Gear Assembly Angular Error Reduction in Toner Cartridge
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Solution Overview
Problem
Modulations in angular velocity of imaging components in electrophotographic printing devices due to gear errors lead to print defects like horizontal bands, which existing gear assemblies fail to minimize effectively.
Innovation Solution
The design incorporates a gear assembly with large-radius gear teeth in the drive coupler and drive gears, along with idler gears, to reduce angular error by distributing torque load and minimizing gear tooth deflection, ensuring precise rotational motion transfer from the image forming device to the toner cartridge components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If small-radius gear teeth are used in the drive coupler and drive gears, then the device complexity is reduced and manufacturing is easier, but angular error increases causing print defects like horizontal bands
Solution Approach 1:
The patent changes the critical parameter of gear tooth radius from small to large. Specifically, the drive coupler includes gear teeth with a radius of curvature of at least 0.05 inches, and drive gears have pitch circle diameters of at least 0.5 inches. This parameter change directly reduces angular error and eliminates print defects while maintaining manufacturing feasibility through standardized large-radius gear geometry.
2Reliability
If gear teeth with large radius of curvature are used, then angular error is reduced and print quality improves, but the gear assembly becomes more complex and requires more space
Solution Approach 1:
The patent applies local quality by specifying large radius of curvature (at least 0.05 inches) only for the critical drive coupler gear teeth that directly engage with the photoconductive drum, while other gears in the system can use standard dimensions. This localized application of large-radius geometry concentrates the precision improvement where it is most needed for print quality without unnecessarily complicating the entire gear assembly.
3Stability of the object's composition
If standard small gears are used in the drive coupler, then the device is more compact, but torque load distribution is poor causing gear tooth deflection and angular velocity modulation
Solution Approach 1:
The patent changes the volume parameter of the drive coupler by using gear teeth with large radius of curvature (at least 0.05 inches) and pitch circle diameters of at least 0.5 inches. This parameter change improves torque load distribution across the gear teeth, reduces deflection, and stabilizes angular velocity transmission, while the increased volume is acceptable given the critical need for angular stability in the photoconductive drum drive.
Data Source
AI summary
A toner cartridge according to one example embodiment includes a developer roll and a toner adder roll. First and second drive gears are rotatably connected to and coaxial with the developer roll and toner adder roll, respectively. The toner cartridge includes a drive coupler exposed to receive rotational motion when the toner cartridge is installed in an image forming device. Gear teeth of the first drive gear are directly meshed with gear teeth of the drive coupler of the toner cartridge. The second drive gear is rotatably connected to the drive coupler through a pair of idler gears.