JP6912989B2 - Flexible meshing gear device - Google Patents

Description

The present invention relates to a flexible meshing gear device.

A flexure meshing gear device is known as a gear device that is compact, lightweight, and can obtain a high reduction ratio. Conventionally, the exciter, the external gear that is flexed and deformed by the exciter, the first internal gear that meshes with the external gear, and the first internal gear are arranged adjacent to each other in the axial direction and have external teeth. A so-called flat type flexural meshing gear device including a second internal gear that meshes with the gear has been proposed (for example, Patent Document 1).

International Publication No. 2016/21011

In a flexure meshing gear device as described in Patent Document 1, an external moment load causes misalignment of the gear, which causes the gear to hit one side and excessively wear the gear.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a flexible meshing gear device capable of suppressing excessive wear of a gear.

In order to solve the above problems, the flexural meshing gear device according to an aspect of the present invention includes a oscillating body, an external gear that is flexed and deformed by the oscillating body, and a first internal gear that meshes with the external gear. A flexible meshing gear device including a second internal gear that is arranged side by side with the first internal gear in the axial direction and meshes with the external gear. The external gear is a first internal gear. It has a first external tooth portion that meshes with a second external tooth portion that meshes with a second internal gear. The tooth tips of the first outer tooth portion include a first outermost diameter portion having the maximum outer diameter, a first outer outer diameter portion whose outer diameter decreases from the first outermost diameter portion toward the outer side in the axial direction, and a first outer diameter portion. It has a first inner diameter reducing portion whose outer diameter decreases from the outermost outer diameter portion toward the inner side in the axial direction. The tooth tips of the second outer tooth portion include a second outermost diameter portion having the maximum outer diameter, a second outer diameter reducing portion whose outer diameter decreases from the second outermost diameter portion toward the outer side in the axial direction, and a second outer diameter portion. It has a second inner diameter reducing portion whose outer diameter decreases from the outermost outer diameter portion toward the inner side in the axial direction.

Another aspect of the present invention is a flexible meshing gear device. This device is arranged side by side in the axial direction with the exciter, the external gear that is flexed and deformed by the exciter, the first internal gear that meshes with the external gear, and the first internal gear. A flexible meshing type gear device including a second internal gear that meshes with a gear, and the tip of the internal tooth of the first internal gear has a first inner diameter portion having a minimum inner diameter and a first inner diameter portion. It has a first outer increasing portion in which the inner diameter increases from the inner diameter portion toward the outer side in the axial direction, and a first inner increasing portion in which the inner diameter increases from the first innermost inner diameter portion toward the inner side in the axial direction. The tooth tips of the internal tooth portions of the second internal gear have a second innermost inner diameter portion that minimizes the inner diameter, a second outer inner diameter portion that increases the inner diameter from the second innermost diameter portion toward the outer side in the axial direction, and a second outer inner diameter portion. It has a second inner diameter increasing portion whose inner diameter increases from the innermost inner diameter portion toward the inner side in the axial direction.

Yet another aspect of the present invention is also a flexible meshing gear device. This device is arranged side by side in the axial direction with the exciter, the external gear that is flexed and deformed by the exciter, the first internal gear that meshes with the external gear, and the first internal gear. A flexible meshing type gear device including a second internal gear that meshes with the first internal gear, wherein the external gear has a first external tooth portion that meshes with the first internal tooth portion of the first internal gear and a second internal tooth. It has a second external tooth portion that meshes with the second internal tooth portion of the gear. The tooth tips of the first outer tooth portion include a first outermost diameter portion having the maximum outer diameter and a first outer outer diameter reducing portion whose outer diameter decreases from the first outermost diameter portion toward the outer side in the axial direction. Have. The tooth tips of the second outer tooth portion include a second outermost diameter portion having the maximum outer diameter and a second outer diameter reducing portion whose outer diameter decreases from the second outermost diameter portion toward the outer side in the axial direction. Have. The tooth tip of the first internal tooth portion has a first innermost inner diameter portion having a minimum inner diameter and a first inner inner diameter increasing portion whose inner diameter increases in the axial direction from the first innermost inner diameter portion. The tooth tip of the second internal tooth portion has a second innermost inner diameter portion having a minimum inner diameter and a second inner inner diameter increasing portion whose inner diameter increases in the axial direction from the second innermost inner diameter portion.

Yet another aspect of the present invention is also a flexible meshing gear device. This device is arranged side by side in the axial direction with the exciter, the external gear that is flexed and deformed by the exciter, the first internal gear that meshes with the external gear, and the first internal gear. A flexible meshing type gear device including a second internal gear that meshes with the first internal gear, wherein the external gear has a first external tooth portion that meshes with the first internal tooth portion of the first internal gear and a second internal tooth. It has a second external tooth portion that meshes with the second internal tooth portion of the gear. The tooth tips of the first outer tooth portion include a first outermost diameter portion having the maximum outer diameter and a first inner diameter reducing portion whose outer diameter decreases in the axial direction from the first outermost diameter portion. Have. The tooth tips of the second outer tooth portion include a second outermost diameter portion having the maximum outer diameter and a second inner diameter reducing portion whose outer diameter decreases in the axial direction from the second outermost diameter portion. Have. The tooth tip of the first internal tooth portion has a first innermost inner diameter portion having a minimum inner diameter and a first outer inner diameter portion whose inner diameter increases outward in the axial direction from the first innermost inner diameter portion. The tooth tip of the second internal tooth portion has a second innermost inner diameter portion having a minimum inner diameter and a second outer inner diameter portion whose inner diameter increases outward in the axial direction from the second innermost inner diameter portion.

Yet another aspect of the present invention is also a flexible meshing gear device. This device is arranged side by side in the axial direction with the oscillating body, the external tooth gear that is flexed and deformed by the oscillating body, the first internal tooth gear that meshes with the external tooth gear, and the first internal tooth gear. A flexible meshing type gear device including a second internal tooth gear that meshes with the tooth gear, and the external tooth gear is a first external tooth portion that meshes with the first internal tooth portion of the first internal tooth gear. The first external tooth portion having a different number of teeth from the internal tooth portion and the second external tooth portion that meshes with the second internal tooth portion of the second internal tooth gear, and has the same number of teeth as the second internal tooth portion. It has a tooth part. The tooth tips of the second outer tooth portion are a second outermost diameter portion having the maximum outer diameter and a second inner diameter reducing portion in which the outer diameter continuously decreases from the second outermost diameter portion toward the inner side in the axial direction. And have. The second medial reduction portion occupies 80% or more of the axial range of the tooth tip of the second external tooth portion.

Yet another aspect of the present invention is a flexible meshing gear device. This device is arranged side by side in the axial direction with the oscillating body, the external tooth gear that is flexed and deformed by the oscillating body, the first internal tooth gear that meshes with the external tooth gear, and the first internal tooth gear. A flexible meshing gear device including a second internal gear that meshes with the internal gear, and the internal gear is a second internal tooth that meshes with the second external tooth of the external gear. It has a second internal tooth part with the same number of teeth as the part. The second internal tooth portion has an innermost inner diameter portion that minimizes the inner diameter, and an inner inner diameter portion that continuously increases the outer diameter from the innermost inner diameter portion toward the inner side in the axial direction. The medial augmentation portion occupies 80% or more of the axial range of the tooth tip of the second internal tooth portion.

It should be noted that any combination of the above components and those in which the components and expressions of the present invention are mutually replaced between methods, devices, systems and the like are also effective as aspects of the present invention.

According to the present invention, it is possible to provide a flexure meshing gear device capable of suppressing excessive wear of a gear.

