阅读说明：本技术 齿轮装置 (Gear device ) 是由 田村光扩 山本章 渡边真大 的场年昭 于 2020-05-12 设计创作，主要内容包括：一种齿轮装置具备：外齿轮(14)；及内齿部件(16),设置有与外齿轮(14)啮合的内齿轮(24),其中,内齿部件(16)由树脂类材料制成,齿轮装置还具备加强部件(60),所述加强部件(60)抑制内齿轮(24)基于与外齿轮(14)的啮合而向径向外侧变形,加强部件(60)设置于内齿部件(16)的外周部中的距内齿轮(24)的内齿的径向距离最小的外周部。(A gear device is provided with: an external gear (14); and an internal gear member (16) provided with an internal gear (24) that meshes with the external gear (14), wherein the internal gear member (16) is made of a resin-based material, and the gear device further comprises a reinforcing member (60), wherein the reinforcing member (60) suppresses deformation of the internal gear (24) radially outward due to meshing with the external gear (14), and the reinforcing member (60) is provided on an outer peripheral portion of the external peripheral portion of the internal gear member (16) that has a minimum radial distance from the internal teeth of the internal gear (24).)

1. A gear device is provided with:

an outer gear; and

an internal gear member provided with an internal gear meshed with the external gear,

the gear unit is characterized in that it is,

the internal tooth member is made of a resin-like material,

the gear device further includes a reinforcing member that suppresses the internal gear from being deformed radially outward due to engagement with the external gear,

the reinforcing member is provided on an outer peripheral portion of the internal gear member, the radial distance from the internal teeth of the internal gear being smallest.

2. A gear device is provided with:

an outer gear; and

an internal gear member provided with an internal gear meshed with the external gear,

the gear unit is characterized in that it is,

the internal tooth member is made of a resin-like material,

the gear device includes a reinforcing member that suppresses the internal gear from deforming radially outward due to engagement with the external gear,

the reinforcing member is formed of a member different from the bearing and the bolt.

3. Gear unit according to claim 1 or 2,

the reinforcing member is in the form of an endless loop.

4. Gear unit according to any of claims 1 to 3,

the reinforcing member is fitted to an outer peripheral portion of the internal gear member and is made of a metal-based material.

5. Gear unit according to any of claims 1 to 4,

the reinforcing member is provided at a position overlapping with the internal teeth of the internal gear as viewed in the radial direction.

6. The gear arrangement according to claim 5,

the reinforcing member is provided at a position overlapping with a total axial length of the internal teeth of the internal gear as viewed in a radial direction.

7. Gear unit according to one of the claims 1 to 6,

the gear device further includes an oscillator that causes the external gear to be deformed by flexing,

the internal gear member includes:

a 1 st internal gear member provided with a 1 st internal gear that rotates the external gear; and

a 2 nd internal gear member provided with a 2 nd internal gear synchronized with a rotation component of the external gear,

the reinforcing member includes a 1 st reinforcing member that suppresses the 1 st internal gear from deforming radially outward.

Technical Field

The present invention relates to a gear device.

Background

In recent years, applications of gear devices have been diversified, and weight reduction thereof has been demanded in some cases. As a gear device that satisfies this requirement, patent document 1 discloses a gear device in which an internal gear member having an internal gear is made of a resin-based material.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-155313

Disclosure of Invention

Technical problem to be solved by the invention

The present inventors have studied the technique of patent document 1 and, as a result, have obtained the following new findings. Generally, the rigidity of resin materials is lower than that of metal materials. Therefore, when the internal gear member made of a resin material is used, the internal gear is more likely to be deformed radially outward due to the meshing with the external gear than when a metal material is used. Accordingly, normal meshing of the external gear and the internal gear may not be ensured. The technique of patent document 1 is not a technique that has been studied intensively from this viewpoint, and there is room for improvement.

One embodiment of the present invention has been made in view of such circumstances, and an object thereof is to provide a gear device that can achieve weight reduction and can ensure normal meshing between an external gear and an internal gear.

