Gear device and robot

Abstract

To inhibit leakage of a lubricant from a bearing to the outside in a gear device and a robot.SOLUTION: A gear device includes: an internal gear 20; an external gear 30 configured to engage with the internal gear 20 partially; a wave motion generator 40 which contacts with the inner peripheral surface of the external gear 30; a bearing 50 which supports the internal gear 20 and the external gear 30 in a manner that allows relative rotation therebetween; and an oil seal 60. In the gear device, a first space 54 which is open on one end surface of the bearing 50 and a second space 55 which is open on the other end surface are formed. A gear side space 70 communicating with 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 external gear 30 includes: a flexible cylindrical part 31; a diaphragm part 33 located at the end of the cylindrical part 31; and a rigid boss part located at the outer peripheral edge of the diaphragm part 33. The boss part is attached to an attachment member. The boss part is provided with a communication hole which communicates with the first space 54 or the gear side space 70 and the communication hole communicates with the internal space 31A of the cylindrical part 31 through the attachment member.SELECTED DRAWING: Figure 11

Description

[Technical field]

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

[0002] A top hat type wave gearing described in International Publication No. 2018 / 189798 (Patent Document 1 below) is known. This top hat type wave gearing 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 so that they can rotate relative to each other. Between its inner and outer rings, the bearing has a first gap portion that opens into a first end face on one side of the bearing, and a second gap portion that opens into a second end face on the other side of the bearing.

[0003] The first gap portion communicates with the outside and is sealed by an oil seal. The oil seal prevents excess lubricant that has flowed into the bearing from leaking out to the outside. The second gap portion communicates with the gear-side gap portion that is disposed on the outer periphery 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 side. This prevents excess lubricant from flowing from the gear-side gap portion into the second gap portion, and allows excess lubricant that has flowed into the bearing to escape from the second gap portion to the gear-side gap portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 189798 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned top hat type wave gear device, if the bearing seal is maintained in a position in which the open end of the second gap is open for some reason, it becomes impossible to prevent the inflow of lubricant from the gear side gap to the second gap, which can result in an excessive inflow of lubricant into the bearing and leaking out from the oil seal. [Means for solving the problem]

[0006] The gear device disclosed herein is a gear device mounted on a mounting member, and includes an internal gear, an external gear partially meshed with the internal gear, a wave generator that contacts the inner circumferential surface of the external gear and rotates the meshing position of the internal gear and the external gear about a rotation axis, a bearing that includes an inner ring and an outer ring and supports the internal gear and the external gear so that they can rotate relative to each other, and an oil seal, wherein a first space that opens into one end face of the bearing is formed between the inner ring and the outer ring, and a second space that opens into the other end face of the bearing is formed between the inner ring and the outer ring, and the external gear and a gear-side space communicating with the second space is formed between the bearing and the external gear, the oil seal seals the first space, the external gear comprises a flexible cylindrical portion arranged coaxially inside the internal gear, a diaphragm portion extending outward from the end of the cylindrical portion, and a rigid boss portion extending from the outer peripheral edge of the diaphragm portion and forming an annular shape, the boss portion is attached to the mounting member, at least the boss portion has a communication hole formed therein that communicates with the first space or the gear-side space, and the communication hole communicates with the internal space of the cylindrical portion via a groove provided in the mounting member. Effect of the Invention

[0007] According to the present disclosure, it is possible to suppress leakage of lubricant from bearings to the outside in gear devices and robots. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a gear device according to a first embodiment. [Diagram 2] FIG. 2 is a view of the gear device seen from a direction parallel to the rotation axis. [Diagram 3] FIG. 3 is a cross-sectional view of the gear device and the arm taken along the line AA in FIG. [Figure 4] FIG. 4 is a cross-sectional view of a gear device according to a second embodiment, which corresponds to FIG. [Diagram 5] FIG. 5 is a cross-sectional view of a gear device according to a third embodiment, which is a cross-sectional view corresponding to FIG. [Figure 6] FIG. 6 is a cross-sectional view of a gear device according to a fourth embodiment, which is a cross-sectional view corresponding to FIG. [Figure 7] FIG. 7 is a cross-sectional view of a gear device according to a fifth embodiment, which corresponds to FIG. [Figure 8] FIG. 8 is a cross-sectional view of a gear device according to a sixth embodiment, which corresponds to FIG. [Figure 9] FIG. 9 is a cross-sectional view of a gear device according to a modified example of the sixth embodiment, and is a view showing a cross-section corresponding to FIG. [Figure 10] FIG. 10 is a cross-sectional view of a gear device according to the seventh embodiment, which is a cross-sectional view corresponding to FIG. [Figure 11] FIG. 11 is a cross-sectional view of a gear device according to an eighth embodiment, which corresponds to FIG. [Figure 12] FIG. 12 is a cross-sectional view of a gear device according to a ninth embodiment, which is a cross-sectional view corresponding to FIG. [Figure 13] FIG. 13 is a cross-sectional view of a gear device according to a tenth embodiment, which is a cross-sectional view corresponding to FIG. [Figure 14] FIG. 14 is a cross-sectional view of a gear device according to an eleventh embodiment, which is a cross-sectional view corresponding to FIG. [Figure 15] 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 a cross-section corresponding to FIG. [Figure 16]FIG. 16 is a cross-sectional view of a gear device according to Modification 2 of the eleventh embodiment, and shows a cross-section corresponding to FIG. [Figure 17] FIG. 17 is a cross-sectional view of a gear device according to a third modification of the eleventh embodiment, and shows a cross-section corresponding to FIG. [Figure 18] FIG. 18 is a cross-sectional view of a gear device according to a twelfth embodiment, which is a cross-sectional view corresponding to FIG. [Figure 19] FIG. 19 is a cross-sectional view of a gear device according to a thirteenth embodiment, which corresponds to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described. (1) A gear device disclosed herein is a gear device mounted on a mounting member, the gear device comprising: an internal gear; an external gear partially meshed with the internal gear; a wave generator that contacts an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis; an inner ring and an outer ring, a bearing that supports the internal gear and the external gear so that they can rotate relative to one another; and an oil seal; a first space that opens to one end face of the bearing is formed between the inner ring and the outer ring, and a second space that opens to the other end face of the bearing is formed between the inner ring and the outer ring, and the external gear is supported by the bearing. and the bearing, a gear-side space communicating with the second space is formed between the bearing and the oil seal, the oil seal seals the first space, the external gear includes a flexible cylindrical portion arranged coaxially inside the internal gear, a diaphragm portion extending outward from an end of the cylindrical portion, and a rigid boss portion extending from the outer circumferential edge of the diaphragm portion and forming an annular shape, the boss portion is attached to the mounting member, at least the boss portion has a communication hole formed therein that communicates with the first space or the gear-side space, and the communication hole communicates with the internal space of the cylindrical portion via a groove provided in the mounting member.

[0010] Since the first space or the gear side space is connected to the internal space of the cylindrical portion via the communication hole and the groove of the mounting member, the lubricant that has flowed into the first space or the gear side space can be returned to the internal space of the cylindrical portion, thereby preventing an excessive flow of lubricant into the first space and preventing the lubricant from leaking from the oil seal.

[0011] Furthermore, since the communication holes are formed at least in the boss portion which has a high rigidity, a decrease in the strength of the external gear is suppressed.

[0012] (2) In the gear device described in (1), the communication hole may be formed in the boss portion and the outer ring, and may communicate with the first space.

[0013] The communication holes are formed in the boss portion and the outer ring and communicate with the first space, so that the lubricant that has flowed into the first space can be returned to the internal space of the cylindrical portion via the communication holes and the groove in the mounting member, thereby preventing leakage of the lubricant from the oil seal.

[0014] (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.

[0015] The communication hole is formed in the boss and communicates with the gear space, so that lubricant attempting to flow from the gear space into the bearing can be returned to the internal space of the cylindrical part via the communication hole and the groove in the mounting member, thereby preventing leakage of lubricant from the oil seal.

[0016] (4) The gear device of the present disclosure comprises an internal gear, an external gear partially meshed with the internal gear, a wave generator contacting the inner circumferential surface of the external gear and rotating the meshing position of the internal gear and the external gear around a rotation axis, a bearing including an inner ring and an outer ring and supporting the internal gear and the external gear so that they can rotate relative to each other, a first sealing member, and a second sealing member separate from the first sealing member, wherein the inner ring and the internal gear constitute an inner member, a third space opening into one end face of the bearing is formed between the inner member and the outer ring, a second space opening into the other end face 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 first sealing member is an oil seal and seals the third space, and the second sealing member is arranged inside the third space relative to the first sealing member and seals the third space.

[0017] The first seal member and the second seal member, which are oil seals, can doubly suppress leakage of the lubricant.

[0018] (5) In the gear device described in (4), the second seal member may be an oil seal.

[0019] The two oil seals provide doubly effective means of preventing lubricant leakage.

