Research On Vibration And Noise Control Of Roller Driving System

Roller driving devices are widely used in industry. The huge noise generated by roller driving devices is the main source of the producing workshop noise, which not only threats workers’health, but also affects the production. It has already restricted the progress of entire social economy. This research is focusing on exploring control technology and research methods about noise and vibration of roller driving system. Mechanism of noise generated and measures of noise and vibration reducing of this system are researched by theoretical analysis, finite element simulation and experiment method. In brief, the main contents are as following:1. Roller driving system is modeled. Applying lumped parameter method, the whole system is simplified into37lumped masses. Therefore, a mechanics model is established. After determining the system parameters, vibration differential equation of roller driving system is calculated by Mode Superposition Method. The calculation process is programmed into MATLAB language of vibration response characteristics of the system.2. Vibration response characteristic, velocity response spectrum and calculation method of the radiated noise are studied, accompanied by establishing radiated noise prediction model of roller driving system. The vibration acceleration data are extracted from four kinds of experimental conditions of system. Finite element model of the roller system is built. With the load identification inverse function of virtual.lab software, the equivalent excitation spectrum is obtained. The character of radiated noise of roller system is researched through loading excitation spectrum into the noise prediction model. Furthermore, the noise prediction model is revised by comparing and analyzing tested noise radiation. The revised model is used to predict noise of the other conditions and develop great success, so it is demonstrated that noise prediction model of roller driving system is correct.3. The AML finite element method is proposed to solve the noise radiation problem according to structure character of roller driving system. Due to the particularity of system structure and running condition, there will be certain complexity on vibration and noise researching. The modal analysis of driving parts, base components and overall roller system is carried out. Meanwhile, the structural finite element model of roller system is established and vibration response character is studied. Acoustic finite element model is also established based on running condition of roller driving system. Then, the AML finite element method is used to research system radiated sound field after analyzing each acoustical boundary condition. The sound field pressure of the roller system is obtained, which is well consistent with test data. It is verified that AML finite element method is reliable to calculate radiated sound field of radiation surface of local boundary.4. Some influence factors of radiation noise of roller system are studied. It is researched that noise and vibration energy is mainly concentrated in the range of350Hz～1300Hz and the top peak and second top peak of vibration and noise at multiple lumped mass positions are around the two frequency points of400Hz and600Hz, which is closed to the eighteenth order of natural frequency of roller system model. The influence factors of system vibration and noise are researched respectively, such as roller dimensional discrepancy, roller friction, roller added structural damping materials, incentive uneven and so on. Moreover, all factors are studied comprehensively by grey relational theory. The results show that radiation noise is mostly caused by the intermediate position deviation on the wheel of roller system.5. A few structure schemes of roller driving system with low noise are proposed. One set of low noise system is designed according to these schemes. Various vibration and noise reduction schemes are put forward by researching main factors of radiation noise. A low noise system is manufactured which is installed and commissioned on site in order to contrast testing result. The researching results show that reduction effect of low noise system is obvious. Average noise reduction achieves10dB. New roller driving system has been applied to production practice and obtained great social and economic benefits.6. A new method of noise measuring and evaluating method of roller driving system is proposed. The theoretical research is carried out about radiation noise of the roller system. After analyzing relative national standards about calculation methods of radiated sound power of machinery equipment, semi-cylinder surface method is proposed to measure radiated sound power of roller system. According to actual condition on site, sound pressure measured in certain distance from roller axis is proposed to evaluate the radiation noise of roller system.This research work is aimed to establish prediction model of vibration and noise and study the dynamic and radiation noise characters of roller system. The radiation noise of roller system is solved by finite element AML method successfully. Some low noise structrures of roller system are poposed and one of them is conducted based on researching the influence factors of radiation noise of roller system. A new method is put forward of measuring and evaluating the radiation noise of roller driving system. A series of practical results are obtained for solving the difficult technical problems about vibration and noise of roller system It has important significance to reduce vibration and noise of automotive and transportation devices.