JPH09327183A - Oscillatory wave drive unit and equipment provided with this unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the durability and develop a large driving force by forming a frictional contact section of either a vibrator or a contactor from fiber contained resin and forming that of the other member from ceramic. SOLUTION: In the case of a ring-shaped vibrating motor, a vibrator 1 is formed in the shape of a ring and a plurality of projections are formed in the circumferential direction of an upper face of it. Frictional material 1a joined to the end of each projection which is a contact section is made mainly of fluorine contained resin and contains carbon fiber. To a contact section of a contactor 2, ceramic frictional material is joined. The frictional material for the contactor 2 is first formed into a ring-shaped thin plate and then is pasted to the surface of the contactor 2 with an epoxy adhesive and a part of the face corresponding to a sliding face is processed to be smooth. A sensing element 3 receives an alternating voltage and generates progressive vibrating waves in the projections of the vibrator 1. As a result, driving force can be increased with the increase in a coefficient of friction and the adhesion of the frictional materials is suppressed and thereby the decrease in frictional force can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration wave driving apparatus for exciting a vibration in a vibrating body by an electro-mechanical energy conversion element or the like and frictionally driving a contact body in contact therewith.

[0002]

2. Description of the Related Art A friction material is attached to the frictional contact surfaces of a vibrating body and a contact body of a vibration wave driving device as described above so that vibrations generated in the vibrating body can be efficiently transmitted to the contact body. For example, Japanese Patent Application Laid-Open No. 5-212785 proposes a vibration wave driving device in which one of a friction material on the vibrating body side and a friction material on the contacting body side is formed of a polyimide resin and the other is formed of alumina. .

[0003]

However, there is a problem that the resin easily wears, which contributes to shortening the life of the vibration wave driving device. In addition, a part of the resin may adhere to the sliding surface of the alumina to hinder the smooth operation of the vibration wave driving device (for example, cause uneven rotation), resulting in deterioration of performance.

When a thick resin transfer film is formed on the surface of the friction material of the other party by sliding with such a resin,
This transfer film functions as an anti-wear film for the friction material on the other side, but since the friction material slides between the resins due to the presence of the transfer film, the friction coefficient between the friction surfaces is substantially small. Therefore, there is an adverse effect that a large driving force cannot be generated.

Further, when the vibration wave driving device is left in a high humidity and then dried, a phenomenon occurs in which the friction material on the vibrating body side and the friction material on the contacting body side adhere to each other to prevent the vibration wave driving device from starting. However, when the transfer film is formed, the gap between both sliding surfaces is filled and a fixing force acts on a large area, so that the vibrating body and the contact body are firmly fixed to each other. There is also.

Therefore, a first object of the present invention is to provide a vibration wave drive device having high durability and capable of generating a large driving force.

A second object of the present invention is to provide a vibration wave drive device capable of reliably preventing sticking between friction materials.

[0008]

In order to achieve the above object, in the first invention of the present application, a vibration wave for relatively frictionally driving a vibrating body that generates vibration and a contact body that contacts the vibrating body. In the drive device, one of the vibrating body and the contacting body is made of a fiber-containing resin, and the other is made of ceramic.

That is, by bonding a resin containing a fiber reinforced material such as carbon fiber or potassium titanate fiber and having improved wear resistance to a friction contact portion as a friction material, the vibration wave drive device has a long life. In addition to increasing the friction coefficient, the driving force generated is increased. Moreover, by using a hard ceramic as a counterpart of the frictional contact of the fiber-containing resin, it is possible to prevent the transfer film itself from being formed, suppress the sticking phenomenon, and prevent the reduction of the frictional force. .

Furthermore, since abrasion due to friction with the fiber-containing resin is not only caused by a grinding action, but also caused by a chemical action, that is, mutual diffusion between two materials, it is not simply hard. This is not sufficient, and ceramics are selected in the present invention as a material in consideration of these.

Here, the sticking phenomenon is the same as the ringing of the block gauge or the phenomenon that the optical planes are brought into close contact with each other with a strong force, and is caused by the surface tension of oil or water existing in the gap.

