JP2013138583A - Vibration actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration actuator simplifying a structure that supplies a lubricant to a contact part between a rotor and a vibrator.SOLUTION: A vibration actuator 101 includes: a roller 1; a vibrator 2 having a first contact surface 2a1 and a second contact surface 2b1 that contact with the roller 1; a piezoelectric element 3 vibrating the vibrator 2; a preload member 8 pressurizing the vibrator 2 with the roller 1; and a lubrication member 10 provided near the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2 so as to contact with the roller 1. The lubrication member 10 holds a lubricant, and the roller 1 has cylindrical surfaces 1aa and 1ba that respectively contact with the first contact surface 2a1 and the second contact surface 2b1. Each cylindrical surface has a recessed part V.

Description

  The present invention relates to a vibration actuator, and more particularly to a vibration actuator capable of lubricating a contact portion between a rotor and a vibrator of the vibration actuator.

A vibration actuator that generates and drives ultrasonic vibrations is used as an actuator that is used in a portion that is required to be driven with a high degree of freedom and high torque.
The vibration actuator is provided with vibration means such as a piezoelectric element that generates ultrasonic vibrations, a vibrator fixed in contact with the vibration means, and a rotor disposed in contact with the vibrator. The vibrator generates vibration at the contact portion with the rotor by a composite vibration composed of ultrasonic vibration generated by the vibration means, and the rotor is rotated by the frictional force generated between the vibrating contact portion and the vibrator. Is done. In such a vibration actuator, since the rotor is rotated in contact with the vibrator, wear occurs at these contact portions. Therefore, a technique for reducing the wear of the contact portion between the rotor and the vibrator has been proposed.

  For example, Patent Document 1 describes a vibration actuator that rotates and moves a spherical rotor (rotor). In this vibration actuator, the vibration means and the vibrator (stator) are connected to each other to form a cylindrical outer shape, and a cylindrical concave portion is formed on the surface of the vibrator opposite to the contact surface with the vibration means. The rotor is arranged in contact with the annular corner of the recess. Further, preload is applied to the rotor from the side opposite to the concave portion in the direction in which the rotor is pressed against the vibrator. Further, the preload portion is formed with a recess that opens toward the rotor, and a lubricant such as grease is accommodated in the recess. Also, a lubricant such as grease is accommodated in the recess of the vibrator. Each of the preload portion and the vibrator is provided with a lubricant supply path communicating with the recess of the preload portion and the recess of the vibrator. Lubricant is supplied to each recess from outside the preload portion and the vibrator. Can be replenished. Therefore, in the vibration actuator of Patent Document 1, the lubricant is supplied between the preload portion and the rotor from the recess of the preload portion to be lubricated, and the lubricant is interposed between the resonator and the rotor from the recess of the vibrator. Supplied and lubricated.

JP 2008-206251 A

  However, in the vibration actuator of Patent Document 1, the preload section and the vibrator are provided with a recess for accommodating the lubricant and a path for supplying the lubricant to each recess, so that the structure becomes complicated and the number of manufacturing steps increases. Therefore, there is a problem that the cost increases. Furthermore, when the rotor is not a sphere but a roller or the like, and the preload is applied not from the outside of the rotor but from the inside, the structure of the concave portion for accommodating the lubricant is further complicated, and the cost is increased. is there.

  The present invention has been made to solve such problems, and an object thereof is to provide a vibration actuator that simplifies a structure for supplying a lubricant to a contact portion between a rotor and a vibrator. To do.

A vibration actuator according to the present invention includes a rotor, a vibrator having a contact surface that contacts the rotor, a vibration means that vibrates the vibrator, a preload means that pressurizes the rotor against the vibrator, A supply body provided near the contact surface and in contact with the rotor, the supply body holds a lubricant, and the rotor has a facing surface that contacts the contact surface of the vibrator. The opposing surface has a recess.
By holding the lubricant supplied from the supply body in the recess and transporting / supplying the lubricant to the contact surface of the vibrator along with the rotation of the rotor, the occurrence of wear can be efficiently prevented with a simpler structure.

In the vibration actuator according to the present invention, the opposing surface of the rotor may have a flat portion that is in surface contact with the contact surface of the vibrator, and the concave portion may have a plurality of holes that can hold the lubricant.
Further, the recess may have at least one groove formed on the opposing surface of the rotor that can hold the lubricant.
Moreover, the recessed part may have a plurality of grooves, and the grooves may have a plurality of groove directions intersecting each other.
Further, the vibrator has a protruding claw portion, a contact surface is formed on a part of the surface of the protruding claw portion, and the supply body is in contact with at least a part of the protruding claw portion, The surface can also have a plurality of grooves capable of holding lubricating oil.
The supply body may be a porous member impregnated with a lubricant.
Furthermore, the vibration of the vibration means may be controlled such that the position of the vibration antinode or the vicinity of the vibration antinode is included in the contact surface of the vibrator.

  According to the present invention, the structure for supplying the lubricant to the contact portion between the rotor and the vibrator of the vibration actuator can be simplified.

