JPH04219483A - Fluid transfer pump - Google Patents

Abstract

PURPOSE:To accurately control minute flow rate in a fluid transfer pump using an ultrasonic actuator as a driving source. CONSTITUTION:When a piezoelectric transducer 1 is given an AC signal having frequency equal to its resonance frequency, one-way vibrational displacement along the direction of a polarization axis occurs on the side of the transducer 1. The vibrational displacement is transmitted to a rotor 2 through a friction member 3. The rotor 2 rotates, and a bearing 4 attached to the rotor 2 also rotates. After an elastic tube 7 is passed from the one opening of a metallic pipe 6 to its another opening, the tube 7 is coiledly wound around the outer wall of the pipe 6. When the bearing 4 rotates with the coiled part of the elastic tube 7 pressed against the pipe 6, the elastic tube 7 unaidedly draws fluid by utilizing its restoring force to transfer the fluid in the tube 7 in the moving direction of the bearing 4. Thus this pump can accurately control the minute flow rate by pulse driving, and moreover can be used even in a strong magnetic field as a magnet need not be used.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid transfer pump that transfers fluid using elastic vibrations generated by an ultrasonic actuator using a columnar vibrator as a driving source.

0002

2. Description of the Related Art Conventional metering pumps are almost limited to those using electromagnetic motors as a driving source, and are broadly classified into discontinuous types and continuous types. Among the discontinuous types, FMI metering pumps in particular can continuously change the transfer amount per step, so in principle the transfer amount can be reduced quantitatively infinitely, but the adjustment part is not mechanical. Since it is a formula, it lacks accuracy and has problems with controllability. Some continuous pumps can control the flow rate continuously using voltage control, and although it is possible to control minute flow rates, they have the disadvantage of being prone to backflow because they have no moving parts, which can result in problems with controllability. leave.

[0003] Furthermore, in order to reduce the flow rate and improve controllability, the apparatus has to be larger in size.

0004

Problems to be Solved by the Invention With conventional metering pumps, it is difficult to accurately control minute amounts, and the devices are generally large.

Therefore, in the present invention, by using an ultrasonic actuator as a driving source, it is possible to accurately control minute flow rates, and furthermore, the device can be used in a strong magnetic field, the device is compact, lightweight, noiseless, and low. To provide a pump for transferring fluids aimed at enabling power consumption. Note that there are already detailed descriptions of the vibrator type actuator (Japanese Patent Application No. 129122/1983, Japanese Patent Application No. 1/2013).
No. 26950).

[0006]

Means for Solving the Problems The fluid transfer pump according to claim 1 provides a fluid transfer pump in which a plurality of cylindrical bearings are used to press an elastic tube filled with fluid in a direction perpendicular to the axis while moving the bearings along the axis. In the fluid transfer pump that transfers the fluid within the elastic tube by moving the fluid substantially along the elastic tube, the elastic tube is coiled around a cylinder in a single layer, and the plurality of bearings are arranged around the outer periphery of the elastic tube to move the rotation axis along the elastic tube. They are characterized by being arranged parallel to the axis of the cylinder and at equal intervals.

The fluid transfer pump according to claim 2 is characterized in that the elastic tube is wound around the cylinder a plurality of times, and each bearing presses a plurality of turns of the elastic tube against the cylinder. do.

[0008] In the fluid transfer pump according to claim 3, the cylinder is a cylindrical body with openings at both ends, and the elastic tube extends from one of the openings through the inside of the cylindrical body to the other opening. It is characterized by extending from the opening and being wrapped around the outer periphery of the cylindrical body.

A fluid transfer pump according to a fourth aspect of the present invention includes a piezoelectric vibrator having electrodes on both end surfaces of a columnar piezoelectric ceramic, and a piezoelectric vibrator that contacts the piezoelectric vibrator and receives vibrational displacement generated in the piezoelectric vibrator; It is characterized in that it comprises a rotating body that rotates around an axis concentric with a cylinder, the both end faces are perpendicular to the polarization axis of the piezoelectric ceramic, and the shaft of the bearing is attached to the rotating body.