In the case of an oscillatory wave drive device, because of the pressure contact force applied between two friction surfaces to generate a friction force, the surface on the resin side follows the surface on the side of a hard mating material, and between the two surfaces. The gap becomes a very narrow range, and the area of such a part is widened. When kept in this state under high humidity, water is condensed in the very narrow gap. The distance in which water can be condensed depends on the relative humidity, and the higher the humidity, the greater the distance. This value is
For example, relative humidity of 90% is 0.01 μm, 97% is 0.0
36 μm.

Then, an adhesion force (called a stick cushion) acts on the place where the water is condensed. According to the experiment by the applicant, in the combination of the friction material of ceramic and metal, the higher the relative humidity is, the stronger this adhesive force is, and in the case where one of them is the resin friction material, after being held once under high humidity, The adhesion became stronger when left in low humidity. This can be explained by any of the following reasons. First, the higher the humidity, the greater the distance that water will condense, so
It is considered that the projected area where water condenses also increases.
However, the extent to which the projected area increases depends on the nature of the surface roughness. And, as the area increases, so does the adhesive strength, which is not necessarily the case. This is because the suction force (adhesion force) per unit area decreases as the condensed distance increases. For example, when the condensation distance is doubled and the condensed area is doubled or more, the overall adhesion is increased. It seems that was the case with the combination of metal and ceramics.

If one is made of resin, the condensation distance is 2
Even if it doubles, it is considered that the condensed area does not increase up to twice.

From the above, the relative humidity is 97% in the equilibrium state.
There is a possibility that a stronger adhesive force may be exerted at about 90% than under high humidity. Or, as another way of thinking, the receding contact angle may be extremely small. That is, there is a possibility that the curvature of the meniscus may be extremely small due to the water once condensed under high humidity being placed under low humidity. It seems that the internal pressure of condensed water is decreasing while the condensed area remains almost unchanged. This is not in equilibrium. It is different from the condition that it is kept in the same low humidity from the beginning.

In any case, according to the present invention, as described above, the friction material containing the fibrous reinforcing material, which is significantly harder than the resin, can be substantially brought into contact with the hard material such as ceramic. Therefore, a narrow gap where water is condensed is not formed in a wide range. This is because neither the fiber-containing resin nor the ceramic is sufficiently hard to show the behavior of "accompaniing the surface shape of the other party".

Furthermore, the formation state of the transfer film depends on the material and surface roughness of the mating material and its shape. For example, as will be described in the following embodiments, in the case of chromium, a transfer film is likely to be formed thick on its surface. When this transfer film is collected and its components are analyzed, a large amount of chromium is detected. In other words, it seems that the reinforcing material or resin and the chromium chemically reacted. Aluminum, titanium, lead, etc. are known as such materials, but they are chemically very active (trying to bond with other elements immediately) once the surface passivation film (oxide film) is peeled off. It's all metal. Further, depending on the surface roughness and the shape thereof, the transfer film is likely to be formed by a phenomenon similar to the phenomenon of clogging of the file eye, such as when rubbing a file soft material.

However, since ceramic has a low chemical reactivity, it hardly reacts with the mating material. The ceramic was originally produced by baking at a high temperature of 1500 ° C. or higher, and is an oxide, nitride, or carbide that is stable not only in the surface layer but also inside. For this reason,
Normal metal has a very thin layer on its surface (passivation film thickness of aluminum, titanium, stainless steel, etc.
(01 μm or less) is different from the oxide,
The surface is always chemically stable, even if there is wear due to friction. Therefore, ceramic is the most suitable as the mating material.

When the above-mentioned metal such as aluminum exhibits such a behavior that the passive film is too fast to be regenerated in a timely manner or the surface is momentarily scraped, it reacts immediately with the mating material to cause a phenomenon of seizure. Therefore, it is not suitable as a mating material.

Among the ceramics, it is desirable to further improve the wear resistance by using one having alumina or zirconia as a main component, which is particularly excellent in wear resistance.

