JP4923241B2 - Surface acoustic wave actuator, moving element, and stator - Google Patents

Description

  The present invention relates to a surface acoustic wave actuator such as a surface acoustic wave motor, a moving element used for the surface acoustic wave actuator, and a stator used for the surface acoustic wave actuator.

  In recent years, with the development of semiconductor manufacturing technology and industrial robots, development of high performance and high performance actuators is required. Ultrasonic motors have features such as large thrust that can be extracted, large holding force and holding torque, and no magnetic field generation, and are expected to be applied to industry. The surface acoustic wave motor is a kind of the ultrasonic motor, and is an actuator using a surface acoustic wave (SAW) which is one of ultrasonic vibrations.

  Such a surface acoustic wave motor as an actuator that directly drives an object is expected to be applied to a motor for driving an autofocus lens of a camera, a drive of a blind or a curtain, etc. Especially, a high speed, a high thrust, a high speed response are expected. It is expected as a compact actuator.

  Specifically, there has been proposed a motor in which a traveling wave is excited in a stator piezoelectric film of a surface acoustic wave motor and a slider on the stator piezoelectric film is used as a moving element (see Patent Document 1). In the surface acoustic wave motor, the vibration of the stator piezoelectric film is extracted as a thrust through a frictional force. On the friction drive surface where the stator piezoelectric film and the moving element face each other, it is necessary to devise such that the contact pressure becomes high in order to secure the friction force.

A “silicon slider” has been proposed as a method for realizing a stable contact while eliminating the influence of the unevenness on the contact surface serving as the friction drive surface (see Patent Document 1). For silicon sliders, by reactive ion etching (RIE), cylindrical protrusions (disk shape) with a diameter of about 10 μm and a height of about 1 μm are distributed on the entire surface of the silicon slider in a matrix form on the silicon wafer surface. is doing. The end faces (upper surfaces) of a plurality of cylinders arranged in two-dimensional islands in contact with the stator piezoelectric film are elastically deformed to realize surface contact on the friction drive surface. By arranging a large number of cylindrical protrusions on the entire bottom surface of the silicon slider, the entire contact area is secured.
Japanese Patent Laid-Open No. 9-233865 N. Osakabe and three others, "Surface acoustic wave linear motor using silicon slider", January 1998, IEEE International Workshop on Micro Electromechanical Systems (IEEE International Workshop on Micro Electro Mechanical Systems), Proceedings, p.390-395

  Since silicon is anisotropically etched by RIE, the upper surface (end surface) of the cylinder and the side surface of the cylinder are substantially perpendicular to each other in the silicon slider. On the friction drive surface of the surface acoustic wave motor, microscopic collisions are repeated in order to repeat contact and non-contact at the island-shaped protrusions constituting the silicon slider. For this reason, wear of the cylindrical protrusions occurs, and the life of the surface acoustic wave motor is limited.

  This problem of the friction drive surface is not a problem specific to only a surface acoustic wave motor, but is common to any surface acoustic wave actuator having a structure including a stator and a slider (moving element) that moves relative to the stator. It is a problem.

  In view of the above problems, the present invention provides a surface acoustic wave actuator that can ensure a friction coefficient between a moving element and a stator and has a long life and high reliability, a moving element used for the surface acoustic wave actuator, and the surface acoustic wave actuator. It aims at providing the stator to be used.

In order to achieve the above object, an aspect of the present invention is a slider that obtains kinetic energy of Rayleigh waves from the surface of a stator and moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh waves. , mover segment the moving element and the moving element substrate, made from an array of a plurality of the moving element segments of a material having a large Young's modulus than the moving element substrate, the upper surface of each of the plurality of the moving element segments are in contact with the stator The length of one side, the length of the diagonal line, or the diameter of the mover segment, which characterizes the size of each of the plurality of mover segments, is 1/40 to 1 of the wavelength of the Rayleigh wave It is a mover that is / 80 .
Another aspect of the present invention includes a stator, a moving element that obtains kinetic energy of Rayleigh waves from the surface of the stator, and moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh waves, and the moving element. A slider used for a surface acoustic wave actuator having a slider pressing plate that holds the stator while pressing the stator, wherein the slider is provided on the stator substrate and the stator side surface of the slider substrate. It consists of an array of multiple mover segments made of a material with a higher Young's modulus, and a mover segment array in which each upper surface of the multiple mover segments is in contact with the stator and a hemisphere, and moves on the equatorial plane of this hemisphere A free wheel head connected to the surface on the side opposite to the stator side surface of the sub board, the free wheel head against the slider pressure plate, While moving, characterized in that it is a mover that rotates freely.

Still another aspect of the present invention is a stator that propagates a Rayleigh wave to a surface, and moves a moving element relative to the direction opposite to the propagation direction of the Rayleigh wave by the kinetic energy of the Rayleigh wave. The stator comprises a stator piezoelectric film and an array of a plurality of stator segments made of a material having a Young's modulus larger than that of the stator piezoelectric film, and each stator segment array includes a stator segment array in contact with the moving element . Characterizing the size of each of the plurality of stator segments, the length of one side of the stator segment, the length of the diagonal line, or the diameter is 1/40 to 1/80 of the wavelength of the Rayleigh wave And

Still another aspect of the present invention provides a stator that propagates Rayleigh waves to the surface, and obtains kinetic energy of Rayleigh waves from the surface of the stator, and moves relative to the stator in the direction opposite to the Rayleigh wave propagation direction. A surface acoustic wave actuator including a movable body, the movable body comprising a movable body substrate and an array of a plurality of movable body segments made of a material having a higher Young's modulus than the movable body substrate. Any one of the length of one side, the length of a diagonal line, or the diameter of each of the plurality of slider segments, each of which includes a slider segment array in which the upper surface of each segment contacts the stator , and characterizes the size of each of the plurality of slider segments Is a surface acoustic wave actuator having a wavelength of 1/40 to 1/80 of the wavelength of the Rayleigh wave .
Still another aspect of the present invention provides a stator that propagates Rayleigh waves to the surface, and obtains kinetic energy of Rayleigh waves from the surface of the stator, and moves relative to the stator in the direction opposite to the Rayleigh wave propagation direction. And a slider pressurizing plate that holds the mover while pressing the mover against the stator.The mover is provided on the mover substrate and the stator side surface of the mover substrate, It consists of an array of a plurality of slider segments made of a material having a higher Young's modulus than the slider substrate. Each of the plurality of slider segments consists of a slider segment array whose upper surface is in contact with the stator, and a hemisphere. A freewheel head having a surface connected to a surface on the side opposite to the stator side surface of the movable substrate, and the freewheel head is a slider To the pressure plate, while sliding, characterized in that it is a surface acoustic wave actuator to rotate freely.

