Thin-Walled Universal Joint Structure for Lightweight Propeller Shafts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing automobile propeller shafts face challenges with high cost, complex processing technology, low processing efficiency, and inability to meet mass production requirements due to material delamination, deformation, and high torque loads, particularly in lightweight designs using aluminum alloy and carbon fiber.

Innovation Solution

A lightweight universal joint and splined pair design that optimizes the stress state by transferring torque through fixed wings, bearings, and rolling elements, reducing the socket's load, and using thin-walled structures with chipless machining, while the splined pair optimizes material distribution and reduces stress and friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If lightweight materials such as aluminum alloy and carbon fiber are used to reduce propeller shaft weight, then weight is reduced, but cost increases and production difficulty increases

Engineering Contradiction:
Improvepropeller shaft weightVSAvoidproduction difficulty
Core Design Contradiction:
Weight of moving objectVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from traditional lightweight materials (aluminum alloy, carbon fiber) to thin-walled steel structure, achieving weight reduction while maintaining manufacturability and cost-effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies thin-walled structure design to the socket and spline components, using thin-walled steel tubes with optimized wall thickness to achieve weight reduction without compromising structural integrity or manufacturing ease

Inventive Principle:
Principle #30Flexible shells and thin films

2Weight of moving object

If the socket wall thickness is reduced to decrease weight, then weight is reduced, but structural strength decreases and deformation occurs under torque

Engineering Contradiction:
Improvesocket weightVSAvoidsocket structural strength
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent optimizes the wall thickness parameter of the socket to a specific range (0.5-3mm) and changes the structural configuration by adding reinforcement ribs, achieving weight reduction while maintaining sufficient strength through parameter optimization rather than simple thinning

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local reinforcement ribs at critical stress areas of the socket, providing localized strength enhancement where torque loads are highest, allowing the overall wall thickness to be reduced while maintaining structural integrity at key locations

Inventive Principle:
Principle #3Local quality

3Weight of moving object

If the socket structure is optimized to reduce weight, then weight is reduced, but processing complexity increases and processing efficiency decreases

Engineering Contradiction:
Improvesocket weightVSAvoidprocessing efficiency
Core Design Contradiction:
Weight of moving objectVSProductivity

Solution Approach 1:

The patent adopts thin-walled tube structure for the socket that can be manufactured using standard cold drawing or extrusion processes, avoiding complex machining while achieving weight reduction, thus maintaining high processing efficiency

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent segments the socket structure into modular components with reinforcement ribs that can be formed through standard metal forming processes, simplifying manufacturing steps and improving processing efficiency compared to monolithic complex structures

Inventive Principle:
Principle #1Segmentation

4Strength

If the splined pair uses traditional design with small diameter and large wall thickness, then structural strength is sufficient, but weight is excessive and material distribution is suboptimal

Engineering Contradiction:
Improvespline structural strengthVSAvoidsplined pair weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent changes the dimensional parameters of the splined pair by increasing the outer diameter and reducing wall thickness, optimizing the diameter-to-thickness ratio to achieve better material distribution, reduced weight, and improved bending capacity while maintaining sufficient strength

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent optimizes the spline tooth geometry and material distribution locally within the splined pair structure, concentrating material where stress is highest (in the spline teeth) while reducing material in less critical areas, achieving weight reduction without compromising load-bearing capacity

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4464910B1Lightweight universal joint, splined pair, and propeller shaft
Publication Date: 2026.03.18 QINGDAO ACME INNOVATION TECH CO LTD
  • EP4464910B1 patent drawingFigure 1~3
  • EP4464910B1 patent drawingFigure 4~7
  • EP4464910B1 patent drawingFigure 8~9(b)

AI summary

A lightweight universal joint, a splined pair, and a propeller shaft are provided. The lightweight universal joint includes a socket (3), a ball (1), and a straight shaft (2), where the socket (3) is a thin-walled structure, and is not configured to transfer a transmission torque; the ball (1) is provided in the socket (3) in a hinged manner, and the ball (1) is provided with a transmission hole; the straight shaft (2) runs through the transmission hole; two ends of the socket (3) are connected to fixed wings (8), respectively; and each of the fixed wings (8) is provided with a carrying hole (8-1) and a transmission key (8-2). The lightweight splined pair includes a spline shaft (16) and a spline sleeve (17) that are thin-walled structures. The lightweight propeller shaft includes the lightweight universal joint and/or the lightweight splined pair. By forming the socket (3) and the splined pair into integrated thin-walled structures, the present disclosure achieves chipless or partial chipless machining, improves production efficiency and quality stability, reduces part weight and processing costs, and meets the demand for lightweight development of automobile parts.