JP3721740B2 - Power transmission mechanism and electronic timepiece - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power transmission mechanism that accelerates the rotation of a rotating weight whose center of rotation and center of gravity are eccentric and transmits the rotation to a rotor of a generator, and an electronic timepiece including the power transmission mechanism.
[0002]
[Prior art]
Conventionally, batteries have been used as energy sources for small electronic devices such as electronic watches. However, since the battery has a lifetime, it takes time to replace the battery regularly. In recent years, a method of mounting a generator in an electronic device and omitting the battery has been proposed (Japanese Patent Publication No. 7-38029). ).
[0003]
This generator has a rotor having a rotor magnet made of a permanent magnet, a stator made of a high permeability material arranged around the rotor, and a coil connected to the stator, and has a rotation center, a center of gravity, and Is mounted on a watch or the like with an eccentric rotating weight. A speed increasing wheel train, which is a power transmission mechanism, is provided between the rotating weight and the rotor of the generator so that the rotational motion of the rotating weight is accelerated by the speed increasing wheel train and transmitted to the rotor. It has become. In the generator, the change in the magnetic field generated by the rotation of the rotor is transmitted to the coil through the stator, and electric power is generated by electromagnetic induction.
[0004]
In the power transmission mechanism, a rotating spindle fixed to the rotary spindle, a rotor gear fixed to the rotor, and a transmission wheel composed of a large gear and a small gear arranged between the rotary spindle and the rotor gear. The rotating motion is transmitted by meshing with each other. These gears are usually provided with a backlash in order to reduce friction during meshing.
[0005]
[Problems to be solved by the invention]
In this method, since the rotor tries to stand still in a magnetically stable state (angle) with respect to the stator magnetized by the rotor, the direction in which the rotor is rotated by the rotation of the rotating weight and the rotor is magnetic. The directions to rotate in order to remain in the stable position coincide with each other or are opposite to each other. When these directions are switched, the gears are provided with the above-described backlash, so that the teeth (tooth surfaces) collide with each other between the meshed gears. Due to this collision, vibration is generated and propagates to other parts and casings constituting the device and resonates, which causes a problem that sound is generated during power generation. In terms of power transmission, energy loss due to backlash occurs each time the mechanical rotation direction and the magnetic rotation direction are switched, resulting in a decrease in power generation efficiency.
[0006]
In particular, when such a power generation mechanism is provided on a wristwatch or the like, the rotating weight rotates irregularly in both directions due to the movement of the arm, so that the rotation direction of the gears is irregular depending on the rotating direction of the rotating weight. Switch. When the rotation direction is switched, the teeth collide with each other between the gears, which causes the generation of the above-described sound and the decrease in power generation efficiency.
[0007]
An object of the present invention is to provide a power transmission mechanism that can reduce generation of sound during power generation and improve power generation efficiency.
[0008]
[Means for Solving the Problems]
The present invention provides a rotor including a permanent magnet, Said A stator made of a high permeability material arranged around the rotor, a generator having a coil connected to the stator and converting the rotational motion of the rotor into electric energy, and a rotation center and a center of gravity are eccentric. A power transmission mechanism that is provided between the weights and transmits the rotation of the rotary weight to the rotor by increasing the rotation speed. The power transmission mechanism is configured by combining a plurality of gears, and the plurality of gears. At least one of the gears includes a backlash absorbing mechanism for closing a gap between the teeth and the teeth of the mating gear, and the backlash absorbing mechanism is fixed to the rotating shaft and transmits power. A main gear for transmission, a pair of sub-gears rotatably mounted on the same axis as the main shaft, and a hairspring for urging each of the pair of sub-gears The balance spring is attached to the main gears in opposite directions to urge the sub gears in opposite rotation directions with respect to the main gear, so that backlash generated in both rotation directions of the power transmission mechanism is generated. It is characterized by absorbing.