Still another aspect of the present invention provides a stator that propagates Rayleigh waves to the surface, and obtains kinetic energy of Rayleigh waves from the surface of the stator, and moves relative to the stator in the direction opposite to the Rayleigh wave propagation direction. The stator includes a stator piezoelectric film and an array of a plurality of stator segments made of a material having a Young's modulus larger than that of the stator piezoelectric film, and each of the plurality of stator segments. A stator segment array in which the top surface of the stator segment is in contact with the moving element, and the length of one side, the length of the diagonal line, or the diameter of each of the stator segments characterizing the size of each of the plurality of stator segments is It is a surface acoustic wave actuator having a wavelength of 1/40 to 1/80 .

Still another aspect of the present invention provides a stator that propagates Rayleigh waves to the surface, and obtains kinetic energy of Rayleigh waves from the surface of the stator, and moves relative to the stator in the direction opposite to the Rayleigh wave propagation direction. A movable body comprising a movable body substrate and an array of a plurality of movable body segments made of a material having a higher Young's modulus than the movable body substrate. and a moving element segment array, each of the upper surface of the child segment is in contact with the stator, the stator, and the stator piezoelectric film, made from an array of a plurality of stator segments of a material having a large Young's modulus than the stator piezoelectric film, the multiple a stator segment array, each of the upper surface in contact with the moving element of the stator segments, a plurality of the movable element segment Characterizing the respective size of the bets, the length of one side of the moving element segments, the diagonal length, or any diameter, in the surface acoustic wave actuator is 1 / 40-1 / 80 of the wavelength of the Rayleigh wave It is characterized by being.

  According to the present invention, a surface acoustic wave actuator that can secure a friction coefficient between a moving element and a stator and has a long life and high reliability, a moving element used for the surface acoustic wave actuator, and a stator used for the surface acoustic wave actuator are provided. Can be provided.

  Next, first to third embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  The first to third embodiments shown below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is The material, shape, structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

(First embodiment)
FIG. 1 shows a basic configuration diagram of a surface acoustic wave actuator according to a first embodiment of the present invention. A first drive electrode 13a and a second drive electrode 13b made of interdigital electrodes (comb electrodes) are arranged on the surface of the stator 11 so as to face each other. As shown in FIGS. 2 and 3, the stator 11 includes a stator piezoelectric film 111 made of a 128 ° Y-cut lithium niobate (LiNbO ₃ ) substrate, which is a piezoelectric material, and a stator substrate 112 on which the stator piezoelectric film 111 is mounted. With. The thickness of the LiNbO ₃ substrate may be selected to be, for example, about 1 mm if the driving frequency is 10 MHz, and the thickness of the LiNbO ₃ substrate is about 1/5 of the driving frequency of 50 MHz that is five times higher. can do. If the mechanical strength is not important, the stator substrate 112 may be omitted, and the stator 11 may be configured by only the stator piezoelectric film 111.

As shown in FIG. 1, the first drive electrode 13a is supplied with a high frequency from a high frequency oscillator 18 via a first output amplifier 15a, and the second drive electrode 13b is supplied with a second output amplifier 15b. Thus, the high frequency from the high frequency transmitter 18 is supplied. By applying a high frequency voltage to the first drive electrode 13a, a Rayleigh wave, which is a type of surface acoustic wave, can be excited from the first drive electrode 13a to the right, and can propagate through the surface of the stator piezoelectric film 111. By applying a high frequency voltage to the second drive electrode 13b, a Rayleigh wave can be excited from the second drive electrode 13b in the left direction and propagated on the surface of the stator piezoelectric film 111. The Rayleigh wave is a wave as a large swell in which the longitudinal wave and the transverse wave are combined on the surface of the stator piezoelectric film 111, and the surface of the stator piezoelectric film 111 is elliptically moving in the traveling wave of the Rayleigh wave. When a moving element (slider) 12 is pressed against the surface of the stator piezoelectric film 111 as shown in FIG. 1, the moving element (slider) 12 is affected by the friction between the moving element (slider) 12 and the stator 11. The elliptical motion is transmitted to the slider (slider) 12 and is driven in the direction opposite to the traveling direction of the Rayleigh wave. That is, the slider (slider) 12 is driven leftward when a high frequency voltage is applied to the first drive electrode 13a, and rightward when a high frequency voltage is applied to the second drive electrode 13b. Further, in order to obtain a sufficient frictional force between the moving element (slider) 12 and the stator 11, a preload is given to the moving element (slider) 12, whereby the thrust can be increased.
Although not shown in FIG. 1, in order to guide relative movement of the slider (slider) 12 relative to the stator 11, a stator 11 that slidably holds the stator 11 as shown in FIG. The slider 22, the slider press plate 23 that holds the slider (slider) 12 while pressing the stator 11, bolts 25 a and 25 b that connect the stator slide 22 and the slider press plate 23, and nuts 26 a and 26 b are provided. The linear guide provided is used. The stator 11 is held at both ends before and behind the paper surface of FIG. Then, the linear guide moves linearly with respect to the stator 11 together with the mover (slider) 12 in the direction perpendicular to the paper surface of FIG. However, the linear guide shown in FIG. 2 is an example, and any other structure can be adopted as long as the structure guides relative movement of the slider (slider) 12 with respect to the stator 11. There is no reason to limit to such a linear guide structure.

  A constant preload for obtaining a sufficient frictional force between the slider (slider) 12 and the stator 11 is realized by a slider pressure plate 23 having a leaf spring structure constituting a linear guide. For this reason, a strain gauge is attached to the slider pressurizing plate 23 so that the preload can be controlled. If the slider (slider) 12 does not contact the surface of the stator 11 in parallel, it will be difficult to drive. Therefore, as shown in FIG. 3, the moving element (slider) 12 includes a freewheel head 121 made of a rigid hemisphere obtained by cutting a steel ball in half, and a slider fixed to the freewheel head 121 by bonding or the like. The substrate 122 and a slider segment array including a plurality of slider segments (slider segments) 123 arranged in a matrix on the surface of the slider substrate 122 are configured. The free wheel head 121 is freely rotated while sliding with respect to the slider pressure plate 23, thereby providing a degree of freedom and eliminating the difficulty of preload adjustment.

