JP5029948B2 - Ultrasonic motor - Google Patents

Description

  The present invention relates to an ultrasonic motor.

  Conventionally, an ultrasonic motor using vibration of a piezoelectric element has been used. This ultrasonic vibrator is not affected by magnetism, is small in size, has a high torque, has a high response speed, and is stopped in a non-energized state. It has characteristics. Therefore, the ultrasonic transducer is a promising element particularly for an autofocus drive mechanism of a mobile phone.

  A structure in which an ultrasonic transducer is in contact with the inner peripheral surface of a cylindrical rotor, that is, an ultrasonic motor having an inscribed structure, does not require a dedicated support mechanism for the rotor, and the diameter of the cylindrical rotor is the same. For example, the number of parts can be reduced as compared with an ultrasonic motor having a structure in which the ultrasonic vibrator is in contact with the outer peripheral surface of the cylindrical rotor, that is, an external structure. Therefore, it is possible to reduce the volume of the ultrasonic motor.

FIG. 28 shows an example of an ultrasonic motor 900 disclosed in Japanese Patent Laid-Open No. 1-81671, which has an inscribed structure that does not have a support mechanism dedicated to the rotor. The ultrasonic motor 900 has a stator 901 designed such that each of the primary longitudinal vibration and the secondary bending vibration is generated at the same frequency. Two AC signals having a phase difference of 90 ° are applied to the stator 901. As a result, the stator 901 elliptically vibrates and elliptical motion is transmitted from the stator 901 to the rotor 902. As a result, the rotor 902 rotates. Further, the rotor 902 is tightened by using bolts 903 so that the inner periphery of the rotor 902 becomes small. Thereby, a static compressive stress is applied from the rotor 902 to the stator 901.
JP-A-1-81671

  In the ultrasonic motor 900 disclosed in Japanese Patent Laid-Open No. 1-81671, it is necessary to reduce the wear of the rotor 902 or the stator 901 due to the rotation of the rotor 902, and adverse effects due to their manufacturing errors. It is necessary to compensate. Therefore, it is necessary to adjust the compressive stress (preload) applied from the rotor 902 to the stator 901. In this adjustment, it is necessary to adjust the tightening force of the bolt 903.

  However, this adjustment changes the diameter of the rotor 902. Therefore, when it is necessary to keep the diameter of the rotor 902 constant, there arises a problem that the tightening force of the bolt 903 cannot be adjusted. Further, according to the adjustment of the tightening force of the bolt 903, the force generated between the rotor 902 and the stator 901 can be changed only in the elastic deformation region of the material constituting the rotor 902. For example, when a brittle material such as ceramic is used as the rotor material, it is very difficult to adjust the force generated between each other by applying a large force from the rotor 902 to the stator 901.

  Further, in the ultrasonic motor 900 described above, the rotor 902 is not a complete cylinder, and the rotor 902 has a seam at a portion for adjusting the compressive stress. Therefore, since the rotor 902 and the stator 901 are not in contact with each other at the joint position, a driving force cannot be obtained. Therefore, it is difficult to obtain uniform rotation characteristics (rotation speed, torque) over the entire circumference of the rotor 902.

  Further, in the above-described ultrasonic motor 900, in order to simultaneously generate the primary longitudinal vibration and the secondary bending vibration, as shown in FIG. 28, the short side (W) of the stator 901 with respect to the long side (D). Since the ratio (W / D) needs to be 0.26, the size of the stator 901 in the rotation plane of the rotor 902 (xy plane) is determined by the diameter of the rotor 902. For this reason, the occupation area of the stator 901 is determined by the inner diameter of the rotor 902 at the height where the stator 901 exists.

  Furthermore, according to the ultrasonic motor 900 described above, as shown in FIG. 29, a straight line connecting two points that support the rotor 902 crosses the center O of the rotor 902. According to this configuration, when a force in the z-axis direction, that is, a direction perpendicular to the paper surface is applied to a position other than the position of the contact point between the stator 901 and the rotor 902, as indicated by the white arrows R1 and R2, The rotor 902 rotates around the y axis.

  Further, in the ultrasonic motor 900 described above, the rotor 902 and the stator 901 are in contact with each other only at two points. Therefore, when the stator 901 or the rotor 902 is worn as shown in FIG. There is a risk of skidding with respect to 902, that is, displacement in the xy plane. Due to this skidding, the stator 901 bites into the rotor 902, and the straight line connecting the two contact points shifts from the center of the rotor. As a result, the rotor 902 rotates around the y axis. As a result, the rotor 902 may not be able to rotate continuously.

  A problem similar to the above-described problem also occurs in an ultrasonic motor in which an ultrasonic transducer rotates along the inner peripheral surface of a fixing member having a circular inner peripheral surface.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an inscribed ultrasonic motor capable of obtaining substantially the same rotational characteristics over the entire circumference of the rotational motion. It is.

  In addition, a problem similar to the above-described problem also occurs in an inscribed ultrasonic motor in which a linear mover or an ultrasonic transducer moves back and forth linearly. Accordingly, another object of the present invention is to provide an inscribed linear ultrasonic motor capable of obtaining substantially the same motion characteristics over the entire length of linear reciprocation of a linear mover or ultrasonic transducer. is there.

  An ultrasonic motor according to one aspect of the present invention includes a rotor having a circular inner peripheral surface in a plan view, one or more ultrasonic vibrators that contact the inner peripheral surface at two or more points, and one or two. A connecting member connected to each of the ultrasonic transducers. Each of the ultrasonic motors is provided on the connecting member, and the position of the rotation center of the rotor is set in cooperation with one or two or more ultrasonic vibrators while moving the rotor in the tangential direction of the inner peripheral surface. One or more contact mechanisms that contact the inner peripheral surface at one point so as to be maintained are provided. Further, the ultrasonic motor is a connecting member that presses two or more points on one or more ultrasonic transducers and one point on each of the one or more contact mechanisms from the center of the rotor toward the inner peripheral surface. Is provided with a pressing mechanism that can be elastically deformed.

  According to the above configuration, at least three points are pressed from the center of the rotor toward the inner wall surface by the pressing mechanism. Therefore, compared with the case where two points are pressed against the rotor, uniform rotational characteristics can be easily obtained over the entire circumference of the rotor. Furthermore, since the inner peripheral surface of the rotor is supported at three or more points, the ultrasonic transducer in the direction perpendicular to the rotor rotation surface and slip between the ultrasonic transducer and the rotor in the rotor rotation surface. Slip between the rotor and the rotor is smaller than when the inner peripheral surface of the rotor is supported at two points. As a result, it is easy to maintain a stable contact state between the ultrasonic transducer and the rotor.

  Further, in the ultrasonic motor, each of one or two or more ultrasonic transducers has a rectangular flat plate shape, and two or more points are respectively formed on two or more corners of the rectangle or two or more corners. It may be a point on two or more provided projections. According to this, two points on one ultrasonic transducer can be brought into contact with the inner peripheral surface of the rotor with a simple configuration.

  Further, in the ultrasonic motor, each of one or two or more ultrasonic transducers has an arc shape, and two or more points are points on two projections provided on the outer peripheral surface of the arc shape. Or the point on the processus | protrusion provided in each of 2 processus | protrusions may be sufficient. According to this, since the amplitude of the ultrasonic transducer in the normal direction and the tangential direction of the inner peripheral surface is larger than when using an ultrasonic transducer having a rectangular flat plate shape with the same volume, a high power Can be generated.

  An ultrasonic motor according to another aspect of the present invention includes a fixing member having a circular inner peripheral surface in plan view, one or more ultrasonic vibrators that contact the inner peripheral surface at two or more points, A connection member connected to each of the two or more ultrasonic transducers. In addition, each of the ultrasonic motors is provided on the connection member, and moves in the tangential direction of the inner peripheral surface while cooperating with the one or two or more ultrasonic vibrators. One or more contact mechanisms are provided that contact the inner peripheral surface at one point so that the center position of rotation along the inner peripheral surface of the rotor can be maintained. Further, the ultrasonic motor is a connecting member that presses two or more points on one or more ultrasonic transducers and one point on each of the one or more contact mechanisms from the center of the rotor toward the inner peripheral surface. Is provided with a pressing mechanism that can be elastically deformed.

  According to the above configuration, as in the invention of the aforementioned one aspect, uniform rotation characteristics can be easily obtained over the entire circumference of the rotor, and a stable contact state between the ultrasonic transducer and the rotor is maintained. It becomes easy to do.

  An ultrasonic motor according to another aspect of the present invention includes a linear movable element having two inner wall surfaces that are parallel to each other in plan view, and one or more ultrasonic vibrators that are in contact with the two inner wall surfaces at two or more points. And a connection member connected to each of the one or two or more ultrasonic transducers. Each of the ultrasonic motors is provided on the connection member, and maintains a state in which the linear movable element can be moved in parallel with each of the two inner wall surfaces in cooperation with one or more ultrasonic vibrators. As can be obtained, one or more contact mechanisms that contact at any one of the two inner wall surfaces are provided. Further, the ultrasonic motor elastically deforms the connecting member so as to press two or more points on one or more ultrasonic transducers and one point on each of one or more contact mechanisms against two inner wall surfaces. A pressing mechanism is provided.

  According to the above configuration, uniform movement characteristics can be easily obtained over the entire length of the inner wall surface of the linear movable element, and a stable contact state between the ultrasonic transducer and the linear movable element can be easily maintained.

