Sealing devices, rotating devices, and industrial robots

Abstract

To provide a seal device capable of sufficiently satisfying sealability under various use environments and capable of facilitating parts management, a rotary device, and an industrial robot.SOLUTION: A seal device 10 of the embodiment comprises: a cylindrical cover 5 having an opening part 5d; an output plate 9 that is fitted into an inner peripheral surface 5b of the cover 5; a main seal part 28 that seals between the cover 5 and the output plate 9; and an auxiliary seal part 29 provided closer to the opening part 5d than the main seal part 28, and formed by at least the cover 5 and the output plate 9.SELECTED DRAWING: Figure 3

Description

Technical Field

[0005] , , ,

[0001] The present invention relates to a sealing device, a rotating device, and an industrial robot.

Background Art

[0002] Various rotating devices are used as drives in industrial robots such as machine tools. For example, in a machine tool such as a machining center, a motor with a speed reducer (motor drive device) is used to drive a tool changer. The motor with a speed reducer includes a cylindrical casing, an electric motor housed in the casing, and a speed reducer as a rotating device to which the rotation of the electric motor is input. The output part of the speed reducer is fixed to a mating member (for example, a tool changer). Under such a configuration, the motor with a speed reducer decelerates the rotation of the electric motor and outputs it to the mating member.

[0003] By the way, since the speed reducer transmits the rotational force to the mating member, the speed reducer cannot be completely sealed by the casing due to its structure. Therefore, a sealing part for sealing between the casing and the output part of the speed reducer is provided between the casing and the output part of the speed reducer. The sealing part attempts to prevent the intrusion of water and dust from between the casing and the output part into the motor drive device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional technology described above may not adequately satisfy the function of the seal depending on the operating environment, and there was a possibility that it could not reliably prevent the intrusion of fluids such as water or dust into the gearbox. For example, if there are strict hygiene requirements and the motor with a gearbox is high-pressure cleaned, there was a possibility that fluids such as water could enter the gearbox. Simply put, increasing the number of sealing parts would increase the number of components, potentially making parts management more complicated.

[0006] The present invention provides a sealing device, a rotating device, and an industrial robot that can adequately satisfy sealing requirements in various operating environments and facilitate parts management. [Means for solving the problem]

[0007] A sealing device according to one aspect of the present invention comprises a cylindrical first member having an opening, a second member fitted into the first member, a main sealing portion that seals the space between the first member and the second member, and a secondary sealing portion provided on the opening side of the main sealing portion and formed by at least the first member and the second member.

[0008] This configuration allows the secondary seal to mitigate the force with which fluids and dust particles move toward the main seal. As a result, the sealing performance of the main seal can be fully satisfied in a variety of operating environments. Since the secondary seal portion is formed by at least the first and second members, there is no need to prepare a separate secondary seal portion. This makes it easier to manage the parts of the sealing device.

[0009] In the above configuration, the sub-seal portion includes a cover portion provided on the opening side of the second member, the cover portion facing the axial end of the first member in the axial direction so as to cover the opening, and the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member may be greater than the width between the cover portion and the axial end of the first member.

[0010] In the above configuration, the sub-seal portion may have a recess formed on at least one of the inner circumferential surface of the first member or the outer circumferential surface of the second member.

[0011] In the above configuration, the sub-seal portion may have a protrusion formed on at least one of the inner circumferential surface of the first member or the outer circumferential surface of the second member.

[0012] In the above configuration, the sub-seal portion has a side surface that is radially opposed to the main seal portion with a gap in between and is positioned adjacent to the main seal portion, and the side surface may be positioned in a range that avoids the radially outer end and the radially inner end of the main seal portion when viewed from the axial direction.

[0013] In the above configuration, when the width between the two sides is Wg1 and the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member at the location where the main seal portion is provided is Wg2, then widths Wg1 and Wg2 are, Wg² / 3 ≤ Wg1 ≤ Wg² / 2 It may satisfy the requirement.

[0014] In the above configuration, when the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member of the sub-seal portion is Wg1, and the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member at the location where the main seal portion is provided is Wg2, then widths Wg1 and Wg2 are, Wg² / 3 ≤ Wg1 ≤ Wg² / 2 It may satisfy the requirement.

[0015] In the above configuration, the first member may be made of stainless steel.

[0016] Another aspect of the present invention provides a sealing device comprising: a cylindrical first member having an opening made of stainless steel; a second member fitted into the first member; a main sealing portion that seals the space between the first member and the second member; and a secondary sealing portion provided on the opening side of the main sealing portion and formed by at least the first member and the second member, wherein the secondary sealing portion includes a cover portion provided on the opening side of the second member, the cover portion facing the axial end of the first member in the axial direction so as to cover the opening, and the width between the cover portion and the axial end of the first member is smaller than the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member.

[0017] For example, if a high-pressure fluid (high-pressure water) is applied to the gap between the first and second members, the high-pressure fluid will first enter the space between the lid and the axial end of the first member, and then enter the space between the inner surface of the first member and the outer surface of the second member. Here, since the width between the inner surface of the first member and the outer surface of the second member is greater than the width between the lid and the axial end of the first member, it is possible to prevent the pressure of the fluid that has entered the space between the inner surface of the first member and the outer surface of the second member from rising. In other words, the sub-seal can mitigate the force of the fluid toward the main seal, for example, so that the sealing performance of the main seal can be fully satisfied.

[0018] Another aspect of the present invention provides a sealing device comprising: a cylindrical first member having an opening made of stainless steel; a second member fitted into the first member; a main sealing portion that seals the space between the first member and the second member; and a sub-sealing portion provided on the opening side of the main sealing portion and formed by at least the first member and the second member, wherein the sub-sealing portion has a side surface that faces the main sealing portion radially with a gap between them and is positioned adjacent to the main sealing portion, and the side surface is positioned in a range that avoids the radially outer end and the radially inner end of the main sealing portion when viewed from the axial direction.

[0019] The radially outer and radially inner ends of the main seal portion are the points where the main seal portion contacts the inner circumferential surface of the first member and the outer circumferential surface of the second member. If fluid or other substances directly come into contact with the space between the inner circumferential surface of the first member and the main seal portion, and between the outer circumferential surface of the second member and the main seal portion, the fluid or other substances can easily penetrate further into the interior than the main seal portion. Here, the gap between radially opposing side surfaces adjacent to the main seal portion is a passage through which fluid or other substances can enter. If this passage is positioned in a range that avoids the radially outer and radially inner ends of the main seal portion when viewed from the axial direction, it is possible to prevent fluid or other substances from directly coming into contact with the space between the inner circumferential surface of the first member and the main seal portion, and between the outer circumferential surface of the second member and the main seal portion. Therefore, the sealing performance of the main seal portion can be further sufficiently satisfied.

