Developer Containing Device Heat Dissipation via Rotation Shaft Groove

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Solution Overview

Problem

In electrophotographic image forming apparatuses, the increased heat generation in bearing units due to higher print speeds leads to developer melting and sealing failures, causing insufficient sealing and rotation issues, which existing solutions attempt to address but often result in increased apparatus size and cost.

Innovation Solution

A developer containing device with a partitioned structure featuring a communication groove on the rotation shaft that creates an air flow to efficiently dissipate heat externally, preventing developer melting and maintaining apparatus size without additional cooling components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transporting speed of the recording member is increased to comply with higher print speed requirements, then productivity is improved, but heat generation in the bearing unit increases causing developer melting and sealing failures

Engineering Contradiction:
Improveprint speedVSAvoidsealing performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent extracts the harmful heat generated in the bearing unit by introducing a cooling airflow that passes through the hollow rotation shaft. This removes the thermal problem from the system without changing the high-speed transport function, allowing both high productivity and reliable sealing to coexist

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces air as an intermediary cooling medium that flows through the rotation shaft to carry heat away from the bearing unit. This intermediary substance enables heat removal without directly contacting the developer or sealing components, resolving the contradiction between high-speed operation and sealing reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If a pump and heat exchanger are added to cool the rotation shaft, then heat generation is suppressed, but device complexity and cost increase

Engineering Contradiction:
Improvebearing unit temperatureVSAvoidcooling system structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The rotation shaft itself serves as the cooling channel by utilizing its hollow structure. The shaft's own geometry is repurposed for heat dissipation, eliminating the need for separate cooling devices and reducing system complexity while effectively controlling bearing unit temperature

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The rotation shaft performs dual functions: transporting developer and serving as a cooling channel. This multi-functionality eliminates the need for dedicated cooling components, reducing device complexity while maintaining effective temperature control in the bearing unit

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

3Temperature

If heat-radiation fins are added to the rotation shaft, then heat dissipation is improved, but the developer may still be heated to melt it before heat is released

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoiddeveloper melting
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts heat directly from the bearing unit through the hollow rotation shaft before it can transfer to the developer. By removing thermal energy from the source rather than attempting to radiate it away, the system prevents developer melting while maintaining effective heat dissipation

Inventive Principle:
Principle #2Taking out (Extraction)

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 effectively suppresses heat generation in the bearing unit, preventing developer melting and sealing failures, while maintaining the compact size of the image forming apparatus, thereby enhancing reliability and print quality.

Implementation Method 1

a communication groove arranged at the surface of the rotation shaft for connecting the outer space to a closed space isolated by the sealing member from the inner space

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The communication groove has a groove form causing an air flow in an axial direction on a surface of the communication groove according to rotation of the rotation shaft

Methodology Applied
Scientific EffectHeat dissipation: Convection

Data Source

PatentEP2395400B1Developer containing device and image forming apparatus
Publication Date: 2019.05.08 KONICA MINOLTA BUSINESS TECH INC
  • EP2395400B1 patent drawingFigure 1~2
  • EP2395400B1 patent drawingFigure 3A~3B
  • EP2395400B1 patent drawingFigure 4~5

AI summary

A developer containing device (4A) for containing a developer includes a partition (13S) arranged between an outer space (13B) and an inner space (13A) for containing the developer, a bearing (19) arranged on the partition (13S), a rotation shaft (14) carried by the bearing (19) and extending from the outer space (13B) to the inner space (13A), a sealing member (18) arranged on the inner space (13A) side, having one end side (18a, 18c) fixed to the partition (13S) and the other end side (18b, 18d) being in contact with a surface of the rotation shaft (14), and thereby isolating the bearing (19) from the inner space (13A), a communication groove (21) arranged at the surface of the rotation shaft (14), and connecting the outer space (13B) to a closed space (20) isolated from the inner space (13A) by the sealing member (18), and a communication passage (13h) arranged on the partition (13S) for connecting the outer space (13B) to the closed space (20).