| 摘要 |
PURPOSE:To reduce noise generated from an oil pump and oil piping by perfectly enclosing the oil pump and the oil piping with an air duct plate reaching to a floor and providing a high acoustic absorptivity sound adsorbing material also on the floor. CONSTITUTION:The oil piping 2b connecting an oil-filled electric apparatus 1 housed in a soundproof enclosure 3 and a cooler 7 and an oil pump 4 positioned in the middle of the piping 2b are perfectly enclosed with air duct plates 15, 16 which reach to the surface of a floor between the wall 3a of the soundproof enclosure 3 and the air inlet duct 9 of the cooler 7 and sound absorbing materials 17, 19 are placed on the floor 14 enclosed with the wall 3a of the soundproof enclosure 3 and the air duct plates 15, 16 and at the lower part of the air inlet duct 9 of the cooler 7. In this construction, the rise of a sound pressure is restrained by the sound shut-out effect of the air duct plates 15, 16, the sound absorbing material 17 stuck to the air duct plates 15, 16 and the wall 3a of the soundproof enclosure 3 and the sound absorbing effect of the sound absorbing material 19 placed on the floor and the external propagation of noise is greatly restrained. The rise of the sound pressure at a sound absorbing gate 9a is also controlled by the sound absorbing material 19 placed on the floor under the gate. |
