CN116608013A - Semi-floating turbine nozzle ring - Google Patents

Abstract

The present application provides various methods and systems for an open vane nozzle of a turbine. In one example, the turbine may include at least one biasing device disposed at an interface between the nozzle ring and the turbine shroud. The at least one biasing device may be configured to exert an axial force on the nozzle ring to maintain contact between the vane tips of the nozzle ring and the volute wall.

Description

Semi-floating turbine nozzle ring

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application 63/268,093 entitled "SEMI-floating turbine nozzle ring (SEMI-FLOATING TURBINE NOZZLE RING)" filed on 2.16 of 2022. The entire contents of the above-mentioned applications are incorporated herein by reference for all purposes.

Technical Field

Embodiments of the subject matter disclosed herein relate to a vaned ring for a turbocharger.

Background

Vehicles may include an internal combustion engine that combusts a mixture of fuel and air. In some examples, the power output of the engine may be increased by compressing intake air (i.e., intake air) prior to combustion of the engine, thereby increasing the amount of air charge (e.g., the density of oxygen molecules) and allowing for an increase in the corresponding amount of injected fuel. Compression of the intake air may be achieved by installing a turbocharger in the vehicle, wherein a compressor of the turbocharger is coupled to an intake system of the engine and a turbine of the turbocharger is coupled to an exhaust system of the engine. The turbine and the compressor are connected by a shaft, and rotation of the turbine drives rotation of the compressor under the drive of the exhaust stream.

For radial turbochargers, vaned rings may be included at the compressor (e.g., diffuser) and at the turbine (e.g., nozzle ring). At the turbine, the performance of the turbine flow stage (flow stage) may be adversely affected, particularly during transient operation, as the airflow bypasses the open-bladed nozzle ring by flowing over the tips of the blades. For example, to accommodate thermally driven axial growth of the blades during turbocharger operation, the axial length of the blades may be selected to provide a gap between the tips of the blades and the wall of the turbine shroud through which exhaust gas may leak. Thermal expansion may also cause relative movement between the base of the nozzle ring and the turbine shroud wall.

As a result of the above-described problems, the open-bladed nozzle ring may be subjected to high stresses at the blades and at the surfaces in contact with the blades, especially during transient-rise operation. The efficiency of the flow stage may be reduced by the clearance at the blade tips, particularly during steady state operation, and the air flow over the open-bladed nozzle ring may exert rotational forces that require the mounting mechanism of the nozzle ring to provide sufficient resistance to inhibit rotation of the nozzle ring. It may be desirable to have a different nozzle ring than currently available.

Disclosure of Invention

In one embodiment, the turbine may include at least one biasing device disposed at an interface between the nozzle ring and the turbine shroud, the at least one biasing device configured to exert an axial force on the nozzle ring to maintain contact between the blade tips of the nozzle ring and the volute wall. Thus, the nozzle ring can accommodate thermal expansion of the plurality of vanes without causing airflow losses at the tips of the vanes.

Drawings

FIG. 1 illustrates an example embodiment of a vehicle having a turbocharger;

FIG. 2 illustrates an embodiment of a turbine that may be included in the turbocharger of FIG. 1;

FIG. 3A illustrates a detailed cross-sectional view of a portion of a turbine;

FIG. 3B illustrates an enlarged view of a portion of the view shown in FIG. 3A;

FIG. 4 illustrates a detailed perspective view of a portion of a semi-floating nozzle ring of a turbine;

FIG. 5 shows a cross-sectional view of a portion of a turbine illustrating details of the anti-rotation structure of a semi-floating nozzle ring.

Detailed Description

Embodiments of the application are disclosed in the following description and relate to methods and systems for a turbocharger of a vehicle. More specifically, the description herein relates to a nozzle ring for a turbine of a turbocharger. Turbochargers may be used in multi-fuel systems for internal combustion engines (internal combustion engine, ICE). The internal combustion engine may be operated by a combination of different fuels. These fuels may have relatively different carbon contents. In one example, the internal combustion engine may be a multi-fuel engine configured to combust multiple fuels. Each of the plurality of fuels may be stored in a separate fuel tank. In one embodiment, one or more fuels and their corresponding fuel tanks may be housed in different fuel tanks, including different fuels. In one example, a gas fuel tank including a gas fuel may be disposed within an interior volume of a liquid fuel tank including a liquid fuel.

