+

WO1996018823A1 - Ventilateur vibrant en polyfluorure de vinylidene renforce par du metal - Google Patents

Ventilateur vibrant en polyfluorure de vinylidene renforce par du metal Download PDF

Info

Publication number
WO1996018823A1
WO1996018823A1 PCT/US1995/013616 US9513616W WO9618823A1 WO 1996018823 A1 WO1996018823 A1 WO 1996018823A1 US 9513616 W US9513616 W US 9513616W WO 9618823 A1 WO9618823 A1 WO 9618823A1
Authority
WO
WIPO (PCT)
Prior art keywords
vibrational
fan
layer
piezoelectric
core layer
Prior art date
Application number
PCT/US1995/013616
Other languages
English (en)
Inventor
John R. Boles
Kyung Tae Park
Minoru Toda
Original Assignee
The Whitaker Corporation
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by The Whitaker Corporation filed Critical The Whitaker Corporation
Publication of WO1996018823A1 publication Critical patent/WO1996018823A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D33/00—Non-positive-displacement pumps with other than pure rotation, e.g. of oscillating type

Definitions

  • the present invention is directed to a miniature vibrational fan composed of a piezoelectric material bonded to a metal reinforcing layer.
  • An a.c. voltage is applied to the piezoelectric material with the frequency turned to the mechanical resonance of the fan, causing vibration of both the piezoelectric material and the metal reinforcing layer bonded thereto, and resulting in air-flow across the surface of the metal layer.
  • piezoelectric vibrational fans are known in the art.
  • most known fan systems utilize piezoelectric ceramic bimorphs, e.g. lead-zirconium titanate (PZT) as the piezoelectric material, such as those fans disclosed in U.S. patent nos. 4,684,328 and 4,753,579, both to Murphy, 4,498,851 to Kolm et al. and 4,780,062 to Yamada et al.
  • PZT lead-zirconium titanate
  • Disadvantages to the use of piezoelectric ceramic materials in vibrational fans are high cost of manufacture, high power input and limitations on the ability to miniaturize such systems.
  • U.S. patent nos. 5,008,582 to Tanuma et al. and 4,342,936 to Marcus et al . none have recognized the benefits of the combination of materials as disclosed herein.
  • the above-cited references are hereby incorporated by reference.
  • the primary object of the present invention is to provide an improved vibrational fan which has an increased capacity for air movement across any particular device in need of air cooling.
  • the vibrational fan of the present invention comprises a metallic layer bonded to a layer of preferably piezoelectric polymer material however other piezoelectric materials to include composite and ceramic piezoelectric materials while less preferable will suffice, wherein the length of the metal layer exceeds the length of the polymer layer.
  • Application of a.c. voltage to the piezoelectric polymer results in repetitive bending motion or vibration of the polymer, which causes bending of the metal layer and while the system vibrates showing a maximum at the resonance, resulting in the ability of the system to force air movement.
  • the vibrational fan comprises an aluminum core layer having two flat surfaces, defined by a length, 2 1; a width, w, and said core layer having a thickness, t A ; a piezoelectric polymer film layer, comprising polyvinylidene fluoride, having a length, 1 2 , a width, w, and a thickness, t p ; and electrical means for electrically exciting the piezoelectric polymer film layer in order to induce a vibration in the vibrational fan, wherein said piezoelectric film layer is bonded to one flat surface of said aluminum core layer and I ⁇ >-- - -
  • the vibrational fan comprises more than one piezoelectric polymer film layer.
  • This embodiment may include the situation wherein a piezoelectric film layer is bonded to both flat surfaces of said aluminum core layer, one polymer layer on each side of said aluminum core layer.
  • two piezoelectric film layers may be bonded to one flat surface of said aluminum core layer or other thermally conductive material, both polymer layers on one side of the aluminum core layer.
  • two piezoelectric film layers may be bonded to both flat surfaces of said aluminum core layer, that is, two layers of polymer on each side of the aluminum core layer.
  • a third embodiment of the present invention is wherein the basic piezoelectric fan is mounted on a conventional heat sink for cooling purposes in computer and other electronics assemblies.
  • FIGURE 1 is a perspective view of the first embodiment of the piezoelectric vibrational fan of the present invention.
  • FIGURE 2 is a perspective view of the first embodiment of the piezoelectric vibrational fan of the present invention mounted as shown on a substrate.
  • FIGURE 3 is a cross-sectional view of a second embodiment of the present invention.
  • FIGURE 4 is a perspective view of the second embodiment of the piezoelectric vibrational fan of the present invention mounted as shown on a substrate.
  • FIGURE 5 is a cross-sectional view of an alternative of the second embodiment of the present invention.
  • FIGURE 6 is a perspective view of an alternative of the second embodiment of the piezoelectric vibrational fan of the present invention mounted as shown on a substrate.
  • FIGURE 7 is an exploded view of a section of the piezo polymer of Figure 6.
  • FIGURE 8 is a cross-sectional view of another alternative of the second embodiment of the present invention.
  • FIGURE 9 is a perspective view of another alternative of the second embodiment of the present invention.
  • FIGURE 10 is an exploded view of a section of the fan of FIGURE 9.
  • FIGURE 11 is an exploded view of the fan assembly for the third embodiment.
  • FIGURES 12-14 are views of the fan assembly of Figure 11 mounted in heat sinks.
  • the vibrational fan of the present invention comprises a metallic layer and piezoelectric polymer layer bonded together wherein the length of the metal layer exceeds the length of the polymer layer and other end is clamped.
  • the polymer chain direction is chosen to be parallel to the direction from the clamped end to the moving edge.
  • the a.c. voltage induces strain to the polymer so that that length towards the polymer chain repeats expansion and shrinkage.
  • both piezoelectric layers are so driven as to be our-of-phase strain and more effectively bending force is generated.
  • the subject of the present invention is a metal reinforced PVDF fan wherein an aluminum sheet doesn't "clamp" bonded to at least is clamped or bonded to at least one sheet of PVDF
  • PVDF sheet polyvinylidene fluoride
  • the length of the PVDF sheet is less than that of the aluminum sheet.
  • the choice of aluminum for the core layer results in improved air movement by the inventive fan.
