turbocharger turbine wheel

Abstract

An exhaust gas turbocharger turbine impeller may include: a hub including a protrusion, a back disk having a shaft joint portion, and a rotational axis; blades extending from the hub to define an exhaust gas flow channel, wherein each of the blades includes a leading edge, a trailing edge, a hub profile, a shroud profile, a pressure side, and a suction side; wherein the back disk includes an outer peripheral radius measured from the rotational axis of the hub, an intermediate radius at the shaft joint portion measured from the rotational axis of the hub, and an annular groove arranged between the intermediate radius and the outer peripheral radius and partially defined by a three-dimensional reinforcement area, wherein each of the three-dimensional reinforcement areas includes a footprint and a height measured at least partially in the direction of the rotational axis of the hub.

Description

Technical Field

[0001] The subject matter disclosed herein generally relates to turbocharger turbine wheels for internal combustion engines. Background Art

[0002] A turbocharger can include a rotating group that includes a turbine wheel and a compressor wheel connected to each other by a shaft. For example, the turbine wheel can be welded or otherwise connected to the shaft to form a shaft and impeller assembly (SWA), and the compressor wheel can be assembled to the free end of the shaft. As an example, a shaft attached to one or more bladed impellers can be supported by one or more bearings disposed in a bearing housing, which can form a center housing rotating assembly (CHRA). During operation of the turbocharger, the shaft can be expected to rotate at speeds exceeding 200,000 rpm, depending on factors such as the size of the various components. To ensure proper rotordynamic performance, the rotating group should be well balanced under a wide range of conditions (e.g., operating, temperature, pressure, etc.). BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The various methods, devices, assemblies, systems, arrangements, and their equivalents described herein may be more completely understood by reference to the following detailed description when considered in conjunction with the examples illustrated in the accompanying drawings, in which:

[0004] Figure 1 It is a diagram of a turbocharger and an internal combustion engine together with the controller;

[0005] Figure 2 is a cross-sectional view of an example of a turbocharger assembly and an end view and a cross-sectional view of an example of a journal bearing;

[0006] Figure 3 is a side view of an example of a turbocharger;

[0007] Figure 4 is a perspective and enlarged view of an example of a shaft and impeller assembly (SWA);

[0008] Figure 5 is an example of a stress diagram for a portion of a turbine wheel;

[0009] Figure 6 An example of a drawing of a three-dimensional reinforcement area of ​​a back disk of a turbine impeller and an example of a drawing of a fillet area;

[0010] Figure 7 is an example of a drawing of a portion of a three-dimensional reinforcement area of ​​a back disk of a turbine wheel;

[0011] Figure 8 is a series of views of an example of a turbine wheel;

[0012] Figure 9 yes Figure 8 a cross-sectional view of a turbine impeller;

[0013] Figure 10 is a projection diagram of an example of a turbine impeller blade having a radial inflow leading edge and a projection diagram of an example of a turbine impeller blade having a mixed flow inflow leading edge;

[0014] Figure 11 yes Figure 9 an enlarged cross-sectional view of a portion of a turbine impeller;

[0015] Figure 12 is a radial coordinate Figure 9 An enlarged cross-sectional view of a portion of a turbine impeller and a cross-sectional view with axial coordinates Figure 9 an enlarged cross-sectional view of a portion of a turbine impeller;

[0016] Figure 13 yes Figure 8 a cross-sectional view of a turbine impeller;

[0017] Figure 14 yes Figure 13 A series of enlarged cross-sectional views of a portion of a turbine wheel;

[0018] Figure 15 is a series of profiles of various examples of turbine impellers;

[0019] Figure 16 is a series of example plots of turbine wheel mass and inertia;

[0020] Figure 17 is a series of example plots of turbine wheel balance notch depth and inertia; and

[0021] Figure 18 is a schematic diagram of examples of a 2D backplate profile and a 3D backplate profile. DETAILED DESCRIPTION

[0022] Hereinafter, an example of a turbocharged engine system is described, and thereafter various examples of components, assemblies, methods, etc. are described.

[0023] Turbochargers are frequently used to increase the output of internal combustion engines. Figure 1 As an example, the system 100 may include an internal combustion engine 110 and a turbocharger 120. Figure 1As shown, the system 100 may be part of a vehicle 101 , where the system 100 is positioned in an engine compartment and connected to an exhaust duct 103 that directs exhaust gas to an exhaust outlet 109 , for example, located behind a passenger compartment 105 . Figure 1 In the example of FIG. 1 , a processing unit 107 may be provided to process the exhaust gas (eg, to reduce emissions via catalytic conversion of molecules, etc.).

[0024] like Figure 1 As shown, internal combustion engine 110 includes an engine block 118 housing one or more combustion chambers that operably drive a shaft 112 (e.g., via pistons), as well as intake ports 114 that provide a flow path for air to flow into engine block 118 and exhaust ports 116 that provide a flow path for exhaust gas from engine block 118.

[0025] The turbocharger 120 can be used to extract energy from the exhaust and provide energy to the intake air, which can be combined with fuel to form combustion gases. Figure 1 As shown, turbocharger 120 includes an air inlet 134, a shaft 122, a compressor housing assembly 124 for a compressor wheel 125, a turbine housing assembly 126 for a turbine wheel 127, another housing assembly 128, and an exhaust outlet 136. Housing assembly 128 may be referred to as a center housing assembly because it is disposed between compressor housing assembly 124 and turbine housing assembly 126.

[0026] exist Figure 1 In the embodiment of the present invention, shaft 122 can be a shaft assembly including various components (e.g., consider a shaft and wheel assembly (SWA) in which turbine wheel 127 is welded to shaft 122, etc.). As an example, shaft 122 can be rotatably supported by a bearing system (e.g., journal bearing(s), rolling element bearing(s), etc.) disposed in housing assembly 128 (e.g., in a bore defined by one or more bore walls), such that rotation of turbine wheel 127 causes rotation of compressor wheel 125 (e.g., due to being rotatably coupled by shaft 122). As an example, a center housing rotating assembly (CHRA) can include compressor wheel 125, turbine wheel 127, shaft 122, housing assembly 128, and various other components (e.g., a compressor side plate disposed axially between compressor wheel 125 and housing assembly 128).

[0027] exist Figure 1In the example of FIG, a variable geometry assembly 129 is shown as being partially disposed between the housing assembly 128 and the housing assembly 126. Such a variable geometry assembly may include vanes or other components to change the geometry of the passage to the turbine wheel space in the turbine housing assembly 126. As an example, a variable geometry compressor assembly may be provided.

[0028] exist Figure 1 In the example shown, a wastegate valve (or simply wastegate) 135 is positioned proximate to the exhaust inlet of the turbine housing assembly 126. Wastegate valve 135 can be controlled to allow at least some exhaust gas from exhaust port 116 to bypass turbine wheel 127. Various wastegates, wastegate components, and the like can be applied to conventional fixed nozzle turbines, fixed vane nozzle turbines, variable nozzle turbines, twin-scroll turbochargers, and the like. As an example, the wastegate can be an internal wastegate (e.g., at least partially within the turbine housing). As an example, the wastegate can be an external wastegate (e.g., operably coupled to a conduit in fluid communication with the turbine housing).

[0029] exist Figure 1 In the example of FIG. 1 , an exhaust gas recirculation (EGR) conduit 115 is also shown, which may be provided optionally with one or more valves 117 , for example to allow exhaust gas to flow to a location upstream of the compressor impeller 125 .

[0030] Figure 1 Also shown are an exemplary arrangement 150 for exhaust gas flow to an exhaust turbine housing assembly 152 and another exemplary arrangement 170 for exhaust gas flow to an exhaust turbine housing assembly 172. In arrangement 150, passages 156 are included within cylinder head 154 to direct exhaust gas from the cylinders to turbine housing assembly 152, while in arrangement 170, manifold 176, for example, provides for mounting turbine housing assembly 172 without requiring any separate intermediate length exhaust ducting. In both exemplary arrangements 150 and 170, turbine housing assemblies 152 and 172 can be configured for use with a wastegate, variable geometry assembly, and the like.

[0031] exist Figure 1In FIG, an example controller 190 is shown as including one or more processors 192, memory 194, and one or more interfaces 196. Such a controller may include circuitry, such as that of an engine control unit (ECU). As described herein, various methods or techniques may optionally be implemented in conjunction with the controller, for example, via control logic. The control logic may depend on one or more engine operating conditions (e.g., turbine rpm, engine rpm, temperature, load, lubricant, cooling, etc.). For example, sensors may transmit information to the controller 190 via the one or more interfaces 196. The control logic may be based on such information, and the controller 190 may output control signals to control engine operation. The controller 190 may be configured to control lubricant flow, temperature, a variable geometry assembly (e.g., a variable geometry compressor or turbine), a wastegate (e.g., via an actuator), an electric motor, or one or more other components associated with the engine, a turbocharger (or multiple turbochargers), and the like. As an example, the turbocharger 120 may include one or more actuators and / or one or more sensors 198, which may be coupled to one or more interfaces 196 of the controller 190, for example. As an example, the wastegate 135 may be controlled by a controller including an actuator responsive to an electrical signal, a pressure signal, etc. As an example, the actuator for the wastegate may be, for example, a mechanical actuator that may operate without requiring electrical power (e.g., considering a mechanical actuator configured to respond to a pressure signal supplied via a conduit).

[0032] Figure 2 An example of a turbocharger assembly 200 is shown including a shaft 220 supported by a journal bearing 230 disposed in a center housing 280 between a compressor wheel 240 and a turbine wheel 260; note that a thrust spacer 270 is shown positioned between the compressor wheel 240 and a shoulder of the shaft 220 relative to a bore in a back plate 290. Figure 2 As shown, the shoulder is formed by a step in the diameter of the shaft 220 from a smaller diameter to a larger diameter, thereby forming an annular axial surface (eg, a compressor side). Figure 2 In the example shown, the thrust spacer 270 abuts the axial surface of the shaft 220 on one side and the annular axial surface of the compressor impeller 240 on the opposite side. The journal bearing 230 is at least partially located in the through-bore of the center housing 280 via a locating pin 210. The locating pin 210 can be secured by being threaded into a socket 285 of the housing 280 and can be received by an aperture 235 of the journal bearing 230 to locate the journal bearing 230 in the through-bore of the center housing 280. As an example, the locating pin 210 can axially and azimuthally locate the journal bearing 230 in the through-bore of the center housing 280.

[0033] As an example, the journal bearing 230 can move radially in the through hole of the center housing 280, for example, the journal bearing 230 can move up and down relative to the axis of the locating pin 210 while being axially and azimuthally constrained by the locating pin 210 (for example, the journal bearing 230 can be a semi-floating journal bearing).

