JP2971389B2 - Electrostatic actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electrostatic actuator driven by electrostatic force and an electrostatic support mechanism for supporting a movable element of the actuator with low friction.

[0002]

2. Description of the Related Art Conventionally, as a linear actuator for driving a micromachine, a combination of a motor using an electromagnetic force or a piezoelectric element and a mechanism such as a gear has been known. However, with this type of actuator, as the size becomes smaller, it becomes difficult to obtain a sufficient output, and it is not possible to secure a sufficient space for arranging a mechanism such as a gear and a coil which is a source of electromagnetic force. Therefore, it becomes difficult to design a compact and high-performance actuator. For this reason, in the case of a small size, an electrostatic actuator utilizing an electrostatic force which is advantageous from the viewpoint of output has been developed, but does not always have sufficient performance. One of the main causes is
It is a problem of friction between the mover and the stator.

[0003] As a solution to this problem, there is an electrostatic actuator in which the mover is supported by an elastic body so that the mover and the stator do not come into direct contact with each other. However, in such a configuration, since the movable element is supported by the elastic body, the movable range of the movable element is limited. It is also conceivable to provide a structure in which the movable element is supported by bearings or a guide mechanism for the movable element is provided so that the movable element does not come into direct contact with the stator while ensuring the movable range of the movable element. However, such a configuration is not preferable from the viewpoint of improving the output of the actuator because friction occurs in the bearing and the guide mechanism.

[0004]

As described above, it is difficult to obtain an electrostatic actuator that can sufficiently secure the movable range of the mover while solving the problem of friction between the mover and the stator. .

The present invention has been made in view of such circumstances, and an electrostatic actuator capable of sufficiently securing a movable range of a mover while reducing friction between the mover and a stator. And an electrostatic support mechanism capable of reducing friction without limiting the movable range of the mover.

[0006]

In order to achieve the above object, an electrostatic actuator according to the present invention comprises an inner peripheral surface having a predetermined diameter forming a substantially columnar space therein, and an inner peripheral surface formed on the inner peripheral surface. A stator having a plurality of stator electrodes provided in the stator, and having an outer peripheral surface disposed inside the stator and having a diameter smaller than an inner peripheral surface of the stator. A mover having a mover electrode extending in the direction, wherein the plurality of stator electrodes are arranged spirally as a whole by being arranged at predetermined intervals in the axial direction and the circumferential direction, By sequentially applying voltages to the plurality of stator electrodes in a spiral direction, the mover is configured to move in the axial direction while rotating inside the stator. .

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment An embodiment of the present invention will be described below with reference to the drawings. First, a first embodiment will be described. FIG.
5 are diagrams showing a first embodiment of the present invention.

As shown in FIG. 1, an electrostatic actuator 1
A stator 10 having an inner peripheral surface forming a substantially cylindrical space therein and having a cylindrical shape as a whole;
And a movable element 30 having a columnar shape disposed inside the movable element 30.

As shown in FIG. 1, the stator 10 includes an upper stator 10a and a lower stator 10b. The stator 10 is bonded to the split surfaces 14a and 14b facing each other by an adhesive. I have. As shown in FIGS. 1 and 2, the upper stator 10a and the lower stator 10b each have a cylindrical base 11 made of a substance having a high electric resistance, for example, glass or ceramic.
It has a film-shaped or plate-shaped stator electrode pattern 20 a to 20 h provided on the inner peripheral surface of the base 11. FIG.
As shown in the figure, the base 11 and the stator electrode pattern 20a
An insulating layer 13 is continuously formed on the upper and lower portions of the upper and lower stators 10a and 10b.

Further, as shown in FIG.
Like the stator 10, it has a columnar substrate 31 made of a substance having a high electric resistance, for example, glass or ceramics, and a film-shaped or plate-shaped movable element electrode pattern 40 formed on the substrate 31. . As shown in FIG. 2, an insulating layer 32 is continuously formed on the base 31 and the movable element electrode pattern 40, and the entire outer peripheral surface of the movable element 30 is covered with the insulating layer 32. The mover 30 has an outer diameter smaller than the inner diameter of the stator 10.

In this embodiment, the insulating layer 1
Although the example in which 3, 32 is provided on both the stator 10 and the mover 30 is shown, the present invention is not limited to this, and it is sufficient if at least one of the stator 10 and the mover 30 is provided. . Hereinafter, it is assumed that an insulating layer is always provided on the inner peripheral surface of the base 11 and the outer peripheral surface of the base 31. Similarly, in the second and subsequent embodiments, insulating layers are similarly provided on the inner peripheral surface of the stator base and the outer peripheral surface of the mover base.

Next, the stator electrode patterns 20a to 20h and the mover electrode pattern 40 will be described in detail with reference to FIGS. First, the stator electrode patterns 20a to 20h will be described. As shown in FIG. 3A, among the stator electrode patterns 20a to 20h, the stator electrode patterns 20a
Are composed of a plurality of stator electrodes 22a, 23a,... And connection electrodes 21a extending in the axial direction and electrically connecting the plurality of stator electrodes. Stator electrode 22
a, 23a... extend in the circumferential direction of the inner peripheral surface of the stator 10, that is, in the direction orthogonal to the connection electrodes 21a. Are arranged at a predetermined interval in the axial direction, and have the same overall length. These stator electrodes 22a, 23a ...
Are located on the same straight line. In addition, the stator electrode patterns 20b to 20h also correspond to the stator electrode patterns 20a.
It has substantially the same configuration.

