Patent Description:
Exhaust driven turbochargers include a rotating group that includes a turbine wheel and a compressor wheel that are connected to one another by a shaft. The shaft is typically rotatably supported within a center housing by one or more bearings. During operation, exhaust from an internal combustion engine drives a turbocharger's turbine wheel, which, in turn, drives the compressor wheel to boost charge air to the internal combustion engine. The related prior art discloses the following:.

The invention is defined in claim <NUM>, embodiments of the invention are defined in the appended claims.

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 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 <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 assembly <NUM> that includes a shaft <NUM> supported by a bearing <NUM> (e.g., a journal bearing, a bearing assembly such as a rolling element bearing with an outer race, etc.) disposed in a bore (e.g., a through bore defined by one or more bore walls) of a housing <NUM> between a compressor assembly <NUM> that defines a compressor side (left) and a turbine assembly <NUM> that defines a turbine side (right). The compressor assembly <NUM> includes a compressor housing <NUM> that defines a volute <NUM> and that houses a compressor wheel <NUM>. As shown in <FIG>, the turbine assembly <NUM> includes a turbine housing <NUM> that defines a volute <NUM> and that houses a turbine wheel <NUM>. The turbine wheel <NUM> may be, for example, welded or otherwise attached to the shaft <NUM> to form a shaft and wheel assembly (SWA) where a free end of the shaft <NUM> allows for attachment of the compressor wheel <NUM>.

As an example, a wheel, whether a turbine wheel or a compressor wheel, can include an inducer portion and an exducer portion, for example, characterized in part by an inducer radius (ri) and an exducer radius (re). As an example, an individual blade can include an inducer edge (e.g., a leading edge) and an exducer edge (e.g., a trailing edge). A wheel may be defined in part by a trim value that characterizes a relationship between inducer and exducer portions.

For a compressor wheel, the inducer portion can be characterized by a "minor" diameter; whereas, for a turbine wheel, the inducer portion can be characterized by a "major" diameter. During operation, inlet flow to a compressor wheel or a turbine wheel occurs with respect to its inducer portion and outlet flow from a compressor wheel or a turbine wheel occurs with respect to its exducer portion.

As to air flow, during operation of the turbocharger <NUM>, air can be directed from the compressor wheel <NUM> to the volute <NUM> via a diffuser section defined in part by the compressor housing <NUM> and a compressor side plate <NUM> as the compressor wheel <NUM> rotates, drawing air into a passage <NUM> via an inlet <NUM>, both of which may be defined by the compressor housing <NUM>. As indicated in <FIG>, during operation of the turbocharger <NUM>, the compressor wheel <NUM> acts to boost air pressure such that air pressure in the volute <NUM> (Pcv) is greater than air pressure in the passage <NUM> (Pco). Rotation of the compressor wheel <NUM> can generate a negative pressure that acts to "suck" air into the compressor assembly <NUM> and to direct such air to the volute <NUM> via the diffuser section. As an example, where exhaust gas recirculation (EGR) is implemented, environmental air may be mixed with exhaust (e.g., upstream and/or downstream of the compressor wheel <NUM>).

In the example of <FIG>, an axial locating pin <NUM> is received in an opening of the bearing <NUM>, which may be a cross-bore of the bearing <NUM>. As an example, one or more other types of axial locating mechanisms may be included in a turbocharger that act to limit axial movement of a bearing (e.g., and/or movement in one or more other directions). As an example, a locating pin may allow for radial movement of a bearing, which may allow for effective operation of one or more lubricant films disposed about a surface of the bearing.

In the example of <FIG>, the shaft <NUM> includes a step (e.g., a shoulder) that forms an axial annular face. In the example of <FIG>, a thrust collar <NUM> (e.g., a type of collar) includes a surface that is seated against the axial annular face of the shaft <NUM>. In such an example, a lock nut <NUM> can include threads that match threads of an end portion of the shaft <NUM> such that tightening of the lock nut <NUM> with respect to the shaft <NUM> loads the compressor wheel <NUM> and the thrust collar <NUM> against the axial annular face of the shaft <NUM>, which can place the shaft <NUM> (e.g., from the step to its end portion) in tension. In such an example, the shaft <NUM>, the compressor wheel <NUM> and the lock nut <NUM> can rotate as a unit (e.g., responsive to exhaust driving the turbine wheel <NUM>). As shown in the example of <FIG>, the compressor side plate <NUM> can include a bore (e.g., an opening) in which at least a portion of the thrust collar <NUM> is positioned where the thrust collar <NUM> (and/or the compressor side plate <NUM>) can include a groove or grooves that may seat a seal element or seal elements (e.g., O-rings, piston rings, etc.).

In the example of <FIG>, the turbine assembly <NUM> includes a variable geometry assembly <NUM>, which may be referred to as a "cartridge" (e.g., the cartridge <NUM>), that may be positioned using an plate component <NUM>, which may be referred to as a flange (e.g., optionally shaped as a stepped annular disc or annular plate), of the cartridge <NUM> that clamps between the housing <NUM> and the turbine housing <NUM>, for example, using bolts <NUM>-<NUM> to <NUM>-N and a heat shield <NUM> (e.g., optionally shaped as a stepped annular disc), the latter of which is disposed between the cartridge <NUM> and the housing <NUM> and may be resilient in that it can apply a biasing force. As shown in the example of <FIG>, the cartridge <NUM> includes a nozzle wall component <NUM> and the plate component <NUM>. As an example, one or more mounts or spacers <NUM> may be disposed between the nozzle wall component <NUM> and the plate component <NUM> (e.g., or annular plate component), for example, to axially space the nozzle wall component <NUM> and the plate component <NUM> (e.g., forming a nozzle space).