The internal combustion engine may burn one or more of gasoline, diesel, hydrogenated Derived Renewable Diesel (HDRD), alcohols (alcohols), ethers, ammonia, biodiesel, hydrogen, natural gas, kerosene, syngas, and the like. The plurality of fuels may include gaseous fuels, liquid fuels, and solid fuels, alone or in combination. The replacement ratio of the primary fuel to the secondary fuel of the internal combustion engine may be determined based on the current engine load. In one embodiment, the substitution ratio may correspond to an injected amount of fuel having a relatively low or zero carbon content (e.g., hydrogen or ammonia). As the substitution ratio increases, the relative proportion of fuel having a lower or zero carbon content increases, and the total amount of carbon content in the mixed fuel decreases. Additionally or alternatively, the substitution ratio may correspond to an injection or delivery of gaseous fuel relative to liquid fuel.

In one example, an internal combustion engine may burn a fuel including diesel and hydrogen. During some modes of operation, the internal combustion engine may combust only diesel, only hydrogen, or a combination thereof (e.g., during the first, second, and third conditions, respectively). When hydrogen is provided, operating conditions may be adjusted to promote enhanced combustion of the hydrogen. The engine system may burn a mixture of three or more fuels including diesel, hydrogen, and ammonia. Additionally or alternatively, ethanol may be included in the combustion mixture.

In one example, a system and method of a multi-fuel engine may include: combusting the primary fuel and one or more secondary fuels. Multi-fuel engines may burn main fuel alone. During certain conditions, a multi-fuel engine may reduce the amount of primary fuel used by replacing one or more secondary fuels into the combustion mixture. The secondary fuel may include a reduced carbon content relative to the primary fuel. Additionally or alternatively, the secondary fuel may be cheaper, more usable, and/or more efficient. The ignitability and burn rate of the secondary fuel may be different. The timing of ignition of the multi-fuel engine may be adjusted in response to the combustion mixture to account for the inclusion of the secondary fuel. For example, the ignition timing may be retarded as the amount of hydrogen increases. As another example, the ignition timing may be advanced as the amount of ammonia increases. The ignition timing may be further adjusted in this manner in response to the addition and subtraction of the primary fuel and one or more secondary fuels to the combustion mixture. By so doing, knocking and pre-combustion can be reduced.

The methods described herein may be used with various engine types and various engine drive systems. Some of these systems may be stationary while others may be on a semi-mobile platform or mobile platform. The semi-mobile platform may be repositioned during the operational period, such as being mounted on a flatbed trailer. The mobile platform includes a self-propelled vehicle. Such vehicles may include road transport vehicles such as automobiles, trucks, and buses. Suitable vehicles may include mining equipment, marine vessels, rail vehicles, and other off-highway vehicles (OHV). For clarity of illustration, a locomotive is provided as an example of a mobile platform/rail vehicle supporting a system incorporating embodiments of the present application.

Before further discussing methods for improving engine starting efficiency, one example platform is shown in which these methods may be implemented. Fig. 1 depicts an exemplary embodiment of a vehicle system 100, shown as a rail vehicle 106. The rail vehicle runs on the rail 102 via a plurality of wheels 112 and includes an engine system having an engine 104. The engine receives intake air for combustion through an intake passage 114, the intake passage 114 receiving ambient air from outside the rail vehicle. Exhaust gas generated during engine combustion is supplied to the exhaust passage 116 and flows out of the exhaust pipe of the rail vehicle.

The engine system includes a turbocharger 120 disposed between the intake passage and the exhaust passage. Turbochargers increase the amount of air charge of ambient air absorbed into the intake passage to provide greater charge density during combustion to increase power output and/or engine operating efficiency. The turbocharger may include a compressor (not shown in fig. 1) that is driven at least in part by a turbine (not shown in fig. 1). While a single turbocharger is shown, the engine system may include multiple turbines and/or compressor stages. The turbine is shown in more detail with reference to fig. 2-5. More specifically, embodiments of a semi-floating nozzle ring for a turbine are described.

In some examples, the vehicle system may further include an exhaust treatment system coupled in an upstream or downstream of the exhaust passage of the turbocharger. For example, an exhaust treatment system may include a diesel oxidation catalyst (diesel oxidation catalyst, DOC) and a diesel particulate filter (diesel particulate filter, DPF), and one or more emission control devices. The emission control devices may include selective catalytic reduction (selective catalyst reduction, SCR) catalysis, three-way catalysis, NOx traps, and the like.

