JP2013031285A - Oscillating wave motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oscillating wave motor capable of inhibiting change in frictional force of an oscillating wave motor occurring in association with change in humidity and of reducing deterioration of performance of the oscillating wave motor due to change in humidity.SOLUTION: The oscillating wave motor comprises: an electromechanical energy conversion element; an oscillating body that is fixed to the electromechanical energy conversion element and oscillated by applying a voltage to the electromechanical energy conversion element; a moving body that is pressure-contacted with the oscillating body and friction-driven by the oscillation; a pressure member for pressure-contacting the oscillating body with the moving body; and pressure-regulating means for regulating pressure generating in the pressure member, where the pressure-regulating means regulates the pressure force depending on change in humidity.

Description

  The present invention relates to a so-called vibration wave motor that frictionally drives a moving body by contacting the moving body with pressure, and particularly relates to a pressure structure of the vibration wave motor.

In general, a vibration wave motor has a vibrating body in which a progressive vibration wave is formed and a moving body that is in pressure contact with the vibrating body, and frictionally drives the vibrating body and the moving body with a progressive vibration wave. Get driving force.
Conventionally, as such a vibration wave motor, for example, Patent Document 1 proposes a vibration wave motor configured as shown in FIG.
In FIG. 9, the vibrating body 62 fixed to the housing 61 has an annular shape, and a plurality of protrusions 62d are provided on the entire upper portion of the elastic body 62b.
The elastic body 62b is made of stainless steel, and the protrusion 62d is subjected to nitriding treatment for enhancing durability.
The piezoelectric ceramic 62a is bonded to the bottom surface of the elastic body 62b with an adhesive, and two AC voltages having a phase difference are applied by a drive circuit (not shown) when the motor is driven to generate a progressive vibration wave.
The moving body 63 includes an annular main body 63a made of stainless steel that has been hardened, a support portion 63b, and a contact portion 63c having a sliding surface that frictionally contacts the protrusion 62d of the vibrating body 62. Yes.
The support portion 63b and the contact portion 63c are formed with a thickness having spring properties, and can stably contact the vibrating body 62.
A pressure spring 67 b is attached to the upper surface of the moving body 63 via a spring receiving member 65 and a pressure spring rubber 66. The inner peripheral portion of the pressure spring 67 b is attached to a disk 67 a that is shrink-fitted to the output shaft 68, and transmits the driving force of the moving body 63 to the output shaft 68.
The spring receiving member 65 includes a damping rubber 65a and an annular weight member 65b.
Thereby, unnecessary vibration generated in the moving body 63 is prevented, noise generation and efficiency reduction are suppressed, and stable driving of the vibration wave motor is realized.

Patent Document 2 proposes a vibration wave motor configured as shown in FIG.
In FIG. 10, a friction material 72 f made of a polymer material or the like is joined to the protrusion 72 d of the vibrating body 72. The moving body 73 is made of a material having high hardness such as a metal or a nitride thereof.
The friction material 72f made of a polymer material or the like provided on the protrusion 72d of the vibrating body 72 can stabilize the performance of the vibration wave motor and improve the durability.

JP 2010-263769 A JP-A-11-262280

However, in the vibration wave motor having the vibrating body 62 and the moving body 63 shown in FIG. 9 as in Patent Document 1, the performance of the vibration wave motor sometimes deteriorates as the humidity changes.
That is, the elastic body 62b of the vibration wave motor is made of nitriding stainless steel, and the moving body 63 is made of quenching stainless steel.
When such a vibration wave motor is left in a high-humidity environment, minute moisture adheres to a slight gap between the sliding surfaces of the vibrating body 62 and the moving body 63, thereby causing the vibrating body 62 and the moving body 63 to move. In some cases, the frictional force between them may decrease. For example, such a phenomenon may occur when a vibration wave motor is used in an environment with high humidity.
As a result, the torque generated at the start of the vibration wave motor is reduced, the start of the moving body 63 is delayed, the original speed cannot be obtained immediately after the start, and it may take time until the performance returns. there were.
Further, the vibration wave motor shown in FIG. 10 as in the above-mentioned Patent Document 2 has a high humidity environment in which moisture adheres between the friction material 72f made of the polymer material of the vibration body 72 and the moving body 73. The frictional force increases.
Therefore, there is a possibility that the rotation of the moving body 73 is hindered or cannot be activated.

  In view of the above problems, the present invention suppresses a change in frictional force of a vibration wave motor that occurs with a change in humidity, and can reduce deterioration in the performance of the vibration wave motor due to a change in humidity. The object is to provide a motor.

