Compressor Wheel With Supports

- BorgWarner Inc.

In one aspect of the present disclosure, a compressor wheel is disclosed that includes a body, a plurality of blades, and one or more supports. The supports add strength to the compressor wheel and may be configured as ribs, for example. The body has a first face (e.g., an outer or front face), which may include the blades, and a second face (e.g. an inner or rear face), which may include the supports. The supports may include an arcuate configuration curving forward in a direction of rotation of the compressor wheel.

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Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of, and priority to, U.S. Provisional Patent Application Ser. No. 62/462,070, filed on Feb. 22, 2017, the entire content of which is hererby incorporated by reference.

BACKGROUND

Compressor wheels in forced induction devices (e.g., turbochargers or superchargers for internal combustion engines) accelerate at high rates (e.g., up to 200,000 rpm per second) and rotate in steady state at high speeds (e.g., up to 300,000 rpm), which can subject the compressor wheel to high stress. For example, during acceleration, the wheel may be subject to higher torsional loading and, thereby, higher stress (e.g., shear stress) as torque is transferred radially outward from the drive shaft through the compressor wheel. More particularly, as the inner regions of the compressor wheel move ahead of the outer regions, stress (i.e., shear stress) is created and builds in the material comprising the compressor as torque is transferred radially outward.

Conventional compressor wheels are typically made of metallic materials and have a solid body in which the metal material extends continuously in an axial direction from a first face (e.g., an outer or front face) to a second face (e.g., an inner or rear face). In known compressor wheels, the first (outer) face is generally curved and includes a plurality of blades, while the second (inner) face is generally planar and/or extends axially away from the first face. This construction (i.e., materials and structure) allows conventional compressor wheels to distribute and manage torsional loading and stress during acceleration.

Compressor wheels including (e.g., formed from) composite materials may offer various advantages over metallic compressor wheels, such as, for example, reduced mass and reduced moment of inertia, which can facilitate quicker response and/or allow for reduced motor size (e.g., in electric motor-driven forced induction devices). Composite compressor wheels, however, may be subject to different strength considerations. The present disclosure addresses the concern by providing composite compressor wheels that include strengthening supports to increase structural rigidity and the ability of the composite compressor wheels to withstand the torsional loads and stresses created during acceleration.

SUMMARY

In one aspect of the present disclosure, a compressor wheel is disclosed that includes a body, a plurality of blades, and one or more supports. The supports add strength to the compressor wheel and may be configured as ribs, for example. The body has a first face (e.g., an outer or front face), which may include the blades, and a second face (e.g. an inner or rear face), which may include the supports. The supports may include an arcuate configuration curving forward in a direction of rotation of the compressor wheel.

In certain embodiments, the body, the blades, and the supports may be integrally formed. For example, the body, the blades, and the supports may be injection molded from a composite material (e.g., glass-filled nylon).

In certain embodiments, the blades may have a width that increases from an intermediate region to inner and outer regions spaced radially inward and outward from the intermediate region, respectively.

In certain embodiments, the blades may have a substantially constant width (e.g., over a majority of a radial length thereof).

In certain embodiments, the supports may increase in thickness moving in an axial direction toward a rear surface of the rear face of the body.

In certain embodiments, the supports may have a filleted transition to the rear face of the body, which may have a substantially constant radius over a majority of a radial length thereof.

In certain embodiments, a radially inner end of each support may be offset relative to the axis.

In certain embodiments, the compressor wheel may include a hub with a shaft coupling that protrudes radially rearward form the rear face of the body.

In certain embodiments, the hub and the shaft coupling may be integrally formed with the body.

In certain embodiments, a trailing edge of each support may be positioned in tangential relation to the hub.

In certain embodiments, an end of the hub may have a diameter that defines a minimum radial dimension extending across the hub in perpendicular relation to the axis of rotation.

In certain embodiments, the trailing edge of each support may be positioned in tangential relation to the diameter defined by the end of the hub.

In certain embodiments, a leading edge of each support may intersect the trailing edge of an adjacent support.

In certain embodiments, the diameter of the hub may intersect the leading edge of one or more of the supports and the trailing edge of one or more of the supports.

In certain embodiments, the leading edge may be offset relative to the axis.

