Seal structure and seals

Abstract

The present invention provides a sealing structure and a sealing member. The sealing structure of the present invention comprises: a housing having an inner peripheral portion whose diameter increases as it moves from the outer side to the inner side in the axial direction; a shaft member arranged inside the housing; and a sealing member that seals between the housing and the shaft member.

Description

Technical Field

[0001] The invention relates to a sealing structure and a sealing member. Background Art

[0002] As robots move at higher speeds and higher frequencies, the operating environment of the reducers mounted on them has become harsher. For example, when the reducer moves at high speed or high temperatures, the temperature of the reducer sometimes rises, and the pressure inside the reducer increases to a level greater than the desired pressure. As the internal pressure of the reducer increases, the oil seal may fall off the reducer.

[0003] In addition, the rubber material of the oil seal may undergo chemical changes such as solidification due to the lubricant or the solvent from the outside, causing deformation such as reduction in outer diameter. As the oil seal deforms, it may fall off from the speed reducer.

[0004] In view of these problems, for example, it is difficult to reliably prevent the oil seal from falling off from the reducer simply by increasing the pressing force of the oil seal relative to the mounting fixing portion by making the outer diameter of the oil seal larger. In the past, a sealing device having an anti-falling member for preventing the oil seal from falling off is known (see, for example, Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-109190 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, the sealing device is provided with a fixing member that fixes the anti-dropout member in a detachable manner. Thus, the special member required for the structure of the sealing device, such as the anti-dropout member, the fixing member and the member for fixing the fixing member to be installed, etc., may cause the device structure to become complicated.

[0010] The present invention provides a sealing structure and a sealing member capable of properly sealing the interior with a simple structure.

[0011] Solutions for solving problems

[0012] A sealing structure according to one aspect of the present invention includes a housing, a shaft member, and a sealing member.

[0013] The housing has an inner peripheral portion whose diameter increases from the outer side to the inner side in the axial direction. The shaft member is arranged inside the housing. The sealing member seals between the housing and the shaft member.

[0014] By such a configuration, the inner peripheral portion of the housing in contact with the sealing member increases in diameter from the outer side in the axial direction toward the inner side. As a result, the normal reaction force of the inner peripheral portion of the housing acts radially inwardly from the outer side in the axial direction toward the inner side. For example, compared with the case where the normal reaction force of the inner peripheral portion of the housing is parallel to the radial direction, the sealing member is pressed toward the inner side in the axial direction, thereby preventing the sealing member from detaching toward the outer side in the axial direction.

[0015] A sealing structure according to one aspect of the present invention includes a housing, a shaft member, and a sealing member.

[0016] The shaft member is arranged inside the housing. The sealing member has an outer peripheral portion whose diameter increases from the outer side toward the inner side in the axial direction. The sealing member seals between the housing and the shaft member.

[0017] By such a configuration, the outer peripheral portion of the sealing member in contact with the inner peripheral portion of the housing increases in diameter from the outer side in the axial direction toward the inner side. As a result, the normal reaction force of the inner peripheral portion of the housing is greater on the inner side in the axial direction than on the outer side in the axial direction. The sealing member is more strongly held on the inner side in the axial direction, thereby preventing the sealing member from escaping to the outer side in the axial direction.

[0018] A sealing structure of one embodiment of the present invention comprises a housing, a shaft member, a sealing member, and a connecting portion. The shaft member is arranged inside the housing. The sealing member seals between the housing and the shaft member. The connecting portion connects the outer peripheral portion of the sealing member in contact with the housing and the inner peripheral portion of the sealing member in contact with the shaft member. The connecting portion is bent into a convex shape toward the inner side in the axial direction.

[0019] By such a configuration, the internal pressure from the axial inner side is used to supplement the force of pressing the outer peripheral portion of the sealing member against the inner peripheral surface of the housing by the connecting portion that is bent convexly toward the axial inner side. For example, compared with the case where the connecting portion is not bent, the sealing member is pressed more strongly toward the housing, thereby preventing the sealing member from detaching toward the outer side in the axial direction.

[0020] In the above configuration, the connection portion preferably includes a curved portion on the outer peripheral side thereof that is curved in a convex shape toward the inner side in the axial direction.