[0009]
In the present invention, since the backlash absorbing mechanism is provided in the gear constituting the power transmission mechanism, the direction in which the rotor is rotated by the rotation of the rotary weight and the direction in which the rotor is rotated in order to remain in the magnetically stable position. The teeth collide with each other when the gears match or reverse each other, or when the rotation directions of the gears meshed with each other change due to changes in the rotation direction of the rotating weight. Disappears. Therefore, since generation | occurrence | production of the vibration by a collision of a tooth can be prevented, since the energy loss by backlash can be reduced, electric power generation efficiency can be improved. In addition, if the gear is configured to include the biased sub gear, the main gear and the sub gear can be engaged with the mating gear with the mating gear held between the main gear and the sub gear. it can. Further, since the angle of the sub gear with respect to the main gear is changed according to the meshing state with the other tooth, and the width of the tooth gap of the gear is changed, the width of the tooth gap can be changed according to the other tooth. Therefore, it is possible to reliably engage with each other even if the distance from the other gear is not strict, and the manufacture of the power transmission mechanism can be facilitated. Furthermore, by energizing the sub gear in both directions, it is possible to absorb backlash even when the rotation direction of the gear is switched to any direction, so that generation of sound can be prevented more reliably, thus ensuring power generation efficiency. it can.
[0016]
In the present invention, the rotor includes a permanent magnet, a stator made of a high permeability material disposed around the rotor, and a coil connected to the stator to electrically rotate the rotor. A power transmission mechanism that is provided between a generator that converts energy and a rotating weight having a center of rotation and a center of gravity that are eccentric, and that increases the rotation of the rotating weight and transmits the rotation to the rotor, The power transmission mechanism is configured by combining a plurality of gears, and at least one of the plurality of gears includes a backlash absorbing mechanism for closing a gap between the teeth and the teeth of the mating gear. The gear having the backlash absorbing mechanism includes teeth that are displaceable with a base end as a fulcrum, and the width of the tooth gap is smaller than the tooth thickness of the counterpart gear, Teeth By displacing during engagement, characterized in that it is capable sandwich the teeth of the mating gear.
[0017]
Thus, by making the width of the tooth gap smaller than the tooth thickness of the counterpart gear and making it variable, the tooth gap is expanded to a width corresponding to the tooth thickness of the counterpart tooth when meshing with the counterpart gear. , Will come to hold the opponent's teeth. Therefore, since the backlash can be reliably absorbed regardless of the rotation direction of the gear, the generation of sound can be reliably prevented and the energy loss can be reduced, so that a significant improvement in power generation efficiency can be expected.
[0018]
In addition, since the width of the tooth gap changes, it is not necessary to make the distance from the gear of the other party strict, so that the power transmission mechanism can be easily manufactured.
[0019]
In the above, the gear provided with the backlash absorbing mechanism among the plurality of gears is not particularly limited, but the plurality of gears are arranged on the same axis as the rotating weight and coupled to the rotating weight, the rotor, A rotor gear arranged on the same axis and coupled to the rotor, a large gear of a different size arranged between the rotary spindle wheel and the rotor gear and provided on the same axis and integrated with each other; When configured to include a small gear, it is desirable that at least one of the rotating spindle wheel and the large gear has a backlash absorbing mechanism.
[0020]
Here, the integrated large gear and small gear are not limited to one set, but also include a plurality of sets.
[0021]
In this way, by providing the backlash absorbing mechanism in at least one of the rotating spindle wheel and the large gear, which are relatively large gears among the plurality of gears, the miniaturization of the gear structure can be avoided. It is easier to manufacture than a small gear with a backlash absorbing mechanism.
[0022]
The power transmission mechanism of the present invention is preferably used for an electronic timepiece. In particular, when the mechanism using the main gear and the sub-gear described above is employed, it is not necessary to downsize the plurality of gears, the urging means for urging the sub-gear, and the like, which can be manufactured easily and at low cost.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0024]
[First embodiment]
FIG. 1 shows a main part of a wristwatch which is a small electronic device provided with the power transmission mechanism 13 of the first embodiment. This wristwatch includes a rotating weight 11 having an eccentric center of rotation and a center of gravity, a generator 12, and a power transmission mechanism 13 that accelerates the rotation of the rotating weight 11 and transmits the rotation to the rotor 21 of the generator 12. It is configured.
