Drive Shaft Coupling for Image Forming Apparatus
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Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately and easily coupling a drive shaft and a developing roller, leading to potential uneven image density and banding due to slippage, which increases production costs and complicates assembly with known mechanisms.
Innovation Solution
The apparatus includes a drive unit with a drive force generator, a drive substrate, a drive shaft, a bracket with a cylindrical bearing seating, and an elastic member to support the drive shaft, allowing radial movement, and a substrate bearing to support the drive shaft in both radial and thrust directions, facilitating accurate and easy coupling of the drive shaft and developing roller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a tentative holding member (second bearing) with radial freedom is used to absorb displacement between drive shaft and driven shaft, then coupling accuracy is improved, but the coupling may slip causing uneven image density or banding
Solution Approach 1:
The patent combines the tentative holding member (second bearing) with a constant-velocity joint into an integrated coupling mechanism. This merging allows the structure to simultaneously provide radial displacement absorption and prevent slippage, resolving the contradiction between coupling accuracy and reliability.
2Reliability
If a constant-velocity joint is used as the coupling to prevent slippage, then reliability is improved, but production costs increase and assembly becomes complicated
Solution Approach 1:
The patent merges the constant-velocity joint with the tentative holding member into a single integrated coupling structure. This reduces the number of separate components and simplifies assembly while maintaining the reliability benefits of the constant-velocity joint mechanism.
Solution Approach 2:
The integrated coupling structure serves multiple functions simultaneously: it acts as both the tentative holding member for radial displacement absorption and the constant-velocity joint for slippage prevention. This multi-functionality reduces overall device complexity while maintaining reliability.
3Manufacturing precision
If complex coupling mechanisms are used to ensure accurate coupling, then manufacturing precision is improved, but production costs increase
Solution Approach 1:
The patent combines multiple coupling mechanisms into a single integrated structure that can be manufactured as one unit or pre-assembled module. This merging reduces the number of separate manufacturing processes and quality control steps, lowering production costs while maintaining coupling accuracy.
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 ensures reliable and easy installation of the process cartridge, preventing uneven image density and banding while reducing production costs and simplifying assembly by allowing for radial movement and thrust support of the drive shaft.
Implementation Method 1
an elastic member provided between the bearing seating and the bracket bearing to allow movement of the drive shaft in a radial direction
Implementation Method 2
a bracket bearing provided inside the bearing seating to support the drive shaft in a thrust direction
Implementation Method 3
a substrate bearing provided to the drive substrate to support the drive shaft in both the radial and thrust directions
Data Source
AI summary
An image forming apparatus including a process cartridge having a developing device and detachably installable in the image forming apparatus, and a drive unit to rotatively drive the developing device. The drive unit includes a drive force generator to generate a drive force to rotatively drive the developing device, a drive substrate to support the drive force generator, a drive shaft to transmit the drive force to the developing device, a bracket having a cylindrical bearing seating, a bracket bearing provided inside the bearing seating to support the drive shaft in a thrust direction, and an elastic member provided between the bearing seating and the bracket bearing to allow movement of the drive shaft in a radial direction, and a substrate bearing provided to the drive substrate to support the drive shaft in both the radial and thrust directions.