In certain embodiments, the leading and trailing edges of each support may be positioned in tangential relation to the hub, but in opposite directions.

In certain embodiments, the blades may curve in a direction opposite to the direction of curvature of the supports.

In certain embodiments, the body may include one or more cavities on the rear face thereof located between adjacent supports.

In certain embodiments, the compressor wheel may be incorporated into a forced induction device, such as an exhaust driven turbocharger.

In another aspect of the present disclosure, a compressor wheel is disclosed that includes a body having opposing first and second faces, and a hub that is configured and dimensioned for mechanical connection to a shaft to facilitate rotation of the compressor wheel about an axis of rotation. The compressor wheel also includes a plurality of blades included on the first face of the body and extending radially outwardly from the hub, and a plurality of supports included on the second face of the body.

Each support includes a first end that is positioned adjacent to the hub and an opposing second end that is spaced radially from the first end (i.e., in certain embodiments, the supports may extend radially outward from the hub). The supports are configured and dimensioned to transfer torque radially outward across the body of the compressor wheel to reduce stress in the body during acceleration.

In certain embodiments, the body, the blades, and the supports may be integrally formed.

In certain embodiments, the compressor wheel may be formed from a composite material, for example, glass-filled nylon.

In certain embodiments, each of the supports may include a first end that is positioned adjacent the hub and an opposing second end that is spaced radially from the first end. In such embodiments, each of the supports may be arcuate in configuration and may curve from the first end to the second end. For example, the supports may curve from the first end to the second end in correspondence with a direction of rotation of the compressor wheel.

In certain embodiments, the blades may include an arcuate configuration, and may curve in a direction opposite to the supports.

In certain embodiments, the supports may each define a thickness extending orthogonally in relation to the axis of rotation. The thickness may be constant or variable between the first and second ends of the supports. For example, the supports may each include a first section adjacent the first end of the support, a second section adjacent the second end of the support, and an intermediate section positioned between the first section and the second section, wherein the first section defines a first thickness, the second section defines a second thickness, and the third section defines a third thickness that is less than the first thickness and the second thickness.

In certain embodiments, the supports may each define a centerline that intersects the axis of rotation. Alternatively, however, the supports may each define a centerline that is offset from the axis of rotation whereby the supports extend tangentially from the hub.

In certain embodiments, the supports may each include a leading edge spaced a first radial distance from the axis of rotation and a trailing edge spaced a second radial distance from the axis of rotation less than the first radial distance.

In certain embodiments, the supports may be configured, dimensioned, and positioned such that the leading edge of each support intersects the trailing edge of an adjacent support.

In another aspect of the present disclosure, a compressor wheel is disclosed that includes a body having opposing first and second faces (e.g., outer/front and inner/rear faces), a plurality of blades included on the first face, and a plurality of supports included on the second face.

The body of the compressor wheel also includes a hub that is configured and dimensioned for mechanical connection to a shaft to facilitate rotation of the compressor wheel about an axis of rotation.

In certain embodiments, the blades may extend radially outward from the hub and may curve in a first direction (e.g., in correspondence with a direction of rotation of the compressor wheel), whereas the supports may extend radially outward from the hub and may curve in a second direction opposite the first direction.

Each of the supports defines a thickness extending orthogonally in relation to the axis of rotation. In certain embodiments, the thickness of each support may be constant between first and second ends thereof. Alternatively, however, the thickness of each support may vary. For example, in certain embodiments, the supports may each include a first section adjacent a first end of the support, a second section adjacent an opposing second end of the support, and an intermediate section positioned between the first section and the second section, wherein the first section defines a first thickness, the second section defines a second thickness, and the third section defines a third thickness less than the first thickness and the second thickness.

In another aspect of the present disclosure, a compressor wheel is disclosed that includes a body having opposing first and second faces (e.g., outer/front and inner/rear faces), a plurality of blades included on the first face, and a plurality of supports included on the second face.

The body of the compressor wheel also includes a hub that is configured and dimensioned for mechanical connection to a shaft to facilitate rotation of the compressor wheel about an axis of rotation.

In certain embodiments, each of the supports may define a centerline that is offset from the axis of rotation whereby the supports extend tangentially from the hub.

