Two-part Torsional Vibration Damper Hub Design
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Solution Overview
Problem
Traditional methods for producing torsional vibration damper hubs are either heavy and costly due to casting or lack the necessary wear resistance for seal noses in lighter designs, and welded two-part constructions are aesthetically unappealing and require specialized equipment.
Innovation Solution
A two-part hub design where a seal nose made of nodular or gray cast iron is mechanically engaged to a primary hub component of softer steel, eliminating the need for welding and providing axial and angular integrity through threaded connections and keyways.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If stamping or forming is used to produce the hub, then the hub becomes lighter and cheaper, but the seal nose lacks sufficient wear resistance
Solution Approach 1:
The hub is divided into two separate components: a formed hub body (produced by stamping or forming for lightness and cost-effectiveness) and a separate seal nose (produced from wear-resistant material). This segmentation allows each component to be optimized for its specific function while being manufactured by appropriate processes.
Solution Approach 2:
The invention uses composite construction by combining the formed hub body with a seal nose made from material having sufficient wear resistance (such as nodular iron or gray cast iron). This composite approach allows the assembly to exhibit both the lightness of formed structures and the wear resistance of tougher materials at the critical seal nose interface.
2Stability of the object's composition
If a two-piece construction with welding is used, then axial and angular integrity is provided, but specialized equipment is required and the appearance is unappealing
Solution Approach 1:
The invention replaces the welding process (thermal/mechanical system requiring specialized equipment) with a mechanical fastening system using bolts or screws. This mechanical substitution achieves the same goal of providing axial and angular integrity between the hub body and seal nose while eliminating the need for welding equipment and producing an aesthetically acceptable appearance.
3Reliability
If nodular or gray cast iron is used for the seal nose, then wear resistance is sufficient, but the material is heavier than formed steel
Solution Approach 1:
The invention applies local quality by using wear-resistant nodular or gray cast iron specifically at the seal nose interface where wear resistance is critical, while the rest of the hub body can be made from lighter formed steel. This localized use of heavier material minimizes overall weight increase while providing sufficient wear resistance where needed.
Data Source
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AI summary
Two-part hubs for torsional vibration dampers are disclosed that have a main body made of a softer material than a seal nose and do not require a welded joint to join them together. The main body has a plate defining a front face and a back face, an annular core extending axially outward from the back face of the plate and defining an innermost, outer radial surface and a first bore through the main body, and an outermost, radial, elastomer- receiving surface spaced apart from the innermost outer radial surface by the plate. The seal nose is mated to the innermost, outer radial surface of the annular core and mechanically engaged with the main body for rotation together. Torsional vibration dampers that include the two-part hubs are also disclosed, as well as a front end accessory drive including the same, and methods of manufacturing the two-part hubs.