  As shown in FIG. 1, a position sensor 14a for measuring the position of the movable element (slider) 12 is disposed in the vicinity of the first drive electrode 13a, and the movable element (slider) is also disposed in the vicinity of the second drive electrode 13b. A position sensor 14b for measuring the position of 12 is arranged to make it possible to measure the position and speed of the slider (slider) 12. The reversal position of the linear movement of the slider (slider) 12 is monitored by the position sensor 14 a and the position sensor 14 b, and output signals from the position sensor 14 a and the position sensor 14 b are input to the control circuit 16. An optical sensor such as a photo interrupter can be used as the position sensor 14a and the position sensor 14b. Instead of the position sensor 14a and the position sensor 14b, a linear encoder may be adopted, and the position and speed of the slider (slider) 12 may be detected and calculated by the linear encoder. The control circuit 16 controls the changeover switch 17 to switch the high-frequency supply from the high-frequency transmitter 18 to the first output amplifier 15a or the second output amplifier 15b. That is, when the position sensor 14a detects that the movable element (slider) 12 is approaching the turning point (end point) on the first drive electrode 13a side, the first output amplifier 15a to the second output amplifier 15b. The connection is switched, the second drive electrode 13b is driven, and the slider (slider) 12 is reversed and moved in the direction of the second drive electrode 13b. On the other hand, when the position sensor 14b detects that the slider (slider) 12 is approaching the turning point on the second drive electrode 13b side, the connection is switched from the second output amplifier 15b to the first output amplifier 15a. The first drive electrode 13a is driven to move the slider (slider) 12 in the reverse direction in the direction of the first drive electrode 13a. By repeating this operation, the slider (slider) 12 reciprocates between the first drive electrode 13a and the second drive electrode 13b.

A slider segment array comprising an array of slider segments (slider segments) 123 constituting the slider (slider) 12 is provided in a matrix on the surface of the slider substrate 122 as shown in FIG. It is an island-shaped protrusion of a hard material having a Young's modulus larger than 122. If aluminum (Al) having a Young's modulus of 68 GPa or magnesium (Mg) having a Young's modulus of 58 GPa is used as the slider substrate 122, the hard material is preferably a material having a Young's modulus of 100 GPa or more, and preferably a Young's modulus of 150 GPa. The material of the island-shaped projections constituting the slider segment (slider segment) 123 is preferably an abrasion-resistant material. As a representative example of the abrasion-resistant material having a Young's modulus of 150 GPa or more, diamond-like carbon ( DLC) is preferred. In DLC, Young's modulus can be 180 GPa or more. Other examples of wear resistant materials include nitrides such as titanium (Ti), silicon (Si), chromium (Cr), tungsten (W), tantalum (Ta), niobium (Nb), for example, TiN, TiAlN , Si ₃ N ₄ , CrN, SiAlON, TiAlBN, NbN, etc., or carbides thereof, such as TiC, SiC, Cr ₃ C ₂ , WC, W ₂ C, W ₃ C, TaC, NbC, etc., or these It may be a composite. Further, borides of Ti, zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), Ta, Cr, molybdenum (Mo), W, lanthanum (La), for example, TiB ₂ , ZrB _{2 , HfB 2, VB 2, NbB} 2, TaB 2, CrB 2, MoB, WB, LaB 6 , etc., or may be one in which these were complexed. Further, diamond, cubic boron nitride, Al ₂ O ₃ , or ZnO may be used. However, the Young's modulus and wear resistance of these materials depend on the film forming method and the like. For example, the Young's modulus of SiC is about 400 GPa in the bulk but 100 to 200 GPa in the thin film, so care must be taken. .

  In FIG. 4, the top view is a shape of a slider segment (slider segment) 123 that is almost square, but the top shape of the slider segment (slider segment) 123 is not limited to a square, but is a rectangle, triangle, 5 Other polygons, such as a square, a hexagon, and an octagon, may be sufficient, and a circle, an ellipse, an ellipse, etc. may be sufficient.

  FIG. 5 shows a cross-sectional structure of one of the plurality of slider segments (slider segments) 123 shown in FIG. 4, but the upper surface of the slider segment (slider segment) 123 has a radius of curvature R of about 10 μm to 1 mm. The curved surface is preferably a curved surface having a radius of curvature R of approximately 50 μm to 300 μm, more preferably a radius of curvature R of approximately 80 μm to 150 μm. Typically, for example, a value having a radius of curvature R of approximately 100 μm can be employed. Schematically, the curvature radius R formed by the upper surface of the slider segment (slider segment) 123 is about 4 to 8 times the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123. However, a hemispherical slider segment (slider segment) 123 that is half the diameter may be used.

  Moreover, it is preferable that the edge part of the upper surface of the slider segment (slider segment) 123 located in the circle | round | yen shown with the code | symbol A of FIG. 5 has a roundness of about R> = 1 micrometer.

  The upper surface of the slider segment (slider segment) 123 does not necessarily have to be a curved surface having a single curvature radius R, and is a curved surface comprising a combination of a plurality of curvature radii selected from the range of the curvature radius R = about 10 μm to 1 mm. It doesn't matter.

  In particular, the DLC film has a high hardness among amorphous carbon films, and has excellent tribological characteristics such as a low coefficient of friction and wear resistance. In the surface acoustic wave actuator according to the first embodiment, the DLC film shown in FIG. By making a set of a plurality of slider segments (slider segments) 123 arranged in a matrix as shown in FIG. 5, the tribological characteristics are further improved as compared with a normal DLC film as a single film. be able to.

As shown in FIG. 4, a plasma using methane (C ₂ H ₂ ) as a source gas is used to manufacture a slider segment array comprising a plurality of slider segments (slider segments) 123 arranged in a matrix. CVD may be used. For example, 13.56 MHz is used as an RF power supply frequency for plasma excitation, a substrate bias voltage is −10 kV _p , a methane flow rate is 14.1 × 10 ⁻³ L / min, a CVD pressure is 3 Pa, and a CVD time is 2 hours. Then, as shown in FIG. 4, a plurality of slider segments (slider segments) 123 having a thickness of about 200 nm to 2 μm, preferably about 0.8 μm to 1.5 μm, for example, about 1.2 μm are arranged in a matrix. Thus, a mover segment array can be manufactured. It is preferable to sputter-etch an aluminum (Al) substrate as the slider substrate 122 before the DLC is deposited. This is for removing impurities on the slider substrate 122 and removing an oxide film on the surface of the slider substrate 122. Argon (Ar) is used as the sputtering gas. For example, Ar flow rate of 1.69 × 10 ⁻² Pa · m ³ / sec (= 10 sccm), pressure of 11 Pa, and output of 50 W can be used for about 10 minutes. However, it need not be limited to this. When a metal substrate such as aluminum (Al) is used as the slider substrate 122, a silicon layer is thickened as an intermediate layer between the DLC film and the metal substrate by magnetron sputtering in order to increase the adhesion between the DLC film and the metal substrate. It is sufficient to deposit about 100 to 200 nm.