[0025]
In the wristwatch of this embodiment, the rotational movement of the rotary weight 11 due to the movement of the arm is accelerated by the power transmission mechanism 13 and transmitted to the rotor 21 of the generator 12, and the rotor 21 is rotated to generate an alternating current. Although not shown, this alternating current is rectified by a rectifier circuit and stored in a storage means such as a large-capacity capacitor, for example, an electric double layer capacitor. Then, using this power storage means as a power source, a control circuit including a time standard crystal and a drive circuit controlled by the control circuit are operated, and a drive signal sent from the drive circuit is rotated in a converter such as a step motor. The rotational movement is transmitted to the pointer through the reduction gear train, and the pointer is driven.
[0026]
The generator 12 includes a disk-shaped rotor 21 including a two-pole magnetized permanent magnet, a stator 22 made of a high permeability material disposed around the rotor 21, and a coil connected to the stator 22. 23, and the rotary motion of the rotor 21 is converted into electric energy. The coil 23 is obtained by winding an electric wire 23 </ b> B around a magnetic core 23 </ b> A, and the magnetic core 23 </ b> A is fixed to the stator 22 with a screw 24.
[0027]
As shown in FIG. 2, the rotation center of the rotary weight 11 is attached to the rotary shaft 15 via a ball bearing 14. An inner ring 141 of a ball bearing 14 is fixed to the rotating shaft 15, and an outer ring 142 of the bearing 14 is fixed to the rotating weight 11. A screw 151 that covers the bearing 14 is screwed into the upper end of the rotating shaft 15.
[0028]
The power transmission mechanism 13 between the rotary weight 11 and the generator 12 is a speed increasing wheel train combining a plurality of gears. The power transmission mechanism 13 is fixed to a rotary spindle 31 coupled to the rotary weight 11 and the rotor 21. The rotor gear 32 and a transmission wheel 33 disposed between the rotary spindle 31 and the rotor gear 32 are included.
[0029]
The rotary spindle 31 is provided on the same rotary shaft 15 as the rotary spindle 11 and is connected to the rotary spindle 11 via the outer ring 142 of the ball bearing 14. The opening end 31A of the shaft hole of the rotary spindle 31 is press-fitted into a groove 142A formed on the outer periphery of the outer ring 142, whereby the rotational movement of the rotary spindle 11 is caused at the connecting portion between the rotary spindle 31 and the outer ring 142. Is formed by a frictional force.
[0030]
In the clutch mechanism 16, when the rotary weight 11 rotates at a predetermined speed or less, a frictional force acts between the opening end 31 </ b> A of the rotary spindle 31 and the groove 142 </ b> A of the outer ring 142, and the rotary weight 11 rotates. Is reliably transmitted to the rotary spindle 31. On the other hand, when the rotational speed of the rotary weight 11 exceeds a predetermined speed, the opening end 31A of the rotary weight 11 and the groove 142A slip, and the rotary motion of the rotary weight 11 is not sufficiently transmitted to the rotary spindle 31. As a result, the power transmitted to the rotor 21 is limited, and the rotational speed of the rotor 21 can be limited to a speed corresponding to the performance of the generator 12.
[0031]
The rotor gear 32 is provided on the same rotation shaft 25 as the rotor 21 and is fixed to the rotor 21. The rotor gear 32 is a gear whose diameter is significantly smaller than that of the rotary spindle 31 described above.
[0032]
A transmission wheel 33 between the rotor gear 32 and the rotary spindle 31 is composed of a large gear 34 and a small gear 35 having different sizes (diameters). These gears 34 and 35 are fixed with respect to the same rotating shaft 36 and are coupled via the rotating shaft 36. In such a transmission wheel 33, the small gear 35 meshes with the rotary spindle 31, and the large gear 34 meshes with the rotor gear 32.
