Structurally supported non-pneumatic wheel with reinforcements and method of manufacture
View Patent ↗A non-pneumatic wheel with reinforcement bands that provide structural support for the wheel and a method of manufacture of such a wheel are described. The reinforcement band forms part of an annular reinforcement structure that includes foam spacers positioned between the annular reinforcement band. The foam can be a reticulated foam into which a matrix material such as a polyurethane is introduced. The matrix material can also be used to form one or more features of the non-pneumatic wheel such as spokes, a mounting band, and a hub.
1. A method for manufacturing a non-pneumatic wheel, comprising:
positioning inner and outer reinforcement bands in a substantially concentric relationship inside a first mold having an inner side wall and an outer side wall;
connecting a plurality of spacing elements with the inner and outer reinforcement bands
inserting material to form a polymer foam spacer into the mold and into a substantially annular space located between the inner and outer reinforcement bands so as to provide a casting that includes the polymer foam spacer, the spacing elements, and the inner and outer reinforcement bands;
maintaining the relative positions of the inner and outer reinforcement bands in the first mold during said step of inserting material to form the polymer foam spacer;
providing a second mold having at least one cavity for the molding of one or more features of the non-pneumatic wheel;
placing the casting from said step of inserting into the second mold; and, introducing a matrix material into the second mold so as form one or more features of the non-pneumatic wheel.
2. A method for manufacturing a non-pneumatic wheel as in claim 1 , further comprising the step of reticulating the polymer foam spacer.
3. A method for manufacturing a non-pneumatic wheel as in claim 2 , wherein said step of reticulating the polymer foam spacer creates a fraction of voids to net volume of about 75 percent or greater.
4. A method for manufacturing a non-pneumatic wheel as in claim 1 , further comprising the step of placing a tread band around an intermediate from said step of introducing a matrix material.
5. A method for manufacturing a non-pneumatic wheel as in claim 1 , further comprising the step of placing a tread band around the casting from said inserting step before said step of placing the casting.
6. A method for manufacturing a non-pneumatic wheel as in claim 1 , wherein the matrix material of said step of introducing is created by an in situ reaction in voids of the polymer foam spacer.
7. A method for manufacturing a non-pneumatic wheel as in claim 1 , wherein the matrix material comprises a polyurethane elastomer that hardens after said step of introducing.
8. A method for manufacturing a non-pneumatic wheel as in claim 1 , further comprising the step of permeating the inner and outer reinforcement bands with the polymer foam spacer.
9. A method for manufacturing a non-pneumatic wheel as in claim 1 , wherein said step of introducing a matrix material further comprises the step of permeating voids in the polymer foam spacer with the matrix material.
10. A method for manufacturing a non-pneumatic wheel as in claim 1 , wherein the first mold has an outer side wall positioned outside of the outer reinforcement band and the first mold has an inner side wall positioned inside of the inner reinforcement band and further comprising the step of maintaining the inner and outer reinforcement bands in spaced relationship from the inner side wall and outer side wall, respectively.
11. A non-pneumatic wheel, the wheel defining radial and circumferential directions, the wheel comprising:
an annular band for supporting a ground contacting tread portion, said annular band extending about the circumferential direction;
an annular reinforcement structure positioned within said annular band, said reinforcement structure comprising:
an inner reinforcement band extending along the circumferential direction;
an outer reinforcement band extending along the circumferential direction and positioned radially-outside of said inner reinforcement band;
a plurality of spacing elements connected with at least one of said inner reinforcement band and said outer reinforcement band, and configured for maintaining the relative position of said inner reinforcement band, said outer reinforcement band, or both, within said annular reinforcement structure;
a foam spacer positioned at least partially between said inner and outer reinforcement bands;
a mounting band positioned radially-inward of said annular band; and
a plurality of web spokes connected between said annular band and said mounting band.
12. A non-pneumatic wheel as in claim 11 , wherein said foam spacer comprises a reticulated foam.
13. A non-pneumatic wheel as in claim 12 , wherein said reticulated foam has a fraction of voids to net volume of about 75 percent or greater.
14. A non-pneumatic wheel as in claim 11 , wherein said annular band, said reinforcement structure, said mounting band, and said web spokes are comprised of a polyurethane.
15. A non-pneumatic wheel as in claim 11 , further comprising a tread band supported by said annular band.
16. A non-pneumatic wheel as in claim 11 , wherein said foam spacer comprises a foam that is cast in place with said inner and said outer reinforcements.
17. A non-pneumatic wheel as in claim 11 , wherein said foam spacer permeates pores located in said inner reinforcement band, said outer reinforcement band, or both.