Rotating Machinery

Abstract

To provide a technology capable of ensuring stable sealing performance while reducing the axial dimension of a rotary machine.SOLUTION: A rotary machine includes an outer peripheral member 50 and an inner peripheral member 52 that rotate relative to each other, a sealing member 54 disposed between the outer peripheral member 50 and the inner peripheral member 52 to seal an internal space of the outer peripheral member 50, and a bearing 56 disposed between the outer peripheral member 50 and the inner peripheral member 52 on the inner space side from the seal member 54. The seal member 54 includes a main lip part 76a biased toward either the outer peripheral member 50 or the inner peripheral member 52 by a biasing member 78, and an auxiliary lip part 82a provided closer to the internal space 58 in an axial direction than the main lip portion 76a, one of the outer peripheral member 50 and the inner peripheral member 52 is provided with a slide correspondence surface 90 on which the auxiliary lip part 82 includes a sliding part to cope with sliding, and a portion of the slide correspondence surface 90 overlaps the bearing 56 in a radial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to rotary machines. [Background technology]

[0002] Patent Document 1 discloses a rotary machine including an outer peripheral member and an inner peripheral member that rotate relative to each other, and a seal member disposed between the outer peripheral member and the inner peripheral member. The seal member includes a main lip portion that is biased toward the inner peripheral member by a biasing member, and an auxiliary lip portion that is disposed closer to the interior space than the main lip portion. The auxiliary lip portion of the seal member is used to prevent foreign matter, such as wear powder, from entering between the inner peripheral member and the main lip portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-48920 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present application have recognized that there is room for improvement in the prior art in terms of ensuring stable sealing performance by the auxiliary lip portion of the seal member while reducing the axial dimension of the rotary machine.

[0005] An object of the present disclosure is to provide a technique that can ensure stable sealing performance while reducing the axial dimension of a rotary machine. [Means for solving the problem]

[0006] The rotary machine of the present disclosure is a rotary machine comprising an outer circumferential side member and an inner circumferential side member that rotate relative to each other, a sealing member that is disposed between the outer circumferential side member and the inner circumferential side member and seals the internal space of the outer circumferential side member, and a bearing that is disposed between the outer circumferential side member and the inner circumferential side member, axially closer to the internal space than the sealing member, wherein the sealing member comprises a first lip portion that is urged toward either the inner circumferential side member or the outer circumferential side member by a biasing member, and a second lip portion that is provided axially closer to the internal space than the first lip portion, and one of the inner circumferential side member or the outer circumferential side member has a sliding-compatible surface that includes a portion on which the second lip portion slides and is treated to accommodate sliding, and a portion of the sliding-compatible surface radially overlaps the bearing. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to ensure stable sealing performance while reducing the axial dimension of a rotary machine. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side cross-sectional view of a rotary machine according to a first embodiment. [Figure 2] 1 is an enlarged cross-sectional view of a rotary machine according to a first embodiment. [Figure 3] FIG. 3(A) is an enlarged cross-sectional view of a rotary machine of the first reference form, FIG. 3(B) is an enlarged cross-sectional view of a rotary machine of the first embodiment, and FIG. 3(B) is an enlarged cross-sectional view of a rotary machine of the second reference form. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a rotary machine according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes the embodiments. Identical components are designated by the same reference numerals, and redundant explanations will be omitted. In each drawing, components are omitted, enlarged, or reduced as appropriate for the sake of convenience. The drawings should be viewed in accordance with the orientation of the reference numerals.

[0010] (First embodiment) Refer to FIG. 1. A rotating machine 10 of this embodiment is a gear device that uses a gear mechanism 14. This rotating machine 10 includes an input member 12 to which input rotation is input from a driving device, a gear mechanism 14 that transmits the rotation of the input member 12, and an output member 16 that outputs the output rotation transmitted from the gear mechanism 14 to a driven member. Specific examples of the driving device are not particularly limited and include, for example, a motor, a gear motor, and an engine. Specific examples of the driven member are not particularly limited and include, for example, a part of a conveyor, a wheel, a machine tool, a robot (industrial robot, service robot, etc.). In addition, the rotating machine 10 includes a casing 18 that houses the gear mechanism 14, and a carrier 20 that is arranged axially laterally with respect to an external gear 24 that constitutes the gear mechanism 14.

