JP4950496B2 - Gear and manufacturing method thereof - Google Patents

Description

  The present invention relates to a gear and a manufacturing method thereof.

When force is transmitted between the gears by meshing the two gears, a predetermined backlash is provided in order to smoothly perform the rotational movement. However, when backlash occurs more than necessary, the accuracy in positioning decreases. For this reason, there has been proposed one in which a groove is formed from the tooth tip toward the center so that backlash does not occur (see, for example, Patent Document 1). In this case, since the grooves are formed, the teeth can be elastically deformed, and the accuracy can be maintained by maintaining the pressure contact state between the tooth surfaces of both gears together with the counterpart gear.
JP 09-210143 A

However, in the case of the conventional gear, since the width other than the end portion of the groove is substantially the same, the rigidity of the tooth increases toward the tooth base side. Therefore, the surface pressure due to elastic deformation when engaged with the counterpart gear is increased, and the loss due to the frictional force when engaged to transmit the force is increased, so that the transmission efficiency is lowered.
However, when the groove width is increased in order to reduce the surface pressure, the elastic deformation occurs more than necessary with respect to the load applied to the gear, and the rigidity of the teeth decreases. Further, when the tooth constituent material is softened without changing the width of the groove, the wear resistance on the pressure contact surface is lowered.

  The present invention has been made in view of the above circumstances, can reduce backlash, minimizes the reduction in transmission efficiency between gears and wear resistance of tooth surfaces, and is highly accurate. It is an object of the present invention to provide a gear that can be positioned and a manufacturing method thereof.

The present invention employs the following means in order to solve the above problems.
A gear according to the present invention is a gear branched into two elastic support portions that can be elastically deformed when a force is transmitted by a groove provided over the entire tooth width from the tooth tip toward the center portion. The groove includes an end tooth side groove and a tooth base side groove having a groove width larger than the groove width of the end tooth side groove, and the elastic support is provided when the groove width of the end tooth side groove meshes with a counterpart gear. The elastic deformation amount is larger than the elastic deformation amount at the tooth tip of the portion and smaller than the allowable deformation amount at the tooth tip of the elastic support portion with respect to the transmission direction of the force between the gears.

  The present invention can prevent one elastic support portion and the other elastic support portion from coming into contact with each other even when the elastic support portion is engaged with the counterpart gear and bent by a predetermined deflection amount in a direction in which the elastic support portions approach each other. Therefore, the force can be transmitted in a state where a predetermined surface pressure due to the elastic force of one elastic support portion is applied to the tooth surface without forming a gap between the gears.

  At this time, since the tooth root side groove has a larger groove width than the tooth end side groove, the rigidity of the tooth root side can be reduced, and the surface pressure of the entire tooth surface can be reduced as compared with the conventional case. Further, since the groove width is smaller than the allowable deformation amount of the elastic support portion, an external force larger than the force transmitted between the gears is applied to one elastic support portion, and the tooth tip or the vicinity thereof contacts the other elastic support portion. When contacting, the rigidity of not only one elastic support portion but also the other elastic support portion can be added. Therefore, the rigidity of the whole tooth can be increased.

Moreover, the gear according to the present invention is the gear, wherein a groove width of the end tooth side groove is provided so as to gradually expand toward the tooth tip side.
When an external force larger than the force transmitted between the gears is applied to one elastic support portion, the present invention can receive the force not only in the vicinity of the tooth tip but also on the entire surface of the addendum side groove. It is possible to further increase the rigidity of the teeth by suppressing wear due to the frictional force therebetween.

Moreover, the gear according to the present invention is the gear, wherein unevenness that meshes with each other is formed on the opposing surface of the end-end groove of each elastic support portion.
According to the present invention, even if an external force larger than the force transmitted between the gears is applied to one elastic support portion and the one elastic support portion and the other elastic support portion come into contact with each other, the diameter of the gear between the elastic support portions is The displacement of the direction can be suppressed, and wear due to the frictional force between the elastic support portions can be suppressed to further increase the rigidity of the teeth.