It is a perspective view which shows the structure of the vibration actuator which concerns on Embodiment 1 of this invention. It is a side view which shows the structure of the vibration actuator shown in FIG. It is a schematic diagram which shows the roughness curve and surface state of the cylindrical surface of the rotor in the vibration actuator shown in FIG. It is a perspective view which shows the structure of the vibration actuator which concerns on Embodiment 2 of this invention. FIG. 5 is a development view and an enlarged view showing the shape of the entire cylindrical surface of the rotor in the vibration actuator shown in FIG. 4. FIG. 5 is a development view and an enlarged view showing a modification of the shape of the entire cylindrical surface of the rotor in the vibration actuator shown in FIG. It is a perspective view which shows the structure of the vibrator | oscillator in the vibration actuator which concerns on Embodiment 3 of this invention. FIG. 8 is a plan view illustrating a state in which the vibrator illustrated in FIG. 7 is viewed from above. FIG. 8 is a schematic diagram illustrating the shape of the entire groove provided in a part of the contact surface of the vibrator illustrated in FIG. 7. FIG. 8 is a schematic diagram illustrating a modification of the shape of the entire groove provided in a part of the contact surface of the vibrator illustrated in FIG. 7.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
First, the configuration of the vibration actuator 101 according to the first embodiment of the present invention will be described with reference to FIGS.

Referring to FIG. 1, the vibration actuator 101 includes a pair of first roller portion 1a and second roller portion 1b having a cylindrical shape. The first roller portion 1a and the second roller portion 1b have the same shape and are provided facing each other. The first roller portion 1a and the second roller portion 1b are connected by a roller shaft 1c and can rotate integrally around the roller shaft 1c. The first roller portion 1a, the second roller portion 1b, The roller shaft 1c forms one roller 1. Here, the roller 1 constitutes a rotor.
Furthermore, columnar arm members 6 are connected to the first roller portion 1a and the second roller portion 1b on the respective cylindrical surfaces 1aa and 1ba. Therefore, when the first roller portion 1a and the second roller portion 1b are rotated in the clockwise direction P or counterclockwise direction Q on the paper surface around the roller shaft 1c, the arm member 6 is moved to the first roller portion 1a and the second roller portion 1b. Together with the second roller portion 1b, it rotates in the direction P or the direction Q.
The cylindrical surfaces 1aa and 1ba constitute opposing surfaces.

  Here, FIG. 3A is a portion schematically showing the roughness curve of the cylindrical surface 1aa of the first roller portion 1a measured along the cutting line L′-L ″ shown in FIG. 1 and the surface state thereof. 3A, the cylindrical surface 1aa is formed with a flat portion W that forms a flat surface over the entire surface and a concave portion V that forms a fine hole or groove. The flat portion W is formed so that the distance from the center of the first roller portion 1a is equal in each portion of the cylindrical surface 1aa, and the first contact surface 2a1 and the second contact surface of the vibrator 2 described later. The concave portion V is concave in the opposite direction to the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2, which will be described later, on the cylindrical surface 1aa of the roller 1. The depth of the concave portion V from the flat portion W is about 0.5 to 2.0 μm. When the surface roughness of the cylindrical surface 1aa of the first roller portion 1a shown in Fig. 3 (a) is expressed by a ten-point average roughness RZJIS, the value is about 1.6 µm The cylindrical surface of the second roller portion 1b The same applies to 1ba.

  As shown in FIGS. 1 and 2, the vibration actuator 101 includes a substantially cylindrical vibrator 2 arranged so as to be in contact with the cylindrical surfaces 1aa and 1ba of the first roller portion 1a and the second roller portion 1b, respectively. have. The vibrator 2 is formed with a first projecting claw portion 2a and a second projecting claw portion 2b that project in a strip shape in parallel on the end surface 2c on the first roller portion 1a and second roller portion 1b side. And the 1st protrusion nail | claw part 2a and the 2nd protrusion nail | claw part 2b form the groove part 2ab between these. Further, the first projecting claw portion 2a and the second projecting claw portion 2b are curved surfaces whose corners on the groove portion 2ab side are in contact with the cylindrical surfaces 1aa and 1ba of the first roller portion 1a and the second roller portion 1b, respectively. It is chamfered into a shape. This chamfered portion forms a first contact surface 2a1 and a second contact surface 2b1. Therefore, the vibrator 2 includes the first contact surface 2a1 of the first protrusion claw portion 2a and the second contact surface 2b1 of the second protrusion claw portion 2b, the cylindrical surface 1aa of the first roller portion 1a, and the second roller portion. It is made to contact with the cylindrical surface 1ba of 1b.

The vibration actuator 101 has a cylindrical piezoelectric element 3 on the end surface of the vibrator 2 opposite to the first roller part 1a and the second roller part 1b. They are connected and fixed to each other. The piezoelectric element 3 has a structure in which a plurality of piezoelectric element plates that are electrically connected to a drive circuit (not shown) are stacked. The plurality of piezoelectric element plates of the piezoelectric element 3 generate ultrasonic vibrations when an AC voltage is applied. Here, the piezoelectric element 3 constitutes vibration means.
Further, a cylindrical first base block 4 and a second base block 5 are sequentially provided on the end surface of the piezoelectric element 3 opposite to the vibrator 2 and are fixed to each other.