[0011] The rotating machine 10 of this embodiment is an eccentric oscillating gear device that includes an external gear 24 and an internal gear 26 that mesh with each other as the gear mechanism 14. This type of gear device can transmit output rotation to the output member 16 by oscillating one of the external gear 24 and the internal gear 26 (here, the external gear 24) by a crankshaft 28. In this embodiment, an example will be described in which the carrier 20 serves as the output member 16, but the casing 18 may also serve as the output member 16.

[0012] The input member 12 in this embodiment is a crankshaft 28. The crankshaft 28 has at least one (two in this case) eccentric body 30 that is eccentric with respect to a rotation center C28 of the crankshaft 28. The external gear 24 is supported by the eccentric body 30 of the crankshaft 28 via a gear bearing 32 so as to be rotatable relative to the eccentric body 30. The internal gear 26 is integrated with the casing 18.

[0013] The carrier 20 of this embodiment is disposed individually on both axial sides of the external gear 24. The rotating machine 10 of this embodiment includes an inner pin 34 that protrudes from the carrier 20 in the axial direction and penetrates the external gear 24. The inner pin 34 can receive a load from the external gear 24 and can synchronize with the rotation component of the external gear 24 together with the carrier 20.

[0014] The operation of the above rotating machine 10 (gear device) will now be described. When the input member 12 rotates due to the input rotation transmitted from the drive device, the gear mechanism 14 operates. When the gear mechanism 14 operates, the output rotation is transmitted from the gear mechanism 14 to the output member 16, and the output rotation is output to the driven member.

[0015] When an eccentric oscillating gear device is used as in this embodiment, when the input member 12 (crankshaft 28) rotates, the external gear 24 oscillates due to the eccentric body 30 of the crankshaft 28. When the external gear 24 oscillates, the meshing position between the external gear 24 and the internal gear 26 changes in the circumferential direction. Accordingly, with each rotation of the crankshaft 28, the external gear 24 rotates by an amount corresponding to the difference in the number of teeth between the external gear 24 and the internal gear 26. This rotation component is transmitted to the output member 16 (here, the carrier 20) as output rotation. In this embodiment, output rotation is slower than the input rotation.

[0016] Here, the rotary machine 10 includes an outer peripheral member 50 and an inner peripheral member 52 that rotate relative to each other when the rotary machine 10 is in operation, and a seal member 54 and a bearing 56 that are arranged between the outer peripheral member 50 and the inner peripheral member 52. In this embodiment, the outer peripheral member 50 is the casing 18, and the inner peripheral member 52 is the carrier 20. Hereinafter, in this specification, the direction along the center of rotation Ca of the relative rotation of the outer peripheral member 50 and the inner peripheral member 52 is referred to as the axial direction X, and the circumferential direction and radial direction about the center of rotation Ca are simply referred to as the circumferential direction and the radial direction.

[0017] Similar to the carrier 20, the inner peripheral members 52 of this embodiment are individually provided at intervals on both sides in the axial direction X. In this embodiment, the seal members 54 and the bearings 56 are disposed between the individual inner peripheral members 52 and outer peripheral members 50 on both sides in the axial direction X.

[0018] The seal member 54 of this embodiment is an oil seal that seals the gap between the outer peripheral side member 50 and the inner peripheral side member 52. The seal member 54 separates an external space 57 formed outside the rotary machine 10 from an internal space 58 formed inside the outer peripheral side member 50, and seals the internal space 58. An enclosed material (not shown) is enclosed in the internal space 58. The enclosed material is, for example, a lubricant used to lubricate the gear mechanism 14. The lubricant is semi-solid or liquid grease, lubricating oil, or the like.

