Robot Joint Dynamic Sealing Structure for Low-Friction Dust Protection
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Solution Overview
Problem
Existing robot joints face issues with large frictional resistance and short service life due to dust and rainwater ingress, affecting normal movement and functionality.
Innovation Solution
A dynamic sealing structure using a soft and hard combined composite seal ring, where two sealing rings with different hardness butt against each other to maintain joint movement while preventing ingress, featuring small sliding friction and strong tolerance to load changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single sealing ring is used to seal the joint, then sealing effectiveness is improved, but frictional resistance increases and service life decreases
Solution Approach 1:
The sealing ring is divided into two separate sealing rings with different hardness values (first sealing ring with hardness 40-60 Shore A and second sealing ring with hardness 70-90 Shore A). Each sealing ring performs a specific function: the softer first sealing ring provides better sealing conformity, while the harder second sealing ring provides better wear resistance. This segmentation resolves the contradiction by distributing different functional requirements to different components.
Solution Approach 2:
The patent uses composite material principle by combining two sealing rings made of different materials with different hardness characteristics. The first sealing ring uses softer material (40-60 Shore A) for conformal sealing, while the second sealing ring uses harder material (70-90 Shore A) for wear resistance. This composite approach allows the sealing system to simultaneously achieve both good sealing effectiveness and long service life.
2Duration of action of moving object
If a sealing ring with high hardness is used to increase wear resistance, then service life is improved, but frictional resistance increases affecting normal movement
Solution Approach 1:
The sealing function is segmented between two rings: the first softer sealing ring (40-60 Shore A) contacts the rotating output shaft and provides low-friction sealing, while the second harder sealing ring (70-90 Shore A) provides structural support and wear resistance. This segmentation allows the system to achieve both movement smoothness and service life.
Solution Approach 2:
Different local qualities are assigned to different sealing rings: the first sealing ring has low hardness (40-60 Shore A) optimized for low-friction contact with the rotating shaft, while the second sealing ring has high hardness (70-90 Shore A) optimized for wear resistance and structural stability. Each local quality is optimized for its specific function.
3Ease of operation
If a soft sealing ring is used to reduce friction, then movement smoothness is improved, but wear resistance decreases
Solution Approach 1:
The sealing system is segmented into two rings with complementary properties: the first softer ring (40-60 Shore A) provides low-friction movement smoothness, while the second harder ring (70-90 Shore A) provides wear resistance. The segmented structure allows each ring to optimize for its primary function without compromising the other.
Solution Approach 2:
The patent applies composite material principle by using two different materials with different hardness characteristics in the sealing system. The softer material (40-60 Shore A) is used where low friction is critical, while the harder material (70-90 Shore A) is used where wear resistance is critical, achieving both movement smoothness and long service life through material composition.
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 structure effectively prevents dust and rainwater from entering the joint, protecting the robot's components while allowing normal movement with reduced friction and wear.
Implementation Method 1
the first sealing ring is deformed after squeezed to produce a pre-tightening force
Implementation Method 2
the friction coefficient of the first sealing ring is greater than the friction coefficient of the second sealing ring; since the friction of the second sealing ring is small, the wear is small
Data Source
AI summary
A robot joint having a dynamic sealing structure includes a power unit housing and an output shaft rotatable relative to the power unit housing. A soft and hard combined composite sealing ring is provided between the power unit housing and the output shaft. A soft first sealing ring is tightly connected with a joint to effectively seal the rotating joint. A hard second sealing ring slides relative to the joint while sealing the joint, thus reducing the obstruction to the movement of the joint. A quadruped robot applies the robot joint having the dynamic sealing structure. The two sealing rings with different hardness butt against each other to form a dynamic sealing structure used for sealing the joint and capable of maintaining the normal movement of the joint, effectively preventing rainwater, dust and the like from entering the joint, thus protecting the joint of the robot.