A preload member 8 is rotatably provided on the roller shaft 1c. The preload member 8 is rotatably attached to the roller shaft 1c so as to surround the roller shaft 1c, and the vibrator 2, the piezoelectric element 3, and the first base block 4 are connected to the attachment portion 8a. It has a bar-shaped shaft portion 8b that penetrates, and a biasing portion 8c that is provided on the second base block 5 and is connected to the shaft portion 8b on the opposite side of the mounting portion 8a. The urging portion 8c applies a pulling force in the direction F opposite to the attachment portion 8a with respect to the shaft portion 8b. Therefore, the shaft portion 8 b is attracted in the direction F by the tensile force of the urging portion 8 c of the preload member 8, and the first roller portion 1 a and the second roller portion 1 b are pressed against the vibrator 2. That is, the first roller portion 1 a and the second roller portion 1 b are fixed to the vibrator 2 by applying a pre-pressure that pressurizes the vibrator 2. The preload member 8 constitutes a preload means.
Here, for convenience of explanation, the axial direction of the shaft portion 8b of the preload member 8 from the second base block 5 toward the roller shaft 1c is defined as the positive z-axis direction, and the axis of the roller shaft 1c is perpendicular to the z-axis. It is assumed that the x-axis extends in the direction and the y-axis extends perpendicular to the x-axis and the z-axis.

The vibration actuator 101 has a lubricating member 10 that is provided in the groove 2ab of the vibrator 2 and has a substantially rectangular parallelepiped shape that extends in the x-axis direction. The lubricating member 10 is provided so as to be adjacent to and in contact with the first protruding claw portion 2a and the second protruding claw portion 2b of the vibrator 2, and from the position adjacent to the first abutting surface 2a1, the second abutting surface 2b1. The first roller portion 1a and the second roller portion 1b are in contact with each other between the positions adjacent to the first roller portion 1b and the end surface 2c of the groove portion 2ab of the vibrator 2. At this time, in each of the 1st roller part 1a and the 2nd roller part 1b, the site | part which the lubricating member 10 is contacting with, the 1st contact surface 2a1 of the 1st protrusion claw part 2a, and the 2nd protrusion claw part 2b The second contact surface 2b1 does not overlap with the portion in contact with the second contact surface 2b1. That is, the lubricating member 10, and the first contact surface 2a1 and the second contact surface 2b1 are in direct contact with the first roller portion 1a and the second roller portion 1b, respectively.
Here, the lubricating member 10 constitutes a supply body.

The lubricating member 10 is obtained by impregnating a porous resin member having flexibility and / or elasticity with a lubricant such as lubricating oil or lubricating fine particles. In the following embodiments, lubricating oil such as oil or grease is used as the lubricant.
Then, the lubricating member 10 comes into contact with and is crushed by the first roller portion 1a and the second roller portion 1b pressed against the vibrator 2 by the preload, and deforms to follow the shapes of the cylindrical surfaces 1aa and 1ba. doing. Therefore, the lubricating member 10 is fixed to the groove portion 2ab of the vibrator 2 by the interaction between the preload and the elastic force of the lubricating member 10 that works in the direction of restoring deformation against the preload. That is, the lubricating member 10 is fixed to the groove portion 2ab by using a preload that fixes the first roller portion 1a and the second roller portion 1b to the vibrator 2.

  Further, the resin member of the lubricating member 10 absorbs and holds the lubricating oil in the resin member using the capillary phenomenon of the porous structure of the porous body, and when it comes into contact with the first roller portion 1a and the second roller portion 1b. The lubricating oil is discharged and supplied to the cylindrical surface 1aa of the first roller portion 1a and the cylindrical surface 1ba of the second roller portion 1b by the pump effect due to the surface tension. In addition, since the cylindrical surfaces 1aa and 1ba are formed with a large number of fine holes (recesses) V on the entire surface, the lubricating oil discharged and supplied to the cylindrical surfaces 1aa and 1ba is sucked into the recesses V by capillary action, Retained.

Further, the resin member of the lubricating member 10 has a higher amount of impregnation of the lubricating oil as the porosity is higher, and a larger amount of the lubricating oil is supplied as the pore diameter is larger. For this reason, a resin member having a high porosity is preferable. For example, it is preferable to use a PVA resin (polyvinyl alcohol) having a porosity of about 90% or more. And the supply amount of lubricating oil can be set by selecting the resin member which has a desired pore diameter.
Further, as the lubricating oil, for example, fluorine-based, glycol-based, synthetic hydrocarbon-based, or ester-based oil or grease can be used.

Next, the operation of the vibration actuator 101 according to the first embodiment of the present invention will be described with reference to FIG.
Referring to FIG. 1, when an AC voltage is applied to each piezoelectric element plate inside the piezoelectric element 3 by a drive circuit (not shown), each piezoelectric element plate generates ultrasonic vibrations having different vibration directions. Further, the composite vibration of these ultrasonic vibrations is transmitted to the vibrator 2, and elliptic vibration around the x axis is generated at the tips of the first projecting claw part 2 a and the second projecting claw part 2 b of the vibrator 2. Each of the first protruding claw portion 2a and the second protruding claw portion 2b generates a traveling wave by performing ultrasonic elliptical vibration around the x-axis on the first contact surface 2a1 and the second contact surface 2b1 at the tip thereof. Thus, the cylindrical surface 1aa of the first roller portion 1a and the cylindrical surface 1ba of the second roller portion 1b are scratched and rotated in the direction P or the direction Q. Thereby, in the vibration actuator 101, the arm member 6 operates so as to be refracted with respect to the vibrator 2, the piezoelectric element 3, the first base block 4, and the second base block 5 with the roller 1 as the center. In addition, the rotation direction of the 1st roller part 1a and the 2nd roller part 1b is controlled by controlling the alternating voltage applied to the piezoelectric element 3. FIG.
The ultrasonic vibration generated by the piezoelectric element 3 is the vibration vibration having the largest amplitude in the ultrasonic vibration transmitted from the piezoelectric element 3 to the vibrator 2, or the vicinity of the vibration antinode is the vibration of the vibrator 2. The positions of the first contact surface 2a1 of the first projecting claw portion 2a and the second contact surface 2b1 of the second projecting claw portion 2b, that is, included in the first contact surface 2a1 and the second contact surface 2b1. As described above, the phase of vibration is controlled by controlling the AC voltage applied to the piezoelectric element 3. For this reason, the amplitude of the ultrasonic vibration is large at the first contact surface 2a1 and the second contact surface 2b1 at or near the position of the vibration antinode, that is, the vibration is large.

