JPH05184168A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To provide an ultrasonic motor which has a high output transmission efficiency and a high reliability by bringing a vibrating body and a moving body into uniform contact and to simplify a manufacturing process of the mov ing body, to make the moving body light in weight and to reduce the manufac turing cost thereof. CONSTITUTION:A moving body 22 is formed of carbon fiber reinforced resin complex simple substance which is strengthened by using at least a carbon fiber. And, the moving body 22 is constituted of a main body section 20 and a contacting section 21 which is extended from the outer surface of the main body section 20. At that time, L/T<=2, H/W<=3, where the length of the main body section 20 is L, the thickness is T, the height of the contacting section 21 is H, and the width is W. The moving body 22 and a traveling elastic wave of flexural vibration of radial first order and circumferential third order or above are excited and a disc-type vibrating body 25 which has a projecting body 23a located at a place which is brought into contact with neither the inner face nor the outer face of an elastic substrate 23 is combined with the moving body 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor which generates a driving force by exciting elastic waves using a piezoelectric body such as a piezoelectric ceramic, and more specifically, the material and structure of a moving body of the ultrasonic motor. And a combination of a moving body and a vibrating body.

[0002]

2. Description of the Related Art In recent years, attention has been paid to ultrasonic motors that use elastic vibration as a driving force by vibrating a vibrating body formed of a piezoelectric body.

A conventional technique of an ultrasonic motor will be described below with reference to the drawings. FIG. 5 is a partially cutaway perspective view of a conventional annular type ultrasonic motor. In the figure,
Reference numeral 3 denotes a ring-shaped vibrating body formed by bonding a ring-shaped piezoelectric body 2 to the bottom surface of a ring-shaped elastic substrate 1 having a plurality of protrusions 1a. Reference numeral 6 denotes a moving body in which a wear-resistant friction material 5 is coupled to the annular elastic body 4 and is installed in pressure contact with the vibrating body 3.

Here, in the conventional example of the ultrasonic motor, as the material of the elastic body 4, a metal such as steel or stainless steel has been conventionally used, and the elastic body 4 has abrasion resistance. The moving member 6 of the ultrasonic motor is constructed by connecting the friction materials 5 of 1. by a method such as adhesion.

Incidentally, the applicant of the present invention, by using at least carbon fiber and resin as the material of the friction material 5,
It has been proposed that an ultrasonic motor having excellent long-term reliability can be realized (Japanese Patent Laid-Open No. 62-58887).

Further, in addition to the moving body in which a specific friction material is coupled to the elastic body proposed by the present applicant, as another moving body constitution, the moving body 6 is made of aluminum and aluminum alloy, and FIG. As shown, there has been proposed an ultrasonic motor in which abnormal shape is generated and driving efficiency is improved by setting the shape and size of the moving body 6 within a specific range (Japanese Patent Laid-Open No. 63-174581). ).

What can be said in common with the above-mentioned conventional example is that the material of the moving body is made of metal, and the ultrasonic motor moves in order to bring the vibrating body and the moving body into pressure contact. It is considered that there was a thought that unless the material of the body is a material having a high elastic modulus such as metal, there is a problem in mechanical strength when a pressure is applied to the moving body. Therefore, the idea that the moving body of the ultrasonic motor is made of resin alone has not existed so far.

Next, the operation of the annular ultrasonic motor configured as described above will be described below with reference to the drawings. FIG. 7 shows the operating principle of the ultrasonic motor. First, the piezoelectric body 2 has two sets of drive electrodes. When two alternating voltages having a predetermined phase difference are applied to the drive electrodes, the piezoelectric body 2 expands and contracts and the elastic substrate 1 expands and contracts. Since it acts so as to resist, the traveling wave of the flexural vibration is excited in the vibrating body 3 by the same effect as the bimetal. An arbitrary point on the surface of the vibrating body 3 moves along an elliptical locus by a traveling wave of flexural vibration. The protrusion 1a magnifies the lateral displacement (ζ in FIG. 7) of this elliptical locus. The moving body 6 installed in pressure contact with the protrusion 1a of the vibrating body 3 is driven by frictional force by the enlarged lateral displacement to rotate.

