JP2006149083A - Actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator of linear movement type and rotational movement type capable of facilitating downsizing. <P>SOLUTION: A second traveling body 12 and an end surface 13a of a piezoelectric element 13 comes into contact with an inner wall 11a of a cylindrical first traveling body 11, where an end surface 13b of the piezoelectric element is fixed on a stationary member. A frictional force from the end surface 11a of the first traveling body 11 acts on the second traveling element 12, and a frictional force from the end surface 13a of the piezoelectric element 13 acts on the inner wall 11a of the first traveling body 11. The piezoelectric element 13 includes electrodes 13d, 13d on the right and left surfaces of a piezoelectric ceramics 13c. The piezoelectric ceramics 13c is polarized in an arrow direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a linear movement type and rotary movement type actuator, and more particularly to a linear movement type and rotary movement type actuator that can be easily miniaturized.

FIG. 17 is a conceptual diagram of a transport apparatus 1 using a piezoelectric element described in Patent Document 1 (Japanese Patent Laid-Open No. 5-105291). A voltage V is slowly applied to the electrodes 3a and 3b at both ends of the piezoelectric element 2 polarized in a direction perpendicular to the voltage application direction (FIG. 17A). Thereby, the conveyed product 4 placed on the electrode 3a moves in the Y direction along with the deformation of the action portion 2a (FIG. 17B). Following this operation, the application of voltage is stopped and the piezoelectric element 2 is rapidly returned to the original position in the X direction. At this time, since the dynamic friction coefficient is smaller than the static friction coefficient, the conveyed product 4 does not move from the moved position, and only the deformation of the action portion 2a of the piezoelectric element 2 can be returned to the original position (FIG. 17 ( c)). By repeatedly performing such a series of operations, the conveyed product 4 can be moved in the Y direction.
Japanese Patent Laid-Open No. 5-105291

Patent Document 1 describes a basic concept of a transport device that uses the piezoelectric element 2, but does not describe moving a plurality of types of transported objects using the piezoelectric element 2.
The present invention is for solving the above-described conventional problems, and provides a linear movement type and rotary movement type actuator that can transfer a plurality of types of moving bodies with a small number of piezoelectric elements and is easy to downsize. The purpose is to do.

The present invention relates to an actuator having a linearly movable or rotatable movable body and a drive body that gives the movable body a linear driving force or a rotational driving force.
The moving body includes a first moving body and a second moving body, and the driving body is an electromechanical energy conversion element to which a voltage is applied in a direction crossing the polarization direction. The electromechanical energy conversion element One end face of both end faces parallel to the polarization direction is fixed to a fixing member, and the other end face is in contact with a surface parallel to the linear moving direction or the rotational tangential direction of the first moving body,
By displacing the other end face of the electromechanical energy conversion element at a speed different from the normal direction of the linear moving direction or rotational tangential direction of the first moving body, the linear moving direction or rotational tangential direction And moving the first moving body.

  The electromechanical energy conversion element used in the present invention is, for example, a piezoelectric element, and a voltage is applied in a direction crossing the polarization direction. One end face of both end faces parallel to the polarization direction of the piezoelectric element is fixed to a fixing member, and the other end face is in contact with a face parallel to the linear moving direction or the rotational tangential direction of the first moving body. Therefore, when a voltage is applied to the piezoelectric element, a sliding displacement occurs in the polarization direction intersecting with the voltage direction, and the first moving body moves linearly or rotates.

  In the present invention, since the sliding displacement of the piezoelectric element is used, the piezoelectric element can be installed on a plane parallel to the moving direction of the first moving body. For this reason, it becomes easy to keep the size of the entire actuator small.

In the present invention, the moving body includes a first moving body and a second moving body.
The second moving body is supported on the first moving body by, for example, a frictional force. When the moving speed of the first moving body is small and the force applied to the second moving body is a static frictional force, the second moving body moves together with the first moving body and the first moving body The relative position of the second moving body with respect to is not moved.

  Alternatively, by moving the other end face of the electromechanical energy conversion element at a different speed in the direction opposite to the linear movement direction or the rotational tangential direction of the first moving body, the linear movement direction or rotation The relative position of the second moving body with respect to the first moving body in the tangential direction can also be moved.

