CN107806516B

CN107806516B - Device comprising a sealing member

Info

Publication number: CN107806516B
Application number: CN201710775495.9A
Authority: CN
Inventors: 纪平诚人
Original assignee: Nabtesco Corp
Current assignee: Nabtesco Corp
Priority date: 2016-09-08
Filing date: 2017-08-31
Publication date: 2021-06-29
Anticipated expiration: 2037-08-31
Also published as: TW201816309A; JP6807684B2; KR20180028375A; JP2018040436A; TWI732026B; DE102017213785A1; KR102430244B1; CN107806516A

Abstract

Disclosed are a sealing body, a sealing adapter, and a sealing member that prevent fluid from flowing between an external space on the outside of a device and an internal space on the inside of the device. The sealing body is provided with: a sealing member having a sealing portion crimped to a surface of the device; a preventing part which prevents foreign matters generated in the inner space from entering between the sealing part and the surface of the device.

Description

Device comprising a sealing member

Technical Field

The present invention relates to a seal body, a seal adapter, and a seal member for preventing a fluid contained in a device from flowing out and a fluid from flowing into the device.

Background

Sealing members are used in various technical fields. For example, the sealing member is used to prevent oil sealed inside the device from leaking. Alternatively, the sealing member is used to prevent the liquid from flowing into the device (Japanese unexamined patent publication No. 62-100374).

The sealing member in jp 62-100374 a has two portions that abut against the outer peripheral surface of the rotating shaft. One of the two regions is the main lip. The other of the two parts is a dust lip. Since the dust lip abuts the outer peripheral surface of the rotary shaft at a position outside the main lip, foreign matter (e.g., dust) floating outside the device is less likely to reach the main lip.

Fine foreign matter may be generated from parts disposed inside the apparatus while the apparatus is in use. For example, iron powder is generated from tooth surfaces of gears arranged inside the device. The dust lip of jp 62-100374 a does not contribute to preventing foreign matter generated inside the device from reaching the main lip. Therefore, foreign matter generated inside the device may enter the boundary between the main lip and the rotating shaft. In this case, the foreign matter may damage the outer peripheral surface of the main lip and/or the rotary shaft. The friction of the outer peripheral surface of the main lip and/or the rotary shaft significantly degrades the sealing performance of the seal member.

Disclosure of Invention

The invention aims to provide a technology which is not easy to cause the reduction of sealing performance caused by foreign matters generated in the device.

The sealing body according to an aspect of the present invention prevents a fluid from flowing between an outer space outside a device and an inner space inside the device. The sealing body is provided with: a sealing member having a sealing portion crimped to a surface of the device; a prevention part that prevents foreign matter generated in the inner space from entering between the sealing part and the surface of the device.

A seal adapter according to another aspect of the present invention is disposed between a housing of the device and a shaft inserted into a through hole formed in the housing. The seal adapter includes the seal body and an attachment portion attached to the housing. The mounting portion includes an inner peripheral surface surrounding the shaft. The shaft has an outer peripheral surface as the surface of the device. The annular space is formed between the outer peripheral surface of the shaft and the inner peripheral surface of the mounting portion.

A seal member according to still another aspect of the present invention is disposed in an annular space formed in an apparatus, and prevents fluid from flowing between an outer space outside the apparatus and an inner space inside the apparatus. The sealing member includes: an annular main lip having a sealing portion crimped to a surface of the device; a pressing portion that presses the main lip against the surface of the device; a dust lip pressed against the surface of the device at a position outside the main lip. The inner diameter of the dust lip is smaller than that of the sealing part.

The sealing technique described above can make it difficult for the sealing performance to be reduced by foreign matter generated inside the device.

Drawings

Fig. 1 is a schematic cross-sectional view of a seal body according to embodiment 1.

Fig. 2 is a schematic cross-sectional view of the seal body according to embodiment 2.

Fig. 3 is a schematic cross-sectional view of the sealing body according to embodiment 3.

Fig. 4 is a schematic sectional view of the sealing adapter of embodiment 4.

Fig. 5 is a schematic view of a mounting process for mounting the shaft to the seal adapter.

Fig. 6 is a schematic view of an attachment process of attaching an assembly of a shaft and a seal adapter to a housing.

Fig. 7 is a schematic cross-sectional view of the seal member according to embodiment 5.

Detailed Description

< embodiment 1 >

The present inventors have developed a technique for preventing the reduction of sealing performance due to foreign matter generated inside the device. In embodiment 1, an exemplary sealing body capable of maintaining good sealing performance for a long period of time will be described.

Fig. 1 is a schematic cross-sectional view of a seal body 100 according to embodiment 1. The sealing body 100 will be described with reference to fig. 1.

The sealing body 100 shown in fig. 1 is incorporated into the apparatus APT. The device APT comprises a shaft SFT and a housing HSG. In the following description, a space surrounded by the housing HSG and the shaft SFT is referred to as an "internal space". The space outside the housing HSG is referred to as "external space".

If the housing HSG is fixed, the shaft SFT rotates about the rotation axis RAX. If the shaft SFT is fixed, the housing HSG rotates about the rotation axis RAX. The apparatus APT may be a retarder or other apparatus. The principle of the present embodiment is not limited to a specific mechanism used as the apparatus APT.