[0034] Figure 2 The turbocharger assembly 200 can be oil-cooled as well as air-cooled, for example by being in an environment with ambient air or vehicle engine compartment air. The turbocharger can be cooled via one or more mechanisms. For example, the turbocharger can be cooled via air, water, oil, or other fluids. There are some trade-offs with regard to lubricant cooling (e.g., oil, whether natural or synthetic, etc.). For example, if a carbonaceous lubricant reaches too high a temperature for too long (e.g., considering a time-temperature relationship), carbonization (e.g., also referred to as coke formation or "coking") may occur. Coking can exacerbate heat generation and heat retention through any of a variety of mechanisms, and over time, coke deposits can shorten the life of the lubricated bearing system. As an example, coke deposits can result in a reduction in heat transfer and an increase in heat generation, which can lead to failure of the bearing system.

[0035] To combat coking, turbochargers can be configured to improve lubricant flow. For example, a pump can pressurize the lubricant to increase flow rate, thereby reducing the lubricant's residence time in high-temperature areas. However, increased lubricant pressure can exacerbate various types of lubricant leakage. For example, increased lubricant pressure in the bearing system can cause lubricant to leak into the exhaust turbine, the air compressor, or both. Escape from the exhaust turbine can result in observable levels of smoke, while escape from the air compressor can cause lubricant to enter the intercooler, combustion chamber (e.g., combustion cylinder), and so on.

[0036] As for the temperatures experienced during operation, they can depend on the temperature of the exhaust gas flowing to the exhaust turbine of the turbocharger, which temperature can depend on whether the internal combustion engine is gasoline-fueled or diesel-fueled; as an example, consider a diesel engine having exhaust gas that can be approximately 860 degrees Celsius, and as an example, consider a gasoline engine having exhaust gas that can be approximately 1050 degrees Celsius. Thus, a turbocharger in communication with the exhaust fluid of an internal combustion engine fueled by gasoline can experience higher temperatures when compared to an internal combustion engine fueled by diesel. Further, consider Figure 1 The arrangements 150 and 170 , in which the turbine housing assemblies 152 and 172 are in close proximity to the combustion cylinders, may cause the turbine housing assemblies 152 and 172 to experience higher exhaust temperatures and / or higher ambient temperatures.

[0037] Figure 3 An example of a turbocharger 300 is shown including a compressor assembly 340 having a compressor housing for a compressor impeller, a turbine assembly 360 having a turbine housing for a turbine impeller, a center housing 380 for bearings, a bearing or bearing assembly for a shaft rotatably supporting a shaft and impeller assembly (SWA), and an actuator 350 having a connecting rod 354 to a control arm assembly 358 for a wastegate of the turbine assembly 360. The turbocharger 300 can include Figure 2 One or more of the components shown. Figure 2 In the view of FIG, the exhaust inlet of the turbine assembly 360 is not visible because it is on the opposite side. The general direction of flow of air or exhaust is shown by arrows. The actuator 350 is shown as being mounted to the compressor assembly 340, which can help reduce the temperature experienced by the actuator 350 (e.g., compared to mounting the actuator to the turbine housing). The turbocharger 300 can be a vehicle (such as, for example, Figure 1 As an example, the turbine assembly 360 may be optionally arranged in a vehicle such as Figure 1 In one of the exemplary arrangements 150 or 170 .

[0038] Figure 4 A perspective view of a shaft and wheel assembly (SWA) 400 is shown. As shown, SWA 400 includes a shaft 420, a seal portion 440, and a turbine wheel 460, wherein turbine wheel 460 includes a nose 470, a back disk 480, and blades 490. Turbine wheel 460 can be a single, unitary piece of material and referred to as a single component or single piece. A portion of turbine wheel 460 can be referred to as a hub. For example, back disk 480 can be a portion of the hub from which blades 490 extend. The hub can include back disk 480 and the nose and extend the length of the turbine wheel, as shown by an axial length ztw measured along the z-axis of rotation of SWA 400.

[0039] As an example, the sealing portion 440 can be formed partially by the turbine wheel 460 and partially by the shaft 420, can be formed by the shaft 420, or can be formed by the turbine wheel 460. As an example, the sealing portion 440 can be formed at least partially by the shaft 420. The sealing portion 440 can be defined by an outer radius, which can be referred to as a parameter Rshaft, which is a ratio of Figure 4 The radius of the outer surface 451 of the shaft joint portion 450 is a smaller radius.

[0040] like Figure 4As shown, the SWA can include a shoulder 452 (or stepped back) from the turbine wheel 460 toward the shaft 420. For example, Figure 4 , shoulder 452 tapers from outer surface 451 of shaft coupling portion 450 at radius Rsjp to outer surface 455, which can be at a radius equal to or approximately equal to the radius of sealing portion 440. As shown, shaft coupling portion 450 can include surface 453, which is an annular axial surface that can form a portion of shoulder 452.

[0041] As an example, the shaft joint portion 450 can include a shaft joint surface that can be at least partially defined by a shaft joint radius. For example, consider a shaft joint surface that can be used to join a shaft (e.g., via welding, etc.) to a turbine wheel (e.g., see Figure 8 Surface 457 of the turbine wheel shaft joint surface. In such an example, the turbine wheel shaft joint surface can be a mating surface that mates with the turbine wheel shaft joint surface, wherein the two surfaces can be brought into close or direct contact and joined (e.g., via welding). As an example, the shaft joint surface can be an annular surface that can be welded to a surface of the shaft to form a SWA.

[0042] The SWA 400 can include dimensions such as, for example, an axial dimension for a compressor wheel portion zc, which may include one or more pilot surfaces, a set of threads, etc., and a bearing portion zj, which may include one or more journal surfaces (e.g., a compressor-side journal surface and a turbine-side journal surface, etc.).

[0043] like Figure 4 As shown, the sealing portion 440 can include one or more annular grooves that can be configured to receive one or more sealing elements (e.g., one or more sealing rings). As shown, the sealing portion 440 can be defined in part by an axial dimension zsp. As an example, the sealing element can be a split ring, such as a piston ring. As mentioned, the SWA can be formed by welding a shaft to a turbine wheel, such that the resulting SWA has the shaft and turbine wheel arranged and fixed along a common axis of rotation.

[0044] Figure 4 An enlarged perspective view of a portion of the SWA 400 is shown, wherein the backplate minimum outer peripheral diameter Dbp is indicated. min (For example, as an inscribed circle) and the size of the sealing portion diameter Dsp. As shown in the figure, the minimum outer diameter of the back plate Dbp min Exceeds the sealing portion diameter Dsp. For example, consider Dbp min Greater than twice Dsp.

[0045] As an example, a turbine wheel may be defined using a diameter, which may be a circle that inscribes a feature of the turbine wheel. For example, where the turbine wheel includes an odd number of blades, a line cannot be drawn from the leading edge of one blade to the leading edge of another blade as the diameter. In such an example, the diameter can be defined via a circle that inscribes the leading edges of the blades or, for example, is exactly twice the radius. The turbine wheel may be defined by an inducer diameter (e.g., associated with exhaust gas inflow) and an exducer diameter (e.g., associated with exhaust gas outflow). As an example, the inducer diameter may exceed the exducer diameter. As an example, the edge of a turbine wheel may be defined by using its inducer diameter and its exducer diameter. When referring to a diameter, it may refer to the diameter of a circle that can be drawn relative to a feature of the turbine wheel.

[0046] As shown, the back disk 480 can be a sector-shaped back disk such that there is a scallop between adjacent connection areas where each blade 490 is joined to the back disk 480. As an example, the connection area can extend radially outward from the back disk 480 beyond the diameter Dbp. min The sector may be a radially inwardly curved region that may coincide with the axial lower boundary of the passage defined between two adjacent blades. As an example, the sector may be defined in a cylindrical coordinate system that includes axial, radial, and azimuthal coordinates (e.g., r, z, and As an example, the sectors of the backing disc can have the same shape. For example, in the case of a turbine wheel comprising eleven blades, the turbine wheel can comprise eleven channels and eleven sectors, wherein the blades have a common size, the channels have a common size, and the sectors have a common size.

[0047] As an example, the balancing process can alter one or more dimensions of the turbine wheel, for example, through material removal. For example, consider removing material from protrusion 470 of turbine wheel 460 of SWA 400. As shown, protrusion 470 has an outer diameter that is smaller than the outer diameter of back disk 480. Another option is to remove material from back disk 480; however, back disk 480 supports blades 490. If material is removed from back disk 480, one or more issues may arise regarding the mechanical support of blades 480 and / or the overall integrity of turbine wheel 460 during operation. As an example, material can be removed from shaft joint portion 450 (e.g., at one or more of surfaces 451 and 453). In such an example, the material removal can minimize the impact on back disk 480's ability to support blades 490.

[0048] Balancing that relies on removing material from protrusions can be limited in practice due to the radius from the axis of rotation at which the material is removed. For example, where a larger radius is available for balancing, less material can be removed to achieve the same balancing effect as removing more material at a smaller radius; noting that aerodynamic, mechanical and / or thermal phenomena can affect one or more of the balance, integrity, performance, etc. of the turbine wheel and, therefore, the turbocharger. With respect to using a shaft joint portion to remove material for balancing, the effect can depend on the shape and / or size of the shaft joint portion. For example, a larger radius shaft joint portion can provide the ability to help reduce the amount of material to be removed to achieve acceptable balancing compared to a smaller radius shaft joint portion. However, a larger radius shaft joint portion can increase the mass of the turbine wheel, which may be undesirable in various circumstances.

[0049] For balancing, there are various techniques, which may include component balancing techniques and assembly balancing techniques. For example, consider balancing a turbine wheel as a component, or balancing a SWA or balancing a rotating assembly in the case where a compressor wheel is assembled to a SWA. Generally speaking, balancing is performed (e.g., using a balancing device, etc.) to achieve the desired operating specifications. As an example, balancing may include one or more of the following: balancing the inside of the turbine wheel, balancing the outside of the turbine wheel, balancing the inside of the compressor wheel, balancing the outside of the compressor wheel, assembling the rotating group into a rotor assembly, check balancing the rotor assembly and balancing one or more sides of the compressor wheel and / or one or more sides of the turbine wheel, assembling the center housing rotating assembly (CHRA), and performing final balancing using a high-speed balancing machine. Generally speaking, balancing involves material removal, which, as mentioned above, may be the material of the turbine wheel, wherein material may be removed from one or more portions of the turbine wheel.