  • the end opposite to the free moving edge (no PVDF) is securely clamped by a metallic structure.
  • PVDF film devices of the present invention have inherent advantages over those utilizing conventional piezoelectric materials, such as low excitation current, improved flexibility and low cost, due to the ability to mass produce PVDF materials in a continuous roll process.
  • multilayer PVDF devices especially thin film devices (less than 10 ⁇ m) , are difficult to produce at low cost due to difficulties in handling, bonding the layers together and attaching lead wires to each layer.
  • the inventors of the presently claimed devices propose a new structure which comprises a PVDF film clamped or bonded to an aluminum core layer, wherein the length of the aluminum core layer exceeds the length of the PVDF film.
  • Qm mechanical quality factor
  • the high elastic constant of aluminum means that it is elastically hard and applying a certain force produces very little bending.
  • the expansion and shrinkage of the PVDF film upon excitation the expansion and shrinkage of the PVDF film generates a bending force, but the aluminum layer is too hard to bend.
  • the situation is different at the resonance frequency, wherein the amplitude of the deflection due to the bending force increases by a factor of Qm of the system. This means that a high Qm material can be very easily bent at the resonance frequency.
  • FIGURE 1 illustrates a first embodiment of the present invention, wherein the vibrational fan comprises an aluminum core layer, 1, having two flat surfaces, defined by a length, 2 17 a width, w, and said core layer having a thickness, t A ; a piezoelectric polymer film layer, 2, comprising polyvinylidene fluoride, having a length, 1 2 , a width, w, and a thickness, t p ; and electrical means for electrically exciting the piezoelectric polymer film layer in order to induce a vibration in the vibrational fan, wherein said piezoelectric film layer is bonded to one flat surface of said aluminum core layer and 1 >1 2 -
  • the polarization direction of the piezoelectric film are shown by the arrows 3 in Figures 4,6,7,9 and 10.
  • FIGURE 3 illustrates a second embodiment of the present invention, wherein the vibrational fan comprises more than one piezoelectric polymer film layer.
  • This embodiment may include the situation wherein a piezoelectric film layer is bonded to both flat surfaces of said aluminum core layer, one polymer layer on each side of said aluminum core layer.
  • FIGURE 5 illustrates an alternative to the second embodiment of the present invention, wherein two piezoelectric film layers may be bonded to one flat surface of said aluminum core layer, both polymer layers on one side of the aluminum core layer.
  • the two polymer layers may either be two distinct and separate layers with a suitable connection or two layers formed by folding the PVDF film over itself, as illustrated.
  • FIGURE 8 illustrates another alternative to the second embodiment of the present invention, wherein two piezoelectric film layers may be bonded to both flat surfaces of said aluminum core layer, that is, two layers of polymer on each side of the aluminum core layer.
  • the two polymer layers may either be two distinct and separate layers or two layers formed by folding the PVDF film over itself, as illustrated.
  • Example 1 is provided to illustrate various configurations of the specific embodiments, described above, and are not intended to be limitative of the possible configurations of the invention within the scope of the claims.
  • Example 1 is provided to illustrate various configurations of the specific embodiments, described above, and are not intended to be limitative of the possible configurations of the invention within the scope of the claims.
  • Example 4 Various vibrational fans were designed according to the second embodiment, as illustrated in Fig. 4. The dimensions and performance characteristics are as follows:
  • Comparative Example A comparative vibrational fan was designed comprising two layers of PVDF bonded together, without an intervening aluminum core layer.
  • the dimensions and performance characteristics are as follows: Excitation conditions 100 V @ 1-4 mA
  • the inventors believe that the presently disclosed fans may be made to any desired width, w, with an increase or decrease in air flow rate varying approximately linearly with the width.
  • the relative lengths of the layers should be limited such that the ratio of 1 1 /1 2 is greater than 1.4, and preferably such that the ratio of 1 ' 1 2 is between 1.45 and 3.4, with the maximum length of l being about 10 cm .
  • the maximum benefits of the present invention are obtained when the thickness, t p , is between about 7-55 microns and the thickness, t A , is between about 10 and 100 microns.
  • the fan assembly 110 for use in a heat sink system for use in a computer or other electronic equipment which requires heat dissipation.
  • the fan 111 can be any of the above described assemblies. It is clamped by clamp 112 which is preferably metal or some other material capable of dissipating heat itself.
  • the clamp is clamped to the fan via screws or other fasteners and there are electrical leads as at 113.
  • This clamped fan assembly is then mounted preferably as is shown in heat sink assemblies of Figures 12-14.
  • the clamp is mounted to the heat sinks 121, 141 preferably by thermally conductive material such as conductive gel, conductive epoxy, solder or mechanical fasteners such as rivets or screws.
  • the fan requires an electric motor that is generally integral and thus itself adds heat to the system.
  • the instant invention places the piezoelectric fans as described above in between the heat sink fins, thereby greatly increasing the available heat sink surface area.
  • the fans placed in the fins maximizes the area of the heat sink causing the air to flow directly therebetween the fins.
  • the efficiency of the design further uses the heat dissipative effects of the clamp to increase the heat dissipation of the heat sink fan assembly.
  • a copolymer of PVDF and trifluoroethylene may be used to enhance the ability to bond the piezoelectric layer to the aluminum layer without an additional bonding substance, such as epoxy.
  • the presently claimed vibrational fans may be used in a variety of applications, such as for cooling a power transistor, a microprocessor or a large scale integration.
  • a particular benefit of the present invention, when configured according to Figs. 1 and 5, is that the aluminum layer may contact the device to be cooled directly. In this case, the exceptional thermal conductivity of the aluminum core layer provides additional cooling to the heated device, by acting as a heat sink.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

