JP2003324980A - Driving device of multiple degrees of freedom - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device of multiple degrees of freedom which does not require any special bearing and allows reduction in frictional resistance. <P>SOLUTION: The driving device of multiple degrees of freedom comprises a spherical portion 1a, first and second cases 2 and 3, and first and second vibration generating members 4 and 5. The first case 2 is supported in a ball bearing 11 so that the first case is rotatable on the α-axis line which runs through the center of the spherical portion 1a. The second case 3 is supported in a ball bearing 12 so that the second case is rotatable on the β-axis line which runs through the center of the spherical portion 1a and is orthogonal to the α-axis line. The first vibration generating member 4 is supported in the first case 2 so that the first vibration generating member is rotatable on a first orthogonal axis line orthogonal to the α-axis line. The first vibration generating member 4 has a contact portion 21e which is pressed against and brought into contact with the spherical portion 1a, and generated vibration at the contact portion 21e in a plurality of directions. The second vibration generating member 5 is supported in the second case 3 so that the second vibration generating member is rotatable on a second orthogonal axis line orthogonal to the β-axis line. the second vibration generating member 5 has a contact portion 41e which is pressed against and brought into contact with the spherical portion 1a, and generates vibration at the contact portion 41e in a plurality of directions. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor that drives a rotor to rotate about a plurality of axes.

[0002]

2. Description of the Related Art In recent years, a multi-degree-of-freedom drive device has been proposed which uses an ultrasonic motor for rotationally driving a rotor around a plurality of axes. In the stator of this multi-degree-of-freedom drive device, a piezoelectric element is provided at a contact portion so that vibration can be generated in a plurality of directions. The rotor has a substantially spherical spherical portion, and the spherical portion is pressed into contact with the contact portion. Then, the rotor (spherical portion) rotates about a plurality of axes based on vibrations in a plurality of directions generated by the stator.

[0003]

By the way, in the multi-degree-of-freedom drive device as described above, the contact portion is formed in order to press the spherical portion into contact with the contact portion and to support the spherical portion so as to be rotatable about a plurality of axes. At the same time, it is conceivable to use a slide bearing along the spherical portion so as to sandwich the spherical portion (curved spherically).

However, there is a problem that the sliding bearing along the spherical portion is special and its cost is high.
Further, there is a problem that the efficiency of the multi-degree-of-freedom drive device is reduced due to the frictional resistance of the slide bearing.

An object of the present invention is to provide a multi-degree-of-freedom drive device which can reduce frictional resistance without requiring a special bearing.

[0006]

According to a first aspect of the present invention, there is provided a substantially spherical spherical portion, and a first spherical portion rotatably supported by the spherical portion about a first axis passing through the center of the spherical portion. 1 support member and the spherical portion, the first through the center of the spherical portion
A second support member rotatably supported about a second axis perpendicular to the axis, and a first support member rotatably supported on a first orthogonal axis perpendicular to the first axis, and the spherical portion. A first vibration generating member that has a contact portion that is pressed into contact with the contact portion, and that generates vibration in a plurality of directions at the contact portion; and the second support member that rotates about a second orthogonal axis line that is orthogonal to the second axis line. A second portion that has a contact portion that is movably supported and is pressed into contact with the spherical portion, and that vibrates in a plurality of directions in the contact portion.
A gist of the present invention is a multi-degree-of-freedom drive device including a vibration generating member.

According to a second aspect of the present invention, in the multi-degree-of-freedom drive device according to the first aspect, the spherical portion is provided with a first support shaft extending in the first axial direction, and the first support shaft is a ball bearing. Is rotatably supported by the first support member, or the first support member is provided with a first support shaft extending in the first axial direction, and the first support shaft is rotatable by a ball bearing in the spherical portion. And a second support shaft extending in the second axial direction is provided on the spherical portion so that the second support shaft is rotatably supported on the second support member by a ball bearing, or on the second support member. A second support shaft extending in the second axis direction is provided, and the second support shaft is rotatably supported by the spherical portion by a ball bearing.

The invention described in claim 3 is the invention according to claim 1 or 2.
In the multi-degree-of-freedom drive device described in [1],
The supporting member has a spherical portion side supporting member and a vibration generating side supporting member, respectively, and is integrated by a screw mechanism that they have, and the contact portion and the aforesaid contact portion are formed at a screwing angle of the screw mechanism. The pressing force with the spherical part can be set.

(Operation) According to the invention described in claim 1,
By causing the first vibration generating member to generate vibration, the spherical portion, the second vibration generating member, and the first and second support members can be rotated about the first orthogonal axis with respect to the first vibration generating member. . Further, by causing the first vibration generating member to generate vibration, the spherical portion, the second vibration generating member, and the first and second support members are rotated about the first axis with respect to the first vibration generating member. You can

Further, by causing the second vibration generating member to generate vibration, the spherical portion, the first vibration generating member, the first and second supporting members are centered on the second orthogonal axis with respect to the second vibration generating member. It can be rotated. Further, by causing the second vibration generating member to generate vibration, the spherical portion, the first vibration generating member, and the first and second support members are rotated about the second axis with respect to the second vibration generating member. You can

Thus, the second vibration generating member can be rotated (tilted) about the plurality of axes with respect to the first vibration generating member. Since each member is rotatably supported about one axis, it is not necessary to use a slide bearing or the like along the sphere that rotatably supports the sphere about a plurality of axes. For example, a general ball bearing can be easily used. Further, by using the ball bearing, it is possible to reduce the frictional resistance (compared to the slide bearing), and it is possible to improve the efficiency of the multi-degree-of-freedom drive device.