The seal body 100 is annular as a whole. The shaft SFT is cylindrical as a whole. The shaft SFT includes an outer peripheral surface OSF against which the seal body 100 abuts. The housing HSG is cylindrical in shape as a whole. The housing HSG includes a 1 st inner circumferential surface FIS, a 2 nd inner circumferential surface SIS, and a shoulder surface SSF. The 1 st inner circumferential surface FIS surrounds the shaft SFT between the outer space and the inner space to form an annular space. The seal body 100 is fitted into an annular space formed between the outer peripheral surface OSF and the 1 st inner peripheral surface FIS. The 2 nd inner peripheral surface SIS surrounds the shaft SFT at a position inward of the 1 st inner peripheral surface FIS in the axial direction of the shaft SFT. At least a part of the internal space is formed between the 2 nd inner peripheral surface SIS and the outer peripheral surface OSF. The diameter of the 2 nd inner peripheral surface SIS is smaller than the diameter of the 1 st inner peripheral surface FIS. Thus, the shoulder surface SSF is formed between the 1 st inner circumferential surface FIS and the 2 nd inner circumferential surface SIS. The shoulder surface SSF is an annular surface along an imaginary plane orthogonal to the rotation axis RAX.

The lubricating oil is contained in the internal space. The lubricating oil may be used for lubricating parts (not shown; e.g., gears) of the apparatus APT disposed in the internal space. The principle of the present embodiment is not limited to a specific component lubricated with the lubricating oil.

The seal body 100 is inserted into the annular space to isolate the interior space from the exterior space. As a result, the lubricant oil from the internal space is prevented from flowing out by the seal body 100. When a liquid (e.g., a cleaning liquid) spreads around the apparatus APT, the sealing body 100 prevents the liquid existing in the external space from flowing into the internal space.

The seal body 100 includes an annular seal member 200 and an annular prevention ring 300. The seal member 200 and the prevention ring 300 are disposed in an annular space formed between the 1 st inner peripheral surface FIS of the housing HSG and the outer peripheral surface OSF of the shaft SFT. The prevention ring 300 is disposed inward of the seal member 200 in the axial direction of the shaft SFT. I.e. to prevent the ring 300 from facing the inner space. On the other hand, the sealing member 200 faces the external space.

The seal member 200 includes a main ring portion 210, an annular main lip 220, an annular dust lip 230, and a spring ring 240. The main ring portion 210 has a substantially L-shaped cross section on an imaginary plane including the rotation axis RAX. The main ring portion 210 includes a metal ring 211 and a cladding layer 212. The metal ring 211 has a substantially L-shaped cross section on an imaginary plane including the rotation axis RAX. The cladding layer 212 entirely covers the metal ring 211. The covering layer 212 may be formed of a rubber material or a resin having elasticity.

The coating layer 212 forms a 1 st contact surface 213, a 2 nd contact surface 214, an outer surface 215, an inner surface 216, and an inner circumferential surface 217. The 1 st abutment surface 213 is connected to one end in the 2 nd abutment surface 214 in the axial direction, and extends from the one end in the radial direction so as to oppose the prevention ring 300. The 1 st contact surface 213 contacts the outer peripheral region of the prevention ring 300, and presses the outer peripheral region of the prevention ring 300 against the shoulder surface SSF of the housing HSG. Thus, the prevention ring 300 is fixed between the sealing member 200 and the shoulder surface SSF.

The 2 nd contact surface 214 is a surface facing the 1 st inner circumferential surface FIS side of the housing HSG, and extends in the axial direction along the 1 st inner circumferential surface FIS. The 2 nd contact surface 214 contacts the 1 st inner peripheral surface FIS of the housing HSG. The area of the region where the 2 nd abutment surface 214 contacts the 1 st inner peripheral surface FIS is larger than the area of the region where the main lip 220 and the dust lip 230 contact the outer peripheral surface OSF of the shaft SFT. Thus, the 2 nd abutment surface 214 is fixed with respect to the 1 st inner peripheral surface FIS, and the main lip 220 and the dust lip 230 slide on the outer peripheral surface OSF.

The outer surface 215 faces the opposite side of the 1 st abutment surface 213, and is exposed to the outside space. The outer surface 215 is connected to the other end (the end on the opposite side to the end to which the 1 st abutment surface 213 is connected) in the 2 nd abutment surface 214 in the axial direction, and extends from the other end in the radial direction.

The inner surface 216 includes: a 1 st region 218 that extends from a radially inner end of the 1 st abutment surface 213 toward the outer surface 215 and faces the outer peripheral surface OSF of the shaft SFT; and a 2 nd region 219 that expands from the 1 st region 218 toward the outer peripheral surface OSF of the shaft SFT and opposes the prevention ring 300.

The inner circumferential surface 217 is connected to a radially inner end of the outer surface 215 and extends axially inward therefrom. The inner peripheral surface 217 is radially opposed to the outer peripheral surface OSF.

The dust lip 230 is formed between the inner peripheral surface 217 and the outer peripheral surface OSF. The dust lip 230 protrudes in a direction from the inner peripheral surface 217 of the coating layer 212 toward the outer peripheral surface OSF of the shaft SFT and toward the outer space. The dust lip 230 is pressed against the outer peripheral surface OSF of the shaft SFT, and prevents foreign matter floating in the external space from reaching the main lip 220. The dust lip 230 may also be formed of the same material as the cladding layer 212.