[0050] Turbine wheels can be designed to account for one or more issues associated with balancing material, which is material that can be removed to adequately balance the turbine wheel. During design, a decision can be made as to where to locate balancing material that can provide a sufficient amount of balancing capacity (BC). Balancing material can be located at one or more locations, such as a protrusion, a backing disc, or at a shaft joint (e.g., adjacent to the backing disc). Protrusions can serve various purposes in design, one or more of which may limit the scope of the design. As mentioned, the backing disc supports the blades, so removing material from the backing disc at or near its periphery is limited by constraints (e.g., stress, integrity, etc.). In various examples herein, the turbine wheel can include features that provide for material removal for balancing, optionally while satisfying constraints (e.g., stress, integrity, etc.), optionally while also reducing polar inertia.

[0051] As explained herein, turbine polar inertia represents the resistance to rotational acceleration of a turbocharger, which can be a cause of the so-called turbo effect. To reduce the turbo effect, a smaller turbine wheel can be provided, for example, exhibiting less polar inertia. Such a turbine wheel can provide increased responsiveness, making it more agile and exhibiting less response lag during transients. While a smaller size (e.g., maximum diameter) can reduce polar inertia, turbine wheel size can be a specification of the turbocharger to meet one or more performance targets. Where a maximum diameter is specified (e.g., for a rim, housing, etc.), one or more approaches can be taken to provide improved polar inertia while providing sufficient material for balancing (e.g., balancing stock) and while meeting stress and / or integrity standards.

[0052] As explained herein, a method of turbine wheel design can be directed to optimizing size and balancing capability (BC). For example, the method can provide a specially designed backing disk for a turbine wheel that is directed to include balancing material concentrated on a relatively small diameter where the turbine wheel can significantly reduce the turbine wheel polar inertia.

[0053] As explained, because the turbine wheel will operate under severe conditions (e.g., high temperature, high speed, etc.), it must be able to perform from a structural integrity perspective while also providing adequate balancing capacity (BC); however, an increase in BC can increase the turbine wheel weight and its polar inertia.

[0054] The various turbine wheels described in the examples herein are shaped to provide more optimized polar inertia (e.g., less turbine effect) while also providing adequate integrity (e.g., stress handling capabilities, etc.). In various examples, integrity is enhanced by a three-dimensional backing plate design, wherein the backing plate includes shaped elements positioned to strengthen the backing plate. By way of example, such shaped elements, when included, may be referred to as three-dimensional bolster regions (e.g., 3D bolster regions).

[0055] like Figure 4 As shown in the example of FIG, the exhaust gas turbocharger turbine wheel 460 may include: a hub 465 including a protrusion 475, a back disk 480, a shaft joint portion 450 (e.g., as part of the back disk 480), and an axis of rotation (z-axis); blades 490 extending from the hub 465 to define an exhaust gas flow path, wherein each blade 490 includes a leading edge, a trailing edge, a hub profile, a shroud profile, a pressure side, and a suction side; wherein the back disk 480 includes an outer peripheral radius measured from the axis of rotation of the hub 465 (e.g., see Dbp minor Dbp max ), an intermediate radius at the periphery of the shaft joint portion 450 measured from the axis of rotation of the hub 465 (see, for example, radius Rsjp at surface 451), and an annular groove 483 disposed between the intermediate radius and the peripheral radius and defined in part by three-dimensional reinforcement areas 485, wherein each three-dimensional reinforcement area 485 includes a footprint and a height measured at least partially in the direction of the axis of rotation of the hub 465. For example, in the case of Figure 4 In the case where the axis of rotation is the z-axis, the height of the three-dimensional reinforced region 485 can be measured at least in part as the difference between two z-coordinates (e.g., if z=0.05 and z=0.07, the height can be 0.02). As an example, the height can be measured in the direction of a normal to the footprint (which can be a projected footprint). For example, consider a footprint projected onto a surface that is substantially identical to the back disk surface surrounding the three-dimensional reinforced region. In such an example, a normal can be defined and the height of the three-dimensional reinforced region can be measured along the normal. As an example, the balancing process can optionally include removing material, which results in a reduction in the height of the corresponding three-dimensional reinforced region. As an example, material can be removed from one or more portions of the turbine wheel. For example, material can be removed from a protrusion, a back disk portion, and / or multiple back disk portions, where the back disk portion can include a shaft joint portion.

[0056] As for the shaft joint portion 450, it is shown as being substantially cylindrical at surfaces 451 and 455. As an example, the back disk 480 can be defined as a lower portion of the hub 465 that includes at least a portion of the shaft joint portion 450 and extends outward from a radius of surface 455 to the maximum periphery of the back disk 480 (see, for example, Dbp max ).

[0057] As explained, the shaft joint portion 450 can incorporate the sealing portion 440, which can be an integral part of the shaft 420. As an example, the sealing portion 440 can be welded to the shaft joint portion 450 to form a welded joint that will permanently join the shaft 420 and the turbine wheel 460 to form a shaft and wheel assembly (SWA).

[0058] refer to Figure 2 , the sealing portion is shown as being part of the shaft 220 and being coupled to the turbine wheel 260 to form the SWA. The sealing portion can include Figure 2One or more annular grooves are shown, in which one or more corresponding sealing elements (e.g., sealing rings) can be at least partially disposed to form one or more seals between the lubricant region of the center housing 280 and the exhaust region where the turbine wheel 260 is disposed. As shown, the center housing 280 includes a turbine side bore in which the sealing portion and seal are disposed. The bore includes a bore wall in which the seal can contact the bore wall (e.g., consider a piston ring as a split ring that can be compressed during installation and expand once installed to form a seal).

[0059] like Figure 2 As shown, the turbine impeller 260 has a 2D back disk that includes a flat annular portion and a profile that transitions from the flat annular portion to the shaft joint portion. As shown, the 2D back disk of the turbine impeller 260 transitions from a large diameter to a small diameter and is performed without an annular groove or with an annular groove having a z, - A 2D profile in a plane that is constant from 0 to 360 degrees around the axis of rotation of the turbine wheel 260. The turbine wheel 260 does not include a 3D reinforcement area that would make the back disk of the turbine wheel 260 three-dimensional (e.g., not representable by a single cross-sectional profile). Figure 2 In the embodiment, the shaft 220 and its sealing portion have a diameter that is smaller than the maximum outer diameter of the turbine wheel 260. Generally, the shaft or the sealing portion do not have a diameter that is equal to or greater than the maximum outer diameter of the turbine wheel because this approach would result in the shaft and sealing portion having a relatively large mass compared to a smaller diameter shaft and a smaller diameter sealing portion. Figure 2 As shown, the SWA can be defined as generally stepping down in diameter from right to left; note that some variation can exist between the journals and necks, and between the guides and necks. For example, shaft 220 includes a turbine-side journal, a compressor-side journal, and a neck therebetween. Further, shaft 220 includes two guides along the compressor wheel portion, with a neck therebetween. As an example, a shaft can include one or more necks, which can be intended to reduce the mass of the shaft.

[0060] As an example, the shaft can be made of the same material as the turbine wheel or a different material than the turbine wheel. In the case of different materials, the materials are generally capable of being welded so that a SWA can be formed. As mentioned, the compressor wheel can be made of a material having a lower specific gravity than the material of the turbine wheel. Generally speaking, the compressor wheel experiences a lower operating temperature than the operating temperature of the turbine wheel. Figure 2In the embodiment, the rotating assembly may include a shaft 220 and a turbine wheel 260 as a SWA and a compressor wheel 240 and a nut (e.g., for a compressor wheel with a through hole). As an example, a so-called holeless compressor wheel may be used, where the compressor wheel can be coupled to the shaft without the use of an end nut. Figure 2 Because bearing 230 is positioned by locating pin 210, bearing 230 does not rotate or rotates minimally (e.g., a few degrees). As an example, a thrust collar may be included as part of a turbocharger and located between the bearing and the compressor wheel. Such a thrust collar may be configured to rotate, which may provide lubricant slinging (e.g., to help reduce lubricant flow from the center housing space to the compressor wheel space). As an example, the bearing may be a journal bearing or a rolling element bearing. A rolling element bearing may include rolling elements (e.g., rollers, balls, etc.) and an outer raceway and, optionally, an inner raceway.

[0061] The rotating assembly may have a mass that is determined by and defined by the individual masses of the components comprising the rotating assembly. The rotating assembly may be positioned in the turbocharger under the influence of gravity. For example, a journal surface of a shaft may rest against a journal surface of one or more bearings. During a start-up phase of operation, lubricant may be pumped into the center housing and result in a certain amount of hydraulic support, which may lift the rotating assembly. As mentioned, the flow of exhaust gas to an exhaust turbine disposed in a turbine housing may be the driver for causing the rotating assembly to rotate, wherein mass and other factors may determine how much exhaust gas must flow before rotation begins.

[0062] The speed of the rotor blades of the turbine wheel has an impact on the power produced by the turbine assembly and therefore the power produced by the turbocharger. One factor that affects the dynamics of the turbine is the polar inertia of the rotating components (e.g., SWA, compressor wheel, etc.). The polar inertia can limit the rate of change of the rotating components during transients in the operation of the internal combustion engine. The polar inertia can therefore affect the so-called "drivability" of a vehicle with a turbocharged internal combustion engine. Most of the polar inertia of the rotating components is found in the turbine wheel, which is made of a material that tends to be heavier (e.g., denser or with a greater specific gravity) than the material of the compressor wheel, for example in order to provide a higher level of temperature resistance. As an example, the turbine wheel can be made of a nickel alloy. For example, consider a NiCrFe based alloy (e.g., HASTALLOY TM Materials, INCONEL TM materials, etc.) or other alloys. In contrast, the compressor impeller can be made of a lighter material such as, for example, aluminum or an aluminum alloy. The turbine impeller material can have a specific gravity that is twice or more that of aluminum (for INCONEL TM625 material, approximately 2.7 versus approximately 8.4). Thus, turbine wheels, etc. may be selected, designed, or the like as a result of one or more trade-offs between factors that may include performance, inertia, operating life, and durability.

[0063] Trade-offs can be made between efficiency and inertia, including moving towards low inertia at lower efficiency.Operational life and durability in a hot gas environment can also place limits on various factors (such as blade shape) that may result in less aerodynamic efficiency.

[0064] As mentioned, polar inertia can be a drag on turbocharger rotational acceleration and the cause of the so-called "turbo effect." Therefore, in various applications (e.g., vehicles, etc.), a relatively small turbine wheel polar inertia (I0) is desirable in order to improve turbocharger transient response.