According to the second aspect of the present invention, a very general structure can be adopted in which the first and second support shafts are rotatably supported by ball bearings. Also, by using ball bearings (compared to plain bearings)
Friction resistance is reduced, and the efficiency of the double-degree-of-freedom drive device is increased.

According to the third aspect of the present invention, the first and second supporting members respectively have a spherical portion side supporting member and a vibration generating side supporting member, and they are integrated by a screw mechanism which they have. The pressing force between the contact portion and the spherical portion can be set by the screwing angle of the screw mechanism. Therefore, the pressing force between the contact portion and the spherical portion can be set with a simple configuration.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the multi-degree-of-freedom drive device includes an intermediate member 1, a first and a second member.
It is provided with first and second cases 2 and 3 as support members, and first and second vibration generating members 4 and 5.

As shown in FIG. 2, the intermediate member 1 has a substantially spherical spherical portion 1a made of a rigid body such as stainless steel, and a first axial line passing through the center of the spherical portion 1a and extending in the α-axis direction as a first axial line. 1 support shaft 1b, and a second support shaft 1c extending in the β axis direction as a second axis line that passes through the center of the spherical portion 1a and is orthogonal to the α axis line.

The first case 2 includes a vibration generating side first case 6 as a vibration generating side supporting member and a spherical portion side first case 7 as a spherical portion side supporting member. The vibration generating side first case 6 is formed in a substantially cylindrical shape and has a male screw 6a formed at one end (end on the intermediate member 1 side) and a radially inner side at the other end (end on the side opposite the intermediate member 1). A disk portion 6b extending in the direction is formed. The spherical portion side first case 7 is formed in a substantially cylindrical shape and has one end portion (end portion on the intermediate member 1 side) thereof.
Is formed with a pair of arm portions 7a (only one is shown in FIG. 1) extending in the axial direction of the male thread 6a at intervals of 180 degrees, and the other end portion (end portion on the side opposite the intermediate member 1) is screwed to the male screw 6a. Possible female threads 7b are formed. Then, the vibration-generating-side first case 6 and the spherical portion-side first case 7 have the male screw 6
It is fixed by screwing a into the female screw 7b (first case 2
Have been integrated).

The second case 3 is composed of the same parts as the first case 2. Specifically, the second case 3 is provided with a vibration generating side second case 8 as a vibration generating side supporting member and a spherical portion side second case 9 as a spherical portion side supporting member. The vibration generating side second case 8 is formed in a substantially cylindrical shape, has a male screw 8a formed at one end portion (end portion on the intermediate member 1 side), and a radially inner side at the other end portion (end portion on the side opposite the intermediate member 1). A disk portion 8b extending in the direction is formed. Second spherical part
The case 9 is formed in a substantially cylindrical shape, and a pair of arm portions 9a extending in the axial direction of the case 9 is formed at one end portion (end portion on the side of the intermediate member 1) of the case 9 at intervals of 180 degrees, and the other end portion (the opposite intermediate member 1). Female screw 9 that can be screwed into the male screw 8a at the side end)
b is formed. Then, the vibration generating side second case 8
And the spherical portion side second case 9, the male screw 8a is the female screw 9b.
It is fixed (integrated as a second case) by being screwed into. In this embodiment, the male screws 6a and 8a and the female screws 7b and 9b form a screw mechanism.

In the first case 2, the front ends of a pair of arm portions 7a (only one of which is shown by broken lines in FIG. 1) are connected to the first support shaft 1b via a ball bearing 11, so that It is rotatably supported at the center of the support shaft 1b (center of the α axis).

In the second case 3, the front ends of the pair of arm portions 9a are connected to the second support shaft 1c via the ball bearings 12, so that the second case 3 can rotate about the center of the second support shaft 1c (center of the β axis). It is supported.

The first vibration generating member 4 is a so-called bolted Langevin type vibrator, and includes a fastening member 21, first and second metal blocks 22 and 23, and first and second piezoelectric elements 24 and 25. , And a nut 26.

The fastening member 21 includes a bolt portion 21a as a bolt, a first connecting portion 21b as an input shaft extending coaxially from one end of the bolt portion 21a, and a bolt portion 21.
The disk portion 21c extends radially outward from the other end of a, and the tubular portion 21d extends in a tubular shape from the outer edge of the disk portion 21c. A contact portion 21e set to come into contact with a spherical surface (spherical portion 1a) provided above the cylindrical portion 21d at an annular surface is formed at the tip end opening portion.

The first and second metal blocks 22 and 23 are
It is made of a conductive metal and is made of an aluminum alloy in this embodiment. Each of the first and second metal blocks 22 and 23 is a substantially columnar body, and a through hole penetrating in the axial direction is formed in the central axis portion thereof.

The first piezoelectric element 24, as shown in FIG.
It is formed in a substantially disc shape, and a through hole is formed in the central shaft portion thereof. The polarization direction of the first piezoelectric element 24 is one direction perpendicular to the plane (that is, in the axial direction). An electrode (schematically indicated by a thick line in FIG. 1) 27 is provided on the entire upper surface (the surface on the side of the intermediate member 1) of the first piezoelectric element 24. Electrodes (schematically indicated by thick lines in FIG. 1) are provided on the entire lower surface (the surface on the side opposite to the intermediate member 1) of the first piezoelectric element 24.