The primary lip 220 may also be formed of the same material as the cladding layer 212. The main lip 220 is located axially inward of the dust lip 230, and includes a pressure contact portion 221 and a coupling portion 222. The pressure contact part 221 is connected to the dust lip 230 by the connection part 222, and is pressed against the outer peripheral surface OSF of the shaft SFT between the dust lip 230 and the prevention ring 300. The main lip 220 prevents liquid from flowing in toward the interior space via the dust lip 230. Further, the main lip 220 prevents the lubricating oil from flowing out toward the external space via the prevention ring 300. In the present embodiment, the surface region of the main lip 220 is an example of a seal portion that is pressed against the surface of the apparatus APT. The surface of the device is exemplified by the outer peripheral surface OSF of the shaft SFT.

The connection portion 222 protrudes from the inner surface 216 of the main ring portion 210 toward the axially inner side (i.e., toward the prevention ring 300), and is connected to the pressure-bonding portion 221. As described above, the dust lip 230 prevents entry of foreign matter floating in the external space, and therefore, the foreign matter hardly enters the space surrounded by the dust lip 230, the coupling portion 222, the pressure-bonding portion 221, and the outer peripheral surface OSF of the shaft SFT.

The spring coil 240 is fitted into an annular groove formed in the outer peripheral surface of the crimping portion 221 of the main lip 220 (i.e., the surface opposite to the 1 st region 218 of the inner surface 216 of the main ring portion 210 in the radial direction). If the shaft SFT is inserted into the sealing member 200, the spring coil 240 is elastically extended. As a result, a force toward the rotation axis RAX acts on the pressure-bonding section 221. The crimping portion 221 is elastically compressively deformed. Thus, a good sealing structure is formed at the boundary between the crimping part 221 and the outer peripheral surface OSF of the shaft SFT. In this embodiment, the pressing portion is exemplified by a spring coil 240. Alternatively, the pressing portion may be formed of another member that elastically elongates in accordance with the insertion of the shaft SFT. The principle of the present embodiment is not limited to a specific component used for the pressing portion.

The prevention ring 300 includes a ring wall 310 and a lip 320. The annular wall 310 includes an inner abutment surface 311, an outer abutment surface 312, an outer circumferential surface 313, and an inner circumferential surface 314.

The outer peripheral surface 313 extends in the axial direction and abuts against the 1 st inner peripheral surface FIS of the housing HSG. The inner abutment surface 311 is continuous with one end in the axial direction in the outer peripheral surface 313, and extends from the one end toward the radially inner side. The inner abutment surface 311 includes an outer circumferential region that abuts against the shoulder surface SSF of the housing HSG in the vicinity of the outer circumferential surface 313 and an inner circumferential region that faces the internal space.

The outer contact surface 312 is a surface facing the opposite side of the inner contact surface 311 in the axial direction. The outer abutment surface 312 is continuous with the other end (the end on the opposite side from the end to which the inner abutment surface 311 is continuous) in the axial direction of the outer peripheral surface 313, and extends radially inward from the other end. The outer abutment surface 312 includes: an outer peripheral region that abuts against the 1 st abutment surface 213 of the seal member 200; an inner peripheral region axially opposite the 2 nd region 219 of the inner surface 216 of the seal member 200.

The inner peripheral surface 314 is a surface facing the side opposite to the outer peripheral surface 313 in the radial direction. The diameter of the inner peripheral surface 314 is larger than the diameter of the shaft SFT. The inner peripheral surface 314 radially faces the outer peripheral surface OSF of the shaft SFT. The lip 320 is located between the inner peripheral surface 314 and the outer peripheral surface OSF.

The annular wall 310 includes an annular elastic wall 315 and a rigid ring 316. The elastic wall 315 forms an outer circumferential surface 313, an inner circumferential surface 314, and an inner abutment surface 311. Furthermore, the elastic wall 315 forms a part of the outer abutment surface 312.

The rigid ring 316 is more rigid than the elastic wall 315. The elastic wall 315 is formed of a rubber material or a resin material having elasticity, and the rigid ring 316 may be formed of a metal or a hard resin. The rigid ring 316 maintains the shape of the annular wall 310, and therefore, the worker can easily dispose the prevention ring 300 in the apparatus APT. The principles of this embodiment are not limited to the particular materials utilized for the flexible wall 315 and the rigid ring 316.

The rigid ring 316 is fitted into a groove recessed in a region of the elastic wall 315 on the side opposite to the inner circumferential surface 314. As a result, the rigid ring 316 is fixed to the elastic wall 315 so as to surround the inner circumferential surface 314.

The lip 320 is integrally formed with the resilient wall 315. The lip 320 may also be formed of the same material as the resilient wall 315. The lip 320 protrudes from the inner peripheral surface 314 of the annular wall 310 (the inner peripheral edge of the elastic wall 315) toward the shaft SFT. The lip portion 320 is slightly bent toward the inner space in the vicinity of the outer peripheral surface OSF of the shaft SFT, and is pressed against the outer peripheral surface OSF. As a result, the crimping portion 221 is prevented from isolating the ring 300 from the internal space. In the present embodiment, the inner periphery is exemplified by the inner peripheral surface 314 of the annular wall 310.

Fig. 1 shows iron powder IPD generated in the internal space. For example iron powder IPD is produced from the tooth surfaces of the gears arranged in the device APT. The principle of the present embodiment is not limited to a specific generation source for generating the iron powder IPD.

