Automatic Transmission Rotating Member Clinching for Compact Joining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Automatic transmissions face challenges in reducing axial dimensions while joining different material parts, such as aluminum and ferrous materials, for the power transmission parts, which can lead to increased size and potential strength issues due to the difficulty in welding these materials together.
Innovation Solution
The automatic transmission employs a mechanical clinching method to join different material parts at a caulking part, where the outer rotating member made of aluminum and the inner rotating member made of ferrous material are connected via extending parts, allowing for reduced size and increased strength by optimizing material distribution and joining without spline-engagement teeth or subsidiary materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If parts made of different materials (ferrous and aluminum-based materials) are joined by welding, then strength is improved, but welding is difficult between these materials
Solution Approach 1:
The patent introduces an intermediary joining method (mechanical clinching via caulking part) between the ferrous and aluminum-based materials, avoiding direct welding while achieving strong connection. The caulking part acts as a mediator that accommodates both materials' properties without requiring compatible welding characteristics.
Solution Approach 2:
The patent replaces the thermal-mechanical welding process with a purely mechanical joining method (clinching). This substitution eliminates the complexity of welding dissimilar materials while maintaining joining strength through mechanical interlocking at the caulking part.
2Ease of manufacture
If the caulking part is formed by recessing in the axial direction, then joining of different materials is achieved, but the size of the automatic transmission increases in the axial direction
Solution Approach 1:
The patent applies the nesting principle by placing the protrusion of the caulking part inside the recess of the second extending part. This nested configuration allows the joining structure to be contained within the existing radial space rather than extending axially, thus achieving material joining without increasing axial dimension.
Solution Approach 2:
The patent resolves the axial dimension problem by shifting the joining structure into the radial dimension. The protrusion and recess are formed in the radial direction, allowing the caulking part to accommodate different material thicknesses without affecting the axial length of the transmission.
3Weight of moving object
If aluminum-based material is used for rotating members, then weight is reduced, but strength may be insufficient for power transmission parts
Solution Approach 1:
The patent applies local quality by using aluminum-based material for the outer rotating member where weight reduction is prioritized, while using ferrous material for the inner rotating member where strength is critical for power transmission. This localized material selection optimizes both weight and strength requirements in different regions.
Solution Approach 2:
The patent creates a composite structure by combining aluminum-based material and ferrous material in a single rotating member assembly. This composite approach allows the system to benefit from both the low weight of aluminum and the high strength of ferrous material, achieving overall weight reduction without sacrificing power transmission capability.
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
This configuration reduces the axial size of the transmission, enhances torsional resistance, and improves fuel efficiency by minimizing inertia, while ensuring structural integrity and cost-effectiveness through appropriate material selection and joining techniques.
Implementation Method 1
The outer extending part and the inner extending part of the first rotating member are coupled through a first extending part formed by joining the outer extending part and the inner extending part to each other in an axial direction of the automatic transmission at a caulking part via mechanical clinching.
Data Source
AI summary
An automatic transmission which includes a first rotating member and a second rotating member is provided. The first rotating member includes an outer rotating member having a first outer power transmission part and an outer extending part, and an inner rotating member which is made of a different material from the outer rotating member and has a first inner power transmission part and an inner extending part. The outer and inner extending parts are coupled through a first extending part formed by axially joining them to each other at a caulking part. The second rotating member includes a second extending part having a recess indented on an opposite side of the first extending part. The caulking part has a protrusion protruding by being recessed from the first extending part to the second extending part. At least a part of the protrusion is located inside the recess.