It is sectional drawing which shows the bending mesh type gear device which concerns on embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of FIG. 1. 3A and 3B are diagrams showing simulation results. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the flexible meshing type gear device which concerns on 2nd Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the flexible meshing type gear device which concerns on 3rd Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the flexible meshing type gear device which concerns on 4th Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the flexible meshing type gear device which concerns on 5th Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the flexible meshing type gear device which concerns on 6th Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the bending meshing type gear device which concerns on the modification of 1st Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the bending meshing type gear device which concerns on the modification of 2nd Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the bending meshing type gear device which concerns on the modification of 3rd Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the bending meshing type gear device which concerns on the modification of 4th Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the bending meshing type gear device which concerns on the modification of 5th Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the bending meshing type gear device which concerns on another modification of the 5th Embodiment. It is a figure for demonstrating the shape of the external gear, the 1st internal gear, and the 2nd internal gear of the bending meshing type gear device which concerns on the modification of 6th Embodiment.

Hereinafter, the same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and redundant description will be omitted as appropriate. In addition, the dimensions of the members in each drawing are shown enlarged or reduced as appropriate for easy understanding. In addition, some of the members that are not important for explaining the embodiment in each drawing are omitted and displayed.

FIG. 1 is a cross-sectional view showing a flexure meshing gear device 100 according to an embodiment. The flexure meshing gear device 100 decelerates and outputs the input rotation. The flexible meshing type gear device 100 includes a wave generator 2, an external gear 4, a first internal gear 6, a second internal gear 8, a housing 10, a first regulating member 12, and a second. A regulating member 14, a main bearing 16, a first bearing housing 18, and a second bearing housing 20 are provided. A lubricant (for example, grease) is sealed in the meshing gear device 100. The lubricant lubricates the meshing portion between the external gear 4 and the first internal gear 6 and the second internal gear 8, each bearing, and the like.

The wave generator 2 includes a oscillating body shaft 22, a first oscillating body bearing 21a arranged between the oscillating body shaft 22 and the external tooth gear 4 (the first external tooth portion 4a), and oscillating. It has a second oscillator bearing 21b arranged between the body shaft 22 and the external gear 4 (the second external tooth portion 4b). The first vibrating body bearing 21a includes a plurality of first rolling elements 24a, a first cage 26a, and a first outer ring member 28a. The second oscillator bearing 21b includes a plurality of second rolling elements 24b, a second cage 26b, and a second outer ring member 28b. The exciter shaft 22 is an input shaft, is connected to a rotation drive source such as a motor, and rotates about the rotation shaft R. The exciter shaft 22 is integrally formed with the exciter 22a having a substantially elliptical cross section orthogonal to the rotation axis R.

Each of the plurality of first rolling elements 24a has a substantially cylindrical shape, and is provided at intervals in the circumferential direction in a state in which the axial direction is oriented substantially parallel to the rotation axis R direction. The first rolling element 24a is rotatably held by the first cage 26a and rolls on the outer peripheral surface 22b of the oscillating body 22a. That is, the inner ring of the first oscillating body bearing 21a is integrally formed with the outer peripheral surface 22b of the oscillating body 22a, but the present invention is not limited to this, and a dedicated inner ring separate from the oscillating body 22a is provided. You may. The second rolling element 24b is configured in the same manner as the first rolling element 24a. The plurality of second rolling elements 24b are rotatably held by the second cage 26b arranged so as to be aligned with the first cage 26a, and roll on the outer peripheral surface 22b of the oscillating body 22a. That is, the inner ring of the second oscillating body bearing 21b is integrally formed with the outer peripheral surface 22b of the oscillating body 22a, but the present invention is not limited to this, and a dedicated inner ring separate from the oscillating body 22a is provided. You may. Hereinafter, the first rolling element 24a and the second rolling element 24b are collectively referred to as a “rolling body 24”. Further, the first cage 26a and the second cage 26b are collectively referred to as a "retainer 26".

The first outer ring member 28a surrounds a plurality of first rolling elements 24a. The first outer ring member 28a has flexibility and is elliptically bent by the oscillating body 22a via the plurality of first rolling elements 24a. When the oscillating body 22a (that is, the oscillating body shaft 22) rotates, the first outer ring member 28a continuously bends and deforms according to the shape of the oscillating body 22a. The second outer ring member 28b is configured in the same manner as the first outer ring member 28a. The second outer ring member 28b is formed as a separate body from the first outer ring member 28a. The second outer ring member 28b may be integrally formed with the first outer ring member 28a. Hereinafter, the first outer ring member 28a and the second outer ring member 28b are collectively referred to as an "outer ring member 28".

The external tooth gear 4 is a flexible annular member, and a vibrating body 22a, a rolling element 24, and an outer ring member 28 are fitted inside the external gear 4. The external tooth gear 4 is bent in an elliptical shape by fitting the exciting body 22a, the rolling element 24, and the outer ring member 28. When the oscillating body 22a rotates, the external tooth gear 4 continuously bends and deforms according to the shape of the oscillating body 22a. The external tooth gear 4 includes a first external tooth portion 4a located outside the first outer ring member 28a, a second external tooth portion 4b located outside the second outer ring member 28b, and a base material 4c. The first external tooth portion 4a and the second external tooth portion 4b are formed on a base material 4c which is a single base material, and have the same number of teeth.

The first internal tooth gear 6 is an annular member having rigidity, and a first internal tooth portion 6a is formed on the inner circumference thereof. The first internal tooth portion 6a surrounds the first external tooth portion 4a of the external tooth gear 4 bent in an elliptical shape, and is the first outer tooth portion (2 regions) in a predetermined region (2 regions) near the long axis of the exciter 22a. It meshes with the tooth portion 4a. The first internal tooth portion 6a has more teeth than the first external tooth portion 4a.

The second internal gear 8 is arranged (adjacent to) the first internal gear 6 in the axial direction. The second internal tooth gear 8 is a rigid cylindrical member, and a second internal tooth portion 8a is formed on the inner circumference thereof. The second internal tooth portion 8a surrounds the second external tooth portion 4b of the external tooth gear 4 bent in an elliptical shape, and the second outer tooth portion 8a is a predetermined region (two regions) in the major axis direction of the exciter 22a. It meshes with the tooth portion 4b. The second internal tooth portion 8a has the same number of teeth as the second external tooth portion 4b. Therefore, the second internal gear 8 rotates in synchronization with the rotation of the second external tooth portion 4b and thus the external gear 4.

The first regulating member 12 is a flat ring-shaped member, and is arranged between the external gear 4, the first outer ring member 28a, the first cage 26a, and the first bearing housing 18. The second regulating member 14 is a flat ring-shaped member, and is arranged between the external gear 4, the second outer ring member 28b, the second cage 26b, and the second bearing housing 20. The first regulating member 12 and the second regulating member 14 regulate the axial movement of the external gear 4, the outer ring member 28, and the cage 26.

The casing 10 is a substantially cylindrical member and surrounds the second internal gear 8. The first internal gear 6 is in-row fitted to the casing 10 and integrated with bolts (not shown). A main bearing 16 is arranged between the casing 10 and the second internal gear 8. The main bearing 16 is a cross roller bearing in the present embodiment, and includes a plurality of rollers (rollers) 46 provided at intervals in the circumferential direction. The plurality of rollers 46 roll on the rolling surface 8b of the second internal gear 8 and the rolling surface 10a of the casing 10. That is, the outer peripheral side of the second internal gear 8 functions as the inner ring of the main bearing 16, and the inner peripheral side of the casing 10 functions as the outer ring of the main bearing 16. The casing 10 supports the second internal gear 8 so as to be relatively rotatable via the main bearing 16. The type of bearing of the main bearing 16 is not particularly limited, and may be, for example, a 4-point contact ball bearing.