[0033]
The rotating shaft 36 of the transmission wheel 33 and the rotating shaft 25 of the rotor 21 are supported by the main plate 17 and the train wheel bridge 18 arranged orthogonal to these shafts 25, 36.
[0034]
The large gear 34 includes a backlash absorbing mechanism 4 for closing a gap between the teeth and the teeth 32 </ b> A of the mating rotor gear 32. Specifically, the large gear 34 includes a main gear 41 that is fixed to the rotary shaft 36 and transmits power, and a pair of sub gears 42 and 43 provided on the same shaft 36 as the main gear 41. The main gear 41 is interposed between the pair of sub gears 42 and 43.
[0035]
The sub gears 42 and 43 are rotatably locked with respect to the rotary shaft 36 and are connected to the main gear 41 via hairsprings 44 each wound with a fine wire. These hairsprings 44 are mounted in opposite directions so that the sub gears 42 and 43 can be urged in the opposite rotation directions with respect to the main gear 41. The sub gears 42 and 43 may be connected to the rotary shaft 36 via the hairspring 44.
[0036]
The sub gears 42 and 43 are energized by rotating in the opposite directions with respect to the main gear 41, and mesh with the rotor gear 32 together with the main gear 41 in this energized state. The magnitude of the urging force, that is, the torque that sandwiches the teeth 32A of the rotor gear 32 can be adjusted by changing the pitch at which the sub gears 42 and 43 are shifted with respect to the main gear 41. As a result, the sub gears 42 and 43 follow the teeth in the urged directions at the meshing portions of the large gear 34 and the rotor gear 32, so the width of the tooth groove of the large gear 34 is set to the tooth thickness of the rotor gear 32. Since it can be changed according to the meshing state, the backlash between the main gear 41 and the rotor gear 32 can be absorbed.
[0037]
When manufacturing such a large gear 34, the sub-gears 42, 43 are rotated by a desired pitch with respect to the main gear 41, and the gears 41, 42, 43 are pinned. Alternatively, by fixing with a clip or the like and engaging the large gear 34 and the rotor gear 32 at the time of assembly and then removing the pins and the like, the trouble of adjusting the urging state of the sub gears 42 and 43 at the time of assembly can be eliminated. So it can be manufactured easily.
[0038]
Specifically, power is transmitted between the transmission wheel 33 and the rotor gear 32 of the present embodiment as follows.
[0039]
That is, when the large gear 34 rotates in the direction of the arrow L as shown in FIG. 3 due to the rotation of the rotary weight 11 at the meshing portion of the large gear 34 and the rotor gear 32 of the transmission wheel 33, the main gear 41 and The sub gears 43 urged in the same rotational direction (arrow L direction) overlap to push one tooth surface 32B of the teeth 32A of the rotor gear 32 to transmit the rotational motion.
[0040]
At this time, the sub gear 42 urged in the direction of the arrow R opposite to the rotation direction (arrow L direction) shifts from the main gear 41 in the direction of the arrow R opposite to the rotation direction (arrow L direction), It abuts on the other tooth surface 32C of the tooth 32A. Even if the distance between the main gear 41 and the other tooth surface 32C of the rotor gear 32 changes due to the rotation of the large gear 34 and the transmission wheel 33, the sub gear 42 follows the other tooth surface 32C. That is, the amount of displacement of the sub gear 42 with respect to the main gear 41 changes according to the meshing state.
[0041]
On the contrary, as shown in FIG. 4, when the large gear 34 rotates in the direction of arrow R, the main gear 41 and the sub gear 42 urged in the same rotation direction (direction of arrow R) overlap, The other tooth surface 32C of the tooth 32A of the rotor gear 32 is pushed to transmit the rotational motion. At this time, the sub gear 43 urged in the direction of the arrow L opposite to the rotation direction (the direction of the arrow R) deviates from the main gear 41 and comes into contact with the other tooth surface 32B of the tooth 32A of the rotor gear 32 to follow. To come.