[0020] Another aspect of the present invention provides a rotating device comprising: a cylindrical cover having an opening; a reduction gear fitted to the inner circumferential surface of the cover; an output plate attached to the reduction gear and fitted to the inner circumferential surface of the cover; and a sealing device that seals the space between the cover and the output plate, wherein the reduction gear is fitted to the inner circumferential surface of the cover and comprises: an internal gear having internal teeth; an oscillating gear having external teeth that mesh with the internal teeth and is oscillating; a crankshaft to which the rotational force of a power generating unit is input and which has an eccentric portion that rotatably supports the oscillating gear and transmits the rotational force of the power generating unit to the oscillating gear; and a carrier to which the output plate is attached and which transmits the rotational force of the oscillating gear and outputs the rotational force of the oscillating gear to the output plate, wherein the sealing device comprises: a main sealing portion that seals the space between the cover and the output plate; and a sub-seal portion provided on the opening side of the main sealing portion and formed by at least the cover and the output plate.

[0021] This configuration provides a rotating device that can adequately satisfy sealing requirements in various operating environments and facilitates parts management.

[0022] An industrial robot according to another aspect of the present invention includes a cylindrical cover having an opening, a speed reducer fitted to the inner peripheral surface of the cover, an output plate attached to the speed reducer and fitted to the inner peripheral surface of the cover, a mating member attached to the opposite side in the axial direction of the output plate from the speed reducer, a sealing device for sealing between the cover and the output plate, and a power generation unit for generating a rotational force. The speed reducer includes an internal gear having internal teeth and fitted to the inner peripheral surface of the cover, a swing gear having external teeth meshing with the internal teeth and swing-rotated, a crankshaft having an eccentric portion to which the rotational force of the power generation unit is input and rotatably supporting the swing gear, and transmitting the rotational force of the power generation unit to the swing gear, and a carrier to which the output plate is attached, transmitting the rotational force of the swing gear, and outputting the rotational force of the swing gear to the output plate. The sealing device includes a main sealing portion for sealing between the cover and the output plate, and a sub-sealing portion provided on the opening side of the main sealing portion and formed at least by the cover and the output plate.

[0023] By configuring as described above, an industrial robot can be provided that can sufficiently satisfy the sealing performance in various usage environments and can easily perform parts management.

Advantages of the Invention

[0024] The above-described sealing device, rotating device, and industrial robot can sufficiently satisfy the sealing performance in various usage environments and can easily perform parts management.

Brief Description of the Drawings

[0025] [Figure 1] It is a partial cross-sectional view of an industrial robot in the first embodiment of the present invention. [Figure 2] It is a configuration diagram of a speed reducer in the first embodiment of the present invention. [Figure 3] It is an enlarged view of part III in FIG. 1. [Figure 4]This is an explanatory diagram of the operation of the sealing device in the first embodiment of the present invention. [Figure 5] This is a schematic diagram showing a modified example of the sealing device in the first embodiment of the present invention. [Figure 6] This is a schematic diagram of the sealing device in a second embodiment of the present invention. [Modes for carrying out the invention]

[0026] Next, embodiments of the present invention will be described with reference to the drawings.

[0027] [First Embodiment] <Industrial Robots> Figure 1 is a partial cross-sectional view of industrial robot 1. Industrial robot 1 is, for example, a machine tool such as a machining center. As shown in Figure 1, the industrial robot 1 comprises two mating members 2 and 3 (a first mating member 2 and a second mating member (an example of mating members according to the claim)) and a motor with a reduction gear (an example of a rotating device according to the claim) 4 that rotatably connects the two mating members 2 and 3.

[0028] For example, the first mating member 2 is a support column installed on a machine tool. For example, the second mating member 3 is a tool changer. The motor 4 with a reduction gear rotates the second mating member 3 around the rotation axis C1 relative to the first mating member 2.

[0029] <Motor with reduction gear> The motor with a reduction gear 4 mainly consists of a cylindrical cover (an example of the first member of the claim) 5, a reduction gear 6 fitted into the cover 5, a motor flange 7 fitted into the cover 5 for fixing the reduction gear 6 to the first mating member 2, an electric motor 8 fixed to the motor flange 7 on the opposite side of the reduction gear 6, an output plate (an example of the second member of the claim) 9 provided on the opposite side of the motor flange 7 of the reduction gear 6 and fitted into the cover 5, and a sealing device 10 for sealing the space between the cover 5 and the output plate 9. In the following explanation, the direction parallel to the rotation axis C1 is referred to as the axial direction. The direction around the rotation axis C1 is referred to as the circumferential direction. The radial direction of the motor 4 with a reduction gear, which is perpendicular to the axial and circumferential directions, is simply referred to as the radial direction.

[0030] The cover 5 is made of, for example, stainless steel. The first end 5a of the cover 5 on the side facing the first mating member 2 abuts against the first mating member 2. On the inner circumferential surface 5b of the cover 5, a flange fitting projection 11 is formed via a stepped portion 11a, extending from approximately the axial center to slightly before the first end 5a. The inner diameter of the flange fitting projection 11 is smaller than the inner diameter of the inner circumferential surface 5b of the cover 5. The flange fitting projection 11 is formed around the entire circumference. The motor flange 7 is fitted onto the inner circumferential surface 11b of the flange fitting projection 11.

[0031] On the inner circumferential surface 5b of the cover 5, a gearbox fitting projection 12 is formed on the second mating member 3 side of the flange fitting projection 11 via a stepped portion 12a. The inner diameter of the gearbox fitting projection 12 is smaller than the inner diameter of the flange fitting projection 11. The gearbox fitting projection 12 is formed around the entire circumference. The gearbox 6 is fitted onto the inner circumferential surface 11b of the gearbox fitting projection 12.

[0032] The motor flange 7 is integrally molded from a disc-shaped flange body 14 and a cylindrical portion 15 that protrudes from the flange body 14 toward the reduction gear 6. A reduced-diameter portion 14c is formed on the outer circumferential surface 14a of the flange body 14, slightly toward the cylindrical portion 15 from the axial center, via a stepped portion 14b. The outer diameter of the reduced-diameter portion 14c is smaller than the outer diameter of the outer circumferential surface 14a of the flange body 14. The outer circumferential surface of the reduced-diameter portion 14c and the outer circumferential surface of the cylindrical portion 15 are formed to be on the same plane. These outer circumferential surfaces of the reduced-diameter portion 14c and the cylindrical portion 15 are fitted into the inner circumferential surface 11b of the flange fitting projection 11.