0010

[Operation] When the fluid transfer pump according to claim 1 is used, the bearing moves approximately along the axis of the elastic tube while compressing the elastic tube that is wound in a single layer in a cylindrical coil shape. The elastic tube is sequentially compressed along the axis, and the fluid within the elastic tube is transferred in the direction of movement of the bearing. At this time, since the elastic tube is sequentially restored as the bearing passes, the elastic tube self-suctions the fluid by utilizing this restoring force. In this manner, the fluid transfer pump of the present invention performs fluid suction and discharge, that is, pumping. The pumping effect can be further increased by rotating a plurality of the bearings along the outer periphery of the elastic tube. Furthermore, by arranging a plurality of bearings at regular intervals so that their rotational axes are parallel to the axis of the cylinder, the axis of the cylinder is kept stable without shifting, allowing accurate pumping. If the elastic tube is of a cartridge type fixed to the cylinder, the entire cartridge can be replaced when replacing the tube, which not only simplifies the tube replacement but also enables pumping under the same conditions at all times. .

In the fluid transfer pump according to claim 2, the elastic tube is wound around the cylinder a plurality of times, and each bearing presses the portion of the elastic tube around which it is wound against the cylinder. There is. Therefore,
Since the same load is always applied to the elastic tube at the portion where the bearing is sandwiched between the cylinder and the cylinder, uniform and accurate pumping can be performed and fluid transfer can be easily controlled.

[0012] In the fluid transfer pump according to claim 3, the cylinder is a cylindrical body with openings at both ends, and the elastic tube extends from one of the openings through the inside of the cylindrical body to the other opening. Since it extends from the opening and is wrapped around the outer circumference of the cylindrical body, the elastic tube and the cylinder form an integrated structure. The tube can be replaced easily by using the cartridge type integral structure, and pumping can be performed under the same conditions at all times.

In the fluid transfer pump according to the fourth aspect, an AC signal having a frequency equal to a resonance frequency of a piezoelectric vibrator having electrodes on both end faces perpendicular to the polarization axis of a columnar piezoelectric ceramic is applied to the piezoelectric vibrator. When the voltage is applied through the electrodes, the piezoelectric vibrator is excited, and a unidirectional vibrational displacement is generated on the side surface of the piezoelectric ceramic. The vibration displacement is transmitted to a rotating body that contacts a side surface of the piezoelectric vibrator and rotates around an axis concentric with the cylinder, and the rotating body rotates. Since the shaft of the bearing is attached to the rotating body, when the rotating body rotates, the bearing also rotates around the cylinder while rotating around the axis of the bearing. At this time, the bearing sequentially presses the elastic tube against the cylinder by rotating on its own axis and around the cylinder, thereby performing a pumping function. This device uses an ultrasonic actuator made of a piezoelectric vibrator as a driving source, and because it has a fast response speed to input, pulse driving can be performed accurately and easily, and the holding force is large when no input is applied. Therefore, precise control of minute flow rates is possible and there is no backflow.
Transfer amount can be changed easily and continuously. Additionally, it can be driven with low power consumption and produces no noise. Furthermore, since low-speed, high-torque rotation is possible, gears are not required, so the device can be made smaller and lighter. Since it does not require the use of a magnet, it can also be used in strong magnetic fields.

[0014]

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples. FIG. 1 is a perspective view showing an embodiment of the fluid transfer pump of the present invention, FIG. 2 is a side view of the fluid transfer pump of FIG. 1 when viewed from the front in the opposite direction, and FIG. It is a side view when seen from above. This embodiment includes a piezoelectric vibrator 1 to which terminals P and Q made of copper foil are attached, a rotating body 2, a friction material 3, a bearing 4, a bearing shaft 5, a metal pipe 6, and an elastic tube. It consists of 7. However, FIG. 2 also shows a power supply section that supplies AC voltage to the piezoelectric vibrator 1.

