Friction shaft damper for axial vibration mode

Patent metadata

Field	Value
Publication number	US-10677312-B2
Application number	US-201815897232-A
Country	US
Kind code	B2
Filing date	Feb 15, 2018
Priority date	Feb 15, 2018
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Friction shaft damper includes springy projections pressing against inside surface of a portion of rotor such as drive shaft with spring force. Central mass may be positioned inside surface of drive shaft by projections extending outwardly from central mass and slideably engaging inside surface of drive shaft. Enlarged section or chamber of shaft may surround and axially trap damper. Axially spaced apart sets of springy fingers may position mass inside shaft and radially inner ends of fingers may be secured to mass and radially outer ends of fingers may be positioned and free to slide along inside surface of shaft. Two axially spaced apart annular deflection limiters may be placed around mass with small clearances C between deflection limiters and inside surface of shaft. Damper may be a multi-lobed wave spring having multi-lobed rim attached to mass by struts. Damper may be multi-lobed wave spring with crests.

First claim

What is claimed is:

1. A friction shaft damper assembly comprising a friction shaft damper including springy projections pressing against an inside surface of a portion of a rotor with a spring force, the springy projections extending outwardly from and secured to a central mass of the friction shaft damper, the springy projections comprising radially inner ends secured to the central mass and radially outer ends positioned and free to axially slide along the inside surface of the rotor.

2. The friction shaft damper assembly as claimed in claim 1 , further comprising:
the rotor including a drive shaft,
the central mass positioned inside the drive shaft by the springy projections, and
the springy projections slideably engaging the inside surface of the drive shaft.

3. The friction shaft damper assembly as claimed in claim 2 , further comprising an enlarged section or chamber of the drive shaft surrounding and axially trapping the friction shaft damper.

4. The friction shaft damper assembly as claimed in claim 2 , further comprising the springy projections including at least two axially spaced apart sets of springy fingers positioning the central mass inside the drive shaft.

5. The friction shaft damper assembly as claimed in claim 4 , further comprising the fingers having a spiral shape or logarithmic spiral shape.

6. The friction shaft damper assembly as claimed in claim 2 , further comprising at least two axially spaced apart annular deflection limiters around the central mass and small clearances C between the deflection limiters and the inside surface of the drive shaft.

7. The friction shaft damper assembly as claimed in claim 6 , further comprising each of the annular deflection limiters including radial spokes extending radially outwardly from an annular hub circumscribing the central mass and the radial spokes extending radially outwardly to an annular rim.

8. The friction shaft damper assembly as claimed in claim 6 , further comprising an enlarged section or chamber of the drive shaft surrounding and axially trapping the friction shaft damper.

9. A friction shaft damper assembly comprising a friction shaft damper including springy projections pressing against an inside surface of a portion of a rotor with a spring force, the springy projections extending outwardly from and secured to a central mass of the friction shaft damper, the springy projections comprising
a multi-lobed wave spring having a multi-lobed rim secured to the central mass by struts, wherein radially inner ends of the struts are secured to the central mass and radially outer ends of the struts are secured to the multi-lobed rim.

10. The friction shaft damper assembly as claimed in claim 9 , further comprising:
the multi-lobed rim having a wavy shape,
the multi-lobed rim including lobes, radially inner troughs, and radially outer crests, and
the radially outer crests being positioned relative to and free to slide along the inside surface of the drive shaft.

11. The friction shaft damper assembly as claimed in claim 10 , further comprising the radially outer ends of the struts attached to the radially inner troughs.

12. The friction shaft damper assembly as claimed in claim 11 , further comprising an enlarged section or chamber of the drive shaft surrounding and axially trapping the friction shaft damper.

13. The friction shaft damper assembly as claimed in claim 9 , further comprising the multi-lobed wave spring sitting at least partially inside the portion of the rotor.

14. The engine as claimed 13 , further comprising the portion of the rotor including a rotating labyrinth seal having knife edge seals which seal against a non-rotating seal land.

15. A gas turbine engine comprising:
in downstream serial flow relationship and circumscribed about a longitudinal centerline or axis a compressor section, a combustor section, and a turbine section;
a rotor circumscribed about the longitudinal centerline or axis; and
a friction shaft damper including springy fingers pressing against an inside surface of a portion of the rotor with a spring force, the springy fingers extending outwardly from and secured to a central mass of the friction shaft damper, the springy fingers comprising radially inner ends secured to the central mass and radially outer ends positioned and free to axially slide along the inside surface of the rotor.

16. The gas turbine engine as claimed in claim 15 , further comprising:
the rotor including a drive shaft,
the central mass positioned inside the drive shaft by the springy fingers, and
the springy fingers slideably engaging the inside surface of the drive shaft.

17. The engine as claimed in claim 16 , further comprising an enlarged section or chamber of the drive shaft surrounding and axially trapping the friction shaft damper.

18. The engine as claimed in claim 17 , further comprising:
the central mass positioned inside the drive shaft by at least two axially spaced apart sets of springy fingers.

19. The engine as claimed in claim 16 , further comprising:
at least two axially spaced apart annular deflection limiters around the central mass and small clearances C between the deflection limiters and the inside surface of the drive shaft,
each of the annular deflection limiters including radial spokes extending radially outwardly from an annular hub circumscribing the central mass, and
the radial spokes extending radially outwardly to an annular rim.

20. The engine as claimed in claim 17 , further comprising an electrical generator drivenly connected to the drive shaft and the enlarged section or chamber of the friction shaft damper located in the electrical generator.

Assignees

• Gen Electric

Inventors

• Wesling Richard Alan
• Gibson Nathan Evan Mccurdy

Classifications

• F02K3/04

  the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type · CPC title

• F16F15/129

  characterised by friction-damping means ({F16F15/1202, F16F15/1238} , F16F15/131 take precedence) · CPC title

• F16F15/1201 Primary

  for damping of axial or radial, i.e. non-torsional vibrations (F16F15/13107 takes precedence) · CPC title

• F01D5/026 Primary

  Shaft to shaft connections · CPC title

• F01D5/10

  Anti- vibration means {(specially adapted for radial flow machines or engines F01D5/04)} · CPC title