JP7408431B2 - electromechanical converter - Google Patents

Description

The present invention relates to electromechanical transducers.

Conventionally, there are power generation mechanisms and drive mechanisms that use electrostatic force. Patent Document 1 describes a first substrate, a second substrate disposed parallel to the first substrate so as to be movable relative to the first substrate, a first charged film disposed on one of the first substrate and the second substrate, An electrostatic induction generator is disclosed that includes a first counter electrode that is disposed on the other of the first substrate or the second substrate and is disposed to face the first charged film.

Japanese Patent Application Publication No. 2015-186424

In an electromechanical converter that generates power or drives using electrostatic force, if the position of the rotor in the axial direction changes, the power generation efficiency and drive efficiency will fluctuate. It is desirable to be able to suppress efficiency fluctuations in electromechanical converters.

An object of the present invention is to provide an electromechanical converter that can suppress fluctuations in efficiency.

The electromechanical converter of the present invention includes a rotating member having a plate-shaped rotor, a first rotating shaft engaged with the rotor, and a first stator facing a first surface of the rotor. a second stator facing the second surface of the rotor; a first charged film disposed on one of the first surface and the first stator; and the first surface and the first stator. a first converting section having an electrode disposed on the other of the second surface and the second stator; a second charged film disposed on one of the second surface and the second stator; an electrode disposed on the other side, and the first converter and the second converter have an electrostatic force in the first converter and an electrostatic force in the second converter. The rotor is configured to apply a force toward one side in the axial direction to the rotor by the sum of the above.

The electromechanical converter according to the present invention is configured to apply a force toward one side in the axial direction to the rotor by the sum of the electrostatic force in the first conversion section and the electrostatic force in the second conversion section. has been done. According to the electromechanical converter according to the present invention, it is possible to suppress fluctuations in efficiency due to changes in the position of the rotor.

FIG. 1 is a front view of a timepiece according to a first embodiment. FIG. 2 is a sectional view of the timepiece according to the first embodiment. FIG. 3 is a cross-sectional view of the electromechanical converter according to the first embodiment. FIG. 4 is a schematic configuration diagram of the first conversion section according to the first embodiment. FIG. 5 is a schematic configuration diagram of the second conversion section according to the first embodiment. FIG. 6 is a cross-sectional view showing the force acting on the rotating member of the first embodiment. FIG. 7 is a diagram showing an example of the manufacturing process of the rotating member. FIG. 8 is a cross-sectional view showing the charging process for a rotor with burrs formed thereon. FIG. 9 is a schematic configuration diagram showing an example of the second conversion section. FIG. 10 is a cross-sectional view showing an example of the second conversion section. FIG. 11 is a diagram showing the relationship between the rotor position and the power generation output. FIG. 12 is a diagram showing the relationship between the natural period and the amount of relative rotation. FIG. 13 is a cross-sectional view showing the resultant force of electrostatic forces directed toward the first stator. FIG. 14 is a cross-sectional view showing the resultant force of electrostatic force and the force due to self-weight. FIG. 15 is a front view of a timepiece according to the second embodiment. FIG. 16 is a sectional view of a timepiece according to the second embodiment. FIG. 17 is a cross-sectional view of the electromechanical converter according to the second embodiment. FIG. 18 is a diagram showing a schematic configuration of an electromechanical converter according to the second embodiment. FIG. 19 is a cross-sectional view of the first converting section and the second converting section according to the second embodiment. FIG. 20 is a diagram showing a method for driving an electromechanical converter according to the second embodiment.

EMBODIMENT OF THE INVENTION Below, the electromechanical converter based on embodiment of this invention is demonstrated in detail, referring drawings. Note that the present invention is not limited to this embodiment. Furthermore, the components in the embodiments described below include those that can be easily imagined by those skilled in the art or those that are substantially the same.

[First embodiment]
A first embodiment will be described with reference to FIGS. 1 to 14. This embodiment relates to an electromechanical converter. 1 is a front view of a timepiece according to the first embodiment, FIG. 2 is a cross-sectional view of the timepiece according to the first embodiment, FIG. 3 is a cross-sectional view of the electromechanical converter according to the first embodiment, and FIG. is a schematic configuration diagram of the first conversion unit according to the first embodiment, FIG. 5 is a schematic configuration diagram of the second conversion unit according to the first embodiment, and FIG. 6 is a diagram that acts on the rotating member of the first embodiment. 7 is a cross-sectional view showing an example of the manufacturing process of a rotating member; FIG. 8 is a cross-sectional view showing a charging process for a rotor with burrs formed thereon; FIG. 9 is an example of a second converting section FIG. 10 is a cross-sectional view showing an example of the second conversion section.

FIG. 11 is a diagram showing the relationship between the rotor position and the power generation output, FIG. 12 is a diagram showing the relationship between the natural period and the relative rotation amount, and FIG. 13 is a diagram showing the resultant force of the electrostatic force directed toward the first stator. The cross-sectional view shown in FIG. 14 is a cross-sectional view showing the resultant force of electrostatic force and the force due to its own weight. FIG. 2 shows a cross section taken along line II--II in FIG. 3, FIG. 6, FIG. 10, FIG. 13, and FIG. 14 show the III-III cross section of FIG. 1.

As shown in FIG. 1, a timepiece 1 according to the first embodiment is a timepiece having hands 4, and is, for example, an analog electronic timepiece. As shown in FIGS. 1 to 3, the timepiece 1 includes an exterior case 2, a dial 3, hands 4, a main plate 7, a receiving plate 9, and an electromechanical converter 30. The electromechanical converter 30 is a converter for a watch, typically a watch. The electromechanical converter 30 includes a rotating member 5 , a first stator 11 , a second stator 12 , a first converter 6 , and a second converter 8 . The hands 4 include a second hand 4a, a minute hand 4b, and an hour hand 4c. The base plate 7 has a window 73 that allows the rotor 51 of the rotating member 5 to be viewed.

