Driving device and driving method

Abstract

To provide a technique that can prevent a malfunction of a driving device even when one vibration type actuator fails.SOLUTION: A driving device comprises: an output shaft 150; a first member 110 and a second member 120 configured to be rotatable relative to the output shaft 150; a third member 130 fastened to the output shaft 150; a first vibration type actuator 10-1 that drives to rotate the first member 110 around the output shaft 150; a second vibration type actuator 10-2 that drives to rotate the second member 120 around the output shaft 150; and rolling elements 140 that are rotatably held by the second member 120 and are in contact with and sandwiched by the first member 110 and the third member 130. At least one of the first vibration type actuator 10-1 and the second vibration type actuator 10-2 drives to rotate the third member 130 and the output shaft 150 in an integrated manner.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a drive device and a drive method. [Background technology]

[0002] A vibration actuator that can be included in a driving device has characteristics such as a large torque at low speed and a holding torque when not energized, and therefore has been put to practical use, for example, as an autofocus driving motor for the photographing lens of a single-lens reflex camera. In recent years, vibration actuators are also expected to be applied to various driving devices other than cameras. For example, vibration actuators are expected to be applied to driving the joints of robot arms, driving the rotation of robot hands, and performing remote operations in remote locations such as in space environments.

[0003] In recent years, the need for larger torque has increased due to the increase in size of driving devices, while the increased density of driving devices has led to a demand for more compact vibration actuators. For example, there is a technology for linking multiple vibration actuators to one output shaft, as in the output device (driving device) described in Patent Document 1, which achieves space saving while increasing torque. Specifically, in Patent Document 1, the rotation speed of the output shaft is controlled by fixing the drive voltage of multiple vibration actuators and changing the drive frequency to an appropriate value for each. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-205190 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the technology described in Patent Document 1, since multiple vibration actuators are connected to one output shaft, if one vibration actuator breaks down, it becomes a load on the other vibration actuators that are operating normally. This causes a problem that the driving efficiency of the drive device decreases, leading to operational malfunction (including failure) of the drive device. In particular, under conditions where the drive device is used in a remote location such as outer space, it is difficult to retrieve the drive device and repair it.

[0006] The present invention has been made in view of the above problems, and has an object to provide a technique that can suppress operational malfunctions of a drive device even when one vibration actuator breaks down. [Means for solving the problem]

[0007] The driving device of the present invention comprises an output shaft, a first member and a second member configured to be rotatable relative to the output shaft, a third member fixed to the output shaft, a first vibration type actuator that rotates the first member around the output shaft, a second vibration type actuator that rotates the second member around the output shaft, and a rolling element that is rotatably held on the second member and is sandwiched in contact with the first member and the third member, and the third member and the third member rotate together when at least one of the first vibration type actuator and the second vibration type actuator is driven. The present invention also includes a method for driving the above-mentioned drive device. Effect of the Invention

[0008] According to the present invention, even if one vibration actuator breaks down, malfunction of the drive device can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] 1 is an exploded perspective view showing an example of a schematic configuration of a vibration actuator according to a first embodiment. [Diagram 2] 1 is a cross-sectional view showing a first example of a schematic configuration of a drive device according to a first embodiment. [Diagram 3] 1 is an exploded perspective view showing a first example of a schematic configuration of a drive device according to a first embodiment. [Figure 4] 4 is a diagram showing a second example of a schematic configuration of the drive device according to the first embodiment. FIG. [Diagram 5] FIG. 11 is an exploded perspective view showing a third example of the schematic configuration of the drive device according to the first embodiment. [Figure 6] FIG. 11 is a cross-sectional view showing an example of a schematic configuration of a drive device according to a second embodiment. [Figure 7] FIG. 13 shows a third embodiment, and is a diagram showing an example of a schematic configuration of a camera head device including a plurality of driving devices described in the first and second embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] (First embodiment) First, the first embodiment will be described.

[0012] 1 is an exploded perspective view showing an example of a schematic configuration of a vibration actuator 10 according to a first embodiment. As shown in FIG. 1, the vibration actuator 10 includes a vibrating body 13, a felt 14, a pressing member 15, and a base 16.

[0013] The vibrating body 13 is configured to have, in addition to the elastic body 11 and piezoelectric body 12 shown in Fig. 1, a power supply member (flexible printed circuit board) (not shown) that supplies power to the piezoelectric body 12. In the example shown in Fig. 1, the elastic body 11 of the vibrating body 13 has a rectangular portion. In the rectangular portion of the elastic body 11, two protrusions 11a are formed on one surface (upper surface in Fig. 1), and the piezoelectric body 12 is fixed to the other surface (lower surface in Fig. 1) by adhesion or other means. The piezoelectric body 12 is an electro-mechanical energy conversion element, and a power supply member (not shown) that supplies power to the piezoelectric body 12 is fixed to the other surface (lower surface in Fig. 1) by adhesion or other means.