[0009]

However, in a moving body having a structure in which an abrasion resistant friction material is coupled to an elastic body as in the above-mentioned conventional example, the friction material is laterally moved (progressed) by an external load of the motor. When the thickness of the friction material is reduced in order to prevent large elastic deformation in the wave traveling direction),
There is a problem in that the output transmission efficiency may decrease due to the generation of noise. This is because by making the thickness of the friction material thin, the elastic deformation in the longitudinal direction of the moving body becomes too small, so that uniform contact cannot be realized and the damping against unnecessary vibration becomes small. There is a big problem in practical use.

Further, in order to prevent output transmission loss due to elastic deformation of the contact surface between the vibrating body and the moving body, when a material having a high elastic modulus such as metal or ceramic is used for the contact surface, when the pressure is applied. Since the elastic deformation in the vertical direction becomes too small, it is difficult to realize uniform contact, and there is a problem that the output transmission efficiency is reduced due to the generation of noise.

On the other hand, as a means for solving the above-mentioned problems, another prior art in which the contact state between the moving body and the vibrating body is improved by forming the moving body with a metal material and limiting the structural dimensions within a specific range. In the examples, there is a problem in that long-term reliability is deteriorated due to characteristic deterioration due to wear of the contact portion of the moving body.

Further, the process for joining the friction material and the elastic body is complicated, and the process for machining the metal material to a specific size as described above is also complicated, which is a major factor of cost increase. It was.

Further, as in the above-mentioned two conventional examples, when a moving body is constructed by coupling a wear-resistant friction material to an elastic body such as metal, or when it is made up of a single metal, a metal material is used. Since the specific gravity is large, the weight of the moving body is large, and as a result, the total weight of the motor is large, which causes a limit in reducing the weight of the ultrasonic motor.

On the other hand, from the viewpoint of miniaturization of the ultrasonic motor, as the outer diameter of the conventional ring-shaped vibrating body is reduced, the kinetic energy stored in the vibrating body becomes smaller and the load becomes smaller. It had a problem that it was easily affected.

In addition to the above-mentioned problems, it is difficult for the moving body to combine the friction material or process it into the specific shape shown in FIG. 6 due to the miniaturization, which further increases the cost. Had challenges.

An object of the present invention is to provide an ultrasonic motor capable of solving the above conventional problems.

[0017]

In order to solve the above-mentioned problems, the ultrasonic motor of the present invention comprises a moving body composed of a single carbon fiber reinforced resin composite reinforced with at least carbon fiber, and The structure includes a main body and a contact portion extending from the outer periphery of the main body, and at the same time, the length of the main body, the thickness of the main body, the width of the contact portion, and the height of the contact portion are set in a specific range.

Further, at least the carbon fiber reinforced resin composite reinforced with carbon fibers is used alone, and the moving body is composed of the main body and the contact portion extending from the outer periphery of the main body, and at the same time, the length of the main body is increased. , A moving body in which the thickness of the main body portion, the width of the contact portion, and the height of the contact portion are set in a specific range, and elastic traveling waves of flexural vibration of primary in the radial direction and tertiary or more in the circumferential direction are excited and elastic. An ultrasonic motor is constructed by combining with a disk-shaped vibrating body in which a protrusion is arranged at a position that does not come into contact with any of the inner and outer diameters of the substrate.

[0019]

[Operation] The moving body is composed of the main body and the contact portion extending from the outer periphery of the main body, and at the same time, the length of the main body, the thickness of the main body, the width of the contact portion, and the height of the contact portion are set within a specific range. With this structure, the effect of absorbing the undulations of the contact surface between the vibrating body and the moving body (surface correction effect) can be provided, and stable uniform contact can be ensured. The traveling wave can be efficiently transmitted to the moving body.

Further, since the moving body is composed of a carbon fiber reinforced resin composite which is reinforced with at least carbon fiber, the composite has excellent wear resistance and, at the same time, by using carbon fiber, friction is improved. Since it has the effect of imparting appropriate lubricity to the contact surface, it is possible to maintain stable motor characteristics even during long-term driving, and to realize an ultrasonic motor with excellent long-term reliability. You can

In addition, since the moving body is composed of a single carbon fiber reinforced resin composite which is reinforced with at least carbon fibers, the number of parts of the moving body is larger than that of the structure in which the friction material is bonded to the metal elastic body. The manufacturing process can be simplified by reducing the
The weight of the moving body can be reduced, and therefore the ultrasonic wave mode can be reduced.
It is possible to reduce the weight and cost of the computer.

