JP3393603B2 - Bearing seal structure for cutter drum of shield machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing seal structure for a cutter drum of a shield machine, and in particular, the structure can be simplified, and when the machine is used for long-distance excavation, earth and sand and mud enter the machine body. The present invention relates to a bearing seal structure for a cutter drum of a shield machine that can prevent the above.

[0002]

BACKGROUND ART A shield machine is a tunnel for subways, water and sewage systems, power cables and communication cables,
It is used for excavation of shield pits (tunnels), etc., and the usual shield machine is a front body, rear body, cutter disk, rotary drive mechanism of cutter disk, multiple shield jacks, earth removal equipment, excavated The inner surface of the tunnel has an erector for lining the segment. According to this shield machine, a cutter disk is rotationally driven to excavate a face and excavate a predetermined length (for one ring) while generating excavation thrust through a segment that has been lined with a plurality of shield jacks. Each time, the segment is lined with the erector on the inner surface of the tunnel, and the tunnel is dug while repeating this.

A partition wall defining a chamber is provided on the rear side of the cutter disk, and a cutter drum connected to the cutter disk via a plurality of connecting members is rotatable in an annular recess formed in the partition wall. It is housed in.
Equipped with a plurality of sealing members for sealing the inner peripheral part of the cutter drum and a plurality of sealing members for sealing the outer peripheral part of the cutter drum, it has a structure that prevents muddy water and earth and sand from entering the machine body. There is.

By the way, when the digging distance by the shield machine is long, if the contact surface of each seal member against the seal lip is worn or the seal member is worn or damaged,
It becomes impossible to seal the inner and outer circumferences of the cutter drum, and earth and sand and muddy water enter the excavator body from the chamber. Recently, bearing seal structure for cutter drum shield machine capable of preventing the sand or mud from entering the shield machine main body even when used for long-distance excavation is practically been proposed (Japanese Patent Public Japanese Laid-Open Patent Application No. 3-11360, Fairness 6
-9111).

In the shield machine of Japanese Patent Publication No. 3-11360, two radial first seal members for sealing the inner peripheral portion of the cutter drum are arranged at the inner peripheral portion and the outer peripheral portion of the seal ring, respectively. The two radial second sealing members for sealing the outer peripheral portion of the cutter drum are respectively arranged on the inner peripheral portion and the outer peripheral portion of the seal ring. In the initial stage of excavation, the front end of each seal ring is fixed to the cutter drum with a sealing plate, and the inner seal member of the first seal member and the outer seal member of the second seal member are used. Prevents dirt and muddy water from entering the excavator body.
When the seal members have worn out, the seal rings are unfixed to the sealing plate, each seal ring is fixed to the partition wall with the sealing plate, and the remaining two stages of sealing members are used to deposit earth and sand inside the machine. And to prevent intrusion of muddy water.

In the tunnel excavator disclosed in Japanese Utility Model Publication No. 6-9111, a plurality of first and second sealing members for respectively sealing the inner peripheral portion and the outer peripheral portion of the cutter drum, and the first and second sealing members which are in sliding contact with the seal lips of the respective sealing members. 1, a second seal sleeve, and a first seal sleeve are fixed to the inner peripheral wall of the annular recess, the second seal sleeve is fixed to the inner peripheral portion of the cutter drum, respectively, and the axial length is such that the second seal sleeve can be relocated by a predetermined small distance in the axial direction. And a plurality of mounting members having different heights. During long distance excavation, when the contact surface of the seal sleeve with the seal lip is worn,
The mounting members having different lengths are replaced to move the position of the seal sleeve in the axial direction, and the non-wearing portion of the seal sleeve is brought into contact with the seal lip. It is empirically known that the contact surface (metal surface) with respect to the seal lip has a larger amount of wear than the seal member.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the conventional structure described in Japanese Patent Publication No. 360, the number of seal members required for four stages increases the number of parts, complicates the seal structure itself, and increases the manufacturing cost. Only the front end of each seal ring is fixed to the cutter drum or partition wall with a sealing plate, so the rigidity of the seal ring is low,
Moreover, since the seal ring and the two-stage seal member must be disposed in the narrow annular gap, each seal member has a thin wall structure. Therefore, there is a problem that the strength of this bearing seal structure is reduced. Further, since the seal member can be switched substantially only once, it is not suitable for long-distance excavation. Furthermore, if the contact surface of the cutter drum or the wall of the annular recess with respect to the seal member wears, the contact surface must be repaired or the member replaced when it is reused.

In the prior art disclosed in Japanese Utility Model Publication No. 6-9111, it is necessary to disassemble the cutter drum in order to relocate the mounting members having different lengths and move the position of the seal sleeve in the axial direction. Therefore, the work load is large and the work time is long, and the stop time during the excavation is long. When a plurality of seal members are worn or damaged, the seal members have to be replaced one by one, resulting in low work efficiency. An object of the present invention is to simplify the structure of a bearing seal structure for a cutter drum of a shield machine and to increase the strength, to shorten the working time for restoring the sealing function, and to reduce the work load. And so on.