[0019] The bearing 56 is disposed between the outer peripheral side member 50 and the inner peripheral side member 52, closer to the internal space 58 in the axial direction X than the seal member 54. The bearing 56 connects the outer peripheral side member 50 and the inner peripheral side member 52 so as to be rotatable relative to each other. The bearing 56 in this embodiment is an angular contact spherical bearing, but the specific example is not particularly limited, and a tapered bearing, a cross roller bearing, etc. may also be used.

[0020] Referring to FIG. 2 , the bearing 56 includes a plurality of rolling elements 60, an outer ring 62 and an inner ring 64 on which the rolling elements 60 roll, and a retainer 66 that maintains the relative positions of the rolling elements 60. In this embodiment, the rolling elements 60 are balls, but they may be rollers or the like. The bearing 56 in this embodiment includes a dedicated outer ring 62. Alternatively, the bearing 56 may not include a dedicated outer ring 62, and the inner circumferential surface of the outer circumferential member 50 may double as the outer ring. The bearing 56 in this embodiment does not include a dedicated inner ring 64, and the outer circumferential surface of the inner circumferential member 52 doubles as the inner ring 64. An inner rolling surface 68 on which the rolling elements 60 roll is provided on the outer circumferential surface of the inner circumferential member 52 that doubles as the inner ring 64. Alternatively, the bearing 56 may include a dedicated inner ring 64. In this embodiment, the inner circumferential surface 66a of the retainer 66 is inclined with respect to the axial direction X so as to approach the inner circumferential member 52 side as it moves away from the external space 57 in the axial direction X.

[0021] The seal member 54 includes a main seal body 70 and an auxiliary seal body 72. The main seal body 70 includes a first metal ring 74 and a first elastic member 76 integrated with the first metal ring 74. The first elastic member 76 is made of rubber and is integrated with the first metal ring 74 by vulcanization bonding or the like.

[0022] The first metal ring 74 includes a cylindrical first fitting portion 74a that is fitted and fixed to the inner circumferential surface of the outer-periphery side member 50 by an interference fit, and a first flange portion 74b that extends radially inward from the end of the first fitting portion 74a that faces the external space 57. The first fitting portion 74a in this embodiment is fitted and fixed to the inner circumferential surface of the outer-periphery side member 50 via a covering portion 76c (described later) of the first elastic member 76. Alternatively, the first fitting portion 74a may be directly fitted and fixed to the inner circumferential surface of the outer-periphery side member 50. It can also be said that the seal member 54 is fixed to the outer-periphery side member 50 by an interference fit, with either the first metal ring 74 or the first elastic member 76 in contact.

[0023] The first elastic member 76 includes a main lip portion 76a (first lip portion) that extends from the first flange portion 74b of the first metal ring 74 toward the internal space 58 in the axial direction X and slides on the inner peripheral side member 52. In addition, the first elastic member 76 includes a dust lip portion 76b (third lip portion) that is located closer to the external space 57 than a contact point (a lip end portion 76d described later) of the main lip portion 76a with the internal peripheral side member 52 and slides on the internal peripheral side member 52, and a covering portion 76c that covers the first metal ring 74. The dust lip portion 76b contacts the outer peripheral surface of the internal peripheral side member 52, thereby preventing dust from entering from the external space 57 toward the main lip portion 76a.

[0024] The main lip portion 76a contacts the inner peripheral member 52, thereby preventing leakage of the encapsulated material from the internal space 58 to the external space 57. The main lip portion 76a includes a lip end portion 76d that protrudes toward the inner peripheral member 52 and contacts the inner peripheral member 52.

[0025] The main seal body 70 includes a biasing member 78 attached to the main lip portion 76a on the radially opposite side of the lip end portion 76d. The biasing member 78 is, for example, an endless garter strip that continues in the circumferential direction. The biasing member 78 applies a tension force that presses the main lip portion 76a against the inner peripheral member 52, thereby biasing the main lip portion 76a toward the inner peripheral member 52.

