JPH03173368A - Oscillatory wave motor - Google Patents

Abstract

PURPOSE:To obtain an excellent sliding characteristic in the range of high temperature by using as a composite resin layer a material in which an aromatic polyimide resin is filled and blended with a friction conditioning material and an abrasion resistance improvement agent of non-fiber type. CONSTITUTION:A movable body 7 is provided with a ring-like supporting body 5 comprising a metal of high thermal conductivity such as an aluminum alloy and a sliding body 6 which is bonded to the body 5 concentrically on the surface thereof by a heatproof bonding agent of epoxy group. The sliding body 6 is contacted with an oscillatory body 2 on the sliding surface thereof. A material in which a base material of an aromatic polyimide resin is filled and blended with a friction conditioning agent and if necessary an abrasion resistance improvement agent, is used as the composite resin layer of the sliding body 6. Thereby, even if being in the range of high temperature, the sliding body 6 and the oscillatory body 2 exhibit an excellent sliding characteristic and an oscillatory wave motor 19 of high torque and high efficiency in which the waviness and unevenness of the torque thereof are reduced can be obtained.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention generates a progressive vibration wave in a vibrating body by applying a voltage to an electro-mechanical energy conversion element, and generates a progressive vibration wave in a vibrating body by applying a voltage to an electric-mechanical energy conversion element. The present invention relates to a vibration wave motor that causes relative movement between the motors by friction drive, and particularly to a high-output vibration wave motor.

(Prior Art) Conventional vibration wave motors, particularly high-output vibration wave motors, have a group of thin annular piezoelectric elements fixed to the back surface of a circular vibrating body substrate made of stainless steel, and tungsten carbide and tungsten carbide on the surface. A hard sliding surface is formed by thermally spraying a superhard material made of cobalt and further polished to form a vibrating body.On the other hand, as a member that comes into contact with this, a support such as an aluminum alloy has a glass inversion point. Thermoplastic resins with a temperature of 100°C or higher, specifically polyimide (PI), polyamideimide (P^), polyetherimide (PEI), polyetheretherketone (PEE), polyethersulfone (PES), polyarylate (PAR), polysulfone (PSF), aromatic polyamide (P^), and other heat-resistant resins are filled with reinforcing materials such as carbon fiber, and a reinforced composite resin layer is fixed to the sliding body. A member in contact with the vibrating body is configured to move relative to each other by frictional drive due to progressive vibration waves generated in the vibrating body.

Note that the relative movement between the contacting member and the vibrating body may be either fixed or movable, but in the following description of this specification, the vibrating body will be explained for the sake of simplicity. This is shown as an example in which the contacting member is fixed and the contacting member is moved, and therefore the contacting member is referred to as a "moving body."

Now, in the conventional vibration wave motor mentioned above, the glass transition point of the reinforced composite resin layer forming a part of the moving body is 100.
The reason why we use a sliding body made of thermoplastic resin with a temperature of ℃ or above is because these heat-resistant resins have low temperature dependence as a material property, and the resin material does not soften even when the temperature rises when the motor is driven. This is because there is no phenomenon of torque down caused by this, and the performance accuracy of the motor can be stabilized.

Also, the reason why reinforcing materials such as carbon fibers are mixed and filled in the resin material is that the sliding surface of the moving body is This is to ensure that the properties of the moving surface are always stable and have sufficient wear resistance even during long-term operation.Secondly, the material properties such as the elastic modulus or hardness of the sliding body are increased, This is to improve motor performance such as output, and thirdly, to improve motor performance such as efficiency by improving the thermal conductivity of the sliding body.

(Problems to be Solved by the Invention) As mentioned above, the sliding body that provides the sliding surface of the moving body in a vibration wave motor is reinforced by filling a heat-resistant thermoplastic resin with a glass transition point of 100°C or higher with carbon fiber. By using mold composite resin, the performance and precision of the motor are stable even when the temperature rises due to motor drive, and the wear resistance of the carbide material that forms the sliding surface of the vibrating body is maintained even when driven for a long time. This is sufficient, and motor performance such as output efficiency also shows high values.