As an example, vanes <NUM> may be positioned between the nozzle wall component <NUM> and the plate component <NUM>, for example, where a control mechanism may cause pivoting of the vanes <NUM>. As an example, the vane <NUM> may include a vane post <NUM> that extends axially to operatively couple to a control mechanism, for example, for pivoting of the vane <NUM> about a pivot axis defined by the vane post <NUM>.

As to exhaust flow, during operation of the turbocharger <NUM>, higher pressure exhaust in the volute <NUM> passes through passages (e.g., a nozzle or nozzles, a throat or throats, etc.) of the cartridge <NUM> to reach the turbine wheel <NUM> as disposed in a turbine wheel space defined at least in part by the cartridge <NUM> and at least in part by the turbine housing <NUM>. After passing through the turbine wheel space, exhaust travels axially outwardly along a passage <NUM> defined by a wall of the turbine housing <NUM> that also defines an opening <NUM> (e.g., an exhaust outlet). As indicated, during operation of the turbocharger <NUM>, exhaust pressure in the volute <NUM> (Ptv) is greater than exhaust pressure in the passage <NUM> (Pto).

As an example, exhaust pressure in the turbine assembly <NUM> can depend on position or positioning of the vanes <NUM>. For example, closing and/or opening of the vanes <NUM> (e.g., narrowing or widening throats) can effect exhaust gas pressure at one or more locations.

While <FIG> shows a general direction of gravity (G, Earth's gravity), the orientation of the turbocharger <NUM> may be in an orientation in an engine compartment that is suitable for operation given particulars of lubricant feed, flow and drainage.

As an example, a turbine assembly of an exhaust gas turbocharger can include vanes as part of a variable geometry turbine (VGT) or variable nozzle turbine (VNT). Vanes may be disposed at least in part in a cartridge where the cartridge is disposed between a turbine housing and a center housing of a turbocharger.

As an example, a cartridge may include a nozzle wall component and a plate component spaced axially by mounts (e.g., spacers) where vanes are accommodated to control exhaust flow from a volute to a turbine wheel space. As an example, a vane may include a trailing edge and a leading edge with a pressure side airfoil and a suction side airfoil that meet at the trailing edge and the leading edge. Such a vane may have a planar upper surface and a planar lower surface where a clearance exists between the planar upper surface and the nozzle wall component (e.g., between a lower planar surface of an annular portion of the nozzle wall component) and/or where a clearance exists between the planar lower surface and the plate component (e.g., between an upper planar surface of an annular portion of the plate component).

As an example, each vane may include an axis about which the vane may pivot (e.g., a pivot axis). As an example, each vane may include a post (e.g., or axle) that defines a pivot axis. As an example, a post may be integral with a vane (e.g., cast as a single piece of metal, alloy, etc.) or a post may be a separate component that can be operatively coupled to a vane.

As an example, movement of a vane (e.g., arcwise) may be less closer to the pivot axis and greater further away from the pivot axis. For example, a trailing edge or a leading edge may be disposed a distance from the pivot axis such that upon pivoting of a vane, the leading edge and/or the trailing edge sweeps a maximum arc of the vane for a desired amount of pivoting. If clearance between an upper surface of a vane and a lower surface of a nozzle wall component is diminished, the vane may bind (e.g., stick), where the risk may increase depending on arc length as interaction area can increase with respect to arc length. In such an example, deformation to a nozzle wall component may cause a vane or vanes to bind upon pivoting or even in a static position. Binding (e.g., sticking) can result in loss of control, stress to a control mechanism, wear, etc..

As an example, forces acting on a vane and/or a post of a vane may cause a vane or vanes to bind upon pivoting or even in a static position. Binding can result in loss of control, stress to a control mechanism, wear, etc..

As to pressure differentials and temperatures in a variable geometry turbine assembly, as an example, exhaust in a volute may have pressure in a range of approximately <NUM> kPa to approximately <NUM> kPa and possible peak pressure of up to approximately <NUM> kPa (absolute) and, for example, temperature in a range of approximately <NUM> degrees C to approximately <NUM> degrees C; whereas, at a location axially downstream of a turbine wheel, exhaust may have pressure in a lower range and temperature in a lower range. Exhaust gas temperatures in a gasoline fuel internal combustion engine may exceed those of a diesel fuel internal combustion engine. Where a variable geometry turbine assembly is utilized with a gasoline fuel internal combustion engine, the environment may be harsher in terms of temperature when compared to a diesel fuel internal combustion engine.

As an example, one or more components of a variable geometry turbine assembly (e.g., VGT assembly or variable nozzle turbine (VNT) assembly) can include at least a portion made of a material that can withstand pressures and temperatures in the aforementioned ranges. For example, a material can be the INCONEL <NUM> alloy (Specialty Materials Corporation, New Hartford, NY). Some other examples of materials include INCONEL <NUM>, C263 (aluminum-titanium age hardening nickel), René <NUM> (nickel-based alloy), WASPALOY alloy (age hardened austenitic nickel-based alloy, United Technologies Corporation, Hartford, CT), etc..

As an example, a cartridge can include vanes that are disposed at least in part between two components. As an example, at least a portion of a vane may be made of a material such as HK30, which is a chromium-nickel-iron stainless steel alloy including approximately <NUM>% chromium and <NUM>% nickel, with the balance being predominantly iron (percentages by mass). As an example, at least a portion of a vane may be made of a HK series stainless steel alloy that includes about <NUM>-<NUM>% nickel by mass. Such an alloy can be fully austenitic. As an example, one or more components of a cartridge may be made of a material such as, for example, PL23 alloy or <NUM> SS alloy.

As an example, an exhaust gas variable geometry turbine assembly can include a number of pivotable vanes that define, at least in part, throats within an exhaust gas nozzle where each of the pivotable vanes includes a corresponding post.