[0021] By configuring in this way, the internal pressure from the axial inner side is used to supplement the force of the curved portion to press the outer peripheral portion against the inner peripheral surface of the housing. For example, compared with a case where there is no curved portion, the sealing member is pressed more strongly toward the housing, thereby preventing the sealing member from detaching to the outer side in the axial direction. In addition, for example, compared with a case where a curved portion is provided on the inner peripheral side, the resistance between the shaft member and the sealing member can be suppressed.

[0022] A sealing structure according to one aspect of the present invention includes a housing, a shaft member, and a sealing member.

[0023] The shaft member is disposed inside the housing. The sealing member seals between the housing and the shaft member. The thermal expansion coefficient of the sealing member is greater than the thermal expansion coefficient of the housing.

[0024] With this configuration, the sealing member is more likely to expand than the housing when the temperature rises.

[0025] For example, compared with a case where the thermal expansion coefficients of the sealing member and the housing are approximately the same or the thermal expansion coefficient of the sealing member is smaller than the thermal expansion coefficient of the housing, the sealing member is more strongly held by the housing, thereby preventing the sealing member from detaching axially outward.

[0026] A sealing member according to one aspect of the present invention includes a lip portion, a base portion, and a connecting portion. The lip portion is used to contact a member arranged on the inner periphery of a housing. The base portion is used to be fixed to the housing.

[0027] The connecting portion connects the base portion and the lip portion. The force applied by the housing to the base portion is greater on the inner side in the axial direction than on the outer side.

[0028] With this configuration, for example, compared with a case where the force applied by the housing to the base portion is smaller in the axial direction inside than in the axial direction outside, the seal is held more strongly in the axial direction inside, thereby preventing the seal from coming off in the axial direction outside.

[0029] A sealing member of one embodiment of the present invention comprises a lip portion, a base portion, a connecting portion, and an enlargement component. The lip portion is used to contact a member arranged on the inner periphery of a housing. The base portion is used to be fixed to the housing. The connecting portion connects the base portion and the lip portion. The enlargement component increases the force with which the lip portion presses the housing as the pressure in the housing increases.

[0030] With such a configuration, as the pressure in the housing increases, the lip portion presses the housing more strongly, thereby preventing the seal from coming off to the outside in the axial direction.

[0031] A sealing member of one embodiment of the present invention comprises a lip portion, a base portion, a connecting portion, and an enlarged component. The lip portion is used to contact a member arranged on the inner periphery of a housing. The base portion is used to be fixed to the housing. The connecting portion connects the base portion and the lip portion. The enlarged component increases the force with which the lip portion presses the housing as the temperature inside the housing rises.

[0032] With such a configuration, as the temperature in the housing rises, the lip portion presses the housing more strongly, thereby preventing the seal from coming off to the outside in the axial direction.

[0033] In the above configuration, it is preferred that an enlarged member is formed at the connecting portion.

[0034] With such a configuration, the connecting portion acts on the base portion to supplement the force pressing the housing. For example, compared with a case where no enlarged member is formed in the connecting portion, the seal is pressed more strongly toward the housing, thereby preventing the seal from detaching outward in the axial direction.

[0035] In the above configuration, the enlarged member preferably includes a curved portion that is curved in a convex shape toward the inside in the axial direction.

[0036] With this configuration, the internal pressure from the axial inside complements the force of the curved portion pressing the base portion against the housing. For example, compared with a case without a curved portion, the seal is pressed more strongly toward the housing, thereby preventing the seal from detaching axially outward.

[0037] In the above structure, the enlarged member is formed of a material having a thermal expansion coefficient larger than that of the housing, and forms at least a part of the lip portion, the base portion, and the connecting portion.

[0038] By configuring in this way, at least a part of the lip, the base, and the connecting portion is easier to expand than the housing when the temperature rises. For example, compared with a case where the thermal expansion coefficients of the lip, the base, and the connecting portion are substantially the same as the thermal expansion coefficient of the housing or a case where the thermal expansion coefficients of the lip, the base, and the connecting portion are smaller than the thermal expansion coefficient of the housing, the seal is more strongly held by the housing, thereby preventing the seal from being separated outward in the axial direction.