Next, the mutual relationship between the stator electrode patterns 20a to 20h and the stator electrodes 22a to 22h, 23a to 22h,... Constituting the stator electrode patterns 20a to 20h will be described. Stator electrode pattern 20a
20h are sequentially arranged at positions where the inner peripheral surface of the stator 10 is equally divided into eight in the circumferential direction. Therefore, the stator electrodes 22a to 22h constituting the stator electrode patterns 20a to 20h
, 22h, 23a to 22h,...
0 at the position where the inner peripheral surface of the zero is equally divided into eight in the circumferential direction, that is,
They are sequentially arranged at a predetermined interval x (see FIGS. 3A and 3B) in the circumferential direction R. Also, the stator electrode 2
Are arranged in this order while being shifted by a predetermined interval y in the axial direction A in this order. By arranging the stator electrodes in this way, the stator electrodes 22a to 22h, 23a to 23h,... Are arranged spirally as a whole.

Conductors 2a to 2h are connected to axial ends of the connection electrodes 20a to 20h, respectively.
The potentials of the stator electrode patterns 20a to 20h can be independently and externally adjusted via a to 2h.

As shown in FIG. 3B, the mover electrode pattern 40 includes a plurality of mover electrodes 41a to 41i,
And a connection electrode 42 for electrically connecting the mover electrodes 41a to 41i. Each mover electrode 41a
41i extend over the entire circumference in the circumferential direction of the outer periphery of the mover 30, and have an annular shape. The mover electrodes 41a to 41i are arranged in parallel with each other and at equal intervals in the axial direction A. Also, the end 4 of the connection electrode 42
A conductor 4 is connected to 2a, and the potential of the mover electrode pattern 40 can be adjusted from the outside via the conductor. The distance d in the axial direction between the mover electrodes 41a to 41i adjacent to each other is equal to the distance between the adjacent stator electrodes 21a to 21h, 22a to 22h,.
Is larger than the axial distance y. In this case, the interval d is preferably smaller than 1.5 times the interval y. In this embodiment, the distance d and the distance y are 7.5.
d = 9y (see FIGS. 3A and 3B).

The stator electrode patterns 20a to 20h and the mover electrode pattern 40 having such a configuration
It may be formed by bonding a metal thin film of a predetermined shape to the substrates 1 and 31, or a conductive film is deposited on the substrates 11 and 31 by means such as sputtering or vapor deposition and patterned by an etching process or the like. May be formed. The insulating layers 13 and 32 may be formed by bonding a thin sheet made of a substance having a high electric resistance over the conductive film, or by depositing a silicon oxide film by a sputtering method or a CVD method. May be. The conductive wires 2a to 2h, 4 are bonded using a conductive adhesive or joined using a means such as wire bonding.

In this embodiment, the stator 1
Although the example in which 0 is divided into two of the upper stator 10a and the lower stator 10b has been described, the present invention is not limited to this, and the stator 10 may be divided into three or more.
In the present embodiment, the stator electrode is connected to the stator 1.
Although the example in which the inner peripheral surface of 0 is arranged at a position equally divided into eight in the circumferential direction is shown, the present invention is not limited to this. For example, it is arranged at a position equally divided into two to seven in the circumferential direction. Or may be arranged at nine or more equally spaced positions.

Next, the operation of the first embodiment of the present invention having such a configuration will be described with reference to FIGS. 4 and 5 (a).
This will be described with reference to (b) and (c). Here, FIG.
0 and stator electrodes 22a to 22h, 23a to 23h,
FIG. 5 is a view showing a positional relationship between the movable member 30 and the movable member 30 in the radiation direction. FIG. 5 shows the movable member electrodes 41 a to 41 i and the stator electrode 2.
It is a figure which shows the relative positional relationship of 2a-22h, 23a-23h, ... in the axial direction. In FIG. 4, arrows R1 and R2 indicate the movement of the outer peripheral surface of the mover 30 in the rotational direction (that is, the direction of the rotation of the mover 30).
Arrows C1 and C2 indicate the locus of the center axis of the mover 30 (that is, the direction of the revolving motion of the mover 30), and arrows A1 and A2 in FIGS. 5A, 5B, and 5C.
Indicates the axial movement of the mover 30.

First, by grounding the conductive wire 4, the potential of the mover electrode pattern 40 of the mover 30 is set to 0, and the potentials of the mover electrodes 41a to 41i are set to 0. In this case, the potentials of the mover electrode patterns 20a to 20h are all 0, and the mover 30 is at the solid line position in FIG. 4 and the position in FIG.