<FIG> show perspective views of the example cartridge <NUM> of <FIG>. In <FIG>, the nozzle wall component <NUM> includes a lower surface that can be a nozzle upper surface <NUM> of an annular plate portion <NUM>. As an example, the nozzle wall component <NUM> can include a cylindrical pipe portion <NUM>. Where the nozzle wall component <NUM> includes the cylindrical pipe portion <NUM>, the overall shape of the nozzle wall component <NUM> can be referred to as a hat shape. As shown, the annular plate portion <NUM> includes an outer perimeter defined by an outer surface <NUM>. The outer surface <NUM> meets opposing annular surfaces <NUM> and <NUM> where the annular surface <NUM> includes a shroud portion <NUM> as a shroud of a turbine wheel space for a turbine wheel where a clearance exists between the shroud portion <NUM> and a suitable turbine wheel disposed in the turbine wheel space.

As shown, the nozzle wall component <NUM> includes a plurality of bores <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> (e.g., spacer bores), which receive a plurality of spacers <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>, which space the nozzle wall component <NUM> axially with respect to the plate component <NUM>. As shown, the plate component <NUM> includes an upper surface that can be a nozzle lower surface <NUM> where a nozzle is defined by the nozzle upper surface <NUM> and the nozzle lower surface <NUM>. The bores <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> are shown as being cylindrical and extending between the opposing surfaces <NUM> and <NUM> of the nozzle wall component <NUM> where the bores <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> each has a diameter and an axial length along a bore axis where the bore axes are at a radius of an axis defined by the turbine wheel space, for example, as defined by the shroud portion <NUM>, which may be referred to as a rotational axis (e.g., an intended rotational axis of a turbine wheel disposed in the turbine wheel space). In the example of <FIG>, the cartridge <NUM> can be installed in a turbocharger, which may then be installed in an engine compartment of an internal combustion engine. The nozzle wall component <NUM> can be subjected to various conditions (e.g., forces, temperatures, pressures, etc.), which can impact the nozzle wall component <NUM> (e.g., as to integrity, shape, etc.).

As to the cylindrical pipe portion <NUM>, it includes an inner surface <NUM> and an outer surface <NUM>, as well as an end surface <NUM>. The cylindrical pipe portion <NUM> can be defined at least in part by an inner diameter, an outer diameter and an axial length, for example, as measured along the rotational axis. In the example shown, the outer surface <NUM> includes one or more grooves <NUM> that can receive one or more seal elements (e.g., seal components such as or akin to piston rings). In the example shown, the surface <NUM> and the surface <NUM> meet and form a shoulder that has an angle of approximately <NUM> degrees. As to the surface <NUM> and the surface <NUM>, they meet at respective ends of the shroud portion <NUM>. For example, the surface <NUM> can be substantially flat, meet the shroud portion <NUM>, which is contoured, which then meets the surface <NUM>, which extend axially to the end surface <NUM>. As shown, the end surface <NUM> is an annular surface the meets the inner surface <NUM> and the outer surface <NUM>.

The perspective views show one or more seal rings <NUM> seated in the one or more grooves <NUM> of the nozzle wall component <NUM>, the plurality of spacers <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>, a plurality of vanes <NUM> (e.g., <NUM>-<NUM> to <NUM>-N) and corresponding vane posts <NUM>-<NUM> to <NUM>-N, a plurality of vane control arms <NUM>, a unison ring <NUM>, a plurality of pins <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>, and a plurality of guides <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>.

In the example of <FIG>, the unison ring <NUM> may be rotated about a central axis (e.g., substantially aligned with the axis of rotation of a turbine wheel) to cause the plurality of vane control arms <NUM> to rotate about respective post axes of individual vane posts <NUM> of the plurality of vanes <NUM>. The plurality of pins <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> and the plurality of guides <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> may help to align the unison ring <NUM> with respect to other components of the cartridge <NUM>.

In the example of <FIG>, one or more ends of the spacers <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> may be fixed (e.g., riveted, capped, etc.). For example, an end of a spacer may be flattened to a radius that is greater than an opening of a bore through which the spacer extends such that the spacer cannot be moved axially into the bore. As shown, each of the spacers <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> includes a nozzle portion with a radius and/or a diameter that is greater than a corresponding end portion of opposing end portions that are received by respective spacer bores of the nozzle wall component <NUM> and the plate component <NUM>. For example, a spacer can be defined by one or more radii and/or one or more diameters as well as one or more axial dimensions such as an axial dimension of a nozzle portion.

The nozzle portion of each of the spacers <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> can include opposing shoulders where one shoulder abuts the nozzle wall component <NUM> and the other shoulder abuts the plate component <NUM> to define a nozzle axial dimension, which can be slightly larger than a vane axial dimension to allow vanes to pivot in the nozzle where a clearance may be defined based at least in part on one or more thermal considerations (e.g., thermal expansion, contraction, etc.).

In the example of <FIG>, the cartridge <NUM> may be secured as a cartridge unit via riveting ends of the spacers <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>, which fixes an axial distance between the nozzle wall component <NUM> and the plate component <NUM> at a given temperature (e.g., an ambient temperature during assembly). Such a riveting process may introduce some amount of stress at the passages (e.g., bores) of the nozzle wall component <NUM> and/or the plate component <NUM> through which the spacers <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> pass.