The vibration wave motor of the present invention includes an electromechanical energy conversion element,
A vibrating body fixed to the electro-mechanical energy conversion element and vibrated by application of a voltage to the electro-mechanical energy conversion element;
A moving body that is in pressure contact with the vibrating body and frictionally driven by the vibration;
A pressurizing member for bringing the vibrating body and the movable body into pressure contact with each other;
A vibration wave motor having
A pressure adjusting means for adjusting the pressure generated in the pressure member;
The pressurizing force adjusting means adjusts the pressurizing force according to a change in humidity.

  According to the present invention, a vibration wave motor capable of suppressing the change in the frictional force of the vibration wave motor that occurs with a change in humidity and reducing the deterioration in the performance of the vibration wave motor due to the change in humidity is realized. can do.

Sectional drawing explaining the structure of the vibration wave motor which concerns on Example 1 of this invention. Sectional drawing which expanded a part of vibration wave motor shown in FIG. 1 of Example 1 of this invention. The figure which shows the mode of a deformation | transformation of the pressurization adjustment member in the vibration wave motor shown in FIG. 1 of Example 1 of this invention. Fig.4 (a) is sectional drawing to which the pressurization adjustment member which concerns on the 1st modification of the vibration wave motor which concerns on Example 1 of this invention was expanded. FIG. 4B is an enlarged sectional view of the pressure adjusting member according to the second modification. Sectional drawing explaining the structure of the vibration wave motor which concerns on Example 2 of this invention. Sectional drawing explaining the structure of the modification of the vibration wave motor which concerns on Example 2 of this invention. Sectional drawing explaining the structure of the vibration wave motor which concerns on Example 3 of this invention. The figure which shows the mode of a deformation | transformation of the pressurization adjustment member in the vibration wave motor shown in FIG. 7 of Example 3 of this invention. Sectional drawing explaining the structure of the vibration wave motor in a prior art example. The perspective view explaining the structure of the vibration wave motor in another prior art example.

  The mode for carrying out the present invention will be described with reference to the following examples.

[Example 1]
As a first embodiment, a configuration example of a vibration wave motor to which the present invention is applied will be described with reference to FIG.
As shown in FIG. 1, the vibration wave motor of the present embodiment is formed in an annular shape, and includes a vibrating body 2 and a moving body 3 that is in frictional contact with the vibrating body.
The vibrating body 2 is formed by a piezoelectric element 2a that is an electro-mechanical energy conversion element that converts an electrical quantity into a mechanical quantity, and an elastic body 2b that is coupled to the piezoelectric element 2a.
Then, a driving voltage (alternating voltage) is applied to the piezoelectric element 2a, and an elliptical motion is generated in the vibrating body 2 by a progressive vibration wave by a known technique. Rotate relatively.

The elastic body 2 b includes a base portion 2 c, a projecting portion 2 d, and a flange portion 2 e that extends from the base portion 2 c and fixes the elastic body 2 b to the housing 1.
The protrusion 2d is disposed concentrically with respect to the central axis of the elastic body 2b along the outer peripheral side of the base 2c. The surface of the protrusion 2d on the moving body 3 side is a sliding surface with the moving body 3.
The elastic body 2b is a metal elastic member, and is formed of stainless steel in this embodiment. Furthermore, as a hardening process for enhancing durability, the sliding surface of the protrusion 2d with the moving body 3 is nitrided.

The moving body 3 includes an annular main body portion 3a formed of an elastic member, a support portion 3b, and a contact portion 3c having a sliding surface that makes frictional contact with the protrusion 2d of the vibrating body 2. In this embodiment, the moving body 3 is formed of stainless steel that has been subjected to quenching treatment.
The support portion 3b and the contact portion 3c are formed with a thickness having a spring property, and stable contact with the vibrating body 2 is possible.
A spring receiving member 5, a pressure spring rubber 6, and a pressure member 7 are attached to the upper surface of the movable body 3 via a pressure adjustment member (pressure adjustment means) 4.
The pressure member 7 includes a disk 7a and a pressure spring 7b. The inner peripheral portion of the pressure spring 7 b is attached to a disk 7 a that is shrink-fitted to the output shaft 8, and transmits the driving force of the moving body 3 to the output shaft 8.
The pressure spring rubber 6 is made of butyl rubber or chloroprene rubber. Due to the elastic deformation of the pressure spring rubber 6, the influence of the flatness of the surface of the spring receiving member 5 on which the pressure spring rubber 6 is provided is mitigated.
Therefore, the pressing force from the pressure spring 7b is uniformly applied to the moving body 3 without unevenness in the rotational direction, and the stable contact between the vibrating body 2 and the moving body 3 is maintained.
The output shaft 8 is rotatably supported by a pair of rolling bearings 9 a and 9 b having an outer ring fixed to the housing 1 and an inner ring fitted to the outer periphery of the output shaft 8.
The inner ring of the rolling bearing 9a is preloaded by the amount of displacement of the pressure spring 7b for bringing the movable body 3 into pressure contact with the vibrating body 2 with an appropriate force.
Thereby, the radial play of the rolling bearing 9a is eliminated, and the shake of the output shaft 8 in the radial direction can be suppressed.