Further, by combining the moving body having the specific structure with the vibrating body having the specific structure, a large kinetic energy can be obtained without reducing the outer diameter size and the influence of an external load can be suppressed. Thus, a highly efficient ultrasonic motor can be realized.

[0023]

[Embodiments] Before describing specific embodiments, a more detailed description will be given of the technical significance of forming the moving body material from a resin material.

The ultrasonic motor uses the principle of operation shown in FIG. 7 to apply a traveling wave of flexural vibration having an amplitude of about several microns (ξ in FIG. 7) to a vibrating body composed of a piezoelectric body and an elastic substrate. This is a motor that is excited to expand the lateral displacement (ζ in FIG. 7) due to this traveling wave by the projection and drive the moving body that is placed in pressure contact with the tip of the projection.

Therefore, in order to efficiently transmit the traveling wave of the flexural vibration by the vibrating body to the moving body and ensure long-term reliability, a contact state between the moving body and the vibrating body satisfying the following items is realized. There is a need to.

A) The moving body has dynamic elasticity in the macroscopic length at the wavelength level of the traveling wave of the flexural vibration of the vibrating body. This is necessary in order to uniformly contact the moving body in the vicinity of the peaks of all the waves of the traveling wave and efficiently transmit the traveling wave of the flexural vibration by the vibrating body to the moving body.

As a measure of this dynamic elasticity, it is desirable that the amount of longitudinal elastic deformation of the moving body material at the time of pressurization is as close to the amplitude of the vibrating body as possible within the range of the amplitude of the traveling wave or less. .. Therefore, the optimum value of this dynamic elasticity cannot be uniquely defined, and it depends on the pressure of the ultrasonic motor and the wave number of the traveling wave excited by the piezoelectric body,
Optimal design is required according to the driving conditions of the ultrasonic motor.

B) The moving body should have rigidity in a micro length at the level near the contact portion (A in FIG. 7) of the traveling wave of the flexural vibration by the vibrating body. This is necessary to reduce output transmission loss due to elastic deformation of the moving body contact portion.

As a measure of this rigidity, it is necessary to suppress the lateral elastic deformation of the moving body due to the lateral displacement of the traveling wave as much as possible. For example, the bending elastic modulus of the moving body material is 1000 kg / mm ^2. The above is desirable. Furthermore, in addition to the lateral displacement, it is necessary to suppress lateral elastic deformation of the moving body due to an external load, and the optimum value of rigidity required for the moving body cannot be uniquely defined.
Optimal design is required according to the driving conditions of the ultrasonic motor.

C) The moving body has an appropriate lubricity. This is necessary to maintain stable friction and reduce wear.

As a measure for this lubrication, it is desirable that the dynamic friction coefficient of the moving body material is within the range of 0.15 to 0.40.

D) The moving body has static elasticity according to the pressure applied by the ultrasonic motor. This is necessary in order to absorb the undulations of the contact surface between the moving body and the vibrating body and ensure uniform contact.

As a measure of this static elasticity, it varies depending on the machining accuracy of the vibrating body and the molding accuracy of the moving body or the pressing force of the motor, but the strain amount of the moving body at the time of pressurization is 1-10
It is desirable to set the thickness to about μm.

In the conventional method, a wear resistant friction material satisfying the above four conditions is bonded to a metal elastic body, or a metal moving body satisfies conditions other than condition c. The only idea was to surface treat the surface of the contact portion in order to improve the wear resistance while having a different structure.

This is because the ultrasonic motor brings the vibrating body and the moving body into pressure contact with each other. Therefore, unless the moving body is made of a material having a high elastic modulus such as metal, a pressing force is applied to the moving body. It is probable that there was an idea that there was a problem in mechanical strength.

Therefore, the idea that the moving body of the ultrasonic motor is made of a resin alone has not existed so far.

In the present invention, focusing attention on the above items, by making the material of the moving body a simple carbon fiber reinforced resin composite reinforced with at least carbon fiber, the rigidity of the micro length can be increased by the carbon fiber. , The resin component has dynamic elasticity of macro length.