[0033] The motor flange 7 is positioned axially relative to the cover 5 by the stepped portion 14b abutting against the stepped portion 11a of the flange fitting projection 11. With the motor flange 7 positioned relative to the cover 5, the tip 15a of the cylindrical portion 15 and the stepped portion 12a of the gearbox fitting projection 12 face each other with a gap in between. A recess 15b is formed on the tip 15a of the cylindrical portion 15, covering most of the inner circumference. The speed reducer 6 is received in the recess 15b. Multiple first female threaded portions 15d are formed at equal intervals in the circumferential direction on the bottom 15c of the recess 15b. The speed reducer 6 is fixed to the cylindrical portion 15 by tightening bolts (not shown) into the multiple first female threaded portions 15d.

[0034] The first end face 14d of the flange body 14 on the side facing the first mating member 2 is located on the same plane as the first end 5a of the cover 5. That is, the first end face 14d of the flange body 14 abuts against the first mating member 2. Multiple second female threaded portions 14e are formed on the first end face 14d of the flange body 14, coaxially with the first female threaded portion 15d. The first mating member 2 is fixed to the flange body 14 by tightening bolts (not shown) into the multiple second female threaded portions 14e.

[0035] Two O-ring grooves 16a and 16b (first O-ring groove 16a and second O-ring groove 16b) are formed on the outer circumferential surface of the flange body 14 on the side of the reduced diameter portion 14c that is closer to the first mating member 2. Of the two O-ring grooves 16a and 16b, the second O-ring groove 16b, which is closer to the first end face 14d, opens toward the first end face 14d. O-rings 17a and 17b (first O-ring 17a and second O-ring 17b) are fitted into these O-ring grooves 16a and 16b, respectively.

[0036] Of the two O-rings 17a and 17b, the first O-ring 17a, which is fitted into the first O-ring groove 16a, seals the space between the flange body 14 and the cover 5. Of the two O-rings 17a and 17b, the second O-ring 17b, which is fitted into the second O-ring groove 16b, seals the space between the flange body 14 and the cover 5, as well as the space between the flange body 14 and the first mating member 2.

[0037] A disc-shaped motor base 18 is integrally molded on the first end face 14d of the flange body 14, projecting toward the first mating member 2, over most of the radial center. An electric motor 8 is mounted on the motor base 18. The electric motor 8 is positioned with its rotating shaft 8a facing toward the reduction gear 6. A stepped through hole 19 is formed in the radial center of the motor base 18 into which the rotating shaft 8a is inserted.

[0038] The stepped through-hole 19 is formed to penetrate in the axial direction. The stepped through-hole 19 has a first through-hole 19a, a second through-hole 19b, and a third through-hole 19c, which are formed sequentially from the first mating member 2 toward the reduction gear 6 side. These through-holes 19a, 19b, and 19c are connected in the axial direction. The second through-hole 19b is formed with an inner diameter smaller than that of the first through-hole 19a via a stepped portion 19d. The third through-hole 19c is formed with an inner diameter smaller than that of the second through-hole 19b via a stepped portion 19e.

[0039] An oil seal 20 is installed in the second through-hole 19b to seal the space between the stepped through-hole 19 and the input gear 21 attached to the rotating shaft 8a of the electric motor 8. The inner diameter of the third through-hole 19c is large enough to accommodate the input gear 21 attached to the rotating shaft 8a of the electric motor 8.

[0040] The input gear 21 comprises an attachment 22 mounted on the rotating shaft 8a and a pinion gear 23 mounted on the attachment 22. The attachment 22 is integrally molded with a cylindrical base 22a mounted on the rotating shaft 8a and a shaft portion 22b protruding from the radial center of the base 22a toward the reduction gear 6. A coupling recess 22d is formed at the radial center of the end face 22c of the base 22a on the electric motor 8 side. The attachment 22 is attached to the rotating shaft 8a by fitting the rotating shaft 8a into the coupling recess 22d. The space between the outer circumferential surface of the base 22a and the second through hole 19b of the stepped through hole 19 formed in the motor flange 7 is sealed by an oil seal 20.

[0041] The shaft portion 22b is positioned radially inward of the cylindrical portion 15 of the motor flange 7. A pinion gear 23 is attached to the shaft portion 22b. The pinion gear 23 meshes with the transmission gear 48 of the reduction gear 6, which will be described later.

[0042] <Reducer> Figure 2 is a diagram showing the configuration of the reduction gear 6, and corresponds to Figure 1 mentioned above. As shown in Figure 2, the reduction gear 6 comprises a cylindrical internal gear 13 fitted onto the inner circumferential surface 12b of the reduction gear fitting projection 12, a carrier (an example of an output unit according to the claim) 41 positioned radially inward of the internal gear 13, and a rotation input unit 42 connecting the rotating shaft 8a (pinion gear 23) and the carrier 41.

[0043] The internal gear 13 also serves as the outer casing of the reducer 6. An outer flange portion 43, which protrudes radially outward, is integrally molded to the outer circumferential surface 13a of the internal gear 13. The outer circumferential surface 43a of the outer flange portion 43 is fitted onto the inner circumferential surface 12b of the reducer fitting projection 12. The axial end face of the outer flange portion 43 abuts against the bottom 15c of the recess 15b. A bolt (not shown) is inserted into the outer flange portion 43 from above a flat washer 24 positioned in the step portion 12c between the inner circumferential surface 5b of the cover 5 and the reducer fitting projection 12. This bolt is tightened into the first female thread portion 15d of the motor flange 7. This positions the reducer 6 relative to the cover 5 and fixes the reducer 6 to the motor flange 7.

[0044] Internal teeth 44 are provided on the inner circumferential surface of the internal gear 13. The internal teeth 44 are pin-shaped (cylindrical) teeth provided on the inner circumferential surface of the internal gear 13. Multiple internal teeth 44 are arranged at equal intervals in the circumferential direction. The carrier 41 is rotatably supported on the internal gear 13 by a pair of main bearings 45a and 45b, which are spaced apart in the axial direction. The main bearings 45a and 45b are, for example, angular contact ball bearings. The carrier 41 is positioned coaxially with the rotation axis C1.

[0045] The carrier 41 comprises a disc-shaped end plate portion 46 positioned on the electric motor 8 side in the axial direction, and a disc-shaped base plate portion 47 positioned on the output plate 9 side. The end plate portion 46 and the base plate portion 47 are integrated with a column portion (not shown) in between, maintaining a constant distance in the axial direction. Multiple through holes 46a and 47a (for example, three in this embodiment) are formed in the end plate portion 46 and the base plate portion 47, into which the crankshaft (an example of the input portion of the claim) 49 of the rotation input portion 42, described later, is inserted. The through holes 46a and 47a are arranged at equal intervals in the circumferential direction.