[0039] Effects of the Invention

[0040] According to the present invention, the interior can be properly sealed with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a cross-sectional view showing the structure of a rotary machine including a seal structure according to a first embodiment of the present invention.

[0042] Figure 2 yes Figure 1 An enlarged cross-sectional view of the sealing member is shown.

[0043] Figure 3 It is a cross-sectional view of a sealing member according to a modified example of the first embodiment of the present invention.

[0044] Figure 4 It is a cross-sectional view of a sealing member according to a second embodiment of the present invention.

[0045] Figure 5 It is a cross-sectional view of a sealing member according to a third embodiment of the present invention.

[0046] Description of Reference Numerals

[0047] 1. Rotating machinery; 2. Housing; 2a. Inner circumference; 3. Shaft member; 10, 50, 60. Sealing member (seal); 11, 51. Base; 11a. Outer circumference; 11b, 51b. Connecting portion; 12. Lip (inner circumference); 21. Core; 22. Covering; 41. Inner diameter changing portion; 41A. Inner circumferential surface; 42. Outer diameter changing portion; 42B. Outer circumferential surface; 54. Bend portion. DETAILED DESCRIPTION

[0048] (First embodiment)

[0049] Below, while referring to the attached Figure 1 A first embodiment of the sealing structure for a rotary machine according to the present invention will be described.

[0050] Figure 1 It is a cross-sectional view showing the structure of a rotary machine 1 including the sealing structure according to the first embodiment. Figure 2 yes Figure 1 An enlarged cross-sectional view of the sealing member 10 is shown.

[0051] like Figure 1 and Figure 2 As shown, the rotary machine 1 of the present embodiment includes a housing 2 , a shaft member 3 , two bearings 4 , and a seal member 10 .

[0052] The outer shape of the housing 2 is formed in, for example, a cylindrical shape.

[0053] The shaft member 3 has a cylindrical outer shape, for example. The shaft member 3 is disposed inside the housing 2. The central axis O of the shaft member 3 is coaxial with the central axis of the housing 2. The shaft member 3 rotates around the central axis O relative to the housing 2.

[0054] The two bearings 4 are respectively arranged on the first end 1a side and the second end 1b side of the axial direction D of the rotating machine 1 and arranged between the housing 2 and the shaft member 3. The two bearings 4 support the shaft member 3 so that it can rotate around the central axis O relative to the housing 2. In addition, the axial direction D is a direction parallel to the central axis O of the shaft member 3.

[0055] Each bearing 4 includes, for example, an outer ring 5 , an inner ring 6 , and a plurality of balls 7 .

[0056] The outer ring 5 is formed in, for example, an annular shape. The outer ring 5 is fitted into the inner side of the housing 2 and is in contact with the inner peripheral surface 2A of the housing 2 .

[0057] The outer shape of the inner ring 6 is formed in, for example, an annular shape. The inner ring 6 is fitted outside the shaft member 3 and is in contact with the outer peripheral surface 3B of the shaft member 3 .

[0058] The outer shape of each of the plurality of balls 7 is formed into a spherical shape, for example. The plurality of balls 7 are arranged between the outer ring 5 and the inner ring 6. The plurality of balls 7 are arranged on the entire circumference at predetermined intervals in the circumferential direction. Each ball 7 rolls between the outer ring 5 and the inner ring 6.

[0059] The seal member 10 has an annular outer shape, for example. The seal member 10 is disposed on the first end 1a side in the axial direction D of the rotary machine 1 and outside the bearing 4 . The seal member 10 seals the annular space formed between the housing 2 and the shaft member 3 .

[0060] The sealing member 10 includes, for example, a base portion 11 and a lip portion 12 .

[0061] The outer shape of the base portion 11 is formed into a circular ring shape, for example, with a cross section along the axial direction D and the radial direction R bent into an L shape. The base portion 11 includes a core portion 21 and a covering portion 22 covering the core portion 21. The core portion 21 is formed of an elastic material such as metal. The covering portion 22 is formed of an elastic material such as rubber or resin.

[0062] The base portion 11 includes an outer peripheral portion 11a in contact with the inner peripheral surface 2A of the housing 2 and a connecting portion 11b connecting the outer peripheral portion 11a and the lip portion 12. The outer peripheral portion 11a and the connecting portion 11b are formed integrally.