  A DLC having a segment structure arranged in a matrix as shown in FIG. 4 has a slider substrate 122 surface on a mesh electrode (cathode) 30 made of a tungsten wire wire mesh as shown in FIG. It may be mounted facing downward and disposed so as to face the anode inside the plasma CVD apparatus using the support portions 31a, 31b, and 31c (the vertical relationship between the actual slider substrate 122 and the mesh electrode (cathode) 30 is 6 may be reversed, in other words, a part of the surface of the slider substrate 122 may be masked with a wire mesh of tungsten wire). The mesh electrode (cathode) 30 has a mesh size of 20 μm × 20 μm, a tungsten wire diameter of φ20 μm, and the surface of the slider substrate 122 is masked in a grid pattern, thereby arranging the segments arranged in a matrix as shown in FIG. A structure can be realized. The mesh electrode (cathode) 30 uses the support portions 31a, 31b, and 31c, and is in an electrically floating state during CVD film formation.

As a result, as shown in FIG. 4, a plurality of slider segments (slider segments) 123 having an area per slider segment (slider segment) 123 of about 20 × 20 mm ² is arranged in a matrix at regular intervals. It becomes a distributed structure. When a 4 mm square slider substrate 122 is used, the total contact area of all the slider segments (slider segments) 123 is about 4.2 mm ² .

  A uniform contact state is required on the friction drive surface between the slider (slider) 12 of the surface acoustic wave actuator and the stator 11. “Uniform” means that the contact pressure between the slider (slider) 12 and the stator 11 is constant regardless of the location and is not easily affected by the unevenness of each other. The silicon slider described in the Background section has a structure in which a protrusion distribution is formed on the surface of a silicon wafer by dry etching and the upper surface of the protrusion is used as a friction drive surface. Although there is a report that the silicon slider has obtained uniform contact and has obtained excellent driving characteristics, there are problems such as the need to use a silicon wafer as the base material and the difficulty of rounding the ends of the protrusions. Contains. In the surface acoustic wave actuator according to the first embodiment, by performing plasma CVD using a mesh electrode (cathode) 30 made of a wire mesh of tungsten wire as shown in FIG. 6, movement as shown in FIG. The top surface of the child segment (slider segment) 123 is a curved surface with a radius of curvature R of about 10 μm to 1 mm, and the end of the top surface of the slider segment (slider segment) 123 is rounded with about R ≧ 1 μm. Therefore, it is possible to easily solve the processing problem of the silicon slider.

  As shown in FIG. 4, the use of a mover segment array consisting of an array of mover segments (slider segments) 123 improves wear resistance, and at the same time, ensures the same or better performance as a conventional silicon slider. it can.

  The silicon slider is made of silicon having a large Young's modulus of 130 GPa in the <100> direction, 170 GPa in the <110> direction, and 190 GPa in the <111> direction. Furthermore, the material of the friction drive surface facing the silicon slider is often a hard material having a large Young's modulus. When both the stator piezoelectric film and the slider (moving element) are hard materials, macroscopic parallelism can be obtained by using a freewheel head 121 made of a rigid hemisphere as shown in FIG. Even so, when a silicon slider is used, it is difficult to make it microscopically parallel, so that the contact area at the contact surface between the slider (slider) 12 and the stator 11 is reduced, and the performance is improved. It will decline.

  In the surface acoustic wave actuator according to the first embodiment, the slider (122) is formed on the slider substrate 122 and the surface of the slider (slider) 12 on the friction drive surface where the slider (slider) 12 and the surface of the stator 11 are in contact. A friction drive surface composed of a slider segment (slider segment) 123 is formed, and the stator 11 is a flat surface of a general material. As described above, the material constituting the slider segment (slider segment) 123 is a hard material having a Young's modulus larger than that of the slider substrate 122. As shown in FIG. 5, if the upper surface (surface used for friction drive) of the slider segment (slider segment) 123 is a curved surface or the end is rounded, as shown in FIG. (Slider segment) When the upper surface of 123 contacts the surface of the pair of stator piezoelectric films 111, the contact surface of the slider segment (slider segment) 123 changes its posture according to the unevenness of the surface of the pair of stator piezoelectric films 111. (In FIG. 7, the micro convex part of height (DELTA) is typically shown.). If a slider substrate 122 that supports the slider segment (slider segment) 123 is selected from a soft material having a smaller Young's modulus than the slider segment (slider segment) 123, as shown in FIG. Further, the slider substrate 122 is elastically deformed, and the posture of the slider segment (slider segment) 123 is passively microscopically parallel to the facing surface, so that microscopically uniform contact can be realized.

In the case of the stator piezoelectric film 111 made of a 128 ° Y-cut LiNbO ₃ substrate, when the surface acoustic wave frequency is 200 MHz, the surface acoustic wave wavelength is about 20 μm. When the surface acoustic wave has a high frequency of 50 MHz or more, the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123 is the same as the wavelength of the surface acoustic wave as shown in FIG. It can be set to about or several times that. If the pitch at which the plurality of slider segments (slider segments) 123 are arranged in a matrix is too long with respect to the surface acoustic wave wavelength, it is not preferable because the number of parts that do not come into contact increases. Therefore, when a plurality of slider segments (slider segments) 123 are arranged in a matrix, the distance between adjacent slider segments (slider segments) 123 is approximately equal to the wavelength of the surface acoustic wave or the surface acoustic wave. It is preferable to set it to be shorter than the wavelength.

On the other hand, in the case of the stator piezoelectric film 111 made of a 128 ° Y-cut LiNbO ₃ substrate, when the surface acoustic wave frequency is 10 MHz, the surface acoustic wave wavelength is about 400 μm. It is theoretically possible to set the length of one side of the segment) 123, the length of the diagonal line, or the diameter to the same level as the wavelength of the surface acoustic wave or several times as shown in FIG. Yes, but not very efficient. When the surface acoustic wave frequency is about 10 MHz to 50 MHz, the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123 is compared with the wavelength of the surface acoustic wave as shown in FIG. Is preferably set sufficiently small. “Set sufficiently small” means at least 1/5 or less, preferably 1/10 or less, more preferably 1/20 or less of the wavelength of the surface acoustic wave. More specifically, the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123 may be set to about 1/40 to 1/80 of the surface acoustic wave wavelength.

  The pitch and density when a plurality of slider segments (slider segments) 123 are arranged in a matrix are set in consideration of the surface acoustic wave wavelength and the total contact area of the slider segments (slider segments) 123. In general, a pitch equivalent to the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123 is preferable.

  However, it is too difficult to reduce the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123 and the pitch of the placement of the slider segment (slider segment) 123. Is accompanied. Even when the surface acoustic wave has a high frequency of 50 MHz or more, the length of one side, the length of the diagonal line or the diameter of the slider segment (slider segment) 123, and the pitch of arrangement of the slider segment (slider segment) 123 are set. Although it is preferable to set it sufficiently small compared to the surface acoustic wave wavelength, the higher the surface acoustic wave frequency, the more fine processing is required. It will be decided.