[0046] The rotation input unit 42 rotates the carrier 41 at a rotational speed reduced by a constant ratio to the rotational speed of the rotating shaft 8a (pinion gear 23). The rotation input unit 42 comprises a plurality of transmission gears (for example, three in this embodiment) 48 that mesh with the pinion gear 23 (an example of the input unit in the claim), a plurality of crankshafts 49 (for example, three in this embodiment) with one end fixed to the transmission gears 48, and a first oscillating gear (an example of the oscillating gear in the claim) 50a and a second oscillating gear (an example of the oscillating gear in the claim) 50b that oscillate in conjunction with the rotation of the crankshafts 49.

[0047] The crankshaft 49 is positioned along the axial direction. That is, the crankshaft 49 rotates around a crank rotation axis C2 that is parallel to the rotation axis C1. The crankshaft 49 is rotatably supported on the end plate portion 46 via a first crankshaft support 51. The crankshaft 49 is also rotatably supported on the base portion 47 via a second crankshaft support 52. The first crankshaft support 51 and the second crankshaft support 52 are, for example, tapered roller bearings.

[0048] At the axial center of the crankshaft 49, a first eccentric portion 49a and a second eccentric portion 49b are formed, eccentric to the axis of the crankshaft 49. The first eccentric portion 49a and the second eccentric portion 49b are arranged adjacent to each other in the axial direction between the first crankshaft support 51 and the second crankshaft support 52. The first eccentric portion 49a and the second eccentric portion 49b are offset from each other by a phase angle. The first oscillating gear 50a and the second oscillating gear 50b are rotatably supported by the first eccentric portion 49a and the second eccentric portion 49b via roller bearings 53a and 53b.

[0049] The first oscillating gear 50a and the second oscillating gear 50b are positioned between the end plate portion 46 and the base portion 47 of the carrier 41. The first oscillating gear 50a and the second oscillating gear 50b have through holes (not shown) into which the column portion of the carrier 41 is inserted. The first oscillating gear 50a and the second oscillating gear 50b have external teeth 54a and 54b that mesh with the internal teeth 44 of the internal gear 13.

[0050] As a result, the first eccentric portion 49a and the second eccentric portion 49b oscillate as the crankshaft 49 rotates, the first oscillating gear 50a and the second oscillating gear 50b oscillate while meshing with the internal teeth 44 of the internal gear 13. Since a column is inserted into each oscillating gear 50a and 50b, the carrier 41 rotates relative to the internal gear 13 in accordance with the oscillating rotation of each oscillating gear 50a and 50b.

[0051] The output plate 9 comprises an annular plate body 25 and a cylindrical portion 26 integrally molded with the outer circumference of the plate body 25 and protruding from the plate body 25 toward the motor flange 7. The plate body 25 and the cylindrical portion 26 form an output unit receiving recess 27. This recess 27 fits into the base plate portion 47 of the carrier 41. The outer circumferential surface 26a of the cylindrical portion 26 fits into the inner circumferential surface 5b of the cover 5.

[0052] The second mating member 3 is superimposed on one side 25a of the plate body 25 opposite to the reduction gear 6. The second mating member 3 faces the second end (an example of the axial end according to the claim) 5c of the cover 5 in the axial direction, opposite to the first end 5a. The second mating member 3 covers the opening 5d of the cover 5 on the second end 5c side, with a small gap G1 (see Figure 2) in between. An annular O-ring groove 25b is formed on one surface 25a of the plate body 25, slightly radially inward from the cylindrical portion 26. An O-ring 30 is fitted into the O-ring groove 25b. The O-ring 30 seals the space between the plate body 25 and the second mating member 3.

[0053] The plate body 25 of the output plate 9 and the second mating member 3 are fixed to the carrier 41 (base plate portion 47) of the reduction gear 6 by bolts (not shown) inserted from the second mating member 3 side. As a result, the plate body 25 of the output plate 9, the second mating member 3, and the carrier 41 of the reduction gear 6 rotate together as a single unit.

[0054] <Sealing device> Figure 3 is an enlarged view of part III of Figure 1. As shown in Figures 1 and 3, the sealing device 10 is composed of the cylindrical portion 26 of the output plate 9 and the area around the second end 5c of the cover 5. More specifically, the sealing device 10 includes a main sealing portion 28 provided on the motor flange 7 side of the cylindrical portion 26 and sealing the space between the cover 5 and the cylindrical portion 26, and a sub-sealing portion 29 provided on the opening 5d side of the cover 5, closer to the main sealing portion 28.

[0055] The main seal portion 28 is fitted into a seal groove 31 formed around the entire circumference of the outer circumferential surface 26a of the cylindrical portion 26. For example, a so-called X-ring can be used as the main seal portion 28. However, it is not limited to this, and various sealing members that can seal the space between the cover 5 and the cylindrical portion 26, such as O-rings and oil seals, can be used.

[0056] The size of the main seal portion 28, the groove depth Hm1 and groove width Wm of the seal groove 31, and the minute gap G2 between the inner circumferential surface 5b of the cover 5 and the outer circumferential surface 26a of the cylindrical portion 26 are determined based on the inner diameter ΦD of the cover 5. For example, the size of the main seal portion 28, the groove depth Hm1 and groove width Wm of the seal groove 31, and the minute gap G2 between the inner circumferential surface 5b of the cover 5 and the outer circumferential surface 26a of the cylindrical portion 26 are determined by so-called catalog values.

[0057] The sub-seal portion 29 is formed by the cover 5 and the cylindrical portion 26. Furthermore, of the second mating member 3 fixed to the output plate 9, the portion that faces the second end portion 5c of the cover 5 in the axial direction, so as to cover the opening 5d of the cover 5, functions as the sub-seal portion 29. Here, the second mating member 3 is an example of the cover portion of the claim. That is, the width W1 between the inner circumferential surface 5b of the cover 5 and the outer circumferential surface 26a of the cylindrical portion 26 is greater than the width W2 between the second mating member 3 and the second end portion 5c of the cover 5. This dimensional relationship functions as the sub-seal portion 29. Furthermore, the width W2 between the second mating member 3 and the second end portion 5c of the cover 5 is smaller than the minute gap G2 between the inner circumferential surface 5b of the cover 5 and the outer circumferential surface 26a of the cylindrical portion 26. In addition, the sub-seal portion 29 has a recess 33 formed around the entire circumference of the outer circumferential surface 26a of the cylindrical portion 26.

[0058] <Operation of industrial robots and function of sealing devices> Next, the operation of the industrial robot 1 and the function of the sealing device 10 will be explained based on Figures 1 to 4. Figure 4 is an explanatory diagram of the operation of the sealing device 10, and corresponds to Figure 3 mentioned above. As shown in Figures 1 to 4, when the electric motor 8 is driven, the rotation of the rotating shaft 8a is transmitted to the transmission gear 48, causing the transmission gear 48 to rotate. As a result, the crankshaft 49 and the transmission gear 48 rotate together around the crank rotation axis C2.

