Influence of Design and Operational Parameters on the Dynamic Behaviour of Gear Pumps.

This work concerns external gear pumps for automotive applications, which operate at high speed and low pressure and presents a sensitivity analysis about the influence of design and operational parameters on the pump dynamic behaviour. In previous work, a non-linear lumped-parameter kineto-elastodynamic model was developed, with the aim of including all the important effects, as well as to get a rather simple model. Two main sources of noise and vibration can be considered: pressure variation and gear meshing. The model has been validated by comparison with experimental vibration data, in a wide range of operational conditions and for different gear designs and several profile errors. This paper is focused on the analysis of the influence of the main design and operational parameters on the pump dynamic behaviour. In particular, the effect of operational pressure and speed, the influence of the clearance in the journal bearing and between tooth tip and pump case, and the effect of the dimension of the relief grooves in the bushes will be thoroughly discussed in the paper. Finally, the model could be a very useful and powerful tool in order to evaluate design improvements for noise and vibration reduction.