Vickers hardness of about 1500 is necessary in order to prevent abrasion due to friction with the fiber reinforcing material contained on the resin side, but it is necessary to take chemical reactivity into consideration. Silicon carbide, silicon nitride and sialon are slightly more worn than alumina. The reason for this is
It is considered that silicon is contained in these ceramics, and this element reacts with oxygen in the air to form SiO2, and this silicon oxide has a Vickers hardness of about 500, which is softer than the ceramics themselves and causes wear. . This is so-called oxidative wear. Further, in the case of aluminum nitride, since aluminum nitride is slightly softer than other ceramics, scratches may occur on the circumference of the friction material. From the above, a ceramic containing alumina or zirconia as a main component is particularly suitable as a mating material.

Further, in the second aspect of the present invention, by securing the center line average roughness of the friction contact surface of the ceramic to be 0.5 μm or more, it is possible to effectively suppress the adhesion of the friction materials.

Unlike a ductile metal, a material such as ceramic is unlikely to have a sharp convex surface when subjected to a smoothing process such as a lapping process, and thus a smooth surface is easily obtained. If the hard material has a number of sharp projections that are particularly protruding from other portions, the surface pressure will be abnormally high only at those local portions, and the mating material tends to be easily scraped.

For the purpose of simply suppressing the sticking phenomenon, the rougher the surface, the better. However, if the surface roughness is too large, the wear of the mating resin friction material increases. Therefore, in the present invention, the friction surface of the ceramic is appropriately roughened to obtain the effect of alleviating the above-mentioned phenomenon of sticking between the vibrating body and the contact body.

In order to suppress the sticking phenomenon, increasing the surface roughness of alumina has a permanent effect.
This is because there is almost no wear of alumina. It is not desirable if the surface roughness changes due to wear during friction driving.

In the third invention of the present application, the corners of the smoothed ceramic are rounded by buffing or chemical polishing to reduce the abrasion of the resin without reducing the center line average roughness. .

Specifically, once the surface having irregularities is subjected to buffing or chemical polishing, as shown in FIG. 4B, a part of a sphere (a part of an arbitrary curved surface may be formed on a plane). ) Is added to form a flat surface shape, and the corners are sharpened, making it difficult for the mating material to wear (Note that the right diagram in Fig. 4 (b)
Since the ordinate and the abscissa have different magnifications, they are not displayed with a constant curvature.) Therefore, abrasion powder is not accumulated in the concave portion of the ceramic, and the sticking suppressing effect is further effective.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a ring-shaped vibration wave motor (vibration wave drive device) according to a first embodiment of the present invention. The driving principle of this vibration wave motor is disclosed in JP-A-59 / 59
Since it is already known from Japanese Patent Publication No. 2016165, etc., its explanation is omitted here.

In the figure, 1 is a vibrating body. The vibrating body 1 is formed in a ring shape having a diameter of 30 mm, and a large number of protrusions are formed in the circumferential direction of the upper surface. The friction material 1a is joined to the tip of each protrusion, that is, the contact portion. The friction material 1a is made of a fluororesin as a base material, and is made of carbon fiber having a diameter of 10 μm and a length of 0.1 mm.
Contains 0 weight percent.

Reference numeral 2 denotes a moving body (contact body), and a friction material, which will be described later, is joined to the contact portion of the contact body 2.

Reference numeral 3 denotes an electro-mechanical energy conversion element joined to the vibrating body 1. The converting element 3 receives an alternating voltage and generates a progressive vibration wave on the protrusion of the vibrating body 1. As a result, the moving body rotates, but this movement is a relative movement that occurs via frictional force, and if the vibrating body 1 is fixed, the moving body 2 rotates and, conversely, the moving body 2 is rotated. If fixed, the vibrating body 1 rotates.

FIG. 2 shows the moving body 2 studied in this embodiment.
Is a list of friction materials for joining to. These friction materials are manufactured as a ring-shaped thin plate and then attached to the surface of the moving body 2 with an epoxy adhesive. After that, a surface corresponding to the sliding surface of the friction material is smoothed by a lapping machine supplied with 3 μm-sized diamond abrasive grains.

The sliding surfaces of the friction material 2 processed in this manner were all less than 0.1 μm in center line average roughness (Ra) except for alumina having pores.