As shown in FIG. 2, the exterior case 2 includes a case body 21 and a back cover 22. The case body 21 has a substantially cylindrical shape. In the following description, the axial direction of the case body 21 will be simply referred to as "axial direction Z." The internal space of the case body 21 is open toward the front side and the back side in the axial direction Z, respectively. The back cover 22 closes the opening on the back side of the case body 21. The transparent windshield 20 closes the opening on the front side of the case body 21.

Inside the exterior case 2, a base plate 7 and a receiving plate 9 are arranged. The main plate 7 functions as a base for incorporating various parts, a support plate, an interior casing, and the like. Further, the receiving plate 9 has the function of supporting the shaft of the rotating body and fixing and holding parts. The base plate 7 and the receiving plate 9 are fixed to the case body 21. The receiving plate 9 is located on the back side of the base plate 7. The dial 3 is arranged on the front side of the main plate 7 and covers the main plate 7. As shown in FIG. 3, the dial 3 has a window 31 corresponding to the window 73 of the main plate 7.

As shown in FIG. 2, the timepiece 1 includes a storage battery 27, a motor 28, and a speed reduction mechanism 29. The storage battery 27 is a secondary battery that can be charged and discharged. The storage battery 27 is fixed to the base plate 7. The motor 28 converts the electric power supplied from the storage battery 27 into kinetic energy of rotational motion. The speed reduction mechanism 29 is interposed between the output shaft of the motor 28 and the pointer 4. The speed reduction mechanism 29 includes, for example, a speed reduction wheel train. The motor 28 moves the pointer 4 via a deceleration mechanism 29.

The watch 1 of this embodiment includes an electromechanical converter 30 that converts electrical energy and mechanical energy. As shown in FIG. 3, the electromechanical converter 30 includes a rotating member 5, a first stator 11, a second stator 12, a first converter 6, and a second converter 8. The electromechanical converter 30 generates power using the relative rotation of the rotor 51 with respect to the first stator 11 and the second stator 12. The electromechanical converter 30 converts kinetic energy of a rotary weight 26, which will be described later, into electrical energy and charges a storage battery 27.

The rotating member 5 is rotatably supported by the base plate 7 and the receiving plate 9. The rotating member 5 has a rotor 51, a first rotating shaft 52, and a gear 53. The rotor 51 is a member formed of a substrate material such as a silicon substrate, a glass epoxy substrate provided with a charging electrode surface, or an aluminum plate. The shape of the rotor 51 is, for example, a disk shape. The rotor 51 is engaged with the first rotation shaft 52 and rotates together with the first rotation shaft 52. The first rotating shaft 52 passes through the center of the rotor 51 in the thickness direction.

The base plate 7 holds a receiving stone 71 and a hole stone 72 that support one end of the first rotating shaft 52. The hole stone 72 has a hole through which the first rotating shaft 52 is inserted, and positions the first rotating shaft 52 in a direction perpendicular to the axial direction Z. The jewel 71 faces the tip of the first rotating shaft 52 in the axial direction Z, and rotatably supports the first rotating shaft 52. The receiving stone 71 is arranged on the front side in the axial direction Z with respect to the first rotating shaft 52.

The receiving plate 9 holds a receiving stone 91 and a hole stone 92 that support the other end of the first rotating shaft 52. The hole stone 92 has a hole through which the first rotating shaft 52 is inserted, and positions the first rotating shaft 52 in a direction perpendicular to the axial direction Z. The receiving stone 91 faces the tip of the first rotating shaft 52 in the axial direction Z, and rotatably supports the first rotating shaft 52. The receiving stone 91 is arranged on the back side of the first rotating shaft 52 in the axial direction Z.

The gear 53 is a member that is engaged with the first rotating shaft 52 and rotates integrally with the first rotating shaft 52. The gear 53 is located on the back side of the rotor 51 in the axial direction Z. As shown in FIG. 2, the gear 53 meshes with the gear 25 of the second rotating shaft 23. The second rotating shaft 23 is a different axis from the first rotating shaft 52. The illustrated second rotation axis 23 is a rotation axis that is arranged on a different axis from the first rotation axis 52 and is parallel to the first rotation axis 52. The second rotating shaft 23 is rotatably supported by a bearing 93 arranged on the receiving plate 9.

The rotating weight 26 is engaged with the second rotating shaft 23 and rotates together with the second rotating shaft 23 . The rotating weight 26 of this embodiment is a substantially fan-shaped member, and is arranged on the back side of the receiving plate 9 in the axial direction Z. An end portion 26a of the rotating weight 26 is connected to the second rotating shaft 23. The rotary weight 26 is a weight that rotates by capturing the movement of the user's arm. When the rotary weight 26 rotates, its rotational motion is transmitted from the gear 25 to the gear 53. Due to the rotational torque transmitted from the gear 25 to the gear 53, the rotor 51 rotates relative to the first stator 11 and the second stator 12. Note that the gear 25 and the gear 53 mesh with each other so as to transmit rotational torque and not substantially transmit force in the axial direction Z. The gear 25 and the gear 53 are, for example, spur gears.

As shown in FIG. 3, the first conversion section 6 includes an electrode 61 and a first charged film 64. The first charged film 64 is formed on the first surface 51a of the rotor 51. The illustrated first surface 51a is the front surface of the rotor 51 in the axial direction Z. The electrode 61 is arranged on the back surface 11b of the first stator 11. The back surface 11b faces the first surface 51a in the axial direction Z.

As shown in FIG. 4, a plurality of first charged films 64 are formed on the first surface 51a of the rotor 51. As shown in FIG. The plurality of first charged films 64 are arranged at equal intervals along the circumferential direction centered on the first rotating shaft 52. The first charged film 64 is a thin film made of an electret material. The first charged film 64 of this embodiment is charged to a negative potential. The shape of the first charged film 64 is fan-shaped. In other words, the width of the first charged film 64 increases toward the outside in the radial direction. A through hole 51c is formed in the rotor 51 between adjacent first charged films 64.

