Mounted on the floor of the refrigeration unit Isolation

Mounted on the floor of the refrigeration unit isolation research sowing rain Chen a, using secondary isolation to reduce unit noise refrigeration unit weight 2590kg, speed of 1000 rpm, respectively primary and the secondary vibration isolation. Isolator once a "composite isolator" I invented the company's patent No. ZL 2013 2 0491115.6, for a variety of types and models of equipment isolation. After computing a vibration isolation efficiency 97.27%, for the first time after the refrigeration unit uses vibration isolation, room noise to residents 33-35dBA, the effect is not ideal. Secondary isolation using another patented product of our invention, isolation efficiency was calculated to reach 99.79%, calculated results are shown in Table 1. With inverter, when working speed increased to 1450 rpm, the same stiffness ratio and the mass ratio of the case, the second vibration isolation efficiency of 99.96%, isolation efficiency by 17 percent. The results are shown in Table 2. It should be noted that the isolation efficiency calculation, is calculated using software developed by our company, the accuracy and precision to meet the design requirements. For the calculation of the heavy workload of the project, this calculation software is necessary. Another issue related to the software was published, this is no longer introduced. Second, the isolation efficiency analysis from the calculation results, when the natural frequency ω1 and the angular frequency ω close to the excitation force, there is resonance, or to isolation efficiency is greatly decreased. Therefore, the choice of the mass ratio must pay attention to avoid system resonance. The results can be seen from the table, when the speed increases, both the frequency of the exciting force increases the isolation efficiency can be improved. And when the mass ratio increases, vibration isolation efficiency, but when the mass ratio of 0.4-0.6 after the isolation efficiency margin does not increase. Therefore, the quality of the project should select the appropriate ratio, or according to the site need to select the appropriate quality ratio. Increased stiffness ratio is to ensure that the amount of deformation of the elastic element are basically the same, within reasonable limits, is not the bigger the better. III Conclusion quadratic isolator unit for vibration isolation, isolation can achieve high efficiency and meet noise requirements. The choice should pay attention to avoid resonance mass ratio, but do not have to choose a large mass ratio. While using computing software to calculate isolation efficiency can be improved calculation speed and accuracy, calculated in Table 1 S excitation frequency stiffness ratio η% by mass vibration isolation efficiency coefficient μ isolation efficiency ratio 1.00 0.05 104.7 104.7 1.07 0.08 -698.28 7.9628 resonance 96.35 0.03652 0.00860 99.14 97.27 0.15 97.27 104.7 1.14 104.7 1.21 104.7 1.29 0.23 99.49 97.27 0.31 99.62 0.00514 0.00378 0.00306 99.69 97.27 0.39 97.27 104.7 1.36 104.7 1.43 104.7 1.50 0.46 99.74 97.27 0.54 99.77 0.00261 0.00231 0.00208 97.27 99.79 0.62 1.57 97.27 104.7 Calculation Table 2 Exciting frequency stiffness ratio S mass ratio μ vibration isolation efficiency η% coefficient Tf 151.8 1.00 0.03 1.07 0.08 99.66 151.8 resonance resonance 0.00342 0.00146 151.8 151.8 1.14 0.15 99.85 1.21 0.23 99.90 1.29 0.31 99.93 151.8 0.00097 0.00075 0.00062 151.8 151.8 1.36 0.39 99.94 1.43 0.46 99.95 0.00054 0.00048 151.8 151.8 1.50 0.54 99.95 0.62 99.96 1.57 0.00044