[0063] The outer peripheral portion 11 a is formed in an annular shape extending along the axial direction D.

[0064] The outer shape of the connection portion 11 b is formed in an annular shape extending radially inward from an axially outer end portion 11 c of the outer peripheral portion 11 a .

[0065] The base 11 is embedded in the inner peripheral surface 2A of the housing 2, for example, with the outer peripheral portion 11a of the base 11 elastically deformed radially inward, so that the sealing member 10 is held in the housing 2. The outer peripheral portion 11a is elastically deformed radially inward and is pressed against the inner peripheral surface 2A of the housing 2 by the elastic force.

[0066] The lip 12 has an annular shape protruding radially inward from the end 11d of the connecting portion 11b. The lip 12 is made of an elastic material such as rubber or resin. The lip 12 is formed integrally with the connecting portion 11b, for example.

[0067] The lip portion 12 includes a dust lip 31 , a contact lip 32 , and a spring ring 33 .

[0068] The outer shape of the dust lip 31 is formed into, for example, an annular shape that protrudes radially inward in a manner that is inclined axially outward from the end 11d of the connecting portion 11b. The tip 31a of the dust lip 31 contacts the outer peripheral surface 3B of the shaft member 3 in a manner that is pressed against the outer peripheral surface 3B of the shaft member 3. The dust lip 31 prevents foreign matter floating outside the rotating machine 1 from entering the internal space of the rotating machine 1 (the space surrounded by the housing 2 and the shaft member 3).

[0069] The contact lip 32 has an annular shape that protrudes radially inwardly and tilts axially inwardly from the end 11d of the connection portion 11b. The tip 32a of the contact lip 32 contacts the outer peripheral surface 3B of the shaft member 3 while being pressed against the outer peripheral surface 3B.

[0070] The spring ring 33 is embedded in the annular recess 32b formed on the outer peripheral surface 32A of the contact lip 32. The spring ring 33 is a so-called annular spiral spring (garter spring), for example, a spring in a circular ring shape formed by connecting the two ends of a spiral spring. The spring ring 33 is formed of an elastic material. The spring ring 33 elastically stretches in a state of being mounted and fixed to the contact lip 32. The spring ring 33 uses elastic force to press the top end of the contact lip 32 against the outer peripheral surface 3B of the shaft member 3 in the radial direction, so that the contact lip 32 is compressed and deformed.

[0071] The contact lip 32 prevents liquid foreign matter from flowing into the internal space from the outside of the rotary machine 1 through the dust lip 31 and prevents liquid lubricant from flowing out from the internal space of the rotary machine 1 to the outside.

[0072] The sealing member 10 is fixed to the housing 2 by means of the base portion 11. When the housing 2 and the shaft member 3 rotate relative to each other or when at least one of the housing 2 and the shaft member 3 rotates, the dust lip 31 and the contact lip 32 of the lip portion 12 rotate relative to the outer peripheral surface 3B of the shaft member 3 in a state of being in contact with the outer peripheral surface 3B of the shaft member 3.

[0073] The inner peripheral portion 2a of the housing 2 in contact with the sealing member 10 includes an inner diameter varying portion 41 whose inner diameter increases from the outer side to the inner side in the axial direction D. The inner peripheral surface 41A of the inner diameter varying portion 41 is formed into a tapered shape inclined at a predetermined angle θ relative to the axial direction D, for example.

[0074] The normal direction of the inner peripheral surface 41A of the inner diameter changing portion 41 is inclined at a predetermined angle θ with respect to the radial direction R. Thus, the inner diameter changing portion 41 of the housing 2 acts in the radial direction inwardly from the outer side in the axial direction D toward the inner side, with a normal reaction force RF to the force acting from the outer peripheral portion 11a of the sealing member 10 to the inner peripheral portion 2a of the housing 2 being inclined.

