Isolators including damper assemblies having variable annuli and spacecraft isolation systems employing the same

Patent metadata

Field	Value
Publication number	US-9670983-B2
Application number	US-201313864952-A
Country	US
Kind code	B2
Filing date	Apr 17, 2013
Priority date	Apr 17, 2013
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

Embodiments of an isolator are provided, as are embodiments of a spacecraft isolation system employing a number of three parameter isolators. In one embodiment, the isolator includes a damper assembly and a thermal compensator external to the damper assembly. The damper assembly includes, in turn, a damper housing and a first hydraulic chamber, which is located within the damper housing and which is configured to contain a damping fluid. The thermal compensator includes a thermal compensator chamber, which is fluidly coupled to the first hydraulic chamber and which is configured to exchange damping fluid therewith during operation of the isolator. A thermal compensator bellows bounds an inner circumference of the thermal compensator chamber such that the bellows is externally pressurized when the first hydraulic chamber and the thermal compensator chamber are filled with the damping fluid.

First claim

What is claimed is:

1. An isolator, comprising:
a spring; and
a damper assembly coupled in series with the spring, the damper assembly comprising:
a damper housing containing opposing hydraulic chambers configured to be filled with a damping fluid;
a damper piston movably mounted within the damper housing for translational movement along a working axis, the damper piston exposed to the damping fluid in the opposing hydraulic chambers when the opposing hydraulic chambers are filled therewith; and
a variable annulus fluidly coupling the opposing hydraulic chambers, the variable annulus configured to cooperate with the damper piston to the impart the damper assembly with a first average damping coefficient (C A1 ) for piston displacement less than a first predetermined displacement threshold (D 1 ) from a centered position of the damper piston and with a second average damping coefficient (C A2 ) for piston displacements greater than a second predetermined threshold (D 2 ) from the centered position of the damper piston, wherein C A1 exceeds C A2 by at least 25%, and wherein D 1 is between 2.5 and 2500 microns.

2. The isolator of claim 1 wherein C A1 is between about 12 and about 30 pounds per inch per second, while C A2 is between about 3 and about 10 pounds per inch per second.

3. The isolator of claim 1 wherein the damper assembly has a damping coefficient-versus-damper displacement profile generally characterized by a piecewise profile.

4. The isolator of claim 3 wherein the damping coefficient-versus-damper displacement profile comprises:
a first substantially linear segment representative of damper piston displacement less than the first predetermined displacement threshold (D 1 );
a second segment representative of damper piston displacement from the first predetermined displacement threshold (D 1 ) to the second predetermined threshold (D 2 ); and
a third substantially linear segment representative of damper piston displacement greater than the second predetermined threshold (D 2 ).

5. The isolator of claim 4 wherein at least one of the first substantially linear segment and the third substantially linear segment has a slope substantially equivalent to zero.

6. An isolator, comprising:
a spring; and
a damper assembly coupled in series with the spring, the damper assembly comprising:
a damper housing containing opposing hydraulic chambers configured to be filled with a damping fluid;
a damper piston movably mounted within the damper housing for translational movement through a stroke range between first and second positional extremes, the damper piston exposed to the damping fluid in the opposing hydraulic chambers when the opposing hydraulic chambers are filled therewith; and
a variable annulus fluidly coupling the opposing hydraulic chambers, the variable annulus and the damper piston combining to the impart the damper assembly with a damping coefficient-versus-damper displacement profile generally characterized by a piecewise function including a first segment corresponding to an on-orbit mode of the isolator and including a second segment corresponding to a launch mode of the isolator;

wherein the variable annulus comprises a circumferential gap, which circumscribes the damper piston throughout the stroke range thereof and which has a maximum width when the damper piston moves into either of the first and second positional extremes; and
wherein the first segment of the piecewise function corresponding to the on-orbit mode of the isolator is limited to a stroke range of the damper piston of less than 2500 microns, as taken in either direction from a centered position between the first and second positional extremes; and
wherein the first segment corresponding to the on-orbit mode has a first average damping coefficient (C A1 ), wherein the second segment corresponding to the launch mode has a second average damping coefficient (C A2 ), and wherein C A1 is greater than C A2 .

7. The isolator of claim 6 wherein at least one of the first segment and the second segment has a slope substantially equivalent to zero.

8. The isolator of claim 6 wherein the piecewise function further includes a third substantially linear segment providing a transition between the first and second segments and having a negative slope.

Assignees

• Honeywell Int Inc

Inventors

• Martinez Daniel
• Pagan Jose
• Goold Ryan

Classifications

• B64G2001/228

  Operations & Transport · mapped topic

• F16F13/007

  the damper being a fluid damper · CPC title

• F16F9/483

  characterised by giving a particular shape to the cylinder, e.g. conical · CPC title

• B64G1/22

  Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles · CPC title

• F16F15/022 Primary

  using dampers and springs in combination · CPC title