Patent Application
20220402301
The invention relates in general to a vehicle wheel, and more particularly to a non-pneumatic tire and rim assembly.
The pneumatic tire has been the solution of choice for vehicular mobility for over a century. The pneumatic tire is a tensile structure. The pneumatic tire has at least four characteristics that make the pneumatic tire so dominate today. Pneumatic tires are efficient at carrying loads, because all of the tire structure is involved in carrying the load. Pneumatic tires are also desirable because they have low contact pressure, resulting in lower wear on roads due to the distribution of the load of the vehicle. Pneumatic tires also have low stiffness, which ensures a comfortable ride in a vehicle. The primary drawback to a pneumatic tire is that it requires compressed fluid. A conventional pneumatic tire is rendered useless after a complete loss of inflation pressure.
A tire designed to operate without inflation pressure may eliminate many of the problems and compromises associated with a pneumatic tire. Neither pressure maintenance nor pressure monitoring is required. Structurally supported tires such as solid tires or other elastomeric structures to date have not provided the levels of performance required from a conventional pneumatic tire. A structurally supported tire solution that delivers pneumatic tire-like performance would be a desirous improvement.
Non-pneumatic tires are typically defined by their load carrying efficiency. “Bottom loaders” are essentially rigid structures that carry a majority of the load in the portion of the structure below the hub. “Top loaders” are designed so that all of the structure is involved in carrying the load. Top loaders thus have a higher load carrying efficiency than bottom loaders, allowing a design that has less mass.
Thus, an improved non-pneumatic tire is desired that has all the features of the pneumatic tires without the drawback of the need for air inflation is desired. It is also desired to have an improved non-pneumatic tire that has longer tread life as compared to a pneumatic tire of the same size.
The invention provides in a first aspect a non-pneumatic tire and wheel assembly comprising: a rim, a spoke ring structure having an inner ring that is mounted on an outer surface of the rim, wherein the inner ring has one or more retention nubs aligned for reception in complementary shaped grooves on the outer surface of the rim, wherein the spoke ring structure has a plurality of spoke members, and an outer tread ring mounted on the outer circumference of the spoke ring.
“Aspect Ratio” means the ratio of a tire's section height to its section width.
“Axial” and “axially” means the lines or directions that are parallel to the axis of rotation of the tire.
“Belt Structure” or “Reinforcing Belts” means at least two annular layers or plies of parallel cords, woven or unwoven, underlying the tread, unanchored to the bead, and having both left and right cord angles in the range from 17° to 27° with respect to the equatorial plane of the tire.
“Breakers” or “Tire Breakers” means the same as belt or belt structure or reinforcement belts.
“Circumferential” means lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction; it can also refer to the direction of the sets of adjacent circular curves whose radii define the axial curvature of the tread as viewed in cross section.
“Radial” and “radially” mean directions radially toward or away from the axis of rotation of the tire.
The invention will be described by way of example and with reference to the accompanying drawings in which:
Referring to the Figures, a non-pneumatic tire and rim assembly 10 of the present invention is shown. The non-pneumatic tire and rim assembly 10 includes an outer annular tread ring 30, a spoke ring structure 20, and a split rim assembly formed of an inner rim 40 mounted to a spindle, and an outer rim 50. The outer annular tread ring 30 is preferably a one piece annular structure that is formed of a polymer, rubber or other desired elastomer. The tread ring 30 may be molded and cured as a one piece ring, and is mounted on the outer periphery of the spoke ring. The outer tread ring 30 is preferably removable from the outer spoke ring for replacement. The outer surface of the tread ring 30 may include tread elements such as ribs, blocks, lugs, grooves, and sipes as desired in order to improve the performance of the tire in various conditions.
The tread ring 30 may further include one or more reinforcement layers, wherein the reinforcement layers comprise a plurality of parallel reinforcement cords. The reinforcement cords may be angled in the range of −40 to +40 degrees with respect to the circumferential direction. Preferably, there are two reinforcement layers, with the first reinforcement layer angled in the range of 0 to 20 degrees, and the second reinforcement layer oriented at the same angle in the opposite direction, i.e., in the range of 0 to −20 degrees. An optional shear layer may be located between the two reinforcement layers.
The non-pneumatic tire and rim assembly 10 further includes a spoke ring structure 20. The spoke ring structure 20 has an inner ring 22 that is mounted on the inner rim 40 of the split rim assembly 60. The spoke ring structure 20 has an axial width approximately the same axial width of the nonpneumatic tire assembly 10. The inner ring 22 has a plurality of retaining nubs or projections 24, as shown in
The spoke ring structure further includes an outer ring 26 having an outer surface that is joined to the inner tread surface 32 by an adhesive polymer. The spoke ring structure further includes a plurality of spoke members that extend between the inner ring 22 to the outer ring 26. As shown in
The spoke ring structure 20 is preferably an integrally formed annular structure made of a resilient elastomeric material or moldable polymeric material such as natural rubber, styrene butadiene rubber, polybutadiene rubber or EPDM rubber or a blend of two or more of these rubbers which can be utilized in either injection molding or compression molding. The spoke ring structure 20 has an axial thickness equal to the axial thickness of the non-pneumatic tire. The spoke ring structure 20 has a plurality of spokes that connect an inner ring 22 and an outer ring 24.
The spoke disks are preferably formed of an elastic material, more preferably, a thermoplastic elastomer. The material of the spoke disks is selected based upon one or more of the following material properties. The tensile (Young's) modulus of the spoke disk material is preferably in the range of 15 MPa to 100 MPa.
The split rim assembly is formed of an inner rim 40 that is mounted to the vehicle spindle by fasteners. The rim 40 has a tire supporting outer circumferential surface with mating grooves 42. The spoke structure is then removably mounted on the inner rim so that the nubs are aligned and received in the mating grooves of the inner rim 40. The inner rim is shown in
The split rim assembly further includes an outer rim 50. The outer rim 50 has an outer surface having a plurality of complementary shaped grooves 52 that mate with the nubs of the spoke disk structure. The outer rim 50 secures to the inner rim 40 via fasteners.
In one example, the tire of the present invention is provided on a mobile delivery vehicle 100 as shown in
Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.
| Number | Date | Country | |
|---|---|---|---|
| 63211235 | Jun 2021 | US |
