Constant Velocity Joint Raceway Geometry for Lower Contact Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional constant velocity joints experience high contact pressure at single points, leading to early wear and potential damage of ball raceways.
Innovation Solution
The design of the constant velocity joint incorporates axially extending grooves forming raceways with two contact points per ball raceway, distributing contact pressure more evenly by using radii of curvature with offset center points in quadrants, allowing for four contact points in total.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If single contact point design is used, then torque transmission is simple, but contact pressure is very high leading to early wear
Solution Approach 1:
The ball raceway contact interface is segmented from a single contact point into multiple contact points (at least two per ball raceway). This segmentation distributes the contact pressure across multiple locations, reducing the stress concentration that causes wear and extending the service life of the constant velocity joint.
Solution Approach 2:
The invention transitions from a point-contact geometry to a multi-point contact geometry by designing the ball raceways with specific curvature radii in different quadrants. This dimensional change in the contact interface allows the ball to engage the raceway at multiple points simultaneously, effectively distributing the load and reducing contact pressure.
2Stress or pressure
If multiple contact points are used, then contact pressure distribution improves, but manufacturing complexity increases
Solution Approach 1:
The invention achieves multiple contact points by carefully selecting and configuring the curvature radii of the ball raceways in different quadrants. By changing the geometric parameters (radii of curvature) of the raceway profile, the design naturally creates multiple contact points without requiring complex assembly or additional components, thus maintaining ease of manufacture while improving pressure distribution.
3Reliability
If four contact points are active, then wear is reduced, but sliding proportion increases
Solution Approach 1:
The invention optimizes the curvature radii of the ball raceways to achieve a balance between contact points and sliding. By carefully selecting the radius values in different quadrants, the design creates four contact points that reduce wear while minimizing excessive sliding, thereby reducing energy loss through friction.
Data Source
AI summary
A constant velocity joint includes an outer part having a connecting portion and an opening portion and a plurality of axial grooves forming outer raceways, and an inner part having a plurality of axial grooves forming inner raceways. Each outer raceway and inner raceway form a raceway pair, a ball being disposed in each raceway pair. Each raceway pair defines a region in axial cross-section with respect to a groove longitudinal axis conceptually divided into four quadrants. The outer raceway is in the first and second quadrants and the inner raceway is in the third and fourth quadrants. With torque transmission in a first direction, the ball has two contact points in the first quadrant and/or two contact points in the third quadrant, and with torque transmission in a second direction, the ball has two contact points in the second quadrant and/or two contact points in the fourth quadrant.