Next, the conductors 2a to 2h of the stator 10 are connected to the voltage applying device 35, and the changeover switch 36 is switched so that the stator electrode pattern 20g is connected via the conductor 2g.
Is switched from 0 to a predetermined potential V. In this case, the predetermined potential V may be positive or negative. By such switching to the predetermined potential V, the stator electrode 2 of the stator electrode pattern 20g is
.. And the mover electrodes 41a to 41i, and an electrostatic force acts between the stator electrodes 22g, 23g, and the mover electrodes 41a to 41i. In this case, the electrostatic force is a force inversely proportional to the square of the distance,
Among the stator electrodes 22g, 23g,.
g is sufficiently separated from the mover electrodes 41a to 41i.
The action of the stator electrodes other than g is negligible. Therefore, only the electrostatic force acting between the stator electrode 22g and the mover electrodes 41a to 41i is considered. In this case, the mover electrodes at positions close to the stator electrode 22g are 41e and 41f,
Of these, the mover electrode closest to the stator electrode 22g is 41f. Accordingly, the largest electrostatic force acts between the stator electrode 22g and the mover electrode 41f, and the mover electrode 41f moves so as to coincide with the stator electrode 22g due to the electrostatic force. R1
While moving in the direction, it moves in the direction of arrow A1, and reaches the position shown by the broken line in FIG. 4 and the position shown in FIG. 5B. With this movement, the central axis 30a of the mover 30 moves in the direction of arrow C1.

Next, by switching the changeover switch 36 of the voltage applying device 35, the potential of the stator electrode pattern 20g is switched from the predetermined potential V to 0 and the conductor 2h
, The potential of the stator electrode pattern 20h is switched from 0 to a predetermined potential V. In this case, based on the same principle as above, the mover electrode 41g located closest to the stator electrode 22h.
(See FIG. 5 (b)). Due to this electrostatic force, the mover electrode 41g moves so as to coincide with the stator electrode 22h.
Moves in the A1 direction while rotating in the R1 direction, and reaches the position shown by the dashed line in FIG. 4 and the position in FIG. 5C. With this movement, the central axis 30a of the mover 30 moves in the direction of arrow C1.

Thus, the stator electrode pattern 20 g,
By applying voltages sequentially in the order of 20h, 20a, 20b,..., That is, in the order of the alphabet at the end of the code, the mover 30 moves along the inner peripheral surface of the stator 10 in FIG.
While revolving in the direction of arrow R1, it revolves in the direction of arrow C1 and moves in the axial direction (along arrow A1 in FIG. 5). That is, the stator 10 moves while drawing a spiral trajectory. In addition, if the order of applying the voltage to the stator electrode group is reversed, the mover 30 rotates along the inner peripheral surface of the stator 10 in the direction of arrow R2 in FIG.
And revolves in the axial direction (along arrow A2 in FIG. 5). This operation principle is known as the operation principle of the wobble motor.

As described above, according to the present embodiment, since the mover 30 can be moved in the axial direction while rotating along the inner peripheral surface of the stator 10, the mover 30 and the stator 10 The mover 30 can be moved in a state where the friction between them is reduced. In addition, by increasing the length of the stator 10 in the axial direction and providing a large number of stator electrodes corresponding thereto, the moving range of the mover 30 can be expanded as desired.

Second Embodiment Next, a second embodiment will be described. 6 to 8 are views showing a second embodiment of the present invention. The second embodiment differs from the first embodiment only in the arrangement of the stator electrode patterns and the correlation between the stator electrode patterns and the mover electrode patterns. They are almost the same. In the second embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. As shown in FIGS. 6 and 7A and 7B,
The stator electrode pattern 50 includes a first electrode pattern 51 and a second electrode pattern 52 provided on the upper stator 10a, and a third electrode pattern 53 and a fourth electrode pattern 54 provided on the lower stator 10b. It is configured.

The first electrode pattern 51 provided on the upper stator 10a includes a plurality of stator electrodes 51a, 51b,..., 51e as shown in FIG. A connection electrode 51f for electrically connecting the electrodes 51a to 51e. Of these, the stator electrodes 51a-5
1e extends in the circumferential direction of the inner peripheral surface of the upper stator 10a and has the same length. In addition, these stator electrodes 51
a to 51e are arranged at equal intervals in the axial direction at a predetermined pitch p. The connection electrode 51f extends in the axial direction, is connected to the stator electrodes 51a to 51e at one end of the stator electrodes 51a to 51e, and the first electrode pattern 51 has a comb-like shape as a whole. ing.

The second electrode pattern 52 also includes a plurality of stator electrodes 52a to 52e and connection electrodes 52f.
As a whole, it has a comb shape like the first electrode pattern 51. Also, the stator electrode 52 of the second electrode pattern 52
The pitch p between a to 52e is the same as the pitch p between the stator electrodes 51a to 51e of the first electrode pattern 51.

First electrode pattern 51 and second electrode pattern 52
, 52a, 52a, 51b,..., 52 so that the teeth of the combs are combined with each other in a state of being shifted by a half pitch p in the axial direction.
d, 51e, and 52e are arranged so as to be alternately arranged in the axial direction in this order. In this case, a predetermined interval is provided between the stator electrodes 51a to 51e and 52a to 52e that are adjacent to each other in the axial direction, and the first electrode pattern 51 and the second electrode pattern 52 are provided at any positions. They do not touch each other.

The third stator 10b provided on the lower stator 10b
The electrode pattern 53 and the fourth electrode pattern 54 are
0a are arranged in the same manner as the first electrode pattern 51 and the second electrode pattern 52 provided on the third electrode pattern 5a.
3 and the pitch p between the stator electrodes 54a to 54e of the fourth electrode pattern 54.
Are the same as the pitch p between the stator electrodes of the first and second electrode patterns 51 and 52.