  When the relative moving speed of the first moving body with respect to the second moving body is large and the force applied to the second moving body is a dynamic frictional force, the second moving body is caused to inertia by the first moving body. It will not move with. At this time, the second moving body moves relative to the first moving body.

  As described above, in the present invention, the first moving body is driven, and the relative position of the second moving body on the first moving body is fixed or moved. it can.

  The first moving body receives a frictional force from the driving body, and a pressure member that presses the first moving body toward the driving body is provided around the first moving body. It is preferable that the frictional force that the first moving body receives from the driving body can be adjusted.

  Accordingly, in the present invention, the movement pattern in which the relative position of the first moving body with respect to the driving body is moved and the relative position of the second moving body with respect to the first moving body is not changed, and the first It is easy to control the movement pattern that changes the relative position of the second moving body with respect to the first moving body without moving the relative position of the moving body with respect to the driving body.

  In the present invention, since the sliding displacement of the piezoelectric element is used, the piezoelectric element can be installed on a plane parallel to the moving direction of the first moving body. For this reason, it becomes easy to keep the size of the entire actuator small.

  In the present invention, the driving body in contact with the first moving body moves the relative position of the first moving body with respect to the driving body and the second moving body with respect to the first moving body. Since the relative position movement can be controlled, the mechanism can be simplified.

1 is a partially exploded perspective view showing an actuator according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. FIG. 2 is a top view of the actuator shown in FIG.
In this actuator 10, an inner wall 11a of a cylindrical first moving body 11 is in contact with an end face (the other end face) 13a of a second moving body 12 and a piezoelectric element (electromechanical energy conversion element) 13, so that the piezoelectric An end face (one end face) 13 b of the element is fixed to the fixing member 14. Friction force from the inner wall 11a of the first moving body 11 acts on the second moving body 12, and friction force from the end face 13a of the piezoelectric element 13 acts on the inner wall 11a of the first moving body 11. is doing. In addition, illustration of the 2nd mobile body 12 is abbreviate | omitted in FIG.

  The piezoelectric element 13 has electrodes 13d and 13d provided on the left and right surfaces of the piezoelectric ceramic 13c. The piezoelectric ceramic 13c is polarized in the arrow direction shown in FIGS. Therefore, the voltage is applied in a direction crossing the polarization direction. The end faces 13a and 13b of the piezoelectric element 13 are end faces parallel to the polarization direction.

  A piezoelectric element 15 and a fixing member 16 are provided on the outside of the first moving body 11 as pressure members that press the first moving body 11 toward the piezoelectric element 11. The polarization direction of the piezoelectric element 15 is a direction in which the first moving body 11 is pressed toward the piezoelectric element 13, and is a direction perpendicular to the outer wall 11b of the first moving body as shown in FIG.

  A mechanism in which the first moving body 11 linearly moves in a direction parallel to the end face 13a of the piezoelectric element 13 will be described with reference to FIGS.

  From the state shown in FIG. 2, a voltage having different rising speed and falling speed, for example, a sawtooth voltage, is applied between the electrodes 13d and 13d of the piezoelectric element 13 as shown in FIG.

  First, the voltage rises slowly (section (B) in FIG. 7). At this time, the piezoelectric element 13 slips in the polarization direction intersecting with the voltage direction, and the first moving body linearly moves upward in the figure along with the displacement of the end face 13a of the piezoelectric element 13 (FIG. 4).

  Next, the voltage drops rapidly (section (C) in FIG. 7), and the piezoelectric element 13 rapidly returns to its original shape. At this time, the frictional force applied to the inner wall 11a of the first moving body 11 becomes a dynamic frictional force from the end face 13a of the piezoelectric element, and the dynamic frictional force is smaller than the static frictional force. As a result, the first moving body 11 does not move from the position of FIG. 4, and only the end face 13a of the piezoelectric element 13 returns to the original position (FIG. 5). By repeating such a series of operations, the first moving body 11 can be moved upward in the drawing.

  When a sawtooth voltage having different rising speed and falling speed as shown in FIG. 7B is applied between the electrodes 13d and 13d of the piezoelectric element 13, the first moving body 11 moves downward in the figure.

  In the present invention, since the sliding displacement of the piezoelectric element is used, the piezoelectric element 13 can be installed on the end face 13 a parallel to the moving direction of the first moving body 11. For this reason, it becomes easy to keep the vertical dimension of the actuator 10 shown in the figure small.

