JP6807684B2 - Seal adapter - Google Patents

Description

The present invention relates to a sealing technique for preventing the outflow of the fluid contained in the apparatus and the inflow of the fluid into the apparatus.

Sealing members are used in various technical fields. For example, the sealing member is used to prevent leakage of oil encapsulated inside the device. Alternatively, the sealing member is used to prevent the inflow of liquid into the device (Patent Document 1).

The seal member of Patent Document 1 has two portions that come into contact with the outer peripheral surface of the rotating shaft. One of the two parts is the main lip. The other of the two sites is dust strip. Since the dust strip abuts on the outer peripheral surface of the rotating shaft on the outside of the main lip, foreign matter (eg, dust) floating on the outside of the device is less likely to reach the main lip.

Jitsukaisho 62-100374

While the device is in use, small debris may be generated from parts located inside the device. For example, iron powder is generated from the tooth surface of a gear arranged inside the device. The dust strip of Patent Document 1 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 main lip and / or the outer peripheral surface of the rotating shaft. Scratching the outer peripheral surface of the main lip and / or the rotating shaft significantly reduces the sealing performance of the sealing member.

An object of the present invention is to provide a technique for making it difficult for deterioration of sealing performance due to foreign matter generated inside an apparatus to occur.

The seal adapter according to another aspect of the present invention includes a seal body that prevents fluid from flowing between an external space outside the device and an internal space inside the device, and a mounting portion attached to the housing of the device. , Equipped with. The seal body includes a seal member having a seal portion that is pressed against the surface of the device, and a prevention portion that prevents foreign matter generated in the internal space from entering the seal portion. The prevention portion includes a lip portion that is pressed against the surface of the device. The lip portion isolates the seal portion from the internal space. The prevention portion is a prevention ring arranged in an annular space formed in the device. The prevention ring is integrally formed with the lip portion, and is fixed to the elastic wall so as to surround the inner peripheral edge and an annular elastic wall having an inner peripheral edge on which the lip portion protrudes. Includes a rigid ring, which has a higher rigidity than the elastic wall. The mounting portion includes an inner peripheral surface surrounding the shaft of the device. 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, the annular space in which the seal body is arranged is formed between the outer peripheral surface of the shaft and the inner peripheral surface of the mounting portion, so that the operator attaches the mounting portion to the housing of the device. Moreover, when the shaft is arranged in the housing, the internal space formed by the housing and the outer peripheral surface of the shaft is separated from the external space outside the device by the sealing body. Since the seal body has a preventive portion, foreign matter generated in the internal space does not reach the seal portion of the seal member. Therefore, the sealing performance of the sealing portion is maintained for a long period of time.
With respect to the above configuration, the prevention portion may be integrated with the seal member.
According to the above configuration, since the prevention portion is integrated with the seal member, the operator can easily attach the seal body to the attachment portion.
The seal adapter according to still another aspect of the present invention includes a seal body that prevents fluid from flowing between an external space outside the device and an internal space inside the device, and a mounting portion attached to the housing of the device. And. The seal body includes a seal member having a seal portion that is pressed against the surface of the device, and a prevention portion that prevents foreign matter generated in the internal space from entering the seal portion. The prevention portion includes a lip portion that is pressed against the surface of the device. The lip portion isolates the seal portion from the internal space. The seal member has an annular main lip having the seal portion and arranged in the annular space formed in the apparatus, and a pressing portion for pressing the main lip against the surface of the apparatus. Including. The lip portion is integral with the main lip and projects from the main lip into the internal space. The mounting portion includes an inner peripheral surface surrounding the shaft of the device. 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, the annular space in which the seal body is arranged is formed between the outer peripheral surface of the shaft and the inner peripheral surface of the mounting portion, so that the operator attaches the mounting portion to the housing of the device. Moreover, when the shaft is arranged in the housing, the internal space formed by the housing and the outer peripheral surface of the shaft is separated from the external space outside the device by the sealing body. Since the seal body has a preventive portion, foreign matter generated in the internal space does not reach the seal portion of the seal member. Therefore, the sealing performance of the sealing portion is maintained for a long period of time.
With respect to the above configuration, the seal portion may be pressed against the surface of the device by a first pressure contact force. The lip portion may be pressed with a second pressure contact force smaller than the first pressure contact force.
According to the above configuration, since the lip portion is pressed by the second pressure contact force smaller than the first pressure contact force, the frictional force between the seal body and the surface of the device does not become excessively large. Therefore, the seal body of the seal adapter does not generate an excessively large drag against the operation of the device.

