Gear device and robot

Abstract

This gear device (10) is attached to an attachment member, and is provided with: an internal gear (20); an external gear (30) partially engaged with the internal gear (20); a wave generator (40) that is in contact with the inner peripheral surface of the external gear (30) and rotates the meshing position of the internal gear (20) and the external gear (30) about a rotating shaft (10A); a bearing (50) which is provided with an inner ring (51) and an outer ring (52) and supports the internal gear (20) and the external gear (30) in a relatively rotatable manner; and an oil seal (60) in which a first space (54) open at one end surface of the bearing (50) is formed between the inner ring (51) and the outer ring (52), a second space (55) open at the other end surface of the bearing (50) is formed between the inner ring (51) and the outer ring (52), a gear-side space (70) communicating with the second space (55) is formed between the external gear (30) and the bearing (50), and the oil seal (60) seals the first space (54). The external gear (30) is provided with: a flexible cylindrical part (31) coaxially disposed on the inside of the internal gear (20); a diaphragm section (33) extending outward from the end of the cylindrical section (31); and a rigid annular hub section (34) extending from the outer peripheral edge of the diaphragm section (33), the hub section (34) being attached to the attachment member, a communication hole (80) communicating with the first space (54) or the gear-side space (70) being formed at least in the hub section (34), and the communication hole (80) communicating with the internal space (31A) of the cylindrical section (31) via a groove (2A) provided in the attachment member.

Description

Technical Field

[0001] The present disclosure relates to a gear device and a robot. Background Art

[0002] In the past, a silkhat type wave gear device described in International Publication No. 2018 / 189798 (hereinafter referred to as Patent Document 1) is known. The silkhat type wave gear device includes: an internal gear; an external gear; a wave generator that meshes the external teeth of the external gear with the internal teeth of the internal gear and rotates the meshing position of the external teeth relative to the internal teeth; and a cross roller bearing that supports the internal gear and the external gear in a relatively rotatable manner. The bearing has a first gap portion opened at a first end face of one side of the bearing and a second gap portion opened at a second end face of the other side of the bearing between its inner and outer rings.

[0003] The first gap portion is connected to the outside and is sealed by an oil seal. The oil seal prevents excess lubricant that has flowed into the bearing from leaking to the outside. The second gap portion is connected to a gear side gap portion that is arranged on the outer peripheral side of the external gear. A bearing seal is provided between the second gap portion and the gear side gap portion. The bearing seal seals the open end of the second gap portion from the gear side gap portion. Thus, it is possible to prevent excess lubricant from flowing from the gear side gap portion into the second gap portion, and it is possible to allow excess lubricant that has flowed into the bearing to escape from the second gap portion to the gear side gap portion.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2018 / 189798 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the top-hat type wave gear device described above, if the bearing seal is maintained in a posture with the opening end of the second gap portion open for some reason, the lubricant cannot be prevented from flowing from the gear side gap portion into the second gap portion. Therefore, there is a possibility that the lubricant flows excessively into the bearing and leaks out from the oil seal to the outside.

[0009] Technical solutions to solve problems

[0010] The gear device disclosed in the present invention is installed on a mounting member, wherein the gear device comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner peripheral surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate around a rotation axis; a bearing comprising an inner ring and an outer ring and supporting the internal gear and the external gear in a relatively rotatable manner; and an oil seal, wherein a first space opening on one end face of the bearing is formed between the inner ring and the outer ring, and a second space opening on the other end face of the bearing is formed between the inner ring and the outer ring, and an oil seal is formed between the inner ring and the outer ring. A gear side space connected to the second space is formed between the external gear and the bearing, and the oil seal seals the first space. The external gear comprises: a flexible cylindrical portion coaxially arranged on the inner side of the internal gear; a diaphragm portion extending outward from the end of the cylindrical portion; and a rigid hub portion extending from the outer peripheral edge of the diaphragm portion and in an annular shape. The hub portion is mounted on the mounting component, and a connecting hole connected to the first space or the gear side space is formed at least in the hub portion, and the connecting hole is connected to the internal space of the cylindrical portion via a groove provided in the mounting component.

[0011] Effects of the Invention

[0012] According to the present disclosure, in the gear device and the robot, it is possible to suppress the lubricant from leaking out from the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a perspective view of the gear device according to the first embodiment.

[0014] Figure 2 This is a diagram of the gear device viewed from a direction parallel to the rotation axis.

[0015] Figure 3 yes Figure 2 A cross-sectional view of the gear device and the arm in section AA.

[0016] Figure 4 is a cross-sectional view of a gear device according to Embodiment 2, showing Figure 3 The corresponding cross-sectional view.

[0017] Figure 5 is a cross-sectional view of a gear device according to Embodiment 3, showing Figure 3 The corresponding cross-sectional view.

[0018] Figure 6 is a cross-sectional view of a gear device according to Embodiment 4, showing Figure 3 The corresponding cross-sectional view.

[0019] Figure 7is a cross-sectional view of a gear device according to Embodiment 5, showing Figure 3 The corresponding cross-sectional view.

[0020] Figure 8 is a cross-sectional view of a gear device according to Embodiment 6, showing Figure 3 The corresponding cross-sectional view.

[0021] Fig. 9 is a cross-sectional view of a gear device according to a modified example of the sixth embodiment, showing Figure 3 The corresponding cross-sectional view.

[0022] Fig.10 is a cross-sectional view of a gear device according to Embodiment 7, showing Figure 3 The corresponding cross-sectional view.

[0023] Fig.11 is a cross-sectional view of a gear device according to Embodiment 8, showing Figure 3 The corresponding cross-sectional view.

[0024] Fig.12 is a cross-sectional view of a gear device according to Embodiment 9, showing Figure 3 The corresponding cross-sectional view.

[0025] Fig.13 is a cross-sectional view of a gear device according to Embodiment 10, showing Figure 3 The corresponding cross-sectional view.

[0026] Fig.14 is a cross-sectional view of a gear device according to Embodiment 11, showing Figure 3 The corresponding cross-sectional view.

[0027] Fig.15 is a cross-sectional view of a gear device according to a first modification of the eleventh embodiment, and is a view showing Figure 3 The corresponding cross-sectional view.

[0028] Fig.16 is a cross-sectional view of a gear device according to a second variation of the eleventh embodiment, and is a view showing Figure 3 The corresponding cross-sectional view.

[0029] Fig.17 is a cross-sectional view of a gear device according to a third variation of the eleventh embodiment, and is a view showing Figure 3 The corresponding cross-sectional view.

[0030] Fig.18 is a cross-sectional view of a gear device according to Embodiment 12, showing Figure 3 The corresponding cross-sectional view.

[0031] Fig.19 is a cross-sectional view of a gear device according to Embodiment 13, showing Figure 3 The corresponding cross-sectional view. DETAILED DESCRIPTION

[0032] [Description of Embodiments of the Present Disclosure]

[0033] First, embodiments of the present disclosure are listed for description.

[0034] (1) The gear device of the present disclosure is mounted on a mounting member, wherein the gear device comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner peripheral surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate around a rotation axis; a bearing comprising an inner ring and an outer ring and supporting the internal gear and the external gear in a manner capable of relative rotation; and an oil seal, wherein a first space opening to one end surface of the bearing is formed between the inner ring and the outer ring, and a second space opening to the other end surface of the bearing is formed between the inner ring and the outer ring, A gear side space connected to the second space is formed between the external gear and the bearing, and the oil seal seals the first space. The external gear comprises: a flexible cylindrical portion coaxially arranged on the inner side of the internal gear; a diaphragm portion extending outward from the end of the cylindrical portion; and a rigid hub portion extending from the outer peripheral edge of the diaphragm portion and in an annular shape. The hub portion is mounted on the mounting component, and a connecting hole connected to the first space or the gear side space is formed at least in the hub portion, and the connecting hole is connected to the internal space of the cylindrical portion via a groove provided in the mounting component.

[0035] Since the first space or the gear side space is connected to the internal space of the cylindrical portion via the connecting hole and the groove of the mounting member, the lubricant flowing into the first space or the gear side space can be returned to the internal space of the cylindrical portion. Therefore, it is possible to suppress the lubricant from excessively flowing into the first space, thereby suppressing the lubricant from leaking from the oil seal.

[0036] Furthermore, since the communicating hole is formed at least in the rigid boss portion, it is possible to suppress a reduction in the strength of the external gear.

[0037] (2) In the gear device described in (1), the communication hole may be formed in the boss portion and the outer ring and communicate with the first space.

[0038] Since the communicating hole is formed in the hub portion and the outer ring and communicates with the first space, the lubricant flowing into the first space can be returned to the inner space of the cylindrical portion via the communicating hole and the groove of the mounting member, thereby suppressing the leakage of the lubricant from the oil seal.

[0039] (3) In the gear device described in (1), the communication hole may be formed in the boss portion and communicate with the gear side space.

[0040] Since the communication hole is formed in the hub portion and communicates with the gear side space, the lubricant that is to flow into the bearing from the gear side space can be returned to the inner space of the cylindrical portion via the communication hole and the groove of the mounting member. Therefore, leakage of the lubricant from the oil seal can be suppressed.

[0041] (4) The gear device disclosed in the present invention comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner peripheral surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate around a rotation axis; a bearing comprising an inner ring and an outer ring and supporting the internal gear and the external gear in a manner capable of relative rotation; a first sealing member; and a second sealing member separate from the first sealing member, the inner ring and the internal gear constituting an inner member, a third space opening at one end face of the bearing being formed between the inner member and the outer ring, a second space opening at the other end face of the bearing being formed between the inner ring and the outer ring, a gear side space communicating with the second space being formed between the external gear and the bearing, the first sealing member being an oil seal and sealing the third space, and the second sealing member being arranged on the inner side of the third space than the first sealing member and sealing the third space.

[0042] The first sealing member serving as an oil seal and the second sealing member can double-control the leakage of the lubricant.

[0043] (5) In the gear device described in (4), the second sealing member may be an oil seal.

[0044] The two oil seals can doubly suppress the leakage of the lubricant.

[0045] (6) In the gear device described in (5), the outer ring may include: an outer ring body; and an extension plate fixed to the outer ring body and extending toward the internal gear from the inner ring, and the first sealing member is arranged between the extension plate and the internal gear.

[0046] By adding an extended plate to the outer ring body, the design of the gear device may be facilitated.

[0047] (7) According to the gear device described in (6), it can also be that the gear device is installed on a mounting member, wherein the external gear comprises: a flexible cylindrical portion coaxially arranged on the inner side of the internal gear; a diaphragm portion extending outward from the end of the cylindrical portion; and a rigid hub portion extending from the outer peripheral edge of the diaphragm portion and being annular, and a connecting hole connected to the third space is formed on the outer ring and the hub portion, and the connecting hole is connected to the internal space of the cylindrical portion via a groove provided in the mounting member.

[0048] In addition to the double seal structure formed by the two oil seals, the leakage of the lubricant can be further suppressed by returning the lubricant flowing into the third space to the internal space of the cylindrical portion via the communicating hole and the groove of the mounting member.