FIG. 4 is a perspective view of the piezoelectric vibrator 1. The piezoelectric vibrator 1 includes a cylindrical piezoelectric ceramic 20, and electrodes 21 and 22 provided on each end face of the piezoelectric ceramic 20 perpendicular to the polarization axis. The piezoelectric ceramic 20 has a diameter of 10 mm.
, height 10mm, material is TDK 91A material (product name)
, and its resonant frequency is approximately 138kHz. T
The OK91A material is used in this example because it has a large electromechanical coupling coefficient. The electrode 21 is provided on a portion of one end surface of the piezoelectric ceramic 20 excluding a 2 mm wide portion perpendicularly from the tangent, while the electrode 22 covers the entire other end surface. The arrow in the figure indicates that the piezoelectric ceramic 20 is in a resonant state when an AC signal is applied to the piezoelectric vibrator 1.
shows the vibrational displacement that occurs on the side of the Since one electrode 21 has the shape shown in the figure and is asymmetrical to the electrode 22, it is displaced in one direction.

FIG. 5 is a perspective view showing how the elastic tube 7 is attached to the metal pipe 6, and FIG. 6 is a perspective view showing how the elastic tube 7 filled with fluid is coiled on the outer wall of the metal pipe 6 as shown in FIG. FIG. 7 is a cross-sectional view schematically showing how the elastic tube 7 filled with fluid in FIG. 6 is wrapped.
FIG. 4 is a cross-sectional view showing how the metal pipe 6 is pressed by the bearing 4. FIG. Elastic tube 7 with an outer diameter of 1 mm and an inner diameter of 0.5 mm has an outer diameter of 3 mm, an inner diameter of 2 mm, and a length of 15 m.
After passing from one opening of a cylindrical metal pipe 6 to the other opening through an internal cavity, the metal pipe 6 is wound in a coil along the outer wall of the metal pipe 6. In this example, the diameter is 15
Three bearings 4 with a diameter of 10 mm and a thickness of 10 mm are provided, and these three bearings 4 rotate together around the axis of the metal pipe 6 when the fluid transfer pump is driven.
Accordingly, the elastic tube 7 is sequentially compressed, and the fluid surrounded by the tube wall 30 is also sequentially moved.

