JP3517537B2 - Vibration wave drive - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration wave drive device such as a vibration wave motor, and more particularly to a vibration wave drive device in which a sliding member of a contact body that contacts an elastic body is made of ceramic.

[0002]

8 and 9 are cross-sectional views of a vibration wave motor shown as a conventional example of the present invention. FIG. 8 shows a pressure spring before installation and FIG. 9 shows a pressure contact after setting the pressure spring. The detailed drawing of a part is shown. In FIG. 8, reference numeral 1 is an elastic body in which vibration is excited, and 2 is a piezoelectric element fixed to the bottom surface of the elastic body 1 with an adhesive, which constitutes a vibrator 21 as a whole. Reference numeral 3 is a moving body as a contact body, and a ring-shaped ceramic member 4 as a sliding member is adhered only to a contact portion with the elastic body 1.

Reference numeral 5 is a central shaft, and 6 is a pressing disc spring. The leaf spring 6 is press-fitted into the central shaft 5 and then fixed by adhesion. Reference numeral 7 is a housing, 8 and 9 are bearings, and 10 is a pushing ring for fixing the vibrator, which is fixed by a screw formed on the housing 7. Reference numeral 11 denotes a fixing member, and the housing 7 is fixed to the fixing member 11 with a screw 12.

By the way, the ceramic member generally has the following features as compared with the metal member.

1) Hard and has high wear resistance.

2) No rust (chemically stable) 3) Small thermal expansion 4) High compression strength For this reason, it has been proposed to use a ceramic material as a sliding material of the vibration wave motor, Mobile unit 3 is A5056
Thin ceramics member 4 on the ring to aluminum base material such as
It is manufactured by bonding.

[0007]

On the other hand, however, ceramic members also have the following drawbacks.

1) Weakness to local stress 2) Low tensile stress Therefore, as shown in FIG. 9, the pressing of the elastic body 1 and the moving body 3 after setting the pressing leaf spring 6 (that is, in the motor state). When observing the parts and the contact state, by pushing the vicinity of the center with the pressing leaf spring 6, a bending stress acts on the moving body from the center toward the outer diameter with the contact portion as a fulcrum. Therefore, tensile stress acts on the ceramic ring 4 bonded to the moving body 2 as the base material in the direction of the arrow, and cracks, cracks, local damage, adhesive peeling, and the like are likely to occur. was there.

[0009] The engagement Ru inventions of interest application, provides crack ceramic sliding material constituting the contact body, cracks, local damage, the vibration wave driving device capable of preventing the adhesion peeling off or the like occurs To do.

[0010]

A first invention according to the present application is a vibrator for forming driving vibration in an elastic body, and a contact body.
Attach a ceramic sliding body to the contacting part with the elastic body.
Contact with the elastic body under pressure through the pressure means.
A vibration body, and the elastic body and the contact body.
In the vibration wave drive device that moves relative to each other, the sliding member is joined to the contact body in a state of being previously compressed in the radial direction.

With this structure, even when a tensile stress is applied to the sliding body, only the force for restoring the compressive stress is applied to the sliding body itself.

A second aspect of the present invention is characterized in that a spigot portion for press-fitting the outer peripheral portion of the sliding body is formed in the contact body.

With this structure, it is possible to more easily fix the device under the condition that the compressive stress is applied.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION ( Premise Example of the Present Invention ) FIG. 1 is a premise example showing a technique which is a premise of the present invention.

The vibration wave motor of this premise example has the same type as that of the conventional example shown in FIG. 8, and only different points will be described below.

First, the basic idea of this premise example will be described with reference to FIGS. 2 and 3 are views for explaining the shape and the direction of force when a bending stress is applied to a general homogeneous plate material (or beam). When bending stress is applied to a generally homogeneous plate material, , The shape is as shown in Fig. 2 and P
Compressive stress acts on the surface side, and tensile stress acts on the Q surface side.
The direction and magnitude of the force in the thickness direction are as shown in FIG. 3, and there is a stress-free surface at the center of the plate, which is called the neutral surface.

This premise example uses such a concept,
In the figure , a stepped portion 3b cut out to the neutral plane position of the moving body 3 is formed on the outer peripheral portion of the moving body 3a, and an annular ceramic sliding body 4 is joined by an adhesive.

As a result, even when a bending stress is applied to the moving body 3, the lateral stress on the joint surface is
It was possible to minimize the amount, and it was possible to prevent cracks, cracks, local damages, and adhesive peeling of the ceramic sliding body.

[0019] (First Embodiment) FIG. 4 shows a first embodiment of the present invention.

In this embodiment, in a ring-shaped moving body, a ceramic sliding body 4 is adhered and fixed to a moving body 3 in advance under compressive stress. Formed in the tool 36. The joining jig 36 is adapted to be attached to the sliding body 4 in a state where compressive stress is applied from the outer diameter side when joining the moving body main body and the sliding body 4. An adhesive 34 is applied in advance to the joint surface with the sliding body 4 of the movable body 3a placed on the pan 35 that is arranged so as to be possible.

Further, the ceramic annular slide body 4 is fixed in a state in which a compressive force is applied by, for example, a ball plunger 33 or the like provided at several positions on the outer diameter side of the joining base 31. While maintaining this state, the joining screw 32 is rotated to raise the tray 35 to join the moving body 3a and the sliding body 4.

