JP2001037270A - Vibrating wave drive and vibrator used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce energy loss at a low cost without receiving the effect of pressure distribution in a clamping boundary face by integrally connecting an axial rod into the center hole of a rod-shaped electrical-to-mechanical energy transducer vibrating body so as to serve as a vibrator. SOLUTION: An axial rod (b) formed out of ferroalloy is inserted into the center hole of a cylindrical piezoelectric element (a) as a vibrator and bonded with an adhesive to integrally from a vibrator (S). A flexible substrate (c) supplies electric energy to the vibrator (S) because of the generation of vibration and retrieves electric charge generated on the vibrator (S) to the outside. The axial rod (S) whose upper end is fixed and lower end is supported supports the vibrator (s). The piezoelectric element (a) generates bending vibration (a dotted line indicates the bending displacement distribution of the axis) in a different direction by the supply of an alternating signal having a different phase from the flexible substrate (c), and the piezoelectric element (a) itself circularly or elliptically moves around the axial rod (b) as a resultant vibration. A contact body R is brought into contact with the upper end of the vibrator (S) and rotatingly driven by the resultant vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a camera lens and an office automation system.
The present invention relates to a vibration wave driving device used for equipment and the like and a vibrator used for the vibration wave driving device.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. Hei 4-91671 discloses a rod-type vibration wave driving device, for example, an ultrasonic motor, and its driving principle and the like are described therein.

In the vibrator disclosed here, an electromechanical energy conversion element (hereinafter, referred to as a piezoelectric element) is sandwiched and fixed from both sides by an elastic body, and the vibrator is constituted by the piezoelectric element and the elastic body.

[0004]

In the former example, the vibrator has a structure in which the electro-mechanical energy conversion element is sandwiched between a plurality of elastic bodies such as metals, so that the pressure distribution at the interface existing between the respective parts varies. Due to the influence of vibrator, individual differences occur in the performance of the vibrator, and the high-precision finishing of the interface has caused a cost increase.

Accordingly, the present inventor has devised that the vibrator in the vibrator is constituted by the electro-mechanical energy conversion element itself, and that the existence of such an interface is eliminated to stabilize the vibrator performance and reduce the cost. .

The inventor has recognized that when the vibrator of the vibrator is constituted by the electromechanical energy conversion element itself, the following problems must be considered.

First, the element strength is low. That is,
A piezoelectric element such as PZT is generally used as the electro-mechanical energy conversion element. However, it is considered that a brittle material having particularly low tensile strength may be damaged by support or vibration.

The second point is that the energy loss in the device is large. In other words, if a high-Q material (low-loss material) is used among piezoelectric elements such as PZT, a Q value of vibration of 1000 or more can be obtained, and it is sufficiently used as a vibrator for an actuator. Although it is possible, when the amount of distortion generated in the element due to vibration exceeds a certain value, the loss increases rapidly, so that it cannot be applied to a motor with a large output.

An object of the present invention is to solve the above-mentioned problems and to realize an inexpensive vibration-wave driving device and a vibrator having small individual differences.

[0010]

According to a first aspect of the present invention, there is provided a vibrating body comprising a substantially rod-shaped electro-mechanical energy conversion element, and a shaft rod integrally connected to a center hole of the vibrating body. A vibrator having a contact body pressed against the vibrating body of the vibrator and frictionally driven by the vibration of the vibrating body to be relatively rotated with the vibrator, wherein the vibrator has the shaft It is characterized by a vibration wave driving device supported by a rod.

According to a second aspect of the present invention, the substantially rod-shaped vibrating body is configured to excite bending vibration in a direction of the shaft bar, and the outer dimension of the antinode of the bending vibration of the vibrating body has an end dimension. It is characterized by a vibration wave driving device that is larger than the external dimensions of the part.

The invention according to a third aspect is characterized in that the vibrating body further has electrodes on the outer surface and the surface of the center hole, and is provided with a vibration wave driving device which is polarized in a radial direction.

