VEHICLE WHEEL DISC, VEHICLE WHEEL INCLUDING SUCH A WHEEL DISC AND METHOD FOR PRODUCING SUCH A WHEEL DISC AND VEHICLE WHEEL

BACKGROUND OF THE INVENTION

[0001] The present invention relates in general to a vehicle wheel disc and vehicle wheel and in particular to an improved wheel disc, vehicle wheel including such a wheel disc and method for producing such a wheel disc and vehicle wheel.

[0002] Wheels for automotive vehicles may be produced from light weight metals to reduce the weight of the wheels. For example, the vehicle wheels may be produced as a single cast component made from aluminum or alloys thereof. The weight of such wheels may be further reduced by removing mass or material from the wheels. A reduction in the weight of vehicle wheels may have the advantage of increasing the wheel's performance by reducing the unsprung mass of that component of the vehicle.

[0003] However, removing mass from the wheel also may reduce the stiffness and rigidity of the wheel. It is generally desirable to remove mass from the wheel without a significant reduction in stiffness and rigidity. In some situations, the aesthetic look of a reduced mass wheel may not appeal to consumers. Thus, it may be desirable to form the wheel such that a reduced mass is obtained while maintaining the aesthetic appeal of the wheel. SUMMARY OF THE INVENTION

[0004] The present invention relates to an improved wheel disc, vehicle wheel including such a wheel disc and method for producing such a wheel disc and vehicle wheel as illustrated and/or described herein.

[0005] According to one embodiment, the wheel disc may comprise, individually and/or in combination, one or more of the following features, elements, or advantages: a wheel disc for a vehicle wheel including a centrally located hub having a plurality of bolt holes formed therein, wherein the hub defines a wheel axis. A plurality of spokes radially extend outwardly from the hub, wherein each of the spokes defines a proximal portion, a distal portion, and an end portion. The proximal portion is connected to and extends radially outwardly from the hub and has a thickness which decreases as extending in a radially outward direction. The distal portion extends radially outwardly from the proximal portion and has a thickness which decreases as extending in the radially outward direction such that the thickness decreases at a greater rate than the decreasing thickness of the proximal portion. The end portion extends radially outwardly from the distal portion and has a thickness which increases as extending in the radially outward direction, and wherein the end portion is adapted to be connected with an outer annular rim. A web is disposed between and connected to each pair of adjacent spokes and extends outwardly from the hub. The web has an outer edge extending between the adjacent spokes, and wherein a vent opening is defined between the pair of adjacent spokes and the outer edge of the web. [0006] According to this embodiment, the radially extending lengths of the proximal portions of the plurality of spokes are greater than the radially extending lengths of the distal portions.

[0007] According to this embodiment, the radially extending length of the proximal portions is about twice the radially extending length of the distal portions.

[0008] According to this embodiment, the radially extending lengths of the proximal portions of the plurality of spokes are greater than the radially extending lengths of the distal portions by an amount within the range of about 1.8 to about 2.2 times.

[0009] According to this embodiment, the radially extending lengths of the distal portions are greater than the radially extending lengths of the end portions.

[0010] According to this embodiment, the hub and the spokes define depths extending in the axial direction such that the depth of the hub is greater than the depth of the proximal and distal portions of the plurality of spokes.

[0011] According to this embodiment, the depth of the proximal portions of the plurality of spokes decreases as extending in the radially outward direction.

[0012] According to this embodiment, the depth of the distal portions of the plurality of spokes increases as extending in the radially outward direction. [0013] According to this embodiment, the depth of the proximal portions of the plurality of spokes decreases as extending in the radially outward direction.

[0014] According to this embodiment, the depth of the end portions of the plurality of spokes increases as extending in the radially outward direction.

[0015] According to this embodiment, the web continuously extends along the length of each of the proximal portions of the plurality of spokes.

[0016] According to this embodiment, the outer edge of each web has a single arcuate shape such that the edge of the web has a center portion which is closer to the wheel axis than outer portions of the edge connecting to the adjacent spokes.

