JPH11113272A - Vibration-type driving device and device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the aging of driving performance, by providing a press part for operating applied pressure for driving for pressing a vibration body to a contact body and a tapered sliding contact surface, and by taper-machining the sliding contact surface while applied pressure for machining is being operated at a machining part. SOLUTION: A moving body 7 is constituted of an annular support 5 consisting of aluminum alloy or the like and a composite resin layer 6. In the support 5, a connection part of a thin part is formed and flexibility is applied in an axial direction. When machining the sliding contact surface of the moving body 7 being brought into press contact with a vibration body, a rotary flat surface plate 20 made of resin including abrasive is provided, the moving body 7 is supported by an annular support tool 1 with an outer diameter of ϕd, and an applied pressure F for machining is applied to a fixing part with an outer diameter of ϕD. In this case, the moving body 7 is elastically deformed, the rotary flat surface plate 20 is rotated while the internal diameter side part of the surface of the composite resin layer 6 is being strongly pressed, and a tapered sliding contact surface that inclines toward the inside of a diameter direction is formed on the composite resin layer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating body driving device, and more particularly, to processing of a vibrating body which is a component of the vibrating body driving device and a sliding surface of a contacting member.

[0002]

2. Description of the Related Art A vibration type driving device called a vibration type motor or the like utilizes the friction between a vibrating body and a contact body pressed against the vibrating body to transfer the kinetic energy of the high frequency vibration of the vibrating body to the contact body. (Hereinafter, referred to as a moving body). For this reason, the state of contact between the two sliding contact surfaces is particularly important, and the sliding contact surfaces must be made of a material having high wear resistance.

In a conventional vibration type driving device, a sliding surface of a vibrating body is perpendicular to an axial direction and has a flatness of 2 μm or less, and one moving body has an annular sliding portion and an output shaft. The sliding part of the sliding part is also perpendicular to the axial direction, and has a flatness of 3 μm or less.

A conventional vibration-type driving device supports a vibrating body and a moving body, each of which has flexibility in the axial direction, concentrically, and moves the moving body in a state where the sliding surfaces of the two are in contact with each other. A predetermined pressing force (driving pressing force) in the axial direction is applied to the fixing portion of the assembling. At this time, in a state in which the driving pressure is applied, the sliding contact surface of the moving body comes into contact with the sliding contact surface of the vibrating body on the inner diameter side, and there is a gap on the outer diameter side and there is no contact. .

The sliding surface of the vibrator is coated with a fluororesin (PTFE) in a weight ratio of 2.5 for the purpose of self-lubrication.
%, And a cured film of electroless nickel plating (Ni-P) having a thickness of about 30 [mu] m is formed.
To form a sliding contact surface having a Vickers hardness (Hv) of 850.

On the other hand, the sliding surface of the moving body is made of a thermoplastic resin, polyether nitrile (PEN), as a reinforcing material, 25% by weight of granular glassy carbon having an average particle size of about 12 μm, and a solid lubricant. Fluororesin (PTF
It is formed of a composite resin layer filled with 5% of E).

As described above, the sliding surface of the vibrating body is a cured film having self-lubricating properties, and the sliding surface of the moving body is a composite resin layer having excellent heat resistance and abrasion resistance. This is because it is considered that the friction coefficient between the contact surfaces is constantly stabilized, and it is possible to minimize the wear of both.

[0008]

However, in the above-described conventional vibration type driving device, the rotational load is reduced by 5 k.
gf and a continuous operation test at a rotation speed of 64 rpm for 1800 hours showed that the abrasion of the composite resin layer on the sliding surface of the moving body was small, but the cured film on the sliding surface of the vibrating body had a circumferential direction. Abrasion marks were formed on the inner surface, and the cross section of the surface was deeper on the inner diameter side and the outer diameter side was shallow. For this reason, it was found that the amount of wear and the form of wear needed to be improved.

Further, when the driving performance of the vibration type driving device is measured in the course of the continuous operation, there is a problem that the driving performance such as torque varies with time. In other words, the driving performance is the largest at the beginning of the operation, becomes smaller as time progresses, becomes the smallest around 500 hours, and then becomes 180%.
Until 0 hours, it declined with a gentle slope.