The stator electrode 5 of the third electrode pattern 53
The first electrode pattern 51 is axially displaced from the stator electrode 51a of the first electrode pattern 51 by ピ ッ チ pitch p, so that the stator electrodes 51 of the first to fourth electrode patterns are disposed.
a, 53a, 52a, 54a, 51b,..., 54
d, 51e, 53e, 52e, and 54e are each shifted by 1/4 pitch p in this order with respect to the axial direction.

The connection electrodes 51f, 52f, 53
conductors 5a, 5b, 5 at the axial ends of f, 54f, respectively.
c and 5d are connected, and the potentials of the first to fourth electrode patterns 51 to 54 can be independently and externally adjusted via these conductive wires 5a to 5d.

The mover electrode pattern 60 is the same as that shown in FIG.
As shown in (b), a plurality of mover electrodes 61a to 61e
And a connection electrode 62 for electrically connecting the mover electrodes 61a to 61e. Each mover electrode 61a-
Reference numeral 61e extends in the circumferential direction of the outer periphery of the mover 30 and has an annular shape. Further, the mover electrodes 61a to 61e are arranged in parallel with each other and at equal intervals in the axial direction, and the gaps in the axial direction between the mover electrodes 61a to 61e adjacent to each other are determined by the respective electrode patterns of the stator 10. 51, 52, 5
3, 54, which is equal to the pitch p between the stator electrodes. A conductor 6 is connected to the end 62 a of the connection electrode 62, and the potential of the mover electrode pattern 60 can be adjusted from outside via the conductor 6.

Next, the operation of the second embodiment having such a configuration will be described with reference to FIGS. In FIGS. 8A to 8E, the electrodes that are painted black represent electrodes having a predetermined potential V, and the white electrodes represent electrodes having a potential of 0.

First, as shown in FIG. 7 (b), by grounding the conducting wire 6, the mover electrodes 41a to 41a of the mover 30 are moved.
The potential of 41i is set to 0. In this case, the first of the stator 10
The potentials of the fourth to fourth electrode patterns 51 to 54 are all 0, and the mover 30 is at the position shown in FIG. Next, FIG.
As shown in (a), the conductors 5a to 5d of the stator 10 are tangent to the voltage application device 70.

Next, by switching the changeover switch 71 of the voltage applying device 70, as shown in FIG.
The potential of the first electrode pattern 51 of the stator 10 is switched from 0 to a predetermined potential V via the conductor 5a. In this case, V may be positive or negative. In this case, a potential difference occurs between the stator electrodes 51a to 51e of the first electrode pattern 51 and the mover electrodes 61a to 61e, and an electrostatic force acts. Due to this electrostatic force, the mover electrodes 61a to 61e are attracted to the closest stator electrodes 51a to 51e, respectively.
0 moves upward (FIG. 8B).

Next, as shown in FIG. 8B, the potential of the first electrode pattern 51 of the first electrode pattern 51 is returned to 0, and the potential of the third electrode pattern 53 is switched from 0 to a predetermined potential V. . As a result, an electrostatic force acts between the stator electrodes 53a to 53e of the third electrode pattern 53 and the mover electrodes 61a to 61e, and the mover electrodes 61a to 61e respectively contact the closest stator electrodes 53a to 53e. Attracted,
This causes the mover 30 to move diagonally downward (FIG. 8).
(C)).

Next, as shown in FIG. 8C, the potential of the third electrode pattern 53 is returned to 0, and the potential of the second electrode pattern 52 is switched from 0 to a predetermined potential V. As a result, in the same manner as described above, the mover electrodes 61a to 61e are attracted to the closest stator electrodes 52a to 52e, whereby the mover 30 moves obliquely upward (FIG. 8).
(D)).

Next, as shown in FIG. 8D, the potential of the second electrode pattern 52 is returned to 0, and the potential of the fourth electrode pattern 54 is switched from 0 to a predetermined potential V. As a result, in the same manner as described above, the mover electrodes 61a to 61e are attracted to the closest stator electrodes 54a to 54e, whereby the mover 30 moves obliquely upward (FIG. 8).
(E)).

As described above, the first electrode pattern 51,
By sequentially switching the potential from 0 to a predetermined potential V in the order of the third electrode pattern 53, the second electrode pattern 52, and the fourth electrode pattern 54, the stator 30 moves in the movable element 10 up and down in the axial direction. (FIGS. 8A to 8E). If the order of applying the voltage to the electrode patterns 51 to 54 is reversed, the stator 30 is moved in the opposite direction (FIG. 8A).
To (e) left side).

As described above, according to the present embodiment, since the mover 30 can be moved in the axial direction while moving the inside of the stator 10 up and down, the mover 30 and the stator 10 can be moved.
The mover 30 can be moved in a state where the friction between the mover 30 and the moving member 30 is reduced. In addition, by increasing the length of the stator 10 in the axial direction and providing a large number of stator electrodes corresponding thereto, the moving range of the mover 30 can be expanded as desired.

Third Embodiment Next, a third embodiment will be described. FIGS. 9 to 13 show a third embodiment of the present invention. FIG.
As shown in FIG. 1, the electrostatic support mechanism 100 includes a pair of fixed electrodes 101a and 101b made of a conductive material, and a movable section 115 provided between the pair of fixed electrodes 101a and 101b. , Fixed electrodes 101a, 10
1b, a pair of action parts 110a, 11
0b and a connecting portion 120 for connecting the pair of acting portions 110a and 110b to each other.