[0026] The auxiliary seal body 72 includes a second metal ring 80 and a second elastic member 82 that is integrated with the second metal ring 80. The second elastic member 82 is made of rubber and is integrated with the second metal ring 80 by vulcanization bonding or the like.

[0027] The second metal ring 80 includes a cylindrical second fitting portion 80a that is fixed in a tight fit engaged with the inner circumferential surface of the main seal body 70, and a second flange portion 80b that extends radially inward from the end of the second fitting portion 80a on the internal space 58 side in the axial direction X.

[0028] The second elastic member 82 includes an auxiliary lip portion 82a (second lip portion) that is located closer to the internal space 58 in the axial direction than the main lip portion 76a and slides on the inner peripheral member 52. The auxiliary lip portion 82a is integrated with the second flange portion 80b of the second metal ring 80. The auxiliary lip portion 82a prevents foreign matter from entering between the inner peripheral member 52 and the main lip portion 76a from the internal space 58 side. Examples of foreign matter include wear particles generated by meshing of the gear mechanism 14. Providing the auxiliary lip portion 82a on the seal member 54 can prevent a decrease in sealing performance caused by foreign matter getting caught in the main lip portion 76a.

[0029] The bearing 56 does not overlap with the main lip portion 76a of the seal member 54 in the radial direction, and is provided closer to the internal space 58 in the axial direction than the main lip portion 76a. The bearing 56 does not overlap with the auxiliary lip portion 82a of the seal member 54 in the radial direction, either, and is provided closer to the internal space 58 in the axial direction than the auxiliary lip portion 82a.

[0030] The inner peripheral member 52 includes a sliding surface 90 provided in an axial range including the portions where the lip portions (main lip portion 76a, auxiliary lip portion 82a, and dust lip portion 76b) of the seal member 54 slide. The sliding surface 90 is provided on the outer peripheral surface of the inner peripheral member 52. The sliding surface 90 has been subjected to a treatment for sliding (hereinafter referred to as a sliding treatment). The sliding treatment here refers to, for example, a treatment for reducing sliding friction. This treatment may include, for example, grinding or surface treatment for reducing surface roughness. Alternatively, the sliding treatment here may be surface treatment for reducing wear of the lip portions of the seal member 54. In this embodiment, this sliding treatment is performed as a finishing treatment (finishing process). The sliding surface 90 in this embodiment can also be referred to as a finished surface (finish-processed surface). The sliding surface 90 in this embodiment is a smooth surface provided by performing finishing grinding using a grindstone or the like. The sliding corresponding surface 90 of this embodiment is a straight surface that extends straight along the axial direction X and has the same outer diameter along the axial direction X.

[0031] The sliding surface 90 extends from a contact position Pa with the auxiliary lip portion 82a of the seal member 54 toward the bearing 56. As a result, a first variation absorption allowance 92 is provided in the sliding surface 90 in a range from the contact position Pa with the auxiliary lip portion 82a to an end 90a on the internal space 58 side. Furthermore, the sliding surface 90 extends from a contact position Pb with the external space-side lip portion 94 of the seal member 54 toward the external space 57. As a result, a second variation absorption allowance 96 is provided in the sliding surface 90 in a range from the contact position Pb with the external space-side lip portion 94 to an end 90b on the external space 57 side. The external space-side lip portion 94 here refers to the lip portion of the multiple lip portions of the seal member 54 that is closest to the external space 57 in the axial direction X. In this embodiment, the external space-side lip portion 94 is the dust lip portion 76b. In contrast, if the seal member 54 does not have the dust lip portion 76b, the exterior space side lip portion 94 becomes the main lip portion 76a.

[0032] A portion of the sliding corresponding surface 90 overlaps with at least a portion of the bearing 56 in the radial direction. Here, "a portion of the sliding corresponding surface 90" refers to a portion of the first variation absorption allowance 92 of the sliding corresponding surface 90. Here, "at least a portion of the bearing 56" refers to the retainer 66 of the bearing 56 in this embodiment. The sliding corresponding surface 90 in this embodiment does not overlap with the outer ring 62 of the bearing 56 in the radial direction. A gap 98 is formed in a location sandwiched radially between the bearing 56 and the sliding corresponding surface 90. It can also be said that the bearing 56 is not disposed on the sliding corresponding surface 90.

