Curved Shaft Coupling for Stable Drive Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrophotographic image forming apparatuses, the variation in rotation speed between the photosensitive member and the intermediate transfer member due to component tolerances leads to image defects like white spots and poor transferability, as the coupling between the cartridge and the apparatus main body experiences momentary separation, disrupting the transmission of driving force.
Innovation Solution
The image forming apparatus incorporates a motor, a shaft supporting the receiving member of the cartridge, a transmission member to rotate and transmit drive force, and a bending unit that curves the shaft to apply a force counteracting the separation force, ensuring stable drive force transmission by maintaining contact between the couplings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rotational axis of the coupling of the cartridge is positioned offset from the central axis of the coupling of the apparatus main body to allow attachment/detachment, then the ease of operation is improved, but the reliability deteriorates due to variation in rotation speed causing image defects
Solution Approach 1:
The coupling surfaces are designed with spherical curvature, where the coupling of the cartridge main body has a spherical outer surface and the coupling of the apparatus main body has a corresponding spherical inner surface. This spherical geometry allows the couplings to maintain point contact regardless of angular misalignment, enabling attachment/detachment operations while preventing variation in rotation speed that would cause image defects.
2Manufacturing precision
If the difference in speed between the photosensitive member and the intermediate transfer member is reduced to improve transferability, then the image quality is improved, but the coupling separation problem worsens due to reverse speed states causing momentary separation
Solution Approach 1:
A spring member is introduced as a counteracting force mechanism. The spring member applies a constant urging force to maintain contact between the coupling of the cartridge and the coupling of the apparatus main body. This counter force compensates for the separation tendency that occurs when the intermediate transfer member rotates faster than the photosensitive member, preventing momentary coupling separation while allowing the speed difference to be minimized for improved image transfer quality.
3Ease of operation
If the coupling is designed with clearance for attachment/detachment, then the ease of operation is improved, but the manufacturing precision deteriorates due to offset in rotational axes causing rotation speed variation
Solution Approach 1:
The spherical coupling design eliminates the need for precise rotational axis alignment. The spherical geometry ensures that contact occurs at a single point on the spherical surfaces, and this point contact is maintained regardless of angular misalignment within the clearance. This allows easy cartridge replacement operations while preventing the rotational speed variation that would result from offset axes in traditional rigid coupling designs.
Data Source
AI summary
An image forming apparatus may transfer an image to a transfer-receiving material. The image forming apparatus includes a main body to which a cartridge is detachably mounted. The cartridge includes an image bearing member in contact with the transfer-receiving material and a receiving member to receive driving force from the main body to drive and rotate the image bearing member. The image forming apparatus also includes a shaft passing through and supporting the receiving member of the cartridge and a transmission member to rotate around the shaft and to transmit drive force from a motor to the receiving member. A bending unit included with the image forming apparatus bends the shaft passing through and supporting the receiving member and the transmission member.