The rail vehicle also includes a controller 148 for controlling various components associated with the vehicle system. In one example, a controller includes a computer control system and a computer readable storage medium including code for implementing in-vehicle monitoring and controlling vehicle operation. The controller may receive signals from various engine sensors 150 to determine operating parameters and operating conditions and adjust each engine actuator 152 accordingly to control the operation of the rail vehicle while monitoring control and management of the vehicle system.

As described above, a turbocharger for a vehicle may include at least one turbine that utilizes exhaust energy, and converts the utilized energy through a shaft into rotation of a compressor coupled to the turbine. The turbocharger components may be formed of metal, such as stainless steel, aluminum, and the like. The turbine may be included in a radial turbocharger, an embodiment of which is shown in partial cross-section in fig. 2. Further details of the turbine are shown in the cross-sectional views of fig. 3A-3B, wherein the turbine includes a semi-floating nozzle ring. A portion of a semi-floating nozzle ring is depicted in fig. 4, which shows details of the anti-rotation structure. Fig. 5 shows the relative positioning of the anti-rotation structure in different sectional views of the turbine.

Turning now to fig. 2, a turbine 200 of a radial turbocharger is depicted. A set of reference axes 201 is provided, indicating the y-axis, x-axis and z-axis. In one example, the y-axis may be parallel to the vertical direction of the radial turbocharger, the x-axis is parallel to the lateral direction of the radial turbocharger, and the z-axis is parallel to the longitudinal direction of the radial turbocharger.

As shown in fig. 2 and in the cross-sectional view of the turbine of fig. 3A-3B (taken along line 203 shown in fig. 2), the turbine has a volute 202, a turbine wheel 204, and a vaned nozzle ring 206, wherein the volute circumferentially surrounds the turbine wheel, and at least a portion of the nozzle ring is positioned at an interface between the volute and the turbine shroud 302. The cut-away profile depicts a turbine cut through the slot 312 of the nozzle ring, which is shown more clearly in FIG. 4 and will be discussed further below. As shown in fig. 3A, the nozzle ring may have an annular vane base 304, the vane base 304 being centered about a center axis of rotation 301 of the turbine wheel and turbine. In one example, as shown and described herein, the nozzle ring may be a semi-floating open vane nozzle ring having vanes 306 extending from a vane base along the z-axis. Further, the vanes may extend across the interior volume of the scroll, for example, across the distance between oppositely disposed walls of the scroll. In one example, the blade may have a fixed geometry and may form a single continuous unit with the blade base.

The nozzle ring may be made of a rigid durable material that readily expands when exposed to a hot environment. For example, the nozzle ring may be formed of stainless steel, aluminum, or other metal alloys. As shown in fig. 3B, the nozzle ring has an outer surface 303 defining the outermost circumference of the vane base and an inner surface 305 defining the innermost circumference of the vane base. The outer surface of the blade base may be in contact with the volute, and the inner surface of the blade base may be in contact with the turbine shroud.

The blades extend along the z-axis between the blade base and the volute wall 308. The blades have blade tips 310 that contact the volute wall. As the turbocharger operates and turbine temperature increases, the blades may expand in an axial direction (e.g., along the z-axis). Axial expansion of the blades may cause the blade tips to press against the volute wall in the z-axis direction and the blade base to press against the turbine shroud. In addition, the volute may expand, which may result in leakage and loss of discharge pressure in the turbine.

For example, an enlarged view of a portion of the turbine of FIG. 3A is shown in FIG. 3B, as indicated by the dashed rectangle 350, to illustrate thermal expansion in the turbine. During vehicle operation, exhaust gas flowing through the turbine may increase the temperature of the turbine, which may drive expansion of the scroll. Expansion of the scroll may increase the internal distance 352 between oppositely disposed portions of the scroll wall. When the scroll expands in a manner independent of the expansion of the nozzle ring, the internal distance between portions of the scroll wall may become greater than the length of the vanes (the length defined along the z-axis). As a result, a gap may be formed between the blade tip and the portion of the volute wall that would otherwise be in contact with the blade tip. The gap may provide a clearance through which exhaust gas may escape from the volute, as indicated by arrow 354, thereby reducing the discharge pressure transferred to the turbine wheel.