With respect to the above configuration, the seal adapter may further include a holding cylinder extending from the mounting portion to the internal space and a bearing fitted between the holding cylinder and the outer peripheral surface of the shaft. The lip portion may project from the elastic wall or the main lip toward the bearing and may be pressed against 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 into the internal space, so that the shaft can rotate in the housing. Alternatively, the housing can rotate around the shaft. The lip portion protrudes from the elastic wall or the main lip toward the bearing and is pressed against the outer peripheral surface of the shaft. Therefore, when the operator inserts the shaft into the bearing through the sealing body, the insertion direction of the shaft is the lip portion. Matches the protruding direction of. Therefore, the lip portion is less likely to bend on the outer peripheral surface of the shaft.

The above-mentioned sealing technique can make it difficult to cause deterioration of sealing performance due to foreign matter generated inside the device.

It is the schematic sectional drawing of the seal body of 1st Embodiment. It is the schematic sectional drawing of the seal body of 2nd Embodiment. It is the schematic sectional drawing of the seal body of 3rd Embodiment. It is the schematic sectional drawing of the seal adapter of 4th Embodiment. It is the schematic of the mounting process which attaches a shaft to a seal adapter. It is the schematic of the mounting process which attaches an assembly including a shaft and a seal adapter to a housing. It is the schematic sectional drawing of the seal member of 5th Embodiment.

<First Embodiment>
The present inventors have developed a technique for preventing deterioration of sealing performance due to foreign matter generated inside the device. In the first embodiment, an exemplary seal 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 the seal body 100 of the first embodiment. The seal body 100 will be described with reference to FIG.

The seal body 100 shown in FIG. 1 is incorporated in the device APT. The device APT includes a shaft SFT and a housing HSG. In the following description, the 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 the "exterior space".

If the housing HSG is fixed, the shaft SFT rotates about the axis of rotation RAX. If the shaft SFT is fixed, the housing HSG will rotate about the axis of rotation RAX. The device APT may be a speed reducer or another device. The principle of this embodiment is not limited to the specific mechanism used as the device APT.

The seal body 100 is generally annular. The shaft SFT is generally columnar. The shaft SFT includes an outer peripheral surface OSF to which the seal body 100 is in contact. The housing HSG has an overall cylindrical shape. The housing HSG includes a first inner peripheral surface FIS, a second inner peripheral surface SIS, and a shoulder surface SSF. The first inner peripheral 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 first inner peripheral surface FIS. The second inner peripheral surface SIS is inward of the first inner peripheral surface FIS and surrounds the shaft SFT. At least a part of the internal space is formed between the second inner peripheral surface SIS and the outer peripheral surface OSF. The second inner peripheral surface SIS is smaller in diameter than the first inner peripheral surface FIS. Therefore, the shoulder surface SSF is formed between the first inner peripheral surface FIS and the second inner peripheral surface SIS. The shoulder plane SSF is an annular plane along a virtual plane orthogonal to the rotation axis RAX.

The lubricating oil is housed in the internal space. Lubricating oil may be used to lubricate components of the device APT (not shown: eg gears) located in the interior space. The principle of this embodiment is not limited to specific parts lubricated by lubricating oil.

The seal body 100 is fitted in the annular space and separates the internal space from the external space. As a result, the outflow of the lubricating oil from the internal space is hindered by the seal body 100. If a liquid (eg, cleaning liquid) is sprayed around the device APT, the seal 100 prevents the liquid present in the exterior space from flowing into the interior 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 arranged in an annular space formed between the first inner peripheral surface FIS of the housing HSG and the outer peripheral surface OSF of the shaft SFT. The prevention ring 300 is arranged inward of the seal member 200. That is, the prevention ring 300 faces the internal space. On the other hand, the seal member 200 faces the external space.