[0010] This is because in the initial stage of operation, the respective sliding contact surfaces of the vibrating body and the moving body are in contact only near the inner diameter part,
Since the pressing force per unit area of the contact portion is larger than the set value, high driving performance can be obtained. However, after 500 hours, the respective sliding contact surfaces are adapted to be in contact with the entire predetermined sliding contact surface. That is, the pressing force per unit area is as set, but it is considered that the driving performance is reduced.

Therefore, according to the present invention, it is possible to reduce the temporal fluctuation of the driving performance in the continuous operation, and to minimize the wear of the oscillating body and the sliding contact surface of the contacting body. It is an object of the present invention to provide a vibration-type driving device capable of improving a wear form of a sliding contact surface.

[0012]

In order to achieve the above object, the present invention provides a vibration type driving apparatus in which a vibrating body for which vibration is excited and a contact body which presses against the vibrating body relatively slide. One of the body and the contact body is provided with a pressurizing portion for applying a driving pressure for bringing the vibrating body and the contact body into pressure contact with each other, and a tapered sliding contact surface. In a state where a processing pressure greater than the driving pressure is applied to the pressurizing portion, taper processing is performed by a rotary flat plate or the like containing an abrasive.

That is, in the case where the vibrating body and the moving body are ring-shaped and flexible, if the processing pressure is equal to or less than the driving pressure, the tapered sliding contact surface having a small taper angle is in contact with the flat sliding contact surface. And come into contact from the inner diameter side. However, if the processing pressure is larger than the driving pressure, the taper sliding contact surface having a deep taper angle comes into contact with the planar sliding contact surface from the outer diameter side, so that the contact radius increases. For this reason, it is possible to obtain a large driving torque as compared with the case where the contact is made from the inner diameter side, and the fluctuation of the driving performance is reduced even if the operation time is long.

In the above-mentioned drive device, when the contact body has a tapered sliding contact surface, the base of the contact body is made of an aluminum alloy, and the tapered sliding contact surface contains at least a reinforcing material in a resin or a resin composition. In addition to forming a composite resin layer, a hardened film of electroless nickel plating with eutectoid fluorine resin is formed on the tapered sliding surface, and tungsten carbide and cobalt are sprayed on the tapered sliding surface to make sliding contact. The wear resistance of the surface may be improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows an overall configuration of a vibration wave motor (vibration type driving device) according to a first embodiment of the present invention, and FIG. The body and the moving body (contact body) are shown in an enlarged manner.

In these figures, reference numeral 1 denotes a thin ring-shaped piezoelectric element. Reference numeral 2 denotes a vibrating body made of an elastic material, and four protrusions (comb teeth) per [lambda] / 2 are formed on the sliding surface side of the vibrating body 2 at equal intervals over the entire circumference. The surface (sliding contact surface) of each comb tooth is the same as that of the conventional vibration wave motor, that is, a fluororesin (PTF).
E) is about 30% in thickness by joint bending about 2.5% by weight
Is a cured film of electroless nickel plating (Ni-P), which is cured by heating at 300 ° C. to have a Vickers hardness (Hv) of 8
Fifty cured films are formed.

Further, the entire surface of the electrode surface of the piezoelectric element 1 is fixed to the surface of the vibrating body 2 opposite to the sliding contact surface, and the two constitute a stator. Note that the vibrating body 2 has flexibility in the axial direction.

Reference numeral 3 denotes a housing of the vibration wave motor, and a vibrating body 2 is fixed to the housing 3 concentrically by screws 4. The outer ring of the first ball bearing 11 is fixed to the center of the housing 3. Reference numeral 10 denotes a rotating shaft, and an intermediate member 15 is fixed to an axially intermediate portion of the rotating shaft 10 by, for example, shrink fitting. One end of the rotating shaft 10 is axially slidably supported by the inner ring of the first ball bearing 11, and the other end is axially slidably supported by the inner ring of the second ball bearing 12. The second ball bearing 1
The outer ring 2 is fixed to the center of a housing cover 8 fixed to the housing 3 with screws 9.

On the outer peripheral portion of the intermediate member 15, a ring-shaped moving body 7 is provided to fit concentrically. The moving body 7 is made of an annular support made of an aluminum alloy or the like, and a thermoplastic resin equivalent to a conventional vibration wave motor fixed concentrically to the surface of the support 5 with an adhesive, that is, a thermoplastic resin. A composite resin layer 6 in which a certain polyether nitrile (PEN) is filled with 25% by weight of granular glassy carbon having an average particle size of about 12 μm as a reinforcing material and 5% of a fluororesin (PTFE) as a solid lubricant. It is configured. The support 5 has flexibility in the axial direction.

