JP2013162575A - Vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve: a smooth rotation of a roller; and wear reduction of a contact portion of a stator and a roller by satisfactorily maintaining lubrication therebetween.SOLUTION: A point contact portion at which a stator 21 and a roller 31 make a point contact with respect to a thickness direction of the roller 31, and a lubricant holding portion for holding lubricant 45a are disposed at opposite portions of a mount part 22 of the stator 21 and an outer peripheral surface 311 of the roller 31. Specifically, the point contact portion is formed by forming on the mount part 22 of the stator 21 a curved surface 22a that curves with respect to the thickness direction of the roller 31.

Description

  The present invention relates to a vibration actuator.

  As a vibration actuator for rotating a roller using ultrasonic vibration, for example, there is one disclosed in Patent Document 1. As shown in FIG. 11, the vibration actuator 100 of Patent Document 1 includes vibration means 101 such as a piezoelectric element that generates ultrasonic vibration, and a stator 102 (vibrator) fixed in contact with the vibration means 101. A roller 103 (rotor) supported in contact with the stator 102 is provided. The roller 103 is pressed against the stator 102 by a traction device (preloading means) (not shown). As a result, the roller 103 is in surface contact with the stator 102 in a pressed state. When the stator 102 vibrates due to the composite vibration composed of ultrasonic vibration from the vibration means 101, contact and non-contact are repeated between the stator 102 and the roller 103 by the vibration of the stator 102. Further, when the stator 102 and the roller 103 come into contact with each other, friction is generated at the contact portion between the stator 102 and the roller 103, and the roller 103 is caused to rotate by this friction.

  In such a vibration actuator 100, since the roller 103 rotates while being in contact with the stator 102, wear occurs at a contact portion between the stator 102 and the roller 103. Therefore, for example, lubricating oil (lubricant) is supplied between the stator 102 and the roller 103. Specifically, when the stator 102 and the roller 103 are not in contact with each other due to the vibration of the stator 102, the lubricating oil is supplied to the gap between the stator 102 and the roller 103. Thereby, the space between the stator 102 and the roller 103 is lubricated, and wear at the contact portion between the stator 102 and the roller 103 is suppressed.

JP 2008-199772 A

  Incidentally, in the vibration actuator 100 of Patent Document 1, the stator 102 and the roller 103 are in surface contact. In general, assuming that the preload means generates equal preload, the larger the contact area between the stator 102 and the roller 103, the smaller the force applied to one point of the roller 103 on the stator 102. In the configuration of Patent Document 1 in which lubricating oil is supplied to the contact portion between the stator 102 and the roller 103, even if the roller 103 is pressed against the stator 102 by the preloading means, one point of the roller 103 is the stator due to the wide contact area. The force applied to 102 becomes small, and the lubricating oil supplied between the stator 102 and the roller 103 becomes difficult to cut. If the lubricating oil remains between the stator 102 and the roller 103, that is, if the lubrication state between the stator 102 and the roller 103 is fluid lubrication, friction is less likely to occur at the contact portion between the stator 102 and the roller 103. There is a risk that the roller 103 cannot be smoothly rotated.

  The present invention has been made in order to solve the above-mentioned problems, and the object thereof is to enable the roller to rotate smoothly and to maintain good lubrication between the stator and the roller and to contact the two members. An object of the present invention is to provide a vibration actuator capable of reducing wear of a part.

  In order to achieve the above object, according to the first aspect of the present invention, a stator, a vibrating means for vibrating the stator, and a mounting portion of the stator that vibrates by the vibrating means are rotated in contact with an outer peripheral surface. A cylindrical roller, a preloading means for pressing the roller against the stator, a lubricant supply means for supplying a lubricant to a facing portion between the outer peripheral surface of the roller and the mounting portion of the stator, A point contact portion where the stator and the roller are in point contact with each other in a thickness direction of the roller, at a portion facing the mounting portion of the stator and the outer peripheral surface of the roller. The gist of the present invention is that a lubricant holding portion for holding the lubricant is provided.