[0075] As described above, in the sealing structure of the rotary machine 1 of the first embodiment, the inner peripheral surface 41A of the inner diameter change portion 41 of the housing 2 is formed into a tapered shape inclined at a predetermined angle θ relative to the axial direction D. As a result, the normal reaction force RF of the inner diameter change portion 41 of the housing 2 acts radially inwardly from the outer side of the axial direction D toward the inner side. For example, compared with the case where the normal reaction force of the inner peripheral portion 2a of the housing 2 is parallel to the radial direction, by pressing the sealing member 10 toward the inner side of the axial direction D, it is possible to suppress the sealing member 10 from being disengaged toward the outer side of the axial direction D.

[0076] In addition, in the first embodiment described above, the base portion 11 may be composed of only the outer peripheral portion 11a, and the sealing member 10 may include the base portion 11 (outer peripheral portion 11a), the connecting portion 11b, and the lip portion 12. In this case, the base portion 11 (outer peripheral portion 11a) is fixed to the housing 2, and the connecting portion 11b connects the base portion 11 (outer peripheral portion 11a) and the lip portion 12.

[0077] Furthermore, in the above-described first embodiment, the lip portion 12 is in contact with the shaft member 3 , but the present invention is not limited thereto, and the lip portion 12 may be in contact with another member disposed on the inner periphery of the housing 2 .

[0078] (Variation of the first embodiment)

[0079] Hereinafter, a modification of the first embodiment will be described. Note that the same reference numerals are given to the same configurations as those of the first embodiment described above, and the description thereof will be omitted or simplified.

[0080] Figure 3 It is a cross-sectional view of a sealing member 10 according to a modified example of the first embodiment.

[0081] In the above embodiment, the inner peripheral portion 2 a of the housing 2 in contact with the sealing member 10 includes the inner diameter changing portion 41 , but the present invention is not limited thereto, and the outer peripheral portion 11 a of the sealing member 10 may include the outer diameter changing portion 42 .

[0082] like Figure 3 As shown, in the modification of the first embodiment, the inner peripheral surface 2A of the inner peripheral portion 2 a of the housing 2 that contacts the sealing member 10 is parallel to the axial direction D.

[0083] The outer peripheral portion 11a of the sealing member 10 has an outer diameter changing portion 42 whose outer diameter increases from the outside to the inside in the axial direction D in a natural state before being mounted and fixed to the housing 2. The outer peripheral surface 42B of the outer diameter changing portion 42 (for example, Figure 3 The outer peripheral surface 42B) indicated by the dotted line is formed into a tapered shape inclined at a predetermined angle θ relative to the axial direction D in a natural state before being mounted and fixed to the housing 2.

[0084] When the outer peripheral portion 11a of the sealing member 10 is mounted and fixed to the housing 2, the force with which the outer peripheral portion 11a is pressed against the inner peripheral surface 2A of the housing 2 is greater on the inner side in the axial direction D than on the outer side in the axial direction D. Thus, the normal reaction force RF of the inner peripheral portion 2a of the housing 2 to the force acting from the outer peripheral portion 11a of the sealing member 10 to the inner peripheral portion 2a of the housing 2 is greater on the inner side in the axial direction D than on the outer side in the axial direction D.

[0085] As described above, in the sealing structure of the rotary machine 1 of the modified example of the first embodiment, the outer peripheral surface 42B of the outer diameter change portion 42 of the sealing member 10 is formed into a tapered shape that is inclined at a predetermined angle θ relative to the axial direction D in a natural state before being mounted and fixed to the housing 2. As a result, the normal reaction force RF of the inner peripheral portion 2a of the housing 2 to the force acting from the outer peripheral portion 11a of the sealing member 10 to the inner peripheral portion 2a of the housing 2 is greater on the inner side of the axial direction D than on the outer side of the axial direction D. For example, compared with a case where the normal reaction force RF of the inner peripheral portion 2a of the housing 2 is substantially the same on the outer side and the inner side of the axial direction D, the sealing member 10 is more strongly held on the inner side of the axial direction D, thereby being able to suppress the sealing member 10 from being disengaged to the outer side of the axial direction D.

[0086] In the modification of the first embodiment, the outer diameter change portion 42 of the sealing member 10 is not limited thereto, and other structures may be used to make the force of the housing 2 acting on the base portion 11 larger on the inner side in the axial direction D than on the outer side in the axial direction D.