The second piezoelectric element 25, as shown in FIG.
It is formed in a substantially disc shape, and a through hole is formed in the central shaft portion thereof. The polarization direction of the second piezoelectric element 25 is perpendicular to the plane (that is, the axial direction), and is opposite for each half of the plane (see “+” and “−” in the polarization direction column of FIG. 3). There is. On the upper surface (the surface on the side of the intermediate member 1) of the second piezoelectric element 25, four electrodes (schematically shown by thick lines in FIG. 1 and schematically shown in FIG. 2) are divided at intervals of 90 degrees. 28a to 28d are shown. Of these four electrodes 28a-28d, two electrodes 28a, 28b
Is arranged corresponding to one polarization direction (polarization direction of FIG. 3, “−”), and the other two electrodes 28c and 28d correspond to the other polarization direction (polarization direction of FIG. 3, “+”). Are arranged. The electrodes 28a, 28b, 28c, 28d are arranged clockwise in this order when viewed from the intermediate member 1 side.
An electrode (schematically indicated by a thick line in FIG. 1) is provided on the entire lower surface (surface on the side opposite to the intermediate member 1) of the second piezoelectric element 25.

Then, as shown in FIG. 1, the first metal block 22, the first piezoelectric element 24, the second piezoelectric element 25, and the second piezoelectric element 25.
The metal blocks 23 are stacked in this order, and are fastened by screwing a nut 26 onto one end portion (end portion on the coupling portion 21b side) of the bolt portion 21a inserted into each through hole from the second metal block 23 side. Has been done. At this time, an insulating collar 29 is interposed between the inner peripheral surfaces of the first and second piezoelectric elements 24 and 25 and the bolt portion 21a.

The first vibration generating member 4 is provided with the nut 2
Since 6 is connected to the disk portion 6b of the first case 2 via the ball bearing 31, the center of the axis of the first case 2, that is, the center of the first orthogonal axis orthogonal to the first support shaft 1b (α-axis). It is rotatably supported. In the present embodiment,
The outer ring of the ball bearing 31 is fixed to the nut 26,
The inner ring of the ball bearing 31 is fixed to the disc portion 6b to be connected.

At this time, the contact portion 21e of the first vibration generating member 4 is pressed into contact with the spherical portion 1a. Here, the pressing force between the contact portion 21e and the spherical portion 1a has a desired value depending on the screwing angle (number of screwing) of the male screw 6a of the vibration generating side first case 6 and the female screw 7b of the spherical portion side first case 7. Is set to. Further, at this time, the first vibration generating member 4 is substantially housed in the first case 2. Incidentally, in the present embodiment, the first and second support shafts 1b and 1c of the intermediate member 1 with respect to the first
The position of the second piezoelectric element 25 of the vibration generating member 4 is the basic position in the state shown in FIG. That is, as shown in FIG. 2, the polarization boundary line (electrode 28a,
A state in which the boundary line between 28b and the electrodes 28c and 28d) is parallel to the first support shaft 1b (α axis) is the basic position in the present embodiment.

The second vibration generating member 5 is made of the same component as the first vibration generating member 4. Therefore, the second vibration generating member 5 will be described only with respect to the points different from those of the first vibration generating member 4.

The second vibration generating member 5 includes a fastening member 41,
First and second metal blocks 42, 43, and first and second
The piezoelectric elements 44 and 45 and the nut 46 are provided. The fastening member 41, like the fastening member 21, has a bolt portion 41 a as a bolt and a second connecting portion 41 as an output shaft.
b, a disc portion 41c, and a cylinder portion 41d. A contact portion 41e is formed at the tip end opening of the cylinder portion 41d.

The first piezoelectric element 44 corresponds to the first piezoelectric element 2
Similar to 4, the electrode (the surface on the side of the intermediate member 1 and the lower surface in FIG. 2) 47 is provided with an electrode (schematically indicated by a thick line in FIG. 1) 47 as a whole. .

The second piezoelectric element 45 is the second piezoelectric element 2
Similarly to 5, the upper surface (the surface on the side of the intermediate member 1 and the lower surface in FIG. 2) is divided into four electrodes (schematically illustrated in FIG. 1) so as to be divided at intervals of 90 degrees. It is indicated by a thick line in FIG.
Inside, the boundaries are schematically shown) 48a to 48d. Of the four electrodes 48a to 48d, the two electrodes 48a and 48b have one polarization direction (the polarization direction in FIG.
"+") And the other two electrodes 48c,
48d is arranged corresponding to the other polarization direction (polarization direction in FIG. 3, "-"). The electrodes 48a, 48b, 48
c and 48d are arranged clockwise in this order when viewed from the intermediate member 1 side.

Then, as shown in FIG. 1, the first metal block 42, the first piezoelectric element 44, the second piezoelectric element 45, and the second
The metal blocks 43 are stacked in this order, and are fastened by screwing a nut 46 onto one end portion (end portion on the coupling portion 41b side) of the bolt portion 41a that is inserted into each through hole from the second metal block 43 side. Has been done. At this time, an insulating collar 49 is interposed between the inner peripheral surfaces of the first and second piezoelectric elements 44 and 45 and the bolt portion 41a.

Then, the second vibration generating member 5 includes the nut 4
6 is connected to the disk portion 8b of the second case 3 via the ball bearing 51, so that the shaft center of the second case 3, that is, the center of the second orthogonal axis orthogonal to the second support shaft 1c (β axis). It is rotatably supported. In the present embodiment,
The outer ring of the ball bearing 51 is fixed to the nut 46,
The inner ring of the ball bearing 51 is fixed to the disc portion 8b so as to be connected.

