双层隔振(或二级隔振)装置在50年代以前主要应用于商品包装、仪表保护以及其他一些小型设备上。到60年代才开始用在舰船柴油机装置上,而目前已被应用在对隔声要求特别高的舰船上。近二、三十年来,随着柴油机功率及转速的提高,它的振动与噪声强度越来越大,频率范围不断加宽。这种高频振动,一方面从机器表面辐射出来形成空 Double-layer vibration isolation (or second-level vibration isolation) device before the 50’s mainly used in commodity packaging, instrumentation protection and other small devices. It was not until the 1960s that it began to be used in marine diesel engines. At present, it has been applied to ships that require extremely high sound insulation. Nearly two or three decades, with the diesel engine power and speed increase, its vibration and noise intensity is increasing, the frequency range continues to widen. This high-frequency vibration, on the one hand, radiated from the machine surface to form an empty space