When the fluid transfer pump is driven, a frequency equal to the resonance frequency of the piezoelectric vibrator 1 is applied to the piezoelectric vibrator 1 via a terminal P provided on the electrode 21 and a terminal Q provided on the electrode 22. An alternating current signal having the following values is applied. The piezoelectric vibrator 1 is excited, and a piezoelectric ceramic 20 is placed on the side surface of the piezoelectric ceramic 20.
A unidirectional vibrational displacement along the direction of the polarization axis occurs. The rotating body 2 consists of two large and small disks and a cylinder connecting them. The larger disk has a diameter of 56 mm and a thickness of 3 mm, and a friction material 3 is placed on one plate surface concentrically with the center of the disk. It is fixed in a ring shape with a width of 8 mm and a thickness of 1 mm. The smaller disk has a diameter of 33 mm and a thickness of 3 mm, and on one plate surface, three bearing axes 5 of 6 mm diameter and 1.3 mm length are parallel to the axis of the metal pipe 6 and spaced equally apart. It is fixed. The cylinder that connects the two large and small disks has a diameter of 5 mm.
, with a length of 35 mm, with the centers of two large and small disks concentric,
It passes through the center of the large disc and reaches the small disc. At this time, the large disk and the small disk become parallel, and the distance between them is 17 mm. The piezoelectric vibrator 1 has a friction material 3 fixed to a rotating body 2.
is in contact with. At this time, since the piezoelectric vibrator 1 is cylindrical, the shape of the portion where the piezoelectric vibrator 1 contacts the friction material 3 is a straight line connecting both end surfaces of the piezoelectric vibrator 1 and perpendicular to both end surfaces. The distance between the straight line and the center of the rotating body 2 is 21 mm. The friction material 3 was made of epoxy resin mixed with polyamide. The unidirectional vibrational displacement generated on the side surface of the piezoelectric ceramic 20 is transmitted from the linear portion to the rotating body 2 via the friction material 3, and the rotating body 2 rotates around its axis. At this time, the friction material 3 not only prevents wear of the piezoelectric ceramic 20 and the large disk of the rotating body 2 due to rotation, but also prevents electromagnetic interference caused by high voltage generated between the rotating body 2 and the piezoelectric vibrator 1 due to rotation. Prevent noise. As the rotating body 2 rotates, the shaft 5 of the bearing fixed to the small disc of the rotating body 2 also rotates around the axis of the rotating body. Bearings 4, which are attached to surround the metal pipe 6, rotate around the axis of the metal pipe 6. At this time, the bearing 4 sequentially presses a portion of the elastic tube 7 that is coiled around the metal pipe 6 against the outer wall of the metal pipe 6 while rotating around the shaft 5 of the bearing. Since the elastic tube 7 is sequentially restored as the bearing 4 moves, the elastic tube 7 sucks fluid from one opening of the elastic tube 7 by its restoring force. The aspirated fluid moves within the elastic tube 7 and is forced out of the other opening of the elastic tube 7. Elastic tube 7 sandwiched between bearing 4 and metal pipe 6
Since the load is applied uniformly at all locations, uniform and accurate pumping is always possible.

By changing the frequency of the alternating current signal applied to the piezoelectric vibrator 1 within a certain range, it is possible to arbitrarily control not only the magnitude of the vibrational displacement generated on the side surface of the piezoelectric ceramic 20 but also its direction. . Therefore, it is possible to control the rotational speed of the rotating body 2 and drive it in reverse, so that the speed and direction of the fluid moving inside the elastic tube 7 can be freely controlled.

Since the elastic tube 7 is an integral structure fixed to the metal pipe 6, when replacing the tube, the entire integral structure can be replaced, which not only saves time but also ensures that the conditions are always the same. pumping is possible.

FIG. 8 is a characteristic diagram showing the relationship between the admittance and phase of the piezoelectric vibrator 1 with respect to frequency. 140
It resonates around kHz and anti-resonates around 168kHz. Resonance cracking occurs in which the admittance peak at a resonant frequency of approximately 140 kHz is divided into two. This means that the electrode 21 is connected to the piezoelectric ceramic 20 as shown in FIG.
This is due to the fact that it is provided on a part of the end face of.

FIG. 9 is a characteristic diagram showing the relationship between the applied voltage and the number of rotations when the bearing 4 rotates around the metal pipe 6. The rotational speed has a linear relationship with the applied voltage, and the slope thereof is about 0.4 rpm/V. Note that the frequency of the applied voltage signal is approximately equal to the resonance frequency of the piezoelectric vibrator 1, which is approximately 138 kHz.

FIG. 10 is a block diagram for pulse driving when an rf pulse is applied. The waveform within the ellipse between the pulse generator and the mixer is the waveform produced by the pulse generator. The waveform within the ellipse between the signal generator and the mixer is the waveform generated by the signal generator. The waveform within the ellipse between the mixer and the power amplifier is a combination of the waveform generated by the pulse generator and the waveform generated by the signal generator. During pulse driving, an AC signal representing a waveform synthesized in this manner is applied to the piezoelectric vibrator 1.