[0017] According to this embodiment, outer portions of the edge of the webs are connected to an end at the distal portions of the plurality of spokes.

[0018] According to this embodiment, the hub, the plurality of spokes, and the webs each define a front surface that smoothly blend into one another, thereby forming a combined front surface having a smooth continuous profile.

[0019] According to this embodiment, the combined front surface is planar and is perpendicular to the wheel axis.

[0020] According to this embodiment, the combined front surface has a concave profile generally perpendicular to the wheel axis. [0021] According to this embodiment, the combined front surface has a convex profile generally perpendicular to the wheel axis.

[0022] According to this embodiment, the wheel disc of claim 1 further includes an annular outer wheel rim adapted to receive a tire, and wherein each of the end portions of the plurality of spokes is connected to an interior wall of the wheel rim.

[0023] According to this embodiment, the wheel disc and the wheel rim are formed as a single cast structure.

[0024] According to this embodiment, each of the end portions of the plurality of spokes defines a front portion and a rear portion axially spaced from the front portion, wherein the front portions of the end portions are spaced from the interior wall of the wheel rim, and wherein the rear portions of the end portions are connected to the interior wall of the wheel rim.

[0025] According to one embodiment, a vehicle wheel may comprise, individually and/or in combination, one or more of the following features, elements, or advantages: an outer annular wheel rim; an aluminum wheel disc configured to be connected to the wheel rim and having centrally located hub having a plurality of bolt holes formed therein, wherein the hub defines a wheel axis; a plurality of spokes radially extending outwardly from the hub, wherein each of the spokes defines a proximal portion, a distal portion, and an end portion; and a web disposed between and connected to each pair of adjacent spokes and extending outwardly from the hub, wherein the web has an outer edge extending between the adjacent spokes, and wherein a vent opening is defined between the pair of adjacent spokes and the outer edge of the web; wherein each of the end portions of the plurality of spokes defines a front portion and a rear portion axially spaced from the front portion, wherein the front portions of the end portions are spaced from an interior wall of the wheel rim, and wherein the rear portions of the end portions are connected to the interior wall of the wheel rim.

[0026] According to this embodiment, the vehicle wheel is a one piece vehicle wheel or a vehicle wheel including at least two separate parts configured to be connected together.

[0027] Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Fig. 1 is a front perspective view of a first embodiment of a vehicle wheel in accordance with the present invention.

[0029] Fig. 2 is a rear perspective view of the wheel of Fig. 1.

[0030] Fig. 3 is a front elevational view of the wheel of Fig. 1.

[0031] Fig. 4 is a rear elevational view of the wheel of Fig. 1.

[0032] Fig. 5 is a side elevational view of the wheel of Fig. 1. [0033] Fig. 6 is a cross-sectional perspective view of the wheel taken along lines 6-6 of Fig. 1.

[0034] Fig. 7 is a cross-sectional view of the wheel generally taken along lines 7-7 of Fig. 3.

[0035] Fig. 8 is a cross-sectional view of a second embodiment of a wheel illustrating a two-piece configuration.

[0036] Fig. 9 is a schematic representation of the wheel of Fig. 1 illustrating the planar front face.

[0037] Fig. 10 is a schematic representation of an alternate embodiment of a wheel having a convex front face.

[0038] Fig. 11 is a schematic representation of another alternate embodiment of a wheel having a concave front face.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Referring now to the drawings, there is illustrated in Figs. 1 through 7 a vehicle wheel, indicated generally at 10. The wheel 10 generally incudes an inner wheel disc, indicated generally at 12, and an annular outer rim 14. Although the invention is illustrated and described in conjunction with the particular vehicle wheel construction disclosed herein, it will be appreciated that the invention can be used in conjunction with other types of vehicle wheel constructions. [0040] In a preferred embodiment (and as illustrated herein), the wheel disc 12 and the outer rim 14 are unitarily or monolithically produced, such as for example, as a single casting. After production of the casting, portions of the casting can be machined or otherwise worked to form the wheel 10.

