Search Results

A joint development program between Metaldyne and Victrex Polymer Solutions was established with the goal of developing a cost effective net shape injection molded gear that provides improvements in NVH (Noise Vibration and Harshness) and operating efficiency over conventional high quality iron gears. A detailed DOE (Design of Experiments) evaluating NVH performance of machined gears was performed in a calibrated NVH test cell. Variables in the DOE included material, gear geometry and backlash variation. The DOE showed the PEEK material gears had different geometric sensitivities, such as helix angle effects, on NVH performance. The results of the DOE were then used to develop an optimal injection molded PEEK polymer gear design. A production quality injection molding gear tool was constructed. Net shape production quality PEEK polymer gears were injection molded and the gears were evaluated in a current production mass balance unit for NVH, mechanical efficiency and durability.

The paper describes a finite element procedure and material model that can be used to predict the post-impact geometry of a thermoplastic bumper energy absorber. The material used in the study is a thermoplastic PC/PBT blend. The methodology presented determines the final geometric shape based on a new finite element material model. The material model uses a secant return modulus that is a function of the plastic strain. The conversion of material data into a finite element material model, along with a finite element procedure for analyzing multiple impacts, is discussed. Comparisons of finite element predictions to test data are also presented.