity index of the axial velocity is <NUM> where Dout is approximately <NUM> percent of Ds and approximately <NUM> percent of Δz and where De is approximately <NUM> percent of Dout and <NUM> percent of Ds, along with Δze being approximately <NUM> percent of Δz; noting, that as mentioned, Δze may define Δz where the peak <NUM> extends past the end <NUM>. As shown in the plots <NUM> and <NUM>, the axial velocity tends to be more uniform with lesser differences between low and high contours such that the higher near the wall <NUM> velocities are reduced compared to the example of <FIG>.

<FIG> shows a perspective view of an example of a portion of a turbocharger <NUM> with the turbine housing <NUM> that includes one or more inlet passages <NUM> and the wall <NUM>, which can define at least part of an outlet passage <NUM>. As shown, the axis of the turbine wheel <NUM> is offset (e.g., shifted) from an axis of the opening <NUM>. In such an example, the axes may be parallel or, for example, the axis of the opening <NUM> may be tilted slightly with respect to the axis of the turbine wheel <NUM> (e.g., less than approximately <NUM> degrees). In the example of <FIG>, the one or more inlet passages <NUM> extend outwardly where the axis of the opening <NUM> is offset from the axis of the turbine wheel <NUM> in a general direction of the one or more inlet passages <NUM>. In such an example, the size of the opening <NUM> may be sufficiently large to couple to a treatment unit without enlarging an overall footprint of the turbine housing <NUM>; noting that in various other examples, a turbine housing may be shaped differently, configured differently, etc., with respect to one or more inlet passages (see, e.g., the turbine housing <NUM> of <FIG>, which may be integral with the manifold <NUM>).

<FIG> also shows an example of a cylindrical coordinate system with a z coordinate along a z-axis, an r coordinate in r-direction and an azimuthal angle Θ. In the example of <FIG>, the wall <NUM> and one or more other features of the turbine housing <NUM> and/or the turbocharger <NUM> can be defined using dimensions in the cylindrical coordinate system. As an example, a surface of the wall <NUM> may be a revolved surface in an azimuthal direction, denoted by the angle Θ, where revolution may be about the z-axis. As an example, the wall <NUM> may extend equally to a rim (e.g., the peak <NUM>) about <NUM> degrees or, for example, the wall <NUM> may extend to a rim that is of different heights, for example, from a base, which may be even or uneven. As an example, a rim (e.g., the peak <NUM>) may be in a plane that is perpendicular to the z-axis or that is tilted at an angle with respect to the z-axis.

In the example of <FIG>, the angle Θ may be zero degrees in a direction that may be a direction of the one or more inlet passages <NUM> and/or a volute inlet. In such an example, the peak <NUM> (e.g., rim) may be closest to the wall <NUM> at or approximately at angle Θ equal to zero (e.g., plus or minus <NUM> degrees). As an example, the wall <NUM> may transition to the wall <NUM> without a valley where it is closest to the wall <NUM> (e.g., the valley <NUM> may be less than <NUM> degrees about the wall <NUM>).

<FIG> shows a cross-sectional view of a portion of the turbocharger <NUM>, as including a shaft and wheel assembly <NUM> that includes the turbine wheel <NUM>, as including an insert <NUM> of a variable nozzle cartridge (e.g., a VNT, etc.) and as including the turbine housing <NUM>. <FIG> also shows a dimension Δzf, as an axial distance from the peak <NUM> to the end <NUM> of the turbine housing <NUM>. In <FIG>, an angle γ is shown that can at least in part define the valley <NUM>, for example, with respect to a plane where the rotational axis (e.g., axis of the turbine wheel space) is perpendicular (normal) to the plane. In the example of <FIG>, the angle γ is approximately <NUM> degrees as defined by a line passing through the two labeled valley points <NUM>-<NUM> and <NUM>-<NUM>. In the example of <FIG>, the angle γ may be a maximum angle where the valley point <NUM>-<NUM> is the highest and where the value point <NUM>-<NUM> is the lowest. As an example, for a portion of a turbine housing, a valley point may be approximately even with a peak point. As an example, a valley may be a contiguous annular valley or, for example, may be a portion of an annulus (e.g., less than <NUM> degrees about a peak). Where the wall <NUM> is surrounded by a valley <NUM> that is less than a full annulus (e.g., less than <NUM> degrees), the wall <NUM> may include a region that transitions to the wall <NUM> without descending to the valley <NUM>. For example, in <FIG>, the valley <NUM> of the turbine housing <NUM> may be less than <NUM> degrees about the wall <NUM> such that, for a portion of <NUM> degrees, the wall transitions to the wall <NUM> without descending to the valley <NUM>.

