Constant Velocity Joint Ball Tracks for High-Angle Torque Transfer
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Solution Overview
Problem
Existing constant velocity universal joints face challenges in maximizing torque transmission while minimizing construction volume, particularly at high deflection angles (over 50°), and achieving smooth running and efficiency.
Innovation Solution
The design incorporates two types of ball track pairs: neutral balls with concentric, high-angle-of-contact tracks and controlled balls with sections curved in opposite directions, allowing for efficient torque transmission and reduced frictional losses, with the cage maintaining the balls in a common joint center plane during flexion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional single-type ball track design is used, then structure is simple, but torque transmission capacity is limited at high deflection angles
Solution Approach 1:
The ball track configuration is segmented into two distinct types: neutral ball tracks with concentric center lines and controlled ball tracks with non-concentric center lines. This segmentation allows each type to perform specialized functions - neutral tracks maintain high torque capacity while controlled tracks manage ball positioning - thereby resolving the contradiction between torque transmission and structural simplicity.
Solution Approach 2:
Different regions of the ball track system are assigned different geometric properties. Neutral ball tracks have center lines concentric with the joint center plane for optimal torque transmission, while controlled ball tracks have offset center lines for ball control. This local differentiation enables the system to achieve high torque capacity at high deflection angles without requiring complete redesign of all tracks.
2Strength
If ball tracks are designed for high torque transmission, then torque capacity increases, but frictional losses increase
Solution Approach 1:
The ball track system is divided into neutral and controlled tracks that perform different functions. Neutral tracks are optimized for torque transmission with concentric geometry that maintains axial force neutrality, reducing friction. Controlled tracks handle ball positioning with offset geometry. This functional segmentation allows the torque-transmitting neutral tracks to operate with minimal friction while controlled tracks manage positioning separately.
3Adaptability or versatility
If joint deflection angle is increased, then adaptability improves, but torque transmission capacity decreases
Solution Approach 1:
The ball track center lines are designed with specific dynamic characteristics. Neutral ball tracks maintain concentric geometry that preserves torque capacity across the full range of deflection angles. Controlled ball tracks dynamically adjust ball positioning through their offset center line design. This dynamic geometric design enables the joint to maintain high torque transmission capacity even at large deflection angles, resolving the contradiction between adaptability and strength.
Data Source
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AI summary
The invention relates to a constant velocity joint (10) for transmitting torque, in which a first type of track pairs of ball tracks (20a; 40a) is designed in such a way that centers of curvature of the center lines (MN) of the ball tracks lie in the joint center plane (EM) when the joint (10) is in a straight line. A second type of track pairs of ball tracks (20b; 40b) is designed in such a way that the center lines (MS) thereof have at least two portions (MSi; MSa). Each center line (MS) of the outer ball tracks (20b) of the second type of track pairs has at least one inner portion (MSi) and one outer portion (MSa), the inner portion (MSi) lying on the connection side (61) of the joint outer part (11) while the outer portion (MSa) lies on the opening side (60) of the joint outer part (11), and the inner portion (MSi) being curved. The center of curvature (OT) of this inner portion (MSi) lies within the hollow volume of the joint outer part (11) at an offset from the joint center plane (EM) toward the opening side (60) when the joint (10) is in a straight line, while the center line (MS) flares out through the outer portion (MSa) toward the opening side (60).