Photosensitive Member Gear Layout for Reliable Drive Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrophotographic image forming apparatuses face challenges in efficiently transmitting driving force from the main assembly to the cartridge, leading to issues with image formation and maintenance.
Innovation Solution
A photosensitive member unit is designed with a first unit side helical gear portion and a second unit side helical gear portion, which mesh with corresponding main assembly side helical gear portions. The twisting direction and helix angle of the unit side gear portions are optimized to ensure proper engagement and drive transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional gear structures are used to transmit driving force from the main assembly to the cartridge, then the structure is simple and easy to manufacture, but the driving force transmission efficiency is insufficient leading to image formation and maintenance issues
Solution Approach 1:
The patent applies local quality by making the two gear portions on the same axis have different helix angles and twisting directions. Specifically, the first gear portion has a first helix angle and the second gear portion has a second helix angle that is different from the first, allowing each gear portion to be optimized for its specific engagement requirements with the main assembly, thereby improving overall transmission efficiency without requiring complete redesign of the entire gear system
Solution Approach 2:
The patent employs asymmetry by configuring the helical gears with different helix angles and opposite twisting directions on the same axis. The first helical gear portion has a right-hand twist while the second has a left-hand twist, creating an asymmetric configuration that enables differentiated force transmission characteristics for improved reliability
2Manufacturing precision
If the helix angle and twisting direction of gear portions are not optimized, then the manufacturing process is simpler, but the engagement accuracy and drive transmission reliability are insufficient
Solution Approach 1:
The patent applies parameter changes by specifying different helix angles for the first and second gear portions, and by defining opposite twisting directions (right-hand vs left-hand). These parameter variations enable each gear portion to achieve optimal engagement accuracy with the main assembly while maintaining manufacturability through standard helical gear manufacturing processes
3Power
If a single gear portion is used on the cartridge axis, then the structure is simpler, but the driving force transmission is insufficient for reliable image formation and maintenance operations
Solution Approach 1:
The patent applies segmentation by dividing the drive transmission function into two separate gear portions on the cartridge axis. Each gear portion independently engages with the main assembly to transmit driving force, and the combined effect of both portions provides sufficient total power for reliable operation of the image forming apparatus
Solution Approach 2:
The patent merges the output of two separately engaged gear portions into a single rotational motion of the cartridge. By combining the driving force from two gear engagements, the system achieves reliable power transmission that would be insufficient with a single gear portion, while maintaining a compact structure
Data Source
AI summary
A photosensitive member unit detachably mountable to a main assembly of an image forming apparatus, the image forming apparatus including a first main assembly side helical gear portion and a second main assembly side helical gear portion which are coaxially rotatable, the photosensitive member unit includes a photosensitive member rotatable about a rotational axis thereof; a first unit side helical gear portion for meshing engagement with the first main assembly side helical gear portion; and a second unit side helical gear portion for meshing engagement with the second main assembly side helical gear portion, wherein a twisting direction of a tooth of the second unit side helical gear portion is the same as the twisting direction of a tooth of first unit side helical gear portion, wherein a helix angle of the tooth of the second unit side helical gear portion is larger than a helix angle of the tooth of the first unit side helical gear portion, and wherein the first unit side helical gear portion and the second unit side helical gear portion are rotatable in a state in which the first unit side helical gear portion is in meshing engagement with the first main assembly side helical gear portion, and the second unit side helical gear portion is in meshing engagement with the second main assembly side helical gear portion.