As shown in FIG. 4, a plurality of electrodes 61 are formed on the back surface 11b of the first stator 11. The first stator 11 of this embodiment is a transparent substrate. The first stator 11 is made of, for example, a transparent resin such as polyethylene terephthalate (PET). The color of the substrate 10 may be colorless. The first stator 11 is arranged on the back side of the base plate 7 and is fixed to the back face 7b of the base plate 7. The first stator 11 of this embodiment has a disk shape as shown in FIG. 4 . The first stator 11 is provided with a through hole 11c through which the first rotating shaft 52 of the rotating member 5 is inserted.

The electrode 61 is, for example, a film formed using ITO (Indium Tin Oxide). Electrode 61 is transparent and substantially colorless. That is, the first stator 11 and the electrode 61 of this embodiment are a transparent substrate and an electrode, respectively. The electrode 61 has a first electrode 61a and a second electrode 61b. On the back surface 11b of the first stator 11, first electrodes 61a and second electrodes 61b are alternately arranged along the circumferential direction. The shapes of the first electrode 61a and the second electrode 61b are fan-shaped. The first electrode 61a and the second electrode 61b are connected to the storage battery 27 via a rectifier circuit 63.

As shown in FIG. 3, the second conversion section 8 includes an electrode 81 and a second charged film 84. The second charged film 84 is formed on the second surface 51b of the rotor 51. The illustrated second surface 51b is the back surface of the rotor 51 in the axial direction Z. The electrode 81 is arranged on the front surface 12a of the second stator 12. The front surface 12a faces the second surface 51b of the rotor 51 in the axial direction Z.

As shown in FIG. 5, a plurality of second charged films 84 are formed on the second surface 51b of the rotor 51. The plurality of second charged films 84 are arranged at equal intervals along the circumferential direction. The second charged film 84 is a thin film made of an electret material. The second charged film 84 of this embodiment is charged to a negative potential. The shape of the second charged film 84 is fan-shaped. A through hole 51c is located between adjacent second charged films 84. The shape, area, and number of the second charged film 84 may be the same as the shape, area, and number of the first charged film 64.

As shown in FIG. 5, a plurality of electrodes 81 are formed on the front surface 12a of the second stator 12. The second stator 12 of this embodiment is a colored substrate made of glass epoxy resin or the like. The second stator 12 may be opaque. The second stator 12 is fixed to the case body 21, for example. The shape of the second stator 12 of this embodiment is a disk shape, as shown in FIG. The second stator 12 is provided with a through hole 12c through which the first rotating shaft 52 of the rotating member 5 is inserted.

The electrode 81 is, for example, a colored electrode made of a conductive metal such as copper or gold. The electrode 81 has a third electrode 81a and a fourth electrode 81b. On the front surface 12a of the second stator 12, third electrodes 81a and fourth electrodes 81b are alternately arranged along the circumferential direction. The shapes of the third electrode 81a and the fourth electrode 81b are fan-shaped. The third electrode 81a and the fourth electrode 81b are connected to the storage battery 27 via a rectifier circuit 83. The shape, area, and number of electrodes 81 may be the same as the shape, area, and number of electrodes 61.

The electromechanical converter 30 of this embodiment is configured to suppress fluctuations in power generation efficiency in the electromechanical converter 30, as described with reference to FIG. 6. FIG. 6 shows the force acting on the rotating member 5 of this embodiment. The attractive force F1 is a force that acts on the rotor 51 due to the electrostatic force of the first converter 6. The attraction force F1 is a force that pulls the rotor 51 toward the electrode 61 of the first stator 11. Note that the attractive force F1 is the sum of electrostatic forces acting between the electrode 61 of the first stator 11 and the first charged film 64.

The attractive force F2 is a force that acts on the rotor 51 due to the electrostatic force of the second converter 8. The attraction force F2 is a force that pulls the rotor 51 toward the electrode 81 of the second stator 12. Note that the attractive force F2 is the sum of electrostatic forces acting between the electrode 81 of the second stator 12 and the second charged film 84.

The resultant force Fe of the attractive forces F1 and F2 is an axial force that acts on the rotor 51 due to the sum of the electrostatic force in the first converter 6 and the electrostatic force in the second converter 8. In the following description, the resultant force Fe of the attraction forces F1 and F2 will be simply referred to as "resultant force Fe of electrostatic forces." As shown in FIG. 6, the electromechanical transducer 30 of this embodiment is configured such that the magnitude of the attraction force F2 is greater than the magnitude of the attraction force F1. That is, the electromechanical converter 30 is configured to apply a resultant force Fe of electrostatic force toward the back side of the rotor 51 in the axial direction Z.

The rotating member 5 is attracted toward the back side in the axial direction Z by the resultant force Fe of the electrostatic force. This makes it easier to stabilize the position of the rotor 51 in the axial direction Z. As a comparative example, consider an electromechanical transducer designed to equalize the magnitude of attraction force F1 and attraction force F2. In the electromechanical transducer of the comparative example, the position of the rotor 51 in the axial direction Z is likely to change due to a change in the posture of the watch 1, an impact on the watch 1, or the like. When the position of the rotor 51 changes, the amount of the gap between the first charged film 64 and the electrode 61 and the amount of the gap between the second charged film 84 and the electrode 81 change. These changes in the gap amount lead to a decrease in power generation efficiency in the electromechanical converter of the comparative example.

In contrast, in the electromechanical transducer 30 of the present embodiment, changes in the gap amount between the first charged film 64 and the electrode 61 and the gap amount between the second charged film 84 and the electrode 81 are suppressed. be done. Therefore, according to the electromechanical converter 30 of this embodiment, fluctuations in power generation efficiency in the first converter 6 and the second converter 8 are suppressed.

As a configuration in which the resultant force Fe of electrostatic forces directed toward the second stator 12 is applied to the rotor 51, for example, even if the charging voltage of the second charged film 84 is made larger than the charging voltage of the first charged film 64, good. With such a configuration, it is possible to make the magnitude of the suction force F2 larger than the magnitude of the suction force F1.

As a method for making the charging voltage of the second charged film 84 higher than the charging voltage of the first charged film 64, the rotating member 5 may be manufactured as follows, for example. FIG. 7 shows an example of a process for manufacturing a rotating member. As shown in FIG. 7A, films 65 and 85 of electret material are formed on the first surface 51a and second surface 51b of the rotor 51, respectively. The rotor 51 is made of a material that is electrically conductive and has sufficient rigidity against the generated electrostatic force, such as a metal such as aluminum.

