Gearbox planet attenuation spring damper

• US 9,677,659 B1
• Filed: 01/28/2016
• Issued: 06/13/2017
• Est. Priority Date: 01/28/2016
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Ertas, Bugra Han, Bradley, Donald Albert, Niergarth, Daniel Alan, Miller, Brandon Wayne, Dickman, Joseph Robert
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US15/008,986
• Time in Patent Office: 502 Days
• Field of Search: None
• CPC Class Codes: F01D 25/164 Flexible supports; Vibration damping means associated with the bearing
• CPC Class Codes: F02C 7/36 Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user F02C3/107 - F02C3/13 and F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H
• CPC Class Codes: F02K 3/06 with front fan
• CPC Class Codes: F05D 2260/40311 of the epicyclical, planetary or differential type
• CPC Class Codes: F05D 2260/96 Preventing, counteracting or reducing vibration or noise
• CPC Class Codes: F16C 19/28 with two or more rows of rollers
• CPC Class Codes: F16C 2360/23 Gas turbine engines in general F02C
• CPC Class Codes: F16C 2361/61 Toothed gear systems, e.g. support of pinion shafts in general F16H57/02
• CPC Class Codes: F16C 27/045 with a fluid film, e.g. squeeze film damping
• CPC Class Codes: F16F 15/0237 involving squeeze-film damping
• CPC Class Codes: F16H 1/28 with gears having orbital motion
• CPC Class Codes: F16H 2057/0012 for reducing drive line oscillations
• CPC Class Codes: F16H 2057/085 Bearings for orbital gears
• CPC Class Codes: F16H 57/0006 Vibration-damping or noise reducing means specially adapted for gearings devices for varying tension of belts, ropes or chains with damping means F16H7/0829; toothed members with construction providing vibration damping F16H55/14; reducing vibrations or noise of the gearbox casing F16H57/028; suppression of vibrations or noise of gear selectors F16H59/0208; control of hydrostatic fluid gearing preventing or reducing vibrations or noise F16H61/4183
• CPC Class Codes: F16H 57/028 characterised by means for reducing vibration or noise
• CPC Class Codes: F16H 57/08 of gearings with members having orbital motion
• CPC Class Codes: F16H 57/082 Planet carriers

Abstract

An epicyclic gearing arrangement includes a planet gear rotatable on a planet bearing that is mounted via a support pin to a carrier of the epicyclic gearing arrangement. An attenuation spring is disposed between the outer surface of the bearing'"'"'s outer ring and the opposing inner surface of the planet gear and includes an annular gap. A spring film damper is disposed between the cylindrical outer surface of the support pin and the opposing inner surface of the inner ring of the planet bearing and includes an annular gap. The support pin (96) and/or outer ring include oil feed holes that open into the respective annular gap(s). A gas turbine engine includes an epicyclic gearing arrangement having such a planet bearing.

Claims

1. A planet gearbox for connection to a carrier of an epicyclic gearing arrangement that has only a single input and a single output and that includes a sun gear and a ring gear surrounding the planet gearbox and the sun gear, the planet gearbox comprising:

a support pin is configured to be fixed to the carrier, the support pin is a hollow body that is defined by a cylindrical outer surface that is radially equidistant from a virtual central axis that extends in an axial direction, the support pin is further defined by an inner surface disposed opposite the cylindrical outer surface;

an inner ring is non-rotatably connected to the support pin and defines an inner surface opposed to the outer surface of the support pin, the inner ring defining an outer surface that defines at least one track, each track defined in the outer surface being configured to receive and rotatably guide therein a respective plurality of cylindrical rollers;

an outer ring defines an inner cylindrical surface that is disposed facing toward the at least one track, the outer ring defining an outer cylindrical surface that is disposed facing toward the ring gear;

a respective plurality of cylindrical rollers rotatably disposed within each respective track of the inner ring, and each of the plurality of rollers rotatably contacting the inner cylindrical surface of the outer ring; and

a planet gear is non-rotatably connected to the outer ring and defines an inner surface opposed to the outer surface of the outer ring, the planet gear defining an outer surface that defines a gear tooth surface that is configured to mesh with both the sun gear and the ring gear; and

an attenuation spring disposed between the outer surface of the outer ring and the inner surface of the planet gear.

2. The planet gearbox of claim 1, wherein the planet gear is non-rotatably connected to the outer ring by welding.

3. The planet gearbox of claim 1, wherein the planet gear is non-rotatably connected to the outer ring by mechanical fasteners.

4. The planet gearbox of claim 3, wherein the mechanical fasteners that non-rotatably connect the planet gear to the outer ring include a spring finger housing.

5. The planet gearbox of claim 1, wherein an annular gap extends between the cylindrical outer surface of the outer ring and the inner surface of the planet gear and the attenuation spring is disposed in the annular gap.

6. The planet gearbox of claim 5, wherein the dimension of the annular gap depends upon the degree of compression of the attenuation spring.

7. The planet gearbox of claim 1, further comprising a squeeze film damper that includes an annular gap that is defined between the cylindrical outer surface of the support pin and the inner surface of the inner ring.