[0049] (8) The gear device disclosed in the present invention comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner peripheral surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate around a rotation axis; a bearing comprising an inner ring and an outer ring and supporting the internal gear and the external gear in a manner capable of relative rotation; an oil seal; a first bearing seal; a second bearing seal separate from the first bearing seal; a first plate fixed to the inner ring; and a spacer, wherein a first space opening to one end face of the bearing is formed between the inner ring and the outer ring, a second space opening to the other end face of the bearing is formed between the inner ring and the outer ring, and a gear side space connected to the second space is formed between the external gear and the bearing, the oil seal seals the first space, and the spacer seals the first space. The external gear comprises: a flexible cylindrical portion coaxially arranged on the inner side of the internal gear; a diaphragm portion extending outward from the end of the cylindrical portion; and a rigid hub portion extending from the outer peripheral edge of the diaphragm portion and being annular, the first bearing seal comprises a first base portion and a first front end portion extending from the first base portion, the second bearing seal comprises a second base portion and a second front end portion extending from the second base portion, the spacer is clamped and fixed by the outer ring and the hub portion, the first base portion is clamped and fixed by the spacer and the outer ring, the second base portion is clamped and fixed by the spacer and the hub portion, the first front end portion contacts the first plate from the second space side to seal the second space, and the second front end portion contacts the first plate from the gear side space side to separate the gear side space.

[0050] Since the first front end portion of the first bearing seal contacts the first plate from the second space side, it is possible to suppress the lubricant from being squeezed out from the second space into the gear side space. Since the second front end portion of the second bearing seal contacts the first plate from the gear side space side, it is possible to suppress the lubricant from flowing from the gear side space into the second space. Therefore, it is possible to suppress the lubricant from flowing excessively into the first space, thereby suppressing the lubricant from leaking from the oil seal.

[0051] Furthermore, since the first bearing seal and the second bearing seal are separate bodies, it is easy to ensure the volume of the space between the first bearing seal and the second bearing seal, and even if the lubricant enters the space, the first bearing seal and the second bearing seal are not released from contact with the first plate.

[0052] (9) The gear device disclosed in the present invention comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner peripheral surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate around a rotation axis; a bearing having an inner ring and an outer ring and supporting the internal gear and the external gear in a manner capable of relative rotation; an oil seal; a third bearing seal; and a second plate fixed to the inner ring, a first space opening at one end surface of the bearing being formed between the inner ring and the outer ring, a second space opening at the other end surface of the bearing being formed between the inner ring and the outer ring, and a second space opening at the other end surface of the bearing being formed between the inner ring and the outer ring. A gear side space connected to the second space is formed between the gear and the bearing, and the oil seal seals the first space. The external gear comprises: a flexible cylindrical portion coaxially arranged on the inner side of the internal gear; a diaphragm portion extending outward from the end of the cylindrical portion; and a rigid hub portion extending from the outer peripheral edge of the diaphragm portion and in an annular shape. The third bearing seal comprises: a base; a first lip extending from the base; and a second lip extending from the base, the base is clamped and fixed by the second plate and the inner ring, and the first lip and the second lip are in contact with the diaphragm portion to separate the gear side space.

[0053] By providing the first lip and the second lip on the third bearing seal, it is possible to suppress the extrusion of lubricant from the second space into the gear side space and the inflow of lubricant from the gear side space into the second space. Therefore, it is possible to suppress the excessive inflow of lubricant into the first space, thereby suppressing the leakage of lubricant from the oil seal.

[0054] Furthermore, by increasing the space between the first lip and the second lip, the third bearing seal can be configured so that one of the first lip and the second lip does not interfere with the other and the contact between the first lip and the second lip and the diaphragm portion is not released.

[0055] (10) The gear device disclosed in the present invention comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner peripheral surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate about a rotation axis; a bearing comprising an inner ring and an outer ring and supporting the internal gear and the external gear in a manner capable of relative rotation; an oil seal; a fourth bearing seal; and a third plate fixed to the inner ring, wherein a first space opening to one end surface of the bearing is formed between the inner ring and the outer ring, a second space opening to the other end surface of the bearing is formed between the inner ring and the outer ring, a gear side space communicating with the second space is formed between the external gear and the bearing, the oil seal seals the first space, and the fourth bearing seal comprises: a base; a first lip extending from the base; and a second lip extending from the base, the base being clamped and fixed by the third plate and the inner ring, the first lip and the second lip contacting the outer ring and separating the second space from the gear side space.

[0056] By providing the first lip and the second lip on the fourth bearing seal, it is possible to suppress the extrusion of lubricant from the second space into the gear side space and the inflow of lubricant from the gear side space into the second space. Therefore, it is possible to suppress the excessive inflow of lubricant into the first space, thereby suppressing the leakage of lubricant from the oil seal.

[0057] Furthermore, by increasing the space between the first lip and the second lip, the fourth bearing seal can be configured so that one of the first lip and the second lip does not interfere with the other and the contact between the first lip and the second lip and the outer ring is not released.

[0058] (11) The gear device disclosed in the present invention comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner peripheral surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate around a rotation axis; a bearing having an inner ring and an outer ring and supporting the internal gear and the external gear in a manner capable of relative rotation; an oil seal; a fifth bearing seal; and a fourth plate fixed to the outer ring and extending toward the inner ring, a first space opened on one end surface of the bearing being formed between the inner ring and the outer ring, and a space opened on the other end surface of the bearing being formed between the inner ring and the outer ring. A second space with an end face opening, a gear side space connected to the second space is formed between the external gear and the bearing, the oil seal seals the first space, a fourth space connecting the gear side space and the second space is formed between the fourth plate and the inner ring, the fifth bearing seal comprises: a base; a first lip extending from the base; and a second lip extending from the base, the base is accommodated in a groove formed on one of the fourth plate and the inner ring, the first lip and the second lip are in contact with the other of the fourth plate and the inner ring to separate the fourth space.

[0059] By providing the first lip and the second lip on the fifth bearing seal, it is possible to suppress the extrusion of lubricant from the second space into the gear side space and the inflow of lubricant from the gear side space into the second space. Therefore, it is possible to suppress the excessive inflow of lubricant into the first space, thereby suppressing the leakage of lubricant from the oil seal.

[0060] Furthermore, by increasing the space between the first lip and the second lip, the fifth bearing seal can be configured so that one of the first lip and the second lip does not interfere with the other and the contact between the first lip and the second lip and the fourth plate or the inner ring is not released.

[0061] (12) A robot according to the present disclosure includes the gear device described in any one of (1) to (11).

[0062] The lubricant can be prevented from leaking out of the gear device.

[0063] (13) The gear device disclosed in the present invention comprises: an internal gear; an external gear partially meshing with the internal gear; a wave generator contacting the inner circumferential surface of the external gear and causing the meshing position of the internal gear and the external gear to rotate around a rotation axis; a bearing comprising an inner ring and an outer ring and supporting the internal gear and the external gear in a manner capable of relative rotation; and an oil seal, wherein a first space opening on one end face of the bearing is formed between the inner ring and the outer ring, a second space opening on the other end face of the bearing is formed between the inner ring and the outer ring, a gear side space connected to the second space is formed between the external gear and the bearing, the oil seal seals the first space, and the gear device forms a connecting hole connecting the gear side space to the atmosphere.

[0064] Since the gear side space is connected to the atmosphere through the connection hole, the pumping action caused by the deflection of the external gear disappears, so the lubricant is not sent from the gear side space into the bearing. Therefore, the leakage of the lubricant from the oil seal can be suppressed.

[0065] (14) In the gear device described in (13), the connecting hole may be formed in the inner ring and the internal gear.

[0066] (15) In the gear device described in (13), the external gear may include: a flexible cylindrical portion coaxially arranged on the inner side of the internal gear; a diaphragm portion extending outward from the end of the cylindrical portion; and a rigid hub portion extending from the outer peripheral edge of the diaphragm portion and in an annular shape, and the connecting hole is formed in the hub portion.

[0067] (16) The robot disclosed in the present invention comprises: a gear device described in any one of (13) to (15); a first component to which the gear device is fixed; and an air tube, wherein the first component has a through hole connected to the connecting hole, one end of the air tube is connected to the through hole and mounted on the first component, and the other end of the air tube is open to the atmosphere.

[0068] Since the air tube is provided, even when the lubricant enters the connection hole, it is possible to suppress the lubricant from leaking to the outside.

[0069] (17) In the robot described in (16), at least a portion of the air tube may be in a coil shape.

[0070] Since at least a part of the air tube is coiled, the length of the air tube can be increased, thereby further suppressing the lubricant from leaking to the outside.

[0071] [Details of the embodiments of the present disclosure]

[0072] The following is a description of the embodiments of the present disclosure. In addition, the present disclosure is not limited to these examples, but is shown by the scope of the claims, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims. In the following description, sometimes only part of the same components are marked with numbers, and the numbers of other components are omitted.

[0073] [Implementation Method 1]

[0074] <Gear device>

[0075] Reference Figures 1 to 3 Embodiment 1 of the present disclosure is described. Figure 1 and Figure 2 As shown, the gear device 10 of this embodiment includes: an internal gear 20; an external gear 30 arranged on the inner side of the internal gear 20; a wave generator 40 arranged on the inner side of the external gear 30; and a bearing 50 that supports the internal gear 20 and the external gear 30 in a manner that allows relative rotation.

[0076] <Robot, Arm>

[0077] The gear device 10 is used, for example, as a speed reducer of a rotating part of a robot or the like. Figure 3 As shown, the robot 1 involved in this embodiment includes: a base (not shown); an arm 2 supported in a manner that can rotate relative to the base; a gear device 10 that transmits a driving force from one of the base and the arm 2 to the other; and a motor (not shown) that is a driving source of the gear device 10. The internal gear 20 is fixed to the base. The external gear 30 is connected to the arm 2. The wave generator 40 is connected to the motor. In this embodiment, the arm 2 is an example of a mounting member.

[0078] In this manner, the wave generator 40 rotates at the same speed as the motor, and the rotation of the wave generator 40 is transmitted to the meshing position of the external gear 30 and the internal gear 20. Since the number of teeth of the external gear 30 is different from the number of teeth of the internal gear 20, the external gear 30 and the internal gear 20 are rotated around the rotation axis 10A (see Figure 1 ) relative rotation. When the number of teeth of the internal gear 20 is greater than the number of teeth of the external gear 30, the external gear 30 can be rotated at a speed lower than the speed of the motor. Therefore, it is possible to construct a speed reducer with the wave generator 40 as the input shaft side and the external gear 30 as the output shaft side.

[0079] <Internal gear, external gear>

[0080] Below, refer to Figure 3 The detailed structure of the gear device 10 will be described.