However, if the sliding surface of a composite resin layer made of a heat-resistant thermoplastic resin reinforced with the carbon fibers of the moving body is brought into pressure contact with the hard sliding surface of the vibrating body made of a superhard material, 4 kg crn, 1100 as the condition
When driving is started at RP, torque waviness may become a problem as the temperature of the friction sliding surface increases, and there are some points that need to be improved to further improve performance accuracy. It was discovered.

In addition, during continuous operation at the rated torque, there was a torque unevenness of about 5% with respect to the rated torque value, and further improvements were desired.

Furthermore, although there is no problem when the load torque is large,
The problem of the so-called 'Ol tg J' phenomenon occurring due to sliding friction due to driving when no load or low load is applied has been solved.

The purpose of the present invention, which has been made from this point of view, is to provide a highly efficient vibration wave motor that exhibits excellent sliding characteristics even under high temperatures and has reduced torque "undulation" and torque unevenness. purpose.

Another object of the present invention is to provide a vibration wave motor with a novel configuration that can eliminate the "squeal" that occurs during no-load or low-load operation, which is a problem with vibration wave motors, especially high-output types. The purpose of the present invention is to provide a vibration wave motor.

Still another object of the present invention is to provide a vibration wave motor that uses a sliding surface of a vibrating body that comes into contact with a moving body as a hard surface that can be formed at low cost by electroless plating. be.

(Means for Solving the Problems) The vibration wave motor of the present invention achieved in order to achieve the above object is characterized by a composite resin that provides a contact surface with a vibrating body that generates progressive vibration waves. A vibration wave motor in which a member having a layer is brought into pressurized contact and a vibrating body and the member in pressurized contact are moved relative to each other by frictional drive by progressive vibration waves generated in the vibrating body, the composite resin layer as described above. However, it is constructed of a composite resin in which a friction modifier and, if necessary, a non-fibrous wear resistance improver are filled and blended into an aromatic polyimide resin base material.

The vibration wave motor of the present invention applies a voltage to the drive phase, typically consisting of an electro-mechanical energy conversion element, to generate progressive vibration waves in the annular vibrating body provided with this drive phase. The movable body is configured as a vibration wave motor that frictionally drives a movable body that is in pressurized contact with the vibrating body, and the movable body has a support body made of a thermally conductive aluminum alloy, etc., and is integrated with this support body. and the composite resin layer which provides a sliding surface that contacts the vibrating body. Further, in the vibrating body of the vibration wave motor of the present invention, as in conventional ones, superhard materials such as tungsten carbide and cobalt are thermally sprayed on the surface of the vibrating body substrate made of metal or the like, and polished as necessary. It is also possible to use a sliding surface made of silicon carbide (
The diagnosis can be made by using a nickel-phosphorus based alloy containing one or more of the following: StC), boron carbide (84G), boron titanium (TiBt), and boron nitride (8N), on which a carbide surface is formed.

The vibration wave motor of the present invention has a movable body formed using the above-mentioned composite resin material, or a movable body formed by fixing and integrating a sliding body formed using the composite resin material to a support body. It is characterized by

A method for forming such a composite resin layer and a method for integrating it onto a support of a moving body include: forming a sliding body of the composite resin material in the shell by injection molding or extrusion molding;
This can be constructed by fixing and integrating this onto a support using an adhesive. Note that the sliding body made of a composite resin material is fixed on the support when the glass transition point is 100.
This can be done using an adhesive with a temperature of 100°C or higher, and a specific example of such an adhesive is a chemically reactive epoxy adhesive that has sufficient heat-resistant adhesive strength and heat aging properties at 100°C. can do.

The present invention is characterized in that an aromatic polyimide resin is used as the base material of the composite resin layer that provides a sliding surface with the vibrating body.

This aromatic polyimide resin is a thermosetting resin, typically a condensation product of biphenyltetracarboxylic dianhydride and aromatic diamine ("Ubilex" (trade name; manufactured by Ube Industries, Ltd.)) Birome\lift acid anhydride An example of this is a condensate of diaminodiphenyl ether and diaminodiphenyl ether (“Besbre” (trade name: manufactured by DuPont)). This condensate has excellent properties at high temperatures among a wide range of plastics. For example, the heat distortion temperature at a load of 18.8 kg/am2 is 350°C, and even at a continuous use temperature of 260°C, it has excellent properties at high temperatures. Indicates the strength of engineering plastics at room temperature.