At this time, the contact portion 41e of the second vibration generating member 5 is pressed into contact with the spherical portion 1a. Here, the pressing force between the contact portion 41e and the spherical portion 1a has a desired value depending on the screwing angle (number of screwing) of the male screw 8a of the vibration generating side second case 8 and the female screw 9b of the spherical portion side second case 9. Is set to. At this time, the second vibration generating member 5 is substantially housed in the second case 3. In addition, in the present embodiment, the second member with respect to the first and second support shafts 1b and 1c of the intermediate member 1 is provided.
The position of the second piezoelectric element 45 of the vibration generating member 5 is the basic position in the state shown in FIG. That is, as shown in FIG. 2, the polarization boundary line (electrode 48a,
The state where the boundary line between 48d and the electrodes 48c and 48b) is parallel to the second support shaft 1c (β axis) is the basic position in the present embodiment.

The multi-degree-of-freedom drive device configured as described above includes the first piezoelectric elements 24 and 44 and the second piezoelectric elements 25 and 4.
5, each electrode 27, 28a-28d, 47, 48
a to 48d are respectively connected to a high frequency power supply device (not shown).

In the multi-degree-of-freedom drive device configured as described above, a high-frequency voltage is supplied from the high-frequency power supply device to the first piezoelectric elements 24, 44 and the second piezoelectric elements 25, 45 based on the operation of an operation switch (not shown). To be done.

First, in the basic position, as shown in FIG. 1, the first and second orthogonal axes (first and second vibration generating members 4 and 5) are on a straight line (γ axis). , First
The second connecting portion 41b is connected to the connecting portion 21b by the same straight line (γ
The case of rotating around an axis will be described.

In this case, the first and second vibration generating members 4,
On the other hand, on the other hand, for example, when viewed from above in FIG. 1, vibration is generated to rotate the intermediate member 1 (spherical portion 1a) in the opposite direction.

For example, the second connecting portion 41b is rotated clockwise with respect to the first connecting portion 21b when viewed from above in FIG. 1 (see FIG. 2).
(In the middle, γ1 rotation), as shown in FIG.
A high frequency voltage (A, B) is supplied to the piezoelectric elements 25, 45. The high frequency voltage A is a high frequency voltage that is 90 degrees out of phase (advanced) with the high frequency voltage B.

More specifically, as shown in FIG. 3, the electrodes 28a, 28 of the second piezoelectric element 25 of the first vibration generating member 4 are formed.
The high frequency voltage A is supplied to c, and the high frequency voltage B is supplied to the electrodes 28b and 28d. At this time, the second piezoelectric element 25
The electrode on the lower surface (the surface on the side opposite to the intermediate member 1) is connected to the ground.

Then, the second piezoelectric element 25 is connected to the electrode 28c.
The portion corresponding to the electrode 28d from the portion corresponding to
Vibrations extending in the thickness direction are repeatedly generated in the order of the portion corresponding to 8a and the portion corresponding to the electrode 28b. Then, based on the vibration, the spherical portion 1a (intermediate member 1)
The force of the right rotation (γ1 rotation in FIG. 2) acts on. Then, the first vibration generating member 4 (first connecting portion 21b)
On the other hand, together with the intermediate member 1, the first and second cases 2,
3, the second vibration generating member 5 is rotated to the right (γ1 rotation in FIG. 2).

On the other hand, at this time, as shown in FIG.
Electrode 48 in second piezoelectric element 45 of vibration generating member 5
High frequency voltage A is supplied to a and 48c, and electrodes 48b and 48c
The high frequency voltage B is supplied to d. At this time, the electrode on the lower surface of the second piezoelectric element 45 (the surface on the side opposite to the intermediate member 1 and the upper surface in FIGS. 1 and 2) is connected to the ground.

Then, the second piezoelectric element 45 has the electrode 48a.
From the part corresponding to the electrode 48b to the electrode 4b
Vibrations extending in the thickness direction are repeatedly generated in the order of the portion corresponding to 8c and the portion corresponding to the electrode 48d. Then, based on the vibration, the spherical portion 1a (intermediate member 1)
A force of left rotation (γ2 rotation in FIG. 2) acts on. Then, the second vibration generating member 5 (second connecting portion 41b) rotates rightward (γ1 rotation in FIG. 2) with respect to the intermediate member 1 (first and second cases 2 and 3, first vibration generating member 4). ) Will be done.

Therefore, the second connecting portion 41b rotates rightward (γ1 rotation in FIG. 2) at a higher speed (twice as compared with the rotation by only the first vibration generating member 4) with respect to the first connecting portion 21b. ) Will be done.

On the contrary, the second connecting portion 41b is rotated counterclockwise with respect to the first connecting portion 21b when viewed from above in FIG. 1 (in FIG. 2,
In the case of (γ2 rotation), as shown in FIG. 3, the high frequency voltage A and the high frequency voltage B are reversely supplied as compared with the case of the right rotation (γ1 rotation in FIG. 2). Then, the second connecting portion 41b is rotated counterclockwise (γ2 rotation in FIG. 2) with respect to the first connecting portion 21b at a high speed (twice as compared with the rotation by only the first vibration generating member 4).

Further, in the basic position, as shown in FIG. 1, the first and second orthogonal axes (first and second vibration generating members 4, 5) are on a straight line (γ axis). , The second connecting portion 41b with respect to the first connecting portion 21b, the first support shaft 1b
The case of rotating around the (α-axis) will be described.