FIG. 2 shows an enlarged cross-sectional view of a part of the vibration wave motor shown in FIG.
In FIG. 2, the spring receiving member 5 is formed of an annular elastic member, and includes a weight portion 5a and restricting portions 5b and 5c.
In this embodiment, the spring receiving member 5 is made of brass. The restricting portion 5 b is in contact with the inner peripheral surface of the pressure adjusting member 4, and the restricting portion 5 c is in contact with the outer peripheral surface of the pressure adjusting member 4.
The pressure adjusting member 4 is made of a so-called water-expandable rubber containing butyl rubber or chloroprene rubber having high vibration damping performance as a main material and containing a highly water-absorbing resin.
For this reason, the pressurizing adjustment member 4 and the spring receiving member 5 suppress unnecessary vibration of the moving body 3 that occurs during driving of the vibration wave motor, and prevent noise and output of the vibration wave motor from decreasing.

FIG. 3 shows how the pressure adjusting member 4 is deformed when the humidity of the vibration wave motor shown in FIG. 1 is increased.
In FIG. 3, the pressure adjusting member 4 is constituted by a pressure adjusting member that deforms in response to a change in the humidity containing the highly water-absorbent resin, so when the humidity of the environment around the vibration wave motor rises, The superabsorbent resin absorbs moisture, and the pressure adjusting member 4 expands. Since the inner and outer circumferences of the pressure adjusting member 4 are in contact with the restricting portions 5b and 5c of the spring receiving member 5, the pressure adjusting member 4 has a larger amount of deformation in the rotational axis direction than in the radial direction of the vibration wave motor. Yes.
At this time, the axial rigidity of the vibrating body 2 and the moving body 3 is sufficiently higher than that of the pressurizing spring 7b. The disk 7a is fixed in the axial direction with respect to the output shaft 8.
Therefore, when the pressure adjusting member 4 expands and is deformed in the rotation axis direction, the spring receiving member 5 moves to the pressure spring 7b side in the rotation axis direction.
Thereby, the displacement of the pressurizing spring 7b increases, and the pressure applied to the vibrating body 2 and the movable body 3 by the pressurizing spring 7b increases.

On the other hand, when the humidity of the environment around the vibration wave motor rises, minute moisture adheres to a slight gap between the sliding surfaces of the vibrating body 2 and the moving body 3, thereby causing a gap between the vibrating body 2 and the moving body 3. The coefficient of friction decreases.
Since the frictional force is determined by the product of the applied pressure and the friction coefficient, the frictional force acting between the vibrating body 2 and the moving body 3 is offset by the increase in the applied pressure accompanying the increase in humidity and the decrease in the friction coefficient. It becomes difficult to change even if the humidity rises.
On the other hand, when the humidity decreases, the superabsorbent resin contained in the pressure adjusting member 4 releases moisture, and the pressure adjusting member 4 contracts.
Thereby, the pressurizing force is reduced by reducing the displacement of the pressurizing spring 7b. And the water | moisture content in the slight clearance gap of the sliding surface of the vibrating body 2 and the moving body 3 decreases, and the friction coefficient between the vibrating body 2 and the moving body 3 rises.
Therefore, the frictional force acting between the vibrating body 2 and the moving body 3 is less likely to change even when the humidity is reduced by offsetting the decrease in the applied pressure accompanying the decrease in humidity and the increase in the friction coefficient.