[0020] (6) In the gear device described in (5), the outer ring may comprise an outer ring main body and an extension plate fixed to the outer ring main body and extending toward the internal gear further than the inner ring, and the first seal member may be arranged between the extension plate and the internal gear.

[0021] The addition of an extension plate to the outer ring body may facilitate the design of the gear arrangement.

[0022] (7) The gear device described in (6) is a gear device that is attached to a mounting member, wherein the external gear comprises a flexible cylindrical portion arranged coaxially inside the internal gear, a diaphragm portion extending outward from the end of the cylindrical portion, and a rigid boss portion extending from the outer peripheral edge of the diaphragm portion and forming an annular shape, and the outer ring and the boss portion have communication holes formed therein that communicate with the third space, and the communication hole may be connected to the internal space of the cylindrical portion via a groove provided in the mounting member.

[0023] In addition to the double sealing structure provided by the two oil seals, the lubricant that flows into the third space is returned to the internal space of the cylindrical section via the communicating hole and the groove in the mounting member, thereby further suppressing leakage of the lubricant.

[0024] (8) A gear device disclosed herein includes an internal gear, an external gear partially meshed with the internal gear, a wave generator that contacts an inner circumferential surface of the external gear and rotates a meshing position of the internal gear and the external gear about a rotation axis, an inner ring and an outer ring, a bearing that supports the internal gear and the external gear so that they can rotate relative to each other, an oil seal, a first bearing seal, a second bearing seal that is separate from the first bearing seal, a first plate fixed to the inner ring, and a spacer, wherein a first space that opens into one end face of the bearing is formed between the inner ring and the outer ring, a second space that opens into the other end face of the bearing is formed between the inner ring and the outer ring, a gear side space that communicates with 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 inside the internal gear, a diaphragm portion extending outward from an end of the cylindrical portion, and a rigid boss portion extending from an outer circumferential edge of the diaphragm portion and forming an annular shape; the first bearing seal comprises a first base and a first tip portion extending from the first base; the second bearing seal comprises a second base and a second tip portion extending from the second base; the spacer is sandwiched and fixed between the outer ring and the boss portion, the first base is sandwiched and fixed between the spacer and the outer ring, the second base is sandwiched and fixed between the spacer and the boss portion, the first tip portion contacts the first plate from the second space side to seal the second space, and the second tip portion contacts the first plate from the gear-side space side to partition the gear-side space.

[0025] The first tip of the first bearing seal contacts the first plate from the second space side, so that the lubricant is prevented from being pushed out from the second space into the gear-side space. The second tip of the second bearing seal contacts the first plate from the gear-side space side, so that the lubricant is prevented from flowing from the gear-side space into the second space. This prevents an excessive flow of lubricant into the first space, and prevents the lubricant from leaking from the oil seal.

[0026] In addition, because 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 lubricant enters this space, contact between the first bearing seal and the second bearing seal and the first plate is not released.

[0027] (9) A gear device according to the present disclosure includes an internal gear, an external gear partially meshed with the internal gear, a wave generator that contacts an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis, an inner ring and an outer ring, a bearing that supports the internal gear and the external gear so as to be rotatable relative to one another, an oil seal, a third bearing seal, and a second plate fixed to the inner ring, wherein a first space that opens to one end face of the bearing is formed between the inner ring and the outer ring, and a second space that opens to the other end face of the bearing is formed between the inner ring and the outer ring, and the external gear and the bearing are fixed to the inner ring. a gear-side space communicating with the second space is formed between the external gear and the third bearing seal, the oil seal seals the first space, the external gear comprises a flexible cylindrical portion arranged coaxially inside the internal gear, a diaphragm portion extending outward from an end of the cylindrical portion, and a rigid boss portion extending from the outer circumferential edge of the diaphragm portion and forming 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 sandwiched and fixed between 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.

[0028] By providing the third bearing seal with the first lip and the second lip, it is possible to suppress the extrusion of the lubricant from the second space to the gear side space and the inflow of the lubricant from the gear side space to the second space, thereby suppressing the inflow of an excessive amount of lubricant into the first space and the leakage of the lubricant from the oil seal.

[0029] In addition, 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, preventing the first lip and the second lip from releasing contact with the diaphragm portion.

[0030] (10) A gear device disclosed herein includes an internal gear, an external gear partially meshed with the internal gear, a wave generator that contacts an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis, an inner ring and an outer ring, a bearing that supports the internal gear and the external gear so that they can rotate relative to each other, an oil seal, a fourth bearing seal, and a third plate fixed to the inner ring, wherein a first space that opens to one end face of the bearing is formed between the inner ring and the outer ring, and a first space that opens 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 external gear and 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 includes a base, a first lip extending from the base, and a second lip extending from the base, the base is sandwiched and fixed between the third plate and the inner ring, and the first lip and the second lip contact the outer ring to separate the second space and the gear-side space.

[0031] By providing the fourth bearing seal with the first lip and the second lip, it is possible to suppress the extrusion of the lubricant from the second space to the gear side space and the inflow of the lubricant from the gear side space to the second space, thereby suppressing an excessive inflow of the lubricant into the first space and suppressing leakage of the lubricant from the oil seal.

[0032] In addition, 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, preventing the first lip and the second lip from releasing contact between the outer ring and the outer ring.

[0033] (11) A gear device disclosed herein includes an internal gear, an external gear partially meshed with the internal gear, a wave generator that contacts an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis, an inner ring and an outer ring, a bearing that supports the internal gear and the external gear so that they can rotate relative to each other, an oil seal, a fifth bearing seal, and a fourth plate that is fixed to the outer ring and extends toward the inner ring, wherein a first space that opens to one end face of the bearing is formed between the inner ring and the outer ring, and a second space that opens to the other end face 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, a fourth space communicating with 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 inside a groove formed in one of the fourth plate and the inner ring, and the first lip and the second lip contact the other of the fourth plate and the inner ring to separate the fourth space.

[0034] By providing the fifth bearing seal with the first lip and the second lip, it is possible to suppress the extrusion of the lubricant from the second space to the gear side space and the inflow of the lubricant from the gear side space to the second space, thereby suppressing the inflow of an excessive amount of lubricant into the first space and the leakage of the lubricant from the oil seal.

[0035] In addition, 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, preventing the first lip and the second lip from releasing contact between the fourth plate or the inner ring.

[0036] (12) A robot according to the present disclosure is a robot including a gear device according to any one of (1) to (11).

[0037] This makes it possible to prevent the lubricant from leaking out from the gear device.

[0038] (13) A gear device disclosed herein includes an internal gear, an external gear partially meshed with the internal gear, a wave generator contacting the inner circumferential surface of the external gear and rotating the meshing position of the internal gear and the external gear around a rotation axis, a bearing having an inner ring and an outer ring and supporting the internal gear and the external gear so that they can rotate relative to each other, and an oil seal, 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, 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 a connection hole is formed connecting the gear side space to the atmosphere.

[0039] By connecting the gear-side space to the atmosphere through the connection hole, the pumping action caused by the flexure of the external gear is eliminated, and lubricant is no longer pumped from the gear-side space into the bearing, thereby preventing leakage of lubricant from the oil seal.

[0040] (14) In the gear device described in (13), the connection hole may be formed in the inner ring and the internal gear.

[0041] (15) In the gear device described in (13), the external gear may include a flexible cylindrical portion arranged coaxially inside the internal gear, a diaphragm portion extending outward from the end of the cylindrical portion, and a rigid boss portion extending from the outer peripheral edge of the diaphragm portion and forming an annular shape, and the connection hole may be formed in the boss portion.

[0042] (16) A robot of the present disclosure is a robot comprising: a gear device according to any one of (13) to (15); a first member to which the gear device is fixed; and an air tube, wherein the first member has a through hole communicating with the connection hole, one end of the air tube is attached to the first member through the through hole, and the other end of the air tube is open to the atmosphere.

[0043] Since the air tube is provided, even if the lubricant enters the connection hole, the lubricant can be prevented from leaking out to the outside.

[0044] (17) In the robot described in (16), at least a portion of the air tube may be coiled.

[0045] Since at least a portion of the air tube is coiled, the length of the air tube can be increased, which further prevents the lubricant from leaking out.

[0046] [Details of the embodiment of the present disclosure] Hereinafter, embodiments of the present disclosure will be described. Note that the present disclosure is not limited to these examples, but is intended to include all modifications within the scope of the claims and meaning equivalent to the claims. In the following description, for multiple identical members, only some of the members may be labeled with reference numerals, and the reference numerals of the other members may be omitted.

[0047] [Embodiment 1] <Gear system> A first embodiment of the present disclosure will be described with reference to Figures 1 to 3. As shown in Figures 1 and 2, a gear device 10 of this embodiment includes an internal gear 20, an external gear 30 arranged inside the internal gear 20, a wave generator 40 arranged inside the external gear 30, and a bearing 50 that supports the internal gear 20 and the external gear 30 so that they can rotate relative to each other.