Here, the reason for using carbon fiber is as follows.
With the same fiber content compared to inorganic fibers such as glass fiber,
The effect of improving the rigidity of the moving body is large, so that the rigidity of the moving body can be increased with a smaller fiber content and the mechanical strength of the moving body can be improved. In addition to the above, carbon fibers are used to impart appropriate lubricity to the friction interface.

Further, the structure of the moving body is constituted by the main body portion and the contact portion extending from the outer periphery of the main body portion, and at the same time, the length of the main body portion, the thickness of the main body portion, the height of the contact portion, the width of the contact portion. By setting to a specific range, the waviness of the contact surface between the moving body and the vibrating body is absorbed, and uniform contact is secured.

A detailed description will be given below of an embodiment for forming the above-mentioned moving body structure with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing the main part of an ultrasonic motor according to an embodiment of the present invention. 2 in the figure
Reference numeral 2 denotes a moving body that is configured by the main body portion 20 and the contact portion 21 extending from the outer periphery of the main body portion 20 to have elasticity in the pressing direction. Further, 25 is a rectangular protrusion 23
This is a vibrating body in which a piezoelectric body 24 is coupled to an elastic substrate 23 having a. Further, by applying pressure to the vibrating body 25 on the A surface of the moving body and bringing it into contact with the vibrating body 25 at the contact portion 21 of the moving body, an ultrasonic motor is configured.

Here, in the figure, it is assumed that the length of the moving body is L, the thickness of the moving body is T, the height of the moving body contact portion is H, and the width of the moving body contact portion is W. In order to efficiently transmit the traveling wave of flexural vibration by the vibrating body to the moving body,
It is necessary to set the above dimensions within a specific range.

First, regarding the ratio L / T between the length L of the moving body and the thickness T of the moving body, if this ratio is greater than 2, the mechanical strength of the moving body becomes insufficient and The output transmission efficiency is reduced due to the resonance of the moving body, so it is necessary to set the value to 2 or less.

Next, regarding the ratio H / W of the height H of the moving body contact portion and the width W of the moving body contact portion, if this ratio is larger than 3, the mechanical strength of the moving body is insufficient. At the same time, when the external load is applied, the moving body contact portion is deformed to reduce the output transmission efficiency, so that it is necessary to set it to 3 or less.

Further, regarding the width W of the moving body contact portion,
When it is less than 0.3 mm, pressure is concentrated on the contact portion of the moving body, wear of the moving body is accelerated and there is a problem in long-term reliability, and when it is more than 2.0 mm, the contact state is different. Motor characteristics vary, and it becomes difficult to secure stable and uniform contact.
It must be set within the following range.

Further, since the rigidity and elasticity in the pressing direction required for the moving body 12 differ depending on the pressure applied by the ultrasonic motor, the content of the carbon fiber contained in the carbon fiber reinforced resin composite and the moving body are not changed. By adjusting the width or height of the contact portion, the rigidity of the moving body 12 and the elasticity in the pressing direction can be adjusted.

This embodiment will be described in more detail with specific numerical values. First, a kneaded material of 30% by weight of carbon fiber and 70% by weight of polyphenylene sulfide resin is injection-molded to form a main body portion 20 and a contact portion 21 extending from the outer periphery of the main body portion 20. In, the ratio L / T of the length L of the moving body main part to the thickness T of the moving body main part is 1.31, and the ratio H / of the height H of the moving body contact portion and the width W of the moving body contact portion is H / A mobile body 22 having a structure in which W was set to 1.60 and having a specific gravity of 1.45 was obtained.

Next, on the bottom surface of the disk-shaped elastic substrate 23 made of stainless steel, which is provided with a plurality of rectangular projections 23a at positions not contacting any of the inner and outer diameters of the elastic substrate, the primary in the radial direction,
A disk-shaped vibrating body 25 having an outer diameter of 10 mm was formed by bonding a piezoelectric body 24 having an electrode structure (not shown) that excites vibration modes of the third order or higher in the circumferential direction. further,
A disk type ultrasonic motor was constructed by placing the moving body 22 in pressure contact with the disk type vibrating body 25 using a disc spring (not shown) of 0.3 kgf.