[0065] Various turbine wheel backing plates can be described as 2D because -The cross-section in the plane is constant about the z-axis of rotation. For example, the back disk can be defined by a 2D planar solid of revolution (or solid of revolution). Note that on such a solid of revolution, the blade is a 3D shape. A 2D back disk allows for focus on a single profile sufficient to meet various objectives (e.g., quality, performance, machinability, integrity, etc.). Such an approach does not necessarily consider blades that define a channel for the exhaust flow. The blade can be defined as having a pressure side and a suction side, where the pressure side can be generally concave and the suction side can be generally convex. During operation, the forces experienced by the blade (e.g., forces on the respective sides, etc.) can be transferred to the back disk. Therefore, when the blade encounters the back disk (such as within the inducer section), the forces can differ between the pressure side and the suction side. For the channel, these are areas where the blade is not attached to the back disk. The channel area may require less support than the area where the blade is attached to the back disk. For example, in the channel region, the 3D back disk can be scalloped radially inwardly so that the minimum outer radius of the 3D back disk exists in the channel region; and the maximum radius of the 3D back disk exists in the region where the blades join the 3D back disk. While scalloping can reduce mass, there are other considerations that can impose some limits on the amount of scalloping.

[0066] As an example, a 3D turbine wheel backing disc may include a material region that can improve integrity while being optionally machined for balancing (e.g., as balancing stock). Such a material region may be referred to as a reinforcement region. As an example, the reinforcement region may be formed to have a predetermined shape. For example, consider a reinforcement region formed to have a shape that may be defined by a footprint and a volume. As an example, the footprint may be approximately circular, oval, elliptical, etc. The footprint may be defined as, for example, r, -projection in a plane; noting that the footprint can include variations in the z-direction. As an example, a reinforced region can be formed to have a shape similar to a droplet of liquid (e.g., a viscous liquid) on a surface, where the droplet has a shape formed by an energy balance (e.g., taking into account surface tension). As an example, a reinforced region can be defined in part by a diameter and a height. For example, consider a reinforced region having a footprint defined by a diameter and a volume defined by a curve rising from the perimeter of the footprint to a maximum height. As an example, such a curve can be defined by a mathematical equation. As an example, a reinforced region can be defined by multiple curves rising from the perimeter of the footprint to a common height at a point in the reinforced region.

[0067] As an example, a reinforced region can be defined by a radius from the turbine wheel's axis of rotation (e.g., the z-axis). As an example, a turbine wheel can have a 3D backing disk with a scalloped region and a reinforced region. Such a turbine wheel can be a reduced-mass turbine wheel having a relatively low polar inertia.

[0068] As mentioned, the turbine wheel is capable of operating under severe conditions, such as high temperatures, high rotational speeds, exhaust flow transients, etc. Therefore, the turbine wheel must be capable from a structural integrity perspective, and the turbine wheel must also provide a required level of balancing capability (BC).

[0069] Balancing capacity (BC) has an impact on turbine wheel mass and I0. An increase in BC can increase turbine wheel mass and I0. Balancing of the turbine wheel can provide balancing of the turbine wheel itself and / or one or more components of the SWA (e.g., a shaft) and / or one or more components assembled on the SWA (e.g., a compressor wheel, one or more races of a bearing, a nut, etc.). Again, balancing is required because the rotating assembly can be expected to rotate at speeds exceeding 100,000 rpm or even exceeding 200,000 rpm. The balancing process can be performed relative to a balancing device or a balancing machine. The balancing process can include measuring the imbalance and removing material, which can be performed iteratively until a desired level of balance (e.g., minimum imbalance) is achieved.

[0070] For a turbine wheel, the decision about where to locate balancing stock (eg, extra material that may be cut away during the balancing process) that provides an adequate level of BC is a decision that involves other factors that may affect various turbine performance parameters.

[0071] For example, a turbine wheel may include a material for the BC that is contained within the radius of the turbine wheel axis, which can provide a relatively thin backplate (e.g., at larger radii) and reduce polar inertia. However, reducing the backplate thickness toward manufacturing limits can result in overheating and centrifugal stresses (e.g., due to backplate bending) at or near its outer diameter. Therefore, the ability to reduce the backplate thickness is often limited for reasons of turbine wheel integrity, stress, durability, etc.

[0072] As explained, a turbine wheel can include 3D reinforcement regions (e.g., 3D shaped elements) shaped, sized, and positioned to strengthen the turbine wheel's back disk. Such reinforcement regions can be positioned in otherwise high-stress areas of a "thin" back disk, where such high-stress areas can be near the back disk's outer diameter. Such an approach can optionally allow for further back disk thickness reduction through the use of reinforcement regions, which can maximize the turbine wheel's BC at smaller radii. Such an approach can also be designed to provide a reduction in polar inertia (e.g., a reduction in I0).

[0073] As an example, "smart" 3D backplate reinforcement regions (e.g., stiffening regions) can be precisely located at high stress areas, for example, to increase backplate stiffness where it is particularly needed to support turbine wheel durability, without significantly increasing turbine wheel mass or turbine wheel polar inertia; noting that an overall reduction in turbine wheel mass and / or turbine wheel polar inertia can be achieved because the reinforcement region approach can allow for a thinner backplate with less mass. Such a 3D backplate reinforcement region approach can improve turbine wheel performance, and therefore turbocharger performance, compared to turbine wheels that rely on axisymmetric 2D approaches for reinforcement.

[0074] With respect to considerations related to mass, size (eg, radius), balancing capacity (BC), and polar inertia (I0), exemplary equations 1, 2, 3, and 4 are as follows:

[0075] BC = mass * radius (1)

[0076] I0 = mass * radius * radius (2)

[0077] I0=BC*radius(3)

[0078] I0 / BC=radius(4).

[0079] As shown in the equations above, I0 is proportional to the square of the radius (Equation 2); however, BC is proportional to the radius (Equation 1). Therefore, an I0-BC trade-off can exist. For example, consider the curves in the form of Equation 3 or Equation 4. It is apparent that I0 for a given BC is smaller if placed at a smaller radius. As an example, a turbine wheel may include a backing disk, where a range of radii may exist for the material that contributes to BC. A BC accommodated close to the turbine wheel's axis of rotation may allow for a relatively thin backing disk with a low I0. However, as mentioned, the gradual reduction in backing disk thickness towards manufacturing limits can lead to overheating and centrifugal stresses (e.g., due to backing disk bending) at its outer diameter, and must be limited due to turbine wheel durability. In some examples, a turbine wheel can be designed to improve polar inertia without including reinforced regions; however, where stresses approach the limits, in various examples, the turbine wheel can be designed with reinforced regions located at high stress points, which can be identified through testing, numerical simulation, or the like without the reinforced regions. For example, a turbine wheel backing disk design can be achieved by determining the appropriate size and shape without a reinforced area, identifying high stress points and comparing them to acceptable limits, and based on this comparison, determining whether and / or where to position a reinforced area to improve the integrity of the turbine wheel. Once the location is determined, additional parameters regarding the size, shape, etc. of the reinforced area can be determined and the appropriate turbine wheel manufactured.

[0080] As an example, a back disk of a turbine wheel can include a reinforcement region formed as a 3D shaped element, where such an element can be positioned, sized, and shaped to help strengthen the turbine wheel at other high stress areas, which are often near the outer perimeter of the back disk. Such an approach can, for example, provide further thickness reduction and then provide maximum utilization of BC for I0 reduction on relatively small radius turbine wheels.

[0081] As an example, a turbine wheel may include a 3D back disk having reinforcement provided by a plurality of reinforced regions of material positioned at high stress areas. In such an example, there may be a stiffness increase limited to areas where the stiffness increase is beneficial in supporting turbine wheel durability, with no or limited increase in turbine wheel mass and / or I0 when compared to an axisymmetric 2D back disk reinforcement approach.

[0082] Figure 5An example of a stress diagram 500 is shown as generated using a finite element model of a turbine wheel having a backing disk 480, wherein the backing disk 480 does not include a 3D reinforcement region. The backing disk 480 includes individual regions where individual blades join the backing disk 480, referred to as blade joining regions (e.g., or extensions), and regions between the blade joining regions, referred to as channel regions. Figure 5 As shown in the example of FIG. 5 , the maximum stress is at a radius that is smaller than the maximum radius of the outer perimeter of the blade junction area and smaller than the minimum radius of the outer perimeter of the channel area, which radius may be the minimum radius defined by the sector. As shown in stress graph 500 , the high stress contour extends from the maximum stress toward the perimeter of the back disk 480 in a direction toward the channel area rather than toward the blade junction area. The maximum stress point shown in stress graph 500 is also relative to Figure 5 The pressure and suction sides of the blades 490 are shown offset; note that the curved arrows show the direction of rotation. Specifically, the maximum stress point is from the axis of rotation of the turbine wheel (z-axis) and where the blades 490 are connected to the back disk 480 (rl b ) are offset toward the suction side of the blade 490 (which is away from the pressure side of the blade 490).

[0083] Figure 6 Example plots 610 and 630 are shown regarding features that may be included in a 3D backplate. Specifically, plot 610 shows a 3D reinforcement region 485 positioned at Figure 5 In plot 610, the 3D reinforcement region 485 can be defined, for example, with respect to a cylindrical coordinate system, which is shown with z BSR Axis, r BSR Axis and azimuth BSR As shown in the figure, the shape radius R BSR , axial shape height Z BSR and an azimuth span from 0 degrees to 360 degrees defines a 3D reinforcement region 485 .

[0084] exist Figure 6 , the 3D reinforced region 485 extends outward in the z-direction relative to the axis of rotation of the turbine wheel 460 in a manner elevated above the maximum stress point. The 3D reinforced region 485 has a droplet shape (e.g., like a droplet on a surface) having a perimeter defining a footprint and an elevation or height that can be compared to a backplate without the 3D reinforced region 485. As an example, the 3D reinforced region 485 can be defined as a portion of a 3D body (e.g., a portion of a sphere, a portion of a spheroid, a portion of an ellipsoid, etc.).

[0085] With respect to plot 630, fillet regions 487 are shown, which exist around the perimeter of 3D reinforcement region 485 and can be defined, for example, using the cylindrical coordinate system shown in plot 610 (e.g., a local cylindrical coordinate system that is local to the individual 3D reinforcement regions). Fillet regions 487 can provide a smooth transition between the surface of backing disc 480 and 3D reinforcement region 485. For example, fillet regions 487 can be transition regions shaped to serve one or more purposes, such as, for example, reducing corners, reducing aerodynamic drag, reducing the effects of material removal, reducing stress, reducing thermal gradients, and the like. With respect to corners, consider a 3D reinforcement region shaped such that it forms corners at its perimeter. In such an example, the fillet regions can provide a smooth transition between the surface of the backing disc and the 3D reinforcement region to reduce or eliminate corners at the perimeter (e.g., for improved stress, improved aerodynamics, etc.).