[0014] 1, a pressing member 15 is pressed by a spring (not shown) via felt 14 toward a contact body (moving body) (not shown) that contacts protrusions 11a of elastic body 11. In addition, elastic body 11 has fixing parts 11b at both ends in the longitudinal direction, and these fixing parts 11b are fixed to a base 16.

[0015] In the vibrating body 13, an AC driving voltage is applied as power from a power supply member (not shown) to the piezoelectric body 12 fixed to the elastic body 11, and two bending vibrations are excited to generate elliptical motion at the tip of the protrusion 11a. A contact body (moving body) (not shown) that comes into contact with the protrusion 11a of the vibrating body 13 moves relatively due to the elliptical motion generated at the tip of the protrusion 11a.

[0016] Fig. 2 is a cross-sectional view showing a first example of a schematic configuration of the drive device 100 according to the first embodiment. In the following description, the drive device 100 according to the first example of the first embodiment shown in Fig. 2 will be referred to as "drive device 100-11." In Fig. 2, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0017] 2, the driving device 100-11 includes a first vibration actuator 10-1 and a second vibration actuator 10-2, which are two vibration actuators 10 as the vibration actuator 10 shown in Fig. 1. The driving device 100-11 also includes a first member 110, a second member 120, a third member 130, a rolling element 140, an output shaft 150, bearings 161 and 162, a locking screw 163, springs 171 and 172, a housing 180, and a cover 190, as shown in Fig. 2.

[0018] In the driving device 100-11, the first member 110, the second member 120, and the third member 130 are each inserted into an output shaft 150. The first member 110 is configured to be rotatable relative to the output shaft 150 via a bearing 161. The second member 120 is configured to be rotatable relative to the output shaft 150 via a bearing 162. The third member 130 is fixed to the output shaft 150 via a locking screw 163.

[0019] Fig. 3 is an exploded perspective view showing a first example of the schematic configuration of the drive device 100 according to the first embodiment. In Fig. 3, the same components as those shown in Fig. 2 are given the same reference numerals, and detailed description thereof will be omitted. For simplification, the housing 180 and the cover 190 shown in Fig. 2 are not shown in the drive device 100-11 shown in Fig. 3.

[0020] As shown in FIG. 2, the first member 110 having a circular ring shape shown in FIG. 3 is in contact with the protrusion 11a of the first vibration actuator 10-1. That is, the first member 110 is a contact body (moving body) that is in contact with the protrusion 11a of the first vibration actuator 10-1. The first member 110 rotates around the output shaft 150 due to the elliptical motion generated in the protrusion 11a of the first vibration actuator 10-1. As shown in FIG. 2, a bearing 161 is disposed between the first member 110 and the output shaft 150, and the first member 110 is free to rotate with respect to the output shaft 150. As described above, the first vibration actuator 10-1 rotates the first member 110 around the output shaft 150.

[0021] As shown in FIG. 2, the second member 120 having a circular ring shape shown in FIG. 3 is in contact with the projection 11a of the second vibration actuator 10-2. That is, the second member 120 is a contact body (moving body) that contacts the projection 11a of the second vibration actuator 10-2. The second member 120 rotates around the output shaft 150 due to the elliptical motion generated in the projection 11a of the second vibration actuator 10-2. As shown in FIG. 2, a bearing 162 is disposed between the second member 120 and the output shaft 150, and the second member 120 is free to rotate with respect to the output shaft 150. As described above, the second vibration actuator 10-2 rotates the second member 120 around the output shaft 150.

[0022] The third member 130 is disposed coaxially with the first member 110 and is fixed to the output shaft 150 with a set screw 163 .

[0023] The rolling elements 140 are rotatably (rotatably) held in the plurality of holes 121 in the second member 120, and are sandwiched in contact with the first member 110 and the third member 130 as shown in FIG. 2. In this embodiment, the plurality of holes 121 in the second member 120 are arranged coaxially with the output shaft 150 as shown in FIG. 3. Specifically, a plurality of rolling elements 140, for example, metal balls, are arranged concentrically around the output shaft 150 between the first member 110 and the third member 130. The rolling elements 140 are sandwiched between the first member 110 and the third member 130 in a state in which pressure is applied in the axial direction (vertical direction in FIG. 1) by the first vibration actuator 10-1 and a spring 171 that pressurizes the first member 110.