The iron powder IPD may enter a boundary between the crimp part 221 and the outer peripheral surface OSF of the shaft SFT as a foreign matter. However, as shown in fig. 1, the lip 320 intercepts the iron powder IPD, and thus, the iron powder IPD hardly enters a space formed between the prevention ring 300 and the sealing member 200. Thus, there is very little risk that the iron powder IPD causes friction at the boundary between the crimp part 221 and the outer circumferential surface OSF of the shaft SFT. As a result, the sealing body 100 can exhibit good sealing performance for a long period of time. In the present embodiment, the prevention portion is exemplified by the prevention ring 300.

The lip portion 320 may be pressed against the outer peripheral surface OSF of the shaft SFT with a force weaker than the press-fit portion 221. As a result, the frictional force generated between the shaft SFT and the seal body 100 is not unnecessarily high. In the present embodiment, the 1 st crimping force is exemplified by a compression force (i.e., a pressing force generated by the spring coil 240) acting on the crimping portion 221. The 2 nd crimping force is exemplified by a force of pressing the lip portion 320 against the outer peripheral surface OSF of the shaft SFT.

< embodiment 2 >

The prevention ring described in association with embodiment 1 has a composite structure composed of an elastic material and a rigid material. However, the prevention ring may be formed of a single material. In embodiment 2, an exemplary seal body having a check ring made of a single material will be described.

Fig. 2 is a schematic cross-sectional view of the seal body 100A according to embodiment 2. The sealing body 100A is explained with reference to fig. 2. The description of the above embodiments applies to elements labeled with the same reference numerals as those of the above embodiments.

The sealing body 100A includes the sealing member 200, as in embodiment 1. The description of embodiment 1 is applied to the seal member 200.

The seal body 100A further includes a prevention ring 300A. The prevention ring 300A is formed of a felt material as a whole.

The prevention ring 300A includes an inner abutment surface 311A, an outer abutment surface 312A, an outer peripheral surface 313A, and an inner peripheral surface 314A. The outer peripheral surface 313A extends in the axial direction and abuts the 1 st inner peripheral surface FIS of the housing HSG. The inner abutment surface 311A is continuous with one end in the axial direction of the outer peripheral surface 313A, and extends from the one end toward the radially inner side. The inner contact surface 311A includes an outer peripheral region that contacts the shoulder surface SSF of the housing HSG in the vicinity of the outer peripheral surface 313A, and an inner peripheral region that faces the inner space.

The outer contact surface 312A is a surface facing the opposite side of the inner contact surface 311A in the axial direction. The outer abutment surface 312A is continuous with the other end (the end on the opposite side from the end to which the inner abutment surface 311A is continuous) in the outer peripheral surface 313A in the axial direction, and extends from the other end toward the radially inner side. The outer abutment surface 312A includes: an outer peripheral region that abuts against the 1 st abutment surface 213 of the seal member 200; an inner peripheral region axially opposite the 2 nd region 219 of the inner surface 216 of the seal member 200.

The inner peripheral surface 314A is a surface facing the opposite side of the outer peripheral surface 313A in the radial direction. The inner peripheral surface 314A extends in the axial direction and abuts against the outer peripheral surface OSF of the shaft SFT. Thus, the sealing member 200 is prevented from being isolated from the inner space by the ring 300A.

As shown in fig. 2, the iron powder IPD floating in the internal space is captured by the inner contact surface 311A of the prevention ring 300A. Thus, the iron powder IPD hardly enters the gap between the prevention ring 300A and the seal member 200. Since the risk of the iron powder IPD causing friction at the boundary between the crimp part 221 and the outer peripheral surface OSF of the shaft SFT is very small, the seal body 100A can exhibit good sealing performance for a long period of time.

< embodiment 3 >

With the above-described embodiment, the prevention portion for intercepting foreign matter generated inside the apparatus is formed as a member separate from the sealing member. Alternatively, the prevention portion may be formed integrally with the seal member. In this case, the operator can easily attach the sealing body to the device. In embodiment 3, an exemplary sealing body having a prevention portion integrated with a sealing member will be described.

Fig. 3 is a schematic cross-sectional view of the seal body 100B according to embodiment 3. Referring to fig. 1 and 3, the sealing body 100B is explained. The description of the above embodiments applies to elements labeled with the same reference numerals as those of the above embodiments.

The seal body 100B includes an annular seal member 200B and a lip portion 320B. The lip 320B is used to catch the iron powder IPD, similarly to the lip 320 described with reference to fig. 1. Unlike the above-described embodiment, the lip 320B is integral with the seal member 200B. In the present embodiment, the prevention portion is exemplified by the lip portion 320B.

The seal member 200B includes the main ring portion 210, the dust lip 230, and the spring ring 240, as in embodiment 1. The description of embodiment 1 applies to these elements.

The seal member 200B also includes an annular main lip 220B. As in embodiment 1, the main lip 220B includes a coupling portion 222. The description of embodiment 1 is applied to the connection portion 222.

The main lip 220B also includes a crimp portion 221B. The crimp portion 221B is crimped to the outer peripheral surface OSF of the shaft SFT between the dust lip 230 and the lip portion 320B by the spring ring 240. The main lip 220B prevents liquid from flowing in toward the inner space via the dust lip 230. Further, the main lip 220B prevents the lubricating oil from flowing out toward the external space via the lip portion 320B. In the present embodiment, the surface region of the main lip 220B is an example of a seal portion that is pressed against the surface of the apparatus APT.

