Patent Application
20230141345
The invention relates in general to a vehicle wheel, and more particularly to a nonpneumatic tire and wheel 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 nonpneumatic tire that has longer tread life as compared to a pneumatic tire of the same size.
The invention provides in a first aspect a nonpneumatic tire and wheel assembly comprising: a wheel, a spoke ring structure having a discontinuous inner ring that is mounted on an outer wheel mounting surface of the wheel, wherein the discontinuous inner ring has one or more gaps, 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.
The invention provides in a second aspect a nonpneumatic tire and wheel assembly comprising: a wheel, a spoke ring structure having an inner ring that is mounted on an outer rim mounting surface of the wheel, 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, wherein the wheel is axially recessed within the nonpneumatic tire and wheel assembly.
The invention provides in a third aspect a nonpneumatic tire and wheel assembly comprising: a wheel, a spoke ring structure having an inner ring that is mounted on an outer rim mounting surface of the wheel, 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, wherein at least one of the spoke members has an axially outer edge, wherein the axially outer edge is radiused.
The invention provides in a fourth aspect a nonpneumatic tire and wheel assembly comprising: a wheel, a spoke ring structure having an inner ring that is mounted on an outer rim mounting surface of the wheel, 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, wherein each spoke member has a radially inner portion and a radially outer portion, wherein the radially inner portion has an axial width less than the radially outer portion.
“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 pewheeleter 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 tread ring 30 may optionally include one or more layers 32 of reinforced fabric, wherein the reinforced fabric is preferably formed of parallel reinforcement cords. The reinforcement cords may be nylon, polyester or steel. The reinforced fabric layer 32 is preferably coated with rubber for adhesion to the tread. Alternatively, the tread ring may optionally include one or more layers of rubber coated wire that is spirally wound so that it forms an angle of about zero degrees, so that the wire is oriented in the circumferential direction. More preferably, there are at least two layers of reinforced fabric with no spacing in between.
The nonpneumatic tire and wheel assembly 10 further includes a spoke ring structure 20. The spoke ring structure 20 has an inner portion 22 that is mounted on the wheel rim mounting surface 42. The inner portion 22 is a discontinuous ring divided into two or more segments with gaps 24 between the segments and along the inner radius to allow for ease of assembly with the wheel. Preferably, the inner portion 22 has an interference fit on the outer rim mounting surface 42 of the wheel 40.
The spoke ring structure further includes an outer ring 26 having an outer surface that is joined to the inner tread surface 34 by an adhesive polymer. The spoke ring structure further includes a plurality of spoke members that extend between an inner portion 22 to the outer ring 26. In a first example shown in
As shown in cross-section in
The spoke ring structure 20 is preferably an integrally formed annular structure preferably made of a resilient and/or moldable polymeric material such as but not limited to, a thermoplastic elastomer, natural rubber, styrene butadiene rubber, polybutadiene rubber or EPDM rubber or a blend of two or more of these materials which can be utilized in either injection molding or compression molding. The material of the spoke ring structure 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 5 MPa to 100 MPa, and more preferably in the range of 10 MPa to 70 MPa.
The wheel 40 is shown in
In one example, the tire of the present invention is provided on a mobile delivery vehicle. The mobile delivery vehicle has at least three, preferably four or more nonpneumatic tire and wheel assemblies of the present invention, and more particularly, six nonpneumatic tire and wheel assemblies. The tire has an outer rubber tread and a spoke ring structure that is injection molded and formed of a polyurethane material having a tensile modulus of about 20-25 MPA. The spoke ring structure may also be three dimensionally printed. The nonpneumatic tire and wheel of the present invention has a spring rate in the range of 250 to 300 pounds per inch. The nonpneumatic tire and wheel of the present invention has an axial width of about 1.5 inches with 36 X shaped spokes having a radial height of about 1 inch. While the nonpneumatic tire and wheel assembly is described as having X shaped spokes, other spoke designs could be used. The wheel has an outer diameter of about 5 inches, but could be sized to be smaller in the outer diameter to provide a greater radial height of the spoke ring structure. The weight of the tire is 570 grams and is designed for a minimum tread life of 5000 km, preferably 20,000 km or more.
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 | |
|---|---|---|---|
| 63263713 | Nov 2021 | US |
