Torque Converter Pilot Assembly for Stronger Edge Welds
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Solution Overview
Problem
Torque converters with pilots welded to one axial side face issues with fatigue life due to poorly bonded or unbonded regions at the edges of the weld, leading to stress notches and potential cracks, which existing methods fail to address cost-effectively without increasing costs, weight, or assembly time.
Innovation Solution
A method involving a torque converter assembly where a pilot with an annular projection is welded to a cover with a complementary recess or groove, featuring sharp corners and clearance to enhance weld bond strength and penetration, preventing material expansion and ensuring sealing functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the pilot is welded to the torque converter cover using conventional methods, then the pilot is attached to the cover, but poorly bonded or unbonded regions form at the weld edges creating stress notches that reduce fatigue life
Solution Approach 1:
The recess is provided with sharp corners at specific locations to concentrate the weld material and improve bonding at critical edge regions. This local modification of geometry ensures that weld material accumulates at the sharp corners rather than spreading uniformly, preventing unbonded regions and stress notches at the weld periphery while maintaining overall weld strength
Solution Approach 2:
The recess with sharp corners is pre-formed in the torque converter cover before the welding process. This preliminary geometric preparation guides the weld material flow and ensures proper bond formation at the pilot-cover interface, preventing defects before they can occur during welding
2Area of stationary object
If the weld material spreads during welding, then the weld area increases, but unbonded or poorly bonded regions form at the edges creating stress notches
Solution Approach 1:
The recess geometry with sharp corners creates localized regions where weld material is concentrated and bonded, rather than allowing uniform spreading. The sharp corners act as anchors that ensure proper bonding at the periphery while the recess walls guide the weld material flow, maintaining high bond quality throughout the weld area
3Strength
If a complementary recess or groove is added to the torque converter cover, then weld bond strength and penetration are enhanced, but the manufacturing complexity increases
Solution Approach 1:
The recess is designed with specific geometric parameters (sharp corners at defined locations, controlled depth) that can be integrated into standard cover manufacturing processes. By optimizing these parameters, the recess can be formed using conventional stamping or molding techniques, minimizing the impact on manufacturing complexity while achieving the desired weld enhancement
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly improves weld bond strength and penetration, reducing the likelihood of poorly bonded regions and maintaining the sealing function, thereby enhancing the fatigue life of torque converter assemblies without increasing costs or assembly time.
Implementation Method 1
The welding process results in metal fusing and forming the welded connection. applying force and energy to the pilot to weld the pilot to the torque converter cover
Data Source
AI summary
A method of assembling a pilot to a torque converter cover is provided with the method including: (a) providing the pilot having an annular projection in a connection region; (b) forming a torque converter cover of a torque converter with a complementary recess or annular groove to the annular projection in a mating connection region; (c) positioning the pilot on the torque converter cover with the annular projection at least partially received in the complementary recess or annular groove; and (d) applying force and energy to the pilot to weld the pilot to the torque converter cover. A torque converter assembly is also provided.