According to a fourth aspect of the present invention, there is provided a vibration wave driving device further comprising electrodes on at least two opposing surfaces of the outer shape of the vibrating body, and performing polarization processing between the two opposing surfaces.

According to a fifth aspect of the present invention, there is provided a vibration wave driving device further comprising a driving and / or vibration detecting electrode disposed on an end face of the vibrating body.

According to a sixth aspect of the present invention, there is further provided a vibration device in which a friction material layer is formed on an end face of the vibrating body, the contact body is pressed against the end face, and the contact body is rotated about the shaft rod as a center of rotation. It features a wave driving device.

According to a seventh aspect of the present invention, there is provided a vibration wave driving device in which an outer dimension of the friction material layer is larger than an outer dimension of an end face of the vibrating body.

The invention according to claim 8 is characterized in that a vibration wave driving device further comprises an outer dimension of the contact body larger than an outer dimension of an end face of the vibrating body.

According to a ninth aspect of the present invention, there is provided a vibration wave driving device further comprising a circuit board having a pattern for power supply and / or signal detection contacting the end face of the vibrating body.

According to a tenth aspect of the present invention, there is further provided a vibration wave driving device in which the outer dimensions at the antinode position of the bending vibration of the vibrator are larger than the outer dimensions at both ends.

An eleventh aspect of the present invention is further characterized in that the vibrating body has a vibration wave driving device in which the outer shape is formed in a circular shape.

According to a twelfth aspect of the present invention, there is further provided a vibration wave driving device in which the outer shape of the vibrator is formed in a square shape.

According to a thirteenth aspect of the present invention, there is provided a vibration wave driving device in which the outer shape of the vibrating body is formed in a square shape and the cross section is set to be rectangular.

According to a fourteenth aspect of the present invention, there is provided a vibration wave driving device in which the substantially rod-shaped vibrator is formed of a piezoelectric element and the shaft is formed of metal.

According to a fifteenth aspect of the present invention, there is provided a vibration wave driving device having a vibrating body constituted by a substantially rod-shaped electro-mechanical energy conversion element itself, and a shaft rod integrally connected to a center hole of the vibrating body. Is characterized by the vibrator used for the above.

According to a sixteenth aspect of the present invention, the substantially rod-shaped vibrating body is configured to excite bending vibration in the direction of the shaft bar, and the outer dimension of the antinode of bending vibration of the vibrating body has an end dimension. A vibrator used for a vibration wave driving device larger than the outer dimensions of the portion is characterized.

The invention according to claim 17 is characterized in that the vibrator has electrodes on the outer surface and the surface of the center hole, and is used in a vibrating wave driving device which is polarized in a radial direction. I do.

The invention according to claim 18 is characterized in that the vibrator has electrodes on at least two opposing surfaces of the outer peripheral portion thereof, and the vibrator is used for a vibration wave driving device in which polarization is applied between the two opposing surfaces. And

According to a nineteenth aspect of the present invention, there is provided a vibrator for use in a vibration wave driving device further comprising a driving and / or vibration detecting electrode disposed on an end face of the vibrating body.

According to a twentieth aspect of the present invention, there is provided a vibrator for use in a vibration wave driving device in which a friction material layer is formed on an end face of the vibrator.

According to a twenty-first aspect of the present invention, there is provided a vibrator for use in a vibration wave driving device in which the outer dimensions of the friction material layer are larger than the outer dimensions of an end face of the vibrator.

According to a twenty-second aspect of the present invention, there is provided a vibrator for use in a vibration wave driving device in which a circuit board having a pattern for power supply and / or signal detection is brought into contact with an end face of the vibrating body.

According to a twenty-third aspect of the present invention, there is further provided a vibrator used in a vibration wave driving device in which the outer dimensions of antinode positions of bending vibration of the vibrator are larger than the outer dimensions at both ends.

A twenty-fourth aspect of the present invention is further characterized in that the vibrator is used for a vibration wave driving device in which the outer shape of the vibrator is formed in a circular shape.

According to a twenty-fifth aspect of the present invention, there is further provided a vibrator for use in a vibration wave driving device in which the outer shape of the vibrator is formed in a square shape.

