Axle Sleeve Mechanical Lock Eliminates Weld Stress Risers
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Solution Overview
Problem
Existing heavy-duty vehicle axle-to-beam connections face issues with stress risers and local mechanical property changes due to welds, leading to reduced durability and life expectancy.
Innovation Solution
The implementation of an axle-to-beam connection that eliminates welds by using a sleeve with mated depressions that engage with corresponding depressions on the axle, creating a mechanical lock without additional fasteners, thereby preventing stress risers and enhancing durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welds are used to connect the axle to the beam, then the connection strength is improved, but stress risers and local mechanical property changes occur that reduce durability
Solution Approach 1:
A sleeve is introduced as an intermediary component between the axle and the beam. The sleeve receives welds from the beam but connects to the axle through mechanical deformation (swaging, squeezing, or crimping) rather than welding, thereby eliminating stress risers on the axle while maintaining connection strength.
Solution Approach 2:
The welding process is replaced with a mechanical deformation process (swaging, squeezing, or crimping) for connecting the sleeve to the axle. This substitution eliminates the thermal effects and stress concentrations associated with welding, improving the durability and reliability of the axle.
2Strength
If welds are used to connect the sleeve to the axle, then the connection strength is improved, but the axle's durability is reduced due to stress risers
Solution Approach 1:
The sleeve serves as an intermediary that isolates the axle from direct welding. The beam is welded to the sleeve, and the sleeve is mechanically deformed onto the axle, preventing stress risers on the axle while maintaining strong connections throughout the assembly.
Solution Approach 2:
The welding process is extracted from the axle-sleeve connection and applied only to the beam-sleeve connection. This separation removes the harmful effects of welding from the axle, extending its service life while maintaining connection integrity.
3Reliability
If additional fasteners are used to connect the sleeve to the axle, then the connection reliability is improved, but the device complexity increases
Solution Approach 1:
The sleeve and axle are connected through direct mechanical deformation of the sleeve material around the axle, merging the connection function into the sleeve itself rather than requiring separate fasteners. This reduces component count while maintaining reliable connection.
Solution Approach 2:
The sleeve performs its own fastening function through mechanical deformation (swaging, squeezing, or crimping) that creates an interference fit with the axle. The sleeve serves both as a structural component and as its own fastener, eliminating the need for additional fasteners.
Data Source
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AI summary
A vehicle axle/suspension system includes an axle (632) having at least one depression 608) formed therein. A sleeve (631) is formed with at least one depression (606) and disposed about the axle so that the axle depression and the sleeve depression matingly engage one another to form a mated pair of depressions. A method of forming the connection includes providing an axle and disposing a sleeve about the axle. At least one mated pair of depressions is simultaneously formed in the axle and the sleeve. A brake system (628) is mounted on the sleeve.