In certain embodiments, the supports may each include a leading edge that is spaced a first radial distance from the axis of rotation and a trailing edge that is spaced a second radial distance from the axis of rotation less than the first radial distance. In such embodiments, the leading edge of each support may intersect the trailing edge of an adjacent support.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. The description herein makes reference to the accompanying drawings, wherein like referenced numerals refer to like parts throughout several views, and wherein:

FIG. 1 is a partial cross-sectional view of a forced induction device.

FIG. 2 is a rear, perspective view of an embodiment of a compressor wheel of the forced induction device of FIG. 1

FIG. 3 is a front, perspective view of the compressor wheel of FIG. 2.

FIG. 4 is a schematic, rear, plan view of the compressor wheel shown in FIG. 2.

FIG. 5 is a cross-sectional view of the compressor wheel taken along line 5-5 in FIG. 4.

FIG. 6 is a cross-sectional view of the compressor wheel taken along line 6-6 in FIG. 4.

FIG. 7 is a cross-sectional view of the compressor wheel taken along line 7-7 in FIG. 4.

FIG. 8 is a front, perspective view of an alternate embodiment of the compressor wheel seen in FIG. 2.

FIG. 9 is a rear perspective view of an alternate embodiment of the compressor wheel seen in FIG. 2.

FIG. 10 is a rear perspective view of another embodiment of the compressor wheel seen in FIG. 2.

FIGS. 11A, 11B, and 11C are rear perspective views of the compressor wheels shown in FIGS. 3, 9, and 10, respectively, which depict stress in the compressor wheels during acceleration conditions.

FIGS. 12A, 12B, and 12C are rear perspective views of the compressor wheels shown in FIGS. 3, 9, and 10, respectively, which depict stress in the compressor wheels during steady state conditions.

FIGS. 13A, 13B, and 13C are rear perspective views of the compressor wheels shown in FIGS. 3, 9, and 10, respectively, which depict displacement of the compressor wheels during steady state conditions.

DETAILED DESCRIPTION

The present disclosure describes a compressor wheel for use in a forced induction device, such as a turbocharger or a supercharger, which may be formed from non-metallic materials, such as polymers and/or composite materials. The presently disclosed compressor wheel is configured and dimensioned to distribute and/or otherwise manage torsional loading and stress created during acceleration. More specifically, the compressor wheel includes strengthening supports that are configured and dimensioned to transfer torque radially through the compressor wheel, such as, for example, via compression during acceleration, to reduce stress. The strengthening supports may be curved and/or linear in configuration, and may be facilitate uniformity in radial growth of the compressor wheel in outer portions thereof.

With reference to FIGS. 1-7, a forced induction device 100 is illustrated that includes a housing 140 and a compressor wheel 210 that is positioned within the housing 140. In use, the forced induction device 100 may be configured as part of a powertrain of a vehicle and be arranged to supply compressed air to an internal combustion engine of the powertrain. The compressor wheel 210 may be actuated (i.e., rotated) through connection to, or communication with, any suitable drive source. For example, the compressor wheel 210 may be configured and dimensioned for connection to an electric motor. Additionally, or alternatively, it is envisioned that the compressor wheel 210 may be configured, dimensioned, and positioned for rotation via exhaust gas from the engine (e.g., in the context of a turbocharger) or via mechanical power transfer from the engine (e.g., in the context of a supercharger).

The compressor wheel 210 may be formed from any suitable material, such as, for example, polymer(s), composite materials, such as glass-filled nylon, and/or other non-metallic materials. In certain embodiments, it is envisioned that the compressor wheel 210 may be unitary in construction, and that the compressor wheel 210 may be formed, for example, through a molding process, such as injection or insert molding.