The composite resin layer of the present invention is filled with a friction modifier, preferably a powdered friction modifier. Such friction modifiers are filled to improve the lubricity of the base material thermosetting resin, and solid lubricants in the form of amorphous powder are generally used as such friction modifiers. Specifically, powders of fluororesin, molybdenum disulfide, graphite, carbon, lead oxide, lead, etc. (all non-fibers) can be exemplified.

The friction modifier is typically 30% by weight relative to the base material.
% or less of lead compound powder such as lead monoxide, and 5% by weight
Particularly preferred is the simultaneous addition of 40% to 40% of a fluororesin such as tetrafluoroethylene.

The above-mentioned tetrafluoroethylene resin is a low coefficient of friction resin, so if the amount filled is too large, the coefficient of friction will become small.
Since the material strength and abrasion resistance decrease, the above range is set.

The above-mentioned lead oxide powder and tetrafluoroethylene resin powder are both effective as solid lubricants to supplement the lubricity of the thermosetting resin that is the base material. When the sliding surface is frictionally driven, -lead oxide powder has the effect of transferring a coating of tetrafluoroethylene resin to the sliding surface of the vibrating body, and is used to constantly stabilize the coefficient of friction especially during sliding at high temperatures. It is an effective substance.

The above-mentioned lubricants, such as lead compounds such as lead oxide powder and fluororesin powders such as tetrafluoroethylene resin, are suitable for use as a composite resin layer in terms of abrasion resistance and adhesion to the base material thermoplastic resin. For example, the average grain size is 20 to ensure material strength.
It is preferable to set it to t1m or less. Note that tetrafluoroethylene resin (PTFE) is a resin with a low coefficient of friction, so if the amount of filling is large, the coefficient of friction will decrease, but the material strength and wear resistance will decrease.

Further, the composite resin layer may be further filled with transition metal powder, if necessary, for the purpose of improving wear resistance and improving stability against temperature changes of the sliding surface. Specific examples of such transition metal powders include tungsten, molybdenum, chromium, cobalt, titanium, and nickel.
20 μm or less) or 15% or less molybdenum powder (20 pm or less). In addition, as a non-fibrous type wear resistance improver, in place of the above-mentioned transition metal, an average particle size of 10 to 30 μm may be used.
Spherical carbon may be used, and in particular, carbon beads, which have high hardness and high thermal conductivity like carbon fibers, may be used.

(Example) The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a vibration wave motor according to the present invention.

In this figure, 2 is an annular vibrating body substrate made of a metal member such as stainless steel, and on the back side of the substrate, a group of thin annular piezoelectric elements 1 are connected concentrically with a heat-resistant epoxy resin adhesive. The sliding surface on the front side has a tooth-like shape with a large number of grooves cut in the axial direction in the circumferential direction in order to increase the imaging amplitude of the progressive vibration wave.

Reference numeral 3 denotes a housing made of a highly thermally conductive metal material, in which a first ball bearing 11 is provided in the center, and the vibrating body 2 is screwed concentrically with the axis of the first Hall bearing 11. It is fixed at 4.

Reference numeral 10 denotes an output shaft having a flange portion 10c formed in the middle, one end side 10a of which is supported through the inner ring of the first ball bearing 11 so as to be able to slide in the axial direction, and the other end side 10b is an output shaft. , is axially slidably and rotatably fitted into an inner ring of a second ball bearing 12 (described later) and a shaft hole of a spring pressure adjusting nut member 18 (described later). 15 is the above output shaft 1
It is a disk-shaped intermediate member fixed to the flange portion 10c of the 0 with screws 16, and a movable body 7 formed in an annular shape is concentrically fitted and fixed to the outer peripheral end of the intermediate member.

