阅读说明：本技术 波动齿轮装置的波动发生器 (Wave generator for wave gear device ) 是由 小林修平 折井大介 城越教夫 山崎宏 于 2018-08-30 设计创作，主要内容包括：在波动齿轮装置(1)的波动发生器(4)中,刚性的波动插塞(42)的非圆形轮廓的插塞外周面(43)通过压入以及粘接剂而固定于波动轴承(44)的内圈内周面(45)。插塞外周面(43)为槽形成面,该槽形成面形成有能够保持粘接剂的粘接剂保持槽、即微细槽(46)。当将波动插塞(42)压入到波动轴承(44)中时,能够降低从它们之间挤出的粘接剂的量,能够提高它们之间的结合力并且防止结合力的不均。(In a wave generator (4) of a wave gear device (1), a plug outer peripheral surface (43) of a non-circular contour of a rigid wave plug (42) is fixed to an inner ring inner peripheral surface (45) of a wave bearing (44) by press-fitting and an adhesive. The plug outer peripheral surface (43) is a groove forming surface on which an adhesive holding groove capable of holding an adhesive, that is, a fine groove (46) is formed. When the wave plug (42) is pressed into the wave bearing (44), the amount of adhesive squeezed out from between them can be reduced, the bonding force between them can be improved, and unevenness of the bonding force can be prevented.)

1. A wave generator of a wave gear device, wherein,

a wave generator of the wave gear device comprises: a rigid wave plug and a wave bearing,

the inner ring inner peripheral surface of the wave bearing is fixed to the plug outer peripheral surface of the wave plug having a non-circular contour by press-fitting and an adhesive,

one or both of the plug outer circumferential surface and the inner ring inner circumferential surface are groove forming surfaces in which an adhesive holding groove capable of holding the adhesive is formed.

2. A wave generator of a wave gear device according to claim 1,

the adhesive holding groove is a fine groove having a width and a depth of a micrometer scale or less,

an arrangement pattern is formed on the groove forming surface by the fine grooves,

the arrangement pattern is a 1 st direction arrangement pattern or a cross arrangement pattern,

the 1 st direction array pattern is an array pattern in which the fine grooves extend linearly or curvilinearly along the 1 st direction at a predetermined pitch,

the intersecting pattern is a pattern in which the 1 st direction alignment pattern and the 2 nd direction alignment pattern intersect with each other, and the 2 nd direction alignment pattern is an alignment pattern in which the fine grooves extend linearly or curvilinearly in the 2 nd direction at a predetermined pitch.

3. A wave generator of a wave gear device according to claim 2,

the 1 st direction alignment pattern is formed on the groove forming surface,

the 1 st direction is: the groove forming surface may have a circumferential direction, an axial direction orthogonal to the circumferential direction, or an inclined direction inclined with respect to the circumferential direction and the axial direction.

4. A wave generator of a wave gear device according to claim 2,

the groove forming surface is formed with the cross arrangement pattern,

the 1 st direction and the 2 nd direction are respectively: the groove forming surface may have a circumferential direction, an axial direction orthogonal to the circumferential direction, or an inclined direction inclined with respect to the circumferential direction and the axial direction.

5. A wave generator of a wave gear device according to claim 2,

the groove forming surface includes: a 1 st groove forming surface formed on one of the plug outer circumferential surface and the inner ring inner circumferential surface; and a 2 nd groove forming surface formed on the other of the plug outer peripheral surface and the inner ring inner peripheral surface,

the 1 st direction alignment pattern or the cross alignment pattern is formed on the 1 st groove forming surface and the 2 nd groove forming surface, respectively.

6. A wave generator of a wave gear device according to claim 5,

the 1 st direction alignment pattern is formed on the 1 st groove forming surface,

the 2 nd direction alignment pattern is formed on the 2 nd groove forming surface,

the 1 st direction and the 2 nd direction are respectively: a circumferential direction of the groove forming surface, an axial direction orthogonal to the circumferential direction, or an inclined direction inclined with respect to the circumferential direction and the axial direction,

the 1 st direction and the 2 nd direction are mutually different directions.

7. A wave generator of a wave gear device according to claim 2,

the outer peripheral surface of the plug is in an oval shape,

in the groove forming surface, the depth of the fine groove formed at a portion where a major axis of the elliptical shape is located is shallower than the depth of the fine groove formed at a portion where a minor axis of the elliptical shape is located.

8. A wave gear device in which, in a wave gear device,

the wave gear device has:

a rigid internally toothed gear;

a flexible externally toothed gear; and

a wave generator as claimed in claim 1.

