Non-Pneumatic Tire Expanded Region for Wheelbarrow Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires used in wheelbarrows are inadequate for rugged environments due to puncture susceptibility, varying tread surface engagement, balance issues, and rim width constraints, while polyurethane flat-free tires are too heavy for sandy soils, leading to instability and sinking.
Innovation Solution
A non-pneumatic tire with an expanded region and a ribbed flat tread surface, featuring a mounting region, transition region, and a wider expanded region for increased stability and a narrower rim, along with a ribbed tread surface to prevent lateral shifting and debris accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a pneumatic tire is used, then the weight and cost of the tire is reduced, but the tire is subject to deflation due to punctures and cannot maintain consistent tread surface engagement
Solution Approach 1:
The patent uses a solid polyurethane tire material that is inexpensive to manufacture and replace compared to pneumatic tires with steel belts and complex internal structures. The solid construction eliminates puncture vulnerability while keeping the tire itself a relatively simple, replaceable component.
Solution Approach 2:
The patent employs solid polyurethane as the tire material, which combines the benefits of rubber-like elasticity with the puncture resistance of solid material. This composite approach eliminates the need for inner tubes, chambers, and steel reinforcement layers found in pneumatic tires.
2Loss of energy
If a pneumatic tire with curved profile is used, then drag is minimized, but the active tread surface varies with load causing balance issues
Solution Approach 1:
The patent incorporates an arced transition region in the tire profile that provides a curved transition from the mounting region to the expanded region. This curvature minimizes drag when the tire engages the ground while the overall expanded geometry maintains a larger, more consistent tread footprint.
Solution Approach 2:
The patent transitions from a traditional two-dimensional tire cross-section to a three-dimensional expanded region that protrudes axially beyond the rim width. This dimensional change creates a larger contact patch with the ground, improving stability and balance while the arced transition maintains low drag characteristics.
3Reliability
If a polyurethane flat-free tire is used, then puncture resistance is improved, but the tire weight increases causing sinking in sandy soils
Solution Approach 1:
The patent changes the density and distribution parameters of the polyurethane material by creating an expanded region with axial protrusion. This geometric parameter change increases the tread surface area without proportionally increasing the overall tire mass, reducing ground pressure and preventing sinking in sandy soils while maintaining puncture resistance.
Solution Approach 2:
The expanded region creates additional volume in the axial dimension beyond the rim width, effectively increasing the tread footprint without requiring a proportional increase in tire mass. This dimensional expansion distributes the wheelbarrow's weight over a larger area, reducing ground pressure on sandy surfaces.
4Stability of the object's composition
If a polyurethane flat-free tire is used, then stability is improved, but the tire is too heavy for sandy soils requiring narrower rims
Solution Approach 1:
The expanded region protrudes axially beyond the rim width, creating a wider effective tread surface that improves stability without requiring a wider rim. This allows the use of narrower, simpler rims while maintaining the stability benefits of a wider contact patch.
Solution Approach 2:
The patent concentrates the stability-enhancing geometry in the expanded region at the tire's outer perimeter, while the mounting region near the rim maintains a narrower profile. This local differentiation allows the tire to achieve wide-tread stability without requiring a wide rim structure throughout the entire tire assembly.
Data Source
AI summary
A wheelbarrow that incorporates a stand coupled to a tub, a handle at the distal end of the wheelbarrow, and a wheel mount at the proximal end of the wheelbarrow. A wheel is rotatably coupled to the wheel mount and comprises a rim surrounded by a non-pneumatic tire. The tire has a mounting region and an expanded region. The axial width of the expanded region is substantially greater than the axial width of the mounting region and the tire has a relatively flat tread surface.