Pneumatic suspension and vibration isolation system employing low friction cable isolators

Patent metadata

Field	Value
Publication number	US-9334915-B2
Application number	US-201414169040-A
Country	US
Kind code	B2
Filing date	Jan 30, 2014
Priority date	Jan 30, 2013
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

The present invention provides a suspension and vibration isolation system having cable isolators. The cable isolators employ low-friction air-bearing pneumatic cylinders and cables to isolate a suspended payload from vibrations of a carrier or to isolate the carrier from vibrations of the payload. Using such air-lubricated cylinder to piston interfaces virtually eliminates static friction and so improves the effectiveness of the isolation for small forces and displacement. The use of pneumatic cylinders also permits the system to be tuned to the required resonance frequency to isolate the payload from vibrations in a desired frequency band.

First claim

What is claimed is:

1. A cable isolator for isolating vibrations between a carrier and a payload, comprising:
a plurality of pneumatic air bearing cylinders each having a piston rod,
a traveler, coupled to free ends of the piston rods, the traveler and piston rods forming a part of a traveling assembly,
a cable comprising a first end coupled to the traveler and a second end coupled to the payload,
a pulley configured to mate with the cable,
a linear rail and carriage system configured to guide the traveling assembly,
a chassis coupled to the pulley, the pneumatic air bearing cylinders and a shaft, and
a pneumatic system configured to supply pressurized air to inlet ports of the pneumatic air bearing cylinders,
wherein the payload and the carrier are isolated from vibrations by each other at a frequency above a resonant frequency of the cable isolator.

2. The cable isolator of claim 1 , wherein the plurality of pneumatic air bearing cylinders are identical in construction.

3. The cable isolator of claim 1 , wherein the chassis is securely coupled to framework of the carrier.

4. The cable isolator of claim 1 , wherein each of the pneumatic air bearing cylinders is rigidly coupled to the chassis and aligned on a common alignment direction, wherein a piston of each of the pneumatic air bearing cylinders is configured to push to result in a zero moment on the traveler when balanced against tension of the cable; each piston being configured to push in unison in a common direction parallel to the common alignment direction when air pressure is applied to a cylinder portion of the air bearing cylinders.

5. The cable isolator of claim 1 , wherein the piston rod of each of the pneumatic air bearing cylinders terminates at a first end on the traveler, and at a second end on a center of a piston head.

6. The cable isolator of claim 4 , wherein the cable is configured to be drawn from the traveler in a direction parallel to the common alignment direction, and toward the air bearing cylinders so that tension in the cable opposes a force applied by the piston rods of the air bearing cylinders on the traveler.

7. The cable isolator of claim 1 , wherein the pulley is coupled to the chassis wherein a wheel of the pulley is configured to rotate and mate with the cable so the cable can exert a force on the traveler and the payload.

8. The cable isolator of claim 1 , wherein the linear rail and carriage system is rigidly coupled to the chassis and configured to constrain the traveling assembly to move in a direction parallel to the common alignment direction, so the traveling assembly can move smoothly and friction free, and wherein the linear rail and carriage system is configured to constrain and guide displacements of the traveling assembly to lie in a direction parallel to the common alignment direction.

9. The cable isolator of claim 1 , wherein the pneumatic system comprises an air supply and an air pressure regulator to deliver a regulated supply of pressurized air to the inlet ports of the pneumatic air bearing cylinders through an air supply line.

10. The cable isolator of claim 9 , wherein the pneumatic system is configured to supply air pressure and air flow rates to the inlet ports of the pneumatic air bearing cylinders to provide a required force on the traveler to maintain a zero moment.

11. The cable isolator of claim 10 , wherein the pneumatic air bearing cylinders comprise a symmetric arrangement, the pneumatic system being configured to supply identical air pressure to each of the pneumatic air bearing cylinders, so that the pneumatic air bearing cylinders operate in unison.

12. The cable isolator of claim 10 wherein the pneumatic system is configured to supply air pressure to the pneumatic air bearing cylinders to apply a force on respective piston heads to move in a frictionless motion via an air bearing.

13. The cable isolator of claim 1 , wherein the cable is configured to mate with a plurality of pulleys to apply a force in a required direction and with a required mechanical advantage to the payload.

14. The cable isolator of claim 1 , wherein the cable is configured to apply force to the payload in a substantially horizontal direction, wherein the payload is vibrationally isolated from the effects of lateral motions of the carrier.

15. The cable isolator of claim 1 , wherein the cable is configured to apply a force to the payload in a substantially vertical direction, wherein the payload is suspended by the cable isolator and is vibrationally isolated from the effects of vertical motions of the carrier.

16. The cable isolator of claim 1 , wherein the linear rail and carriage system comprises a shaft rigidly coupled to the chassis and oriented in a direction parallel to the common alignment direction, the shaft being coupled to the traveler through a hole in the traveler, to permit the traveler being configured to move smoothly along the shaft friction free, and wherein the traveler comprises a plurality of separate holes for receiving a plurality of shafts, and
whereby an air bearing is configured to provide a low friction motion.

17. The cable isolator of claim 9 , comprising a controller and an input sensor, the input sensor selected from the group consisting of displacement transducers, velocity sensors, load cells, strain gauges, accelerometers, inclinometers, rotation rate actuators, gyros, pressure gauges, thermometers, barometers, and infrared, radar and laser rangers, wherein the controller is configured to adjust the air pressure regulator to control the cable isolator.

18. The cable isolator of claim 1 , wherein the carrier is a vehicle and the payload is suspended, the cable isolator being configured to isolate the payload from vibrations of the carrier.

19. The cable isolator of claim 18 , wherein the cable isolator is a tow frame of a towed carrier.

20. The cable isolator of claim 18 , wherein the carrier is an airborne carrier and wherein the payload comprises an instrument selected from the group consisting of gravity meters, gravity gradiometers, magnetometers, induction coils, radars, lidars, accelerometers, rotation rate actuators, optical sensors, cameras and pointing devices.

21. The cable isolator of claim 9 , wherein the carrier is a towed airborne electromagnetic bird, the payload comprises a magnetometer, the cable isolator being configured to isolate the payload from carrier vibrations at frequencies of at least about 3 Hz.

22. The cable isolator of claim 10 , wherein the pneumatic system comprises,
a buffering reservoir,
an accumulator reservoir,
a first supply line connecting the air pressure regulator to the buffering reservoir,
a second supply line connecting the buffering reservoir to the accumulator reservoir,
a manifold connecting the inlet ports of respective cylinder portions of the pneumatic air bearing cylinders, and
a third supply line connecting the manifold to the second supply line, wherein:
the air pressure regulator controls the air pressure from the air supply into the buffering reservoir,

the buffering reservoir being configured to hold pressurized air at a pressure set by the air pressure regulator and cause air at the regulated pressure to flow to the accumulator reservoir,
the buffering reservoir having a volume that minimizes pressure variations resulting from pressure fluctuations in the pneumatic air bearing cylinders,

wherein:
the second supply line comprises an orifice to control air flow thro

Assignees

• Vale Sa

Inventors

• Polzer Benjamin David

Classifications

• F16F9/0281

  Details · CPC title

• B64D3/00

  Aircraft adaptations to facilitate towing or being towed · CPC title

• B60P7/16

  Protecting against shocks {(B60P7/065 takes precedence)} · CPC title

• F16F15/023 Primary

  using fluid means · CPC title

• F16F9/0209 Primary

  Telescopic (F16F9/04 takes precedence) · CPC title