Supply Roller Through-Hole Design for Friction-Free Insertion

Solution Overview

Problem

Existing electrophotographic image forming apparatuses face the issue of damaging the peripheral surface of the supply roller when inserting it into the frame due to the smaller cross-section of the through-hole, causing friction and potential damage.

Innovation Solution

The through-hole in the frame is designed to be larger than the supply roller's cross-section, allowing for insertion without rubbing against the inner edge, and includes a guide hole system to facilitate smooth alignment and assembly, preventing damage to the supply roller.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the through-hole cross-section is made smaller than the supply roller cross-section, then the supply roller is securely positioned in the frame, but the peripheral surface of the supply roller is damaged due to rubbing against the inner edge during insertion

Engineering Contradiction:

Improvepositioning accuracy of supply rollerVSAvoiddamage to supply roller peripheral surface

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The through-hole is divided into two distinct sections: a first through-hole section with a larger cross-section that allows the supply roller to pass through without contact, and a second through-hole section with a smaller cross-section that provides secure positioning. This segmentation enables the hole to perform both functions of allowing insertion and securing the roller without compromising the roller's peripheral surface.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the through-hole have different cross-sectional dimensions tailored to specific functions. The first section has a larger cross-section to prevent damage during insertion, while the second section has a smaller cross-section to provide secure positioning. This local variation in geometry allows each section to optimize its specific function.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If the through-hole cross-section is made larger than the supply roller cross-section, then the supply roller can be inserted without rubbing, but the positioning accuracy and security of the supply roller in the frame is reduced

Engineering Contradiction:

Improvedamage to supply roller peripheral surfaceVSAvoidpositioning accuracy of supply roller

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The through-hole is divided into two distinct sections: a first through-hole section with a larger cross-section that allows the supply roller to pass through without contact, and a second through-hole section with a smaller cross-section that provides secure positioning. This segmentation enables the hole to perform both functions of allowing insertion and securing the roller without compromising the roller's peripheral surface.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the through-hole have different cross-sectional dimensions tailored to specific functions. The first section has a larger cross-section to prevent damage during insertion, while the second section has a smaller cross-section to provide secure positioning. This local variation in geometry allows each section to optimize its specific function.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If a guide hole system is added to facilitate smooth alignment and assembly, then the ease of assembly is improved, but the device complexity increases

Engineering Contradiction:

Improveease of assemblyVSAvoidstructure complexity of frame

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The hole structure is segmented into multiple functional sections (first through-hole section and second through-hole section) with different cross-sectional dimensions. This segmentation inherently provides alignment guidance during insertion while maintaining a relatively simple overall structure that does not require additional complex guide mechanisms.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS9081323B2Developing device, process cartridge, and image forming apparatus

Publication Date: 2015.07.14 CANON KK

AI summary

A developing device includes a frame configured to store developer, a developing roller arranged at an opening of the frame and configured to bear the developer and to form a developer image on an image bearing member, and a supply roller including a rotational shaft passing through a through-hole provided in the frame and configured to supply the developer to the developing roller, wherein the through-hole is formed so that the supply roller is insertable from an outside of the frame in an axial direction of the supply roller, and has such a size that the supply roller is insertable without rubbing an inner edge of the through-hole.