The compressor wheel 210 includes a body 212 (FIGS. 2, 3) having a first (outer/front) face 214 and a second (inner/rear) face 216. The body 212 includes a hub 217 that facilitates connection to a drive shaft 152 (FIG. 1) such that the compressor wheel 210 is rotatable about an axis of rotation 212a (FIG. 2) via connection to, or communication with, the aforementioned drive source. In the illustrated embodiment, for example, the hub 217 includes a shaft coupling 218 formed integrally with the body 212 that incorporates an engagement structure 219. In the embodiment seen in FIGS. 2 and 3, for example, the engagement structure 219 includes a circular bore 219a and a series of recesses 219b that collectively define a generally cruciform configuration. It should be appreciated, however, that in alternate embodiments of the disclosure, the specific configuration and components of the engagement structure 219 may be varied in alternate embodiments of the disclosure. For example, it is envisioned that the engagement structure 219 may include a hexagonal cross-sectional configuration. Additionally, or alternatively, the engagement structure 219 may include any structure suitable for the intended purpose of connecting the drive shaft 152 to the compressor wheel 210 for rotation in the manner described herein, such as, for example, ribs, detents, etc.

The hub 217 extends axially with respect to inner and outer surfaces 216a, 216b of the body 212 so as to define respective inner and outer faces 217a, 217b having transverse cross-sectional dimensions (e.g., a diameters) that extends in orthogonal relation to the axis of rotation 212a. Although illustrated as including a generally cylindrical configuration in the illustrated embodiments, whereby the hub 217 defines a circular cross-section, it is envisioned that the hub 217 may assume alternate geometrical configurations. For example, it is envisioned that the hub 217 may be generally frusto-conical in configuration.

Although the engagement structure 219 is shown and described as being integrally formed with the hub 217 in the embodiment illustrated in FIGS. 1-7, in an alternate embodiment, the engagement structure 219 may be provided on a separate insert that is configured and dimensioned for receipt by the hub 217. For example, with reference to FIG. 8, an insert 219c is disclosed that is positionable within an opening 217c defined by the hub 217. The insert 219c includes a series of projections 219d that are configured and dimensioned for engagement with corresponding projections 217d defined by the hub 217. In such embodiments, it is envisioned that the insert 219c and the hub 217 may be connected in any suitable manner, such as, for example, via a press-fit engagement, welding, etc., and that the hub 217 and the insert 219c may include any suitable cross-sectional geometry, e.g., square, hexagonal, flat, etc.

It is envisioned that the insert 219c may be formed from the same material as the hub 217 and the compressor wheel 210, or that the hub 217 and the insert 219c may be formed from different materials. For example, the hub 217 may be formed from a non-metallic material, such as glass-filled nylon, whereas the insert 219c may be formed from a metallic material, such as aluminum, steel, etc.

It is envisioned that the insert 219c may serve as a compression limiter to reduce or eliminate load on the hub 217. Additionally, it is envisioned that the insert 219c may increase achievable tip speeds by reducing bore stress on the hub 217.

With reference again to FIGS. 1-7, the outer face 214 of the body 212 includes (e.g., defines or forms) the outer surface 216a (FIG. 3), and is generally convex in configuration. The outer face 214 includes a plurality of blades 220 that extend outwardly from the outer surface 214a. The blades 220 are configured and dimensioned to draw air from an intake (not shown) and compress the air such that it is expelled from an outlet (not shown) at a higher pressure for forced induction into an internal combustion engine, for example. It is envisioned that the plurality of blades 220 may be formed integrally with the body 212 (e.g., as part of the molding process), and thus, that the blades 220 and the body 212 may be formed from the same material. Alternatively, it is envisioned that the blades 220 may be formed separately from the body 212 and attached thereto, such as, for example, via welding. In such embodiments, the body 212 and the blades 220 may be formed from the same or different materials.

In certain embodiments, the blades 220 may include a curved configuration, as shown in FIG. 3, for example. More particularly, it is envisioned that the curvature of the blades 220 may oppose the direction of rotation of the compressor wheel 210, which is indicated by arrow 1, or that the curvature of the blades 220 may be configured in correspondence with the direction of rotation of the compressor wheel 210.

The inner face 216 of the body 212 includes (e.g., defines or forms) the inner surface 216b, and approaches/intersects the outer face 214 an outer periphery 215 of the body 212. The inner face 216 is generally concave in configuration, and includes one or more supports 222, as well as one or more recess 224. The recess(es) 224 extend between adjacent supports 222 and are collectively defined by the inner surface 216a, the hub 217, and the supports 222. In certain embodiments, it is envisioned that the recesses 224 may reduce the overall wall thickness, and thus, the overall weight of the body 212, and/or that the recesses 224 may be positioned to increase consistency in the wall thickness of the body 212, which may be advantageous in forming the compressor wheel 210 using an injection molding process. The recesses 224 may thus “hollow” the body 212 in contrast to the solid design employed in many known conventional compressor wheels, as described above.

