Noise Reduction in Spur Gear Systems

Abstract

This article lists some tips for reducing gear case noise. With this aim, a static analysis was carried out in order to describe how stresses resulting from meshing gears affect the acoustic emissions. Different parameters were taken into account, such as the friction, material, and lubrication, in order to validate ideas from the literature and to make several comparisons. Furthermore, a coupled Eulerian–Lagrangian (CEL) analysis was performed, which was an innovative way of evaluating the sound pressure level of the aforementioned gears. Different parameters were considered again, such as the friction, lubrication, material, and rotational speed, in order to make different research comparisons. The analytical results agreed with those in the literature, both for the static analysis and CEL analysis—for example, it was shown that changing the material from steel to ductile iron improved the gear noise, while increasing the rotational speed or the friction increased the acoustic emissions. Regarding the CEL analysis, air was considered a perfect gas, but its viscosity or another state equation could have also been taken into account. Therefore, the above allowed us to state that research into these scientific fields will bring about reliable results.

On-Road Detection of Driver Fatigue and Drowsiness during Medium-Distance Journeys

“…This section describes the sleepiness detection procedure based on heart rate variability (HRV) acquired through a sensor integrated in the seat back that allows constant contact with the driver’s body [ 46 ]. The characteristics of the cardiac signal are extracted from the RRI data (interval between wave peaks) recorded while driving and the information obtained from the analysis of this signal is used in a predictive algorithm that provides the closest sleepiness/fatigue index possible to the values obtained with the PERCLOS indicator and which also manages to highlight a trend of sleepiness/fatigue phases [ 47 , 48 , 49 , 50 ]. In turn, the levels of sleepiness and fatigue are quantified using the Karolinska Sleepiness Scale (KSS) and the driver’s subjective estimate, respectively.…”

Reverse engineering of geometric design parameters using shape information of non‐standard spur gear

“…Formula (5) is the working pressure angle. The amount of shift is calculated as the product of the module (m) and the profile shift coefficient (x), and the value obtained by adding 2mx to the pitch circle diameter becomes the working pitch circle diameter (D w ) as shown in Formula (6).…”

“…As a result, manufacturing or development of new gears is attempted by correcting the three-dimensional shape, but these methods do not consider the design tolerances and machining tolerances of the gears at all, so serious problems (gear mesh, strength, transmission error, vibration, noise, etc.) is highly likely to occur [5,6].…”

A Novel Fault Diagnosis Method of Rolling Bearing Based on Integrated Vision Transformer Model

“…Bearing failure can lead to equipment failure and cause serious economic losses or casualties to the enterprise. Therefore, it is very important to monitor and diagnose the health status of rolling bearings through their vibration data to ensure normal production in enterprises [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ].…”