The moving body 7 includes an annular support 5 made of a highly thermally conductive metal such as an aluminum alloy, and a sliding body 6 concentrically bonded to the surface of the support 5 with a heat-resistant epoxy adhesive. In this example, the sliding body 6 has a thickness of, for example, 1 m.
The annular body of m is formed as a composite resin layer having the formulation and structure described below. This sliding body 6 contacts the sliding surface of the vibrating body 2.

The movable body 7 is supported by an intermediate member 15 via an elastic sheet member 17 made of rubber provided at the bottom thereof, and the flange portion 10 of the output shaft 10 is supported by an intermediate member 15.
The axial load generated by the coiled compression spring member 14 elastically mounted between C and the second ball bearing 12 is applied in the axial direction of the support body 5 via this elastic sheet member 17. The sliding surface of the vibrating body 2 and the sliding body 6 of the movable body 7 are brought into pressure contact.

Reference numeral 8 denotes a housing cover of the vibration wave motor, which is fixed to the housing 3 with screws 9. A second ball bearing 12 is fitted into the bearing fitting hole 8b formed in the center thereof so as to be slidable in the axial direction, and a screw portion 8c is further provided on the inner circumferential surface of the bearing fitting hole 8b. A spring pressure adjusting nut member 18 is screwed onto the spring pressure adjusting nut member 18. The spring pressure adjusting nut member 18 is in contact only with the outer ring 12a of the second ball bearing 12, and the inner ring 12b of the second ball bearing 12 is provided to be slidable in the axial direction and rotatable with respect to the output shaft 1o. and two small holes 18a, 18a formed in the spring pressure adjusting nut member 18.
For example, a jig with two wooden insertion rods formed at the tip (
By inserting the insertion rod (not shown) and turning it clockwise, the spring pressure adjusting nut member 18 screws to the left in the figure and pushes the second ball bearing 12 in the same direction, causing the compression spring member 14 The spring force can be increased by compressing the spring, and by rotating it in the opposite direction, the compression spring member 14 can be expanded and the spring force can be weakened. ing. Note that the output shaft lO
After adjusting the axial load, the outer ring 12a of the second ball bearing 12 is usually fixed to the housing cover 8 by pouring an adhesive through the small hole 8a of the housing cover 8.

Further, one end of the compression spring member 14 and the second ball bearing 12
A spacer 13 is arranged between the second ball bearing 12 and the inner ring 12b of the second ball bearing 12, and one end of the compression spring member 14 comes into contact with the spacer 13 so that the output shaft can rotate smoothly without any hindrance. ing. Note that the compression spring member 14 preferably has a spring constant as small as possible in order to reduce fluctuations in the axial load with respect to deflection.

As shown in FIG. 2, the piezoelectric element group 1 of the vibrating body 2 described above includes driving piezoelectric element group 1a and B piezoelectric element group 1b, each of which has been subjected to 8i processing as shown, and which detects the vibration state. Two piezoelectric elements 1c for vibration detection and a common electrode 1 for grounding
d, and the B piezoelectric element group 1b is composed of the A piezoelectric element group 1a.
They are arranged at a pitch shifted by 174 of the wavelength (λ) of the excited beam frequency.

By applying frequency voltages having phases different by 90 degrees to the A piezoelectric element group 1a and the B piezoelectric element group 1b, progressive vibration waves are generated on the surface of the vibrating body 2, and the above-mentioned vibration waves are generated on the surface of the vibrating body 2. The movable body 7 brought into pressure contact is frictionally driven to rotate the output shaft 10 via the intermediate member 15.

In order to study the material of the vibrating body 6, which is the composite resin layer of the moving body 7, for the vibration wave motor having the above configuration, a plate-like body as a sliding body having the composition shown in Table 1 in Shimokita was formed.Example 1
．． 2 and Reference Examples 1 to 6), their flexural modulus was measured according to the following.

The sliding body of the example is as follows, in which the non-fibrous filler described in the table is blended with an aromatic polyimide resin as a base material.

Example 1: Tetrafluoroethylene resin powder (average particle size 9Bm) was added as a non-fibrous filler to an aromatic polyimide resin which is a condensate of biphenyltetracarboxylic dianhydride and aromatic diamine at a weight ratio of 8 The base was filled with 6.0% by weight lead oxide powder (average particle size 10 pm), compression molded, and cut into a 1 mm plate-like body (sliding body).