[0042]
As described above, in the large gear 34 of the present embodiment, the width of the tooth gap changes depending on the magnitude of the backlash regardless of the rotation direction of the gear, and the transmission of the rotational motion is always performed by the teeth 32A of the rotor gear 32. It is performed in a state of sandwiching.
[0043]
In the wristwatch of this embodiment, the rotor gear 32 is rotated by the rotational motion transmitted from the large gear 34, and the rotor 21 of the generator 12 is rotated along with this rotation. Since the rotor 21 is dipole magnetized, the rotor 21 rotates by 180 degrees, and each time it rotates by 180 degrees, it is a magnetically stable state, that is, a force that tries to stay in a state attracted to the stator 22 magnetized by the rotor 21. Occurs. At the time of power generation, the direction of this force and the direction of the rotational motion transmitted from the large gear 34 are matched or reversed, and the tooth surfaces 32B and 32C with which the main gear 41 contacts are switched. At this time, since the teeth 32A of the rotor gear 32 are always held between the gears 41 to 43 of the large gear 34, the teeth collide between the large gear 34 and the rotor gear 32 when the rotation direction is switched. There is nothing.
[0044]
Further, even when the rotation direction of the rotary weight 11 is changed and the rotation direction of the gears 31, 32, 33 is switched, the collision of the teeth between the large gear 34 and the rotor gear 32 can be avoided.
[0045]
According to this embodiment, there are the following effects.
[0046]
That is, since the backlash absorbing mechanism 4 is provided in the large gear 34 constituting the power transmission mechanism 13, the rotation is performed in order to rotate the rotor 21 by the rotation of the rotary weight 11 or because the rotor 21 remains in the magnetically stable position. The teeth do not collide between the large gear 34 and the rotor gear 32 when the directions to be matched or reversed, or when the rotation directions of the gears 31, 32, 33 are switched. . Therefore, generation of vibration due to tooth collision can be prevented, so that generation of sound due to resonance can be reduced, and in terms of motion transmission, energy loss due to backlash can be reduced, so that power generation efficiency can be improved.
[0047]
The large gear 34 includes a main gear 41 and sub gears 42 and 43. These sub gears 42 and 43 are attached in a direction opposite to the rotation direction of the large gear 34, which is a rotation direction that absorbs backlash. Therefore, the tooth 32A of the rotor gear 32 can be engaged with the main gear 41 and the sub gears 42 and 43 at the meshing portion with the rotor gear 32, so that backlash can be absorbed reliably. .
[0048]
Further, since the width of the tooth groove of the large gear 34 can be changed according to the rotor gear 32, the teeth 32A of the rotor gear 32 can be clamped even if the distance between the large gear 34 and the rotor gear 32 is not strict. Therefore, the assembly of the power transmission mechanism 13 can be facilitated.
[0049]
Further, since the sub gears 42 and 43 are provided in a pair and are biased in the opposite rotation directions, backlash can be reliably absorbed even when the rotation directions of the gears 31, 32 and 33 are switched to any direction. Therefore, generation of sound can be prevented more reliably and excellent power generation efficiency can be secured.
[0050]
Furthermore, since the backlash absorbing mechanism 4 is provided on the large gear 34 that is a relatively large gear among the plurality of gears 31, 32, 34, and 35, the structure of the backlash absorbing mechanism 4 can be prevented from being miniaturized. Therefore, it can be manufactured more easily than the relatively small small gear 35, the rotor gear 32, etc., and the main gear 41, the sub gears 42, 43, the hairspring 44 and the like need not be downsized, and can be manufactured at low cost. .
[0051]
Further, since the backlash absorbing mechanism 4 is provided on the large gear 34 and the clutch mechanism 16 is provided on the rotary spindle 31, these mechanisms 4 and 16 are dispersed, and therefore, due to the concentration of the mechanisms 4 and 16. The complexity of the structure can be prevented.
[0052]
[Second Embodiment]
The power transmission mechanism of the second embodiment shown in FIG. 5 uses a large gear 51 made of an elastic body instead of the large gear 34 of the first embodiment as a gear having a backlash absorbing mechanism. The same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different parts are described in detail below.