Means for solving the technical problem

In order to solve the above problem, one embodiment of the present invention relates to a gear device. The gear device includes an external gear, an internal gear provided with an internal gear meshing with the external gear, wherein the internal gear is made of a resin material, and a reinforcing member that suppresses the internal gear from deforming radially outward due to meshing with the external gear, the reinforcing member being provided in an outer peripheral portion of the external gear, the outer peripheral portion having a minimum radial distance from internal teeth of the internal gear.

A gear device according to another embodiment of the present invention includes an external gear, an internal gear member provided with an internal gear meshing with the external gear, wherein the internal gear member is made of a resin material, and a reinforcing member that suppresses the internal gear from deforming radially outward due to meshing with the external gear, the reinforcing member being formed of a member different from a bearing and a bolt.

Effects of the invention

According to one embodiment of the present invention, the weight can be reduced, and the normal meshing between the external gear and the internal gear can be ensured.

Drawings

Fig. 1 is a side sectional view of a gear device of an embodiment.

Fig. 2 is an enlarged view of fig. 1.

Detailed Description

An example of an embodiment of the present invention will be described below. In the following, the same constituent elements are denoted by the same reference numerals, and redundant description thereof is omitted. In the drawings, for convenience of explanation, a part of the constituent elements is omitted as appropriate, and the size is shown as enlarged or reduced as appropriate. According to the orientation view of the symbol. The structure or shape mentioned in the present specification is not limited to the structure or shape strictly corresponding to the mentioned shape, but includes a structure or shape deviating from the amount of error such as dimensional error or manufacturing error.

Refer to fig. 1. The gear device 10 of the embodiment mainly includes an input member 12, an external gear 14, an internal gear 16, a housing 18, a carrier 20, and an output member 22. The internal gear member 16 is provided with an internal gear 24 that meshes with the external gear 14. Hereinafter, the direction along the center axis La of the internal gear 24 is simply referred to as "axial direction X", and the circumferential direction and the radial direction around the center axis La are simply referred to as "circumferential direction" and "radial direction".

The gear device 10 of the present embodiment is a flexural-mesh gear device that operates while causing the external gears 14 to be flexurally deformed by a vibration generator 26, which will be described later, to rotate the external gears 14 and output the rotation component thereof. The gear device 10 of the present embodiment is a so-called cylindrical type flexible engagement gear device using a plurality of internal gear members 16.

The input member 12 is coupled to a drive device (not shown) and receives input of rotation from the drive device. The driving device is, for example, a motor, a gear motor, an engine, or the like. The drive device is disposed on one side (right side in the figure) in the axial direction X with respect to the input member 12. Hereinafter, for convenience of explanation, one side in the axial direction X is referred to as an input side, and the other side (left side in the drawing) is referred to as an opposite-input side.

The input member 12 of the present embodiment is constituted by a so-called vibrating body 26. The oscillator 26 is a cylindrical member having such rigidity that the external gear 14 can be flexurally deformed by its rotation. The oscillator 26 includes an intermediate shaft 26a at an intermediate portion in the axial direction X. The outer peripheral shape of the cross section of the intermediate shaft portion 26a perpendicular to the axial direction X is elliptical. The term "ellipse" in the present specification is not limited to an ellipse in a geometrically strict sense, but includes a substantially ellipse.

The external gear 14 is disposed on the outer peripheral side of the input member 12, and is rotatably supported by the input member 12 via a 1 st bearing 28 disposed between the input member 12 and the external gear. The external gear 14 of the present embodiment is a flexible cylindrical member, and is disposed on the outer peripheral side of the intermediate shaft portion 26a of the oscillator 26.

The internal gear member 16 is an annular member disposed on the outer peripheral side of the external gear 14, and an internal gear 24 is provided on the inner peripheral portion thereof. The internal gear 24 is composed of a plurality of internal teeth provided over the entire circumference of the internal gear member 16. The internal gear member 16 of the present embodiment has rigidity to such an extent that it does not deform following the rotation of the oscillator 26. The internal gear member 16 of the present embodiment includes a speed reduction internal gear member 16A (1 st internal gear member) disposed on the input side and an output internal gear member 16B (2 nd internal gear member) disposed on the opposite side from the input side.