The invention according to a twenty-sixth aspect is characterized in that the vibrator is used in a vibration wave driving device in which the outer shape of the vibrator is formed in a square shape and the cross section is set to be rectangular.

The invention according to a twenty-seventh aspect is characterized by a vibrator used in a vibration wave driving device in which the substantially rod-shaped vibrator is formed of a piezoelectric element and the shaft rod is formed of metal.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG.
An embodiment will be described.

Reference numeral a denotes a columnar piezoelectric element as a vibrating body, and a shaft rod b made of an iron-based alloy is formed integrally through a center hole, and is formed by the columnar piezoelectric element a and the shaft rod b. Vibrator s
Is formed.

The shaft rod b and the piezoelectric element a are firmly connected with each other by bonding or screwing, and are in a state where they can be regarded as vibrationally integrated.

Reference numeral c denotes a flexible substrate which is used to supply electric energy to the vibrator s for generating vibration or to take out electric charges for detecting vibration generated by the vibrator s.

D denotes a flexible substrate for conducting the electrical connection between the electrode surface formed of a conductive paint or the like from the outer peripheral portion or the inner peripheral portion of the vibrator s to the end surface (the lower end surface in the figure) and the flexible substrate c. This is a nut for crimping c and the piezoelectric element a. Therefore, the shaft b is threaded.

The shaft b is fixed at the upper end and supported at the lower end, and supports the vibrator s.

The piezoelectric element a causes the shaft b to bend in different directions (for example, 90 degrees) in response to the supply of an alternating signal having a different phase, for example, an AC signal from the flexible substrate c (the dotted line indicates the bending displacement distribution of the shaft). Is generated, and the piezoelectric element a itself makes a circular or elliptical motion around the shaft rod b as a synthetic vibration.

R is a contact body that comes into contact with the upper end of the vibrator s, and is driven to rotate by the combined vibration of the vibrator s. R1 is a contact spring that directly contacts the vibrator s, and B is a contact body R
Are rotatably supported with respect to the shaft rod b. SP is a coil spring as a spring member for pressing the contact body R against the vibrator s, and enables frictional contact between the vibrator s and the contact body.

The notch AX formed on the inner diameter surface of the upper end of the vibrator s is a rigidity reducing portion for increasing the amplitude near the driving portion of the contact body R.

Since the vibrator s shown in FIG. 1 has a cylindrical outer shape, it has a large degree of freedom in processing and can be manufactured at low cost.
Not suitable for obtaining large amplitudes.

FIG. 2 shows a strain distribution generated when the primary bending vibration is excited. The numerical value described in the contour line indicates the absolute value of the distortion. (The larger the value, the greater the distortion).

(Second Embodiment) In the embodiment shown in FIG. 1 and FIG. 2, the distortion becomes maximum at the central portion of the vibrator s in the axial direction and at the outer peripheral portion in the radial direction.

That is, since the distortion of the outer peripheral portion is large, the amplitude of the bending vibration can be made equal to reduce the distortion by reducing the diameter. However, since the area of the surface perpendicular to the axis of the piezoelectric element becomes small, the vibration becomes small. The force generated by the vibrator becomes small, and when the vibrator is used as a vibrator for an ultrasonic motor as a vibration wave driving device, the generated torque becomes small.

Therefore, a method of reducing the maximum distortion without reducing the diameter is desirable.

The reason why the distortion near the center is large is that, as shown by the middle line in FIG. 2, the distortion shapes 1 to 3 of the vibration mode change rapidly in the center of the vibrator s, that is, near the antinode of vibration.

In order to alleviate this phenomenon, as shown in FIG. 3 as the present embodiment, the rigidity near the antinode of vibration may be increased.

Specifically, a vibrator s which is a free end of vibration
The diameter of the area a1 near the center where the vibration antinode exists may be larger than the diameter a2 of the end of the (piezoelectric element a).

FIG. 3 shows an external view of the vibrator, and FIG. 4 shows a strain distribution after the improvement.