The first bearing housing 18 is an annular member and surrounds the exciter shaft 22. Similarly, the second bearing housing 20 is an annular member and surrounds the exciter shaft 22. The first bearing housing 18 and the second bearing housing 20 are arranged so as to axially sandwich the external gear 4, the rolling element 24, the cage 26, the outer ring member 28, the first regulating member 12, and the second regulating member 14. NS. The first bearing housing 18 is in-row fitted to the first internal gear 6 and bolted. The second bearing housing 20 is in-row fitted to the second internal gear 8 and bolted. A bearing 30 is incorporated in the inner circumference of the first bearing housing 18, a bearing 32 is incorporated in the inner circumference of the second bearing housing 20, and the exciter shaft 22 is provided via the bearing 30 and the bearing 32. It is rotatably supported with respect to the first bearing housing 18 and the second bearing housing 20.

An oil seal 40 is arranged between the exciter shaft 22 and the first bearing housing 18, an O-ring 34 is arranged between the first bearing housing 18 and the first internal gear 6, and the first internal gear is arranged. An O-ring 36 is arranged between the casing 10 and the casing 10, an oil seal 42 is arranged between the casing 10 and the second internal gear 8, and the second internal gear 8 and the second bearing housing 20 are arranged. An O-ring 38 is arranged between them, and an oil seal 44 is arranged between the second bearing housing 20 and the exciter shaft 22. As a result, it is possible to prevent the lubricant in the flexible meshing gear device 100 from leaking.

The operation of the flexible meshing type gear device 100 configured as described above will be described. Here, the number of teeth of the first external tooth portion 4a is 100, the number of teeth of the second external tooth portion 4b is 100, the number of teeth of the first internal tooth portion 6a is 102, and the number of teeth of the second internal tooth portion 8a is 100. Will be described as an example. Further, a case where the second internal gear 8 and the second bearing housing 20 are connected to the driven member will be described as an example.

When the exciter shaft 22 rotates in a state where the first external tooth portion 4a is in mesh with the first internal tooth portion 6a at two points in the elliptical shape in the long axis direction, the first external tooth portion 4a and the first external tooth portion 4a are rotated accordingly. The meshing position with the first internal tooth portion 6a also moves in the circumferential direction. Since the number of teeth is different between the first external tooth portion 4a and the first internal tooth portion 6a, at this time, the first external tooth portion 4a rotates relative to the first internal tooth portion 6a. Since the first internal gear 6 and the first bearing housing 18 are in a fixed state, the first external tooth portion 4a rotates by the amount corresponding to the difference in the number of teeth. That is, the rotation of the exciter shaft 22 is significantly decelerated and output to the first external tooth portion 4a. The reduction ratio is as follows.
Reduction ratio = (number of teeth of the first external tooth portion 4a-number of teeth of the first internal tooth portion 6a) / number of teeth of the first external tooth portion 4a = (100-102) / 100
= -1/50

Since the second external tooth portion 4b is integrally formed with the first external tooth portion 4a, it rotates integrally with the first external tooth portion 4a. Since the second external tooth portion 4b and the second internal tooth portion 8a have the same number of teeth, relative rotation does not occur, and the second external tooth portion 4b and the second internal tooth portion 8a rotate integrally. Therefore, the same rotation as the rotation of the first external tooth portion 4a is output to the second internal tooth portion 8a. As a result, the output obtained by reducing the rotation of the exciter shaft 22 to -1/50 can be taken out from the second internal gear 8.

Subsequently, the configurations of the external gear 4, the first internal gear 6, and the second internal gear 8 will be described in more detail.

FIG. 2 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8. In FIG. 2, the tooth tip of the first external tooth portion 4a of the external tooth gear 4, the tooth tip of the second external tooth portion 4b, and the tooth of the first internal tooth portion 6a of the first internal tooth gear 6 as viewed from the circumferential direction. First, the tooth tip of the second internal tooth portion 8a of the second internal tooth gear 8 is shown. FIG. 2 shows a state in which the tooth tips of the first internal tooth portion 6a and the tooth tips of the second internal tooth portion 8a are slid outward in the radial direction so as to be separated from the external gear 4 in order to facilitate understanding. .. In FIG. 2, the horizontal axis is a position in the axial direction from a certain reference position. The vertical axis shows a dimensional scale in the radial direction (1 scale is 10 μm) for reference. Further, in FIG. 2, the center line C1 is a line orthogonal to the rotation axis R (not shown in FIG. 2), and is in the axial direction of the meshing range between the first external tooth portion 4a and the first internal tooth portion 6a. Shows a line passing through the center. In the present embodiment, the first internal tooth portion 6a has a shorter axial length than the first external tooth portion 4a, and meshes with the first external tooth portion 4a over the entire range in the axial direction. Therefore, the axial length of the meshing range between the first external tooth portion 4a and the first internal tooth portion 6a is equal to the axial length of the first internal tooth portion 6a, and the center line C1 is the first internal tooth portion 6a. It passes through the center of the tooth tip in the axial direction. Further, the center line C2 is a line orthogonal to the rotation axis R and indicates a line passing through the center of the meshing range between the second outer tooth portion 4b and the second inner tooth portion 8a in the axial direction. In the present embodiment, the second internal tooth portion 8a has a shorter axial length than the second external tooth portion 4b, and meshes with the second external tooth portion 4b in the entire axial direction. Therefore, the axial length of the meshing range between the second external tooth portion 4b and the second internal tooth portion 8a is equal to the axial length of the second internal tooth portion 8a, and the center line C2 is the second internal tooth portion 8a. It passes through the center of the tooth tip in the axial direction.

The tooth tips of the first outer tooth portion 4a are the first outermost diameter portion 4a1 having the maximum outer diameter in the first outer tooth portion 4a and the first outermost diameter portion 4a1 toward the outer side in the axial direction (that is, the first). From the first outer tooth portion 4a2 where the outer diameter decreases (toward the direction away from the center) between the first outer tooth portion 4a and the second outer tooth portion 4b, and from the first outermost diameter portion 4a1 toward the inside in the axial direction. It has a first inner reducing portion 4a3 whose outer diameter decreases (that is, toward the center between the first outer tooth portion 4a and the second outer tooth portion 4b).

The first outermost diameter portion 4a1 is outside the center line C1, in other words, outside the center in the axial direction of the meshing range between the first outer tooth portion 4a and the first inner tooth portion 6a, in other words, the first. It is located outside the axial center of the tooth tip of the internal tooth portion 6a. Further, in the present embodiment, the first outermost diameter portion 4a1 is located outside the axial center of the tooth tip of the first outer tooth portion 4a. The first outer diameter reducing portion 4a2 is configured so that the outer diameter decreases in a curved manner from the first outermost diameter portion 4a1 toward the outer side in the axial direction. The first inner diameter reducing portion 4a3 is configured so that the outer diameter decreases in a curved manner from the first outermost diameter portion 4a1 toward the inner side in the axial direction. Further, the first inner reducing portion 4a3 is configured to extend to a portion corresponding to (that is, facing) the radial inner side of the gap 7 between the first internal gear 6 and the second internal gear 8. Further, in each of the first outer diameter reducing portion 4a2 and the first inner diameter reducing portion 4a3, the ratio of the outer diameter decrease with respect to the axial direction (= the amount of decrease in the outer diameter / the amount of movement in the axial direction) as the distance from the first outermost diameter portion 4a1 increases. ) Is configured to increase.

The tooth tips of the second outer tooth portion 4b have a second outer diameter portion 4b1 having the maximum outer diameter in the second outer tooth portion 4b and an outer diameter outward from the second outermost diameter portion 4b1 in the axial direction. It has a second outer reducing portion 4b2 that decreases, and a second inner reducing portion 4b3 whose outer diameter decreases in the axial direction from the second outermost diameter portion 4b1.

