Flexural Pivot

• US 20180209475A1
• Filed: 01/24/2017
• Published: 07/26/2018
• Est. Priority Date: 01/24/2017
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Balaban, Scott, Bullard, Andrew L.
• Granted Patent: US 10,443,649 B2
• Time in Patent Office: Days
• CPC Class Codes: B23H 9/005 Machining elongated bodies, e.g. rods
• CPC Class Codes: F16C 11/12 incorporating flexible connections, e.g. leaf springs
• CPC Class Codes: F16D 3/005 incorporating leaf springs, flexible parts of reduced thickness or the like acting as pivots

Abstract

A flexural pivot is disclosed. The flexural pivot can include a first flexure support member, a second flexure support member rotatably coupled to the first flexure support member for relative rotation about a first axis, and a third flexure support member rotatably coupled to the second flexure support member for relative rotation about a second axis. In addition the flexural pivot can include a plurality of cross blade flexures rotatably coupling the flexure support members to one another. Each cross blade flexure can have first and second flexible blade units that have flexible blades arranged in a cross configuration. The flexible blade units can have blade supports disposed at opposite ends of the flexible blades to facilitate coupling the flexible blade units to the flexure support members. The flexible blade and the blade supports of each flexible blade unit can form a monolithic structure.

Claims

1. A flexural pivot, comprising:

a first flexure support member;

a second flexure support member rotatably coupled to the first flexure support member for relative rotation about a first axis;

a third flexure support member rotatably coupled to the second flexure support member for relative rotation about a second axis; and

a plurality of cross blade flexures rotatably coupling the flexure support members to one another, each cross blade flexure comprising first and second flexible blade units that have flexible blades arranged in a cross configuration, the flexible blade units comprising blade supports disposed at opposite ends of the flexible blades to facilitate coupling the flexible blade units to the flexure support members, wherein the flexible blade and the blade supports of each flexible blade unit form a monolithic structure.

2. The flexural pivot of claim 1, wherein at least one of the flexible blade units further comprises travel stops associated with the blade supports to mechanically limit a rotatable range of motion.

3. The flexural pivot of claim 1, wherein the flexible blades extend perpendicularly from planar surfaces of the blade supports.

4. The flexural pivot of claim 1, wherein the flexible blade units are coupled to the flexure support members with fasteners, and the blade supports comprise openings to receive the fasteners.

5. The flexural pivot of claim 1, wherein the blade supports are welded to the flexure support members.

6. The flexural pivot of claim 1, wherein adjacent blade supports of the first and second flexible blade units are welded to one another.

7. The flexural pivot of claim 1, wherein the first and second flexible blade units of at least one of the cross blade flexures are substantially identical.

8. The flexural pivot of claim 1, wherein interface surfaces of the blade supports and the flexure support members are planar.

9. The flexural pivot of claim 1, wherein the flexible blades are recessed relative to interface surfaces of the blade supports to prevent the flexible blades from contacting adjacent components.

10. The flexural pivot of claim 1, wherein the flexible blade units are made of titanium or steel.

11. A flexural pivot system, comprising:

a flexural pivot including

a first flexure support member,

a second flexure support member rotatably coupled to the first flexure support member for relative rotation about a first axis,

a third flexure support member rotatably coupled to the second flexure support member for relative rotation about a second axis, and

a plurality of cross blade flexures rotatably coupling the flexure support members to one another, each cross blade flexure comprising first and second flexible blade units that have flexible blades arranged in a cross configuration, the flexible blade units comprising blade supports disposed at opposite ends of the flexible blades to facilitate coupling the flexible blade units to the flexure support members, wherein the flexible blade and the blade supports of each flexible blade unit form a monolithic structure;

a first structure coupled to the first flexure support member; and

a second structure coupled to the third flexure support member to facilitate relative rotation of the first and second structures about the first and second axes.

12. The system of claim 11, wherein at least one of the flexible blade units further comprises travel stops associated with the blade supports to mechanically limit a rotatable range of motion.

13. The system of claim 11, wherein the first and second flexible blade units of at least one of the cross blade flexures are substantially identical.

14. A method for making a cross blade flexure, comprising:

obtaining a workpiece having a length;

forming a profile in the workpiece of a flexible blade and blade supports disposed at opposite ends of the flexible blade such that the profile extends along the length;

dividing the workpiece into portions along the length to form a plurality of flexible blade units, each having the same profile of flexible blades and blade supports in a monolithic structure; and

pairing two of the flexible blade units such that the flexible blades are arranged in a cross configuration to form a cross blade flexure.

15. The method of claim 14, wherein forming a profile in the workpiece comprises machining the workpiece.

16. The method of claim 15, wherein machining the workpiece comprises electrical discharge machining (EDM).

17. The method of claim 14, further comprising forming a profile in the workpiece of travel stops associated with the blade supports,

18. The method of claim 14, further comprising recessing the flexible blades relative to interface surfaces of the blade supports.

19. The method of claim 14, wherein the flexible blades extend perpendicularly from planar surfaces of the blade supports.

20. The method of claim 14, further comprising forming openings in the blade supports to receive fasteners.