US3029743A

US3029743A - Ceramic diaphragm pump

Info

Publication number: US3029743A
Application number: US22207A
Authority: US
Inventors: James F Johns
Original assignee: Curtiss Wright Corp
Current assignee: Curtiss Wright Corp
Priority date: 1960-04-14
Filing date: 1960-04-14
Publication date: 1962-04-17
Anticipated expiration: 1979-04-17

Description

MaLMG-a.

J. F. JOHNS Filed April 14, 1960 A DIAPHRAGM VOLTAGE)\! VALVE V0 LTAG E I $AQ/ I 16D I68 I 23 a 3 wmssn -zs- 2 55s 1 3/3; 2,4OA 33 I78 40E I70 I? 2 POWER sgg a s :10 WA 22 I \Q Q g "4IA'\ I4A F Q: :13:

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FIG.3.

INVEN TOR. JAMES F. JOHNS BY FIG.4. /T', LL 'T T T ATTORNEYS.

3,029,743 CERAMIG DIAPHRAGM PUMP James F. Johns, Santa Barbara, Calif., assignor to Curtiss-Wright Corporation, Goleta, Calif., a corporation of Delaware Filed Apr. 14, 1960, Ser. No. 22,207 3 Claims. (til. 103150) The present invention relates to a novel pump involving the use of elements which deform upon the application thereto of a voltage.

Briefly, the pump described herein consists of two dual thickness voltage responsive ceramic diaphragms closing the ends of a cylindrical cavity. These ceramic diaphragms vibrate in flexure mode in timed relationship with respect to an alternating current voltage applied thereto with, however, one of the diaphragms vibrating 180 out of phase with respect to the other diaphragm to alternately expand and contract a cavity defined by the two spaced diaphragms to achieve a pumping action.

Another feature is that the flow of fluid into and out of such cavity is controlled by an inlet and an outlet valve element, both of which likewise are of a voltageresponsive material operated in timed relationship with respectto contraction and expansion of such cavity.

It is therefore a general object of the present invention to provide a novel pump having one or more of the features indicated above. 7 a

Another object of the present invention is to provide a pump of this character in which a pumping action occurs at a relatively high rate at, for example, 3,000 cycles per second.

Another object of the present invention is to provide an improved pump of this character in which the flow of fluid discharged therefrom may be conveniently controlled by simply shifting the phase of the voltage applied to the valve elements or by adjusting the intensity of the voltage applied to the diaphragms defining the pump cavity.

Another object of the present invention is to provide a pump of this character which may be made relatively small and without the necessity of providing a rotary driving motor therefor.

Another object of the present invention is to provide a pump of this character which may be made relatively small and inexpensive considering the fact that the same incorporates its own driving motor.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which:

FIGURE 1 illustrates a sectional view through a pump embodying features of the present invention, the section being taken substantially on the line 11 in FIGURE 2, and FIGURE 1 also illustrates the electrical connections to the various electrically polarized ceramic elements.

FIGURE 2 is a sectional view taken substantially on the line 2-2 of FIGURE 1.

FIGURE 3 is an enlarged sectional view of one of the valve elements incorporated in the pump shown in FIGURE 1. v

FIGURE 4 is a series of six graphs illustrating the alternating'current voltages applied to the diaphragms and valves and also illustrates the resulting diaphragm and valve motion.

The pump shown in FIGURE 1 includes a cylindrical metallic housing formed with externally-threaded rates 3,029,743 Patented Apr. 17, 1962 nipples 11 and 12 which comprise respectively the inlet and outlet ports of the pump.

Opposite ends of the cylindrical member 10 are'closed by a pair of

discs

13 and 14 which are threaded in the cylindrical member and which are suitably apertured to receive

insulating bushings

13A and 14A and 14B through which leads to the various voltage-responsive ceramic elements pass.

These two

discs

13 and 14 retain an assembly comprising the two dual thickness diaphragms 16 and-17,

the cylindrical insert 13 and the two ring-

shaped elements

19 and 20, each of which are annularly grooved to retain the corresponding O-

rings

21 and 22.