The sealing member 200 includes a main ring portion 210, an annular main lip 220, an annular dust strip 230, and a spring ring 240. The main ring portion 210 has a substantially L-shaped cross section on a virtual plane including the rotation axis RAX. The main ring portion 210 includes a metal ring 211 and a coating layer 212. The metal ring 211 has a substantially L-shaped cross section on a virtual plane including the rotation axis RAX. The coating layer 212 covers the metal ring 211 as a whole. The coating layer 212 may be formed of a rubber material or an elastic resin.

The covering layer 212 forms a first contact surface 213, a second contact surface 214, an outer surface 215, an inner surface 216, and an inner peripheral surface 217. The first contact surface 213 abuts on 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. Therefore, the prevention ring 300 is fixed between the seal member 200 and the shoulder surface SSF. The second contact surface 214 abuts on the first inner peripheral surface FIS of the housing HSG. The area of the region where the second contact surface 214 contacts the first inner peripheral surface FIS is larger than the area of the region where the main lip 220 and the dust strip 230 contact the outer peripheral surface OSF of the shaft SFT. Therefore, the second contact surface 214 is fixed to the first inner peripheral surface FIS, while the main lip 220 and dust strip 230 slide on the outer peripheral surface OSF. The outer surface 215 is exposed to the external space. The inner surface 216 extends from the first contact surface 213 toward the outer surface 215, and extends from the first region 218 toward the outer peripheral surface OSF of the shaft SFT and the first region 218 surrounding the outer peripheral surface OSF of the shaft SFT. It also includes a second region 219 facing the prevention ring 300. The inner peripheral surface 217 faces the outer peripheral surface OSF. The dust strip 230 is formed between the inner peripheral surface 217 and the outer peripheral surface OSF.

The dust strip 230 projects from the inner peripheral surface 217 of the covering layer 212 in the direction toward the outer peripheral surface OSF of the shaft SFT and in the direction toward the outer space. The dust strip 230 is pressed against the OSF on the outer peripheral surface of the shaft SFT to prevent foreign matter floating in the external space from reaching the main lip 220. The dust strip 230 may be formed from the same material as the coating layer 212.

The main lip 220 may be formed of the same material as the coating layer 212. The main lip 220 includes a pressure contact portion 221 and a connecting portion 222. The pressure contact portion 221 is pressure-welded to the outer peripheral surface OSF of the shaft SFT between the dust strip 230 and the prevention ring 300. The main lip 220 prevents the inflow of liquid toward the internal space through the dust strip 230. In addition, the main lip 220 prevents the lubricating oil from flowing out to the external space through the prevention ring 300. In this embodiment, the seal portion is exemplified by the surface region of the main lip 220 that is pressed against the outer peripheral surface OSF. The surface of the device is exemplified by the outer peripheral surface OSF of the shaft SFT.

The connecting portion 222 projects inward (that is, toward the prevention ring 300) from the inner surface 216 of the main ring portion 210 and is connected to the pressure contact portion 221. As described above, the dust strip 230 prevents the intrusion of foreign matter floating in the external space, so that the foreign matter is mostly contained in the space surrounded by the dust strip 230, the connecting portion 222, the pressure contact portion 221 and the outer peripheral surface OSF of the shaft SFT. Don't get in.

The spring ring 240 is fitted into an annular groove formed on the outer peripheral surface of the pressure contact portion 221 of the main lip 220 (that is, the surface of the inner surface 216 of the main ring portion 210 facing the first region 218). When the shaft SFT is fitted into the seal member 200, the spring ring 240 is elastically extended. As a result, the force toward the rotation axis RAX acts on the pressure contact portion 221. The pressure contact portion 221 is elastically compressed and deformed. Therefore, a good sealing structure is formed at the boundary between the pressure contact portion 221 and the outer peripheral surface OSF of the shaft SFT. In this embodiment, the pressing portion is exemplified by a spring ring 240. Alternatively, the pressing portion may be formed by another member that is elastically stretched in response to the fitting of the shaft SFT. The principle of this 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 portion 320. The ring wall 310 includes an inner contact surface 311, an outer contact surface 312, an outer peripheral surface 313, and an inner peripheral surface 314. The outer peripheral surface 313 is in contact with the first inner peripheral surface FIS of the housing HSG. The inner contact surface 311 includes an outer peripheral region that is in contact with the shoulder surface SSF of the housing HSG near the outer peripheral surface 313 and an inner peripheral region that faces the internal space. The outer contact surface 312 on the opposite side of the inner contact surface 311 has an outer peripheral region that is in contact with the first contact surface 213 of the seal member 200 and an inner region that faces the second region 219 of the inner surface 216 of the seal member 200. Includes the circumferential region. The inner peripheral surface 314 on the opposite side of the outer peripheral surface 313 is larger in diameter than the shaft SFT. The inner peripheral surface 314 faces the outer peripheral surface OSF of the shaft SFT. The lip portion 320 is located between the inner peripheral surface 314 and the outer peripheral surface OSF.