[0059] As the crankshaft 49 rotates, the first oscillating gear 50a rotates while meshing with the internal teeth 44 due to the oscillation of the first eccentric portion 49a. Similarly, the second oscillating gear 50b rotates while meshing with the internal teeth 44 due to the oscillation of the second eccentric portion 49b. In other words, the crankshaft 49 rotates around the crank rotation axis C2 and also revolves around the rotation axis C1. Consequently, the carrier 41 rotates at a reduced speed around the rotation axis C1 compared to the rotation of the crankshaft 49. In other words, the carrier 41 rotates at a reduced speed around the rotation axis C1 relative to the internal teeth gear 13. The base portion 47 of the carrier 41 has the plate body 25 of the output plate 9 and the second mating member 3 integrated into it. Therefore, the output plate 9 and the second mating member 3 rotate together with the carrier 41.

[0060] The motor flange 7 to which the reduction gear 6 is fixed is also fixed to the first mating member 2. Therefore, the second mating member 3 is rotated around the rotation axis C1 relative to the first mating member 2 via the motor 4 with the reduction gear. Here, the sealing device 10 is formed by the cylindrical portion 26 of the output plate 9 and the area around the second end portion 5c of the cover 5. This ensures a seal between the cover 5 and the output plate 9. When the second mating member 3 rotates around the rotation axis C1 relative to the first mating member 2, the output plate 9 rotates relative to the cover 5. In order to rotate the output plate 9 and the second mating member 3 relative to the cover 5 in this way, a small gap G1 is formed between the second end portion 5c of the cover 5 and the second mating member 3. In addition, the main sealing portion 28 slides relative to the cover 5.

[0061] Next, we will explain the case where the motor 4 with a reduction gear is subjected to high-pressure cleaning, for example. As shown in Figure 4, when high-pressure water R is applied to the motor 4 with a reduction gear, this high-pressure water R is applied to the sub-seal portion 29 of the sealing device 10. The high-pressure water R attempts to enter the cover 5 through a minute gap G1 between the cover 5 and the second mating member 3 (see arrow Y1 in Figure 4). After passing through this minute gap G1, the high-pressure water R further attempts to enter the interior of the cover 5 by passing between the cover 5 and the cylindrical portion 26 of the output plate 9 (see arrow Y2 in Figure 4). The pressure of the high-pressure water R is, for example, about 10 [MPa].

[0062] Here, the width W1 between the inner circumferential surface 5b of the cover 5 and the outer circumferential surface 26a of the cylindrical portion 26 is greater than the width W2 between the second mating member 3 and the second end portion 5c of the cover 5. In other words, the width of the passage for high-pressure water R between the cover 5 and the cylindrical portion 26 is greater than the width of the passage for high-pressure water R between the second mating member 3 and the cover 5. Therefore, an increase in the water pressure of the high-pressure water R that has passed between the second mating member 3 and the second end portion 5c of the cover 5 is prevented. That is, the force of the high-pressure water R is mitigated as it passes between the cover 5 and the cylindrical portion 26. Consequently, the high-pressure water R does not come into contact with the main seal portion 28 while maintaining high pressure. In other words, the sub-seal portion 29 plays a role in mitigating the force of the high-pressure water R directed toward the main seal portion 28.

[0063] Furthermore, the sub-seal portion 29 has a recess 33 formed around its entire circumference on the outer circumferential surface 26a of the cylindrical portion 26. The recess 33 further widens the gap between the inner circumferential surface 5b of the cover 5 and the outer circumferential surface 26a of the cylindrical portion 26. As a result, the recess 33 more reliably mitigates the force of the high-pressure water R directed toward the main seal portion 28. In addition, the high-pressure water R that enters between the cover 5 and the cylindrical portion 26 is stored in the recess 33. The water stored in the recess 33 flows downward by gravity through the recess 33 and is drained.

[0064] As described above, in the first embodiment, the sealing device 10 comprises a main sealing portion 28 that seals the space between the cover 5 and the cylindrical portion 26, and a sub-sealing portion 29 provided on the opening 5d side of the cover 5, closer to the main sealing portion 28. Therefore, the sub-sealing portion 29 can mitigate the force of water and dust toward the main sealing portion 28. As a result, the sealing performance of the main sealing portion 28 can be fully satisfied in various usage environments. The sub-seal portion 29 is formed by the cover 5 and the cylindrical portion 26 of the output plate 9. Therefore, the sub-seal portion 29 does not require a separate component like the main seal portion 28. This makes it easier to manage the parts of the sealing device 10.

[0065] Of the second mating member 3, the portion facing the second end 5c of the cover 5 in the axial direction functions as a sub-seal portion 29. That is, the width W1 between the inner circumferential surface 5b of the cover 5 and the outer circumferential surface 26a of the cylindrical portion 26 is greater than the width W2 between the second mating member 3 and the second end 5c of the cover 5. Therefore, when high-pressure water R is applied to the sub-seal portion 29 of the sealing device 10 (the gap between the cover 5 and the cylindrical portion 26), it is possible to prevent the water pressure of the high-pressure water R from rising as it passes between the second mating member 3 and the second end 5c of the cover 5. In other words, the force of the high-pressure water R can be mitigated as it passes between the cover 5 and the cylindrical portion 26. Consequently, it is possible to prevent high-pressure water R from being applied to the main seal portion 28 while maintaining high pressure. Thus, the sealing performance of the main seal portion 28 can be more reliably satisfied.

[0066] The sub-seal portion 29 has a recess 33 formed around the entire circumference of the outer circumferential surface 26a of the cylindrical portion 26. Therefore, the recess 33 more reliably reduces the force of the high-pressure water R directed towards the main seal portion 28. Furthermore, the high-pressure water R that enters between the cover 5 and the cylindrical portion 26 can be stored in the recess 33. In other words, the recess 33 can function as a reservoir for water that enters between the cover 5 and the cylindrical portion 26. This further enhances the sealing performance of the main seal portion 28. Furthermore, water that enters the recess 33 flows downwards along the bottom surface of the recess 33 due to gravity and is drained at the bottom. Therefore, the recess 33 can more reliably block water from flowing towards the main seal portion 28.

[0067] The cover 5 is made of, for example, stainless steel. Using stainless steel improves the rust-preventive properties of the cover 5. This allows the motor 4 with a gearbox to be used in a variety of environments. And the industrial robot 1 can be used in a variety of environments.

[0068] [Modified version of the first embodiment] <Sealing device> Next, a modified example of the first embodiment will be described based on Figure 5. Figure 5 is a schematic diagram showing a modified example of the sealing device 10 of the first embodiment. Figure 5 corresponds to Figure 3 described above.

