Spherical Wheel with Articulated Caps and Rollers
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Solution Overview
Problem
Conventional spherical wheels with directional capabilities face challenges in achieving small turning radii and experience discontinuity issues when transitioning through the equatorial plane, leading to potential loss of grip and noise, especially at high speeds, due to the design of hemispherical components and the need for additional rotational freedom to prevent slipping.
Innovation Solution
A spherical wheel design featuring two caps articulated with a pivot connection around an axis perpendicular to their respective planes, with circular openings for rollers that balance forces during transitions from one cap to another, allowing for smoother rotation and reduced kinetic energy input, thereby minimizing friction and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If two hemispheres are used with a horizontal drive shaft, then the wheel can rotate and provide directional movement, but the equatorial plane contact causes discontinuity and loss of traction
Solution Approach 1:
The wheel is divided into two caps instead of two hemispheres, with each cap bounded by an inclined plane rather than a horizontal equatorial plane. This segmentation allows the contact point to transition smoothly between caps along the inclined surfaces, eliminating the discontinuity that occurs when the equatorial plane contacts the ground in conventional designs.
2Strength
If the drive shaft diameter is increased to ensure rigidity, then the shaft can support the wheel structure, but the distance between hemispheres increases causing larger discontinuities
Solution Approach 1:
The inclined planes of the two caps are arranged asymmetrically relative to the horizontal equatorial plane, with each plane angled to facilitate smooth rolling transition. This asymmetric arrangement allows the caps to overlap in a way that eliminates the discontinuity gap, enabling the drive shaft to maintain rigidity without requiring excessive diameter while preserving continuous ground contact.
3Reliability
If rollers are added to prevent slippage at singularity, then directional stability is improved, but the device complexity increases
Solution Approach 1:
The inclined planes of the caps are designed with curved surfaces that follow the spherical geometry of the wheel, allowing smooth rolling transitions without the need for additional rollers or complex mechanical elements. The curved surfaces naturally guide the contact point through the singularity configuration, preventing slippage while maintaining a relatively simple structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enhances the wheel's ability to maintain contact and reduce rotational speed changes near singularities, minimizing friction and kinetic energy demands, thus improving stability and reducing the risk of jolts during high-speed movements.
Implementation Method 1
each cap being bounded by a plane, these two planes intersecting. In other words, the axes of the two pivot joints are no longer aligned.
Implementation Method 2
each wheel head (or hemisphere) includes a roller positioned in line with the pivot joint of that head, ensuring rolling on the spherical surface
Implementation Method 3
making the planes delimiting the two hemispheres intersecting. In practice, the term 'hemisphere' can no longer be used and is replaced by the term 'cap' to define the two wheel sections
Implementation Method 4
a spherical wheel, each capable of pivoting on its own axis
Data Source
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AI summary
The invention relates to a spherical wheel intended for moving a vehicle and to a vehicle using the wheel. The wheel (10) includes two cups (15, 16) whose surface follows the spherical surface of the wheel (10), the cups (15, 16) being each hinged by means of a pivoting link (19, 20) relative to a shaft. The wheel (10) also includes two casters (28, 29) each arranged in an opening of each of the cups (15, 16), the opening being centred on the axis (21, 22) of the corresponding pivot link (19, 20), each caster (28, 29) being aligned with the pivot link (19, 20) of the cup in question (15, 16). Each caster (28, 29) provides rolling on the spherical surface. Radii S of the opening of each cup (15, 6) and r of the corresponding caster (28, 29) are defined substantially such as to balance the forces necessary for driving a cup (15, 16) and the corresponding caster (28, 29) when the wheel (10) goes from resting on the ground on a cup (15, 16) at the edge of the opening to resting on the ground on the corresponding caster (28, 29).