The internal gear member for deceleration 16A of the present embodiment is fixed to an external member (not shown). A reduction internal gear 24A (1 st internal gear) that meshes with the external gear 14 is provided on an inner peripheral portion of the reduction internal gear member 16A. The number of teeth of the reduction internal gear 24A is different from the number of teeth of the external gear 14, and in the present embodiment, the number of teeth of the reduction internal gear 24A is larger than the number of teeth of the external gear 14. Thus, when the oscillator 26 rotates once, a shift in rotational phase corresponding to the difference in the number of teeth between the reduction internal gear 24A and the external gear 14 occurs in the external gear 14, and the external gear 14 rotates by the amount of the shift. The reduction internally toothed gear 24A rotates the externally toothed gear 14 in conjunction with the rotation of the oscillator 26. The external gears 14 rotate at a rotation speed reduced from the rotation speed of the oscillator 26 based on the reduction gear ratio corresponding to the difference in the number of teeth between the reduction internal gear 24A and the external gears 14.

An output internal gear 24B (2 nd internal gear) that meshes with the external gear 14 is provided on an inner peripheral portion of the output internal gear 16B. The number of teeth of the output internal gear 24B is the same as that of the external gear 14. Accordingly, when the external gear 14 rotates by one rotation of the oscillator 26, the rotation of the same magnitude as the rotation component is output to the output internal gear member 16B. When the external gear 14 rotates in conjunction with the rotation of the oscillator 26, the internal gear 24B for output synchronizes with the rotation component.

The housing 18 is an annular member provided on the outermost periphery of the gear device 10. The housing 18 of the present embodiment is disposed radially outward of the output ring gear 24B. A main bearing 30 is disposed between the casing 18 and the output ring gear 24B. The casing 18 of the present embodiment rotatably supports the output ring gear 24B via the main bearing 30. The housing 18 of the present embodiment is integrated with the decelerating internal gear 24A by fitting, bolts, or the like.

The main bearing 30 includes rolling elements 30a, an inner ring 30b, and an outer ring 30 c. The rolling elements 30a in the present embodiment are spheres, but may be rollers or the like. In the present embodiment, the inner ring 30B is formed of a member different from the internal gear member for output 16B, and the outer ring 30c is formed of a member different from the housing 18. However, the inner ring 30B may be constituted by the output internal gear member 16B, and the outer ring 30c may be constituted by the housing 18.

The carrier 20 of the present embodiment includes an input-side carrier 20A disposed on the input side and an opposite-input-side carrier 20B disposed on the opposite side. The input-side carrier 20A of the present embodiment is integrated with the reduction ring gear 24A by being coupled to the reduction ring gear 24A by the 1 st bolts B1. The non-input-side carrier 20B of the present embodiment is integrated with the output ring gear 24B by being coupled to the output ring gear 24B by the 2 nd bolts B2. A 2 nd bearing 32 is disposed between each carrier 20 and the input member 12, and the carrier 20 rotatably supports the input member 12 via the 2 nd bearing 32.

The output member 22 is coupled to the driven device and integrated with the driven device, thereby outputting rotational power to the driven device. The output member 22 of the present embodiment is the input-side carrier 20B.

Next, the operation of the gear device 10 will be described.

When rotation is transmitted from the drive device to the input member 12, the rotation is transmitted to the output member 22 via the speed reduction mechanism constituted by the external gear 14 and the internal gear 24. At this time, the rotation of the input member 12 is reduced at the reduction ratio of the reduction mechanism and then output from the output member 22 to the driven device.