[0048] <Robot, Arm> The gear device 10 is used, for example, in a reducer for a rotating part of a robot or the like. As shown in Fig. 3, the robot 1 according to this embodiment includes a base (not shown), an arm 2 rotatably supported on the base, a gear device 10 that transmits driving force from one of the base and the arm 2 to the other, and a motor (not shown) that is a drive source for 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 an attachment member.

[0049] In this embodiment, the wave generator 40 rotates at the same rotational speed as the motor, and the rotation of the wave generator 40 is transmitted to the meshing position between the external gear 30 and the internal gear 20. Because the number of teeth of the external gear 30 and the number of teeth of the internal gear 20 are different, the external gear 30 and the internal gear 20 rotate relatively around the rotation axis 10A (see FIG. 1) due to the difference in the number of teeth. If 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 rotational speed lower than the rotational speed of the motor. Therefore, a reducer can be configured with the wave generator 40 on the input shaft side and the external gear 30 on the output shaft side.

[0050] <Internal gears, external gears> Hereinafter, the detailed configuration of the gear device 10 will be described with reference to FIG. 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 at one end of the cylindrical portion 31, a disk-shaped diaphragm portion 33 extending radially outward from the other end of the cylindrical portion 31, and an annular boss portion 34 formed continuously with the outer peripheral edge of the diaphragm portion 33. The external teeth 32 are configured to be able to mesh with the internal teeth 22. The number of teeth of the external gear 30 (the number of external teeth 32) is smaller 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 boss portion 34 is rigid. The external gear 30 and the internal gear 20 are rotatable around the same rotation axis 10A.

[0051] <Wave generator> The wave generator 40 bends the cylindrical portion 31 of the external gear 30 into a non-circular shape, for example an ellipse, to mesh 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 circumferential surface of the cam plate and the inner circumferential surface of the cylindrical portion 31. The cam plate is connected to a motor and rotates around the rotation shaft 10A. The rotation of the cam plate is transmitted to the external gear 30 via the wave bearing, and moves the meshing position between the external gear 30 and the internal gear 20 in the circumferential direction.

[0052] <Bearings> The bearing 50 is disposed coaxially surrounding the cylindrical portion 31. The bearing 50 in this embodiment is a cross roller bearing. The bearing 50 includes an inner ring 51, an outer ring 52 disposed on the outside of the inner ring 51, and rollers 53 disposed 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 boss portion 34.

[0053] <First space, second space, oil seal> 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 internal gear 20 side and opens to the outside from one end face of the bearing 50. The second space 55 opens to the other end face of the bearing 50. The first space 54 is sealed by an oil seal 60.

[0054] <Gear side space> 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.

[0055] <Communication hole> In the gear device 10 of this embodiment, a communication hole 80 communicating with the first space 54 is formed. In detail, the communication hole 80 is composed of a first communication hole 81 and a second communication hole 82 communicating with the first communication hole 81. The first communication hole 81 is formed in the outer ring 52. The first communication hole 81 is composed of a first hole 83 extending in the radial direction and a second hole 84 communicating with the first hole 83 and extending along the rotating shaft 10A. The first hole 83 communicates with the first space 54. The second hole 84 opens on the end face of the outer ring 52 on the boss portion 34 side. The second communication hole 82 is formed in the boss portion 34. The second communication hole 82 communicates with the second hole 84.

[0056] <groove> Further, a groove 2A communicating with the second communication hole 82 is formed in the arm 2. The groove 2A is recessed from the end face of the arm 2 to which the boss portion 34 is attached. The groove 2A extends radially inward from the second communication hole 82 side. The groove 2A communicates with an internal space 31A formed on the radially inner side of the cylindrical portion 31 via a space between the end face 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 communication hole 81, the second communication hole 82, and the groove 2A.

[0057] <Lubricant> A lubricant is appropriately placed in advance in each part of the gear device 10, specifically, the meshing portion between the internal gear 20 and the external gear 30, the internal space 31A of the cylindrical part 31, the fitting portion between the external gear 30 and the wave generator 40, etc. The lubricant is, for example, grease.

[0058] When the gear device 10 is in operation, the cylindrical portion 31 is repeatedly deflected in the radial direction at the meshing portion between the internal gear 20 and the external gear 30. This deflection generates a pumping action in which the lubricant is pushed out from the meshing portion between the internal gear 20 and the external gear 30 into the gear-side space 70. The lubricant pushed out by the pumping action passes through the gear-side space 70 and flows toward the raceway groove of the bearing 50. The lubricant flows from the raceway groove of the bearing 50 into the first space 54.

[0059] In this embodiment, since the communication 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 flow into the communication hole 80. This makes it possible to prevent excess lubricant from accumulating in the first space 54 and leaking out from the oil seal 60. In addition, the lubricant that flows into the communication hole 80 flows back into the internal space 31A of the cylindrical portion 31 through the groove 2A of the arm 2.

[0060] 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 makes it possible to prevent excess lubricant from accumulating in the first space 54.

[0061] [Effects of the First Embodiment] As described above, the gear device 10 of embodiment 1 is a gear device 10 that is attached to a mounting member (arm 2), and includes an internal gear 20, an external gear 30 that is partially meshed 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 a rotation axis 10A, a bearing 50 that has an inner ring 51 and an outer ring 52 and supports the internal gear 20 and the external gear 30 so that they can rotate relative to each other, and an oil seal 60. Between the inner ring 51 and the outer ring 52, a first space 54 that opens to one end face of the bearing 50 is formed, and between the inner ring 51 and the outer ring 52, a second space 55 that opens to the other end face of the bearing 50 is formed. a gear side space 70 communicating with the second space 55 is formed between the external gear 30 and the bearing 50; an oil seal 60 seals the first space 54; the external gear 30 comprises a flexible cylindrical portion 31 arranged coaxially inside the internal gear 20, a diaphragm portion 33 extending outward from the end of the cylindrical portion 31, and a rigid boss portion 34 extending from the outer periphery of the diaphragm portion 33 and forming an annular shape, the boss portion 34 is attached to a mounting member, and at least the boss portion 34 has a communication hole 80 formed therein that communicates with the first space 54, and the communication hole 80 communicates with the internal space 31A of the cylindrical portion 31 via a groove 2A provided in the mounting member.

[0062] Since the first space 54 communicates with the internal space 31A of the cylindrical portion 31 via the communication hole 80 and the groove 2A of the mounting member, the lubricant that has flowed into the first space 54 can be returned to the internal space 31A of the cylindrical portion 31. This makes it possible to prevent an excessive flow of lubricant into the first space 54 and to prevent the lubricant from leaking from the oil seal 60.

[0063] Furthermore, since the communication holes 80 are formed at least in the boss portion 34 which has rigidity, a decrease in the strength of the external gear 30 is suppressed.

[0064] In the gear device 10 of 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 .

[0065] The communication hole 80 is formed in the boss portion 34 and the outer ring 52 and communicates with the first space 54, so that the lubricant that has flowed into the first space 54 can be returned to the internal space 31A of the cylindrical portion 31 via the communication hole 80 and the groove 2A of the mounting member. Therefore, leakage of the lubricant from the oil seal 60 can be suppressed.

[0066] The robot 1 of the first embodiment is a robot 1 equipped with a gear device 10.

[0067] This makes it possible to prevent the lubricant from leaking out from the gear device 10 to the outside.

[0068] [Embodiment 2] A second embodiment of the present disclosure will be described with reference to Fig. 4. In a gear device 110 and a robot 101 of the second embodiment, the state of a communication hole 180 is different from that of the first embodiment. Other configurations, actions, and effects are the same as those of the first embodiment, so the same reference numerals as those of the first embodiment are used to designate the same members as those of the first embodiment, and detailed descriptions thereof will be omitted.

[0069] The communication hole 180 of the gear device 110 is composed of a first communication hole 181 and a second communication hole 182 that communicates with the first communication hole 181. The first communication hole 181 is composed of a first hole 83 that extends in the radial direction and a second hole 184 that communicates with the first hole 83 and extends along the rotating shaft 10A. The second hole 184 is formed by penetrating the outer ring 52. The second communication hole 182 is formed in the boss portion 34. The second communication hole 182 communicates with the second hole 184.

[0070] A groove 2A communicating with the second communication 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 communication hole 181, the second communication hole 182, and the groove 2A. Furthermore, a bolt fastening hole 102B is formed in the arm 102 so as to be recessed from the bottom surface of the groove 2A. A female thread is provided on the inner surface of the bolt fastening hole 102B.

[0071] The outer ring 52 is fixed to the arm 102 by a bolt 102C. In detail, the bolt 102C is inserted through the second hole 184 and the second communication hole 182, and is screwed into the female thread of the bolt fastening hole 102B. A seal washer 102D is disposed between the head of the bolt 102C and the outer ring 52. This prevents the lubricant that has flowed into the communication hole 180 from the first space 54 from leaking out from between the head of the bolt 102C and the outer ring 52 to the outside.