[0086] As an example, the 3D reinforcement area can be shaped to have a rounded corner area. As an example, the rounded corner area can be a relatively annular area that spans a distance from the perimeter of the shape defined at the 3D reinforcement area. For example, consider the distance from the inner radius to the outer radius r. FR The distance spans from approximately 0.5 mm to approximately 10 mm. Figure 6 In the example of FIG. 4 , the rounded area 487 at its widest point may be 100 mm from the defined Figure 6 The shape of the 3D reinforcement area 485 shown in FIG has a perimeter of about 2 mm to about 6 mm. As shown, the rounded area 487 can change the shape of the perimeter. For example, Figure 6 The perimeter shown in FIG is oval in shape without the rounded corner regions 487, and with the rounded corner regions 487, the perimeter is substantially elliptical in shape because there is a deviation near the scallop of the back disc 480. As mentioned, the rounded corner regions can provide one or more of stress reduction, erosion reduction, aerodynamic drag reduction, thermal effect reduction, etc.

[0087] Figure 7 Shown Figure 6 610 of the 3D reinforcement area 485 of the outline. As shown, the outline can be defined by various dimensions, including, for example, along the axis r BSR Shape radius R BSR and along the axis z BSR Shape height or shape altitude Z BSR The height of the shape (Z BSR ) can be measured at least partially in the same direction as the axis of rotation of the turbine wheel. Figure 7In FIG, the dashed line represents a line parallel to the z-axis (eg, the axis of rotation of the turbine wheel). Figure 7 As shown in the figure, the shape height (Z BSR ) includes components that can be measured about the dashed line.

[0088] exist Figure 7 In the example of FIG, various points are shown, where the form height or form elevation can be a maximum form height or form elevation located at or near a maximum stress point, which can be determined using one or more techniques such as, for example, finite element modeling. As mentioned, adding material at specific locations on the back tray can provide one or more benefits, which may include reduced stress.

[0089] Figure 8 An exemplary turbine wheel 460 is shown in plan view from the nose end, side view, and plan view from the back disk end. The plan view from the nose end includes line AA, where Figure 9 A cross-sectional profile along line AA is shown.

[0090] Figure 8 Shown is marked D max The size of , which is the maximum diameter of the turbine wheel 460, as defined by the circle shown with a dotted line spaced at two points. max The circle consists of N circles with radius r max , one for each of blades 490-1 to 490-N (note that r max is with R max different parameters). Figure 8 In the example, N is equal to eleven. Figure 8 Also shown is labeled Δzbp min The dimension of is the axial dimension at the radial position. For example, Figure 4 Shown is the minimum diameter Dbp of the outer circumference of the back plate min The diameter of Figure 8 The back disk 480 may include an axial dimension Δzbp at a particular diameter or radius. min , which can be in diameter Dbp min At or slightly inset from this. Size Δzbp min It can be the minimum thickness of the back tray 480 .

[0091] Figure 8Also shown is a shaft joint portion 450 having a shoulder 452 and surfaces 453, 455, and 457. As shown, surface 457 may be a surface that is a mating surface of shaft joint portion 450 for coupling the shaft to a turbine wheel 460. As mentioned, the outer diameter of shaft joint portion 450 at surface 455 may be approximately equal to the outer diameter of a seal portion (e.g., see seal portion 440).

[0092] As mentioned, the minimum diameter or minimum radius of the outer periphery of the backing disk can correspond to a sector of the turbine wheel. The turbine wheel can be asymmetric, including an odd number of blades, such that the minimum radius may not correspond to the minimum diameter (as represented by the line). For example, consider a plurality of sectors, each having a defined radius, wherein a cutting plane through the turbine wheel does not intersect two sectors in the same manner, such that the minimum diameter may be greater than twice the defined radius. As an example, where the turbine wheel includes sectors, each sector may include a common radius. As an example, the sectors may include a plurality of sectors each having a defined radius. Figure 8 The area at the radius shown by the dashed circle in a plane viewed from the back-disk end of the turbine wheel. As an example, a sector can be defined by a radius that can span an azimuth angle about the axis of rotation of the turbine wheel. For example, consider a turbine wheel having a certain number of blades N, where the sector can be defined by an angle less than 360 degrees divided by N. Figure 8 In the example of , N is equal to eleven, and for each sector (as may be partially defined by a portion of an inscribed circle), the angle is approximately 16 degrees. Figure 8 In the figure, the angle φ is shown. s , which can be the azimuth span angle of the sector part.

[0093] As an example, a turbine wheel back disk may be defined by a portion extending radially beyond a radius or diameter. Figure 8 In FIG. 4 , the back disk of the turbine wheel 460 may be defined in part by an inscribed circle and a portion extending radially outward beyond the radius of the inscribed circle. Figure 8 As shown, the number of radially outwardly extending portions is equal to the number of blades, and each of these portions corresponds to one of the blades. Such an approach can be used, for example, for blade support at or near the leading edge of the blade where the blade intersects the back disk. Figure 8 As shown, the dot-dash circle inscribes eleven extensions and defines the maximum radius or maximum diameter Dbp of the back plate. max .

[0094] like Figure 8 As shown, with Dbp min The circle and Dbp maxThere is a difference between the circles, where such a difference can be represented as an annular area comprising a number of extensions equal to the number of blades.

[0095] for Figure 8 Each of the 3D reinforcement regions 485 shown in the example turbine wheel 460 is primarily located within the inscribed dashed circle (Dbp min ). As an example, the centroid of a 3D reinforced region of a back disk of a turbine wheel can be radially inward of a circle inscribing a sector of the back disk. For example, a 3D reinforced region formed of a material (e.g., the material of the turbine wheel itself) can be defined via a geometric centroid that is the center of mass of the 3D reinforced region. As an example, a back disk of a turbine wheel can include 3D reinforced regions, wherein each 3D reinforced region can be defined by a geometric centroid, wherein the geometric centroid can be at an azimuth angle about the rotational axis of the turbine wheel and at a radius measured from the rotational axis of the turbine wheel. As an example, the back disk can be defined in part by the angle from the geometric centroid of multiple 3D reinforced regions to the geometric centroid. In such an example, the angle can be approximately 360 degrees divided by the number of blades. For example, for eleven blades, the angle can be approximately 32.7 degrees. In the case where the back plate includes a sector-shaped region and an extension portion, the angle spanned by the sector-shaped region may be approximately half of the angle obtained by dividing 360 degrees by the number of blades, and the angle spanned by the extension portion may be approximately half of the angle obtained by dividing 360 degrees by the number of blades. Figure 8 In the example backing disk 480 of turbine wheel 460, there are eleven blades, wherein each sector spans approximately 16.3 degrees, and wherein each extension spans approximately 16.3 degrees, wherein the leading edges of the blades are spaced approximately 32.7 degrees apart where they intersect the backing disk, and wherein the 3D reinforcement regions are spaced approximately 32.7 degrees apart (e.g., from center of mass to center of mass). As shown, there is a transition region between each extension and the corresponding sector.

[0096] Although the number of blades is used as a reference in various examples, the number of 3D reinforcement regions may be less than, equal to, or greater than the number of blades. For example, it is contemplated that multiple 3D reinforcement regions may be positioned at less than all identified maximum stress points, or at all identified maximum stress points and at one or more other identified stress points (e.g., submaximal stress points, etc.).

[0097] like Figure 9As shown in the example of FIG. 4 , turbine wheel 460 includes various blade features, such as a leading edge 491 (or inducer edge), a trailing edge 499 (or extractor edge), a back point 492 of leading edge 491, a tip point 493 of leading edge 491, a hub point 494 of trailing edge 499, and a tip point 495 of trailing edge 499. As shown, turbine wheel 460 has a maximum blade outer diameter at tip point 493 of leading edge 491 (e.g., inducer edge); another blade outer diameter at tip point 495 of trailing edge 499 (e.g., extractor edge); and a minimum blade diameter at hub point 494 at trailing edge 499 (e.g., extractor edge).

[0098] Figure 9 Also shown are various features of shaft joint portion 450 , including surfaces 451 , 453 , 455 , and 457 , with shoulder 455 defined as a step down from surface 451 to surface 455 (eg, from a radius of surface 451 to a smaller radius of surface 455 ).

[0099] like Figure 9 As shown in the example of FIG, the dashed line represents the hub profile of the blade 490 - 5 , while the solid line 498 represents at least a portion of the shroud profile of the blade 490 - 5 .

[0100] like Figure 9 , crosshairs mark the radial and axial positions of points associated with the 3D reinforcement region 485 as partially defining the annular groove 483. The distance between the lowest points on the outer circumference of the backing disc 480 is shown relative to the hub profile 496 and is represented as Δzsm.

[0101] like Figure 9 As shown in the example of FIG, the backing disc 480 includes a profile that defines and forms an annular groove 483, wherein the 3D reinforcement area 485 defines a portion of the surface of the annular groove 483. Again, the crosshairs are marked at locations along the hub profile 496 of the blade 490-5.

[0102] Figure 10 A plan view of an example of a blade 490 is shown, and Figure 9 Various points and contours described. Figure 10 Also shown are arrows indicating the intended direction of exhaust gas flow from leading edge 491 to trailing edge 499, where two adjacent blades define a flow path for the exhaust gas (e.g., an exhaust gas flow path). As mentioned, one side of the blade can be defined as the pressure side, while the opposite side of the blade can be defined as the suction side. Figure 10 The plan view of is a projection view so that the concave and convex shapes of the blade 490 are not visible. Figure 10, blade 490 can be defined with respect to radial and axial coordinates. As an example, a polar angle plot can be used to provide additional information defining blade 490. For example, consider a plot of the wrap angle along an camber line. As an example, blade 490 can be defined using one or more equations, parameters, etc., of an airfoil or impeller.

[0103] As an example, the turbine wheel may be a radial inflow turbine wheel or may be a mixed flow turbine wheel, wherein an angle may define at least a portion of the leading edge such that the incoming exhaust gas has both a radial component and an axial component. Figure 10 An example of a mixed flow turbine wheel blade 1090 is shown where the leading edge 1091 is at an angle other than 90 degrees relative to the r-axis and at an angle other than 0 degrees relative to the z-axis. As an example, the turbine wheel blades may or may not be radially stacked.

[0104] Figure 11 Show Figure 9 The various features herein may relate to and may include r, z, and The coordinates are described in terms of the cylindrical coordinate system.

[0105] Figure 12 Show Figure 9 The various features herein can relate to the turbine wheel 460 and can include r, z and The coordinate system is used to describe the Figure 12 , the first view includes various features that can be described with respect to radial coordinates, and the second view includes various features that can be described with respect to axial coordinates.

