ACOUSTIC TRANSDUCER

• US 20190321851A1
• Filed: 09/07/2017
• Published: 10/24/2019
• Est. Priority Date: 10/31/2016
• Status: Active Grant

• Current Assignee: Thales Australia Limited (Thales SA)
• Original Assignee: Thales Australia Limited (Thales SA)
• Inventors: Jones, David Ronald
• Granted Patent: US 11,697,134 B2
• Time in Patent Office: Days
• CPC Class Codes: B06B 1/0603 using a piezoelectric bender, e.g. bimorph
• CPC Class Codes: B06B 2201/74 Underwater
• CPC Class Codes: G10K 11/006 Transducer mounting in underwater equipment, e.g. sonobuoys
• CPC Class Codes: H04R 1/24 Structural combinations of separate transducers or of two parts of the same transducer and responsive respectively to two or more frequency ranges
• CPC Class Codes: H04R 1/2834 for loudspeaker transducers
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 1/44 Special adaptations for subaqueous use, e.g. for hydrophone
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H04R 31/003 for diaphragms or their outer suspension

Abstract

An acoustic transducer (30), comprising: a support structure (36); an active assembly comprising a base plate (32) supported by the support structure (36) and a piezoelectric body (34) supported by the base plate (32); and a passive vibrator (38) supported by the support structure (36) and coupled via the support structure (36) to the active assembly (32, 34) so that vibration of the active assembly (32, 34) drives the passive vibrator (38). The active assembly (32, 34) and the passive vibrator (38) have the same resonant frequency.

Claims

1. An acoustic transducer, comprising:

a support structure;

an active assembly comprising a base plate supported by the support structure and a piezoelectric body supported by the base plate; and

a passive vibrator supported by the support structure and coupled via the support structure to the active assembly so that vibration of the active assembly drives the passive vibrator;

wherein the active assembly and the passive vibrator have the same resonant frequency.

2. An acoustic transducer as claimed in claim 1, wherein the piezoelectric body is a piezoelectric ceramic body.

3. An acoustic transducer as claimed in claim 1, wherein the base plate and the passive vibrator are of the same metallic composition, the passive vibrator differing in thickness from the base plate such that the active assembly and the passive vibrator have a common resonant frequency.

4. An acoustic transducer as claimed in claim 1, wherein the passive vibrator comprises a plate.

5. An acoustic transducer as claimed in claim 1, wherein the transducer is circular.

6. An acoustic transducer as claimed in claim 1, wherein the transducer is elliptical or rectangular.

7. An acoustic transducer as claimed in claim 1, wherein a cavity defined by the active assembly, the vibrator and the support structure is filled with a fluid.

8. An acoustic transducer as claimed in claim 1, wherein the support structure is integral with the base plate and/or the passive vibrator.

9. A transducer array, comprising:

a plurality of acoustic transducers as claimed in claim 1;

wherein the plurality of acoustic transducers are spaced apart to utilise mutual interaction and thereby increase performance.

16. An acoustic transducer as claimed in claim 2, wherein the base plate and the passive vibrator are of the same metallic composition, the passive vibrator differing in thickness from the base plate such that the active assembly and the passive vibrator have a common resonant frequency.

17. An acoustic transducer as claimed in claim 16, wherein the passive vibrator comprises a plate.

18. An acoustic transducer as claimed in claim 17, wherein a cavity defined by the active assembly, the vibrator and the support structure is filled with a fluid.

19. An acoustic transducer as claimed in claim 18, wherein the support structure is integral with the base plate and/or the passive vibrator.

20. An acoustic transducer as claimed in claim 16, wherein a cavity defined by the active assembly, the vibrator and the support structure is filled with a fluid.

10. A method of manufacturing an acoustic transducer, the method comprising:

coupling an active assembly comprising a base plate and a piezoelectric body supported by the base plate to a passive vibrator by a support structure, such that vibration of the active assembly drives the passive vibrator at a common resonant frequency.

11. A method as claimed in claim 10, wherein the piezoelectric body is a piezoelectric ceramic body.

12. A method as claimed in claim 10, wherein the base plate and the passive vibrator are of the same metallic composition, the passive vibrator differing in thickness from the base plate such that the active assembly and the passive vibrator have a common resonant frequency.

13. A method as claimed in claim 10, wherein the passive vibrator comprises a plate.

14. A method as claimed in claim 10, wherein the transducer is circular, elliptical or rectangular.

15. A method as claimed in claim 10, wherein a cavity defined by the active assembly, the vibrator and the support structure is filled with a fluid.