In this case, the first vibration generating member 4 is caused to generate vibration for rotating the intermediate member 1 (spherical portion 1a) about the first support shaft 1b (α axis). For example, when the second connecting portion 41b is rotated counterclockwise (α1 rotation in FIG. 2) from the front side in the direction orthogonal to the paper surface of FIG. 1 with respect to the first connecting portion 21b, as shown in FIG. First of the generating member 4
Also, the high frequency voltage (A, B) is supplied to the second piezoelectric elements 24, 25.

More specifically, as shown in FIG. 3, the high frequency voltage A is supplied to the electrode 27 of the first piezoelectric element 24 of the first vibration generating member 4, and the high frequency voltage A is supplied to the electrodes 28a and 28b of the second piezoelectric element 25. B is supplied to the electrode 28
A high frequency voltage -A is supplied to c and 28d. At this time, the electrodes on the lower surfaces (the surfaces on the side opposite to the intermediate member 1) of the first and second piezoelectric elements 24 and 25 are connected to the ground.

Then, the portions corresponding to the electrodes 28a and 28b repeatedly generate vibrations based on the expansion and contraction of the first and second piezoelectric elements 24 and 25, respectively. On the other hand, the electrode 28
The portions corresponding to c and 28d do not substantially vibrate because the second piezoelectric element 25 contracts when the first piezoelectric element 24 extends. Then, based on the vibration (vibration of the portions corresponding to the electrodes 28a and 28b), the force of left rotation (α1 rotation in FIG. 2) acts on the spherical portion 1a (intermediate member 1). Then,
With respect to the first vibration generating member 4 (first connecting portion 21b) and the first case 2, the second case 3, the second vibration generating member 5 (second connecting portion 41b) together with the intermediate member 1 are rotated to the left (FIG. Two
Medium, α1 rotation). Therefore, the second connecting portion 41b is rotated counterclockwise (α1 rotation in FIG. 2) with respect to the first connecting portion 21b when viewed from the front side in the direction orthogonal to the paper surface of FIG.

On the contrary, when the second connecting portion 41b is rotated to the right with respect to the first connecting portion 21b when viewed from the front side in the direction orthogonal to the paper surface of FIG. 1, (a2 rotation in FIG. 2), as shown in FIG. The high-frequency voltage A and the high-frequency voltage B supplied to the second piezoelectric element 25 are supplied in reverse as compared with the case of the left rotation (α1 rotation in FIG. 2). Then, the second connecting portion 41b
Is rotated to the right with respect to the first connecting portion 21b when viewed from the front side in the direction orthogonal to the paper surface in FIG. 1 (α2 rotation in FIG. 2).

In the basic position, as shown in FIG. 1, the first and second orthogonal axes (first and second vibration generating members 4, 5) are on a straight line (γ axis). , The second connecting portion 41b with respect to the first connecting portion 21b, the second support shaft 1c
The case of rotating around the (β axis) will be described.

In this case, the second vibration generating member 5 is caused to generate vibration for rotating the intermediate member 1 (spherical portion 1a) about the second support shaft 1c (β axis). For example, when the second connecting portion 41b is rotated counterclockwise with respect to the first connecting portion 21b when viewed from the left side of the paper surface of FIG. 1 (β1 rotation in FIG. 2), as shown in FIG. The high frequency voltage (A, B) is supplied to the first and second piezoelectric elements 44, 45.

Specifically, as shown in FIG. 3, the high frequency voltage B is supplied to the electrode 47 of the first piezoelectric element 44 of the second vibration generating member 5, and the high frequency voltage A is supplied to the electrode 48a of the second piezoelectric element 45. The high frequency voltage -B is supplied to the electrode 48b, the high frequency voltage B is supplied to the electrode 48c, and the high frequency voltage -A is supplied to the electrode 48d. At this time, the electrodes on the lower surface (the surface on the side opposite to the intermediate member 1) of the first and second piezoelectric elements 44 and 45 are connected to the ground.

Then, the portions corresponding to the electrodes 48a and 48d repeatedly generate vibrations based on the expansion and contraction of the first and second piezoelectric elements 44 and 45, respectively. On the other hand, the electrode 48
The portions corresponding to b and 48c do not substantially vibrate because the second piezoelectric element 45 contracts when the first piezoelectric element 44 extends. Then, based on the vibration (vibration of the portions corresponding to the electrodes 48a and 48d), a force that rotates rightward (β2 rotation in FIG. 2) acts on the spherical portion 1a (intermediate member 1). Then, with respect to the intermediate member 1 (first case 2, first vibration generating member 4), the second vibration generating member 5 (second connecting portion 41b) and the second case 3 rotate to the left (β1 rotation in FIG. 2). ) Will be done. Therefore, the second connecting portion 41b is the first connecting portion 21b.
On the other hand, when viewed from the left side in FIG.
Medium, β1 rotation).

On the contrary, the second connecting portion 41b is rotated clockwise with respect to the first connecting portion 21b when viewed from the left side of the drawing in FIG.
As shown in FIG. 3, the high frequency voltage A and the high frequency voltage B supplied to the second piezoelectric element 45 are reversed in the case of rotating β2 in the middle, as compared with the case of rotating left (β1 in FIG. 2). , And positive and negative (+-) are supplied in reverse. Then, the second
The connecting portion 41b is rotated to the right with respect to the first connecting portion 21b when viewed from the left side of the paper surface in FIG. 1 (β2 rotation in FIG. 2).