Technical Field

The present invention relates to a wave gear device having a wave generator including a wave plug and a wave bearing. More specifically, the present invention relates to a wave generator that increases the pull-out force of a wave plug that is fixed to a wave bearing by press-fitting and adhesive.

Background

As a wave generator of a wave gear device, there is known a wave generator including: a rigid wave plug, and a wave bearing fitted to the elliptical outer peripheral surface of the wave plug. The wave plug and the wave bearing are fixed by press-fitting and an adhesive. In the flexural-mesh gear device (wave gear device) described in patent document 1, an inner ring member (inner ring of the wave bearing) is fixed to a vibration generating body (wave plug) by bonding or press-fitting.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018 and 96456, paragraph 0017

Disclosure of Invention

In order to improve the bonding force between the wave bearing and the wave plug, the two components are fixed by pressing and bonding. In this case, in order to improve workability when the wave plug is press-fitted into the wave bearing, the elliptical outer peripheral surface of the wave plug is press-fitted into the inner ring inner peripheral surface of the wave bearing in a perfect circle state while the adhesive is applied only to the inner ring inner peripheral surface of the wave bearing. The wave bearing is forcibly deflected into an elliptical shape by the pressing-in of the wave plug. During press fitting, the plug outer circumferential surface of the wavy plug having the elliptical profile slides in the axial direction while pressing and expanding the inner circumferential surface of the inner ring of the wavy bearing. The adhesive applied to the inner circumferential surface of the inner ring is pushed out in the axial direction by the plug outer circumferential surface. During press-fitting, the amount of adhesive pushed out from between the inner ring inner peripheral surface and the plug outer peripheral surface is large. Therefore, the bonding effect between the wave bearing and the wave plug is reduced, and the bonding effect is uneven.

In view of the above-described problems, it is an object of the present invention to provide a wave generator of a wave gear device, which can reduce the amount of adhesive squeezed out from between a wave plug and a wave bearing when the wave plug is pressed into the wave bearing, and can improve the bonding effect between them and prevent the unevenness of the bonding effect.

In order to solve the above problem, a wave generator of a wave gear device according to the present invention includes: the wave plug comprises a rigid wave plug and a wave bearing, wherein the inner ring inner peripheral surface of the wave bearing is fixed to the plug outer peripheral surface of the wave plug with a non-circular outline by press-fitting and adhesive, one or both of the plug outer peripheral surface and the inner ring inner peripheral surface are groove forming surfaces, and adhesive holding grooves capable of holding the adhesive are formed on the groove forming surfaces.

In the present invention, the adhesive holding groove is formed in at least one of the plug outer circumferential surface and the inner ring inner circumferential surface. When the wave plug is pressed in, the adhesive between the plug outer circumferential surface and the inner ring inner circumferential surface is held in the adhesive holding groove. By forming the adhesive holding groove appropriately, a required amount of adhesive can be held between the plug outer circumferential surface and the inner ring inner circumferential surface after press-fitting. The binding force between the fluctuation plug and the fluctuation bearing can be improved, and the unevenness of the binding force can be inhibited. Therefore, the drawing force for drawing the wave plug out of the wave bearing can be increased and the variation in the drawing force can also be reduced.

In the present invention, as the adhesive holding groove, a fine groove having a width and a depth of the order of micrometers or less can be used. Further, on the groove forming surface, a 1 st direction array pattern in which fine grooves linearly or curvilinearly extend in the same direction (1 st direction) at a predetermined pitch is formed. Alternatively, a cross arrangement pattern is formed in which a 1 st direction arrangement pattern in which the fine grooves extend linearly or curvilinearly in the 1 st direction at a predetermined pitch and a 2 nd direction arrangement pattern in which the fine grooves extend linearly or curvilinearly in the 2 nd direction at a predetermined pitch intersect.

The arrangement pattern of the fine grooves formed on the groove forming surface has high wettability, and the amount of the adhesive extruded at the time of pressure reduction can be reduced. As a result, the amount of the adhesive remaining between the wave bearing and the wave plug after press-fitting can be increased, and thus the pulling force of the wave plug can be improved and stabilized. The arrangement pattern of the fine grooves having a width and a depth of the order of micrometers or less can be formed on the plug outer circumferential surface and the inner ring inner circumferential surface by laser processing using a femtosecond laser, for example.