As shown in the example of <FIG>, the wall <NUM> can include an inner axial height and an outer axial height where the outer axial height can be defined in part via the valley <NUM> where the outer axial height may vary azimuthally about an axis of the turbine wheel space. As an example, the wall <NUM> may define a volume with respect to the wall <NUM> where the volume may be asymmetric. For example, the volume can be greater where the valley <NUM> is deeper.

As explained, function of a catalyst of a treatment unit can depend on heat distribution to the inlet of the treatment unit. A flow uniformity index can be utilized to define how uniform flow is at an inlet or, for example, computational fluid dynamics (CFD) may be utilized where flow and flow patterns may be analyzed (e.g., contours, streamlines, etc.). As explained, an increase in flow uniformity can increase catalyst reaction efficiency. As the position of a turbocharger turbine wheel axis may be shifted with respect to a catalyst treatment unit axis, without a wall such as the wall <NUM>, heat can be less uniformly distributed at a catalyst inlet area and, for example, may be other than in a perpendicular direction to the catalyst inlet area. Lack of uniformity can impact catalyst reaction efficiency and stability of gas conversion (e.g., emissions).

As shown in the example of <FIG>, the wall <NUM> can be a housing duct portion that directs exhaust gas flow to a desired area of an outlet where, for example, distances may be relatively short (e.g., as measured by a turbine wheel axial length, a turbine wheel leading edge blade axial height, etc.). Such a housing duct portion (e.g., an internal duct or passage portion) can direct exhaust gas where the exhaust gas flow can be more uniform at a catalyst inlet area of a treatment unit. The wall <NUM> can help to aim exhaust gas into a catalytic region, which can also help to ensure stable function. The wall <NUM> may be referred to as an internal housing stack pipe, which can be at least in part interior to an outer wall (e.g., the wall <NUM>) such that a turbine housing may be referred to as "double walled" at least over an azimuthally defined portion. Such an internal housing stack pipe can help to achieve a desired catalyst inflow uniformity index value (e.g., flow profile, etc.) and, for example, a desired pressure gradient (e.g., pressure profile, etc.), for proper treatment unit catalyst functionality.

As an example, the wall <NUM> can be shaped such that more uniform flow is achieved, for example, in a manner that does not risk over heating of catalyst in a region of a treatment unit when a turbocharger may be operating at peak power. For example, uniform flow can reduce risk of hot spot formation. Where flow is not uniform, it may be of a considerably greater velocity along a centerline where impingement of such higher velocity flow can cause a hot spot in a catalyst region of a treatment unit.

In the example of <FIG>, the "double-wall" approach can provide for some amount of heat conservation as the wall <NUM> is at least in part bounded by the wall <NUM> where the wall <NUM> is an exterior wall (e.g., consider heat exchange with a cooler ambient environment about the exterior wall). In <FIG>, the wall <NUM> acts as a duct or pipe that can help to separate flow from the wall <NUM> in a particular axial location, which can promote flow uniformity in front of a catalyst region of a treatment unit.

In the example of <FIG>, the wall <NUM> may be appropriately sized and/or shaped to accommodate one or more standardization of attachment diameters of one or more treatment units. In the example, of <FIG>, the wall <NUM> performs a flow uniformity function while the wall <NUM> performs a turbine housing shape function for operatively coupling a turbine housing to a treatment unit. In the example of <FIG>, the "double-wall" approach can tailor each wall separately to perform its particular function or functions while, for example, providing for some amount of heat retention (e.g., reduced heat loss) where a space (e.g., a volume) exists between at least a portion of the wall <NUM> and the wall <NUM>. As explained, the wall <NUM> can be at least in part an interior wall and the wall <NUM> can be an exterior wall where flow and heat can be appropriately directed to a catalyst inlet region of a treatment unit.

In various examples, an internal duct may be cast as part of a turbine housing and/or be provided as a separate part that can be fit to a turbine housing. As an example, a turbine housing can include attachment features such as threads or bayonets where a wall can include corresponding attachment features. In such an example, depending on the application, the treatment unit, space, etc., an appropriate wall may be selected and then coupled to a turbine housing to provide for flow uniformity to the treatment unit.

<FIG> shows a cross-sectional view of the turbine housing <NUM> along with an angle dimension, α, which is an angle of the wall <NUM>, an overall length dimension ΔzTH and a center housing coupling dimension DCH.