The second outermost diameter portion 4b1 is outside the center line C2, in other words, outside the center in the axial direction of the meshing range between the second outer tooth portion 4b and the second inner tooth portion 8a, in other words, the second outer diameter portion 4b1. It is located outside the axial center of the tooth tip of the internal tooth portion 8a. Further, in the present embodiment, the second outermost diameter portion 4b1 is located outside the axial center of the tooth tip of the second outer tooth portion 4b. The second outer diameter reducing portion 4b2 is configured so that the outer diameter is curvedly reduced from the second outermost diameter portion 4b1 toward the outer side in the axial direction. The second inner diameter reducing portion 4b3 is configured so that the outer diameter decreases in a curved manner from the second outermost diameter portion 4b1 toward the inner side in the axial direction. Further, the second inner reducing portion 4b3 is configured to extend to a portion corresponding to the radial inner side of the gap 7 between the first internal gear 6 and the second internal gear 8. Further, both the second outer diameter reducing portion 4b2 and the second inner diameter reducing portion 4b3 are configured so that the reduction ratio of the outer diameter with respect to the axial direction increases as the distance from the second outermost diameter portion 4b1 increases. The second outer reducing portion 4b2 is configured so that the reduction ratio of the outer diameter with respect to the axial direction is larger than that of the first outer reducing portion 4a2.

In each of the first outer reduction portion 4a2, the first inner reduction portion 4a3, the second outer reduction portion 4b2, and the second inner reduction portion 4b3, the reduction ratio of the outer diameter with respect to the axial direction satisfies the following equation. It is composed.
(Equation 1) Decrease rate = decrease in outer diameter (diameter) (mm) / movement in the axial direction (mm) ≤ 0.1
Here, in general, the reduction rate of the outer diameter with respect to the axial direction in the case of chamfer satisfies the following equation.
(Equation 2) Decrease in chamfer outer diameter (diameter) (mm) / Axial movement (mm) ≥ 1.15
Therefore, each reduction and chamfer has a different order and is clearly distinguished.

The tooth tip of the first internal tooth portion 6a is configured so that the inner diameter is substantially constant in the axial direction. Similarly, the tooth tip of the second internal tooth portion 8a is configured so that the inner diameter is substantially constant in the axial direction.

According to the flexible meshing gear device 100 according to the present embodiment described above, the tooth tips of the first outer tooth portions 4a have outer diameters from the first outermost diameter portion 4a1 toward the outer diameter in the axial direction and the inner diameter in the axial direction. The tooth tip of the second outer tooth portion 4b is configured so that the outer diameter decreases from the second outermost diameter portion 4b1 toward the outer side in the axial direction and the inner side in the axial direction. As a result, the one-sided load generated at the tooth width end (position corresponding to the axial end of the internal tooth) of the first external tooth portion 4a and the second external tooth portion 4b can be reduced, and excessive wear of the gear can be reduced. ..

Further, according to the flexible meshing type gear device 100 according to the present embodiment, each outermost diameter portion of the external tooth gear 4 is located outside the axial center of the meshing range of the external tooth portion and the internal tooth portion. .. As a result, the one-sided load can be further reduced as compared with the case where each outermost diameter portion is located at the center of the meshing range in the axial direction or inside the center in the axial direction.

Further, according to the flexible meshing type gear device 100 according to the present embodiment, the first inner reducing portion 4a3 and the second inner reducing portion 4b3 have gaps between the first internal gear 6 and the second internal gear 8, respectively. It is configured to extend to the portion corresponding to the radial inside of 7. As a result, it is possible to absorb the influence of the external gear being displaced with respect to the internal gear in the axial direction.

The present inventors performed a simulation to confirm the effect. FIG. 3A shows a simulation result of the flexible meshing gear device according to the comparative example, and FIG. 3B shows a simulation result of the flexible meshing gear device 100 according to the present embodiment. In FIGS. 3A and 3B, the horizontal axis is the axial position of the external gear 4, and the vertical axis is the radial load applied to the external gear 4 at the axial position. In the flexible meshing type gear device according to the comparative example, the diameters of the tooth tips of the first external tooth portion, the second external tooth portion, the first internal tooth portion and the second internal tooth portion are substantially axial. It is configured to be constant.

As shown in FIG. 3A, in the flexible meshing type gear device according to the comparative example, the radial load at the tooth width end (the portion surrounded by the dotted line) of the external gear is relatively large, and one-sided contact occurs. You can see that.

On the other hand, as shown in FIG. 3B, in the flexible meshing type gear device 100 according to the present embodiment, the radial load at the tooth width end of the external gear is relatively small, and the one-sided contact is reduced. You can see that. Further, in the flexible meshing type gear device 100 according to the present embodiment, the radial load acting on the external gear 4 is reduced as a whole, not limited to the tooth width end. From these, it can be seen that according to the present embodiment, excessive wear of the gear can be reduced.

(Second Embodiment)
FIG. 4 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the second embodiment. FIG. 4 corresponds to FIG. 2 of the first embodiment. The main difference from the first embodiment is that the diameter of the tooth tip of the internal tooth portion changes in the axial direction, not the diameter of the tooth tip of the external tooth portion. Hereinafter, the differences from the flexible meshing type gear device 100 according to the first embodiment will be mainly described.

The tooth tip of the first external tooth portion 4a is configured so that the outer diameter is substantially constant in the axial direction. Similarly, the tooth tips of the second external tooth portion 4b are configured so that the outer diameter is substantially constant in the axial direction. Both the first external tooth portion 4a and the second external tooth portion 4b are configured to extend to a portion corresponding to the radial inside of the gap 7 between the first internal gear 6 and the second internal gear 8. ..

The tooth tips of the first internal tooth portion 6a are a first inner diameter portion 6a1 having a minimum inner diameter in the first internal tooth portion 6a, and a first inner diameter increasing outward from the first inner diameter portion 6a1 in the axial direction. It has an outer increasing portion 6a2 and a first inner increasing portion 6a3 whose inner diameter increases in the axial direction from the first innermost inner diameter portion 6a1.

The first innermost inner diameter portion 6a1 is outside the center line C1, in other words, outside the center in the axial direction of the meshing range between the first outer tooth portion 4a and the first internal tooth portion 6a, in other words (first). The outer tooth portion 4a and the first internal tooth portion 6a, whichever has the shorter axial length), is located outside the axial center of the tooth tip of the first internal tooth portion 6a. The first outer inner diameter portion 6a2 is configured so that the inner diameter increases in a curve from the first innermost inner diameter portion 6a1 toward the outer side in the axial direction. The first inner diameter increasing portion 6a3 is configured so that the inner diameter increases in a curve from the first innermost inner diameter portion 6a1 toward the inner side in the axial direction. Further, the first inner diameter increasing portion 6a3 is configured so that the increase ratio of the inner diameter with respect to the axial direction (= the increase amount of the inner diameter / the movement amount in the axial direction) increases as the distance from the first innermost inner diameter portion 6a1 increases.

The tooth tips of the second internal tooth portion 8a have a second innermost inner diameter portion 8a1 having the smallest inner diameter in the second inner tooth portion 8a and a second inner diameter increasing outward in the axial direction from the second innermost inner tooth portion 8a1. It has an outer increasing portion 8a2 and a second inner increasing portion 8a3 whose inner diameter increases in the axial direction from the second innermost inner diameter portion 8a1.

The second innermost inner diameter portion 8a1 is outside the center line C2, in other words, outside the center in the axial direction of the meshing range between the second outer tooth portion 4b and the second inner tooth portion 8a, in other words (second). The outer tooth portion 4b and the second internal tooth portion 8a, whichever has the shorter axial length), is located outside the axial center of the tooth tip of the second internal tooth portion 8a. The second outer inner diameter portion 8a2 is configured so that the inner diameter increases in a curve from the second innermost inner diameter portion 8a1 toward the outer side in the axial direction. The second inner diameter increasing portion 8a3 is configured so that the inner diameter increases in a curve from the second innermost inner diameter portion 8a1 toward the inner side in the axial direction. Further, the second inner diameter increasing portion 8a3 is configured so that the increase ratio of the inner diameter with respect to the axial direction increases as the distance from the second innermost inner diameter portion 8a1 increases.