In the case of a wave plug provided with a plug outer peripheral surface having an elliptical contour as a wave generator, a flexible externally toothed gear is flexed into an elliptical shape. The external gear is meshed with the rigid internal gear at a portion where the major axis of the elliptical shape is located. A large stress is generated at the meshing portion of the two gears. In a wave generator that holds an external gear in an elliptical deflected state, a large surface pressure acts on a portion where a major axis of the elliptical shape is located, and substantially no surface pressure acts on a portion where a minor axis is located.

Therefore, on the groove forming surface, it is preferable to make the depth of the fine groove formed in the portion where the major axis of the elliptical shape is located where a large surface pressure acts shallower, and to make the fine groove formed in the portion where the minor axis of the elliptical shape is located where a surface pressure hardly acts deeper, so that more adhesive can be held.

Drawings

Fig. 1 is a schematic longitudinal sectional view and a schematic end view showing an example of a wave gear device to which the present invention is applied.

Fig. 2 is an explanatory view and a schematic end view showing a wave plug and a wave bearing of the wave generator.

Fig. 3 is an explanatory view showing an arrangement pattern of fine grooves on a groove forming surface.

FIG. 4 is an explanatory view showing an arrangement pattern of fine grooves on the 1 st and 2 nd groove forming surfaces.

Fig. 5 is an explanatory view showing the depth of the fine groove formed in the part where the major axis of the elliptical shape is located and the part where the minor axis is located on the groove forming surface.

Detailed Description

Hereinafter, an embodiment of a wave generator to which the wave gear device of the present invention is applied will be described with reference to the drawings. The following description is an example of a wave generator in which the present invention is applied to a silk-hat type wave gear device. The present invention can also be applied to a wave generator of a cup-type wave gear device or a flat-type wave gear device.

Fig. 1(a) is a schematic longitudinal sectional view showing the overall structure of a silk-hat type wave gear device (hereinafter, simply referred to as "wave gear device"), and fig. 1(b) is a schematic end view thereof. The wave gear device 1 is configured to include: an annular rigid internally toothed gear 2; a silk hat-shaped flexible external gear 3 coaxially disposed inside the internal gear 2; and an elliptical-shaped wave generator 4 fitted inside the external gear 3.

The external gear 3 includes a main body 31, a diaphragm 32, and a boss 33, and is formed in a top hat shape as a whole. The body 31 has a cylindrical shape and can be bent in the radial direction. One end of the body 31 is an open end 34, and external teeth 35 are formed on the outer peripheral surface of the body on the open end 34 side. The diaphragm 32 is extended outward in the radial direction so as to be continuous with the other end of the body 31. An annular boss 33 having a rectangular cross section is formed continuously with the outer peripheral edge of the diaphragm 32. The boss 33 is a rigid body portion for attaching the external gear 3 to another member (not shown). The internal gear 2 is disposed so as to surround the external teeth 35 of the external gear 3. The external teeth 35 can mesh with the internal teeth 21 formed on the inner peripheral surface of the internal gear 2.

The wave generator 4 is configured to include: a hollow hub 41; an elliptical rigid fluctuation plug 42 fitted to the outer periphery of the hollow boss 41; and a wave bearing 44 fitted to the elliptical plug outer peripheral surface 43 of the wave plug 42. The wave generator 4 causes the portion of the main body portion 31 of the external gear 3 where the external teeth 35 are formed to be deformed from the perfect circle of the original shape into an elliptical shape. The external teeth 35 mesh with the internal teeth 21 of the internal gear 2 at positions on both ends of the major axis Lmax of the ellipse.

When the wave generator 4 rotates about the central axis 1a, the meshing position of the gears 2 and 3 rotates in the circumferential direction. By this rotation, relative rotation is generated between the external gear 3 and the internal gear 2 in accordance with the difference in the number of teeth between the external teeth 35 and the internal teeth 21. For example, if the internal gear 2 is fixed and the wave generator 4 is used as a high-speed rotation input element, the external gear 3 is used as a reduced-speed rotation output element, and a rotation output reduced in speed according to the difference in the number of teeth between the gears 2 and 3 is taken out.

Fig. 2(a) is an explanatory view showing the wave plug 42 and the wave bearing 44 of the wave generator 4, and fig. 2(b) is a schematic end view thereof. The plug outer circumferential surface 43 of the wavy plug 42 having an elliptical contour is fixed to the inner ring inner circumferential surface 45 of the wavy bearing 44 by press fitting and an adhesive. One or both of the plug outer circumferential surface 43 and the inner ring inner circumferential surface 45 form a groove forming surface in which an adhesive holding groove capable of holding an adhesive is formed.

