CA1202406A - Underwater transducer with depth compensation - Google Patents
Underwater transducer with depth compensationInfo
- Publication number
- CA1202406A CA1202406A CA000444314A CA444314A CA1202406A CA 1202406 A CA1202406 A CA 1202406A CA 000444314 A CA000444314 A CA 000444314A CA 444314 A CA444314 A CA 444314A CA 1202406 A CA1202406 A CA 1202406A
- Authority
- CA
- Canada
- Prior art keywords
- water
- bladder
- transducer
- ring
- diaphragms
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 48
- 125000006850 spacer group Chemical group 0.000 claims abstract description 9
- 238000004891 communication Methods 0.000 claims description 3
- 239000011152 fibreglass Substances 0.000 claims description 3
- 238000005452 bending Methods 0.000 claims description 2
- 238000002347 injection Methods 0.000 claims description 2
- 239000007924 injection Substances 0.000 claims description 2
- 239000000919 ceramic Substances 0.000 abstract description 4
- 229910000831 Steel Inorganic materials 0.000 abstract 1
- 239000010959 steel Substances 0.000 abstract 1
- 238000010276 construction Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- ORQBXQOJMQIAOY-UHFFFAOYSA-N nobelium Chemical compound [No] ORQBXQOJMQIAOY-UHFFFAOYSA-N 0.000 description 2
- 240000008881 Oenanthe javanica Species 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R17/00—Piezoelectric transducers; Electrostrictive transducers
- H04R17/04—Gramophone pick-ups using a stylus; Recorders using a stylus
- H04R17/08—Gramophone pick-ups using a stylus; Recorders using a stylus signals being recorded or played back by vibration of a stylus in two orthogonal directions simultaneously
Landscapes
- Transducers For Ultrasonic Waves (AREA)
Abstract
ABSTRACT
An underwater transducer in which a ring of piezo-electric ceramic elements vibrates radially in response to an applied voltage. Spacer elements formed of steel are placed between pairs of ceramic elements and used to couple the ring movement to convex diaphragms. Each diaphragm is formed with radially extending fingers, which attach to the spacer elements.
A water bladder assembly within the transducer forms a passive internal pressure compensation system. Preferably, the water bladder assembly is attached to the ring in a manner that mechanically decouples the bladder assembly from the ring.
An underwater transducer in which a ring of piezo-electric ceramic elements vibrates radially in response to an applied voltage. Spacer elements formed of steel are placed between pairs of ceramic elements and used to couple the ring movement to convex diaphragms. Each diaphragm is formed with radially extending fingers, which attach to the spacer elements.
A water bladder assembly within the transducer forms a passive internal pressure compensation system. Preferably, the water bladder assembly is attached to the ring in a manner that mechanically decouples the bladder assembly from the ring.
Description
This invention relates to underwater transducers.
Such an underwater transducer is described in appli-cant's co-pendin~ Canadian pa-tent application 392,962. This co-pendlng application describes an underwater transducer of rugged construction, which gives improved coupling of energy from the ceramic elements to the diaphragms, and also provides depth compensation over a range of operating depths, and an extended maximum operating depth, It is known to provide underwater transducers that have a driving ring or collar of electrostrictive material wi-th flexible diaphragms that cover the top and bo-ttom of the driving ring. As the ring vibrates radially, the vibration is communi-cated in amplified form to the diaphragms and then coupled directly to the water.
As will be apparent from the description, -the appli-cant's invention eliminates the high thermally-induced stresses, which can exist in the prior art and further increases the maxi-mum operating depth of the underwater transducer.
The ~ain object of this invention is to provide a sealed underwater transducer having a plurality of electro-strictive elements and spacer elements arranged to form a driving ring; the elements have opposed surfaces axially of the ~ing, and the ring surrounds a space radially internally of the same; and the driving ring is expandable radially in response to an applied voltage.
A pair of flexible diaphragms closes off said space axially of the ring, and the diaphragms are each formed with a plurality of extensions extending radially outwardly. The 12~Z~(~6 extensions are connected to the opposed surfaces of the elements so as to prevent mechanical bending stresses peripherally of the diaphragm Erom being trans~erred to -the elec-trostrictive elements.