Example 2: Filling amount of tetrafluoroethylene resin powder was 9.4
%, and a plate-shaped body was molded in the same manner as in Example 1, except that the weight ratio of molybdenum powder was 6.5%.

As a reference example, each heat-resistant thermoplastic resin with a glass transition point of 100°C or higher is dispersed and filled with carbon fibers in the amounts listed in Table 1 to improve wear resistance, and a plate-like material similar to that of the example is prepared. The results of molding into a body and measuring its flexural modulus are shown in the same table. Note that the main purpose of filling carbon fibers is to improve wear resistance, and from this purpose it is desirable that the amount of carbon fibers is large, but if the amount of filling exceeds 30%, injection molding becomes difficult. It is known that filling carbon fiber increases the elastic modulus and hardness of the material, resulting in improved performance of motors and the like.

! Thickness 3.2 as measured based on Niriyodo ASTM D792
A plate of mm was used.

As is clear from the table above, the composite resin layer of this example, for example, Example 1.2, has a much higher thermal deformation than the plate-shaped body of the reference example using a thermoplastic resin as the base material. It is understood that it indicates temperature.

In addition, the example has a higher flexural modulus than the reference example using thermoplastic resin as the base material despite not being filled with carbon fibers, indicating that the aromatic polyimide has high mechanical strength. .

EXAMPLE A movable body was prepared by fixing the plate-like bodies (sliding bodies) shown in Table 1 to a support, and this was used to fabricate the vibration wave motor shown in FIG.

The vibrating body substrate of the vibrating body 2 is made of an elastic material whose thermal expansion coefficient approximates that of the piezoelectric element group 1 to which it is fixed in the plane direction, and which has a relatively small thermal expansion coefficient for a metal and has a small internal loss. Using martensitic stainless steel,
It is formed into an annular shape with a diameter of 73 mm and an axial dimension of 7 mm, and the sliding member with which the moving body comes into pressure contact is made of nickel-coated silicon carbide (Sin) eutectoid (approximately 10%).
The hard surface (Hv=600) of the phosphorus-based alloy was annealed to increase the hardness (l(v=1100)) and used.

The moving body was manufactured by forming an annular support body of approximately the same size as the vibrating body from an aluminum alloy, and using an epoxy adhesive as a composite resin layer using the plate-like body (sliding body) shown in the table above. It was fixed with adhesive. The sliding body 6 is made by cutting a 10 mm thick plate material, which is an injection molded product, to a thickness of approximately 111111 so that one side of the plate material becomes a sliding surface, and after fixing it to the support 5, the sliding surface is cut or polished by a minute amount. ) and finally 1 m
The thickness was made m, and the carbon fibers were exposed on the sliding surface in order to avoid any difference between the initial performance and the performance over time of the motor.

The composite resin layers of Reference Examples 2 and 4.5 were filled with 5% PTFE to improve lubricity during sliding. Furthermore, in the vibration wave motor of the reference example, the composite resin layer that provides the sliding surface of the moving body is filled with carbon 1G fibers, so the sliding surface of the vibrating body is made of the above-mentioned carbide made of tungsten carbide and cobalt. The material was thermally sprayed into a hard surface (HV"F1200).

Composite resin layer consisting of the above sliding bodies (Reference Examples 1 to 6 above,
The movable body to which Examples 1 to 4) were fixed was incorporated into the large-output type vibration wave motor described in FIG. 1, and "squeal", "output", and "torque unevenness" were measured according to the following.

[01 Measurement] The pressing force generated by the compression spring member 14 in the vibration wave motor shown in FIG. 1 was set to 9 kgf, and the noise during no-load rotation was measured using FFT. The measurement results are shown as approximately squealing and no squealing.

[Measurement of Output] The sharpness of the output at the rated torque (4 kgcm) was measured using a low-speed torque detector. The measurement results were divided into dog, medium, and small depending on the size of the output.

[Measurement of torque unevenness] Torque unevenness when continuously driven at rated (4 kgcm, 10,100 rpm) was measured using a low-speed torque detector. The measurement results were divided into medium and small depending on the amount of torque fluctuation.