For example, the plug outer peripheral surface 43 of the wave plug 42 is a groove forming surface, and here, a fine groove 46 having a width and a depth of the order of micrometers or less is formed as an adhesive holding groove. The fine grooves 46 can be formed by laser processing using a femtosecond laser, for example. In the fine grooves 46 of this example, an array pattern 47 of fine grooves 46 is formed on the plug outer circumferential surface 43 at a constant interval in the plug circumferential direction and the plug width direction (direction of the center axis 1 a). In each of the arrangement patterns 47, the fine grooves 46 linearly extending in the plug width direction (the direction of the central axis 1 a) are arranged at a constant pitch along the plug circumferential direction.

In the wave generator 4 of the wave gear device 1 of this example, the elliptical plug outer peripheral surface 43 of the wave plug 42 is used as a groove forming surface on which fine grooves 46 functioning as adhesive holding grooves are formed. In the state after the wave plug 42 is pressed into the wave bearing 44, the amount of adhesive held therebetween can be increased. Further, during the press-fitting, a part of the adhesive flows along the fine grooves 46, and the amount of the adhesive extruded to the outside is reduced. Therefore, the variation in the drawing force of the fluctuation plug 42 can be reduced, and the lower limit value thereof can be increased.

(forms of groove forming surfaces)

Fig. 3 is an explanatory view showing examples of the arrangement pattern of fine grooves formed on the groove forming surface. The plug outer peripheral surface 43 of the wave plug 42, the inner ring inner peripheral surface 45 of the wave bearing 44, or both surfaces 43 and 45 can be used as groove forming surfaces on which the fine grooves 46 are formed.

The fine grooves 46 are formed in an array pattern extending linearly or in a curved shape in a predetermined direction at a predetermined pitch on the groove forming surface. For example, as shown in fig. 3(a), on the groove forming surface, an arrangement pattern in which the fine grooves 46 linearly extend at a constant pitch along the circumferential direction of the groove forming surface (the circumferential direction of the plug outer circumferential surface 43 or the inner ring inner circumferential surface 45) can be formed. As shown in fig. 3(b), on the groove forming surface, an array pattern in which the fine grooves 46 extend in a wave-like manner at a constant pitch in the circumferential direction can be formed.

As shown in fig. 3 c, on the groove forming surface, an array pattern in which the fine grooves 46 linearly extend at a constant pitch along an axial direction (a width direction of the plug outer circumferential surface 43 or the inner ring inner circumferential surface 45) orthogonal to a circumferential direction of the groove forming surface can be formed. As shown in fig. 3(d), on the groove forming surface, an array pattern in which the fine grooves 46 extend in a wave shape at a constant pitch along an axial direction orthogonal to the circumferential direction of the groove forming surface can be formed. As shown in fig. 3(e), on the groove forming surface, an inclined array pattern can be formed in which the fine grooves 46 linearly extend at a constant pitch in an inclined direction inclined with respect to the circumferential direction and the axial direction of the groove forming surface.

As shown in fig. 3(f) and (g), on the same groove forming surface, a crossing array pattern can be formed in which a 1 st direction array pattern in which the fine grooves 46 extend in the 1 st direction at a constant pitch and a 2 nd direction array pattern groove in which the fine grooves 46 extend in the 2 nd direction different from the 1 st direction at a constant pitch intersect with each other. In the cross arrangement pattern shown in fig. 3(f), the 1 st direction arrangement pattern is constituted by fine grooves 46 linearly extending in the circumferential direction, and the 2 nd direction arrangement pattern is constituted by fine grooves 46 linearly extending in the axial direction. In the cross arrangement pattern shown in fig. 3(g), the 1 st direction arrangement pattern is: an oblique alignment pattern formed by linear fine grooves 46 extending in a direction inclined by 45 degrees with respect to the circumferential direction and the axial direction, the 2 nd direction alignment pattern being: and an oblique arrangement pattern formed by fine linear grooves 46 extending in a direction inclined by 45 degrees in a direction opposite to the circumferential direction and the axial direction. Further, on the groove-forming surface, a cross arrangement pattern in which the arrangement pattern shown in fig. 3(a) and the arrangement pattern shown in fig. 3(b) overlap with each other can be formed.

Fig. 4 is an explanatory diagram showing an example in the case where the plug outer peripheral surface 43 of the wave plug 42 is a 1 st groove forming surface and the inner ring inner peripheral surface 45 is a 2 nd groove forming surface. In this case, the adhesive holding grooves formed on the 1 st and 2 nd groove forming surfaces may be fine grooves having a width and a depth of the order of micrometers or less. The fine grooves may be formed on the 1 st groove forming surface and the 2 nd groove forming surface in the same pattern as that shown in fig. 3.