A closeable gas inlet means is provlded for injecting a compressed gas into the space. The improvement consists of a water bladder assembly attached within the driving ring in a manner in which the assembly is mechanically decoupled ~rom the driving ring. The assembly includes a water bladder expandable to the shape of a torus, a water inlet means in communication with the exterior o~
the transducer. The water bladder is collapsible by injection of a compressed gas at a predetermined pressure into the space via the gas inlet means. The water bladder is expandable from a collapsed condition to a conditi.on substantially filling the space thereby to protect the diaphragms against collapse under excessive ambientpressures. The water bladder assembly also includes a pair of semirigid supports positioned in the space between the bladder and the diaphragms. The supports substan-tially enclose the torus shaped water bladder when the lat-ter is substantially filled with water such that down to a predetermined operating depth, when the outside water pressure exceeds the internal gas pressure, the bladder expands and is supported by the supports such that the water bladder is preven-ted from touching the diaphragms thus impeding the operation of the trans-ducer, and hence extending the operating depth.
The invention will be described in conjunction with -the accompanying drawings in which:
Figures 1, 2 and 3 show cross-sectional views oE the
Such an underwater transducer is described in appli-cant's co-pendin~ Canadian pa-tent application 392,962. This co-pendlng application describes an underwater transducer of rugged construction, which gives improved coupling of energy from the ceramic elements to the diaphragms, and also provides depth compensation over a range of operating depths, and an extended maximum operating depth, It is known to provide underwater transducers that have a driving ring or collar of electrostrictive material wi-th flexible diaphragms that cover the top and bo-ttom of the driving ring. As the ring vibrates radially, the vibration is communi-cated in amplified form to the diaphragms and then coupled directly to the water.
As will be apparent from the description, -the appli-cant's invention eliminates the high thermally-induced stresses, which can exist in the prior art and further increases the maxi-mum operating depth of the underwater transducer.
The ~ain object of this invention is to provide a sealed underwater transducer having a plurality of electro-strictive elements and spacer elements arranged to form a driving ring; the elements have opposed surfaces axially of the ~ing, and the ring surrounds a space radially internally of the same; and the driving ring is expandable radially in response to an applied voltage.
A pair of flexible diaphragms closes off said space axially of the ring, and the diaphragms are each formed with a plurality of extensions extending radially outwardly. The 12~Z~(~6 extensions are connected to the opposed surfaces of the elements so as to prevent mechanical bending stresses peripherally of the diaphragm Erom being trans~erred to -the elec-trostrictive elements.
A closeable gas inlet means is provlded for injecting a compressed gas into the space. The improvement consists of a water bladder assembly attached within the driving ring in a manner in which the assembly is mechanically decoupled ~rom the driving ring. The assembly includes a water bladder expandable to the shape of a torus, a water inlet means in communication with the exterior o~
the transducer. The water bladder is collapsible by injection of a compressed gas at a predetermined pressure into the space via the gas inlet means. The water bladder is expandable from a collapsed condition to a conditi.on substantially filling the space thereby to protect the diaphragms against collapse under excessive ambientpressures. The water bladder assembly also includes a pair of semirigid supports positioned in the space between the bladder and the diaphragms. The supports substan-tially enclose the torus shaped water bladder when the lat-ter is substantially filled with water such that down to a predetermined operating depth, when the outside water pressure exceeds the internal gas pressure, the bladder expands and is supported by the supports such that the water bladder is preven-ted from touching the diaphragms thus impeding the operation of the trans-ducer, and hence extending the operating depth.
The invention will be described in conjunction with -the accompanying drawings in which:
Figures 1, 2 and 3 show cross-sectional views oE the
2--12~2~06 preferred embodiment of this invention in which the transducer has a toroidal~shaped rubber bladder;
Figure 1 shows the water inlet port and the internal bladder in lts neutral or just-filled shape;
Figure 2 shows a detailed view of the air inlet port of -the transducer; and Figure 3 shows a detailed view a-t a point where -the bladder assembly is attached to the ceramic riny.