By combining the above-mentioned operations, the second connecting portion 41b can be rotated (tilted) about the plurality of axes with respect to the first connecting portion 21b.
Next, the characteristic actions and effects of the multi-degree-of-freedom drive device configured as described above will be described below.

(1) Since the connected members (the intermediate member 1 and the first case 2 etc.) are rotatably supported about one axis, the spherical portion 1a is rotated about a plurality of axes. It is not necessary to use a slide bearing or the like having a special shape along the spherical portion 1a that supports it as much as possible. As a result, the first and second support shafts 1b and 1c are connected to the ball bearing 11,
It is possible to adopt a very general configuration in which the rotatably supported by 12. Therefore, the cost of the multi-degree-of-freedom drive device can be reduced. And ball bearing 1
By using 1 and 12, the frictional resistance is reduced (compared to the plain bearing), and the efficiency of the multi-degree-of-freedom drive device is improved.

(2) When the first and second vibration generating members 4 and 5 generate vibrations simultaneously, the vibration of one vibration generating member causes rotation (tilting) about a plurality of axes. Compared with the above, it is possible to shorten the time until the angular position of the second vibration generating member 5 with respect to the first vibration generating member 4 reaches a desired angular position.

(3) A set of the first case 2 and the first vibration generating member 4 and a set of the second case 3 and the second vibration generating member 5 are arranged around the intermediate member 1 (spherical portion 1a). It Since the first and second cases 2 and 3 are the same component and the first and second vibration generating members 4 and 5 are the same component, the weight balance of each set is centered around the intermediate member 1 (spherical portion 1a). Will be equal. Thereby, the intermediate member 1 (spherical portion 1a)
When using as a joint part of a robot, the balance of the robot and the like can be easily improved. Also, the first
Since the second case 2 and 3 are the same part and the first and second vibration generating members 4 and 5 are the same part, the part numbers of the parts forming the multi-degree-of-freedom drive device are reduced. Therefore, the manufacturing cost, the component management cost, and the like can be reduced.

(4) The first case 2 (second case 3) is
It has a vibration generating side first case 6 (vibration generating side second case 8) and a spherical portion side first case 7 (spherical portion side second case 9), and they have a male screw 6a (8a) and a female screw 7b.
(9b), that is, they are integrated by a screw mechanism. Then, depending on the screwing angle (number of screwing) of the screw mechanism, the contact portion 21e
The pressing force between (41e) and the spherical portion 1a is set. Therefore, the contact portion 21e (41e) and the spherical portion 1 have a simple structure.
The pressing force with a can be set.

Further, for example, the spherical portion 1a is supported (assembled) on the spherical portion side first case 7 (the spherical portion side second case 9), and the vibration generating side first case 6 (the vibration generating side second case 8) is supported. ), The first vibration generating member 4 (second vibration generating member 5) is supported (assembled), and then they can be assembled by a screw mechanism. Thereby, for example, it is not necessary to perform a difficult assembling work such as assembling the spherical portion 1a to the spherical portion side first case 7 while setting (adjusting) the pressing force. Therefore,
The assembling work becomes easy.

(5) The first and second cases 2 and 3 are the first
Since the second vibration generating members 4 and 5 are substantially housed, dust and dirt are prevented from being applied to the first and second vibration generating members 4 and 5, and dust and dirt adhere to the contact portions 21e and 41e. Is prevented. Therefore, it is possible to prevent the frictional state between the spherical portion 1a and the contact portions 21e and 41e from being changed due to the adhesion of dust or the like, and thus the reliability of the operation is improved.

(6) Bolt tightening Since the first and second connecting portions 21b and 41b as input / output shafts are formed on the bolt portions 21a and 41a constituting the Langevin type vibrator, the input / output shafts of different members are fixed. The number of parts is reduced as compared with the case of providing.

The above embodiment may be modified as follows. In the above embodiment, the first and second vibration generating members 4,
5 is a first piezoelectric element 24, 44 and a second piezoelectric element 25,
Although the second connecting portion 41b is rotated (inclined) about the plurality of shaft centers with respect to the first connecting portion 21b at 45, if the same operation can be performed, the first and second vibration generating members 4,
The configuration of 5 may be changed. Of course, the control method (high-frequency voltage supply method) may be appropriately changed.

For example, it may be changed as shown in FIGS. As shown in FIG. 4, the first vibration generating member 61 is
This is a so-called bolted Langevin type vibrator, which includes a fastening member 62, first and second metal blocks 63 and 64, first to third piezoelectric elements 65 to 67, and a nut 68. In this example, in the first vibration generating member 61, the first and second piezoelectric elements 24,
25 is changed to the first to third piezoelectric elements 65 to 67, and other points are substantially similar to each other, and detailed description thereof will be omitted.

As shown in FIG. 5, the polarization direction of the first piezoelectric element 65 is one direction perpendicular to the plane (that is, in the axial direction). An electrode (schematically indicated by a thick line in FIG. 4) 71 is provided on the entire upper surface (the surface on the side of the intermediate member 1) of the first piezoelectric element 65. Electrodes (schematically indicated by thick lines in FIG. 4) are provided on the entire lower surface (the surface on the side opposite to the intermediate member 1) of the first piezoelectric element 65.

The polarization direction of the second piezoelectric element 66 is perpendicular to the plane (that is, the axial direction), and is opposite by half of the plane (see "+" and "-" in the polarization direction column of FIG. 6). It is said that. On the upper surface (the surface on the side of the intermediate member 1) of the second piezoelectric element 66, two electrodes (for each polarization direction) corresponding to the polarization direction (schematically indicated by thick lines in FIG. 4, and in FIG. 72a and 72b are schematically arranged.
Further, an electrode (schematically indicated by a thick line in FIG. 4) is provided on the entire lower surface (the surface on the side opposite to the intermediate member 1) of the second piezoelectric element 66.