As described above, by adopting the vibrating body structure which excites the elastic vibration of the primary in the radial direction and the tertiary or higher in the circumferential direction,
Regardless of the reduction of the outer diameter size, a large amount of kinetic energy is provided, and by providing a protrusion on the portion that does not reach the inner and outer diameters of the vibrating body, the influence of the load can be suppressed and vibration can be efficiently excited. it can.

Therefore, the outer diameter of the ultrasonic motor is φ10 mm.
Even if it is downsized, it is possible to reduce the decrease in vibration energy, and at the same time, it is not easily affected by the load fluctuation, and further downsizing is possible. Further, since the protrusion, which is the pressurizing point of the moving body and the vibrating body, is not provided at the maximum displacement position of the vibration displacement distribution, the motor characteristics are less likely to be affected by the unevenness of the pressing force and the fluctuation of the external load, An ultrasonic motor with stable characteristics and excellent reliability can be easily obtained.

On the other hand, the moving body has a specific gravity of 1.4 as described above.
By configuring the carbon fiber reinforced resin alone which is 5,
It is possible to significantly reduce the weight of the moving body as compared with the case where a moving body having the same size is joined to stainless steel with a friction material, and it is possible to greatly contribute to weight reduction of the ultrasonic motor. In addition, a specific moving body material is molded by a method such as injection molding without the need for an adhesive process for joining the friction material to the elastic body or complicated machining for limiting the metallic moving body to a specific structure. It can be a simple process of just molding.

As described above, in the ultrasonic motor according to the present embodiment, the moving body is made of resin, so that the contact state between the vibrating body and the moving body is improved and the wear resistance is remarkably improved. Greatly improved efficiency and motor life.

Further, since the moving body is made of resin, it can be easily manufactured by injection molding, and the manufacturing cost can be reduced as compared with the conventional case.

(Second Embodiment) A second embodiment will be described with reference to FIG. By injection-molding a kneaded product of 30% by weight of carbon fiber and 70% by weight of polyetheretherketone resin, the mixture has the same structure as in Example 1 and a specific gravity of 1.
We obtained a moving object that is 44.

The ultrasonic motor of this embodiment constructed by using this moving body is different from that of the first embodiment in that the moving body of this embodiment has a moving body contact portion 21 as shown in FIG. That is, the surface of the contact portion is formed in a slope shape with the outer peripheral side being lowered. Further, in this embodiment, a moving body and a vibrating body are brought into pressure contact with each other by using a disc spring of 0.2 kgf.

In the ultrasonic motor of this embodiment, in addition to the same effects as in the ultrasonic motor of the above-described first embodiment, the effect that the characteristic variation is improved can be obtained.

Actually, the characteristic variations of the ten motors of this embodiment are ± 3% in the starting torque, ± 1% in the no-load rotation speed, and ± 3% in the maximum efficiency, and the characteristic variations are very small. The ultrasonic motor could be obtained.

On the other hand, for comparison, when an ultrasonic motor was constructed by using the same moving body as that of this embodiment except that the taper was not provided, the average variation of 10 motor characteristics was ± 27%, ± 3% at no-load rotation speed, and ± 16% at maximum efficiency.

As described above, the effect of providing the taper on the surface of the contact portion of the moving body so that the outer peripheral side is lowered is that the elastic vibration of the primary in the radial direction and the tertiary or higher in the circumferential direction is excited. Since the amplitude of the vibrating body on the outer peripheral side is larger,
It is considered that the above-mentioned surface state can realize a more ideal contact state between the moving body and the vibrating body.

(Third Embodiment) Next, a third embodiment will be described with reference to FIG. A kneaded product of 30% by weight of carbon fiber and 70% by weight of polyethylene sulfone resin was injection-molded to obtain a mixture shown in FIG.
The moving body 32 of No. 1 was formed. The moving body 32 is composed of the body portion 30 and the contact portion 31 extending from the outer periphery of the body portion 30, and has the length L of the moving body body portion and the thickness T of the moving body body portion shown in FIG. The ratio L / T is set to 1.31, the ratio H / W between the height H of the moving body contact portion and the width W of the moving body contact portion is set to 1.40, and L / 2 of the upper surface of the main body 30 is set. The structure is such that the taper is provided from the position to the thickness T / 2 of the main body portion 30. The specific gravity is 1.47.