Referring to Figure 1, the bladder assembly is attached to the driving ring in a manner in which the assembly is mechani-cally decoupled from said driving ring. The bladder assembly comprises a toroidal-shaped rubber bladder 112, an optional plastic center ring 113, and two fiberglass reinforced plastic (FRPJ supports 114. The bladder 11~ is expandable to the shape of a torus and further takes the shape of the inside of the FRP
supports 114 so that the bladder 112 cannot touch the central portion of either diaphragm 110 when only partially filled with water, as shown in Figure 3. The shape of the bladder 112 allows for an increase in the internal volume available for a compressed gas, thereby reducing the stiffening effect of the gas and increasing the operating depth range. The bladder 112 is supported between the two fiherglass supports 11~ which are strong enough to support the weight of the water :in the bladder without deflecting significantly. The ring 113, and supports 11 are bonded and/or bolted together. However, for clarity, no bolts are shown in the figures. ~ne or more water inlets 116 are in communication with the exterior of the transducer to , ,. , . , . ,. ~, ,,, ,,~", ~, ~,",." . .... , . . _, _ _ . _ ._ _.. , .. ~_ _ _ __ . _ _ _ _ . _. _ .. .
~2~36 enable water to enter said bladder. The water inlets are sealed into the bladder 112 via nipples 127, which are molded as part of the rubber bladder. The water inlet 116 is also bonded and sealed to a particular metal spacer element 117 and -the fiber-glass wrapping 105.
In Figure 1, the bladder 112 is shown fully inflated;
a condition occurring at the maximum operating depth. Immersion to a depth greater than the maximum operating depth exposes the bladder 112 to an external water pressure greater than the internal gas pressure with the result that the bladder 112 expands to substantially fill the space 124 between the two diaphragms 110 and will tend to further compress the internal gas and deEorm the FRP supports 114, so that they are forced against the metal diaphragms. This protects the diaphragms 110 against collapse due to excessive external water pressure.
Figuxe 2 shows a cross-sectional view of the transducer at a closeable gas inlet 122 used to prefill the internal space 124 of the transducer to a predetermined pressure. The bladder 112 is shown ~ully deflated as it might appear after the space 124 is prefilled with a compressed gas. Also shown is one of the several projections 1~8, which are molded as part o~ the xubber bladder 112, and which serve to secure the bladder within the bladder assembly. In this embodiment the bladder is secured to the center xing 113. The projections 128 are themselves bonded into holes in-the center ring 113 using a suitable adhesive. The center ring 113 is an optional part of the water bladder assembly as the water bladder 112 could also be secured 4~
at the projections 128 to the two supports 11~ which would be configured to form, once bonded together, holes to match the projections 128 of the bladder 112.
Flgure ~ shows a cross-sectional view of the transducer with the bladder 112 only partially filled with water.
The water bladder assembly is supported in a cen-tral position within the driving ring at a number of support points, shown at 129 in Figure 3. In the embodiment of Figure 3, a support peg 129 is threaded at one end into a spacer element 102 and at the other end the peg is made to be slideab]e in a hole in the center ring 113. Hence, the water bladder assembly is free to move radially within the space 124 relative to the driving ring. The above represents only one embodiment of a number of possible attachment methods. The peg 129, for example, can alternatively be threaded at the center ring 113 and made slide-able in the spacer element 102. I'he support means can also consist of an elastic support or a spring or other connecting means functioning so as to mechanically decouple the water bladder assembly from said driving ring, thereby preventing high stresses between the bladder assembly and the ring. Such stresses would result from differential thermal strains and dynamic vibratory strains~ if the bladder assembly and the ring were not decoupled.
Thus, there has been described an improved underwater transducer of rugged construction in which compensation for water pressure is provided, which also functions to protect the trans-ducer against destruction at excessive depth. Ingress of water expands the bladder and compresses the internal air, supplying Z ~
-the necessary pressure compensation without seri.ously impeding the vibration oE the diaphragms. A convex conEiguration o:E the dlaphragms is used to provide a greater in-ternal air volume and hence a greater operating depth ranye.