  According to the present invention, compared to the case where the stator and the roller are in surface contact, the contact area between the stator and the roller can be reduced, and when the roller contacts the stator, one point of the roller contacts the stator. The applied force can be increased. Therefore, when the roller comes into contact with the stator, the lubricant supplied between the stator and the roller is easily cut off, so that both members can be brought into proper contact while maintaining the lubrication state of both members. That is, the lubrication state between the stator and the roller can be boundary lubrication. Specifically, a point contact portion where the stator and the roller are in direct contact and a lubricant holding portion where the lubricant is held can be formed at a portion where the mounting portion of the stator and the outer peripheral surface of the roller are opposed to each other. it can. Therefore, the roller can be smoothly rotated by the friction at the point contact portion between the stator and the roller, and the lubrication between the stator and the roller can be satisfactorily maintained by the lubricant held by the lubricant holding portion. It is possible to reduce wear at the contact portions of both members.

  According to a second aspect of the present invention, in the first aspect of the present invention, the stator is placed on the opposite portion between the stator placement portion and the outer peripheral surface of the roller with respect to the rotation direction of the roller. The gist of the present invention is that a line contact portion where the portion and the outer peripheral surface of the roller are in line contact is provided.

  According to the present invention, for example, the contact area between the stator and the roller is larger than that in the case where the contact portion between the stator and the roller is in point contact in the rotation direction of the roller. The roller can be rotated smoothly.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the mounting portion of the stator has a curved surface that is curved with respect to the thickness direction of the roller, or the thickness direction of the roller. The gist is that the point contact portion is provided by forming a tapered surface inclined with respect to the surface.

According to the present invention, it is possible to easily provide the point contact portion at the facing portion between the mounting portion of the stator and the outer peripheral surface of the roller only by changing the shape of the stator.
The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the lubricant supply means is a supply body impregnated with the lubricant, and the supply body is The gist is that it is provided in the vicinity of the mounting portion of the stator and in contact with the outer peripheral surface of the roller.

  According to this invention, the lubricant can be smoothly supplied to the facing portion between the mounting portion of the stator and the outer peripheral surface of the roller.

  According to the present invention, the roller can be smoothly rotated, and the lubrication between the stator and the roller can be maintained well, and the wear at the contact portion of both members can be reduced.

(A) is the front view which looked at the vibration actuator in embodiment from the radial direction of the roller, (b) is the partial perspective view which expands and shows the opposition site | part periphery of a stator and a roller. The side view of a vibration actuator. AA line sectional view in FIG. (A) is a partially enlarged front view of the vibration actuator, (b) is a cross-sectional view taken along line BB in FIG. 2, (c) is a cross-sectional view taken along line CC in FIG. 4 (a), and (d) is FIG. The DD sectional view taken on the line in a). The fragmentary sectional view which expands and shows the opposition site | part periphery of the stator and roller in another embodiment. The fragmentary sectional view which expands and shows the opposition site | part periphery of the stator and roller in another embodiment. The fragmentary sectional view which expands and shows the opposition site | part periphery of the stator and roller in another embodiment. The fragmentary sectional view which expands and shows the opposition site | part periphery of the stator and roller in another embodiment. The fragmentary sectional view which expands and shows the opposition site | part periphery of the stator and roller in another embodiment. The fragmentary sectional view which expands and shows the opposition site | part periphery of the stator and roller in another embodiment. The perspective view which shows the vibration actuator in a prior art example.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIGS. 1A and 2, the vibration actuator 10 is provided with a piezoelectric element 11 as vibration means. The piezoelectric element 11 is cylindrical and has a structure in which a plurality of disk-shaped piezoelectric element plates are stacked. The piezoelectric element 11 is electrically connected to a drive circuit (not shown), and generates an ultrasonic vibration when an AC voltage is applied from the drive circuit.

  A block-shaped stator 21 (vibrator) is fixed to one end surface of the piezoelectric element 11 in contact with the piezoelectric element 11. A cylindrical base block 12 is fixed to the other end surface (surface opposite to the stator 21) of the piezoelectric element 11.