The nozzle vanes may also undergo thermally driven expansion, resulting in expansion of the vanes at least along their length (e.g., axially), as indicated by arrow 356. In some cases, the blades may expand axially such that the length of the blades is equal to or greater than the internal distance between oppositely disposed portions of the volute wall. Expansion of the blades may cause the blade tips to press into the volute wall and the blade bases to press into the turbine shroud.

When the blade expands, stresses (e.g., compressive stresses) may be imposed on the blade. In some examples, the structural integrity of the blades may be challenged when the axial growth of the blades drives the blade tips into the volute wall (particularly during transient operation of the turbocharger). However, the use of blades having an initial length that compensates for thermal expansion (e.g., a length when the blade is unheated), such as blades having an initial length that is shorter than the internal distance between oppositely disposed portions of the volute wall, may exacerbate emissions leakage when the blade is unheated and expanded. The discharge pressure loss due to leakage via the clearance between the blade tips and the volute wall may reduce the stage efficiency of the turbine. There may be leakage during steady state turbocharger operation.

As shown in fig. 2-5, the biasing device 316 may be coupled to a nozzle ring of a turbine according to an embodiment of the application. While the adaptation of the biasing device to the turbine is described herein, the biasing device may be similarly applied to a diffuser of a compressor. For example, a suitable biasing means may be a concave or convex flexible structure, such as a belleville washer (Belleville washers). In one embodiment, the biasing device is crushable. Some biasing devices may be coupled to one of a plurality of anti-rotation structures that inhibit rotation of the nozzle ring. However, in other examples, the biasing device may not be coupled to multiple anti-rotation structures. Instead, the biasing means may be located in a recess in the face of the nozzle ring. Alternatively, a single large diameter biasing means may be used instead of separate biasing means distributed around the circumference of the nozzle ring.

A suitable biasing means may be a spring. The biasing device may elastically deform, for example, compress with a target amount of resistance due to a compressive force, and automatically expand to return to the original geometry when the compressive force is released. In addition to the belleville washer set, other mechanisms or devices may additionally or alternatively be used to provide a biasing force, a tension force, or a spring force to displace the nozzle ring along the z-axis. In other words, the biasing device may allow the nozzle ring to axially displace within the turbine while providing a degree of resistance to the axial displacement of the nozzle ring such that when the vanes axially expand, the nozzle ring is subjected to opposing forces exerted by the biasing device.

The length of the blades may be similar to the distance between oppositely disposed portions of the volute wall. The clearance between the vane base and the turbine shroud may be occupied by a biasing device, which may deform and flatten out along the z-axis when compressed by the nozzle ring, for example. For example, when the volute and nozzle ring are at ambient temperature and are not subject to expansion, the play between the vane base and the turbine shroud may be minimal, and the biasing device may be compressed by an amount less than the maximum amount of compression of the biasing device (e.g., application of maximum compression results in the biasing device becoming completely flat). As a result, the blade tips can be pressed against the volute wall by the spring force of the biasing means, which can eliminate the gap between the blade tips and the volute wall without exerting a force stressing the blades. Furthermore, due to the spring force and compressibility of the biasing means, the stress applied to the volute wall can be maintained uniform regardless of the expansion state of the blades and the operation state of the turbocharger.

As the scroll expands and the distance between the oppositely disposed portions of the scroll wall increases, the resistance of the biasing device to compression causes the biasing device to exert an axial force (e.g., a force in the z-axis direction) on the blade base, as indicated by arrow 358, which causes the blade tip to remain in contact with the scroll wall. In this way, the biasing means may be selected to continue to exert an axial force on the nozzle ring even as the scroll expands. The ability of the biasing means to maintain axial force may be balanced with the resistance of the biasing means to compression, which may reduce or no longer exert stress on the blades when the scroll is unexpanded.

When the blade expands (e.g., when an axial growth occurs), the blade base may push against the biasing device. This movement may compress the biasing means and slow the increase in force exerted by the blade tips against the volute wall. Compression of the biasing means allows axial displacement of the blade base to accommodate axial growth of the blade. In one example, compression of the biasing device absorbs axial forces exerted by the blade tips that would otherwise be exerted on the volute wall. Thus, the biasing means may cushion the effect of the thermally induced expansion of the blade.