[0033] The sliding surface 90 is subjected to the same sliding treatment at a position where it radially overlaps with the bearing 56 and at a position where it comes into contact with the auxiliary lip portion 82a of the seal member 54. It can also be said that the sliding surface 90 is subjected to the same finishing treatment (finishing process) at these positions. Here, the position where it radially overlaps with the bearing 56 refers to a position where it radially overlaps with at least one of the outer ring 62, the inner ring 64, and the retainer 66 of the bearing 56 (the retainer 66 in this embodiment). In this embodiment, in addition to these, the same sliding treatment is also applied to positions where the other lip portions 76a and 76b of the seal member 54 come into contact.

[0034] The conditions regarding the position of each component of the rotary machine 10 (e.g., the outer peripheral component 50, the inner peripheral component 52, the seal component 54, the bearing 56, etc.) described so far are satisfied when these components are in a predetermined design reference position. The first variation absorption allowance 92 is provided to absorb any axial variation of the auxiliary lip portion 82a of the seal component 54 or the corresponding sliding surface 90 from the reference position, thereby maintaining contact between the auxiliary lip portion 82a and the corresponding sliding surface 90. The variation of the auxiliary lip portion 82a here refers to, for example, a case where the axial position of the auxiliary lip portion 82a is shifted toward the internal space 58 (to the right in FIG. 2 ) from the reference position due to assembly error or processing error. The variation of the corresponding sliding surface 90 refers to, for example, a case where the axial position of the end 90a of the corresponding sliding surface 90, located on the internal space 58 side, is shifted toward the external space 57 (to the left in FIG. 2 ) from the reference position due to processing error. The axial dimension of the first variation absorption allowance 92 of the sliding corresponding surface 90 is, for example, 3.0 mm or less.

[0035] The second variation absorption allowance 96 is provided to absorb any variation in the axial position of the exterior-space-side lip portion 94 of the seal member 54 or the sliding corresponding surface 90 from a reference position, thereby maintaining contact between the exterior-space-side lip portion 94 and the sliding corresponding surface 90. Here, variation in the exterior-space-side lip portion 94 refers to, for example, a case where the axial position of the exterior-space-side lip portion 94 is shifted toward the exterior space 57 from the reference position due to assembly error or processing error. Furthermore, variation in the sliding corresponding surface 90 refers to, for example, a case where the axial position of an end 90b of the sliding corresponding surface 90 on the exterior space 57 side is shifted toward the interior space 58 from the reference position due to processing error.

[0036] The effects of the rotary machine 10 described above will be explained.

[0037] Reference is made to Figures 3(A) to 3(C). Figures 3(A) to 3(C) show portions of the rotary machine 10 of the first reference mode, the first embodiment, and the second reference mode, respectively. Figure 3(A) shows an example in which a portion of the slide corresponding surface 90 does not overlap the bearing 56 in the radial direction, and a first variation absorption allowance 92 of the axial dimension is provided on the slide corresponding surface 90, the same as in the example of Figure 3(B) (first embodiment). In the example of Figure 3(A), in order to provide such a first variation absorption allowance 92 of the axial dimension on the slide corresponding surface 90, the position of the end 90a of the slide corresponding surface 90 is shifted by a distance L toward the external space 57 compared to the example of Figure 3(B). Accordingly, the axial position of the seal member 54 is shifted by the distance L toward the external space 57, and the axial dimensions of the outer peripheral side member 50 and the inner peripheral side member 52 are longer by the distance L toward the external space 57. Fig. 3(C) shows an example in which a portion of the sliding corresponding surface 90 does not overlap the bearing 56 in the radial direction, and a first variation absorption allowance 92 having an axial dimension that is shorter than that of the example of Fig. 3(B) is provided on the sliding corresponding surface 90. In the example of Fig. 3(C), the axial position of the seal member 54 and the axial dimensions of the outer peripheral side member 50 and the inner peripheral side member 52 are the same as those in the example of Fig. 3(B).