Alternatively, the wheel disc 12 and outer rim 14 may be produced separately, such as separate castings and/or non-castings, and then joined together by any suitable means, to produce a "fabricated" vehicle wheel 10. In this fabricated example illustrated in Figs. 1 through 7, the wheel disc 12 and the outer rim 14 are preferably produced as a single casting.

[0041] The wheel 10 can be produced or cast from any suitable material. For example, the wheel 10 may be an all-cast wheel design formed from aluminum or alloys thereof. Aluminum is advantageous in that it is relatively inexpensive, lightweight, easily machinable, and can provide sufficient rigidity. Other suitable materials in which the wheel 10 can be made of include magnesium, titanium or alloys thereof, steel, carbon fiber and/or composite materials.

[0042] As shown in Fig. 1, the combination of the wheel disc 12 and the outer rim 14 defines a wheel axis X for the wheel 10. The outer rim 14 can have any suitable annular shape for receiving and supporting a tire (not shown). In one embodiment, the outer rim 14 is machined after the wheel 10 is cast to provide a continuous annular shape relative to the wheel axis X for accommodating the tire. It should be appreciated that the outer rim 14 can have any desired diameter and/or shape. In the illustrated embodiment as best shown in Figs. 6 and 7, the outer rim 14 includes a front facing circumferential edge 15, and a rear facing circumferential edge 16. The outer rim 14 includes a tapered frustoconical sidewall 18 extending inwardly from the front facing circumferential edge 15. The outer rim 14 further includes a generally tubular central wall 19 extending from the end of the sidewall 18. The central wall 19 can have any suitable shape. As will be explained in detail below, the sidewall 18 and the central wall 19 provide for attachment or connection locations of the wheel disc 12 to the outer rim 14. As stated above, the wheel 10 may be formed in a single casting such that the attachment or connection locations between the wheel disc 12 and the outer rim 14 are integrally formed together in the casting process.

[0043] The wheel disc 12 is generally comprised of a centrally located hub 20, a plurality of spokes 22, and a plurality of webs 24 that connect with and are disposed between adjacent spokes 22, as will be discussed in detail below. As stated previously, it is preferred that the wheel disc 12 is a single cast component such that the hub 20, the spokes 22, and the webs 24 are all formed together as a single cast.

[0044] The hub 20 is generally defined as the central portion of the wheel disc 12 from which the spokes 22 extend radially outward therefrom. The hub 20 defines a front side 26, as seen in Figs. 1, 3, 6, and 7, and a rear side, as seen in Figs. 2, 4, 6 and 7. The front side 26 is located on the outboard side of the wheel 10 when mounted on a vehicle. The rear side 28 is located on the inboard side of the wheel 10 when mounted on a vehicle. The hub 20 functions as a wheel mounting portion or center mounting portion of the wheel 10 for connecting with an axle (not shown) via a plurality of lug bolts (not shown) and lug nuts (not shown). In a preferred embodiment, the front side 26 of the hub 20 has a planar surface which is perpendicular to the wheel axis X. In a preferred embodiment, the front side 26 of the hub 20 is also planar and flush with front surfaces of the spokes and the webs 24, as will be discussed in detail below. The rear side 28 of the hub 20 may have any suitable shape. In the illustrated embodiment, the hub 20 includes five relatively stunted extensions 27 extending radially outwardly from a central body 29 of the hub 20 to generally define a 5 sided star shaped body. The extensions 27 of the hub 20 generally conform to and blend in with each of the spokes 22 at their connecting/mating locations. Of course, the hub 20 does not need to be "star" shaped but may have any suitable shape such as a standard or traditional circular shape.