The ring wall 310 includes an annular elastic wall 315 and a rigid ring 316. The elastic wall 315 forms an outer peripheral surface 313, an inner peripheral surface 314, and an inner contact surface 311. In addition, the elastic wall 315 forms part of the outer contact surface 312. The rigid ring 316 is greater in rigidity than the elastic wall 315. The elastic wall 315 may be formed of a rubber material or a resin material having elasticity, while the rigid ring 316 may be formed of a metal or a hard resin. Since the rigid ring 316 maintains the shape of the ring wall 310, the operator can easily place the prevention ring 300 within the device APT. The principle of this embodiment is not limited to the specific material used for the elastic wall 315 and the rigid ring 316.

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

The lip portion 320 is formed integrally with the elastic wall 315. The lip portion 320 may be formed of the same material as the elastic wall 315. The lip portion 320 projects from the inner peripheral surface 314 of the ring wall 310 toward the shaft SFT. The lip portion 320 is slightly bent toward the internal space near the outer peripheral surface OSF of the shaft SFT and is pressed against the outer peripheral surface OSF. As a result, the pressure contact portion 221 is separated from the internal space by the prevention ring 300. In this embodiment, the inner peripheral edge is exemplified by the inner peripheral surface 314 of the ring wall 310.

FIG. 1 shows an iron powder IPD generated in the internal space. For example, iron powder IPD arises from the tooth surface of a gear located within the device APT. The principle of this embodiment is not limited to a specific source for generating iron powder IPD.

The iron powder IPD may try to enter the boundary between the pressure contact portion 221 and the outer peripheral surface OSF of the shaft SFT as a foreign substance. However, as shown in FIG. 1, since the lip portion 320 dams the iron powder IPD, the iron powder IPD hardly enters the space formed between the prevention ring 300 and the seal member 200. Therefore, the risk of iron powder IPD causing scratches at the boundary between the pressure contact portion 221 and the outer peripheral surface OSF of the shaft SFT is very small. As a result, the sealing body 100 can exhibit good sealing performance for a long period of time. In this embodiment, the prevention unit 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 weaker force than the pressure contact portion 221. As a result, the frictional force generated between the shaft SFT and the seal body 100 does not become unnecessarily high. In the present embodiment, the first pressure contact force is exemplified by the compressive force acting on the pressure contact portion 221 (that is, the pressing force generated by the spring ring 240). The second pressure contact force is exemplified by a force that presses the lip portion 320 against the outer peripheral surface OSF of the shaft SFT.

<Second Embodiment>
The prevention ring described in connection with the first embodiment has a composite structure composed of an elastic material and a rigid material. However, the prevention ring may be formed from a single material. In a second embodiment, an exemplary seal body with a protective ring formed from a single material is described.

FIG. 2 is a schematic cross-sectional view of the seal body 100A of the second embodiment. The seal body 100A will be described with reference to FIG. The description of the above-described embodiment is incorporated into elements with the same reference numerals as those of the above-described embodiment.

Similar to the first embodiment, the seal body 100A includes a seal member 200. The description of the first embodiment is incorporated in the seal member 200.

The seal body 100A further includes a prevention ring 300A. The prevention ring 300A is entirely made of felt material.