[0038] When the seal member 54 has the auxiliary lip portion 82a, the axial range of the sliding corresponding surface 90 needs to be wider toward the internal space 58 compared to when the auxiliary lip portion 82a is not present. For this reason, when the bearing 56 is present near the seal member 54, in order to ensure the first variation absorption allowance 92 of the sliding corresponding surface 90 on the external space 57 side of the bearing 56, as shown in FIG. 3(A), the space 100 between the seal member 54 and the bearing 56 needs to be wider.

[0039] (A) In this regard, according to the present embodiment, as shown in FIG. 3(B), a portion of the corresponding slide surface 90 overlaps with the bearing 56 in the radial direction. This allows a portion of the first variation absorption allowance 92 of the corresponding slide surface 90 to overlap with the bearing 56 in the radial direction. Therefore, compared to when the first variation absorption allowance 92 of the same axial dimension is provided closer to the external space 57 than the bearing 56 (as in FIG. 3(A)), by bringing the seal member 54 closer to the bearing 56, the space 100 between the seal member 54 and the bearing 56 can be narrowed. Accordingly, the axial dimensions of the outer circumferential side member 50 and the inner circumferential side member 52 can be shortened by the amount by which the seal member 54 is brought closer to the bearing 56. For example, by bringing the seal member 54 closer to the bearing 56 by a distance L than in the example of FIG. 3(A), the axial dimensions of the outer circumferential side member 50 and the inner circumferential side member 52 can be shortened by the amount of the distance L. Consequently, the axial dimension of the rotating machine 10 can be reduced.

[0040] (A) Furthermore, compared to the case where the axial dimension of the slide corresponding surface 90 is shortened by shifting only the axial position of the end 90a of the slide corresponding surface 90 toward the external space 57 relative to the bearing 56 (as in FIG. 3(C)), the axial dimension of the first variation absorption allowance 92 of the slide corresponding surface 90 can be made longer. Therefore, even when the axial positions of the auxiliary lip portion 82a of the seal member 54 or the slide corresponding surface 90 vary significantly, the first variation absorption allowance 92 can absorb the variation, making it possible to easily maintain the auxiliary lip portion 82a in contact with the slide corresponding surface 90. Consequently, stable sealing performance by the auxiliary lip portion 82a can be ensured even when the axial positions of the seal member 54 or the slide corresponding surface 90 vary significantly.

[0041] (B) The seal member 54 includes a dust lip 76b in addition to the main lip 76a and the auxiliary lip 82a, which can prevent dust from entering the internal space 58 from the external space 57.

[0042] Another feature of the rotary machine 10 described above will be described. Reference is made to FIG. 2 . The inner peripheral member 52 is provided with a step 102 between the corresponding slide surface 90 and the inner rolling surface 68, the step 102 having an outer diameter smaller than the outer diameter of the corresponding slide surface 90. The step 102 is provided at a position radially overlapping with the retainer 66 of the bearing 56. In this embodiment, the step 102 extends straight along the axial direction X. A chamfered portion 104 is provided between the corresponding slide surface 90 of the inner peripheral member 52 and the step 102, the outer diameter of which continuously decreases toward the internal space 58.

[0043] By providing the step portion 102 on the inner peripheral side member 52, it is possible to hold lubricant in the step portion 102. In addition, by providing the step portion 102 on the inner peripheral side member 52, it is possible to partially widen the gap 98 between the retainer 66 of the bearing 56 and the inner peripheral side member 52, compared to when the sliding corresponding surface 90 is continuous to the inner rolling surface 68. This makes it easier to avoid interference with the retainer 66 even when the position of the retainer 66 of the bearing 56 is misaligned radially inward.

