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.
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.
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:
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
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 (
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
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
In certain embodiments, the blades 220 may include a curved configuration, as shown in
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
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
As shown in
In one embodiment, the supports 222 may include a curved configuration, as shown in
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
Although shown as including first, second, and third portions in
With continued reference to
With reference to
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
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.
The simulations reflected in
The simulations reflected in
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.
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.
Number | Date | Country | |
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62462070 | Feb 2017 | US |