  The ultrasonic motor includes a fixing member having two inner wall surfaces that are parallel to each other in plan view, one or more ultrasonic vibrators that are in contact with the two inner wall surfaces at two or more points, and one or two or more ultrasonic waves. And a connection member connected to each of the acoustic wave vibrators. In addition, each of the ultrasonic motors is provided on the connection member, and the inner wall surface is maintained so that one or two or more ultrasonic transducers can move in parallel with respect to each of the two inner wall surfaces. Are provided with one or more contact mechanisms. The ultrasonic motor can elastically deform the connecting member so as to press two or more points on one or more ultrasonic transducers and one point on each of the one or more contact mechanisms against two inner wall surfaces. A pressing mechanism is provided.

  Also with the above configuration, uniform movement characteristics can be easily obtained over the entire length of the inner wall surface of the linear movable element, and a stable contact state between the ultrasonic transducer and the linear movable element can be easily maintained.

  An ultrasonic motor according to still another aspect of the present invention maintains a position of the rotation center of the rotor in a state where the rotor having a circular inner peripheral surface in a plan view and the rotor can be moved in a tangential direction of the inner peripheral surface. As obtained, a plurality of ultrasonic transducers that contact the inner peripheral surface at three or more points and a connection member connected to each of the plurality of ultrasonic transducers are provided. Further, the ultrasonic motor includes a mechanism that can elastically deform the connecting member so as to press three or more points from the center of the rotor toward the inner peripheral surface.

  According to said structure, all the site | parts which contact a rotor are any points on several ultrasonic transducer | vibrators. Therefore, as compared with the case where the rotor and the contact mechanism are in contact, high power can be obtained by the amount of loss of the rotational force of the rotor caused by the contact between the rotor and the contact mechanism.

  In the ultrasonic motor, each of the plurality of ultrasonic transducers has a rectangular flat plate shape, and three or more points are three or more corners of the ultrasonic transducer having a plurality of rectangular flat plate shapes. It may be a point on a part or a point on three or more protrusions provided at three or more corners.

  According to said structure, the ultrasonic motor which is a simple structure and can obtain high power is realizable.

  In the ultrasonic motor, each of the plurality of ultrasonic transducers has an arc shape, and three or more points are on projections provided on three or more outer peripheral surfaces of the plurality of arc-shaped ultrasonic transducers. It may be a point.

  According to the plurality of arc-shaped ultrasonic vibrators, the amplitude in the normal direction of the inner peripheral surface of the rotor and the inner diameter of the rotor are compared with the ultrasonic vibrators having a plurality of rectangular flat plates each having the same volume. All of the amplitudes in the tangential direction of the peripheral surface are large. Therefore, high power can be generated.

  An ultrasonic motor according to another aspect maintains a center position of rotation along the inner peripheral surface in a state where the ultrasonic motor can move in a tangential direction of the inner peripheral surface with a fixing member having a circular inner peripheral surface in a plan view. As is possible, a plurality of ultrasonic transducers that contact the inner peripheral surface at three or more points are provided. The ultrasonic motor includes a connecting member connected to each of the plurality of ultrasonic transducers and a mechanism capable of elastically deforming the connecting member so as to press three or more points from the central position toward the inner peripheral surface. I have.

  According to said structure, all the site | parts which contact a fixing member are any points on several ultrasonic transducer | vibrators. Therefore, as compared with the case where the contact mechanism and the fixing member are in contact with each other, higher power can be obtained by the amount of loss of the moving force of the ultrasonic transducer due to the contact between the contact mechanism and the contact mechanism.

  Still another aspect of the ultrasonic motor includes a linear mover having two inner wall surfaces that are parallel to each other in a plan view, and a linear mover that can move the linear mover in a direction parallel to the two inner wall surfaces. Are provided with a plurality of ultrasonic transducers that are in contact with the inner wall surface at three or more points. The ultrasonic motor includes a connection member connected to each of the plurality of ultrasonic transducers and a mechanism capable of elastically deforming the connection member so as to press three or more points against the two inner wall surfaces. Yes.

  According to said structure, all the site | parts which contact a linear needle | mover are any points on several ultrasonic transducer | vibrators. Therefore, compared with the case where a contact mechanism and a linear mover contact, high power can be obtained by the amount of loss of the moving force of the linear mover caused by the contact between the contact mechanism and the linear mover.

  Further, the ultrasonic motor of a different aspect is capable of maintaining the direction of movement in a state where the fixing member has two inner wall surfaces parallel to each other in a plan view and can move in a direction parallel to the two inner wall surfaces. And a plurality of ultrasonic transducers that are in contact with the two inner wall surfaces at three or more points. The ultrasonic motor includes a connection member connected to each of the plurality of ultrasonic transducers and a mechanism capable of elastically deforming the connection member so as to press three or more points against the two inner wall surfaces. Yes.

  According to said structure, all the site | parts which contact a fixing member are any points on several ultrasonic transducer | vibrators. Therefore, as compared with the case where the fixing member and the contact mechanism are in contact with each other, higher power can be obtained by the amount of loss of the moving force of the ultrasonic transducer due to the contact between the contact mechanism and the fixing member.

Hereinafter, an ultrasonic motor according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
First, the ultrasonic motor according to the first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the ultrasonic motor 1 of the first embodiment is driven by a rectangular flat plate type ultrasonic transducer 11 having a rectangular flat plate shape, and the ultrasonic transducer 11. A rotor 200 is provided. Further, the ultrasonic motor 1 includes a disk member 61 as a contact mechanism that contacts the rotor 200. The disk member 61 presses the rotor 200 in the normal direction of the inner peripheral surface while moving the rotor 200 in the tangential direction of the inner peripheral surface. The ultrasonic motor 1 includes a shaft 100 connected to the main body of the apparatus.

  The ultrasonic motor of the present invention may be any one as long as the ultrasonic transducer is in contact with the inner peripheral surface of the rotor and generates a desired elliptical vibration. It is not limited to the ultrasonic motor having the structure shown in the form. For example, the size, shape, material, and the like of the ultrasonic transducer may be any as long as the object of the present invention can be achieved and the effect can be obtained.

<Overall configuration>
As described above, the ultrasonic motor 1 has the rectangular flat plate type ultrasonic transducer 11. The ultrasonic motor 1 has a rectangular diaphragm 21. The diaphragm 21 is supported by the upper connection member 30 and the lower connection member 31 in the vicinity of the position of the longitudinal vibration node. The upper connecting member 30 has five movements with respect to the shaft 100 other than the translational movement in the z-axis direction, that is, the translational movement in the x-axis direction, the translational movement in the y-axis direction, the rotational movement around the x-axis direction, and the y-axis. It is connected so that five motions consisting of a rotational motion around and a rotational motion around the z-axis are constrained. The lower connecting member 31 is fixed to the shaft 100 so that all of the six motions obtained by adding the translational motion in the z-axis direction to the above-described five motions are restrained.

  The ultrasonic motor 1 includes a contact mechanism. The contact mechanism includes a disk member 61 and a disk support member 60. The contact mechanism is attached to the upper connection member 30 on the opposite side of the ultrasonic transducer 11 with respect to the shaft 100. The shaft 100 is fixed to a main body of an apparatus provided outside (not shown). Two corners of the side opposite to the side on which the upper side connection member 30 and the lower side connection member 31 of the diaphragm 21 are provided are in contact with the inner peripheral surface of the rotor 200.

  The ultrasonic transducer 11 is provided with two electrodes 71, 72, 73, 74, 75 and two piezoelectric elements 50. Each of the electrodes 71, 72, 73, 74, and 75 and the piezoelectric element 50 are provided symmetrically in the vertical direction. The electrodes 71, 72, 73, 74 and 75 are electrically connected to a control device (not shown) so that a predetermined signal can be inputted.

  In the ultrasonic transducer 11 of the present embodiment, the piezoelectric element 50 vibrates due to an alternating electric field applied to the electrodes 71, 72, 73, 74, and 75 using the inverse piezoelectric effect. The vibration of the piezoelectric element 50 is transmitted to the diaphragm 21. As a result, the diaphragm 21 vibrates so that the corners S1 and S2 draw elliptical orbits indicated by arrows E1 and E2, respectively. As a result, the rotor 200 in contact with the corners S1 and S2 moves along the circular path C. That is, the rotor 200 rotates. The inner diameter of the rotor 200 is 10 mm.

<Ultrasonic transducer>
Next, the structure of the rectangular flat plate type ultrasonic transducer 11 will be described in more detail.

  As shown in FIGS. 1 to 3, the ultrasonic transducer 11 includes a vibration plate 21 including an upper main plate portion 40 and a lower main plate portion 41, an electrode 75, two piezoelectric elements 50, and electrodes 71, 72, 73. And 74 are provided.

  The upper main plate portion 40 and the lower main plate portion 41 constituting the diaphragm 21 are provided such that one main surfaces of each other are in contact with each other in the vertical direction. One main surface of the electrode 75 is bonded to the other main surface of each of the upper main plate portion 40 and the lower main plate portion 41. Electrodes 71, 72, 73 and 74 are bonded to the other main surface of each of the two electrodes 75 on the piezoelectric element 50.

  The upper main plate portion 40 and the lower main plate portion 41 are each formed of a flat plate member having a width of 1.35 mm, a length of 6.0 mm, and a thickness of 0.2 mm, and is parallel to the xy plane in FIG. . Further, the upper connecting member 30 extends obliquely upward from the central position of the long side of the upper main plate portion 40 with respect to the xy plane. The lower connection member 31 extends obliquely downward from the center position of the long side of the lower main plate portion 41 with respect to the xy plane.