[0081] The internal gear 20 includes: an annular member 21 having a substantially rectangular cross-sectional shape; and internal teeth 22 formed on the inner peripheral surface of the annular member 21. The external gear 30 includes: a cylindrical portion 31; external teeth 32 formed on the outer peripheral surface on one end side of the cylindrical portion 31; a disc-shaped diaphragm portion 33 extending radially outward from the other end of the cylindrical portion 31; and an annular hub portion 34 formed continuously with the outer peripheral edge of the diaphragm portion 33. The external teeth 32 are configured to be meshable with the internal teeth 22. The number of teeth of the external gear 30 (the number of external teeth 32) is less than the number of teeth of the internal gear 20 (the number of internal teeth 22). The cylindrical portion 31 and the diaphragm portion 33 are flexible. The hub portion 34 is rigid. The external gear 30 and the internal gear 20 are rotatable around the same rotation axis 10A.

[0082] <Wave Generator>

[0083] The wave generator 40 bends the cylindrical portion 31 of the external gear 30 into a non-circular shape, such as an elliptical shape, thereby meshing the external teeth 32 with the internal teeth 22. The wave generator 40 includes: a cam plate; and a wave bearing provided between the outer peripheral surface of the cam plate and the inner peripheral surface of the cylindrical portion 31. The cam plate is connected to the motor and rotates around the rotating shaft 10A. The rotation of the cam plate is transmitted to the external gear 30 via the wave bearing, so that the meshing position of the external gear 30 and the internal gear 20 moves in the circumferential direction.

[0084] <Bearings>

[0085] The bearing 50 is arranged so as to coaxially surround the cylindrical portion 31. The bearing 50 of the present embodiment is a cross roller bearing. The bearing 50 includes an inner ring 51, an outer ring 52 arranged outside the inner ring 51, and rollers 53 arranged in a raceway groove between the inner ring 51 and the outer ring 52. The inner ring 51 is located between the internal gear 20 and the diaphragm portion 33 in the direction along the rotation axis 10A, and is fixed to the internal gear 20. The outer ring 52 is fixed to the hub portion 34.

[0086] <First Space, Second Space, Oil Seal>

[0087] A first space 54 and a second space 55 are formed between the inner ring 51 and the outer ring 52. The first space 54 is located on the inner gear 20 side and is open to the outside from one end surface of the bearing 50. The second space 55 is open to the other end surface of the bearing 50. The first space 54 is sealed by an oil seal 60.

[0088] <Gear side space>

[0089] A gear side space 70 is formed between the external gear 30 and the bearing 50 . The gear side space 70 extends from the meshing portion between the internal teeth 22 and the external teeth 32 along the cylindrical portion 31 and the diaphragm portion 33 . The gear side space 70 communicates with the second space 55 .

[0090] <Communication hole>

[0091] The gear device 10 of the present embodiment is formed with a connecting hole 80 connected to the first space 54. In detail, the connecting hole 80 is composed of a first connecting hole 81 and a second connecting hole 82 connected to the first connecting hole 81. The first connecting hole 81 is formed in the outer ring 52. The first connecting hole 81 is composed of a first hole 83 extending in the radial direction and a second hole 84 connected to the first hole 83 and extending along the rotation axis 10A. The first hole 83 is connected to the first space 54. The second hole 84 opens on the end face of the outer ring 52 on the side of the hub portion 34. The second connecting hole 82 is formed in the hub portion 34. The second connecting hole 82 is connected to the second hole 84.

[0092] <slot>

[0093] In addition, a groove 2A communicating with the second communicating hole 82 is formed in the arm 2. The groove 2A is recessed from the end surface of the mounting boss portion 34 of the arm 2. The groove 2A extends radially inward from the second communicating hole 82 side. The groove 2A communicates with the internal space 31A formed radially inward of the cylindrical portion 31 via the space between the end surface of the arm 2 and the diaphragm portion 33. Therefore, the first space 54 communicates with the internal space 31A of the cylindrical portion 31 via the first communicating hole 81, the second communicating hole 82, and the groove 2A.

[0094] <Lubricant>

[0095] Lubricant is appropriately placed in advance in various parts of the gear device 10, specifically, in the meshing portion between the internal gear 20 and the external gear 30, the internal space 31A of the cylindrical portion 31, and the fitting portion between the external gear 30 and the wave generator 40. The lubricant is, for example, grease.

[0096] When the gear device 10 is operated, the cylindrical portion 31 repeatedly bends in the radial direction at the meshing portion of the internal gear 20 and the external gear 30. Due to this bending, a pumping action is generated to squeeze the lubricant from the meshing portion of the internal gear 20 and the external gear 30 into the gear side space 70. The lubricant squeezed out by the pumping action flows toward the track groove of the bearing 50 through the gear side space 70. The lubricant flows from the track groove of the bearing 50 into the first space 54.

[0097] In the present embodiment, since the communicating hole 80 communicating with the first space 54 is formed, even if the lubricant flows into the first space 54 as described above, the lubricant can also flow into the communicating hole 80. Therefore, it is possible to suppress the situation where the excess lubricant accumulates in the first space 54 and leaks to the outside from the oil seal 60. In addition, the lubricant that has flowed into the communicating hole 80 flows back to the internal space 31A of the cylindrical portion 31 through the groove 2A of the arm 2.

[0098] Although not shown, a check valve may be provided in the communication hole 80 to allow the lubricant to flow from the first space 54 to the groove 2A side and to restrict the lubricant from flowing from the groove 2A side to the first space 54. This can prevent excess lubricant from accumulating in the first space 54.

[0099] [Effects of Embodiment 1]

[0100] As described above, the gear device 10 of embodiment 1 is installed on the mounting member (arm 2), wherein the gear device 10 includes: an internal gear 20; an external gear 30 partially meshing with the internal gear 20; a wave generator 40 that contacts the inner peripheral surface of the external gear 30 and rotates the meshing position of the internal gear 20 and the external gear 30 around the rotation axis 10A; a bearing 50 that includes an inner ring 51 and an outer ring 52 and supports the internal gear 20 and the external gear 30 in a manner that allows relative rotation; and an oil seal 60 that forms a first space 54 opened at one end surface of the bearing 50 between the inner ring 51 and the outer ring 52, and a space between the inner ring 51 and the outer ring 52 at the end surface of the bearing 50. A second space 55 with an opening on another end face is formed with a gear side space 70 communicating with the second space 55 between the external gear 30 and the bearing 50. The oil seal 60 seals the first space 54. The external gear 30 comprises: a flexible cylindrical portion 31 coaxially arranged on the inner side of the internal gear 20; a diaphragm portion 33 extending outward from the end of the cylindrical portion 31; and a rigid hub portion 34 extending from the outer peripheral edge of the diaphragm portion 33 and in an annular shape. The hub portion 34 is mounted on a mounting member, and a connecting hole 80 communicating with the first space 54 is formed at least in the hub portion 34. The connecting hole 80 is connected to the internal space 31A of the cylindrical portion 31 via a groove 2A provided in the mounting member.

[0101] Since the first space 54 is connected to the internal space 31A of the cylindrical portion 31 via the communicating hole 80 and the groove 2A of the mounting member, the lubricant flowing into the first space 54 can be returned to the internal space 31A of the cylindrical portion 31. Therefore, it is possible to suppress the lubricant from excessively flowing into the first space 54, and to suppress the lubricant from leaking from the oil seal 60.

[0102] Furthermore, since the communicating hole 80 is formed at least in the rigid boss portion 34 , it is possible to suppress a reduction in the strength of the external gear 30 .

[0103] In the gear device 10 according to the first embodiment, the communication hole 80 is formed in the boss portion 34 and the outer ring 52 , and communicates with the first space 54 .

[0104] Since the communicating hole 80 is formed in the hub portion 34 and the outer ring 52 and communicates with the first space 54, the lubricant flowing into the first space 54 can be returned to the internal space 31A of the cylindrical portion 31 via the communicating hole 80 and the groove 2A of the mounting member. Therefore, the leakage of the lubricant from the oil seal 60 can be suppressed.

[0105] The robot 1 according to the first embodiment is a robot 1 including a gear device 10 .

[0106] It is possible to suppress the lubricant from leaking out from the gear device 10 to the outside.

[0107] [Implementation Method 2]

[0108] Reference Figure 4 Embodiment 2 of the present disclosure is described. In the gear device 110 and the robot 101 of Embodiment 2, the method of the connecting hole 180 is different from that of Embodiment 1. As for other structures and effects, since they are the same as those of Embodiment 1, the same reference numerals as those of Embodiment 1 are given to the components equivalent to those of Embodiment 1, and detailed descriptions are omitted.

[0109] The communication hole 180 of the gear device 110 is composed of a first communication hole 181 and a second communication hole 182 connected to the first communication hole 181. The first communication hole 181 is composed of a first hole 83 extending in the radial direction and a second hole 184 connected to the first hole 83 and extending along the rotation axis 10A. The second hole 184 is formed by passing through the outer ring 52. The second communication hole 182 is formed in the hub portion 34. The second communication hole 182 is connected to the second hole 184.

[0110] A groove 2A communicating with the second communicating hole 182 is formed in the arm 102 (an example of a mounting member) of the robot 101. As in the first embodiment, the first space 54 communicates with the internal space 31A of the cylindrical portion 31 via the first communicating hole 181, the second communicating hole 182, and the groove 2A. In addition, a bolt fastening hole 102B is formed recessed from the bottom surface of the groove 2A in the arm 102. An internal thread is provided on the inner surface of the bolt fastening hole 102B.

[0111] The outer ring 52 is fixed to the arm 102 by the bolt 102C. Specifically, the bolt 102C is inserted through the second hole 184 and the second communicating hole 182, and is screwed with the internal thread of the bolt fastening hole 102B. A sealing gasket 102D is arranged between the head of the bolt 102C and the outer ring 52. Thus, the lubricant flowing from the first space 54 into the communicating hole 180 does not leak to the outside from between the head of the bolt 102C and the outer ring 52.

[0112] Although not shown, a check valve may be provided in the first hole 83 of the communicating hole 180 to allow the lubricant to flow from the first space 54 to the groove 2A side and to restrict the lubricant from flowing from the groove 2A side to the first space 54. Thus, it is possible to prevent excess lubricant from accumulating in the first space 54.

[0113] [Implementation method 3]

[0114] Reference Figure 5 Embodiment 3 of the present disclosure is described. In the gear device 210 and the robot 201 of Embodiment 3, the method of the connecting hole 280 is different from that of Embodiment 1. As for other structures and effects, since they are the same as those of Embodiment 1, the same reference numerals as those of Embodiment 1 are given to the components equivalent to those of Embodiment 1, and detailed descriptions are omitted.

[0115] The boss portion 234 of the gear device 210 is formed with a communication hole 280 that communicates with the gear side space 70 .

[0116] The arm 2 of the robot 201 is formed with a groove 2A that communicates with the communication hole 280. The groove 2A is recessed from the end surface of the mounting boss portion 234 of the arm 2. The groove 2A communicates with the internal space 31A of the cylindrical portion 31 via the space between the end surface of the arm 2 and the diaphragm portion 33. Therefore, the gear side space 70 communicates with the internal space 31A of the cylindrical portion 31 via the communication hole 280 and the groove 2A.

