Optimization of the Housing Shape Design for Radiated Noise Reduction of an Agricultural Electric Vehicle Gearbox

Gwan-Hee Son,Young-Jun Park,Beom-Soo Kim,Seung-Je Cho

doi:10.3390/app10238414

Gwan-Hee Son, Young-Jun Park + Show 2 more

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https://doi.org/10.3390/app10238414

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Abstract

As the demand for agricultural electric vehicles increases, it is becoming important to conduct noise reduction in consideration of the characteristics of an electric powertrain. This study was conducted to optimize the shape design of gearbox housing for radiated noise reduction of an agricultural electric vehicle gearbox. The noise and vibration of the gearbox were measured considering the noise characteristics of the electric vehicle gearbox, which radiates high-frequency pure tone noise. The main noise source radiated by the structural vibration of the gearbox housing was identified and considered when modeling the loading conditions in the numerical analysis. To improve the reliability, the finite element (FE) model was updated and validated. Internal machine elements were modeled as a substructure through a reduced-order modeling method to reduce the computing time and apply a constant gear excitation force. The weak areas of structure were determined and it was used as the design area for optimization. The topology optimization technique was used to reduce the equivalent radiated power (ERP) which was used as an indicator of radiated noise level. The maximum value of the ERP decreased under all operating conditions at the rated speed.

Highlights

With increasing interest in reducing greenhouse gases and fine dust, the development and dissemination of eco-friendly vehicles is expanding
For a conventional engine-driven vehicle, the engine is the main noise source; for an electric vehicle, there is no engine noise, but the gear noise owing to the driving of the electric motor is the main noise source [3]
The objective of this study is to reduce the structural vibration of the gearbox housing owing to the gear mesh excitation force and resulting radiated noise

Summary

Introduction

With increasing interest in reducing greenhouse gases and fine dust, the development and dissemination of eco-friendly vehicles is expanding. In the agricultural machinery industry, the demand for the development of electric vehicles is increasing as a result of the electrification of power transmission systems [1]. The electric motor of an electric vehicle is operated at a relatively high rotational speed and low torque compared to the engine of an internal combustion locomotive. To adjust the driving speed of the electric vehicle to the internal combustion locomotive, a speed-reducing gearbox is required [2]. The noise of the motor and gearbox generated during driving shows relatively high-frequency characteristics compared to that of the engine noise.

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