<FIG> shows a plan view of a portion of a cartridge <NUM> that includes a plurality of vanes <NUM>. The vanes <NUM> are represented in <FIG> via solid lines and dashed lines where the solid lines indicate an open position of the vanes <NUM> and where the dashed lines indicate a closed position of the vanes <NUM>. Open headed arrows are shown to approximately illustrate the direction of exhaust flow between adjacent pairs of the vanes <NUM> when in the open position. In the closed position, the vanes <NUM> act as obstacles to exhaust flow such that pressure can be higher in a region radially outward from the vanes <NUM> in comparison to a region radially inwardly from the vanes <NUM>. In such an example, clearances between the vanes <NUM> and the upper and lower nozzle surfaces <NUM> and <NUM> are minimal such that bypass of exhaust in such clearances is minimized. Exhaust flow that does occur may be referred to as exhaust leakage. As explained, however, the clearances are to be sufficient to reduce risk of binding where vane binding against the nozzle surfaces <NUM> and <NUM> can confound controllability. Where risk of binding exists, an actuator may demand more power, which may mean larger size, more cost, more energy consumption, etc. Hence, design of the cartridge <NUM> generally involves balancing risk of binding (e.g., sticking) and exhaust leakage in the closed position.

In the example of <FIG>, in the open position, the trailing edges of the vanes <NUM> can define a circle as indicated by a thick dashed line and, in the closed position, the trailing edges of the vanes <NUM> can define another circle, which may be approximately the same as a circle that circumscribes the pivot axis (e.g., vanes posts <NUM>) of the vanes <NUM>. Hence, as the vanes <NUM> move from a closed position to an open position, a circle of decreasing radius (e.g., diameter) can be defined by the trailing edges of the vanes <NUM>. Further, as shown, the leading edges of the vanes <NUM> may define a circle of increasing radius (e.g., diameter).

As an example, a range of angles for a set of vanes can be defined using a closed position and a fully open position. In such an example, the closed position may be defined where pivoting is limited for one or more reasons. For example, one reason for limitation of pivoting is vane contact where neighboring vanes contact each other (e.g., vane-to-vane contact). Another reason may be due to one or more stops that are built into an actuator or other control linkage. As to a fully open position, it can be defined utilizing one or more references. For example, an outer radius of a turbine wheel can be utilized where, in a fully open position, trailing edges of a set of vanes are within a range of approximately <NUM> percent to approximately <NUM> percent of the outer radius of the turbine wheel. In such a range, the trailing edges can be spaced a distance sufficiently away from blades of a turbine wheel such that leading edges of the blades do not contact trailing edges of the vanes when the set of vanes is in the fully open position. Such a distance can be tailored to be not too large for purposes of appropriate performance and not too small for purposes of avoiding turbine wheel-to-vane contact (e.g., given vibration, thrust forces on a turbine wheel, thermal effects, etc.). A range of angles can have a minimum angle and a maximum angle where an intermediate angle can be defined as being a <NUM> percent open angle. As explained, one or more features of a set of vanes (e.g., leading edges and/or trailing edges) may be utilized to define one or more radii (e.g., one or more diameters) that can be utilized to define one or more features of an assembly.

<FIG> shows a plan view and a cut-away view of a portion of the cartridge <NUM> where various angles are indicated, including a <NUM> degree closed angle with a corresponding circle, a <NUM> degree open angle with a corresponding circle, a <NUM> degree angle with a corresponding circle and a <NUM> degree full open angle with a corresponding circle.

As shown in the example of <FIG>, the vane <NUM> includes a trailing edge <NUM> and a leading edge <NUM> with a pressure side airfoil and a suction side airfoil that meet at the trailing edge <NUM> and the leading edge <NUM>. As shown, the vane <NUM> can have a planar upper surface <NUM> and a planar lower surface <NUM> where a clearance exists between the planar upper surface <NUM> and the upper nozzle surface <NUM> of the wall component <NUM> and/or where a clearance exists between the planar lower surface <NUM> and lower nozzle surface <NUM> of the plate component <NUM>.

In the example of <FIG>, the trailing edge <NUM> or the leading edge <NUM> may be disposed a distance from a pivot axis <NUM> of the vane <NUM> such that upon pivoting of the vane <NUM>, the leading edge <NUM> and/or the trailing edge <NUM> sweeps a maximum arc of the vane <NUM> for a desired amount of pivoting. As explained, if clearance between the upper surface <NUM> of the vane <NUM> and the upper nozzle surface <NUM> is diminished, the vane <NUM> may bind (e.g., stick), where the risk may increase depending on arc length as interaction area can increase with respect to arc length. In such an example, deformation to the nozzle wall component <NUM> may cause the vane <NUM> to bind upon pivoting or even in a static position. Binding (e.g., sticking) can result in loss of control, stress to a control mechanism, wear, etc..

As an example, a turbine assembly can include a non-uniform or variable clearance between an upper surface of a vane and an upper nozzle surface. For example, the clearance can increase with respect to decreasing radius of the upper nozzle surface. In such an example, the clearance may be sufficiently small in a closed position of vanes for purposes of reduced exhaust leakage and be larger in an open position of the vanes for purposes of reduced binding and/or decreased resistance to exhaust flow. For example, a clearance may increase for vane open positions that are greater than or equal to <NUM> percent of a fully open position. In such an example, the vane open position where clearance increases may be defined using an angle, a diameter, etc., for example, as explained with respect to the example of <FIG>.

<FIG> shows a perspective view of the vane <NUM> where a pressure side airflow surface <NUM> and a suction side airflow surface <NUM> are indicated with respective labels. Further, an outline of the upper nozzle surface <NUM> is shown as existing above the vane <NUM> as would be present in an assembled turbine assembly where the nozzle surface <NUM> can be a relatively constant region that meets a first transition point <NUM> that meets a variable region <NUM> that meets a second transition point <NUM> that meets an elevated region <NUM>.

In the example of <FIG>, various dimensions are illustrated, including a vane height zv, a nozzle height zn (e.g., between nozzle surfaces <NUM> and <NUM>), a clearance zc (e.g., between surfaces <NUM> and <NUM>), a variable clearance zc(r) and an enlarged clearance zc*. In such an example, the first transition point <NUM> can correspond to a <NUM> percent open position of the trailing edge <NUM> of the vane <NUM>.