[0117] In the present embodiment, since the communicating hole 280 communicating with the gear side space 70 is formed, a part of the lubricant that is to flow from the gear side space 70 into the second space 55 due to the pump action can flow into the communicating hole 280. Therefore, it is possible to suppress the lubricant from excessively flowing from the gear side space 70 into the first space 54 through the second space 55 and leaking to the outside from the oil seal 60. In addition, the lubricant that has flowed into the communicating hole 280 flows back to the internal space 31A of the cylindrical portion 31 through the groove 2A of the arm 2.

[0118] The communicating hole 280 is preferably disposed radially apart from the second space 55. With such a structure, it is easy to suppress the lubricant that has once flowed into the communicating hole 280 from flowing back into the second space 55.

[0119] Although not shown, a check valve may be provided in the communication hole 280 to allow the lubricant to flow from the gear side space 70 to the groove 2A side and to restrict the lubricant from flowing from the groove 2A side to the gear side space 70. Thus, the lubricant can be prevented from flowing from the gear side space 70 to the inside of the bearing 50, and therefore, the excess lubricant can be prevented from accumulating in the first space 54.

[0120] [Effects of Embodiment 3]

[0121] The gear device 210 of embodiment 3 is installed on the mounting member (arm 2), and includes: an internal gear 20; an external gear 30 partially meshing with the internal gear 20; a wave generator 40 that contacts the inner peripheral surface of the external gear 30 and rotates the meshing position of the internal gear 20 and the external gear 30 around the rotation axis 10A; a bearing 50 that includes an inner ring 51 and an outer ring 52 and supports the internal gear 20 and the external gear 30 in a manner that allows relative rotation; and an oil seal 60 that forms a first space 54 opened at one end face of the bearing 50 between the inner ring 51 and the outer ring 52, and a second space 54 opened at the other end face of the bearing 50 between the inner ring 51 and the outer ring 52. Two spaces 55, a gear side space 70 connected to the second space 55 is formed between the external gear 30 and the bearing 50, and the oil seal 60 seals the first space 54. The external gear 30 comprises: a flexible cylindrical portion 31, coaxially arranged on the inner side of the internal gear 20; a diaphragm portion 33, extending outward from the end of the cylindrical portion 31; and a rigid hub portion 234, extending from the outer peripheral edge of the diaphragm portion 33 and being annular. The hub portion 234 is mounted on a mounting component, and a connecting hole 280 connected to the gear side space 70 is formed at least in the hub portion 234, and the connecting hole 280 is connected to the internal space 31A of the cylindrical portion 31 via a groove 2A provided in the mounting component.

[0122] Since the gear side space 70 is connected to the internal space 31A of the cylindrical portion 31 via the connecting hole 280 and the groove 2A of the mounting member, the lubricant flowing into the gear side space 70 can be returned to the internal space 31A of the cylindrical portion 31. Therefore, it is possible to suppress the lubricant from excessively flowing into the first space 54, thereby suppressing the lubricant from leaking from the oil seal 60.

[0123] Furthermore, since the communicating hole 280 is formed at least in the rigid boss portion 234 , it is possible to suppress a reduction in the strength of the external gear 30 .

[0124] In the gear device 210 of the third embodiment, the communication hole 280 is formed in the boss portion 234 and communicates with the gear side space 70 .

[0125] Since the communicating hole 280 is formed in the hub portion 234 and communicates with the gear side space 70, the lubricant that flows from the gear side space 70 into the bearing 50 can be returned to the internal space 31A of the cylindrical portion 31 via the communicating hole 280 and the groove 2A of the mounting member. Therefore, the leakage of the lubricant from the oil seal 60 can be suppressed.

[0126] [Implementation Method 4]

[0127] Reference Figure 6Embodiment 4 of the present disclosure is described. In the gear device 310 and the robot 301 of Embodiment 4, a first sealing member 361 and a second sealing member 362 are provided, and the connecting hole 80 of Embodiment 1 is not formed. As other structures and effects are the same as those of Embodiment 1, the same reference numerals as those of Embodiment 1 are given to the components equivalent to those of Embodiment 1, and detailed descriptions are omitted.

[0128] <First Sealing Member, Second Sealing Member>

[0129] The first sealing member 361 is an oil seal similar to that of Embodiment 1. The second sealing member 362 is a separate body from the first sealing member 361 and is disposed inside the bearing 50 relative to the first sealing member 361. The second sealing member 362 of this embodiment is an oil seal similar to the first sealing member 361.

[0130] <Third Space>

[0131] In the present embodiment, the outer ring 352 has an extension portion 352A extending toward the inner gear 20 side from the inner ring 51. When the member formed by the inner ring 51 and the inner gear 20 is set as the inner member 320A, a third space 354A is formed between the inner member 320A and the outer ring 352. The third space 354A opens at the end surface of the bearing 50 on the side opposite to the gear side space 70. In the first embodiment, the first space 54 is provided between the inner ring 51 and the outer ring 52, but the third space 354A of the present embodiment includes the first space 54 and extends further toward the outside of the bearing 50 than the first space 54.

[0132] In the present embodiment, the third space 354A that communicates with the outside from the bearing 50 is doubly sealed by the first sealing member 361 and the second sealing member 362 , and therefore it is possible to suppress the lubricant from leaking to the outside.

[0133] Although not shown in the drawings, both the first sealing member 361 and the second sealing member 362 may be disposed in the first space 54 , that is, between the inner race 51 and the outer race 52 .

[0134] [Effects of Embodiment 4]

[0135] The gear device 310 of the fourth embodiment includes: an internal gear 20; an external gear 30 partially meshing with the internal gear 20; a wave generator 40 that contacts the inner peripheral surface of the external gear 30 and rotates the meshing position of the internal gear 20 and the external gear 30 around the rotation axis 10A; a bearing 50 that includes an inner ring 51 and an outer ring 352 and supports the internal gear 20 and the external gear 30 in a manner that allows relative rotation; a first sealing member 361; and a second sealing member 361 that is separate from the first sealing member 361, and the inner ring 51 and the internal gear 20 constitute an inner member 320 A, a third space 354A is formed between the inner member 320A and the outer ring 352, which is open on one end surface of the bearing 50, a second space 55 is formed between the inner ring 51 and the outer ring 352, and a gear side space 70 connected to the second space 55 is formed between the external gear 30 and the bearing 50. The first sealing member 362 is an oil seal, which seals the third space 354A, and the second sealing member 362 is arranged on the inner side of the third space 354A than the first sealing member 361 to seal the third space 354A.

[0136] The first sealing member 361 and the second sealing member 362 serving as oil seals can double-control leakage of the lubricant.

[0137] In the gear device 310 of the fourth embodiment, the second sealing member 362 is an oil seal.

[0138] The two oil seals can doubly suppress the leakage of the lubricant.

[0139] [Implementation method 5]

[0140] Reference Figure 7 Embodiment 5 of the present disclosure is described. In the gear device 410 and the robot 401 of Embodiment 5, the configuration of the first sealing member 461 and the structure of the second sealing member 462 are different from those of Embodiment 4. As for other structures and effects, since they are the same as those of Embodiment 1 and Embodiment 4, the same reference numerals as those of Embodiment 1 are given to the components equivalent to those of Embodiment 1, and detailed descriptions are omitted.

[0141] The gear device 410 of the fifth embodiment includes a first sealing member 461 and a second sealing member 462. The first sealing member 461 is an oil seal similar to that of the first embodiment. The first sealing member 461 is disposed between the inner ring 451 and the outer ring 52, and seals the first space 54. The second sealing member 462 is disposed on the inner side of the first space 54 than the first sealing member 461. The second sealing member 462 of the present embodiment is annular, and includes a base 462A and a front end 462B extending from the base 462A.

[0142] The base 462A is fixed by being clamped by the inner wall of the outer ring 52 and the spacer 463 constituting the first space 54. The spacer 463 is pressed by the first sealing member 461. The front end 462B is in contact with the abutment portion 451A formed on the inner ring 451. The abutment portion 451A is formed to extend radially outward in the first space 54. The front end 462B extends from the inner side of the first space 54 closer to the abutment portion 451A toward the abutment portion 451A side and contacts the abutment portion 451A. The first space 54 is sealed by the second sealing member 462.

[0143] According to the structure of this embodiment, since the outer ring 52 does not extend toward the inner gear 20 side more than the inner ring 451, the first space 54 substantially corresponds to the third space 354A of embodiment 4, and exerts the same effect as embodiment 4. According to this embodiment, compared with embodiment 4, a double sealing structure can be provided in the gear device 410 without increasing the size of the outer ring 52.

[0144] [Implementation Method 6]

[0145] Reference Figure 8 and Fig. 9 Embodiment 6 of the present disclosure is described. In the gear device 510 and the robot 501 of Embodiment 6, the structure of the outer ring 552 is different from that of Embodiment 4. As for other structures and effects, since they are the same as those of Embodiment 1 and Embodiment 4, the same reference numerals as those of Embodiment 4 are given to the components equivalent to those of Embodiment 4, and detailed descriptions are omitted.

[0146] <Outer ring body, extension plate>

[0147] In this embodiment, if Figure 8 As shown, the outer ring 552 includes: an outer ring body 552A; and an extension plate 552B fixed to the outer ring body 552A. The outer ring body 552A is substantially the same as the outer ring 52 of the first embodiment in which the first connecting hole 81 is omitted. The extension plate 552B extends toward the inner gear 20 side than the inner ring 51. The first sealing member 361 is arranged between the extension plate 552B and the inner gear 20, and seals the third space 354A. The second sealing member 362 is arranged between the outer ring body 552A and the inner ring 51, and seals the third space 354A.

[0148] The outer ring body 552A and the extension plate 552B are fixed by bolt fastening. Specifically, the extension plate 552B is provided with a bolt insertion hole 552C, and the outer ring body 552A is provided with a bolt fastening hole 552D. The bolt 552E is inserted through the bolt insertion hole 552C and screwed with the internal thread of the bolt fastening hole 552D.

[0149] In addition, as a variation of the sixth embodiment, Fig. 9 As shown, the outer ring body 552A, the extension plate 552B, the hub portion 534 and the arm 502 of the robot 501 may be fixed by bolt fastening. Specifically, bolt insertion holes 552C, 552F, and 534A may be provided in the extension plate 552B, the outer ring body 552A, and the hub portion 534, respectively, and the bolt fastening hole 502A may be provided in the arm 502. The bolt 552G may also be inserted through the bolt insertion holes 552C, 552F, and 534A and screwed with the internal thread of the bolt fastening hole 502A.

[0150] [Effects of Embodiment 6]

[0151] In the gear device 510 of the sixth embodiment, the outer ring 552 includes an outer ring body 552A and an extension plate 552B fixed to the outer ring body 552A and extending toward the internal gear 20 from the inner ring 51 , and the first sealing member 361 is disposed between the extension plate 552B and the internal gear 20 .

[0152] By adding the extended plate 552B to the outer ring body 552A, the design of the gear device 510 may be facilitated.