The lip 320B is formed integrally with the crimping portion 221B. The lip 320B protrudes from the pressure contact portion 221B toward the inner space and the outer peripheral surface OSF of the shaft SFT, and is pressed against the outer peripheral surface OSF of the shaft SFT.

The crimping portion 221B is surrounded by the spring ring 240, while the lip 320B is not surrounded by the spring ring 240. Thus, the pressing force generated due to the elastic deformation of the spring ring 240 acts strongly on the crimping portion 221B, and weakly acts on the lip portion 320B. As a result, the frictional force between the seal body 100B and the outer peripheral surface OSF of the shaft SFT is not unnecessarily high.

The surface area of the crimp portion 221B crimped to the outer peripheral surface OSF of the shaft SFT is isolated from the inner space and the outer space by the lip portion 320B and the dust prevention lip 230. Therefore, the iron powder IPD floating in the inner region and the foreign matter floating in the outer space are less likely to cause friction at the boundary between the pressure-bonding section 221 and the shaft SFT.

< embodiment 4 >

Since the dust lip is exposed to the external space, the worker can visually recognize whether or not the dust lip incorporated in the device is bent. However, since the lip portion for intercepting the foreign matter generated in the internal space is exposed to the internal space, the worker cannot visually recognize whether or not the lip portion of the sealing body is bent. When the lip portion is bent in the device, foreign matter floating in the internal space may reach the main lip, causing friction at the boundary between the shaft and the main lip. In embodiment 4, an exemplary technique for reducing the risk of the lip portion bending in the device will be described.

Fig. 4 is a schematic sectional view of a sealing adapter 400 according to embodiment 4. Referring to fig. 1, 3 and 4, a sealing adapter 400 is illustrated. The description of the above embodiments applies to elements labeled with the same reference numerals as the above embodiments.

The seal adapter 400 includes a seal body 100C, a bearing 410, a stopper ring 420, and an adapter tube 430. The seal 100C may be the seal 100 described with reference to fig. 1. Alternatively, the seal 100C may be the seal 100B described with reference to fig. 3. The description of the

seals

100, 100B is applied to the seal 100C.

Adapter barrel 430 includes an annular flange 431 and a retaining barrel 432. The flange 431 includes: an inner surface 441; an outer surface 442 facing the side opposite the inner surface 441; an inner peripheral surface 443 connecting an inner end of the inner surface 441 and an inner end of the outer surface 442; an outer peripheral surface 444 facing the opposite side of the inner surface 443; a shoulder surface 445 extending radially inward from the inner peripheral surface 443. The inner surface 441 abuts against a surface of a housing (not shown). The outer surface 442 on the side opposite to the inner surface 441 is exposed to the external space. A plurality of through-holes 446 extending from the outer surface 442 to the inner surface 441 are formed in the flange 431. The plurality of screws are inserted into the plurality of through holes 446, respectively, and are screwed into screw holes formed in the housing. As a result, the flange 431 is fixed to the housing. In the present embodiment, the mounting portion is exemplified by the flange 431.

Outer peripheral surface 444 surrounds inner peripheral surface 443. The axial length of the outer peripheral surface 444 substantially matches the depth of a circular recess (not shown) formed in the housing. The outer peripheral surface 444 has a diameter substantially equal to a diameter of a circular recess formed in the housing.

An inner peripheral surface 443 on the opposite side of the outer peripheral surface 444 forms a space into which a shaft (not shown) is inserted. The inner peripheral surface 443 has a diameter larger than that of the shaft. Thus, the inner circumferential surface 443 surrounds the shaft, and an annular space is formed between the inner circumferential surface 443 and an outer circumferential surface (not shown) of the shaft. The seal body 100C is fitted into the annular space.

The inner peripheral surface 443 has a diameter larger than the inner diameter of the holding cylinder 432. Thus, a shoulder surface 445 is formed between the inner peripheral surface 443 and the holding cylinder 432. The shoulder surface 445 is an annular surface formed along an imaginary plane orthogonal to the rotation axis RAX. The operator can press the seal body 100C against the shoulder surface 445 by pressing the seal body into the space formed by the inner peripheral surface 443.

The retention cylinder 432 extends from the shoulder surface 445 toward the interior space. The holding cylinder 432 includes a main portion 451 and a tip portion 452. The inner diameter of the tip portion 452 is smaller than the inner diameter of the main portion 451. Thus, the tip portion 452 protrudes from the main portion 451 toward the rotation axis RAX. The operator pushes the bearing 410 into the holding cylinder 432, and brings the bearing 410 into contact with the distal end portion 452.

The main portion 451 includes an inner circumferential surface 453 abutting against the outer race of the bearing 410. An annular groove surrounding the rotation axis RAX is formed in the inner circumferential surface 453. After the bearing 410 is fitted into the holding cylinder 432, the worker fits the stopper ring 420 into the annular groove formed in the inner circumferential surface 453. Since the stopper ring 420 and the distal end portion 452 sandwich the bearing 410, the bearing 410 is not displaced in the extending direction of the rotation axis RAX. After the operator mounts the stopper ring 420 to the holding cylinder 432, the sealing body 100C is fitted into the flange 431. As a result, the sealing adapter 400 is completed.

Fig. 5 is a schematic view of an attachment process for attaching the shaft SFT to the seal adapter 400. The mounting process is explained with reference to fig. 1, 3, and 5.