  The gear manufacturing method according to the present invention includes a step of applying a photosensitive material on a substrate on which a patterned planar conductive layer is disposed on the surface, and exposing to form a mold; And depositing an electroformed product, and forming the mold so as to form grooves having different widths in the middle from the tooth tip toward the central portion over the entire tooth width.

  According to the present invention, a high-precision mold can be manufactured, and even a small gear used for a timepiece part can be manufactured with high accuracy. Further, the surface roughness of the tooth surface can be reduced, and friction during sliding can be reduced.

  According to the present invention, it is possible to reduce backlash, minimize the reduction in transmission efficiency between gears and wear resistance of the tooth surface, and perform highly accurate positioning.

A first embodiment according to the present invention will be described with reference to FIGS.
The gear 1 according to the present embodiment is, for example, a spur gear, and as shown in FIGS. 1 to 3, grooves 3 provided in each tooth 2 over the entire tooth width from the tooth tip toward the center C of the gear 1. Thus, the tooth 2 is branched into one elastic support portion 5 and the other elastic support portion 6 that can be elastically deformed when force is transmitted. The groove 3 includes an end tooth side groove 7 and a tooth base side groove 8 having a groove width (T2) larger than the groove width (T1) of the end tooth side groove 7.

  Regardless of the gear 1 module, the groove width (T1) of the addendum-side groove 7 is the amount of elastic deformation (h1) of each of the elastic support portions 5 and 6 when meshed with the counterpart gear 10, as shown in FIG. , H2) and, as shown in FIG. 5, the allowable deformation amount of one elastic support portion 5 with respect to the transmission direction (F) of the force between the gears (a value larger than h3 in the figure). Is formed to be smaller.

Next, a method for manufacturing the gear 1 according to the present embodiment will be described with reference to FIGS.
In this manufacturing method, a negative photoresist (photosensitive material) is applied on a substrate (base material) 12 on which a planar conductive layer 11 having a pattern formed is arranged, and a mold 13 is formed by exposure. The method includes a step (S01), a step (S02) of depositing the electroformed product 15 on the mold 13, and a step (S03) of removing the mold 13 from the electroformed product 15 by polishing the surface.

In the step of forming the mold 13 (S01), first, in the so-called yellow room (not shown) where the wavelength at which the negative photoresist is exposed is cut, on the surface of the substrate 12 including the conductive layer 11, for example, an epoxy-based material A chemically amplified negative photoresist based on resin is applied.
Subsequently, a photomask 17 for forming an uncured layer 16 that is not cured on the negative photoresist is disposed on the surface of the negative photoresist and exposed. Thereby, as shown in FIG. 6, the cured layer 18 and the uncured layer 16 that is not cured are formed. At this time, the photomask 17 is adjusted to form the hardened layer 18 so as to form the end tooth side groove 7 and the root side groove 8 on the tooth 2 of the gear 1 described above. And what was manufactured by the process mentioned above is immersed in a developing solution, As shown in FIG. 7, the unhardened layer 16 is removed and the type | mold 13 is formed.

Subsequently, the process proceeds to a step of depositing the electroformed product 15 on the mold 13 (S02).
That is, in a state where the mold 13 is immersed in an electroforming liquid not shown, a voltage is applied to the conductive layer 11 to supply electrons. As a result, Ni ions eluted from an electrode (not shown) move and Ni is gradually deposited on the conductive layer 11 to obtain an electroformed product 15 as shown in FIGS.

  Then, the process proceeds to a step of removing the mold 13 from the electroformed product 15 by polishing the surface (S03). After the surface is polished so that the electroformed product 15 has a predetermined thickness, for example, the hardened layer 18 is melted and removed with an organic solvent to obtain the gear 1 as shown in FIG.

