Cross-Groove CV Joint Layout to Prevent Ball Sticking in Collisions
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Solution Overview
Problem
The cross groove type constant velocity joint experiences ball slippage and increased collision load when a vehicle collides, as the outer race member is shorter than the inner race member, causing the ball to get stuck between the propeller shaft and the inner race member.
Innovation Solution
A constant velocity joint design featuring an outer race member with an angled recessed groove and an inner race member with intersecting angled grooves, where the ball is positioned to escape into the gap between the outer and inner race members during a collision, preventing it from getting stuck and reducing collision load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer race member is formed to be shorter than the inner race member in the rotational axis direction, then the constant velocity joint can accommodate axial displacement during vehicle collision, but the ball may slip off to the side where the propeller shaft is located and get stuck between the propeller shaft and the inner race member, increasing collision load
Solution Approach 1:
The patent applies asymmetry by making the distances from the ball position to the groove end portions asymmetric. Specifically, the distance from the ball position to the first outer race groove end portion is made longer than the distance from the ball position to the second inner race groove end portion. This asymmetric design ensures that during axial displacement in a collision, the ball will move toward the longer distance side (first outer race groove end portion side) and not slip off to the propeller shaft side, thereby preventing the ball from getting stuck and increasing collision load.
2Strength
If the ball is retained in the cross groove type constant velocity joint, then the outer race member and inner race member are connected, but during vehicle collision the ball may slip off and get stuck, increasing collision load
Solution Approach 1:
The patent uses asymmetric groove design where the outer race groove and inner race groove have different lengths in the rotational axis direction. The outer race groove is made longer than the inner race groove, creating an asymmetric structure that guides the ball to remain within the groove boundaries during axial displacement, preventing the ball from slipping off and maintaining both connection strength and collision performance.
Data Source
AI summary
The present invention comprises an outer race member including an outer race groove portion that is provided at an inner periphery of the outer race member formed into a cylindrical shape, in a recessed manner so as to be angled to a rotational axis of a constant velocity joint, a first outer race groove end portion situated on a first propeller shaft side of the outer race groove portion, and a second outer race groove end portion situated on a second propeller shaft side of the outer race groove portion; a ball member disposed in the outer race groove portion; and an inner race member provided on an inner peripheral side of the outer race member and connected to the second propeller shaft of a propeller shaft, the inner race member including an inner race groove portion provided at an outer periphery of the inner race member in a recessed manner so as to be angled to the rotational axis of the constant velocity joint and intersect with the outer race groove portion, the inner race groove portion being formed to have a larger outer diameter than the second propeller shaft, a first inner race groove end portion situated on the first propeller shaft side of the inner race groove portion, and a second inner race groove end portion situated on the second propeller shaft side of the inner race groove portion. Distance from a position at which the ball member is situated in the outer race groove portion to the first outer race groove end portion of the outer race groove portion is set longer than distance from a position at which the ball member is situated in the inner race groove portion to the second inner race groove end portion of the inner race groove portion.