[0009]

A bearing seal structure for a cutter drum of a shield machine according to claim 1 has a cutter disk, a partition wall defining a chamber on the rear side, and a cutter drum formed in the partition wall. A shield machine having an annular recess, a plurality of first sealing members for sealing an inner peripheral portion of the cutter drum, and a plurality of second sealing members for sealing an outer peripheral portion of the cutter drum, wherein an inner peripheral portion of the annular recess is provided. A first ring member having a plurality of first seal members attached thereto is provided, and the first ring member can be moved together with the first seal member rearward in the axial direction by a predetermined small distance in order to restore the sealing function. Set up a mechanism
The partition wall and the inner peripheral wall portion forming the inner peripheral portion of the annular recess are
An outer peripheral wall portion forming an outer peripheral portion of the annular recess,
The sealing member is fixed to the front end of the inner peripheral wall and is attached to the front end of the inner peripheral wall.
The first seal member transfer machine having opposing flange portions
The structure is such that the flange portion of the first ring member has a plurality of spacers.
Plural bolt members fixed to the front end of the inner peripheral wall via
It is characterized by having .

When this shield machine is used for long-distance excavation, the wear amount of the inner peripheral portion of the cutter drum, which is in sliding contact with the first seal member during the excavation, exceeds a predetermined value in the radial direction (for example, about 5 mm or more). When it reaches, the first seal member transfer mechanism moves the first ring member together with the first seal member rearward in the axial direction by a predetermined small distance. That is, digging
In the initial stage, multiple flanges
Use a bolt member to the front end of the inner wall through the spacers.
Since it is fixed, the first seal member
The wear amount of the inner peripheral part of the cutter drum that slides on the
Once the bolt reaches the top, remove the bolt member once and use one spacer
If you remove only this and fix it again with the bolts,
The sealing member together with the first seal member is rearward in the axial direction.
It can be relocated for a small distance. Then, the sealing function of the first sealing member is restored, and it is possible to prevent the entry of dirt and muddy water into the excavator body from the inner peripheral portion of the cutter drum. When the amount of wear of the inner peripheral portion of the cutter drum that comes into sliding contact with the first seal member after the restart of the excavation has reached a predetermined value or more, the transfer work by the first seal member transfer mechanism is performed in the same manner as described above, and the excavation distance is long. If this happens, this transfer operation can be repeated for the number of spacers .

Even in the plurality of second seal members, for example, a seal member transfer mechanism substantially similar to the first seal member transfer mechanism is provided, and the wear amount of the outer peripheral wall portion of the partition wall slidingly contacting the second seal member is reduced. By performing the relocation work in parallel with the above relocation work when the predetermined value or more is reached, it is possible to restore the sealing function of the entire bearing seal in the cutter drum.

According to a second aspect of the present invention, there is provided a bearing seal structure for a cutter drum of a shield machine according to the first aspect, wherein a second ring member having a plurality of second seal members attached to the outer periphery of the cutter drum is provided. In order to restore the function, a second seal member transfer mechanism capable of transferring the second ring member together with the plurality of second seal members rearward in the axial direction by a predetermined small distance is provided. The second seal member transfer mechanism has substantially the same operation as the first seal member transfer mechanism of the first aspect on the outer peripheral portion of the cutter drum, and therefore has the same operation as the first aspect.

[0013]

[0014]

In the bearing seal structure for a cutter drum of a shield machine according to claim 3 , in the invention of claim 2 , the cutter drum is connected to a cutter disk through a plurality of connecting members, and each connecting member is a cutter drum. a flange plate which is secured to the front end of the second sealing member relocation mechanism includes a plurality of bolt members extending forwardly inserted fixed and the flange plate to the front end portion of the second ring member,
The present invention is characterized by comprising a plurality of nut members that are respectively screwed to these bolt members and rotatably mounted on the flange plate.

In the initial stage of the excavation, for example, the front end of the second ring member is brought into contact with the flange plate of the cutter drum, and the amount of wear of the outer peripheral wall of the partition wall which is in sliding contact with the second seal member is predetermined during the excavation. When the plurality of nut members are rotated by a predetermined pitch when the value exceeds the value, the second ring member can be moved rearward along the axial center by a predetermined small distance together with the second seal member and the plurality of bolt members. Second
The sealing member transfer mechanism can restore the sealing function in the outer peripheral portion of the cutter drum.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a bearing seal structure for a cutter drum connected to a cutter disk of a shield machine. First, the overall structure of the shield machine will be outlined, and then the bearing seal structure for the cutter drum of the shield machine will be described. In addition, the excavation direction is defined as the front, and the left and right are defined as the left and right toward the front.

As shown in FIGS. 1 to 3, the shield machine 1 includes a cutter disk 2 and a chamber 3 on the rear side thereof.
Partition wall 4, a cylindrical body member 5, a rotary drive mechanism 6 for the cutter disk 2, a plurality of shield jacks 7 for generating a thrusting force, and a segment S covered on the inner surface of the excavated tunnel. It is equipped with an erector 8 to be worked, a perfect circle holding device 9, and an earth discharging facility 10 for discharging the excavated earth and sand.