  The upper connecting member 30 is connected to one side of the upper plate 80 having a square through hole of 1.0 mm × 1.0 mm and the other side facing the one side. The lower connection member 31 is connected to one side of the lower plate 80 having a 1.0 mm × 1.0 mm square through-hole and the other side facing the one side. The square through hole of the upper plate 80 and the square through hole of the lower plate 80 are provided at the same position in plan view in a direction perpendicular to the xy plane. The shape of each through hole of the two plates 80 is almost the same as the outer shape of the shaft 100. Further, in a plan view in a direction perpendicular to the xy plane, the distance from the center of the through hole of the plate 80 to the contact point between the ultrasonic transducer 11 and the rotor 200 matches the radius of the rotor 200, that is, The lengths of the upper connecting member 30 and the lower connecting member 31 are set so that the center of the through hole 80 coincides with the center of the rotor 200. The upper main plate portion 40 and the lower main plate portion 41 are bonded to each other. The contact mechanism described above is provided at the opposite end of the diaphragm 21. The contact mechanism includes a disk member 61 and a disk support member 60. The disk member 61 is provided so as to contact the inner peripheral surface of the rotor 200. The disk member 61 is in contact with the inner peripheral surface of the rotor 200 to support the rotor 200, and the disk support member 60 prevents the rotation of the rotor 200 from being hindered by friction generated between the disk member 61 and the rotor 200. , And is supported rotatably around the z axis. The piezoelectric element 50 is a flat plate-like member having a rectangular planar shape with a width of 1.35 mm, a length of 5.35 mm, and a width of 0.2 mm. In addition, in the plan view in the direction perpendicular to the xy plane, the piezoelectric element 50 has the electrodes 75 arranged on the upper main plate portion 40 so that the long side of the piezoelectric element 50 and the long side of the upper main plate portion 40 overlap each other. It is fixed in a state of being interposed between the two. In addition, the piezoelectric element 50 has the electrode 75 with respect to the lower main plate portion 41 so that the long side of the piezoelectric element 50 and the long side of the lower main plate portion 41 overlap in a plan view in a direction perpendicular to the xy plane. Are fixed in a state of being interposed between each other.

  The dimensions and shapes of the diaphragm 21 and the piezoelectric element 50 are not limited to the above dimensions and shapes, and as described above, the elliptical motion necessary for the rotation of the rotor 200 can be generated, and Other dimensions and shapes may be used as long as the rotor 200 can be rotated by contacting the inner peripheral surface of the rotor 200. The material of the diaphragm 21 is not particularly limited as long as vibration attenuation is small and an elliptical motion with a large amplitude can be obtained by resonance. However, a material having conductivity such as stainless steel is desirable. Moreover, although the upper side connection member 30 and the lower side connection member 31, and the upper side main board part 40 and the lower side main board part 41 may consist of separate members, they should be integrally formed by one member. Is desirable.

  The piezoelectric element 50 is made of lead zirconate titanate (PZT), but may be made of any material as long as it vibrates when a voltage is applied. On one main surface of the piezoelectric element 50, electrodes 71, 72, 73 and 74 are attached. The electrodes 71, 72, 73, and 74 are provided in each of the four rectangular regions, assuming that one main surface of the piezoelectric element 50 is divided into substantially the same four rectangular regions. A substantially rectangular electrode 75 is provided on the other main surface of the piezoelectric element 50. The electrode 75 is a flat plate member having the same rectangular planar shape as the other main surface of the piezoelectric element 50.

  In the rectangular flat plate type ultrasonic transducer 11 of the present embodiment, one piezoelectric element 50 has an electrode 75 interposed between each other with respect to the main surface facing the main surface bonded to the upper main plate portion 40. It is fixed in an intervening state. The other piezoelectric element 50 is fixed to the main surface facing the main surface bonded to the lower main plate portion 41 with the electrodes 75 interposed therebetween.

  The upper electrode 75 is fixed to the main surface of the upper main plate portion 40 so that its long side and the long side of the upper main plate portion 40 overlap when viewed along the z-axis direction. The lower electrode 75 is fixed to the main surface of the lower main plate portion 41 so that its long side and the long side of the lower main plate portion 41 overlap when viewed along the z-axis direction. The upper electrode 75 and the lower electrode 75 are bonded to the upper main plate portion 40 and the lower main plate portion 41 with a conductive adhesive such as silver paste, respectively. Note that the conductive adhesive itself can serve as the upper electrode 75 and the lower electrode 75. In this case, the adhesion between the two main plate portions 40 and 41 and the piezoelectric element 50 and the formation of the electrode 75 are simultaneously performed.

  Further, the upper main plate portion 40 and the lower main plate portion 41 constitute the vibration plate 21 and are arranged mirror-symmetrically with respect to the xy plane. Further, the piezoelectric element 50 attached to one main surface of the diaphragm 21 and the electrodes 71, 72, 73, 74 and 75 attached to the piezoelectric element 50 and the piezoelectric element attached to the other main surface of the diaphragm 21. The element 50 and the electrodes 71, 72, 73, 74, and 75 attached to the element 50 are arranged in mirror symmetry with respect to the xy plane of the diaphragm 21. Therefore, the vibration characteristic of the piezoelectric element 50 on one main surface of the vibration plate 21 and the vibration characteristic of the piezoelectric element 50 on the other main surface of the vibration plate 21 are substantially the same. Therefore, the diaphragm 21 of the present embodiment vibrates in the in-plane direction. Further, since the upper main plate portion 40 and the lower main plate portion 41 of the diaphragm 21 are rectangular, the corner portions S1 and S2 of the diaphragm 21 vibrate elliptically in the above-described in-plane direction.

  Next, a method for driving the rectangular flat plate type ultrasonic transducer 11 according to the present embodiment will be described with reference to FIGS. When the rectangular flat plate type ultrasonic transducer 11 is driven, a predetermined signal is input to the electrodes 71, 72, 73, 74 and 75 from a control device (not shown) provided outside. A signal (applied voltage) input to the electrodes 71, 72, 73 and 74 positioned on one main surface side of the diaphragm 21 is an electrode 71 positioned on the other main surface side of the diaphragm 21. , 72, 73, and 74 are input in a mirror-symmetric manner on the xy plane.

  As shown in FIG. 3, the electrode 71 and the electrode 73 are connected, and the same signal (φ1) is input. The electrode 72 and the electrode 74 are connected, and the same signal (φ2) is input. Therefore, the signals inputted to the electrodes 71, 72, 73, 74 and 75 have four modes (A), (B), (C) and (D) as shown in FIG. . Further, as shown in FIG. 5, the signals input to the electrode 71 and the electrode 73 and the signals input to the electrode 72 and the electrode 74 have a difference of 90 degrees in the phase, but the same Has amplitude and frequency.

  The vibration plate 21 of the ultrasonic transducer 11 described above performs vibration in combination with the stretching vibration shown in FIG. 6 and the bending motion shown in FIG. According to the stretching vibration shown in FIG. 6, the diaphragm 21 is compressed or expanded in the long side direction as indicated by the white arrow. Thereby, each of the corner portions S1 and S2 vibrates in the long side direction. On the other hand, according to the bending vibration shown in FIG. 7, the diaphragm 21 changes from one S-shape to another S-shape that is mirror-symmetrical to it. Thereby, the corner | angular part of the diaphragm 21 vibrates in a short side direction, as shown by the white arrow.

  When a voltage having the same frequency as the resonance frequency of the stretching vibration is applied to each of the electrodes 71, 72, 73 and 74 in the same phase, the diaphragm 21 performs stretching vibration in the direction indicated by the arrow in FIG. In addition, a voltage (positive) that changes at the same phase and frequency as the resonance frequency of the bending vibration is applied to each of the electrodes 71 and 73, and a voltage (negative) that has an opposite phase to the electrodes 71 and 73 is applied to the electrodes 72 and 74. When applied to each of these, the diaphragm 21 performs flexural vibration as shown by arrows in FIG. A reference potential (0 V) is always applied to each of the two electrodes 75. The shape of each electrode is not limited to a rectangle, and any shape may be used as long as the ultrasonic transducer 11 can generate both stretching vibration and bending vibration.

  Voltages having the same frequency and phase as the resonance frequency a of the stretching vibration and the resonance frequency b of the bending vibration are applied to the electrodes 71 and 73, respectively, and have the same frequency as the electrodes 71 and 73 and the phase is shifted by +90 degrees. A voltage is applied to the electrodes 72 and 74. Thereby, the stretching vibration and the bending vibration of the ultrasonic transducer 11 of the rectangular flat plate type are generated on the vibration plate 21 in a state where the phases are shifted by 90 degrees. As a result, the corners S1 and S2 of the diaphragm 21 in contact with the rotor 200 perform elliptical vibration as indicated by arrows E1 and E2 in FIG.

  In addition, a voltage having the same frequency as the voltage applied to the electrodes 71 and 73 and having a phase shifted by −90 degrees from the phase of the voltage applied to the electrodes 71 and 73 is applied to the electrodes 72 and 74. And corner | angular part S1 and S2 perform elliptical vibration of the reverse direction to the direction shown by arrow E1 and E2 in FIG. If the phase of one of the signals input to the electrodes 71 and 73 and the electrodes 72 and 74 changes by 180 degrees with the rotor 200 rotating in a certain direction, the rectangular flat plate type The rotation direction of the rotor 200 in contact with the corners S1 and S2 of the ultrasonic transducer 11 is reversed.