As described above, it is possible to suppress the change in the frictional force of the vibration wave motor that occurs with the change in humidity, which has been a problem in the conventional structure.
As a result, it can be considered that the generated force of the vibration wave motor is substantially proportional to the frictional force, so that even if the humidity changes, the change in the generated force of the vibration wave motor can be suppressed. Degradation of performance can be reduced.
Here, the amount of change in the applied pressure accompanying the change in humidity is the thickness of the pressure spring 7b, the thickness of the pressure adjustment member 4, the type and content of the superabsorbent resin, the regulating portion 5b of the spring receiving member 5, Adjustment is possible with the shape of 5c.
For example, when the change in the friction coefficient accompanying the change in humidity is large, it is possible to increase the thickness of the pressure spring 7 b and increase the amount of change in the applied pressure with respect to the deformation of the pressure adjustment member 4.
It is also possible to increase the amount of change in the applied pressure by increasing the thickness of the pressure adjusting member 4 and increasing the deformation amount of the pressure adjusting member 4.
On the other hand, when the change in the friction coefficient accompanying the change in humidity is small, it is possible to reduce the thickness of the pressure spring 7b and reduce the amount of change in the applied pressure with respect to the deformation of the pressure adjusting member 4. .
Further, by expanding the radial distance between the restricting portions 5b and 5c of the spring receiving member 5 that is in contact with the inner and outer diameters of the pressure adjusting member 4, it can be deformed in the radial direction when the pressure adjusting member 4 is expanded. The amount of deformation in the direction of the rotation axis is reduced, and the amount of change in the applied pressure can be reduced.

In the present embodiment, the vibrating body 2 is made of nitriding stainless steel, and the moving body 3 is made of quenching stainless steel.
However, the present invention is not limited to such a configuration, and the present invention suppresses the change in the generated force of the vibration wave motor as long as it is a combination of materials whose friction coefficient decreases with increasing humidity. Is possible.
For example, a similar effect can be obtained by the present invention even in a vibration wave motor in which the vibrating body 2 is formed by nickel plating on stainless steel and the moving body 3 is formed by anodizing aluminum alloy.
In this embodiment, the pressure adjusting member 4 is formed of a so-called water-swellable rubber containing butyl rubber, chloroprene rubber or the like as a main material and containing a highly water-absorbing resin.
However, the present invention is not limited to such a configuration.
For example, as shown in FIG. 4A, the pressure adjusting member 14 may be formed by sandwiching a highly water-absorbing resin 14a with a vibration damping member 14b such as butyl rubber.
Further, as shown in FIG. 4B, a pressure adjusting member 24 may be formed by sandwiching a material 24a having a high expansion coefficient against humidity such as cork with a vibration damping member 24b such as butyl rubber.
Thereby, it becomes possible to change a pressurizing force with the change of humidity, and it can reduce the deterioration of the performance of the vibration wave motor accompanying the change of humidity.

[Example 2]
As a second embodiment, a configuration example of a vibration wave motor having a different form from the first embodiment will be described with reference to FIGS. 5 and 6.
The vibration wave motor of the present embodiment is different from that of the first embodiment in that the pressure adjusting member has the structure shown in FIG. The other elements (vibrating body, moving body, output shaft, etc.) of the present embodiment are the same as the corresponding ones of the above-described embodiment 1, and thus the description thereof is omitted. In addition, the structure shown in FIG. 5 of a present Example respond | corresponds to FIG.
In FIG. 5, a damping rubber 36 a and a spring receiving member 35 are provided on the upper surface of the moving body 33 to suppress unnecessary vibration of the moving body 33 that occurs during the driving of the vibration wave motor. Noise and output are prevented from decreasing.
A pressure spring 37b is attached to the upper surface of the spring receiving member 35 via a pressure spring rubber 36b.
The pressure adjusting member (pressure adjusting means) 34 is composed of a first pressure adjusting member 34a and a second pressure adjusting member 34b, which are a highly water-absorbing resin, a water-expandable rubber, a cork and the like. The pressure adjusting member is made of a material that expands with an increase in humidity.
The first pressure adjusting member 34 a is provided between the housing 31 and the flange portion 32 e of the vibrating body 32.
The second pressure adjusting member 34b is provided between the disk 37a shrink-fitted on the output shaft 38 and the pressure spring 37b.