[0153] [Implementation method 7]

[0154] Reference Fig.10 Embodiment 7 of the present disclosure will be described. The gear device 610 and the robot 601 of Embodiment 7 are similar to those of Embodiment 6 except that the communicating hole 680 and the groove 602A are provided. Fig. 9 The gear device 510 shown is configured substantially similarly to the robot 501. Regarding the configuration and effects common to those of the sixth embodiment, the same reference numerals as those of the sixth embodiment are used to designate the same components as those of the sixth embodiment, and detailed descriptions thereof are omitted.

[0155] <Communication hole>

[0156] In Embodiment 7, a third hole 680A is formed to connect the bolt insertion holes 552C and 552F with the third space 354A. The third hole 680A is formed between the outer ring body 552A and the extension plate 552B. The bolt insertion holes 552C, 552F, 534A and the third hole 680A constitute a communication hole 680 .

[0157] The arm 602 of the robot 601 is provided with a groove 602A similar to the arm 102 of the first embodiment. The groove 602A communicates with the bolt insertion hole 534A. The groove 602A communicates with the internal space 31A of the cylindrical portion 31. Therefore, the third space 354A communicates with the internal space 31A of the cylindrical portion 31 via the communicating hole 680 and the groove 602A.

[0158] The arm 602 has a bolt fastening hole 502A formed recessed from the bottom surface of the groove 602A. The bolt 552G is inserted through the bolt insertion holes 552C, 552F, and 534A, and is screwed into the internal thread of the bolt fastening hole 502A. The arm 602 is an example of a mounting member.

[0159] Although not shown, a check valve may be provided in the third hole 680A of the communicating hole 680 to allow the lubricant to flow from the third space 354A to the groove 602A side and to restrict the lubricant from flowing from the groove 602A side to the third space 354A. In this way, it is possible to prevent excess lubricant from accumulating in the third space 354A.

[0160] [Effects of Embodiment 7]

[0161] The gear device 610 of embodiment 7 is installed on the mounting member (arm 602), wherein the external gear 30 comprises: a flexible cylindrical portion 31, coaxially arranged on the inner side of the internal gear 20; a diaphragm portion 33, extending outward from the end of the cylindrical portion 31; and a rigid hub portion 534, extending from the outer peripheral edge of the diaphragm portion 33 and being annular, and a connecting hole 680 connected to the third space 354A is formed on the outer ring 552 and the hub portion 534, and the connecting hole 680 is connected to the internal space 31A of the cylindrical portion 31 via a groove 602A provided on the mounting member.

[0162] In addition to the double seal structure formed by the two oil seals, the lubricant flowing into the third space 354A is returned to the internal space 31A of the cylindrical portion 31 via the communication hole 680 and the groove 602A of the mounting member, thereby further suppressing the leakage of the lubricant.

[0163] [Embodiment 8]

[0164] Reference Fig.11 Embodiment 8 of the present disclosure is described. In the gear device 710 and the robot 701 of Embodiment 8, a first bearing seal 790 and a second bearing seal 791 are provided, and the connecting hole 80 of Embodiment 1 is not formed. As other structures and effects are the same as those of Embodiment 1, the same reference numerals as those of Embodiment 1 are given to the components equivalent to those of Embodiment 1, and detailed descriptions are omitted.

[0165] The gear device 710 includes a first bearing seal 790 , a second bearing seal 791 that is separate from the first bearing seal 790 , a first plate 756 fixed to the inner ring 51 , and a spacer 757 fixed to the outer ring 752 .

[0166] <First Plate>

[0167] The first plate 756 includes a contact portion 756A disposed near a boundary between the gear side space 70 and the second space 55. The contact portion 756A extends from the inner ring 51 side to the outside in the radial direction.

[0168] <Spacer>

[0169] The spacer 757 is sandwiched and fixed between the outer ring 752 and the hub portion 734. Specifically, bolt insertion holes 757A and 734A are provided in the spacer 757 and the hub portion 734, and a bolt fastening hole 752A is provided in the outer ring 752. The bolt 752B is inserted through the bolt insertion holes 757A and 734A and screwed into the internal thread of the bolt fastening hole 752A.

[0170] <First bearing seal>

[0171] The first bearing seal 790 includes a first base portion 790A and a first front end portion 790B extending from the first base portion 790A. The first base portion 790A is disposed in a fixing groove provided in the outer ring 752, and is clamped and fixed by the inner wall of the fixing groove and the spacer 757. The first front end portion 790B is disposed in the second space 55, and contacts the abutment portion 756A from the second space 55 side. The second space 55 is sealed by the first front end portion 790B. Thus, the extrusion of the lubricant from the bearing 50 side to the gear side space 70 is suppressed.

[0172] <Second bearing seal>

[0173] The second bearing seal 791 includes a second base portion 791A and a second front end portion 791B extending from the second base portion 791A. The second base portion 791A is disposed in a fixing groove provided in the spacer 757, and is clamped and fixed by the inner wall of the fixing groove and the hub portion 734. The second front end portion 791B is disposed in the gear side space 70, and contacts the abutment portion 756A from the gear side space 70 side. The second front end portion 791B partitions the gear side space 70. Thus, the inflow of lubricant from the gear side space 70 into the bearing 50 is suppressed.

[0174] The first bearing seal 790 and the second bearing seal 791 are disposed with a predetermined space therebetween. Thus, even if the lubricant is disposed in the space, the first bearing seal 790 and the second bearing seal 791 are not easily released from contact with the abutment portion 756A.

[0175] [Effects of Embodiment 8]

[0176] The gear device 710 of the eighth embodiment includes: an internal gear 20; an external gear 30 partially meshing with the internal gear 20; a wave generator 40 that contacts the inner peripheral surface of the external gear 30 and rotates the meshing position of the internal gear 20 and the external gear 30 around the rotation axis 10A; a bearing 50 that includes an inner ring 51 and an outer ring 752 and supports the internal gear 20 and the external gear 30 in a manner that allows relative rotation; an oil seal 60; a first bearing seal 790; and a second bearing seal 791. The first plate 756 is separate from the first bearing seal 790; the first plate 756 is fixed to the inner ring 51; and the spacer 757, a first space 54 is formed between the inner ring 51 and the outer ring 752, which is open to one end face of the bearing 50, a second space 55 is formed between the inner ring 51 and the outer ring 752, which is open to the other end face of the bearing 50, and a gear side space 70 connected to the second space 55 is formed between the external gear 30 and the bearing 50, and the oil seal 60 seals the first space 54, and the external gear 3 The bearing seal 790 includes a flexible cylindrical portion 31 coaxially arranged inside the internal gear 20; a diaphragm portion 33 extending outward from the end of the cylindrical portion 31; and a rigid hub portion 734 extending from the outer peripheral edge of the diaphragm portion 33 and forming an annular shape. The first bearing seal 790 includes a first base portion 790A and a first front end portion 790B extending from the first base portion 790A, and the second bearing seal 791 includes a second base portion 791A and a second front end portion extending from the second base portion 791A. 791B, the spacer 757 is clamped and fixed by the outer ring 752 and the hub portion 734, the first base 790A is clamped and fixed by the spacer 757 and the outer ring 752, the second base 791A is clamped and fixed by the spacer 757 and the hub portion 734, the first front end portion 790B contacts the first plate 756 from the second space 55 side to seal the second space 55, and the second front end portion 791B contacts the first plate 756 from the gear side space 70 side to separate the gear side space 70.

[0177] Since the first front end portion 790B of the first bearing seal 790 contacts the first plate 756 from the second space 55 side, it is possible to suppress the lubricant from being squeezed out from the second space 55 into the gear side space 70. Since the second front end portion 791B of the second bearing seal 791 contacts the first plate 756 from the gear side space 70 side, it is possible to suppress the lubricant from flowing from the gear side space 70 into the second space 55. Therefore, it is possible to suppress the lubricant from excessively flowing into the first space 54, and thus it is possible to suppress the lubricant from leaking from the oil seal 60.

[0178] In addition, since the first bearing seal 790 and the second bearing seal 791 are separate bodies, it is easy to ensure the volume of the space between the first bearing seal 790 and the second bearing seal 791. Even if the lubricant enters the space, the contact between the first bearing seal 790 and the second bearing seal 791 and the first plate 756 will not be released.

[0179] [Implementation Method 9]

[0180] Reference Fig.12 Embodiment 9 of the present disclosure is described. In the gear device 810 and the robot 801 of Embodiment 9, a third bearing seal 890 is provided, and the connecting hole 80 of Embodiment 1 is not formed. As other structures and effects are the same as those of Embodiment 1, the same reference numerals as those of Embodiment 1 are given to the components equivalent to those of Embodiment 1, and detailed descriptions are omitted.

[0181] The gear device 810 includes a third bearing seal 890 and a second plate 856 fixed to the inner ring 51 .

[0182] <Second board>

[0183] The second plate 856 is formed with a mounting groove 856A in which the third bearing seal 890 is mounted.

[0184] <Third bearing seal>

[0185] The third bearing seal 890 includes a base 891, a first lip 892A extending from the base 891, and a second lip 892B extending from the base 891. The base 891 is received in the mounting groove 856A of the second plate 856. The base 891 is sandwiched and fixed by the inner wall of the mounting groove 856A and the end surface of the inner ring 51 facing the diaphragm portion 33.

[0186] The first lip 892A extends from the radially outer end of the base 891 to the radially outer side and the diaphragm 33 side. The second lip 892B extends from the radially outer end of the base 891 to the radially inner side and the diaphragm 33 side. The first lip 892A and the second lip 892B are arranged with a predetermined space in the radial direction. The first lip 892A is arranged in the gear side space 70 on the second space 55 side than the second lip 892B.

[0187] The first lip 892A and the second lip 892B are in contact with the diaphragm portion 33 to partition the gear side space 70. In addition, even when the diaphragm portion 33 is flexed and deformed as the gear device 810 operates, the first lip 892A and the second lip 892B maintain contact with the diaphragm portion 33. The first lip 892A is in contact with the diaphragm portion 33, so that the lubricant is prevented from being squeezed out from the bearing 50 side to the inner side of the gear side space 70 in the radial direction. The second lip 892B is in contact with the diaphragm portion 33, so that the lubricant is prevented from flowing into the bearing 50 from the gear side space 70 arranged on the inner side in the radial direction.

[0188] [Effects of Embodiment 9]

[0189] The gear device 810 of the ninth embodiment comprises: an internal gear 20; an external gear 30 partially meshing with the internal gear 20; a wave generator 40 contacting the inner peripheral surface of the external gear 30 and causing the meshing position of the internal gear 20 and the external gear 30 to rotate around the rotation axis 10A; a bearing 50 comprising an inner ring 51 and an outer ring 52 and supporting the internal gear 20 and the external gear 30 in a manner capable of relative rotation; an oil seal 60; a third bearing seal 890; and a second plate 856 fixed to the inner ring 51, a first space 54 opening at one end face of the bearing 50 is formed between the inner ring 51 and the outer ring 52, a second space 55 opening at the other end face of the bearing 50 is formed between the inner ring 51 and the outer ring 52, and a second space 56 opening at the other end face of the bearing 50 is formed between the inner ring 51 and the outer ring 52. A gear side space 70 connected to the second space 55 is formed between the outer gear 30 and the bearing 50, and the oil seal 60 seals the first space 54. The outer gear 30 comprises: a flexible cylindrical portion 31 coaxially arranged on the inner side of the inner gear 20; a diaphragm portion 33 extending outward from the end of the cylindrical portion 31; and a rigid hub portion 34 extending from the outer peripheral edge of the diaphragm portion 33 and in an annular shape. The third bearing seal 890 comprises: a base 891; a first lip 892A extending from the base 891; and a second lip 892B extending from the base 891. The base 891 is clamped and fixed by the second plate 856 and the inner ring 51. The first lip 892A and the second lip 892B are in contact with the diaphragm portion 33 to separate the gear side space 70.