As an example, a vane may be defined in part via one or more airfoil terms (e.g., dimensions, etc.). For example, the vane <NUM> can be defined in part by one or more of a camber line that can be a surface mid-way between the surfaces <NUM> and <NUM>, a chord length, a thickness, an upper camber, a lower camber, a pivot axis, etc. In the example of <FIG>, the vane <NUM> is shown as being relatively slender with a thickness that is less than the chord length. As shown in <FIG>, the vane <NUM> can have its pivot axis <NUM> located approximately mid-way between the leading and trailing edges <NUM> and <NUM>; noting that the vane <NUM> has a length from the pivot axis <NUM> to the trailing edge <NUM> that is greater than a length from the pivot axis <NUM> to the leading edge <NUM> such that, if the vane <NUM> was spun <NUM> degrees about its pivot axis <NUM> (e.g., as a single vane without interference from other vanes), the leading edge <NUM> would form a circle centered on the pivot axis <NUM> with a smaller radius than a circle centered on the pivot axis <NUM> for the trailing edge <NUM>.

<FIG> shows a plan view and a cut-away view of the example of <FIG>, however, with a different clearance profile between the vane <NUM> and the upper nozzle surface <NUM>, as represented by at least the first transition point <NUM>, the variable surface region <NUM> and the second transition point <NUM>, which may transition to a shroud profile <NUM> that may transition to a relatively vertical surface <NUM>. In comparison to the example of <FIG>, due to the increased clearance region, the vane <NUM> can have reduced risk of binding at open angles greater than approximately <NUM> degrees, which may be a half-open angle, compared to the <NUM> degree full open angle (e.g., fully open).

<FIG> shows a schematic view of the vane <NUM> and a blade <NUM> of a turbine wheel. As shown, the increased clearance region can be defined using the vane height zv. For example, consider a nozzle height zn that can increase to <NUM> to <NUM> times the nozzle height zn of vane open positions less than <NUM> percent open.

As explained, the blade <NUM> can have a leading edge that can be disposed at a radius rw from a rotational axis z of a wheel having the blade <NUM> and the trailing edge of the vane <NUM> can be at a radius rte that depends on an angle of the vane <NUM>. As the vane <NUM> becomes more open, the trailing edge of the vane <NUM> becomes closer to the leading edge of the blade <NUM>. As an example, a blade may be a radial flow blade of a radial flow turbine wheel or a mixed flow blade of a mixed flow turbine wheel. In the example of <FIG>, the blade <NUM> may be a radial flow blade as the leading edge of the blade <NUM> is at a constant radius rw along the height of the leading edge of the blade <NUM>.

In the example of <FIG>, consider the nozzle height zn as being approximately <NUM> where the increased nozzle height zth (e.g., throat height) is approximately <NUM>. In such an example, the radius of the <NUM> percent open position may be approximately <NUM> from a rotational axis of a turbine wheel and the <NUM> percent open position may be approximately <NUM> from the rotational axis of the turbine wheel. For example, an increase may be approximately <NUM> to <NUM> or more. In such an example, exhaust flow may exhibit improved development before experiencing leading edges of blades of a turbine wheel.

As an example, a spacer can define a nozzle height. For example, consider a spacer that defines a nozzle height of <NUM> where a clearance between a vane upper surface and a nozzle upper surface is approximately <NUM>. In such an example, the clearance may increase to at least <NUM>. For example, consider an increased clearance of approximately <NUM> (e.g., <NUM> to <NUM> in terms of nozzle heights). As an example, an increased clearance may provide for an increased flow bypass channel that is defined by a percentage of vane height (e.g., <NUM> percent to <NUM> percent or optionally more).

As shown in the example of <FIG>, the increase may be sloped, stepped, etc. For example, a sloped region may be provided with one or more slopes and/or a stepped region may be provided with an approximately <NUM> degree step. As explained, one or more of a combination of shapes may be utilized to increase clearance.

<FIG> shows a schematic view of the vane <NUM> and an example of the blade <NUM> of a turbine wheel. In the example of <FIG>, the blade <NUM> may be a mixed flow blade as the leading edge of the blade <NUM> is not at a constant radius such that the radius rw can vary along the height of the leading edge of the blade <NUM> (e.g., to define a cone angle). As an example, an approach as in <FIG> and/or an approach as in <FIG> may be utilized with a radial flow turbine wheel or a mixed flow turbine wheel.

As shown in the example of <FIG>, increased clearance regions can be defined using the vane height zv. For example, consider a nozzle height zn that can increase to <NUM> to <NUM> times the nozzle height zn of vane open positions less than <NUM> percent open. In the example of <FIG>, the increase in clearance may be due to shape of a lower nozzle surface (e.g., the surface <NUM>, etc.) and/or an upper nozzle surface (e.g., the surface <NUM>, etc.).

Whether clearance is increased on an upper nozzle surface and/or a lower nozzle surface, one or more of a combination of shapes may be utilized to increase clearance.

<FIG> shows a cut-away view of a portion of an assembly <NUM> that includes the vane <NUM>, component <NUM> and <NUM>, and a turbine housing <NUM>. As shown, the component <NUM> and the turbine housing <NUM> can be assembled using one or more seal members <NUM> (e.g., piston rings, etc.). As an example, the component <NUM> may be floating and biased downwardly during operation by a pressure force or it may be biased by a spring force or it may be fit to one or more spacers.

<FIG> also shows an inset view where the vane <NUM> is shown by dashed lines as its position depends on pivot angle. In the example of the inset, the vane can be in a fully open position (e.g., maximum open pivot angle). As shown, the turbine wheel <NUM> can be defined by a turbine wheel radius rw and the trailing edge of the vane <NUM> can be defined by a trailing edge radius rte as in the fully open position. As explained, in a fully open position, the radius rte of the trailing edge of the vane <NUM> can be approximately <NUM> percent to approximately <NUM> percent more than the radius rw of the turbine wheel (e.g., maximum outer radius). As explained, when the vane <NUM> is in a closed position (e.g., vane-to-vane contact, etc.), the radius of the trailing edge rte will be greater than in the fully open position. A range of vane angles that is from closed to fully open can be defined via such radii where an open position, such as <NUM> percent, can be defined as being intermediate the closed position and the fully open position.