[0087] Thus, for example, compared with a case where the force exerted by the housing 2 on the base portion 11 is smaller on the inner side of the axial direction D than on the outer side of the axial direction D, the sealing member 10 is more strongly held on the inner side of the axial direction D, thereby preventing the sealing member 10 from escaping to the outer side of the axial direction D.

[0088] (Second embodiment)

[0089] Below, while referring to the attached Figure 1 The second embodiment of the sealing structure for a rotary machine according to the present invention will be described. The same reference numerals are used for the same structures as those in the first embodiment described above, and the description thereof will be omitted or simplified.

[0090] Figure 4 It is a cross-sectional view of a sealing member 50 according to the second embodiment.

[0091] like Figure 4 As shown, the sealing member 50 of the second embodiment is different from the sealing member 10 of the first embodiment described above in that it includes a base portion 51 instead of the base portion 11 of the first embodiment.

[0092] The sealing member 50 includes, for example, a base portion 51 and a lip portion 12. The base portion 51 includes a core portion 52 and a covering portion 53 covering the core portion 52. The base portion 51 includes an outer peripheral portion 11a and a connecting portion 51b. The outer peripheral portion 11a and the connecting portion 51b are formed integrally.

[0093] The lip portion 12 protrudes radially inward from the end portion 51d of the connecting portion 51b. The lip portion 12 is formed integrally with the connecting portion 51b.

[0094] The outer shape of the connecting portion 51b is formed into a circular ring shape that is curved convexly toward the axial inner side from the end portion 11c of the axial outer side of the outer peripheral portion 11a and extends radially inward. The connecting portion 51b has a curved portion 54, for example, on the radial outer peripheral side. The outer shape of the curved portion 54 is formed into a circular ring shape that is curved convexly toward the inner side of the axial direction D.

[0095] The curved portion 54 includes, for example, a curved outer peripheral portion 54b extending from an axially outer end 11c of the outer peripheral portion 11a toward an inner distal end 54a of the curved portion 54, and a curved inner peripheral portion 54c extending from the inner distal end 54a toward an end 51d of the connecting portion 51b.

[0096] The curved portion 54 is arranged on the radially outer peripheral side of the connecting portion 51b, so that the inner tip portion 54a of the curved portion 54 is arranged between the outer peripheral portion 11a and the lip portion 12 and closer to the radially outer peripheral side. Accordingly, the area of ​​the inner surface 54C of the curved inner peripheral portion 54c is formed to be relatively larger than the area of ​​the inner surface 54B of the curved outer peripheral portion 54b.

[0097] In addition, the direction (pressure direction) of the internal pressure IP acting on the inner surface 54B of the curved outer peripheral portion 54b is toward the axial outer side and the radial inner side. The direction (pressure direction) of the internal pressure IP acting on the inner surface 54C of the curved inner peripheral portion 54c is toward the axial outer side and the radial outer side. In addition, the internal pressure IP is, for example, the pressure of the internal space of the rotary machine 1.

[0098] Thus, the force pressing the outer peripheral portion 11 a against the inner peripheral surface 2A of the housing 2 acts on the curved portion 54 supplemented by the internal pressure IP.

[0099] As described above, in the sealing structure of the rotary machine 1 of the second embodiment, the sealing member 50 includes the curved portion 54 curved in a convex shape toward the axial inner side on the radial outer peripheral side of the connecting portion 51b connecting the outer peripheral portion 11a and the lip portion 12. Thus, the force of pressing the outer peripheral portion 11a against the inner peripheral surface 2A of the housing 2 is supplemented by the internal pressure IP on the curved portion 54. For example, compared with the case where the connecting portion 11b of the first embodiment does not include the curved portion 54, the sealing member 50 is pressed more strongly toward the housing 2, thereby preventing the sealing member 50 from being separated outward in the axial direction D.

[0100] In addition, the bent portion 54 is formed in the connecting portion 51b, so the connecting portion 51b supplements the base portion 51 with a force pressing the housing 2. For example, compared with a case where the bent portion 54 is not formed in the connecting portion 51b, the sealing member 50 is pressed more strongly toward the housing 2, thereby preventing the sealing member 50 from being separated outward in the axial direction D.

