SYSTEM FOR NON-PNEUMATIC SUPPORT OF A VEHICLE

Abstract

An assembly has a wheel and a nonpneumatic tire. The nonpneumatic tire includes a plurality of helical springs. Each helical spring includes a first end portion, a second end portion, and an arching middle portion. Each helical spring being is interlaced with at least one other helical spring thereby forming a laced toroidal structure extending about an entire circumference of the nonpneumatic tire. The toroidal structure supports an entire load placed on the nonpneumatic tire. The plurality of helical springs are constructed of a predetermined material that maintains strength and ductility down to 17 K.

Claims

1. An assembly having a wheel and a nonpneumatic tire, the nonpneumatic tire comprising a plurality of helical springs, each helical spring comprising: a first end portion, a second end portion, and an arching middle portion, each helical spring being interlaced with at least one other helical spring thereby forming a laced toroidal structure extending about an entire circumference of the tire, the toroidal structure supporting an entire load placed on the nonpneumatic tire, the first end portions of a plurality of helical springs being directly secured to a first annular structure of the wheel and the second end portions of the plurality of helical springs being directly secured to a second annular structure of the wheel, the first end portion of each of the plurality of helical springs being oriented coaxially with the second end portion of each of the plurality of helical springs, the plurality of helical springs being constructed of a predetermined material that maintains strength and ductility down to 17 K.

2. The assembly as set forth in claim 1 wherein the predetermined material is 304ELC stainless steel.

3. The assembly as set forth in claim 1 wherein the predetermined material is 310 Low-C stainless steel.

4. The assembly as set forth in claim 1 wherein the predetermined material is 2024-T4 aluminum.

5. The assembly as set forth in claim 1 wherein the predetermined material is 6061-T6 aluminum.

6. The assembly as set forth in claim 1 wherein the predetermined material is 2219-T87 aluminum.

7. The assembly as set forth in claim 1 wherein the predetermined material is 5052-H38 aluminum.

8. The assembly as set forth in claim 1 wherein the predetermined material is 5083-H38 aluminum.

9. The assembly as set forth in claim 1 wherein the predetermined material is nickel based Monel.

10. The assembly as set forth in claim 1 wherein the predetermined material is TD Nickel.

11. The assembly as set forth in claim 1 wherein the predetermined material is nickel based Hastlelloy B.

12. The assembly as set forth in claim 1 wherein the predetermined material is nickel based Inconel X.

13. The assembly as set forth in claim 1 wherein the predetermined material is nickel based Inconel 718.

14. The assembly as set forth in claim 1 wherein the predetermined material is nickel based Rene 41.

15. The assembly as set forth in claim 1 wherein the predetermined material is 5Al-2.5Sn—Ti ELI titanium.

16. The assembly as set forth in claim 1 wherein the predetermined material is Ti45A [AMS 4902] titanium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The structure, operation, and advantages of the present invention will become more apparent upon contemplation of the following description as viewed in conjunction with the accompanying drawings, wherein:

[0076] FIG. 1 represents a schematic illustration of an example tire and wheel assembly in accordance with the system of the present invention.

[0077] FIG. 2 represents a section taken through line 2-2 in FIG. 1.

[0078] FIG. 3 represents a section taken through line 3-3 in FIG. 2.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE SYSTEM OF THE PRESENT INVENTION

[0079] A tire for use with the present invention and as described by U.S. Pat. Nos. 8,141,606 and 8,662,122, incorporated herein by reference in their entirety, may include an interlaced plurality of helical springs (i.e., coiled wires which deform elastically under load with little energy loss). The tire may define a toroidal shaped structure for mounting to a wheel. The tire may contour to a surface on which the tire engages to facilitate traction while mitigating vibration transmission to a corresponding vehicle. The helical springs support and/or distribute a load of a vehicle.

[0080] Under the weight of the vehicle, the tire may be driven, towed, or provide steering to the vehicle. The helical springs of the tire may passively contour to any terrain by flexing and moving with respect to each other. The interlaced structure of the helical springs provides stability to the tire and prevents the structure from collapsing as the tire rotates and engages variably terrain.

[0081] The helical springs of the tire may be resilient through a finite range of deformation, and thus a relatively rigid frame may be used to prevent excessive deformation. Radially oriented springs may be used to connect the tire to the wheel. These springs may be interlaced. Other springs may be incorporated with the tire at any bias angle, from radial to circumferential, with the purpose of distributing load. These other springs may be helical springs. Further, as one example, these other springs may extend circumferentially around the tire at a radially outer portion of the tire.

[0082] As one example, four basic steps may be utilized to manufacture one example tire: (i) twisting helical springs together to form a rectangular sheet with a length corresponding to the desired tire circumference; (ii) interlacing ends of the rectangular sheet of springs to form a mesh cylinder; (iii) collapsing one end of the mesh cylinder and attaching it to a rim of a wheel; and (iv) flipping the other end of the mesh cylinder inside out and attaching it to another axially opposite rim of the wheel.

[0083] The tire for use with the present invention may be utilized on Earth, the Moon, Mars, and/or any other planetary body, since its elements operate reliably in atmospheric and terrain conditions of these planets. The tire may be utilized on its own, or incorporated as a partial or auxiliary load support/distribution system within another tire type. The tire, however, requires no air, requires no rubber, operates in difficult environments, and contours to all terrains.

