Research on Vibration and Noise of Electric Tool
|Course||Mechanical Manufacturing and Automation|
|Keywords||electric tool finite element boundary element noise prediction|
Electric tools are widely used in civil and industrial field. The noise problems caused by electric tools are especially prominent. If the people who is under high noise environment for a long-term, it will lead to language and hearing damage, poor sleep, cardiovascular disorder, neurological symptoms, and the immune decline and so on. With the increasing concern to the noise pollution and the rigorous state regulations of the noise, it is imperative to develop the electric tool of low vibration and low noise. The noise is caused by the vibration and it can be classified into the category of gears impact noise, fans noise and electromagnetic noise. A backlash exists between the teeth of gears of the electric tool will cause the periodic accelerated separation and meshing, the impact and the vibration of the gears. And the vibration of the gears will induce the vibration of the other components, which can also produce the noise problem. Given the enhancement of the load and revolution of the gears, the noise caused by it is much more prominent than the noise caused by the other acoustic source.The article mainly analyze the dynamic characteristics, dynamic response and noise radiation of the electric tool gears under the influence of the impact load by the method of finite element and boundary element. And then make a comparison with the experiment result to provide a design foundation of the electric tool. The following is the main research work.(1) Import the model which is built in Solidworks into ANSYS, and establish the finite element model in ANSYS.(2) Analyze the natural frequency and vibration mode of the electric tool to prepare for the dynamic analysis.(3) According to the program, obtain the gear meshing incentive, and carry on dynamic analysis of the electric tool. The node displacement data which is got form the dynamic analysis will be taken as the boundary of noise prediction.(4) Build the boundary element model of the electric tool and use the node displacement data as the boundary conditions to process the boundary element calculation and then get acoustic characteristics of the sound field.(5) Make a surface acceleration and a sound pressure test of the electric tool(6) By the contrast between the simulation results and experimental results, verify the simulation results, which provides an effective method for the noise prediction of the electric tool.