The shaft SFT is inserted into the seal adapter 400 in a direction from the external space toward the internal space (i.e., a direction from the outer surface 442 of the flange 431 toward the inner surface 441). The outer peripheral surface OSF of the shaft SFT abuts against the inner peripheral surface of the bearing 410 and is held by the bearing 410. Thus, the shaft SFT can rotate about the rotation axis RAX.

As described in connection with fig. 1 and 3, the

lips

320 and 320B protrude toward the internal space, and therefore the protruding direction of the

lips

320 and 320B coincides with the insertion direction of the shaft SFT. During the insertion of the shaft SFT, the

lips

320, 320B can maintain a posture of protruding toward the bearing 410, and therefore, the

lips

320, 320B are not easily bent.

Shaft SFT includes gear shaft GSF and shaft sleeve STT. The base end of the gear shaft GSF is fitted into the shaft sleeve STT. A gear portion GPT is formed at a tip end portion of the gear shaft GSF. The gear portion GPT meshes with other gears disposed in a device (not shown). The iron powder IPD described with reference to fig. 1 and 3 may be generated by meshing between the gear portion GPT and another gear.

The spindle STT includes a 1 st cartridge FTB and a 2 nd cartridge STB. The 2 nd canister portion STB extends from the 1 st canister portion FTB toward the interior space. The outer diameter of the 1 st barrel FTB is larger than the outer diameter of the 2 nd barrel STB. Thus, shoulder surface SLD is formed at the boundary between 1 st barrel FTB and 2 nd barrel STB. The operator inserts the shaft SFT into the seal adapter 400 until the shoulder surface SLD abuts against the bearing 410. As a result, the seal body 100C is accommodated in the annular space formed between the outer peripheral surface OSF of the 1 st tubular portion FTB and the inner peripheral surface 443 of the flange 431. The tips of the

lips

320 and 320B described with reference to fig. 1 and 3 are pressed against the outer peripheral surface OSF of the 1 st tube FTB. At this time, the bearing 410 is accommodated in an annular space formed between the inner peripheral surface 453 of the holding cylinder 432 and the outer peripheral surface OSF of the 2 nd cylinder STB. In the present embodiment, the surface of the device is exemplified by the outer peripheral surface OSF of the spindle STT.

As shown in the left side of fig. 5, an annular groove AGV is formed in the outer peripheral surface OSF of the 2 nd cylinder part STB. When the shoulder surface SLD abuts against the bearing 410, the annular groove AGV is exposed in the circular space surrounded by the tip end portion 452 of the holding cylinder 432. As shown in the right drawing of fig. 5, the operator fits the stopper ring SPR into the annular groove AGV. As a result, the inner ring of the bearing 410 is sandwiched between the shoulder surface SLD and the snap ring SPR. On the other hand, the outer ring of the bearing 410 is sandwiched between the tip portion 452 of the holding cylinder 432 and the stopper ring 420. Therefore, the bearing 410 is fixed in the holding cylinder 432 in the extending direction of the rotation axis RAX.

Fig. 6 is a schematic view of an attachment process of attaching the assembly of the shaft SFT and the seal adapter 400 to the housing HSH. The mounting process will be described with reference to fig. 1, 3 to 6.

The housing HSH includes: an outer end face OES; a concave surface RCS forming a step with respect to the outer end surface OES; and a retaining wall surface SWS extending in the axial direction from an inner end of the concave surface RCS. The outer end face OES is exposed to the outside space. The concave surface RCS is recessed from the outer end surface OES about the rotation axis RAX. The flange 431 is accommodated in a concave space surrounded by the concave surface RCS. The plurality of screws SCW are inserted through the plurality of through holes 446 (see fig. 4), and are screwed into screw holes formed in the concave surface RCS. As a result, the flange 431 is fixed to the housing HSH.

The holding wall surface SWS forms a through hole that forms a part of the internal space. The shaft SFT penetrates the through hole. The holding cylinder 432 is inserted into a through hole formed by the holding wall surface SWS. The holding cylinder 432 is supported by the holding wall surface SWS.

According to the principle of the present embodiment, the worker prepares the assembly of the shaft SFT and the seal adapter 400 and then fits the assembly into the housing HSH. As described with reference to fig. 5, the

lips

320 and 320B (see fig. 1 and 3) are not easily bent when the assembly is manufactured. When the assembly is mounted to the housing HSH, the adapter 430 is present between the sealing body 100C and the housing HSH, and therefore the sealing body 100C does not interfere with the housing HSH. Therefore, the

lips

320 and 320B are not bent, and can maintain the state of being crimped to the outer peripheral surface OSF of the shaft SFT. The

lips

320 and 320B can effectively catch the iron powder IPD (see fig. 1 and 3) generated from the gear portion GPT and other sliding contact portions, and therefore, the risk of the iron powder IPD damaging the sealing function of the seal body 100C is greatly reduced.

< embodiment 5 >

Grease is applied to reduce the frictional force between the dust lip and the shaft. As described in connection with embodiment 1, since the dust lip is disposed in the vicinity of the main lip, a grease layer may be formed at the boundary between the main lip and the shaft. In this case, the lubricating oil contained in the housing for reducing the frictional force between the gears can be in contact with the grease layer at the boundary between the main lip and the shaft. Although depending on the combination of the components of the lubricating oil and the grease, the contact of the lubricating oil with the grease layer is also attributed to the generation of sludge at the boundary between the main lip and the shaft. Sludge acts as a foreign body and can cause friction in the main lip. In embodiment 5, an exemplary technique for reducing the risk of sludge generation will be described.