[0024] 2 and 3, an example in which metal balls are used as the rolling elements 140 has been described, but this embodiment is not limited to these metal balls, and for example, cermet balls, ceramic balls, resin balls, etc. can also be used. The shape of the rolling elements 140 is not limited to the spherical shape shown in Figs. 2 and 3, and for example, a cylindrical shape or a columnar shape can also be applied to this embodiment. In this case, the same effect can be obtained by providing holes 121 corresponding to the shape of the rolling elements 140 in the second member 120 and fitting the rolling elements 140 into the holes 121.

[0025] The housing 180 and the cover 190 constitute the housing of the driving device 100-11. When the driving device 100-11 is viewed in the axial direction, the cover 190 is provided with a protrusion 191 at a projection location of the first vibration type actuator 10-1 and a protrusion 192 at a projection location of the second vibration type actuator 10-2. In the driving device 100-11, the pressure of the spring 171 is adjusted to an appropriate level by adjusting the distance between the protrusion 191 of the cover 190 and the first vibration type actuator 10-1. Similarly, in the driving device 100-11, the pressure of the spring 172 is adjusted to an appropriate level by adjusting the distance between the protrusion 192 of the cover 190 and the second vibration type actuator 10-2.

[0026] In the normal use state of the driving device 100-11, of the two vibration actuators 10-1 and 10-2, the second vibration actuator 10-2 is stopped and the other first vibration actuator 10-1 is driven. When the first vibration actuator 10-1 is driven, the first member 110 in contact with its protrusion 11a rotates around the output shaft 150 (hereinafter, the output shaft 150 will be referred to as "around the axis" as necessary). At this time, since the second vibration actuator 10-2 is stopped, the second member 120 is stopped by the holding force of the second vibration actuator 10-2. In this case, the rolling element 140 rotates on its own axis without changing its position around the axis because it is in contact with the rotationally driven first member 110 and is rotatably held in the hole 121 of the immovable second member 120. On the other hand, the third member 130 receives the force of the rolling body 140 rotating on its axis, and therefore rotates in the opposite direction to the first member 110. Also, since the third member 130 is fixed to the output shaft 150 by the set screw 163, the output shaft 150 rotates in the same direction as the third member 130. Here, if the rotation speed of the first member 110 is N1 [rpm] and the rotation speed of the third member 130 is N3 [rpm], then N1=-N3 (the rotation direction is reversed). The driving force of the first vibration actuator 10-1 is transmitted from the first member 110 to the third member 130 via the rolling body 140, and is transmitted with only a minimum loss such as the frictional force of sliding between the second member 120 and the rolling body 140. As a result, the driving device 100-11 (first vibration actuator 10-1) can be driven with high efficiency.

[0027] In this embodiment, when some trouble occurs in the first vibration actuator 10-1 and it becomes inoperable (when the first vibration actuator 10-1 breaks down), the second vibration actuator 10-2, which is an auxiliary mechanism, is driven. When the second vibration actuator 10-2 is driven, the second member 120 in contact with the protrusion 11a rotates around the output shaft 150, and the rolling element 140 fitted in the hole 121 of the second member 120 also revolves around the output shaft 150. At this time, the rolling element 140 is in contact with the first member 110, which is held by the first vibration actuator 10-1 and is immobile, and rotates on its axis while revolving. At the same time, the third member 130 rotates in the same direction as the second member 120 due to the rotating force of the rolling element 140, which is also in contact with the third member 130, and as a result, the third member 130 and the output shaft 150, which are fixed by the set screw 163, rotate in the same direction. The rolling element 140 revolves around the output shaft 150 in accordance with the rotation of the second member 120 around the output shaft 150, and at the same time rotates on its axis because it is in contact with the fixed first member 110. The third member 130 rotates at twice the rotation speed of the second member 120 due to the revolution and rotation of the rolling element 140. Here, if the rotation speed of the second member 120 is N2 [rpm] and the rotation speed of the third member 130 is N3 [rpm], then 2N2=N3 (the rotation direction is the same). In this way, the rotation speed of the third member 130 driven by the second vibration actuator 10-2 is doubled, and therefore the rotational force (torque) of the third member 130 is 0.5 times.