  The second moving body 12 is supported on the first moving body 11 by a frictional force. When the moving speed of the first moving body 11 is low and the force applied to the second moving body 12 is a static frictional force, the second moving body 12 moves together with the first moving body 11 and moves to the first moving body 11. The relative position of the second moving body 12 with respect to is not moved. 2, 4, and 5, the relative position of the second moving body 12 with respect to the first moving body 11 is not changed.

  Next, a mechanism for moving the relative position of the second moving body 12 with respect to the first moving body 11 will be described with reference to FIGS. 2, 4, and 6.

  From the state shown in FIG. 2, a sawtooth voltage having different rising speed and falling speed as shown in FIG. 7A is applied between the electrodes 13d and 13d of the piezoelectric element 13. FIG.

  First, the voltage rises slowly (section B in FIG. 7A). At this time, the piezoelectric element 13 undergoes a sliding displacement in the polarization direction intersecting with the voltage direction, and the first moving body linearly moves upward in the drawing along with the displacement of the end face 13a of the piezoelectric element 13. At this time, the second moving body 12 linearly moves upward in the figure together with the first moving body 11 while maintaining the state fixed to the inner wall 11a of the first moving body 11 by the frictional force (FIG. 4).

  Next, the voltage rapidly drops (section C in FIG. 7a), and the piezoelectric element 13 rapidly returns to its original shape. At this time, the frictional force applied to the inner wall 11a of the first moving body 11 is set to be a static frictional force. In the present embodiment, a voltage is applied between the electrodes 15b and 15b of the piezoelectric element 15 that is in contact with the outer wall 11b of the first moving body 11 to expand the piezoelectric element 15 in the horizontal direction in the figure. As a result, the first moving body 11 is pressurized in the center direction, and the static frictional force that the first moving body 11 receives from the end face 13 a of the piezoelectric element 13 is increased.

  Accordingly, the first moving body returns to the original position along with the restoration of the piezoelectric element 13. Here, when the relative moving speed of the first moving body 11 with respect to the second moving body 12 is increased so that the force applied to the second moving body 12 becomes a dynamic frictional force, the inertia works and the second moving body. 12 does not move together with the first moving body 11. At this time, the second movable body 12 moves in the upward direction relative to the first movable body 11 (FIG. 6). By repeating such a series of operations, the second moving body 12 can be moved upward in the drawing.

  When a sawtooth voltage having different rising speed and falling speed as shown in FIG. 7B is applied between the electrodes 13d and 13d of the piezoelectric element 13, the second moving body 12 moves downward in the figure.

  In this way, the first moving body 11 can be driven, and the relative position of the second moving body 12 on the first moving body 11 can be fixed or moved.

  In the present embodiment, the piezoelectric element 13 in contact with the first moving body 11 moves the relative position of the first moving body 11 with respect to the piezoelectric element 13 and the second moving body 12 with respect to the first moving body 11. Since the relative position movement can be controlled, the mechanism can be simplified.

  When the piezoelectric element 15 and the fixing member 16 which are pressure members are provided, the relative position of the first moving body 11 with respect to the piezoelectric element 13 is moved, and the second moving body 12 with respect to the first moving body 11 is moved. Control of a movement pattern that does not change the relative position and a movement pattern that changes the relative position of the second moving body 12 with respect to the first moving body 11 without moving the relative position of the first moving body 11 with respect to the piezoelectric element 13. Becomes easier.

8 is a perspective view showing an actuator according to a second embodiment of the present invention. FIG. 9 is a cross-sectional view taken along the line 9-9 in FIG. It is a top view of the made actuator.
In this actuator 20, the second moving body 22 is in contact with the inner wall 21 a of the cylindrical first moving body 21, and the end face of the piezoelectric element (electromechanical energy conversion element) 23 is in contact with the outer wall 21 b of the first moving body. (The other end face) 23a is in contact. An end face (one end face) 23 b of the piezoelectric element is fixed to the fixing member 24. Friction force from the inner wall 21a of the first moving body 21 acts on the second moving body 22, and friction force from the end face 23a of the piezoelectric element 23 acts on the outer wall 21b of the first moving body 21. is doing.

