Vibrational Monitoring of Nested Planetary Geartrain with Unground Pinion

The nested planetary gear train, which has two integrated single-stage planetary gearsets, is one of the newly developed compound gear train that has been successfully applied to the automobile transmissions. In the current study, a certain type of gear fault in the nested gear train, ungrounded pinion, is investigated using a non-destructive approach monitoring its vibration levels. A novel experimental test stand with open and vertical setup has been designed to collect the vibrational data by mounting the accelerometer directly to the gear clutches. Each of the two layers of the compound gear was tested separately. The measured vibrational data were processed with several signal processing techniques, which includes (a) frequency spectrum analysis, (b) time synchronous averaging (TSA) and (c) modulation sideband analysis. The experimental results show that the existence of the ungrounded pinion can be identified with the frequency spectrum analysis of the vibrational data. In addition, the modulation sidebands are also modeled using a modified version of the traditional technique of physical signal modeling. It is shown that the relative phase of the planet and the meshing vibration strength changed by the unground gear is the critical factor for determining the modulation sideband behavior. In addition, the location of the ungrounded pinion can also be determined by the time history processed by TSA.

Effects of vehicle driveline parameters and clutch judder on gearbox vibrations

Clutch judder causes discomfort in a car. This undesirable event not only creates noise and vibrations, it also disturbs the normal functionality of other components in the driveline, especially the gearbox, which is prone to oscillating inputs. Although there are numerous separate studies on clutch judder and gearbox vibrations, a combined study is necessary in order to investigate the coupled dynamics, especially the effect of vibrations in a clutch on gearbox vibrations. In this paper, a dynamic model is presented for the driveline, including the details of a gearbox and a dry clutch. It allows us to investigate the effect of clutch parameters and to simulate conditions with and without judder. The obtained dynamical equations are then solved numerically. The influence of judder on gear dynamics and passenger comfort is investigated. The results show that judder causes loss of contact in the gearbox in most cases. In more severe cases of judder, it can cause rattle not only in the unloaded gear, but also in the loaded gears. A modal analysis and a frequency spectrum analysis are conducted as well in order to identify the frequency components of the system vibrations and to verify the obtained results. Parts of the results are compared with the theoretical and experimental data from other research studies, which show agreement and serve to validate the model in this work.

A Study on Performance and Noise Analysis of 4 Stroke 4 Cylinder Diesel Engine

In our modern world, rapidly growing environment one of the developing problems is that of “Noise”. This has lead to overcrowded or jammed roads and noise pollution. Engine noise is one of the major sources of noise in vehicles. So, it is necessary to study noise generated by four stroke four cylinder diesel engine at different loads. First the sound pressure level is measure in dB(A) near the engine at four different locations at distance of 1.5m from centre of each side of an engine to find out that location where sound pressure level is maximum. Sound power is calculated using rectangular parallelepiped at different loads. Frequency spectrum analysis is done to measure sound pressure level in 1-1 octave band.

A Review on Study on Performance and Noise Analysis of 4 Stroke 4 Cylinder Diesel Engine

In our modern world, rapidly growing environment one of the developing problems is that of 'Noise'. This has lead to overcrowded or jammed roads and noise pollution. Engine noise is one of the major sources of noise in vehicles. So, it is necessary to study noise generated by four stroke four cylinder diesel engine at different loads. First the sound pressure level is measure in dB (A) near the engine at four different locations at distance of 1.5 m from centre of each side of an engine to find out that location where sound pressure level is maximum. Sound power is calculated using rectangular parallelepiped at different loads. Frequency spectrum analysis is done to measure sound pressure level in 1-1 octave band.