[0045] The central body 29 of the hub 20 includes a centrally located pilot aperture or hub hole 30. The hub hole 30 extends along the wheel axis X. The hub hole 30 may accommodate a portion of the axle and/or receive a protective/decorative cap (not shown). A plurality of lug bolt receiving holes 32 are circumferentially spaced around the hub hole 30 and wheel axis X. In the illustrated embodiment, the hub 20 includes five lug bolt receiving holes 32, which are preferably formed through a respective extension 27 of the hub 20 in alignment with a respective one of each of the spokes 22. Alternatively, the number and/or location of the lug bolt receiving holes 32 may be other than illustrated if so desired. The lug bolt receiving holes 32 receive the lug bolts for securing the vehicle wheel 10 with lug nuts on the axle of an associated vehicle.

[0046] The details of the lug bolt receiving holes 32 will now be discussed. As best shown in Fig. 7, the lug bolt receiving holes 32 define a large diameter bore 33 formed in the front side 26 of the hub 20, and a smaller diameter bore 34 formed in the rear side 28 of the hub 20. Generally, the smaller diameter bores 34 are sized to receive threaded lug bolt shafts (not shown) while the larger diameter bores 33 are sized to receive lug nuts (not shown) and to accommodate a wrench or other tool for fastening the lug nuts to the lug bolts. The bores 33 and 34 define a circular ledge 37 therebetween having a front facing surface. The ledge 37 provides for a contact and mounting surface upon which a lug nut (not shown) is tightened on a corresponding lug bolt to clamp or mount the wheel 10 to the axle. The ledge 37 may be a planar surface perpendicular to the wheel axis X, or may be chamfered or formed as a curved surface to accommodate the contacting or mating portion of the lug nut. Alternatively, the lug bolt receiving holes 32 may be formed as a single hole or bore such that the lug nut will simply contact and engage with the front face 26 of the hub 20 when the wheel 10 is mounted.

[0047] As shown in Fig. 7, the large diameter bore 33 has a diameter Bi. The smaller diameter bore 34 has a diameter B2. Although the lug bolt receiving holes 32 may be formed to any size, in a preferred embodiment the diameter Bi of the large diameter bore 33 is within the range of about 20 millimeters to about 50 millimeters. It is noted that due to the shape and profile of the spokes 22 and the hub 20, windows or openings 38 may be formed through the cylindrical sidewalls of the larger diameter bores 33 such that the bores 33 do not have a continuous and smooth cylindrical sidewall. Such formations of the openings 38 results in providing a relatively small hub 20 which helps reduce the mass of the hub 20 and, therefore, overall weight of the wheel disc 12. Alternatively, the hub 20 may be formed such that the windows 38 are not present.

[0048] The wheel disc 12 and the outer rim 14 may be configured to have any suitable size. As shown in Fig. 4, the outer rim 14 may have an internal radius RR as measured generally from the wheel axis X to the inner wall 19 of the outer rim 14 where the spokes 22 are connected thereto. In a preferred embodiment, the radius RR is within a range of about 170 millimeters to about 290 millimeters. In a more preferred embodiment, the radius RR is within the range of about 220 millimeters to about 240 millimeters.

[0049] As shown in Fig. 4, the hub 20 has a general outermost radial length RH as measured from the wheel axis X to outer end of an extension 27. In a preferred embodiment, the radial length RH is within a range of about 60 millimeters to about 90 millimeters. In a more preferred embodiment, the radial length RH is within the range of about 70 millimeters to about 80 millimeters.

[0050] In the illustrated embodiment, the wheel disc 12 includes five spokes 22 which are shown as being formed integral with the hub 20 and the outer rim 14. Alternatively, the number of the spokes 22 may be other than illustrated if so desired. For example, the vehicle wheel 10 may include less than five spokes 22 or more than five spokes 22. Alternatively, the spokes 22 may be individually formed and secured to the outer rim 14 and the hub 20 by any suitable means and the outer rim 14 may be formed integral but separate from the hub 20 and joined thereto by any suitable method.