  As shown in FIG. 4B, a mounting portion 22 is recessed on the surface of the stator 21 opposite to the piezoelectric element 11, and the mounting portion 22 has a cylindrical roller 31 (rotation). Child) is supported by contact. The roller 31 is disposed such that the outer peripheral surface 311 thereof is in contact with the placement portion 22 of the stator 21. A gap is formed between both side surfaces of the roller 31 (both surfaces positioned in the thickness direction of the roller 31) and the side surface of the mounting portion 22 facing both side surfaces of the roller 31. The stator 21 is made of, for example, stainless steel, and the roller 31 is made of, for example, ceramics or alumina.

  As shown in FIG. 1B, the outer peripheral surface 311 of the roller 31 is formed in a flat surface shape in the thickness direction of the roller 31. A rotation shaft 32 is inserted into the roller 31. The roller 31 rotates integrally with the rotation shaft 32 around the rotation shaft 32. A groove 211 is formed on the surface of the stator 21 opposite to the piezoelectric element 11. The groove 211 extends in the same direction as the direction in which the rotating shaft 32 extends.

  As shown in FIG. 3, the roller 31 is pressed against the mounting portion 22 of the stator 21 by the preloading means 40 and is in pressure contact therewith. The preload means 40 includes an attachment portion 41, a rod-like shaft portion 42 connected to the attachment portion 41, and an urging portion 43 that urges the shaft portion 42. The attachment portion 41 is formed of a pair of attachment pieces 41a and 41b that surround the rotation shaft 32 and supported by the rotation shaft 32 via a bearing 44, and a connecting portion 41c that connects the pair of attachment pieces 41a and 41b. Has been. The connecting part 41c passes through the groove part 211 and connects the base ends located on the piezoelectric element 11 side of the pair of attachment pieces 41a and 41b.

  One end of the shaft portion 42 is connected to the connecting portion 41 c, and the other end penetrates the stator 21, the piezoelectric element 11, and the base block 12 and protrudes from the base block 12. A cylindrical connection member 42 a is fixed to the other end of the shaft portion 42. On the surface of the base block 12 opposite to the piezoelectric element 11, a plurality of annular disc springs 43a are fixedly stacked. A shaft portion 42 is inserted inside each disc spring 43a. A disc-shaped spring receiving member 43b is connected to the disc spring 43a located on the most opposite side to the base block 12 among the plurality of disc springs 43a. The spring receiving member 43b is coupled to the connecting member 42a. And the axial part 42 is urged | biased by the other end side by each disc spring 43a via the spring receiving member 43b and the connection member 42a. As a result, the roller 31 is pressed against the stator 21 via the mounting portion 41 and the rotating shaft 32. Therefore, in this embodiment, the urging | biasing part 43 is comprised by each disc spring 43a and the spring receiving member 43b.

  As shown in FIG. 4A, in the groove portion 211 of the stator 21, a supply body 45 as a lubricant supply means is disposed between the roller 31 and the connecting portion 41c. That is, the supply body 45 is disposed in the vicinity of the placement portion 22 of the stator 21. The supply body 45 is obtained by impregnating a flexible porous resin member with a lubricating oil 45a as a lubricant such as oil or grease. The supply body 45 is crushed in contact with the roller 31 pressed against the mounting portion 22 of the stator 21 so that the lubricating oil 45a oozes out.

  As shown in FIG. 4B, the portion of the mounting portion 22 of the stator 21 excluding the groove 211 is curved in an arc shape so as to be recessed toward the opposite side of the roller 31 with respect to the thickness direction of the roller 31. A curved surface 22a is formed. When the contact portion between the stator 21 and the roller 31 is viewed from the radial direction of the roller 31, both edge portions 31 a of the outer peripheral surface 311 of the roller 31 positioned at both ends in the thickness direction of the roller 31 in the thickness direction of the roller 31. , 31b are in point contact with the curved surface 22a of the stator 21. Therefore, in the present embodiment, a point contact portion where the stator 21 and the roller 31 are in point contact with each other in the thickness direction of the roller 31 is located at a portion where the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 face each other. Is provided. In the present embodiment, two portions where the stator 21 and the roller 31 are in point contact with each other in the thickness direction of the roller 31 are formed.

  Further, as shown in FIG. 4C, the portion of the mounting portion 22 of the stator 21 facing the roller 31 is along the rotation direction of the roller 31 (the direction of the arrow R shown in FIG. 4C). It is curved. The placement portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 are in line contact with the rotation direction of the roller 31. Therefore, in the present embodiment, the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 are opposed to the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 in the rotational direction of the roller 31. A line contact part is provided in which the line contacts.

