Omni-directional Wheel with Offset Roller Rows
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Solution Overview
Problem
Traditional omni-directional wheels experience issues with scrubbing, wear, limited load capacity, and difficulty traversing obstacles due to tapered rollers, which lead to increased rolling friction and reduced stability.
Innovation Solution
The design features at least two rows of rollers with a common angle, axially and rotationally offset, providing a smooth rolling action with reduced scrubbing and wear, and allowing for a higher load capacity and improved obstacle traversal, while the hub is designed to support rollers from both ends and can be made from one piece or multiple parts for enhanced durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If tapered rollers are used in traditional omni-directional wheels, then the wheel can achieve sideways movement capability, but the variation in roller radius within the contact patch causes increased rolling friction and wear
Solution Approach 1:
The wheel is segmented into multiple independent roller elements (typically 3-7 rollers) arranged in a circular pattern around the hub. Each roller can be independently positioned and angled, allowing the wheel to achieve omni-directional movement through coordinated rotation of individual rollers rather than relying on a single tapered roller structure. This segmentation eliminates the continuous radius variation of tapered rollers while maintaining sideways movement capability.
Solution Approach 2:
Each roller in the invention is designed with uniform cylindrical geometry and consistent radius throughout its contact patch, unlike the tapered rollers of prior art. The local quality of each roller surface is optimized for smooth rolling contact with the ground, while the overall wheel achieves complex motion through the spatial arrangement and angular orientation of multiple such rollers rather than through tapering individual rollers.
2Volume of moving object
If smaller tapered rollers are used, then the wheel can maintain compact size, but the load carrying capacity of the wheel is limited
Solution Approach 1:
The invention transitions from relying on the length/diameter dimensions of single large tapered rollers to utilizing the angular distribution and spatial arrangement of multiple smaller cylindrical rollers. By distributing the load across multiple rollers positioned at different angles around the hub, the wheel achieves high load carrying capacity in a compact form factor that would be impossible with traditional tapered roller designs.
Solution Approach 2:
Multiple roller elements are combined into a single integrated wheel assembly, where the collective load-bearing capacity of several smaller rollers equals or exceeds that of a single large tapered roller. The hub structure merges these independent rollers into a unified omni-directional wheel system that maintains compact size while achieving superior load capacity through the synergistic arrangement of multiple contact points.
3Strength
If the size of rollers is increased to improve load capacity, then the wheel itself must be made larger to support the larger rollers
Solution Approach 1:
The invention resolves the scaling problem by moving from a single-dimension solution (one large roller) to a multi-dimensional arrangement (multiple smaller rollers distributed angularly around the hub). This allows the wheel to achieve high load capacity through the number and angular distribution of rollers rather than through the size of individual rollers, enabling compact wheel design with high load-bearing capability.
4Adaptability or versatility
If traditional omni-directional wheels are used, then sideways movement is enabled, but the capacity to traverse obstacles when traveling sideways is limited
Solution Approach 1:
The roller angles and orientations in the invention are specifically designed to be dynamic and adaptive during sideways movement. Unlike traditional fixed-angle tapered rollers, the cylindrical rollers can be positioned and angled to optimize contact with uneven surfaces and obstacles encountered during lateral traversal, enabling the wheel to maintain traction and overcome obstacles that would impede conventional omni-directional wheels.
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
This configuration results in a wheel with reduced wear rate, increased load capacity, improved traction, and enhanced ability to navigate obstacles, with an 8 times reduction in wear rate and twice the load capacity of comparable designs, while maintaining a compact size.
Implementation Method 1
The resultant scrubbing causes increased rolling friction and wear
Implementation Method 2
The hub is designed to support rollers from both ends and can be made from one piece or multiple parts for enhanced durability
Implementation Method 3
The rollers are angled such that their axes are not parallel to the plane of the wheel
Implementation Method 4
A vehicle equipped with such wheels can move forward and backward, sideways, rotate, or any combination thereof, by controlling the rotational speeds of the wheels
Data Source
AI summary
An omni-directional wheel includes a hub rotatable about a wheel axis and a first row of angled rollers about the hub each rotatably supported by the hub. There is at least a second row of angled rollers about the hub each also rotatably supported by the hub. The rollers of the second row are axially offset along the wheel axis from the first row, and rotationally offset from the first row about the wheel axis, and not coaxial with the rollers of the first row.