Inequidistant gearing used to reduce gear noise

Tonal noise is considered to be annoying. Unlike broadband noise, tonal noise is hard for the human brain to ignore. State-of-the-art gears primarily radiate this annoying tonal noise, which is caused by the regularly positioned teeth along the circumference of the gearwheel. In this paper, the inequidistant gearing will be presented. The principle of the regularly positioned (equidistant) teeth will be transgressed. When the positions of the teeth are variable, the gears generate less of a tonal noise and are, therefore, less annoying. Thus, the radiated sound pressure level and the psychoacoustic loudness can be decreased. A theoretical investigation of the emergence of the gear noise of inequidistant gears will be shown, followed by the design of a set of spur gears with inequidistant gearing .The benefits and challenges of this new design will be discussed. A comparison of the experimental results from the gears with inequidistant and equidistant gearing will be presented and discussed. From this, a reduction of the sound pressure level, the psychoacoustic loudness, and the psychoacoustic annoyance can be achieved.