Figure 1 shows the water inlet port and the internal bladder in lts neutral or just-filled shape;
Figure 2 shows a detailed view of the air inlet port of -the transducer; and Figure 3 shows a detailed view a-t a point where -the bladder assembly is attached to the ceramic riny.
Referring to Figure 1, the bladder assembly is attached to the driving ring in a manner in which the assembly is mechani-cally decoupled from said driving ring. The bladder assembly comprises a toroidal-shaped rubber bladder 112, an optional plastic center ring 113, and two fiberglass reinforced plastic (FRPJ supports 114. The bladder 11~ is expandable to the shape of a torus and further takes the shape of the inside of the FRP
supports 114 so that the bladder 112 cannot touch the central portion of either diaphragm 110 when only partially filled with water, as shown in Figure 3. The shape of the bladder 112 allows for an increase in the internal volume available for a compressed gas, thereby reducing the stiffening effect of the gas and increasing the operating depth range. The bladder 112 is supported between the two fiherglass supports 11~ which are strong enough to support the weight of the water :in the bladder without deflecting significantly. The ring 113, and supports 11 are bonded and/or bolted together. However, for clarity, no bolts are shown in the figures. ~ne or more water inlets 116 are in communication with the exterior of the transducer to , ,. , . , . ,. ~, ,,, ,,~", ~, ~,",." . .... , . . _, _ _ . _ ._ _.. , .. ~_ _ _ __ . _ _ _ _ . _. _ .. .
~2~36 enable water to enter said bladder. The water inlets are sealed into the bladder 112 via nipples 127, which are molded as part of the rubber bladder. The water inlet 116 is also bonded and sealed to a particular metal spacer element 117 and -the fiber-glass wrapping 105.
In Figure 1, the bladder 112 is shown fully inflated;
a condition occurring at the maximum operating depth. Immersion to a depth greater than the maximum operating depth exposes the bladder 112 to an external water pressure greater than the internal gas pressure with the result that the bladder 112 expands to substantially fill the space 124 between the two diaphragms 110 and will tend to further compress the internal gas and deEorm the FRP supports 114, so that they are forced against the metal diaphragms. This protects the diaphragms 110 against collapse due to excessive external water pressure.
Figuxe 2 shows a cross-sectional view of the transducer at a closeable gas inlet 122 used to prefill the internal space 124 of the transducer to a predetermined pressure. The bladder 112 is shown ~ully deflated as it might appear after the space 124 is prefilled with a compressed gas. Also shown is one of the several projections 1~8, which are molded as part o~ the xubber bladder 112, and which serve to secure the bladder within the bladder assembly. In this embodiment the bladder is secured to the center xing 113. The projections 128 are themselves bonded into holes in-the center ring 113 using a suitable adhesive. The center ring 113 is an optional part of the water bladder assembly as the water bladder 112 could also be secured 4~
at the projections 128 to the two supports 11~ which would be configured to form, once bonded together, holes to match the projections 128 of the bladder 112.
Flgure ~ shows a cross-sectional view of the transducer with the bladder 112 only partially filled with water.
The water bladder assembly is supported in a cen-tral position within the driving ring at a number of support points, shown at 129 in Figure 3. In the embodiment of Figure 3, a support peg 129 is threaded at one end into a spacer element 102 and at the other end the peg is made to be slideab]e in a hole in the center ring 113. Hence, the water bladder assembly is free to move radially within the space 124 relative to the driving ring. The above represents only one embodiment of a number of possible attachment methods. The peg 129, for example, can alternatively be threaded at the center ring 113 and made slide-able in the spacer element 102. I'he support means can also consist of an elastic support or a spring or other connecting means functioning so as to mechanically decouple the water bladder assembly from said driving ring, thereby preventing high stresses between the bladder assembly and the ring. Such stresses would result from differential thermal strains and dynamic vibratory strains~ if the bladder assembly and the ring were not decoupled.
