Inflatable Robot Joint Seal for Hygienic Gap Sealing

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Solution Overview

Problem

Existing robot joint sealing technologies face challenges in maintaining fluid-tight sealing while allowing for relative movement between joint parts, leading to wear and potential contamination in hygienic environments like food processing.

Innovation Solution

The implementation of an inflatable seal accommodated in the joint gap between the first and second parts of the robot joint, which can be pressurized to provide a fluid-tight sealing and controlled to minimize wear by adjusting pressure based on operational modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional seal is used to provide fluid-tight sealing in robot joints, then sealing performance is improved, but wear increases and lifespan decreases due to sustained dynamic loads and shear forces during operation

Engineering Contradiction:
Improvesealing performanceVSAvoidseal lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The seal pressure is made dynamically adjustable based on operational mode. During operation, lower pressure reduces wear on the seal. During washdown, higher pressure ensures fluid-tight sealing. This dynamic adjustment resolves the contradiction between maintaining sealing performance and extending seal lifespan.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The seal pressure parameter is changed based on operational requirements. By varying the pressure level according to whether the robot is operating or undergoing washdown, the system achieves both extended seal life during operation and reliable sealing during washdown, resolving the lifespan-performance contradiction.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If seal pressure is increased to ensure fluid-tight sealing during washdown, then sealing performance is improved, but wear and energy consumption increase during operation

Engineering Contradiction:
Improvesealing performanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The seal pressure is dynamically adjusted based on operational mode. During operation, lower pressure reduces energy consumption. During washdown, higher pressure ensures sealing performance. This dynamic control resolves the contradiction between sealing performance and energy consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The seal pressure is periodically adjusted between low (during operation) and high (during washdown) states. This periodic action ensures energy efficiency during operation while maintaining sealing performance during washdown, resolving the energy-performance contradiction.

Inventive Principle:
Principle #19Periodic action

3Reliability

If a rigid sealing structure is used to maintain sealing under high pressure, then sealing performance is improved, but adaptability to relative movement between joint parts decreases

Engineering Contradiction:
Improvesealing performanceVSAvoidadaptability to relative movement
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

An inflatable seal membrane is used instead of a rigid sealing structure. The flexible membrane can adapt to relative movement between joint parts while maintaining sealing performance when inflated. This resolves the contradiction between sealing performance and adaptability to movement.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The seal structure transitions from rigid to flexible through inflation. The inflatable membrane provides adaptability during movement and rigidity during sealing, resolving the contradiction between adaptability and sealing performance.

Inventive Principle:
Principle #15Dynamics

4Reliability

If multiple scavenging areas and inflatable seals are added to protect against contamination, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveprotection against contaminationVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The inflatable seal serves multiple functions: sealing during operation, sealing during washdown, and protecting against contamination. This multi-functionality reduces the need for separate scavenging areas and complex sealing structures, resolving the contradiction between reliability and complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Multiple sealing functions are merged into a single inflatable seal structure. By combining operation sealing, washdown sealing, and contamination protection into one versatile component, the system achieves high reliability without excessive complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 solution achieves better sealing performance and extends the lifespan of the seal, reducing wear and the risk of contamination, while maintaining a low cost and hygienic design.

Implementation Method 1

pressurizing the inflatable seal such that the inflatable seal expands in an axial direction towards the second part to seal the joint gap

Methodology Applied
Scientific EffectPressurisation: Pressure Increase

Implementation Method 2

the inflatable seal expands in an axial direction towards the second part to seal the joint gap between the first part and the second part

Methodology Applied
Scientific EffectElastic expansion: Elasticity

Data Source

PatentEP3843957B1Robot joint and method for sealing a joint gap of a robot joint
Publication Date: 2025.05.14 ABB (SCHWEIZ) AG
  • EP3843957B1 patent drawingFigure 1A~2B
  • EP3843957B1 patent drawingFigure 3~5
  • EP3843957B1 patent drawingFigure 6~7

AI summary

A robot joint (20) comprising a first part (22) and a second part (24) arranged to have a relative movement in between, and a joint gap (26) spacing the first part (22) and the second part (24) from each other, wherein the robot joint (20) comprises an inflatable seal (10) accommodated in the joint gap (26) to provide a fluid-tight sealing of the joint (20). The disclosure also relates to a robot (100) comprising the robot joint (20), a system comprising the robot (100) and a method for sealing a joint gap of a robot joint (20).