As shown in FIG. 4, a slider (slider segment) 123 of about 20 × 20 mm ² is placed on a slider (slider) 12 having a 4 mm square slider substrate 122, and a slider 12 having a thickness of 1 mm and 128 ° Y-cut LiNbO is used. ₃ is opposed to the stator piezoelectric film 111 made of the substrate, in the surface acoustic wave linear motor 10 MHz, the input current _{1.2A 0-p, 1.4A 0-} p, 1.7A 0-p, 1.9A 0 FIG. 10 shows the transient response characteristics of the slider speed when _-p is changed to 2.3A _0-p . The preload to the slider (slider) 12 is 20N. FIG. 10 confirms efficient driving of the slider (slider) 12. It can be seen that the maximum slider speed that can be reached increases as the input current is increased from 1.2 A _{0 -p to} 2.3 A _{0 -p} . In the case of FIG. 10, since the stroke of the stator piezoelectric film 111 is as short as 22 mm, the steady speed is not reached, but the maximum speed that can be reached is considered to be further increased.

  FIG. 11 shows the relationship between the input current and the slider thrust when the preload is changed to 11n, 20N, and 29N in the 10MH surface acoustic wave linear motor having the same structure as FIG. The slider thrust was derived from the equivalent mass of the slider (slider) 12 and the rising acceleration. When the input current is increased, the slider thrust obtained is increased. In the measurement range, as the preload was increased, the slider thrust obtained was increased, and the maximum slider thrust 4N was obtained.

  From the results shown in FIGS. 10 and 11, the structure of the slider segment array in which a large number of slider segments (slider segments) 123 are arranged in a matrix is effective as the structure of the friction drive surface of the slider (slider) 12. I understand that.

(Second Embodiment)
As shown in FIG. 13, the basic configuration diagram of the surface acoustic wave actuator according to the second embodiment of the present invention is the same configuration as that in FIG. 1, and interdigital electrodes (comb type) are formed on the surface of the stator piezoelectric film 111. The first drive electrode 13a and the second drive electrode 13b made of electrodes) are arranged to face each other. As described in the surface acoustic wave actuator according to the first embodiment, the stator piezoelectric film 111 is made of a LiNbO ₃ substrate or the like, and the first drive electrode 13a and the second drive electrode are formed on the surface of the stator piezoelectric film 111. The interdigital electrode (comb-shaped electrode) 13b requires a fine processing technique, and its manufacturing cost is higher than that of the disposable slider 12d. For this reason, operation cost will become high if the stator 11 is replaced | exchanged frequently.

  Therefore, in the surface acoustic wave actuator according to the second embodiment, as shown in FIG. 12, a stator comprising an array of a plurality of stator segments 113 arranged in a matrix on the surface of the friction drive surface of the stator piezoelectric film 111. A segment array is formed. A stator segment 113 made of a material having a Young's modulus larger (harder) than that of the stator piezoelectric film 111 is provided on the surface of the stator piezoelectric film 111. Furthermore, by using a wear resistant material for the structure of the stator segment 113, the wear resistance of the stator 11 is improved while ensuring the friction drive performance between the stator piezoelectric film 111 and the disposable slider 12d. Thereby, maintenance of the stator 11 can be made unnecessary for a long time.

  On the other hand, the disposable slider 12d of the surface acoustic wave actuator according to the second embodiment is not shown in the figure, but as in FIG. 3, a free wheel made of a highly rigid hemisphere with a steel ball cut in half. A head 121 and a slider substrate 122 fixed to the free wheel head 121 by adhesion or the like. However, unlike the surface acoustic wave actuator according to the first embodiment, the surface of the slider substrate 122 does not have a plurality of slider segments (slider segments) 123 provided in a matrix, and the stator piezoelectric film 111 A slider substrate 122 made of a material softer than the material constituting the stator segment 113 is exposed on the surface of the disposable slider 12d paired with the friction drive surface. For example, if the slider substrate 122 of the disposable slider 12d is made of a soft material such as a metal plate such as Al or Mg and the stator segment 113 is made of a DLC film, the slider substrate 122 is more easily worn than the DLC film. For this reason, the slider substrate 122 alone is made disposable. In this way, when the driving performance is deteriorated due to wear of the surface of the slider substrate 122, only the slider substrate 122 of the disposable slider 12d needs to be replaced. When the slider substrate 122 of the disposable slider 12d is replaced, the surface acoustic wave actuator returns to a new one, and therefore the life of the surface acoustic wave actuator can be extended by simple maintenance.

  Similar to the slider segment (slider segment) 123, the upper surface shape of the stator segment 113 is not limited to a square, and may be a rectangle, a triangle, a pentagon, a hexagon, an octagon, or another polygon, It may be oval or elliptical. The cross-sectional shape of the stator segment 113 is the same as that of the slider segment (slider segment) 123 shown in FIG. 5, and the upper surface of the stator segment 113 has a radius of curvature R of about 10 μm to 1 mm, preferably a radius of curvature R. = 50 μm to 300 μm, more preferably a curved surface with a radius of curvature R = 80 μm to 150 μm. Typically, for example, a value with a radius of curvature R = 100 μm can be adopted. Schematically, the curvature radius R formed by the upper surface of the stator segment 113 may be set to about 4 to 8 times the length of one side, the length of the diagonal line, or the diameter of the stator segment 113. The hemispherical stator segment 113 may be used.

  Further, it is preferable that the end portion of the upper surface of the stator segment 113 located within the circle indicated by the symbol A in FIG. 5 has a roundness of about R ≧ 1 μm.

  The upper surface of the stator segment 113 does not necessarily have to be a curved surface having a single radius of curvature R, and may be a curved surface having a combination of a plurality of curvature radii selected from the range of the curvature radius R = about 10 μm to 1 mm.

  A DLC having a segment structure arranged in a matrix as shown in FIG. 12 is similar to that described in the surface acoustic wave actuator according to the first embodiment. If a mesh electrode (cathode) 30 made of a wire mesh is used, it can be easily manufactured. That is, if the stator piezoelectric film 111 is mounted on the mesh electrode (cathode) 30 with the surface thereof facing downward, and is disposed so as to face the anode inside the plasma CVD apparatus using the support portions 31a, 31b, and 31c. good. The mesh size of the mesh electrode (cathode) 30 is set to 20 μm × 20 μm, the tungsten wire diameter is set to φ20 μm, and the surface of the stator piezoelectric film 111 is masked in a lattice shape, thereby being arranged in a matrix as shown in FIG. A segment structure can be realized.

