Silicon flexure suspension for single degree or freedom floated gyroscope

• US 6,575,032 B2
• Filed: 07/27/2001
• Issued: 06/10/2003
• Est. Priority Date: 07/27/2001
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Litton Systems Incorporated
• Inventors: Anderson, Richard, Dorai-Raj, Devadas
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/916,614
• Publication Number:
  US 20030019295A1
• Time in Patent Office: 683 Days
• Field of Search: 735/040.2, 735/040.3, 735/040.8, 735/040.9, 735/041.1, 735/140.2, 735/140.1, 735/141.5, 735/10, 735/040.4
• US Class Current: 73/510
• CPC Class Codes: G01C 19/16 Suspensions; Bearings
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values

Abstract

A suspension for a gyroscopic float assembly in a floating gyroscope system comprises a pair of flexures that each have an outer rim and a plurality of flexure beams extending from the outer rim. A plurality of flexure tabs extend outward from outer perimeter portions of the rims for mounting the flexure assembly to a pair of end caps. A plurality of strain relief passages formed in the rims is arranged to provide relief from thermally induced stresses. A plurality of angular stops formed in inner perimeter portions of the rims is arranged to constrain the flexure against rotation about a selected axis.

Claims

1. A flexure suspension for a gyroscopic float assembly for an accelerometer, comprising:

a hub;

an outer rim;

a plurality of flexure beams having a first end connected to the outer rim and a second end connected to the hub;

a plurality of flexure tabs extending outward from outer perimeter portions of the outer rim;

a plurality of stops formed in inner perimeter portions of the rim and arranged to constrain the flexure suspension against rotation about a selected axis; and

a plurality of strain relief passages formed in the outer rim and arranged to provide relief from thermally induced stress.

2. The flexure suspension of claim 1 wherein the outer rim, the plurality of flexure beams, the hub and the plurality of flexure tabs are integrally formed in a silicon crystal.

3. A floating gyroscope system, comprising;

a float assembly having a first end and a second end;

a first end cap;

a second end cap;

a first flexure suspension connected between the first end cap and the float assembly, the first flexure suspension comprising;

a first hub;

a first outer rim;

a first plurality of flexure beams connected between the first outer rim and the first hub;

a first plurality of flexure tabs extending outward from outer perimeter portions of the first outer rim arranged for mounting the first flexure suspension to the first end cap;

a first plurality of stops formed in inner perimeter portions of the first outer riot and arranged to constrain the first flexure suspension against rotation about a selected axis; and

a first plurality of strain relief passages formed in the first outer rim and arranged to provide relief from thermally induced stresses;

a second flexure suspension connected between the second end cap and the float assembly, the second flexure suspension comprising;

a second hub;

a second outer rim;

a second plurality of flexure beams connected between the second outer rim and the second hub;

a second plurality of flexure tabs extending outward from outer perimeter portions of the second outer rim arranged for mounting the second flexure suspension to the second end cap, the first plurality of flexure tabs and the second plurality of flexure tabs cooperating to allow the float assembly to float between the first and second end caps such that the float assembly is free to move in response to acceleration along a sensing axis;

a second plurality of stops formed in inner perimeter portions of the second outer rim and arranged to constrain the second flexure suspension against rotation about a selected axis; and

a second plurality of strain relief passages formed in the second outer rim and arranged to provide relief from thermally induced stresses.

4. The A floating gyroscope system of claim 3 wherein the first outer rim, the first plurality of flexure beams, the first hub and the first plurality of flexure tabs are integrally formed in a first silicon crystal and wherein the second outer rim, the second plurality of flexure beams, the second hub and the second plurality of flexure tabs are integrally formed in a second silicon crystal.