[0028] 2, in the driving device 100-11, the second vibration actuator 10-2 is disposed at a position farther away from the output shaft 150 than the first vibration actuator 10-1. That is, the second vibration actuator 10-2 is disposed in a radially outer direction than the first vibration actuator 10-1 with respect to the output shaft 150. Therefore, even if the driving forces of the first vibration actuator 10-1 and the second vibration actuator 10-2 are equivalent, the rotational force (torque) of the output shaft 150 by the second vibration actuator 10-2 can be set to be equivalent to that of the first vibration actuator 10-1.

[0029] The relationship between the first vibration type actuator 10-1 and the second vibration type actuator 10-2 may be reversed from the above-mentioned embodiment, and the second vibration type actuator 10-2 may operate normally, and the first vibration type actuator 10-1 may operate in an unexpected situation. In addition, the first vibration type actuator 10-1 and the second vibration type actuator 10-2 may be simultaneously driven to assist the output when the load is large, and this embodiment may also be applied to this embodiment. That is, in the driving device 100-11 according to the first embodiment, it is sufficient that the third member 130 and the output shaft 150 rotate together by driving at least one of the first vibration type actuator 10-1 and the second vibration type actuator 10-2. In this case, specifically, the third member 130 and the output shaft 150 rotate together via the rolling element 140 by driving at least one of the first vibration type actuator 10-1 and the second vibration type actuator 10-2.

[0030] Next, the rotation speed and torque when the first vibration actuator 10-1 and the second vibration actuator 10-2 are operated simultaneously will be described. The rotation speed and torque of the first member 110 driven by the first vibration actuator 10-1, the second member 120 driven by the second vibration actuator 10-2, and the third member 130 rotating integrally with the output shaft 150 are defined as follows: First member 110: rotation speed N1, torque T1 Second member 120: rotation speed N2, torque T2 Third member 130: rotation speed N3, torque T3

[0031] The unit of the rotation speed is rpm, and the unit of the torque is Nm. The rotation speeds N1, N2, and N3 and the torques T1, T2, and T3 are positive in the counterclockwise direction as viewed from the top of the paper of Figs. 1 to 3, that is, the θ direction in the rotation coordinate system. Specifically, the rotation speed of the first member 110 is N1, and the torque of the first member 110 is T1 when the first member 110 rotates counterclockwise with respect to the rotation axis of the output shaft 150 (shown by a dashed line in Fig. 2). Similarly, the rotation speed of the second member 120 is N2, and the torque of the second member 120 is T2 when the second member 120 rotates counterclockwise with respect to the rotation axis of the output shaft 150 (shown by a dashed line in Fig. 2). Similarly, the rotation speed of the third member 130 is defined as N3, and the torque of the third member 130 is defined as T3, with the counterclockwise rotation of the third member 130 being positive with respect to the rotation axis of the output shaft 150 (shown by a dashed line in FIG. 2) as the reference.

[0032] First, the rotation speed will be described. Here, it is assumed that no slippage occurs between the rolling body 140 and the first member 110 and the third member 130. At this time, the rolling body 140 revolves around the rotation axis of the output shaft 150 (indicated by a dashed line in FIG. 2) while being sandwiched between the first member 110 and the third member 130. Therefore, the number of revolutions of the rolling body 140 is the average of the number of revolutions N1 of the first member 110 and the number of revolutions N3 of the third member 130. In addition, the number of revolutions of the rolling body 140 is equal to the number of revolutions N2 of the second member 120 that holds the rolling body 140. In other words, the number of revolutions N2 of the second member 120 is the average of the number of revolutions N1 of the first member 110 and the number of revolutions N3 of the third member 130. The relationship is expressed by the following formula (1). N2 = (N1 + N3) / 2 (1)

[0033] From formula (1), the rotation speed N3 of the third member 130 is expressed by the following formula (2). N3 = 2 N2 - N1 (2)

[0034] From equation (2), it can be seen that the rotation direction of the third member 130 changes according to the relationship between the rotation speed N2 of the second member 120 and the rotation speed N1 of the first member 110. For example, assuming N1 > 0 and N2 > 0, when N2 > N1 / 2, N3 is positive, and the third member 130 and the output shaft 150 rotate counterclockwise when viewed from above. Also, assuming N1 > 0 and N2 > 0, when N2 = N1 / 2, N3 = 0 rpm, and the third member 130 and the output shaft 150 do not rotate. Further, assuming N1 > 0 and N2 > 0, when N2 < N1 / 2, N3 is negative, and the third member 130 and the output shaft 150 rotate clockwise when viewed from above.