For example, in the example shown in fig. 4(a), an arrangement pattern in which fine grooves 48 linearly extend in the circumferential direction at a constant pitch is formed in the 1 st groove forming surface 43A. On the 2 nd groove forming surface 45A, an array pattern in which fine grooves 49 linearly extend in the axial direction at a constant pitch is formed. The fine grooves 48 and 49 form a cross-aligned pattern in a state where the 1 st groove forming surface 43A is pressed into the 2 nd groove forming surface 45A and overlapped with each other.

In the example shown in fig. 4(b), the 1 st groove forming surface 43A is formed with an inclined array pattern in which fine grooves 48 linearly extend at a constant pitch in an inclined direction inclined at 45 degrees with respect to the circumferential direction and the axial direction. On the 2 nd groove forming surface 45A, an inclined array pattern is formed in which fine grooves 49 linearly extend at a constant pitch in an inclined direction inclined by 45 degrees in a direction opposite to the circumferential direction and the axial direction. In a state where the 1 st and 2 nd groove forming surfaces 43A and 45A are overlapped, the fine grooves 48 and 49 form a cross arrangement pattern.

Similarly, in the example shown in fig. 4(c), an arrangement pattern in which fine grooves 48 linearly extend in the circumferential direction at a constant pitch is formed in the 1 st groove forming surface 43A. On the 2 nd groove forming surface 45A, an array pattern is formed in which fine grooves 49 extend in a wave-like manner in the circumferential direction at a constant pitch. In a state where the 1-groove forming surface 43A and the 2-groove forming surface 45A overlap each other, the fine grooves 48 and 49 form a crossing arrangement pattern of the fine grooves 48 and 49.

(groove depth at Long and short axis positions of elliptical shape)

As described above, the wave gear device 1 includes the wave plug 42 having the plug outer circumferential surface 43 with the elliptical contour as the wave generator 4, and bends the flexible externally toothed gear 3 into an elliptical shape. The external gear 3 meshes with the rigid internal gear 2 at a portion where the major axis Lmax of the elliptical shape is located. At the meshing portion of the two gears 2, 3 formed at the portion where the major axis Lmax of the elliptical shape is located, force is transmitted between the two gears 2, 3. Therefore, in the wave generator 4 that holds the external gear 3 in the ellipsoidal flexed state, a large surface pressure acts on the portion of the elliptical shape where the major axis Lmax is located, and a surface pressure hardly acts on the portion where the minor axis Lmin is located.

Therefore, on the groove forming surface, the depth of the fine groove formed in the portion where the major axis Lmax of the elliptical shape to which a large surface pressure is applied is located can be made shallow, and the fine groove formed in the portion where the minor axis Lmin of the elliptical shape to which a surface pressure is hardly applied is located can be made deep, so that more adhesive can be held. For example, in the case where the micro fine groove 46 linearly extending in the circumferential direction is formed using the plug outer circumferential surface 43 as the groove forming surface (the case shown in fig. 3 a), the groove depth of the micro fine groove 46 is determined as shown in the explanatory view of fig. 5, for example. The depth of the fine groove 46 is exaggeratedly shown in the figure. As shown in the drawing, in the plug outer peripheral surface 43 of the fluctuation plug 42, the depth of the minute groove 46 is formed to be the maximum depth h1 at the portion where the minor axis Lmin of the elliptical shape is located and to be the minimum depth h2 at the portion where the major axis Lmax is located, along the circumferential direction thereof. In addition, the groove depth gradually decreases from the maximum depth h1 toward the minimum depth h2 in the circumferential direction.

(other embodiments)

In the above example, the fine grooves are formed as the adhesive holding grooves by laser processing. The adhesive holding groove can be formed by machining, etching, sandblasting, or other processing methods. In addition, an adhesive holding groove of a millimeter level may be used according to circumstances. Although the cross-sectional shape of the adhesive holding groove is not particularly described, grooves having various cross-sectional shapes such as a rectangular cross-sectional groove, a semicircular cross-sectional groove, and a V-shaped groove can be used.