La présente invention traite d'un ventilateur vibrant miniature constitué d'un matériau piézo-électrique lié à une couche métallique de renforcement. On applique au matériau piézo-électrique une tension alternative, d'une fréquence en rapport avec la résonance mécanique du ventilateur, ce qui fait vibrer tant le matériau piézo-électrique que la couche métallique de renforcement et, partant, produit un flux d'air sur la surface de la couche métallique.
PCT/US1995/013616 1994-12-15 1995-10-20 Ventilateur vibrant en polyfluorure de vinylidene renforce par du metal WO1996018823A1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US35609794A 1994-12-15 1994-12-15
US08/356,097 1994-12-15
US35996694A 1994-12-20 1994-12-20
US08/359,966 1994-12-20
US42637395A 1995-04-21 1995-04-21
US08/426,373 1995-04-21

Publications (1)

Publication Number Publication Date
WO1996018823A1 true WO1996018823A1 (fr) 1996-06-20

Family

ID=27408248

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1995/013616 WO1996018823A1 (fr) 1994-12-15 1995-10-20 Ventilateur vibrant en polyfluorure de vinylidene renforce par du metal

Country Status (1)

Country Link
WO (1) WO1996018823A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0995908A1 (fr) * 1998-10-20 2000-04-26 vanden Brande, Pierre Pompe moléculaire
JPWO2013157346A1 (ja) * 2012-04-17 2015-12-21 株式会社村田製作所 圧電ファン
WO2016032429A1 (fr) * 2014-08-25 2016-03-03 Ge Aviation Systems Llc Générateur d'écoulement d'air et réseau de générateurs d'écoulement d'air
US9856868B2 (en) * 2012-02-13 2018-01-02 Murata Manufacturing Co., Ltd. Piezoelectric fan