The polarization direction of the third piezoelectric element 67 is perpendicular to the plane (that is, the axial direction) and is opposite by half of the plane (see "+" and "-" in the polarization direction column of FIG. 6). It is said that. On the upper surface (the surface on the side of the intermediate member 1) of the third piezoelectric element 67, two electrodes (for each polarization direction) corresponding to the polarization direction (schematically indicated by thick lines in FIG. 4, and in FIG. 73 a and 73 b are schematically arranged.
Further, an electrode (schematically indicated by a thick line in FIG. 4) is provided on the entire lower surface (the surface on the side opposite to the intermediate member 1) of the third piezoelectric element 67.

Then, the first vibration generating member 61 is assembled in the same manner as in the above embodiment. However, in the first vibration generating member 61, the second piezoelectric element 66 and the third piezoelectric element 6
The polarization boundary lines of 7 are arranged so as to be orthogonal to each other. In this example, the polarization boundary line of the second piezoelectric element 66 (the electrode 72a
And the boundary line with the electrode 72b) is the first support shaft 1b (α axis)
The state parallel to is the basic position.

The second vibration generating member 81 is made of the same component as the first vibration generating member 61. This second vibration generating member 81
With respect to the above, only the reference numerals are changed from those of the first vibration generating member 61, and the detailed description thereof is omitted. That is, the fastening member 82 of the second vibration generating member 81 is similar to the fastening member 62, and the first and second metal blocks 83 and 84 are the first and second metal blocks.
Like the metal blocks 63 and 64, the first to third piezoelectric elements 85 to 87 are formed similarly to the first to third piezoelectric elements 65 to 67, and the nut 88 is formed similarly to the nut 46. Further, the electrode 91 of the second vibration generating member 81 (see FIG. 5)
Is similar to the electrode 71, the electrodes 92a and 92b are similar to the electrodes 72a and 72b, and the electrodes 93a and 93b are similar to the electrodes 73a and 73b. In this example, the polarization boundary line of the third piezoelectric element 87 (the electrode 93a
And the boundary line with the electrode 93b) is the second support shaft 1c (β axis)
The state parallel to is the basic position.

Also in the multi-degree-of-freedom drive device configured as described above, as in the above-described embodiment, the second connecting portion 82 is used.
It is possible to rotate (tilt) a with respect to the first connecting portion 62a about a plurality of axes. In this case, the first to third piezoelectric elements 65 to 67, 85 to 87 (electrodes 71, 72a, 7
2b, 73a, 73b, 91, 92a, 92b, 93
a, 93b), the high frequency voltages A and B are supplied to the second connecting portion 82a to the first connecting portion 62a as shown in FIG.
It is possible to rotate (tilt) about a plurality of axes. Then, the same effect as that of the above-described embodiment can be obtained.

In the above embodiment, the first support shaft 1b extending from the spherical portion 1a is supported by the first case 2 with the ball bearing 11, but the first case 2 (first support member) is used.
A first support shaft is provided on the side and a spherical portion is formed on the first support shaft by a ball bearing (one in which the first support shaft 1b is not provided).
May be rotatably supported. Also, the second support shaft 1c extending from the spherical portion 1a was supported by the second case 3 by the ball bearing 12, but the second case 3 (second support member) was used.
A second support shaft is provided on the side and a spherical portion is formed on the second support shaft by a ball bearing (one in which the second support shaft 1c is not provided).
May be rotatably supported. Even in this case, the same effect as that of the above-described embodiment can be obtained. The ball bearings 11 and 12 may be changed to other general bearings. Even in this case, since the slide bearing having a special shape is not required, the cost of the multi-degree-of-freedom drive device can be reduced.

In the above embodiment, the first case 2 (second case 3) is replaced with the vibration generating side first case 6 (vibration generating side second case 8) and the spherical portion side first case 7 (spherical portion side). Second
Case 9) and. Then, the male screw 6a (8a) and the female screw 7b (9b) that they have, that is, they are fixed (integrated) by a screw mechanism, and the contact portion 21e (41e) is connected by the screwing angle (number of screwing) of the screw mechanism. Although the pressing force with respect to the spherical portion 1a is set, the pressing force may be set to another configuration. Even in this case, the same effects as the effects (1) to (3), (5), and (6) of the above-described embodiment can be obtained.

In the above-described embodiment, the first and second cases 2 and 3 are supposed to house the first and second vibration generating members 4 and 5, but if they are connected in the same manner, the first and second vibration generating members 4 and 5 will be especially used. Alternatively, the second vibration generating members 4 and 5 may not be housed in another configuration (other first and second support members). Even in this case, the same effects as the effects (1) to (4) and (6) of the above embodiment can be obtained.

In the above-described embodiment, the first and second connecting portions 21b and 41b as the input / output shafts are formed on the bolt portions 21a and 41a that constitute the bolted Langevin type vibrator, but the input / output of separate members is performed. The shaft (the connecting portion with the outside) may be fixed and provided. Even in this case, the same effects as the effects (1) to (5) of the above embodiment can be obtained.

The technical ideas that can be understood from the above-described embodiments and other examples will be described below along with their effects. (A) In the multi-degree-of-freedom drive device according to any one of claims 1 to 3, the first and second support members (2, 2)
3) The same component, and the first and second vibration generating members (4,5, 61, 81) are the same component. By doing so, the product numbers of the components that form the multi-degree-of-freedom drive device are reduced.

