A passive vibration-cancelling isolation mount

An analysis of an idealized passive vibration-cancelling two-terminal mount with one degree of freedom at each mechanical terminal isolating a nonrigid machine from a nonrigid foundation is presented. To evaluate a vibration-cancelling (VC) mount, its effectiveness as a function of frequency is compared with the effectiveness of both conventional and compound mounts isolating a rigid machine from a nonrigid foundation. The comparisons indicate that a carefully designed and manufactured VC mount should provide substantially greater vibration reduction at its cancellation frequency than either a conventional or compound mount having the same low frequency stiffness, i.e., stiffness at the natural frequency of the machine mount system.