  In the ultrasonic motor 1 whose xz sectional view is shown in FIG. 8, the upper main plate portion 40, the lower main plate portion 41, the upper connection member 30, the lower connection member 31, and the disk support member 60 are made of two stainless steels. It is formed of a plate. The two stainless steel plates are bonded at the position of the diaphragm 21 and the position of the upper main plate portion 60. The upper connection member 30 and the lower connection member 31 are each bent by 45 degrees with respect to the xy plane so that a pantograph shape is formed by them. The dimensions of the upper main plate portion 40, the lower main plate portion 41, the upper connection member 30, the lower connection member 31, and the disk support member 60 are as shown in FIG. In addition, the two corner portions S1 and S2 of the diaphragm 21 are in contact with the inner peripheral surface of the rotor 200 at a total of three locations.

  In the ultrasonic motor 1 of the above-described embodiment, the plate 80 and the shaft 100 of the lower connection member 31 are fixed, but the upper connection member 30 is pressed by the pressing mechanism 1000 shown in FIG. Thus, it can move downward along the length direction (z direction) of the shaft 100. Therefore, if the pressing mechanism 1000 presses the upper connection member 30 downward, and the position of the upper connection member 30 is fixed in a state where the upper support member 30 and the lower support member 31 are elastically deformed, Two points consisting of the corner portions S1 and S2 of the acoustic wave oscillator 11 and one point on the circumference of the disk member 61 are strongly pressed toward the inner peripheral surface of the rotor 200. Therefore, the contact state between the rotor 200 and the ultrasonic transducer 11 is stabilized. Note that the pressing mechanism 1000 according to the present embodiment elastically deforms the upper connection member 30 and the lower connection member 31 by applying a force from the upper side to the lower side to the upper connection member 30, but the upper connection described above. The upper connection member 30 and the lower connection member 31 are attached to the shaft 100 so that the restraint relationship between the member 30 and the lower connection member 31 is reversed upside down, and a downward upward force is applied to the lower connection member 31. Thus, the upper connection member 30 and the lower connection member 31 may be elastically deformed. Moreover, you may attach both the upper side connection member 30 and the lower side connection member 31 to the shaft 100 in the state in which the above-mentioned five movements were restrained, respectively. In this case, the pressing mechanism 1000 applies a force from the upper side to the lower side for the upper connection member 30 and a force from the lower side to the upper side for the lower connection member 31. The side connection member 31 is elastically deformed. Furthermore, the pressing mechanism of the present invention can apply elastic force to the ultrasonic vibrator 11 such as the upper connection member 30 and the lower connection member 31 and the connection member connected to the contact mechanism, thereby elastically deforming them. Any thing can be used as long as it is possible. In short, the pressing mechanism of the present invention may be any mechanism as long as it can press the ultrasonic transducer 11 and the contact mechanism toward the inner peripheral surface of the rotor 200. Further, the state in which each of the two plates 80 spreads in parallel to the xy plane is maintained, and the pressing mechanism 1000 and the pressing mechanism 1000 are separated by frictional force between the pressing mechanism 1000 and the plate 80 or their adhesion. The shaft 100 may not be provided as long as the rotation slip around the z axis with the plate 80 is prevented and the pressing mechanism 1000 or the plate 80 is connected to the main body instead of the shaft 100. .

  As a result of the piezoelectric analysis simulation conducted by the inventors, in the rectangular flat plate type ultrasonic vibrator 11 in which the longitudinal primary vibration and the bending secondary vibration occur at the same resonance frequency, the electrodes 71, 72, 73 and 74 are described above. As shown in FIG. 9, the four corners move elliptically. At this time, it is clear that the difference between the phase of the elliptical orbit of the corner portion S1 and the elliptical locus of the corner portion S2 is about 180 degrees.

  As shown in FIG. 10, when attention is paid to one corner S1, the ultrasonic transducer 11 contacts the inner peripheral surface of the rotor 200 in the second half cycle WOK of the elliptical vibration. In the half cycle WNO, the ultrasonic transducer 11 does not contact the inner peripheral surface of the rotor 200. Further, when paying attention to the other corner S2, the ultrasonic transducer 11 contacts the inner peripheral surface of the rotor 200 in the first half cycle WOK of the elliptical vibration, but in the second half cycle WNO of the elliptical vibration, The ultrasonic transducer 11 does not contact the inner peripheral surface of the rotor 200. Therefore, when two points including the corner portion S1 and the corner portion S2 are in contact with the inner peripheral surface of the rotor 200, the ultrasonic transducer is used in the second half cycle of the corner portion S1 and the first half cycle of the corner portion S2. 11 contacts the inner peripheral surface of the rotor 200. Therefore, the ultrasonic transducer 11 can transmit vibration to the inner peripheral surface of the rotor 200 over the entire period of the ultrasonic transducer 11.

  The dynamic friction force generated between the rectangular flat plate type ultrasonic transducer 11 and the inner peripheral surface of the rotor 200 is a force in a direction perpendicular to the inner peripheral surface of the rotor 200, that is, a normal direction of the inner peripheral surface. It is proportional to the product of the force (vertical drag) and the dynamic friction coefficient. If the frictional force is increased in order to increase the power of the rotor 200, it is necessary to increase the above-described vertical drag. However, when the above-described normal force is increased, the rectangular flat plate type ultrasonic transducer 11 and the rotor 200 are proportional to the vertical force generated between them at the position where the rotor 200 and the ultrasonic transducer 11 are in contact with each other. Elastically deforms.

  For example, when the amplitude of the elliptical motion increases, the amount of elastic deformation described above increases. In this case, it is conceivable that a situation occurs in which the rotor 200 and the rectangular flat plate type ultrasonic transducer 11 are in contact with each other during one period of the elliptical motion. If such a situation occurs, the rotor 200 cannot rotate. Therefore, the normal force that can be applied from the ultrasonic transducer 11 to the rotor 200 must be a value equal to or less than a predetermined value determined by considering the elastic deformation ability of the ultrasonic transducer 11 and the rotor 200.

  In the present embodiment, the rotor 200 and the ultrasonic transducer 11 are in contact at two points. Therefore, the normal force that can be applied from the ultrasonic transducer 11 to the rotor 200 is twice that in the case where the rotor 200 and the ultrasonic transducer 11 contact at one point. The maximum power that can be extracted from one rectangular flat plate type ultrasonic transducer 11 according to the present embodiment is the maximum power that can be extracted from the ultrasonic transducer when the rotor 200 and the ultrasonic transducer 11 are in contact at one point. Doubled.

  In the present embodiment, a movable disk member 61 is used as the contact mechanism. However, a fixed disk member is used if the member has a circular tip and a very small frictional resistance. May be. Any contact mechanism may be used as long as it can push the rotor 200 from the center toward the outside and does not hinder the rotation of the rotor 200.

  In the present embodiment, each of the two corners S 1 and S 2 of the rectangular flat plate type ultrasonic transducer 11 and the disk member 61 are in contact with the inner peripheral surface of the rotor 200. Protrusions 94 and 95 are provided at the corners S1 and S2, and the ultrasonic transducer 11 and the inner peripheral surface of the rotor 200 may be in contact with each other through the protrusions 94 and 95. Further, as shown in FIG. 11, the projection 92 and the two disk members 61 provided at one corner S <b> 1 or S <b> 1 of the rectangular flat plate type ultrasonic transducer 11 are in contact with the inner peripheral surface of the rotor 200. A sonic motor may be used. Also by this, since the rotor 200, the ultrasonic transducer | vibrator 11, and the two disc members 61 are contacting at three points, a stable contact state is easily maintained.

  Further, the ultrasonic motor of the present invention has one or two or more disk members 61 and one or two or more ultrasonic transducers 11, and these and the rotor 200 have three or more points on the inner peripheral surface of the rotor 200. If it is in contact with each other, the pressing mechanism 1000 can be used to maintain a stable contact state between the rotor 200 and each of the one or more disk members 61 and the one or more ultrasonic transducers 11. . However, in order to maintain a stable contact state between the rotor member 200 and each of the one or more disk members 61 and the one or more ultrasonic transducers 11, for example, as shown in FIG. Is three, it is necessary that the three contacts H, I, and J are arranged at a position surrounding the center O of the rotor 200. Similarly, when there are four or more contacts (for example, see FIG. 25), if the four or more contacts are not provided so as to surround the center O of the rotor 200, the rotor 200 can be stably held. Can not.

  In the present embodiment, the ultrasonic vibrator 11 and the disk member 61 are fixed to the apparatus main body, and the ultrasonic motor 1 in which the rotor 200 rotates is described. However, the rotor 200 is fixed to the apparatus main body. Even if the ultrasonic vibrator 11 and the disk member 61 rotate around the center of the rotor 200 as a fixed member while contacting the inner peripheral surface of the rotor 200, the above-described pressing is performed. If the mechanism 1000 is used, a stable contact state between the ultrasonic transducer 11 and the disk member 61 and the rotor 200 as a fixed member is maintained.

(Embodiment 2)
Next, the ultrasonic motor according to the second embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 13, the ultrasonic motor 2 includes two rectangular flat plate type ultrasonic transducers 11, a shaft 100, and a rotor 200. Note that the same reference numerals are assigned to components that realize the same configuration and function as those of the ultrasonic motor 1 shown in the first embodiment, and description thereof will not be repeated.

  The two rectangular flat plate type ultrasonic transducers 11 in the present embodiment are the diaphragm 21 and the electrodes 71 and 72 having the same size and shape as the rectangular flat plate type ultrasonic transducer 11 described in the first embodiment. 73, 74 and 75. As shown in FIGS. 14 to 16, the two rectangular flat plate type ultrasonic transducers 11 are mirror-symmetric with respect to a plane including the central axis of the shaft 100, that is, a plane including the rotation central axis of the rotor 200. Is arranged.