As shown in FIG. 2, the support 5 has a fixing portion (pressing portion) 5b connected to the flange portion of the intermediate member 15 and the composite resin layer 6 bonded to each other. It has a sliding portion 5a and a connecting portion 5c having a thin portion for connecting the sliding portion 5a and the fixed portion 5b.

An elastic sheet material 17 made of rubber is interposed between the fixing portion 5b of the support 5 and the flange portion of the intermediate member 15, so that the intermediate member 15 and the inner ring of the second ball bearing 12 The axial pressing force generated by the compression spring member 14 provided between them acts on the support 5 in the axial direction via the elastic sheet member 17. By this axial pressure, the sliding contact surface of the moving body 7 (the surface of the composite resin layer 6) is pressed against the sliding contact surface of the vibrating body 2.

The axial pressure (driving pressure) generated by the compression spring member 14 is adjusted by a spacer member (not shown) provided between the inner ring of the second ball bearing 12 and the compression spring member 14. can do.

Next, the processing of the sliding contact surface (the surface of the composite resin layer 6) of the moving body 7 in the vibration wave motor thus configured will be described with reference to FIG.

In FIG. 3A, reference numeral 20 denotes a rotary platen of a processing machine. The rotary platen 20 is made of a resin containing an abrasive and has a surface roughness of, for example, # 2000. The rotary platen 20 rotates at 500 rpm.

Reference numeral 21 denotes a ring-shaped support jig having an outer diameter of φd. This support jig 21 supports the moving body 7,
A load (processing pressure) F is applied to the fixed portion 5b having an outer diameter of φD.
Is given. As shown, the outer diameter φd of the support jig 21 is smaller than the outer diameter φD of the fixing portion 5b.

Here, the load F is set to be larger than the pressing force applied by the compression spring member 14 in the assembled vibration wave motor. The specific value of the load F is set in consideration of the flexibility of the vibrating body 2. For example, when the pressing force of the compression spring member 14 is 19 kgf, the load F
Is set to 22 kgf. .

In this manner, when the movable platen 7 is elastically deformed upwardly and concavely, and the rotary platen 20 is rotated in a state where the surface of the composite resin layer 6 is more strongly pressed against the rotary platen 20 toward the inner side, FIG. As shown in b), a tapered sliding contact surface that is inclined inward in the radial direction is formed on the composite resin layer 6. Here, the inclination (taper angle) of the sliding contact surface is θ = 9 minutes (0.15 degrees), and the height difference h in the axial direction is 2.6 μm.
It is about.

Then, the movable body 7 having the tapered surface of the sliding contact surface with the load F of 22 kgf applied to the fixed portion 5b is assembled in the vibration wave motor, and the compression spring member 1 is mounted.
When a pressing force of 19 kgf is applied to the fixed portion 5b by the step 4, the inclination (9 minutes) of the sliding contact surface is larger than the inclination (7.2 minutes) of the taper processing under the load of 19 kgf. Is in contact with the flat sliding contact surface of the vibrating body 2 on the outer diameter side, and 0.5 μm on the inner diameter side.
A very small gap of about m is formed.

Here, Table 1 shows target performance of the vibration wave motor of the present embodiment, and Table 2 shows design specifications.

[0030]

[Table 1]

[0031]

[Table 2]

FIGS. 4 to 6 show the results of a continuous operation test of the vibration wave motor manufactured according to the above design specifications. In the test, a perm torque (manufactured by Kojin Seisakusho) was connected to the output side of the rotating shaft 10 of the motor, the rotating load was set to 5 kgcm, the rotating plate of the encoder was attached to the other end of the rotating shaft 10, and the rotation was fixed at 64 rpm. The rotation was controlled. The motor performance was measured at intervals of 100 hours or 300 hours, and the time variation of the motor performance up to 1800 hours was confirmed. Furthermore, the wear amount of the sliding contact surface is 3
Measurements were taken at intervals of 00 hours or 900 hours.