  The piezoelectric element 23 has electrodes 23d and 23d provided on the left and right surfaces of the piezoelectric ceramic 23c. The piezoelectric ceramic 23c is polarized in the arrow direction shown in FIG. Therefore, the voltage is applied in a direction crossing the electrode polarization direction. The end faces 23a and 23b of the piezoelectric element 23 are end faces parallel to the polarization direction.

  Outside the fixed member 24, a piezoelectric element 25 and a fixed member 26 are provided as pressure members that press the piezoelectric element 23 toward the first moving body 21. The polarization direction of the piezoelectric element 25 is a direction in which the first moving body 21 is pressed toward the piezoelectric element 23, and is a direction perpendicular to the outer wall 21b of the first moving body as shown in FIG.

  A sawtooth voltage having different rising speed and falling speed as shown in FIG. 7A is applied between the electrodes 23d and 23d of the piezoelectric element 23.

  First, the voltage rises slowly (section (B) in FIG. 7). At this time, the piezoelectric element 23 slides in the polarization direction intersecting with the voltage direction, and the first moving body linearly moves upward in the drawing along with the displacement of the end face 23a of the piezoelectric element 23.

  Next, the voltage drops rapidly (section (C) in FIG. 7), and the piezoelectric element 23 rapidly returns to its original shape. At this time, the frictional force applied to the outer wall 21b of the first moving body 21 becomes a dynamic frictional force from the end face 23a of the piezoelectric element, and the dynamic frictional force is smaller than the static frictional force. As a result, the first moving body 21 does not move, and only the end face 23a of the piezoelectric element 23 returns to the original position. By repeating such a series of operations, the first moving body 21 can be moved upward in the drawing.

  When a sawtooth voltage having different rising speed and falling speed as shown in FIG. 7B is applied between the electrodes 23d and 23d of the piezoelectric element 23, the first moving body 21 moves downward in the figure.

  In the present invention, since the sliding displacement of the piezoelectric element is used, the piezoelectric element 23 can be installed on the end face 23 a parallel to the moving direction of the first moving body 21. For this reason, it becomes easy to keep the vertical dimension of the actuator 10 shown in the figure small.

  The second moving body 22 is supported on the first moving body 21 by a frictional force. When the moving speed of the first moving body 21 is small and the force applied to the second moving body 22 is a static frictional force, the second moving body 22 moves together with the first moving body 21 and moves to the first moving body 21. The relative position of the second moving body 22 with respect to does not move.

  However, like the actuator shown in FIGS. 1 to 3, the second moving body 22 can be moved relative to the first moving body 21.

  By applying a voltage between the electrodes 25b, 25b of the piezoelectric element 25 that is in contact with the outer wall 21b of the first moving body 21 and extending the piezoelectric element 25 in the horizontal direction in the figure, the piezoelectric element 23 is applied in the center direction. To increase the static frictional force that the first moving body 21 receives from the end face 23 a of the piezoelectric element 23. In this state, the piezoelectric element 23 is driven to move the first moving body 21 upward in the drawing.

  Here, when the first moving body 21 is moved upward, the second moving body 22 is moved at a slow speed so as to move together with the first moving body 21 supported by the first moving body 21. . On the other hand, when the first moving body 21 is moved downward, the relative moving speed of the first moving body 21 with respect to the second moving body 22 is set so that the force applied to the second moving body 22 becomes a dynamic friction force. Enlarge. Then, inertia works and the second moving body 22 does not move together with the first moving body 21. At this time, the second moving body 22 moves in the upward direction in the drawing relative to the first moving body 21. By repeating such a series of operations, the second moving body 22 can be moved upward in the drawing.

  When a sawtooth voltage having different rising speed and falling speed as shown in FIG. 7B is applied between the electrodes 23d and 23d of the piezoelectric element 23, the second moving body 22 moves downward in the figure.

  In this way, the first moving body 21 can be driven, and the relative position of the second moving body 22 on the first moving body 21 can be fixed or moved.

  In the present embodiment, the piezoelectric element 23 in contact with the first moving body 21 moves the relative position of the first moving body 21 relative to the piezoelectric element 23 and the second moving body 22 relative to the first moving body 21. Since the relative position movement can be controlled, the mechanism can be simplified.