  Also, the cylindrical surface 1aa of the first roller portion 1a and the cylindrical surface 1ba of the second roller portion 1b are supplied with lubricating oil held by the lubricating member 10 due to the pumping effect of surface tension by contacting the lubricating member 10. The The lubricating oil supplied to the cylindrical surfaces 1aa and 1ba is rotated with the rotation of the roller 1 so that the first contact surface 2a1 of the first projecting claw portion 2a and the second contact surface 2b1 of the second projecting claw portion 2b. It is supplied without interruption throughout. Further, in the first roller portion 1a and the second roller portion 1b to which ultrasonic vibration is applied via the vibrator 2, the lubricating oil supplied from the lubricating member 10 to the cylindrical surfaces 1aa and 1ba is most vibrated. Gather in the vicinity of the place where This is because the liquid has a characteristic that it collects at the antinode of ultrasonic vibration, which is the place where the vibration becomes the largest on the surface of the member that vibrates ultrasonically. For this reason, the lubricating oil supplied to the cylindrical surfaces 1aa and 1ba of the roller 1 gathers at the contact portion between the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2 that becomes the antinode of ultrasonic vibration, It penetrates the entire contact area between the cylindrical surfaces 1aa and 1ba and the first contact surface 2a1 and the second contact surface 2b1 to form an oil film. The supply of the lubricating oil to the contact portion is performed even if each of the roller portions 1a and 1b does not rotate as long as ultrasonic vibration is applied to the first roller portion 1a and the second roller portion 1b.

  Further, the cylindrical surface 1aa and the cylindrical surface 1ba are formed with concave portions V which are fine holes or grooves formed by connecting holes over the entire surface. Therefore, when the lubricating member 10 comes into contact with the cylindrical surface 1aa and the cylindrical surface 1ba, the lubricating oil is sucked into the concave portion V and held by the capillary phenomenon. Further, since the ultrasonic vibration is transmitted to the first roller portion 1a and the second roller portion 1b via the vibrator 2, the suction of the lubricating oil to the concave portion V is further promoted. As the first roller portion 1a and the second roller portion 1b rotate, the concave portions V holding the lubricating oil in the cylindrical surfaces 1aa and 1ba become the first contact surface 2a1 and the second contact surface of the vibrator 2. Contact surface 2b1. As a result, the lubricating oil held in the recesses V of the cylindrical surfaces 1aa and 1ba is released, and the entire contact portion between the cylindrical surfaces 1aa and 1ba and the first contact surface 2a1 and the second contact surface 2b1 is lubricated. Oil is supplied.

Therefore, the contact location between the 1st roller part 1a and the 2nd roller part 1b, and the vibrator | oscillator 2 is lubricated with lubricating oil. Therefore, the occurrence of wear between the vibrator 2 and the first roller portion 1 a and the second roller portion 1 b that rotate while being pressed against the vibrator 2 by the preload member 8 is suppressed. That is, the life as a vibration actuator is extended.
In particular, since the lubricating oil is instantaneously supplied by ultrasonic vibration in a state where the oil film is likely to be cut by preload at the time of startup, wear at the time of startup is suppressed. That is, the activation of the vibration actuator becomes smooth.

At this time, since the force acting on the first roller portion 1a and the second roller portion 1b from the lubricating member 10 is only an elastic force that restores the deformation of the lubricating member 10, a flexible resin member such as PVA resin is used. By using it, the drive resistance given to the 1st roller part 1a and the 2nd roller part 1b can be restrained low.
Further, the higher the viscosity of the lubricating oil used for the lubricating member 10, the lower the friction coefficient between the first roller portion 1a and the second roller portion 1b and the vibrator 2 due to the oil film formed by the lubricating oil, and This can suppress a decrease in driving force of the first roller portion 1a and the second roller portion 1b. At the same time, the higher the viscosity of the lubricating oil used, the more the wear between the first roller portion 1a and second roller portion 1b and the vibrator 2 can be suppressed. Accordingly, the lubricating oil preferably has a high viscosity, and for example, a lubricating oil having a viscosity of ISO VG 180 or higher in the ISO viscosity classification is preferable. In addition, although the components of the lubricating oil easily evaporate under an ultrasonic environment, a fluorine-based component is preferable because it is difficult to volatilize (evaporate). In addition, the supply of lubricating oil is maintained even in an environment where the temperature rises.

  In addition, any type of lubricating oil for the lubricating member 10 can be used, but in particular, by using a fluorine-based lubricating oil, the driving force of the first roller portion 1a and the second roller portion 1b can be reduced. The lowering and wear between the first roller portion 1a and the second roller portion 1b and the vibrator 2 are further suppressed.