[0051] As best shown in Figs. 2 and 4, the spokes 22 are preferably essentially identical in structure with one another and thus only one will be described in detail below. Of course, one or more the spokes 22 may have differing shapes dependent of the placement about the hub 20 is so desired. Each of the spokes 22 can be described as having three sections or portions: a proximal portion, indicated generally at 40, a distal portion, indicated generally at 42, and an end portion, indicated generally at 44. The proximal portion 40 is connected to the hub 20 and extends radially outwardly therefrom. More specifically, the proximal portion 40 includes an inner end, indicated generally at 50, which is connected to and extends from a respective extension 27 of the hub 20. The proximal portion 40 includes an outer end, indicated generally at 52, which is connected to an inner end 54 of the distal portion 42. The distal portion 42 includes an outer end, indicated generally at 56, which is connected to an inner end, indicated generally at 58, of the end portion 44. The end portion 44 has an outer end, indicated generally at 60, which is connected to the outer rim. As stated above, the wheel disc 12 and the outer rim 14 are preferably formed as a single component, and thus the outer end 60 of the end portion 44 is integrally formed with portions of the sidewall 18 and the central wall 19 of the outer rim 14, as best shown in Fig. 7.

[0052] Referring now to Fig. 4, the spokes 22 can be described as having the three sections or portions (the proximal portion 40, the distal portion 42, and the end portion 44) due to the difference in their thicknesses (across the radial direction), and more specifically, the rate of change of their thicknesses. As shown in Fig. 4, the proximal portion 40 and the distal portion 42 have decreasing thickness as extending along the radial outwardly direction. However, they preferably do not decrease in thickness in the same proportional manner. The distal portion 42 decreases in thickness at a greater rate than compared to the proximal portion 40. Thus, the distal portion 42 tapers or "necks down" more rapidly along the outwardly radial direction. The reduction in thicknesses helps in reducing the overall mass and weight of the wheel disc 12 while still maintaining sufficient strength and rigidity thereof. In a preferred embodiment, both the proximal portion 40 and the distal portion 42 decrease thickness in a linear manner along their radial length such the outer edges, as viewing Fig. 4, are not curved but are generally straight. Of course, a slight curve may be formed at the junction of the outer end 52 of the proximal portion 40 and the inner end 54 of the distal portion 42 such that a sharp edge is not formed but rather forms a smooth blended transition.

[0053] As shown in Fig. 4, the inner end 50 of the proximal portion 40 has a thickness ti. The outer end 52 of the proximal portion 40 and the inner end 54 of the distal portion 42 has a thickness t2. The outer end 56 of the distal portion 42 and the inner end 58 of the end portion 44 has a thickness t3. The outer end 60 of the end portion 44 has a thickness U. In a preferred embodiment, the thickness ti is within a range of about 20 millimeters to about 46 millimeters. In a more preferred embodiment, the thickness ti is within the range of about 28 millimeters to about 38 millimeters. In a preferred embodiment, the thickness t2 is within a range of about 10 millimeters to about 36 millimeters. In a more preferred embodiment, the thickness t2 is within the range of about 18 millimeters to about 28 millimeters. In a preferred embodiment, the thickness t3 is within a range of about 5 millimeters to about 25 millimeters. In a more preferred embodiment, the thickness t3 is within the range of about 10 millimeters to about 20 millimeters. In a preferred embodiment, the thickness t4 is within a range of about 18 millimeters to about 38 millimeters. In a more preferred embodiment, the thickness U is within the range of about 23 millimeters to about 33 millimeters.

[0054] It is preferred that the proximal portions 40 of the spokes 22 are longer in radial length than the distal portions 42. The end portions 44 may also be shorter in radial length than the distal portions 42. As shown in Fig. 4, the spokes 22 generally have an overall radial length Lo. The proximal portions 40 have a radial length Li. The distal portions 42 have a radial length L2. The end portions 44 have a radial length L3. In a preferred embodiment, the radial length Lo is within a range of about 130 millimeters to about 230 millimeters. In a more preferred embodiment, the radial length Lo is within the range of about 150 millimeters to about 160 millimeters. In a preferred embodiment, the radial length Li is within a range of about 70 millimeters to about 110 millimeters. In a more preferred embodiment, the radial length Li is within the range of about 85 millimeters to about 95 millimeters. In a preferred embodiment, the radial length L2 is within a range of about 35 millimeters to about 55 millimeters. In a more preferred embodiment, the radial length L2 is within the range of about 40 millimeters to about 50 millimeters. In a preferred embodiment, the radial length L3 is within a range of about 5 millimeters to about 35 millimeters. In a more preferred embodiment, the radial length L3 is within the range of about 15 millimeters to about 25 millimeters.