[0106] Figure 12 The view of FIG. 4 illustrates an annular groove 483 and a 3D reinforcement region 485 of a backing disc 480, wherein the backing disc 480 includes the shaft joint portion 450. The backing disc 480 may be at least partially defined by a radius r1 and a radius r6 (as measured from the z-axis of rotation of the turbine wheel 460). As shown, the contour of the annular groove 483 (illustrated by the bold line) extends radially from r1 to r6, wherein the 3D reinforcement region 485 spans from r3 to r5 and includes r4, which may be the center of mass (e.g., geometric center of mass) and / or a point corresponding to the maximum stress point of the turbine wheel 460 without the 3D reinforcement region 485. As can be appreciated, in the cross-sectional view, the 3D reinforcement region 485 is disposed behind the cutting plane, illustrated by the diagonal lines. The contour of the annular groove 483 may vary, for example, it may vary at an azimuth angle that coincides with a portion of the 3D reinforcement region 485. Furthermore, the contour of the annular groove 483 may be different, for example, where it corresponds to a sector-shaped area of ​​the back plate 480. Figure 12, radius r1 is the radius of surface 451 of shaft joint portion 450, wherein an annular corner may be formed between surfaces 451 and 453. As mentioned, shaft joint portion 450 of backing plate 480 may provide balancing material because material may be removed from shaft joint portion 450 to balance the turbine wheel or an assembly including the turbine wheel.

[0107] like Figure 12 As shown, the z coordinates include: z1, which is the lowest z coordinate of the outer perimeter of the backing disk 480 corresponding to the blade bonding area; z2, which is the z coordinate of an area of ​​the turbine wheel 460 radially inward from the annular groove 483 (e.g., corresponding to the surface 453); z3, which is the z coordinate of a sector-shaped area (e.g., a channel area) of the backing disk 480; z4, which is the z coordinate of the point where the backing disk 480 bends upward at the outer perimeter of the blade bonding area 485; z5, which is the z coordinate of the lowest point of the perimeter of the 3D reinforcement area 485; z6, which is the z coordinate of the center of mass of the 3D reinforcement area 485; z7, which is the z coordinate of the highest point of the perimeter of the 3D reinforcement area 485; z8, which is the z coordinate of the highest point of the annular groove 483; and z9, which is the point above the center of mass of the 3D reinforcement area 485 along the hub profile 496. As shown, the backing disk 480 can be defined by a thickness, labeled Th, which can vary with respect to radius and, for example, azimuth. exist Figure 12 In the example shown, the thickness Th may vary differently for cross sections throughout the 3D reinforced region 485 .

[0108] exist Figure 12 The radius is marked as Th-z min The thickness of the turbine wheel 460 is Th-z, and represents the minimum thickness measured in the axial direction about the z-axis (being the axis of rotation of the turbine wheel 460). As an example, for a turbine wheel having an outer blade diameter (e.g., as an inscribed circle) of approximately 39 mm, Th-z min It may be at a radius of approximately 15.5 mm (eg, a diameter of approximately 31 mm) and may be less than approximately 1 mm (eg, considering 0.75 mm).

[0109] As an example, a back disk of a turbine wheel including a 3D reinforcement region may be thinner at various portions than a back disk without the 3D reinforcement region. For example, the annular groove region of the back disk may be defined by a lower surface (back disk side) closer to an upper surface (blade side or protrusion side), wherein the thickness of the back disk is defined by the axial dimension therebetween (e.g., see Figure 18 ).

[0110] Figure 13 Shown Figure 9 An enlarged view of a cross-sectional view of a turbine wheel 460, which is Figure 11Specifically, Figure 13 A cross-sectional view of FIG. 48 is through one of the 3D reinforcement areas 485 - 1 , which can be seen via an outward ridge in the back tray 480 , where the ridge enters the groove 483 . Figure 13 Another adjacent 3D reinforcement area 485-2 is also shown. Thus, the back plate 480 includes multiple 3D reinforcement areas. Figure 13 In the example, you can include r, z and The cylindrical coordinate system of coordinates is used to describe various features.

[0111] Figure 13 The E-plane and Z-plane are also shown. The E-plane is indicated by a thick line and can be used as a baseline for sizing and measuring during manufacturing. In some cases, it can be where the location for material removal during balancing can be defined. The Z-plane is the baseline for blade aerodynamic design. It can be a plane perpendicular to the axis passing through the theoretical intersection of the hub and blade leading edge profiles (indicated by the point inside the circle).

[0112] Figure 14 Shown Figure 13 485 . As shown, recess 483 is partially defined by 3D reinforced region 485 and partially defined by surface 451, which can be a relatively cylindrical surface (e.g., having a relatively constant radius across the axial extent). By way of example, the shape of surface 451 can vary from relatively cylindrical, e.g., considering a surface in which the radius increases with respect to the axial dimension such that the surface is relatively conical. By way of example, surface 451 can be used as balancing stock that can be cut away to remove material from turbine wheel 460 for balancing turbine wheel 460 and / or a component including turbine wheel 460.

[0113] exist Figure 14 In this example, the 3D reinforcement region 485 can be defined, for example, by various geometric shapes, such as a line or plane, an ellipse, or an ellipsoid. For example, the ellipsoid can intersect a plane, where the plane can be a tangent plane to the backing disc. In such an example, the plane can be a portion of a cone, for example, considering a cone that can approximate the lower surface of the backing disc 480 without the 3D reinforcement region 485. In such an example, the 3D reinforcement region can be approximately a portion of the ellipsoid, where the portion of the cone cuts through the entire ellipsoid. Figure 14 An inset diagram showing a portion of a cone cutting an ellipsoid.

[0114] An ellipsoid is a quadratic surface that can be defined as the zero set of a quadratic polynomial in three variables. Among quadratic surfaces, an ellipsoid is characterized by either of the following two properties: 1. An ellipsoid can be bounded, meaning that it can be enclosed in a sufficiently large sphere.

[0115] An ellipsoid consists of three paired perpendicular axes of symmetry that intersect at their center of symmetry, called the ellipsoid's center. Line segments separated by the ellipsoid's axes of symmetry are called the ellipsoid's major axes, or simply axes. If these three axes have different lengths, the ellipsoid is considered triaxial or, more rarely, anisometric, and the axes are uniquely defined.

[0116] If two of the axes have the same length, the ellipsoid is a spheroid of revolution, also known as a spheroid of revolution. If the third axis is shorter, the ellipsoid is an oblate spheroid; if it is longer, it is a prolate spheroid. If the three axes have the same length, the ellipsoid is a sphere. As an example, the 3D reinforcement area can be an ellipsoid cap or can be approximately an ellipsoid cap (for example, an ellipsoid cut by a surface, which can be a plane surface, a conical surface (see for example) Figure 14 )wait.

[0117] An ellipsoid can be defined in Cartesian coordinates with axes a, b, and c by the following equation: 2 / a 2 + y 2 / b 2 +z 2 / c 2 = 1. As an example, a three-dimensional reinforced region may be defined or approximated by such an equation. For example, while the equation may define a closed surface having a volume greater than the volume of the three-dimensional reinforced region, a portion of the closed surface may define or approximate the three-dimensional reinforced region, for example, before material is removed from the three-dimensional reinforced region to balance a turbine wheel of a turbocharger.

[0118] Figure 15 A series of profiles of an example turbine wheel are shown, showing various radii, including Rmax values ​​of 15.7, 12.0, 10, 8.8 and 7.95 and Rshaft value of 5.95. For Rmax, it can be as follows Figure 4 The parameter Rsjp shown (see also Figure 9451 in the backing disc 480). Rmax may represent the maximum radius of available balancing material provided by the shaft joint portion 450 of the backing disc 480 of the turbine wheel 460; while another parameter, Rmin, may represent the minimum radius of available balancing material provided by the shaft joint portion 450 of the backing disc 480 of the turbine wheel 460. For example, a method may include balancing the turbine wheel and / or a component including the turbine wheel by removing material from the balancing material at one or more radii within Rmax and Rmin.

[0119] Figure 15 Rmax in can also be expressed as Figure 12 The r1 parameter is compared with the r1 parameter, which is the distance from the rotation axis of the back plate 480 to the groove 483 (see also Figure 12 For an Rmax value of 15.7, the groove, if present, is minimal (e.g., surface 451 of shaft joint portion 450 may not be present because surface 453 may extend to the periphery of the back disk); and for an Rmax value of 7.95, the groove is the largest of the series of profiles shown (e.g., the minimum value of Rsjp).

[0120] As explained, the backing disc can provide a material that is a balancing material that contributes to the turbine wheel's BC. When the backing disc is able to provide more material at smaller radii, it can provide a lower polar inertia overall while still providing sufficient BC. Furthermore, depending on the thickness of the backing disc at larger radii (e.g., along a portion defining a groove), the thinness of the backing disc may or may not warrant the inclusion of a reinforced region. As an example, a turbine wheel can include a backing disc shape that provides sufficient BC, improved polar inertia, and sufficient integrity. Such a turbine wheel can include a reinforced region, which can allow for a thinner portion of the backing disc and improved polar inertia.

[0121] exist Figure 15 In an example, a turbine wheel may include a fan diameter of approximately 31.4 mm, a blade hub outer diameter of approximately 33.54 mm, a blade tip maximum diameter of approximately 39.05 mm, an Rshaft radius of approximately 5.95 mm, and an Rbackdisk radius of approximately 15.70 mm. For example, Rmax=15.7 may correspond to a turbine wheel in which Rmax is approximately Rbackdisk (e.g., with no or minimal grooves). For other examples, the Rmax value may be expressed in millimeters (e.g., 12 mm, 10 mm, 8.8 mm, 7.9 mm, etc.).

[0122] Figure 16Example plots 1610 and 1630 are shown in which turbine wheel mass and inertia are plotted against relative radius. The relative radius may be defined as r = (Rmax - Rshaft) / (Rbackdisk - Rshaft), where Rbackdisk may be, for example, the minimum outer radius (e.g., Figure 4 and Figure 8 0.5*Dbp min ), where the back plate includes a sector-shaped area. As shown in the figure, the reduction of Rmax from 15.7 mm to 10 mm (r = 0.4) reduces I0 and also reduces the mass (see for example Figure 15 and Rmax = 10.0); however, further reduction in relative radius provides no additional I0 benefit and begins to increase turbine wheel mass. Such a plot can be used to design a turbine wheel with a desired polar inertia and a desired mass.