[0069] In the first embodiment described above, the sub-seal portion 29 was described in which a recess 33 is formed around the entire circumference of the outer circumferential surface 26a of the cylindrical portion 26. However, it is not limited to this, and as shown in Figure 5, a flange portion (an example of the protrusion in the claim) 34 that protrudes toward the recess 33 may be formed on the inner circumferential surface 5b of the cover 5. The inner diameter ΦDi of the flange portion 34 is slightly larger than the diameter ΦDc of the outer circumferential surface 26a of the cylindrical portion 26. By forming the flange portion 34, the passage for the high-pressure water R in the sub-seal portion 29 can be made more complex. As a result, the force of the high-pressure water R toward the main seal portion 28 can be further reduced. Thus, the sealing performance of the main seal portion 28 can be further sufficiently satisfied.

[0070] Alternatively, the recess 33 may be formed on the inner circumferential surface 5b of the cover 5 instead of the outer circumferential surface 26a of the cylindrical portion 26. The recess 33 may be formed on either the outer circumferential surface 26a of the cylindrical portion 26 or the inner circumferential surface 5b of the cover 5. Furthermore, a flange portion may be formed on either the inner circumferential surface 5b of the cover 5 or the outer circumferential surface 26a of the cylindrical portion 26. Any combination of the recess 33 and the flange portion 34 can be selected.

[0071] [Second Embodiment] <Sealing device> Next, a second embodiment will be described based on Figure 6. Figure 6 is a schematic diagram of the sealing device 210 in the second embodiment. Figure 6 corresponds to Figure 3 described above. In the following description, the same reference numerals are used for components identical to those in the first embodiment described above, and their descriptions are omitted.

[0072] As shown in Figure 6, the difference between the first embodiment and the second embodiment lies in the fact that the sealing device 10 of the first embodiment and the sealing device 210 of the second embodiment are different. First, the sealing device 210 of the second embodiment is the same as the first embodiment described above in the following respects. That is, the sealing device 210 of the second embodiment is the same as the first embodiment described above in that it includes a main sealing portion 28 provided on the motor flange 7 side of the cylindrical portion 26 and sealing the space between the cover 5 and the cylindrical portion 26, and a sub-sealing portion 229 provided on the opening 5d side of the cover 5, which is further away from the main sealing portion 28. The sub-sealing portion 229 is formed by the cover 5 and the cylindrical portion 26 of the output plate 9, which is the same as the first embodiment described above.

[0073] In the sealing device 210 of the second embodiment, the second mating member 3 does not function as a sub-sealing portion 229. Furthermore, in the second embodiment, the groove depth Hm2 of the seal groove 231 in which the main seal portion 28 is installed is shallower than the groove depth Hm1 of the seal groove 31 in the first embodiment. For this reason, in the second embodiment, the position of the outer circumferential surface 26a of the cylindrical portion 26 is located approximately in the radial center of the main seal portion 28.

[0074] The second end portion 5c of the cover 5 is positioned further apart from the second mating member 3 than in the first embodiment. A flange portion (an example of the protrusion in the claim) 35 projecting radially inward is integrally molded to the second end portion 5c of the cover 5. The end face 35a of the flange portion 35 opposite to the second mating member 3 is positioned on the same plane as the inner surface 31a of the seal groove 31 on the second mating member 3 side.

[0075] In other words, the inner circumferential surface (an example of a side surface as defined in the claim) 35b of the flange portion 35 of the sub-seal portion 229 and the outer circumferential surface (here, an example of a side surface as defined in the claim) 26a of the cylindrical portion 26 of the sub-seal portion 229, which is radially opposite to this inner circumferential surface 35b, are adjacent to the main seal portion 28. In other words, the minute gap (an example of a gap as defined in the claim) G3 formed by the inner circumferential surface 35b of the flange portion 35 of the sub-seal portion 229 and the outer circumferential surface 26a of the cylindrical portion 26 is connected to the main seal portion 28 at a position that overlaps with the main seal portion 28 in the axial direction. That is, being adjacent to the main seal portion 28 means that the inner circumferential surface 35b of the flange portion 35 and the outer circumferential surface 26a of the cylindrical portion 26 of the sub-seal portion 229 are continuous with the main seal portion 28. And it means that the minute gap G3 formed by these inner circumferential surface 35b and outer circumferential surface 26a is directly connected to the main seal portion 28.

[0076] The inner circumferential surface 35b of the flange portion 35 and the outer circumferential surface 26a of the cylindrical portion 26 are located approximately in the center between the inner and outer diameters of the main seal portion 28. In other words, the minute gap G3 is located approximately in the center between the inner and outer diameters of the main seal portion 28. Here, let Wg1 be the width between the inner circumferential surface 35b of the flange portion 35 and the outer circumferential surface 26a of the cylindrical portion 26 (the width of the minute gap G3), and let Wg2 be the width between the inner circumferential surface 5b of the cover 5 where the main seal portion 28 is provided and the outer circumferential surface 26a of the cylindrical portion 26, that is, the bottom surface of the seal groove 231. Then, the widths Wg1 and Wg2 are: Wg² / 3 ≤ Wg1 ≤ Wg² / 2 ···(1) It is desirable to satisfy these conditions.

[0077] Under this configuration, the minute gap G3 becomes a passage through which high-pressure water R enters. Because this passage is located approximately in the center between the inner and outer diameters of the main seal portion 28, the high-pressure water R does not directly come into contact with the radially outer end 28a or the radially inner end 28b of the main seal portion 28. The radially outer end 28a of the main seal portion 28 is in contact with the inner circumferential surface 5b of the cover 5. The radially inner end 28b of the main seal portion 28 is in contact with the seal groove 231. If high-pressure water R or the like is directly applied to such contact points, water or the like can easily penetrate further into the interior than the main seal portion 28.

[0078] Therefore, in the sub-seal portion 229 of the second embodiment, it is possible to prevent high-pressure water R from directly hitting the radially outer end 28a or radially inner end 28b of the main seal portion 28. As a result, the sealing performance of the main seal portion 28 can be further sufficiently satisfied.

[0079] Furthermore, if the width Wg1 between the inner circumferential surface 35b of the flange portion 35 and the outer circumferential surface 26a of the cylindrical portion 26, and the width Wg2 between the inner circumferential surface 5b of the cover 5 where the main seal portion 28 is provided and the bottom surface of the seal groove 231 satisfy the above formula (1), it is possible to prevent the width Wg1 from becoming too narrow. If the width Wg1 is too narrow, the water pressure of the high-pressure water R passing through the minute gap G3 will increase. Therefore, by suppressing the increase in the water pressure of the high-pressure water R, the momentum of the high-pressure water R toward the main seal portion 28 can be mitigated. Thus, the sealing performance of the main seal portion 28 can be sufficiently satisfied.