The operation of the gear 1 according to the present embodiment thus obtained will be described. In addition, the following effect | action demonstrates the gear 1 which concerns on this embodiment as a driven gear.
When meshed with the counter gear 10, the elastic support portions 5, 6 are pressed in a direction approaching each other and elastically deformed. When a force is transmitted from the counterpart gear 10, bending stress is further generated in one elastic support portion 5, and the tooth tip of one elastic support portion 5 bends in the direction of the other elastic support portion 6. Moving.

  At this time, the groove width (T1) of the addendum-side groove 7 is formed to be larger than the sum of the elastic deformation amounts (h1, h2) of the elastic support portions 5, 6, so that as shown in FIG. Even if the elastic support portions 5 and 6 are bent by a predetermined amount of deflection in a direction in which they approach each other, the one elastic support portion 5 and the other elastic support portion 6 do not contact each other. For this reason, it is possible to suppress a sudden change in the surface pressure applied to the one elastic support portion 5 in the process of transmitting the force, and the surface pressure of the one elastic support portion 5 is suppressed within a predetermined range.

  On the other hand, when a load or an external force is applied in a direction opposite to the rotation direction of the gear 1, bending stress is applied to the one elastic support portion 5, thereby further bending. At this time, since the groove width of the end-end side groove 7 is smaller than the allowable deformation amount (a value larger than h3) of the elastic support portions 5 and 6 with respect to the transmission direction (F) of the force between the gears, one elastic support While the portion 5 is elastically deformed, the tooth tip 5a contacts the tooth tip 6a of the other elastic support portion 6 as shown in FIG.

  At this time, the rigidity of the teeth 2 is not only the rigidity of one elastic support part 5 but also the rigidity of the other elastic support part 6. Therefore, after the elastic support portions 5 and 6 come into contact with each other, the rigidity as the tooth 2 changes discontinuously and rapidly increases, and the reaction force against the external force increases.

  According to the gear 1, even if the elastic gears 5 and 6 mesh with the counterpart gear 10 and bend in the direction in which the elastic support parts 5 and 6 approach each other with a predetermined amount of bending, the one elastic support part 5 and the other elastic support part 6 are connected. It is possible to prevent contact. Accordingly, the force can be transmitted in a state where a predetermined surface pressure due to the elastic force of one elastic support portion 5 is loaded on the tooth surface without forming a gap between the gears.

  At this time, since the tooth root side groove 8 has a larger groove width than the tooth end side groove 7, the rigidity of the tooth root side can be reduced, and the surface pressure of the entire tooth surface can be reduced as compared with the conventional case. Furthermore, since the groove width is smaller than the allowable deformation amount of each of the elastic support portions 5 and 6, an external force larger than the force transmitted between the gears is applied to one elastic support portion 5 and the tooth tip 5a is supported by the other elastic support portion. When contacting the tooth tip 6a of the part 6, the rigidity of not only one elastic support part but also the other elastic support part can be added.

  Accordingly, the rigidity of the entire tooth 2 when an external force is applied can be increased, and the wear resistance of the tooth surface can be increased. As a result, it is possible to reduce backlash that becomes a gap between the gears, to minimize a reduction in transmission efficiency between the gears and wear resistance of the tooth surface, and to perform high-precision positioning. .

  Moreover, since the gear 1 according to the present embodiment is manufactured by electroforming, a highly accurate mold 13 can be manufactured, and even if the gear 1 is small like a watch part, it can be manufactured with high accuracy. . Further, the tooth surface can be finished close to a mirror surface to reduce the surface roughness, and friction caused by sliding during meshing can be reduced.

Next, a second embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the component similar to 1st Embodiment mentioned above, and description is abbreviate | omitted.
The difference between the second embodiment and the first embodiment is that the groove width of the addendum-side groove 21 of the gear 20 according to this embodiment is directed to the tooth tips 22a and 23a side of the respective elastic support portions 22 and 23. It is said that it has been gradually expanded.