FIG. 11 is a characteristic diagram showing the relationship between pulse width and rotation angle per pulse when pulse driving is performed at an applied voltage of 100 Vp-p and a frequency of about 138 kHz. Let T be the time required for N rotations,
When the pulse repetition frequency is fp, the rotation angle θ per pulse is given by equation (1). θ (deg.)
=360N/(fp ・T) (1) Pulse width is 20
At mS or more, there is a nearly linear relationship between the pulse width and the rotation angle per pulse, so the time from applying voltage until driving starts and becomes constant, and the time from when voltage is released until driving stops. It can be seen that the time required for this is at least several tens of milliseconds or less. Compared to the spontaneous stop of an electromagnetic motor, which takes several hundred milliseconds to several seconds, the response speed of the drive source of this device is extremely fast. Further, the minimum pulse width that allowed operation was 1 mS, and the rotation angle at that time was about 0.003°.

FIG. 12 is a characteristic diagram showing the relationship between the pulse width and the amount of transfer per pulse, which was determined from FIG. 11 and the amount of transfer when the bearing 4 makes one rotation around the metal pipe 6. The distance between the center of the bearing 4 and the center of the metal pipe 6 corresponds to the rotation radius of the bearing 4. If the rotation radius is a and the inner diameter of the elastic tube 7 is r,
The transfer amount Mt per rotation is given by equation (2). However, the elastic tube 7 has a circular cross section. Mt = (travel distance of bearing 4 per rotation) × (internal cross-sectional area of elastic tube 7) = 2πa × πr2 /4

(2) In order to transfer a very small amount, it is necessary to reduce the rotational speed and to make the Mt value as small as possible. In order to decrease the Mt value, the a value and the r value may be decreased. In the fluid transfer pump of this embodiment, an elastic tube with a smaller inner diameter can be used regardless of the size of the bearing, so the transfer amount can be further reduced. By the way, since the transfer section of this embodiment is small, the internal cross-section of the elastic tube 7 changes from circular to elliptical as the bearing 4 passes. Therefore, the transfer amount was determined by actual measurements. The Mt value was approximately 0.75 nl when the transfer amount at 2,500 revolutions was converted into one revolution and the three measurements were averaged. Let S be the internal cross-sectional area of the elastic tube 7 in equation (2), and Mt = 0.75 nl
Substituting , it becomes S=59.7×10−9 m 2 . On the other hand, the theoretical S value when the pipe internal cross section is circular is S = 1
At 96.3×10 −9 m 2 , the S value becomes approximately 1/3 due to the change in the pipe internal cross section from circular to elliptical. Therefore, the transfer amount per rotation is reduced to 1/3, so that the transfer section of this embodiment can transfer an even smaller amount. Further, the transfer amount at the minimum pulse width of 1 mS that allows operation is 0.00622 pl, and it can be said that control is possible from an extremely small amount.

FIG. 13 is a characteristic diagram showing the relationship between the pulse repetition frequency and the amount of transfer per minute when the applied voltage is 100 Vp-p and the frequency is approximately 138 kHz. In this figure, the pulse widths are 1, 2, 3, and 3, respectively.
The characteristics when pulse driving is performed at 5, 10, 20, 30, and 40 mS are shown. It can be seen that minute amount control is possible in a wide range of pulse width driving.

There are two methods for starting the fluid transfer pump of this embodiment: pulse drive and continuous drive, but pulse drive is more suitable for accurate control of minute amounts. By using a rotary encoder in conjunction with pulse drive, it became possible to control the transfer amount more accurately. A rotary encoder is used to convert angles into electrical signals. The fluid transfer pump of this embodiment is of an incremental type that sequentially generates pulses for each unit angle. The highest resolution of the incremental type is 6000 pulses per rotation, so the rotation angle per pulse is 0.06°, which is shown in Figure 11.
From FIG. 12, the transfer amount per pulse is 0.124 pl. This 0.124 pl is the minimum transfer amount of the fluid transfer pump when the incremental type is also used. Also,
Regarding errors, the minimum rotation angle in pulse drive is shown in Figure 1.
Since it is 0.003° from 1 and the resolution of the incremental type is 0.06°, the maximum error is 5%, which is 0.0062 pl in terms of capacity, which is an extremely small value. Therefore, if the incremental type is used in combination, minute and accurate control of the transfer amount can be further improved.