Next, a method for driving the ultrasonic motor 2 according to the second embodiment will be described.
Signals input to the electrodes 71, 72, 73, 74 and 75 are the same as the signals input to the electrodes of the first embodiment. That is, the voltage is applied to the electrodes 71, 72, 73 and 74 in the manner shown in FIGS. The two diaphragms 21 have corner portions S5 and S6 and corner portions S7 and S8, respectively. These four corners S5, S6, S7, and S8 are in contact with the inner peripheral surface of the rotor 200.

  In the second embodiment, all points that contact the inner peripheral surface of the rotor 200 are points on the ultrasonic transducer 11. Therefore, according to the ultrasonic motor 2 of the present embodiment, the rotation of the rotor 200 is compared with that in which the disk member 61 as a contact mechanism like the ultrasonic motor 1 of the first embodiment contacts the rotor 200. Since there is no contact acting as a resistor, the rotation efficiency of the rotor 200 is high.

  In the xz sectional view of the ultrasonic motor 2 shown in FIG. 16, the upper main plate portion 40, the lower main plate portion 41, the upper connection member 30, and the lower connection member 31 are formed of two stainless steel plates. The two stainless steel plates are bonded at the positions of the two vibration plates 21. The upper connection member 40 and the lower connection member 41 are each bent by 45 degrees with respect to the xy plane so that a pantograph shape is formed by them. The dimensions of the upper main plate portion 40, the lower main plate portion 41, the upper connection member 30, and the lower connection member 31 are as shown in FIG.

  In the above-described ultrasonic motor 2 of the present embodiment, the plate 80 and the shaft 100 of the lower connection member 31 are fixed, and the upper connection member 30 is pressed by the pressing mechanism 1000 shown in FIG. It is possible to move downward along the length direction (z direction) of the shaft 100. Therefore, if the pressing mechanism 1000 presses the upper connecting member 30 downward and the position of the upper connecting member 30 is fixed, the four corners S5, S6, S7 and S8 of the two ultrasonic transducers 11 are The inner peripheral surface of the rotor 200 can be pressed. Therefore, the contact state between the rotor 200 and the four corners of the two ultrasonic transducers 11 is stabilized. In the ultrasonic motor of the present embodiment, the projections 96 and 97 are provided at the four corners S5, S6, S7, and S8 of the two ultrasonic transducers 11, respectively, and the projections 96 and 97 are used as mediators. The acoustic transducer 11 and the inner peripheral surface of the rotor 200 may be in contact with each other. The pressing mechanism 1000 according to the present embodiment elastically deforms the upper connection member 30 and the lower connection member 31 by applying a force from the upper side to the lower side to the upper connection member 30. The upper connection member 30 and the lower connection member 31 are attached to the shaft 100 so that the restraint relationship between the upper connection member 31 and the lower connection member 31 is reversed upside down, and a downward upward force is applied to the lower connection member 31. Accordingly, the upper connection member 30 and the lower connection member 31 may be elastically deformed. Moreover, you may attach both the upper side connection member 30 and the lower side connection member 31 to the shaft 100 so that the five above-mentioned movements may be restrained. In this case, the pressing mechanism 1000 applies a force from the upper side to the lower side for the upper connection member 30 and a force from the lower side to the upper side for the lower connection member 31. The side connection member 31 is elastically deformed. Furthermore, the pressing mechanism of the present invention can apply elastic force to the ultrasonic vibrator 11 such as the upper connection member 30 and the lower connection member 31 and the connection member connected to the contact mechanism, thereby elastically deforming them. Any thing can be used as long as it is possible. In short, the pressing mechanism of the present invention may be any mechanism as long as it can press the ultrasonic transducer 11 and the contact mechanism toward the inner peripheral surface of the rotor 200. Further, the state in which each of the two plates 80 is parallel to the xy plane is maintained, and the pressing mechanism 1000 and the plate 80 are separated by a frictional force between the pressing mechanism 1000 and the plate 80 or their adhesion. The shaft 100 does not have to be provided if the rotation slip around the z-axis is prevented and the pressing mechanism 1000 or the plate 80 is connected to the main body instead of the shaft 100.

  In addition, the ultrasonic motor of the present invention has a plurality of ultrasonic transducers 11 and uses the pressing mechanism 1000 if the rotor 200 and the rotor 200 are in contact with the inner peripheral surface of the rotor 200 at three or more points. Thus, the plurality of ultrasonic transducers 11 and the rotor 200 can maintain a stable contact state. However, in order to maintain a stable contact state between the plurality of ultrasonic transducers 11 and the rotor 200, for example, when there are three contacts, as shown in FIG. I and J need to be set to positions that surround the center O of the rotor 200. Similarly, when there are four or more contacts (for example, refer to FIG. 25), the rotor 200 cannot be stably held unless the four contacts are provided so as to surround the center O of the rotor 200. .

(Embodiment 3)
Next, the ultrasonic motor 3 according to the third embodiment of the present invention will be described with reference to FIGS. The ultrasonic motor 3 includes two arc-shaped flat plate type ultrasonic transducers 13, a shaft 100, and a rotor 200. Note that components having the same configuration and the same function as those of the ultrasonic motors described in the first and second embodiments are denoted by the same reference numerals, and the description thereof will not be repeated unless particularly necessary. .

<Ultrasonic transducer>
Here, the structure of the arc-shaped flat plate type ultrasonic transducer 13 will be described in more detail.

  As shown in FIGS. 17 to 19, the arc-shaped flat plate type ultrasonic transducer 13 includes a diaphragm 22. The diaphragm 22 includes an upper connecting member 30 connected to the shaft 100 so that five motions other than the translational motion in the z-axis direction are constrained, and six vibrations including a translational motion in the z-axis direction in addition to the five motions. A lower connecting member 31 connected to the shaft 100 so that all of the movement is restrained, and an upper main plate portion 42 and a lower main plate portion 43 formed integrally with the upper connecting member 30 and the lower connecting member 31 are provided. Have.

  The upper main plate portion 42 and the lower main plate portion 43 are formed by arc-shaped flat plates having an inner diameter of 5.8 mm, an outer diameter of 9.8 mm, and an angle of 90 degrees. Here, a portion corresponding to the outer fan-shaped arc is referred to as an outer peripheral portion, and a portion corresponding to the inner fan-shaped arc concentric with the outer fan-shaped arc is referred to as an inner peripheral portion. The upper connection member 30 and the lower connection member 31 extend from the center positions of the inner peripheral portions of the upper main plate portion 42 and the lower main plate portion 43, respectively. At the center position of the upper connection member 30 and the lower connection member 31, a plate 80 having a square through hole with a side of 0.6 mm square when viewed from the direction perpendicular to the xy plane is provided. The through hole of the plate 80 has substantially the same shape as the outer shape of the shaft 100. When viewed in a direction perpendicular to the xy plane, the distance from the center of the through hole of the plate 80 to the contact point between the arc-shaped flat plate type ultrasonic transducer 13 and the rotor 200 matches the radius of the rotor 200. In other words, the lengths of the upper connection member 30 and the lower connection member 31 are set so that the center of the through hole of the plate 80 coincides with the rotation center of the rotor 200.

  The upper main plate portions 42 and 43 of the upper connection member 30 and the lower connection member 31 are bonded to each other. The piezoelectric element 51 is an arc-shaped flat plate member having an inner diameter of 5.2 mm, an outer diameter of 9.8 mm, and an angle of 90 degrees. Further, the upper piezoelectric element 51 has the electrode 70 with respect to the upper main plate portion 42 so that the outer peripheral portion of the piezoelectric element 51 and the outer peripheral portion of the upper main plate portion 42 overlap when viewed in the direction perpendicular to the xy plane. It is fixed in an intervening state. On the other hand, the lower piezoelectric element 51 has the lower main plate portion 43 so that the outer peripheral portion of the lower piezoelectric element 51 and the outer peripheral portion of the lower main plate portion 43 overlap when viewed in the direction perpendicular to the xy plane. In contrast, the electrode 70 is fixed in a state of being interposed therebetween.

  The dimensions and shapes of the diaphragm 22 and the piezoelectric element 51 are not limited to the dimensions and shapes described above, and may be other dimensions and shapes. The material of the diaphragm 22 is not particularly limited as long as vibration attenuation is small and elliptical motion with a large amplitude can be obtained by resonance. However, a material having conductivity such as stainless steel is desirable. Moreover, although the upper side connection member 30 and the lower side connection member 31, the upper side main board part 42, and the lower side main board part 43 may consist of separate members, they should be integrally formed by one member. Is desirable.

  The piezoelectric element 51 is made of lead zirconate titanate (PZT), but may be made of any material as long as it is an element that vibrates when a voltage is applied thereto. On one main surface of each of the two piezoelectric elements 51, electrodes 76, 77, 78, and 79 are attached. The dimensions of electrodes 76, 77, 78, and 79 are as shown in FIG. An electrode 70 is provided on the other main surface of each of the two piezoelectric elements 51. The electrode 70 is a flat plate member having the same arcuate planar shape as the other main surface of the piezoelectric element 51.

  In the arc-shaped flat plate type ultrasonic transducer 13 of the present embodiment, the upper piezoelectric element 51 has the electrode 70 on the main surface opposite to the main surface bonded to the upper main plate portion 42. It is fixed in an intervening state. The lower piezoelectric element 51 is fixed to the main surface opposite to the main surface bonded to the lower main plate portion 43 with the electrode 70 interposed therebetween.