Thus, there has been described an improved underwater transducer of rugged construction in which compensation for water pressure is provided, which also functions to protect the trans-ducer against destruction at excessive depth. Ingress of water expands the bladder and compresses the internal air, supplying Z ~
-the necessary pressure compensation without seri.ously impeding the vibration oE the diaphragms. A convex conEiguration o:E the dlaphragms is used to provide a greater in-ternal air volume and hence a greater operating depth ranye.
Claims (7)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A sealed underwater transducer having a plurality of electrostrictive elements and spacer elements arranged to form a driving ring, said elements having opposed surfaces axially of the ring, said ring surrounding a space radially internally of the same, said driving ring being expandable radially in response to an applied voltage; a pair of flexible diaphragms closing off said space axially of said ring, said diaphragms each being formed with a plurality of extensions extending radially outwardly, said extensions being connected to said opposed surfaces of the elements so as to prevent mechanical bending stresses peripherally of the diaphragm from being transferred to the electrostrictive elements; a closeable gas inlet means for injecting a compressed gas into said space; and wherein the improvement consists of a water bladder assembly attached within said driving ring in a manner in which the assembly is mechani-cally decoupled from said driving ring, including a water bladder expandable to the shape of a torus, said water bladder having water inlet means in communication with the exterior of the transducer, said water bladder being collapsible by injection of a compressed gas at a predetermined pressure into said space via said gas inlet means, said water bladder being expandable from said collapsed condition to a condition substantially filling said space thereby to protect the diaphragms against collapse under excessive ambient water pressures, and a pair of supports positioned in said space between said bladder and said diaphragms, said supports substantially enclosing the torus shaped bladder when the latter is being filled with water, such that down to a predetermined operating depth, when the outside water pressure slightly exceeds the internal gas pressure the bladder expands and is supported by said supports to prevent said water bladder from touching the diaphragms thus impeding the operation of said transducer, and hence extending the operating depth range.
2. A sealed underwater transducer as defined in claim 1 wherein the water bladder has a water inlet tube extending through one spacer element to enable water to enter said bladder.
3. A sealed underwater transducer as defined in claim 1 wherein the transducer has closeable gas inlet means extending through one spacer element to fill the space with the pressurized gas.
4. A sealed underwater transducer as defined in claim 1 wherein the supports are thin annular rings made of fiberglass reinforced plastic.
5. A sealed underwater transducer as defined in claim 1 wherein the water bladder assembly is supported in a central position within said driving ring by connecting means so as to isolate mechanical stresses in the water bladder assembly from said driving ring.
6. A sealed underwater transducer as defined in claim 1 wherein the water bladder is attached in said water bladder assembly by means of molded projections forming part of the water bladder and being bonded to said two supports of said assembly.
7. A sealed underwater transducer as defined in claim 1 wherein the diaphragms have a convex shape.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000444314A CA1202406A (en) | 1983-12-28 | 1983-12-28 | Underwater transducer with depth compensation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000444314A CA1202406A (en) | 1983-12-28 | 1983-12-28 | Underwater transducer with depth compensation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1202406A true CA1202406A (en) | 1986-03-25 |
Family
ID=4126832
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000444314A Expired CA1202406A (en) | 1983-12-28 | 1983-12-28 | Underwater transducer with depth compensation |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1202406A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4858206A (en) * | 1988-03-11 | 1989-08-15 | Minister Of National Defence Of Her Majesty's Canadian Government | Ring-shell projector |
| US4928263A (en) * | 1988-12-19 | 1990-05-22 | Hermes Electronics Limited | Hydrophones and similar devices |
| CN117775240A (en) * | 2024-02-23 | 2024-03-29 | 山东航天电子技术研究所 | Miniature underwater air bag compensation device and compensation method |
-
1983
- 1983-12-28 CA CA000444314A patent/CA1202406A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4858206A (en) * | 1988-03-11 | 1989-08-15 | Minister Of National Defence Of Her Majesty's Canadian Government | Ring-shell projector |
| US4928263A (en) * | 1988-12-19 | 1990-05-22 | Hermes Electronics Limited | Hydrophones and similar devices |
| CN117775240A (en) * | 2024-02-23 | 2024-03-29 | 山东航天电子技术研究所 | Miniature underwater air bag compensation device and compensation method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |