An Appraisal of the Sound Field Generated by Helical Gear Pairs with Different Helix Angles, Manufactured by Various Technologies

摘要

This paper aims to present the influence of the gear manufacturing technology on the sound pressure level (SPL) of a single stage helical gearbox. For this purpose, three gear pairs, having different helix angles (9°, 11° and, 13°, respectively) have been manufactured by three distinctive technologies. The first manufacturing alternative consisted of machining the gear teeth by milling with an accuracy grade 8, according to ISO 1328. The second alternative was designed to increase the quality class of the gears by grinding them with an accuracy grade 6 (according to ISO 1328), while the third manufacturing version involved applying a special fluoropolymer coating on the milled gear teeth. The gear pairs, which had different helix angles, and were manufactured by different technological variants, were tested, in various operating conditions, on an open energy test stand. The degree to which the different manufacturing technologies had an influence on the sound field generated by these helical gears was assessed, and the corresponding advantages and disadvantages of each manufacturing alternative were concluded. It was established that the best results in term of SPL were obtained by the gears which have been grinded, respective the gears with the special fluoropolymer coating. In fact, these two investigated manufacturing technologies lead to very similar results regarding the intensity of the generated sound field.