[0027]

Effects of the Invention As explained in detail above, in the fluid transfer pump of the present invention, a plurality of bearings presses an elastic tube coiled around the outer wall of a metal pipe while moving it approximately along the axis of the elastic tube. and move. The fluid within the elastic tube is then transported in the direction of movement of the bearing. At this time, the elastic tube is sequentially restored as the bearing passes, so the elastic tube self-suctions the fluid by utilizing this restoring force. By forming a structure in which multiple bearings are arranged at equal intervals so that their rotational axes are parallel to the axis of the metal pipe, the axis of the metal pipe is kept stable without shifting, allowing accurate pumping at all times. The amount of fluid transferred Mt when the bearing rotates once around the axis of the metal pipe depends on the distance a between the center of the bearing and the center of the metal pipe and the inner diameter r of the elastic tube.To decrease Mt, a , r must be decreased. By adopting a structure in which the bearing rotates around the outer periphery of the metal pipe, r can take any small value regardless of the size of the bearing. Therefore, a minute flow rate can be transferred.

[0028] By adopting a structure in which the elastic tube is wrapped around the metal pipe multiple times and the bearing presses the wrapped portion of the elastic tube against the metal pipe, the elastic tube is not sandwiched between the bearing and the metal pipe. The elastic tube in the attached part always receives a uniform load at all points, so uniform and accurate pumping is possible.
Fluid transfer control becomes easier.

[0029] A structure is adopted in which the elastic tube is passed through the metal pipe from one opening to the other and then wound in a coil along the outer periphery of the metal pipe, so that the elastic tube and the metal pipe are integrated into one piece. By making it an object, when replacing the tube, it is only necessary to replace the entire integral structure, which saves time and effort. Furthermore, pumping can always be performed under the same conditions.

An ultrasonic actuator is used as a driving source for the fluid transfer pump of the present invention. Electrodes are provided on both end faces perpendicular to the polarization axis of the columnar piezoelectric ceramic. One electrode is provided on a part of the end surface, and the other electrode covers the entire end surface, and both electrodes have an asymmetric shape. A piezoelectric vibrator is made of such a piezoelectric ceramic and electrodes. When an AC signal with a frequency equal to the resonant frequency is applied to the piezoelectric vibrator through both electrodes, the piezoelectric vibrator is excited and a unidirectional vibration displacement along the polarization axis of the piezoelectric ceramic is generated on the side of the piezoelectric ceramic. occurs. This vibrational displacement is transmitted to the rotating body through the friction material, and the rotating body rotates around an axis concentric with the metal pipe. The friction material at this time not only prevents wear due to rotation between the piezoelectric ceramic and the rotating body, but also prevents electromagnetic noise caused by high voltage generated between the two due to rotation. Therefore, use in high magnetic fields is also possible. Since the rotating body is provided with a bearing shaft, as the rotating body rotates, the bearing also rotates around the axis of the metal pipe. At this time, the bearing rotates while pressing the elastic tube against the outer wall of the metal pipe, so as the bearing passes, the cross section of the elastic tube changes from a circle to an ellipse, and then returns to a circle again. The elastic tube self-suctions and transfers fluid from one opening of the elastic tube due to this restoring force. As described above, since the fluid transfer pump of the present invention has a simple structure from the piezoelectric vibrator to the bearing, the device can be designed to be smaller and lighter. Furthermore, since low-speed, high-torque rotational drive is possible, gears are not required, making the device even smaller and lighter. Additionally, it can be driven with low power consumption and produces no noise.

The fluid transfer pump of the present invention can be driven not only continuously but also in pulses. Since the response speed to input is fast and the holding force is large when no input is input, accurate control of minute flow rates by pulse drive is possible. Therefore, there is no backflow and the transfer speed can be easily and continuously changed.

