Vibration isolation system

A vibration isolation system comprises four tunable dual-axis hydraulic inertial isolators, an array of accelerometers, and a controller. The controller inputs signals from the accelerometers and outputs signals to tune the isolators to minimize the vibration transmitted from a vibrating body to an isolated body. The isolators are tuned by varying the dimensions of their tuning passages or by application of magnetohydrodynamic force to the liquid within the tuning passages.

We claim:

1. A dual-axis vibration isolator comprising:

first and second fluid-filled chambers;

a first piston having a first end for varying the volume of said first chamber and an opposed second end for varying the volume of said second chamber, said variation of said volumes being responsive to relative motion between a vibrating body and an isolated body along an axis of said first piston; and

a first fluid-filled tuning passage connecting said first and second chambers;

third and fourth fluid-filled chambers;

a second piston having a first end for varying the volume of said third chamber and an opposed second end for varying the volume of said fourth chamber, said variation of said third and fourth chamber volumes being responsive to relative motion between said vibrating and isolated bodies along an axis of said second piston;

a second fluid-filled tuning passage connecting said third and fourth chambers;

at least one of said tuning passages including a longitudinally-extending channel;

a movable member disposed in said channel, said movable member being movable transversely of said tuning passage to vary the volume thereof and thereby vary an operating characteristic of the vibration isolator; and

one of said first and second chambers and said first piston being connected to one of said third and fourth chambers and said second piston such that said first piston axis is disposed at an angle to said second piston axis.

2. The vibration isolator of claim 1 further comprising an actuator for moving said movable wall portion.

3. A vibration isolator comprising:

first and second fluid-filled chambers and a fluid-filled tuning passage connecting the chambers;

a piston including a first end for varying the volume of the first chamber and a second end for varying the volume of the second chamber, variation of the volumes being responsive to relative motion between a vibrating body and an isolated body along a piston axis;

a longitudinally-extending slot in a wall of the tuning passage, the slot being substantially longitudinally coextensive with the tuning passage; and

a substantially rigid tuning member at least partially disposed in the slot, the tuning member being substantially longitudinally coextensive with the slot and transversely movable relative to the tuning passage.

4. The vibration isolator of claim 3 further comprising an actuator for moving the tuning member.

5. The vibration isolator of claim 3 further comprising a control system for the tuning member, which control system is responsive to vibration of the isolated body or the vibrating body substantially parallel to the piston axis.

6. A vibration isolator comprising:

first and second fluid-filled chambers and a fluid-filled tuning passage connecting the chambers;

a piston including a first end for varying the volume of the first chamber and a second end for varying the volume of the second chamber, variation of the volumes being responsive to relative motion between a vibrating body and an isolated body along a piston axis;

a longitudinally-extending slot in a wall of the tuning passage; and

a tuning member at least partially disposed in the slot, the tuning member being substantially longitudinally coextensive with the slot and transversely movable with respect to the tuning passage.

7. The vibration isolator of claim 6 wherein the slot is substantially longitudinally coextensive with the tuning passage.

8. The vibration isolator of claim 7 wherein the tuning member is substantially laterally coextensive with the slot.

9. The vibration isolator of claim 7 wherein the tuning member is substantially rigid.

10. The vibration isolator of claim 6 wherein the length of the slot is at least a portion of the length of the tuning passage.

11. The vibration isolator of claim 10 wherein the tuning member is substantially laterally coextensive with the slot.

12. The vibration isolator of claim 10 wherein the tuning member is substantially rigid.

13. The vibration isolator of claim 6 wherein the tuning member is substantially laterally coextensive with the slot.

14. The vibration isolator of claim 6 wherein the tuning member is substantially rigid.