First, the fixed electrodes 101a and 101b will be described in detail. As shown in FIG. 9, the fixed electrodes 101a, 1
01b are arranged at point-symmetric positions with respect to the center point 130, respectively. The fixed electrode 101a has a concave portion 102a defined by a bottom surface 103a and two side surfaces 104a and 105a on a side facing the fixed electrode 101b.
Are formed. These two side surfaces 104a, 105
“a” is inclined so that the cross-sectional shape of the concave portion 102a becomes smaller toward the bottom surface 103a side, and the angles formed by the side surface 104a and the side surface 105a with the bottom surface 103a are equal to each other. Also, the bottom surface 1 that defines the recess 102a
03a and the surfaces of side surfaces 104a and 105a are covered with an insulating layer (not shown). In addition, the fixed electrode 10
1b has the same configuration and shape dimensions as the fixed electrode 101a.
And the detailed description is omitted. Conductive wires (not shown) are connected to the fixed electrodes 101a and 101b, respectively, so that the potentials of the fixed electrodes 101a and 101b can be adjusted from outside via these conductive wires.

Next, the movable section 115 will be described in detail. As described above, the movable portion 115 includes the pair of action portions 110a,
110b and the connecting portion 120, and the action portions 110a,
110b is a concave portion 102 of the fixed electrodes 101a and 101b.
a, 102b. The operating portion 110a includes a first operating portion electrode 111a disposed on a side opposite to the bottom surface 103a of the fixed electrode 101a, and a connecting portion 1a.
It comprises a second working portion electrode 112a disposed on the 20 side, and an insulating layer 113a provided between the first working portion electrode 111a and the second working portion electrode 112a. The insulating layer 113a is made of a material having a high electric resistance, for example, glass or ceramics.
a and the second working portion electrode 112a are formed of a film-like or plate-like conductive material.

The lateral direction of the action portion 110a (FIG. 12X)
Direction) is the opposite side surface 104 of the fixed electrode 101a.
a, 105a is smaller than the distance in the horizontal direction (X direction in FIG. 12) (see FIGS. 12 to 14).
Even when a is displaced to the maximum in the vertical direction (Y direction in FIG. 12), the side surface of the action portion 110a is the side surface 1 of the fixed electrode 101a.
04a, 105a. Further, the distance between both end faces of the movable section 115, that is, the end face of the first action section electrode 111a of the action section 110a and the action section 11
0b is equal to the end face of the first working portion electrode 111b.
It is smaller than the distance between the bottom surface 103a of the fixed electrode 101a and the bottom surface 103b of the fixed electrode 101b.

The first working portion electrodes 111a, 111b
Conductors (not shown) are connected to the and the second working portion electrodes 112a and 112b, respectively, and the potentials of the first and second working portion electrodes can be independently adjusted from outside via these conducting wires. It has become.

In this embodiment, an example is shown in which the whole of the fixed electrodes 101a and 101b is made of a conductive material. However, the present invention is not limited to this, and as shown in FIG. The fixed electrodes 101a, 101 shown in FIG.
The fixed electrode may be formed by forming the base 106 having substantially the same shape as 1b and providing the film-shaped or plate-shaped conductive substance 107 over the entire surface of the concave portion of the base 130. Also in this case, the insulating layer 108 is formed on the conductive material 107.
Is provided.

Further, the side surfaces 104a, 105a, 104b, 105b of the fixed electrodes 101a, 101b do not necessarily have to be inclined, but are respectively formed on the bottom surfaces 103a, 103b.
May be provided vertically, but is preferably inclined.

Next, the operation of the third embodiment having such a configuration will be described with reference to FIGS.

First, referring to FIG. 11, the fixed electrodes 101a,
Side surface 104a, 105a, 104b, 105 of 101b
The basic operation of the electrostatic support mechanism 100 when b is not inclined will be described. As shown in FIG. 11, a positive potential V is applied to the first working portion electrode 111a and the fixed electrode 101a by the voltage applying device 170, and a negative potential −V is applied to the second working portion electrode 112a. In addition, the potentials V and -V are applied to the fixed electrode 101b and the electrodes of the action section 110b (not shown) in a similar manner. In this case, the distribution of lines of electric force in the concave portion 102a is as shown by a broken line in FIG. 12, and an upward force is acting on the action portion 110a. Also, the center point 1
A downward force acts on the action portion 110b provided at a symmetrical position with respect to 30. Here, since the forces acting on the action section 110a and the action section 110b are equal, the movable section 11
5 is the bottom surface 103a of the fixed electrode 101a and the fixed electrode 10
1b fixed electrodes 101a, 101b between bottom face 103b
It is held in the air without touching the surface.

Next, referring to FIG. 12, the fixed electrodes 101a,
Side surface 104a, 105a, 104b, 105 of 101b
The operation when b is inclined will be described. Also in this case, as shown in FIG. 13, a positive potential V is applied to the first working portion electrodes 111a and 111b and the fixed electrodes 101a and 101b by the voltage applying device 180, and a negative potential is applied to the second working portion electrodes 112a and 112b. Is applied.