[0035] Next, torque will be described. The kinetic energy (W) in the rotation of the first member 110, the second member 120, and the third member 130 is represented by the following equations (3) to (5), respectively, in relation to torque and rotational speed. Kinetic energy of the first member 110: W1 = 2π·T1·N1 / 60 ···(3) Kinetic energy of the second member 120: W2 = 2π·T2·N2 / 60 ···(4) Kinetic energy of the third member 130: W3 = 2π·T3·N3 / 60 ···(5)

[0036] Note that the kinetic energy W3 of the third member 130 is equal to the kinetic energy of the output shaft 150. When the energy losses due to rolling elements 140, bearings 161 and 162, etc. are extremely small and negligible, the kinetic energy W3 of the third member 130 is the sum of the kinetic energy W1 of the first member 110 and the kinetic energy W2 of the second member 120, resulting in the following equation (6). W3 = W1 + W2 ···(6)

[0037] Then, from equations (3) to (6) described above, the following equation (7) is obtained. T3·N3 = T1·N1 + T2·N2 ···(7)

[0038] From equations (2) and (7), the torque T3 of the third member 130 is given by the following equation (8). T3 (2 N2-N1) = T1 N1 + T2 N2 T3=(T1·N1+T2·N2) / (2·N2-N1) ···(8)

[0039] Next, a description will be given of a driving method for rotating the third member 130 (output shaft 150) at the rotation speed N3 in the same direction as the rotation speed N1 of the first member 110. In other words, since N3 / N1>0, the following formula (9) is obtained from the above formula (2). N3 / N1=2 N2 / N1-1>0 N2 / N1>0.5 (9) When this formula (9) is satisfied, the third member 130 (the output shaft 150) can be driven in the same direction as the first member 110.

[0040] Furthermore, when N2 / N1=0.5, that is, when N2=N1 / 2, the rotation speed N3 of the third member 130 (output shaft 150) becomes 0 rpm. Furthermore, when N2 / N1<0.5, the third member 130 (output shaft 150) can be rotated in the opposite direction to the first member 110.

[0041] Next, a description will be given of a driving method (including the same rotation speed) for increasing the rotation speed N3 of the third member 130 (output shaft 150) to be higher than the rotation speed N1 of the first member 110. That is, since N3 is equal to or higher than N1, the following formula (10) is obtained from the above formula (2). N3=2·N2-N1≧N1 N2 ≧ N1 (10) When formula (10) is satisfied, the rotation speed N3 of the third member 130 (output shaft 150) can be made higher than the rotation speed N1 of the first member 110.

[0042] Also, taking into consideration that the rotation speed N3 of the third member 130 (output shaft 150) becomes 0 rpm when N2 = N1 / 2, when N1 / 2 ≦ N2 ≦ N1, the rotation speed N3 of the third member 130 (output shaft 150) can be reduced to be lower than the rotation speed N1 of the first member 110.

[0043] Next, a description will be given of a driving method (including the same torque) for making the torque T3 of the third member 130 (output shaft 150) greater than the torque T1 of the first member 110. In other words, since T3≧T1, the following formula (11) is obtained from the above formula (8).

number

[0044] Next, another example of the schematic configuration of the drive device 100 according to the first embodiment will be described.

[0045] Fig. 4 is a diagram showing a second example of the schematic configuration of the drive device 100 according to the first embodiment. In the following description, the drive device 100 according to the second example of the first embodiment shown in Fig. 4 will be referred to as "drive device 100-12." In Fig. 4, the same components as those shown in Figs. 1 to 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0046] The driving device 100-11 shown in Figs. 2 and 3 is configured to include one each of the first vibration type actuator 10-1 and the second vibration type actuator 10-2. In contrast, the driving device 100-12 shown in Fig. 4 is configured to include a plurality of the first vibration type actuator 10-1 and the second vibration type actuator 10-2 according to the required rotational force (torque). In the example shown in Fig. 4, the first vibration type actuator 10-1 and the second vibration type actuator 10-2 are each configured to be multiple, but this is not limited to this in the present embodiment. In the present embodiment, a configuration in which at least one of the first vibration type actuator 10-1 and the second vibration type actuator 10-2 is provided multiple times can also be applied.

