Compact vibration cancellation device

• US 6,443,273 B1
• Filed: 08/24/2001
• Issued: 09/03/2002
• Est. Priority Date: 08/24/2001
• Status: Expired due to Term

• Current Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Popelka, David, Ledbetter, Timothy K., Bothwell, Christopher M., Stamps, Brad, Smith, Michael Reaugh
• Primary Examiner(s): Schwartz, Christopher P.
• Application Number:
  US09/939,127
• Time in Patent Office: 375 Days
• Field of Search: 188/378-380, 267/136, 244/17-1-, 248/550, 248/562, 248/566, 248/636, 248/638
• US Class Current: 188/379
• CPC Class Codes: B64C 2027/005 using suspended masses
• CPC Class Codes: B64C 27/001 Vibration damping devices
• CPC Class Codes: F16F 7/116 on metal springs

Abstract

The present invention relates to an improved vibration cancellation device designed to overcome many of the shortcomings inherent in prior devices. In many embodiments, the vibration cancellation device is smaller in scale than prior designs, facilitating more versatility with respect to design options. The device of the present invention achieves a smaller size partly due to the use of suspension springs having an offset, rather than a parallel arrangement.

Claims

1. A vibration cancellation device comprising:

a mass

having a center of mass,

having an axis of motion,

having a central plane passing through the center of mass and orthogonal to the axis of motion,

having a first set of two substantially planar surfaces substantially orthogonal to the axis of motion and facing in a first direction toward the central plane, and

having a second set of two substantially planar surfaces substantially orthogonal to the axis of motion and facing in a second direction substantially opposite the first direction;

a first set of two compression springs acting on the mass through the first set of surfaces; and

a second set two compression of springs acting on the mass through the first set of surfaces; and

wherein the mass is completely suspended by the first and second sets of compression springs.

2. The device of claim 1 wherein the first and second sets of springs are coil springs.

3. The device of claim 1 further comprising a set of tuning masses.

4. A vibration cancellation device comprising:

a mass

having a center of mass,

having an axis of motion,

having a central plane passing through the center of mass and orthogonal to the axis of motion,

having a first set of two mounting features disposed on a first set of surfaces facing in a first direction toward the central plane of the mass, and

having a second set of two mounting features disposed on a second set of surfaces facing in a second direction substantially opposite the first direction;

a first set of two coil springs acting on the mass through the first set of two mounting features; and

a second set of two coil springs acting on the mass through the second set of two mounting features; and

wherein the mass is completely suspended by the first and second sets of coil springs.

5. The device of claim 4 wherein the first and second sets of springs are compression springs.

6. The device of claim 4 wherein the first and second sets of springs are extension springs.

7. The device of claim 4 further comprising a set of tuning masses.

8. A vibration cancellation device comprising:

a mass

having a center of mass,

having an axis of motion,

having a first central plane passing through the center of mass and orthogonal to the axis of motion,

having a second central plane passing through the center of mass and orthogonal to the first central plane and having a first and second side, and

having a third central plane passing through the center of mass and orthogonal to the first and second central planes and having a first and second side;

a first spring having a central axis substantially parallel to the axis of motion and disposed on the first side of the second central plane and the first side of the third central plane;

a second spring having a central axis substantially parallel to the axis of motion and disposed on the first side of the second central plane and the second side of the third central plane;

a third spring having a central axis substantially parallel to the axis of motion and disposed on the second side of the second central plane and the first side of the third central plane;

a fourth spring having a central axis substantially parallel to the axis of motion and disposed on the second side of the second central plane and the second side of the third central plane;

wherein the first and third springs compress and extend together; and

wherein the second and fourth springs compress and extend together and in opposition to the first and third springs; and

wherein the mass is completely suspended by the first, second, third, and fourth springs.

9. The device of claim 8 wherein the device further comprises a set of tuning masses.

10. The device of claim 9 wherein the tuning masses comprise metal plates.

11. The device of claim 9 wherein the tuning masses are retained by one or more threaded fasteners.

12. The device of claim 9 wherein the device further comprises a case having a window disposed therein for installing and removing tuning masses as desired.

13. The device of claim 8 wherein the springs are coil springs.

14. The device of claim 8 wherein the springs are compression springs.

15. The device of claim 8 wherein the springs are extension springs.

16. A vibration cancellation device comprising:

a frame

having an axis of motion,

having a first set of two spring pockets shaped and disposed to accept and retain a first set of two springs along a first set of two spring axes parallel to the axis of motion, and

having a second set of two spring pockets, facing opposite the first set of two spring pockets and shaped and disposed to accept and retain a second set of two springs along a second set of two spring axes parallel to the axis of motion;

a first set of two springs disposed within the first set of two spring pockets; and

a second set of two springs disposed within the second set of two spring pockets;

wherein the first set of two spring axes and the second set of two spring axes are not coincident.