Next, in order to change the ratio of the convex portions, a surface having once smooth surface roughness as described above is further added to the surface.
Using diamond abrasive grains as large as 0 μm, the surface was processed by a lapping machine. In other words, it means that they have intentionally scratched the surface. This makes it possible to produce a friction material having a center line average roughness (Ra) of 0.5 μm or more, as will be described later. In addition, in the present embodiment, in order to further smooth only a part of the convex portion, an alumina lapped with diamond abrasive grains having a size of 3 μm was manufactured as a prototype.

Here, the ratio of the convex portions in the present embodiment will be described. Analysis of the surface roughness of ordinary materials shows that the areas occupied by them are distributed in various proportions from the most convex to the most concave.

For example, the surface finished by using a grindstone or loose abrasive grains has a relatively small area in the vicinity of the highest place and the vicinity of the lowest place. For example, as shown in FIG. If expressed in a graph called bearing ratio,
The height of the unevenness is plotted on the vertical axis, and the cumulative value of the area is plotted on the horizontal axis, which is represented by an S-shaped graph.

The surface cut with a cutting tool having a certain angle is represented by a linear graph as shown in FIG. 3 (b). Further, the surface of which the tip is cut with a round-shaped cutting tool is represented by a graph of a downwardly convex multidimensional curve, as shown in FIG.

A surface obtained by smoothing only a part of the convex portion of the once roughened surface is represented by the graph shown in FIG. 3 (d).
In the drawings on the right side in FIGS. 3A to 3D, the surface shape is shown in a larger scale in the vertical direction than in the horizontal direction.

The ratio of the convex portions defined in this embodiment is the ratio of the area occupied from the highest point (H) in the surface shape to the lowest point by 0.1 μm. The number of 0.1 μm is the distance that may cause the condensation of water mentioned above. Because the larger this ratio is, the more the area where water is condensed increases.
This is because the fixing force between the moving body 2 and the vibrating body 1 also tends to increase.

Next, the evaluation of each friction material will be described with reference to FIG. NO. The stainless steel No. 1 is equivalent to JIS standard SUS420J2, and was tempered to a Vickers hardness of 700 by quenching and tempering. Porosity was set to 0% because almost no holes were observed on the surface. Since the maximum surface roughness was 0.1 μm, the ratio of the convex portions was 100% according to the above definition. When the vibration wave motor of FIG. 1 is driven for 100 hours with the stainless steel joined to the moving body 2, the wear amount of the stainless steel is
It was 2.2 μm.

The wear particles of this stainless steel are red rust-like, and when observed with a scanning electron microscope, they are flaky and resemble the typical fretting wear particles generated in steel materials. In addition, the amount of wear of the mating material fluororesin is 30
μm. Although the same tendency was observed for other materials, generally, as the wear amount of stainless steel increased, the wear amount on the resin side also increased. This is for non-chrome
This is because the mechanism in which the generated abrasion powder scrapes and wears the resin side is dominant.

In the case of stainless steel, the generated red rust-like wear powder is considered to be hematite (Fe2 O3), which has a Vickers hardness of about 500. That is, the wear powder is softer than the base material, stainless steel. The generated abrasion powder is not red rust but black rust, that is, magnetite (F
e3 O4), the Vickers hardness is 150
Since it is considered to be small in size, it seems that the action of scraping the resin of the other party is a little smaller.

Next, in the case of NO. After driving the vibration wave motor using the friction material of No. 1 for 100 hours to make the sliding surfaces conform to each other, leave it in the environment of relative humidity of 95% for 4 hours, and then reduce the humidity to 50% for 1 day. After leaving, the moving body 2 was peeled off from the vibrating body 1 to examine the degree of sticking between the moving body 2 and the vibrating body 1, and the result was that the degree of sticking was “strong”. It is considered that this is because a large number of carbon fibers on the other side were transferred to the sliding surface on the moving body 2 side.

NO. The chrome plating of No. 2 is NO. P of 3
The same evaluation as VD chromium was obtained. PVD chrome is PVD in which nitrogen is injected into chrome at the same time as film formation.
It is a chromium film formed by the (physical vapor deposition) method.