[0053]
The large gear 51 of the second embodiment includes a gear main body 52 having an annular rim portion 52A and a meshing portion 53 attached to the rim portion 52A. Of these, the gear body 52 is made of a rigid body such as metal, and the meshing portion 53 is formed of an elastic body that can be elastically deformed. As this elastic body, an elastomer such as synthetic rubber, a resin such as urethane, or the like can be employed.
[0054]
Further, the tooth gap width W of the large gear 51 is made smaller than the tooth thickness T of the rotor gear 32, and the teeth 53A of the large gear 51 are elastically deformed at the time of meshing, whereby the teeth 32A of the rotor gear 32 can be clamped. It is said that.
[0055]
In the present embodiment configured as described above, the tooth groove of the large gear 51 is expanded by the teeth 32 </ b> A of the rotor gear 32, so that the width W thereof corresponds to the tooth thickness T of the rotor gear 32. Therefore, transmission of the rotational motion from the large gear 51 to the rotor gear 32 is always performed with the teeth 32A of the rotor gear 32 being sandwiched, so that backlash can be reliably absorbed regardless of the rotational direction.
[0056]
According to this embodiment, the same operation and effect as in the first embodiment can be obtained, and the meshing portion 53 of the large gear 51 is formed by the elastic body to adjust the width W of the tooth gap. Therefore, the backlash absorbing mechanism 5 can be easily configured with a simple structure.
[0057]
[Third embodiment]
The power transmission mechanism of the third embodiment shown in FIG. 6 uses a large gear 61 having displaceable teeth instead of the large gear 51 of the second embodiment. The same parts are denoted by the same reference numerals, detailed description thereof is omitted, and only different parts will be described in detail below.
[0058]
The large gear 61 of the third embodiment includes a disc-shaped gear main body 62 and meshing pieces 63 as a plurality of teeth provided radially around the gear main body 62. The meshing piece 63 is integrally formed of an elastic material.
[0059]
The meshing piece 63 has a tooth depth larger than that required for meshing with the rotor gear 32, and can be displaced with the base end portion 63A as a fulcrum. Further, in order to avoid stress concentration when the engagement piece 63 is displaced, a notch portion 64 is formed between the base end portions 63 </ b> A of the adjacent engagement pieces 63 in the main body portion 62. .
[0060]
As in the second embodiment, the width W of the tooth gap of the large gear 61 of the present embodiment is made smaller than the tooth thickness T of the rotor gear 32, and the meshing piece 63 of the large gear 61 has its base end portion 63A. The teeth 32A of the rotor gear 32 are clamped by being displaced along the rotation direction about the fulcrum.
[0061]
In the present embodiment configured as described above, the tooth groove of the large gear 61 is pushed and widened by the teeth 32A of the rotor gear 32. Therefore, the width W of the tooth groove is a width corresponding to the tooth thickness T of the rotor gear 32. Become. Therefore, transmission of the rotational motion from the large gear 61 to the rotor gear 32 is always performed with the teeth 32A of the rotor gear 32 being sandwiched, so that backlash can be reliably absorbed regardless of the rotational direction.
[0062]
According to this embodiment, the same operations and effects as those of the first and second embodiments can be achieved.
[0063]
In addition, this invention is not limited to the said embodiment, Other modifications etc. which can achieve the objective of this invention are included, The deformation | transformation etc. which are shown below are also contained in this invention.
[0064]
In each of the embodiments described above, the clutch mechanism 16 is provided between the rotary spindle 31 and the rotary shaft 15. However, the place where the clutch mechanism 16 is provided is not limited to this. For example, the large gear 34 or the small gear 35 and the rotation thereof. It may be provided between the shaft 36 and between the rotor gear 32 and the shaft 25. When the clutch mechanism is provided on the large gear 34, the backlash absorbing mechanism is preferably provided on the rotating spindle wheel in order to prevent the structure from becoming complicated.