Next, using the same vibrating body as in Example 1,
A disk-type ultrasonic motor was constructed by pressing and using a disc spring of 0.3 kgf.

In the present embodiment, in addition to the same effect as in the first embodiment, by providing a taper on the upper surface of the moving body on the side opposite to the moving body contact portion so that the outer circumferential side is lowered, the outer circumference of the moving body is reduced. It is possible to obtain a larger surface correction effect on the side than on the inner peripheral side. As a result, it is necessary to design the moving body in consideration of the radial amplitude that the radial amplitude of the vibrating body that excites the elastic vibration of the primary in the radial direction and the tertiary or higher in the circumferential direction is larger on the outer peripheral side. You can

As shown in the above-mentioned three examples, by constructing the moving body from a single carbon fiber reinforced resin composite reinforced with at least carbon fibers, a conventional annular ultrasonic motor can be obtained. As described above, it is possible to easily mold the friction material by using a mold without a bonding step for connecting the friction material to the metal elastic body and by a method such as injection molding or compression molding.

Further, by adopting the above-mentioned structure, the moving body is compared with a moving body of the same size constituted by connecting a friction material to a stainless steel elastic body like a conventional ring type ultrasonic motor. Thus, the weight of the moving body can be reduced.

As shown in FIG. 4, even if the resin moving body shown in each of the above embodiments is used in combination with the conventional vibrating body, the contact state of the contact surface between the moving body and the vibrating body Is improved as compared with the conventional one, so that the motor efficiency is naturally improved. Of course, the service life is extended.

Although specific examples have been described above, in the above three specific examples, the content of carbon fibers contained in the carbon fiber reinforced resin composite constituting the moving body depends on the ultrasonic motor. It can be adjusted according to the applied pressure,
If the fiber content is less than 5% by weight, the effect for improving the rigidity is insufficient and the abrasion resistance of the frictional contact surface of the moving body is insufficient.

When the fiber content exceeds 50% by weight, the molding becomes difficult and the mechanical strength of the molded article becomes brittle, although it depends on the molding method or the fluidity of the resin. It must be in the range of less than or equal to weight%. Judging from the material properties required for the moving body, the formability of the moving body, the cost of the moving body, etc.,
It is desirable that the content is 15% by weight or more and 35% by weight or less.

In the same embodiment, carbon fiber was used as the type of reinforcing fiber, but it is also possible to use inorganic fiber other than carbon fiber in combination with the above-mentioned carbon fiber. In order to adjust the lubricity, it is also possible to combine the above fibers with an inorganic filler such as graphite powder, tetrafluoroethylene powder, molybdenum sulfide powder, graphite fluoride powder.

Further, in the above three specific examples, thermoplastic resins such as polyphenylene sulfide resin, polyether ether ketone resin, and polyether sulfone resin were used as the resin constituting the carbon fiber reinforced resin composite. However, the present invention is not limited to these.

As a guideline for selecting the resin constituting the carbon fiber reinforced resin composite, it is desirable to use a resin having a heat resistance of 150 ° C. or higher and a high heat deformation temperature, because the resin is When a resin with a heat resistance of 150 ° C or less and a low heat distortion temperature is used, wear of the frictional contact part of the moving body is promoted, causing deterioration of motor performance, etc. to ensure long-term reliability. Becomes difficult.

From the above viewpoint, in addition to the resins shown in the examples, a thermoplastic resin such as polysulfone resin, polyarylate resin, polyamideimide resin, polyetherimide resin, polyimide resin, wholly aromatic polyester resin or the like, or It is also possible to use a thermosetting resin such as a phenol resin, a bismaleimide / triazine resin, or a polyimide resin.

[0072]

As described above, according to the present invention, the moving body is composed of a single carbon fiber reinforced resin composite reinforced with at least carbon fiber, and the moving body is extended from the main body and the outer periphery of the main body. The following effects can be obtained as the overall result of constructing the contact part and at the same time setting the length of the main part, the thickness of the main part, the width of the contact part, and the height of the contact part within a specific range. Is.

A) It is possible to realize an ultrasonic motor having high output transmission efficiency. b) It is possible to realize an ultrasonic motor having excellent long-term reliability.