[0055] In one embodiment, the radial length Li of the proximal portions 40 is about twice the size of the radial length L2 of the distal portions 42. Thus, in a preferred embodiment, the radial length Li of the proximal portions 40 is about 1.8 to about 2.2 times the radial length L2 of the distal portions 42.

[0056] Referring now to Fig. 7, it is shown in the preferred embodiment of the wheel 10 that the spokes 22 have a depth, as measured in an axial direction parallel to the wheel axis X, that is non-continuous or has a thinning portion in a central region of the spokes 22. This thinning helps to reduce the overall mass and weight of the spokes 22 while providing a relatively large depth at the connection points with the hub 20 and the outer rim 14. Thus, the depth between these connection points can be narrowed for reducing mass while maintaining sufficient strength and rigidity. More specifically, it is preferred that the hub 20 has a depth Di which is generally equal to or greater than the depths of the proximal portions 40 and the distal portions 42 of the spokes 22. In a preferred embodiment, the depth of the proximal portions 40 decreases as extending in the radial outwardly direction. The depth of the distal portions 42 preferably increases as extending in the radially outward direction. As shown in Fig. 7, the inner ends 50 of the proximal portions 40 have a depth Di and decrease to a depth D2 at their outer ends 52. The inner ends 54 of the distal portions 42 have a depth D2 and increase to a depth D3 at their outer ends 56. It is noted that the proximal portions 40 generally decrease in depth in a linear manner such that a rear surface 64 of the proximal portions 40 is relatively straight (although could have a slight curve). In contrast, the distal portions 42 generally increase in depth in an increasingly progressive (non-linear) manner such that a rear surface 66 of the distal portions has a curved profile. Of course, the changes in depths of the proximal and distal portions 40 and 42 may have any suitable configuration such as linear or non-linear.

[0057] In a preferred embodiment, the depth Di is within a range of about 40 millimeters to about 100 millimeters. In a more preferred embodiment, the depth Di is within the range of about 60 millimeters to about 80 millimeters. In a preferred embodiment, the depth D2 is within a range of about 20 millimeters to about 60 millimeters. In a more preferred embodiment, the depth D2 is within the range of about 30 millimeters to about 50 millimeters. In a preferred embodiment, the depth D3 is within a range of about 30 millimeters to about 110 millimeters. In a more preferred embodiment, the depth D3 is within the range of about 70 millimeters to about 90 millimeters.

[0058] Referring to Fig. 7, it is shown that the outer ends 60 of the end portions 44 of the spokes 22 are connected to the outer rim 14. However, the entire outer ends 60 need not be connected to the outer rim 14. The outer ends 60 of the end portions 44 may have a front portion 60a which is spaced from the frustoconical sidewall 18 of the outer rim 14 by a gap G. The outer ends 60 of the end portions 44 may define a rear portion, indicated generally at 60b, which integrally connects with the central wall 19 of the outer rim 14. The gap G helps in reducing mass of the spokes 22 and provides for an aesthetically pleasing appearance of the wheel 10.

[0059] Although the illustrated embodiment of the wheel 10 in Figs. 1 through 7 illustrates a one-piece or single cast component, it should be understood that the wheel disc 12 could be formed separate from the outer rim 14. For example, there is illustrated in Fig. 8 an alternate embodiment of a wheel 10' which is similar to the wheel 10. One exception being that the wheel 10' has a wheel disc 12' which is separate from an outer rim 14'. The wheel disc 12' may be attached to the outer rim 14' by any suitable manner, such as be welding an outer end 60' of spokes 22' to a central wall 19' of the outer rim 14'.