Fig. 7 is a schematic cross-sectional view of a seal member 200D according to embodiment 5. Referring to fig. 7, the sealing member 200D is explained. The description of the above embodiments applies to elements labeled with the same reference numerals as those of the above embodiments.

As in embodiment 1, the seal member 200D includes a main ring portion 210, a main lip 220, and a spring ring 240. The description of embodiment 1 applies to these elements.

Fig. 7 shows the device APU. As in embodiment 1, the apparatus APU includes a housing HSG. The description of embodiment 1 applies to the housing HSG.

The apparatus APU further comprises a shaft SFU. The shaft SFU is surrounded by the housing HSG. The seal member 200D is fitted into an annular space formed between the housing HSG and the shaft SFU, and prevents fluid from flowing between the external space and the internal space.

The shaft SFU includes: 1 st outer peripheral surface FOS; a 2 nd outer peripheral surface SOS located axially outward of the 1 st outer peripheral surface FOS; and a tapered circumferential surface TPC which connects the 1 st outer circumferential surface FOS and the 2 nd outer circumferential surface SOS and is inclined so as to reduce the diameter of the shaft SFU toward the outside in the axial direction. At least a part of the internal space is formed between the housing HSG and the 1 st outer circumferential surface FOS. The main lip 220 is pressed against the 1 st outer circumferential surface FOS by the spring coil 240. In this embodiment, the pressing portion is exemplified by a spring coil 240.

The 2 nd outer circumferential surface SOS is locally exposed to the external space. The diameter of the 2 nd outer circumferential surface SOS is smaller than the diameter of the 1 st outer circumferential surface FOS. The tapered circumferential surface TPC forms a circumferential surface of a truncated cone that narrows from the 1 st outer circumferential surface FOS toward the 2 nd outer circumferential surface SOS.

The seal member 200D further includes a dust lip 230D extending from the inner peripheral surface 217 of the main ring portion 210 toward the No. 2 outer peripheral surface SOS. The dust lip 230D includes a tip portion 231 abutting on the 2 nd outer peripheral surface SOS. That is, the tip 231 is pressed against the surface of the shaft SFU at a position outside the main lip 220.

The inner diameter of the dust lip 230D defined by the tip portion 231 is smaller than the inner diameter of the main lip 220. As described above, the 2 nd outer peripheral surface SOS has a diameter smaller than the 1 st outer peripheral surface FOS, and therefore, the tip portion 231 is not pressed against the 2 nd outer peripheral surface SOS excessively strongly. In this embodiment, the surface of the device is exemplified by the 1 st outer peripheral surface FOS and the 2 nd outer peripheral surface SOS.

The operator can apply grease to the 2 nd outer circumferential surface SOS to reduce friction between the distal end 231 and the 2 nd outer circumferential surface SOS. The tapered circumferential surface TPC between the 1 st outer circumferential surface FOS and the 2 nd outer circumferential surface SOS prevents the grease applied to the 2 nd outer circumferential surface SOS from migrating toward the 1 st outer circumferential surface FOS. Therefore, the grease is less likely to contact the lubricating oil contained in the internal space. This means that the risk of the generation of sludge between the main lip 220 and the 1 st outer peripheral face FOS is reduced. As a result, the risk of friction between the main lip 220 and the 1 st outer circumferential surface FOS is also reduced.

The design principles described in connection with the various embodiments described above can be applied to various seal configurations. Some of the various features described in connection with 1 of the various embodiments described above may also be applied to the sealing technique described in connection with another embodiment.

The outline of the above embodiment is as follows.

The seal body of the above-described embodiment prevents a fluid from flowing between an external space outside the device and an internal space inside the device. The sealing body is provided with: a sealing member having a sealing portion crimped to a surface of the device; a prevention part that prevents foreign matter generated in the inner space from entering between the sealing part and the surface of the device.

According to the above configuration, since the sealing body includes the preventing portion that prevents foreign matter generated in the internal space from entering the sealing portion, a reduction in sealing performance due to foreign matter generated inside the device is less likely to occur.

With the above-described structure, the prevention portion may include a lip portion that is crimped to the surface of the device. The lip portion isolates the sealing portion from the interior space.

According to the above configuration, the lip portion pressed against the surface of the device separates the sealing portion from the internal space, and therefore, foreign matter generated in the internal space of the device is less likely to reach the sealing portion. Therefore, the sealing performance is less likely to be lowered by foreign matter generated inside the device.

With the above configuration, the sealing portion may be pressed against the surface of the device by the 1 st pressing force. The lip may be pressed by a 2 nd crimping force smaller than the 1 st crimping force.

According to the above configuration, the lip portion is pressed by the 2 nd press contact force smaller than the 1 st press contact force, and therefore, the frictional force between the sealing body and the surface of the device does not excessively increase. Therefore, the sealing body does not generate excessive resistance against the operation of the device.

In the above-described configuration, the prevention unit may be a prevention ring disposed in an annular space formed in the device. Also, the prevention ring may include: an annular elastic wall having an inner periphery from which the lip portion protrudes; and a rigid ring that is fixed to the elastic wall so as to surround the inner circumferential edge and has a rigidity higher than that of the elastic wall.