The strain values shown in FIG. 4 are obtained when the radial displacement at the end is equal to that of the vibrator s in FIG. 2 (since the frequencies of both vibrators are substantially equal, the peripheral velocity at the end is equal to the displacement. Proportional).

By making the antinode position thicker than the end, the strain distribution can be made uniform, and the vibrator s can be driven with a small distortion while keeping the displacement of the end equal.

Although omitted in the figure, the vibrator s
It is assumed that a structure including the contact body shown in the first embodiment is formed at the upper end of the.

(Third Embodiment) FIG. 5 shows a third embodiment. In the embodiment shown in FIG. 3, the piezoelectric element a has a stepped cylindrical shape.
Has a large diameter and gradually decreases in diameter toward both ends a2. Since there is no step compared to the second embodiment, the rigidity changes continuously without strength reduction due to stress concentration. Therefore, the strain distribution in the axial direction can be made more uniform, and larger vibration can be obtained.

However, in FIG. 3, an inexpensive manufacturing process of sintering the piezoelectric sheet after press working can be taken, but this is not possible in the present embodiment. Therefore, the number of steps of the diameter difference in FIG. 3 may be increased to approximate the shape in FIG.

Although omitted in the figure, the vibrator s
It is assumed that a structure including the contact body shown in the first embodiment is formed at the upper end of the.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment.

In the present embodiment, since the second-order bending vibration is used, the vicinity a3 of the two antinode positions is made thicker (the outer diameter is made larger). Note that the line in the figure shows the secondary displacement distribution of the shaft bending.

However, since the distortion near the node position in the secondary bending vibration, that is, the central part a5 of the vibrator s (piezoelectric element a) is larger than the end a4 which is the free end of the vibration,
It may be thicker than the vicinity of the end or the same diameter as the vicinity of the belly.

Although omitted in the figure, the vibrator s
It is assumed that a structure including the contact body shown in the first embodiment is formed at the upper end of the.

(Fifth Embodiment) The embodiment shown in FIG. 7 is an example in which the vibrator s of FIG. 6 is configured as a sheet conveying device.

Since the piezoelectric element a has low wear resistance as it is, ceramic sheets i1 and i2 made of alumina or the like having high wear resistance are attached to the side surfaces of the vibrator s.

E is a sheet as a contact body to be conveyed, f is a shaft, and g1 and g2 are rollers rotating about the shaft f. h indicates a spring, and the vibrator s and the sheet e are rollers g
It serves to press through 1 and g2.

Although not shown, an encoder is attached to the rollers g1 and g2, and the signal is fed back to control the vibration of the vibrator s.

(Sixth Embodiment) FIG. 8 shows a specific example of electrodes and polarization of a vibrator used in this embodiment. Electrodes a-d6 are formed on the entire inner peripheral portion of the piezoelectric element a, and the electrodes a divided into four in the circumferential direction are formed on the outer peripheral portion.
-D2, a-d3, a-d4, and a-d5 are formed parallel to the axial direction.

Each of the electrodes extends around the lower end surface of the vibrator s, from which an electric signal for driving (AC signal) is supplied by a flexible substrate c. The arrow in the cross-sectional view indicates the polarization direction of the piezoelectric element a.

During driving, the piezoelectric element a is connected to the inner peripheral electrode a-
d6 is dropped to the ground, and the outer electrodes a-d2 to a-
A two-phase AC electric field is applied to d5, and two sets of bending vibrations having different time phases are excited. Specifically, the piezoelectric element a
The bending vibration generated in the direction of the electrodes a-d2 and the electrode a-d5 around the shaft rod b and the bending vibration generated in the directions of the electrodes a-d3 and the electrodes a-d4 having a spatial phase different from that by 90 degrees, As a result, the piezoelectric element a (vibrator s) moves circularly or elliptically around the shaft rod b as synthetic vibration. Where sinw
t and coswt indicate the time phase relationship of the applied AC electric field. When an AC electric field of Va · sin (wt) is applied to the electrodes a−d2 and a−d5, the directions of polarization are reversed.
When the a-d2 part extends in the axial direction due to the piezoelectric transverse effect, the electrode
In the section a-d5, the entire shrinkage vibrator bends. Electrode a
Similar bending vibrations in which the time phases of the applied electric fields differ by 90 degrees are also performed by the -d3 and a-d4 portions.

(Seventh Embodiment) FIG. 9 shows another specific example of the electrodes and the polarization of the vibrator used in the present embodiment.

In this example, two sets of electrodes for exciting the bending vibration are divided vertically in the axial direction. Electrodes a-d7, a-d8
Are formed on the peripheral surface of the piezoelectric element a over substantially half the circumference, and the electrodes a-d9, a-d
10 is also formed on the peripheral surface.

In order to supply an AC electric field as an electric signal from the lower end face of the vibrator s, electrodes a-d7, a
The electrode extends from −d8 to the lower end of the piezoelectric element a in the figure.

Also in the present embodiment, as in FIG. 8, polarization may be performed in the radial direction using the inner peripheral electrodes a-d11.
As seen in the cross-sectional BB 'diagram, between the opposing electrodes,
Polarization may be applied between the electrodes a-d7 and a-d8 and between the electrodes a-d9 and a-d10, or an electric field for driving the vibrator may be applied.

Therefore, although the inner peripheral electrodes a-d11 are provided in the figure, the inner electrodes a-d11, s-electrodes a-d9,
When applying a polarization or an electric field for driving the vibrator between a and d10, there is also an advantage that there is no need to provide an inner peripheral electrode,
This is particularly effective in a configuration in which the shaft is not penetrated by the vibrator.

The electrodes a-d12 formed on the lower end face of the vibrator s
a-d13 are vibration detecting electrodes for independently detecting bending vibrations in two directions, and are arranged in accordance with two sets of bending vibration directions.

(Eighth Embodiment) FIG. 10 shows a rod-shaped ultrasonic motor as a vibration wave driving device using the vibrator s shown in the embodiment.

Although the vibrator s has the shape shown in FIG. 3, the same operation can be performed by using another vibrator.

This rod-shaped ultrasonic motor rotates the rotor K as a contact body pressed by the circular or elliptical motion generated on the end face of the vibrator s.

Reference numeral i3 denotes a friction material in which a high-strength ceramic such as alumina or the like is adhered to an upper end surface serving as a sliding portion of the vibrator s, and has an outer diameter larger than the end diameter of the vibrator s. .

Reference numeral j denotes a cylindrical contact spring protruding from the rotor K, which is provided so as to contact the vicinity of the outer peripheral portion of the friction member i3. With such a configuration, since the motor output torque can be obtained with a small pressing force, the pressure generated on the friction surface is reduced, which is advantageous for extending the life.

The contact spring j is driven by the vibrator s by the coil spring l.
Is brought into pressure contact. The end of the contact spring j on the side opposite to the friction surface has projections in the axial direction at several places on the circumference. The projections engage with the recesses of the gear m as a rotation output member, and the friction of the rotor K The driving torque is transmitted to the gear m, and the gear m is rotated.

N is an additional mass and is integrally fastened to the shaft rod b. As a result, the shaft b is fixed to the device through the additional mass n.

Although not shown in FIG.
A flexible substrate is provided between and the piezoelectric element a.

(Ninth Embodiment) FIG. 11 mainly shows a shape for shortening the axes of a vibrator and a shaft.

B20 and b30 reduce the rigidity by making a part of the shaft rod b thin, thereby reducing the flow of vibration energy to the end of the shaft rod.

Numeral 0 denotes an additional mass for reducing the vibration displacement at the end of the shaft and suppressing the propagation of vibration to the apparatus.

Reference numeral a20 denotes a circumferential groove for lowering the natural frequency of the vibrator s. Due to the presence of the circumferential groove a20, distortion at the outer periphery of the main groove increases, so that it is difficult to obtain a large amplitude.
Good for small output applications.