  When the piezoelectric element 25 and the fixing member 26 which are pressure members are provided, the relative position of the first moving body 21 with respect to the piezoelectric element 23 is moved, and the second moving body 22 with respect to the first moving body 21 is moved. Control of a movement pattern that does not change the relative position and a movement pattern that changes the relative position of the second moving body 22 relative to the first moving body 21 without moving the relative position of the first moving body 21 relative to the piezoelectric element 23. Becomes easier.

In FIG. 1 thru | or FIG. 10, the 1st moving bodies 11 and 21 move to the up-down direction shown in figure.
Here, when the polarization directions of the piezoelectric elements 13 and 23 are set in the direction along the circumference of the first moving bodies 11 and 21 as shown by the arrow directions in FIGS. By applying the sawtooth voltage shown in FIGS. 7A and 7B, the first moving bodies 11 and 21 can be rotated in the circumferential direction.

  As shown in FIGS. 13 and 14, the polarization direction of a part of the plurality of piezoelectric elements 13 and 23 is set to the direction along the circumference of the first moving body 11 and 21, and the other is the first When the moving bodies 13 and 23 are directed upward (Z direction in the drawing), the first moving body 11 and the piezoelectric elements 13 and 23 are appropriately applied with the sawtooth voltage shown in FIGS. 21 can be moved straight in the vertical direction, rotated in the circumferential direction, or spirally moved.

  FIG. 15 is a top view showing an actuator according to another embodiment of the present invention, and FIG. 16 is a cross-sectional view of the actuator shown in FIG.

In the actuator 30, the second moving body 32 is in contact with the inner wall 31 a of the cylindrical first moving body 31. The end face (the other end face) 35a of the piezoelectric element (electromechanical energy conversion element) 35 is in contact with the outer wall 31b of the first moving body 31. An end surface (one end surface) 35 b of the piezoelectric element 35 is fixed to the fixing member 36. Friction force from the inner wall 31 a of the first moving body 31 acts on the second moving body 32, and friction force from the end face 35 a of the piezoelectric element 35 acts on the outer wall 31 b of the first moving body 31. The end face (the other end face) 33a of the piezoelectric element (electromechanical energy conversion element) 33 is in contact with the inner wall 31a of the first moving body 31, and the end face (one end face) 33b of the piezoelectric element 33 is It is fixed to the fixing member 34. A frictional force from the end face 33 a of the piezoelectric element 33 acts on the inner wall 31 a of the first moving body 31.

In FIG. 15, the second moving body 32 is not shown.
The piezoelectric element 35 has electrodes 35d and 35d provided on the left and right surfaces of a piezoelectric ceramic 35c. The piezoelectric ceramic 35c is polarized in the direction of the arrow shown in FIG. The piezoelectric element 33 is provided with electrodes 33d and 33d on the left and right surfaces of the piezoelectric ceramic 33c. Since the piezoelectric ceramics 33c and 35c are polarized in the direction of the arrow shown in FIGS. 15 and 16, the voltage is applied in a direction crossing the polarization direction.

  Outside the fixed member 36, a piezoelectric element 37 and a fixed member 38 are provided as pressure members that press the piezoelectric element 35 toward the first moving body 31. The polarization direction of the piezoelectric element 37 is a direction in which the piezoelectric element 35 is pressed toward the first moving body 31, and is a direction perpendicular to the outer wall 31b of the first moving body as shown in FIG.

  By applying a sawtooth voltage having different rising speed and falling speed as shown in FIG. 7A between the electrodes 35d and 35d of the piezoelectric element 35, the first moving body 31 is moved in the vertical direction shown in FIG. Can be moved to.

  Further, like the actuator shown in FIGS. 1 to 3, the second moving body 32 can be moved relative to the first moving body 31.

  By applying a voltage between the electrodes 37b and 37b of the piezoelectric element 37 that is in contact with the outer wall 31b of the first moving body 31, the piezoelectric element 37 is expanded in the left-right direction in the figure, thereby adding the piezoelectric element 35 in the central direction. To increase the static frictional force that the first moving body 31 receives from the end face 35 a of the piezoelectric element 35. In this state, the piezoelectric element 35 is driven to move the first moving body 31 upward in the drawing.