<FIG> shows a cross-sectional view of an example of a turbine housing <NUM> where the angle α is shown to be approximately <NUM> degrees and where an open angle of a cone may be twice α, for example, approximately <NUM> degrees. <FIG> also shows a dimension b, as a turbine wheel leading edge blade height, a dimension Δzbc from the leading edge blade top to a wall <NUM> that can be defined by the angle α and a dimension Δzc that may be a cone dimension that can characterize the wall <NUM>, noting that a dimension h may be a cone dimension that is measured from a vertex or origin of a cone.

As an example, the wall <NUM> may be characterized by the angle α within a range from approximately <NUM> degrees to approximately <NUM> degrees or, for example, within a range from greater than <NUM> degrees to approximately <NUM> degrees. As to a cone open angle (e.g., 2α), consider greater than <NUM> degrees to approximately <NUM> degrees.

A right cone or a portion thereof may be defined using a dimension along an axis such as a z-axis in a cylindrical coordinate system where the right cone or portion thereof increases in its radial dimension as may be measured by an r-axis. A surface may be a revolved surface in an azimuthal direction, denoted by an angle Θ. As an example, a cone may extend equally to a rim about <NUM> degrees or, for example, a cone may extend to a rim that is of different heights from a base, which may be even or uneven.

As an example, a right cone may be defined in part by open angle. For example, consider a right cone of a height h and a radius r where an open angle (or opening angle) ϑ (e.g., consider 2α) can be defined via an equation as follows: <MAT>.

As an example, a region may be defined via a volume, one or more areas, one or more slant heights, etc. For example, consider a volume of cone (e.g., <MAT>, where Ab is a base area or top area).

<FIG> shows a cross-sectional view of an example of a turbine housing <NUM> where the wall <NUM> may be formed integrally with the turbine housing <NUM> and/or via a separate wall component <NUM> that can be fit to the turbine housing <NUM>. For example, consider the turbine housing <NUM> as including features <NUM> such as threads, etc., and the wall component <NUM> with features such as mating threads <NUM>, etc. As shown, the wall component <NUM> can include an axial height Δzw, which may be selectable via selecting a particular compatible wall component (e.g., with a desired size, shape, etc.). As an example, the wall component <NUM> may be threaded into a socket of the turbine housing <NUM> such that threads mate for securing the wall component <NUM> to the turbine housing <NUM>. Where the wall component <NUM> is utilized, the wall <NUM> may be defined in part via a wall <NUM> of the turbine housing <NUM> and in part via the wall component <NUM>. In such an example, the dimension Δzc may be a sum of two axial heights. While threads are mentioned in the example of <FIG>, one or more other techniques, technologies, etc., may be utilized (e.g., bayonet, interference fit, welding, etc.).

As an example, where the separate wall component <NUM> is utilized, one or more gaps <NUM> (e.g., radial gap(s)) may exist, which may help to reduce heat transfer from the wall component <NUM> to the turbine housing <NUM>. Where heat transfer is reduced, more exhaust gas heat may be retained for utilization by a catalyst region of a treatment unit.

In the example of <FIG>, the angle α is shown to be approximately <NUM> degrees, where an open angle of a cone may be twice α, for example, approximately <NUM> degrees. <FIG> also shows a dimension b, as a turbine wheel leading edge blade axial height, a dimension Δzbc from the leading edge blade top to a wall <NUM> that can be defined by the angle α and a dimension Δzc that may be a cone dimension that can characterize the wall <NUM>, noting that a dimension h may be a cone dimension that is measured from a vertex or origin of a cone.

As an example, the wall <NUM> may be characterized by the angle α within a range from approximately <NUM> degrees to approximately <NUM> degrees or, for example, within a range from greater than <NUM> degrees to approximately <NUM> degrees. As to a cone open angle or opening angle (e.g., 2α), consider greater than <NUM> degrees to approximately <NUM> degrees.

As shown in various examples (see, e.g., <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG>), the turbine housing <NUM> (or turbine housings <NUM> or <NUM>) can include a bearing housing end <NUM> and a treatment unit end <NUM>; a volute wall <NUM> that defines a volute; a wall <NUM> (e.g., a wall <NUM> or a wall <NUM>) that defines at least a portion of a turbine wheel space that defines a turbine wheel space axis and a turbine wheel space diameter Ds, where the wall <NUM> extends to an axial peak to define an extended space with an extended space outlet having an extended space outlet dimension De; and an outlet wall <NUM> that defines an outlet space with a treatment unit end outlet having an outlet dimension Dout, where the extended space is disposed axially between the turbine wheel space and the outlet space to increase axial velocity uniformity at the treatment unit end outlet.

As an example, the wall <NUM>, the wall <NUM> or the wall <NUM> may be symmetric about an axis and represented by revolution, for example, according to an angle α or, for example, a cone open angle 2α, or, for example, the wall <NUM>, the wall <NUM> or the wall <NUM> may be characterized by an angle α while differing in part from a surface of revolution about an axis. For example, consider utilizing the angle α to characterize a mean diameter of the wall <NUM>, the wall <NUM> or the wall <NUM> between a smaller upstream diameter and a larger downstream diameter.

