Developing Cartridge Segmented Drive Gear for Independent Speed Control

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Solution Overview

Problem

Existing developing cartridges face challenges in reducing the circumferential speed of the supply roller without affecting the developing roller, leading to increased friction and wear of gear teeth, which can deteriorate toner images.

Innovation Solution

The developing cartridge employs a driving force transmission gear with separate first and second gear parts, allowing for adjustable circumferential speed of the supply roller without altering the developing roller's speed, and reduces gear wear by meshing the developing and supply roller driving gears with these separate parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the supply roller driving gear and developing roller driving gear are meshed with the same input gear, then the structure is simple and easy to manufacture, but the gear teeth wear quickly and the circumferential speed of the supply roller cannot be independently adjusted

Engineering Contradiction:
Improveease of manufactureVSAvoidgear wear
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The input gear is divided into two separate gear parts: a first gear part that meshes with the developing roller driving gear, and a second gear part that meshes with the supply roller driving gear. This segmentation allows independent control of each gear's wear and enables independent adjustment of the supply roller's circumferential speed without affecting the developing roller, thereby resolving the contradiction between manufacturing simplicity and gear reliability.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If the circumferential speed of the supply roller is reduced to decrease friction with the developing roller, then toner deterioration is reduced, but the gear transmission ratio must be changed which affects the developing roller speed

Engineering Contradiction:
ImprovefrictionVSAvoidsupply roller speed
Core Design Contradiction:
Object-affected harmful factorsVSSpeed

Solution Approach 1:

By segmenting the input gear into separate first and second gear parts, the transmission ratio for the supply roller can be independently adjusted to reduce its circumferential speed and minimize friction with the developing roller, while the first gear part maintains the developing roller's speed unchanged. This resolves the contradiction between reducing friction and maintaining developing roller speed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gear diameters of the first and second gear parts are designed with different ratios to the supply roller driving gear, allowing independent parameter adjustment of the supply roller's circumferential speed without affecting the developing roller. This enables optimization of friction reduction while maintaining stable developing roller operation.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If the gear diameter of the supply roller driving gear is enlarged to reduce the supply roller's circumferential speed, then friction is reduced, but the space required for gear arrangement increases

Engineering Contradiction:
ImprovefrictionVSAvoidgear space
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The input gear is segmented into two separate parts with different diameters optimized for their respective functions. The second gear part has a diameter specifically designed to achieve the desired supply roller speed reduction without requiring excessive space, while the first gear part maintains appropriate size for the developing roller drive. This segmentation allows space-efficient speed control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of uniformly enlarging the entire input gear, the invention changes the parameters of individual gear parts selectively. The second gear part's diameter is optimized to achieve the required speed reduction ratio with minimal space consumption, while the first gear part maintains its original size for the developing roller, thus resolving the contradiction between friction reduction and space requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2343607B1Developing cartridge
Publication Date: 2018.03.14 BROTHER KOGYO KK
  • EP2343607B1 patent drawingFigure 1
  • EP2343607B1 patent drawingFigure 2
  • EP2343607B1 patent drawingFigure 3

AI summary

A developing cartridge includes: a developing roller that is rotatable about a developing roller axis line, which extends in a predetermined direction; a supply roller, which is rotatable about a supply roller axis line, which extends in the predetermined direction, and which supplies developer to the developing roller; a developing roller driving gear that is connected to the developing roller; a supply roller driving gear that is connected to the supply roller; and a driving force transmission gear, which is rotatable about a gear axis line extending in the predetermined direction, and which includes: a first gear part meshed with the developing roller driving gear; and a second gear part meshed with the supply roller driving gear. The driving force transmission gear transmits driving force to the developing roller driving gear and the supply roller driving gear.