  Further, when the first roller portion 1a and the second roller portion 1b rotate, wear powder is generated between the first roller portion 1a and the second roller portion 1b and the vibrator 2, but the lubricating member 10 is generated. It is also possible to supply a supply amount of lubricating oil that prevents the worn powder from adhering to the first roller portion 1a and the second roller portion 1b. At this time, in the resin member of the lubricating member 10, the pore diameter is selected according to the hardness and size of the wear powder. For example, by setting the pore diameter of the resin member of the lubricating member 10 to 40 μm to 130 μm, it is possible to prevent adhesion of hard and fine wear powder. In addition, since the pore diameter of 40 μm to 130 μm is sufficiently larger than the generated abrasion powder, the lubricating member 10 having such a pore diameter has a cylindrical surface when the first roller portion 1a and the second roller portion 1b are rotated. It also has an effect of wiping away abrasion powder and fine dust adhering to 1aa and 1ba.

Next, a method for processing the cylindrical surfaces 1aa and 1ba of the first roller portion 1a and the second roller portion 1b will be described with reference to FIGS. Here, FIG. 3B is a partially enlarged view schematically showing the roughness curve of the cylindrical surface 1aa or 1ba of the roller 1 before surface polishing and the surface state thereof. FIG. 3C is a diagram showing a roughness curve of the cylindrical surface 1aa or 1ba in a state where the surface flatness is enhanced by sufficiently performing the surface polishing of the cylindrical surface 1aa or 1ab of the roller 1.
First, the first roller portion 1a and the second roller portion 1b are roughly processed into a cylindrical shape by a known method after shaping and baking a ceramic material into a predetermined shape. In this rough-processed state, the cylindrical surfaces 1aa and 1ba of the roller 1 have a concavo-convex layer U made up of a convex portion W ′ projecting acutely and a concave portion V recessed in a hole shape. (Refer FIG.3 (b)). The value when the surface roughness of the cylindrical surfaces 1aa and 1ba in the rough machining state is expressed by a ten-point average roughness RZJIS is about 3.2 μm. When the roller 1 in a state where only such rough machining is performed is used for the vibration actuator 101, the convex portions W ′ protruding at acute angles of the cylindrical surfaces 1aa and 1ba are formed on the first contact surface 2a1 of the vibrator 2 and the first contact surface 2a1. There is a possibility that the two abutting surfaces 2b1 are attacked and damaged, and the wear of the vibrator 2 is promoted. On the other hand, when the cylindrical surfaces 1aa and 1ba of the roller 1 are sufficiently polished until the surface roughness becomes RZJIS = 0.8 μm as shown in FIG. 3C, the flat portion W is dominant on the surface. The recesses V are reduced and the depth of the remaining recesses V is shallow. Therefore, when the roller 1 having a high surface flatness is used for the vibration actuator 101, the cylindrical surface 1aa and 1ba of the roller 1 have almost no recess V for adsorbing and holding the lubricating oil. Therefore, the lubricating oil supplied when it comes into contact with the lubricating member 10 cannot be sufficiently held on the cylindrical surfaces 1aa and 1ba of the roller 1. Therefore, the lubricating oil cannot be efficiently supplied to the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2.
Therefore, in the present embodiment, by adjusting the polishing time, the amount of the abrasive, and the like so that the cylindrical surfaces 1aa and 1ba of the roller 1 are in a state where both the flat portion W and the concave portion V coexist. The cylindrical surfaces 1aa and 1ba of the roller 1 are subjected to surface polishing. For example, when polishing is performed until the surface roughness of the cylindrical surfaces 1aa and 1ba in the state where only rough machining is performed is approximately RZJIS = 3.2 μm, the surface roughness is approximately RZJIS = 1.6 μm. The surface states of the cylindrical surfaces 1aa and 1ba are shown in FIG. In the cylindrical surfaces 1aa and 1ba of the roller 1 in FIG. 3 (a), the concave portions V existing in the rough-processed cylindrical surfaces 1aa and 1ba remain, and many convex portions W exist in the rough-processed cylindrical surfaces 1aa and 1ba. 'Is cut away to form a flat portion W. That is, the cylindrical surfaces 1aa and 1ba of the roller 1 are polished so that the flat portion W and the concave portion V coexist. Accordingly, when the roller 1 in this state is used for the vibration actuator 101, the flat portions W of the cylindrical surfaces 1aa and 1ba of the roller 1 come into contact with the vibrator 2, and therefore the first contact surface 2a1 of the vibrator 2 And the second contact surface 2b1 is not damaged. Further, since a plurality of fine concave portions V remain on the cylindrical surfaces 1aa and 1ba of the roller 1, the lubricating oil supplied when contacting the lubricating member 10 can be held in the concave portions V of the cylindrical surfaces 1aa and 1ba. it can.

  Thus, the vibration actuator 101 according to the first embodiment vibrates the roller 1, the vibrator 2 having the first contact surface 2 a 1 and the second contact surface 2 b 1 in contact with the roller 1, and the vibrator 2. A piezoelectric element 3, a preload member 8 that presses the roller 1 against the vibrator 2, and a lubricating member provided in contact with the roller 1 in the vicinity of the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2. 10, the lubricating member 10 holds a lubricant, and the roller 1 has concave portions V on the cylindrical surfaces 1aa and 1ba that are in contact with the first contact surface 2a1 and the second contact surface 2b1.