The prevention ring 300A includes an inner contact surface 311A, an outer contact surface 312A, an outer peripheral surface 313A, and an inner peripheral surface 314A. The outer peripheral surface 313A is in contact with the first inner peripheral surface FIS of the housing HSG. The inner contact surface 311A includes an outer peripheral region that is in contact with the shoulder surface SSF of the housing HSG near the outer peripheral surface 313A and an inner peripheral region that faces the internal space. The outer contact surface 312A on the opposite side of the inner contact surface 311A has an outer peripheral region that is in contact with the first contact surface 213 of the seal member 200 and an inner region that faces the second region 219 of the inner surface 216 of the seal member 200. Includes the circumferential region. The inner peripheral surface 314A opposite to the outer peripheral surface 313A is in contact with the outer peripheral surface OSF of the shaft SFT. Therefore, the seal member 200 is separated from the internal space by the prevention 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. Therefore, the iron powder IPD hardly enters the gap between the prevention ring 300A and the seal member 200. Since the risk of iron powder IPD causing scratches at the boundary between the pressure contact portion 221 and the outer peripheral surface OSF of the shaft SFT is very small, the seal body 100A exhibits good sealing performance over a long period of time. Can be done.

<Third Embodiment>
With respect to the above-described embodiment, the prevention portion for blocking foreign matter generated inside the device is formed as a member different from the seal member. Alternatively, the preventive portion may be formed integrally with the seal member. In this case, the operator can easily attach the seal body to the device. In the third embodiment, an exemplary seal body having a preventive portion integrated with the seal member will be described.

FIG. 3 is a schematic cross-sectional view of the seal body 100B of the third embodiment. The seal body 100B will be described with reference to FIGS. 1 and 3. The description of the above-described embodiment is incorporated into elements with the same reference numerals as those of the above-described embodiment.

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

Similar to the first embodiment, the seal member 200B includes a main ring portion 210, a dust strip 230, and a spring ring 240. The description of the first embodiment is incorporated into these elements.

The sealing member 200B further includes an annular main lip 220B. Similar to the first embodiment, the main lip 220B includes a connecting portion 222. The description of the first embodiment is incorporated in the connecting portion 222.

The main lip 220B further includes a pressure contact portion 221B. The pressure contact portion 221B is pressure-welded to the outer peripheral surface OSF of the shaft SFT between the dust strip 230 and the lip portion 320B by the spring ring 240. The main lip 220B prevents the inflow of liquid toward the internal space through the dust strip 230. In addition, the main lip 220B prevents the lubricating oil from flowing out to the external space through the lip portion 320B. In this embodiment, the seal portion is exemplified by the surface region of the main lip 220B which is pressed against the outer peripheral surface OSF.

The lip portion 320B is integrally formed with the pressure contact portion 221B. The lip portion 320B projects from the pressure contact portion 221B toward the internal 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 pressure contact portion 221B is surrounded by the spring ring 240, while the lip portion 320B is not surrounded by the spring ring 240. Therefore, the pressing force generated by the elastic deformation of the spring ring 240 acts strongly on the pressure contact portion 221B, but acts weakly 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 does not increase unnecessarily.

The surface region of the pressure contact portion 221B that is pressed against the outer peripheral surface OSF of the shaft SFT is separated from the internal space and the external space by the lip portion 320B and the dust strip 230. Therefore, the iron powder IPD floating in the internal region and the foreign matter floating in the external space are less likely to cause scratches at the boundary between the pressure contact portion 221 and the shaft SFT.

<Fourth Embodiment>
Since the dust strip is exposed to the external space, the operator can visually recognize whether or not the dust strip incorporated in the device is bent. However, since the lip portion for blocking the foreign matter generated in the internal space is exposed in the internal space, the operator cannot visually recognize whether or not the lip portion is bent in the seal body. If the lip is bent in the device, foreign matter floating in the interior space can reach the main lip and cause scratches on the boundary between the shaft and the main lip. In the fourth embodiment, an exemplary technique for reducing the risk of the lip portion bending in the device will be described.

FIG. 4 is a schematic cross-sectional view of the seal adapter 400 of the fourth embodiment. The seal adapter 400 will be described with reference to FIGS. 1, 3 and 4. The description of the above-described embodiment is incorporated into elements with the same reference numerals as those of the above-described embodiment.

The seal adapter 400 includes a seal body 100C, a bearing 410, a retaining ring 420, and an adapter cylinder 430. The seal body 100C may be the seal body 100 described with reference to FIG. Alternatively, the seal body 100C may be the seal body 100B described with reference to FIG. The description regarding the seal bodies 100 and 100B is incorporated in the seal body 100C.