In the example of <FIG>, the component <NUM> can be a substantially annular component that defines clearances with respect to the upper surface <NUM> of the vane <NUM>. For example, consider an upper nozzle surface <NUM> that meets a first transition point <NUM> that meets a variable surface region <NUM> that meets a second transition point <NUM>. As shown, the second transition point <NUM> can be at an innermost end of the component <NUM> where the one or more seal members <NUM> can provide for sealing as to exhaust movement from a volute <NUM> to the nozzle or vice versa.

In the example of <FIG>, the turbine housing <NUM> includes a lower surface <NUM> that transitions to a shroud surface <NUM>. The turbine housing <NUM> can also include various annular notch features that can accommodate the component <NUM>. For example, consider cylindrical surfaces <NUM> and <NUM>, which may be separated by an annular recess <NUM> that can provide for positioning and stabilizing the one or more seal members <NUM>. As shown, the cylindrical surface <NUM> can extend to an axial face <NUM>, which may then transition to a surface <NUM> that defines in part the volute <NUM>.

In the example of <FIG>, a region of constant clearance of approximately <NUM> may be increased via a slope (e.g., a conical shape) to a region with a clearance that is at least approximately <NUM>. In the example of <FIG>, a clearance between the upper surface <NUM> of the vane <NUM> and the surface <NUM> of the turbine housing <NUM> may be approximately <NUM>. In such an example, the increased clearance can span in part the component <NUM> and can span in part the turbine housing <NUM>. In such an example, exhaust flow may utilize the additional space (e.g., increased nozzle space, etc.) for some expansion and/or development prior to encountering a turbine wheel. In such an approach, some amount of efficiency may be gained by the increased space.

In the example of <FIG>, the component <NUM> can include a lower nozzle surface <NUM> that meets a first transition point <NUM> that meets a variable surface region <NUM> that meets a second transition point <NUM>. As shown, the second transition point <NUM> can be at an innermost end of the component <NUM>. As shown, the components <NUM> and <NUM> may be shaped differently though providing for an increased clearance for a range of vane open positions. As an example, the assembly <NUM> may include features as to an upper nozzle surface and/or features as to a lower nozzle surface to provide for increased clearance for a range or ranges of vane open positions.

As an example, a cartridge and a turbine housing may be shaped such that upon installation of the cartridge in the turbine housing, contact does not occur between vanes and the turbine housing. For example, rims may contact before contact between vanes and the turbine housing can occur. In such an example, risk of the upper surface <NUM> of the vane <NUM> contacting the surface <NUM> of the turbine housing <NUM> can be reduced. As an example, the component <NUM> may be of an axial height such that the component <NUM> contacts the surface <NUM> before contact between the surface <NUM> and the upper surface <NUM> of the vane <NUM> can occur.

As explained, a cartridge may be axially movable in a turbocharger via one or more spring-like mechanism. Where a shroud surface is positioned on a turbine housing rather than a component such as the component <NUM>, clearance between a turbine wheel and the shroud surface may be more certain during operation.

In the example assembly <NUM>, the component <NUM> may be smaller when compared, for example, to the component <NUM> of <FIG>, which may provide for lesser thermal effects, stresses, etc. Further, in the assembly <NUM>, the shroud contour for the turbine wheel is on the turbine housing and not the component <NUM>. Also, by having the component <NUM> thinner at its inner end compared to its outer end, some thermal effects may be reduced (e.g., consider thermal expansion and contraction due to volume).

<FIG> shows an approximate cutaway view of a portion of an assembly <NUM> during a transient in temperature, where the assembly <NUM> includes the plate component <NUM>, the spacer <NUM> and the annular plate portion <NUM> of the nozzle wall component <NUM>, along with a plot <NUM> of coefficients of thermal expansion (CTE) with respect to temperature.

In the plot <NUM>, a vane materials region and a nozzle wall materials region are approximately shown. For example, a vane can be made of a material that has a higher CTE than a material of a nozzle wall (e.g., upper and/or lower). As a vane is generally made from a higher CTE material and smaller (less volume) than a nozzle wall, the vane will react more rapidly to a change in temperature than a nozzle wall (e.g., the plate component <NUM>, the annular plate portion <NUM>, etc.). As a vane has less mass, it has less thermal capacity so it will heat and cool faster than a nozzle wall(s) even if materials utilized have the same CTE. As such, clearance(s) can be altered, including being reduced. For example, consider a cold clearance (e.g., ambient temperature) of approximately <NUM> and a hot clearance of approximately <NUM>. During transient operation, where vanes can be moving, reduced clearance can lead to control issues (e.g., sticking, binding, etc.); whereas, in a thermal steady state, clearances can be as suitably designed as components can be at steady state temperature distribution. As an example, one or more increased clearances, as explained, can be provided such that dynamic operation under dynamic thermal conditions does not lead to control issues (e.g., sticking, binding, etc.). During dynamic thermal conditions, a temperature transient can be non-uniform as defined about a rotational axis such that individual vanes in a set of vanes can be experiencing different temperatures. Given such spatially non-uniform transient conditions, one or more of the individual vanes may be more likely to stick (e.g., bind) than one or more others, which may also cause uneven (e.g., non-uniform) wear in a turbine assembly. By providing one or more increased clearances, as explained, risk of one or more of the individual vanes sticking (e.g., binding) can be reduced; noting that control issues can arise from sticking (e.g., binding) of a single vane in a set of vanes.