[0084] The tire provides an improvement over the conventional wire mesh tire of the Apollo LRV. The tire provides higher load capacity, since wire size of the helical springs may be increased with relatively little functional alteration. The tire provides a longer cycle life, since wire stresses of the helical springs are more uniformly distributed throughout the structure. Further, the tire provides relatively low weight per unit of vehicle weight supported, since the interlaced helical spring network is fundamentally stronger than a crimped wire mesh. Additionally, the tire provides improved manufacturability, since the helical springs may be screwed, or interwoven, into one another, rather than woven together. Furthermore, helical springs are able to compress and elongate to accommodate manufacturing variations. Finally, the tire provides improved design versatility, since load distribution springs may be added to vary the tire strength in different tire locations and directions.

[0085] A tire for use with the present invention may thus be utilized where low vehicle energy consumption is required, where tire failure poses a critical threat, for traveling through rough terrain, where the vehicle is exposed to extreme high and low temperatures or high levels of radiation. As shown in FIGS. 1 through 3, an example assembly 100 in accordance with the present invention includes a wheel 200 and a tire 300. The wheel 200 has an annular rim 202 at each axial side for securing the tire 300 to the wheel. Each rim is fixed 202 relative to the other rim 202. Each rim 202 may include a plurality of socket holes 204 for aligning the tire 300 with the rim. Any other suitable means may be used for securing the tire 300 to the rim 200.

[0086] The tire 300 may include a plurality of helical springs 310 extending radially away from the wheel 200 in an arching configuration and radially back toward the wheel. Each end 315 of each spring 310 may be secured to wheel at a corresponding rim 202 of the wheel. Each spring 310 has a middle portion interconnecting the ends 315. Each end 315 may be secured at an axial orientation or at an angled orientation, with the spring 310 extending outward from one rim 202, then away from the wheel 300, then back over itself, then inward, and finally toward the other rim 202. Each end 315 of each spring may thereby be oriented coaxially (or at an angle) with the other end 315 of the same spring.

[0087] Further, each spring 310 may be interlaced with adjacent springs 310 enabling load sharing between springs. Each spring 310 is interlaced, or interwoven, with an adjacent spring 310 on a first side of the spring and further being interlaced with an adjacent spring 310 on a second opposite side of the spring. Thus, the springs 310 extend radially and axially and form a laced toroidal structure extending about an entire circumference of the tire 300 (FIGS. 1 through 3).

[0088] The helical springs 310 may be any suitable length, gauge, and pitch. The helical springs 310 may vary in coil diameter (i.e., barrel springs may be used) to create continuity in the mesh through the range of radial positions in the tire. The helical springs 310 may be further structured as two or more plies, one or more radially inner plies being radially overlapped by one or more radially outer plies.

[0089] The purely metallic, conventional non-pneumatic spring tire 300 described above has been developed for space applications. The structure is a series of interwoven springs as seen in FIG. 3. This structure was well suited to space applications where rubber is not permitted due to temperature variations (40K to 400K). In addition, the spring tire 300 may achieve excellent traction where soil composition may be soft sand such as the Moon.

[0090] It has been found that permanently shadowed craters on the Moon may feature some of the lowest temperatures in the solar system—down to 20 K. Water ice may be stable at these temperatures, and it is believed that some of these craters harbor significant ice deposits. Consequently, according to the present invention, the spring tire 300 may be constructed of a material that retains its strength and ductility at temperatures as low as 17 K.

[0091] A conventional spring tire for the Moon has been constructed of materials which can survive and remain stable between 40 K and 400 K based on the then knowledge of the lunar temperature. As stated above, lunar temperatures may be as cold as 20K. Therefore, a new spring tire needs to be considered for lunar exploration to the permanent shadowed region of the lunar surface. Thus, a spring tire 300 with metallic alloys that would survive temperatures ranging from 17 K to 400 K is desirable. Ideally, such metallic alloys would function at extremely low cryogenic temperatures as low as 17 K and even down to 0 K.

[0092] One suitable material may be 304ELC stainless steel and/or 310 Low-C stainless steel. Such a material may maintain strength and ductility down to 17 K.

[0093] Another suitable material may be 2024-T4 aluminum, 6061-T6 aluminum, 2219-T87 aluminum, 5052-H38 aluminum, and/or 5083-H38 aluminum. Such a material may maintain strength and ductility down to 17 K.

[0094] Still another suitable material may be nickel based monel, TD Nickel, nickel based Hastlelloy B, nickel based Inconel X, nickel based Inconel 718, and/or nickel based Rene 41. Such a material may maintain strength and ductility down to 17 K.

[0095] Yet another suitable material may be 5Al-2.5Sn—Ti ELI titanium and/or Ti45A [AMS 4902] titanium. Such a material may maintain strength and ductility down to 17 K.

[0096] Still another suitable material may be Nickel-Based Inconel 600. Such a material may maintain strength and ductility down to 17 K.

[0097] Yet another suitable material may be multiphase Co-35Ni-20Mo-10Cr alloy MP35N. Such a material may maintain strength and ductility down to 17 K.

[0098] In the foregoing description, certain terms have been used for brevity, clearness, and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirement of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the present invention is by way of example, and the scope of the present invention is not limited to the exact details shown or described.

[0099] Having now described the features, discoveries, and principles of the present invention, the manner in which the present invention is constructed and used, the characteristics of the construction, and the advantageous, new, and useful results obtained, the scope of the new and useful structures, devices, elements, arrangements, parts, and combinations are hereby set forth in the appended claims.