Here, when the humidity of the environment around the vibration wave motor rises, the first pressure adjusting member 34a and the second pressure adjusting member 34b absorb moisture and expand.
When the first pressure adjusting member 34a expands and deforms in the rotation axis direction, the vibrating body 32 moves to the pressure spring 37b side in the rotation axis direction, and the spring receiving member 35 also moves to the pressure spring 37b side in the rotation axis direction. Move to.
Thereby, the displacement of the pressurizing spring 37b increases, and the applied pressure applied to the vibrating body 32 and the moving body 33 by the pressurizing spring 37b increases.
Further, when the second pressure adjusting member 34b expands and deforms in the direction of the rotation axis, the inner peripheral side of the pressure spring 37b attached to the second pressure adjustment member 34b becomes the vibrating body 32 in the direction of the rotation axis. Move to the side. Thereby, the displacement of the pressurizing spring 37b increases, and the applied pressure increases.

On the other hand, when the humidity of the environment around the vibration wave motor rises, minute moisture adheres to a slight gap between the sliding surfaces of the vibrating body 32 and the moving body 33, thereby causing a gap between the vibrating body 32 and the moving body 33. The coefficient of friction decreases.
Therefore, the frictional force acting between the vibrating body 32 and the moving body 33 is less likely to change even when the humidity increases by offsetting the increase in the applied pressure accompanying the increase in humidity and the decrease in the friction coefficient.
On the other hand, when the humidity decreases, the pressure adjusting member 34 releases moisture, and the first pressure adjusting member 34a and the second pressure adjusting member 34b contract.
Thereby, the pressurizing force is reduced by reducing the displacement of the pressurizing spring 37b.
And the water | moisture content in the slight clearance gap of the sliding surface of the vibrating body 32 and the moving body 33 decreases, and the friction coefficient between the vibrating body 32 and the moving body 33 rises.
Therefore, the frictional force acting between the vibrating body 32 and the moving body 33 is less likely to change even when the humidity is reduced by offsetting the decrease in the applied pressure accompanying the decrease in humidity and the increase in the friction coefficient.

As described above, it is possible to change the applied pressure with a change in humidity, and it is possible to reduce the deterioration of the performance of the vibration wave motor with the change in humidity.
Further, by providing two pressure adjusting members 34, the amount of change in the applied pressure accompanying a change in humidity is increased as compared with the case where one pressure adjusting member 34 is provided.
As a result, the frictional force can be adjusted even for a vibration wave motor made of a material having a large change in the friction coefficient caused by a change in humidity, and the deterioration of the performance of the vibration wave motor can be suppressed. become able to.
The vibration wave motor of the present embodiment is provided with two pressure adjusting members 34 composed of a first pressure adjusting member 34a and a second pressure adjusting member 34b. It is not limited to these structures.
For example, as shown in FIG. 6, the pressure adjusting member 44 is composed of three pressure adjusting members, a first pressure adjusting member 44a, a second pressure adjusting member 44b, and a third pressure adjusting member 44c. It is configured.
As a result, the amount of change in the pressing force of the pressurizing spring 47b accompanying a change in humidity is further increased, and even for a vibration wave motor composed of a material having a large change in friction coefficient caused by a change in humidity, The frictional force can be adjusted, and the deterioration of the performance of the vibration wave motor can be reduced.

[Example 3]
As a third embodiment, a configuration example of a vibration wave motor having a different form from the above-described first embodiment will be described with reference to FIG.
The vibration wave motor of the present embodiment is different in configuration from the above embodiments in that the pressure adjusting member, the vibrating body, and the moving body are structured as shown in FIG. The other elements (piezoelectric element, output shaft, etc.) of the present embodiment are the same as the corresponding ones in the above embodiments, and thus the description thereof is omitted. Note that the configuration shown in FIG. 7 of the present embodiment corresponds to FIGS.
In FIG. 7, a friction material 52f is coupled to the protrusion 52d of the elastic body 52b of the vibrating body 52 by bonding with an adhesive or the like.
The friction material 52f is formed of a resin produced by firing using a fluororesin powder (PTFE: polytetrafluoroethylene) as a main material and carbon fiber, polyimide, and molybdenum disulfide as additives.

The moving body 53 is formed of an aluminum alloy. Tungsten carbide-cobalt spray material is sprayed on the sliding surface of the moving body 53 with the friction material 52f of the vibrating body 52 as a hardening process for enhancing durability.
Since the friction material 52f of the vibrating body 52 is formed of resin, it is elastically deformed when in contact with the moving body 53, enabling stable contact with the moving body 53 and improving durability.
A damping rubber 56a and a spring receiving member 55 are provided on the upper surface of the moving body 53 to suppress unnecessary vibration of the moving body 53 that occurs during driving of the vibration wave motor, and to reduce noise and output of the vibration wave motor. The decline is prevented.
A pressure spring 57b is attached to the upper surface of the spring receiving member 55 via a pressure spring rubber 56b.
The pressure adjusting member (pressure adjusting means) 54 is formed of a pressure adjusting member made of a material that expands with an increase in humidity, such as a highly water-absorbent resin, water-expandable rubber, or cork.
The pressure adjusting member 54 is provided between a disk 57a shrink-fitted on the output shaft 58 and the pressure spring 57b, and is fixed by adhesion or the like.

