Turbine assembly with auxiliary wheel

Patent metadata

Field	Value
Publication number	US-2018320601-A1
Application number	US-201715587318-A
Country	US
Kind code	A1
Filing date	May 4, 2017
Priority date	May 4, 2017
Publication date	Nov 8, 2018
Grant date	—

Abstract

Various embodiments of the present application provide one or more of: (1) auxiliary wheel that (a) enables accurate speed detection of a turbine disc and/or (b) presents a machining surface for balance correction; and/or (2) techniques for mounting an auxiliary wheel to a rotor, such as a turbine disc.

First claim

We claim:

1 . A turbine assembly comprising:
a turbine disc connected to a coaxial central shaft; an auxiliary wheel secured to the turbine disc and coaxial with the central shaft, the auxiliary wheel comprising an annular target portion, the target portion comprising a plurality of first features and a plurality of different second features, the plurality of first features alternating with the plurality of second features about a circumference of the annular target portion; a speed sensing system comprising a probe and a controller, the speed sensing system being configured to estimate a rotational speed of the turbine disc based on a rate that the plurality of first features and the plurality of second features are carried past the probe.

2 . The turbine assembly of claim 1 , where the coaxial central shaft is a spool, the turbine disc is non-magnetic, the auxiliary wheel is magnetic such that both the plurality of first features and the plurality of different second features are magnetic, and the probe comprises a magnet.

3 . The turbine assembly of claim 2 , further comprising a clamping disc coaxial with the spool and the turbine disc, the clamping disc coupling the turbine disc with the central shaft.

4 . The turbine assembly of claim 1 , wherein the plurality of first features are teeth and the plurality of second features are channels defined between consecutive teeth.

5 . The turbine assembly of claim 1 , wherein the plurality of first features are magnetic and the probe comprises a magnet.

6 . The turbine assembly of claim 5 , wherein the probe is configured to generate a first magnetic field when the probe is proximate to the one of the plurality of first features and to not generate the first magnetic field when the probe is proximate to one of the plurality of second features.

7 . The turbine assembly of claim 1 , wherein the turbine disc comprises an annular mount coaxial with the central shaft and the auxiliary wheel is disposed on the mount.

8 . The turbine assembly of claim 1 , further comprising one or more balance weights carried by the mount.

9 . The turbine assembly of claim 8 , comprising a plurality of the balance weights positioned about a circumference of the mount, the auxiliary wheel comprising an annular balance land.

10 . An engine comprising:
the turbine assembly of claim 1 , wherein the central shaft is a spool mechanically coupling the turbine disc with one of a fan and a compressor; a fuel supply valve, and a spool speed sensor configured to sense a rotational speed of the spool at a location upstream of the turbine disc; the controller being configured to:
(a) estimate a rotational speed of the spool based on reports from the spool speed sensor,
(b) compare the estimated rotational speed of the spool with the estimated rotational speed of the turbine disc, and
(c) adjust the fuel supply valve based on the comparison.

11 . A turbine assembly comprising:
a turbine disc connected to a coaxial central shaft; an auxiliary wheel secured to the turbine disc and coaxial with the central shaft, the auxiliary wheel comprising an annular target portion, the target portion comprising a plurality of first features and a plurality of different second features, the plurality of first features alternating with the plurality of second features about a circumference of the auxiliary wheel.

12 . The turbine assembly of claim 11 , wherein the auxiliary wheel is directly mounted to the turbine disc.

13 . The turbine assembly of claim 12 , wherein the auxiliary wheel is magnetic.

14 . The turbine assembly of claim 13 , wherein the turbine disc is non-magnetic.

15 . A gas turbine engine comprising:
a turbine disc connected to a coaxial central shaft, the turbine disc comprising an annular mount coaxial with the central shaft; an auxiliary wheel secured to the turbine disc and directly disposed on the annular mount, the auxiliary wheel being coaxial with the central shaft, the auxiliary wheel comprising an annular target portion, the target portion comprising a plurality of magnetic teeth spaced about a circumference of the auxiliary wheel; a speed sensing system comprising a controller and a probe with a magnet, the speed sensing system being configured to estimate a rotational speed of the turbine disc based on a rate that the plurality of magnetic teeth are carried past the probe.

16 . A method of sensing a rotational speed of a turbine disc of a turbine assembly, the turbine assembly comprising:
the turbine disc, which is connected to a coaxial central shaft; the auxiliary wheel, which is secured to the turbine disc and coaxial with the central shaft, the auxiliary wheel comprising an annular target portion, the target portion comprising a plurality of first features and a plurality of second features, the plurality of first features alternating with the plurality of second features about a circumference of the annular target portion; and a speed sensing system comprising a probe and a controller; the method comprising, via the speed sensing system:
estimating a rotational speed of the turbine disc based on a rate that the plurality of first features and the plurality of second features are carried past the probe.

17 . The method of claim 16 , wherein the turbine disc is non-magnetic, the first features are magnetic, and the probe comprises a magnet.

18 . The method of claim 16 , further comprising comparing the rotational speed of the turbine disc with a rotational speed of the coaxial central shaft.

19 . The method of claim 18 , further comprising automatically adjusting a fuel valve based on the comparison between the rotational speeds.

20 . The method of claim 19 , wherein combusted fuel supplied by the fuel valve drives the turbine disc.

Assignees

• Rolls Royce Corp

Inventors

• Snyder Brandon R
• Whitten Michael R
• Sellhorn James E
• Riehle Bradford John

Classifications

• F02K3/06

  with front fan · CPC title

• F05D2270/304

  Spool rotational speed · CPC title

• F02C7/232

  Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) · CPC title

• F02C3/04

  having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) · CPC title

• F01D5/027

  Arrangements for balancing (for balancing rotating bodies in general F16F15/32; for compensating imbalance G01M1/36) · CPC title