  The upper electrode 70 is fixed to one main surface of the upper main plate portion 42 so that the outer peripheral portion thereof overlaps with the outer peripheral portion of the upper main plate portion 42 when viewed along the direction perpendicular to the xy plane. . The lower electrode 70 is fixed to one main surface of the lower main plate portion 43 so that the outer peripheral portion thereof overlaps with the outer peripheral portion of the lower main plate portion 43 when viewed along a direction perpendicular to the xy plane. Has been. The two electrodes 70 are respectively bonded to the upper main plate portion 42 and the lower main plate portion 43 by a conductive adhesive such as silver paste. Note that the conductive adhesive itself may serve as the upper electrode 70 and the lower electrode 70. In this case, the above-described two main plate portions 40 and 41 and the piezoelectric element 50 are bonded together and the electrode 75 is formed simultaneously.

  Further, the upper main plate portion 42 and the lower main plate portion 43 that constitute the diaphragm 22 are arranged in mirror symmetry with respect to the xy plane. Furthermore, the piezoelectric element 51 received on one main surface of the diaphragm 22 and the piezoelectric element 51 attached to the other main surface of the diaphragm 22 are arranged in mirror symmetry with respect to the xy plane. Yes. The electrodes 76, 77, 78, 79 and 80 bonded to the upper main plate portion 42 and the electrodes 76, 77, 78, 79 and 70 bonded to the lower main plate portion 43 are mirror-symmetric with respect to the xy plane. Has been placed.

  Therefore, the vibration characteristic of the piezoelectric element 51 on one main surface of the diaphragm 22 and the vibration characteristic of the piezoelectric element 51 on the other main surface of the diaphragm 22 are substantially the same. Therefore, the diaphragm 22 of the present embodiment vibrates in the in-plane direction. In addition, protrusions 90 and 91 each having a side of 0.2 mm are provided at two corners positioned at both ends of the outer peripheral portion of the upper main plate portion 42 and the lower main plate portion 43 of the diaphragm 22. The protrusions 90 and 91 of the two diaphragms 22 are in contact with the inner peripheral surface of the rotor 200 at a total of four positions S9, S10, S11, and S12 in FIG. The two protrusions 90 and 91 move elliptically in the in-plane direction, as indicated by arrows E9 and E10 in FIG.

  Next, a method of driving the arcuate flat plate type ultrasonic transducer 13 according to the present embodiment will be described with reference to FIGS. When the arc-shaped flat plate type ultrasonic transducer 13 is driven, a predetermined signal is input to the electrodes 76, 77, 78, 79 and 70 from a control device (not shown) provided outside. A signal (applied voltage) input to the electrodes 76, 77, 78, 79 positioned on one main surface side of the diaphragm 22 is applied to the electrode 76, positioned on the other main surface side of the diaphragm 22, The signals (applied voltages) input to 77, 78, and 79 are input mirror-symmetrically with respect to the xy plane.

  As shown in FIG. 17, the electrode 76 and the electrode 78 are connected, and the same signal (φ1) is input. The electrode 77 and the electrode 79 are connected, and the same signal (φ2) is input. Therefore, the signals input to the electrodes 76, 77, 78 and 79 have four modes (A), (B), (C) and (D) as shown in FIGS. Yes. Further, as shown in FIG. 23, the signals input to the electrode 76 and the electrode 78 and the signals input to the electrode 77 and the electrode 79 have a deviation of 90 degrees in the phase, but the same Has amplitude and frequency.

  The vibration plate 22 of the above-described arc-shaped flat plate type ultrasonic vibrator 11 performs vibration in combination with the stretching vibration shown in FIG. 20 and the bending motion shown in FIG. According to the stretching vibration shown in FIG. 20, the diaphragm 22 is compressed or expanded in the tangential direction of the inner peripheral surface of the rotor 200 as indicated by a white arrow. Accordingly, the corners S1 and S2, that is, the protrusions 90 and 91 vibrate along the outer peripheral portion of the diaphragm 22, that is, in the tangential direction of the inner peripheral surface of the rotor 200. On the other hand, according to the bending vibration shown in FIG. 21, the diaphragm 22 vibrates as shown by the white arrow. Thereby, the corners S1 and S2 of the diaphragm 22, that is, the protrusions 90 and 91 of the diaphragm 22 are respectively in the short side direction, that is, the normal direction of the inner peripheral surface of the rotor, as indicated by the white arrows. Vibrates along.

  When a voltage that changes at the same frequency and phase as the resonance frequency and phase of the stretching vibration is applied to each of the electrodes 76, 77, 78, and 79, the vibration plate 22 is in the direction indicated by the arrow in FIG. Performs stretching vibration. In addition, a voltage (positive) that changes at the same frequency and phase as the resonance frequency and phase of the bending vibration is applied to the electrodes 76 and 78, respectively. ) Is applied to each of the electrodes 77 and 79, the diaphragm 22 performs bending vibration as indicated by arrows in FIG. A reference potential (0 V) is always applied to each of the two electrodes 70.

  The shape of the electrode is not limited to an arc shape, and any shape can be used as long as the arc-shaped flat plate type ultrasonic transducer 11 can generate both stretching vibration and bending vibration. Good.

  Voltages having the same frequency and phase as the resonance frequency a of the stretching vibration and the resonance frequency b of the bending vibration are applied to the electrodes 76 and 78, respectively, and have the same frequency as the electrodes 76 and 78 and the phase is shifted by +90 degrees. Voltage is applied to electrodes 77 and 79. Thereby, the expansion and contraction vibration and the bending vibration of the arc-shaped flat plate type ultrasonic vibrator 11 are simultaneously generated in the vibration plate 22. As a result, the four protrusions 90 and 91 perform elliptical vibration as indicated by arrows E9, E10, E11, and E12 in FIG. The four protrusions 90 and 91 are provided at the corners S9, S10, S11, and S12 of the two diaphragms 22 and are in contact with the inner peripheral surface of the rotor 200. Rotate in the direction.

  When a voltage having the same frequency as that of the electrodes 76 and 78 and having a phase shifted by −90 degrees is applied to the electrodes 77 and 79, the directions indicated by arrows E9, E10, E11, and E12 in FIG. Elliptical vibration in the opposite direction occurs. If one of the signals input to the electrodes 76 and 78 and the electrodes 77 and 79 changes by 180 degrees with the rotor 200 rotating in a certain direction, an arc-shaped flat plate type The rotation direction of the rotor 200 in contact with the projections 90 and 91 of the ultrasonic transducer 11 is reversed.

  Next, the simulation results of the vibration characteristics of the above-described arc-shaped flat plate type ultrasonic transducer 11 will be described with reference to Table 1.

  Table 1 shows the frequency response analysis results of the arc-shaped flat plate type ultrasonic transducer 13 and the rectangular flat plate type ultrasonic transducer 11 each having the same volume. In Table 1, Vn represents the velocity component of the primary longitudinal vibration and the vibration velocity component of the secondary bending vibration in the normal direction of the rotor, and Vt represents the vibration in the tangential direction of each of the primary longitudinal vibration and the secondary bending vibration. The velocity component is shown. As shown in Table 1, according to the arc-shaped flat plate type ultrasonic vibrator 13, the vibration velocity components in the tangential direction and the normal direction are rectangular in both the longitudinal primary vibration and the bending secondary vibration. It is larger than the respective vibration velocity components in the tangential direction and normal direction of the flat plate type ultrasonic transducer 11.

  From the above, according to the ultrasonic motor 3 using the arc-shaped flat plate type ultrasonic transducer 13 as a driving source, the power is larger than that of the ultrasonic motor 1 using the rectangular flat plate type ultrasonic transducer 11 as a driving source. Can be generated.

  Next, the upper main plate portion 42, the lower main plate portion 43, the upper connection member 30, and the lower connection member 31 will be described with reference to the xz sectional view of the above-described ultrasonic motor 3 shown in FIG. The upper main plate portion 42, the lower main plate portion 43, the upper connection member 30, and the lower connection member 31 are formed using two stainless steel plates. The two stainless steel plates are bonded at the respective positions of the two vibration plates 22.

  The upper connection member 30 and the lower connection member 31 are each bent by 45 degrees with respect to the xy plane so that a pantograph shape is formed by them. The dimensions of the upper main plate portion 42, the lower main plate portion 43, the upper connection member 30, and the lower connection member 31 are as shown in FIG. A total of four locations of the four protrusions 90 and 91 provided at the corners S 1 and S 2 of the two diaphragms 22 are in contact with the inner peripheral surface of the rotor 200.