First, the movable portion 115 of the electrostatic support mechanism 100
Is in an equilibrium position, that is, a position where the midpoint 130a of the connecting portion 120 of the movable portion 115 and the center point 130 of the pair of fixed electrodes 101a and 101b coincide with each other.
Reference numerals 0a and 110b are located at the two-dot chain lines in FIG. Here, for example, it is assumed that an external force in the axial direction (vertical direction in FIG. 12) is applied to the connecting portion 120 of the movable portion 115, and the movable portion 115 is displaced toward the fixed electrode 101a (the position indicated by the solid line in FIG. 12). In this case, the side surfaces 104a, 105a,
Since the portions 104b and 105b are inclined, the movable portion 115
Is in the equilibrium position, the action portion 110a and the side surface 1
The distances from 04a and 105a are small. Since the electrostatic force is a force that is inversely proportional to the square of the distance, the density of the lines of electric force becomes dense as shown by the broken line in FIG. 13, whereby the force for pulling up the action portion 110a upward by the electrostatic force increases. On the other hand, the distance between the action portion 110b and the side surfaces 104b and 105b becomes large, and the line of electric force density becomes low as shown by the broken line in FIG. 12, whereby the force for pulling the action portion 110a downward decreases. Therefore, a force for returning to the equilibrium state, that is, an upward force acts on the entire movable portion 115, and the movable portion 115 returns to the equilibrium position (the position indicated by the two-dot chain line in FIG. 12).

As described above, according to the present embodiment, since the movable portion 115 can be held in a non-contact state, it is possible to obtain the electrostatic support mechanism 100 that does not generate resistance due to frictional force. Further, in particular, the fixed electrode 101
a, side surfaces 104a, 105a, 104b, 1 of 101b
When the movable portion 115 is displaced in the axial direction of the connecting portion 120 when the movable portion 05b is inclined, a force is applied to the movable portion 115 to return to the equilibrium state by itself. It is possible to obtain the electrostatic support mechanism 100 having a dispensing function.

In this embodiment, an example in which a pair of fixed electrodes and a pair of action parts are provided is shown. However, the present invention is not limited to this. For example, as shown in FIG. As two pairs of fixed electrodes 101a, 101
b and 101c, 101d and action parts 110a, 110
b and 110c, 110d. In this case, a pair of action parts 110a, 110b and 110
c, 110d, two connecting portions 120a, 1
20b are orthogonal to each other. In this way, the movable section 115 can be supported not only in the vertical direction but also in the horizontal direction.

Fourth Embodiment Next, a fourth embodiment will be described. FIG. 14 shows a fourth embodiment. The fourth embodiment is different from the third embodiment in that the fixed electrode is divided into two parts that are electrically independent from each other.
This is substantially the same as the embodiment. In the fourth embodiment, the same portions as those in the third embodiment are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 14, the fixed electrode 140 comprises a first fixed electrode 141 and a second fixed electrode 142,
An insulator 143 is provided between the first fixed electrode 141 and the second fixed electrode 142. That is, the fixed electrode 140 in the present embodiment has a shape obtained by dividing the fixed electrodes 101a and 101b in the third embodiment into two at the center. Conductive wires 144 and 145 are connected to the first fixed electrode 141 and the second fixed electrode 142, respectively, and the potentials of the first fixed electrode 141 and the second fixed electrode 142 are independent from the outside via these conductive wires 144 and 145. Can be adjusted.

Next, the operation of the present embodiment having the above configuration will be described. First, as shown in FIG. 14, the conductors 144 and 145 are connected to the voltage application device 190, and the changeover switch 191 is switched at high speed. When the changeover switch 191 is set to the solid line position, the potential of the first fixed electrode 141 becomes V, and the potential of the second fixed electrode 142 becomes 0. In this case, the distribution of lines of electric force in the concave portion 140a is indicated by a broken line, and the acting portion 110a has a force for pulling up the acting portion 110a and a acting portion 110a.
To the side surface 141 a of the fixed electrode 141. On the other hand, when the changeover switch 191 is set to the position indicated by the two-dot chain line, the potential of the first fixed electrode 141 becomes 0, and the potential of the second fixed electrode 142 becomes V. in this case,
The distribution of the lines of electric force in the concave portion 102a is indicated by a two-dot chain line and the action portion 110a is
The force for pulling the upper portion 10a upward and the force for pulling the action portion 110a to the left side toward the side surface 142a of the fixed electrode 142 act simultaneously. That is, since the force in the left-right direction is alternately applied to the action portion 110a at a high cycle, the action portion 110a is connected to the side surface 141a or the side surface 142a.
Can be prevented from being adsorbed to any one of the above.

Fifth Embodiment Next, a fifth embodiment will be described. FIGS. 15 to 18 are diagrams showing a fifth embodiment of the present invention. In the fifth embodiment, an electrostatic actuator having substantially the same operating principle as the electrostatic actuator described in the second embodiment is substantially the same as the electrostatic support mechanism described in the fifth embodiment. Is provided with an electrostatic support mechanism having the operation principle described above. As shown in FIGS. 15 and 16, the electrostatic actuator 200 includes a stator 210 and a movable element 230 housed inside the stator 210 and having a columnar shape as a whole.