[0060] As stated above, the wheel disc 12 preferably includes membranes or webs 24 that connect with and are disposed between adjacent spokes 22. As such, the illustrated embodiment of the wheel disc 12 includes five webs 24. The shape and configuration of the webs 24 provides for a relatively large vent opening, indicated generally at 70, between outer ends of adjacent spokes 22. Thus, five vent openings 70 are provided in the illustrated embodiment of the wheel 10. The vent openings 70 are generally defined as windows or openings located between adjacent spokes 22, the central wall 19 of the outer rim 14, and an outer edge 72 of the webs 24. Of course, the webs 24 can include any number of vent openings or may be formed with no vent openings at all.

[0061] The webs 24 can generally be described as relatively thin membranes which span between adjacent spokes 22. The webs 24 generally provide structural stiffness to the wheel disc 12, thereby increasing its rigidity. As shown in Fig. 7, the webs 24 have a generally maximum depth Dw. The depth Dw is much thinner than the depth Di of the hub 20 or even the depth D2 of the narrowest portion of the spokes 22. The webs 24 provide rigidity for the wheel 10 while minimizing the mass required to support the spokes 22. In a preferred embodiment, the depth Dw is within the range of about 4 millimeters to about 20 millimeters. In a more preferred embodiment, the depth Dw is within the range of about 8 millimeters to about 12 millimeters. In the illustrated embodiment, the depth Di of the hub 20 is about 6 or 7 times the depth Dw. In the illustrated embodiment, the depth D2 or the narrowest portion of the spoke 22 is about 4 times the depth Dw.

[0062] Each of the webs 24 are preferably formed as a single structure spanning between adjacent spokes 22 as well as connecting with the hub 20, such as between adjacent extensions 27, as well as the central body 29 of the hub 20. Of course, the webs 24 can have any suitable configuration and may be connected to the hub 20, the spokes 22, and the outer rim 14 other than as shown in Figs. 1 through 7. For example, the webs 24 may have portions that are spaced from portions of the hub 20, the spokes 22, and/or the outer rim 14. The webs 24 may also have openings (not shown) formed therethrough as compared to having a single expanse.

[0063] Referring now to Figs. 3 and 4, each web 24 can be defined as having a center portion 80 and a pair of outer portions 82. The center portion 80 generally connects with the hub 20 and extends radially outwardly to the outer edge 72. Each of the outer portions 82 preferably continuously extend radially outwardly along the entire length of the proximal portions 40 of the respective pair of adjacent spokes 22. Outermost ends 82a of the outer portions 82 generally end and blend in with the distal portions 42 of the spokes 22. Of course, the outermost ends 82a may extend to the end portions 44 of the spokes 22 or to the outer rim 14. As shown in Fig. 4, the center portion 80 of the web 24 generally extends by a radial length Ri from the wheel axis X. The outermost ends 82a extend by a radial length R2 from the wheel axis X. In a preferred embodiment, the radial length Ri is within the range of about 80 millimeters to about 160 millimeters. In a more preferred embodiment, the radial length Ri is within the range of about 110 millimeters to about 130 millimeters. In a preferred embodiment, the radial length R2 is within the range of about 170 millimeters to about 250 millimeters. In a more preferred embodiment, the radial length R2 is within the range of about 200 millimeters to about 220 millimeters.

[0064] In a preferred embodiment, the outer edge 72 of each web 24 has a single arcuate shape such that the outer edge 72 at the center portion 80 of the web 24 is closer to the wheel axis X than the outer portions 82. The single arcuate shape can be defined as emanating from a center point CP having a radial length R3. The center point CP may be spaced from the wheel axis X by a radial length R4. In the illustrated embodiment, the radial length R4 is about double the radial length Ri. In a preferred embodiment, the radial length R3 is within the range of about 80 millimeters to about 210 millimeters. In a more preferred embodiment, the radial length R3 is within the range of about 130 millimeters to about 160 millimeters. In a preferred embodiment, the radial length R4 is within the range of about 200 millimeters to about 340 millimeters. In a more preferred embodiment, the radial length R4 is within the range of about 250 millimeters to about 290 millimeters.