The supports 222 are configured, dimensioned, and positioned to transfer torque radially outward across the body 212 of the compressor wheel 210 so as to reduce stress in the body 212 during acceleration. Although configured as a plurality of ribs in the illustrated embodiments, the supports 222 may assume any configuration suitable for the intended purpose of transferring torque radially outward in the manner described herein, such as, for example, struts, brackets, walls, etc.

It is envisioned that the supports 222 may be formed integrally with the body 212 (e.g., as part of the molding process), as illustrated in FIGS. 2 and 3, for example, and thus, that the supports 222 and the body 212 may be formed from the same material. Alternatively, it is envisioned that the supports 222 may be formed separately from the body 212 and attached thereto, such as, for example, via welding. In such embodiments, it is envisioned that the body 212 and the supports 222 may be formed from the same or different materials. As seen in FIGS. 2 and 3, forming the supports 222 integrally with the body 212 eliminates any physical division between the hub 217 and the supports 222, whereby the transverse cross-sectional dimension of the hub 217 (e.g., the diameter) acts as an imaginary dividing line separating the hub 217 from the supports 222.

Each of the supports 222 each includes a first end 222a positioned adjacent (e.g., coupled to or formed integrally with) the hub 217 and a second end 222b spaced radially from the first end 222a. It is envisioned that ends 222b of the supports 222 may extend into an outer/peripheral region of the compressor wheel 210, as shown in FIG. 2, for example, or alternatively, that the ends 222b may extend to the outer periphery 215 of the body 212. The supports 222 each define a first edge 222c (e.g., an inner or leading edge) spaced a first radial distance R1 (FIG. 4) from the axis of rotation 212a, a second edge 222d (e.g., an outer or leading edge) spaced a second radial distance R2 from the axis of rotation 212a that is greater than the first distance, and a centerline 222e positioned equidistant from the first edge 222c and the second edge 222d.

As shown in FIG. 2, for example, it is envisioned that the supports 222 may be spaced evenly across the inner face 216. For example, the compressor wheel 210 may include four supports 222 spaced at 90-degree intervals. In alternate embodiments, however, the number of supports 222 included on the compressor wheel 210 may be varied. For example, the compressor wheel 210 may include three supports 222 spaced at 120-degree intervals, five supports 222 spaced at 72-degree intervals, etc.

In one embodiment, the supports 222 may include a curved configuration, as shown in FIG. 2, for example. More particularly, it is envisioned that the supports 222 may curve in the direction of rotation of the compressor wheel 210, which indicated by arrow 1 in FIG. 2, or alternatively, that the supports 222 may curve in a direction opposite that of rotation of the compressor wheel 210. It is envisioned that the curvature of the supports 222 may be chosen to facilitate the transfer of torque radially outward during acceleration of the compressor wheel 210 as a compressive load along the supports 222. As can be appreciated through reference to FIGS. 2 and 3, it is envisioned that the curvature defined by the supports 222 may be opposite that defined by the blades 220.

It is envisioned that the configuration, dimensions, and positions of the supports 222 may be varied in alternate embodiments of the compressor wheel 210. For example, based upon the desired performance of the compressor wheel 210 and/or the loads/stresses experienced by the compressor wheel 210 during operation, the curvature, cross-sectional shape, and/or location of the supports 222 may be varied. In particular, the curvature of the supports 222 may be varied such that, during acceleration, the supports 222 are loaded primarily in compression and minimize any bending load or moment. The curvature of the supports 222 may also be chosen to inhibit or prevent drawing lubricants (e.g., oil or grease) from bearings positioned adjacent the inner face 216 of the compressor wheel 210 (e.g., by creating a small positive pressure on the second face 216).

