Semicircular Arc Slide Bearings for Heating Roller Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fixing devices for electrophotographic image forming apparatuses face challenges in easy assembly, size reduction, and thermal expansion issues due to complex bearing structures and the need for multiple components, which can lead to backlash and damage during temperature changes.
Innovation Solution
A fixing device with a heating roller and presser forming a fixing nip, supported by semicircular arc slide bearings integrated into brackets, allowing for easy assembly and downsizing, with a resin material providing heat and abrasion resistance to match the thermal expansion of the heating roller, eliminating the need for C-rings and reducing assembly complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a slide bearing or C-ring is used in combination with a radial bearing for the heating roller, then the heating roller can be supported and positioned, but the number of components and assembly steps increases
Solution Approach 1:
The patent combines the radial bearing and thrust bearing functions into a single integrated bearing member. The bearing member includes a radial bearing portion that supports the heating roller radially and a thrust bearing portion that supports axial loads, eliminating the need for separate slide bearings or C-rings and reducing assembly complexity.
Solution Approach 2:
The bearing member is designed to perform multiple functions simultaneously: it provides radial support, thrust support, and positioning for the heating roller. This multi-functional design replaces what would traditionally require multiple separate components, simplifying both the structure and assembly process.
2Ease of manufacture
If the heating roller is moved in the thrust direction to mount it on the bearing member, then the heating roller can be installed, but the assembly operation becomes complicated
Solution Approach 1:
The heating roller is designed with a curved end surface that matches the arc shape of the bearing member's opening. This curvature allows the heating roller to be simply inserted into the bearing member without requiring complex thrust direction movements, as the curved surfaces guide the insertion process naturally.
3Reliability
If a C-ring is fitted to the heating roller to regulate thrust direction position, then positioning is achieved, but the process is troublesome and may damage the heating roller
Solution Approach 1:
The positioning function previously performed by a separate C-ring is integrated directly into the bearing member structure. The bearing member includes a positioning portion with a slit that directly engages with the heating roller, eliminating the need for a separate C-ring component and its associated fitting process that could damage the heating roller.
4Ease of manufacture
If a slit is made in the heating roller to permit C-ring fitting, then C-ring installation is possible, but the heating roller must be elongated preventing downsizing
Solution Approach 1:
The slit is removed from the heating roller and transferred to the bearing member. The bearing member is made with a slit that allows it to be fitted around the heating roller without requiring any modification to the heating roller itself. This extraction of the slit feature from the heating roller eliminates the need for elongation and enables downsizing of the heating roller.
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 solution enables easy assembly, reduces device size, and prevents thermal backlash by using semicircular arc slide bearings made of heat-resistant resin, ensuring reliable operation and preventing damage to the heating roller.
Implementation Method 1
a sleeve-like slide bearing composed of two fired bodies that are made of a material mainly containing tetrafluoroethylene resin
Implementation Method 2
the heating roller, which is made of aluminum, expands/contracts to a relatively large degree with a temperature change
Implementation Method 3
a biasing member for pressing the presser against the heating roller to form the fixing nip portion
Data Source
AI summary
A fixing device having: a heating roller and a presser that form a fixing nip portion therebetween; a pair of brackets having holes for supporting both end portions of the heating roller; a biasing member for pressing the presser against the heating roller to form the fixing nip portion; and a pair of semicircular arc slide bearings that are fitted in the holes of the respective brackets so as to be located between the respective brackets and the heating roller, on an opposite side of the heating roller to a side thereof pressed by the presser.