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4498851A (en) * 1980-05-02 1985-02-12 Piezo Electric Products, Inc. Solid state blower
US4684328A (en) * 1984-06-28 1987-08-04 Piezo Electric Products, Inc. Acoustic pump
US4753579A (en) * 1986-01-22 1988-06-28 Piezo Electric Products, Inc. Ultrasonic resonant device
US4780062A (en) * 1985-10-09 1988-10-25 Murata Manufacturing Co., Ltd. Piezoelectric fan
US4834619A (en) * 1987-11-10 1989-05-30 The Boeing Company Ducted oscillatory blade fan
GB2220485A (en) * 1988-04-25 1990-01-10 Pennwalt Piezo Film Gas flow detector
EP0385090A1 (fr) * 1989-03-03 1990-09-05 Microelectronics and Computer Technology Corporation Echangeur de chaleur à ventilateurs piézo-électriques
US5008582A (en) * 1988-01-29 1991-04-16 Kabushiki Kaisha Toshiba Electronic device having a cooling element

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4498851A (en) * 1980-05-02 1985-02-12 Piezo Electric Products, Inc. Solid state blower
US4684328A (en) * 1984-06-28 1987-08-04 Piezo Electric Products, Inc. Acoustic pump
US4780062A (en) * 1985-10-09 1988-10-25 Murata Manufacturing Co., Ltd. Piezoelectric fan
US4753579A (en) * 1986-01-22 1988-06-28 Piezo Electric Products, Inc. Ultrasonic resonant device
US4834619A (en) * 1987-11-10 1989-05-30 The Boeing Company Ducted oscillatory blade fan
US5008582A (en) * 1988-01-29 1991-04-16 Kabushiki Kaisha Toshiba Electronic device having a cooling element
GB2220485A (en) * 1988-04-25 1990-01-10 Pennwalt Piezo Film Gas flow detector
EP0385090A1 (fr) * 1989-03-03 1990-09-05 Microelectronics and Computer Technology Corporation Echangeur de chaleur à ventilateurs piézo-électriques

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0995908A1 (fr) * 1998-10-20 2000-04-26 vanden Brande, Pierre Pompe moléculaire
WO2000023715A1 (fr) * 1998-10-20 2000-04-27 Pierre Vanden Brande Pompe moleculaire
AU763828B2 (en) * 1998-10-20 2003-07-31 Pierre Vanden Brande Molecular pump
US6612816B1 (en) 1998-10-20 2003-09-02 Pierre Vanden Brande Molecular pump
US9856868B2 (en) * 2012-02-13 2018-01-02 Murata Manufacturing Co., Ltd. Piezoelectric fan
JPWO2013157346A1 (ja) * 2012-04-17 2015-12-21 株式会社村田製作所 圧電ファン
WO2016032429A1 (fr) * 2014-08-25 2016-03-03 Ge Aviation Systems Llc Générateur d'écoulement d'air et réseau de générateurs d'écoulement d'air
CN106662122A (zh) * 2014-08-25 2017-05-10 通用电气航空系统有限责任公司 空气流发生器和空气流发生器阵列
JP2017532477A (ja) * 2014-08-25 2017-11-02 ジーイー・アビエイション・システムズ・エルエルシー 気流発生装置および気流発生装置の配列

Similar Documents

Publication Publication Date Title
US7031155B2 (en) Electronic thermal management
EP1384309B1 (fr) Systemes de conversion d'energie au moyen de dispositifs a echelle nanometrique
JPH0340462A (ja) 流体熱交換器
KR20030007429A (ko) 복합 압전변압기
JP2004079883A (ja) 熱電素子
US10085363B2 (en) Integrated compact impingement on extended heat surface
JP3139452B2 (ja) 圧電トランス及びその製造方法
US20200314555A1 (en) Electro-active loudspeaker
JP4955406B2 (ja) 広周波数域電気機械式アクチュエータ
US20110223043A1 (en) Piezoelectric fan and cooling device
US11965529B2 (en) Linear fan forced air cooling
US6140745A (en) Motor mounting for piezoelectric transducer
CN112351634B (zh) 散热装置和电子设备
JPH08330488A (ja) 圧電ファン付きヒートシンク
WO1996018823A1 (fr) Ventilateur vibrant en polyfluorure de vinylidene renforce par du metal
JP2008172106A (ja) 圧電ファン装置及びその製造方法
JPH1158591A (ja) 熱伝導シート
JP4999071B2 (ja) ヒートシンク
JP2008210875A (ja) ヒートシンク
US20130034252A1 (en) Transducer module
US20180226903A1 (en) Hybrid electroactive actuator device
JPS6272149A (ja) 圧電フアン付放熱フイン
JPH0635515Y2 (ja) 電気部品の冷却装置
Sauciuc et al. Key challenges for the piezo technology with applications to low form factor thermal solutions
JPS59158541A (ja) 電気部品の冷却装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CN JP KR

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载