Search Results

This paper discusses approaches to properly design aluminum axles for optimized NVH characteristics. By effectively using well established and validated FEA and other CAE tools, key factors that are particularly associated with aluminum axles are analyzed and discussed. These key factors include carrier geometry optimization, bearing optimization, gear design and development, and driveline system dynamics design and integration. Examples are provided to illustrate the level of contribution from each main factor as well as their design space and limitations. Results show that an aluminum axle can be properly engineered to achieve robust NVH performances in terms of operating temperature and axle loads.

The design of Front Wheel Drive transmission side covers is primarily driven by packaging concerns, and secondarily by structural durability requirements. While the side cover design is a very important element in the NVH performance of a transaxle, there has historically been little consideration of this concern at the design stage. The typical approach to NVH considerations on a side cover is to start with the initial prototype hardware and add any stiffening features in order to reduce the cover vibration or radiated sound. A preferred approach would be to factor the NVH considerations into the initial design. Through consideration of the packaging constraints and a goal of maximizing the fundamental natural frequency of the side cover, it is possible to select from various alternative geometries the one which best meets these objectives.

The design of Front Wheel Drive transmission side covers is primarily driven by packaging concerns, and secondarily by structural durability requirements. While the side cover design is a very important element in the NVH performance of a transaxle, there has historically been little consideration of this concern at the design stage. The typical approach to NVH considerations on a side cover is to start with the initial prototype hardware and add any stiffening features in order to reduce the cover vibration or radiated sound. A preferred approach would be to factor the NVH considerations into the initial design. Through consideration of the packaging constraints and a goal of maximizing the fundamental natural frequency of the side cover, it is possible to select from various alternative geometries the one which best meets these objectives.

This paper presents a study of axle system NVH (noise, vibration and harshness) performance using DFSS (Design for Six Sigma) methods with the focus on the system robustness to typical product variations (tolerances / manufacturing based). Instead of using finite element as the simulation tool, a lumped parameter system dynamics model developed in Matlab/Simulink is used in the study, which provides an efficient way in conducting large size analytical DOE (Design of Experiment) and stochastic studies. The model's capability to predict both nominal and variance performance is validated with vehicle test data using statistical hypothesis test methods. Major driveline system variables that contribute to axle gear noise are identified and their variation distributions in production are obtained through sampling techniques.