The hybrid passenger car of the Technical University of Munich is driven by a diesel and an electric engine, depending on the current driving conditions. The main component of the drive train is an i2-CVT-gearbox with a PIV chain, making use of the transmission ratio of the CVT stage in two directions. Noise measures for the CVT-gearbox components are developed, with the goal to determine sound sources in the gearbox as a part of the entire drive train. A multibody system model of the drive train consisting of 13 rigid bodies for the components and 60 rigid bodies for the chain links was established. It contains two elastic shafts, 95 linear and nonlinear force elements with and without play and has a total of 164 degrees of freedom. Cyclic irregularities of the combustion engine as well as the discrete structure of the metal CVT chain are the major excitation sources. Bearing forces of the shafts were determined from numerical simulation of the entire train. These alternating forces excite gearbox vibrations. The dynamic behaviour of the gear housing was investigated by experimental modal analysis. Force level spectra with A-rating as well as impulse mean values are derived as noise measures for six gear stages and 10 pairs of bearings. A noise map of the gearbox displays the results. Vibrations at one of the four gearbox shafts are determined as major source of housing vibrations. This shaft is connected to the housing at or close to the antinode of two of the dominating eigenforms of the gearbox housing. An order of importance of the gearbox shafts for vibrations is established, which is found to be independent from the state of the clutches within the gearbox at a given speed.
Noise measures for the drive train of the Munich hybrid passenger car
Schallmaßnahmen für den Antriebsstrang des Münchener Hybrid-PKW
International Congress on Sound and Vibration, 7 ; 2829-2836
2000
8 Seiten, 3 Bilder, 1 Tabelle, 3 Quellen
Conference paper
English