As shown in the portion of the assembly <NUM>, the nozzle space, as defined by the components <NUM> and <NUM>, can become V-shaped due to the thermal gradient between the outer and the inner radius of the components <NUM> and <NUM> along with the spacer <NUM> causing some limitations and due to spring-like support from the heat shield <NUM> pressing at and/or near an inner radius of the component <NUM>. In the example of <FIG>, axial heights zrb at a radius "b" and zra at a radius "a" are shown where, during a temperature transient, zrb is greater than zra hence forming a V-shape in cross-section. Given the tendency to form a V-shape at elevated temperatures, etc., utilization of one or more components that can increase clearance between a nozzle wall and a vane can reduce risk of vane sticking (e.g., binding, etc.). For example, by increasing clearance(s) between a vane and one or more nozzle surfaces near and/or at an inner perimeter of a component or components (e.g., to be more than at or near an outer perimeter) can help to recover consumed CTE-related clearance in transient heating and cooling along with consumed clearance that may be a result of one or more other phenomena (e.g., soot deposition, etc.). Thus, by providing clearance(s), performance may be improved (e.g., controllability, lifespan, etc.).

As to some examples of materials of construction for vanes, consider NI-RESIST (high nickel alloy cast irons), NITRONIC <NUM> (alloy <NUM>, e.g., Cr <NUM>, Mn <NUM>, Ni <NUM>, Si <NUM>, N <NUM>, C <NUM>, Fe balance), <NUM> stainless steel (SS), etc. As to some examples of materials of construction for components that define a nozzle space, consider INCONEL <NUM>, SiMoCr, etc. As explained, a component that defines a nozzle space (e.g., a component that forms a nozzle wall) can be formed with one or more features (e.g., step, slope, etc.) to provide for an increased clearance with respect to a set of vanes when the set of vanes are in an open position (e.g., <NUM>% open or more, etc.).

<FIG> shows another cut-away view of the example assembly <NUM> of <FIG>, without the vane <NUM> and without the one or more seal members <NUM>. As shown in <FIG>, the component <NUM> can include the upper nozzle surface <NUM> as a substantially level portion that defines a constant nozzle height where the surface <NUM> meets a first transition point <NUM> that meets a variable surface region <NUM> that increases nozzle height with respect to decreasing radius that meets a second transition point <NUM> that meets a cylindrical surface <NUM> that can define an inner perimeter of the component <NUM>. As shown, the turbine housing <NUM> can include the surface <NUM> as being positioned at a greater axial height than the second transition point <NUM>. The turbine housing <NUM> can also include a surface <NUM> that meets the shroud surface <NUM> where the surface may define a minimum diameter of the turbine housing <NUM>.

As an example, the component <NUM> may be formed via one or more processes to provide for a change in nozzle height. For example, consider machining where such machining can grind a beveled region into a stock non-beveled surface (see, e.g., the surface <NUM>). As an example, one or more bevels may be imparted such that one or more angles, transitions, etc., are formed.

<FIG> shows another cut-away view of the example assembly <NUM> of <FIG>. In the example of <FIG>, the vane <NUM> can be seen, particularly in relationship to the components <NUM> and <NUM> and the housing <NUM> where a substantial portion of the vane <NUM> has an increased clearance in the open position of the vane <NUM> as shown. As explained, such an approach can reduce risk of binding and/or reduce resistance to exhaust flow when a vane is in an open position that is at or beyond <NUM> percent open.

<FIG> shows a cut-away view of the example assembly <NUM> with the turbine housing <NUM> and the component <NUM>. As an example, one or more features of the cartridge <NUM> of <FIG>, <FIG> may be included in such an assembly.

As an example, a turbine assembly with an increased vane to nozzle clearance for vane open positions greater than or equal to <NUM> percent can provide for an expansion flow pass to reduce shock strength at high pressure ratio (PR), can provide for performance map width extension to increase flow capacity without a change to vane height, can maintain the same performance at a vanes position less than <NUM> percent closed, can lower vane aerodynamic torque (e.g., provide for smaller vane height than end wall height), can reduce risk of vane/nozzle wall friction due to thermal expansion, thermal distortion or combustion residual deposits.

<FIG> shows an example plot <NUM> of trial results for two different assemblies for a given pressure ratio (PR) where one of the assemblies includes an increased clearance for vane open positions of at least <NUM> percent (e.g., increased clearance) and where the other one of the assemblies includes a constant clearance. As shown, the assembly with increased clearance can provide for increased efficiency at higher corrected mass flow (kg/s) compared to the constant clearance assembly. Further, at lower corrected mass flow (e.g., less than approximately <NUM>/s), the two assemblies exhibit the same or similar performance. In such an example, the difference may be defined with respect to a maximum efficiency (e.g., a corrected mass flow that corresponds to a peak efficiency for a particular vanes position).

In the example of <FIG>, the increased clearance example exhibits improved efficiency after a vanes open position of <NUM> percent. In such an example, high end performance is improved without performance difference at the low end. In such an example, high cycle fatigue (HCF) loading can be reduced (e.g., early expansion of flow before the wheel leading edge). As an example, in a fully opened position of vanes, an annular clearance can exist between vane trailing edges and a turbine wheel where such an annular clearance may be defined by a radius of the turbine wheel. For example, such a clearance can be between approximately <NUM> percent and <NUM> percent of the radius of a turbine wheel.

Given the data in the plots <NUM> and <NUM>, a turbocharger turbine assembly may be made with vanes of a lesser vane height while being able to achieve suitable performance at high mass flow rates. By using vanes with a smaller vane height, vane loading may be reduced, which can provide for a reduction in actuation force and hence allow for a smaller actuator (e.g., an actuator with lesser maximum force). As explained, a reduced risk of sticking (e.g., binding) may also provide for a reduction in actuation force and hence allow for a smaller actuator (e.g., an actuator with lesser maximum force).