[0047] Fig. 5 is an exploded perspective view showing a third example of the schematic configuration of the drive device 100 according to the first embodiment. In the following description, the drive device 100 according to the third example of the first embodiment shown in Fig. 5 will be referred to as "drive device 100-13." In Fig. 5, the same components as those shown in Figs. 1 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0048] The driving device 100-11 shown in FIG. 2 and FIG. 3 includes the rolling element 140 having a spherical shape, but the driving device 100-13 shown in FIG. 5 includes the rolling element 141 having a gear shape instead of the rolling element 140 having a spherical shape. In the driving device 100-13 shown in FIG. 5, teeth 111 having a shape that matches the gear shape of the rolling element 141 are formed on the part of the first member 110 that contacts the gear shape of the rolling element 141. Similarly, in the driving device 100-13 shown in FIG. 5, teeth 131 having a shape that matches the gear shape of the rolling element 141 are formed on the part of the third member 130 that contacts the gear shape of the rolling element 141. The gear shape of the rolling element 141 shown in FIG. 5 meshes with the shape of the teeth 111 of the first member 110 and the shape of the teeth 131 of the third member 130, making it possible to transmit power without slippage.

[0049] The driving device 100 according to the first embodiment described above includes an output shaft 150, a first member 110 and a second member 120 configured to be rotatable with respect to the output shaft 150, and a third member 130 fixed to the output shaft 150. Furthermore, the driving device 100 according to the first embodiment includes a first vibration actuator 10-1 that rotates the first member 110 around the output shaft 150, and a second vibration actuator 10-2 that rotates the second member 120 around the output shaft 150. Furthermore, the driving device 100 according to the first embodiment includes a rolling element 140 that is rotatably held by the second member 120 and is sandwiched in contact with the first member 110 and the third member 130. In the driving device 100 according to the first embodiment, the third member 130 and the output shaft 150 rotate integrally when at least one of the first vibration type actuator 10-1 and the second vibration type actuator 10-2 is driven. According to this configuration, even if one vibration actuator 10 fails, a differential mechanism is incorporated so that the failure does not become a load on the other vibration actuators 10, so that malfunction of the drive device 100 can be suppressed.

[0050] Second Embodiment Next, a second embodiment will be described. In the following description of the second embodiment, matters common to the first embodiment will be omitted, and only matters different from the first embodiment will be described.

[0051] Fig. 6 is a cross-sectional view showing an example of a schematic configuration of a drive device 100 according to a second embodiment. In the following description, the drive device 100 according to the second embodiment shown in Fig. 6 will be referred to as "drive device 100-2." In Fig. 6, the same components as those shown in Figs. 1 to 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0052] The first vibration actuator 10-1 according to the first embodiment shown in Fig. 2 to Fig. 5 has a rectangular shape, but the first vibration actuator 20-1 according to the second embodiment shown in Fig. 6 has a ring shape. Specifically, the first vibration actuator 20-1 according to the second embodiment shown in Fig. 6 uses a ring-shaped vibrator as the vibrator 23. Moreover, the first vibration actuator 20-1 according to the second embodiment includes the vibrator 23 and a comb-tooth portion 24, as shown in Fig. 6.

[0053] The vibrating body 23 is configured to have a power supply member (flexible printed circuit board) (not shown) that supplies power to the piezoelectric body 22, in addition to the elastic body 21 and piezoelectric body 22 shown in Fig. 6. In the example shown in Fig. 6, the elastic body 21 of the vibrating body 23 has an annular shape. In the elastic body 21, a comb-tooth portion 24 having a plurality of grooves is formed on one surface (the lower surface in Fig. 1), and the piezoelectric body 22 is fixed to the other surface (the upper surface in Fig. 1) by adhesion or other means. The piezoelectric body 22 is an electro-mechanical energy conversion element, and a power supply member (not shown) that supplies power to the piezoelectric body 22 is fixed to the other surface (the upper surface in Fig. 1) by adhesion or other means.

[0054] In the driving device 100-2, a contact spring 201 is provided on the side of the first member 210 that comes into contact with the first vibration actuator 20-1. The contact spring 201 efficiently receives vibrations generated by the first vibration actuator 20-1, and enables the first member 210 and the like to rotate smoothly. In the driving device 100-2 shown in Fig. 6, the configurations of the second vibration actuator 10-2, the second member 120, the third member 130, the rolling element 140, the output shaft 150, the bearings 161 and 162, and the locking screw 163 are the same as those in the first embodiment described above.

[0055] (Third embodiment) Next, a third embodiment will be described. In the following description of the third embodiment, the description of the matters common to the first and second embodiments will be omitted, and only the matters different from the first and second embodiments will be described.

[0056] In the third embodiment, an example will be described in which a pan head device (a rotating device having a rotating base and a plurality of driving units 100 provided on the rotating base) is applied to an imaging device such as a surveillance camera as an apparatus equipped with the driving unit 100 described in the first and second embodiments.