As shown in FIG. 16, the stator 210 includes a first stator 210a, a second stator 210b, and a third stator 210b.
The first to fourth stators 210a to 210d are composed of a stator 210c and a fourth stator 210d, and are fixed to each other via insulating adhesive layers 211a to 211d.
It has a cylindrical shape as a whole. Also, the stator 210
The recesses 212a to 212d extending in the axial direction are formed at positions corresponding to the adhesive layers 211a to 211d on the inner peripheral surface of the. Fixed electrodes 213a to 213d are provided on the surfaces of the recesses 212a to 212d, respectively, and these fixed electrodes 213a to 213d are each divided into two similarly to the fifth embodiment. In addition, each of the two fixed electrodes 213a to 213d is formed of an adhesive layer 211a to 213d.
Insulated from each other by 211d.

As shown in FIGS. 16 and 17A, a stator electrode pattern is formed on the inner peripheral surface of the stator 210. The stator electrode pattern is the first stator 210a.
The first electrode pattern 251 and the second electrode pattern 252 provided on the third stator 210c, and the second stator 21
0c and a third electrode pattern 253 and a fourth electrode pattern 254 provided on the fourth stator 210d.

As shown in FIGS. 16 and 17 (a),
First electrode pattern 251 provided on third stator 210c
And the second electrode pattern 252 are connected to the first stator 2 respectively.
The first electrode pattern 251 and the second electrode pattern 252 provided on 10 a are located at a point symmetric position with respect to the central axis 215 of the stator 210. Further, the third electrode pattern 253 provided on the fourth stator 210d and the fourth
The electrode pattern 254 includes a third electrode pattern 253 and a fourth electrode pattern 2 provided on the second stator 210b.
54 is moved to a point symmetrical position with respect to the center axis 215 of the stator 210. By arranging the first to fourth electrode patterns 251 to 254 in this manner, the stator 21
When moving 0, it is possible to apply only an axial force to the stator 210, and it is possible to prevent the stator 210 from moving in the radial direction.

In the present embodiment, the first to fourth electrode patterns 251 to 25 provided on the inner peripheral surface of the stator are provided.
4 is different from the second embodiment in that each covers 1/4 of the inner peripheral surface of the stator 210 (in the second embodiment, the first to fourth electrode patterns 51 to 54 are different from each other). Each covers one half of the inner peripheral surface of the stator 10), and other points, that is, the configuration, shape, mutual positional relationship, and stator of the electrode patterns 251 to 254 of the respective electrode patterns 251 to 254. The pitch p between the electrodes and the like are substantially the same as those of the first to fourth electrode patterns 51 to 54 in the second embodiment, and a detailed description thereof will be omitted.

FIG. 15, FIG. 16 and FIG.
As shown in the figure, the mover 230 has a cylindrical base 231.
And a mover electrode pattern 240 in the form of a film or plate formed on the base 231. This mover 230
Has a diameter smaller than the diameter of the inner circumference of the stator 210. As shown in FIGS. 15 and 16, action parts 110 a, 110 b, 110 c, and 110 d extending in the axial direction are provided at positions that divide the outer circumference of the mover 230 into four equal parts, and these action parts 110 a to 110 d are provided. Are support portions 160a, 160b, 1 provided on the mover 230, respectively.
It is fixed to the mover 230 via 60c and 160d. The configurations of the operation units 110a to 110d are the same as the configurations of the operation units 110a and 110b in the fifth embodiment, and the detailed description is omitted by attaching the same reference numerals.

As shown in FIG. 17B, the mover electrode pattern 240 includes a first electrode pattern 240a, a second electrode pattern 240b, a third electrode pattern 240c, and a fourth electrode pattern 240d. ~ 4th electrode pattern 2
40a to 240d are first to fourth stators 210a, respectively.
To 210d. The first electrode pattern 240a includes a plurality of mover electrodes 241a to 241a.
1e and connection electrodes 241f for electrically connecting the mover electrodes 240a to 240e. Each of the mover electrodes 241a to 241e extends in the circumferential direction of the outer periphery of the mover 230, and is arranged in parallel with each other and at equal intervals in the axial direction. Also, connection electrode 2
Reference numeral 41f extends in the axial direction through a substantially central portion in the longitudinal direction of each of the mover electrodes 241a to 241e.

As shown in FIGS. 17A and 17B,
The pitch p in the axial direction of the mover electrodes 241a to 241e adjacent to each other is the same as the pitch p between the stator electrodes. Also, the second to fourth electrode patterns 240b to 240d
Has the same shape as the first electrode pattern 240a,
The mover electrodes 241a to 241e, 242a to 242e, and 243a of the first to fourth electrode patterns 240a to 240d.
243e and 244a to 244e are arranged at the same axial position on the outer peripheral surface of the mover 230 as those corresponding to the alphabets at the end of the reference numerals.

In this case, the mover 230 and the supporting portions 160a to 160d provided on the mover correspond to the connecting portion 120 in the fifth embodiment.
Support portions 160a to 160d and action portions 110a to 11
0d corresponds to the movable section 115 in the fifth embodiment.