In the present embodiment, as the oscillator 26 (input member 12) rotates, the intermediate shaft portion 26a of the oscillator 26 deforms the external gear 14 in an elliptical manner by flexing via the 1 st bearing 28. At this time, the meshing position between the external gear 14 and the internal gear 24 is changed in the circumferential direction, and the external gear 14 is flexurally deformed in conformity with the shape of the intermediate shaft portion 26a of the starting body 26. Accordingly, the external gear 14 rotates (rotates) relative to the reduction internal gear 24A by an amount corresponding to the difference in the number of teeth between the external gear 14 and the reduction internal gear 24A per rotation of the oscillator 26. At this time, the relative meshing position of the output ring gear 24B with respect to the ring gears 14 is not changed before and after one rotation of the input member 12, and rotates in synchronization with the rotation component of the ring gears 14. The rotation of the output ring gear 24B is output from the input-side carrier 20B (output member 22) to the driven device.

Refer to fig. 2. The internal gear member 16 is made of a resin material. In the present embodiment, the speed reduction internal gear member 16A and the output internal gear member 16B are both made of a resin material. The "resinous material" herein includes, in addition to engineering plastics and the like, fiber-reinforced resins (i.e., composite materials) such as carbon fiber-reinforced resins and glass fiber-reinforced resins. This makes it possible to reduce the weight of the internal gear member 16, as compared with the case where a metal-based material is used for the internal gear member 16. The "metallic material" herein includes: iron-based materials including cast iron and steel, and aluminum-based materials including aluminum alloys.

The speed reduction internal gear member 16A includes a 1 st annular portion 34, a 1 st protruding portion 36 protruding in the axial direction X from an inner peripheral end portion of the 1 st annular portion 34, and a 2 nd protruding portion 38 protruding from the inner peripheral end portion of the 1 st annular portion 34 toward a side opposite to the 1 st protruding portion 36 in the axial direction X. The speed reduction internal gear member 16A further includes a 3 rd projecting portion 40 projecting in the axial direction X from the outer circumferential end of the 1 st annular portion 34. The decelerating ring gear 24A is provided on inner peripheral portions of the 1 st annular portion 34 and the 1 st projecting portion 36 and an inner peripheral portion of a base end portion of the 2 nd projecting portion 38. An annular recess 42 recessed in the axial direction X is provided between the 1 st projecting portion 36 and the 3 rd projecting portion 40 of the internal gear member for deceleration 16A. The 1 st bolt B1 that couples the speed reduction internal gear member 16A and the input side carrier 20A is screwed into the 2 nd projecting portion 38.

The output internal gear member 16B includes: the 2 nd annular portion 44 is provided with the output ring gear 24B, a 4 th projecting portion 46 on an inner peripheral portion, and projects in the axial direction X from the 2 nd annular portion 44, and a 5 th projecting portion 48 projects from the 2 nd annular portion 44 toward a side opposite to the 4 th projecting portion 46 in the axial direction X. The 4 th projecting portion 46 is screwed with the 2 nd bolt B2 that connects the output internal gear 16B and the input-side carrier 20B. The 5 th projecting portion 48 is disposed inside the annular recessed portion 42 of the speed reduction internal gear member 16A, and is provided at a position overlapping the 1 st projecting portion 36 of the speed reduction internal gear member 16A when viewed in the radial direction.

The speed reduction internal gear member 16A includes a 1 st outer peripheral portion 50 formed by the 1 st projecting portion 36, a 2 nd outer peripheral portion 52 formed by the 2 nd projecting portion 38, and a 3 rd outer peripheral portion 54 formed by the 1 st annular portion 34 and the 3 rd projecting portion 40. The output internal gear member 16B includes a 4 th outer peripheral portion 56 including a base end portion of the 5 th protruding portion 48, the 2 nd annular portion 44, and the 4 th protruding portion 46, and a 5 th outer peripheral portion 58 including a tip end portion of the 5 th protruding portion 48. The "outer peripheral portion" herein means: the region formed by the radially outward facing surface of the internal gear member 16. In the present embodiment, the "surface" is a flat surface extending in the axial direction X and is provided over the entire circumference of the internal gear member 16 around the center axis La.

The radial distances from the internal teeth 64 of the decelerating internal gear 24A of the decelerating internal gear member 16A to the 1 st outer peripheral portion 50, the 2 nd outer peripheral portion 52, and the 3 rd outer peripheral portion 54 are referred to as L1, L2, and L3, respectively. The radial distances from the internal teeth 66 of the output ring gear 24B of the output internal gear member 16B to the 4 th and 5 th outer peripheral portions 56, 58 are referred to as L4, L5, respectively. The "radial distance" means: the distance from the tooth root of the internal teeth of the internal gear 24 to the radially outward surface formed by the outer peripheral portion. In this case, in the present embodiment, the radial distance L1 of the 1 st outer peripheral portion 50 among the plurality of outer peripheral portions 50, 52, 54 of the speed-reducing internal gear member 16A is smallest, the radial distance L2 of the 2 nd outer peripheral portion 52 is next, and the radial distance L3 of the 3 rd outer peripheral portion 54 is largest. In the present embodiment, the radial distance L4 between the 4 th outer peripheral portion 56 and the 5 th outer peripheral portion 58 of the plurality of outer peripheral portions 56 and 58 of the output ring gear 24B is the smallest, and the radial distance L5 is the largest.

Since the internal gear 24 meshes with the external gear 14, the internal gear 24 receives a load directed radially outward, and the internal gear 24 attempts to deform (a deformation in which the outer diameter is locally increased) based on the load. The gear device 10 includes a reinforcing member 60 that suppresses such deformation of the internal gear 24 toward the radial outside due to engagement with the external gear 14. The reinforcing member 60 of the present embodiment includes a 1 st reinforcing member 60A that suppresses deformation of the decelerating ring gear 24A and a 2 nd reinforcing member 60B that suppresses deformation of the outputting ring gear 24B.

The reinforcing member 60 is made of a material having a young's modulus [ Pa ] larger than that of the resin-based material constituting the internal gear member 16 using the reinforcing member 60. To achieve this, the reinforcing member 60 of the present embodiment is made of a metal-based material. This can effectively suppress deformation of the internal gear member 16, compared to when a resin material constituting the internal gear member 16 is used. In relation to this effect, the larger the young's modulus of the reinforcing member 60, the better. The young's modulus of the reinforcing member 60 is set to be, for example, 10 times or more the young's modulus of the resin material constituting the internal gear member 16. This can be achieved, for example, by making the internal toothed member 16 from an engineering plastic and making the reinforcing member 60 from a metallic material (e.g., a ferrous material).

The 1 st reinforcing member 60A is formed of a member different from the bearing and the bolt. The "bearing" herein is disposed between a plurality of components that are used in the gear device 10 and are rotatable relative to each other. In the present embodiment, for example, the 1 st bearing 28, the main bearing 30, and the like correspond to the "bearings". The "bolt" herein is used for connecting a plurality of constituent elements used in the gear device 10. In the present embodiment, for example, the 1 st bolt B1 and the 2 nd bolt B2 correspond to the "bolts". The 2 nd reinforcing member 60B of the present embodiment is constituted by the inner race 30B of the main bearing 30.

The 1 st reinforcing member 60A has an endless ring shape. The 2 nd reinforcing member 60B has an endless ring shape. The term "endless ring" as used herein means: is continuous over the entire circumferential range around the central axis La so as to have no shape of an end portion in the circumferential direction.

The 1 st reinforcing member 60A is fitted to the 1 st outer peripheral portion 50 of the internal gear member for deceleration 16A, and is provided in the 1 st outer peripheral portion 50. The 1 st reinforcing member 60A is provided in the 1 st outer peripheral portion 50 where the radial distance L1 is the smallest among the outer peripheral portions 50, 52, 54 of the internal gear member for deceleration 16A using the 1 st reinforcing member 60A. The 1 st reinforcing member 60A is fitted by interference fit, transition fit, or the like.

In the 1 st annular portion 34 of the internal gear member 16A for deceleration of the present embodiment, an annular groove portion 62 recessed in the axial direction X and extending in the circumferential direction is formed, and a part of the 1 st reinforcing member 60A is fitted into the groove portion 62.

The 2 nd reinforcing member 60B is fitted to the 4 th outer peripheral portion 56 of the output internal gear member 16B and is provided on the 4 th outer peripheral portion 56. The 2 nd reinforcing member 60B is provided in the 4 th outer peripheral portion 56 where the radial distance L4 is the smallest, of the outer peripheral portions 56 and 58 of the output internal gear member 16B using the 2 nd reinforcing member 60B. The 2 nd reinforcing member 60B is fitted by interference fit, transition fit, or the like.

Next, the effects of the gear device 10 will be described.

According to the gear device 10 of the present embodiment, when the internal gear 24 attempts to deform radially outward due to engagement with the external gear 14, the deformation can be suppressed by the reinforcing member 60. Therefore, even when the resin-based material having lower rigidity than the metal-based material is used for the internal gear member 16, the external gear 14 can be surely meshed with the internal gear 24 more properly than the case without the reinforcing member 60. Therefore, by forming the internal gear member 16 using a resin-based material, it is possible to achieve weight reduction and ensure normal meshing of the external gear 14 and the internal gear 24.

If the internal gear 24 is deformed radially outward, the ratchet effect (tooth skip) is more likely to occur between the internal gear 24 and the external gear 14 as the torque acting thereon increases. In this regard, according to the present embodiment, the occurrence of the ratcheting effect can be suppressed by suppressing the deformation of the internal gear 24 to the radially outer side. Therefore, by forming the internal gear member 16 using a resin material, the weight can be reduced, and the allowable torque of the gear device 10 can be increased.

Further, if normal meshing between the external gear 14 and the internal gear 24 cannot be ensured, it becomes a cause of partial wear. In this regard, according to the present embodiment, since the external gear 14 and the internal gear 24 can be surely normally meshed, the local wear can be suppressed.

The reinforcing member 60 is provided on the outer peripheral portions 50, 56 having the smallest radial distance from the internal teeth of the internal gear 24 among the outer peripheral portions of the internal gear member 16. Next, the advantages thereof will be described.

The boundary between the reinforcing member 60 and the internal gear member 16 in the radial direction is referred to as a boundary position, and a case where a constant load toward the radial outside is applied to the tooth contact position of the internal gear 24 that contacts the external gear 14 is considered. In this case, the wider the radial range from the tooth contact position of the internal gear member 16 to the boundary position, the more easily the amount of compressive deformation of the internal gear member 16 in the radial range increases, which results in the more easily the tooth contact position changes in the radial direction.

In this regard, according to the present embodiment, the radial range from the tooth contact position of the internal gear member 16 to the boundary position can be reduced as compared with the case where the reinforcing member 60 is provided at the outer peripheral portions 52, 54, 58 that are distant from the internal teeth of the internal gear 24 in the radial direction. Accordingly, when a load is applied to the tooth contact position of the internal gear 24 that contacts the external gear 14, the amount of compression deformation in the radial range described above can be reduced, and normal meshing between the external gear 14 and the internal gear 24 can be further ensured.

The reinforcing member 60 is in the form of an endless loop. Therefore, as compared with the case where the reinforcing member 60 has an end shape having an end portion in the circumferential direction, the reinforcing member 60 can be made more rigid, and thus deformation of the internal gear member 16 can be more easily suppressed by the reinforcing member 60.

When the reinforcing member 60 is made of a resin material, the reinforcing member 60 is affected by sink marks as well as the internal gear member 16, and it is difficult to ensure the dimensional accuracy of the reinforcing member 60 and the internal gear member 16. Therefore, when the reinforcing member 60 is fitted to the outer peripheral portion of the internal gear member 16, a large gap is likely to be generated between the internal gear member 16 and the reinforcing member 60, and it is difficult to stably obtain the effect of suppressing the deformation of the reinforcing member 60.

In this regard, according to the present embodiment, since the reinforcing member 60 is made of a metal-based material, it is easier to ensure the dimensional accuracy of the reinforcing member 60 than in the case where the reinforcing member 60 is made of a resin-based material. Accordingly, when the reinforcing member 60 is fitted to the outer peripheral portion of the internal gear member 16, a large gap is less likely to be formed between the internal gear member 16 and the reinforcing member 60, and the effect of suppressing deformation of the reinforcing member 60 is easily and stably obtained.