[0065] As best shown in Figs. 1 and 3, the wheel disc 12 generally has a front face, indicated generally at 12a, which is relatively flat and having a generally 5-pointed star shape. This configuration provides for a relatively aerodynamic shape. Additionally, the relatively thin webs 24 provide for a relatively small addition of mass while giving the illusion of a relatively massive or substantial structural look when viewed from the front or outboard side.

[0066] More specifically, the hub 20, the spokes 22, and the webs 24 each have front faces or surfaces 20a, 22a, and 24a, respectively, that are preferably co-planar with one another (as shown in Fig. 7) and are perpendicular to the wheel axis X. Thus, the surfaces 20a, 22a, and 24a, preferably smoothly blend into one another, thereby forming a combined front face 12a having a smooth continuous profile. In the illustrated embodiment of Figs. 1 through 7, the front face 12a has a flat planner shape and is perpendicular to the wheel axis X. This configuration is schematically represented in Fig. 9. Of course, the front face 12a need not be perfectly flat but may have other suitable shapes and having a preferably aerodynamic shape. For example, there is schematically illustrated in Fig. 10 a wheel 10' having a front face 12a' having a slight convex or dometype shape. The front face 12a' extends axially outwardly in the outboard direction. Contrary, there is schematically illustrated in Fig. I l a wheel 10" having a front face 12a" having a slight concave shape. The front face 12a" extends axially inwardly towards the inboard direction.

[0067] Although the wheel 10 is shown such that the front face 12a is on the outboard side of wheel 10, it should be understood that the wheel disc could be "flipped" such that the front face 12a becomes the rear face and faces the inboard direction of the wheel. Thus, the shape of the spokes 22 and hub 20, as shown in the rear view of Fig. 4, would be visible when mounted on a vehicle. Of course, the bolt holes 32 would need to remain configured as shown such that the larger diameter portion faces the outboard side.

[0068] The embodiments of the various wheels and wheel discs described herein offer several advantages over conventionally known wheels. The embodiments of the wheel discs described herein were designed by a topology optimization methodology to obtain such advantages. For example, it is conventionally known that to increase the stiffness of the wheel, the mass of the wheel is generally increased. However, the wheel embodiments described herein have obtained an increase in stiffness while reducing the mass or weight of the wheel. It has been found that an increase in stiffness of about 133% can be obtained while reducing the weight by about 18% compared to conventionally known similar sized and similar material wheels. These advantages can be obtained by utilizing the thin web or membrane connecting adjacent spokes near the hub junction, and/or providing variational spoke cross section to allocate structural mass wherever necessary. These advantages are particular useful for wheels specifically designed for electric vehicles. Wheels for electric vehicles generally demand a relatively low weight or mass so that longer battery range distance can be obtained in such vehicles. Additionally, high stiffness of the wheels is preferred to help reduce NVH (Noise vibration and Harshness) created by the tire/wheel interaction. Since electrical vehicles are often less noisy compared to combustion engine vehicles, the perception of noise generated by the wheels can be more readily heard by the vehicle occupants and thus a reduction in wheel noise is greatly beneficial. The embodiments of the wheels described herein can be utilized for all types of wheel designs such as wheels and/or wheel discs manufactured in alloys such as magnesium, aluminum, steel, and/or a composite. Additionally, the embodiments of the wheels described herein are applicable to vehicle wheels having various dimensions such as wheels having diameters from about 381 millimeters (15 inches) to about 610 millimeters (24 inches), and having widths from about 88.9 millimeters (3.5 inches) to about 300 millimeters (11.8 inches).

[0069] The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiments. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.