  Further, as shown in FIG. 4D, a gap 46 is formed at a portion where the stator 21 and the roller 31 are not in contact with each other at the portion where the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 are opposed to each other. In this gap 46, the lubricating oil 45a exuding from the supply body 45 is held. Therefore, in the present embodiment, the gap 46 functions as a lubricant holding portion that holds the lubricating oil 45a.

Next, the operation of this embodiment will be described.
When an AC voltage is applied to the piezoelectric element 11 from the drive circuit, each piezoelectric element plate of the piezoelectric element 11 generates ultrasonic vibrations having different vibration directions. By transmitting the composite vibration of the ultrasonic vibration to the stator 21, elliptical vibration is generated in the mounting portion 22 of the stator 21. Due to the elliptical vibration of the mounting portion 22 of the stator 21, friction is generated at a point contact portion between the curved surface 22 a of the stator 21 and the outer peripheral surface 311 of the roller 31, and the roller 31 rotates by this friction. Note that switching of the rotation direction of the roller 31 and adjustment of the rotation speed are performed by controlling the AC voltage applied to the piezoelectric element 11.

  Here, in the thickness direction of the roller 31, the curved surface 22 a of the stator 21 and the outer peripheral surface 311 of the roller 31 are in point contact. That is, the stator 21 and the roller 31 are not in surface contact. Therefore, the contact area between the stator 21 and the roller 31 is smaller than when the stator 21 and the roller 31 are in surface contact. As a result, when the roller 31 comes into contact with the stator 21, the force that one point of the roller 31 applies to the stator 21 increases.

  When elliptical vibration occurs in the mounting portion 22 of the stator 21, contact and non-contact are repeated at a point contact portion between the curved surface 22 a of the stator 21 and the outer peripheral surface 311 of the roller 31. When the point contact portion between the curved surface 22a of the stator 21 and the outer peripheral surface 311 of the roller 31 is not in contact, it oozes from the supply body 45 between the curved surface 22a of the stator 21 and the outer peripheral surface 311 of the roller 31. Lubricating oil 45a is supplied.

  When the roller 31 comes into contact with the stator 21, the lubricating oil 45 a supplied between the placement portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 is cut. At this time, the lubricating oil 45 a is held in the gap 46 at a portion facing the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31. As a result, a point contact portion where the stator 21 and the roller 31 are in direct contact with a portion where the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 are in direct contact with the lubricant holding in which the lubricating oil 45a is held. A site is formed. That is, the lubrication state between the stator 21 and the roller 31 is boundary lubrication. As a result, the roller 31 smoothly rotates due to the friction at the point contact portion between the stator 21 and the roller 31, and the lubrication oil 45 a held by the gap 46 maintains good lubrication between the stator 21 and the roller 31. As a result, wear at the contact portion between the stator 21 and the roller 31 is reduced.

In the above embodiment, the following effects can be obtained.
(1) A point contact portion where the stator 21 and the roller 31 are in point contact with each other with respect to the thickness direction of the roller 31 and a lubricating oil 45a at a portion facing the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31. And a lubricant holding portion to be held. Therefore, compared with the case where the stator 21 and the roller 31 are in surface contact, the contact area between the stator 21 and the roller 31 can be reduced, and when the roller 31 contacts the stator 21, one point of the roller 31 is obtained. The force applied to the stator 21 can be increased. Therefore, when the roller 31 comes into contact with the stator 21, the lubricating oil 45 a supplied between the stator 21 and the roller 31 is easily cut off, so that both members are properly brought into contact while maintaining the lubrication state of both members. Can do. That is, the lubrication state between the stator 21 and the roller 31 can be boundary lubrication. Specifically, a point contact portion where the stator 21 and the roller 31 are in direct contact with a portion where the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 are opposed to each other, and a lubricant holding where the lubricating oil 45a is held. A gap 46 that is a part can be formed. Therefore, the roller 31 can be smoothly rotated by the friction at the point contact portion between the stator 21 and the roller 31, and the lubrication oil 45 a held by the gap 46 lubricates the stator 21 and the roller 31. It is possible to reduce the wear at the contact portion of both members while maintaining good.