[0101] Furthermore, in the above-described second embodiment, the sealing member 50 includes one bent portion 54 in the connecting portion 51 b , but the present invention is not limited thereto, and a plurality of bent portions may be included.

[0102] In the second embodiment, an increasing member may be provided to increase the force with which the lip 12 presses the housing 2 as the pressure in the housing 2 increases. The increasing member is not limited to being formed in the connection portion 51b as described above, but may be formed in other locations of the sealing member 50.

[0103] In addition, the enlarged part is not limited to the bent portion 54 formed in the connecting portion 51b as described above, and may have other structures. Thus, as the pressure in the housing 2 increases, the lip 12 presses the housing 2 more strongly, thereby preventing the sealing member 50 from coming off outward in the axial direction D.

[0104] (Third embodiment)

[0105] Below, while referring to the attached Figure 1 A third embodiment of the sealing structure for a rotary machine according to the present invention will be described. The same components as those of the first embodiment are denoted by the same reference numerals and their description will be omitted or simplified.

[0106] Figure 5 It is a cross-sectional view of a sealing member 60 according to the third embodiment.

[0107] like Figure 5 As shown, the sealing member 60 of the third embodiment is formed into the same shape as the sealing member 10 of the first embodiment described above in the natural state before being mounted and fixed to the housing 2. In addition, similarly to the modified example of the first embodiment described above, the inner peripheral surface 2A of the inner peripheral portion 2a of the housing 2 that contacts the sealing member 60 is parallel to the axial direction D.

[0108] The third embodiment is different from the first embodiment and the modified example described above in that the thermal expansion coefficient of the sealing member 60 is relatively larger than the thermal expansion coefficient of the housing 2 .

[0109] For example, the core portion 21 of the sealing member 60 is formed of a metal material having a thermal expansion coefficient relatively larger than that of the housing 2 .

[0110] As described above, in the sealing structure of the rotary machine 1 of the third embodiment, the thermal expansion coefficient of the sealing member 60 is relatively larger than the thermal expansion coefficient of the housing 2. As a result, the sealing member 60 is more likely to expand than the housing 2 when the temperature rises due to the operation of the rotary machine 1. For example, compared with a case where the thermal expansion coefficients of the sealing member 60 and the housing 2 are substantially the same or a case where the thermal expansion coefficient of the sealing member 60 is relatively smaller than the thermal expansion coefficient of the housing 2, the sealing member 60 is more strongly held by the housing 2, thereby preventing the sealing member 60 from escaping to the outside in the axial direction D.

[0111] In addition, in the above-mentioned third embodiment, the core 21 is formed of a metal material having a thermal expansion coefficient relatively larger than the thermal expansion coefficient of the shell 2, but is not limited to this. For example, the core 21 can also be formed of a raw material such as a resin material having a thermal expansion coefficient relatively larger than the thermal expansion coefficient of the shell 2.

[0112] In the third embodiment described above, the thermal expansion coefficient of the core 21 is larger than that of the shell 2, but the present invention is not limited thereto. For example, the thermal expansion coefficient of the cladding 22 may be larger than that of the shell 2 instead of the core 21, or the thermal expansion coefficient of the cladding 22 may be larger than that of the shell 2 in addition to the core 21.

[0113] In addition, in the third embodiment described above, at least a portion of the outer peripheral portion 11a, the connecting portion 11b, and the lip portion 12 of the base portion 11 constituting the sealing member 60 may be formed of a raw material having a thermal expansion coefficient greater than that of the housing 2. Thus, at least a portion of the outer peripheral portion 11a, the connecting portion 11b, and the lip portion 12 of the base portion 11 constituting the sealing member 60 is more likely to expand than the housing 2 when the temperature rises. For example, compared with a case where the thermal expansion coefficients of the lip portion 12 and the base portion 11 are substantially the same as the thermal expansion coefficient of the housing 2 or a case where the thermal expansion coefficients of the lip portion 12 and the base portion 11 are smaller than the thermal expansion coefficient of the housing 2, the sealing member 60 is more strongly held by the housing 2, thereby preventing the sealing member 60 from escaping to the outside in the axial direction D.

