Apparatus and a method of ultrasonically inspecting a component

Patent metadata

Field	Value
Publication number	US-11320404-B2
Application number	US-202016740859-A
Country	US
Kind code	B2
Filing date	Jan 13, 2020
Priority date	Feb 5, 2019
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

An apparatus for ultrasonically inspecting a component of a gas turbine engine at a centre frequency required for ultrasonic inspection of the component. The apparatus comprises an ultrasonic transducer and a waveguide. The ultrasonic transducer and the waveguide are mounted in a holder, the holder is movably mounted in a carrier, and the carrier is movably mounted in a frame. The waveguide has a first end, a second end and a surface. The waveguide is circular in cross-section, the surface of the waveguide between the first end and the second end is concave, and the waveguide reduces in diameter from the first end to the second end. The length of the waveguide is equal to or greater than 0.5 times and equal to or less than 3 times the wavelength of an ultrasonic signal at the centre frequency required for the ultrasonic inspection.

First claim

We claim:

1. An apparatus for ultrasonically inspecting a component of a gas turbine engine at a centre frequency required for ultrasonic inspection of the component, the apparatus comprising:
an ultrasonic transducer and a waveguide;
wherein the ultrasonic transducer and the waveguide are mounted in a holder, the holder is movably mounted in a carrier, and the carrier is movably mounted in a frame;
wherein the waveguide has a first end, a second end and a surface, the waveguide is circular in cross-section, the surface of the waveguide between the first end and the second end is concave, and the waveguide reduces in diameter from the first end to the second end, the length of the waveguide being equal to or greater than 0.5 times and equal to or less than 3 times the wavelength of an ultrasonic signal at the centre frequency required for the ultrasonic inspection; and
wherein the ultrasonic transducer is acoustically coupled to the first end of the waveguide and the second end of the waveguide is arranged adjacent to the component in use.

2. The apparatus of claim 1 , wherein the surface of the waveguide between the first end and the second end is parabolic.

3. The apparatus of claim 1 , wherein the waveguide comprises a metal.

4. The apparatus of claim 1 , wherein the ultrasonic transducer has a centre frequency of 1 MHz, or the ultrasonic transducer has a centre frequency of 2.25 MHz.

5. The apparatus of claim 1 , further comprising a bandpass filter of 400 kHz to 600 kHz.

6. The apparatus of claim 1 , wherein the second end of the waveguide has a diameter of 0.4 mm, the first end of the waveguide has a diameter of 6 mm and the waveguide has a length of 12 mm.

7. The apparatus of claim 1 , wherein the second end of the waveguide has a bend.

8. The apparatus of claim 7 , wherein the second end of the waveguide has a bend greater than 45°.

9. The apparatus of claim 1 , further comprising a signal generator arranged to send a signal to the ultrasonic transducer.

10. The apparatus of claim 9 , wherein the signal generator is arranged to provide a signal with a centre frequency of 500 kHz, the signal has an amplitude of 400 to 800 V peak to peak, and the signal is a 5 cycle tone burst.

11. The apparatus of claim 10 , wherein the signal generator has a pulse repetition rate of 15 Hz and a time base of 1000 μs.

12. The apparatus of claim 1 , wherein the frame is generally U-shaped.

13. The apparatus of claim 12 , wherein the frame comprises two parallel limbs and each limb has a track upon which the carrier is movably mounted.

14. The apparatus of claim 13 , wherein a remote end of each limb of the frame has a part cylindrical surface, and an axis of the part cylindrical surface of each limb is perpendicular to the length of the limb and perpendicular to a direction between the limbs.

15. The apparatus of claim 14 , wherein a remote end of each limb of the frame has a projection that extends from a first side of the limb and is parallel to the limb to form an L-shape with the part cylindrical surface at the remote end of the limb, the projections are arranged in the same plane, and each projection has a part spherical surface.

16. The apparatus of claim 1 , wherein the frame has a first mechanism to adjust the position of the carrier along the limbs of the frame.

17. The apparatus of claim 1 , wherein the carrier has a second mechanism to rotate the holder in a first rotational direction around a pivotal mount, and the carrier has a spring to bias the holder against rotation in the first rotational direction.

18. A method of ultrasonically inspecting a component of a gas turbine engine, the method comprising the steps of:
(a) providing an apparatus according to any preceding claim for ultrasonically inspecting a component of a gas turbine engine at a centre frequency required for ultrasonic inspection of the component, the apparatus comprising an ultrasonic transducer and a waveguide, the waveguide having a first end, a second end and a surface, the waveguide being circular in cross-section, the waveguide reducing in diameter from the first end to the second end, the length of the waveguide being equal to or greater than 0.5 times and equal to or less than 3 times the wavelength of an ultrasonic signal at the centre frequency required for the ultrasonic inspection, the ultrasonic transducer being acoustically coupled to the first end of the waveguide;
(b) arranging the second end of the waveguide adjacent to the component;
(c) transmitting an ultrasonic signal from the ultrasonic transducer through the waveguide into the component; and
(d) detecting the reflected ultrasonic signal in the component using the waveguide and ultrasonic transducer.

19. The method of claim 18 , wherein the component comprises a turbine disc, a turbine drum, a compressor disc, a compressor drum, or a shaft.

20. The method of claim 18 , further comprising converting a longitudinal wave in the ultrasonic transducer to an edge mode wave at the second end of the waveguide.

Assignees

• Rolls Royce Plc

Inventors

• Jeketo Alejandro
• Bowyer Michael
• Corcoran Joseph J
• Leinov Eli

Classifications

• G10K11/004

  Mounting transducers, e.g. provided with mechanical moving or orienting device (mountings specially adapted to a particular sound-producing device, see the preceding groups G10K1/00 - G10K9/00, e.g. G10K1/26, G10K1/28, G10K9/22; arrangements of sonic watch equipment on submarines B63G8/39; buoys B63B22/00) · CPC title

• G01N2291/0289

  Internal structure, e.g. defects, grain size, texture · CPC title

• G01N2291/101

  one transducer · CPC title

• G01N29/265

  by moving the sensor relative to a stationary material · CPC title

• G01N29/225

  Supports, positioning or alignment in moving situation · CPC title