Rotating Member Fixing Structure with Margin Adjusting Part
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotating member fixing structures experience axis displacement and localized stress concentrations due to varying press-fitting margins, leading to potential breakage of teeth parts.
Innovation Solution
A rotating member fixing structure that includes a margin adjusting part to reduce the press-fitting margin between the shaft member and the rotating member, using a combination of differently sized tooth sections and a tapered end surface to align and securely fix the parts, minimizing axis displacement and stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the internal and external teeth parts are press-fitted together using conventional structure, then the rotating member can be fixed to the shaft member, but axis displacement occurs and localized stress concentrations occur leading to potential breakage
Solution Approach 1:
The patent applies local quality by providing a margin adjusting part at specific locations (first and second locations in the circumferential direction) rather than uniformly across the entire press-fitting interface. This localized intervention reduces press-fitting margin only where needed to prevent stress concentration, while maintaining adequate fixation strength in other areas. The margin adjusting part creates local structural modification that addresses the stress concentration problem without compromising overall fixation reliability.
Solution Approach 2:
The margin adjusting part performs preliminary action by pre-reducing the press-fitting margin before the actual press-fitting operation. By having the margin adjusting part (such as a chamfer or groove) already in place on the shaft member or rotating member, the press-fitting process starts with an optimized margin distribution, preventing excessive stress concentration from the beginning rather than trying to correct it after assembly.
2Strength
If larger press-fitting margin is used to ensure adequate fixation, then the fixation strength is improved, but axis displacement and stress concentration occur
Solution Approach 1:
The patent uses local quality to create non-uniform press-fitting margin distribution through the margin adjusting part. Instead of using a uniformly large margin throughout, the margin is reduced locally at critical areas where stress concentration would occur, while maintaining larger margins in non-critical areas. This localized modification ensures adequate fixation strength overall while preventing stress concentration that would compromise reliability.
3Ease of manufacture
If uniform press-fitting margin is maintained throughout, then manufacturing is simplified, but stress concentration occurs at specific locations
Solution Approach 1:
The margin adjusting part represents a relatively simple local feature (such as a chamfer, groove, or reduced section) that can be easily incorporated into existing manufacturing processes. While it creates non-uniform margin distribution, the local nature of the modification keeps manufacturing complexity low compared to redesigning the entire press-fitting interface. The simple geometric form of the margin adjusting part allows it to be added with minimal additional processing steps.
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 structure effectively minimizes axis displacement and stress concentrations, ensuring reliable fixation and preventing breakage of teeth parts by adjusting the press-fitting margin to a prescribed value, thereby enhancing the durability and strength of the fixing mechanism.
Implementation Method 1
the first press-fitting sections and the second press fitting sections are usually plastically deformed in a radial direction
Implementation Method 2
an internal teeth part formed on an inner circumferential surface of a ring (a rotating member) and an external teeth part formed on an outer circumferential surface of a spline shaft are fixed together by press-fitting
Data Source
AI summary
A rotating member fixing structure includes a shaft member and a rotating member. The rotating member has an axial bore section press-fitted to the shaft member. One of the shaft member and the axial bore section of the rotating member includes a margin adjusting part dimensioned to reduce a press-fitting margin between the shaft member and the axial bore section of the rotating member from an initial press-fitting margin to an effective press-fitting margin that is less than or equal to a prescribed value when the rotating member is press-fitted to the shaft member.