When the moving body thus produced is set in place of the moving body of the conventional vibration wave motor shown in FIG. 8, tensile stress is applied to the ceramic sliding body 4, but the sliding body 4 is originally compressed. Since they are bonded in this state, the sliding body 4 can be prevented from being damaged only by the force acting in the returning direction.

[0023] Incidentally, the sliding member of the present embodiment before the above-mentioned
It can also be used for the sliding members shown in the examples or the following third, fourth, and fifth embodiments.

[0024] (Second Embodiment) FIG. 5 shows a second embodiment of the present invention.

The intent of this second embodiment is that
As in the first embodiment, compressive stress is applied to the sliding body 2 in advance, so that the disk-shaped moving body 30 guides the outer peripheral portion of the ceramic member 4 to the outer peripheral portion of the moving body main body 30a. By forming the inner spigot portion 30b and press-fitting and fixing the ring-shaped sliding body 4 into the spigot portion 30b, the sliding body 4 is fixed to the moving body main body 30a in a state where compressive stress is applied to the sliding body 4. ing.

According to the second embodiment, there is no need to prepare such joining jig of the first embodiment, which is simpler.

(First Reference Example ) FIG. 6 is a first reference example showing a reference technique of the present invention.

In the first reference example , the action diameter 6a of the pressing leaf spring 6 makes contact with the moving body 3 larger than the outer diameter of the sliding body 4 so that the leaf spring 6 moves when pressure is applied. Since bending force is applied to the body 3 on the opposite side of the above-mentioned explanatory views, the ceramic member is not subjected to tensile stress but may be subjected to tensile stress, so that damage is prevented. You can

( Second Reference Example ) FIG. 7 shows a second reference example of the present invention.

The intent of this second reference example is to refer to the first reference.
In the same manner as the example, the action portion 6a of the pressing leaf spring 6 is attached to the moving body 3
The contact diameter for contacting with the sliding member 4 is made larger than the outer diameter of the sliding member 4, and, like the second embodiment, the spigot portion 30b for guiding the outer peripheral portion of the ceramic member 4 to the outer peripheral portion of the moving body 30a. Is formed and the ring-shaped sliding body 4 is press-fitted and fixed to the spigot portion 30b, whereby the sliding body 4 is fixed to the moving body main body 30a in a state where compressive stress is applied to the sliding body 4.

Thus, the outer diameter of the ceramic sliding body 4 is guided by the interference fit, so that the damage can be surely prevented.

According to the first and second reference examples , the contact diameter of the spring for bringing the moving body into pressure contact with the elastic body is made larger than the outer diameter of the sliding body, so that the moving body is not affected by the pressure. , Compared to the case where the contact diameter of the spring is smaller than the outer diameter of the sliding body,
Since the bending force on the opposite side was applied, the sliding member was not subjected to tensile stress even though it was subjected to compressive stress, and could be prevented from being damaged.

Further, the sliding body in the second embodiment may be press-fitted into the moving body to be applied as a premise example .

[0034]

According to the first and second aspects of the present invention, tensile stress is applied to the joint surface with the moving body by joining the ceramic slide body in advance with compressive stress applied. Even in such a case, the ceramic sliding body only prevents the compressive force from being removed, and at least prevents a large amount of tensile force that causes damage.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a vibration wave motor according to a premise example showing a technique that is a premise of the present invention.

FIG. 2 is a diagram illustrating the basic principle of a premise example .

FIG. 3 is a diagram illustrating the basic principle of a premise example .

FIG. 4 is a cross-sectional view of a joining jig that forms the moving body according to the first embodiment.

FIG. 5 is a cross-sectional view of main parts of a vibration wave motor according to a second embodiment.

FIG. 6 is a sectional view of a main part of a vibration wave motor according to a first reference example .

FIG. 7 is a sectional view of a main part of a vibration wave motor according to a second reference example .

FIG. 8 is a sectional view of a main part of a conventional vibration wave motor.

FIG. 9 is a diagram for explaining problems of a conventional vibration wave motor.

[Explanation of symbols]

1 ... Elastic body 2 ... Piezoelectric element 3 ... Mobile 3a ... Mobile body 4 ... Ceramics member 5 ... central axis 6 ... leaf spring 6 for pressing 7 ... Housing 8, 9 ... Bearing 10 ... Push ring 11 ... Fixing member 12 ... screw 21 ... Transducer 31 ... Bonding base 32 ... Joint screw 33 ... Ball Plunger 34 ... Adhesive 35 ... Moving body saucer 36 ... Ceramic joining jig

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-261075 (JP, A) JP-A-1-144368 (JP, A) JP-A-1-110068 (JP, A) Actual development Sho-63- 202193 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02N 2/00

Claims (2)

(57) [Claims] 1. A vibrator for forming drive vibration in an elastic body,
And a contact body which is formed by joining a ceramic sliding body to a contact portion of the contact body with the elastic body and which makes pressure contact with the elastic body via a pressure means. The elastic body and the contact body In the vibration wave driving device which relatively moves the sliding member by the driving vibration, the sliding member is bonded to the contact body in a state of being compressed in the radial direction in advance. Wherein the contact body is a vibration wave driving device according to claim 1, characterized in that the spigot part for press fit engagement with the outer peripheral portion of the sliding body is formed.