The method of forming the electret material films 65, 85 is selected depending on the material. The films 65 and 85 are formed, for example, over the entire first surface 51a and second surface 51b. If the electret material is a liquid and a so-called wet process can be used, the film forming method may be an appropriate coating method such as dip coating, spin coating, curtain flow coating, spray coating, or gravure coating. As other methods, the films 65 and 85 may be formed by PVD such as sputtering or ion plating, or vapor deposition such as CVD. The membranes 65 and 85 may be formed by attaching a film of electret material to the rotor 51.

Thereafter, as shown in FIGS. 7(b) and 7(c), the rotor 51 and the membranes 65, 85 are stamped into desired shapes by punching using a press. A through hole 51c and a shaft hole 51d are formed in the rotor 51 by punching. As shown in FIG. 7(d), the first rotation shaft 52 is inserted into the shaft hole 51d and engaged with the rotor 51.

Next, as shown in FIG. 7(e), the films 65 and 85 are charged. As the charging treatment, for example, corona discharge treatment is used. In the charging process, the rotor 51 is grounded. The rotor 51 and the first rotating shaft 52 are arranged between the pair of corona discharge electrodes 100. Due to the corona discharge, charges are applied from the corona discharge electrode 100 to the films 65 and 85. The films 65 and 85 become the first charged film 64 and the second charged film 84 by being charged.

Here, as shown in FIG. 8, the rotor 51 is formed with a burr 51e that protrudes in the punching direction. In the punching process illustrated in FIG. 7, a burr 51e is formed on the first surface 51a side. When the rotor 51 having the burr 51e is grounded and subjected to charging processing, as shown in FIG. It flows to the rotor 51. Therefore, the amount of charge applied to the first charged film 64 near the burr 51e is reduced. As a result, the charging voltage of the first charged film 64 can be made lower than the charging voltage of the second charged film 84. Note that the broken line arrows in FIG. 8 indicate lines of electric force and the movement of charges released along the lines of electric force.

As a means for making the charging voltage of the first charged film 64 and the charging voltage of the second charged film 84 different, the voltage applied to the corona discharge may be made different. For example, the voltage applied to the second charged film 84 may be higher than the voltage applied to the first charged film 64. In the charging process, the charging voltage of the first charged film 64 and the charging voltage of the second charged film 84 may be made different by bringing the rotor 51 closer to one of the pair of corona discharge electrodes 100. For example, in FIG. 7E, the charging process may be performed with the rotor 51 brought close to the lower corona discharge electrode 100.

As a means to make the charging voltage of the first charged film 64 and the second charged film 84 different, for example, one of the first charged film 64 and the second charged film 84 is coated with a fluororesin or the like, and the other is coated with a fluororesin or the like. No coating may be applied. For example, by applying a coating to the second charged film 84, it is possible to make the charging voltage of the second charged film 84 higher than the charging voltage of the first charged film 64.

As a configuration in which the resultant force Fe of electrostatic forces directed toward the second stator 12 acts on the rotor 51, the thickness of the second charged film 84 may be made larger than the thickness of the first charged film 64, for example. With such a configuration, it is possible to make the magnitude of the suction force F2 larger than the magnitude of the suction force F1.

As a configuration in which the resultant force Fe of electrostatic force directed toward the second stator 12 acts on the rotor 51, for example, the area of the electrodes arranged on the second stator 12 is larger than that of the electrodes arranged on the first stator 11. may be larger than the area of As an example, the area of one electrode 81 may be made larger than the area of one electrode 61. Further, the total area of the electrodes 81 may be made larger than the total area of the electrodes 61.

As a configuration in which the resultant force Fe of electrostatic forces directed toward the second stator 12 acts on the rotor 51, the area of the second charged film 84 may be made larger than the area of the first charged film 64. For example, as a means for making the area of the second charged film 84 larger than the area of the first charged film 64, the through hole 51c may be formed by laser processing. In this case, for example, the through hole 51c is formed such that the cross section of the through hole 51c has a trapezoidal shape in a cross section perpendicular to the radial direction of the rotor 51. As a result, the cross-sectional shape of the portion where the first charged film 64 and the second charged film 84 are formed also becomes trapezoidal. This cross-sectional shape is a trapezoid with the second charged film 84 side as the lower base and the first charged film 64 side as the upper base.

As a configuration in which the area of the second charged film 84 is made larger than the area of the first charged film 64, the shape of the rotor 51 may be made into a curved shape. In this case, the shape of the rotor 51 is a curved shape in which the second surface 51b side is a convex surface and the first surface 51a side is a concave surface.

An insulating cover may be formed to cover the rotor 51 so that the area of the second charged film 84 is larger than the area of the first charged film 64. For example, a cover that partially covers the membranes 65 and 85 may be formed on the rotor 51 shown in FIG. 7(a). The exposed portion of the film 65 that is not covered by the cover functions as the first charged film 64 . The exposed portion of the film 85 that is not covered by the cover functions as the second charged film 84 . The cover is formed such that the exposed area of membrane 85 is larger than the exposed area of membrane 65. As a result, the area of the second charged film 84 becomes larger than the area of the first charged film 64.

The configuration shown in FIGS. 9 and 10 may be adopted as a configuration in which the resultant force Fe of the electrostatic force directed toward the second stator 12 is applied to the rotor 51. An example of the configuration of the second converter 8 is shown in FIGS. 9 and 10. As shown in FIGS. 9 and 10, a third charged film 87 is formed on the second surface 51b of the rotor 51. The shape of the third charged film 87 is annular. The third charged film 87 is arranged radially inside the second charged film 84. The third charged film 87 may be connected to the second charged film 84. The third charged film 87 has been subjected to charging treatment.

A fifth electrode 86 is formed on the front surface 12a of the second stator 12. The fifth electrode 86 is arranged at a position facing the third charged film 87. The shape of the fifth electrode 86 is annular. The fifth electrode 86 is an electrode independent of the third electrode 81a and the fourth electrode 81b. The fifth electrode 86 may be grounded.