(B) In the multi-degree-of-freedom drive device according to any one of claims 1 to 3 and (a) above, the first and second support members (2, 3) include the first and second support members. First and second housings that substantially house the vibration generating members (4,5, 61, 81)
A multi-degree-of-freedom drive device characterized by being a case. This prevents dust and dirt from being applied to the first and second vibration generating members, and prevents dust and dirt from adhering to the contact portion.

(C) Claims 1 to 3 and the above (A),
In the multi-degree-of-freedom drive device according to any one of (b),
The first and second vibration generating members (4, 5, 61, 8) are in a state where the first and second orthogonal axes are on a straight line (γ).
1) by causing the spherical portion (1a) to rotate in the opposite direction when viewed from one side, the second vibration generating member (4, 61) with respect to the second vibration generating member (4, 61). 5, 81) is rotated about the first and second orthogonal axis lines. By doing this, by utilizing the vibrations of the first and second vibration generators,
The second vibration generating member can be rotated at high speed with respect to the first vibration generating member.

(D) Claims 1 to 3 and (a) to
In the multi-degree-of-freedom drive device according to any one of (c),
The first and second vibration generators (4,5, 61, 81)
Are piezoelectric elements (25, 45, 66, 6) having different polarization directions.
7, 86, 87) and a bolted Langevin type vibrator. By doing so, it is possible to generate vibration in a plurality of directions at the contact portion.

(E) In the multi-degree-of-freedom drive device described in (d) above, an end portion of the bolt (21a, 41a) constituting the bolted Langevin type vibrator opposite to the contact portion (21e, 41e). I / O axis (21b,
41b) is formed. By doing this, the bolt and the input / output shaft that make up the bolted Langevin type vibrator are integrated,
The number of parts can be reduced.

[0081]

As described in detail above, according to the present invention,
It is possible to provide a multi-degree-of-freedom drive device capable of reducing frictional resistance without requiring a special bearing.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a multi-degree-of-freedom drive device according to an embodiment.

FIG. 2 is an explanatory diagram for explaining an intermediate member and a piezoelectric element according to the present embodiment.

FIG. 3 is an explanatory diagram for explaining a control method according to the present embodiment.

FIG. 4 is a cross-sectional view of a main part of a multi-degree-of-freedom drive device according to another example.

FIG. 5 is an explanatory diagram illustrating another example of an intermediate member and a piezoelectric element.

FIG. 6 is an explanatory diagram illustrating a control method of another example.

[Explanation of symbols]

2 ... 1st case (1st support member), 3 ... 2nd case (2nd support member), 4, 61 ... 1st vibration generation member, 5, 81
... Second vibration generating member, 6, 8 ... First and second vibration generating sides
Case (vibration generation side support member), 7, 9 ... spherical portion side first
And second case (spherical part side support member), 11, 12 ... Ball bearing, 1a ... Spherical part, 1b ... First support shaft, 1
c ... 2nd support shaft, 6a, 8a ... Male screw, 7b, 9b ... Female screw, 21e, 41e ... Contact part.

Continued front page    F term (reference) 5H680 AA06 AA12 BB04 BB15 DD02                       DD14 DD24 DD65 EE03 FF04                       FF36 FF42 GG02

Claims (3)

[Claims] 1. A substantially spherical spherical portion (1a), and a first rotatably supported by the spherical portion (1a) about a first axis (α) passing through the center of the spherical portion (1a). A support member (2) and a spherical member (1a) rotatably supported on a second axis (β) center that passes through the center of the spherical member (1a) and is orthogonal to the first axis (α). The second support member (3) and the first support member (2) are rotatably supported by a first orthogonal axis line orthogonal to the first axis line (α) and are pressed into contact with the spherical portion (1a). Has a contact part (21e)
First that generates vibrations in multiple directions at its contact portion (21e)
The vibration generating member (4, 61) and the second supporting member (3) are rotatably supported about a second orthogonal axis line orthogonal to the second axis line (β) and pressed against the spherical portion (1a). Has a contact portion (41e) to be contacted,
The second that generates vibrations in a plurality of directions at its contact portion (41e)
A multi-degree-of-freedom drive device including a vibration generating member (5, 81). 2. The multi-degree-of-freedom drive device according to claim 1, wherein the spherical portion (1a) is provided with a first support shaft (1b) extending in the first axis (α) direction. 1b) is rotatably supported on the first support member (2) by a ball bearing (11), or a first support shaft extending in the first axial direction is provided on the first support member. Is rotatably supported on the spherical portion by a ball bearing, and the spherical portion (1a) is provided with a second support shaft (1c) extending in the second axis (β) direction. A ball bearing (12) rotatably supports the second support member (3), or a second support shaft extending in the second axis direction is provided on the second support member, and the second support shaft is a ball bearing. A self-supporting structure in which the spherical portion is rotatably supported by Yuri drive. 3. The multi-degree-of-freedom drive device according to claim 1, wherein the first and second support members (2, 3) are a spherical portion side support member (7, 9) and a vibration generating side, respectively. Support member (6
8) and the screw mechanisms (6a, 7b,
8a, 9b) which are integrated with each other and push the contact portion (21e, 41e) and the spherical portion (1a) at the screwing angle of the screw mechanism (6a, 7b, 8a, 9b). A multi-degree-of-freedom drive device capable of setting pressure.