FIG. 4 shows that the vibration amplitude of the motor is constant,
The time variation of the motor torque value when the motor is driven to rotate at 64 rpm is shown. In the drawing, the solid line indicates the torque value of the vibration wave motor of the present embodiment, and the dotted line indicates the torque value of the conventional vibration wave motor. The setting of the vibration amplitude was performed by setting the output voltages from the two detection electrodes of the piezoelectric element 1 fixed to the vibrating body 2 to the same constant voltage value.

As can be seen from FIG. 4, in the conventional motor, a torque of 10 kgcm was generated at the start of the operation, but after 500 hours, the torque value dropped to a little less than 8 kgcm, and thereafter the torque was gradually reduced. The value decreased, and after 1800 hours, decreased to about 7 kgcm.

On the other hand, in the motor of this embodiment, a torque of 7 kgcm was generated at the start of the operation, 8 kgcm after 100 hours, slightly less than 9 kgcm after 300 hours, and after that, it was around 9 kgcm until 1800 hours.
That is, the time variation of the torque value is extremely small as compared with the conventional motor.

The reason why the torque value is small at the start is that the working accuracy of the moving body 7 is insufficient and the contact of the sliding surface on the outer diameter side of the moving body 7 with the sliding surface of the vibrating body 2 is incomplete. Probably because of.

Next, FIG. 5 shows the amount of wear of the composite resin layer 6 of the moving body 7 in relation to time during continuous operation at a rotation speed of 64 rpm and a rotation load of 5 kgcm. In the figure, the solid line indicates the wear amount of the vibration wave motor of the present embodiment, and the dotted line indicates the wear amount of the conventional vibration wave motor.

As can be seen from FIG. 5, in the conventional motor, a wear amount of 18 μm was generated in 1800 hours, and a wear rate per hour was 0.01 μm.

On the other hand, in the motor of this embodiment, 9
5 μm wear amount at 00 hours, 8 μm at 1800 hours
The wear rate was 0.004 μm, which was extremely smaller than that of the conventional motor.

Next, FIG. 6 shows the amount of wear of the cured film of the vibrating body 2 in relation to time. In the drawing, the solid line indicates the amount of wear of the vibration wave motor of the present embodiment, and the dotted line indicates the amount of wear of the conventional vibration wave motor.

As can be seen from FIG. 6, in the conventional motor, the wear marks in the circumferential direction of the cured film after 900 hours are 1 mm in width, 0.7 μm in inner diameter side and 0 μm in outer diameter side. 180, which is 180 degrees.
At 0 hours, the inner diameter side depth is 2 μm and the outer diameter side depth is 1 μm
m was obtained.

On the other hand, in the motor of this embodiment, 9
The circumferential wear marks on the cured film at 00 hours were 1 mm in width, 0.3 μm in inner diameter side and 0.4 μm in outer diameter side.
In 1800 hours, the inner diameter side depth was 0.5 μm and the outer diameter side depth was 0.6 μm. In other words, the wear amount is clearly smaller than that of the conventional motor, and the wear mode has a gentle inclination.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
2 illustrates a vibrating body and a moving body of the vibration wave motor according to the embodiment. The combination of the vibrating body and the moving body according to the present embodiment is as follows.
The vibration wave motor of the second embodiment is compatible with the combination of the vibrating body 2 and the moving body 7 of the vibration wave motor of the first embodiment, and is incorporated in the vibration wave motor of the first embodiment to constitute the vibration wave motor of the second embodiment. be able to.

In FIG. 7, reference numeral 51 denotes a piezoelectric element, and reference numeral 52 denotes a vibrating body to which the piezoelectric element 51 is fixed. The vibrating body 52 is made of the same material and in the same shape as the vibrating body 2 of the first embodiment.

Reference numeral 56 denotes a composite resin layer adhered to the surface of the comb teeth of the vibrator 52. The composite resin layer 56 is formed of a composite resin obtained by filling a base resin or a resin composition with a reinforcing material or a mixture of a reinforcing material and a lubricant.

A moving body 57 is made of an aluminum alloy and has the same shape and dimensions as the moving body 7 (support 5) of the first embodiment. On the sliding contact surface of the moving body 7 (the sliding contact surface with the composite resin layer 56), a cured film of electroless nickel plating (Ni-P) in which a fluorine resin is co-folded in a weight ratio of 1.5 to 8.5%. Is formed to a thickness of about 30 μm.