As shown in FIG. 10, the third charged film 87 and the fifth electrode 86 face each other in the axial direction Z. Therefore, an attractive force F3 directed toward the second stator 12 acts on the rotor 51 due to the electrostatic force between the third charged film 87 and the fifth electrode 86. As shown in FIG. 10, in the second conversion section 8, the electrode 81 and the second charged film 84 face each other, and the fifth electrode 86 and the third charged film 87 face each other. Thereby, the opposing area regarding electrostatic force in the second converting section 8 is larger than the opposing area regarding electrostatic force in the first converting section 6. Therefore, an increase in the resultant force Fe of electrostatic forces directed toward the second stator 12 is realized.

As a configuration in which the resultant force Fe of electrostatic forces directed toward the second stator 12 is applied to the rotor 51, for example, the impedance of the electrode 81 of the second conversion section 8 is smaller than the impedance of the electrode 61 of the first conversion section 6. may be done. In the electromechanical converter 30 of the present embodiment, the electrode 81 of the second conversion section 8 is a colored electrode with relatively high conductivity, and the electrode 61 of the first conversion section 6 is a transparent electrode with relatively low conductivity. It is. With such a configuration, it is possible to make the magnitude of the suction force F2 larger than the magnitude of the suction force F1.

According to the electromechanical converter 30 of this embodiment, the amount of power generation can be maximized, as described below. FIG. 11 shows the relationship between the position of the rotor 51 in the axial direction Z and the amount of power generated in the electromechanical converter 30. In FIG. 11, the horizontal axis indicates the position of the rotor 51 in the axial direction Z, and the vertical axis indicates the power generation output [W].

In FIG. 11, a curve Pw1 shows the power generation output in the first conversion section 6, and a curve Pw2 shows the power generation output in the second conversion section 8. Further, the curve Pwt indicates the total power generation output in the electromechanical converter 30. Note that the values of the power generation output in the first converter 6 and the second converter 8 are, for example, values when the electromechanical converter 30 is operated alone, in other words, when the electromechanical converter 30 is incorporated into the watch 1. This is the value when operating without being installed. The value of the power generation output is, for example, a value when the first rotating shaft 52 is rotated at a constant speed by an external force.

In FIG. 11, the first position Z1 is the position where the rotor 51 is closest to the first stator 11 in its movable range. The second position Z2 is the position where the rotor 51 is closest to the second stator 12 in its movable range. The movable range is determined by the positions of the stones 71 and 91. As can be seen from FIG. 11, the total power generation output Pwt increases when the rotor 51 is at the first position Z1 or when the rotor 51 is at the second position Z2. The first converter 6 and the second converter 8 of this embodiment generate a resultant force Fe of electrostatic forces that directs the rotor 51 toward the second position Z2. Therefore, according to the electromechanical converter 30 of this embodiment, the amount of power generation can be maximized.

Furthermore, the timepiece 1 of this embodiment can suppress fluctuations in the natural period Tej in the rotational operation section 32 (see FIG. 2). The rotation operation unit 32 includes a rotation member 5 , a gear 25 , a second rotation shaft 23 , and a rotation weight 26 . The natural period Tej is a mechanical natural period of the rotary operation section 32, and is expressed by the following formula (1). Here, ja is the load from the rotating weight 26 to the rotor 51, and includes the rotational load of the rotating member 5. The load ja includes, for example, the gear ratio and moment of inertia of the gear 25, the gear 53, and the rotor 51 as parameters. m is the mass of the rotating weight 26, r is the distance from the center of rotation of the rotating weight 26 to the center of gravity of the rotating weight 26, and g is the gravitational acceleration. That is, m·g·r is the gravitational torque generated in the rotating weight 26.
Tej=2・π・√(ja/m・g・r) (1)

In the watch 1 of this embodiment, the natural period Tej is determined so that power can be efficiently generated when the watch 1 is worn on the user's wrist. The natural period Tej is determined, for example, based on the experimental results described with reference to FIG. 12. In FIG. 12, the horizontal axis shows the value of the natural period of the rotating motion part, and the vertical axis shows the measured relative rotation amount. That is, FIG. 12 shows the amount of relative rotation measured when the value of the natural period Tej of the rotational movement section was varied. Note that the value of the relative rotation amount in FIG. 12 is the average value of the relative rotation amount obtained for a plurality of subjects.

In a range where the natural period Tej is smaller than the threshold value Tmin, it may be difficult to establish the rotary operation section 32 as a mechanism that can be mounted on the watch 1, or there may be large variations in the measured values for each subject. Therefore, the natural period Tej is selected in a range equal to or greater than the threshold value Tmin. In the timepiece 1 of this embodiment, the value of the natural period Tej is set to the first period T1 shown in FIG. 12. The first period T1 is a period in which the relative rotation amount reaches a maximum value. The first period T1 is, for example, a value slightly smaller than 1 [sec].

In the electromechanical converter 30 of this embodiment, the rotor 51 is positioned at the second position Z2 due to the resultant force Fe of the electrostatic force acting on the rotor 51. As the value of the load ja in designing the natural period Tej, the value of the load on the rotational operation section 32 when the rotor 51 is in the second position Z2 is used. That is, the timepiece 1 of this embodiment is configured such that the power generation output in the electromechanical converter 30 is maximized when the rotor 51 is in the second position Z2. Therefore, in the watch 1 of the present embodiment, the rotor 51 can be positioned at a position where the power generation output is maximized by the resultant force Fe of the electrostatic forces generated by the first converter 6 and the second converter 8.

The resultant force Fe of the electrostatic forces can restrict movement of the rotor 51 from the second position Z2, and can suppress fluctuations in the value of the natural period Tej. Therefore, the electromechanical converter 30 of this embodiment can continuously generate power with high efficiency.