The adapter cylinder 430 includes an annular flange 431 and a holding cylinder 432. The flange 431 includes an inner surface 441, an outer surface 442, an inner peripheral surface 443, an outer peripheral surface 444, and a shoulder surface 445. The inner surface 441 is in contact with the surface of the housing (not shown). The outer surface 442 opposite to the inner surface 441 is exposed to the outer space. A plurality of insertion holes 446 extending from the outer surface 442 to the inner surface 441 are formed in the flange 431. The plurality of screws are each inserted into the plurality of insertion holes and screwed into the screw holes formed in the housing. As a result, the flange 431 is fixed to the housing. In this embodiment, the mounting portion is exemplified by the flange 431.

The outer peripheral surface 444 surrounds the inner peripheral surface 443. The axial length of the outer peripheral surface 444 substantially coincides with the depth of the circular recess (not shown) formed in the housing. The diameter of the outer peripheral surface 444 substantially matches the diameter of the circular recess formed in the housing.

The 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 diameter of the inner peripheral surface 443 is larger than the diameter of the shaft. Therefore, the inner peripheral surface 443 surrounds the shaft, and an annular space is formed between the inner peripheral surface 443 and the outer peripheral surface (not shown) of the shaft. The seal body 100C is fitted into the annular space.

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

The holding cylinder 432 extends from the shoulder surface 445 to the internal space. The holding cylinder 432 includes a main portion 451 and a tip portion 452. The tip portion 452 is smaller in inner diameter than the main portion 451. Therefore, the tip portion 452 protrudes from the main portion 451 toward the rotation shaft RAX. The operator pushes the bearing 410 into the holding cylinder 432 and brings it into contact with the tip portion 452.

The main portion 451 includes an inner peripheral surface 453 that abuts on the outer race of the bearing 410. An annular groove surrounding the rotating shaft RAX is formed on the inner peripheral surface 453. After fitting the bearing 410 into the holding cylinder 432, the operator fits the retaining ring 420 into the annular groove formed on the inner peripheral surface 453. Since the stop ring 420 and the tip portion 452 sandwich the bearing 410, the bearing 410 does not displace in the extending direction of the rotating shaft RAX. After attaching the retaining ring 420 to the holding cylinder 432, the operator fits the seal body 100C into the flange 431. As a result, the seal 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 will be described with reference to FIGS. 1, 3 and 5.

The shaft SFT is inserted into the seal adapter 400 in the direction from the outer space to the inner space (that is, the direction from the outer surface 442 to the inner surface 441 of the flange 431). The outer peripheral surface OSF of the shaft SFT abuts on the inner peripheral surface of the bearing 410 and is held by the bearing 410. Therefore, the shaft SFT can rotate about the rotation axis RAX.

As described in connection with FIGS. 1 and 3, since the lip portions 320 and 320B project toward the internal space, the projecting directions of the lip portions 320 and 320B coincide with the insertion direction of the shaft SFT. During the insertion of the shaft SFT, the lip portions 320 and 320B can maintain the posture of projecting toward the bearing 410, so that the lip portions 320 and 320B are less likely to bend.

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

The shaft cylinder STT includes a first cylinder portion FTB and a second cylinder portion STB. The second tubular portion STB extends from the first tubular portion FTB toward the internal space. The first cylinder portion FTB has a larger outer diameter than the second cylinder portion STB. Therefore, the shoulder surface SLD is formed at the boundary between the first tubular portion FTB and the second tubular portion STB. The operator inserts the shaft SFT into the seal adapter 400 until the shoulder SLD abuts on the bearing 410. As a result, the seal body 100C fits in the annular space formed between the outer peripheral surface OSF of the first tubular portion FTB and the inner peripheral surface 443 of the flange 431. The tips of the lip portions 320 and 320B described with reference to FIGS. 1 and 3 are pressed against the outer peripheral surface OSF of the first tubular portion FTB. At this time, the bearing 410 fits in the annular space formed between the inner peripheral surface 453 of the holding cylinder 432 and the outer peripheral surface OSF of the second cylinder portion STB. In this embodiment, the surface of the device is exemplified by the outer peripheral surface OSF of the shaft cylinder STT.

As shown in the left figure of FIG. 5, an annular groove AGV is formed on the outer peripheral surface OSF of the second tubular portion STB. When the shoulder surface SLD abuts on the bearing 410, the annular groove AGV appears in a circular space surrounded by the tip 452 of the holding cylinder 432. As shown in the right figure of FIG. 5, the operator fits the retaining ring SPR into the annular groove AGV. As a result, the inner race of the bearing 410 is sandwiched between the shoulder surface SLD and the retaining ring SPR. On the other hand, the outer race of the bearing 410 is sandwiched between the tip portion 452 of the holding cylinder 432 and the retaining ring 420. Therefore, the bearing 410 is fixed in the holding cylinder 432 in the extending direction of the rotating shaft RAX.

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

The housing HSH includes an outer end surface OES, a concave surface RCS, and a holding wall surface SWS. The outer end surface OES is exposed to the external space. The concave RCS is recessed from the outer end surface OES around the rotation shaft RAX. The flange 431 is housed in a recessed space surrounded by a recessed RCS. The plurality of screw SCWs are respectively inserted into the plurality of insertion holes 446 (see FIG. 4) and screwed into the screw holes formed in the concave 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 the 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 operator creates an assembly including the shaft SFT and the seal adapter 400, and then incorporates the assembly into the housing HSH. As described with reference to FIG. 5, the lip portions 320, 320B (see FIGS. 1 and 3) are less likely to bend when the assembly is made. At the time of assembling the assembly into the housing HSH, the adapter cylinder 430 exists between the seal body 100C and the housing HSH, so that the seal body 100C does not interfere with the housing HSH. Therefore, the lip portions 320 and 320B can be maintained in a state of being pressed against the outer peripheral surface OSF of the shaft SFT without being bent. Since the lip portions 320 and 320B can effectively block the iron powder IPD (see FIGS. 1 and 3) generated from the gear portion GPT and other sliding contact portions, the iron powder IPD is the seal body 100C. The risk of impairing the sealing function is greatly reduced.

<Fifth Embodiment>
Grease is applied to reduce the frictional force between the dust strip and the shaft. As described in connection with the first embodiment, since the dust strips are located near the main lip, a grease layer may also be formed at the boundary between the main lip and the shaft. In this case, the lubricating oil contained in the housing to reduce the frictional force between the gears may come into contact with the grease layer at the boundary between the main lip and the shaft. Depending on the combination of lubricating oil and grease components, contact of the lubricating oil with the grease layer can also result in sludge formation at the boundary between the main lip and the shaft. Sludge can act as a foreign body and cause scratches on the main lip. In a fifth embodiment, exemplary techniques for reducing the risk of sludge formation are described.

FIG. 7 is a schematic cross-sectional view of the seal member 200D of the fifth embodiment. The seal member 200D will be described with reference to FIG. The description of the above-described embodiment is incorporated into elements with the same reference numerals as those of the above-described embodiment.

Similar to the first embodiment, the seal member 200D includes a main ring portion 210, a main lip 220, and a spring ring 240. The description of the first embodiment is incorporated into these elements.

FIG. 7 shows the device APU. Similar to the first embodiment, the device APU includes a housing HSG. The description of the first embodiment is incorporated into the housing HSG.

The device APU further includes a shaft SFU. The shaft SFU is surrounded by a housing HSG. The seal member 200D is fitted in an annular space formed between the housing HSG and the shaft SFU to prevent fluid flow between the external space and the internal space.

The shaft SFU includes a first outer peripheral surface FOS, a second outer peripheral surface SOS, and a tapered peripheral surface TPC. At least a part of the internal space is formed between the housing HSG and the first outer peripheral surface FOS. The main lip 220 is pressed against the first outer peripheral surface FOS by the spring ring 240. In this embodiment, the pressing portion is exemplified by a spring ring 240.

The second outer peripheral surface SOS is partially exposed to the external space. The second outer peripheral surface SOS is smaller in diameter than the first outer peripheral surface FOS. The tapered peripheral surface TPC forms a peripheral surface of a truncated cone that narrows from the first outer peripheral surface FOS toward the second outer peripheral surface SOS.