  At this time, the lubricating member 10 is provided in the vicinity of the first contact surface 2 a 1 and the second contact surface 2 b 1 of the vibrator 2 and in contact with the roller 1, so that the lubricating oil of the lubricating member 10 is supplied to the roller 1. Is done. Further, in the roller 1 to which vibration is applied via the vibrator 2, the lubricating oil present in the vicinity of the first contact surface 2a1 and the second contact surface 2b1 is the vibrator that is the most vibrated portion. 2 gathers at the first contact surface 2a1 and the second contact surface 2b1 of the contact portion and penetrates and lubricates the entire contact area between the first contact surface 2a1 and the second contact surface 2b1 and the vibrator 2. . Therefore, the lubricant oil can be supplied to the first contact surface 2a1 and the second contact surface 2b1 regardless of whether the roller 1 is rotated. The lubrication member 10 may have a simple structure that is provided in the vicinity of the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2 and in contact with the roller 1. For this reason, it is possible to simplify the structure for supplying lubricating oil to the contact portion between the roller 1 and the vibrator 2.

  Further, in the first roller portion 1a and the second roller portion 1b, a large number of concave portions V, which are fine holes and grooves, are formed in the cylindrical surfaces 1aa and 1ba, so that each of the concave portions V is supplied from the lubricating member 10. The lubricating oil is retained. Therefore, the first roller portion 1a and the second roller portion 1b rotate, and the portions holding the lubricating oil in the cylindrical surfaces 1aa and 1ba are the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2. The lubricating oil is discharged and supplied to the first contact surface 2a1 and the second contact surface 2b1. Accordingly, it is possible to appropriately lubricate the contact portions between the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2 and the cylindrical surfaces 1aa and 1ba of the roller 1, thereby suppressing the occurrence of wear.

The lubricating member 10 is a porous member impregnated with lubricating oil. At this time, when the lubricating member 10 comes into contact with the roller 1, the lubricating oil can be supplied to the roller 1 without interruption due to the pump effect due to the surface tension. Therefore, the structure of the lubricating member 10 can be further facilitated.
The lubricating member 10 is in contact with the roller 1 at a position different from the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2. At this time, by not interposing the lubricating member 10 in the sliding portion between the vibrator 2 and the roller 1, the resistance that the lubricating member 10 gives to the rotation of the roller 1 can be reduced. Furthermore, the material used for the lubricating member 10 can be selected without requiring consideration of wear strength.

Moreover, the vibrator 2 has a first projecting claw portion 2a and a second projecting claw portion 2b that project, and the first projecting claw portion 2a and the second projecting claw portion 2b have a first contact with the first projecting claw portion 2a. The contact surface 2a1 and the second contact surface 2b1 are formed, and the lubricating member 10 is in contact with at least a part of the first protruding claw portion 2a and the second protruding claw portion 2b. Accordingly, the lubricating member 10 is provided adjacent to and in contact with at least a part of the first protruding claw portion 2a and the second protruding claw portion 2b. Therefore, since the distance between the portion where the lubricating member 10 contacts the roller 1 and the first contact surface 2a1 and the second contact surface 2b1 is reduced, the first contact surface 2a1 and the second contact surface by the lubricant member 10 are reduced. It becomes possible to supply a stable lubricating oil to the surface 2b1.
Further, the piezoelectric element 3 vibrates so that the vibration antinode or the vicinity of the vibration antinode in the vibration for vibrating the vibrator 2 is included in the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2. Be controlled. As a result, the vibrations at the first contact surface 2a1 and the second contact surface 2b1 can be increased, so that the lubricating oil supplied from the lubricating member 10 to the cylindrical surfaces 1aa and 1ba of the roller 1 is applied to the first contact surface 2a1 and the second contact surface 2b1. It is possible to efficiently collect on the contact surface 2a1 and the second contact surface 2b1.

  Further, in the vibration actuator 101 of the first embodiment, the lubricating member 10 is in contact with both the roller 1 and the vibrator 2. Further, the lubricating member 10 is provided so as to be pressurized by the preloading member 8 through the roller 1 in a groove 2ab formed between the roller 1 and the vibrator 2. Thereby, since the lubricating member 10 is fixed by the force for fixing the roller 1 by the preloading member 8, a separate part is not required for fixing, and the cost can be reduced and the space can be saved. become. Further, by providing the lubricating member 10 in the groove 2ab between the first protruding claw portion 2a and the second protruding claw portion 2b of the vibrator 2 instead of outside, the arm member 6 is rotated when the roller 1 rotates. Does not contact the lubricating member 10. Therefore, the movable range of the arm member 6 can be expanded as compared with the case where the lubricating member 10 is provided outside the first protruding claw portion 2a and the second protruding claw portion 2b.

  In the first embodiment, the material of the roller 1 is not limited to ceramics but may be a porous metal. Further, after forming the roller 1 with a metal, the cylindrical surfaces 1aa and 1ba are roughly processed with a grindstone to form an uneven layer, and then both the flat portion W and the recessed portion V are formed on the cylindrical surfaces 1aa and 1ba. Thus, the surface may be polished.

Embodiment 2. FIG.
A vibration actuator 102 according to the second embodiment of the present invention will be described with reference to FIGS. The vibration actuator 102 uses a roller 1 ′ by changing the shapes of the cylindrical surfaces 1aa and 1ba of the roller 1 in the vibration actuator 101 of the first embodiment.
In the following embodiments, the same reference numerals as the reference numerals in the above-described drawings are the same or similar components, and detailed description thereof will be omitted. Each component in the roller 1 ′ is the same as that of the roller 1 according to the first embodiment except for the cylindrical surface.