FIG. 8 shows how the pressure adjusting member 54 is deformed when the humidity in the vibration wave motor shown in FIG. 7 is increased.
In FIG. 8, when the humidity of the environment around the vibration wave motor rises, the pressurizing adjustment member 54 absorbs moisture and expands.
Since the disk 57a is fixed to the output shaft 58, when the pressure adjusting member 54 expands and deforms in the direction of the rotation axis, the inner peripheral side of the pressure spring 57b is deformed in the direction of the arrow in the figure.
As a result, the displacement of the pressure spring 57b is reduced, and the pressure applied to the vibrating body 52 and the movable body 53 by the pressure spring 57b is reduced.

On the other hand, when the humidity of the environment around the vibration wave motor rises, minute moisture adheres to a slight gap between the friction material 52f made of the resin material of the vibration body 52 and the sliding surface of the moving body 53, thereby causing the vibration body. The friction coefficient between 52 and the moving body 53 increases.
Therefore, the frictional force acting between the vibrating body 52 and the moving body 53 is less likely to change even when the humidity increases by offsetting the decrease in the applied pressure accompanying the increase in humidity and the increase in the friction coefficient.
On the other hand, when the humidity decreases, the pressure adjusting member 54 releases moisture and the pressure adjusting member 54 contracts. Thereby, the pressurizing force increases as the displacement of the pressure spring 57b increases.
And the water | moisture content in the slight clearance gap of the sliding surface of the vibrating body 52 and the moving body 53 decreases, and the friction coefficient between the vibrating body 52 and the moving body 53 falls. Therefore, the frictional force acting between the vibrating body 52 and the moving body 53 is less likely to change even when the humidity is reduced by offsetting the increase in the applied pressure accompanying the decrease in humidity and the decrease in the friction coefficient.

As described above, it is possible to change the applied pressure with a change in humidity, and it is possible to reduce the deterioration of the performance of the vibration wave motor with the change in humidity.
In this embodiment, the friction material 52f of the vibrating body 52 is formed of a resin made of a fluororesin powder main material, and the moving body 53 is formed of an aluminum alloy sprayed with a tungsten carbide-cobalt spray material.
However, the present invention is not limited to such a configuration, and the present invention suppresses the change in the generated force of the vibration wave motor as long as it is a combination of materials whose friction coefficient increases with increasing humidity. Is possible.
As described above, according to the configuration of each of the above embodiments of the present invention, the change in the frictional force of the vibration wave motor caused by the change in humidity is suppressed, and the performance of the vibration wave motor due to the change in humidity is reduced. Deterioration can be reduced.

2: Vibrating body 2a: Piezoelectric element 3: Moving body 4: Pressure adjusting member 7b: Pressure spring

Claims (6)

An electromechanical energy conversion element;
A vibrating body fixed to the electro-mechanical energy conversion element and vibrated by application of a voltage to the electro-mechanical energy conversion element;
A moving body that is in pressure contact with the vibrating body and frictionally driven by the vibration;
A pressurizing member for bringing the vibrating body and the movable body into pressure contact with each other;
A vibration wave motor having
A pressure adjusting means for adjusting the pressure generated in the pressure member;
The vibration wave motor according to claim 1, wherein the pressure adjusting means adjusts the pressure according to a change in humidity.   2. The vibration wave motor according to claim 1, wherein the pressurizing force adjusting means is constituted by a pressure adjusting member that is deformed in accordance with a change in humidity.   The vibration wave motor according to claim 2, wherein the pressure adjusting member increases the pressurizing force by deformation accompanying an increase in humidity.   The vibration wave motor according to claim 2, wherein the pressure adjusting member reduces the applied pressure by deformation accompanying an increase in humidity.   5. The vibration wave motor according to claim 2, wherein the pressure adjusting member is deformed due to expansion when the humidity increases. 6.   6. The pressure adjusting member according to claim 2, wherein the pressure adjusting member is formed of a material that expands due to moisture absorption accompanying an increase in humidity and contracts due to moisture release accompanying a decrease in humidity. Vibration wave motor.

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