[0190] By providing the first lip 892A and the second lip 892B in the third bearing seal 890, it is possible to suppress the extrusion of the lubricant from the second space 55 into the gear side space 70 and the inflow of the lubricant from the gear side space 70 into the second space 55. Therefore, it is possible to suppress the excessive inflow of the lubricant into the first space 54, thereby suppressing the leakage of the lubricant from the oil seal 60.

[0191] Furthermore, by increasing the space between the first lip 892A and the second lip 892B, the third bearing seal 890 can be configured so that one of the first lip 892A and the second lip 892B does not interfere with the other and the contact between the first lip 892A and the second lip 892B and the diaphragm portion 33 is not released.

[0192] [Implementation 10]

[0193] Reference Fig.13 Embodiment 10 of the present disclosure is described. In the gear device 910 and the robot 901 of embodiment 10, a fourth bearing seal 990 is provided, and the connecting hole 80 of embodiment 1 is not formed. As other structures and effects are the same as those of embodiment 1, the same reference numerals as those of embodiment 1 are given to the components equivalent to those of embodiment 1, and detailed descriptions are omitted.

[0194] The gear device 910 includes a fourth bearing seal 990 and a third plate 956 fixed to the inner ring 51 .

[0195] <Third Plate>

[0196] The third plate 956 is formed with a mounting groove 956A in which the fourth bearing seal 990 is mounted.

[0197] <Fourth bearing seal>

[0198] The third bearing seal 990 includes a base 991, a first lip 992A extending from the base 991, and a second lip 992B extending from the base 991. The base 991 is received in the mounting groove 956A of the third plate 956. The base 991 is sandwiched and fixed by the inner wall of the mounting groove 956A and the end surface of the inner ring 51 facing the diaphragm portion 33.

[0199] The first lip 992A extends from the radially outer end of the base 991 to the radially outer side and the side opposite to the diaphragm 33. The second lip 992B extends from the radially outer end of the base 991 to the radially outer side and the diaphragm 33 side. The first lip 992A and the second lip 992B are arranged with a predetermined space in the direction along the rotation axis 10A. The second lip 992B is arranged on the gear side space 70 side relative to the first lip 992A.

[0200] The first lip 992A and the second lip 992B contact the inner circumferential surface of the outer ring 52 to separate the second space 55 from the gear side space 70. The contact between the first lip 992A and the inner circumferential surface of the outer ring 52 suppresses the extrusion of the lubricant from the bearing 50 side to the gear side space 70. The contact between the second lip 992B and the inner circumferential surface of the outer ring 52 suppresses the inflow of the lubricant from the gear side space 70 into the bearing 50.

[0201] [Effects of Embodiment 10]

[0202] The gear device 910 of the tenth embodiment comprises: an internal gear 20; an external gear 30 partially meshing with the internal gear 20; a wave generator 40 contacting the inner peripheral surface of the external gear 30 and rotating the meshing position of the internal gear 20 and the external gear 30 around the rotation axis 10A; a bearing 50 having an inner ring 51 and an outer ring 52 and supporting the internal gear 20 and the external gear 30 in a manner capable of relative rotation; an oil seal 60; a fourth bearing seal 990; and a third plate 956 fixed to the inner ring 51, a first space 54 opening at one end surface of the bearing 50 is formed between the inner ring 51 and the outer ring 52, and a third plate 956 is provided in the inner ring 51. A second space 55 opening on the other end face of the bearing 50 is formed between the ring 51 and the outer ring 52, and a gear side space 70 connected to the second space 55 is formed between the external gear 30 and the bearing 50. The oil seal 60 seals the first space 54. The fourth bearing seal 990 comprises: a base 991; a first lip 992A extending from the base 991; and a second lip 992B extending from the base 991. The base 991 is clamped and fixed by the third plate 956 and the inner ring 51. The first lip 992A and the second lip 992B are in contact with the outer ring 52 to separate the second space 55 from the gear side space 70.

[0203] By providing the first lip 992A and the second lip 992B in the fourth bearing seal 990, it is possible to suppress the extrusion of the lubricant from the second space 55 into the gear side space 70 and the inflow of the lubricant from the gear side space 70 into the second space 55. Therefore, it is possible to suppress the excessive inflow of the lubricant into the first space 54, thereby suppressing the leakage of the lubricant from the oil seal 60.

[0204] In addition, by increasing the space between the first lip 992A and the second lip 992B, the fourth bearing seal 990 can be configured so that one of the first lip 992A and the second lip 992B does not interfere with the other and the contact between the first lip 992A and the second lip 992B and the outer ring 52 is not released.

[0205] [Implementation 11]

[0206] Below, refer to Figures 14 to 17 Embodiment 11 of the present disclosure is described. In the gear device 1010 and the robot 1001 of embodiment 11, a fifth bearing seal 1090 is provided, and the connecting hole 80 of embodiment 1 is not formed. As other structures and effects are the same as those of embodiment 1, the same reference numerals as those of embodiment 1 are given to the components equivalent to those of embodiment 1, and detailed descriptions are omitted.

[0207] like Fig.14 As shown, the gear device 1010 includes a fifth bearing seal 1090 and a fourth plate 1056 fixed to the outer ring 1052 .

[0208] <Fourth Plate>

[0209] The fourth plate 1056 includes a fixing portion 1057 and an extension portion 1058 extending from the fixing portion 1057. The fixing portion 1057 is clamped and fixed by the outer ring 1052 and the hub portion 1034. Bolt insertion holes 1057A and 1034A are formed in the fixing portion 1057 and the hub portion 1034. Bolt fastening holes 1052A are formed in the outer ring 1052. Bolts 1052B inserted through the bolt insertion holes 1057A and 1034A are screwed into the internal threads of the bolt fastening holes 1052A.

[0210] The extension portion 1058 extends radially inward from the radially inner end of the fixed portion 1057. Specifically, the extension portion 1058 includes: a first extension portion 1058A extending radially inward from the fixed portion 1057; and a second extension portion 1058B extending from the radially inner end of the first extension portion 1058A along the inner circumferential surface of the inner ring 1051. The first extension portion 1058A is disc-shaped. The second extension portion 1058B is cylindrical.

[0211] <The Fourth Space>

[0212] A fourth space 1070A is formed between the extended portion 1058 and the inner race 1051 . The fourth space 1070A connects the gear side space 70 and the second space 55 .

[0213] <Installation slot>

[0214] An attachment groove 1056A (an example of a groove) is formed in the fourth plate 1056. The attachment groove 1056A is recessed from the end surface of the second extending portion 1058B on the side opposite to the diaphragm portion 33.

[0215] The inner ring 1051 is provided with a contact portion 1051A with which the fifth bearing seal 1090 contacts. The contact portion 1051A extends radially inward and is disposed to face the second extending portion 1058B in the direction along the rotation axis 10A.

[0216] <Fifth bearing seal>

[0217] The fifth bearing seal 1090 includes a base 1091 , a first lip 1092A extending from the base 1091 , and a second lip 1092B extending from the base 1091 . The base 1091 is received in the mounting groove 1056A of the fourth plate 1056 .

[0218] The first lip 1092A extends from the end of the base 1091 on the side opposite to the diaphragm 33 to the outside in the radial direction and to the side opposite to the diaphragm 33. The second lip 1092B extends from the end of the base 1091 on the side opposite to the diaphragm 33 to the inside in the radial direction and to the side opposite to the diaphragm 33. The first lip 1092A and the second lip 1092B are arranged with a predetermined space in the radial direction. The first lip 1092A is arranged at the inner side of the fourth space 1070A than the second lip 1092B.

[0219] The first lip 1092A and the second lip 1092B contact the end surface of the contact portion 1051A on the diaphragm portion 33 side to partition the fourth space 1070A. The first lip 1092A contacts the end surface of the contact portion 1051A to suppress the extrusion of the lubricant from the bearing 50 side to the gear side space 70. The second lip 1092B contacts the end surface of the contact portion 1051A to suppress the inflow of the lubricant from the gear side space 70 into the bearing 50.

[0220] In addition, as a modification 1 of this embodiment, Fig.15 As shown, the mounting groove 1056A of the accommodating base 1091 may be recessed from the outer peripheral surface of the second extending portion 1058B facing the inner peripheral surface of the inner ring 1051 , and the first lip 1092A and the second lip 1092B may contact the inner peripheral surface of the inner ring 1051 .

[0221] Moreover, as another embodiment of the present invention, Fig.16 and Fig.17 As shown, a mounting groove 1051B (an example of a groove) for accommodating the base 1091 may be formed in the inner ring 1051 , and the first lip 1092A and the second lip 1092B may be in contact with the fourth plate 1056 .

[0222] In the second modification of this embodiment, Fig.16 In the embodiment, the mounting groove 1051B is recessed from the inner peripheral surface of the inner ring 1051. The first lip 1092A and the second lip 1092B are in contact with the outer peripheral surface of the second extension portion 1058B that faces the inner peripheral surface of the inner ring 1051.

[0223] In the third modification of the present embodiment, Fig.17 In the embodiment, the mounting groove 1051B is recessed from the end surface of the inner ring 1051 that faces the diaphragm portion 33. The first lip 1092A and the second lip 1092B are in contact with the end surface of the first extension portion 1058A on the inner ring 1051 side. Fig.17 In the embodiment, the extended portion 1058 only needs to include a portion extending in the radial direction that contacts the first lip 1092A and the second lip 1092B ( Figures 14 to 16 The first extension portion 1058A shown in the figure can be used. Fig.17 In the structure shown, although the fourth space 1070A provided between the gear side space 70 and the second space 55 becomes smaller, the structure of the extended portion 1058 can be simplified.

[0224] [Effects of Embodiment 11]

[0225] The gear device 1010 of the eleventh embodiment comprises: an internal gear 20; an external gear 30 partially meshing with the internal gear 20; a wave generator 40 contacting the inner peripheral surface of the external gear 30 and rotating the meshing position of the internal gear 20 and the external gear 30 around the rotation axis 10A; a bearing 50 comprising an inner ring 1051 and an outer ring 1052 and supporting the internal gear 20 and the external gear 30 in a manner capable of relative rotation; an oil seal 60; a fifth bearing seal 1090; and a fourth plate 1056 fixed to the outer ring 1052 and extending toward the inner ring 1051, a first space 54 opening at one end surface of the bearing 50 is formed between the inner ring 1051 and the outer ring 1052, and a second space 55 opening at the other end surface of the bearing 50 is formed between the inner ring 1051 and the outer ring 1052. A gear side space 70 connected to the second space 55 is formed between the external gear 30 and the bearing 50, and the oil seal 60 seals the first space 54. A fourth space 1070A connecting the gear side space 70 and the second space 55 is formed between the fourth plate 1056 and the inner ring 1051. The fifth bearing seal 1090 comprises: a base 1091; a first lip 1092A extending from the base 1091; and a second lip 1092B extending from the base 1091. The base 1091 is accommodated in a groove (mounting groove 1056A or mounting groove 1051B) formed on one side of the fourth plate 1056 and the inner ring 1051. The first lip 1092A and the second lip 1092B contact the other side of the fourth plate 1056 and the inner ring 1051 to separate the fourth space 1070A.

