Patent attributes
A liquid-filled vibration isolator has a first orifice channel providing communication between a pressure receiving chamber and a balancing chamber. One of the pressure receiving chamber and the balancing chamber is communicated via a second orifice channel with an intermediate liquid chamber. The second orifice channel has a shorter distance or a larger cross-sectional area than the first orifice channel. An elastic film member, such as a membrane, separates the intermediate liquid chamber and the other of the pressure receiving chamber and the balancing chamber from each other. A communicating hole of a predetermined size is formed in the elastic film member. An imaginary orifice channel combined from the two orifice channels provides a high damping effect on input vibration of relatively low frequency. As the vibration frequency increases, a gradual transition is made to the damping characteristic of the second orifice channel only.