  On the friction drive surface, the disposable slider 12d and the surface of the stator 11 are in contact with each other. The stator 11 constitutes a friction drive surface composed of a stator piezoelectric film 111 and a stator segment 113 formed on the surface thereof, and the slider substrate 122 is a plane of a general material. The material constituting the stator segment 113 is a material having a Young's modulus greater (harder) than the stator piezoelectric film 111. As shown in FIG. 7 (although it should be interpreted upside down in FIG. 7), when the upper surface of the stator segment 113 contacts the surface of the pair of slider substrates 122, the pair of slider substrates 122 The contact surface of the stator segment 113 must change its posture according to the surface irregularities. Since the stator piezoelectric film 111 that supports the stator segment 113 is softer than the stator segment 113, the stator piezoelectric film 111 is microscopically elastically deformed as shown in FIG. It is possible to achieve a microscopically uniform contact.

  As shown in FIG. 12, it is preferable to set the length of one side, the length of the diagonal line, or the diameter of the stator segment 113 to be sufficiently smaller than the wavelength of the surface acoustic wave. “Set sufficiently small” means at least 1/5 or less, preferably 1/10 or less, more preferably 1/20 or less of the wavelength of the surface acoustic wave. Although depending on the frequency, at 10 MHz, the length of one side, the length of the diagonal line, or the diameter of the stator segment 113 may be about 1/40 to 1/80 of the wavelength of the surface acoustic wave. In addition, the pitch and density in the case where a plurality of stator segments 113 are arranged in a matrix are set in consideration of the surface acoustic wave wavelength and the total contact area of the stator segments 113. A pitch equivalent to the length of one side, the length of the diagonal line, or the diameter is preferable.

  The other structure is basically the same as that of the surface acoustic wave actuator according to the first embodiment shown in FIGS.

(Third embodiment)
In the surface acoustic wave actuator according to the third embodiment, as shown in FIG. 14, a stator segment array comprising an array of a plurality of stator segments 113 arranged in a matrix on the surface of the friction drive surface of the stator piezoelectric film 111. Is forming. On the surface of the stator piezoelectric film 111, a stator segment array including an array of stator segments 113 made of a material having a higher Young's modulus (hard) than the stator piezoelectric film 111 is provided.

  On the other hand, the movable body (slider) 12 of the surface acoustic wave actuator according to the third embodiment is not shown, but, as in FIG. 3, a steel ball is cut in half, and a rigid hemisphere is cut. The free wheel head 121, the slider substrate 122 fixed to the free wheel head 121 by adhesion or the like, and the slider substrate 122 provided with a matrix on the surface thereof has a Young's modulus larger (hard) ) It is composed of a mover segment array composed of an array of a plurality of mover segments (slider segments) 123 of material.

  Further, both the stator segment 113 and the mover segment (slider segment) 123 are made of wear-resistant material. For this reason, while ensuring the friction drive performance between the stator 11 and the slider (slider) 12, the wear resistance of both the stator 11 and the slider (slider) 12 can be improved, and maintenance can be eliminated over a long period of time.

  As described in the surface acoustic wave actuator according to the first embodiment, the upper surface shape of the slider segment (slider segment) 123 is not limited to a square, but is a rectangle, a triangle, a pentagon, a hexagon, an octagon, or the like. Other polygons may be used, and a circular shape, an oval shape, an elliptical shape, or the like may be used. Further, as shown in FIG. 5, the upper surface of the slider segment (slider segment) 123 has a curvature radius R of about 10 μm to 1 mm, preferably a curvature radius R of about 50 μm to 300 μm, and more preferably a curvature radius R of 80 μm to The curved surface is about 150 μm, and typically, for example, a value with a radius of curvature R of about 100 μm can be adopted. Schematically, the curvature radius R formed by the upper surface of the slider segment (slider segment) 123 is about 4 to 8 times the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123. However, a hemispherical slider segment (slider segment) 123 that is half the diameter may be used. Moreover, it is preferable that the edge part of the upper surface of the slider segment (slider segment) 123 located in the circle | round | yen shown with the code | symbol A of FIG. 5 has a roundness of about R> = 1 micrometer. The upper surface of the slider segment (slider segment) 123 does not necessarily have to be a curved surface having a single curvature radius R, and is a curved surface comprising a combination of a plurality of curvature radii selected from the range of the curvature radius R = about 10 μm to 1 mm. It doesn't matter.

  Similar to the slider segment (slider segment) 123, the upper surface shape of the stator segment 113 is not limited to a square, and may be a rectangle, a triangle, a pentagon, a hexagon, an octagon, or another polygon, It may be oval or elliptical. The cross-sectional shape of the stator segment 113 is the same as that of the slider segment (slider segment) 123 shown in FIG. 5, and the upper surface of the stator segment 113 has a radius of curvature R of about 10 μm to 1 mm, preferably a radius of curvature R. = 50 μm to 300 μm, more preferably a curved surface with a radius of curvature R = 80 μm to 150 μm. Typically, for example, a value with a radius of curvature R = 100 μm can be adopted. Schematically, the curvature radius R formed by the upper surface of the stator segment 113 may be set to about 4 to 8 times the length of one side, the length of the diagonal line, or the diameter of the stator segment 113. The hemispherical stator segment 113 may be used. Further, it is preferable that the end portion of the upper surface of the stator segment 113 located within the circle indicated by the symbol A in FIG. 5 has a roundness of about R ≧ 1 μm. The upper surface of the stator segment 113 does not necessarily have to be a curved surface having a single radius of curvature R, and may be a curved surface having a combination of a plurality of curvature radii selected from the range of the curvature radius R = about 10 μm to 1 mm.

  The mover segment (slider segment) 123 and the stator segment 113 shown in FIG. 14 are preferably realized by DLC. In this case, as described in the surface acoustic wave actuator according to the first embodiment, the CVD process is performed. If a mesh electrode (cathode) 30 made of a tungsten wire wire mesh as shown in FIG.

  In the friction drive surface of the surface acoustic wave actuator according to the third embodiment, the slider (122) is provided with a friction drive surface including a slider substrate 122 and a slider segment (slider segment) 123 formed on the surface thereof. The stator 11 has a friction drive surface including a stator piezoelectric film 111 and a stator segment 113 formed on the surface of the stator 11, and is in contact with each other. The material constituting the slider segment (slider segment) 123 is a material having a Young's modulus greater (harder) than the slider substrate 122, and the material constituting the stator segment 113 has a Young's modulus greater (harder) than the stator piezoelectric film 111. Material. When the upper surface of the stator segment 113 comes into contact with the lower surface of the pair of slider segments (slider segments) 123, the stator segments 113 of the pair of slider segments 122 or slider segments (slider segments) 123 are formed according to the unevenness of the surfaces of the slider segments 122 or slider segments (slider segments) 123. The contact surface must change posture. Since the stator piezoelectric film 111 that supports the stator segment 113 is softer than the stator segment 113, the stator piezoelectric film 111 is microscopically elastically deformed, and the attitude of the stator segment 113 is microscopically parallel to the facing surface. become. At the same time, since the slider substrate 122 supporting the slider segment (slider segment) 123 is softer than the slider segment (slider segment) 123, the slider substrate 122 is microscopically elastically deformed, and the slider segment (passive) The attitude of the slider segment 123 is microscopically parallel to the facing surface, and microscopically uniform contact can be realized.

