External Swing Damper for Rotary Joint Friction Disc Replacement

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Solution Overview

Problem

Existing swing dampers for rotary joints in lifting equipment face issues with non-adjustable friction discs and the risk of glued friction linings failing, leading to contamination and reduced effectiveness.

Innovation Solution

A swing damper design where friction discs are attached outside the rotary joint with pressure discs and friction elements in sockets, allowing for adjustable pressure and easy replacement, eliminating the need for glued joints and reducing the risk of failure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If friction discs are integrated inside the rotary joint, then the damping function is compact, but the friction discs cannot be replaced without disassembling the entire rotary joint

Engineering Contradiction:
Improveease of friction disc replacementVSAvoidrotary joint assembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The swing damper is separated from the rotary joint assembly, allowing the friction discs to be accessed and replaced independently. The damper consists of separate components (friction discs, pressure discs, springs) that can be serviced as a modular unit without disassembling the entire rotary joint.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The friction discs are extracted from the internal rotary joint structure and placed in an external swing damper assembly. This extraction allows the friction discs to be easily accessible for replacement while maintaining the damping function separate from the main rotary joint mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If glued friction linings are used, then the friction disc structure is simple, but the glued joint may fail causing contamination and reduced effectiveness

Engineering Contradiction:
Improvefriction lining reliabilityVSAvoidcontamination from failed glued joint
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The friction discs are designed as replaceable wear components that can be easily replaced when worn or damaged. This disposable approach eliminates the risk of contamination from failed glued joints, as the entire friction disc assembly can be quickly replaced without dealing with failing adhesives.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The design anticipates friction disc wear and failure by making them easily replaceable. Regular maintenance intervals can be established before failure occurs, preventing contamination and maintaining system reliability. The modular design allows for proactive replacement rather than reactive repair.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Manufacturing precision

If pressure is adjusted hydraulically, then the pressure adjustment is precise, but disassembling the structure becomes complex and friction linings may get contaminated from leakage

Engineering Contradiction:
Improvepressure adjustment precisionVSAvoiddisassembly complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex hydraulic pressure adjustment mechanisms with simpler mechanical spring-based pressure application. Conical springs provide the necessary pressure to press friction discs against the rotary joint, eliminating hydraulic systems and their associated leakage and disassembly complexity while maintaining adequate pressure control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The pressure adjustment mechanism is extracted from the main rotary joint structure and placed in the external swing damper assembly. This allows the pressure mechanism to be serviced independently and eliminates the risk of hydraulic fluid leakage contaminating the friction surfaces.

Inventive Principle:
Principle #2Taking out (Extraction)

4Volume of moving object

If friction discs are placed inside the rotary joint, then the overall structure is compact, but maintenance and replacement require complete disassembly

Engineering Contradiction:
Improveswing damper volumeVSAvoidfriction disc replacement ease
Core Design Contradiction:
Volume of moving objectVSEase of repair

Solution Approach 1:

The swing damper is extracted from the internal rotary joint structure and positioned externally. This extraction maintains a compact overall structure while making the friction discs easily accessible for maintenance and replacement without requiring disassembly of the rotary joint.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The swing damper acts as an intermediary component between the rotary joint and the external environment. It provides the damping function while serving as an easily replaceable module, isolating the maintenance requirements from the main rotary joint assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design provides a robust damping system that maintains functionality even if one friction element fails, with adjustable pressure and easy maintenance, enhancing operational reliability and reducing contamination risks.

Implementation Method 1

the mutual friction of which unwanted swinging movement is supressed

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

there is a conical disc spring (Belleville spring) package opposite its other end, which is pressed against the bush by pressure bolt

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3409634B1Swing damper of a hanging rotary joint
Publication Date: 2019.07.03 OUE PALMSE MEHAANIKAKODA
  • EP3409634B1 patent drawingFigure 1
  • EP3409634B1 patent drawingFigure 2
  • EP3409634B1 patent drawingFigure 3

AI summary

The present invention relates to a swing dampener 1 for a hanging rotary joint for dampening swing movement between a jib and a work device hanged from the jib by said rotary joint. The swing dampener 1 is mounted at the end of the joint pin 2 and comprises two pressure discs 3 and 4 coaxial with the joint pin 2, wherein the rotation of said pressure discs 3 and 4 around the longitudinal axis of the joint pin 2 is fixed in relation to one half of the rotary joint. Between said pressure discs 3 and 4 there is a friction disc 5 coaxial with the joint pin 2, where the rotation of said friction disc 5 around the longitudinal axis of the joint pin 2 is fixed in relation to another half of the rotary joint. The friction disc 5 comprises at least one through opening 8, comprising a friction element 6, having two opposite planar parallel contact surfaces, which are pressed by the pressure device 7 into contact with the pressure discs 3 and 4 at the opposite sides of the friction disc 5.