  In this case, the distance between the tooth tips 22a and 23a of the elastic support portions 22 and 23 is the same as that of the addendum-side groove 7 according to the first embodiment. And when the tooth tips 22a and 23a contact | abut, it is an angle which the mutual opposing surfaces 22b and 23b contact each other.

  The gear 20 is manufactured by electroforming, as in the first embodiment. At this time, a hardened layer is formed to form a mold so as to form an addendum-side groove that gradually expands toward the addendum side in a portion corresponding to the addendum-side groove, and electroforming is performed.

About the effect | action of the gearwheel 20 which concerns on this embodiment, the case similar to 1st Embodiment is demonstrated.
When meshed with the counterpart gear 10, one elastic support portion 22 and the other elastic support portion 23 do not come into contact with each other, so that force is transmitted by the same action as in the first embodiment.

  When a load or an external force is applied in a direction opposite to the rotation direction of the gear 20, one elastic support portion 22 contacts the other elastic support portion 23. At this time, not only the tooth tips 22a and 23a but also the entire opposing surfaces 22b and 23b contact each other. Therefore, the contact area becomes larger than that in the first embodiment, and the radial movement of the gear 20 between the elastic support portions 22 and 23 is restricted by the frictional force acting on the facing surface.

  According to the gear 20, when an external force larger than the force transmitted between the gears is applied to one elastic support portion 22, wear due to the frictional force between the elastic support portions 22 and 23 is suppressed and the rigidity of the teeth 25 is increased. It can be further increased.

Next, a third embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the component similar to other embodiment mentioned above, and description is abbreviate | omitted.
The difference between the third embodiment and the first embodiment is a triangular shape that meshes with the opposing surfaces 31b, 32b of the end-end grooves 33 of the elastic support portions 31, 32 of the gear 30 according to this embodiment. This is the point that the concave portion 35 and the convex portion 36 are formed.

  The gear 30 is manufactured by electroforming, as in the first embodiment. At this time, a hardened layer is formed so that irregularities are formed in a portion corresponding to the end tooth groove, and a mold is produced and electroformed.

Next, the operation of the gear 30 according to this embodiment will be described.
When meshed with the counter gear 10, the one elastic support portion 31 and the other elastic support portion 32 do not come into contact with each other, so that force is transmitted by the same action as in the first embodiment.
When a load or an external force is applied in a direction opposite to the rotation direction of the gear 30, one elastic support portion 31 comes into contact with the other elastic support portion 32. At this time, the concave portion 35 and the convex portion 36 formed on the opposing surfaces 31b and 32b are engaged with each other. Accordingly, the relative movement of the gear 30 in the radial direction between the elastic support portions 31 and 32 is restricted.

  According to the gear 30, an external force larger than the force transmitted between the gears is applied to one elastic support portion 31, and even if one elastic support portion 31 and the other elastic support portion 32 come into contact with each other, elastic support is provided. The radial displacement of the gear 30 can be suppressed between the portions 31 and 32, and wear due to the frictional force between the elastic support portions 31 and 32 can be suppressed, and the rigidity of the teeth 37 can be further increased.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the gear is a driven gear, but even if it is used as a driving gear, the same actions and effects can be achieved except that the direction of the force during transmission is different.

  Further, the groove width of the end-end side groove is larger than the sum of the elastic deformation amounts (h1, h2) of the respective elastic support portions when meshed with the counterpart gear 10, and the transmission direction of the force between the gears (F ) Is smaller than the allowable deformation amount of the elastic support portion (a value larger than h3), but the allowable deformation amount of the elastic support portion is not further exceeded with respect to the groove width thus determined. The groove width may be determined in consideration of the processing error.

  Furthermore, in the third embodiment, the triangular concave portions 35 and the convex portions 36 that mesh with each other are provided on the opposing surfaces 31b and 32b of the end-end groove 33. However, as shown in FIG. 40 and convex part 41 may be sufficient. Further, it may be polygonal. Also in this case, the same operations and effects as those of the third embodiment can be achieved.

