JPH0880078A - Ultrasonic motor, and device using ultrasonic motor as drive source - Google Patents

Abstract

PURPOSE: To maintain favorable pressure contact between a mover and an oscillator even at continuous drive and get stable high output without causing remarkable deterioration of performance, or occurrence of friction, etc., by using a pressure transmitting material having such quality that the temperature of thermal transformation is 100 deg.C or over. CONSTITUTION: An oscillator consisting of a vibrator 1, electrode boards 2-A, 2-B, and 2-G, piezoelectric elements 3-A and 3-B, a press board 4, and a bolt 5 is bonded and fixed to a fixing member 10 with the whirl-stop member 5-b of a bolt 5, and one end face of the press spring 11 contacts with the fixing member 5, and the other end face contacts with a slide member 12 working as a pressure transmitting member. And, the press spring 10 presses a rotor 7 against the oscillator through a slide member 12, a bearing 13, and a rotor output transmitting member 14. Here, the quality of the slide member 12 is metal where the temperature of thermal transformation is 100 deg.C or over, for example, Bs. Hereby, the temperature rises at continuous operation, high output can be obtained stably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor using ultrasonic vibration and a device using the ultrasonic motor as a drive source.

[0002]

2. Description of the Related Art Conventionally, a vibrator formed in a rod shape is applied with an AC voltage to a piezoelectric element provided on the vibrator to generate vibrations in two bending modes. An ultrasonic motor has been proposed in which an elliptical movement is generated in the surface particles of the above, and a moving body that is in pressure contact with this driving surface is frictionally driven to obtain a rotational force.

This ultrasonic motor was constructed as shown in the sectional view of FIG.

That is, a vibrating body 1 made of brass and piezoelectric elements 3-A, 3-B electrode plates 2-A, 2-made of phosphor bronze.
Presser body 4 made of B, 2-G brass and Ni-on free cutting copper
The vibrator is constituted by the bolt 5 plated with P (nickel-phosphorus), the end surface 1-a of the vibrating body 1 is a friction sliding portion, and one point of the friction sliding portion is the direction of the arrow in the figure. That is, it vibrates in the direction of about 45 ° with the sliding portion, and when viewed from the axial direction of the oscillator, it is a circular motion, and gives a rotary motion to the rotor 7 made of aluminum which is in contact with the friction sliding portion at the 7-a portion.

The constricted portion 1-b of the vibrating body enlarges the displacement of the friction sliding portion.

The shape of the 7-b portion of the rotor 7 is such that the direction of deformation when the contact portion 7-a receives the exciting force from the vibrating body 1 is as shown by the arrow in the figure. It is formed so that friction loss is reduced. Further, for wear resistance, the surface of the rotor 7 is anodized, and the surface of the vibrator 1 is Ni-P (nickel-phosphorus) plated.

FIG. 13 is an exploded view of a vibrator of an ultrasonic motor.

The piezoelectric elements 3-A, 3-B have their polarization axes reversed in a single piezoelectric element with the central axes as boundary lines 3-A-a, 3-B-a. As shown in the figure, the two piezoelectric elements 3-A (hereinafter referred to as A-phase piezoelectric elements) face the same part in the polarization direction, and sandwich the electrode plate 2-A.
Similarly, the two piezoelectric elements 3-B (hereinafter, referred to as B-phase piezoelectric elements) face each other in the same polarization direction as shown in the figure,
The electrode plate 2-B is sandwiched. Then, as shown in the drawing, the two A-phase piezoelectric elements and the two B-phase piezoelectric elements are arranged 90 ° apart from each other with the electrode plate 2-G sandwiched therebetween.
Then, the four piezoelectric elements and the electrode plate arranged as described above are arranged between the vibrating body 1 and the pressing body 4 and fastened and fixed by bolts 5 (not shown).

Electrode plate 2 of the vibrator constructed as described above
When voltages V _A and V _B as shown in FIG. 14 are applied to A and 2-B, respectively, the oscillator vibrates as shown in FIG. 15 due to the vibrations of the A-phase piezoelectric element and the B-phase piezoelectric element. Gives a progressive bending mode which is a vibration like.
Particularly, when the frequency of the AC voltage as shown in FIG. 14 is matched with the resonance frequency of the vibration mode shown in FIG. 15, the vibration of the vibrator becomes maximum and the rotation of the rotor also becomes maximum.

Further, in FIG. 12, the vibrator including the vibrating body 1, the electrode plate 2, the piezoelectric element 3, the pressing body 4, and the bolt 5 is fixed to the fixing member 10 made of zinc, and the rotation preventing portion 5 of the bolt 5 is formed.
It is adhesively fixed at b. Therefore, the oscillator is supported by the bolt 5 and the fixing member 10.

The pressure spring 11 has one end surface fixed to the fixing member 1.
0, and the other end surface is in contact with the slide member 12 made of polyacetal resin. The inner diameter side of the slide member 12 is in contact with the bolt shaft portion 5-c, so that the slide member 12 is movable only in the thrust direction.
The pivot bearing 13 and the slide member 12, and the rotor output transmission member 14 and the rotor 7 are integrated by press fitting or bonding, respectively.
The tip end 14-a of No. 4 has a tapered shape and is in contact with the ball of the pivot bearing 13. The pressurizing force of the pressurizing spring 11 is a pressurizing force for pressing the rotor against the vibrator via the slide member 12, the pivot bearing 13, and the rotor output transmission member 14. The rotor rotates due to the progressive bending mode vibration generated in the vibrator, but at this time, the rotor 7 and the rotor output transmission member 14 rotate together. The rotor output transmission member 14 and the output gear 8 form a detent at the portion A, and the rotational force of the rotor 7 is transmitted to the output gear by the portion A. A plurality of detents A are provided on the same circumference. In the portion A, the rotor output transmission member 14 and the output gear 8 have a play in the radial direction and the thrust direction and can freely move. Further, the rotor output transmission member 14 is formed of stainless steel (SUS) that has been subjected to quenching and tempering.

In the conventional ultrasonic motor having such a structure, a radial force (lateral pressure) is generated when the output gear transmits the output to the transmission gear (not shown).

The portion that axially supports the rotor is not truly parallel to the thrust direction but is slightly inclined.

The contact surface between the rotor and the vibrator is not truly perpendicular to the thrust direction.

The torque reaction force of the plurality of detent portions for transmitting the rotational force of the rotor is not uniform, and as a result, a radial force (side pressure) is generated on the rotor in a plane perpendicular to the thrust direction including the portion A.

The precision of the pressure spring is poor, and the applied pressure is not uniform in the circumferential direction.

In such a case as well, as described below, these do not affect the pressing force of the rotor, and the rotor follows the vibrator and is uniformly pressurized to a predetermined size. Has become.

The output gear 8 is axially supported by the step portion 10-d of the fixed member 10 via a bearing 9 on the fixed member 10 side. Therefore, the radial force (side pressure) received when the output gear 8 transmits the output to the transmission gear (not shown) is transmitted to the step portion 10-d of the fixing member 10 via the bearing 9, and the pressure spring 11 is applied. Has no effect on pressure.

Next, the rotor 7 is a rotor output transmission member 14,
It is pivotally supported by the shaft portion 5-c of the bolt 5 via the pivot bearing 13 and the slide member 12. Normally, the pivot bearing and its shaft are likely to have angular runout, and the action allows the rotor 7 to tilt. This tilt is bolt 5
Absorbs a slight inclination of the shaft portion 5c, and a deviation in which the contact surface of the rotor vibrator is not truly perpendicular to the thrust direction.

The rotation preventing portion A has a structure in which the rotor output transmission member 14 and the output gear 8 have play in the radial direction and the thrust direction and can move freely, so that the shaft portion 5 of the bolt 5
Even if c is slightly inclined or the contact surface between the rotor and the vibrator is not truly perpendicular to the thrust direction, the rotor can follow the vibrator.

Next, the torque reaction force of the plurality of detent portions (A portion) for transmitting the rotational force of the rotor is not uniform, and as a result, the force in the radial direction to the rotor in the plane including the A portion and perpendicular to the thrust direction. (Lateral pressure) is generated. However, as described above, the rotor is axially supported by the shaft portion 5-c of the bolt 5, and is axially supported in the plane perpendicular to the thrust direction including the portion A. Therefore, this side pressure is applied to the shaft portion 5-c of the bolt 5. Does not affect the pressure applied to the vibrator of the rotor.

Next, as shown in FIG. 16, originally, the slide member 12 should be uniformly pressed at a pressure of P ₀ at any place over the entire circumference, whereas one of the slide member 12 should be pressed due to the poor processing accuracy of the spring. It is assumed that the pressure is R ₁ and the other is P ₂ . However, (P ₁ + P ₂ ) / 2 = P
_Set to ₀ . As shown in FIG. 17, P ₁ and P ₂ applied to the end 12-a of the slide member 12 that contacts the pressure spring 11 are P
₁ = P ₀ + (P ₁ −P ₀ ), P ₂ = P ₀ + (P ₂ −P
₀ ) can be decomposed. (P ₁ -P ₀₎ and (P ₂ -P ₀₎ has given moment to the end 12-a.

Therefore, when the forces P ₁ and P ₂ act, a predetermined pressing force P ₀ acts as shown in FIG. 17, and further (P ₁ -P ₀ ) and (P ₂ -P ₀ ) Is equivalent to the action of the moment.

The moment composed of (P ₁ -P ₀ ) and (P ₂ -P ₀ ) is received by the bolt shaft portion 5-c, and as a result, the slide member 12 is uniformly pressured to P ₀ over the entire circumference. There is no difference to being pressurized with.

As described above, the conventional example has a structure in which the rotor follows the vibrator and is uniformly pressed to a predetermined size, so that a high output can be obtained.

[0026]

However, in the above-mentioned conventional example, although high output can be stably obtained when used intermittently, initial high output cannot be maintained when continuously used, There was a drawback that the performance deteriorated in a short time. This will be explained below.

In the initial stage, a conventional ultrasonic motor having a TN characteristic shown in FIG.
30se under a load of × 10 ^-3 N · m (100 gf · cm)
After driving c, stop for 60 seconds, repeat this for 120 cycles (total driving time is 1 hour), then repeat TN
When the characteristics were measured, they almost matched the initial characteristics shown in FIG. However, if it is driven continuously without stopping for 60 seconds, the load will be 9.8 × 10 ⁻³ after about 20 minutes.
The number of revolutions at N · m (100 gf · cm) was about 1/2 of the initial value. At this time, when the TN characteristic was measured, it was significantly lower than the initial characteristic as shown in FIG. At this time, a large amount of abrasion powder was generated from the friction drive surface.

Next, it is considered that the performance does not deteriorate when it is used intermittently because the temperature rise of the ultrasonic motor is small, and after measuring the initial T-N characteristics, air cooling with a cooling fan is performed. 1.5W with a load of 9.8 × 10 ^-3 Nm
When the TN characteristic was measured again after continuously driving for 1 hour with the input of, the performance was hardly deteriorated and the abrasion powder was hardly generated.

From the above, it has been clarified that the remarkable deterioration of performance in continuous driving is related to the temperature rise of the ultrasonic motor. Therefore, a load of 9.8 × 10 ⁻³ N · m is applied next. It was measured how the temperature of the ultrasonic motor rose when continuously driven with an input of 1.5 W. The temperature was measured by attaching a thermocouple to the end B of the bolt 5. At the same time, the amount of eccentricity of the rotation center of the rotor (rotational shake amount) measured by the rotation speed and the optical displacement measuring device
Also measured. The measurement results are shown in FIGS. 20, 21 and 22. Note that the rotation center eccentricity amount in FIG. 22 is a displacement difference in the radial direction when the rotor is positioned most to the right in the drawing of FIG. 12 and when the rotor is most positioned to the left of the drawing in FIG. 12 during one rotation. Yes, this is the amount of rotation blur of the rotor that matches the rotation cycle. This rotation center eccentricity is determined by a plurality of detent portions (A in FIG. 12) that transmit the rotational force of the rotor.
Torque reaction force is not uniform, and as a result, a radial force (side force) is generated on the rotor in a plane perpendicular to the thrust direction including the A portion, slide with the shaft portion 5-c of the bolt 5. It occurs due to radial clearance with the member 12 and deformation of the slide member 12.

As is clear from FIGS. 20, 21, and 22, when the time from the start of driving is 12 minutes or less, the eccentric amount of the rotation center is the shaft portion 5-c of the bolt 5 and the slide member 1.
The clearance in the radial direction with respect to 2 is about 20 μm, and the rotation speed is almost constant during this time. However, when the temperature of the ultrasonic motor reaches the temperature of 94 ° C., which is the thermal deformation temperature of the slide member 12, from 16 minutes to 20 minutes later, the rotation center amount sharply increases and the rotation speed significantly decreases. At the same time, abrasion powder begins to be remarkably generated from the friction drive surface. In addition, the temperature rise width becomes slightly larger. After 20 minutes, the amount of eccentricity of the rotation center remains as large as about 100 μm, and the number of rotations further decreases.

From the above experiment, it is considered that the remarkable deterioration of performance in continuous driving is caused by the following mechanism. That is, as shown in FIG. 23, when the temperature of the ultrasonic motor rises due to continuous driving and reaches the thermal deformation temperature of the slide member, the strength of the slide member decreases. As described above, the radial to the rotor in the plane perpendicular to the thrust direction including the part A, which is caused by the non-uniform components of the torque reaction force of the plurality of rotation preventing parts (part A in FIG. 12) transmitting the rotational force of the rotor. The rotative center eccentric amount is generated by the force in the direction, but when the strength of the slide member decreases, the rotor rotational center eccentric amount increases. As a result, as shown in the schematic diagram of FIG. 24, the 7-a portion of the rotor comes into contact with a place different from the frictional sliding portion 1-a of the vibrator 1 before the eccentricity of the rotor rotation center increases. . Friction sliding part 1-a of the vibrating body 1 before the amount of eccentricity of the rotor rotation center increases
Is a concave part due to steady wear, but the eccentricity of the rotor rotation center increases and
When a place different from a contacts, a portion having a very large surface pressure such as 1-c portion is generated, resulting in significant wear. Due to the significant wear, the efficiency of the ultrasonic motor is greatly reduced and the rotation speed is also reduced. A decrease in efficiency means an increase in loss energy, which is thermal energy, and as a result, the temperature of the ultrasonic motor further rises.

The mechanism described above causes a rapid decrease in the number of rotations, an increase in the amount of eccentricity of the rotation center, and significant wear at the same time when continuously driven. The reason why such a phenomenon does not occur when driven intermittently or when air-cooled is considered to be that the temperature rise of the ultrasonic motor is small and the loop shown in FIG. 23 is cut off.

As described above, in the above-mentioned conventional example, the mechanism described above has a drawback in that, when continuously driven, the performance is significantly deteriorated and the wear is caused in a short time. An object of the present invention is to provide an ultrasonic motor capable of sufficiently withstanding continuous driving.

Another object of the present invention is to provide a device using an ultrasonic motor as a drive source, which solves the above problems.

[0035]

According to a first aspect of the present invention, there is provided a vibrator for sandwiching an electro-mechanical energy conversion element between rod-shaped vibrating elastic bodies, and A moving body that is arranged coaxially with the vibrator so as to come into contact with the driving surface of the vibrator, a pressing member that generates a biasing force along the axial direction of the vibrator, and a pressing force of the pressing member. In an ultrasonic motor having a pressing force transmitting member that receives and transmits the moving force to the moving body, the pressing force transmitting member is an ultrasonic motor in which tilting of the vibrator with respect to the axial direction is restricted.
The heat distortion temperature is 100 ° C. or higher.

In this structure, even if the temperature rises during continuous driving, the pressure transmitting member is not affected by thermal deformation, so that good pressure contact between the moving body and the vibrator is maintained, resulting in a significant deterioration in performance. No significant wear or the like occurs, and stable high output can be obtained even in continuous driving.

The heat distortion temperature here is the temperature obtained by the method A (load 18.5 kg / cm ² ) of the deflection temperature test of hard plastics in the Japanese Industrial Standards, and is a metal or ceramics. Materials that do not reach the specified deflection amount by this test method are considered to have extremely high heat distortion temperature.

Here, as described in claim 2, in claim 1, at least a part of the pressing force transmitting member is made of resin.

With this configuration, the vibration damping property of the pressing force transmitting member is high, and therefore, there is an effect of preventing squeaking.

Further, as described in claim 3 or 4, in claim 1 or 2, the pivot bearing for pivotally supporting the moving body enables the rotating and tilting of the moving body, or the pivoting of the moving body. By adopting a configuration in which the moving body can be rotated and tilted by the spherical bearing, the pressure holding of the moving body against the vibrator becomes even better,
The driving of the moving body in continuous driving can be maintained more stably.

A structure for realizing another object of the present invention is characterized in that, as described in claim 5, the ultrasonic motor according to claim 1, 2, 3 or 4 is used as a drive source.

In this structure, the ultrasonic motor can be used as the drive source of the device which is continuously driven.

[0043]

【Example】

[First Embodiment] The ultrasonic motor in this embodiment is shown in FIG.
2 is the same as the ultrasonic motor of the conventional example, except that the material of the slide member 12 is different, and the other materials, functions, and shapes are the same as those of the ultrasonic motor of the conventional example.

FIG. 1 shows the temperature change of the ultrasonic motor when continuously driving the ultrasonic motor using brass as the material of the slide member 12, FIG. 2 shows the change of the rotation speed, and the change of the eccentric amount of the rotation center of the rotor. Is shown in FIG. These measuring methods and conditions are the same as those in the conventional example shown in FIGS. 20, 21, and 22. As is clear from FIGS. 1, 2 and 3, since the slide member is made of a stable metal at 100 ° C. or lower, the rotational speed and the eccentricity of the rotational center are almost constant up to 120 minutes, and significant abrasion powder is generated. There was no. The TN characteristics measured before and after this measurement were almost the same as those in FIG. As described above, it is possible to stably obtain a high output without causing a significant deterioration in performance or a significant wear even during continuous driving. Needless to say, the same effect can be obtained when the material of the slide member 12 is a metal other than Bs, such as SUS.

The ultrasonic motor in this embodiment is
The slight vibration of the 5-c portion due to the leakage of the vibration of the vibrator 1 affects the contact between the 5-c portion and the slide member 12, and a slight squeal is generated.

[Second Embodiment] This embodiment has the same construction as the conventional ultrasonic motor shown in FIG. 12, except that the material of the slide member 12 is different, and the other materials, functions and shapes are the same. is there.

The material of the slide member is polyacetal K ₂
Fig. 4 shows the temperature change of the ultrasonic motor when the ultrasonic motor made of resin (heat distortion temperature 147 ° C) containing 30% by weight of O.6TiO ₂ single crystal whisker was continuously driven. FIG. 5 shows changes in the amount of eccentricity of the rotation center of the rotor. These measuring methods and conditions are the same as those in the conventional example shown in FIGS. 20, 21, and 22. As is clear from FIGS. 4, 5 and 6, since the slide member is made of a material having a high heat deformation temperature, the rotation speed and the eccentricity of the rotation center are substantially constant for up to 120 minutes, and significant abrasion powder is generated. There was no. The TN characteristics measured before and after this measurement were almost the same as those in FIG. As described above, it is possible to stably obtain a high output without causing a significant deterioration in performance or a significant wear even during continuous driving. Further, since the slide member in this embodiment is made of resin, it has a larger vibration damping effect than the slide member in the first embodiment described above, and does not cause squeal that occurs in the ultrasonic motor in the first embodiment. A quieter motor was obtained. Other than the material used for the slide member of the present embodiment, the same effect can be obtained even if it is a thermosetting resin such as an epoxy resin as long as the heat deformation temperature is 100 ° C. or higher.

[Third Embodiment] This embodiment is similar to the ultrasonic motor of the conventional example shown in FIG.
The material, function, and shape are the same as those of the conventional ultrasonic motor except that the two materials are different.

FIG. 7 shows the temperature change of the ultrasonic motor when the ultrasonic motor was continuously driven when the material of the slide member was SUS and the surface thereof was coated with an epoxy resin with a thickness of about 20 μm. Is shown in FIG. 8, and the change in the eccentricity of the rotation center of the rotor is shown in FIG. These measuring methods and conditions are the same as those in the conventional example shown in FIGS. 20, 21, and 22. As is clear from FIGS. 7, 8 and 9, since the slide member is made of resin-coated metal, the rotation speed and the eccentricity of the rotation center are substantially constant up to 120 minutes, and no significant abrasion powder is generated. . The TN characteristics measured before and after this measurement were almost the same as those in FIG. As described above, it is possible to stably obtain a high output without causing a significant deterioration in performance or a significant wear even during continuous driving. In addition, since the slide member in this embodiment is made of metal coated with resin, it has a greater vibration damping effect than the slide member in the first embodiment described above, and it seems that the ultrasonic motor in the first embodiment generated it. A quieter motor was obtained without any noise.

[Fourth Embodiment] FIG. 10 is a sectional view showing a fourth embodiment. The spherical slide member 15 serves as means for supporting the rotor and enabling the rotor to rotate and tilt.
Also, a spherical bearing by the spherical bearing concave body 16 may be used. Spherical slide member is polyacetal K ₂ O ・ 6T
The rotor output transmission member 14 is made of a resin (heat deformation temperature of 147 ° C.) containing 30% by weight of SiO ₂ single crystal whisker, and the spherical bearing concave body 16 is made of, for example, Teflon resin.
I am engaged with. By setting the thermal deformation temperature of the spherical slide member to 100 ° C. or higher as described above, stable performance and high output can be obtained without significant deterioration in performance or wear even when continuously driven. In addition, the spherical slide member 15
Since the resin is a resin, it has a greater vibration damping effect than the slide member in the first embodiment described above, does not generate the squeal that occurs in the ultrasonic motor in the first embodiment, and is a quieter motor. can get.

[Fifth Embodiment] FIG. 11 is a schematic view showing a fifth embodiment.

The present embodiment is an AF drive mechanism for a camera which uses the ultrasonic motor of the second embodiment shown in FIG. 1 as a drive motor. A transmission gear 50 coaxially includes a large gear 51, a small gear 52, and a rotation pulse plate 53. The large gear 51 meshes with the output gear 8 of the ultrasonic motor, and the small gear 52 rotates the lens barrel. It meshes with the gear 55 of the cylinder 54 and transmits the rotational force of the ultrasonic motor to the rotary cylinder 54 to move the lens. On the other hand, the rotation of the transmission gear 50 is detected by the pulse plate 53 and the photo interrupter 56, and a control circuit (not shown) controls the ultrasonic motor based on the detection signal,
The F operation is performed.

[0053]

According to the first aspect of the invention, even if the temperature rises during continuous driving, the pressure transmitting member is not affected by thermal deformation, so that good pressure is applied between the moving body and the vibrator. The contact is maintained, significant deterioration of performance and occurrence of significant wear do not occur, and stable high output can be obtained even in continuous driving.

According to the second aspect of the invention, the vibration damping property of the pressing force transmitting member is high, and therefore, there is an effect of preventing squeaking.

According to the third and fourth aspects of the present invention, the pressure holding of the moving body and the vibrator is further improved, and the driving of the moving body in the continuous drive can be maintained more stably. .

According to the fifth aspect of the invention, the ultrasonic motor can be used as the drive source of the device that is continuously driven.

[Brief description of drawings]

FIG. 1 is a diagram showing a temperature change during continuous driving in a first embodiment of the present invention.

FIG. 2 is a diagram showing changes in the number of revolutions during continuous driving in the first embodiment of the present invention.

FIG. 3 is a diagram showing an amount of eccentricity of a rotation center during continuous driving in the first embodiment of the present invention.

FIG. 4 is a diagram showing a temperature change during continuous driving in the second embodiment of the present invention.

FIG. 5 is a diagram showing changes in the number of revolutions during continuous driving in the second embodiment of the present invention.

FIG. 6 is a diagram showing the amount of eccentricity of a rotation center during continuous driving in the second embodiment of the present invention.

FIG. 7 is a diagram showing a temperature change during continuous driving in the third embodiment of the present invention.

FIG. 8 is a diagram showing changes in the number of revolutions during continuous driving in the third embodiment of the present invention.

FIG. 9 is a diagram showing the amount of eccentricity of the rotation center during continuous driving in the third embodiment of the present invention.

FIG. 10 is a sectional view of a rod-shaped ultrasonic motor according to a fourth embodiment.

FIG. 11 is a sectional view of an apparatus showing a fifth embodiment.

FIG. 12 is a vertical sectional view of a conventional rod-shaped ultrasonic motor.

13 is an exploded perspective view of the vibrator shown in FIG.

14 is a waveform diagram of a drive signal applied to the vibrator of FIG.

15 is a diagram showing a vibration state of the vibrator shown in FIG.

16 is a sectional view showing a pressure mechanism of the ultrasonic motor of FIG.

17 is a diagram showing a pressing force applied to the slide member of FIG.

18 is a diagram showing the initial performance of the ultrasonic motor of FIG. 12 in terms of the relationship between the rotation speed and the load torque.

FIG. 19 is a diagram showing the performance of the ultrasonic motor of FIG. 12 after continuous driving for 20 minutes, as a relationship between the rotational speed and the load torque.

20 is a diagram showing temperature changes during continuous driving of the ultrasonic motor of FIG.

FIG. 21 is a diagram showing changes in the number of revolutions during continuous driving of the ultrasonic motor of FIG.

22 is a diagram showing a rotation center eccentric amount when the ultrasonic motor of FIG. 12 is continuously driven.

FIG. 23 is a view showing a mechanism of a remarkable performance deterioration of the ultrasonic motor of FIG.

24 is a diagram showing a drive contact portion of the ultrasonic motor of FIG.

[Explanation of symbols]

1 ... Exciter 2-A, 2-B,
2-G ... Electrode plate 3-A, 3-B ... Piezoelectric element 4 ... Presser body 5 ... Bolt 7 ... Rotor 8 ... Output gear 9 ... Bearing 10 ... Fixing member 11 ... Pressure spring 12 ... Slide member 13 ... Bearing 14 ... Rotor output transmission member 15 ... Spherical slide member 16 ... Spherical bearing recess

Claims (5)

[Claims] 1. A vibrator that holds an electro-mechanical energy conversion element between rod-shaped vibrating elastic bodies, and a moving body that is coaxially arranged with the vibrator so as to abut a driving surface of the vibrator.
A pressure member that generates a biasing force along the axial direction of the vibrator;
An ultrasonic motor having a pressing force transmitting member for receiving the pressing force of the pressing member and transmitting the pressing force to the moving body, wherein the pressing force transmitting member is an ultrasonic motor in which tilting of the vibrator with respect to the axial direction is restricted. The ultrasonic motor, wherein the pressing force transmitting member has a heat deformation temperature of 100 ° C. or higher. 2. The pressing force transmitting member according to claim 1,
An ultrasonic motor, at least a part of which is made of resin. 3. The ultrasonic motor according to claim 1 or 2, wherein the movable body can be rotated and tilted by a pivot bearing that pivotally supports the movable body. 4. The ultrasonic motor according to claim 1, wherein the movable body can be rotated and tilted by a spherical bearing that axially supports the movable body. 5. An apparatus using the ultrasonic motor according to claim 1, 2, 3 or 4 as a drive source.