  FIG. 4 is an overall view of the vibration actuator 102. FIG. 4 is a plan view of the cylindrical surface 1'aa or 1'ba and a partially enlarged view of the cylindrical surface 1'aa or 1'ba. As shown in the development view of FIG. 4, the cylindrical surface 1 ′ aa or 1 ′ ba has a rectangular shape in which the short side is the roller width d and the long side is the sliding length e. Here, the sliding length e is the length in the PQ direction of the range in which the cylindrical surfaces 1′aa and 1′ba are in contact with the first contact surface 2a1, the second contact surface 2b1, and the lubricating member 10. Say. In the present embodiment, the first roller portion 1a and the second roller portion 1b slide with the first contact surface 2a1 and the second contact surface 2b1 on the vibrator 2 side except for the attachment portion of the arm member 6, so The sliding length e is obtained by removing the length of the mounting portion of the arm member 6 from the circumferential length of the one roller portion 1a and the second roller portion 1b.

  As shown in the enlarged view of FIG. 5, a plurality of straight lines having two groove directions obliquely intersecting the rotation direction PQ of the roller 1 ′ are processed as grooves on the cylindrical surfaces 1′aa and 1′ba. Has been. Here, the groove direction is a direction in which straight grooves are drawn on the cylindrical surfaces 1'aa and 1'ba. As shown in FIGS. 3 and 4, this groove processing forms a lattice-like pattern as a whole. The depth of the groove is about 2 to 3 μm.

A method of processing the cylindrical surfaces 1′aa and 1′ba in the vibration actuator 102 according to the second embodiment will be described.
First, the cylindrical surfaces 1′aa and 1′ba of the first roller portion 1′a and the second roller portion 1′b are polished, and as shown in FIG. Without processing, the surface flatness is high. Next, grooves that are concave portions are formed by, for example, laser processing on the cylindrical surfaces 1′aa and 1′ba with improved surface flatness. In the present embodiment, grooves that are concave portions are formed in a lattice shape on the cylindrical surface of the roller. Laser processing can finely adjust the groove width and depth.

  As described above, the cylindrical surfaces 1′aa and 1′ba of the first roller portion 1′a and the second roller portion 1′b are grooved so that the cylindrical surfaces 1′aa and 1 ′ are rotated by the rotation of the roller 1 ′. When 'ba comes into contact with the lubricating member 10, the lubricating oil of the lubricating member 10 is sucked and held in the grooves of the cylindrical surfaces 1'aa and 1'ba by capillary action. Further, the grooves formed in the cylindrical surfaces 1′aa and 1′ba of the roller 1 ′ also function as an oil sump, and hold a large amount of lubricating oil on the cylindrical surfaces 1′aa and 1′ba of the roller 1 ′. Can do. As the roller 1 'rotates, the portions holding the lubricating oil in the cylindrical surfaces 1'aa and 1'ba come into contact with the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2. As a result, the lubricating oil retained on the cylindrical surfaces 1′aa and 1′ba is provided at the entire contact location between the cylindrical surfaces 1′aa and 1′ba and the first contact surface 2a1 and the second contact surface 2b1. Is released and supplied. Therefore, the lubricating oil can be sufficiently supplied between the cylindrical surfaces 1′aa and 1′ba and the first contact surface 2a1 and the second contact surface 2b1, thereby suppressing the occurrence of wear more efficiently. Can do.

In addition, the pattern of the groove | channel given to cylindrical surface 1'aa and 1'ba is not restricted to the thing of a present Example. Specifically, as shown in FIG. 6 (a), grooves having a plurality of groove directions drawn parallel to the rotation direction PQ and the x-axis direction of the roller are vertically and horizontally intersected to form a lattice pattern as a whole. Or a groove pattern. Further, as shown in FIG. 6B or 6C, a groove having a single groove direction obliquely intersecting with the rotation direction PQ of the roller and the x-axis direction is drawn in parallel at equal intervals, As shown in FIG. Further, the number of grooves provided on the cylindrical surfaces 1′aa and 1′ba is not limited to a plurality, and may be a single groove.
Moreover, you may form a fine hole in cylindrical surface 1'aa and 1'ba whole.
Furthermore, as long as the cylindrical surfaces 1′aa and 1′ba are in contact with the first abutting surface 2a1 and the second abutting surface 2b1, grooving is performed only on a part of the cylindrical surfaces 1′aa and 1′ba. May be applied.

Embodiment 3 FIG.
Next, a vibration actuator 103 according to Embodiment 3 of the present invention will be described with reference to FIGS. The vibration actuator 103 uses a vibrator 2 ′ in which the shapes of the first contact surface 2a1 and the second contact surface 2b1 of the vibrator 2 in the vibration actuator 101 of the first embodiment are changed.
The constituent elements of the vibrator 2 ′ are the same as those of the vibrator 2 according to the first embodiment except for the contact surface, and thus detailed description thereof is omitted.

  FIG. 7 is a perspective view showing the vibrator 2 ′ according to the vibration actuator 103. As shown in FIG. 7, the vibrator 2 ′ includes contact surfaces 2 ′ a <b> 2 and 2 ′ b <b> 2 on a part of the first contact surface 2 ′ aa and the second contact surface 2 ′ b <b> 1. The contact surfaces 2′a2 and 2′b2 are portions that are in contact with the cylindrical surfaces 1aa and 1ba of the roller 1, and correspond to the first roller portion 1a and the second roller portion 1b, and the first contact surface 2′aa. And a pair on the second contact surface 2′b1. FIG. 8 is a plan view of the vibrator 2 ′ viewed from above, and FIG. 9 is a schematic view of the contact surfaces 2 ′ a 2 and 2 ′ b 2. That is, the contact surfaces 2′a2 and 2′b2 are areas where the cylindrical surfaces 1aa and 1ba are in contact with each other at the first contact surface 2′aa and the second contact surface 2′b1, as shown in FIGS. It is a square range. Here, one side of the contact surfaces 2 ′ a 2 and 2 ′ b 2 is the width (roller width d) of the cylindrical surfaces 1 aa and 1 ba of the roller 1. The other side is the length (cylindrical width f) in the PQ direction of the first contact surface 2a1 and the second contact surface 2b1.

