Wheel With Radially Retractable Arms For Step Navigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wheels for self-propelled vehicles, such as home delivery robots and electric wheelchairs, face complexity in actuator mechanisms and stability issues when transitioning between flat ground and step travel, with previous designs having complicated transformation mechanisms and instability due to non-circular outer rings.
Innovation Solution
A wheel design featuring an outer ring that rotates about a central axis, with independently rotating arm drive gears and arms that protrude or retract radially to navigate steps while maintaining stability on flat ground, utilizing a simple structure and combined torque from arm and outer ring actuators, and an electromagnetic clutch for power transfer control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If transformation actuators are disposed on the wheel side for each divided part, then the wheel can move over steps, but the transfer unit from drive source to actuator becomes complicated
Solution Approach 1:
The patent combines multiple divided parts into a single integrated outer ring structure that transforms as a whole rather than through multiple independent actuators. The outer ring includes multiple arms that can be opened or closed collectively, eliminating the need for separate transfer units for each divided part while maintaining step crossing capability.
Solution Approach 2:
The outer ring serves multiple functions: it acts as the rolling surface on flat ground, transforms to cross steps by opening arms, and provides structural support. This multi-functional design eliminates the need for separate transformation actuators, simplifying the overall drive system while maintaining adaptability.
2Adaptability or versatility
If the outer ring is transformed to move over steps, then step crossing is enabled, but the outer ring is not a complete circle causing instability at traveling
Solution Approach 1:
The outer ring is designed to dynamically change its configuration based on terrain conditions. On flat ground, the arms are closed forming a complete circle for stable rolling. When encountering steps, the arms open to enable the wheel to climb. This dynamic transformation allows the outer ring to maintain circular symmetry during normal travel while adapting to obstacles.
Solution Approach 2:
The outer ring is segmented into multiple arms that can independently open or close. These segments are arranged symmetrically around the wheel center, ensuring that when closed, they form a complete circle for stable traveling. When opened, they provide the necessary geometry for step crossing while maintaining balanced distribution of forces.
3Adaptability or versatility
If multiple actuators are used for arm transformation, then step crossing is achieved, but synchronized control becomes complex
Solution Approach 1:
The patent reduces multiple arm transformation actuators to a single actuator that controls the opening and closing of all arms simultaneously. This single actuator is connected to the outer ring such that its rotation directly opens or closes the arms in unison, eliminating the need for complex synchronization control while maintaining step crossing capability.
Solution Approach 2:
The outer ring structure itself provides the mechanical linkage that synchronizes arm movement. As the single actuator rotates the outer ring, the arms automatically open or close in coordination through the ring's geometry, without requiring electronic synchronization or complex control systems.
Data Source
AI summary
A wheel and a vehicle each having a simple structure and capable of moving over a step while maintaining stability at flat ground traveling are provided. A wheel includes an outer ring that rotates about a wheel rotational axis, an arm drive gear that rotates independently from the outer ring about the wheel rotational axis, and an arm capable of rotating about an arm rotational axis fixed to the outer ring, the arm being configured to partially protrude outside from an outer peripheral surface of the outer ring in a radial direction as the arm drive gear rotates relative to the outer ring in one direction (normal rotational direction) and to be housed inside in the radial direction from the outer peripheral surface of the outer ring as the arm drive gear rotates relative to the outer ring in the other direction (reverse rotational direction) opposite to the one direction.