In addition, when the gas contacts the vanes of the nozzle ring, a rotational force may be exerted on the nozzle ring, forcing the nozzle ring to rotate. To inhibit rotation of the nozzle ring, one or more anti-rotation structures 314 may be coupled to the vane base of the nozzle ring. In one example, the anti-rotation structure may be a pin (pins), as shown in fig. 2-5. In other examples, the anti-rotation structure may be lugs (tabs) integrated into the nozzle ring to engage slots in the turbine shroud and/or lugs (tabs) integrated into the turbine shroud to contact slots in the nozzle ring. For example, the nozzle ring or turbine shroud may be lug cast or machined. Although the anti-rotation structure anchors the vane base against rotational movement of the nozzle ring, the nozzle ring is able to slide axially along the anti-rotation structure. One of the anti-rotation structures is shown in more detail in fig. 4.

Turning now to FIG. 4, a portion of the nozzle ring is shown in a perspective view of the side of the nozzle ring that interfaces with the turbine shroud. The anti-rotation structure may be inserted into a hole 401 (e.g., a blind hole) in the nozzle ring in a direction from the blade bottom toward the portion of the volute wall that contacts the blade tip, and may protrude outward from the nozzle ring along the z-axis. In other words, the first portion of the anti-rotation ring may be inserted into the blind bore while the second portion protrudes from the blind bore. The one or more biasing devices may circumferentially surround the anti-rotation structure when viewed along the z-axis, wherein the anti-rotation structure may have a circular outer geometry. However, other external geometries have been envisaged, such as octagons, hexagons, etc. Further, in other examples, the biasing device may be positioned at other locations than around the anti-rotation structure, such as in a recess of the blade base and/or a recess of the turbine shroud. As another example, one or more wave washers having a diameter similar to the diameter of the nozzle ring may be centered about the z-axis (e.g., central axis of rotation) as a single, continuous interface structure between the nozzle ring and the turbine shroud, as described above.

The biasing means may be a concave or convex disc with a central opening preventing rotational protrusion. For example, the biasing device may be a belleville spring or a conical spring washer oriented coplanar with the volute wall (e.g., with the x-y plane). In one example, the biasing device may be formed of a metal alloy, such as stainless steel, nickel-beryllium alloy, copper-beryllium alloy, inconelSteel, etc. As described above, the mechanical characteristics (e.g., spring force) of the biasing device may be selected based on the desired axial force exerted by the blade during expansion. Further, the number of biasing devices coupled to each anti-rotation structure may vary depending on the amount of expected expansion of the blade.

The nozzle ring may include a plurality of anti-rotation structures uniformly spaced around its circumference. For example, as shown in FIG. 2, the nozzle ring may include three anti-rotation structures, although other numbers are possible. The grooves 402 depicted in fig. 4 may form recesses in the face 404 of the blade base, wherein each groove may extend between two anti-rotation structures. Each groove may be shaped as a portion of a circle, depending on the number of anti-rotation features included in the nozzle ring. Accordingly, the length of the groove measured along the circumference of the nozzle ring may vary depending on the number of anti-rotation features incorporated into the nozzle ring. The grooves may remove material from the blade base to reduce the weight of the base and, thus, may not be included in other examples.

In addition, as previously described, the face of the blade base may also include a slot extending from the blind bore (e.g., into which the anti-rotation structure is inserted) to the inner surface of the blade base. The groove does not extend from the blind hole to the outer surface of the blade base. Thermally driven diametrically opposed radial expansions between the blade base and the turbine shroud may be accommodated by slots. Loading (loading) of the anti-rotation structure is thereby prevented, which might otherwise result in: the constraint of the axial movement of the nozzle can be suppressed and therefore eliminated.

As shown in fig. 3A-3B, the anti-rotation structure may be received by a corresponding hole in the turbine shroud. For example, a portion of the length of the anti-rotation structure (the length defined along the z-axis) may be partially embedded in the corresponding bore of the turbine shroud without any gaps between the surfaces of the anti-rotation structure and the surfaces of the corresponding bore. As an example, the portion of the length of the anti-rotation structure embedded in the corresponding hole of the turbine shroud wall may be the second portion of the anti-rotation member protruding from the blind hole, as described above. Thus, by being inserted into a corresponding hole of the turbine shroud, the anti-rotation structure may remain stationary at least with respect to axial movement.