C) The manufacturing process of the moving body can be simplified and the manufacturing cost can be reduced. d) The weight of the ultrasonic motor can be reduced.

In addition to the above effects, the following effects can be obtained by making the surface of the moving body contact portion inclined so that the outer peripheral side is lowered.

E) It is possible to realize an ultrasonic motor with few characteristic variations. Further, a disk having a moving body of a specific structure, which excites elastic traveling waves of flexural vibration of primary in the radial direction and tertiary or higher in the circumferential direction, and in which a protrusion is arranged at a position not in contact with either the inner or outer diameter of the elastic substrate. In addition to the above-mentioned effects, the following effects can be obtained by combining the mold vibrating body.

F) It is possible to realize an ultrasonic motor which is compact and has high output transmission efficiency.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main configuration of an embodiment of an ultrasonic motor of the present invention.

FIG. 2 is an enlarged cross-sectional view of a contact portion between a moving body and a vibrating body according to still another embodiment of the present invention.

FIG. 3 is a perspective view showing a main configuration in another embodiment of the present invention.

FIG. 4 is a perspective view showing a main configuration in still another embodiment of the present invention.

FIG. 5 is an exploded perspective view showing the main components of a conventional annular ultrasonic motor.

FIG. 6 is a sectional view showing the structure of a moving body of a conventional annular ultrasonic motor.

FIG. 7 is an explanatory diagram of the operation principle of the ultrasonic motor.

[Explanation of symbols]

 1, 23, 43 Elastic substrate 1a, 23a, 43a Projection body 2, 24, 44 Piezoelectric body 3, 25, 45 Vibrating body 4 Elastic body 5 Friction material 6, 22, 32, 42 Moving body 20, 30, 40 Moving body Main body part 21, 31, 41 Moving body contact part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Kawasaki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A moving body is brought into pressure contact with a vibrating body in which a piezoelectric body is coupled to an elastic substrate, and a traveling wave of flexural vibration is excited in the vibrating body so that the vibrating body is moved between the vibrating body and the moving body. In the ultrasonic motor for moving the moving body via the frictional force of the moving body, the moving body is composed of a single carbon fiber reinforced resin composite reinforced with at least carbon fiber, and the moving body is made into a main body part. And a contact portion extending from the outer periphery of the main body portion, where L is the length of the main body portion, T is the thickness of the main body portion, H is the height of the contact portion, and W is the width of the contact portion. , L / T ≦ 2, H / W ≦ 3. 2. The ultrasonic motor according to claim 1, wherein the content of carbon fibers contained in the carbon fiber reinforced resin composite is 5% by weight or more and 50% by weight or less. 3. A moving body is brought into pressure contact with a vibrating body in which a piezoelectric body is coupled to an elastic substrate, and a traveling wave of flexural vibration is excited in the vibrating body, so that the vibrating body is moved between the vibrating body and the moving body. In the ultrasonic motor for moving the moving body via the frictional force of the moving body, the moving body is composed of a single carbon fiber reinforced resin composite reinforced with at least carbon fiber, and the moving body is made into a main body part. And an contact portion extending from the outer periphery of the main body portion, and the contact portion surface has an inclined shape with the outer peripheral side being lowered. 4. The ultrasonic motor according to claim 3, wherein the content of the carbon fibers contained in the carbon fiber reinforced resin composite is 5% by weight or more and 50% by weight or less. 5. A moving body is brought into pressure contact with a vibrating body in which a piezoelectric body is coupled to an elastic substrate, and a traveling wave of flexural vibration is excited in the vibrating body, so that the vibrating body is moved between the vibrating body and the moving body. Is an ultrasonic motor for moving the moving body through the frictional force of, which is formed of a carbon fiber reinforced resin composite simple substance reinforced with at least carbon fiber, and from the outer periphery of the main body and the main body. L / T ≦ 2, where L is the length of the main body, T is the thickness of the main body, H is the height of the contact, and W is the width of the contact. , A moving body set to H / W ≦ 3, and a projecting body that excites elastic traveling waves of flexural vibration of primary in the radial direction and cubic or higher in the circumferential direction, and does not come into contact with any of the inner and outer diameters of the elastic substrate. An ultrasonic motor equipped with a disk-shaped vibrating body in which is arranged.