Note that the direction of the resultant force Fe of the electrostatic forces is not limited to the direction that directs the rotor 51 toward the second stator 12. The electromechanical converter 30 may be configured to apply a resultant force Fe of electrostatic forces directed toward the first stator 11 to the rotor 51 . FIG. 13 shows an example of an electromechanical converter 30 that applies a resultant force Fe of electrostatic forces toward the first stator 11. In the electromechanical transducer 30 shown in FIG. 13, the thickness t1 of the first charged film 64 is larger than the thickness t2 of the second charged film 84. With this configuration, it is possible to cause the resultant force Fe of the electrostatic forces directed toward the first stator 11 to act on the rotating member 5 by the sum of the electrostatic force in the first converter 6 and the electrostatic force in the second converter 8. Become.

Note that the means for applying the resultant force Fe of the electrostatic force toward the first stator 11 to the rotor 51 is not limited to making the thicknesses t1 and t2 of the charged films 64 and 84 different. The means for causing the resultant force Fe of electrostatic forces directed toward the second stator 12 to act on the rotor 51 described above are applied as means for causing the resultant force Fe of electrostatic forces directed toward the first stator 11 to act on the rotor 51. It is possible.

The electromechanical converter 30 sets the resistance value of the electrode 61 provided on the first stator 11 to be higher than the resistance value of the electrode 81 provided on the second stator 12, and moves toward the first stator 11. It may be configured to generate a resultant force Fe of electrostatic forces. In this case, the braking force acting on the rotor 51 becomes smaller. As a result, it can be expected that the amount of rotation of the rotor 51 increases when the attitude of the timepiece 1 changes, and the amount of power generated by the electromechanical converter 30 increases.

Further, the electromechanical converter 30 sets the resistance value of the electrode 81 provided on the second stator 12 to be lower than the resistance value of the electrode 61 provided on the first stator 11, and It may be configured to generate a resultant force Fe of electrostatic forces directed toward . In this case, the amount of power generated per unit rotation amount of the rotor 51 increases.

When the resistance value of the electrode 61 provided on the first stator 11 and the resistance value of the electrode 81 provided on the second stator 12 are made different, the direction of the generated resultant force Fe is determined to maximize the amount of power generation. It is preferable that the The direction of the resultant force Fe of the electrostatic forces may be determined by simulation based on the mass m of the rotating weight 26, the distance r from the rotation center of the rotating weight 26 to the center of gravity of the rotating weight 26, and the like. The direction of the resultant force Fe of the electrostatic forces may be determined based on the measurement result of the amount of power generation obtained by wearing the watch 1 on the wrist of the subject.

The electromechanical converter 30 may be configured to make the resultant force Fe of the electrostatic force larger than the force in the axial direction Z that corresponds to the weight of the rotating member 5 . FIG. 14 shows the resultant force Fe of electrostatic force and the force Fw due to its own weight. FIG. 14 shows a watch 1 in which the axial direction Z coincides with the vertical direction. In FIG. 14, the first stator 11 is located above the second stator 12 in the vertical direction. The force Fw due to its own weight is a force proportional to the mass m1 of the rotating member 5. The mass m1 of the rotating member 5 includes a mass m2 of the rotor 51 including the charged film, a mass m3 of the first rotating shaft 52, and a mass m4 of other members engaged with the first rotating shaft 52. In the rotating member 5 illustrated in FIG. 14, the other member is a gear 53.
m1=m2+m3+m4 (2)

When the posture of the timepiece 1 is the posture shown in FIG. 14, the force Fw acting on the rotating member 5 according to its own weight becomes a force in the axial direction Z. The electromechanical converter 30 is configured, for example, so that the resultant force Fe of electrostatic forces is larger than the force Fw corresponding to its own weight. In this case, the electromechanical converter 30 can position the rotor 51 at one end of the movable range regardless of the posture of the timepiece 1. In the timepiece 1 shown in FIG. 14, the electromechanical converter 30 can position the rotor 51 at a first position Z1 closest to the first stator 11. By making the magnitude of the resultant force Fe of electrostatic force larger than the magnitude of the force due to own weight, fluctuations in power generation efficiency in the electromechanical converter 30 are effectively suppressed. Furthermore, it is possible to maximize the power generation efficiency and power generation output in the electromechanical converter 30.

As explained above, the electromechanical converter 30 of this embodiment includes the rotating member 5, the first stator 11, the second stator 12, the first converter 6, the second converter 8, has. The rotating member 5 includes a plate-shaped rotor 51 and a first rotating shaft 52 that is engaged with the rotor 51. The first stator 11 faces the first surface 51a of the rotor 51. The second stator 12 faces the second surface 51b of the rotor 51.

The first conversion unit 6 includes a first charged film 64 and an electrode 61. The first charged film 64 is arranged on one of the first surface 51a and the first stator 11, and the electrode 61 is arranged on the other of the first surface 51a and the first stator 11. The second conversion unit 8 includes a second charged film 84 and an electrode 81. The second charged film 84 is arranged on one of the second surface 51b and the second stator 12, and the electrode 81 is arranged on the other of the second surface 51b and the second stator 12.

The first converter 6 and the second converter 8 cause a resultant force Fe of electrostatic forces to act on the rotor 51 by the sum of the electrostatic force in the first converter 6 and the electrostatic force in the second converter 8. It is configured as follows. The resultant force Fe of the electrostatic forces is a force directed toward one side in the axial direction Z. Therefore, the electromechanical converter 30 of this embodiment can suppress fluctuations in efficiency due to changes in the position of the rotor 51 in the axial direction Z.

The resultant force Fe of the electrostatic forces may be made larger than the axial force Fw depending on the weight of the rotating member 5. With this configuration, the position of the rotor 51 in the axial direction Z becomes more stable.

The electromechanical converter 30 of this embodiment includes a second rotating shaft 23 and a rotating weight 26 engaged with the second rotating shaft 23. The second rotating shaft 23 is a different shaft from the first rotating shaft 52, and mechanically transmits power to and from the rotating member 5. The rotating member 5 is configured to rotate in conjunction with the rotational movement of the rotating weight 26. Since the rotating weight 26 is engaged with the second rotating shaft 23 that is different from the first rotating shaft 52, it becomes easy to make the resultant force Fe of the electrostatic force larger than the axial force Fw depending on the own weight. .