The reinforcing member 60 includes a 1 st reinforcing member 60A that suppresses deformation of the speed reduction internal gear member 16A that rotates the external gear 14. Next, the advantages thereof will be described.

The output internal gear 24B is synchronized with the rotation component of the external gear 14. Therefore, the external teeth of the external gear 14 to be engaged with the internal teeth of the internal gear 24B for output are preferably always the same regardless of the number of revolutions of the oscillator 26. On the other hand, the reduction internally toothed gear 24A rotates relative to the externally toothed gears 14 by the rotation of the externally toothed gears 14. Therefore, the external teeth of the external gear 14, which is the meshing target of the internal teeth of the internal gear for deceleration 24, change according to the rotation number of the oscillator 26. Since the size of each external tooth of the external gear 14 changes due to the influence of the size error, if the meshing target of each internal tooth of the internal gear 24 changes according to the number of rotations of the oscillator 26, the tooth contact position of each internal tooth with the external gear 14 may also change. As a result, the reduction ring gear 24A has a problem that the tooth tip side is more likely to be partially worn than the output ring gear 24B. According to the present embodiment, even under such a premise, the deformation of the decelerating internal gear 24A can be suppressed by the 1 st reinforcing member 60A, and therefore, the local wear on the tooth tip side can be effectively suppressed.

Next, another point of the reduction gear transmission according to the present embodiment will be described.

The 1 st reinforcing member 60A is provided at a position overlapping the internal teeth 64 of the decelerating internal gear 24A using the 1 st reinforcing member 60A as viewed in the radial direction. In the present embodiment, the 1 st reinforcing member 60A is provided at a position overlapping with a part of the internal teeth 64 of the decelerating internal gear 24A in the axial direction. Specifically, the 1 st reinforcing member 60A is provided at a position overlapping a range including the axial center portion 64a of the internal teeth 64. In the present embodiment, this range is equal to or more than half of the total axial length La of the internal teeth 64.

The 2 nd reinforcing member 60B is provided at a position overlapping the internal teeth 66 of the internal gear for output 24B using the 2 nd reinforcing member 60B as viewed in the radial direction. In the present embodiment, the 2 nd reinforcing member 60B is provided at a position overlapping with a part of the internal teeth 66 of the internal gear for output 24B in the axial direction. Specifically, the 2 nd reinforcing member 60B is provided at a position overlapping a range including the axial direction central portion 66a of the internal teeth 66. In the present embodiment, this range is equal to or more than half of the total axial length Lb of the internal teeth 66.

Thus, when a load is applied radially outward from the tooth contact position of the internal gear 24, the load can be received more easily and more reliably by the reinforcing member 60, as compared to a case where the reinforcing member 60 is provided at a position not overlapping the internal gear 24 when viewed radially. Accordingly, the reinforcing member 60 can effectively suppress the deformation of the ring gear 24 toward the radially outer side.

From the viewpoint of effectively obtaining such an effect, the reinforcing member 60 is preferably provided at a position that overlaps the total axial lengths La, Lb of the internal teeth 66, 68 of the internal gear 24 using the reinforcing member 60 as viewed in the radial direction.

Next, a modified example of each constituent element will be described.

The gear device 10 is not particularly limited as long as it is a device including the external gear 14 and the internal gear member 16 that mesh with each other. For example, an eccentric oscillating type gear device, a simple planetary gear device, or the like may be used in addition to the flexible engagement type gear device. The eccentric oscillating type gear device may be a center crank type in which a crankshaft of the input member 12 is disposed on the center axis La of the ring gear 24. Further, a distributed eccentric oscillating type gear device in which a crankshaft is disposed at a position deviated from the central axis La may be employed. The flexible engagement gear device is not limited to the cylindrical type, and a silk hat type, a cup type, or the like may be used.

The output member 22 may be constituted by any one of the carrier 20, or may be constituted by the casing 18.

