Notched End Seal for Electrophotographic Developer Roll
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Solution Overview
Problem
Toner accumulation between the developer roll and the seal in electrophotographic image forming devices leads to leakage, and existing solutions either increase friction or require larger components to address this issue, which can cause damage or increase the size of the device.
Innovation Solution
An end seal with an elastomeric body featuring a blade seal portion and a curved rotary seal portion, including a cutout at the inner axial side to provide an additional toner exit path, reducing stagnation and improving sealing performance without increasing the seal's width or overall component size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the force of the seal against the developer roll is increased to prevent toner accumulation, then sealing performance is improved, but friction increases risking damage to the seal, developer roll and/or toner
Solution Approach 1:
The seal surface is segmented into multiple helical grooves that divide the contact area between the seal and developer roll. This segmentation allows toner to be channeled through multiple paths rather than accumulating in a single area, reducing the force needed to prevent toner buildup while maintaining effective sealing.
Solution Approach 2:
The seal incorporates a porous structure with helical grooves that allow toner particles to pass through and be redirected back into the toner reservoir. This porous design reduces toner accumulation without requiring excessive sealing force, thereby reducing friction and the risk of damage to components.
2Reliability
If the width of the seal in the axial dimension is increased to provide added sealing, then sealing performance is improved, but the axial lengths of the developer roll and doctor blade must be increased, increasing the overall size of the developer unit
Solution Approach 1:
Instead of increasing the axial width of the seal, the invention utilizes the helical pattern in the radial and circumferential dimensions. The helical grooves create multiple sealing paths that wrap around the developer roll, providing enhanced sealing performance without increasing the axial length of the seal, developer roll, or doctor blade.
Solution Approach 2:
The helical grooves introduce a curved, three-dimensional path for toner redirection that maximizes the use of available space. This curved geometry allows the seal to maintain effective contact with the rotating developer roll while preventing toner accumulation, without requiring additional axial length.
3Object-generated harmful factors
If grooves are formed on the seal surface to direct toner away from the axial ends, then toner leakage is prevented, but toner may accumulate between the developer roll and the seal over time
Solution Approach 1:
The seal surface is divided into multiple helical grooves that segment the toner flow path. This segmentation prevents toner from accumulating in large quantities by providing multiple escape routes, while still directing toner away from the axial ends to prevent leakage. The grooves work together to distribute and redirect toner efficiently.
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
The cutout in the end seal reduces toner stagnation, preventing the seal from being pushed away and enhancing sealing performance while maintaining component stability and minimizing material and production costs.
Implementation Method 1
An end seal for an electrophotographic image forming device according to the present invention includes an elastomeric body
Data Source
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AI summary
An end seal for an electrophotographic image forming device according to one example embodiment includes an elastomeric body having a blade seal portion for sealing against a rear surface of a doctor blade and a curved rotary seal portion that extends from a bottom end of the blade seal portion for sealing against an outer surface of a rotatable developer roll. The end seal includes a cutout in an inner axial side of the body positioned at a point where the rotary seal portion and the blade seal portion meet.