As shown in FIG. 2, it is envisioned that the supports 222 may define a thickness T that varies between the ends 222a, 222b. For example, the supports 222 may each include a first portion 223a adjacent the end 222a defining a first thickness Ta, a second portion 223b adjacent the end 222b defining a second thickness Tb, and one or more intermediate portions 223c positioned between the portions 223a, 223b defining a third thickness Tc. In the particular embodiment shown in FIG. 2, for example, the supports 222 are configured and dimensioned such that the thickness Ta is greater than the thickness Tb, whereby the supports 222 widen to define a fillet adjacent the hub 217, but less than the thickness Tc. It should be appreciated, however, that in alternate embodiments, the thicknesses Ta, Tb, Tc may be altered or varied to achieve any desired effect or to apply structural support to the compressor wheel 210 as needed. For example, the thicknesses Ta, Tb, Tc may be equivalent to each other, the thickness Ta may exceed the thickness Tc, etc. It is envisioned that increasing the thickness of the supports 222 adjacent the ends 222b may offset a reduction in material used in construction of the blades 220 (e.g., to further limit stress concentrations).

Although shown as including first, second, and third portions in FIG. 2, it should be appreciated that the number of the portions may be increased or decreased in alternate embodiments of the disclosure.

With continued reference to FIG. 2, it is envisioned that the supports 222 may define a curvature with a substantially constant radius (e.g., a simple curve) over a majority of the length of the support 222 (e.g., 50% or more of the overall length of the support 222). Alternatively, is envisioned that the curvature of the supports 222 may vary between the ends 222a, 222b. For example, in one embodiment, the curvatures of the portion 223a, 223b, 223c may be unequal (e.g. the curvature of the portion 223a may exceed the curvature of the portion 223b which may exceed the curvature of the portion 223c). It is envisioned that the curvature of the supports 222 may be defined as elliptical or exponential curvature, or any other suitable shape.

With reference to FIGS. 4-7, the supports 222 define a height H that may be varied between the ends 222a, 222b. For example, in the illustrated embodiment it is envisioned that the height H may decrease from the end 222a to the end 222b. It is envisioned that the variation in height H may be gradual, such that the supports 222 include a generally “tapered” configuration, as illustrated in FIGS. 5-7, for example, or that the height H may be reduced incrementally in step-wise fashion.

Dependent upon the desired operation and structural reinforcement provided by the supports 222, it is envisioned that the specific location and/or orientation of the supports 222 may be varied. For example, with reference to FIG. 4, the supports 222 may be positioned such that the centerlines 222e are offset or spaced radially from the axis of rotation 212a, whereby the supports 222 extend tangentially from the hub 217. Alternatively, it is envisioned that the supports 222 may be positioned such that the centerlines 222e intersect the axis of rotation 212a. As seen in FIG. 4, in certain embodiments, the supports 222 may be positioned such that the edges 222d intersect, or are otherwise joined to, the edges 222c of adjacent supports 222.

As discussed above, the supports 222 reduce stress in the body 212 during acceleration when compared to similarly configured compressor wheels without such supports 222, and the effect of these stress reductions is amplified by the curvature of the supports 222. FIG. 11A provides an illustration of a computer simulation performed with respect to the compressor wheel 210 illustrated in FIGS. 2 and 3, for example, whereas FIG. 11B provides an illustration of a computer simulation performed with respect to a similar compressor wheel 310 that is devoid of the supports 222, and FIG. 11C provides an illustration of a computer simulation performed with respect to a similar compressor wheel 410 that includes linear supports 422.

The simulations reflected in FIGS. 11A-11C were performed in both accelerating and steady state conditions for the compressor wheels 210, 310, and 410 to determine stress concentrations. During the simulations, the respective outer peripheries 215, 315, 415 of the compressor wheels 210, 310, 410, were held in place while torque was applied to the respective hubs 217, 317, 417. The regions having different shading indicate different levels of stress (see the legend associated with FIG. 11A). As shown in FIG. 11B, the compressor wheel 310 experiences large stress concentrations of greater than 200 MPa in areas surrounding the hub 317, as well as in inner regions of the body 312, which are reduced gradually as the radial distance from the hub 317 is increased. Stress reduction is also visible in regions associated with the blades 320. As shown in FIG. 11C, the compressor wheel 410 also experiences large stress concentrations of greater than 200 MPa in areas surrounding the hub 417, as well as in inner regions of the body 412, and in the areas of transition between the supports 422 and the body 412. In contrast, as shown in FIG. 11A, the compressor wheel 210 experiences substantially smaller stress concentrations of greater than 200 MPa, which are localized to the areas of transition between the supports 222 and the hub 217.

