Search Results

A significant percentage of energy is lost in internal combustion engines due to valve train friction. The reduction of friction losses of a valve train is an important factor to improve significantly fuel efficiency and consequently emissions reduction. The friction loss of valve train includes the losses of the individual components and factors, such as spring load, temperature, lubricant type, mass of components, operating conditions and others. The breakdown of the friction within the valve train is necessary for the implementation of effective optimization measures. This paper presents an analysis of some influence factors associated to friction loss, utilizing the Design of Experiments approach. The results are based on dynamic measurements on a single overhead camshaft (OHC) engine valve train, performed on a test rig developed for friction torque measurements.

More efficient and more reliable methods to analyze the performance of the bearing test samples help to reduce validation time during development of rolling bearings. This paper presents a study of the impact on airborne noise and structural borne noise of especial prepared rolling bearings with angular contact submitted for durability tests. The study aims to link specific bearing failures to characteristics in airborne noise and structural borne noise using for instance the “envelope technique”. In the future these patterns will enable more effective online monitoring of failure evolution.