  Here, when the first moving body 31 is moved upward, the second moving body 32 is moved at a slow speed so as to move together with the first moving body 31 supported by the first moving body 31. . Conversely, when the first moving body 31 is moved downward, the relative moving speed of the first moving body 31 with respect to the second moving body 32 is set so that the force applied to the second moving body 32 becomes a dynamic friction force. Enlarge. Then, inertia works and the second moving body 32 does not move together with the first moving body 31. At this time, the second moving body 32 moves in the upward direction in the drawing relative to the first moving body 31. By repeating such a series of operations, the second moving body 32 can be moved upward in the drawing.

  When a sawtooth voltage having different rising speed and falling speed as shown in FIG. 7B is applied between the electrodes 35d and 35d of the piezoelectric element 35, the second moving body 32 moves downward in the figure.

  In this way, the first moving body 31 can be driven, and the relative position of the second moving body 32 on the first moving body 31 can be fixed or moved.

  In addition, by applying a sawtooth voltage having different rising speed and falling speed as shown in FIGS. 7A and 7B between the electrodes 33d and 33d of the piezoelectric element 33, the first moving body 31 is moved. It can be rotated in the circumferential direction.

  Further, by simultaneously driving the piezoelectric element 33 and the piezoelectric element 35, the first moving body 31 can be spirally moved.

  The actuator of the present invention can be used for a camera autofocus device or the like. For example, zooming and focusing can be performed using the first moving body as a casing and the second moving body as a lens body.

FIG. 2 is an exploded perspective view showing the actuator according to the first embodiment of the present invention. 1 is a cross-sectional view of the actuator shown in FIG. FIG. 1 is a top view of the actuator shown in FIG. 1 is a cross-sectional view of the actuator shown in FIG. 1 is a cross-sectional view of the actuator shown in FIG. 1 is a cross-sectional view of the actuator shown in FIG. (A) a graph showing an example of a voltage waveform applied to the actuator of the present invention, (b) a graph showing an example of a voltage waveform applied to the actuator of the present invention, The perspective view which shows the actuator of the 2nd Embodiment of this invention, FIG. 9 is a sectional view of the actuator shown in FIG. FIG. 9 is a top view of the actuator shown in FIG. FIG. 6 is a top view showing an actuator according to a third embodiment of the present invention; The top view which shows the actuator of the 4th Embodiment of this invention, A top view showing an actuator of a fifth embodiment of the present invention, FIG. 9 is a top view showing an actuator according to a sixth embodiment of the present invention. A top view showing an actuator of a seventh embodiment of the present invention, Sectional drawing which shows the actuator of the 7th Embodiment of this invention, (A), (b), (c) The conceptual diagram which shows the operation state of the conveying apparatus using the sliding displacement type piezoelectric element,

Explanation of symbols

11, 21, 31 First moving body 12, 22, 32 Second moving body 13, 23, 33 Piezoelectric element 14, 24, 34 Fixed member 15, 25, 35 Piezoelectric element 16, 26, 36 Fixed member

Claims (3)

In an actuator having a linearly movable or rotatable movable body and a drive body that gives a linear driving force or a rotational driving force to the movable body,
The moving body includes a first moving body and a second moving body, and the driving body is an electromechanical energy conversion element to which a voltage is applied in a direction crossing the polarization direction. The electromechanical energy conversion element One end face of both end faces parallel to the polarization direction is fixed to a fixing member, and the other end face is in contact with a surface parallel to the linear moving direction or the rotational tangential direction of the first moving body,
By displacing the other end face of the electromechanical energy conversion element at a speed different from the normal direction of the linear moving direction or rotational tangential direction of the first moving body, the linear moving direction or rotational tangential direction An actuator for moving the first moving body. In an actuator having a linearly movable or rotatable movable body and a drive body that gives a linear driving force or a rotational driving force to the movable body,
The moving body includes a first moving body and a second moving body, and the driving body is an electromechanical energy conversion element to which a voltage is applied in a direction crossing the polarization direction. The electromechanical energy conversion element One end face of both end faces parallel to the polarization direction is fixed to a fixing member, and the other end face is in contact with a surface parallel to the linear moving direction or the rotational tangential direction of the first moving body,
By displacing the other end face of the electromechanical energy conversion element at a speed different from the normal direction of the linear moving direction or rotational tangential direction of the first moving body, the linear moving direction or rotational tangential direction An actuator for moving a relative position of the second moving body with respect to the first moving body.   The actuator according to claim 1, wherein a pressure member that presses the first moving body toward the driving body is provided around the first moving body.