A super hard material made of tungsten carbide and cobalt is coated on the sliding surface of the moving body 57 by 30 μm.
A cured film may be formed by spraying to a thickness of about m. Since the hardened films of tungsten carbide and cobalt have high hardness and high toughness, they are effective in reducing wear marks.

Also in this embodiment, the sliding contact surface (cured film) of the moving body 57 is tapered by the same processing method as the moving body 7 of the first embodiment, and the cured film having a thickness of about 30 μm is inclined. Is θ, and the height difference in the axial direction is h.

When the motor of this embodiment is continuously operated, the effect of reducing the silk value fluctuation and the amount of wear on the sliding contact surface is smaller than that of the conventional motor, as in the first embodiment.

The shape of each part of the vibration type driving device according to the present invention may not be the same as the shape of each part in the first and second embodiments. For example, in a moving body, a sliding portion and a fixed portion are connected by a connecting portion having a thin-walled portion, and a working press force is applied to a load point (a fixed portion or the like) of a drive press force to make sliding contact. The surface may be ground or polished on a flat surface plate so that the sliding contact surface has a tapered shape with a taper angle θ and an axial dimensional difference h.

In each of the above embodiments, the case where the tapered sliding contact surface is formed on the moving member (contact member) has been described. The present invention can be applied to a driving device.

[0052]

As described above, according to the present invention,
In the part where the pressing force for driving the vibrating body or contact body is applied,
Since the tapered sliding contact surface is formed on the vibrating body or the contact body by applying the working pressing force, the sliding surfaces are quickly adapted to each other, and a predetermined pressing force per unit contact area can be obtained quickly. For this reason, it is possible to reduce the wear of each sliding contact surface, and to realize a stable vibration type driving device in which the driving performance varies little over time.

Further, since a large number of processings can be performed on the tapered sliding contact surface in a short time by using the rotary flat surface plate, mass production is possible as compared with the case where the tapered sliding contact surface is processed by polishing on a spherical disk. Excellent in cost and effective for cost reduction.

[Brief description of the drawings]

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

FIG. 2 is a partially enlarged sectional view of a vibrating body and a moving body constituting the vibration wave motor.

FIG. 3 is an explanatory view of processing of a sliding surface of the moving body.

FIG. 4 is a graph showing a time variation of a torque value of the motor.

FIG. 5 is a graph showing the amount of wear of the moving body per unit time of the motor.

FIG. 6 is a graph showing a wear amount of a vibrating body per time of the motor.

FIG. 7 is a sectional view of a vibration wave motor according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1,51 Piezoelectric element 2,52 Vibrator 5 Support 6,56 Composite resin layer 7,57 Moving body 20 Flat surface plate 21 Support jig

Claims (9)

[Claims] 1. A vibration-type driving device in which a vibrating body in which vibration is excited and a contact body that is in pressure contact with the vibrating body relatively slide, wherein one of the vibrating body and the contact body includes the vibrating body. A pressurizing portion for applying a driving pressurizing force for pressing the body and the contact body against each other, and a tapered sliding contact surface; A vibration type driving device characterized in that it is tapered in a state where it is operated. 2. The vibration-type driving device according to claim 1, wherein the processing pressure is larger than the driving pressure. 3. The vibration-type driving device according to claim 1, wherein the tapering of the sliding contact surface is performed using a rotary platen containing an abrasive. 4. The vibration type driving device according to claim 1, wherein the one member is the contact body, and a base material of the contact body is an aluminum alloy. 5. The method according to claim 1, wherein the one member is the contact body, and a sliding surface of the contact body is formed of a composite resin layer containing at least a reinforcing material in a resin. 5. The vibration-type driving device according to any one of 4. 6. The contact member, wherein the one member is the contact member, and a sliding surface of the contact member is formed of a composite resin layer containing at least a reinforcing material in a resin composition. 5. The vibration type driving device according to any one of 1 to 4. 7. The method according to claim 1, wherein the one member is the contact body, and a cured film of electroless nickel plating formed by eutectoid of a fluorine resin is formed on a sliding contact surface of the contact body. 5. The vibration-type driving device according to any one of 4. 8. The vibration mold according to claim 1, wherein the one member is the contact body, and tungsten carbide and cobalt are sprayed on a sliding surface of the contact body. Drive. 9. A device comprising the vibration type driving device according to claim 1 as a driving source.