This paper aims to provide the relation between surface roughness of angle grinder towards vibration amplitude. Prolong usage of angle grinder over excessive force will affect the performance of angle grinder where it tends to vibrate due to surface roughness of gear and create excessive vibration that will lead to hand-arm vibration system. Therefore, this study is conducted to investigate surface roughness of the gear teeth of angle grinder affects the amplitude of vibration. The amplitude of the vibration for angle grinder is conducted by using LMS data acquisition system. Meanwhile, the roughness of the gear teeth is measured by using Keyence Laser Confocal Microscope. The data was taken by every 100 hours of grinding process. The results show that the surface roughness of the gear teeth is steadily decreasing due to contact between gears and subsequently resulted increasing the amplitude of the vibration. For 500 hours measurement, the correlation of surface roughness of gear teeth with the amplitude of vibration is 93.7% for marked tooth and 86.5% for adjacent tooth, this indicates the strongest possible agreement that when surface roughness of the gear teeth decreasing, the vibration amplitude is higher.
This paper presented a concept of single degree of freedom (SDOF) electromagnetic vibration energy harvester device. This technique enable system to operate at wideband frequency range, low frequency and has multi-resonance frequencies. Each mechanical system operates at difference frequency where each system is attached with electromagnetic transducer components. the device is developed based on the parameter factors of vibration transmissibility from external vibration sources into the device through mathematical modelling. A prototype was tested by using vibration exciter and normal human walking. the fabricated device had showed multi-resonant behavior at 4.26 and 8.34 Hz during test. From experiment results, they have showed capability to operate at wide bandwidth frequency from 1.9 until 18.5 Hz at a periodic excitation of 0.04 g. the highest amount of rms voltage that has been produced about 108 mV with a maximum 78 µW average power across the 150 Ω load resistance. So, it has proven the dual-moving mechanical concept with low damping value in system has increased the operating bandwidth frequency and also increased the amount of output voltage from device.
This paper presents information of detecting the gear using frequency domain technique in vibration analysis. In this study, vibration signal is very crucial in determining signal from defective gear. The quality of the signal displayed in the frequency spectrum are depends on the number of sampling frequency taken into account during acquiring the data. Insufficient number of samples may acquire poor signal in contrast with sufficient number of samples. The objective of this research emphasizes the various frequency resolution and centroid shifting frequency location to characterize the normal and defective gear. The development of test rig with a constant speed of 1493 RPM is designed and consist of simple pinion and gear. The DAQ (NI) with algorithm block diagram developed using LabVIEW is used to acquire the frequency domain data. It is found that by varying the number of samples will affect the resolution of the signal and subsequently tune the shifting centroid of frequency. By calculating the centroid shifting frequency have indicate that the amplitude of normal gear is 0.0128g, defect gear (broken tooth) is 0.052 g and defect gear (broken tooth 90°) is 0.0938g. The amplitude of normal gear, defect gear (broken tooth) and defect gear (broken tooth 90°) are located at frequency 745.829Hz, 746.757Hz and 746.2Hz respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.