The claims (modification according to treaty clause 19)

(deletion)

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(deletion)

(modified) a wave generator of a wave gear device, wherein,

a wave generator of the wave gear device comprises: a rigid wave plug and a wave bearing,

the inner ring inner peripheral surface of the wave bearing is fixed to the plug outer peripheral surface of the wave plug having a non-circular contour by press-fitting and an adhesive,

one of the plug outer circumferential surface and the inner ring inner circumferential surface includes: a 1 st groove forming surface on which an adhesive holding groove capable of holding the adhesive is formed, the other of the plug outer circumferential surface and the inner ring inner circumferential surface including: a 2 nd groove forming surface on which the adhesive holding groove capable of holding the adhesive is formed,

the adhesive holding groove is a fine groove having a width and a depth of a micrometer scale or less,

an arrangement pattern is formed on each of the 1 st groove forming surface and the 2 nd groove forming surface by the fine grooves,

the arrangement pattern is a 1 st direction arrangement pattern, a 2 nd direction arrangement pattern or a cross arrangement pattern,

the 1 st direction array pattern is an array pattern in which the fine grooves extend linearly or curvilinearly along the 1 st direction at a predetermined pitch,

the 2 nd direction array pattern is an array pattern in which the fine grooves extend linearly or curvilinearly in a 2 nd direction different from the 1 st direction at a predetermined pitch,

the intersecting pattern is a pattern in which the 1 st direction arrangement pattern and the 2 nd direction arrangement pattern intersect each other.

(modified) a wave generator of a wave gear device according to claim 5, wherein,

the 1 st direction alignment pattern is formed on the 1 st groove forming surface,

the 2 nd direction alignment pattern is formed on the 2 nd groove forming surface,

the 1 st direction and the 2 nd direction are respectively: the first groove forming surface and the second groove forming surface may be formed in a circumferential direction, an axial direction orthogonal to the circumferential direction, or an inclined direction inclined with respect to the circumferential direction and the axial direction.

(modified) a wave generator of a wave gear device according to claim 5, wherein,

the outer peripheral surface of the plug is in an oval shape,

the depth of the fine groove formed at a portion where a major axis of the elliptical shape is located is shallower than the depth of the fine groove formed at a portion where a minor axis of the elliptical shape is located on the 1 st and 2 nd groove forming surfaces.

(modified) a wave gear device, wherein,

the wave gear device has:

a rigid internally toothed gear;

a flexible externally toothed gear; and

a wave generator as claimed in claim 5.

(ii) a wave generator of a wave gear device, wherein,

a wave generator of the wave gear device comprises: a rigid wave plug and a wave bearing,

the inner ring inner peripheral surface of the wave bearing is fixed to the plug outer peripheral surface of the wave plug having a non-circular contour by press-fitting and an adhesive,

one or both of the plug outer circumferential surface and the inner ring inner circumferential surface are groove forming surfaces in which an adhesive holding groove capable of holding the adhesive is formed,

the adhesive holding groove is a fine groove having a width and a depth of a micrometer scale or less,

an arrangement pattern is formed on the groove forming surface by the fine grooves,

the arrangement pattern is a 1 st direction arrangement pattern, a 2 nd direction arrangement pattern or a cross arrangement pattern,

the 1 st direction array pattern is an array pattern in which the fine grooves extend linearly or curvilinearly along the 1 st direction at a predetermined pitch,

the 2 nd direction array pattern is an array pattern in which the fine grooves extend linearly or curvilinearly in a 2 nd direction different from the 1 st direction at a predetermined pitch,

the intersecting pattern is a pattern in which the 1 st direction arrangement pattern and the 2 nd direction arrangement pattern intersect each other,

the outer peripheral surface of the plug is in an oval shape,

in the groove forming surface, the depth of the fine groove formed at a portion where a major axis of the elliptical shape is located is shallower than the depth of the fine groove formed at a portion where a minor axis of the elliptical shape is located.

(addition) a wave generator of a wave gear device according to claim 9, wherein,

the 1 st direction alignment pattern is formed on the groove forming surface,

the 1 st direction is: the groove forming surface may have a circumferential direction, an axial direction orthogonal to the circumferential direction, or an inclined direction inclined with respect to the circumferential direction and the axial direction.

(addition) a wave generator of a wave gear device according to claim 9, wherein,

the groove forming surface is formed with the cross arrangement pattern,

the 1 st direction and the 2 nd direction are respectively: the groove forming surface may have a circumferential direction, an axial direction orthogonal to the circumferential direction, or an inclined direction inclined with respect to the circumferential direction and the axial direction.

(iii) a wave gear device, wherein,

the wave gear device has:

a rigid internally toothed gear;

a flexible externally toothed gear; and

a wave generator as claimed in claim 9.