  (2) The mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 are in line contact with the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 in the rotational direction of the roller 31. Line contact sites were provided. Therefore, for example, compared with the case where the contact portion between the stator 21 and the roller 31 is point-contacted in the rotation direction of the roller 31, the contact area between the stator 21 and the roller 31 is increased, so that the torque transmission region is wide. Thus, the roller 31 can be rotated smoothly.

  (3) A point contact portion was formed by forming a curved surface 22 a that curves in the thickness direction of the roller 31 on the mounting portion 22 of the stator 21. Therefore, by simply changing the shape of the stator 21, it is possible to easily provide a point contact portion at a portion facing the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31.

  (4) The supply body 45 impregnated with the lubricating oil 45 a is provided in the vicinity of the mounting portion 22 of the stator 21 and in contact with the outer peripheral surface 311 of the roller 31. Therefore, the lubricating oil 45a can be smoothly supplied to the facing portion between the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31.

In addition, you may change the said embodiment as follows.
As shown in FIG. 5, a curved surface 52 a that is curved in an arc shape so as to bulge toward the roller 31 side with respect to the thickness direction of the roller 31 is formed in a portion of the placement portion 22 of the stator 21 excluding the groove portion 211. May be. According to this, when the contact portion between the stator 21 and the roller 31 is viewed from the radial direction of the roller 31, the top portion 51 of the curved surface 52 a is in the thickness direction of the roller 31 with respect to the outer peripheral surface 311 of the roller 31. Point contact.

  As shown in FIG. 6, a tapered surface 61 that is inclined with respect to the thickness direction of the roller 31 may be formed at a portion of the placement portion 22 of the stator 21 excluding the groove portion 211. According to this, when the contact portion between the stator 21 and the roller 31 is viewed from the radial direction of the roller 31, one edge portion 31 a of the outer peripheral surface 311 of the roller 31 is formed on the tapered surface 61 in the thickness direction of the roller 31. Point contact is made.

  As shown in FIG. 7, the mounting portion 22 of the stator 21 is formed in a flat surface shape with respect to the thickness direction of the roller 31, and the outer peripheral surface 311 of the roller 31 is arranged on the stator 21 side in the thickness direction of the roller 31. You may make it curve in an arc shape so that it may swell toward. According to this, when the contact portion between the stator 21 and the roller 31 is viewed from the radial direction of the roller 31, the top portion 71 curved in an arc shape on the outer peripheral surface 311 of the roller 31 is formed on the mounting portion 22 of the stator 21. Point contact is made.

  As shown in FIG. 8, the mounting portion 22 of the stator 21 is formed in a flat surface shape with respect to the thickness direction of the roller 31, and the outer peripheral surface 311 of the roller 31 is the roller 31 in the thickness direction of the roller 31. You may make it incline so that it may fall linearly from one edge part 31a of the outer peripheral surface 311 to the other edge part 31b. According to this, when the contact portion between the stator 21 and the roller 31 is viewed from the radial direction of the roller 31, the other edge 31 b of the outer peripheral surface 311 of the roller 31 is Point contact is made with respect to the mounting portion 22.

  As shown in FIG. 9, the mounting portion 22 of the stator 21 is formed in a flat surface shape with respect to the thickness direction of the roller 31, and the outer peripheral surface 311 of the roller 31 is connected to the stator 21 in the thickness direction of the roller 31. May be curved in an arc so as to be recessed on the opposite side. According to this, when the contact portion between the stator 21 and the roller 31 is viewed from the radial direction of the roller 31, both edges 31 a and 31 b of the outer peripheral surface 311 of the roller 31 are in the stator 21 in the thickness direction of the roller 31. The point 22 is in point contact with the mounting portion 22.

  As shown in FIG. 10, the outer peripheral surface 311 of the roller 31 is arcuate so as to swell toward the stator 21 with respect to the thickness direction of the roller 31 so as to have a curvature different from the curvature of the curved surface 22 a of the stator 21. It may be curved. Specifically, the curvature of the outer peripheral surface 311 of the roller 31 is larger than the curvature of the curved surface 22 a of the stator 21. According to this, when the contact portion between the stator 21 and the roller 31 is viewed from the radial direction of the roller 31, the apex 91 that is curved in an arc shape on the outer peripheral surface 311 of the roller 31 corresponds to the curved surface 22 a of the stator 21. Point contact.

