Press-Fit Bearing Shoulder Geometry Without Grind Reliefs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current gear shaft designs require grind reliefs to prevent overheating during machining, which create sharp edges and stress concentrations, complicating the machining process and compromising material integrity.
Innovation Solution
Implement a gear system with a shaft design featuring regions of varying radii and slopes, allowing for interference fit shoulders that eliminate the need for grind reliefs, ensuring precise machining and reducing stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If grind relief is used to prevent overheating during machining, then material integrity is protected, but sharp edges and stress concentrations are created
Solution Approach 1:
The shaft is divided into multiple regions with different radii (first region, second region, third region) and transition zones (first slope, second slope). This segmentation allows each region to serve a specific function: the second region with its larger radius provides a stress-free surface for the shoulder, eliminating the need for grind relief and avoiding stress concentrations, while other regions accommodate bearings and gear mounting requirements.
2Strength
If grind relief is used to prevent overheating during machining, then material integrity is protected, but the machining process becomes more complex
Solution Approach 1:
The shaft geometry is pre-designed with multiple radius regions and transition slopes that eliminate the need for subsequent grind relief operations. The second region's larger radius is built-in from the start, providing a natural stress-free surface for shoulder installation without requiring additional machining steps to create grind reliefs.
3Use of energy by moving object
If oil passages are located in grind relief corners, then bearing lubrication is maintained, but sharp edges difficult to edge break are created
Solution Approach 1:
The shaft design implements local quality variations through different radius regions. The second region with its larger radius specifically addresses the shoulder mounting area, providing a stress-free surface that eliminates sharp edges. This local geometric modification allows oil passages to be positioned without creating problematic sharp corners, as the larger radius naturally provides smoother transitions.
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 new design enables precise machining without grind reliefs, improving gear system integrity and compliance with safety regulations while maintaining functionality and reducing weight.
Implementation Method 1
a shoulder pressed onto the shaft and configured to have an interference fit with the second region
Data Source
AI summary
Systems and methods are described for shoulders that can be implemented on shafts in gear systems, such as a drive train. The shoulders, in combination with other components like bearings, or nuts, can help restrict movement of the shaft within the drive train. Use of the shoulders in various embodiments can avoid the need for grind reliefs in corners. Grind reliefs can help in prior art systems where machining or grinding is used at surfaces where raceways of bearings border shoulders that are integrated with the shaft. Grind reliefs create tight spaces where edge breaks are difficult to create. Press-fit shoulders, such as described herein, allow machining and edge break creation on the shaft prior to installation of the shoulder.