Analysis of Vibrations and Acoustics on Riding Lawn Mower 2021-36-0075

With the growing increase in the use of lawn mowers, it is necessary to control the vibration and sound pressure levels to which operators are exposed during their workday. Noise hearing loss can affect individuals exposed to high Sound Pressure Levels (SPL). Workers using lawn mowers are part of this population. With regard to this equipment, another factor that must be considered is the occupational exposure of the vibration imposed on the operator. Occupational exposure to vibration in the hands and arms is associated with a variety of adverse effects on the health of the individual, being collectively known as the vibration syndrome in the hands and arms. Exposure to full body vibration for seated people is associated with an increased risk of degenerative injuries lumbar spine, disorders in the central nervous system, and possible damage to the digestive and genital / urinary systems. Therefore, the objective of this study is to evaluate the vibration and sound power level emitted by a tractor of this class, under different operating conditions, which are a combination of three parameters: vibration attenuators (engine block cushions), engine speed and a power take-off (PTO) of the tractor. The acoustics tests followed a methodology based on ISO 3744:2010 - “Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for essentially free field over reflecting plane”. The vibrations measurements are base on ISO:8041 “Human response to vibration - Measuring instrumentation”. From the obtained data, the occupational vibration indicators and sound power level were calculated, so that it was possible to compare the different conditions. When comparing the levels obtained in the tests with the ranges provided by the standards, it can be noted that for some conditions the levels of vibration exceeded the desired values, the same happens with noise.