Systems and methods for providing wheels having variable spring rates

Patent metadata

Field	Value
Publication number	US-12145404-B2
Application number	US-202016986349-A
Country	US
Kind code	B2
Filing date	Aug 6, 2020
Priority date	Aug 9, 2019
Publication date	Nov 19, 2024
Grant date	Nov 19, 2024

Abstract

A wheel is disclosed that includes an inner hub, an outer rim, and a plurality of resilient elements that exhibit a first spring constant that is the same for all elements, and a second spring constant that is higher than the first spring constant for elements being compressed beyond a threshold deflection.

First claim

What is claimed is:

1. A wheel comprising:
an inner hub;
an outer rim; and
a plurality of resilient elements extending in a generally radial direction between the inner hub and the outer rim,
each of the plurality of resilient elements comprising an arcuate portion arranged between a hub connection portion and a rim connection portion, the hub connection portion of each resilient element connecting to the inner hub and the rim connection portion of each resilient element connecting to the outer rim, the hub connection portion and the rim connection portion of each resilient element being radially aligned,
the arcuate portion of each resilient element extending in one of a first circumferential direction and a second circumferential direction, wherein the plurality of resilient elements are arranged in an alternating pattern such that the arcuate portion of each resilient element alternates between extending in the first circumferential direction and the second circumferential direction,
wherein adjacent resilient elements define an elliptical void therebetween, the elliptical void having a major axis that is angled with respect to the generally radial direction of the adjacent resilient elements, and further wherein each apex of the arcuate portions of the adjacent resilient elements alternates from being closer to the outer rim than to the inner hub and closer to the inner hub than the outer rim, such that power is transferred from the inner hub to the outer rim faster when a rotational direction of the inner hub is in the direction of the major axis than when the rotational direction of the inner hub is opposite the direction of the major axis.

2. The wheel as claimed in claim 1 , wherein, upon movement between the hub and the rim up to a threshold distance, one or more resilient elements among the plurality of resilient elements between the inner hub and the outer rim in a direction of a movement are compressed at a first spring rate, and one or more other resilient elements among the plurality of resilient elements between the inner hub and the outer rim opposite the direction of the movement are in tension at the first spring rate.

3. The wheel as claimed in claim 2 , wherein, upon movement between the inner hub and the outer rim beyond a threshold distance, the one or more resilient elements between the inner hub and the outer rim in the direction of the movement are compressed at a second spring rate, and the one or more other resilient elements between the hub and rim opposite the direction of the movement are in tension at the first spring rate, wherein the second spring rate is significantly higher than the first spring rate.

4. The wheel as claimed in claim 1 , wherein the wheel is formed of a single monolithic structure that is injection molded.

5. The wheel as claimed in claim 1 , wherein the wheel is formed of a single monolithic structure that is 3D printed.

6. The wheel as claimed in claim 1 , wherein the wheel includes a textured outer tread formed of an elastomeric material.

7. The wheel as claimed in claim 6 , wherein the textured outer tread is fitted to an outer surface of the wheel.

8. A wheel interface for a non-pneumatic wheel defining radial and circumferential directions, the wheel interface comprising:
a plurality of resilient members, each resilient member comprising a curved resilient portion extending in a radial direction from an inner connection portion to an outer connection portion, the inner connection portion and the outer connection portion being radially aligned,
the curved resilient portion of each resilient member being curved in one of a first circumferential direction and a second circumferential direction, wherein the curved resilient portion of each resilient member that is curved in the first circumferential direction is adjacent the curved resilient portion of another resilient member that is curved in the second circumferential direction,
wherein the curved resilient portion of each resilient member has a peak defined as an area a maximum distance away from a line going through the inner connection portion and the outer connection portion,
wherein, upon compression of any of the plurality of resilient members beyond a threshold deflection, the peak of the curved resilient portion for the compressed resilient member comes into contact with the peak of the curved resilient portion for an adjacent resilient member, and
wherein a location of the peak of the curved resilient portion for each resilient member alternates between being closer to the inner connection portion and being closer to the outer connection portion.

9. The wheel interface as claimed in claim 8 , wherein the plurality of resilient members exhibit a first generally constant spring rate when compressed to the threshold deflection, and, upon contacting an adjacent resilient member among the plurality of resilient members, exhibit a second generally constant spring rate, the second generally constant spring rate being higher than the first generally constant spring rate.

10. The wheel interface as claimed in claim 8 , wherein the plurality of resilient members have a first thickness at the inner and outer connection portions, and a second thickness at the peak, wherein the first thickness is thicker than the second thickness.

11. The wheel interface as claimed in claim 8 , wherein the non-pneumatic wheel is formed of a single monolithic structure that is injection molded.

12. The wheel interface as claimed in claim 8 , wherein the non-pneumatic wheel is formed of a single monolithic structure that is 3D printed.

13. The wheel interface as claimed in claim 8 , wherein the non-pneumatic wheel includes a textured outer tread formed of an elastomeric material.

14. The wheel interface as claimed in claim 13 , wherein the textured outer tread is fitted to an outer surface of the non-pneumatic wheel.

15. A non-pneumatic wheel comprising:
a hub defining an axis of rotation of the wheel and having an outer attachment surface;
a rim having an outer ground-engaging surface and an inner attachment surface; and
a plurality of resilient elements extending between the outer attachment surface and the inner attachment surface, each of the plurality of resilient elements having a curved surface having an apex of curvature in a circumferential direction disposed between a hub connection portion and a rim connection portion, the hub connection portion and the rim connection portion of each resilient element being radially aligned,
wherein, the plurality of resilient elements are arranged to define pairs of opposed resilient elements spaced circumferentially around the wheel, wherein the opposed resilient elements are curved in generally opposite and facing directions,
wherein, upon compression of the plurality of resilient elements as the hub and the rim move towards one another, the curved surfaces of the plurality of resilient elements bow in the circumferential direction of their curvature during a first compression stage, and upon making contact with an adjacent curved surface, begin a second compression stage during which the curved surfaces are prevented from bowing further in the circumferential direction of their curvature, and
wherein each apex of curvature of adjacent resilient elements alternates from being closer to the rim than to the hub and closer to the hub than the rim.

16. The non-pneumatic wheel as claimed in claim 15 , wherein the plurality of resilient elements exhibit a first spring rate during the first compression stage, and a second spring rate during the second compression stag

Assignees

• Berkshire Grey Operating Company Inc

Inventors

• Long Guoming Alex

Classifications

• B60B9/26 Primary

  comprising resilient spokes · CPC title

• B60C7/146

  extending substantially radially, e.g. like spokes · CPC title

• B60C7/14

  using springs · CPC title

• B60B9/04 Primary

  in leaf form · CPC title