The seal member 200D further includes a dust strip 230D extending from the inner peripheral surface 217 of the main ring portion 210 toward the second outer peripheral surface SOS. The dust strip 230D includes a tip portion 231 that comes into contact with the second outer peripheral surface SOS. That is, the tip portion 231 is pressed against the surface of the shaft SFU outside the main lip 220.

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

The operator can apply grease to the second outer peripheral surface SOS to reduce the friction between the tip portion 231 and the second outer peripheral surface SOS. The tapered peripheral surface TPC between the first outer peripheral surface FOS and the second outer peripheral surface SOS prevents the grease applied to the second outer peripheral surface SOS from being transferred to the first outer peripheral surface FOS. Therefore, the grease is unlikely to come into contact with the lubricating oil contained in the internal space. This means that the risk of sludge generation between the main lip 220 and the first outer peripheral surface FOS is reduced. As a result, the risk of scratching the main lip 220 and the first outer peripheral surface FOS is also reduced.

The design principles described in relation to the various embodiments described above are applicable to various sealing structures. Some of the various features described in connection with one of the various embodiments described above may be applied to the sealing techniques described in connection with the other other embodiment.

The principles of the above embodiments are suitably used in various mechanical equipment.

100, 100A-100C ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal body 200, 200B, 200D ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal member 220, 220B ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Main lip 240 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Spring ring (pressing part)
300, 300A ... Prevention ring 314 ... Inner circumference (Inner periphery)
315 ... Elastic wall 316 ... Rigid rings 320, 320B ・ ・ ・ ・ ・ ・ ・ Lip part 410 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Bearing 431 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Flange 432 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Holding Cylinder 443 ... Inner peripheral surface APT, APU ... Equipment HSG, HSH ... Housing OSF ..... outer peripheral surface SFT, SFU ... Shaft

Claims (5)

A seal that prevents fluid from flowing between the exterior space outside the device and the interior space inside the device.
A mounting portion that is mounted on the housing of the device.
The seal body includes a seal member having a seal portion that is pressed against the surface of the device, and a prevention portion that prevents foreign matter generated in the internal space from entering the seal portion.
The prevention portion includes a lip portion that is pressed against the surface of the device.
The lip portion isolates the seal portion from the internal space and
The prevention portion is a prevention ring arranged in an annular space formed in the device.
The prevention ring is integrally formed with the lip portion, and is fixed to the elastic wall so as to surround the inner peripheral edge and an annular elastic wall having an inner peripheral edge on which the lip portion protrudes. Includes a rigid ring, which has a higher rigidity than the elastic wall,
The mounting portion includes an inner peripheral surface surrounding the shaft of the device.
The shaft has an outer peripheral surface as the surface of the device.
The annular space is a seal adapter formed between the outer peripheral surface of the shaft and the inner peripheral surface of the mounting portion. The seal adapter according to claim 1, wherein the prevention portion is integrated with the seal member. A seal that prevents fluid from flowing between the exterior space outside the device and the interior space inside the device.
A mounting portion that is mounted on the housing of the device.
The seal body includes a seal member having a seal portion that is pressed against the surface of the device, and a prevention portion that prevents foreign matter generated in the internal space from entering the seal portion.
The prevention portion includes a lip portion that is pressed against the surface of the device.
The lip portion isolates the seal portion from the internal space and
The seal member has an annular main lip having the seal portion and arranged in the annular space formed in the apparatus, and a pressing portion for pressing the main lip against the surface of the apparatus. Including
The lip portion is integral with the main lip and protrudes from the main lip into the internal space.
The mounting portion includes an inner peripheral surface surrounding the shaft of the device.
The shaft has an outer peripheral surface as the surface of the device.
The annular space is a seal adapter formed between the outer peripheral surface of the shaft and the inner peripheral surface of the mounting portion. The seal portion is pressed against the surface of the device by the first pressure contact force.
The seal adapter according to any one of claims 1 to 3, wherein the lip portion is pressed with a second pressure contact force smaller than the first pressure contact force. A holding cylinder extending from the mounting portion to the internal space,
Further provided with a bearing fitted between the holding cylinder and the outer peripheral surface of the shaft.
The seal adapter according to any one of claims 1 to 4, wherein the lip portion projects from the elastic wall or the main lip toward the bearing and is pressed against the outer peripheral surface of the shaft.