Note that the electromechanical converter 30 may be used as a brake in a drive mechanism that drives the pointer 4. For example, the timepiece 1 may include a drive mechanism that transmits the force of a mainspring to the hands 4 to move the hands 4. In this drive mechanism, the electromechanical converter 30 may be used as a braking device that applies braking force to the driving force. The electromechanical converter 30 can apply a braking force to the rotor 51 by converting the kinetic energy of the rotor 51 into electrical energy. For example, a storage battery 27 is charged with the converted electrical energy.

[Second embodiment]
A timepiece 1 and an electromechanical converter 30 according to a second embodiment will be described with reference to FIGS. 15 to 20. Regarding the second embodiment, components having the same functions as those described in the first embodiment are given the same reference numerals, and redundant explanations will be omitted. 15 is a front view of the timepiece according to the second embodiment, FIG. 16 is a cross-sectional view of the timepiece according to the second embodiment, FIG. 17 is a cross-sectional view of the electromechanical converter according to the second embodiment, and FIG. 19 is a diagram showing a schematic configuration of an electromechanical converter according to the second embodiment, FIG. 19 is a cross-sectional view of the first conversion section and the second conversion section according to the second embodiment, and FIG. 20 is a diagram showing the schematic configuration of the electromechanical converter according to the second embodiment. It is a figure showing the driving method of the electromechanical converter concerning this. The timepiece 1 of the second embodiment differs from the timepiece 1 of the first embodiment in that, for example, the electromechanical converter 30 functions as a power generation mechanism for an electrostatic motor.

As shown in FIG. 15, the timepiece 1 of the second embodiment has display hands 54. Rotation of indicator hand 54 is controlled by electromechanical transducer 30. The display hand 54 functions as a second hand, for example. Note that the display hand 54 may function as a chronograph hand, a hand that indicates the internal state of the timepiece 1, or a hand that provides information to the user. As shown in FIG. 16, the display hand 54 is a part of the rotating member 5 and is engaged with the first rotating shaft 52. The display hand 54 is engaged with the front end of the first rotating shaft 52 and rotates together with the first rotating shaft 52.

As shown in FIG. 17, the first conversion unit 6 of the second embodiment has the same electrode 61 and first charged film 64 as in the first embodiment. Further, the second conversion unit 8 of the second embodiment has the same electrode 81 and second charged film 84 as in the first embodiment. Unlike the rotating member 5 of the first embodiment, the rotating member 5 of the second embodiment does not have a gear 53, but transmits power to other gears to control the position of the display hand and the reduction ratio. It may be changed by

As shown in FIG. 18, the electromechanical converter 30 includes a drive section 41 and a control section 42. The drive section 41 is a drive circuit that drives the first conversion section 6 and the second conversion section 8. The drive unit 41 outputs drive pulses whose polarity alternates at a predetermined drive frequency in accordance with a control signal input from the control unit 42 . Specifically, the drive unit 41 outputs a drive pulse to the first electrode 61a and the second electrode 61b, and outputs a drive pulse to the third electrode 81a and the fourth electrode 81b.

As shown in FIG. 19, the electrodes 81 (third electrode 81a, fourth electrode 81b) of the second conversion section 8 are different from the electrodes 61 (first electrode 61a, second electrode 61b) of the first conversion section 6. They are arranged out of phase. The arrangement as in this embodiment is just an example, and the electrode arrangement of the electrostatic motor as a power generation mechanism is not limited to the arrangement in this embodiment.

The drive unit 41 charges the electrode 61 and the electrode 81 using a drive pulse as shown in FIGS. 20(a) to 20(d). The drive unit 41 charges one of the first electrode 61a and the second electrode 61b to a positive potential, and charges the other to a negative potential. Further, the drive unit 41 charges one of the third electrode 81a and the fourth electrode 81b to a positive potential, and charges the other to a negative potential. The drive unit 41 switches the potentials of the first electrode 61a and the second electrode 61b so that the positively charged electrode 61 applies electrostatic attraction in the rotational direction C to the first charged film 64. Further, the drive unit 41 switches the potentials of the third electrode 81a and the fourth electrode 81b so that the positively charged electrode 81 applies electrostatic attraction in the rotational direction C to the second charged film 84.

The first converting section 6 and the second converting section 8 of the second embodiment are configured to rotate in the axial direction Z with respect to the rotor 51 by the sum of the electrostatic force in the first converting section 6 and the electrostatic force in the second converting section 8. It is configured to apply a force toward one side of the

For example, the first converter 6 and the second converter 8 may be configured to generate a resultant force Fe of electrostatic forces directed toward the second stator 12. In this case, a burr 51e may be formed on the first surface 51a side of the rotor 51. Further, the voltage applied to the corona discharge may be made different so that the charging voltage of the first charged film 64 and the charging voltage of the second charged film 84 are made different. Further, the thickness of the second charged film 84 may be made larger than the thickness of the first charged film 64. Further, the area of the electrodes arranged on the second stator 12 may be larger than the area of the electrodes arranged on the first stator 11. Further, the area of the second charged film 84 may be made larger than the area of the first charged film 64. Further, a third charged film 87 may be formed on the second surface 51b of the rotor 51, and a fifth electrode 86 may be formed on the second stator 12. Further, the impedance of the electrode 81 may be made smaller than the impedance of the electrode 61.

The drive unit 41 may control the voltage of the drive pulse so that the resultant force Fe of the electrostatic force directed toward the second stator 12 acts on the rotor 51 . For example, the voltage of the drive pulse output to the electrode 81 of the second stator 12 may be higher than the voltage of the drive pulse output to the electrode 61 of the first stator 11.

According to the electromechanical converter 30 of this embodiment, the rotor 51 is positioned at the second position Z2 because the resultant force Fe of the electrostatic force directed toward the second stator 12 acts on the rotor 51. It will be done. Since the position of the rotor 51 in the axial direction Z is difficult to fluctuate, the transmission rate of power in the electrostatic motor is stabilized. Therefore, the efficiency of the electrostatic motor can be improved. Furthermore, by stabilizing the position of the rotor 51 in the axial direction Z, it becomes possible to optimize the drive pulse and reduce power consumption. For example, the drive pulses for the first converter 6 and the drive pulses for the second converter 8 may be optimized on the premise that the rotor 51 is in the second position Z2.