As shown in fig. 5, in different cross-sectional views of the turbine, there may be a play space between the end 502 of the anti-rotation structure at the blind hole and the face 504 of the nozzle ring, allowing the nozzle ring to be displaced along the z-axis relative to the anti-rotation structure during expansion/contraction of the vanes. For clarity, the turbine shroud is omitted from fig. 5, and the cross-sectional view of fig. 5 is cut through slots that insert the anti-rotation structure.

By configuring the nozzle ring as a semi-floating nozzle ring, stresses on the vanes can be relieved when thermal expansion occurs. As a result, the vanes may be formed of less material, e.g., the vanes may be thinner, allowing for a reduction in the weight, cost, and amount of material used to form the nozzle ring. As described above, the amount of spring force of the biasing device may be selected to counteract the compressive force applied by the nozzle ring, which is applied from the volute wall to the turbine shroud in the direction along the z-axis. For example, the spring force of the biasing means may be twice the compression force.

Thus, by arranging the biasing means between the nozzle ring and the turbine shroud, the turbocharger may operate efficiently at the turbine stage of the turbocharger. The turbine stage may include a semi-floating nozzle ring that limits axial movement to minimize leakage of exhaust flow. The biasing means may accommodate thermal expansion of the nozzle ring vanes and may reduce stress at the vanes. By maintaining the semi-floating nozzle ring in a split ring configuration or design, the nozzle ring may be manufactured by machining, printing, investment casting, or the like. The choice of manufacturing method may affect time and/or cost.

Furthermore, the biasing device and semi-floating nozzle ring can be easily adapted to existing radial turbochargers to improve operating efficiency. For example, for a turbocharger that already includes an anti-rotation structure embedded in the turbine shroud for coupling the nozzle ring thereto, a nozzle ring having blades of appropriate length may be adapted to the turbine with the biasing device. In examples that do not include anti-rotation structures, holes may be machined into the turbine shroud to receive the anti-rotation structures. Retrofitting the semi-floating nozzle ring and biasing device into a radial turbocharger can be accomplished at low cost and without introducing additional complexity and weight.

Fig. 2-5 include drawings to scale, but other relative dimensions may be used.

Fig. 2-5 include example configurations illustrating relative positioning of various components. If shown as being in direct contact with or directly coupled to each other, these elements may be referred to as being in direct contact with or directly coupled to each other, respectively, in at least one example. Similarly, in at least one example, elements that are adjacent or proximate to each other may be adjacent or proximate to each other, respectively. As an example, components that are in coplanar contact with each other may be referred to as coplanar contacts. As another example, in at least one example, only one space between elements located apart from each other and no other components may be so mentioned. As yet another example, elements shown above/below each other, opposite sides of each other, or left/right sides of each other may be so mentioned. Further, as shown, in at least one example, the uppermost element or point may be referred to as the "top" of the component, while the lowermost element or point may be referred to as the "bottom" of the component. As used herein, top/bottom, upper/lower, above/below may be relative to a vertical axis of the drawings and are used to describe the positioning of elements of the drawings relative to each other. Thus, in one example, elements shown above other elements are positioned vertically above the other elements. As yet another example, the shapes of elements depicted in the figures may be referred to as having those shapes (e.g., circular, straight, planar, curved, arcuate, chamfered, angled, etc.). Further, in at least one example, illustrated elements that intersect one another may be referred to as intersecting elements or intersecting one another. Furthermore, in one example, elements shown within or outside of another element may be so mentioned.

The present disclosure describes a turbine that includes at least one biasing device disposed at an interface between a nozzle ring and a turbine shroud, the at least one biasing device being operable to exert an axial force on the nozzle ring to maintain contact between blade tips of the nozzle ring and a volute wall. In a first example of the system, the at least one biasing device is a belleville spring arranged coplanar with the volute wall and is elastically deformable in the axial direction. In a second example of the system, optionally including the first example, the at least one biasing device is disposed in one or more of: the circumferentially surrounding portion is embedded in the turbine shroud at the anti-rotation structure, within the recess of the nozzle ring or turbine shroud, and around the rotational center axis of the turbine, and the at least one biasing device has a diameter similar to the diameter of the nozzle ring when the at least one biasing device is disposed around the rotational center axis of the turbine. In a third example of the system, optionally including one or both of the first and second examples, the at least one biasing device has a spring force that is twice the compressive force exerted on the at least one biasing device by axial expansion of the nozzle ring. In a fourth example of the system, optionally including one or more or each of the first to third examples, the at least one biasing device enables axial movement of the nozzle ring. In a fifth example of the system, optionally including one or more or each of the first to fourth examples, the pressure exerted by the blade tips on the volute wall during turbine operation remains uniform. In a sixth example of the system, optionally including one or more or each of the first to fifth examples, the turbine includes a plurality of at least one biasing device evenly distributed around a circumference of the nozzle ring. In a seventh example of the system, optionally including one or more or each of the first to sixth examples, the turbine is operated in a radial turbocharger.