  In the above-described ultrasonic motor 3 of the present embodiment, the plate 80 and the shaft 100 of the lower connection member 31 are fixed and are pressed by the pressing mechanism 1000 shown in FIG. It is possible to move along the length direction (z direction) of the shaft 100. Therefore, if the pressing mechanism 1000 presses the upper connecting member 30 downward and the position is fixed, the four corners S5, S6, S7 and S8 of the two ultrasonic transducers 11 are strongly applied to the rotor 200. Can be pressed. Note that the pressing mechanism 1000 according to the present embodiment elastically deforms the upper connection member 30 and the lower connection member 31 by applying a force from the upper side to the lower side to the upper connection member 30, but the upper connection described above. The upper connection member 30 and the lower connection member 31 are attached to the shaft 100 so that the restraint relationship between the member 30 and the lower connection member 31 is reversed upside down, and a downward upward force is applied to the lower connection member 31. Thus, the upper connection member 30 and the lower connection member 31 may be elastically deformed. Moreover, you may attach both the upper side connection member 30 and the lower side connection member 31 to the shaft 100 so that the above-mentioned 5 motion may be restrained. In this case, the pressing mechanism 1000 applies a force from the upper side to the lower side for the upper connection member 30 and a force from the lower side to the upper side for the lower connection member 31. The side connection member 31 may be elastically deformed. Furthermore, the pressing mechanism of the present invention can apply elastic force to the ultrasonic vibrator 11 such as the upper connection member 30 and the lower connection member 31 and the connection member connected to the contact mechanism, thereby elastically deforming them. Any thing can be used as long as it is possible. In short, the pressing mechanism of the present invention may be any mechanism as long as it can press the ultrasonic transducer 11 and the contact mechanism toward the inner peripheral surface of the rotor 200. Further, each of the two plates 80 is maintained in a state parallel to the xy plane, and the pressing mechanism 1000 and the plate 80 are caused by a frictional force between the pressing mechanism 1000 and the plate 80 or adhesion between them. The shaft 100 does not need to be provided if the rotation slip around the z-axis between them and the pressing mechanism 1000 or the plate 80 is connected to the main body instead of the shaft 100.

  In addition, the ultrasonic motor of the present invention has a plurality of ultrasonic transducers 13 and uses the pressing mechanism 1000 if the rotor 200 and the rotor 200 are in contact with the inner peripheral surface of the rotor 200 at three or more points. Thus, a stable contact state between the plurality of ultrasonic transducers 13 and the rotor 200 can be maintained. However, in order to maintain a stable contact state between the plurality of ultrasonic transducers 13 and the rotor 200, as shown in FIG. 25, when the number of contacts is four or more, the four contacts are the rotor 200. If it is not provided so as to surround the center O, the rotor 200 cannot be stably held.

(Embodiment 4)
Next, the ultrasonic motor 4 according to the fourth embodiment will be described with reference to FIG. The ultrasonic motor 4 includes a rectangular flat plate type ultrasonic transducer 11, a shaft 100, and a linear mover 400. It should be noted that the same reference numerals are given to the same components and the same functions as those of the ultrasonic motor described in the first embodiment, and the description thereof will not be repeated unless particularly necessary.

  Although the ultrasonic motor 1 according to the first embodiment causes a rotational motion, the ultrasonic motor 4 according to the present embodiment causes the linear movable element 2000 to generate a linear motion. Therefore, in the present embodiment, instead of the rotor 200, a linear mover 2000 having a rectangular opening as viewed in a plane surrounded by four inner wall surfaces is provided, and ultrasonic vibration is provided in the opening. A child member 11 and a disk member 61 as a contact member are provided. Further, protrusions 92 and 93 are provided on both ends of one long side of the ultrasonic transducer 11, respectively. Except for these matters, the ultrasonic motor 4 of the present embodiment is the same as the ultrasonic motor 1 of the first embodiment. More specifically, the structures and functions of the ultrasonic transducer 11, the shaft 100, the plate 80, the upper connection member 30, the lower connection member 31, and the like are the same as those of the first embodiment shown in FIG. .

  Therefore, if the plate 80 is pressed from the top or the bottom or the bottom to the top using the pressing mechanism 1000, the two protrusions 92 and 93 provided at the corners S1 and S2 of the ultrasonic transducer 11 are linearly movable. It is pressed toward the inner wall surface of the child 2000. Note that the two connection mechanisms 1000 may be used to push the upper connection member 30 from the top to the bottom and the lower connection member 31 from the bottom to the top. Further, if each of the two plates 80 is maintained parallel to the xy plane, and the pressing mechanism 1000 or the plate 80 is connected to the main body instead of the shaft 100, the shaft 100 is provided. It does not have to be. The two protrusions 92 and 93 move along the two inner wall surfaces while contacting the two inner wall surfaces parallel to each other. Therefore, the linear mover 2000 reciprocates linearly in the direction indicated by the arrow G in FIG.

  In the present embodiment, a movable disk member 61 is used as the contact mechanism. However, a fixed disk member is used if the member has a circular tip and a very small frictional resistance. May be. The contact mechanism may be anything as long as it can push the linear mover 2000 toward the inner wall surface and does not hinder the reciprocating linear motion of the linear mover 2000.

  In the present embodiment, the two protrusions 92 and 93 and the disk member 61 provided at the two corners S1 and S2 of the rectangular flat plate type ultrasonic transducer 11 are parallel to each other of the linear movable element 2000. The two inner wall surfaces are in contact. However, it is an ultrasonic motor in which one corner S1 and two disk members 61 of a rectangular flat plate type ultrasonic transducer 11 as shown in FIG. 11 are in contact with two parallel inner wall surfaces of the linear mover 2000. Even if it exists, since the linear needle | mover 2000, the ultrasonic transducer | vibrator 11, and the two disk members 61 are contacting at three points, the stable contact state is maintained.

  Further, the ultrasonic motor of the present invention has one or more disk members 61 and one or two or more ultrasonic transducers 11, and two mutually parallel inner wall surfaces of the linear mover 2000. Are in contact with each other at three or more points, using the pressing mechanism 1000, the one or two or more disk members 61, the one or two or more ultrasonic transducers 11, and the linear movable element 2000 have a stable contact state. Can be maintained.

  Further, in the present embodiment, the ultrasonic motor 4 in which the ultrasonic transducer 11 and the disk member 61 are fixed to the apparatus body and the linear mover 2000 reciprocates linearly has been described. Is an ultrasonic motor in which the ultrasonic transducer 11 and the disk member 61 move while contacting the two parallel inner wall surfaces of the linear mover 2000 as a fixed member. However, if the above-described pressing mechanism 1000 is used, a stable contact state between the ultrasonic transducer 11 and the disk member 61 and the linear movable element 2000 as the fixed member is maintained.

(Embodiment 5)
Next, the ultrasonic motor 5 according to the fifth embodiment of the present invention will be described with reference to FIG. The ultrasonic motor 5 includes two rectangular flat plate type ultrasonic transducers 11, a shaft 100, and a linear movable element 2000. It should be noted that the same reference numerals are given to the same components and the same functions as those of the ultrasonic motor described in the first embodiment, and the description thereof will not be repeated unless particularly necessary.

  The ultrasonic motor 5 of the present embodiment is different from the ultrasonic motor 4 of the fourth embodiment in that the ultrasonic vibrator 11 and the disk member 61 are replaced with two ultrasonic vibrators 11.

  The ultrasonic motor 5 of the present embodiment includes two rectangular flat plate type ultrasonic transducers 11, a shaft 100, and a linear movable element 2000. It should be noted that the same reference numerals are given to the same components and the same functions as those of the ultrasonic motor described in the first embodiment, and the description thereof will not be repeated unless particularly necessary.

  Although the ultrasonic motor 2 according to the second embodiment causes a rotational movement, the ultrasonic motor 4 according to the present embodiment causes the linear movable element 2000 to generate a linear movement. Therefore, in the present embodiment, instead of the rotor 200, a linear movable element 2000 having a rectangular opening as viewed in a plane surrounded by four inner wall surfaces is provided. A sound wave oscillator 11 is provided. In addition, protrusions 92 and 93 are provided on both ends of one long side of each of the two ultrasonic transducers 11. Except for these matters, the ultrasonic motor 5 of the present embodiment is the same as the ultrasonic motor 2 of the second embodiment. More specifically, the structures and functions of the ultrasonic transducer 11, the shaft 100, the plate 80, the upper connection member 30, the lower connection member 31, and the like are the same as those of the first embodiment shown in FIG. .

  Therefore, if the plate 80 is pressed from the top or the bottom or the bottom to the top using the pressing mechanism 1000, the two protrusions 92 and 93 provided at the corners S1 and S2 of the ultrasonic transducer 11 are linearly movable. It is pressed toward the inner wall surface of the child 2000. Note that the two connection mechanisms 1000 may be used to push the upper connection member 30 from the top to the bottom and the lower connection member 31 from the bottom to the top. If each of the two plates 80 is maintained parallel to the xy plane, and the pressing mechanism 1000 or the plate 80 is connected to the main body instead of the shaft 100, the shaft 100 is provided. It does not have to be. The two protrusions 92 and 93 move along the two inner wall surfaces while contacting the two inner wall surfaces parallel to each other. Therefore, the linear mover 2000 reciprocates linearly in the direction indicated by the arrow in FIG.

  According to the above-described ultrasonic motor 5 of the present embodiment, the plate 80 and the shaft 100 of the lower connection member 31 are fixed, and the upper connection member 30 is pressed by the pressing mechanism 1000, whereby the shaft 100. It is possible to move along the length direction. Therefore, if the pressing mechanism 1000 presses the upper connecting member 30 downward and the position thereof is fixed, the four corners S5, S6, S7 and S8 of the two ultrasonic transducers 11 become linear movers. It is pressed against two parallel inner wall surfaces of 2000. Thereby, the contact state between the linear movable element 2000 and the ultrasonic transducer 11 is stabilized.

  The ultrasonic motor of the present invention has a plurality of ultrasonic transducers 11 and these and the linear movable element 2000 are in contact with two parallel inner wall surfaces of the linear movable element 2000 at three or more points. Then, using the pressing mechanism 1000, a stable contact state between the plurality of ultrasonic transducers 11 and the linear movable element 2000 can be maintained.