[0072] Although not shown, a check valve may be provided in the first hole 83 of the communication 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. This makes it possible to prevent excess lubricant from accumulating in the first space 54.

[0073] [Embodiment 3] A third embodiment of the present disclosure will be described with reference to Fig. 5. In a gear device 210 and a robot 201 of the third embodiment, the state of a communication hole 280 is different from that of the first embodiment. Other configurations, actions, and effects are the same as those of the first embodiment, so the same reference numerals as those of the first embodiment are used to designate the same members as those of the first embodiment, and detailed descriptions thereof will be omitted.

[0074] A communication hole 280 that communicates with the gear side space 70 is formed in the boss portion 234 of the gear device 210 .

[0075] A groove 2A communicating with the communication hole 280 is formed in the arm 2 of the robot 201. The groove 2A is recessed from the end face of the arm 2 to which the boss portion 234 is attached. The groove 2A communicates with the internal space 31A of the cylindrical portion 31 via the space between the end face 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.

[0076] In this embodiment, since the communication hole 280 communicating with the gear side space 70 is formed, a part of the lubricant attempting to flow from the gear side space 70 to the second space 55 by the pump action can be made to flow into the communication hole 280. This makes it possible to prevent the lubricant from flowing excessively from the gear side space 70 through the second space 55 into the first space 54 and leaking out from the oil seal 60. In addition, the lubricant that has flowed into the communication hole 280 flows back into the internal space 31A of the cylindrical portion 31 through the groove 2A of the arm 2.

[0077] The communication hole 280 is preferably disposed radially away from the second space 55. With such a configuration, it is easy to prevent the lubricant, which has once flowed into the communication hole 280, from flowing back into the second space 55.

[0078] Although not shown, a check valve may be provided in communication hole 280 to allow lubricant to flow from gear side space 70 to groove 2A and to restrict lubricant from flowing from groove 2A to gear side space 70. This makes it possible to prevent lubricant from flowing from gear side space 70 into bearing 50, and therefore makes it possible to prevent excess lubricant from accumulating in first space 54.

[0079] [Effects of the Third Embodiment] The gear device 210 of the third embodiment is a gear device 210 that is attached to a mounting member (arm 2), and includes an internal gear 20, an external gear 30 that is partially meshed 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 between the internal gear 20 and the external gear 30 around a 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 so that they can rotate relative to each other, and an oil seal 60. Between the inner ring 51 and the outer ring 52, a first space 54 that opens to one end face of the bearing 50 is provided. 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, a gear-side space 70 communicating with the second space 55 is formed between the external gear 30 and the bearing 50, and an oil seal 60 seals the first space 54. The external gear 30 comprises a flexible cylindrical portion 31 arranged coaxially inside the internal gear 20, a diaphragm portion 33 extending outward from the end of the cylindrical portion 31, and a rigid boss portion 234 extending from the outer peripheral edge of the diaphragm portion 33 and forming an annular shape, the boss portion 234 is attached to a mounting member, and at least the boss portion 234 has a communication hole 280 formed therein that communicates with the gear-side space 70, and the communication hole 280 communicates with an internal space 31A of the cylindrical portion 31 via a groove 2A provided in the mounting member.

[0080] Since 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 of the mounting member, the lubricant that has flowed into the gear-side space 70 can be returned to the internal space 31A of the cylindrical portion 31. This prevents the lubricant from flowing excessively into the first space 54, and prevents the lubricant from leaking from the oil seal 60.

[0081] Furthermore, since the communication holes 280 are formed at least in the rigid boss portion 234, a decrease in the strength of the external gear 30 is suppressed.

[0082] 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 .

[0083] The communication hole 280 is formed in the boss portion 234 and communicates with the gear-side space 70, so that the lubricant attempting to flow from the gear-side space 70 into the inside of the bearing 50 can be returned to the internal space 31A of the cylindrical portion 31 via the communication hole 280 and the groove 2A of the mounting member. This makes it possible to prevent the lubricant from leaking from the oil seal 60.

[0084] [Embodiment 4] A fourth embodiment of the present disclosure will be described with reference to Fig. 6. In a gear device 310 and a robot 301 of the fourth embodiment, a first seal member 361 and a second seal member 362 are provided, and the communication hole 80 of the first embodiment is not formed. Since other configurations, actions, and effects are similar to those of the first embodiment, the same reference numerals as those of the first embodiment are used to designate equivalent members to those of the first embodiment, and detailed description thereof will be omitted.

[0085] <First seal member, second seal member> The first seal member 361 is an oil seal similar to that in embodiment 1. The second seal member 362 is separate from the first seal member 361, and is disposed further inward of the bearing 50 than the first seal member 361. The second seal member 362 in this embodiment is an oil seal similar to the first seal member 361.

[0086] <Third space> In this embodiment, the outer ring 352 has an extension portion 352A that extends toward the internal gear 20 side more than the inner ring 51. When the member formed by the inner ring 51 and the internal gear 20 is 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 to the end face of the bearing 50 on the opposite side 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 in this embodiment includes the first space 54 and extends further outward from the first space 54 to the bearing 50.

[0087] In this embodiment, the third space 354A communicating with the outside from the bearing 50 is doubly sealed by the first seal member 361 and the second seal member 362, so that leakage of the lubricant to the outside can be suppressed.

[0088] Although not shown, both the first seal member 361 and the second seal member 362 may be disposed in the first space 54, that is, between the inner ring 51 and the outer ring 52.

[0089] [Effects of the fourth embodiment] The gear device 310 of the fourth embodiment includes an internal gear 20, an external gear 30 partially meshed 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 a rotation axis 10A, an inner ring 51 and an outer ring 352, a bearing 50 that supports the internal gear 20 and the external gear 30 so as to be able to rotate relative to each other, a first seal member 361, and a second seal member 362 that is separate from the first seal member 361, and the inner ring 51 and the internal gear 20 form an inner member 320A, and the inner member 320 A third space 354A opening into one end face of the bearing 50 is formed between the inner ring 51 and the outer ring 352, a second space 55 opening into the other end face of the bearing 50 is formed between the inner ring 51 and the outer ring 352, and a gear side space 70 communicating with the second space 55 is formed between the external gear 30 and the bearing 50. The first seal member 361 is an oil seal and seals the third space 354A, and the second seal member 362 is arranged inside the third space 354A relative to the first seal member 361 and seals the third space 354A.

[0090] The first seal member 361 and the second seal member 362, which are oil seals, can doubly suppress leakage of the lubricant.

[0091] In the gear device 310 of the fourth embodiment, the second seal member 362 is an oil seal.

[0092] The two oil seals provide doubly effective means of preventing lubricant leakage.

[0093] [Embodiment 5] A fifth embodiment of the present disclosure will be described with reference to Fig. 7. In a gear device 410 and a robot 401 of the fifth embodiment, the arrangement of a first seal member 461 and the configuration of a second seal member 462 are different from those of the fourth embodiment. The other configurations and effects are the same as those of the first and fourth embodiments, so the same reference numerals as those of the first embodiment are used for the same members as those of the first embodiment, and detailed descriptions thereof will be omitted.

[0094] The gear device 410 of the fifth embodiment includes a first seal member 461 and a second seal member 462. The first seal member 461 is an oil seal similar to that of the first embodiment. The first seal member 461 is disposed between the inner ring 451 and the outer ring 52, and seals the first space 54. The second seal member 462 is disposed inward of the first seal member 461 in the first space 54. The second seal member 462 of the present embodiment has an annular shape and includes a base portion 462A and a tip portion 462B extending from the base portion 462A.

[0095] The base portion 462A is sandwiched and fixed between the inner wall of the outer ring 52 that constitutes the first space 54 and the spacer 463. The spacer 463 is pressed by the first seal member 461. The tip portion 462B abuts against a contact portion 451A formed on the inner ring 451. The contact portion 451A is formed in the first space 54 and extends radially outward. The tip portion 462B extends from inside the first space 54 to the abutment portion 451A side and contacts the abutment portion 451A. The first space 54 is sealed by the second seal member 462.

[0096] According to the configuration of the present embodiment, the outer ring 52 does not extend further toward the internal gear 20 than the inner ring 451, so the first space 54 substantially corresponds to the third space 354A of the fourth embodiment, and the same effects as those of the fourth embodiment are achieved. According to the present embodiment, a double seal structure can be provided in the gear device 410 without increasing the size of the outer ring 52, as compared to the fourth embodiment.

[0097] [Embodiment 6] A sixth embodiment of the present disclosure will be described with reference to Figures 8 and 9. In a gear device 510 and a robot 501 of the sixth embodiment, the configuration of an outer ring 552 is different from that of the fourth embodiment. Other configurations and effects are similar to those of the first and fourth embodiments, so that the same reference numerals as those of the fourth embodiment are used for members equivalent to those of the fourth embodiment, and detailed description thereof will be omitted.