The present disclosure describes an open vane nozzle for a turbine, comprising: a plurality of blades coupled to the blade base to protrude from the blade base in an axial direction of the turbine; one or more pins extending between the blind bore of the blade base and the bore in the turbine shroud, the one or more pins inhibiting rotation of the open-vane nozzle; and at least one biasing device surrounding each of the one or more pins between the blade base and the turbine shroud, the at least one biasing device being elastically deformable in an axial direction and exerting a spring force on the blade base. In a first example of a system, the open vane nozzle is a semi-floating nozzle ring, wherein the plurality of vanes extend across the distance between oppositely disposed walls of the turbine's volute. In a second example of the system, optionally including the first example, the spring force of the at least one biasing device maintains contact between the tips of the plurality of blades and one of the oppositely disposed walls of the scroll as the scroll undergoes thermal expansion and the distance between the oppositely disposed walls of the scroll increases. In a third example of the system, optionally including one or both of the first and second examples, the plurality of blades expand axially when exposed to a hot environment and exert a compressive force on the at least one biasing device when subjected to the axial expansion. In a fourth example of the system, optionally including one or more or each of the first to third examples, when the plurality of blades apply a compressive force, the at least one biasing device deforms, and the deformation of the at least one biasing device is such as to allow the open-bladed nozzle to expand axially without increasing the force applied to the volute wall by the tips of the plurality of blades. In a fifth example of the system, optionally including one or more or each of the first to fourth examples, deformation of the at least one biasing device allows axial displacement of the blade base. In a sixth example of the system, optionally including one or more or each of the first to fifth examples, the one or more pins are held stationary by embedding portions of the one or more pins in holes of the turbine shroud, and the open vane nozzle slides axially along the one or more pins.

The present disclosure describes a radial turbocharger comprising: a volute circumferentially surrounding the turbine wheel; a semi-floating nozzle ring disposed at an interface between the volute and the turbine shroud, the semi-floating nozzle ring including blades coupled to a blade base, the blades being oriented by the blade base proximate the turbine shroud, and tips of the blades being in contact with an inner wall of the volute; a plurality of biasing devices disposed between the semi-floating nozzle ring and the turbine shroud to exert a spring force on the semi-floating nozzle ring along a central axis of the turbocharger; and one or more pins that anchor the semi-floating nozzle ring in place with respect to rotation about the central axis. In a first example of the system, the plurality of biasing devices are further included in a compressor of the radial turbocharger. In a second example of the system, optionally including the first example, the semi-floating nozzle ring includes a slot extending along a face of the semi-floating nozzle ring between a blind hole in the vane base and an inner surface of the vane base. In a third example of the system, optionally including one or both of the first and second examples, there is a clearance space between the end of the one or more pins and the surface of the blade base. In a fourth example of the system, optionally including one or more or each of the first to third examples, the exhaust gas does not flow between the tips of the blades and the inner wall of the scroll.

As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" does not exclude the plural of said elements or steps, unless such exclusion is indicated. Furthermore, references to "one embodiment" of the present application do not exclude the presence of additional embodiments that also include the recited features. Moreover, unless explicitly to the contrary, embodiments "comprising," "including," or "having" an element or a plurality of elements having a particular property may include additional such elements not having that property. The terms "comprising" and "wherein" are used as plain language equivalents of the respective terms "comprising" and "in". Furthermore, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements or a particular order of location on their objects. As used herein, unless otherwise indicated, the term "approximately" refers to plus or minus five percent of a given value or range.

This written description uses examples to disclose the application, including the best mode, and also to enable any person skilled in the relevant art to practice the application, including making and using devices or systems and performing the incorporated methods. The patentable scope of the application is defined by the claims, and may include other examples that occur to those skilled in the art. These other examples are intended to be within the scope of the claimed content if they have structural elements that do not differ from the literal language of the claimed content, or if they include equivalent structural elements with insubstantial differences from the literal language of the claimed content.