  As shown in FIG. 14, it is preferable to set the length of one side, the length of the diagonal line, or the diameter of the stator segment 113 to be sufficiently smaller than the wavelength of the surface acoustic wave. “Set sufficiently small” means at least 1/5 or less, preferably 1/10 or less, more preferably 1/20 or less of the wavelength of the surface acoustic wave. Although depending on the frequency, at 10 MHz, the length of one side, the length of the diagonal line, or the diameter of the stator segment 113 may be about 1/40 to 1/80 of the wavelength of the surface acoustic wave. The pitch and density when the stator segment 113 is disposed are set in consideration of the surface acoustic wave wavelength and the total contact area of the stator segment 113. In general, the length of one side of the stator segment 113 is set. A pitch approximately equal to the length of the diagonal or the diameter is preferable.

  On the other hand, the length of one side, the length of the diagonal line, or the diameter of the slider segment (slider segment) 123 can be set to the same level as the wavelength of the surface acoustic wave or several times as shown in FIG. is there. If the pitch for arranging the plurality of slider segments (slider segments) 123 is too long with respect to the wavelength of the surface acoustic wave, it is not preferable because the number of non-contact portions increases. Therefore, it is preferable to set the distance between adjacent slider segments (slider segments) 123 to be approximately the same as the wavelength of the surface acoustic wave or shorter than the wavelength of the surface acoustic wave.

  The other structure is basically the same as that of the surface acoustic wave actuator according to the first embodiment shown in FIGS.

(Other embodiments)
As described above, the present invention has been described according to the first to third embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, FIG. 1 shows a circuit configuration in which the control circuit 16 controls the changeover switch 17 to switch the high frequency supply from the high frequency oscillator 18 to the first output amplifier 15a or the second output amplifier 15b. The circuit configuration of 1 is an example and is not limited to this. For example, a common output amplifier is connected between the changeover switch 17 and the high-frequency oscillator 18, and the output of the common output amplifier is sent to the first drive electrode 13 a or the second drive electrode 13 b using the changeover switch 17. A circuit configuration for switching may be used. Even in such a circuit configuration, similarly, when the position sensor 14a detects that the movable element (slider) 12 is approaching the folding point (end point) on the first drive electrode 13a side, the second drive electrode 13b is driven to move the slider (slider) 12 in the direction of the second drive electrode 13b, and the position sensor 14b approaches the folding point on the side of the second drive electrode 13b. When this is detected, the first drive electrode 13a can be driven to move the slider (slider) 12 in the reverse direction in the direction of the first drive electrode 13a.

  In the description of the first to third embodiments already described, the surface acoustic wave linear motor including the stator 11 and the moving element (slider) 12 has been described. However, a rotor that rotates with respect to the stator 11 is used. The present invention can be applied to a surface acoustic wave rotary motor provided, and can also be applied to various actuators such as a surface acoustic wave pump.

  Furthermore, in the description of the first to third embodiments already described, the first drive electrode 13a and the second drive electrode 13b made of interdigital electrodes (comb electrodes) are opposed to each other on the surface of the stator piezoelectric film 111. The structure arranged as described above. However, although the power feeding method is devised, a structure in which a drive electrode is provided on the movable element (slider) 12 side and the movable element (slider) 12 is allowed to self-run may be used.

  Alternatively, in the description of the first to third embodiments already described, the position of the slider (slider) 12 is fixed at an absolute coordinate, and the stator 11 side is relatively relative to the slider (slider) 12. It may be a mode of moving. In short, it is sufficient that the slider (slider) 12 and the slider (slider) 12 move relatively, and it is not important which is fixed. Therefore, various surface acoustic wave actuators of the present invention are used. Technical ideas are applicable.

  Further, the surface acoustic wave may be excited using a Gunn diode or the like in addition to the interdigital electrode (comb electrode).

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

It is a block diagram explaining the schematic structure of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention. It is sectional drawing explaining schematic structure including the linear guide of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention. It is sectional drawing explaining the structure of the slider (slider) of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention in detail. It is a top view (photograph) explaining the structure of the slider segment array of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention in detail. It is sectional drawing which illustrates typically the structure of the slider segment (slider segment) 12 which comprises the slider segment array of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention. It is a bird's-eye view which illustrates typically the mesh electrode (cathode) used for plasma CVD which makes a part of manufacturing method of the mover segment array concerning a 1st embodiment of the present invention. It is typical sectional drawing explaining the microscopic elastic deformation of a slider board | substrate in the slider (slider) of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention. It is typical sectional drawing explaining the relationship between the dimension of the slider segment array of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention, and the wavelength of a surface acoustic wave (the 1). It is typical sectional drawing explaining the relationship between the dimension of the slider segment array of the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention, and the wavelength of a surface acoustic wave (the 2). In the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention, it is a figure which shows the transient response characteristic of a slider speed when changing input current. In the surface acoustic wave actuator which concerns on the 1st Embodiment of this invention, it is a figure which shows the relationship between an input electric current when a preload is changed, and a slider thrust. It is typical sectional drawing explaining the relationship between the dimension of the stator segment array of the surface acoustic wave actuator which concerns on the 2nd Embodiment of this invention, and the wavelength of a surface acoustic wave. It is a block diagram explaining the schematic structure of the surface acoustic wave actuator which concerns on the 2nd Embodiment of this invention. It is typical sectional drawing explaining the relationship between the dimension of the slider segment array and stator segment array of a surface acoustic wave actuator which concerns on the 3rd Embodiment of this invention, and the wavelength of a surface acoustic wave.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Stator 12d ... Disposable slider 13a ... 1st drive electrode 13b ... 2nd drive electrode 14a ... Position sensor 14b ... Position sensor 15a ... 1st output amplifier 15b ... 2nd output amplifier 16 ... Control circuit 17 ... Changeover switch 18 ... High frequency Transmitter 22 ... Stator slide 23 ... Slider pressure plate 25a, 25b ... Bolt 26a, 26b ... Nut 30 ... Mesh electrode (cathode)
31a, 31b, 31c ... support part 111 ... stator piezoelectric film 112 ... stator substrate 113 ... stator segment 121 ... freewheel head 122 ... slider substrate 123 ... slider segment (slider segment)