[0065]
The structure of the clutch mechanism is not limited to the structure described in the first embodiment. For example, in the first embodiment, when the clutch mechanism is provided between the large gear 34 and its shaft 36, FIG. As shown in FIG. 3, the main gear 41 is not completely fixed to the rotating shaft 36, and the opening end 41A of the shaft hole of the main gear 41 is connected to the engaging portion 36A formed around the rotating shaft 36 and the rotating shaft. The clutch mechanism 71 that transmits the rotational motion by frictional force may be configured by being sandwiched between the leaf springs 72 attached to 36.
[0066]
In the first embodiment, the backlash absorbing mechanism including the main gear and the sub gear is provided in the large gear 34. However, the gear provided with the backlash absorbing mechanism is arbitrary as long as the gear constitutes the power transmission mechanism. For example, the rotating spindle wheel may be composed of a main gear and a sub gear to absorb backlash between the rotating spindle wheel and the small gear, and a backlash absorbing mechanism is provided for both the large gear and the rotating spindle wheel. It may be provided. Alternatively, the small gear that meshes with the rotating spindle wheel or the rotor gear that meshes with the large gear may be a gear having a backlash absorbing mechanism using a main gear and a sub gear.
[0067]
In the first embodiment, the backlash absorbing mechanism is configured by using two sub gears. However, one sub gear may be used, and according to this, the structure can be simplified.
[0068]
Further, as shown in FIG. 7, the peripheral portion of the sub gear may be curved or bent so as to be close to the main gear 41. According to this, the space for storing the hairspring 44 is ensured, and the large gear is secured. Since the thickness of the portion engaged with the rotor gear 32 of the 34 can be reduced, the thickness of the rotor gear can be reduced, so that the power transmission mechanism, that is, the wristwatch can be thinned.
[0069]
Further, the biasing means for biasing the sub gear is not limited to the hairspring. For example, when there is one sub gear, the sub gear 43 may be urged by a semicircular C ring 73 disposed between the main gear 41 and the sub gear 43 as shown in FIGS. In this structure, both ends of the C ring 73 made of an elastically deformable material, such as rubber, resin, metal, etc. are fixed to the main gear 41 and the sub gear 43, respectively, and then the sub gear 42 is rotated to repel it. Generate power. As an urging means, as shown in FIG. 10, a substantially circular C ring 74 may be used.
[0070]
As shown in FIGS. 11 and 12, an elastic body 75 such as rubber may be used as the biasing means. In this case, the elastic body 75 is disposed between the main gear 41 and the sub gear 43 and fixed to the gears 41 and 43, and then the sub gear 43 is rotated to generate a repulsive force. A plurality of elastic bodies 75 are preferably arranged.
[0071]
Alternatively, a leaf spring 76 may be used as the biasing means as shown in FIGS. In this case, the locking portion 77 is formed in the main gear 41, the leaf spring 76 is attached to the sub gear 43, and the sub gear 43 is rotated in a direction in which the leaf spring 76 is pressed against the locking portion 77 to generate a repulsive force. .
[0072]
Further, as shown in FIG. 15, when the small gear 80 is configured by using the main gear 81 and the sub gear 82, the structure is simplified by using the C ring 78 to urge the sub gear 82 rather than using the balance spring. Can be At this time, a locking hole 78 </ b> A is formed at one end of the C ring 78, and the C ring 78 may be attached to the main gear 81 by being inserted into a protrusion 83 protruding from the main gear 81. .
[0073]
In the second embodiment, the case where the backlash absorbing mechanism is configured by forming the teeth of the large gear 34 by an elastic body has been described. However, the teeth of the small gear are formed by forming the teeth of the rotary spindle by the elastic body. As a result, the backlash absorbing mechanism may be provided on the rotating spindle wheel, or the same backlash absorbing mechanism may be provided on both of them. Furthermore, the teeth of the small gear and the teeth of the rotor gear that mesh with the large gear and the rotary spindle, respectively, may be formed of an elastic body.