Claims (20)

1. A turbine component, comprising:

at least one biasing device disposed at an interface between a nozzle ring and a turbine shroud, the at least one biasing device configured to exert an axial force on the nozzle ring to maintain contact between blade tips of the nozzle ring and a volute wall.

2. The turbine component of claim 1, wherein the at least one biasing device is a belleville spring arranged coplanar with the volute wall and configured to elastically deform in an axial direction.

3. The turbine component of claim 1, wherein the at least one biasing device is arranged at one or more of the following positions: a circumferentially surrounding portion embedded in the turbine shroud at an anti-rotation structure, within a recess of the nozzle ring or the turbine shroud, around a central axis of rotation of the turbine; and wherein the at least one biasing device has a diameter similar to a diameter of the nozzle ring when the at least one biasing device is arranged around the central axis of rotation of the turbine.

4. The turbine component of claim 1, wherein the at least one biasing device has a spring force that is twice a compression force exerted on the at least one biasing device by axial expansion of the nozzle ring.

5. The turbine component of claim 1, wherein the at least one biasing device enables axial movement of the nozzle ring.

6. The turbine component of claim 1, wherein the pressure exerted on the volute wall by the blade tips remains uniform during operation of the turbine.

7. The turbine component of claim 1, wherein the turbine comprises a plurality of the at least one biasing device evenly distributed around a circumference of the nozzle ring.

8. The turbine component of claim 1, wherein the turbine is operated in a radial turbocharger.

9. An open vane nozzle for a turbine, comprising:

a plurality of blades couplable to a blade base to protrude from the blade base in an axial direction of the turbine;

one or more pins extending between the blind bore of the blade base and the bore in the turbine shroud, the one or more pins inhibiting rotation of the open-bladed nozzle; and

at least one biasing device surrounding each of the one or more pins between the blade base and the turbine shroud, the at least one biasing device configured to elastically deform in the axial direction and exert a spring force on the blade base.

10. The open vane nozzle of claim 9, wherein the open vane nozzle is a semi-floating nozzle ring, wherein the plurality of vanes extend across a distance between oppositely disposed walls of a volute of the turbine.

11. The open vane nozzle of claim 10, wherein the spring force of the at least one biasing device maintains contact between tips of the plurality of vanes and one of the oppositely disposed walls of the scroll as the scroll undergoes thermal expansion and the distance between the oppositely disposed walls increases.

12. The open vane nozzle of claim 9, wherein the plurality of vanes axially expand when exposed to a hot environment and when subjected to axial expansion, the plurality of vanes exert a compressive force on the at least one biasing device.

13. The open vane nozzle of claim 12, wherein the at least one biasing device deforms when the plurality of vanes apply the compressive force, and wherein deformation of the at least one biasing device allows the open vane nozzle to expand axially without increasing the force applied to the volute wall by the tips of the plurality of vanes.

14. An open vane nozzle as defined in claim 13, wherein deformation of the at least one biasing device is such as to permit axial displacement of the vane base.

15. The open vane nozzle of claim 9, wherein the one or more pins remain stationary by embedding portions of the one or more pins in the holes of the turbine shroud, and wherein the open vane nozzle slides axially along the one or more pins.

16. A radial turbocharger, comprising:

a volute circumferentially surrounding the turbine wheel;

a semi-floating nozzle ring disposed at an interface between the volute and turbine shroud, the semi-floating nozzle ring comprising blades coupled to a blade base, the blades oriented by the blade base proximate the turbine shroud, and tips of the blades in contact with an inner wall of the volute;

a plurality of biasing devices disposed between the semi-floating nozzle ring and the turbine shroud to exert a spring force on the semi-floating nozzle ring along a central axis of the radial turbocharger; and

one or more pins that anchor the semi-floating nozzle ring in place relative to rotation about the central axis.

17. The radial turbocharger of claim 16, wherein the plurality of biasing devices are further included in a compressor of the radial turbocharger.

18. The radial turbocharger of claim 16, wherein the semi-floating nozzle ring comprises a groove extending along a face of the semi-floating nozzle ring between a blind hole in the vane base and an inner surface of the vane base.

19. The radial turbocharger of claim 16, wherein a clearance space exists between the end of the one or more pins and the surface of the vane base.

20. The radial turbocharger of claim 16, wherein exhaust gas does not flow between the tips of the vanes and the inner wall of the volute.