[0057] 7 shows a third embodiment, and is a diagram showing an example of a schematic configuration of a pan head device 300 including a plurality of driving devices 100 described in the first and second embodiments. The pan head device 300 shown in Fig. 7(a) and the pan head device 300 shown in Fig. 7(b) are views of the pan head device 300 according to the third embodiment, viewed from different directions. For example, Fig. 7(a) is a view of the pan head device 300 viewed from the front, and Fig. 7(b) is a view of the pan head device 300 viewed from the side.

[0058] As shown in FIGS. 7(a) and 7(b), the pan head device 300 includes two driving devices 100-P and 100-T, a head unit 310, a base unit 320, an L-angle unit 330, and an imaging device 340.

[0059] 7(a), the head unit 310 includes two drive devices 100, a drive device 100-P for panning and a drive device 100-T for tilting. The base unit 320 is a component that supports the head unit 310. The L-angle unit 330 is attached to the head unit 310 and is a component for fixing the imaging device 340.

[0060] The panning driver 100-P can be either the driver 100-1 according to the first embodiment or the driver 100-2 according to the second embodiment. The panning driver 100-P has an output shaft 150 connected to a base unit 320, and is a driver for rotating the head unit 310, the L-angle unit 330, and the imaging device 340 around a pan axis relative to the base unit 320.

[0061] As the tilt driving device 100-T, either the driving device 100-1 according to the first embodiment or the driving device 100-2 according to the second embodiment can be applied. The tilt driving device 100-T is a driving device in which the output shaft 150 is connected to the L angle unit 330, and for rotating the L angle unit 330 and the imaging device 340 around the tilt axis relative to the head unit 310.

[0062] 7 includes two driving devices 100-P and 100-T, and thus is capable of changing the orientation of the imaging device 340 at high speed, with high response, quietness, and high accuracy. Furthermore, since the vibration actuator 10 included in the driving device 100 has a high holding torque even when not energized, the orientation of the imaging device 340 can be maintained without consuming power from the vibration actuator 10, even if there is a deviation in the center of gravity around the tilt axis of the imaging device 340. In addition, it is also possible to provide an electronic device that includes a member desired by a user and the driving device 100 provided on that member.

[0063] It should be noted that the above-mentioned embodiments of the present invention are merely illustrative examples of the implementation of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features.

[0064] Disclosure of embodiments of the present invention includes the following configurations and methods. [Configuration 1] An output shaft; A first member and a second member configured to be rotatable relative to the output shaft; A third member fixed to the output shaft; a first vibration actuator that rotates the first member around the output shaft; a second vibration actuator that rotates the second member around the output shaft; a rolling element rotatably held by the second member and sandwiched between the first member and the third member; Equipped with When at least one of the first vibration type actuator and the second vibration type actuator is driven, the third member and the output shaft rotate integrally. A drive device characterized by: [Configuration 2] The third member and the output shaft rotate integrally via the rolling elements when the at least one of them is driven. 2. The driving device according to claim 1, [Configuration 3] The first member, the second member, and the third member are each inserted through the output shaft. 3. The drive device according to configuration 1 or 2. [Configuration 4] The second vibration type actuator is disposed at a position farther from the output shaft than the first vibration type actuator. 4. The drive device according to any one of configurations 1 to 3. [Configuration 5] When one of the first vibration type actuator and the second vibration type actuator is driven while the other is stopped, the third member and the output shaft rotate integrally. 5. The drive device according to any one of configurations 1 to 4. [Configuration 6] When both of the first vibration type actuator and the second vibration type actuator are driven, the third member and the output shaft rotate integrally. 5. The drive device according to any one of configurations 1 to 4. [Configuration 7] A rotation speed of the first member is defined as N1 when the first member rotates counterclockwise with respect to the axial direction of the output shaft as a positive rotation speed, When the second member rotates counterclockwise with respect to the axial direction of the output shaft as a reference, the number of rotations of the second member is defined as N2. N2 / N1>0.5 is satisfied 7. The drive device according to any one of configurations 1 to 6. [Configuration 8] In the above N1 and N2, N2≧N1 is satisfied. 8. The drive device according to claim 7, [Configuration 9] The torque of the first member is defined as T1, and the torque of the first member is defined as T2 when the first member rotates counterclockwise with respect to the axial direction of the output shaft as a positive torque. When the torque of the second member is T2, the torque is positive when the second member rotates counterclockwise with respect to the axial direction of the output shaft, (T1 N1 + T2 N2) / (2 N2-N1) ≥ T1 9. The drive device according to configuration 7 or 8. [Configuration 10] At least one of the first vibration type actuator and the second vibration type actuator is rectangular or annular. 10. The drive device according to any one of configurations 1 to 9. [Configuration 11] At least one of the first vibration type actuator and the second vibration type actuator is provided in plurality. 11. The drive device according to any one of configurations 1 to 10. [Configuration 12] The rolling elements are spherical, cylindrical or columnar. 12. The drive device according to any one of configurations 1 to 11. [Configuration 13] The rolling element includes a gear, The first member and the third member have teeth formed at their locations in contact with the gear. 12. The drive device according to any one of configurations 1 to 11. [Method 1] An output shaft; A first member and a second member configured to be rotatable relative to the output shaft; A third member fixed to the output shaft; a first vibration actuator that rotates the first member around the output shaft; a second vibration actuator that rotates the second member around the output shaft; a rolling element rotatably held by the second member and sandwiched between the first member and the third member; A method for driving a drive device comprising: When at least one of the first vibration type actuator and the second vibration type actuator is driven, the third member and the output shaft rotate integrally. A driving method comprising: [Explanation of symbols]