[0226] By providing the first lip 1092A and the second lip 1092B in the fifth bearing seal 1090, it is possible to suppress the extrusion of the lubricant from the second space 55 into the gear side space 70 and the inflow of the lubricant from the gear side space 70 into the second space 55. Therefore, it is possible to suppress the excessive inflow of the lubricant into the first space 54, thereby suppressing the leakage of the lubricant from the oil seal 60.

[0227] In addition, by increasing the space between the first lip 1092A and the second lip 1092B, the fifth bearing seal 1090 can be configured so that one of the first lip 1092A and the second lip 1092B does not interfere with the other, and the contact between the first lip 1092A and the second lip 1092B and the fourth plate 1056 or the inner ring 1051 is not released.

[0228] [Implementation 12]

[0229] Reference Fig.18 Embodiment 12 of the present disclosure is described. In the gear device 1110 and the robot 1101 of embodiment 12, a connecting hole 1171 and an air tube 1104 are provided, and the connecting hole 80 of embodiment 1 is not formed. As other structures and effects are the same as those of embodiment 1, the same reference numerals as those of embodiment 1 are given to the components equivalent to those of embodiment 1, and detailed descriptions are omitted.

[0230] <Base, through hole>

[0231] The robot 1101 of the present embodiment includes: a base 1103; an arm (not shown) supported so as to be rotatable relative to the base 1103; a gear device 1110 that transmits a driving force from one of the base 1103 and the arm to the other; and a motor (not shown) that is a driving source of the gear device 1110. The internal gear 1120 is fixed to the base 1103. The external gear 30 is connected to the arm. The wave generator 40 is connected to the motor. In the present embodiment, the base 1103 is an example of a first member. A through hole 1103A is formed in the base 1103 and communicates with a connection hole 1171 provided in the gear device 1110.

[0232] <Air pipe>

[0233] The robot 1101 includes an air tube 1104. One end of the air tube 1104 is connected to the base 1103, and the other end of the air tube 1104 is open to the atmosphere. The inner space of the air tube 1104 is connected to the through hole 1103A. At least a portion of the air tube 1104 from one end to the other end is in a coil shape.

[0234] <Connection hole>

[0235] The connection hole 1171 of this embodiment is composed of a first connection hole 1171A provided in the inner ring 1151 and a second connection hole 1171B connected to the first connection hole 1171A and provided in the internal gear 1120. The first connection hole 1171A is composed of a fourth hole 1151A extending in the radial direction and a fifth hole 1151B connected to the fourth hole 1151A and extending in the direction along the rotation axis 10A. The fourth hole 1151A is connected to the gear side space 70.

[0236] The gear side space 70 is connected to the atmosphere via the connection hole 1171, the through hole 1103A of the base 1103, and the air pipe 1104. As a result, the pressure in the gear side space 70 is equal to the atmospheric pressure. Therefore, even if the external gear 30 is repeatedly flexed and deformed due to the operation of the gear device 1110, there is no pumping action that squeezes the lubricant from the meshing portion between the internal gear 1120 and the external gear 30 into the gear side space 70, and the inflow of the lubricant into the gear side space 70 can be suppressed. As a result, since the lubricant is not easy to flow from the gear side space 70 into the bearing 50, the leakage of the lubricant from the oil seal 60 to the outside can be suppressed.

[0237] In addition, the connection hole 1171, the through hole 1103A and the air tube 1104 are preferably arranged above the gear side space 70. With such a structure, the lubricant is unlikely to flow from the gear side space 70 into the connection hole 1171, the through hole 1103A and the air tube 1104 due to gravity.

[0238] The internal gear 1120 has a covering portion 1123 extending from the annular member 21 toward the diaphragm portion 33. The covering portion 1123 is disposed opposite to the opening of the first connection hole 1171A on the gear side space 70 side. By providing the covering portion 1123, it is possible to suppress the lubricant from flowing into the first connection hole 1171A from the meshing portion between the internal gear 1120 and the external gear 30, etc.

[0239] [Effects of Embodiment 12]

[0240] The gear device 1110 of embodiment 12 includes: an internal gear 1120; an external gear 30 partially meshing with the internal gear 1120; a wave generator 40 that contacts the inner circumferential surface of the external gear 30 and rotates the meshing position of the internal gear 1120 and the external gear 30 around the rotating shaft 10A; a bearing 50 that includes an inner ring 1151 and an outer ring 52 and supports the internal gear 1120 and the external gear 30 in a manner that allows relative rotation; and an oil seal 60, wherein a first space 54 is formed between the inner ring 1151 and the outer ring 52 and is open to one end surface of the bearing 50, a second space 55 is formed between the inner ring 1151 and the outer ring 52 and is open to the other end surface of the bearing 50, a gear side space 70 that is connected to the second space 55 is formed between the external gear 30 and the bearing 50, the oil seal 60 seals the first space 54, and the gear device 1110 is formed with a connecting hole 1171 that connects the gear side space 70 to the atmosphere.

[0241] Since the gear side space 70 is connected to the atmosphere through the connection hole 1171, the pumping action caused by the deflection of the external gear 30 disappears, so the lubricant is not sent from the gear side space 70 into the bearing 50. Therefore, the leakage of the lubricant from the oil seal 60 can be suppressed.

[0242] In gear device 1110 according to Embodiment 12, connection hole 1171 is formed in inner ring 1151 and internal gear 1120 .

[0243] The robot 1101 of embodiment 12 comprises: a gear device 1110; a first component (base 1103) for fixing the gear device 1110; and an air tube 1104, the first component having a through hole 1103A connected to the connecting hole 1171, one end of the air tube 1104 is connected to the through hole 1103A and installed on the first component, and the other end of the air tube 1104 is open to the atmosphere.

[0244] Since the air tube 1104 is provided, even when the lubricant enters the connection hole 1171, it is possible to suppress the lubricant from leaking to the outside.

[0245] In the robot 1101 of the twelfth embodiment, at least a portion of the air tube 1104 is in a coil shape.

[0246] Since at least a part of the air tube 1104 is in a coil shape, it is possible to increase the length of the air tube 1104. Therefore, it is possible to further suppress the lubricant from leaking to the outside.

[0247] [Implementation 13]

[0248] Reference Fig.19 Embodiment 13 of the present disclosure is described. In the gear device 1210 and the robot 1201 of embodiment 13, the components provided with the connection hole 1271 are different from those of embodiment 12. As for other structures and effects, since they are the same as those of embodiment 1, the components equivalent to those of embodiment 1 are marked with the same reference numerals as those of embodiment 1, and detailed descriptions are omitted.

[0249] The gear device 1210 of the embodiment 13 is mounted on the robot 1201 in a reverse posture in the vertical direction compared to the gear device 1110 of the embodiment 12. Since the connection hole 1271, the through hole 1205A and the air tube 1204 are arranged above the gear side space 70, the connection hole 1271 is formed in the hub portion 1234 of the external gear 30 in the gear device 1210.

[0250] <First Arm>

[0251] The robot 1201 according to the present embodiment includes: a first arm 1205; a second arm 1206 supported so as to be rotatable relative to the first arm 1205; a gear device 1210 for transmitting a driving force from one of the first arm 1205 and the second arm 1206 to the other; and a motor (not shown) as a driving source of the gear device 1210. The internal gear 20 is fixed to the second arm 1206. The external gear 30 is connected to the first arm 1205. The wave generator 40 is connected to the motor. In the present embodiment, the first arm 1205 is an example of a first member. A through hole 1205A is formed in the first arm 1205 and communicates with a connection hole 1271 provided in the gear device 1210.

[0252] The robot 1201 includes an air tube 1204. One end of the air tube 1204 is connected to the first arm 1205, and the other end of the air tube 1204 is open to the atmosphere. The inner space of the air tube 1204 communicates with the through hole 1205A.

[0253] A connection hole 1271 is formed in the boss portion 1234 of the external gear 30 of this embodiment. The connection hole 1271 communicates with the gear side space 70. Since the effects related to the connection hole 1271 are the same as those of the twelfth embodiment, the description thereof will be omitted.

[0254] [Other embodiments]

[0255] (1) The configurations of the above-described embodiments may be combined within a range that does not conflict with each other.

[0256] (2) In the above embodiments, the gear devices 10, 110, 210, 310, 410, 510, 610, 710, 810, 910, 1010, 1110, and 1210 are configured such that the rotation axis 10A extends in the vertical direction, but the gear device may be configured such that the rotation axis extends in a direction intersecting the vertical direction. In the gear devices 1110 and 1210, the through holes 1103A and 1205A are preferably disposed above the gear devices 1110 and 1210, respectively.

[0257] (3) The member for mounting the gear device in the robot is not limited to the above-mentioned embodiment.

[0258] 1: Robot 2: Arm (mounting member) 2A: Slot

[0259] 10: Gear device 10A: Rotating shaft

[0260] 20: Internal gear 21: Annular member 22: Internal teeth

[0261] 30: External gear 31: Cylindrical portion 31A: Internal space 32: External teeth 33: Diaphragm portion 34: Hub portion

[0262] 40: Wave Generator

[0263] 50: bearing 51: inner ring 52: outer ring 53: roller 54: first space 55: second space

[0264] 60: Oil seal

[0265] 70: Gear side space

[0266] 80: communicating hole 81: first communicating hole 82: second communicating hole 83: first hole 84: second hole

[0267] 101: Robot 102: Arm (mounting member) 102B: Bolt fastening hole 102C: Bolt 102D: Sealing washer

[0268] 110: Gear

[0269] 180: communicating hole 181: first communicating hole 182: second communicating hole 184: second hole

[0270] 201: Robot

[0271] 210: Gear

[0272] 234: Hub 280: Communication hole

[0273] 301: Robot

[0274] 310: Gear

[0275] 320A: Inner member

[0276] 352: Outer ring 352A: Extension 354A: Third space

[0277] 361: first sealing member 362: second sealing member

[0278] 401: Robot

[0279] 410: Gear

[0280] 451: Inner ring 451A: Contact portion

[0281] 461: First sealing member 462: Second sealing member 462A: Base portion 462B: Front end portion

[0282] 463: Spacer

[0283] 501: Robot 502: Arm 502A: Bolt fastening hole

[0284] 510: Gear

[0285] 534: Hub 534A: Bolt insertion hole

[0286] 552: Outer ring 552A: Outer ring body 552B: Extension plate 552C, 552F: Bolt insertion holes 552D: Bolt fastening hole