The first outer augmentation portion 6a2, the first inner augmentation portion 6a3, the second outer augmentation portion 8a2, and the second inner augmentation portion 8a3 are configured so that the increase ratio of the inner diameter with respect to the axial direction satisfies the following equation. Will be done.
(Equation 3) Increase rate = increase in outer diameter (diameter) (mm) / movement in the axial direction (mm) ≤ 0.1
Therefore, as with each of the decreasing parts of the first embodiment, each increasing part and the chamfer are in different orders and are clearly distinguished.

According to the flexible meshing type gear device according to the present embodiment described above, the inner diameter of the tooth tip of the first internal tooth portion 6a increases from the first innermost inner diameter portion 6a1 toward the outer side in the axial direction and the inner side in the axial direction. The tooth tip of the second internal tooth portion 8a is configured so that the inner diameter increases from the second innermost inner diameter portion 8a1 toward the outer side in the axial direction and the inner side in the axial direction. As a result, the one-sided load generated at the tooth width ends of the first external tooth portion 4a and the second external tooth portion 4b can be reduced, and excessive wear of the gear can be reduced.

Further, according to the flexible meshing type gear device according to the present embodiment, the innermost diameter portion of each of the first internal tooth gear 6 and the second internal tooth gear 8 is in the axial direction of the meshing range of the external tooth portion and the internal tooth portion. It is located outside the center. As a result, the one-sided load can be further reduced as compared with the case where the innermost inner diameter portion is located in the axial center or the axial center of the meshing range.

Further, according to the flexible meshing type gear device according to the present embodiment, the tooth tips of the first external tooth portion 4a and the tooth tips of the second external tooth portion 4b are the first internal tooth gear 6 and the second internal tooth, respectively. It is configured to extend to a portion corresponding to the radial inside of the gap 7 with the gear 8. As a result, it is possible to absorb the influence of the external gear being displaced with respect to the internal gear in the axial direction.

(Third Embodiment)
FIG. 5 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the third embodiment. FIG. 5 corresponds to FIG. 2 of the first embodiment. The main difference from the first embodiment is that both the outer tooth portion and the inner tooth portion have a portion in which the diameter of the tooth tip changes in the axial direction. Hereinafter, the differences from the flexible meshing type gear device 100 according to the first embodiment will be mainly described.

The tooth tip of the first external tooth portion 4a has a first outermost diameter portion 4a1 and a first outer reducing portion 4a2 similar to that of the first embodiment. That is, the tooth tip of the first external tooth portion 4a does not have the first inner reducing portion, and instead the first outermost diameter portion 4a1 is outside the center line C1, in other words, the first external tooth portion 4a and the first outer tooth portion 4a. 1 From a position outside the center of the meshing range with the internal tooth portion 6a in the axial direction, in other words, outside the axial center of the tooth tip of the first internal tooth portion 6a, the tooth tip of the second external tooth portion 4b It extends axially to the position where it is connected to, that is, to the portion corresponding to the radial inner side of the gap 7 between the first internal tooth gear 6 and the second internal tooth gear 8. The tooth tip of the first external tooth portion 4a may have a first inner reducing portion.

The tooth tip of the second outer tooth portion 4b has a second outermost diameter portion 4b1 and a second outer reducing portion 4b2 similar to that of the first embodiment. That is, the tooth tip of the second outer tooth portion 4b does not have the second inner reducing portion, and instead the second outermost diameter portion 4b1 is outside the center line C2, in other words, the second outer tooth portion 4b and the second outer tooth portion 4b. 2 From a position outside the center of the meshing range with the internal tooth portion 8a in the axial direction, in other words, outside the axial center of the tooth tip of the second internal tooth portion 8a, the tooth tip of the first external tooth portion 4a It extends axially to the position where it is connected to, that is, to the portion corresponding to the radial inner side of the gap 7 between the first internal tooth gear 6 and the second internal tooth gear 8. The tooth tip of the second external tooth portion 4b may have a second inner reducing portion.

The tooth tip of the first internal tooth portion 6a has a first innermost inner diameter portion 6a1 and a first inner augmentation portion 6a3 similar to that of the second embodiment. That is, the tooth tip of the first internal tooth portion 6a does not have the first outer tooth portion, and instead the first innermost inner diameter portion 6a1 is outside the center line C1, that is, the tooth tip of the first outer tooth portion 4a. It extends from a position outside the center in the axial direction to the outside in the axial direction. The tooth tip of the first internal tooth portion 6a may have a first outer augmentation portion.

The tooth tip of the second internal tooth portion 8a has a second innermost diameter portion 8a1 and a second inner augmentation portion 8a3 similar to that of the second embodiment. That is, the tooth tip of the second internal tooth portion 8a does not have the second outer tooth portion, and instead the first innermost diameter portion 6a1 is outside the center line C2, that is, the tooth tip of the second outer tooth portion 4b. It extends from a position outside the center in the axial direction to the outside in the axial direction. The tooth tip of the second internal tooth portion 8a may have a second outer augmentation portion.

The axial position of the boundary between the first outermost diameter portion 4a1 and the first outer outer diameter portion 4a2 substantially coincides with the axial position of the boundary between the first innermost inner diameter portion 6a1 and the first inner inner diameter portion 6a3. do. Further, these boundaries are outside the center line C1, in other words, outside the center of the meshing range between the first external tooth portion 4a and the first internal tooth portion 6a in the axial direction, in other words, the first internal tooth portion. It is located outside the axial center of the tooth tip of 6a. Further, in the present embodiment, these boundaries are located outside the axial center of the tooth tip of the first external tooth portion 4a.

Similarly, the axial position of the boundary between the second outermost diameter portion 4b1 and the second outer outer diameter reducing portion 4b2 is substantially the same as the axial position of the boundary between the second innermost diameter portion 8a1 and the second inner increasing portion 8a3. Matches. Further, these boundaries are outside the center line C2, in other words, outside the center of the meshing range between the second external tooth portion 4b and the second internal tooth portion 8a in the axial direction, in other words, the second internal tooth. It is located outside the axial center of the tooth tip of the portion 8a. Further, in the present embodiment, these boundaries are located outside the axial center of the tooth tip of the second external tooth portion 4b.

According to the flexible meshing gear device according to the present embodiment, the tooth tip of the external tooth portion has an outer reducing portion as in the first embodiment. On the other hand, the tooth tip of the outer tooth portion does not have the inner reducing portion, unlike the first embodiment. However, instead, the tips of the internal teeth have medial augmentations. As a result, according to the flexible meshing gear device according to the present embodiment, the same operating effect as that produced by the flexible meshing gear device 100 according to the first embodiment is exhibited.

(Fourth Embodiment)
FIG. 6 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the fourth embodiment. FIG. 6 corresponds to FIG. 2 of the first embodiment. The main difference from the first embodiment is that both the outer tooth portion and the inner tooth portion have a portion in which the diameter of the tooth tip changes in the axial direction. Hereinafter, the differences from the flexible meshing type gear device 100 according to the first embodiment will be mainly described.

The tooth tip of the first external tooth portion 4a has a first outermost diameter portion 4a1 and a first inner reducing portion 4a3 similar to that of the first embodiment. That is, the tooth tip of the first external tooth portion 4a does not have the first outer tooth portion, and instead the first outermost diameter portion 4a1 is outside the center line C1, in other words, the first external tooth portion 4a and the first outer tooth portion 4a. 1 The meshing range with the internal tooth portion 6a extends outward from the center in the axial direction, in other words, extends outward in the axial direction from a position outside the axial center of the tooth tip of the first internal tooth portion 6a. The tooth tip of the first external tooth portion 4a may have a first outer reducing portion.

