Robot Joint Sealing Assembly Using Air Pressure Against Contamination

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Solution Overview

Problem

Current industrial robots face performance deterioration due to contamination and debris infiltration in the gap between the base and swing of Axis 1, which can lead to damage of internal structures, especially in humid environments where liquid pollutants can seep in.

Innovation Solution

A sealing arrangement featuring a circular sealing assembly with a gas inlet and outlet, maintaining a higher air pressure inside the cavity to prevent contaminants, comprising a sealing ring, base ring, and radial seal, with an air channel conducting pressured air to create a high-speed airflow that keeps contaminants out.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a gap exists in the region of Axis 1 between the base and the swing, then the robot joint can operate with simpler structure and easier manufacturing, but contaminants and debris can infiltrate into the internal space causing performance deterioration

Engineering Contradiction:
Improveprotection from contaminationVSAvoidsealing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies pneumatic pressure by introducing pressurized air into the cavity formed by the circular sealing assembly. The air channel conducts pressurized air flow into the cavity to maintain air pressure inside the cavity above the air pressure outside, creating a pressure differential that prevents contaminant infiltration while maintaining a relatively simple sealing structure.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent creates an inert environment by filling the cavity with pressurized air, which acts as a protective atmosphere that prevents contaminants from entering the internal space of the robot joint. This inert air environment effectively isolates sensitive internal components from harmful external factors without requiring complex mechanical seals.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Reliability

If pressurized air is used to prevent contamination, then the sealing effectiveness is improved, but the energy consumption increases due to continuous pressurized air supply

Engineering Contradiction:
Improvesealing effectivenessVSAvoidenergy for pressurized air supply
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by providing pressurized air only in the specific region where contamination protection is needed (the cavity between the circular sealing assembly and the internal components), rather than pressurizing the entire robot joint. This localized application of pressurized air achieves effective sealing while minimizing overall energy consumption.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If a circular sealing assembly with cavity is used, then contaminant infiltration is prevented, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveprotection from liquid pollutionVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs a circular sealing assembly that forms a cavity structure, which can be interpreted as a flexible sealing shell. This sealing assembly defines a tubular cavity in a circumferential direction and works in conjunction with pressurized air to prevent liquid pollution and contaminants from entering the internal space, achieving effective protection with a relatively straightforward manufacturing approach.

Inventive Principle:
Principle #30Flexible shells and thin films

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

Effectively isolates the internal space of Axis 1 from external contaminants, ensuring reliable protection and maintaining the robot's performance by preventing solid and liquid pollutants from entering, while allowing for a simple and cost-effective manufacturing process.

Implementation Method 1

maintain an air pressure inside the cavity above an air pressure outside the cavity

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a high-speed airflow out of the gas outlet. The circular sealing assembling comprises: a sealing ring forming a first side wall and a top wall of the cavity

Methodology Applied
Scientific EffectHigh-speed airflow: Jet

Data Source

PatentEP3548230B1Sealing arrangement for use in robot joint
Publication Date: 2023.07.12 ABB (SCHWEIZ) AG
  • EP3548230B1 patent drawingFigure 1
  • EP3548230B1 patent drawingFigure 2
  • EP3548230B1 patent drawingFigure 3

AI summary

A sealing arrangement (100) for use in a robot joint (200) is provided. The sealing arrangement (100) comprises: a circular sealing assembly (110) arranged between a swing (2) and a base (1) of the robot joint (200) in a longitudinal direction (Y), the circular sealing assembly (110) defining a tubular cavity (120) in a circumferential direction (C) and having a gas inlet (111) and a gas outlet (112); and an air channel (1a) coupled to the gas inlet (111) and operable to continuously conduct pressured air flow into the cavity (120) to maintain an air pressure inside the cavity (120) above an air pressure outside the cavity (120), and thereby a high-speed airflow out of the gas outlet (112).