Next, the operation of the present embodiment having the above configuration will be described. First, the mover 230 is inserted into the stator 210 as shown in FIG. next,
As shown in FIG. 18, the fixed electrodes 213a to 213d and the action parts 110a to 110d are connected to the voltage application device 260. In this case, wiring of the fixed electrodes 213a to 213d to the voltage applying device 260 is performed so that a force for rotating the stator 210 does not act when the changeover switch 261 is switched. That is, in FIG. 18, for example, when the changeover switch 261 is switched to the side 261a, the same circumferential force F is applied to all of the acting portions 110a to 110d.
Are wired so that they do not work. Here, when the changeover switch 261 of the voltage applying device 260 is switched at a high speed,
Fifth, based on the same principle as described in the embodiment,
The mover 230 and the acting portions 110a to 110d are held inside the stator 210 without contacting the stator 210.

Next, as shown in FIG.
The fourth electrode patterns 240a to 240d are grounded, and the potentials of the first to fourth electrode patterns 240a to 240d are set to 0. Further, as shown in FIG. 17A, the first to fourth electrode patterns 251 to 254 are connected to the voltage application device 262, and the changeover switch 263 of the voltage application device 262 is set to 263a, 263.
The switching is sequentially performed in the order of b, 263c, and 263d. Then, the mover 230 moves in the axial direction inside the stator 210 on the same principle as that described in the second embodiment.

As described above, according to the present embodiment, the mover 230 is mounted inside the stator 210
Can be moved in the axial direction without contacting the movable member 230, no frictional force is generated between the movable member 230 and the stator 210 due to the contact, and the movable member 230 can be moved extremely smoothly. it can. Therefore, an electrostatic actuator having good operation characteristics can be obtained.

[0074]

As described above, according to the electrostatic actuator of the present invention, no or little frictional force is generated between the mover and the stator, so that an actuator having good operation characteristics can be obtained. be able to. Further, since there is no need to provide a bearing that limits the moving range of the mover, an actuator having a large moving range can be obtained.

[0075]

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention,
FIG. 3 is an axial sectional view of the electrostatic actuator.

FIG. 2 is a diagram showing an AA cross section of FIG. 1;

FIG. 3 is a development view of inner peripheral surfaces of an upper stator and a lower stator in the first embodiment, and a side view of the mover.

FIG. 4 is an axial sectional view showing radial movement of the mover with respect to the stator in the first embodiment.

FIG. 5 is a schematic diagram showing axial movement of the mover with respect to the stator according to the first embodiment.

FIG. 6 is a view showing a second embodiment of the present invention,
FIG. 3 is an axial sectional view of the electrostatic actuator.

FIG. 7 is a development view of inner peripheral surfaces of an upper stator and a lower stator according to the second embodiment, and a side view of the mover.

FIG. 8 is a partial cross-sectional view from the side showing the movement of the mover in the second embodiment.

FIG. 9 is a view showing a third embodiment of the present invention,
FIG. 3 is a perspective view illustrating a configuration of an electrostatic support mechanism.

FIG. 10 is a sectional view showing another configuration of the fixed electrode.

FIG. 11 is a diagram showing the operation of the third embodiment of the present invention.

FIG. 12 is a view showing the operation of the third embodiment of the present invention.

FIG. 13 is a diagram showing an example in which a plurality of sets of fixed electrodes and action parts are provided.

FIG. 14 is a diagram showing the configuration and operation of a fourth embodiment of the present invention.

FIG. 15 is an exploded perspective view showing the configuration of the fifth embodiment of the present invention.

FIG. 16 is a view showing the configuration of the fifth embodiment of the present invention, and is a cross-sectional view in a direction perpendicular to the axial direction.

FIG. 17 is a developed view of an inner peripheral surface of a stator and an outer peripheral surface of a mover according to a fifth embodiment, showing a connection state between a stator electrode pattern, a mover electrode pattern, and a voltage applying device. .

FIG. 18 is a diagram illustrating a connection state of a fixed electrode and a working unit to a voltage application device.

[Explanation of symbols]

10, 210 Stator 22a to 22h, 23a to 23h, ... Stator electrode 30, 230 Mover 35, 70, 262 (for electrostatic actuator) Voltage applying device 41a to 41i, 61a to 61e Mover electrode 51a to 51e, 52a to 52e,... Stator electrodes 101a to 101d Fixed electrodes 102a to 102d Recesses 103a, 103b Bottom surfaces 104a, 104b, 105a, 105b Side surfaces 110 Working portions 111a, 111b First working portion electrodes 112a, 112b Second working Part electrodes 113a, 113b Insulating layer 115 Movable part 120 Connecting part 170, 180, 190, 260 (for electrostatic support mechanism)
Voltage applying devices 241a to 241e, 242a to 242e,...

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02N 1/00

Claims (2)

(57) [Claims] An inner peripheral surface having a predetermined diameter forming a substantially cylindrical space therein; a stator having a plurality of stator electrodes provided on the inner peripheral surface; and an interior of the stator. And a mover having an outer peripheral surface having a smaller diameter than an inner peripheral surface of the stator, and having a mover electrode extending in a circumferential direction on the outer peripheral surface. The electrodes are arranged spirally as a whole by being arranged at predetermined intervals in the axial direction and the circumferential direction, and by sequentially applying a voltage to the plurality of stator electrodes along the spiral direction. An electrostatic actuator, wherein the mover is configured to move in the axial direction while rotating inside the stator. 2. A voltage for sequentially applying a voltage to the plurality of stator electrodes arranged in a spiral in a spiral direction, thereby moving the mover in the axial direction while rotating the mover inside the stator. Characterized by further comprising an application means,
The electrostatic actuator according to claim 1.