Although the amount of wear of chromium itself is considerably smaller than that of stainless steel, the amount of wear of the mating material resin was not different from that of stainless steel. Here, when observing the friction surface on the chromium side, a considerably thick (1-2 μm) transfer film was mottled. When this transfer film was peeled off and analyzed by EPMA attached to a scanning electron microscope,
A large amount of chromium was detected. However, chrome abrasion powder itself could not be confirmed. Since the size of the atomic level of chromium is not visible in the scanning electron microscope, it is considered that chromium and the carbon fiber or resin of the partner chemically react with each other, and mainly wear the resin side.

NO. 4 nickel not heat treated
Phosphorous plating has an amorphous lattice structure with a Vickers hardness of about 550. The wear results of this material are similar to those of stainless steel for both this material and the mating material.

NO. The surface of the stainless steel of No. 5 was ion-nitrided to a thickness of 30 μm and NO. In the case of the high-speed steel No. 6, probably because the hardness was harder than the stainless base metal, although the abrasion was slightly less than that of the stainless steel, red rust-like abrasion powder was generated.

NO. Vanadium carbide was formed on the surface of vanadium carbide by diffusing vanadium on the surface of high speed steel in the salt bath of No. 7 or NO. 8 high-speed steel with physical vapor deposition of titanium nitride on the surface of about 3 μm and N
O. The titanium carbide of No. 9 which was chemically vapor-deposited to a thickness of about 3 μm had very hard surface hardness, so that almost no abrasion was observed. However, for unknown reasons, the resin on the other side was worn about half that of stainless steel.

Further, NO. 10 super hard and NO. 11 T
Similar results were obtained in the case of cermet containing iC as a main component.

In this evaluation, the Vickers hardness is defined as a macro hardness when the hard tungsten carbide such as cemented carbide and the slightly soft cobalt phases are mixed. This means that the hardness test was performed with a sufficiently large indentation so that the effect of hardness was not exerted. The same applies when the pores are internal. For example, even in the case of alumina having the same composition, the macro hardness differs if the porosity is different.

Next, the evaluation of alumina will be described.
First, no. In the case of alumina 12 having a porosity of 15%, the center line average roughness is slightly large due to the holes. As a result of abrasion, alumina itself was 0.1 μm or less, which was in an unreadable range with the accuracy of the surface profile measuring instrument used for measuring the amount of abrasion. Also, the amount of wear of the resin on the other side was about 1/10 of that of stainless steel or the like.

However, with regard to fixation, the proportion of convex portions is 85%.
Perhaps because of this, the transfer of the carbon fiber of the other party was confirmed, which was not much different from the materials such as stainless steel.

NO. 13 translucent alumina or NO. 14
For sapphire, which is a single crystal alumina of No. 1, the wear results are Although it was almost as small as the alumina of No. 12, the surface smoothing treatment was performed only by diamond abrasive grains having a size of 3 μm, the center line average roughness was as small as 0.1 μm or less, and the adhesion was NO. It was about the same as the alumina of No. 12.

No. With respect to the porous alumina of No. 15, the center line average roughness was 0.5 μm, and a clear effect was recognized in the result of fixation. That is, when the moving body 2 was detached from the vibrating body 1, the moving body 2 could be separated with a light force, and the transfer of the carbon fibers was also very small.

No. Alumina Nos. 16 to 21 are obtained by changing the surface smoothing treatment of non-porous alumina. N
o. No. 16 is finished with a copper lapping machine using 3 μm size diamond abrasive grains. No. 17 to 19 are
After the lapping, the surface is roughened by using diamond abrasive grains having a size of 10, 20 or 40 μm. The larger the diamond abrasive grain, the larger the center line average roughness, and the amount of wear of the mating material slightly increased, but good results were obtained for sticking.

No. Alumina of Nos. 20 and 21 is No. 1
After performing a smoothing treatment equivalent to that of No. 9, lapping was performed for a very short time using 3 μm size diamond abrasive grains, and then buffing was performed using 1 μm size diamond abrasive grains (No. 2).
0) or chemical polishing (No. 21) by rubbing with a cloth impregnated with an ammonium fluoride solution to finish to a predetermined surface shape. The former lap processing is
This process was performed to smooth only the vicinity of the apexes of the protrusions on the surface roughened with 40 μm large abrasive grains, and the shape of the protrusions is schematically shown in FIG. 3 (d). In addition, the latter buffing is performed so that the corners near the apex are rounded as shown in FIG. 4A. The results of these samples were that they were less worn and that they were better adhered.

