유연한 가진부 및 기초부를 갖는 다점 지지 마운트 계의 진동파워 절연기법 연구 및 컴프레서 마운트 계에의 응용

Abstract

Audible frequency range vibrations transmitted from operating machinery into supporting and connected structures are often responsible for the noise problems in the whole system as in compressor mount systems in air-conditioners. In these cases, physically meaningful quantity for characterization of the vibratory coupling between subsystems is power rather than transmission forces or velocities. In general, a vibration isolation system consists of a vibrating machine connected to a base structure at multiple points through vibration isolators. The vibrational power which is fed into the base structure is governed by a number of factors; vibrational ``source-strength`` of the machine, influences of vibration controlling measures such as vibration isolators, and flexibilities of the machine structure and the base structure. In this paper, a new performance index is proposed for an isolation system which couples a flexible source structure to a flexible base structure through multiple-point isolation mounts. The performance is defined as vibrational power isolation effectiveness which relates the vibrational power transmission in an isolated system to the one in an unisolated system. A formula of the vibrational power isolation effectiveness is derived for a mounting system connected to non-rigid base structure at multiple points by massless isolators. Usefulness of the vibrational power isolation effectiveness is illustrated by its application to a compressor mount system for air-conditioners.