  A plurality of linear grooves are machined in the contact surfaces 2'a2 and 2'b2 in a direction obliquely intersecting the x-axis direction and the y-axis direction. This groove processing forms a lattice-like pattern as a whole as shown in FIGS. The depth of the groove is about 2 to 3 μm. For the groove processing, laser processing can be used similarly to the processing of the cylindrical surfaces 1'aa and 1'b1 of the vibration actuator 102. Laser processing can be finely adjusted in the groove width and depth directions.

  As described above, the contact surfaces 2′a2 and 2′b2 of the vibrator 2 ′ are directly supplied with the lubricating oil from the lubricating member 10 due to the pumping effect due to the surface tension and the characteristics of the liquid collected at the antinode of the ultrasonic vibration. The Further, the lubricating oil held by the unevenness of the cylindrical surfaces 1aa and 1ba of the roller 1 is conveyed by the rotation of the roller 1 and supplied to the contact surfaces 2'a2 and 2'b2. By applying groove processing to the contact surfaces 2'a2 and 2'b2 of the vibrator 2 ', the lubricating oil supplied to the vibrator 2' is held in the groove. Therefore, it is possible to suppress the occurrence of wear between the cylindrical surfaces 1aa and 1ba of the roller 1 and the first contact surface 2'aa and the second contact surface 2'b1 of the vibrator 2 '.

In addition, the pattern of the groove | channel provided on contact surface 2'a2 and 2'b2 is not restricted to the thing of a present Example. Specifically, as shown in FIG. 10 (a), a plurality of groove directions drawn parallel to the x-axis direction and the y-axis direction are crossed vertically and horizontally so that the lattice pattern as a groove pattern as a whole. Also good. Also, as shown in FIG. 10 (b) or (c), a plurality of grooves having a single groove direction oblique to the x-axis direction and the y-axis direction are drawn in parallel at equal intervals to form a diagonal pattern as a whole. It is also possible to use a groove pattern. Furthermore, as shown in FIG. 10D, a plurality of grooves having a single groove direction parallel to the x-axis direction may be drawn at equal intervals. Further, the number of grooves provided on the contact surfaces 2′a2 and 2′b2 is not limited to a plurality, and may be a single groove.
Moreover, you may form a fine hole in contact surface 2'a2 and 2'b2 whole.
Furthermore, the groove processing may be performed not only on the contact surfaces 2′a2 and 2′b2, but also on the entire first contact surface 2′aa and second contact surface 2′b1.
Further, as a vibration actuator according to another embodiment, a combination of the vibrator 2 ′ according to the third embodiment and the roller 1 ′ according to the second embodiment may be used.

  1, 1 'roller (rotor), 1a, 1'a first roller part (rotor), 1b, 1'b second roller part (rotor), 1c, 1'c roller shaft (rotor), 1aa, 1ba, 1'aa, 1'ba Cylindrical surface (opposing surface), 2, 2 'vibrator, 2a, 2'a first protruding claw portion, 2a1, 2'aa first contact surface (contact surface) ), 2b, 2b ′, second projecting claw, 2b1, 2b′1, second contact surface (contact surface), 2′a2, 2′b2, contact surface, 3 piezoelectric element (vibration means), 8 preload member ( (Preload means), 10 lubrication member, 101, 102, 103 vibration actuator, V concave portion, W flat portion (convex portion), W ′ convex portion.

Claims (7)

A rotor,
A vibrator having a contact surface in contact with the rotor;
Vibration means for vibrating the vibrator;
Preload means for pressurizing the rotor to the vibrator;
A supply body provided near the contact surface of the vibrator and in contact with the rotor;
The supply body holds a lubricant,
The rotor has an opposing surface that comes into contact with the contact surface of the vibrator,
The opposing surface is a vibration actuator having a recess. The opposed surface of the rotor has a flat portion that is in surface contact with the contact surface of the vibrator,
The vibration actuator according to claim 1, wherein the recess has a plurality of holes capable of holding a lubricant.   3. The vibration actuator according to claim 1, wherein the recess has at least one groove formed on the facing surface of the rotor and capable of holding a lubricant.   The vibration actuator according to claim 3, wherein the recess has a plurality of grooves, and the grooves have a plurality of groove directions intersecting each other. The vibrator has a protruding claw portion that protrudes,
The contact surface is formed on a part of the surface of the protruding claw portion,
The supply body is in contact with at least a part of the protruding claw portion;
The vibration actuator according to any one of claims 1 to 4, wherein the contact surface has a plurality of grooves capable of holding lubricating oil.   The vibration actuator according to any one of claims 1 to 5, wherein the supply body is a porous member impregnated with a lubricant.   7. The vibration according to claim 1, wherein the vibration is controlled such that a position of a vibration antinode or a vicinity of the vibration antinode is included in the contact surface of the vibrator. Actuator.

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