[0074]
Further, in the third embodiment, the engagement piece having a long tooth depth is configured to be displaced with the base end portion as a fulcrum. However, by providing elasticity to the engagement piece itself, the width of the tooth gap can be made variable. Good.
[0075]
【The invention's effect】
As described above, according to the present invention, since the backlash absorbing mechanism is provided in the gear constituting the power transmission mechanism, when the rotation direction of the gear is switched due to the change in the rotation direction of the rotary weight, the The teeth do not collide with each other. Therefore, generation of vibration due to tooth collision can be prevented and energy loss due to backlash can be reduced, so that power generation efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a power transmission mechanism of the first embodiment.
FIG. 3 is a diagram showing a state in which power is transmitted from a large gear to a rotor gear in the first embodiment.
FIG. 4 is a diagram showing another state in which power is transmitted from the large gear to the rotor gear in the first embodiment.
FIG. 5 is a diagram showing a second embodiment of the present invention.
FIG. 6 is a diagram showing a third embodiment of the present invention.
FIG. 7 is a sectional view showing another clutch mechanism of the present invention.
FIG. 8 is a cross-sectional view showing another backlash absorbing mechanism of the present invention.
FIG. 9 is a perspective view showing biasing means used in the backlash absorbing mechanism of the present invention.
FIG. 10 is a perspective view showing another urging means used in the backlash absorbing mechanism of the present invention.
FIG. 11 is a view showing still another backlash absorbing mechanism of the present invention.
12 is a cross-sectional view showing the backlash absorbing mechanism of FIG.
FIG. 13 is a view showing another backlash absorbing mechanism of the present invention.
14 is a view showing the position of an urging means used in the backlash absorbing mechanism of FIG.
FIG. 15 is a perspective view showing still another backlash absorbing mechanism of the present invention.
[Explanation of symbols]
4, 5, 6 Backlash absorption mechanism
11 Rotating weight
12 Generator
13 Power transmission mechanism
21 Rotor
31 Rotating spindle
32 Rotor gear
33 Car
34, 51, 61 Large gear
35, 80 small gear
41, 81 Main gear
42, 43, 82 Sub gear

Claims (3)

Generator for converting the rotor is structured to include a permanent magnet, the rotational movement of the rotor with a coil connected stator and the stator made of a high permeability material disposed around the rotor into electrical energy And a power transmission mechanism that is provided between the rotation center and the rotation weight whose center of gravity is eccentric, and that increases the rotation of the rotation weight and transmits it to the rotor,
The power transmission mechanism is configured by combining a plurality of gears,
At least one gear of the plurality of gears includes a backlash absorbing mechanism for closing a gap between the tooth and a tooth of a mating gear.
The backlash absorbing mechanism includes a main gear that is fixed to a rotating shaft and transmits power, a pair of sub gears that are coaxially coupled to the rotating shaft and rotatably engaged via the main gear, and Having a hairspring that energizes each of the pair of sub gears ,
The hairspring is attached to the main gears in opposite directions to urge the sub gears in opposite rotation directions, and absorbs backlash generated in both rotation directions of the power transmission mechanism. Power transmission mechanism. A generator configured to include a permanent magnet, a stator made of a high permeability material arranged around the rotor, and a coil connected to the stator to convert the rotational motion of the rotor into electrical energy And a power transmission mechanism that is provided between the rotation center and the rotation weight whose center of gravity is eccentric, and that increases the rotation of the rotation weight and transmits it to the rotor,
The power transmission mechanism is configured by combining a plurality of gears,
At least one gear of the plurality of gears includes a backlash absorbing mechanism for closing a gap between the tooth and a tooth of a mating gear.
The gear having the backlash absorbing mechanism includes teeth that can be displaced with a base end as a fulcrum, and the width of the tooth gap is made smaller than the tooth thickness of the mating gear, and the gear teeth The power transmission mechanism is characterized in that the teeth of the mating gear can be clamped by being displaced at the time of meshing. An electronic timepiece comprising the power transmission mechanism according to claim 1 .

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