As an example, a turbine housing can include a bearing housing end (see, e.g., the end <NUM>) and a treatment unit end (see, e.g., the end <NUM>); a volute wall (see, e.g., the volute wall <NUM>) that defines a volute; a wall (see, e.g., the walls <NUM>, <NUM> and <NUM>) that defines at least a portion of a turbine wheel space that defines a turbine wheel space axis and a turbine wheel space diameter (Ds), where the wall extends to an axial peak to define an extended space with an extended space outlet having an extended space outlet dimension (De); and an outlet wall (see, e.g., the outlet wall <NUM>) that defines an outlet space with a treatment unit end outlet having an outlet dimension (Dout), where the extended space is disposed at least in part axially between the turbine wheel space and the outlet space to increase axial velocity uniformity at the treatment unit end outlet. In such an example, a portion of the wall that defines the extended space can be disposed at an angle with respect to the turbine wheel space axis, where the angle is greater than <NUM> degrees and less than <NUM> degrees, for example, consider the angle being greater than <NUM> degrees and less than <NUM> degrees. As an example, such an angle may be in a range greater than <NUM> degrees and less than <NUM> degrees.

As an example, a turbine housing can include a turbine wheel space diameter (Ds), an extended space outlet dimension (De); and a treatment unit end outlet having an outlet dimension (Dout) where Ds < De < Dout. As an example, an axial distance from an axial peak of a wall to a treatment unit end outlet may be less than Ds. As an example, De may be greater than <NUM> percent of Ds and less than <NUM> percent of Ds.

As an example, a turbine housing can include a wall (see, e.g., the walls <NUM>, <NUM> and <NUM>) that descends from an axial peak to an axial valley. In such an example, the turbine housing can include a transition from the wall to another wall (see, e.g., the wall <NUM>) where the transition is at the axial valley. As an example, an axial valley may vary in depth with respect to an axial peak or an axial rim. For example, in <FIG>, the axial valley <NUM> can vary with respect to the angle Θ such that it is deeper on one side compared to another, opposing side. For example, depth of an axial valley can vary azimuthally about a turbine wheel space axis. As shown in the example of <FIG>, the axial valley <NUM> is deeper on a side that corresponds to an inlet side of a volute defined at least in part by the turbine housing <NUM> (see, e.g., the one or more inlet passages <NUM> of <FIG>). As an example, an axial valley may define a plane that may be tilted with respect to a turbine wheel space axis (e.g., in a tilt direction as shown in <FIG>, <FIG>, <FIG>, <FIG> or <FIG>).

As an example, a turbine housing can include a treatment unit end outlet that defines an outlet axis that is offset from a turbine wheel space axis. In such an example, an axial peak may be an annular axial peak centered on the turbine wheel space axis.

As an example, a turbine housing can be part of an assembly that includes an insert that defines in part a turbine wheel space. For example, consider an insert that is a variable nozzle cartridge insert (e.g., part of a variable nozzle cartridge, etc.).

As an example, a turbine housing can include a multiple cylinder exhaust manifold. For example, consider a multiple cylinder exhaust manifold that is cast integrally with a turbine housing.

Claim 1:
A turbocharger turbine housing comprising:
a bearing housing end (<NUM>) and a treatment unit end (<NUM>);
a volute wall (<NUM>) that defines a volute;
a wall (<NUM>, <NUM>, <NUM>) that defines at least a portion of a turbine wheel space that defines a turbine wheel space axis and a turbine wheel space diameter (Ds), wherein the wall (<NUM>) extends to an axial peak (<NUM>) to define an extended space with an extended space outlet having an extended space outlet dimension (De), wherein the extended space outlet dimension is greater than <NUM> percent of the turbine wheel space diameter and less than <NUM> percent of the turbine wheel space diameter; and
an outlet wall (<NUM>) that defines an outlet space with a treatment unit end outlet having an outlet dimension (Dout) as a maximum dimension of the outlet space, wherein the outlet dimension is greater than the extended space outlet dimension, wherein the extended space is disposed at least in part axially between the turbine wheel space and the outlet space to increase axial velocity uniformity of exhaust flow at the treatment unit end outlet, and wherein the wall and the outlet wall form a double wall for axial positions at least over an azimuthally defined portion of the turbine housing, with respect to a cylindrical coordinate system with a z coordinate along a turbine wheel space axis and an r coordinate in radial direction of the turbine wheel space axis.