  In the above embodiment, the gear is manufactured by electroforming. However, the gear is not limited to electroforming, and the gear may be made of resin, silicon, metal, ceramics, or the like having elasticity. At this time, in the case of a large metal gear, the groove may be formed by electric discharge machining, and in the case of a resin gear, the groove may be formed by injection molding. In the case of silicon or ceramics, it may be formed by etching or blasting. And this groove | channel may be in an other party gear.

  The reaction force received by each tooth when a force is applied to the tooth 2 of the gear 1 according to the first embodiment and the tooth 37 of the gear 30 according to the third embodiment is the groove width as in the prior art. Compared to the case of a constant gear. FIG. 14 shows a change in the relative magnitude of the reaction force that changes as the elastic support portion is elastically deformed, assuming that the reaction force corresponding to the rigidity required for the teeth has the same magnitude.

  Both the first embodiment and the third embodiment are deformed with a reaction force lower than that of the prior art until the tooth tips of the elastic support portion come into contact with each other. It turns out that it changes discontinuously and grows rapidly. Accordingly, it was found that the force can be transmitted while maintaining a low surface pressure during normal times, and the rigidity can be increased when a large external force is applied.

It is a top view which shows the gearwheel which concerns on the 1st Embodiment of this invention. It is a perspective view centering on the A section of FIG. It is a top view which shows the tooth | gear of the gearwheel which concerns on the 1st Embodiment of this invention. It is a figure showing the state where the gear concerning the 1st embodiment of the present invention and the other party gear meshed. It is a figure showing the state where external force was loaded in the state where the gear concerning the 1st embodiment of the present invention and the other party gear meshed. It is explanatory drawing which shows the state which exposes a negative photoresist in the manufacturing method of the gear which concerns on the 1st Embodiment of this invention. In the manufacturing method of the gear concerning a 1st embodiment of the present invention, after exposure of a negative photoresist, it is an explanatory view showing the state where it developed and developed. In the manufacturing method of the gear concerning a 1st embodiment of the present invention, it is an explanatory view showing the state where electroforming was deposited on the type. It is a top view of FIG. It is sectional drawing which shows the gearwheel obtained by the method of manufacturing the gearwheel concerning the 1st Embodiment of this invention. It is a top view which shows the tooth | gear of the gearwheel which concerns on the 2nd Embodiment of this invention. It is a top view which shows the tooth | gear of the gearwheel which concerns on the 3rd Embodiment of this invention. It is a top view which shows the modification of the gear tooth which concerns on the 3rd Embodiment of this invention. It is a graph which shows the result of having compared the change of the reaction force concerning the tooth of the gear concerning the 1st and 3rd embodiments of the present invention with the conventional gear.

Explanation of symbols

1, 20, 30 Gear 2, 25 Tooth 3 Groove 5, 22, 31 One elastic support portion 5a, 6a, 22a, 23a Tooth tip 6, 23, 32 Other elastic support portion 7, 21, 33 End tooth groove 8 Root side groove 11 Conductive layer 12 Substrate (base material)
13 Type 15 Electroformed product 35 Concave part 36 Convex part C Center (central part)

Claims (2)

A gear branched into two elastic support portions that can be elastically deformed when a force is transmitted by a groove provided over the entire tooth width from the tooth tip toward the center portion,
The groove includes an end tooth side groove and a root side groove having a groove width larger than the groove width of the end tooth side groove;
When the groove width of the end tooth side groove is meshed with the counterpart gear, the amount of elastic deformation at the tooth tip of the elastic support portion is larger, and the tooth tip of the elastic support portion with respect to the direction of transmission of force between the gears gear, characterized in that it is provided with gradually widened toward rather small, the addendum side than the allowable amount of deformation. Applying a photosensitive material on a substrate on which a patterned planar conductive layer is arranged on the surface, and exposing to form a mold; and
  Depositing an electroformed product on the mold,
A method of manufacturing a gear, wherein the mold is formed so as to form a groove that is gradually expanded toward the tooth tip side.

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