Robot Joint Reduction Gear Venting for Lubricant Leak Prevention

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Solution Overview

Problem

Existing robot systems with reduction gears face lubricant leakage issues due to external contact or collision, as the cylindrical body portion protruding from the casing is vulnerable to damage, leading to leakage of the sealed lubricant.

Innovation Solution

A robot system design where the air chamber is placed inside the base, communicating with the lubrication chamber, and the reduction gear is positioned between the base and the arm, ensuring an air layer is maintained to absorb pressure changes and prevent lubricant leakage, even during external contact or collision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cylindrical body portion is provided protruding from the reduction gear casing, then the air vent hole can be provided for pressure equalization, but the cylindrical body portion becomes vulnerable to external contact or collision causing damage and lubricant leakage

Engineering Contradiction:
Improvelubricant sealing reliabilityVSAvoidexternal contact or collision damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The air vent hole function is extracted from the external cylindrical body portion and integrated directly into the reduction gear casing. This eliminates the vulnerable protruding cylindrical body while maintaining the pressure equalization function through an internal air vent hole that communicates with the lubrication chamber.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The air vent hole is nested within the reduction gear casing structure itself rather than being an external component. The air vent hole is formed as an internal passage within the casing, eliminating the need for an external cylindrical body portion while maintaining the air communication function.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If the air chamber is placed outside the base, then it is easily accessible, but it becomes vulnerable to external contact or collision

Engineering Contradiction:
Improveair chamber accessibilityVSAvoidexternal contact or collision damage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The air chamber is nested within the base structure as an internal space. The base casing forms the air chamber that communicates with the lubrication chamber through an internal air vent hole, eliminating the need for an external air chamber while maintaining the pressure equalization function.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If the reduction gear is placed in the joint between base and arm, then it achieves the required mechanical function, but it becomes exposed to external contact or collision

Engineering Contradiction:
Improvereduction gear positioning flexibilityVSAvoidexternal contact or collision damage
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The reduction gear is pre-positioned within the joint structure with proper sealing arrangements before assembly. The sealed lubrication chamber and integrated air vent hole are prepared in advance to prevent lubricant leakage even when external contact or collision occurs during operation.

Inventive Principle:
Principle #10Preliminary action

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 configuration effectively reduces lubricant leakage by maintaining an air layer within the lubrication chamber, ensuring the lubricant remains sealed and the robot system operates reliably despite external interactions.

Implementation Method 1

an air chamber placed inside the housing, the air chamber communicating with the lubrication chamber

Methodology Applied
Scientific EffectAir layer pressure absorption: Compression

Data Source

PatentEP3444082B1Robot and robot system
Publication Date: 2022.08.31 YASKAWA DENKI KK
  • EP3444082B1 patent drawingFigure 1
  • EP3444082B1 patent drawingFigure 2
  • EP3444082B1 patent drawingFigure 3

AI summary

A robot (10) is provided which has: a housing including a plurality of joints; a reduction gear (5) placed in the joint, the reduction gear (5) including a lubrication chamber (26) where a gear mechanism (25) for slowing down and transmitting an output of a motor and lubricant (27) is sealed; and an air chamber (8a) placed inside the housing, the air chamber (8a) communicating with the lubrication chamber (26).