In addition, in both cases, when measuring the noise and output, the vibrating body 2
The vibration amplitude was set to a preset constant value.

In addition, in the measurement of torque unevenness at the rated time, the amount of vibration amplitude of the vibrating body 2 was set for each material of the sliding body so that the rated value could be obtained.

Table 2 As is clear from the results in the above table, first the rating (4k
When continuous operation was started at gcm and 10,100 rpm, torque undulations were observed in all of the reference examples, especially within a few minutes immediately after driving, but in the examples, the amount of undulation was small.

Furthermore, the torque unevenness after 2 hours of continuous operation was about 2% in the example, which was smaller than 5% in the reference example.

Also, looking at the output at the rated state (4kgcIll), the reference example is in the range of 4.8 to 5.4W, while the example is in the range of 5.
．． It was 0 to 5.2w, and compared to the reference example, there was no list price and it was within a range that could be used for practical purposes.

Furthermore, when looking at the noise under no load, the phenomenon of noise was observed in all the sliding bodies of Reference Examples 1 to 6, but in the example, all < Oi
There was no occurrence of the phenomenon described in h.

(Effects of the Invention) As explained above, the large-scale vibration wave motor of the present invention uses an aromatic polyimide resin as a base material to form the sliding body of a moving body, and fills and blends a friction modifier into the aromatic polyimide resin. This has the effect of improving torque undulations, unevenness, etc. at the time of the rated high output.

Furthermore, there is an effect that "squeal" can be avoided when driving under no load or under low load.

Furthermore, as the sliding surface of the vibrating body, an inexpensive hard surface formed by electroless plating of a nickel-phosphorus-based alloy eutectoided with silicon carbide (SiC) can be used. It is possible to construct a high-precision, high-output vibration wave motor equivalent to that obtained by using an expensive hard surface coated with a thermally sprayed material, and there is also the effect that the vibration wave motor can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an outline of the configuration of a vibration wave motor constructed according to the present invention, and FIG. 2 is a plan view illustrating the arrangement of a group of piezoelectric elements constituting a vibrating body. 1; Piezoelectric element group 2: Vibrating body 5: Support body 6; Sliding body 7: Moving body

Claims (1)

[Claims] 1. A member provided with a composite resin layer that provides a contact surface with the vibrating body is brought into pressurized contact with a vibrating body that generates progressive vibration waves, and the vibrating body is brought into pressurized contact with the vibrating body. In a vibration wave motor in which members are moved relative to each other by frictional drive by progressive vibration waves generated in the vibrating body, the composite resin layer includes a base material of an aromatic polyimide resin, a friction modifier, and a non-woven material as necessary. A vibration wave motor characterized by being made of a composite resin filled with a fiber-type wear resistance improver. 2. The vibration wave motor according to claim 1, wherein the aromatic polyimide resin is a condensate of biphenyltetracarboxylic dianhydride and aromatic diamine. 3. The vibration wave motor according to claim 1, wherein the friction modifier is at least one type of lead oxide and a fluororesin. 4. The vibration wave motor according to claim 3, wherein the lead oxide is lead oxide powder and is contained in a weight ratio of 30% or less based on the base material. 5. The vibration wave motor according to claim 3, wherein the fluororesin is a polytetrafluoroethylene resin powder and is filled in a weight ratio of 5 to 40% with respect to the base material. 6. The vibration wave motor according to claim 1, wherein the composite resin layer contains transition metal powder such as molybdenum or tungsten as a filler. 7. A vibration wave motor according to any one of claims 1 to 6, characterized in that the member that presses into contact with the vibrating body is formed by fixing and integrating a support body and a molded body forming a composite resin layer. . 8. A vibration wave motor according to any one of claims 1 to 7, characterized in that the member that presses into contact with the vibrating body is composed only of a molded body forming a composite resin layer. 9. In any one of claims 1 to 8, it is provided that the sliding surface of the vibrating body is a cemented carbide surface of a nickel-phosphorus based alloy containing one or more of silicon carbide, boron carbide, boron titanium, and boron nitride. Features a vibration wave motor.