FIGS. 12A-12C provide illustrations of computer simulations performed in steady state conditions in which the hubs 217, 317, 417 were restrained and a 1-bar load, representative of aerodynamic loading, was applied the blades 220, 320, 420 in conjunction with a centrifugal load of 70,000 RPM. As shown in FIG. 12B, the compressor wheel 310 experienced the lowest magnitude stress concentrations, peaking at approximately 70,000 MPa. As shown in FIG. 12C, however, the compressor wheel 410 experienced peak stress concentrations of approximately 100,000 MPa in the areas of transition between the supports 422 and the body 412 (e.g., as the supports 422 constrain radial growth of the body 412). As shown in FIG. 12A, the compressor wheel 210 also experienced peak stress concentrations of approximately 100,000 MPa in the areas of transition between the supports 222 and the body 212 with the highest stress concentrations being located in outer regions of the compressor wheel 210 (e.g., as the supports 222 expand radially outward in an attempt to straighten).

FIGS. 13A-13C provide illustrations of computer simulations performed in steady state conditions to identify and measure radial displacement (e.g., growth) experienced by the compressor wheels 210, 310, 410. In FIGS. 13A-13C, regions having different shading indicate different amounts of radial growth (see the legend associated with FIG. 13A). As compared to metallic compressor wheels, growth of polymer or composite compressor wheels may be up to 20 times greater. As shown in FIG. 13B, the compressor wheel 210 experiences generally even radial growth. Aerodynamic loading of the blades 220, for example, tends to compress the compressor wheel 210 radially inward, so as to partially offset centrifugal forces. As shown in FIG. 13C, the compressor wheel 410 experiences uneven radial growth with the supports 422 constraining growth at 90-degree intervals. As shown in FIG. 13A, the compressor wheel 210 experiences generally even radial growth but in slightly greater magnitude than the compressor wheel 310.

The simulations reflected in FIGS. 11A-13C illustrate that the compressor wheel 210 experienced substantial reductions in stress when compared to the compressor wheels 310, 410 during acceleration, but higher stresses than the compressor wheel 310 during steady state conditions. Additionally, the simulations illustrate that the compressor wheel 210 experienced slightly greater radial growth than the compressor wheel 310, and substantially more uniformity in radial growth than the compressor wheel 410, during steady state rotation. As a result, the compressor wheel 210 may provide a better compromise of stress in acceleration and steady state conditions, while providing generally even radial growth, which may be provide better durability and/or fatigue life of the compressor wheel 210. Furthermore, the use of curved supports 222 may be particularly advantageous in different applications, such as in exhaust-driven turbochargers, that operate the compressor wheel 210 at higher pressures and/or at higher temperatures (e.g., as compared to electronic or mechanically driven forced induction devices) that may cause greater stress and/or shape distortion.

It is to be understood that the present disclosure is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law. For example, the elements and features shown or described in connection with one embodiment may be combined with those of another embodiment without departing from the scope of the present disclosure.

In the preceding description, reference may be made to the spatial relationship between the various structures illustrated in the accompanying drawings, and to the spatial orientation of the structures. However, as will be recognized by those skilled in the art after a complete reading of this disclosure, the structures described herein may be positioned and oriented in any manner suitable for their intended purpose. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” “inner,” “outer,” etc., should be understood to describe a relative relationship between structures, and/or a spatial orientation of the structures.

Additionally, terms such as “approximately” and “generally” should be understood to allow for variations in any numerical range or concept with which they are associated. For example, it is envisioned that the use of terms such as “approximately” and “generally” should be understood to encompass variations on the order of 25%, or to allow for manufacturing tolerances and/or deviations in design.

Claims

1. A compressor wheel comprising:

a body having opposing first and second faces, and a hub configured and dimensioned for mechanical connection to a shaft to facilitate rotation of the compressor wheel about an axis of rotation;
a plurality of blades included on the first face of the body, the blades extending radially outward from the hub; and
a plurality of supports included on the second face of the body, each of the supports including a first end positioned adjacent the hub and an opposing second end spaced radially from the first end, the supports being configured and dimensioned to transfer torque radially outward across the body to reduce stress in the body during acceleration of the compressor wheel.