[0123] Figure 17 Exemplary plots 1710 and 1730 are shown, in which the equilibrium notch depth and inertia of a turbine wheel are plotted against relative radius (e.g., compared to a maximum I0 value at a maximum radius Rmax). As shown in exemplary plots 1710 and 1730, a decrease in relative radius below approximately 0.4 (e.g., r<0.4) provides an increase in the equilibrium notch depth, which is why further radius reduction becomes ineffective from an I0 perspective.

[0124] As explained, Figure 15 Five examples of turbine impeller backing disc variants with different maximum BC radii (Rmax) are shown for a portion of the backing disc (e.g., the shaft joint portion) that can accommodate radial material removal (e.g., to provide adequate balancing capacity). Centrifugal thermal stress finite element analysis (FEA) was used to design and optimize the examples to provide comparable BC and durability. The examples utilize INCONEL 713LC as the material of construction. As explained, variants with Rmax values ​​of 10 mm (e.g., the outer radius of the balancing material) and less can be equipped with 3D disc reinforcements, which can serve as reinforced areas. For examples with larger Rmax values, 3D reinforcements are optional, as stress modeling results (FEA results) indicate that stresses are within acceptable limits.

[0125] exist Figure 15For the example, balancing simulations (e.g., 83mm grinding wheel, 150-degree sector) were performed to avoid grinding wheel collision with the turbine wheel and provide comparable BC for all variants. For the variant with an Rmax of 15.7 mm, a U-shaped balancing cut was utilized, as it reached the turbine wheel sector diameter; however, for the other variants, an L-shaped balancing cut was utilized. FEA results included a 2D disc variant with an Rmax of 10 mm and no 3D reinforcements to demonstrate the principles and benefits of using reinforced areas for reinforcement. As mentioned, 3D-shaped elements (e.g., reinforcements or reinforcements) can be intentionally positioned at other high-stress points, both angularly and radially, to strengthen the turbine wheel back disc.

[0126] As an example, a turbine wheel may include a back disk defined by a relative radius, where the relative radius r may be defined as r = (Rmax - Rshaft) / (Rbackdisk - Rshaft). Figure 15 The radius is shown measured from the axis of rotation of the turbine wheel. Figure 4 A shaft joint portion 450 is shown, which may be defined in part by a radius such as Rmax (see, for example, Rsjp). For example, consider Figure 15 A variant in which Rmax is equal to 7.95. Figure 12 Also shown is a radius r1 , which may correspond to Rmax (see, for example, a variant with Rmax equal to 10.0 and a variant with Rmax equal to 12.0).

[0127] As explained, since balancing can be achieved by removing a smaller amount of mass at a larger radius, balancing stock tends to be located at a radius close to the outer diameter of the backing disk of the turbine wheel. For example, consider a 2D profile backing disk thickness that is thick enough near the periphery so that a portion of the turbine wheel material can be ground away using grinding so that the thickness remains sufficient to meet standards. Such an approach does not adequately account for the polar inertia of the turbine wheel. As explained herein, balancing stock can be located at a smaller diameter (e.g., a smaller radius) and provide a smaller polar inertia. Such an approach is able to account for the fact that inertia is proportional to the square of the radius (I0 = mass * radius 2 ).

[0128] The various examples of turbine impellers described herein may involve an I0-BC trade-off, which can be characterized by one or more plots (e.g., curves, functions, etc.). As an example, consider equations of the form I0 = BC * radius or I0 / BC = radius. As explained, the inertia of a given BC is lower at smaller radii (e.g., BC = mass * radius). As an example, for a particular turbine impeller, a range of radii can be determined using various equations (e.g., optionally including FEA) to improve inertia with or without the inclusion of reinforcement regions. As mentioned, accommodating the BC closer to the turbine impeller's axis of rotation can allow for a relatively thinner backing disc at larger radii, which can itself reduce turbine impeller inertia. However, as mentioned, a gradual reduction in backing disc thickness toward manufacturing limitations can lead to overheating and centrifugal (e.g., due to disc bending) stresses at its outer diameter, making thinning prohibitive due to turbine impeller durability. Given this consideration, as explained, 3D-shaped elements, known as reinforcement regions, can be included to strengthen the backing disc at high-stress areas. Such an approach can allow for further thickness reduction and then maximize the use of BC on small radius concepts for I0 reduction. A so-called "smart" approach to 3D disk reinforcement precisely located at high stress areas can involve stiffening where needed to support turbine wheel durability, optionally without increasing turbine wheel mass and inertia (e.g., the presence of the reinforced area is offset by a reduction in overall mass). Thus, the various examples of turbine wheels described herein improve performance when compared to an axisymmetric 2D reinforced turbine wheel.

[0129] Figure 18 An example of a 3D back-disk profile in relation to a 2D back-disk profile is shown, where the 3D back-disk profile allows for a reduction in mass and polar inertia. As an example, the 3D back-disk profile can modify stresses in a beneficial manner. As explained, high stresses can be reduced by positioning 3D reinforcement regions at high stress points (e.g., as determined via FEA). As an example, the resulting 3D back-disk profile, through the introduction of 3D reinforcement regions, can increase the BC and durability of a turbine wheel.

[0130] like Figure 18As shown in the example of FIG, the exhaust turbocharger turbine wheel 460 may include: a hub 465 including a protrusion 475, a back disk 480, a shaft joint portion 450 (e.g., as part of the back disk 480), and a rotation axis (z-axis); blades 490 extending from the hub 465 to define an exhaust flow path, wherein each blade 490 includes a leading edge 491, a trailing edge 499, a hub profile 496, a shroud profile 498, a pressure side, and a suction side; wherein the back disk 480 includes an outer peripheral radius (rbd) measured from the rotation axis of the hub 465, a mid-radius (rbd) at the outer periphery of the shaft joint portion 450 measured from the rotation axis of the hub 465, and a rotation axis. int ) and is set at the middle radius (rbd int ) and the outer radius (rbd) and is partially defined by three-dimensional reinforcement areas 485, wherein each three-dimensional reinforcement area 485 includes a footprint and a height measured at least partially in the direction of the axis of rotation of the hub 465. As shown, the turbine wheel 460 can be part of a SWA, wherein a shaft can be coupled thereto (e.g., see seal portion 440). As explained with respect to various examples, the intermediate radius (rbd int ) can be at the outer radius (e.g. 0.5*Dbp depending on the presence or absence of sectors max or 0.5* Dbp min ) and the axis of rotation of the turbine wheel (e.g., the z-axis). The mid-radius (rbd int ) can be, for example, half the diameter of the surface 451 such as Figure 15 Rmax, Figure 4 Rsjp or Figure 12 . While surface 451 is shown as being relatively cylindrical with a relatively constant radius, it may have a different shape in which the radius may vary (e.g., sloping radially outward from where it joins surface 453). As an example, a turbine wheel including one or more balancing cuts may include a shaft joint portion that is distorted by the one or more balancing cuts such that the profile of the shaft joint portion cannot be represented by a single 2D profile. For example, consider starting with a cylinder having an annular corner defined by surfaces 451 and 453, where, at equilibrium, one or more portions of the annular corner may be cut away, or surface 451 may be cut away, and / or surface 453 may be cut away. Such one or more cuts may be located at one or more corresponding specific azimuth angles.

[0131] As mentioned, a 3D reinforcement region can be a 3D shaped element, where multiple such elements can be used to form a 3D back-disc profile that can strengthen the turbine wheel at high stress areas while providing a reduction in inertia and a reduction in mass compared to a 2D back-disc profile. As shown in Table 1 below, a 3.8% reduction in inertia and a 1.6 g mass reduction were achieved.

[0132] Table 1

[0133] plate Rmax Rmin depth r EZ quality <![CDATA[I0]]> <![CDATA[I0 difference]]> mm mm mm mm mm g <![CDATA[kg.mm 2 ]]> % 3D 10.00 6.48 1.17 0.415 0.07 57.95 4.574 0.0 2D 10.00 6.48 1.17 0.415 0.55 59.59 4.750 3.8

[0134] In Table 1, Rmax is the outer (maximum) radius of the balancing stock, Rmin is the minimum radius of the balancing stock, depth is the depth of the balancing cutout, r is the relative outer radius of the balancing stock (see Equation 5 below), and EZ is the distance between the turbine wheel's E-plane and Z-plane. As shown, the 3D method can reduce the distance between the E-plane and the Z-plane. Equation 5 below defines the parameter r in Table 1.

[0135] r=(Rmax-Rshaft) / (Rbackdisk-Rshaft) (5)

[0136] For Rshaft in Equation 5, Figure 4 The diameter Dsp is shown, which may be the diameter corresponding to Rshaft (see, for example, seal portion 440). The data in Table 1 relates to a particular 3D back disk, where other 3D back disks may differ in terms of mass and / or inertia reduction compared to their 2D back disk counterparts. As an example, a 3D back disk may be used in a radial turbine impeller or in a mixed flow turbine impeller (see, for example, Figure 10 Due to the smaller Rmax value, one or more benefits may be greater on a mixed flow turbine impeller compared to a radial flow turbine impeller.

[0137] Using centrifugal thermal stress finite element analysis (FEA), various backplate variants with varying BC, maximum radius, and so on were tested. The tests were performed using a construction material with the composition and properties of INCONEL 713LC. Variants with Rmax equal to 10 mm (outer radius of the balanced material) and less were equipped with 3D backplate reinforcement; note that such 3D reinforcement is not required for variants with larger Rmax values.

[0138] For balancing simulations, the test included an 83 mm grinding wheel with a 150-degree sector. Balancing was performed to avoid collisions between the grinding wheel and the turbine wheel, providing comparable BC for all variants. The backing disc variant with Rmax = 15.7 mm utilized a U-shaped balancing cutout, as it reached the turbine wheel backing disc sector diameter, while the other variants utilized an L-shaped balancing cutout. A 2D backing disc variant with Rmax = 10 mm and no 3D reinforcement was designed to demonstrate the principles and advantages. Table 2 below shows the various parameters and results.

[0139] Table 2 Example parameters and results.

[0140] plate Rmax Rmin depth r EZ quality <![CDATA[I0]]> <![CDATA[I0 difference]]> mm mm mm mm mm g <![CDATA[kg.mm 2 ]]> % 3D 7.95 6.30 4.60 0.205 3.6 59.01 4.539 13.6 3D 8.80 6.30 2.30 0.292 1.30 58.26 4.537 13.6 3D 10.00 6.48 1.17 0.415 0.07 57.95 4.574 12.9 3D 12.00 6.80 0.60 0.621 0.10 60.02 4.831 8.0 3D 15.70 11.00 0.40 1.00 0.40 62.18 5.253 0.0

[0141] As in Table 1, in Table 2, Rmax is the outer (maximum) radius of the balancing stock, Rmin is the minimum radius of the balancing stock, depth is the depth of the balancing cutout, r is the relative outer radius of the balancing stock (see Equation 5), and EZ is the distance between the turbine wheel E-plane and the Z-plane.