[0098] <Outer ring body, extension plate> In this embodiment, as shown in Fig. 8, 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 configured substantially similarly to the outer ring 52 in the first embodiment, omitting the first communication hole 81. The extension plate 552B extends closer to the internal gear 20 than the inner ring 51. The first seal member 361 is disposed between the extension plate 552B and the internal gear 20, and seals the third space 354A. The second seal member 362 is disposed between the outer ring body 552A and the inner ring 51, and seals the third space 354A.

[0099] The outer ring body 552A and the extension plate 552B are fixed by bolt fastening. In detail, a bolt insertion hole 552C is provided in the extension plate 552B, and a bolt fastening hole 552D is provided in the outer ring body 552A. A bolt 552E is inserted into the bolt insertion hole 552C and is screwed into the female thread of the bolt fastening hole 552D.

[0100] 9, an outer race main body 552A, an extension plate 552B, a boss portion 534, and an arm 502 of a robot 501 may be fixed by bolt fastening. In detail, the extension plate 552B, the outer race main body 552A, and the boss portion 534 may be provided with bolt insertion holes 552C, 552F, and 534A, respectively, and a bolt fastening hole 502A may be provided in the arm 502. A bolt 552G may be inserted through the bolt insertion holes 552C, 552F, and 534A, and screwed into the female thread of the bolt fastening hole 502A.

[0101] [Effects of the sixth embodiment] In the gear device 510 of embodiment 6, the outer ring 552 comprises an outer ring main body 552A and an extension plate 552B fixed to the outer ring main body 552A and extending toward the internal gear 20 side more than the inner ring 51, and the first seal member 361 is arranged between the extension plate 552B and the internal gear 20.

[0102] The addition of extension plate 552B to outer race body 552A may facilitate the design of gear train 510.

[0103] [Embodiment 7] A seventh embodiment of the present disclosure will be described with reference to Fig. 10. A gear train 610 and a robot 601 of the seventh embodiment are configured substantially similarly to the gear train 510 and the robot 501 of the sixth embodiment shown in Fig. 9, except that a communication hole 680 and a groove 602A are provided. With respect to configurations and effects common to the sixth embodiment, the same reference numerals as those of the sixth embodiment are used for equivalent members, and detailed descriptions thereof will be omitted.

[0104] <Communication hole> In the seventh embodiment, a third hole 680A is formed to communicate the bolt insertion holes 552C, 552F and 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.

[0105] A groove 602A is formed in the arm 602 of the robot 601, 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 communication hole 680 and the groove 602A.

[0106] A bolt fastening hole 502A is formed in the arm 602 so as to be recessed from the bottom surface of the groove 602A. A bolt 552G is inserted through the bolt insertion holes 552C, 552F, and 534A and is screwed into the female thread of the bolt fastening hole 502A. The arm 602 is an example of a mounting member.

[0107] Although not shown, a check valve may be provided in third hole 680A of communication hole 680 to allow the lubricant to flow from third space 354A to groove 602A and to restrict the lubricant from flowing from groove 602A to third space 354A. This makes it possible to prevent excess lubricant from accumulating in third space 354A.

[0108] [Effects of the seventh embodiment] The gear device 610 of embodiment 7 is a gear device 610 that is attached to a mounting member (arm 602), and the external gear 30 comprises a flexible cylindrical portion 31 arranged coaxially inside the internal gear 20, a diaphragm portion 33 extending outward from the end of the cylindrical portion 31, and a rigid boss portion 534 extending from the outer peripheral edge of the diaphragm portion 33 and forming an annular shape, and the outer ring 552 and the boss portion 534 are formed with a communication hole 680 that communicates with the third space 354A, and the communication hole 680 communicates with the internal space 31A of the cylindrical portion 31 via a groove 602A provided in the mounting member.

[0109] In addition to the double sealing structure using two oil seals, the lubricant that has flowed into the third space 354A is returned to the internal space 31A of the cylindrical portion 31 via the communicating hole 680 and the groove 602A of the mounting member, thereby further suppressing leakage of the lubricant.

[0110] [Embodiment 8] An eighth embodiment of the present disclosure will be described with reference to Fig. 11. In a gear device 710 and a robot 701 of the eighth embodiment, a first bearing seal 790 and a second bearing seal 791 are provided, and the communication hole 80 of the first embodiment is not formed. Since other configurations, actions, and effects are similar to those of the first embodiment, the same reference numerals as those of the first embodiment are used to designate equivalent members to those of the first embodiment, and detailed description thereof will be omitted.

[0111] The gear device 710 includes a first bearing seal 790, a second bearing seal 791 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.

[0112] <First plate> The first plate 756 has a contact portion 756A disposed near the boundary between the gear side space 70 and the second space 55. The contact portion 756A extends radially outward from the inner ring 51 side.

[0113] <Spacer> Spacer 757 is fixed by being sandwiched between outer ring 752 and boss portion 734. In detail, bolt insertion holes 757A, 734A are provided in spacer 757 and boss portion 734, and bolt fastening hole 752A is provided in outer ring 752. Bolt 752B is inserted through bolt insertion holes 757A, 734A and is screwed into the female thread of bolt fastening hole 752A.

[0114] <First bearing seal> The first bearing seal 790 includes a first base portion 790A and a first tip 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 fixed by being sandwiched between the inner wall of the fixing groove and a spacer 757. The first tip portion 790B is disposed in the second space 55, and is in contact with the abutment portion 756A from the second space 55 side. The second space 55 is sealed by the first tip portion 790B. This suppresses the extrusion of lubricant from the bearing 50 side to the gear side space 70.

[0115] <Second bearing seal> The second bearing seal 791 includes a second base portion 791A and a second tip 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 fixed by being sandwiched between the inner wall of the fixing groove and the boss portion 734. The second tip 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 tip portion 791B separates the gear side space 70. This prevents the inflow of lubricant from the gear side space 70 into the bearing 50.

[0116] The first bearing seal 790 and the second bearing seal 791 are disposed with a predetermined space therebetween, so that even if a lubricant is disposed in the space, the first bearing seal 790 and the second bearing seal 791 are unlikely to break contact with the abutment portion 756A.

[0117] [Effects of embodiment 8] The gear device 710 of the eighth embodiment includes an internal gear 20, an external gear 30 partially meshed 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, an inner ring 51, and an outer ring 752, and includes a bearing 50 that supports the internal gear 20 and the external gear 30 so that they can rotate relative to each other, an oil seal 60, a first bearing seal 790, and a separate body from the first bearing seal 790. The bearing 50 includes a second bearing seal 791, a first plate 756 fixed to the inner ring 51, and a spacer 757. Between the inner ring 51 and the outer ring 752, a first space 54 is formed that opens to one end face of the bearing 50. Between the inner ring 51 and the outer ring 752, a second space 55 is formed that opens to the other end face of the bearing 50. Between the external gear 30 and the bearing 50, a gear-side space 70 that communicates with the second space 55 is formed. The oil seal 60 seals the first space 54 and the outer The toothed gear 30 includes a flexible cylindrical portion 31 arranged coaxially inside the internal gear 20, a diaphragm portion 33 extending outward from the end of the cylindrical portion 31, and a rigid boss portion 734 extending from the outer circumferential 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 tip portion 790B extending from the first base portion 790A. The second bearing seal 791 includes a second base portion 791A and a second tip portion 791B extending from the second base portion 791A. In other words, gear device 710 has spacer 757 sandwiched and fixed between outer ring 752 and boss portion 734, first base portion 790A sandwiched and fixed between spacer 757 and outer ring 752, second base portion 791A sandwiched and fixed between spacer 757 and boss portion 734, first tip portion 790B contacts first plate 756 from the second space 55 side to seal second space 55, and second tip portion 791B contacts first plate 756 from the gear side space 70 side to separate gear side space 70.

[0118] A first tip portion 790B of the first bearing seal 790 contacts the first plate 756 from the second space 55 side, thereby preventing the lubricant from being pushed out from the second space 55 into the gear-side space 70. A second tip portion 791B of the second bearing seal 791 contacts the first plate 756 from the gear-side space 70 side, thereby preventing the lubricant from flowing from the gear-side space 70 into the second space 55. This prevents an excessive flow of lubricant into the first space 54, and prevents the lubricant from leaking from the oil seal 60.

[0119] Furthermore, because 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, and even if lubricant enters this space, the contact between the first bearing seal 790 and the second bearing seal 791 and the first plate 756 is not released.

[0120] [Embodiment 9] A ninth embodiment of the present disclosure will be described with reference to Fig. 12. In a gear device 810 and a robot 801 of the ninth embodiment, a third bearing seal 890 is provided, and the communication hole 80 of the first embodiment is not formed. Since other configurations, actions, and effects are similar to those of the first embodiment, the same reference numerals as those of the first embodiment are used to designate equivalent members to those of the first embodiment, and detailed description thereof will be omitted.

[0121] The gear device 810 includes a third bearing seal 890 and a second plate 856 fixed to the inner ring 51 .