Note that the electromechanical converter 30 may be configured to apply a resultant force Fe of electrostatic forces toward the first stator 11.

The electromechanical converter 30 of the second embodiment may be configured such that the resultant force Fe of the electrostatic forces is larger than the force Fw acting on the rotating member 5 according to its own weight. Note that the mass of the rotating member 5 according to the second embodiment includes the mass of the rotor 51 including the charged films 64 and 84, the mass of the first rotating shaft 52, and the mass of the indicator needle 54. Note that a train wheel may be provided between the display hand 54 and the first rotating shaft 52. In this case, the mass of the rotating member 5 includes the mass of the members that are engaged with the first rotating shaft 52 among the members that constitute the wheel train. For example, when the first gear that constitutes the wheel train is engaged with the first rotating shaft 52, the first gear is included in the rotating member 5.

[Modification of embodiment]
Modifications of the first and second embodiments will be described. The arrangement of the first converting section 6 and the second converting section 8 is not limited to the arrangement illustrated in each embodiment. For example, the second converting section 8 may be arranged on the base plate 7 side, and the first converting section 6 may be arranged on the receiving plate 9 side. The timepiece 1 does not need to have a skeleton structure that makes the rotor 51 visible. That is, the dial 3 and the main plate 7 do not need to have the windows 31 and 73.

The first charged film 64 and the second charged film 84 may be arranged on the stators 11 and 12 instead of the rotor 51. In this case, the electrodes 61 and 81 are arranged on the rotor 51. For example, the first conversion unit 6 may include a first charged film 64 formed on the first stator 11 and an electrode 61 formed on the rotor 51. For example, the second conversion unit 8 may include a second charged film 84 formed on the second stator 12 and an electrode 81 formed on the rotor 51.

In the first and second embodiments described above, one of the two converters 6 and 8 was referred to as the "first converter 6" and the other was referred to as the "second converter 8," but these The name is for convenience to distinguish between the two converters. Therefore, the arrangement and components of the two conversion units 6 and 8 are not limited to those exemplified in each embodiment.

The watch 1 may be the digital watch of the first embodiment that displays the time using a digital display and has the power generation mechanism of the first embodiment. In this case, the watch 1 does not need to have the hands 4 that indicate the time.

The contents disclosed in each of the embodiments and modifications described above can be executed in combination as appropriate.

1 Clock 2 Exterior case 3 Dial plate 4 Pointer 4a: Second hand, 4b: Minute hand, 4c: Hour hand 5 Rotating member 6 First conversion section 7 Main plate 7a: Front, 7b: Back 8 Second conversion section 9 Receiving plate 11 First fixing Child 12 Second stator 20: Windshield, 21: Case body, 22: Back cover 23: Second rotating shaft, 25: Gear, 26: Rotating weight 27: Storage battery, 28: Motor, 29: Reduction mechanism 30 Electromechanical conversion Container 31 Window 32 Rotating operation unit 41 Drive unit, 42: Control unit 51: Rotor, 52: First rotating shaft, 53: Gear, 54: Display hand 61: Electrode, 61a: First electrode, 61b: Second electrode, 63: rectifier circuit,
64: first charged film, 65: film 71: stone receiving stone, 72: hole stone, 73: window 81: electrode, 81a: third electrode, 81b: fourth electrode, 83: rectifier circuit,
84: Second charged film, 85: Membrane, 86: Fifth electrode, 87: Third charged film 91: Stone receiving stone, 92: Hole stone m: Mass, r: Distance from the center of rotation of the rotating weight to the center of gravity, ja : Load Tej Natural period, T1: First period F1, F2, F3: Attraction force, Fe: Resultant force of electrostatic force, Fw: Force according to own weight Z Axial direction Z1: First position, Z2: Second position

Claims (9)

a rotating member having a plate-shaped rotor and a first rotating shaft engaged with the rotor;
a first stator facing the first surface of the rotor;
a second stator facing the second surface of the rotor;
a first conversion unit having a first charged film disposed on one of the first surface and the first stator; and an electrode disposed on the other of the first surface and the first stator;
a second conversion unit having a second charged film disposed on one of the second surface and the second stator, and an electrode disposed on the other of the second surface and the second stator;
Equipped with
The first conversion section and the second conversion section generate a force directed toward one side in the axial direction with respect to the rotor due to the sum of the electrostatic force in the first conversion section and the electrostatic force in the second conversion section. It is configured to act on
The axial force acting on the rotor due to the sum of the electrostatic force in the first conversion section and the electrostatic force in the second conversion section is greater than the axial force according to the weight of the rotating member. Also big
An electromechanical converter characterized by: The electromechanical converter according to claim 1, wherein a charging voltage of the second charged film is higher than a charging voltage of the first charged film. The electromechanical converter according to claim 1 or 2, wherein the impedance of the electrode of the second conversion section is smaller than the impedance of the electrode of the first conversion section. The electrode of the second conversion section is a colored electrode,
The electromechanical converter according to any one of claims 1 to 3, wherein the electrode of the first converting section is a transparent electrode. The electromechanical transducer according to any one of claims 1 to 4, wherein the thickness of the second charged film is greater than the thickness of the first charged film. The electromechanical converter according to any one of claims 1 to 5, wherein the rotating member includes, in addition to the rotor, another member engaged with the first rotating shaft. The electromechanical converter according to claim 6 , wherein the other member includes a gear. The electromechanical transducer according to claim 6 or 7 , wherein the other member includes an indicator needle. a second rotating shaft that is different from the first rotating shaft and mechanically transmits power to and from the rotating member;
a rotating weight engaged with the second rotating shaft;
Equipped with
The electromechanical converter according to any one of claims 1 to 8 , wherein the rotating member rotates in conjunction with the rotational movement of the rotating weight.

Images