As an example, a method can include determining a vanes position for a maximum efficiency with respect to corrected mass flow. In such an example, the vanes position can be translated into a radius or diameter as to trailing edges of the vanes. In such an example, a component or components of a cartridge may be machined to provide for increased clearance (e.g., exhaust passage) for vanes position equal to or greater than the vanes position that corresponds to the maximum efficiency.

As explained, vane top and/or bottom clearance in a nozzle can have a detrimental impact on VNT stage performance. Generally, such clearances are maintained as small as possible along an entire vane opening range which increases the risk of vane binding (e.g., sticking) and/or vane to nozzle/pipe friction. Thus, to increase the flow range of a VNT stage, a larger vane height is needed, which, in turn, increases vane loading. With an increased load, a larger actuator is needed to pivot the vanes.

As explained, an assembly can include an increased clearance region for passage of exhaust above and/or below each vane in a nozzle, which can improve high end performance, lower HCF excitation and reduce risk of vane to nozzle wall(s) friction or sticking. By providing an increased clearance as a bypass passage at/near the inner perimeter of a nozzle ring, the performance flow range can be increased while using a smaller vane height for a lower actuation force.

As an example, a method can include machining a stock annular component (e.g., as a hat or flat component) and/or selecting vanes with a smaller height.

As an example, a turbine housing assembly can include a turbine housing that defines a rotational axis for a turbine wheel; and a cartridge receivable by the turbine housing, where the cartridge includes a nozzle wall component with an upper nozzle surface and a plate component with a lower nozzle surface, where the upper nozzle surface and the lower nozzle surface define a nozzle space, and vanes positioned in the nozzle space, where the vanes are pivotable between a closed vanes position of <NUM> percent open and a fully open vanes position of <NUM> percent open, and where, for a vanes position of at least <NUM> percent open and less than <NUM> percent open, an axial dimension of the nozzle space increases with respect to decreasing radius as measured from the rotational axis. In such an example, for a vanes position less than <NUM> percent open, the axial dimension of the nozzle space can be constant.

As an example, an axial dimension of a nozzle space can increase with respect to decreasing radius at a transition radius, where the transition radius is defined by trailing edges of the vanes for a vanes position of at least <NUM> percent open and less than <NUM> percent open. In such an example, the vanes position can correspond to a maximum efficiency with respect to corrected mass flow.

As an example, for a fully open vanes position, an annular clearance can exist with respect to a turbine wheel and trailing edges of vanes, where the annular clearance can be at least <NUM> percent of a radius of the turbine wheel and less than <NUM> percent of the radius of the turbine wheel.

As an example, for a closed vanes position, contact can exist between adjacent vanes. In such an example, the contact can act to limit rotation (e.g., pivoting) of the vanes. As an example, a cartridge, a control linkage, etc., may include one or more features that act as a physical stop that may define a closed vanes position. In such an example, the vanes may be nearly in contact where throats defined between adjacent vanes are small such that the vanes act as barriers to exhaust flow from a volute to a turbine wheel space. In such an example, nearly in contact may be defined via a vane-to-vane clearance (e.g., throat width) of less than approximately <NUM>. A closed vanes position can define a minimum exhaust flow condition for a turbine housing assembly while a fully open position may define a maximum exhaust flow condition for a turbine housing assembly.

As an example, in a turbine housing assembly, an axial dimension of a nozzle space can increase to a constant axial dimension. As an example, an axial dimension of a nozzle space can increase according to a slope and/or a step.

As an example, in a turbine housing assembly, each of a plurality of vanes (e.g., a set of vanes) can have a constant axial vane height between a respective trailing edge and a respective leading edge. For example, consider a slight chamfer at a leading edge and a slight chamfer at a trailing edge where the axial vane height is constant over approximately <NUM> percent or more of a length of the vane.

As an example, a turbine housing assembly can include a component that defines a nozzle space where a surface of the component provides an upper nozzle surface that is sloped and/or can include a component that defines a nozzle space where a surface of the component provides a lower nozzle surface that is sloped.

As an example, a turbine housing assembly can include a component that defines a nozzle space where a surface of the component provides an upper nozzle surface that is stepped and/or can include a component that defines a nozzle space where a surface of the component provides a lower nozzle surface that is stepped.

As an example, a turbine housing assembly can include a component that defines a nozzle space where a surface of the component provides an upper nozzle surface that is sloped and/or stepped and/or can include a component that defines a nozzle space where a surface of the component provides a lower nozzle surface that is sloped and/or stepped.

As an example, a turbine housing assembly can include a turbine housing that includes a shroud surface. In such an example, the shroud surface can define in part a turbine wheel space for a turbine wheel.

As an example, a turbine housing assembly can include a nozzle wall component that includes a shroud surface. In such an example, the shroud surface can define in part a turbine wheel space for a turbine wheel.

Claim 1:
A turbine housing assembly comprising:
a turbine housing (<NUM>, <NUM>) that defines a rotational axis for a turbine wheel (<NUM>); and
a cartridge (<NUM>) receivable by the turbine housing, wherein the cartridge comprises a nozzle wall component (<NUM>) with an upper nozzle surface (<NUM>) and a plate component (<NUM>) with a lower nozzle surface (<NUM>), wherein the upper nozzle surface and the lower nozzle surface define a nozzle space, and vanes (<NUM>) positioned in the nozzle space, wherein the vanes are pivotable between a closed vanes position of <NUM> percent open and a fully open vanes position of <NUM> percent open, and wherein, for a vanes position of at least <NUM> percent open and less than <NUM> percent open, an axial dimension of the nozzle space increases with respect to decreasing radius as measured from the rotational axis, and
wherein, for a vanes position of less than <NUM> percent open, the axial dimension of the nozzle space is constant with respect to decreasing radius as measured from the rotational axis.