[0122] <Second Plate> The second plate 856 is formed with a mounting groove 856A in which the third bearing seal 890 is mounted.

[0123] <Third bearing seal> 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 accommodated in a mounting groove 856A of the second plate 856. The base 891 is sandwiched and fixed between the inner wall of the mounting groove 856A and the end face of the inner ring 51 that faces the diaphragm portion 33.

[0124] The first lip 892A extends from the radially outer end of the base 891 radially outward and toward the diaphragm portion 33. The second lip 892B extends from the radially outer end of the base 891 radially inward and toward the diaphragm portion 33. The first lip 892A and the second lip 892B are disposed with a predetermined space therebetween in the radial direction. The first lip 892A is disposed in the gear side space 70, closer to the second space 55 than the second lip 892B.

[0125] The first lip 892A and the second lip 892B are in contact with the diaphragm portion 33 to separate the gear-side space 70. Even if the diaphragm portion 33 is flexed and deformed as the gear device 810 is operated, the first lip 892A and the second lip 892B are configured to maintain contact with the diaphragm portion 33. The contact between the first lip 892A and the diaphragm portion 33 suppresses the extrusion of lubricant from the bearing 50 side toward the radially inward direction of the gear-side space 70. The contact between the second lip 892B and the diaphragm portion 33 suppresses the inflow of lubricant from the gear-side space 70 located radially inward into the bearing 50.

[0126] [Effects of embodiment 9] The gear device 810 of the ninth embodiment includes an internal gear 20, an external gear 30 partially meshed 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, an inner ring 51 and an outer ring 52, a bearing 50 that supports the internal gear 20 and the external gear 30 so that they can rotate relative to each other, an oil seal 60, a third bearing seal 890, and a second plate 856 fixed to the inner ring 51. A first space 54 that opens to one end face of the bearing 50 is formed between the inner ring 51 and the outer ring 52, and a second space 55 that opens to 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 communicating with the second space 55 is formed between the first space 54 and the second plate 856, and the oil seal 60 seals the first space 54; the external gear 30 comprises a flexible cylindrical portion 31 arranged coaxially inside the internal gear 20, a diaphragm portion 33 extending outward from the end of the cylindrical portion 31, and a rigid boss portion 34 extending from the outer circumferential edge of the diaphragm portion 33 and forming 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 fixed by being sandwiched between the second plate 856 and the inner ring 51, and the first lip 892A and the second lip 892B are in contact with the diaphragm portion 33 to separate the gear-side space 70, resulting in a gear device 810.

[0127] By providing the third bearing seal 890 with the first lip 892A and the second lip 892B, it is possible to suppress the extrusion of lubricant from the second space 55 to the gear side space 70, and the inflow of lubricant from the gear side space 70 to the second space 55. This makes it possible to suppress an excessive inflow of lubricant into the first space 54, and to suppress leakage of the lubricant from the oil seal 60.

[0128] 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, preventing the first lip 892A and the second lip 892B from releasing contact between the diaphragm portion 33 and the diaphragm portion 33.

[0129] [Embodiment 10] A tenth embodiment of the present disclosure will be described with reference to Fig. 13. In a gear train 910 and a robot 901 of the tenth embodiment, a fourth bearing seal 990 is provided, and the communication hole 80 of the first embodiment is not formed. Since other configurations, actions, and effects are similar to those of the first embodiment, the same reference numerals as those of the first embodiment are used to designate equivalent members to those of the first embodiment, and detailed description thereof will be omitted.

[0130] The gear device 910 includes a fourth bearing seal 990 and a third plate 956 fixed to the inner ring 51 .

[0131] <Third Plate> The third plate 956 is formed with a mounting groove 956A in which the fourth bearing seal 990 is mounted.

[0132] <4th bearing seal> The fourth 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 accommodated in a mounting groove 956A of the third plate 956. The base 991 is sandwiched and fixed between the inner wall of the mounting groove 956A and the end face of the inner ring 51 that faces the diaphragm portion 33.

[0133] The first lip 992A extends from the radially outer end of the base 991 radially outward and toward the opposite side to the diaphragm portion 33. The second lip 992B extends from the radially outer end of the base 991 radially outward and toward the diaphragm portion 33 side. The first lip 992A and the second lip 992B are arranged with a predetermined space between them in the direction along the rotation shaft 10A. The second lip 992B is arranged closer to the gear side space 70 than the first lip 992A.

[0134] 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. Contact between the first lip 992A and the inner circumferential surface of the outer ring 52 suppresses the extrusion of lubricant from the bearing 50 side to the gear-side space 70. Contact between the second lip 992B and the inner circumferential surface of the outer ring 52 suppresses the inflow of lubricant from the gear-side space 70 into the bearing 50.

[0135] [Effects of the Tenth Embodiment] The gear device 910 of the tenth embodiment includes an internal gear 20, an external gear 30 partially meshed 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, an inner ring 51 and an outer ring 52, a bearing 50 that supports the internal gear 20 and the external gear 30 so that they can rotate relative to each other, an oil seal 60, a fourth bearing seal 990, and a third plate 956 fixed to the inner ring 51. A first space 54 that opens to one end face of the bearing 50 is formed between the inner ring 51 and the outer ring 52, and a second space 55 that opens to one end face of the bearing 50 is formed between the inner ring 51 and the outer ring 52. a second space 55 opening to the other end face of the bearing 50 is formed between the external gear 30 and the bearing 50, a gear side space 70 communicating with 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 has 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 sandwiched and fixed between the third plate 956 and the inner ring 51, and the first lip 992A and the second lip 992B are in contact with the outer ring 52 to separate the second space 55 and the gear side space 70, resulting in a gear device 910.

[0136] By providing the fourth bearing seal 990 with the first lip 992A and the second lip 992B, it is possible to suppress the extrusion of lubricant from the second space 55 to the gear side space 70, and the inflow of lubricant from the gear side space 70 to the second space 55. This makes it possible to suppress an excessive inflow of lubricant into the first space 54, and to suppress leakage of the lubricant from the oil seal 60.

[0137] 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, preventing contact between the first lip 992A and the second lip 992B and the outer ring 52 from being released.

[0138] [Embodiment 11] An eleventh embodiment of the present disclosure will be described with reference to Fig. 14 to Fig. 17. In a gear device 1010 and a robot 1001 of the eleventh embodiment, a fifth bearing seal 1090 is provided, and the communication hole 80 of the first embodiment is not formed. Since other configurations, actions, and effects are similar to those of the first embodiment, the same reference numerals as those of the first embodiment are used to designate equivalent members to those of the first embodiment, and detailed description thereof will be omitted.

[0139] As shown in FIG. 14, the gear device 1010 includes a fifth bearing seal 1090 and a fourth plate 1056 that is fixed to the outer ring 1052 .

[0140] <4th Plate> The fourth plate 1056 includes a fixed portion 1057 and an extension portion 1058 extending from the fixed portion 1057. The fixed portion 1057 is fixed by being sandwiched between the outer ring 1052 and the boss portion 1034. The fixed portion 1057 and the boss portion 1034 are formed with bolt insertion holes 1057A and 1034A. The outer ring 1052 is formed with a bolt fastening hole 1052A. A bolt 1052B inserted into the bolt insertion holes 1057A and 1034A is screwed into the female thread of the bolt fastening hole 1052A.

[0141] The extension portion 1058 extends radially inward from the radially inner end of the fixed portion 1057. In detail, 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 disk-shaped. The second extension portion 1058B is cylindrical.

[0142] <4th space> A fourth space 1070A is formed between the extension portion 1058 and the inner ring 1051. The fourth space 1070A communicates between the gear side space 70 and the second space 55.

[0143] <Mounting groove> 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 face of the second extension portion 1058B on the opposite side to the diaphragm portion 33.

[0144] The inner ring 1051 is provided with a contact portion 1051A against which the fifth bearing seal 1090 contacts. The contact portion 1051A extends radially inward and is disposed opposite the second extension portion 1058B in the direction along the rotating shaft 10A.

[0145] <5th bearing seal> 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 a mounting groove 1056A of the fourth plate 1056.

[0146] The first lip 1092A extends from an end of the base 1091 opposite the diaphragm portion 33 radially outward and opposite the diaphragm portion 33. The second lip 1092B extends from an end of the base 1091 opposite the diaphragm portion 33 radially inward and opposite the diaphragm portion 33. The first lip 1092A and the second lip 1092B are arranged with a predetermined space between them in the radial direction. The first lip 1092A is arranged on the back side of the fourth space 1070A relative to the second lip 1092B.

[0147] The first lip 1092A and the second lip 1092B are in contact with an end face of the abutment portion 1051A on the diaphragm portion 33 side to separate the fourth space 1070A. The contact between the first lip 1092A and the end face of the abutment portion 1051A suppresses the extrusion of lubricant from the bearing 50 side to the gear side space 70. The contact between the second lip 1092B and the end face of the abutment portion 1051A suppresses the inflow of lubricant from the gear side space 70 into the bearing 50.