By changing the frequency of the AC signal applied to the piezoelectric vibrator within a certain range, it is possible to freely change the magnitude and direction of the vibrational displacement generated on the side surface of the piezoelectric ceramic, thereby controlling the fluid transfer speed and transfer. Direction can be controlled quickly.

[0033] By using a rotary encoder together with the pulse drive, the minute flow rate can be controlled more accurately.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a fluid transfer pump of the present invention.

FIG. 2 is a side view of the fluid transfer pump of FIG. 1 when viewed from the front in the opposite direction.

FIG. 3 is a side view of the fluid transfer pump of FIG. 1 when viewed from above.

FIG. 4 is a perspective view of the piezoelectric vibrator 1.

FIG. 5 is a perspective view showing how the elastic tube 7 is attached to the metal pipe 6.

6 is a cross-sectional view schematically showing how an elastic tube 7 filled with fluid is wound around the outer wall of a metal pipe 6 in a coil shape as shown in FIG. 5. FIG.

7 is a cross-sectional view showing how the fluid-filled elastic tube 7 of FIG. 6 is pressed against the metal pipe 6 by the bearing 4. FIG.

FIG. 8 is a characteristic diagram showing the relationship between admittance and phase with respect to frequency of the piezoelectric vibrator 1.

FIG. 9 is a characteristic diagram showing the relationship between applied voltage and the number of rotations when the bearing 4 rotates around the metal pipe 6.

FIG. 10 is a configuration diagram for pulse driving when an rf pulse is applied.

FIG. 11 is a characteristic diagram showing the relationship between pulse width and rotation angle per pulse when pulse driving is performed with an applied voltage of 100 Vp-p and a frequency of approximately 138 kHz.

FIG. 12 shows the structure shown in FIG. 11, and the bearing 4 is a metal pipe 6.
FIG. 3 is a characteristic diagram showing the relationship between the pulse width determined from the amount of transfer per one rotation around the pulse and the amount of transfer per pulse.

FIG. 13 is a characteristic diagram showing the relationship between pulse repetition frequency and transfer amount per minute during pulse driving with an applied voltage of 100 Vp-p and a frequency of approximately 138 kHz.

[Explanation of symbols]

1 Piezoelectric vibrator 2 Rotating body 3 Friction material 4 Bearing 5 Bearing shaft 6 Metal pipe 7 Elastic tube 20 Piezoelectric ceramic 21, 22 Electrode 30 Tube wall

Claims (4)

[Claims] Claim 1: While pressing an elastic tube filled with fluid with a plurality of cylindrical bearings in a direction perpendicular to the axis, the bearings are moved substantially along the axis to transfer the fluid within the elastic tube. In the fluid transfer pump, the elastic tube is wound around a cylinder in a single layer in a coil shape, and the plurality of bearings are arranged at equal intervals around the outer circumference of the elastic tube with their rotational axes parallel to the axis of the cylinder. A fluid transfer pump featuring: 2. The fluid transfer device according to claim 1, wherein the elastic tube is wound around the cylinder a plurality of times, and each bearing presses a plurality of turns of the elastic tube against the cylinder. pump. 3. The cylinder is a cylindrical body with openings at both ends, and the elastic tube passes from one of the openings through the cylindrical body to the other opening, and extends from the other opening to extend around the outer periphery of the cylindrical body. 3. The fluid transfer pump according to claim 2, wherein the fluid transfer pump is wound around the fluid transfer pump. 4. A piezoelectric vibrator having electrodes on both end surfaces of a columnar piezoelectric ceramic, and a piezoelectric vibrator that contacts the piezoelectric vibrator and receives vibrational displacement generated in the piezoelectric vibrator, and rotates about an axis concentric with the cylinder. Claims 1 and 2, further comprising: a rotating body, wherein both end surfaces are perpendicular to a polarization axis of the piezoelectric ceramic, and an axis of the bearing is attached to the rotating body.
or the fluid transfer pump according to 3.