Constant Velocity Joint Backlash Elimination via Localized Hardening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing constant velocity universal joints with recess- and projection engagement configurations experience backlash, leading to inaccurate torque transmission, reduced fatigue strength, and abnormal noise, and require additional components and processes, increasing costs.
Innovation Solution
A constant velocity universal joint with a recess-projection engagement configuration where the engagement contacting regions of projections and recesses are in close contact over the whole region, utilizing a hardened layer on the outer diameter of the inner joint component and an un-quenched inner diameter for improved engagement and strength, without the need for a stopper ring or additional spline sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If hardening process is performed on axial hole inner diameter and axial end outer diameter to form hardened layers, then strength is ensured, but backlash occurs and torque transmission accuracy decreases
Solution Approach 1:
The patent applies different heat treatment states to different regions of the inner joint component. The axial hole inner diameter is kept in an un-quenched (softer) state to enable close contact engagement and eliminate backlash, while other regions may be hardened for strength. This local differentiation of material properties resolves the contradiction between strength and precision.
2Reliability
If stopper ring and additional spline sections are added to prevent dislocation, then reliability improves, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent removes the stopper ring component entirely by integrating the dislocation prevention function directly into the spline engagement mechanism. The close contact engagement between the un-quenched axial hole inner diameter and the axial end outer diameter inherently prevents dislocation, eliminating the need for separate stopper ring components and simplifying the overall structure.
Solution Approach 2:
The patent merges the dislocation prevention function with the torque transmission function by designing the spline engagement to provide both capabilities simultaneously. The close contact engagement that transmits torque also prevents dislocation, combining multiple functions into a single integrated mechanism.
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
This configuration eliminates backlash, enhances torque transmission accuracy, increases durability, reduces noise, and simplifies assembly while reducing the number of components and processes, resulting in a more reliable and cost-effective joint.
Implementation Method 1
A hardening process by, for example, induction hardening or carburizing and quenching is performed on the axial hole inner diameter of the inner joint component on which the female spline is formed and on the axial end outer diameter of the shaft on which the male spline is formed, thereby forming hardened layers.
Implementation Method 2
The axial end outer diameter of the shaft is pressed into the axial hole inner diameter of the inner joint component, and the male spline and the female spline mesh.
Data Source
AI summary
A constant velocity universal joint having a recess-projection engagement configuration in which backlash at a shaft connecting region does not easily occur, and an inner joint component and a shaft can he firmly connected. hi the constant velocity universal joint, the inner joint component and the shaft (5) fitted into an axis hole (22) of the inner joint component are connected by die recess-projection engagement configuration. Engagement contacting regions (38) of projections (35) and recesses (36) corresponding thereto are in close contact over the whole region.