Other, No. Regarding the evaluation results of various ceramics of Nos. 22 to 28, some wear was observed in themselves except for the alumina containing SiC fiber, alumina-zirconia and zirconia, and the wear of the mating material was also larger than that of alumina.

According to the above evaluation results, the friction material on the moving body 2 side of the motor of this embodiment is preferably ceramics as compared with metals, charcoal and cermets, and among the ceramics, alumina and zirconia are the main components. Those that do are preferred. Moreover, among those containing alumina as the main component, N
o. The one that has been subjected to buffing or chemical polishing of 20, 21 is most suitable.

In this embodiment, the case where the carbon fiber-containing fluororesin is joined to the vibrating body 1 and the ceramic or the like is joined to the moving body 2 has been described. However, the carbon fiber-containing fluororesin is joined to the moving body 2. A ceramic or the like may be bonded to the vibrating body 1.

(Second Embodiment) FIG. 5 shows a cross section of a vibration wave motor (vibration wave drive device) according to a second embodiment of the present invention. A vibrator (vibrating body) of this motor includes a piezoelectric element (electric-mechanical or mechanical-electrical energy converting element) 3 for driving and a sensor and an electrode plate 4, and an upper vibrator constituent body 1.
It is sandwiched between the lower oscillator structure 5 and the lower oscillator structure 5 and then fastened with a bolt 6. In addition, the upper oscillator structure 1
An insulating sheet 7 is interposed between the bolt 6 and the bolt 6 to electrically insulate them.

The magnitude of the vibration displacement generated on the sliding surface 1b of the vibrator is adjusted by the thickness of the constricted portion 1d. The sliding surface 2b of the moving body (contact body) 2 is pressed against the sliding surface 1b by the urging force of the coil spring 8. The displacement generated on the sliding surface 1b of the vibrator is transmitted to the moving body 2 by friction, and the gear 9
Output to the outside through

FIG. 6 is an enlarged view of the sliding portion of this motor, showing a portion incorporating the friction material described in the first embodiment.

A ring-shaped friction material 1a such as alumina, which is a separate member, is adhesively bonded to the upper vibrator assembly 1. Conventionally, the upper vibrator structure 1 was formed by cutting free-cutting brass and then plating the entire surface with Ni—P—SiC with a thickness of about 30 μm and using the plating itself as a friction material. , This upper oscillator structure 1 was made by zinc die casting and had a thickness of 5 to maintain corrosion resistance.
Ni-P plating processing of about μm is performed.

The ring-shaped friction material is produced by press punching in the case of stainless steel, but in the case of ceramics such as alumina, a tubular fired body is produced and then a cutting stone containing diamond abrasive grains is used. It is made into slices. Then, after the ceramic in a sliced state is adhered to the upper oscillator structure 1 with an epoxy resin, the sliding surface thereof is subjected to the smoothing processing described in the first embodiment.

In the case of ceramic, instead of the above method, the ring-shaped member may be directly punched out by a sheet forming method.

On the other hand, as for the friction material on the moving body 2 side, as shown in FIG. 6, the sliding surface of the moving body 2 is coated with the friction material 2a made of resin by spraying. This resin is made by using PEEK (polyether ether ketone) as a base material and containing 20% by weight of potassium titanate whiskers (diameter 0.5 μm, length 20 μm) as a reinforcing material.

In the resin-made friction material used in the first embodiment, thick and long carbon fibers having a diameter of 10 μm and a length of about 0.1 mm can be used as a reinforcing material, but this also has a large vibration amplitude. This is because the sliding surface has a wide width and the carbon fibers can be uniformly dispersed within the sliding surface.

For example, when the diameter of the vibration wave motor of this embodiment is 10 mm, the diameter is smaller than 30 mm of the vibration wave motor of the first embodiment, so the displacement generated at the sliding portion of the vibrator is small. It is usually designed to be Also, the width of the sliding surface is reduced according to the outer diameter. This is because, firstly, when the strain (dimensionless) of the vibrator is increased, the internal loss of the vibrator also tends to be increased, and this must be suppressed. Secondly, the sliding loss (due to relative slippage) This is to keep the contact (contact surface pressure) of the sliding surface, which affects the (object), uniform.