[0080] In the second embodiment described above, the position of the inner circumferential surface 35b of the flange portion 35 and the outer circumferential surface 26a of the cylindrical portion 26 in the sub-seal portion 229 was described as being approximately in the center between the inner and outer diameters of the main seal portion 28. However, it is not limited to this, and the position of the inner circumferential surface 35b of the flange portion 35 and the outer circumferential surface 26a of the cylindrical portion 26 in the sub-seal portion 229 is sufficient as long as it avoids the radially outer end 28a and radially inner end 28b of the main seal portion 28 when viewed from the axial direction. By configuring it in this way, the same effects as in the second embodiment described above can be achieved.

[0081] In the second embodiment described above, the width Wg1 between the inner circumferential surface 35b of the flange portion 35 and the outer circumferential surface 26a of the cylindrical portion 26, and the width Wg2 between the inner circumferential surface 5b of the cover 5 where the main seal portion 28 is provided and the bottom surface of the seal groove 231 do not have to satisfy formula (1) above. The amount of protrusion of the flange portion 35 from the cover 5 may be small. Even in such cases, it is possible to prevent high-pressure water R from directly hitting the radially outer end 28a or radially inner end 28b of the main seal portion 28. Therefore, the sealing performance of the main seal portion 28 can be further sufficiently satisfied.

[0082] The present invention is not limited to the embodiments described above, but includes various modifications to the embodiments described above, without departing from the spirit of the invention. For example, in the above-described embodiment, the industrial robot 1 was described as being a machine tool such as a machining center. However, it is not limited to this, and industrial robots include various drive devices and robots such as electric wheelchairs, mobile devices, and collaborative robots.

[0083] In the above-described embodiment, the motor with a reduction gear 4 was explained in the case where it is used in an industrial robot 1. However, it is not limited to this, and the motor with a reduction gear 4 can be used in various devices other than industrial robots 1. In the above embodiment, the case in which seal grooves 31 and 231 are formed on the outer circumferential surface 26a of the cylindrical portion 26 was described. However, the invention is not limited to this, and seal grooves 31 and 231 may also be formed on the cover 5. In the second embodiment, if seal grooves 231 are formed on the cover 5, the flange portion 35 may be formed on the outer circumferential surface 26a of the cylindrical portion 26. Alternatively, the flange portion 35 may be formed on either the cover 5 or the cylindrical portion 26.

[0084] In the above-described embodiment, the case in which a sealing device 10 is used with a motor 4 equipped with a reduction gear was explained. In the above-described embodiment, the cylindrical first member was described as a cover 5, and the second member fitted to the first member was described as an output plate 9. However, the sealing device 10 is not limited to this, and can be used for various purposes to seal the space between the cylindrical first member and the second member fitted to the first member.

[0085] In the above-described embodiment, the portion of the second mating member 3 fixed to the output plate 9 that faces the second end 5c of the cover 5 in the axial direction functions as a lid for the sub-seal portion 29,229. However, the invention is not limited to this, and the lid portion only needs to be configured to cover the opening side (e.g., opening 5d) of the second member (e.g., output plate 9) that fits into the first member (e.g., cover 5), and to face the axial end (e.g., second end 5c) of the first member in the axial direction.

[0086] In the above-described embodiment, an electric motor 8 was used as the power generation unit that generates rotational force and inputs this rotational force to the reduction gear 6. However, the invention is not limited to this, and various power generation units that generate rotational force can be used. For example, instead of the electric motor 8, various power generation units such as a hydraulic motor or an engine can be used.

[0087] In the above-described embodiment, the case in which a reduction gear 6 is provided in a motor 4 with a reduction gear as the rotating device was explained. The case in which the reduction gear 6 is fitted into the cover 5 was explained. However, the device is not limited to this, and various rotating devices can be employed that have an input unit into which rotational force is input, and an output unit that outputs the rotational force input to the input unit, instead of the reduction gear 6.

[0088] Furthermore, the description has focused on cases where the reduction gear 6 is a rotating device such as a so-called eccentric oscillating type reduction gear having multiple crankshafts and oscillating gears rotated by the crankshafts, or a planetary gear reduction gear having a multi-stage planetary mechanism. However, it is not limited to these cases, and various rotating devices can be used. For example, the rotating device may be configured to increase the speed of the rotation of the electric motor 8 and output it to the output plate 9 instead of the reduction gear 6. Alternatively, the rotating device may be configured to simply transmit the rotation of the electric motor 8 to the output plate 9 without reducing or increasing the speed.

[0089] In the above-described embodiment, the reduction gear 6 was described as comprising a cylindrical internal gear 13, a carrier 41 arranged radially inward of the internal gear 13, and a rotation input unit 42 that rotates the carrier 41 at a rotational speed reduced by a constant ratio to the rotational speed of the rotating shaft 8a. The rotation input unit 42 was described as a so-called eccentric oscillating type reduction gear comprising a plurality of crankshafts 49 and a first oscillating gear 50a and a second oscillating gear 50b that oscillate in conjunction with the rotation of the crankshafts 49.

[0090] However, the number of crankshafts 49 is not limited to multiple. The reduction gear 6 only needs to have at least one crankshaft 49 that rotates around a rotation axis along the rotation axis C1 in response to the rotation of the power generation unit (e.g., electric motor 8). The rotation input unit 42 can be an eccentric oscillating type reduction gear that reduces the rotation of the crankshaft 49 and transmits it to the carrier 41.

[0091] For example, let's describe in more detail an eccentric oscillating type speed reducer having a single crankshaft. In this case, the speed reducer has a so-called center crankshaft that is coaxial with the rotation axis C1 as the crankshaft. As this center crank rotates, the first oscillating gear 50a and the second oscillating gear 50b are rotated in an oscillating motion. Furthermore, eccentric oscillating type reducers such as the reducer 6 can also rotate the internal gear 13 relative to the carrier 41.

[0092] In the above-described embodiment, the internal gear 13 also serves as the case forming the outer casing of the reduction gear 6. However, the invention is not limited to this, and for example, the internal gear 13 may be fitted to the inner circumferential surface of a cylindrical case. In this case, the case is also considered part of the internal gear 13.

[0093] In the embodiments described above, water was used as an example of the fluid to which the sealing device 10,210 is applied. However, it is not limited to this, and the sealing device 10,210 can adequately satisfy the sealing performance of the main sealing portion 28 for various fluids. The fluid is limited to liquids, but also includes gases. In addition to water, other examples of fluids include oil, gas, etc.

[0094] In the embodiments described above, the input gear 21 of the industrial robot 1 was described as having an attachment 22 and a pinion gear 23 provided separately. However, it is not limited to this, and the input gear 21 may have the attachment 22 and the pinion gear 23 as an integrated unit.