The tooth tip of the second external tooth portion 4b has a second outermost diameter portion 4b1 and a second inner reducing portion 4b3 similar to that of the first embodiment. That is, the tooth tip of the second outer tooth portion 4b does not have the second outer tooth portion, and instead the second outermost diameter portion 4b1 is outside the center line C2, in other words, the second outer tooth portion 4b and the second outer tooth portion 4b. 2 The meshing range with the internal tooth portion 8a extends outward from the center in the axial direction, in other words, extends outward in the axial direction from a position outside the axial center of the tooth tip of the second internal tooth portion 8a. The tooth tip of the second outer tooth portion 4b may have a second outer reducing portion.

The tooth tip of the first internal tooth portion 6a has a first innermost diameter portion 6a1 and a first outer augmentation portion 6a2 similar to that of the second embodiment. That is, the tooth tip of the first internal tooth portion 6a does not have the first medial augmentation portion, and instead the first innermost tooth portion 6a1 is outside the center line C1, in other words, the first external tooth portion 4a and the first. It extends outward from the center of the meshing range with the internal tooth portion 6a in the axial direction, in other words, extends inward in the axial direction from a position outside the axial center of the tooth tip of the first internal tooth portion 6a. The tooth tip of the first internal tooth portion 6a may have a first inner augmentation portion.

The tooth tip of the second internal tooth portion 8a has a second innermost diameter portion 8a1 and a second outer augmentation portion 8a2 similar to that of the second embodiment. That is, the tooth tip of the second internal tooth portion 8a does not have the second inner tooth portion, and instead the second innermost tooth portion 8a1 is outside the center line C2, in other words, the second outer tooth portion 4b and the second. It extends outward from the center of the meshing range with the internal tooth portion 8a in the axial direction, in other words, extends axially inward from a position outside the axial center of the tooth tip of the second internal tooth portion 8a. The tooth tip of the second internal tooth portion 8a may have a second inner augmented portion.

The axial position of the boundary between the first outermost diameter portion 4a1 and the first inner reduction portion 4a3 substantially coincides with the axial position of the boundary between the first innermost diameter portion 6a1 and the first outer outer diameter portion 6a2. do. Further, these boundaries are outside the center line C1, in other words, outside the center of the meshing range between the first external tooth portion 4a and the first internal tooth portion 6a in the axial direction, in other words, the first internal tooth portion. It is located outside the axial center of the tooth tip of 6a. Further, in the present embodiment, these boundaries are located outside the axial center of the tooth tip of the first external tooth portion 4a.

Similarly, the axial position of the boundary between the second outermost diameter portion 4b1 and the first inner reducing portion 4a3 is substantially the same as the axial position of the boundary between the second innermost diameter portion 8a1 and the second outer inner diameter portion 8a2. Matches. Further, these boundaries are outside the center line C2, in other words, outside the center of the meshing range between the second external tooth portion 4b and the second internal tooth portion 8a in the axial direction, in other words, the second internal tooth portion. It is located outside the axial center of the tooth tip of 8a. Further, in the present embodiment, these boundaries are located outside the axial center of the tooth tip of the second external tooth portion 4b.

According to the flexible meshing gear device according to the present embodiment, the tooth tip of the external tooth portion has an inner reducing portion as in the first embodiment. On the other hand, the tooth tip of the outer tooth portion does not have the outer reducing portion, unlike the first embodiment. However, instead, the tooth tips of the internal teeth have lateral augmentations. As a result, according to the flexible meshing gear device according to the present embodiment, the same operating effect as that produced by the flexible meshing gear device 100 according to the first embodiment is exhibited.

(Fifth Embodiment)
FIG. 7 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the fifth embodiment. FIG. 7 corresponds to FIG. 2 of the first embodiment. The main difference from the first embodiment is that only the diameter of the tooth tip of the second external tooth portion 4b changes in the axial direction. Hereinafter, the differences from the flexible meshing type gear device 100 according to the first embodiment will be mainly described.

The tooth tips of the first external tooth portion 4a, which has a different number of teeth from the first internal tooth portion 6a, have a substantially constant outer diameter in the axial direction and the same outer diameter as the minimum outer diameter of the second external tooth portion 4b. It is configured to be.

The tooth tip of the second external tooth portion 4b having the same number of teeth as the second internal tooth portion 8a has a second outermost diameter portion 4b1 and a second inner reducing portion 4b3. That is, the tooth tip of the second outer tooth portion 4b does not have the second outer reducing portion. The second outermost diameter portion 4b1 is located at the end portion on the outer side in the axial direction. The second inner reducing portion 4b3 occupies 80% or more of the axial range of the tooth tip of the second outer tooth portion 4b (almost 100% in the illustrated example), and the second outermost diameter portion 4b1 occupies the axial direction. It is configured so that the outer diameter decreases continuously toward the inside, and more specifically, the outer diameter decreases in a curvilinear manner.

The tooth tip of the first internal tooth portion 6a is configured so that the inner diameter is substantially constant in the axial direction. Similarly, the tooth tip of the second internal tooth portion 8a is configured so that the inner diameter is substantially constant in the axial direction.

According to the flexible meshing type gear device according to the present embodiment, the teeth of the second external tooth portion 4b having the same number of teeth as the second internal tooth portion 8a, that is, the teeth of the second external tooth portion 4b which is the output side gear. At the tip, the outer diameter decreases from the second outermost diameter portion 4b1 toward the inner side in the axial direction, and the reduced portion (that is, the second inner diameter decreasing portion 4b3) is the axial direction of the tooth tip of the second outer tooth portion 4b. It is configured to occupy more than 80% of the range. As a result, it is possible to reduce the one-sided load generated at the tooth width end of the second external tooth portion 4b, which is the external tooth portion on the output side where the load is more likely to be applied, and it is possible to reduce excessive wear of the gear.

Further, according to the flexible meshing type gear device according to the present embodiment, the tooth tips of the first external tooth portion 4a and the tooth tips of the second external tooth portion 4b (particularly, the second inner reducing portion 4b3) are in the first inner portion, respectively. It is configured to extend to a portion corresponding to the gap 7 between the tooth gear 6 and the second internal tooth gear 8. As a result, it is possible to absorb the influence of the external gear being displaced with respect to the internal gear in the axial direction.

(Sixth Embodiment)
FIG. 8 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the sixth embodiment. FIG. 8 corresponds to FIG. 4 of the second embodiment. The main difference from the second embodiment is that only the diameter of the tooth tip of the second internal tooth portion 8a changes in the axial direction. Hereinafter, the differences from the flexible meshing type gear device 100 according to the first embodiment will be mainly described.

The tooth tip of the first external tooth portion 4a is configured so that the outer diameter is substantially constant in the axial direction. Similarly, the tooth tips of the second external tooth portion 4b are configured so that the outer diameter is substantially constant in the axial direction.

The inner diameter of the tooth tip of the first internal tooth portion 6a, which has a different number of teeth from the first external tooth portion 4a, is substantially constant in the axial direction and has the same inner diameter as the minimum inner diameter of the second internal tooth portion 8a. It is composed.

The tooth tip of the second internal tooth portion 8a having the same number of teeth as the second external tooth portion 4b has a second innermost inner diameter portion 8a1 and a second inner side augmentation portion 8a3. That is, the tooth tip of the second internal tooth portion 8a does not have the second outer augmentation portion. The second innermost diameter portion 8a1 is located at an end portion on the outer side in the axial direction. The second inner increasing portion 8a3 occupies 80% or more of the axial range of the tooth tip of the second inner tooth portion 8a (almost 100% in the illustrated example), and is axially inner from the second innermost inner diameter portion 8a1. It is configured so that the inner diameter increases continuously toward, and more specifically, the inner diameter increases in a curvilinear manner.