[0114] In addition, in the third embodiment described above, an increasing member may be provided to increase the force with which the lip 12 presses the housing 2 as the temperature inside the housing 2 rises. The increasing member is not limited to the case where at least a portion of the sealing member 60 is formed of a material having a thermal expansion coefficient greater than that of the housing 2 as described above, and may have other structures. Thus, as the temperature inside the housing 2 rises, the lip 12 presses the housing 2 more strongly, thereby preventing the sealing member 60 from detaching to the outside in the axial direction D.

[0115] In the above-described embodiments and modifications, the rotary machine 1 may be, for example, a speed reducer such as an eccentric oscillating speed reducer or a rotary electric machine.

[0116] In addition, in each of the above-mentioned embodiments and modifications, each of the sealing members 10 , 50 , 60 may be attached and fixed to a member such as a motor flange and an oil seal flange instead of being attached and fixed to the housing 2 .

[0117] In addition, in each of the above-mentioned embodiments and modifications, each sealing member 10 , 50 , 60 may be simply referred to as each sealing member 10 , 50 , 60 .

[0118] The embodiments of the present invention are provided as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the main purpose of the invention. These embodiments and their variations are included in the scope and main purpose of the invention, and are also included in the schemes recorded in the claims and their equivalents.

Claims

1. A sealing structure comprising: case; A shaft member disposed inside the housing; a sealing member that seals between the housing and the shaft member; and a connecting portion connecting an outer peripheral portion of the sealing member in contact with the housing and an inner peripheral portion of the sealing member in contact with the shaft member, and being curved inward in the axial direction in a convex shape, The outer peripheral portion and the connecting portion of the sealing member have a buried core portion, The core is formed of a metallic elastic material, The connecting portion includes a curved portion on the outer peripheral side thereof, the curved portion being curved in a convex shape toward the inner side in the axial direction. The bent portion has: a curved outer peripheral portion extending from an axially outer end portion of the outer peripheral portion to an inner front end portion of the curved portion; and a curved inner peripheral portion, which is folded back from the inner top end portion and extends to the axially outer end portion of the inner peripheral portion, The outer peripheral portion and the curved outer peripheral portion extend in the axial direction, The curved inner peripheral portion extends in a direction intersecting the axial direction, The area of ​​the surface of the curved inner peripheral portion located on the inner peripheral portion side is larger than the area of ​​the surface of the curved outer peripheral portion located on the outer peripheral portion side. The core portion is embedded from an end portion on the inner side of the outer peripheral portion in the axial direction to an end portion on the inner peripheral portion side of the curved inner peripheral portion via the curved outer peripheral portion and the curved inner peripheral portion.

2. The sealing structure according to claim 1, wherein: The sealing member has a thermal expansion coefficient greater than a thermal expansion coefficient of the housing.

3. A seal, comprising: a lip portion for contacting a member disposed on the inner periphery of the housing; A base portion, which is used to be fixed to the housing; a connecting portion connecting the base portion and the lip portion; and an enlarging member formed at the connecting portion, which increases the force with which the lip portion presses the housing as the pressure in the housing increases, The base portion and the connecting portion of the seal have an embedded core portion, The core is formed of a metallic elastic material, The enlarged member includes a curved portion that is curved inwardly in a convex shape in the axial direction. The bent portion has: a curved outer peripheral portion extending from the axially outer end of the base portion to an inner top end portion of the curved portion; and a curved inner peripheral portion, which is folded back from the inner top end portion and extends to the axially outer end portion of the lip portion, The base portion and the curved outer peripheral portion extend in the axial direction, The curved inner peripheral portion extends in a direction intersecting the axial direction, The area of ​​the surface of the curved inner peripheral portion located on the lip portion side is larger than the area of ​​the surface of the curved outer peripheral portion located on the base portion side. The core portion is embedded from an inner end portion of the base portion in the axial direction to an end portion of the curved inner peripheral portion on the lip portion side via the curved outer peripheral portion and the curved inner peripheral portion.

4. The seal according to claim 3, wherein: The increasing member increases the force with which the lip portion presses the housing as the temperature inside the housing increases.

5. The seal according to claim 4, wherein: The enlarged member is formed of a material that forms at least a part of the lip portion, the base portion, and the connecting portion and has a thermal expansion coefficient greater than that of the housing.

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