Abstract: A system (20) which includes a frequency-dependent decoupler (21) arranged in a series-spring relationship with an actuator (26) for supplying active forces to cancel vibration. The system (20) also includes a spring (28) for providing a primary load path. The system (20) is responsive to at least one sensor (32, 34, 36 or 38) and is controlled via controller (30). The decoupler (26) has greater frequency dependency than the spring (28) and allows the actuator (26) to be effectively decoupled at low frequency, yet coupled at high frequency. This frequency dependent coupling allows the system (20)to accommodate transient static and low frequency loads and motions by allowing motion across the decoupler (21). However, at high frequency, the decoupler (21) becomes stiffer and couples the actuator (26) with the moving members (22) and (24) such that motion across the decoupler (26) is minimized and the actuator (26) becomes more effective at high frequency attenuation.

Abstract: A fluid mount with the capability of actively controlling the amount of vibrational energy transmitted thereacross. An actuator is provided in series or in parallel with the inertia track passageway of a double pumper isolation mount to permit the dynamic stiffness of the mount to be varied so as to control the amount of vibrational energy transmitted in a desired manner. A control system for permitting frequency-shaped force feedback control of the device is also disclosed. Utilization of the device as a tuned absorber is also described.

Abstract: The damper assembly has improved valve means that includes at least one annular movable valve member of the voice-coil type. Such valve member is formed at least in part of composite material that increases the strength and stiffness of the member, while reducing its coefficient of thermal expansion and its weight. In a preferred embodiment of the invention, the assembly includes two movable annular valve members which are driven in unison with each other such that when one occupies a flow-permitting position the other occupies a flow-inhibiting position. Check valves utilized in the assembly preferably are of a resilient split-ring type.