[0095] Among the embodiments disclosed herein, those composed of multiple objects may be integrated, and conversely, those composed of a single object may be divided into multiple objects. Whether or not they are integrated, the invention can be constructed in a way that achieves its objective. [Explanation of Symbols]

[0096] 1…Industrial robots 3…Second mating member (matting member, lid) 4… Motor with reduction gear (rotating device) 5…Cover (First component) 5b…Inner peripheral surface 5d...Opening 6…Gear reducer (rotating equipment) 8…Electric motor (power generation unit) 9…Output plate (second component) 10,210... Sealing device 13…Internal gear 13a...Outer surface 25…Plate body 26…Cylindrical section 26a…Outer surface (side surface) 28... Main sealing part 28a...Radially outer end 28b...Radially inner end 29,229... Sub-seal part 33…recess 34…Flange section (protruding section) 35…Flange section 35b…Inner peripheral surface (side surface) 41…Career 42... Rotation input section 44…Inner teeth 49... Crankshaft 49a...First eccentric part (eccentric part) 49b…Second eccentric part (eccentric part) 50a...First oscillating gear (oscillating gear) 50b... Second oscillating gear (oscillating gear) 54a, 54b…external teeth G3…Minute gap (gap)

Claims

1. A cylindrical first member having an opening, A second member fitted to the inner circumferential surface of the first member, A main sealing portion that seals the space between the first member and the second member, A sub-seal portion is provided on the opening side of the main seal portion and is formed by at least the first member and the second member, Equipped with, The sub-seal portion comprises a cover portion provided on the opening side of the second member, The lid portion faces the axial end of the first member in the axial direction, and a gap is formed between the lid portion and the axial end of the first member. Sealing device.

2. The width between the inner surface of the first member and the outer surface of the second member is greater than the width of the gap between the lid and the axial end of the first member. The sealing device according to claim 1.

3. The sub-seal portion has a recess formed on at least one of the inner circumferential surface of the first member or the outer circumferential surface of the second member. The sealing device according to claim 1 or claim 2.

4. The sub-seal portion has a protrusion formed on at least one of the inner circumferential surface of the first member or the outer circumferential surface of the second member. The sealing device according to claim 1 or claim 2.

5. The sub-seal portion has two sides that are radially opposed to each other with a gap in between and are positioned adjacent to the main seal portion. The sealing device according to claim 1 or claim 2, wherein the two aforementioned sides are positioned in a range that avoids the radially outer end and the radially inner end of the main seal portion when viewed from the axial direction.

6. When the width between the two sides is defined as Wg1, and the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member at the location where the main seal portion is provided is defined as Wg2, then widths Wg1 and Wg2 are, Wg2 / 3≦Wg1≦Wg2 / 2 satisfies The sealing device according to claim 5.

7. When the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member of the sub-seal portion is defined as Wg1, and the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member at the location where the main seal portion is provided is defined as Wg2, then widths Wg1 and Wg2 are, Wg2 / 3≦Wg1≦Wg2 / 2 satisfies The sealing device according to claim 1.

8. The first member is made of stainless steel. The sealing device according to claim 1.

9. A cylindrical first member having an opening formed of stainless steel, A second member fitted to the inner circumferential surface of the first member, A main sealing portion that seals the space between the first member and the second member, A sub-seal portion is provided on the opening side of the main seal portion and is formed by at least the first member and the second member, Equipped with, The sub-seal portion comprises a cover portion provided on the opening side of the second member, The lid portion is positioned so as to cover the opening, and is axially opposite to the axial end of the first member. The width between the lid portion and the axial end of the first member is smaller than the width between the inner circumferential surface of the first member and the outer circumferential surface of the second member. Sealing device.

10. A cylindrical first member having an opening formed of stainless steel, A second member fitted to the inner circumferential surface of the first member, A main sealing portion that seals the space between the first member and the second member, A sub-seal portion is provided on the opening side of the main seal portion and is formed by at least the first member and the second member, Equipped with, The sub-seal portion has a side surface that is radially opposed to the main seal portion with a gap in between, and is positioned adjacent to the main seal portion. The aforementioned side surface is positioned in a range that avoids the radially outer end and the radially inner end of the main seal portion when viewed from the axial direction. Sealing device.

11. A cylindrical cover having an opening, A reduction gear fitted to the inner circumferential surface of the cover, An output plate is attached to the aforementioned reduction gear and fitted to the inner circumferential surface of the cover, The system includes a sealing device that seals the space between the cover and the output plate, The aforementioned reduction gear is An internal gear having internal teeth is fitted to the inner circumferential surface of the cover, A rocking gear having external teeth that mesh with the internal teeth and which is rotated by rocking motion, The crankshaft has an eccentric portion that receives the rotational force of the power generation unit and rotatably supports the oscillating gear, and transmits the rotational force of the power generation unit to the oscillating gear, The output plate is attached to which the rotational force of the oscillating gear is transmitted, and a carrier is provided that outputs the rotational force of the oscillating gear to the output plate, Equipped with, The sealing device is, A main sealing portion that seals the space between the cover and the output plate, A sub-seal portion is provided on the opening side of the main seal portion and is formed by at least the cover and the output plate, Equipped with, The sub-seal portion comprises a cover portion provided on the opening side of the output plate, The lid portion faces the axial end of the cover in the axial direction, and a gap is formed between the lid portion and the axial end of the cover. Rotating device.

12. A cylindrical cover having an opening, A reduction gear fitted to the inner circumferential surface of the cover, An output plate is attached to the aforementioned reduction gear and fitted to the inner circumferential surface of the cover, A mating member mounted on the output plate opposite the reduction gear in the axial direction, A sealing device for sealing the space between the cover and the output plate, A power generation unit that generates rotational force, Equipped with, The aforementioned reduction gear is An internal gear having internal teeth is fitted to the inner circumferential surface of the cover, A rocking gear having external teeth that mesh with the internal teeth and which is rotated by rocking motion, The crankshaft has an eccentric portion to which the rotational force of the power generation unit is input and which rotatably supports the oscillating gear, and transmits the rotational force of the power generation unit to the oscillating gear, The output plate is attached to which the rotational force of the oscillating gear is transmitted, and a carrier is provided that outputs the rotational force of the oscillating gear to the output plate, Equipped with, The sealing device is, A main sealing portion that seals the space between the cover and the output plate, A sub-seal portion is provided on the opening side of the main seal portion and is formed by at least the cover and the output plate, Equipped with, The sub-seal portion comprises a cover portion provided on the opening side of the output plate, The lid portion faces the axial end of the cover in the axial direction, and a gap is formed between the lid portion and the axial end of the cover. Industrial robots.

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