Wheel assembly and robot cleaner having same
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Solution Overview
Problem
Conventional robot cleaners experience a decrease in drive wheel contact force when navigating surfaces with height differences due to changes in elastic member displacement, affecting traveling performance on various floor conditions.
Innovation Solution
A wheel assembly with a rotation arm and elastic member configuration that adjusts the position of the elastic member's second end relative to the rotation arm, increasing torque and maintaining contact force by changing the angle between the guide and elastic member from obtuse to acute, reducing the reduction in contact force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If an elastic member is used to press the drive wheel against the ground surface, then the drive wheel can generate frictional force for movement, but the contact force decreases when the drive wheel displacement changes on surfaces with height differences
Solution Approach 1:
The patent applies the dynamics principle by making the elastic member movable relative to the rotation arm. The second end of the elastic member is installed to be vertically movable on the rotation arm, allowing the system to dynamically adapt to changes in drive wheel displacement. This dynamic configuration enables the elastic member to maintain effective torque application even when the drive wheel position changes on surfaces with height differences, thereby stabilizing the contact force.
Solution Approach 2:
The patent utilizes parameter changes by modifying the angle between the guide and the elastic member. As the drive wheel moves, the angle changes from obtuse to acute, which changes the mechanical advantage and torque transmission characteristics. This parameter change allows the system to compensate for displacement variations and maintain consistent contact force on surfaces with height differences.
2Force
If the elastic member position is fixed on the rotation arm, then the structure is simple, but the torque decreases when the drive wheel displacement changes
Solution Approach 1:
The patent implements dynamics by allowing the elastic member to move vertically along the guide on the rotation arm. This movable installation, achieved through a guide structure, enables the elastic member to maintain optimal positioning relative to the rotation arm regardless of drive wheel displacement. The dynamic adjustment mechanism preserves torque effectiveness without requiring complex active control systems.
Solution Approach 2:
The guide structure serves as an intermediary element between the rotation arm and the elastic member. It provides a constrained path for the elastic member's movement, ensuring that the elastic member can adjust its position while maintaining proper alignment and force transmission. This intermediary structure simplifies the overall design compared to active control mechanisms while achieving the desired torque maintenance.
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 solution effectively maintains a consistent contact force of the drive wheel across different floor conditions, including height differences, by adjusting the elastic member's position to increase torque and reduce the decrease in contact force, ensuring stable movement.
Implementation Method 1
an elastic member including a first end installed at the main body and a second end vertically moveably installed at the rotation arm opposite the first end
Implementation Method 2
the drive wheel drives the main body of the robot cleaner using a frictional force generated between the drive wheel and a ground surface
Data Source
Figure 1
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Figure 3
AI summary
Disclosed herein are a wheel assembly and a robot cleaner including a main body and a wheel assembly coupled to the main body to guide movement of the main body. The wheel assembly has a rotation arm including a first end portion rotatably mounted on the main body, a drive wheel rotatably installed on a second end portion of the rotation arm opposite the first end portion, and an elastic member including a first end installed at the main body and a second end vertically moveably installed at the rotation arm opposite the first end, such that a reduction degree of a contact force due to a descent of the drive wheel.