[0142] As an example, an exhaust gas turbocharger turbine wheel may include: a hub including a projection, a backing disc having a shaft joint portion, and an axis of rotation; blades extending from the hub to define an exhaust gas flow channel, wherein each blade includes a leading edge, a trailing edge, a hub profile, a shroud profile, a pressure side, and a suction side; wherein the backing disc includes an outer peripheral radius measured from the axis of rotation of the hub, an intermediate radius measured from the axis of rotation of the hub at the periphery of the shaft joint portion, and an annular groove disposed between the intermediate radius and the outer peripheral radius and partially defined by a three-dimensional reinforcement region, wherein each three-dimensional reinforcement region includes a footprint and a height measured at least partially in the direction of the axis of rotation of the hub. As Figure 13 As shown, the 3D reinforcement regions 485-1 and 485-2 each include a height that can be measured at least partially in the direction of the axis of rotation of the hub (shown as the z-axis). For example, the height can be measured in a direction from the nose to the base of the turbine wheel 460. Figure 14 In the example of , the height can be measured as an axis of the ellipse, which can be the minor axis (e.g., a semi-minor axis, another portion of the minor axis, etc.) Figure 14 The view can be included in Figure 13 The component measured in the direction of the z-axis.

[0143] As an example, an exhaust gas turbocharger turbine wheel may include a shaft joint portion including a shaft joint surface including a shaft joint radius, wherein the backing disc has a relative radius less than 0.5 and greater than 0.2, wherein the relative radius is defined as the difference between a median radius at an outer periphery of the shaft joint portion and the shaft joint radius divided by the difference between an outer periphery radius of the backing disc and the shaft joint radius.

[0144] As an example, an exhaust gas turbocharger turbine wheel may include a balancing cutout in a shaft joint portion. As an example, the turbine wheel may include at least one three-dimensionally reinforced region including the balancing cutout. The balancing cutout may be formed, for example, using a cutting tool that can drill, cut, grind, ablate, or the like to remove material from a backing plate or the like.

[0145] As an example, the exhaust gas turbocharger turbine wheel may be a radial inflow exhaust gas turbocharger turbine wheel, or the exhaust gas turbocharger turbine wheel may be a mixed flow inflow exhaust gas turbocharger turbine wheel, for example.

[0146] As an example, an exhaust gas turbocharger turbine wheel may include a back disk including sector-shaped regions. For example, consider a back disk including blade integration regions, wherein each sector-shaped region is disposed between two of the blade integration regions.

[0147] As an example, an exhaust gas turbocharger turbine wheel may include a three-dimensional reinforcement region having a footprint, wherein the footprint may be defined by a closed curvilinear perimeter.

[0148] As an example, an exhaust gas turbocharger turbine wheel may include three-dimensional reinforced regions, wherein each three-dimensional reinforced region comprises a droplet shape. Such droplet shapes may be defined, for example, using the Young-Laplace equation for wettability of a droplet on a material surface, as used in surface tension analysis (e.g., where wettability is present).

[0149] As an example, an exhaust gas turbocharger turbine wheel may comprise three-dimensional reinforcement regions, wherein each three-dimensional reinforcement region comprises a corresponding rounded corner region.

[0150] As an example, an exhaust gas turbocharger turbine wheel can include a three-dimensional reinforcement region, wherein each three-dimensional reinforcement region encompasses a geometric centroid. For example, consider each geometric centroid as being offset from a corresponding blade interface region of a backing disk toward a suction side of a corresponding one of the blades of the exhaust gas turbocharger turbine wheel.

[0151] As an example, an exhaust gas turbocharger turbine wheel may include at least five three-dimensionally reinforced regions. As an example, an exhaust gas turbocharger turbine wheel may include fewer than thirty-one three-dimensionally reinforced regions. In such an example, this number may correspond to one three-dimensionally reinforced region in an area that may be defined by two adjacent blades (e.g., one three-dimensionally reinforced region per inter-blade area of ​​the backing disk).

[0152] As an example, a method may include: providing an exhaust gas turbocharger turbine wheel comprising: a hub including a protrusion, a backing disk having a shaft joint portion, and an axis of rotation; blades extending from the hub to define an exhaust gas flow path, wherein each blade includes a leading edge, a trailing edge, a hub profile, a shroud profile, a pressure side, and a suction side; wherein the backing disk includes an outer peripheral radius measured from the axis of rotation of the hub, an intermediate radius at the outer periphery of the shaft joint portion measured from the axis of rotation of the hub, and an annular groove disposed between the intermediate radius and the outer peripheral radius and partially defined by a three-dimensional reinforcement region, wherein each three-dimensional reinforcement region includes a footprint and a height measured at least partially in the direction of the axis of rotation of the hub, removing material from the shaft joint portion to form a balanced exhaust gas turbocharger turbine wheel; and installing the balanced exhaust gas turbocharger turbine wheel in the turbocharger. As mentioned, the process for removing material may utilize one or more removal tools, which may provide for drilling, cutting, grinding, ablating, etc., of material from the turbine wheel. For example, a drill can drill materials with a drill bit, a cutting tool can cut materials with a cutting blade, a grinder can grind materials with a grinding head, a laser can ablate materials with a laser beam (such as laser or light ablation), and a power tool can ablate materials with electrical energy and / or magnetic energy (such as electron beam ablation, etc.).

[0153] As an example, a method may include operating a turbocharger by flowing exhaust gas from an internal combustion engine to the turbocharger to rotate a balanced exhaust turbocharger turbine wheel. For example, the above-described method of removing material may provide a balanced exhaust turbocharger turbine wheel that may be used to pressurize intake air of the internal combustion engine using the exhaust gas of the internal combustion engine.

[0154] While certain examples of methods, apparatus, systems, arrangements, and the like have been illustrated in the drawings and described in the foregoing detailed description, it will be understood that the disclosed exemplary embodiments are not limiting and are capable of various rearrangements, modifications, and substitutions.

Claims

1. An exhaust gas turbocharger turbine impeller comprising: a hub including a projection, a backing plate having a shaft joint portion, and an axis of rotation; blades extending from the hub to define an exhaust flow path, wherein each of the blades includes a leading edge, a trailing edge, a hub profile, a shroud profile, a pressure side, and a suction side; wherein the back disk comprises an outer peripheral radius measured from the rotational axis of the hub, an intermediate radius at the outer periphery of the shaft joint portion measured from the rotational axis of the hub, and an annular groove arranged between the intermediate radius and the outer peripheral radius, the annular groove being axially recessed relative to the outer periphery of the back disk in the direction of the blade and being partially defined by a plurality of discrete three-dimensional reinforcement areas, wherein each of the three-dimensional reinforcement areas comprises an outward protrusion in the back disk, wherein the protrusion enters the annular groove, and wherein each of the three-dimensional reinforcement areas comprises a coverage area and a height measured at least partially in the direction of the rotational axis of the hub.

2. The exhaust gas turbocharger turbine wheel according to claim 1, wherein: The shaft joint portion includes a shaft joint surface, the shaft joint surface includes a shaft joint radius, wherein the back disk includes a relative radius less than 0.5 and greater than 0.2, wherein the relative radius is defined as the difference between the intermediate radius at the outer periphery of the shaft joint portion and the shaft joint radius divided by the difference between the outer periphery radius and the shaft joint radius.

3. The exhaust gas turbocharger turbine wheel according to claim 1, wherein: The exhaust gas turbocharger turbine wheel is a radial inflow exhaust gas turbocharger turbine wheel.

4. The exhaust gas turbocharger turbine wheel according to claim 1, wherein: The exhaust gas turbocharger turbine wheel is a mixed flow inflow type exhaust gas turbocharger turbine wheel.

5. The exhaust gas turbocharger turbine wheel according to claim 1, wherein: The back plate includes a sector-shaped area.

6. The exhaust gas turbocharger turbine wheel according to claim 5, wherein: The back plate includes a blade bonding area, and each of the sector areas is disposed between two of the blade bonding areas.

7. The exhaust gas turbocharger turbine wheel according to claim 1, wherein: The coverage area includes a closed curve perimeter.

8. The exhaust gas turbocharger turbine wheel according to claim 1, wherein Each of the three-dimensional reinforced regions has a general droplet shape similar to that of a liquid drop on a surface formed by surface tension.

9. The exhaust gas turbocharger turbine wheel according to claim 1, wherein: Each of the three-dimensional reinforcement regions includes a corresponding rounded corner region.

10. The exhaust gas turbocharger turbine wheel according to claim 1, wherein Each of the three-dimensional reinforcement regions includes a geometric centroid.

11. The exhaust gas turbocharger turbine wheel according to claim 10, wherein: Each of the geometric centroids is offset from a corresponding blade bonding area of ​​the back disk toward the suction side of a corresponding one of the blades.

12. The exhaust-gas turbocharger turbine wheel as claimed in claim 1, wherein said turbine wheel comprises at least five three-dimensionally reinforced regions.

13. The exhaust-gas turbocharger turbine wheel as claimed in claim 12, wherein said turbine wheel comprises fewer than thirty-one three-dimensionally reinforced regions.

14. A method for improving an exhaust gas turbocharger turbine wheel, the method comprising: For an exhaust gas turbocharger turbine wheel, the exhaust gas turbocharger turbine wheel comprising: a hub including a projection, a backing disc having a shaft joint portion, and an axis of rotation; blades extending from the hub to define an exhaust gas flow path, wherein each of the blades includes a leading edge, a trailing edge, a hub profile, a shroud profile, a pressure side, and a suction side; wherein the backing disc includes an outer peripheral radius measured from the axis of rotation of the hub, an intermediate radius at the outer periphery of the shaft joint portion measured from the axis of rotation of the hub, and an annular groove disposed between the intermediate radius and the outer peripheral radius, the annular groove being axially recessed relative to the outer periphery of the backing disc in the direction of the blades and being partially defined by a plurality of discrete three-dimensional reinforcement regions, wherein each of the three-dimensional reinforcement regions includes an outward protuberance in the backing disc, wherein the protuberance extends into the annular groove, and wherein each of the three-dimensional reinforcement regions includes a footprint and a height measured at least partially in the direction of the axis of rotation of the hub, material being removed from the shaft joint portion to form a balanced exhaust gas turbocharger turbine wheel; and The balanced exhaust gas turbocharger turbine wheel is installed in a turbocharger.

15. The method according to claim 14, further comprising: The turbocharger is operated by flowing exhaust gas from an internal combustion engine to the turbocharger to rotate the balanced exhaust gas turbocharger turbine wheel.

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