Further, the length lo of the upper portion of the shaft rod b can be shortened by the presence of the inner circumferential vertical groove (notch) a30.

[0091]

As described above, in the present invention, since the vibrating body is formed by the electromechanical energy conversion element itself, the interface of the holding surface is smaller than that of the vibrating body formed of a metal elastic body. Without being affected by the pressure distribution of
A vibrator which is inexpensive and has little difference in solids such as energy loss can be provided.

Another problem of strength when the vibrating body is formed by the electromechanical energy conversion element itself is that the shaft is integrally connected to the center hole of the vibrating body formed by the electromechanical energy conversion element. It is possible to deal with it by dispersing the load acting on the electro-mechanical energy conversion element, there is no problem with tensile strength, and it is also possible to prevent breakage due to vibration due to brittleness, and a large output vibration wave drive device And a vibrator can be provided.

Further, the outer diameter of the antinode position of the bending vibration of the vibrating body is made larger than that of the end portion to make the strain distribution uniform, thereby reducing the distortion in the electro-mechanical energy conversion element caused by the vibration. When the amount of distortion generated in the electro-mechanical energy conversion element due to vibration exceeds a certain value, it is possible to suppress a sudden increase in loss.

By forming electrodes on the outer surface of the vibrating body and the surface of the center hole and performing polarization processing in the radial direction, it is possible to easily realize the excitation of bending vibration.

By providing electrodes on at least two opposing outer surfaces of the vibrator and performing a polarization process between the two opposing surfaces, it is possible to easily realize the excitation of bending vibration.

The provision of electrodes for driving and / or vibration detection on the end face of the vibrating body facilitates supply / detection of electric signals.

By forming the friction material layer on the end face of the vibrator, the wear characteristics can be improved.

By making the friction material layer provided on the end face of the vibrating body larger than the end face of the vibrating body, the contact portion with the contact body can be made more external and the driving torque can be increased.

By bringing a circuit board having a pattern for power supply and / or signal detection into contact with the end face of the vibrating body,
The contact by simple axial tightening can be made possible.

By forming the shaft rod of a high-strength material metal, it is possible to cover insufficient strength of the vibrator formed by the mechanical-electrical energy conversion element.

[Brief description of the drawings]

FIG. 1 is a sectional view of a vibration wave driving device according to a first embodiment.

FIG. 2 is a diagram illustrating vibration distortion of a vibrator according to the first embodiment.

FIG. 3 is a cross-sectional view of a vibration wave driving device according to a second embodiment.

FIG. 4 is a diagram illustrating vibration distortion of a vibrator according to a second embodiment.

FIG. 5 is a sectional view of a vibration wave driving device according to a third embodiment.

FIG. 6 is a sectional view of a vibration wave driving device according to a fourth embodiment.

FIG. 7 is a sectional view of a vibration wave driving device according to a fifth embodiment.

FIG. 8 is a view showing a specific example of polarization of a vibrator according to a sixth embodiment.

FIG. 9 is a view showing a specific example of polarization of a vibrator according to a seventh embodiment.

FIG. 10 is a sectional view of a vibration wave driving device according to an eighth embodiment.

FIG. 11 is a sectional view of a vibration wave driving device according to a ninth embodiment.

[Explanation of symbols]

 a cylindrical piezoelectric element as vibrator b shaft rod c flexible substrate s vibrator R contact body

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (27)