According to the flexible meshing gear device according to the present embodiment, the same operational effects as those exerted by the flexible meshing gear device according to the fifth embodiment are exhibited.

The flexure meshing gear device according to the embodiment has been described above. It will be appreciated by those skilled in the art that these embodiments are exemplary and that various modifications are possible for each of these components and combinations of processing processes, and that such modifications are also within the scope of the present invention. By the way.

(Modification example 1)
In the first to sixth embodiments, the case where the outer diameter and the inner diameter of each of the decreasing portion and the increasing portion are configured to decrease and increase in a curve has been described, but the present invention is not limited to this, and these are linear. It may be configured to decrease or increase.

FIG. 9 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the modified example of the first embodiment. .. FIG. 9 corresponds to FIG. 2 of the first embodiment. In this modification, the first outer reducing portion 4a2 is configured to linearly decrease the outer diameter toward the outer side in the axial direction, and the first inner reducing portion 4a3 linearly decreases the outer diameter toward the inner side in the axial direction. It is configured to do. Further, the second outer reducing portion 4b2 is configured so that the outer diameter decreases linearly toward the outer side in the axial direction, and the second inner reducing portion 4b3 is configured so that the outer diameter decreases linearly toward the inner side in the axial direction. Will be done. At least one of the first inner reducing portion 4a3 and the second inner reducing portion 4b3 has two straight portions having different inclinations with respect to the axial direction, in other words, different angles with the rotation axis R (see FIG. 1). Have. Of the two straight portions of the inner decreasing portion, the straight portion located on the outer side, that is, the straight portion on the side closer to the outermost diameter portion is more inclined than the straight portion located on the inner side, that is, the straight portion on the side farther from the outermost diameter portion. Is small, that is, the angle formed by the rotation axis R is small. Note that FIG. 9 shows a case where both the first inner reducing portion 4a3 and the second inner reducing portion 4b3 have two straight portions having different inclinations.

FIG. 10 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the modified example of the second embodiment. .. FIG. 10 corresponds to FIG. 4 of the second embodiment. In this modification, the first outer increasing portion 6a2 is configured so that the inner diameter increases linearly toward the outer side in the axial direction, and the first inner increasing portion 6a3 increases the inner diameter linearly toward the inner side in the axial direction. It is composed. Further, the second outer increasing portion 8a2 is configured so that the inner diameter increases linearly toward the outer side in the axial direction, and the second inner increasing portion 8a3 is configured so that the inner diameter increases linearly toward the inner side in the axial direction. .. At least one of the first inner increasing portion 6a3 and the second inner increasing portion 8a3 has two straight portions having different inclinations with respect to the axial direction, in other words, different angles with the rotating axis R (see FIG. 1). Have. Of the two straight portions of the inner increasing portion, the straight portion located on the outer side, that is, the straight portion on the side closer to the innermost diameter portion has a smaller inclination than the straight portion located on the inner side, that is, the straight portion on the side farther from the innermost inner diameter portion. That is, the angle formed by the rotation axis R is small. Note that FIG. 11 shows a case where both the first inner increasing portion 6a3 and the second inner increasing portion 8a3 have two straight portions having different inclinations.

FIG. 11 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the modified example of the third embodiment. .. FIG. 11 corresponds to FIG. 5 of the third embodiment. In this modification, the first outer reducing portion 4a2 is configured to decrease the outer diameter linearly toward the outer side in the axial direction, and the first inner increasing portion 6a3 linearly increases the inner diameter toward the inner side in the axial direction. It is configured as follows. Further, the second outer reducing portion 4b2 is configured so that the outer diameter decreases linearly toward the outer side in the axial direction, and the second inner increasing portion 8a3 is configured so that the inner diameter increases linearly toward the inner side in the axial direction. Will be done.

FIG. 12 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the modified example of the fourth embodiment. .. FIG. 12 corresponds to FIG. 6 of the fourth embodiment. In this modification, the first inner reducing portion 4a3 is configured to decrease the outer diameter linearly toward the inner side in the axial direction, and the first outer increasing portion 6a2 increases the inner diameter linearly toward the outer side in the axial direction. Is configured. Further, the second inner reducing portion 4b3 is configured to decrease the outer diameter linearly toward the inner side in the axial direction, and the second outer increasing portion 8a2 is configured to increase the inner diameter linearly toward the outer side in the axial direction. NS.

FIG. 13 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the modified example of the fifth embodiment. .. FIG. 13 corresponds to FIG. 7 of the fifth embodiment. In this modification, the second inner diameter reducing portion 4b3 is configured so that the outer diameter decreases linearly from the second outermost diameter portion 4b1 toward the inner side in the axial direction.

FIG. 14 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to another modification of the fifth embodiment. Is. FIG. 14 corresponds to FIG. 7 of the fifth embodiment. In this modification, the second inner diameter reducing portion 4b3 is configured so that the outer diameter decreases linearly from the second outermost diameter portion 4b1 toward the inner side in the axial direction. Further, in the present modification, the first external tooth portion 4a has a first outermost diameter portion 4a1 and a first inner reducing portion 4a3. The first outermost diameter portion 4a1 extends in the axial direction. The outer diameter of the first inner reducing portion 4a3 decreases linearly from the first outermost diameter portion 4a1 toward the inner side in the axial direction. The first inner reducing portion 4a3 is particularly configured such that its axial dimension D1 is smaller than the axial dimension D2 of the second inner reducing portion 4b3.

FIG. 15 is a diagram for explaining the shapes of the external gear 4, the first internal gear 6, and the second internal gear 8 of the flexible meshing gear device according to the modified example of the sixth embodiment. .. FIG. 15 corresponds to FIG. 8 of the sixth embodiment. In this modification, the second inner diameter increasing portion 8a3 is configured so that the inner diameter increases linearly from the second innermost inner diameter portion 8a1 toward the inner side in the axial direction.

In the modified examples of FIGS. 9 to 15, each decreasing portion is configured so that the decreasing ratio of the outer diameter with respect to the axial direction satisfies the above-mentioned equation 1, and each increasing portion has the increasing ratio of the inner diameter with respect to the axial direction described above. It is configured to satisfy Equation 2.

According to the modified examples of FIGS. 9 to 15, the same effect as that of the flexible meshing gear device according to the embodiment is exhibited. In addition, according to this modification, a processing machine capable of processing only a linear tooth tip-shaped tooth portion, that is, a processing machine capable of processing a curved tooth tip-shaped tooth portion can be used for manufacturing a gear. ..

(Modification 2)
In the first embodiment, both the first outermost diameter portion 4a1 and the second outermost diameter portion 4b1 are located outside the axial center of the meshing range between the corresponding outer tooth portion and the inner tooth portion. Although the case has been described, the case is not limited to this, and only one of the first outermost diameter portion 4a1 and the second outermost diameter portion 4b1 is more than the axial center of the meshing range between the corresponding outer tooth portion and the inner tooth portion. It may be located on the outside. For example, only the second outer tooth portion 4b having the same number of teeth as the second internal tooth portion 8a, that is, the second outermost diameter portion 4b1 of the second outer tooth portion 4b which is the output side gear, is the second outer tooth. It may be located outside the axial center of the meshing range between the portion 4b and the second internal tooth portion 8a.

Similarly, in the second embodiment, both the first innermost diameter portion 6a1 and the second innermost inner diameter portion 8a1 are located outside the axial center of the meshing range between the corresponding outer tooth portion and the inner tooth portion. However, the case is not limited to this, and only one of the first innermost diameter portion 6a1 and the second innermost inner diameter portion 8a1 is outside the axial center of the meshing range between the corresponding outer tooth portion and the inner tooth portion. It may be located in.