The diaphragm 16, which is circular has its peripheral edge squeezed between the O-ring 21 and the 0-ring 23 recessed within an annular grooved portion of the insert 18. Likewise, the peripheral edge of the other diaphragm 17 is squeezed between the O-ring 22 and the 0-ring 26 recessed within an annular grooved portion of the cylindrical insert 18.-

This cylindrical insert 18 has two axially aligned

bores

18A and 18B which allow the passage of fluid into and out of the chamber 29, such chamber 29 being expansible and contractable and being defined generally by the

flexible diaphragms

16 and 17 and the inner wall of the insert 18. I i

The pump incorporates two

movable valve elements

30 and 31 serving respectively as inlet and outlet valve members. These two

valve members

30 and 31 are supported as cantilevers and each comprise dual thickness ceramic strips 32 and 33 respectively having their lower ends in FIGURE 1 secured in tightly fitted apertured

portions

34 and 35 defined by opposite faces of the cylindrical member 10 and the cylindrical insert 18. If desired, insulation may be interposed between the dual thickness diaphragm strips 32 and 33 at the point where the same are secured at 34 and 35. The upper end of each of the dual thickness diaphragm strips 32 and 33 carry, as shown in FIGURE 3, a

conical projection

30A and 31A respectively engageable with valve seats comprising on the one hand the internal bore of the nipple 11 and the internal bore 18B of the insert 18.

Each of the

diaphragms

16 and 17 and the ceramic strips 32 and 33 are of dual thickness or laminated voltage-responsive ceramic material such as, for example, barium titanate, with the abutting portions of each element being polarized in opposite directions as indicated by the arrows. Thus, as shown in FIGURE 1, the upper diaphragm 16 actually comprises two

discs

16A and 16B electrically polarized in opposite axial directions as indicated by the

arrows

16C and 16D. Likewise, the lower diaphragm 17 comprises two diaphragms 17A and 17B polarized electrically in the direction indicated by the arrows 17C and 17D. Similarly, the valve member 32 comprises two

strips

32A and 32B electrically polarized in the direction indicated by the arrows 32C and 32D. Likewise, the ceramic valve element 33 comprises two strips 33A and 333 which are polarized respectively in the directions indicated by the

arrows

33C and 33D.

These various polarized elements are electrically connected to the power source 40 and the phase shifter 41 in the manner now described. The

diaphragm elements

16A and 17A are each connected to one terminal 40A of the power source 40. The other terminal 403 of the power source is connected to both the diaphragm members 16B and 17B. These

terminals

40A and 40B of the power source 40 are also connected to corresponding input terminals of phase shifter 41 having the output terminals 41A and 41B. The output terminal 41A is connected to both the

ceramic strips

33A and 32A. The other terminal 41B is connected to both the ceramic 3

strips

338 and 32B. The purpose of this phase shifter 41 is generally to control the phase relationship between movement of the valve elements 30A and 61A with respect to movement of the

diaphragms

16 and 17 as now described in connectionwith FIGURE 4.

In FIGURE 4 the graph A represents a sine wave of voltage which is applied from the power source 40 to adjacent elements of the

diaphragms

16 and 17. The graph B in FIGURE 4 also represents a sine waveaof voltage, shifted 9O electrical degrees by phase shifter 41 and applied to adjacent elements of each of the ceramic valve strips 32 and 33. The graphs C and D in FIGURE 4 represent the resulting motion of

diaphragms

16 and 17 respectively and as shown, it is noted that diaphragm 16 vibrates in phase with the voltage represented at A and the diaphragm 17 vibrates in opposite phase, i.e. 180

with respect to the voltage variation A and the vibrational movement C of diaphragm 16. This results in a periodic expansion and contraction of the pump chamber 29 in FIGURE 1 defined by

such diaphragms

16 and 17. Thus at time T indicated in FIGURE 4, the

diaphragms

16 and 17 are spaced apart their maximum distance and there is then a maximum volume of chamber 29. 180 later, as represented at time T the diaphragms 15 and 17 are spaced their closest distance corresponding to a condition of minimum volume of chamber 29. The movement of the valve elements 32 and 33 is synchronized with this periodic expansion and contraction of chamber 29 as now described in connection with graphs E and -F in FIGURE 4. Graph E represents periodic movement of the inlet valve element 32 and graph F represents movement of the outlet valve element 33. It will be seen that the inlet and outlet valve members vibrate 180 out of phase so that when one is open, the other is closed. The inlet valve element 30A is open during the time that the chamber 29 is expanding and is closed when such chamber 29 is contracting. Likewise, the outlet valve 33 is closed when the chamber 29 is expanding and is opened during the time that the chamber 29 is contracting to assure the desired suction and discharge strokes of the pump in a true pumping action. The hatched areas in graphs E and F represent generally the time when the corresponding inlet and outlet valves are closed, it being noted that the inlet and outlet valves are alternately opened and closed to achieve this pumping action.