8. The planet gearbox of claim 7, wherein the squeeze film damper includes a resilient forward toroidal seal at a forward end of the annular gap and a resilient aft toroidal seal at an aft end of the annular gap.

9. The planet gearbox of claim 7, wherein the support pin includes at least a first oil feed hole extending through the support pin between the inner surface and the outer surface of the support pin and defining an exit opening at the outer surface of the support pin, wherein the exit opening of the first oil feed hole is disposed in fluid communication with the annular gap.

10. The planet gearbox of claim 7, wherein the support pin includes at least a first oil feed hole extending through the support pin between the inner surface and the outer surface of the support pin and defining an exit opening at the outer surface of the support pin, wherein the exit opening of the first oil feed hole is disposed in fluid communication with the squeeze film damper.

11. The planet gearbox of claim 7, wherein the inner ring is defined by a forward end and an aft end that is spaced axially apart from the forward end, the squeeze film damper includes a forward groove defined in the forward end of the inner ring and extending circumferentially with respect to the virtual central axis.

12. The planet gearbox of claim 11, wherein the forward groove of the inner ring defines a radial depth that extends from the inner surface of the inner ring in a direction radially away from the virtual central axis, and the squeeze film damper further includes a forward resilient seal disposed within the forward groove of the inner ring, the forward resilient seal defining an inner diameter and an outer diameter that is larger than the inner diameter such that the difference between the inner diameter and the outer diameter defines the uncompressed thickness of the forward resilient seal, and the uncompressed thickness of the forward resilient seal is greater than the radial depth of the forward groove of the inner ring.

13. The planet gearbox of claim 12, wherein the squeeze film damper includes an aft groove defined in the aft end of the inner ring and extending circumferentially with respect to the virtual central axis, the aft groove defines a radial depth that extends from the inner surface of the inner ring in a direction radially away from the virtual central axis, and the squeeze film damper further includes an aft resilient seal disposed within the aft groove of the inner ring, the aft resilient seal defining an inner diameter and an outer diameter that is larger than the inner diameter such that the difference between the inner diameter and the outer diameter of the aft resilient seal defines the uncompressed thickness of the aft resilient seal, and the uncompressed thickness of the aft resilient seal is greater than the radial depth of the aft groove of the inner ring.

14. A gas turbine engine comprising:

a fan including a plurality of blades extending radially from a hub and rotatable about a first axis of rotation defined centrally through the hub;

a compressor disposed downstream from the fan;

a turbine disposed downstream of the compressor;

a rotatable input shaft mechanically coupling the compressor to rotate in unison with the turbine;

an epicyclic gearing arrangement that has only a single input and that includes a carrier, a sun gear rotatable about a second axis of rotation that is parallel to the first axis of rotation, a ring gear disposed circumferentially around the sun gear, at least one planet gearbox that is carried by the carrier and houses a planet gear rotatable with respect to the carrier about a third axis of rotation that is parallel to the second axis of rotation, wherein the at least one planet gear meshes with both the sun gear and the ring gear; and

an engine envelope surrounding the fan, the compressor, the turbine and the epicyclic gearing arrangement, wherein one of the ring gear and the carrier is non-rotatably coupled to the engine envelope; and

the planet gearbox further including;

a support pin is configured to be fixed to the carrier, the support pin is a hollow body that is defined by a cylindrical outer surface that is radially equidistant from a virtual central axis that extends in an axial direction, the support pin is further defined by an inner surface disposed opposite the cylindrical outer surface;

an inner ring is non-rotatably connected to the support pin and defines an inner surface opposed to the outer surface of the support pin, the inner ring defining an outer surface that defines at least one track, each track defined in the outer surface being configured to receive and rotatably guide therein a respective plurality of cylindrical rollers;

an outer ring defines an inner cylindrical surface that is disposed facing toward the at least one track, the outer ring defining an outer cylindrical surface that is disposed facing toward the ring gear;

a respective plurality of cylindrical rollers rotatably disposed within each respective track of the inner ring, and each of the plurality of rollers rotatably contacting the inner cylindrical surface of the outer ring; and

a planet gear is non-rotatably connected to the outer ring and defines an inner surface opposed to the outer surface of the outer ring, the planet gear defining an outer surface that defines a gear tooth surface that is configured to mesh with both the sun gear and the ring gear; and

an attenuation spring disposed between the outer surface of the outer ring and the inner surface of the planet gear.

15. The gas turbine engine of claim 14, wherein the planet gear is non-rotatably connected to the outer ring by welding.

16. The gas turbine engine of claim 14, wherein the planet gear is non-rotatably connected to the outer ring by mechanical fasteners.

17. The gas turbine engine of claim 16, wherein the mechanical fasteners that non-rotatably connect the planet gear to the outer ring include a spring finger housing.

18. The gas turbine engine of claim 14, wherein an annular gap extends between the cylindrical outer surface of the outer ring and the inner surface of the planet gear and the attenuation spring is disposed in the annular gap.

19. The gas turbine engine of claim 18, wherein the dimension of the annular gap depends upon the degree of compression of the attenuation spring.

20. The gas turbine engine of claim 14, further comprising a squeeze film damper that includes an annular gap that is defined between the cylindrical outer surface of the support pin and the inner surface of the inner ring.