In the embodiment, the mounting portion 22 of the stator 21 may be curved in an arc shape so as to be continuously recessed toward the opposite side of the roller 31 with respect to the thickness direction of the roller 31.
In the embodiment, the portion of the mounting portion 22 of the stator 21 that faces the roller 31 is curved so as to follow the rotation direction of the roller 31, but is not limited to this, for example, along the radial direction of the roller 31. It may be formed linearly. The contact portion between the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 may be in point contact in the rotation direction of the roller 31.

  In the embodiment, the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 are set such that the contact area between the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 is equal to or less than a predetermined area. What is necessary is just to design the contact part. Here, the “predetermined area” refers to the mounting portion 22 of the stator 21 and the outer peripheral surface 311 of the roller 31 when the force applied by one point of the roller 31 to the stator 21 is in contact with the stator 21. The contact area is a force that can cut the lubricating oil 45a supplied between the two.

In the embodiment, the material of the stator 21 and the roller 31 is not particularly limited.
In the embodiment, the stator 21 may have a substantially cylindrical shape, for example, and the shape of the stator 21 is not particularly limited.

In the embodiment, the configuration of the preload means 40 is not particularly limited as long as the roller 31 can be pressed against the stator 21.
In the embodiment, for example, the lubricating oil 45a may be stored directly in the groove 211 of the stator 21. In this case, the groove portion 211 corresponds to a lubricant supply unit.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(A) a stator, vibration means for vibrating the stator, a cylindrical roller rotating with an outer peripheral surface coming into contact with a mounting portion of the stator vibrated by the vibration means, and the roller with respect to the stator A vibration actuator comprising preloading means for pressure contact, and lubricant supply means for supplying a lubricant to a facing portion between the outer peripheral surface of the roller and the mounting portion of the stator, wherein the mounting of the stator The vibration actuator is characterized in that a contact portion between the mounting portion of the stator and the outer peripheral surface of the roller is formed so that a contact area between the portion and the outer peripheral surface of the roller is equal to or less than a predetermined area.

  DESCRIPTION OF SYMBOLS 10 ... Vibration actuator, 11 ... Piezoelectric element as a vibration means, 21 ... Stator, 22 ... Mounting part, 22a, 52a ... Curved surface, 31 ... Roller, 311 ... Outer peripheral surface, 40 ... Preload means, 45 ... Lubricant supply Supply body as means, 45a ... lubricating oil as lubricant, 46 ... gap as lubricant holding part, 61 ... tapered surface.

Claims (4)

A stator,
Vibration means for vibrating the stator;
A cylindrical roller that rotates with an outer peripheral surface in contact with the mounting portion of the stator that vibrates by the vibration means;
Preloading means for pressing the roller against the stator;
Lubricant supply means for supplying a lubricant to a facing portion between the outer peripheral surface of the roller and the mounting portion of the stator, and a vibration actuator comprising:
A point contact portion where the stator and the roller are in point contact with each other in a thickness direction of the roller, and a lubrication in which the lubricant is held at a portion facing the mounting portion of the stator and the outer peripheral surface of the roller A vibration actuator characterized in that an agent holding part is provided.   A line contact portion where the stator mounting portion and the outer peripheral surface of the roller are in line contact with each other in the rotational direction of the roller is provided at a portion facing the mounting portion of the stator and the outer peripheral surface of the roller. The vibration actuator according to claim 1, wherein:   The point contact portion is provided by forming a curved surface that is curved with respect to the thickness direction of the roller or a tapered surface that is inclined with respect to the thickness direction of the roller on the mounting portion of the stator. The vibration actuator according to claim 1 or 2. The lubricant supply means is a supply body impregnated with the lubricant,
The said supply body is the vicinity of the mounting part of the said stator, and is provided in contact with the outer peripheral surface of the said roller, The Claim 1 characterized by the above-mentioned. Vibration actuator.