The vibration wave motor M described in the above two embodiments is mounted in the lens barrel 71 of the camera, for example, as shown in FIG. 7, and via the gear train 72 for zooming and AF operation. The lens driving member 73 is moved in the optical axis direction. Since the motor of the first embodiment has a larger drive torque than the motor of the second embodiment, the lens can be driven without the gear train.

(Relationship between Invention and Embodiment) In the above embodiment, the vibrating body 1 of the first embodiment and the upper vibrating body 1 of the second embodiment are the vibrating body of the present invention and the moving body 2. Corresponds to the contact according to the present invention, and the friction materials 1a and 2a correspond to the friction contact portions according to the present invention.

The above is the correspondence relationship between each configuration of the present invention and each configuration of the embodiment, but the present invention is not limited to the configuration of these embodiments, and the mechanism or the embodiment shown in the claims. Any structure may be used as long as the function of the structure can be achieved.

Further, the present invention may be used by combining the above-mentioned embodiments and modified examples, or their technical elements as needed.

Further, the present invention can be applied to various types of cameras such as a single-lens reflex camera, a lens shutter camera, a video camera, etc., and further, optical devices other than the camera and other devices, and those cameras and It can also be applied to devices applied to optical devices and other devices or elements constituting these devices.

[0074]

As described above, according to the first invention of the present application, since the resin that contains fibers and has improved wear resistance is used for the friction contact portion, the length of the vibration wave driving device is long. The life can be extended, and the driving force generated due to the increase in the friction coefficient can be increased. Moreover, since the mating frictional contact portion is made of ceramic, it is possible to prevent the transfer film of resin from being formed there, and prevent the friction materials from sticking to each other and prevent the frictional force from decreasing. can do.

Further, according to the second aspect of the present invention, since the center line average roughness of the contact surface of the ceramic is 0.5 μm or more, it is possible to effectively prevent the friction materials from sticking to each other.

Further, according to the third invention of the present application, the sharp corners of the ceramic can be rounded by buffing or chemical polishing, so that the center line average roughness is not reduced, that is, the sticking suppressing action. It is possible to prevent abrasion on the resin side without damaging the resin.

[Brief description of drawings]

FIG. 1 is a perspective view, a partial cross-sectional view, and an operation explanatory view of a ring-type vibration wave motor that is a first embodiment of the present invention.

FIG. 2 is a table showing the results of evaluation of suitability of various friction materials applied to the vibration wave motor.

FIG. 3 is a graph showing a surface roughness profile and a bearing ratio of the friction material.

FIG. 4 is a graph showing a surface roughness profile and a bearing ratio of the friction material.

FIG. 5 is a sectional view of a rod-shaped vibration wave motor that is a second embodiment of the present invention.

FIG. 6 is a partially enlarged view of the vibration wave motor.

FIG. 7 is a cross-sectional view of a lens barrel using the vibration wave motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibrating body, upper vibrator constituent body 1a Friction material on the vibrating body side 2 Moving body 2a Friction material on the moving body side 3 Mechanical-electrical energy conversion element 4 Electrode plate

Claims (6)

[Claims] 1. A vibration wave drive device that relatively frictionally drives a vibrating body that generates vibration and a contact body that contacts the vibrating body, wherein one of the vibrating body and the contact body has a frictional contact portion. An oscillatory wave drive device characterized in that it is formed of a fiber-containing resin, and the other frictional contact portion is formed of ceramics. 2. The vibration wave driving device according to claim 1, wherein the fiber is carbon or potassium titanate. 3. The vibration wave driving device according to claim 1, wherein the ceramic contains alumina or zirconia as a main component. 4. The vibration wave drive device according to claim 1, wherein the center line average roughness of the frictional contact portion of the ceramic is 0.5 μm or more. 5. The vibration wave driving device according to claim 1, wherein the frictional contact portion of the ceramic is buffed or chemically polished. 6. An apparatus comprising the vibration wave driving device according to any one of claims 1 to 5.