2. The compressor wheel according to claim 1, wherein the body, the blades, and the supports are integrally formed.

3. The compressor wheel according to claim 2, wherein the compressor wheel is formed from a composite material.

4. The compressor wheel according to claim 3, wherein the compressor wheel is formed from glass-filled nylon.

5. The compressor wheel according to claim 1, wherein each of the supports includes an arcuate configuration and curves from the first end to the second end.

6. The compressor wheel according to claim 5, wherein the supports curve from the first end to the second end in correspondence with a direction of rotation of the compressor wheel.

7. The compressor wheel according to claim 6, wherein the blades include an arcuate configuration and curve in a direction opposite to the supports.

8. The compressor wheel according to claim 6, wherein the supports each define a thickness extending orthogonally in relation to the axis of rotation, the thickness being constant between the first and second ends.

9. The compressor wheel according to claim 6, wherein the supports each define a thickness extending orthogonally in relation to the axis of rotation, the thickness varying between the first and second ends.

10. The compressor wheel according to claim 9, wherein the supports each include a first section adjacent the first end of the support, a second section adjacent the second end of the support, and an intermediate section positioned between the first section and the second section, the first section defining a first thickness, the second section defining a second thickness, and the third section defining a third thickness less than the first thickness and the second thickness.

11. The compressor wheel according to claim 5, wherein the supports each define a centerline intersecting the axis of rotation.

12. The compressor wheel according to claim 5, wherein the supports each define a centerline offset from the axis of rotation such that the supports extend tangentially in relation to the hub.

13. The compressor wheel according to claim 12, wherein the supports each include a leading edge and a trailing edge, the leading edge being spaced a first radial distance from the axis of rotation and the trailing edge being spaced a second radial distance from the axis of rotation less than the first radial distance, the leading edge of each support intersecting the trailing edge of an adjacent support.

14. A compressor wheel comprising:

a body having opposing first and second faces, and a hub configured and dimensioned for mechanical connection to a shaft to facilitate rotation of the compressor wheel about an axis of rotation;
a plurality of blades included on the first face of the body, the blades extending radially outward from the hub and curving in a first direction; and
a plurality of supports included on the second face of the body, the supports extending radially outward from the hub and curving in a second direction opposite the first direction, each of the supports defining a thickness extending orthogonally in relation to the axis of rotation.

15. The compressor wheel according to claim 14, wherein the supports curve in correspondence with a direction of rotation of the compressor wheel.

16. The compressor wheel according to claim 14, wherein the thickness of each support is constant.

17. The compressor wheel according to claim 14, wherein the supports each include first and second ends, the thickness of each support varying between the first and second ends thereof.

18. The compressor wheel according to claim 17, wherein the supports each include a first section adjacent a first end of the support, a second section adjacent an opposing second end of the support, and an intermediate section positioned between the first section and the second section, the first section defining a first thickness, the second section defining a second thickness, and the third section defining a third thickness less than the first thickness and the second thickness.

19. A compressor wheel comprising:

a body having opposing first and second faces, and a hub configured and dimensioned for mechanical connection to a shaft to facilitate rotation of the compressor wheel about an axis of rotation;
a plurality of blades included on the first face of the body; and
a plurality of supports included on the second face of the body, each of the supports defining a centerline that is offset from the axis of rotation such that the supports extend tangentially in relation to the hub.

20. The compressor wheel according to claim 19, wherein the supports each include a leading edge and a trailing edge, the leading edge being spaced a first radial distance from the axis of rotation and the trailing edge being spaced a second radial distance from the axis of rotation less than the first radial distance, the leading edge of each support intersecting the trailing edge of an adjacent support.

Patent History

Publication number: 20180238339
Type: Application
Filed: Feb 19, 2018
Publication Date: Aug 23, 2018
Applicant: BorgWarner Inc. (Auburn Hills, MI)
Inventors: Keith Nickson (Huddersfield), Tristram Palmer-White (Bradford)
Application Number: 15/899,037

Classifications

International Classification: F04D 29/28 (20060101); F04D 29/02 (20060101); F04D 29/26 (20060101);