[0287] 552E, 552G: Bolt

[0288] 601: robot 602: arm (mounting member) 602A: slot

[0289] 610: Gear

[0290] 680: connecting hole 680A: third hole

[0291] 701: Robot

[0292] 710: Gear

[0293] 734: Hub 734A: Bolt insertion hole

[0294] 752: Outer ring 752A: Bolt fastening hole 752B: Bolt

[0295] 756: First plate 756A: Abutment portion

[0296] 757: Spacer 757A: Bolt insertion hole

[0297] 790: first bearing seal 790A: first base portion 790B: first front end portion

[0298] 791: Second bearing seal 791A: Second base 791B: Second front end

[0299] 801: Robot

[0300] 810: Gear

[0301] 856: Second board 856A: Mounting slot

[0302] 890: Third bearing seal 891: Base 892A: First lip 892B: Second lip

[0303] 901: Robot

[0304] 910: Gear

[0305] 956: Third plate 956A: Mounting slot

[0306] 990: Fourth bearing seal 991: Base 992A: First lip 992B: Second lip

[0307] 1001: Robot

[0308] 1010: Gear

[0309] 1034: Hub 1034A: Bolt insertion hole

[0310] 1051: Inner ring 1051A: Abutment portion 1051B: Mounting groove (groove)

[0311] 1052: Outer ring 1052A: Bolt fastening hole 1052B: Bolt

[0312] 1056: fourth plate 1056A: mounting groove (groove) 1057: fixing portion 1057A: bolt insertion hole 1058: extension portion 1058A: first extension portion 1058B: second extension portion

[0313] 1070A: The Fourth Space

[0314] 1090: Fifth bearing seal 1091: Base 1092A: First lip 1092B: Second lip

[0315] 1101: Robot 1103: Base (first member) 1103A: Through hole 1104: Air pipe

[0316] 1110: Gear

[0317] 1120: Internal gear 1123: Covering part

[0318] 1151: Inner ring 1151A: Fourth hole 1151B: Fifth hole

[0319] 1171: connection hole 1171A: first connection hole 1171B: second connection hole

[0320] 1201: robot 1204: air pipe 1205: first arm (first member) 1205A: through hole 1206: second arm

[0321] 1210: Gear

[0322] 1234: hub portion 1271: connection hole.

Claims

1. A gear device mounted on a mounting member, wherein: The gear unit has: Internal gear; an external gear partially meshing with the internal gear; a wave generator, which contacts the inner peripheral surface of the outer gear and causes the meshing position of the inner gear and the outer gear to rotate around the rotation axis; a bearing having an inner ring and an outer ring, and supporting the internal gear and the external gear in a manner capable of relative rotation; and Oil seals, A first space is formed between the inner ring and the outer ring and is open on one end surface of the bearing. A second space is formed between the inner ring and the outer ring, which is open to the other end surface of the bearing. A gear side space communicating with the second space is formed between the external gear and the bearing. The oil seal seals the first space. The external gear has: A flexible cylindrical portion coaxially disposed inside the internal gear; a diaphragm portion extending outward from an end of the cylindrical portion; and A rigid hub portion extends from the outer periphery of the diaphragm portion and is annular in shape. The hub portion is mounted on the mounting member, A communication hole communicating with the first space or the gear side space is formed at least in the hub portion. The communication hole communicates with the internal space of the cylindrical portion via a groove provided in the mounting member.

2. The gear device according to claim 1, wherein: The communication hole is formed in the hub portion and the outer ring, and is communicated with the first space.

3. The gear device according to claim 1, wherein: The communication hole is formed in the hub portion and communicates with the gear side space.

4. A gear device comprising: Internal gear; an external gear partially meshing with the internal gear; a wave generator, which contacts the inner peripheral surface of the outer gear and causes the meshing position of the inner gear and the outer gear to rotate around the rotation axis; A bearing having an inner ring and an outer ring, and supporting the inner gear and the outer gear in a relatively rotatable manner; a first sealing member; and a second sealing member, separate from the first sealing member; The inner ring and the inner gear constitute an inner member, A third space is formed between the inner member and the outer ring and is open on one end surface of the bearing. A second space is formed between the inner ring and the outer ring, which is open to the other end surface of the bearing. A gear side space communicating with the second space is formed between the external gear and the bearing. The first sealing member is an oil seal, which seals the third space. The second sealing member is arranged on the inner side of the third space than the first sealing member to seal the third space.

5. The gear device according to claim 4, wherein: The second sealing member is an oil seal.

6. The gear device according to claim 5, wherein: The outer ring includes: an outer ring body; and an extension plate fixed to the outer ring body and extending toward the inner gear side from the inner ring. The first sealing member is arranged between the extending plate and the internal gear.

7. The gear device according to claim 6, wherein: The gear device is mounted on a mounting member, The external gear has: A flexible cylindrical portion coaxially disposed inside the internal gear; a diaphragm portion extending outward from an end of the cylindrical portion; and A rigid hub portion extends from the outer periphery of the diaphragm portion and is annular in shape. The outer ring and the hub portion are formed with a communication hole communicating with the third space. The communication hole communicates with the internal space of the cylindrical portion via a groove provided in the mounting member.

8. A gear device comprising: Internal gear; an external gear partially meshing with the internal gear; a wave generator, which contacts the inner peripheral surface of the outer gear and causes the meshing position of the inner gear and the outer gear to rotate around the rotation axis; A bearing having an inner ring and an outer ring, and supporting the inner gear and the outer gear in a relatively rotatable manner; Oil seals; a first bearing seal; a second bearing seal, separate from the first bearing seal; A first plate fixed to the inner ring; and Spacers, A first space is formed between the inner ring and the outer ring and is open on one end surface of the bearing. A second space is formed between the inner ring and the outer ring, which is open to the other end surface of the bearing. A gear side space communicating with the second space is formed between the external gear and the bearing. The oil seal seals the first space. The external gear has: A flexible cylindrical portion coaxially disposed inside the internal gear; a diaphragm portion extending outward from an end of the cylindrical portion; and A rigid hub portion extends from the outer periphery of the diaphragm portion and is annular in shape. The first bearing seal comprises a first base portion and a first front end portion extending from the first base portion. The second bearing seal includes a second base portion and a second front end portion extending from the second base portion. The spacer is clamped and fixed by the outer ring and the hub portion. The first base is clamped and fixed by the spacer and the outer ring. The second base portion is clamped and fixed by the spacer and the hub portion. The first front end portion contacts the first plate from the second space side to seal the second space. The second front end portion contacts the first plate from the gear side space side to partition the gear side space.

9. A gear device comprising: Internal gear; an external gear partially meshing with the internal gear; a wave generator, which contacts the inner peripheral surface of the outer gear and causes the meshing position of the inner gear and the outer gear to rotate around the rotation axis; A bearing having an inner ring and an outer ring, and supporting the inner gear and the outer gear in a relatively rotatable manner; Oil seals; A third bearing seal; and A second plate, fixed to the inner ring, A first space is formed between the inner ring and the outer ring and is open on one end surface of the bearing. A second space is formed between the inner ring and the outer ring, which is open to the other end surface of the bearing. A gear side space communicating with the second space is formed between the external gear and the bearing. The oil seal seals the first space. The external gear has: A flexible cylindrical portion coaxially disposed inside the internal gear; a diaphragm portion extending outward from an end of the cylindrical portion; and A rigid hub portion extends from the outer periphery of the diaphragm portion and is annular in shape. The third bearing seal comprises: a base; a first lip extending from the base; and a second lip extending from the base. The base is clamped and fixed by the second plate and the inner ring. The first lip and the second lip are in contact with the diaphragm portion to partition the gear side space.

10. A gear device comprising: Internal gear; an external gear partially meshing with the internal gear; a wave generator, which contacts the inner peripheral surface of the outer gear and causes the meshing position of the inner gear and the outer gear to rotate around the rotation axis; A bearing having an inner ring and an outer ring, and supporting the inner gear and the outer gear in a relatively rotatable manner; Oil seals; a fourth bearing seal; and A third plate, fixed to the inner ring, A first space is formed between the inner ring and the outer ring and is open on one end surface of the bearing. A second space is formed between the inner ring and the outer ring, which is open to the other end surface of the bearing. A gear side space communicating with the second space is formed between the external gear and the bearing. The oil seal seals the first space. The fourth bearing seal comprises: a base; a first lip extending from the base; and a second lip extending from the base. The base is clamped and fixed by the third plate and the inner ring. The first lip and the second lip are in contact with the outer ring to separate the second space from the gear side space.

11. A gear device comprising: Internal gear; an external gear partially meshing with the internal gear; a wave generator, which contacts the inner peripheral surface of the outer gear and causes the meshing position of the inner gear and the outer gear to rotate around the rotation axis; A bearing having an inner ring and an outer ring, and supporting the inner gear and the outer gear in a relatively rotatable manner; Oil seals; a fifth bearing seal; and a fourth plate, fixed to the outer ring and extending toward the inner ring, A first space is formed between the inner ring and the outer ring and is open on one end surface of the bearing. A second space is formed between the inner ring and the outer ring, which is open to the other end surface of the bearing. A gear side space communicating with the second space is formed between the external gear and the bearing. The oil seal seals the first space. A fourth space is formed between the fourth plate and the inner ring so that the gear side space communicates with the second space. The fifth bearing seal comprises: a base; a first lip extending from the base; and a second lip extending from the base. The base is received in a groove formed in one of the fourth plate and the inner ring. The first lip and the second lip are in contact with the other of the fourth plate and the inner ring to partition the fourth space.

12. A robot comprising the gear device according to any one of claims 1 to 11.

13. A gear device comprising: Internal gear; an external gear partially meshing with the internal gear; a wave generator, which contacts the inner peripheral surface of the outer gear and causes the meshing position of the inner gear and the outer gear to rotate around the rotation axis; a bearing having an inner ring and an outer ring, and supporting the internal gear and the external gear in a manner capable of relative rotation; and Oil seals, A first space is formed between the inner ring and the outer ring and is open on one end surface of the bearing. A second space is formed between the inner ring and the outer ring, which is open to the other end surface of the bearing. A gear side space communicating with the second space is formed between the external gear and the bearing. The oil seal seals the first space. The gear device is formed with a connection hole connecting the gear side space with the atmosphere.

14. The gear arrangement according to claim 13, wherein: The connecting holes are formed in the inner ring and the inner gear.

15. The gear arrangement according to claim 13, wherein: The external gear has: A flexible cylindrical portion coaxially disposed inside the internal gear; a diaphragm portion extending outward from an end of the cylindrical portion; and A rigid hub portion extends from the outer periphery of the diaphragm portion and is annular in shape. The connection hole is formed in the hub portion.

16. A robot comprising: The gear device according to any one of claims 13 to 15; a first member to which the gear device is fixed; and Air pipe, The first member has a through hole communicating with the connecting hole, One end of the air pipe is connected to the through hole and is installed on the first member. The other end of the air tube is open to the atmosphere.

17. The robot according to claim 16, wherein: At least a portion of the air tube is in a coil shape.

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