[Claims] 1. A vibrator comprising: a vibrating body formed of a substantially rod-shaped electro-mechanical energy conversion element; and a shaft rod integrally connected to a center hole of the vibrating body. A contact body that is pressed by the vibrating body and is frictionally driven by the vibration of the vibrating body to be relatively rotated with the vibrator, wherein the vibrator is supported by the shaft rod. Vibration wave drive. 2. The substantially rod-shaped vibrating body is configured to excite bending vibration in the direction of the shaft bar, and the outer dimension of the antinode position of the bending vibration of the vibrating body is larger than the outer dimension at an end. The vibration wave driving device according to claim 1, wherein: 3. The vibration wave driving device according to claim 1, wherein the vibrating body has electrodes on an outer surface and a surface of the center hole, and is polarized in a radial direction. . 4. An opposing 2 of at least an outer portion of the vibrating body.
The vibration wave driving device according to claim 1, wherein the vibration wave driving device has an electrode on a surface, and polarization treatment is performed between two opposing surfaces. 5. The vibration wave driving device according to claim 1, wherein an electrode for driving and / or detecting vibration is disposed on an end face of said vibrating body. 6. A friction material layer is formed on an end face of the vibrating body,
The vibration wave driving device according to any one of claims 1 to 5, wherein the contact body is pressed against the end surface, and the contact body is rotated around the shaft rod as a center of rotation. 7. The vibration wave device according to claim 6, wherein an outer dimension of the friction material layer is larger than an outer dimension of an end face of the vibrating body. 8. An external dimension of the contact body is made larger than an external dimension of an end face of the vibrating body.
Or the vibration wave driving device according to 7. 9. The vibration wave driving device according to claim 5, wherein a circuit board having a pattern for power supply and / or signal detection is brought into contact with an end face of said vibrator. 10. The vibration wave driving device according to claim 2, wherein an outer dimension at an antinode position of the bending vibration of the vibrator is larger than outer dimensions at both ends. 11. The vibration wave driving device according to claim 1, wherein an outer shape of said vibrating body is formed in a circular shape. 12. The vibration wave driving device according to claim 1, wherein an outer shape of said vibrating body is formed in a square shape. 13. The vibration wave driving device according to claim 12, wherein the outer shape of the vibrator is formed in a square shape, and the cross section is set to be rectangular. 14. The vibration wave driving device according to claim 1, wherein the substantially rod-shaped vibrator is formed of a piezoelectric element, and the shaft rod is formed of metal. 15. A vibrator for use in a vibration wave driving device, comprising: a vibrating body constituted by a substantially rod-shaped electromechanical energy conversion element itself; and a shaft rod integrally coupled to a center hole of the vibrating body. . 16. The substantially rod-shaped vibrating body is configured to excite bending vibration in the direction of the shaft bar, and the outer dimensions of the antinode position of the bending vibration of the vibrating body are larger than the outer dimensions at the end. The vibrator used for the vibration wave driving device according to claim 15, wherein: 17. The vibration wave driving device according to claim 15, wherein the vibrating body has electrodes on an outer surface and a surface of the center hole, and is polarized in a radial direction. Transducer used for 18. The vibration wave drive according to claim 15, wherein electrodes are provided on at least two opposing surfaces of the outer shape of the vibrating body, and a polarization process is performed between the two opposing surfaces. A vibrator used for the device. 19. A driving and / or vibration detecting electrode is disposed on an end face of the vibrating body.
A vibrator used in the vibration wave driving device according to any one of 5 to 18. 20. A vibrator for use in a vibration wave driving device according to claim 15, wherein a friction material layer is formed on an end face of said vibrator. 21. The vibrator used in the vibration wave driving device according to claim 20, wherein an outer dimension of the friction material layer is larger than an outer dimension of an end face of the vibrating body. 22. The vibrator used in the vibration wave driving device according to claim 19, wherein a circuit board having a pattern for power supply and / or signal detection is brought into contact with an end face of said vibrator. 23. The vibrator used in the vibration wave driving device according to claim 16, wherein the outer dimensions at the antinode position of the bending vibration of the vibrator are larger than the outer dimensions at both ends. 24. The vibrator used in the vibration wave driving device according to claim 15, wherein the vibrator has a circular outer shape. 25. The vibrator used in the vibration wave driving device according to claim 15, wherein the outer shape of the vibrator is formed in a square shape. 26. The vibrator used in the vibration wave driving device according to claim 25, wherein an outer shape of the vibrator is formed in a square shape and a cross section is set to be a rectangle. 27. The vibrator used in the vibration wave driving device according to claim 15, wherein the substantially rod-shaped vibrator is formed of a piezoelectric element, and the shaft rod is formed of metal. .