  Further, in the present embodiment, the ultrasonic motor 5 in which the two ultrasonic transducers 11 are fixed to the apparatus main body and the linear movable element 2000 reciprocates linearly has been described. Even if the ultrasonic motor is a fixed member fixed to the main body, and the two ultrasonic transducers 11 move while contacting two parallel inner wall surfaces of the linear movable element 2000 as the fixed member, If the pressing mechanism 1000 is used, a stable contact state between the two ultrasonic transducers 11 and the linear movable element 2000 as a fixed member is maintained. Even in this case, the ultrasonic motor 5 has three or more ultrasonic transducers 11, and the three or more ultrasonic transducers 11 are in contact with two inner wall surfaces parallel to each other at three or more points. Also good.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

FIG. 3 is a plan view when the ultrasonic motor according to the first embodiment is viewed in a direction perpendicular to the xy plane. 1 is a perspective view of an ultrasonic motor according to Embodiment 1. FIG. 1 is an exploded perspective view of an ultrasonic motor according to Embodiment 1. FIG. 4 is a diagram illustrating four modes of the ultrasonic transducer according to Embodiment 1. FIG. FIG. 3 is a diagram showing a phase of an input voltage of the ultrasonic transducer according to the first embodiment. FIG. 3 is a diagram schematically showing longitudinal vibration generated in the ultrasonic transducer of the first embodiment. FIG. 3 is a diagram schematically showing bending vibration generated in the ultrasonic vibrator of the first embodiment. It is sectional drawing when the ultrasonic motor of Embodiment 1 is cut along xz plane. FIG. 3 is a diagram illustrating elliptical motion of four corners of the ultrasonic motor according to the first embodiment. FIG. 3 is a diagram for explaining the principle of two-point contact of the ultrasonic motor according to the first embodiment. FIG. 7 is a plan view of an ultrasonic motor according to a modification of the first embodiment. It is a figure for demonstrating that the triangle comprised by three contact points needs to include the center of a rotor. FIG. 6 is a plan view when the ultrasonic motor according to the second embodiment is viewed from a direction perpendicular to the xy plane. 6 is a perspective view of an ultrasonic motor according to Embodiment 2. FIG. 6 is an exploded perspective view of an ultrasonic motor according to Embodiment 2. FIG. It is sectional drawing when it cuts along the xz plane of the ultrasonic motor of Embodiment 2. It is a top view when the ultrasonic motor of Embodiment 3 is seen in the direction perpendicular to the xy plane. 6 is a perspective view of an ultrasonic motor according to Embodiment 3. FIG. 6 is an exploded perspective view of an ultrasonic motor according to Embodiment 3. FIG. 6 is a diagram showing an outline of longitudinal vibration generated in the ultrasonic transducer of embodiment 3. FIG. FIG. 10 is a diagram showing an outline of bending vibration generated in the ultrasonic transducer according to the third embodiment. 6 is a diagram illustrating four modes of the ultrasonic transducer according to Embodiment 3. FIG. FIG. 10 is a diagram showing the phase of the input voltage of the ultrasonic transducer according to the third embodiment. It is sectional drawing when the ultrasonic motor of Embodiment 3 is cut along xz plane. It is a figure for demonstrating that the square comprised by four contact points needs to include the center of a rotor. It is a top view when the ultrasonic motor of Embodiment 4 is seen from the direction perpendicular to the xy plane. FIG. 10 is a plan view when the ultrasonic motor according to the fifth embodiment is viewed from a direction perpendicular to the xy plane. It is a top view when the ultrasonic motor shown by Unexamined-Japanese-Patent No. 1-81671 is seen in the direction perpendicular | vertical to xy top view. It is a figure which shows schematically rotation around the y-axis of the ultrasonic motor shown by Unexamined-Japanese-Patent No. 1-81671. It is a figure which shows roughly the skid of the ultrasonic motor shown by Unexamined-Japanese-Patent No. 1-81671.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Ultrasonic motor, 11, 12 Rectangular flat plate type ultrasonic transducer, 13 Arc-shaped flat plate type ultrasonic transducer, 30 Upper support portion, 31 Lower support portion, 60 Disc support portion, 61 Disc member, 100 Shaft 200 rotors.

Claims (12)

A rotor having a circular inner peripheral surface in plan view;
One or more ultrasonic transducers that contact the inner peripheral surface at two or more points;
A connecting member connected to each of the one or more ultrasonic transducers;
Each is provided on the connection member, and maintains the position of the rotation center of the rotor in cooperation with the one or more ultrasonic transducers while moving the rotor in a tangential direction of the inner peripheral surface. One or more contact mechanisms that contact the inner peripheral surface at one point to obtain,
The two or more points on the one or two or more ultrasonic transducers and one point on each of the one or more contact mechanisms are pressed from the position of the rotation center of the rotor toward the inner peripheral surface. An ultrasonic motor comprising a pressing mechanism capable of elastically deforming the connecting member. Each of the one or more ultrasonic transducers has a rectangular flat plate shape,
The ultrasonic motor according to claim 1, wherein the two or more points are points on two or more corners of the rectangle or points on two or more protrusions provided at the two or more corners, respectively. Each of the one or more ultrasonic transducers has an arc shape,
The ultrasonic motor according to claim 1, wherein the two or more points are points on two protrusions provided on the arc-shaped outer peripheral surface. A fixing member having a circular inner peripheral surface in plan view;
One or more ultrasonic transducers that contact the inner peripheral surface at two or more points;
A connecting member connected to each of the one or more ultrasonic transducers;
The fixing of the one or two or more ultrasonic transducers is provided on the connecting member and moves in a tangential direction of the inner peripheral surface in cooperation with the one or two or more ultrasonic transducers. One or more contact mechanisms that contact the inner peripheral surface at a single point so as to maintain the center position of rotation along the inner peripheral surface of the member ;
Two or more points on the one or more ultrasonic transducers and one point on each of the one or more contact mechanisms are the one or more ultrasonic transducers, the connecting member, and the one or more ultrasonic transducers. An ultrasonic motor comprising: a pressing mechanism capable of elastically deforming the connection member so as to press the contact mechanism from the center position of the rotation toward the inner peripheral surface of the fixing member . A linear mover having two inner wall surfaces parallel to each other in plan view;
One or more ultrasonic transducers that contact the two inner wall surfaces at two or more points;
A connecting member connected to each of the one or more ultrasonic transducers;
Each is provided in the connecting member, and in cooperation with the one or more ultrasonic transducers, the linear movable element can be maintained in a state where it can be moved in parallel to each of the two inner wall surfaces. One or more contact mechanisms that contact one of the two inner wall surfaces at one point;
Pressing that can elastically deform the connecting member so as to press two or more points on the one or more ultrasonic transducers and one point on each of the one or more contact mechanisms against the two inner wall surfaces And an ultrasonic motor. A fixing member having two inner wall surfaces parallel to each other in plan view;
One or more ultrasonic transducers that contact the two inner wall surfaces at two or more points;
A connecting member connected to each of the one or more ultrasonic transducers;
Each is provided on the connecting member, and one point is provided on the inner wall surface so that the state where the one or more ultrasonic transducers can move in parallel with respect to each of the two inner wall surfaces is maintained. One or more contact mechanisms in contact with,
Pressing that can elastically deform the connecting member so as to press two or more points on the one or more ultrasonic transducers and one point on each of the one or more contact mechanisms against the two inner wall surfaces And an ultrasonic motor. A rotor having a circular inner peripheral surface in plan view;
A plurality of ultrasonic transducers in contact with the inner peripheral surface at three or more points so that the position of the rotation center of the rotor can be maintained in a state where the rotor can be moved in a tangential direction of the inner peripheral surface; ,
A connecting member connected to each of the plurality of ultrasonic transducers;
An ultrasonic motor comprising: a pressing mechanism capable of elastically deforming the connection member so as to press the three or more points from the position of the rotation center of the rotor toward the inner peripheral surface. Each of the plurality of ultrasonic transducers has a rectangular flat plate shape,
The three or more points are points on three or more corners of the ultrasonic transducer having the plurality of rectangular flat plate shapes, or points on three or more protrusions provided at the three or more corners, respectively. The ultrasonic motor according to claim 7. Each of the plurality of ultrasonic transducers has an arc shape,
The ultrasonic motor according to claim 7, wherein the three or more points are points on protrusions provided on three or more outer peripheral surfaces of the plurality of arc-shaped ultrasonic transducers. A fixing member having a circular inner peripheral surface in plan view;
A plurality of ultrasonic transducers that are in contact with the inner peripheral surface at three or more points so that the center position of the rotation along the inner peripheral surface can be maintained while being movable in a tangential direction of the inner peripheral surface. When,
A connecting member connected to each of the plurality of ultrasonic transducers;
A pressing mechanism capable of elastically deforming the connection member so as to press the three or more points toward the inner peripheral surface from the rotation center position of the plurality of ultrasonic transducers and the connection member ; Sonic motor. A linear mover having two inner wall surfaces parallel to each other in plan view;
In a state in which the linear mover can be moved in a direction parallel to the two inner wall surfaces, a plurality of supercontacts that contact the inner wall surface at three or more points so as to maintain the direction of movement of the linear mover. A sound wave oscillator,
A connecting member connected to each of the plurality of ultrasonic transducers;
An ultrasonic motor comprising: a pressing mechanism capable of elastically deforming the connection member so as to press the three or more points against the two inner wall surfaces. A fixing member having two inner wall surfaces parallel to each other in plan view;
A plurality of ultrasonic transducers that are in contact with the two inner wall surfaces at three or more points so that the direction of movement can be maintained while being movable in a direction parallel to the two inner wall surfaces;
A connecting member connected to each of the plurality of ultrasonic transducers;
An ultrasonic motor comprising: a pressing mechanism capable of elastically deforming the connection member so as to press the three or more points against the two inner wall surfaces.

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