| 摘要 |
PURPOSE:To suppress the vibration level to a level which causes no hindrance to the operation of equipment by maintaining the vibration transfer level of a floor surface at 0.003mm. or less in dark vibration level displacement which is indicated at a tolerable value of 60dB or less, and determining the vibration isolating parameter for the amplitude of vibration (displacement) of a pump to be 1.5mm. or less, a value leaving a margin for the tolerable range of a flexible joint. CONSTITUTION:When using an oil-sealed rotary vacuum pump 4 having a displacement of 3,000 liter per minute or above for vacuum exhausting a machining chamber 2, as a means of suppressing the displacement of the oil-sealed rotary vacuum pump 4 at 1.5mm. or less and the amplitude of vibration of a body base 1 at 0.003mm. or less, an additional load 5 of 0.5-0.7 times the load of the oil-sealed rotary vacuum pump 4 is added to the pump 4, the mechanical rigidity of the body base 1 is increased, a vibration isolating system in which the load of body is determined to be about 5,000-8,000kg is provided, and vibration isolating members 6 having a spring constant of 40-60kg/cm<2> and a damping factor of approximately 0.36 are used. Instead of completely preventing the vibration of the vacuum pump 4, by providing a certain tolerable range of vibration, the additional load required for isolating vibration can be reduced. |