The material of the components of the gear device 10 other than the internal gear member 16 is not particularly limited. For example, the external gear 14 may be made of any one of a metal-based material and a resin-based material. Other constituent elements are also the same.

When a plurality of internal gear members 16 are used, a configuration may be adopted in which only one internal gear member 16 is made of a resin-based material and the other internal gear members 16 are made of another material. In this case, the gear device 10 may be provided with the reinforcing member 60 that suppresses deformation of the internal gear member 16 made of a resin material. For example, the gear device 10 may include the 1 st internal gear member 16A made of a resin-based material, the 2 nd internal gear member 16B made of a metal-based material, and the 1 st reinforcing member 60A that suppresses deformation of the 1 st internal gear member 16A, but may not include the 2 nd reinforcing member 60B that suppresses deformation of the 2 nd internal gear member 16B. The gear device 10 may include a 1 st internal gear member 16A made of a metal-based material, a 2 nd internal gear member 16B made of a resin-based material, and a 2 nd reinforcing member 60B that suppresses deformation of the 2 nd internal gear member 16B, but does not include the 1 st reinforcing member 60A that suppresses deformation of the 1 st internal gear member 16A.

The above description has been given of an example in which the reinforcing member 60 is provided on the outer peripheral portion of the internal gear member 16 using the reinforcing member 60, the outer peripheral portion being located radially outward of the internal teeth of the internal gear member 16 and having the smallest radial distance. The reinforcing member 60 may be provided on an outer peripheral portion located radially inward of the internal teeth of the internal gear member 16 and having a minimum radial distance.

When the reinforcing member 60 is formed of a member different from the bearing and the bolt, it may be embedded in the internal gear member 16. In this case, the reinforcing member 60 may be provided in an outer peripheral portion of the internal gear member 16 using the reinforcing member 60, the radial distance of which is greater than that of the other outer peripheral portions. For example, the 1 st reinforcing member 60A may be provided in the 2 nd outer peripheral portion 52 or the 3 rd outer peripheral portion 54 of the 1 st internal gear member 16A.

The reinforcing member 60 may have an end shape having an end in the circumferential direction. For example, it is conceivable that the reinforcing member 60 is formed of a C-shaped retainer ring or the like. The reinforcing member 60 may be formed of a plurality of divided bodies divided in a ring shape in the circumferential direction.

The reinforcing member 60 is not limited to being made of a metal-based material, and may be made of a resin-based material, for example. In this case, the reinforcing member 60 may be made of a material having a young's modulus higher than that of the resin material constituting the internal gear member 16 using the reinforcing member 60. In this case, the reinforcing member 60 may be made of a fiber-reinforced resin in which the same resin material as the internal gear member 16 is used as a matrix material and fibers are embedded in the matrix material. At this time, the fiber-embedded portion becomes the reinforcing member 60. The reinforcing member 60 is not limited to being formed of a member different from the internal gear member 16, and may be formed as a part of the same member as the internal gear member 16.

When the reinforcing member 60 is fitted to the outer peripheral portion of the internal gear member 16, the groove portion 62 may not be formed in the internal gear member 16.

The reinforcing member 60 may be provided at a position that does not overlap with the internal teeth of the internal gear 24 using the reinforcing member 60 when viewed in the radial direction.

The embodiments and modifications of the present invention have been described in detail above. The above-described embodiments and modifications are merely specific examples for carrying out the invention. The contents of the embodiment and the modifications are not intended to limit the technical scope of the present invention, and various design changes such as changes, additions, deletions, and the like of the constituent elements may be made without departing from the scope of the inventive concept. In the above-described embodiments, the description of "embodiment" is given to emphasize the contents in which such a design change is possible, but the design change is allowed even in the contents without such a mark. Any combination of the above constituent elements is also effective as an aspect of the present invention. The hatching lines in the cross section of the drawings do not limit the material of the objects marked with the hatching lines.

Industrial applicability

The present invention relates to a gear device.

Description of the symbols

10-gear unit, 14-external gear, 16-internal gear, 24-internal gear, 26-vibrator, 50, 52, 54, 56, 58-peripheral part, 60-reinforcing part.