[0044] Second Embodiment See Fig. 4. The rotating machine 10 of this embodiment differs from the first embodiment in the configuration around the slide corresponding surface 90 of the inner peripheral side member 52. The slide corresponding surface 90 of this embodiment is provided continuously up to the inner rolling surface 68. This makes it possible to increase the axial dimension of the first variation absorption allowance 92 of the slide corresponding surface 90 compared to when the slide corresponding surface 90 is not continuous up to the inner rolling surface 68. This makes it possible to ensure even more stable sealing performance by the auxiliary lip portion 82a of the seal member 54.

[0045] The sliding surface 90 of this embodiment overlaps the outer ring 62 of the bearing 56 in the radial direction. An end 62a of this outer ring 62 on the external space 57 side is closer to the internal space 58 in the axial direction X than an end 66b of the retainer 66 on the external space 57 side. This makes it possible to increase the axial dimension of the first variation absorption allowance 92 of the sliding surface 90 compared to when the outer ring 62 of the bearing 56 does not overlap in the radial direction. This therefore ensures stable sealing by the auxiliary lip portion 82a of the seal member 54.

[0046] In addition, the rotary machine 10 of this embodiment includes the components (not shown) described above in (A) and (B), and provides the effects corresponding to those descriptions.

[0047] Next, variations of the components described above will be described.

[0048] The rotating machine 10 is not limited to a gear device, but may be, for example, a traction drive, a motor, etc. The combination of the outer circumferential member 50 and the inner circumferential member 52 is not particularly limited. This combination may be, for example, a combination of a motor cover and a motor shaft.

[0049] When the rotating machine 10 is a gear device, the specific example of the gear device is not particularly limited. The gear device may be, for example, an eccentric oscillating gear device, a flexible meshing gear device, a simple planetary gear device, a right-angle gear device, a parallel-axis gear device, or the like. The type of eccentric oscillating gear device is not particularly limited. This type may be a center crank type in which the crankshaft 28 is provided on the center C26 of the internal gear 26 as in the embodiment, or a distributed type in which the crankshaft 28 is provided at a position offset from the center C26 of the internal gear 26. The type of flexible meshing gear device is not particularly limited. This type may be a cylindrical type using a pair of internal gears, or a top hat type or cup type using a single internal gear. The gear device may output an output rotation that is increased in speed relative to the input rotation.

[0050] It is sufficient that a portion of the sliding corresponding surface 90 overlaps a portion of the bearing 56 in the radial direction. Here, the portion of the bearing may be, for example, either the outer ring 62 of the bearing 56 or the retainer 66. Unlike the embodiment, a portion of the sliding corresponding surface 90 may overlap only the outer ring 62 of the bearing 56 in the radial direction.

[0051] In the above example, the seal member 54 is fixed to the outer peripheral member 50, and its lip portions 76a, 76b, 82a, such as the main lip portion 76a, dust lip portion 76b, and auxiliary lip portion 82a, slide against the inner peripheral member 52. Alternatively, the seal member 54 may be fixed to the inner peripheral member 52, and its lip portions 76a, 82a may slide against the outer peripheral member 50. In this case, the seal member 54 may be fixed to the inner peripheral member 52 by an interference fit, with either the metal ring or the elastic material in contact, as in the above example. In this case, the main lip portion 76a of the seal member 54 is biased toward the outer peripheral member 50, instead of the inner peripheral member 52 as described above. In this case, the sliding surface 90 on which the lip portions 76a, 76b, 82a of the seal member 54 slide is provided on the inner surface of the outer circumferential side member 50 instead of the inner circumferential side member 52 described above.

[0052] So far, an example has been described in which the sliding surface 90 provided on one of the outer peripheral member 50 or the inner peripheral member 52 is provided directly on either the inner peripheral surface of the outer peripheral member 50 or the outer peripheral surface of the inner peripheral member 52. Alternatively, the sliding surface 90 may be provided on a tubular member that fits into either of these members and against which the lip portion of the sealing member 54 slides. When a tubular member is fitted onto the inner peripheral surface of the outer peripheral member 50, the sliding surface 90 is provided on the inner peripheral surface of the tubular member, and when a tubular member is fitted onto the outer peripheral surface of the inner peripheral member 52, the sliding surface 90 is provided on the outer peripheral surface of the tubular member.