Further, in the third and fourth embodiments, both the boundary at the first external tooth portion 4a and the first internal tooth portion 6a and the boundary at the second external tooth portion 4b and the second internal tooth portion 8a correspond to each other. The case where the tooth portion is located outside the axial center of the meshing range between the external tooth portion and the internal tooth portion has been described, but the present invention is not limited to this, and the boundary between the first external tooth portion 4a and the first internal tooth portion 6a and Only one of the boundaries at the second external tooth portion 4b and the second internal tooth portion 8a may be located outside the axial center of the meshing range between the corresponding external tooth portion and the internal tooth portion.

(Modification example 3)
In the first to sixth embodiments and the above-described modified examples, the case where the internal tooth portion has a shorter axial length than the external tooth portion has been described, but the present invention is not limited to this. The external tooth portion may be shorter in the axial direction than the internal tooth portion and may be configured to mesh with the internal tooth portion in the entire axial direction. That is, it may be configured so that the axial length of the meshing range between the external tooth portion and the internal tooth portion is equal to the axial length of the external tooth portion. In this case, for example, each outermost diameter portion in the first embodiment, each innermost diameter portion in the second embodiment, and each boundary between the outermost diameter portion and the outer reducing portion in the third embodiment, And each boundary between the outermost diameter portion and the medial reduction portion in the fourth embodiment is outside the axial center of the meshing range of the corresponding external tooth portion and the internal tooth portion, in other words, the corresponding external tooth portion. It is located outside the axial center of the tooth tip.

4 External tooth gear, 4a 1st external tooth part, 4b 2nd external tooth part, 4a1 1st outermost diameter part, 4a2 1st outer reduction part, 4a3 1st inner reduction part, 6th 1st internal tooth gear, 8th 2 Internal tooth gear, 22a oscillator, 100 flexure meshing gear device.

Claims (9)

The oscillating body, the external gear that is flexed and deformed by the oscillating body, the first internal gear that meshes with the external gear, and the external gear that is arranged side by side in the axial direction with the first internal gear. A flexible meshing gear device including a second internal gear that meshes with the gear.
The external tooth gear has a first external tooth portion that meshes with the first internal tooth gear and a second external tooth portion that meshes with the second internal tooth gear.
The tooth tips of the first outer tooth portion include a first outermost diameter portion having the maximum outer diameter and a first outer diameter reducing portion whose outer diameter decreases from the first outermost diameter portion toward the outer side in the axial direction. The first inner diameter portion has a first inner diameter reduction portion whose outer diameter decreases inward in the axial direction from the first outermost diameter portion.
The tooth tips of the second outer tooth portion include a second outermost diameter portion having the maximum outer diameter and a second outer diameter reducing portion whose outer diameter decreases from the second outermost diameter portion toward the outer side in the axial direction. , have a, a second inner reduced portions whose outer diameter decreases toward the axially inward from the second outermost diameter portion,
At least one of the first outer diameter portion and the second outermost diameter portion is located outside the axial center of the tooth portion having the smaller axial width among the outer tooth portion and the inner tooth portion that mesh with each other. A flexible meshing gear device characterized by the fact that. The first outer reduction portion, the first inner reduction portion, the second outer reduction portion, and the second inner reduction portion are claimed so that the reduction ratio of the outer diameter with respect to the axial direction is 0.1 or less. Item 2. The flexible meshing gear device according to item 1. The first or second aspect of claim 1 or 2, wherein the first outer decrease portion, the second outer decrease portion, the first inner decrease portion, and the second inner decrease portion linearly decrease in outer diameter. Flexible meshing gear device. The flexible meshing gear device according to any one of claims 1 to 3, wherein at least one of the first inner reducing portion and the second inner reducing portion has two straight portions having different inclinations. The flexure meshing according to claim 4, wherein the straight portion located on the outer side in the axial direction of the two straight portions having different inclinations has a smaller inclination with respect to the axial direction than the straight portion located on the inner side in the axial direction. Type gear device. The first inner reducing portion and the second inner reducing portion are configured to extend to a portion corresponding to the radial inner side of the gap between the first internal gear and the second internal gear. The flexural meshing gear device according to any one of claims 1 to 5. The oscillating body, the external gear that is flexed and deformed by the oscillating body, the first internal gear that meshes with the external gear, and the external gear that is arranged side by side in the axial direction with the first internal gear. A flexible meshing gear device including a second internal gear that meshes with the gear.
The tooth tips of the internal tooth portions of the first internal gear have a first innermost inner diameter portion having a minimum inner diameter and a first outer inner diameter portion whose inner diameter increases outward in the axial direction from the first innermost inner diameter portion. It has a first inner increasing portion whose inner diameter increases inward in the axial direction from the first innermost inner diameter portion.
The tooth tips of the internal tooth portions of the second internal gear have a second innermost inner diameter portion having a minimum inner diameter and a second outer inner diameter portion whose inner diameter increases outward in the axial direction from the second innermost inner diameter portion. , A flexible meshing gear device comprising a second inner diameter increasing portion whose inner diameter increases inward in the axial direction from the second innermost diameter portion. The oscillating body, the external gear that is flexed and deformed by the oscillating body, the first internal gear that meshes with the external gear, and the external gear that is arranged side by side in the axial direction with the first internal gear. A flexible meshing gear device including a second internal gear that meshes with the gear.
The external tooth gear has a first external tooth portion that meshes with the first internal tooth portion of the first internal gear and a second external tooth portion that meshes with the second internal tooth portion of the second internal gear. death,
The tooth tips of the first outer tooth portion include a first outermost diameter portion having the maximum outer diameter and a first outer outer diameter reducing portion whose outer diameter decreases from the first outermost diameter portion toward the outer side in the axial direction. Have,
The tooth tips of the second outer tooth portion include a second outermost diameter portion having the maximum outer diameter and a second outer diameter reducing portion whose outer diameter decreases from the second outermost diameter portion toward the outer side in the axial direction. Have,
The tooth tip of the first internal tooth portion has a first innermost inner diameter portion having a minimum inner diameter and a first inner inner diameter increasing portion whose inner diameter increases in the axial direction from the first innermost inner diameter portion. ,
The tooth tip of the second internal tooth portion has a second innermost inner diameter portion having a minimum inner diameter and a second inner inner diameter increasing portion whose inner diameter increases in the axial direction from the second innermost inner diameter portion. A flexible meshing gear device characterized by. The oscillating body, the external gear that is flexed and deformed by the oscillating body, the first internal gear that meshes with the external gear, and the external gear that is arranged side by side in the axial direction with the first internal gear. A flexible meshing gear device including a second internal gear that meshes with the gear.
The external tooth gear has a first external tooth portion that meshes with the first internal tooth portion of the first internal gear and a second external tooth portion that meshes with the second internal tooth portion of the second internal gear. death,
The tooth tips of the first outer tooth portion include a first outer diameter portion having the maximum outer diameter and a first inner reducing portion whose outer diameter decreases in the axial direction from the first outer diameter portion. Have,
The tooth tips of the second outer tooth portion include a second outermost diameter portion having the maximum outer diameter and a second inner diameter reducing portion whose outer diameter decreases in the axial direction from the second outermost diameter portion. Have,
The tooth tip of the first internal tooth portion has a first innermost inner diameter portion having a minimum inner diameter and a first outer inner diameter portion whose inner diameter increases outward in the axial direction from the first innermost inner diameter portion. ,
The tooth tip of the second internal tooth portion has a second innermost inner diameter portion having a minimum inner diameter and a second outer inner diameter portion whose inner diameter increases outward in the axial direction from the second innermost inner diameter portion. A flexible meshing gear device characterized by.

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