Fixing Belt Meandering Prevention via Timing Belt

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Solution Overview

Problem

In fixing devices employing the resistance heating system, the meandering of the fixing belt leads to abrasion, shaving, and instability in power feeding, resulting in reduced durability and frequent spark discharges, which compromise the stability of the electrode parts and the overall performance.

Innovation Solution

The design includes meandering prevention members with a rotation center positioned inside a circle coincident with the midpoint between the focal points of the ellipse approximating the belt rotation path, minimizing the difference in peripheral speed between the fixing belt and the prevention members, and a driving unit to adjust their rotational speed, reducing mechanical load and stabilizing contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If meandering prevention members are provided to prevent fixing belt meandering, then belt stability is improved, but abrasion and shaving of the fixing belt occur due to sliding contact

Engineering Contradiction:
Improvefixing belt stabilityVSAvoidfixing belt abrasion
Core Design Contradiction:
Stability of the object's compositionVSLoss of substance

Solution Approach 1:

A timing belt is introduced as an intermediary component between the meandering prevention members and the fixing belt. The timing belt transmits the driving force from the meandering prevention members to the fixing belt through tooth engagement, eliminating direct sliding contact and preventing abrasion while maintaining effective belt control

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The direct friction-based sliding contact mechanism is replaced with a positive engagement toothed belt mechanism. The timing belt with teeth engages with corresponding teeth on the meandering prevention members, substituting the harmful sliding friction with a clean mechanical transmission system

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

2Stability of the object's composition

If meandering prevention members are fastened together with the fixing roller, then belt control is improved, but the difference in peripheral speed causes sliding contact and damage

Engineering Contradiction:
Improvefixing belt controlVSAvoidfixing belt durability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The meandering prevention members are designed to rotate independently rather than being fixed to the fixing roller. This dynamic configuration allows each meandering prevention member to rotate at its own peripheral speed, matching the linear speed of the fixing belt at the contact point and eliminating sliding contact

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system is segmented into independent rotating components (meandering prevention members) that can rotate independently on their own axes. This segmentation allows each component to have different rotational speeds, with the timing belt serving as the coupling element that synchronizes their motion with the fixing belt

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If the fixing belt and pressing member are loosely fit together with space between them, then thermal loss is reduced, but the fixing belt meanders due to not being tightly held

Engineering Contradiction:
Improvethermal lossVSAvoidfixing belt stability
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The timing belt acts as an intermediary constraint mechanism that provides lateral support to the fixing belt without requiring tight contact with the pressing member. This allows the thermal insulation space to be maintained while the timing belt prevents meandering through its toothed engagement with the meandering prevention members

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

This configuration effectively prevents the fixing belt from meandering, reducing abrasion and maintaining stable power feeding, thereby extending the lifespan of the fixing belt and ensuring consistent performance.

Implementation Method 1

an endless fixing belt (200) which includes a resistance heating layer (301) that generates Joule heat when electric power is fed to it

Methodology Applied
Scientific EffectJoule heat: Joule Heating

Data Source

PatentEP2701011B1Fixing device and image forming apparatus
Publication Date: 2020.04.01 KONICA MINOLTA INC
  • EP2701011B1 patent drawingFigure 1
  • EP2701011B1 patent drawingFigure 2
  • EP2701011B1 patent drawingFigure 3

AI summary

A fixing device (100) employing resistance heating system includes: a fixing roller (210) being loosely inserted into an endless fixing belt (200); a pressure member (220) being in pressure-contact with the fixing belt (200) to form fixing nip; meandering prevention members (240) preventing the fixing belt (200) from meandering; prevention member holders (410) holding the meandering prevention members (240) for rotation independently from the fixing roller (210). Each meandering prevention member (240) has rotation center inside circle, where, when seen in rotation axis direction of the fixing roller (210), the circle has center coincident with midpoint between two focal points of ellipse approximating belt rotation path of the fixing belt (200), and has radius equal to distance from the center of the circle to straight line passing through rotation center of the fixing roller (210) and center of the nip in rotational direction of the fixing roller (210).