[0053] The seal member 54 is only required to have at least the main lip portion 76a and the auxiliary lip portion 82a, and is not required to have the dust lip portion 76b.

[0054] Unlike the embodiment, a portion of the bearing 56 may overlap the auxiliary lip portion 82a of the seal member 54 in the radial direction.

[0055] The above-described embodiments and variations are merely examples. The abstract technical concepts should not be interpreted as being limited to the contents of the embodiments and variations. Many design changes are possible in the contents of the embodiments and variations, such as changes, additions, and deletions of components. In the above-described embodiments, the contents that allow such design changes are emphasized by adding the notation "embodiment." However, design changes are also permitted even in contents without such notation. Hatching on cross sections in the drawings does not limit the material of the hatched objects. The structures / numerical values ​​referred to in the embodiments and variations naturally include those that can be considered identical when taking into account manufacturing errors, etc.

[0056] In the embodiments, a component that is made up of a single member may be made up of multiple members. Similarly, in the embodiments, a component that is made up of multiple members may be made up of a single member. [Explanation of symbols]

[0057] 10...rotating machine, 50...outer peripheral member, 52...inner peripheral member, 54...sealing member, 56...bearing, 57...external space, 58...internal space, 60...rolling element, 62...outer ring, 66...retainer, 68...inner rolling surface, 76a...main lip portion (first lip portion), 76b...dust lip portion (third lip portion), 78...urging member, 82a...auxiliary lip portion (second lip portion), 90...sliding corresponding surface, 102...step portion.

Claims

1. A rotary machine comprising: an outer circumferential side member and an inner circumferential side member which rotate relative to each other; a seal member which is disposed between the outer circumferential side member and the inner circumferential side member and seals an internal space of the outer circumferential side member; and a bearing which is disposed between the outer circumferential side member and the inner circumferential side member on the axial side of the seal member toward the internal space, the seal member includes a first lip portion that is biased toward one of the outer peripheral side member or the inner peripheral side member by a biasing member, and a second lip portion that is provided closer to the internal space in the axial direction than the first lip portion, one of the outer peripheral side member and the inner peripheral side member has a sliding corresponding surface that includes a portion on which the second lip portion slides and is treated to correspond to sliding, A rotary machine in which a portion of the sliding corresponding surface radially overlaps with a retainer of the bearing.

2. The rotary machine according to claim 1 , wherein a portion of the sliding corresponding surface overlaps with an outer ring of the bearing in the radial direction.

3. The bearing has an inner rolling surface on which the rolling elements roll, The rotary machine according to claim 1 or 2, wherein the inner peripheral member includes a step portion provided between the corresponding sliding surface and the inner rolling surface and having an outer diameter smaller than that of the corresponding sliding surface.

4. A rotary machine comprising an outer peripheral member and an inner peripheral member which rotate relative to each other, a sealing member disposed between the outer peripheral member and the inner peripheral member and sealing the internal space of the outer peripheral member, and a bearing disposed between the outer peripheral member and the inner peripheral member on the axial side of the internal space closer to the sealing member, the seal member includes a first lip portion that is biased toward one of the outer peripheral side member or the inner peripheral side member by a biasing member, and a second lip portion that is provided closer to the internal space in the axial direction than the first lip portion, one of the outer peripheral side member and the inner peripheral side member has a sliding corresponding surface that includes a portion on which the second lip portion slides and is treated to correspond to sliding, a portion of the sliding corresponding surface overlaps with the bearing in the radial direction; The bearing has an inner rolling surface on which the rolling elements roll, The rotating machine, wherein the sliding corresponding surface is provided continuously to the inner rolling surface.

5. A rotary machine as described in Claim 4, wherein a portion of the sliding surface radially overlaps with the outer ring of the bearing.

6. The rotary machine according to claim 1 , wherein the seal member includes another lip portion provided axially closer to the external space than the contact point of the first lip portion with the inner peripheral member.

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