The dual thickness

ceramic members

16, 17, 32 and 33 are used for a very particular reason. This is largely because barium titanate, when polarized in a given direction, expands on the application of an electrical field in one direction and contracts if the field is applied in the reverse direction; therefore, if two thin sections, as described herein, polarized in opposite directions, are cemented together, an electrical field applied across the two sections causes a bending or flexing movement to be applied to the composite piece as described above in connection with FIGURE 4.

It will be appreciated that the intensity of flow can be regulated by varying the intensity of the AC. voltages applied to the

diaphragms

16 and 17 and further that optimum flow conditions may be achieved by adjustment of the phase shifter 41 which serves to control the timing of the valves, both the inlet and the outlet. One method for varying the intensity of the AC. voltages applied to the

diaphragms

16 and 17 is to vary the position of the tap 51 of the potentiometer 52 connected to the output of the power source 40.

While the particular embodiments of the present in vention have been shown and described,'it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and .modifications as fall within the true spirit and scope of defining a fluid chamber, saidfluid chamber having an inlet adapted to be connected to a source of fluid to be pumped and an outlet leading from said fluid chamber; a pair of flexural ceramic valve means responsive to an alternating voltage for opening and closing said inlet and outlet respectively during alternate periods of said alternating voltage; a pair of flexural ceramic diaphragms responsive to alternating voltages, spaced from each other and forming opposite side walls in said fluid chamber; and voltage means connected to said valve means and said diaphragms for applying out of phase alternating voltages thereto, said voltage means including means for varying the phase relationship of said alternaitng voltages, whereby application of said alternating voltages to said diaphragms oppositely flex the same during alternate periods of said voltage to sequentially expand and contract said fluid chamber and application of said alternating voltages to said ceramic valve means respectively open and close said inlet and outlet during said periods of expansion and contraction of said fluid chamber to alternately admit fluid into said fluid chamber through said inlet and discharge fluid through said outlet.

2 Apparatus as defined in claim 1 wherein the amount of said contraction and expansion of said fluid chamber is determined by the intensity of said alternating voltages applied to said diaphragms andsaid voltage means includes means for varying the intensity of said alternating voltages to vary the capacity of said ceramic pump.

3. A pump comprising a cylindrical member having radially aligned inlet and outlet openings; a cylindrical insert arranged in said cylindrical member and having radial openings therethrough for placing said inlet and outlet openings in communication with each other, said cylindrical insert having grooved portions in opposite ends thereof; an O-ring arranged in each of said grooved portions; at first ring-shaped element adjacent one end of said cylindrical insert; a second ring-shaped element adr jacent the other end of cylindrical insert, each of said ring-shaped elements having a grooved portion respectively; an O-ring arranged in each of the grooved portions of each ofsaid ring-shaped elements; a pair of spaced flexible diaphragm members closing the ends of said cylindrical insert and having their peripheral edges sandwichedbetween respective adjacent O-rings in said cylindrical inserts and said ring-shaped elements, each of said'diaphragms comprising. a pair of abutting voltage responsive elements polarized respectively in opposite directions; an inlet and an outlet valve member, each of said valve members including a voltage-responsive element which is flexed in accordance with voltage applied thereto, said inlet and outlet valves each including means cooperating with one of said radial openings in said cylindrical member to regulate the flow of a fluid into and out of said cylindrical member; and voltage means connected to said valves and said diaphragms for applying alternating voltage thereto, said voltage means including means for shifting the phase relationship between the voltage applied to said diaphragms and the voltage ap plied to said valves.

2 References Cited in the file of this patent UNITED STATES PATENTS