# US 11,441,444 B2 · Electrical resistance wear indicator

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,441,444 B2
- Document ID: US11441444B2
- Status: Granted
- Kind: B2
- Application number: 16/987,965
- Filed: 2020-08-07
- Published: 2021-04-15
- Granted: 2022-09-13
- Earliest claimed: 2017-08-03
- Assignees: Raytheon Technologies Corporation
- Applicants: Raytheon Technologies Corporation
- Inventors: Eli Cole Warren; Corey A. Benoit; Ian F. Agoos; Edward F. Dreger, III
- Web page: https://patentgrep.com/patent/US11441444B2

## CPC

- F01D 21/003: {Arrangements for testing or measuring (for measuring vibrations G01H)}
- F01D 11/08: for sealing space between rotor blade tips and stator (specially-shaped blade tips therefor F01D5/20)
- G01B 7/14: for measuring distance or clearance between spaced objects or spaced apertures (G01B7/30 takes precedence)
- G01B 21/16: for measuring distance of clearance between spaced objects
- G01M 15/14: Testing gas-turbine engines or jet-propulsion engines
- G01N 27/20: Investigating the presence of flaws
- F01D 11/122: {with erodable or abradable material (blades having cutting or grinding tips F01D5/20)}
- F01D 21/04: responsive to undesired position of rotor relative to stator {or to breaking-off of a part of the rotor}, e.g. indicating such position
- F05D 2220/323: for aircraft propulsion, e.g. jet engines
- F05D 2240/55: Seals
- F05D 2260/80: Diagnostics
- F05D 2260/83: Testing, e.g. methods, components or tools therefor
- F05D 2270/80: Devices generating input signals, e.g. transducers, sensors, cameras or strain gauges
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

In combination a wear indicator and a component of a gas turbine engine. The wear indicator is secured to a surface of the component of the gas turbine engine. The wear indicator including: a first component including: a post; and a ribbon wire having a first end and a second end opposite the first end. The first end is operably connected to the post and the ribbon wire is wrapped around the post.

## Claims

### Claim 1

In combination a wear indicator and a component of a gas turbine engine, wherein the wear indicator is secured to a surface of the component of the gas turbine engine, the wear indicator comprising:
a first component including:
a post; and
a ribbon wire having a first end and a second end opposite the first end, wherein the first end is operably connected to the post, and wherein the ribbon wire is wrapped around the post; and
a second component of the wear indicator having a blind hole partially enclosing the first component, wherein the wear indicator is secured to a surface of the component of the gas turbine engine through the second component,
wherein the second component further comprises:
a first side that delaminates when impacted by a blade of the gas turbine engine;
a second side parallel to the first side, the second side being secured to the component of the gas turbine engine; and
a mid-section interposed between the first side and the second side;
wherein the mid-section is conical frustum in shape.

### Claim 2 (depends on 1)

The combination of claim 1, wherein the first component is configured to delaminate when impacted by a blade of the gas turbine engine.

### Claim 3 (depends on 1)

The combination of claim 1, wherein the component is a blade outer air seal.

### Claim 4 (depends on 1)

The combination of claim 1, further comprising a measurement device electrically connected to the first end of the ribbon wire through a first lead line and electrically connected to the second end of the ribbon wire through a second lead line, wherein the measurement device is configured to determine a resistance of the ribbon wire.

### Claim 5 (depends on 1)

The combination of claim 1, wherein:
the post is cylindrical in shape.

### Claim 6 (depends on 1)

The combination of claim 1, wherein:
the ribbon wire is wrapped around an outer surface of the post.

### Claim 7 (depends on 1)

The combination of claim 1, wherein:
the ribbon wire is wrapped around an inner surface of the post.

### Claim 8

A method of detecting blade clearance in a gas turbine engine, the method comprising:
attaching a wear indicator to an inner surface of a gas turbine engine opposite a blade of the gas turbine engine, the wear indicator comprising a first plate, a second plate opposite to the first plate, and a plurality of wires extending from the first plate to the second plate, wherein the first plate is electrically connected to the second plate through the plurality of wires;
measuring a first resistance of the first plate, the second plate, and the plurality of wires;
operating the gas turbine engine at a first selected speed for a first period of time to remove material from the wear indicator;
measuring a second resistance of the first plate, the second plate, and the plurality of wires after material is removed from the wear indicator;
determining a change in resistance between the second resistance and the first resistance; and
determining an amount of material removed from the wear indicator by the blade in response to the change in resistance.

### Claim 9 (depends on 8)

The method of claim 8, further comprising:
determining a clearance between the blade and the inner surface in response to the amount of material removed from the wear indicator.

### Claim 10

In combination a wear indicator and a component of a gas turbine engine, wherein the wear indicator is secured to a surface of the component of the gas turbine engine, the wear indicator comprising:
a first component including:
a post; and
a ribbon wire having a first end and a second end opposite the first end, wherein the first end is operably connected to the post, and wherein the ribbon wire is wrapped around the post; and
a second component of the wear indicator having a blind hole partially enclosing the first component, wherein the wear indicator is secured to a surface of the component of the gas turbine engine through the second component,
wherein the second component further comprises:
a first side that delaminates when impacted by a blade of the gas turbine engine;
a second side parallel to the first side, the second side being secured to the component of the gas turbine engine; and
a mid-section interposed between the first side and the second side,
wherein the mid-section is conical frustum in shape.

### Claim 11 (depends on 10)

The combination of claim 10, wherein the component is a blade outer air seal.

### Claim 12 (depends on 10)

The combination of claim 10, further comprising a measurement device electrically connected to the first end of the ribbon wire through a first lead line and electrically connected to the second end of the ribbon wire through a second lead line, wherein the measurement device is configured to determine a resistance of the ribbon wire.

### Claim 13 (depends on 10)

The combination of claim 10, wherein:
the post is cylindrical in shape.

### Claim 14 (depends on 10)

The combination of claim 10, wherein:
the ribbon wire is wrapped around an outer surface of the post.

### Claim 15 (depends on 10)

The combination of claim 10, wherein:
the ribbon wire is wrapped around an inner surface of the post.