Plunging CV Joint Geometry for High-Angle Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The durability of plunging type constant velocity universal joints is compromised when the operating angle increases, leading to high contact pressure and reduced lifespan, especially at higher normal operating angles during high-speed vehicle travel.
Innovation Solution
A plunging type constant velocity universal joint design featuring a cylindrical outer joint member with six linear track grooves, a spherical inner joint member with opposing grooves, and a cage with offset curvature centers, optimized with specific ratios for torque transmission balls, contact angles, and track groove dimensions to manage increased operating angles and maintain durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the operating angle of the plunging type constant velocity universal joint is increased to improve vehicle travel performance, then the maximum operating angle and normal operating angle are increased, but the contact pressure on torque transmission balls and track grooves increases excessively, reducing durability
Solution Approach 1:
The patent applies parameter changes by optimizing the ratio of torque transmission ball diameter to spline pitch circle diameter within a specific range (0.75 to 0.85). This parameter adjustment allows the joint to accommodate larger operating angles while controlling contact pressure to maintain durability. The cage offset distance is also optimized to balance between achieving large operating angles and preventing excessive contact pressure.
2Speed
If the normal operating angle is increased for high-speed vehicle travel, then vehicle travel performance is improved, but the torque load and contact pressure increase significantly, compromising joint strength
Solution Approach 1:
The patent optimizes the contact angle parameter within a specific range (30° to 35°) to distribute torque loads more effectively at higher normal operating angles. This parameter change allows the joint to maintain strength during high-speed travel by reducing peak contact pressures on the torque transmission balls and track grooves.
3Stress or pressure
If the torque transmission ball diameter is increased to reduce contact pressure, then contact pressure decreases, but the overall joint size increases
Solution Approach 1:
The patent optimizes the ratio of ball diameter to spline pitch circle diameter within a specific range (0.75 to 0.85) to achieve the right balance. This ratio optimization ensures that contact pressure is reduced to acceptable levels while preventing excessive increase in joint size. The optimized parameters allow compact design while maintaining durability under high operating angles.
Data Source
AI summary
A plunging type constant velocity universal joint has six torque transmission balls, and a curvature center of a spherical outer peripheral surface and a curvature center of a spherical inner peripheral surface of a cage are offset toward opposite sides in an axial direction with respect to a joint center. The plunging type constant velocity universal joint is used at a normal operating angle of from 8° to 12°. A ratio DBALL/DSPCD of a diameter (DBALL) of the torque transmission ball to a spline pitch circle diameter (DSPCD) of a coupling hole of an inner joint member is within a range of 0.80 to 0.86. A contact angle of the torque transmission ball and a linear track groove is within a range of 32° to 35°. A contact ratio of the torque transmission ball and the linear track groove is within a range of 1.05 to 1.08.