According to the above configuration, since the rigid ring having a rigidity higher than that of the elastic wall is fixed to the elastic wall so as to surround the inner peripheral edge of the elastic wall, the elastic wall is not easily deformed when the worker disposes the prevention ring in the annular space formed in the device. Therefore, the operator can easily attach the sealing body to the device. Since the lip portion formed integrally with the elastic wall protrudes from the inner peripheral edge of the elastic wall, if the worker disposes the prevention ring in an annular space formed in the device, the lip portion is pressed against the surface of the device. As a result, foreign matter generated in the internal space of the apparatus is less likely to reach the seal portion. Therefore, the sealing performance is less likely to be lowered by foreign matter generated inside the device.

In the above configuration, the prevention unit may be integrated with the seal member.

According to the above configuration, the preventing portion is integrated with the sealing member, and therefore, the sealing body can be easily attached to the device by an operator.

With regard to the above configuration, the sealing member may include: an annular pressure contact part having the seal part and arranged in an annular space formed in the device; a pressing part that presses the crimping part against the surface of the device. The lip may be integral with the crimp portion and protrude from the crimp portion toward the inner space.

According to the above configuration, the annular pressure-bonding section disposed in the annular space formed in the device is pressed against the surface of the device by the pressing section, and therefore the seal body can have a good sealing function. The lip is integrated with the pressure-bonding section, so that the operator can easily attach the sealing body to the device. The lip protrudes from the pressure-bonding section into the internal space and abuts against the surface of the device, and therefore the lip can prevent foreign matter generated in the device from reaching the pressure-bonding section. Therefore, the sealing performance is less likely to be lowered by foreign matter generated inside the device.

The seal adapter of the above-described embodiment is disposed between a housing of the device and a shaft inserted into a through hole formed in the housing, and includes: the above-mentioned seal body; a mounting portion mounted to the housing. The mounting portion includes an inner peripheral surface surrounding the shaft. The shaft has an outer peripheral surface as the surface of the device. The annular space is formed between the outer peripheral surface of the shaft and the inner peripheral surface of the mounting portion.

According to the above configuration, since the annular space in which the seal body is disposed is formed between the outer peripheral surface of the shaft and the inner peripheral surface of the mounting portion, when the operator mounts the mounting portion to the housing of the device and disposes the shaft in the housing, the inner space formed by the housing and the outer peripheral surface of the shaft is isolated from the outer space outside the device by the seal body. The sealing body has a prevention portion, and therefore, foreign matter generated in the internal space does not reach the sealing portion of the sealing member. Therefore, the sealing performance of the sealing portion can be maintained for a long period of time.

With regard to the above configuration, the seal adapter may further include: a holding cylinder extending from the mounting portion to the internal space; a bearing fitted between the holding cylinder and the outer peripheral surface of the shaft. The lip may protrude from the elastic wall or the crimp portion toward the bearing and be crimped to the outer peripheral surface of the shaft.

According to the above configuration, the bearing is fitted between the outer peripheral surface of the shaft and the holding cylinder extending from the mounting portion to the internal space, and therefore, the shaft can rotate within the housing. Alternatively, the housing can rotate about an axis. Since the lip portion protrudes from the elastic wall or the pressure-bonding section toward the bearing and is in pressure-bonding contact with the outer peripheral surface of the shaft, when the shaft is inserted into the bearing through the seal body by an operator, the insertion direction of the shaft coincides with the protruding direction of the lip portion. Therefore, the lip portion is less likely to bend on the outer peripheral surface of the shaft.

The sealing member of the above-described embodiment is disposed in an annular space formed in the apparatus, and prevents fluid from flowing between an outer space outside the apparatus and an inner space inside the apparatus. The sealing member includes: an annular main lip having a sealing portion crimped to a surface of the device; a pressing portion that presses the main lip against the surface of the device; and a dust lip that is pressed against the surface of the device at a position outside the main lip. The inner diameter of the dust lip is smaller than that of the sealing part.

In the above configuration, since the inner diameter of the dust lip is smaller than the inner diameter of the seal portion, a designer can design the surface of the device so that a step is formed between a portion where the dust lip abuts and a portion where the main lip abuts. Therefore, the grease applied to the boundary between the dust lip and the surface of the device is isolated by the step from the portion where the main lip abuts, and therefore, the risk of grease generation due to contact between the grease and the lubricating oil contained in the internal space of the device is greatly reduced. Since the sludge is less likely to be present at the boundary between the seal portion and the surface of the device, the sealing performance of the sludge generated inside the device is less likely to be degraded.

Claims

1. A device comprising a sealing member, wherein,

the device including the sealing member includes:

a housing;

a shaft surrounded by the housing;

the sealing member, which is disposed in an annular space formed between the housing and the shaft in the device and prevents a fluid from flowing between an external space outside the device and an internal space inside the device, includes:

an annular main lip having a sealing portion crimped to a surface of the device;

a pressing portion that presses the main lip against the surface of the device;

a dust lip that is pressed against the surface of the device at a position outside the main lip,

the inner diameter of the dust lip is smaller than that of the sealing part,

the shaft includes: a 1 st outer circumferential surface against which the main lip is pressed; a 2 nd outer peripheral surface located axially outward of the 1 st outer peripheral surface and having a diameter smaller than that of the 1 st outer peripheral surface, the 2 nd outer peripheral surface being in contact with a tip end portion of the dust lip; and a tapered circumferential surface that connects the 1 st outer circumferential surface and the 2 nd outer circumferential surface and is inclined so as to reduce the diameter of the shaft toward the outside in the axial direction.