[0148] In addition, as a first modified example of this embodiment, as shown in FIG. 15, the mounting groove 1056A in which the base 1091 is accommodated is recessed from the outer peripheral surface of the second extension portion 1058B that faces the inner peripheral surface of the inner ring 1051, and the first lip 1092A and the second lip 1092B may be in contact with the inner peripheral surface of the inner ring 1051.

[0149] Furthermore, as another aspect of this embodiment, as shown in Figures 16 and 17, an attachment groove 1051B (an example of a groove) in which the base 1091 is accommodated 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.

[0150] 16 showing the second modified example of the present 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 contact the outer peripheral surface of the second extension portion 1058B that faces the inner peripheral surface of the inner ring 1051.

[0151] In FIG. 17 showing the third modified example of this embodiment, the mounting groove 1051B is recessed from the end face of the inner ring 1051 facing the diaphragm portion 33. The first lip 1092A and the second lip 1092B are in contact with the end face of the first extension portion 1058A on the inner ring 1051 side. In FIG. 17, the extension portion 1058 only needs to have a portion (the first extension portion 1058A shown in FIGS. 14 to 16) extending in the radial direction where the first lip 1092A and the second lip 1092B are in contact. According to the configuration shown in FIG. 17, the fourth space 1070A provided between the gear side space 70 and the second space 55 becomes small, but the configuration of the extension portion 1058 can be simplified.

[0152] [Effects of embodiment 11] The gear device 1010 of the eleventh embodiment includes an internal gear 20, an external gear 30 partially meshed 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, an inner ring 1051 and an outer ring 1052, a bearing 50 that supports the internal gear 20 and the external gear 30 so as to be capable of relative rotation, an oil seal 60, a fifth bearing seal 1090, and a fourth plate 1056 that is fixed to the outer ring 1052 and extends toward the inner ring 1051. Between the inner ring 1051 and the outer ring 1052, a first space 54 that opens to one end face of the bearing 50 is formed, and between the inner ring 1051 and the outer ring 1052, a second space 55 that opens to the other end face of the bearing 50 is formed. Between the fourth plate 1056 and the inner ring 1051, a gear-side space 70 communicating with the second space 55 is formed. The oil seal 60 seals the first space 54. Between the fourth plate 1056 and the inner ring 1051, a fourth space 1070A communicating with the gear-side space 70 and the second space 55 is formed. The fifth bearing seal 1090 has a base 1091, a first lip 1092A extending from the base 1091, and a second lip 1093A extending from the base 1091. The gear device 1010 includes a base 1091 that is accommodated inside a groove (mounting groove 1056A or mounting groove 1051B) formed in one of the fourth plate 1056 and the inner ring 1051, and the first lip 1092A and the second lip 1092B that contact the other of the fourth plate 1056 and the inner ring 1051 to partition the fourth space 1070A.

[0153] By providing the fifth bearing seal 1090 with the first lip 1092A and the second lip 1092B, it is possible to suppress the extrusion of lubricant from the second space 55 to the gear side space 70, and the inflow of lubricant from the gear side space 70 to the second space 55. This makes it possible to suppress an excessive inflow of lubricant into the first space 54, and to suppress leakage of the lubricant from the oil seal 60.

[0154] Furthermore, 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, preventing the first lip 1092A and the second lip 1092B from releasing contact between the fourth plate 1056 or the inner ring 1051.

[0155] [Embodiment 12] A twelfth embodiment of the present disclosure will be described with reference to Fig. 18. In a gear device 1110 and a robot 1101 of the twelfth embodiment, a connection hole 1171 and an air tube 1104 are provided, and the communication hole 80 of the first embodiment is not formed. Since other configurations, actions, and effects are similar to those of the first embodiment, the same reference numerals as those of the first embodiment are used to designate the same members as those of the first embodiment, and detailed description thereof will be omitted.

[0156] <Base, through hole> The robot 1101 according to this embodiment includes a base 1103, an arm (not shown) rotatably supported on the base 1103, a gear device 1110 that transmits 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 this embodiment, the base 1103 is an example of a first member. The base 1103 is formed with a through hole 1103A that communicates with a connection hole 1171 provided in the gear device 1110.

[0157] <Air tube> The robot 1101 is equipped with an air tube 1104. One end of the air tube 1104 is connected to a base 1103, and the other end of the air tube 1104 is open to the atmosphere. The internal space of the air tube 1104 communicates with a through-hole 1103A. At least a portion of the air tube 1104 from one end to the other end is coiled.

[0158] <Connection hole> 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 communicating with 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 communicating with the fourth hole 1151A and extending in the direction along the rotation axis 10A. The fourth hole 1151A communicates with the gear side space 70.

[0159] 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 tube 1104. As a result, the pressure in the gear-side space 70 is equal to atmospheric pressure. Therefore, even if the external gear 30 is repeatedly flexed and deformed by the operation of the gear device 1110, a pumping action in which the lubricant is pushed out from the meshing portion between the internal gear 1120 and the external gear 30 into the gear-side space 70 does not occur, and the inflow of the lubricant into the gear-side space 70 is suppressed. As a result, it becomes difficult for the lubricant to flow from the gear-side space 70 into the bearing 50, so that leakage of the lubricant from the oil seal 60 to the outside can be suppressed.

[0160] Moreover, it is preferable that the connection hole 1171, the through hole 1103A, and the air tube 1104 are disposed relatively above the gear-side space 70. With this configuration, the lubricant is less likely 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.

[0161] The internal gear 1120 has a cover portion 1123 extending from the annular member 21 toward the diaphragm portion 33. The cover portion 1123 is disposed opposite the opening of the first connection hole 1171A on the gear-side space 70 side. The provision of the cover portion 1123 makes it possible to prevent lubricant from flowing into the first connection hole 1171A from the meshing portion between the internal gear 1120 and the external gear 30, etc.

[0162] [Effects of embodiment 12] The gear device 1110 of the twelfth embodiment includes an internal gear 1120, an external gear 30 partially meshed with the internal gear 1120, a wave generator 40 that contacts the inner peripheral surface of the external gear 30 and rotates the meshing position between the internal gear 1120 and the external gear 30 around the rotation axis 10A, an inner ring 1151 and an outer ring 52, a bearing 50 that supports the internal gear 1120 and the external gear 30 so that they can rotate relative to each other, and an oil seal 60. A first space 54 opening to one end face of the bearing 50 is formed between the inner ring 1151 and the outer ring 52, a second space 55 opening to the other end face of the bearing 50 is formed between the inner ring 1151 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, and a connection hole 1171 connecting the gear side space 70 to the atmosphere is formed in the gear device 1110.

[0163] By connecting the gear-side space 70 to the atmosphere via the connecting hole 1171, the pumping action caused by the flexure of the external gear 30 disappears, and the lubricant is no longer sent from the gear-side space 70 into the bearing 50. This makes it possible to suppress leakage of the lubricant from the oil seal 60.

[0164] In the gear device 1110 of the twelfth embodiment, the connection hole 1171 is formed in the inner ring 1151 and the internal gear 1120 .

[0165] The robot 1101 of embodiment 12 comprises a gear device 1110, a first member (base 1103) to which the gear device 1110 is fixed, and an air tube 1104, the first member having a through hole 1103A communicating with the connection hole 1171, one end of the air tube 1104 communicating with the through hole 1103A and attached to the first member, and the other end of the air tube 1104 being open to the atmosphere.

[0166] Since the air tube 1104 is provided, even if the lubricant enters the connection hole 1171, the lubricant can be prevented from leaking out to the outside.

[0167] In the robot 1101 of the twelfth embodiment, at least a portion of the air tube 1104 is coiled.

[0168] At least a portion of the air tube 1104 is coiled, so that it is possible to increase the length of the air tube 1104. This makes it possible to further prevent the lubricant from leaking out.

[0169] [Embodiment 13] A thirteenth embodiment of the present disclosure will be described with reference to Fig. 19. In a gear device 1210 and a robot 1201 of the thirteenth embodiment, the members in which a connection hole 1271 is provided, etc., are different from those of the twelfth embodiment. As the other configurations, actions, and effects are the same as those of the first embodiment, the same reference numerals as those of the first embodiment are used to designate the same members as those of the first embodiment, and detailed descriptions thereof will be omitted.

[0170] The gear device 1210 of embodiment 13 is attached to the robot 1201 in an orientation opposite to the vertical direction compared to the gear device 1110 of embodiment 12. In order to arrange the connection hole 1271, the through hole 1205A, and the air tube 1204 above the gear side space 70, in the gear device 1210, the connection hole 1271 is formed in the boss portion 1234 of the external gear 30.

