Parameter Study and Improvement of Gearbox Whine Noise in Electric Vehicle

Abstract

Gearbox whine noise can seriously reduce the interior sound quality in an electric passenger car. In this work, a six-degree-offreedom (6-DOF) dynamic model of a helical gear system was constructed and the mechanism for generation of whine noise was analyzed. The root cause of the problem was found through noise, vibration and harshness (NVH) testing of the gearbox and the vehicle. A rigid-elastic coupling dynamics model of the reducer assembly was then developed. The accuracy of the model was then validated via modal testing. The structure-borne noise of the reducer under full acceleration conditions was predicted using the acoustic structure coupling model and the rigid-elastic coupling model of the reducer. Gear parameters including the pressure angle, the helix angle and the contact ratio were studied to determine their effects on the whine noise. Gear tooth microgeometry modification parameters were then optimized to reduce the transmission error of the first pair of meshing gears. Finally, the whine noise from the gearbox was eliminated.

Active noise control modeling for an electric bus driving position and its effect on sound quality

“…3 In particular, the noise from motor and transmission abnormal have a medium and high frequency spectrum, close to the sensitive frequency band of human ear to noise, which has a remarkable impact on the whole vehicle acoustic comfort. 4,5 There are passive and active ways to control interior noise, among which passive control measures such as sound absorption and sound insulation can reduce decibel to meet the existing noise limit requirement (GB/T 25982-2010), but it is difficult to effectively regulate vehicle sound quality. 4,6,7 This is because sound quality improvement not only need to reduce the sound pressure level in a certain frequency domain, but also fully consider other psycho-acoustic objective characteristics, such as loudness and roughness.…”

“…4,5 There are passive and active ways to control interior noise, among which passive control measures such as sound absorption and sound insulation can reduce decibel to meet the existing noise limit requirement (GB/T 25982-2010), but it is difficult to effectively regulate vehicle sound quality. 4,6,7 This is because sound quality improvement not only need to reduce the sound pressure level in a certain frequency domain, but also fully consider other psycho-acoustic objective characteristics, such as loudness and roughness. The active control method is based on the principle of acoustic interference, that is, artificially increasing the secondary noise source to offset the original noise signal and achieve the purpose of improving sound quality.…”

Noise analysis and optimization of the gear transmission system for two-speed automatic transmission of pure electric vehicles

“…Singh and Sai (2015) reduced the noise level of transmission by optimizing the stress distribution of the tooth surface. Zhang (2018) established the rigid-flexible coupling model of transmission and reduced the noise of transmission by optimizing parameters such as gear pressure angle and helix angle. Shu et al (2020) established the gear transmission system model of two-speed transmission in the Romax Designer software, optimized the system through the combination of tooth profile modification and tooth lead modification, and improved the vibration and noise levels of the gear transmission system.…”

Numerical Noise Transfer Analysis of a Flexible Supported Gearbox Based on Impedance Model and Noise Transfer Function

“…Results show that the first-stage gear pair makes the most contribution to the excitation and radiation noise. Zhang [12] proposed a transmission system-housing coupled multidynamic model and studied the influence of pressure angle, helix angle, and contact ratio on the whine noise. Zhou et al [1] analyzed the influence of rotational speed and torque on gearbox radiation noise.…”