[0065] 10, 20: vibration type actuator, 11, 21: elastic body, 11a: protrusion, 11b: fixed part, 12, 22: piezoelectric body, 13, 23: vibrating body, 14: felt, 15: pressing member, 16: base, 24: comb tooth part, 100: driving device, 110, 210: first member, 111: teeth, 120: second member, 121: hole, 130: third member, 131: teeth, 140, 141: rolling body, 150: output shaft, 161, 162: bearing, 163: locking screw, 171, 172: spring, 180: housing, 190: cover, 191, 192: protrusion, 201: contact spring, 300: pan head device, 310: head part, 320: base part, 330: L angle part, 340: imaging device

Claims

1. An output shaft; A first member and a second member configured to be rotatable about the output shaft; A third member fixed to the output shaft; a first vibration actuator that rotates the first member around the output shaft; a second vibration actuator that rotates the second member around the output shaft; a rolling element rotatably held by the second member and sandwiched between the first member and the third member; Equipped with When at least one of the first vibration type actuator and the second vibration type actuator is driven, the third member and the output shaft rotate integrally. A drive device characterized by:

2. The third member and the output shaft rotate integrally via the rolling elements when the at least one of them is driven.

2. The drive device according to claim 1 .

3. The first member, the second member, and the third member are each inserted through the output shaft.

2. The drive device according to claim 1 .

4. The second vibration type actuator is disposed at a position farther from the output shaft than the first vibration type actuator.

2. The drive device according to claim 1 .

5. When one of the first vibration type actuator and the second vibration type actuator is driven while the other is stopped, the third member and the output shaft rotate integrally.

2. The drive device according to claim 1 .

6. When both of the first vibration type actuator and the second vibration type actuator are driven, the third member and the output shaft rotate integrally.

2. The drive device according to claim 1 .

7. A rotation speed of the first member is defined as N1 when the first member rotates counterclockwise with respect to the axial direction of the output shaft as a positive rotation speed, When the rotation speed of the second member is defined as N2, the rotation speed of the second member is defined as N2 when the rotation speed of the second member is positive with respect to the axial direction of the output shaft as a reference. N2 / N1>0.5 is satisfied 2. The drive device according to claim 1 .

8. In the N1 and the N2, N2≧N1 is satisfied.

8. The drive device according to claim 7.

9. The torque of the first member is defined as T1, and the torque of the first member is defined as T2 when the first member rotates counterclockwise with respect to the axial direction of the output shaft as a positive torque. When the torque of the second member is T2, the torque is positive when the second member rotates counterclockwise with respect to the axial direction of the output shaft, (T1·N1+T2·N2) / (2·N2-N1)≧T1 8. The drive device according to claim 7.

10. At least one of the first vibration type actuator and the second vibration type actuator is rectangular or annular.

2. The drive device according to claim 1 .

11. At least one of the first vibration type actuator and the second vibration type actuator is provided in plurality.

2. The drive device according to claim 1 .

12. The rolling elements are spherical, cylindrical or columnar.

2. The drive device according to claim 1 .

13. The rolling element includes a gear, The first member and the third member have teeth formed at their locations in contact with the gear.

2. The drive device according to claim 1 .

14. An output shaft; A first member and a second member configured to be rotatable about the output shaft; A third member fixed to the output shaft; a first vibration actuator that rotates the first member around the output shaft; a second vibration actuator that rotates the second member around the output shaft; a rolling element rotatably held by the second member and sandwiched between the first member and the third member; A method for driving a drive device comprising: When at least one of the first vibration type actuator and the second vibration type actuator is driven, the third member and the output shaft rotate integrally. A driving method comprising:

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