[0171] <First Arm> The robot 1201 according to this embodiment includes a first arm 1205, a second arm 1206 rotatably supported relative to the first arm 1205, a gear device 1210 that transmits driving force from one of the first arm 1205 and the second arm 1206 to the other, and a motor (not shown) that is 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 this embodiment, the first arm 1205 is an example of a first member. A through hole 1205A that communicates with a connection hole 1271 provided in the gear device 1210 is formed in the first arm 1205.

[0172] The robot 1201 is equipped with an air tube 1204. One end of the air tube 1204 is connected to a first arm 1205, and the other end of the air tube 1204 is open to the atmosphere. The internal space of the air tube 1204 communicates with a through-hole 1205A.

[0173] A connecting hole 1271 is formed in the boss portion 1234 of the external gear 30 of this embodiment. The connecting hole 1271 communicates with the gear side space 70. The action and effect of the connecting hole 1271 are similar to those of the twelfth embodiment, and therefore description thereof will be omitted.

[0174] [Other embodiments] (1) The configurations of the above embodiments may be combined to the extent that no contradiction occurs.

[0175] (2) In the above embodiment, the gear devices 10, 110, 210, 310, 410, 510, 610, 710, 810, 910, 1010, 1110, and 1210 have the rotation shaft 10A extending in the vertical direction, but the gear devices may have the rotation shaft extending in a direction intersecting the vertical direction. However, in the gear devices 1110 and 1210, it is preferable that the through holes 1103A and 1205A are disposed relatively upward with respect to the gear devices 1110 and 1210, respectively.

[0176] (3) The member to which the gear device is attached in the robot is not limited to that in the above embodiment.

[0177] 1: Robot 2: Arm (mounting part) 2A: Groove 10: Gear device 10A: Rotating shaft 20: Internal gear 21: Annular member 22: Internal teeth 30: external gear 31: cylindrical portion 31A: internal space 32: external teeth 33: diaphragm portion 34: boss portion 40: Wave generator 50: Bearing 51: Inner ring 52: Outer ring 53: Roller 54: First space 55: Second space 60: Oil seal 70: Gear side space 80: Communication hole 81: 1st communication hole 82: 2nd communication hole 83: 1st hole 84: 2nd hole 101: Robot 102: Arm (mounting member) 102B: Bolt fastening hole 102C: Bolt 102D: Seal washer 110: Gear unit 180: Communication hole 181: 1st communication hole 182: 2nd communication hole 184: 2nd hole 201:Robot 210: Gear unit 234: Boss portion 280: Through hole 301:Robot 310: Gearing 320A: Inner member 352: outer ring 352A: extension 354A: third space 361: First seal member 362: Second seal member 401:Robot 410: Gearing 451: Inner ring 451A: Contact part 461: First seal member 462: Second seal member 462A: Base portion 462B: Tip portion 463: Spacer 501: Robot 502: Arm 502A: Bolt fastening hole 510: Gearing 534: Boss part 534A: Bolt insertion hole 552: Outer ring 552A: Outer ring body 552B: Extension plate 552C, 552F: Bolt insertion holes 552D: Bolt fastening holes 552E, 552G: Bolt 601: Robot 602: Arm (mounting member) 602A: Groove 610: Gearing 680: Communication hole 680A: 3rd hole 701:Robot 710: Gearing 734: Boss part 734A: Bolt insertion hole 752: Outer ring 752A: Bolt fastening hole 752B: Bolt 756: First plate 756A: Contact portion 757: Spacer 757A: Bolt insertion hole 790: First bearing seal 790A: First base portion 790B: First tip portion 791: Second bearing seal 791A: Second base portion 791B: Second tip portion 801:Robot 810: Gearing 856: Second plate 856A: Mounting groove 890: 3rd bearing seal 891: Base 892A: 1st lip 892B: 2nd lip 901:Robot 910: Gearing 956: 3rd plate 956A: Mounting groove 990: 4th bearing seal 991: Base 992A: 1st lip 992B: 2nd lip 1001:Robot 1010: Gear unit 1034: Boss part 1034A: Bolt insertion hole 1051: Inner ring 1051A: Contact part 1051B: Mounting groove (groove) 1052: Outer ring 1052A: Bolt fastening hole 1052B: Bolt 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 1070A: 4th space 1090: 5th bearing seal 1091: Base 1092A: 1st lip 1092B: 2nd lip 1101: Robot 1103: Base (first member) 1103A: Through hole 1104: Air tube 1110: Gearing 1120: Internal gear 1123: Cover 1151: Inner ring 1151A: 4th hole 1151B: 5th hole 1171: Connection hole 1171A: First connection hole 1171B: Second connection hole 1201: Robot 1204: Air tube 1205: First arm (first member) 1205A: Through hole 1206: Second arm 1210: Gearing 1234: Boss part 1271: Connection hole

Claims

1. An internal gear; an external gear partially meshing with the internal gear; a wave generator that comes into contact with an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis; a bearing including an inner ring and an outer ring, the bearing supporting the internal gear and the external gear so as to be capable of relative rotation; Oil seal and A first bearing seal; a second bearing seal that is separate from the first bearing seal; A first plate fixed to the inner ring; A spacer, a first space is formed between the inner ring and the outer ring, the first space being open to one end surface of the bearing; a second space is formed between the inner ring and the outer ring, the second space being 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 is A flexible cylindrical portion disposed coaxially inside the internal gear; a diaphragm portion extending outwardly from an end of the cylindrical portion; a rigid boss portion extending from an outer circumferential edge of the diaphragm portion and having an annular shape; the first bearing seal includes a first base portion and a first tip portion extending from the first base portion; the second bearing seal includes a second base portion and a second tip portion extending from the second base portion; the spacer is fixed between the outer ring and the boss portion, the first base portion is fixed between the spacer and the outer ring, the second base portion is fixed between the spacer and the boss portion, the first tip portion contacts the first plate from the second space side to seal the second space, the second tip portion contacts the first plate from the gear-side space side and divides the gear-side space.

2. An internal gear; an external gear partially meshing with the internal gear; a wave generator that comes into contact with an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis; a bearing including an inner ring and an outer ring, the bearing supporting the internal gear and the external gear so as to be capable of relative rotation; Oil seal and A third bearing seal; A second plate fixed to the inner ring, a first space is formed between the inner ring and the outer ring, the first space being open to one end surface of the bearing; a second space is formed between the inner ring and the outer ring, the second space being 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 is A flexible cylindrical portion disposed coaxially inside the internal gear; a diaphragm portion extending outwardly from an end of the cylindrical portion; a rigid boss portion extending from an outer circumferential edge of the diaphragm portion and having 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 portion is fixed by being sandwiched between the second plate and the inner ring, the first lip and the second lip contact the diaphragm portion to separate the gear side space.

3. An internal gear; an external gear partially meshing with the internal gear; a wave generator that comes into contact with an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis; a bearing including an inner ring and an outer ring, the bearing supporting the internal gear and the external gear so as to be capable of relative rotation; Oil seal and 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, the first space being open to one end surface of the bearing; a second space is formed between the inner ring and the outer ring, the second space being 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 portion is fixed by being sandwiched between the third plate and the inner ring, the first lip and the second lip contact the outer ring to separate the second space from the gear side space.

4. An internal gear; an external gear partially meshing with the internal gear; a wave generator that comes into contact with an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis; a bearing including an inner ring and an outer ring, the bearing supporting the internal gear and the external gear so as to be capable of relative rotation; Oil seal and A fifth bearing seal; 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, the first space being open to one end surface of the bearing; a second space is formed between the inner ring and the outer ring, the second space being 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 that communicates between 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 received within a groove formed in one of the fourth plate and the inner ring, the first lip and the second lip contact the other of the fourth plate and the inner ring to partition the fourth space.

5. A robot comprising the gear device according to any one of claims 1 to 4.

6. An internal gear; an external gear partially meshing with the internal gear; a wave generator that comes into contact with an inner peripheral surface of the external gear and rotates a meshing position between the internal gear and the external gear about a rotation axis; a bearing including an inner ring and an outer ring, the bearing supporting the internal gear and the external gear so as to be capable of relative rotation; an oil seal; a first space is formed between the inner ring and the outer ring, the first space being open to one end surface of the bearing; a second space is formed between the inner ring and the outer ring, the second space being 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 gear device, comprising: a connection hole that connects the gear side space with the atmosphere.

7. The gear device according to claim 6 , wherein the connection hole is formed in the inner ring and the internal gear.

8. The external gear is A flexible cylindrical portion disposed coaxially inside the internal gear; a diaphragm portion extending outwardly from an end of the cylindrical portion; a rigid boss portion extending from an outer circumferential edge of the diaphragm portion and having an annular shape; The gear device according to claim 6 , wherein the connection hole is formed in the boss portion.

9. A gear device according to any one of claims 6 to 8; a first member to which the gear unit is fixed; An air tube, the first member has a through hole communicating with the connection hole, One end of the air tube is attached to the first member while communicating with the through hole, The other end of the air tube is open to the atmosphere.

10. The robot of claim 9 , wherein at least a portion of the air tube is coiled.

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