Claims (23)

A moving element that obtains kinetic energy of Rayleigh waves from the surface of the stator and moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh waves, the moving element including a moving element substrate,
Made from an array of a plurality of the moving element segments of a material having a large Young's modulus than the moving element substrate, and a moving element segment array, each of the upper surface of the movable element segment the plurality of contact with the stator, the movement of the plurality Characterizing the size of each child segment, the length of one side, the length of the diagonal line, or the diameter of the moving segment is either 1/40 to 1/80 of the wavelength of the Rayleigh wave. Feature mover.   A stator, a moving element that obtains Rayleigh wave kinetic energy from the surface of the stator, moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh wave, and pressurizes the moving element to the stator. The slider is used in a surface acoustic wave actuator including a slider pressure plate that is held while the slider is
  A mover substrate;
  The mover substrate is provided on a surface on the stator side and includes an array of a plurality of mover segments made of a material having a Young's modulus larger than that of the mover substrate, and each upper surface of the plurality of mover segments has the stator A mover segment array in contact with
  A freewheel head comprising a hemisphere and having an equatorial plane of the hemisphere connected to a surface of the moving substrate opposite to the stator side surface
  And the freewheel head rotates freely while sliding with respect to the slider pressure plate. The mover according to claim 1 or 2 , wherein each of the plurality of mover segments uses a wear-resistant material. The mover according to claim 3 , wherein the wear-resistant material is a diamond-like carbon film. Mover according to any one of claims 1 to 4, characterized in that each of the upper surfaces of the plurality of the moving element segment is curved. Mover according to any one of claims 1 to 5, characterized in that the ends of each of the upper surfaces of the plurality of the moving element segments are rounded. A stator that propagates a Rayleigh wave to the surface and moves the moving element in a direction opposite to the propagation direction of the Rayleigh wave by the kinetic energy of the Rayleigh wave, the stator including a stator piezoelectric film;
A plurality of stator segments made of a material having a Young's modulus larger than that of the stator piezoelectric film, and each stator segment array is in contact with the moving element . Any one of the length of one side of the stator segment, the length of the diagonal line, or the diameter characterizing each size is 1/40 to 1/80 of the wavelength of the Rayleigh wave. . The stator according to claim 7 , wherein each of the plurality of stator segments uses a wear-resistant material.   The stator according to claim 8, wherein the wear-resistant material is a diamond-like carbon film. The stator according to any one of claims 7 to 9 , wherein an upper surface of each of the plurality of stator segments is a curved surface. The stator according to any one of claims 7 to 10 , wherein an end portion of an upper surface of each of the plurality of stator segments is rounded. A stator that propagates Rayleigh waves to the surface, and a mover that obtains kinetic energy of the Rayleigh waves from the surface of the stator and moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh waves. A surface acoustic wave actuator, wherein the movable element includes a movable element substrate,
Made from an array of a plurality of the moving element segments of a material having a large Young's modulus than the moving element substrate, and a moving element segment array, each of the upper surface of the movable element segment the plurality of contact with the stator, the movement of the plurality Characterizing the size of each child segment, the length of one side, the length of the diagonal line, or the diameter of the moving segment is either 1/40 to 1/80 of the wavelength of the Rayleigh wave. Characteristic surface acoustic wave actuator.   A stator that propagates a Rayleigh wave to the surface, a moving element that obtains kinetic energy of the Rayleigh wave from the surface of the stator, and moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh wave; A surface acoustic wave actuator comprising a slider pressing plate that holds the moving member while pressing the moving member against the stator.
  A mover substrate;
  The mover substrate is provided on a surface on the stator side and includes an array of a plurality of mover segments made of a material having a Young's modulus larger than that of the mover substrate, and each upper surface of the plurality of mover segments has the stator A mover segment array in contact with
  A freewheel head comprising a hemisphere and having an equatorial plane of the hemisphere connected to a surface of the moving substrate opposite to the stator side surface
  A surface acoustic wave actuator, wherein the free wheel head freely rotates while sliding with respect to the slider pressure plate. A stator that propagates Rayleigh waves to the surface, and a mover that obtains kinetic energy of the Rayleigh waves from the surface of the stator and moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh waves. A surface acoustic wave actuator, wherein the stator comprises a stator piezoelectric film,
A plurality of stator segments made of a material having a Young's modulus larger than that of the stator piezoelectric film, and each stator segment array is in contact with the moving element . Any one of the length of one side of the stator segment, the length of the diagonal line, or the diameter characterizing each size is 1/40 to 1/80 of the wavelength of the Rayleigh wave. Surface wave actuator. A stator that propagates Rayleigh waves to the surface, and a mover that obtains kinetic energy of the Rayleigh waves from the surface of the stator and moves relative to the stator in a direction opposite to the propagation direction of the Rayleigh waves. A surface acoustic wave actuator,
Mover which the moving element comprises a moving element substrate, a plurality of the movable element segments of sequence consisting of a material having a large Young's modulus than the mover substrate, each of the upper surface of the movable element segment the plurality of contact with the stator A segment array,
The stator is composed of a stator piezoelectric film and an array of a plurality of stator segments made of a material having a Young's modulus larger than that of the stator piezoelectric film, and a stator segment array in which each upper surface of the plurality of stator segments is in contact with the moving element. Wherein the length of one side, the length of the diagonal line, or the diameter of the slider segment is characterized by a size of each of the plurality of slider segments. A surface acoustic wave actuator characterized by being 1/80 . 16. The surface acoustic wave actuator according to claim 12, wherein each of the plurality of mover segments uses a wear-resistant material. 17. The surface acoustic wave actuator according to claim 12 , wherein an upper surface of each of the plurality of mover segments is a curved surface. The surface acoustic wave actuator according to any one of claims 12 , 13 , and 15 to 17 , wherein an end portion of an upper surface of each of the plurality of moving segment segments is rounded. The surface acoustic wave actuator according to claim 14, wherein each of the plurality of stator segments uses a wear-resistant material. The surface acoustic wave actuator according to claim 19 , wherein at least a part of the movable member is disposable. 21. The surface acoustic wave actuator according to claim 14 , wherein an upper surface of each of the plurality of stator segments is a curved surface. The surface acoustic wave actuator according to any one of claims 14 , 15 , and 19 to 21 , wherein end portions of upper surfaces of the plurality of stator segments are rounded. The surface acoustic wave actuator according to any one of claims 13 to 22 , wherein the wear-resistant material is a diamond-like carbon film.