Explaining the cutter disk 2,
As shown in FIGS. 1 and 2, the cutter disc 2 includes a center frame 11, a plurality of cutter spokes 12 and 13 radially extending from the center frame 11, a ring frame 14, and an outer circumference having the same diameter as the body member 5. Ring 15,
A copy cutter 16 provided on two cutter spokes 13 of the plurality of cutter spokes 13 and capable of advancing to the outer peripheral side of the outer peripheral ring 15, a plurality of roller cutters 17 attached to the other cutter spokes 12, and a cutter spoke 12 , 13 attached to a large number of cutter bits 18 and the like.

The body member 5 has a partition wall 4, support walls 19 and 20,
Annular webs 21 and 22, a plurality of brackets 23 and the like are provided. The partition wall 4 is provided inside the front end of the body member 5 to define the chamber 3, and the partition wall 4 is formed with an annular recess 24. An annular cutter drum 26 is connected to the back surface of the cutter disk 2 via a plurality of connecting members 25, and the cutter drum 26 is housed in the annular recess 24 of the partition wall 4 and is rotatably supported. A rotary joint 27 that inserts the partition wall 4 is supported near the center of the back surface of the cutter disk 2, and supplies the hydraulic pressure from the hydraulic pressure supply source to the copy cutter 16 or from the mud addition agent supply source to the mud addition nozzle 28. Supply mud additives. A stirring blade 29 for stirring the earth and sand in the chamber 3 is fixed to the outer peripheral wall of each connecting member 25.

Explaining the partition wall 4, the partition wall 4 includes a central wall portion 30, an inner peripheral wall portion 31 forming an inner peripheral portion of the annular recess 24, and an outer peripheral wall portion 32 forming an outer peripheral portion of the annular recess 24.
It has a support wall portion 33 and the like welded to the body member 5. In addition, the reinforcing frame 34, the motor support frame 35, and the like are joined. The rotation drive mechanism 6 will be described. A ring gear 36 is fixed to the rear end of the cutter drum 26, and a plurality of cutter drive motors 37 are provided on the rear side of the partition wall 4 via a motor support frame 35. The pinion at the tip of the output shaft of each cutter drive motor 37 meshes with the ring gear 36, and the cutter disk 2 is driven to rotate forward and backward by the plurality of cutter drive motors 37.

As shown in FIGS. 1 to 3, a plurality of tail grout seals 38 are provided at the rear end of the body member 5 to prevent the earth and sand from entering the shield machine 1. A rear working deck 39 is provided inside the body member 5 near these tail grout seals 38.
The rear working deck 39 is provided with a perfect circle holding device 9 for keeping the segment S in a perfect circle.

Explaining the shield jack 7,
A plurality of shield jacks 7 are arranged rearward at appropriate intervals in the circumferential direction in the vicinity of the center in the axial direction inside the body member 5, and the jack bodies of these shield jacks 7 are fixed to the partition wall 4 and It is supported by the annular webs 21 and 22 so as to be inserted therethrough. A spreader 41 is pin-connected to the tip of the rod of each shield jack 7 via an eccentric metal fitting 40. The rod of each shield jack 7 is extended, and the spreader 41 is brought into contact with and pressed against the front end of the segment S lined on the inner surface of the tunnel to generate thrust force.

Explaining the erector 8, the erector 8 includes a rotating drum 42, an erector body 43, and the rotating drum 4.
It has an electric or hydraulic drive motor 44 for rotationally driving 2, and the plurality of brackets 23 are provided with support rollers 45, respectively, and the rotary drum 42 is rotatably supported by the plurality of support rollers 45. Every time one tunnel is digging, the segment S is assembled by the erector 8 over the entire circumference of the tunnel pit wall for one ring. Earth removal equipment 1
0, the earth discharging equipment 10 includes a screw conveyor 46, a hopper 47, and the like. The screw conveyor 46 rotates the auger 48, a pair of hydraulic cylinders for driving the auger 48 forward and backward, and the auger 48. It has a drive motor for the purpose, an opening / closing gate for discharging the earth and sand, etc. (all not shown).

Next, the bearing seal structure for the cutter drum will be described. As shown in FIGS. 1 and 4, the cutter drum bearing seal structure includes a first seal member transfer mechanism 49 and a second seal member transfer mechanism 50 for recovering the seal function. Explaining the first seal member transfer mechanism 49, as shown in FIGS. 4 to 6, a plurality of first seal members 51 and annular seal pressing members 52 are alternately attached to the inner peripheral portion of the annular recess 24. First ring member 53
Is provided and the first ring member 53 is the first seal member 51.
The seal holding member 52 and the seal holding member 52 can be moved rearward in the axial direction by a predetermined small distance. The first seal member 5
A grease 54 is filled between the first and the seal pressing member 52 and the inner peripheral portion of the cutter drum 26.

The first ring member 53 has a flange portion 55 fixed to the front end portion thereof and facing the front end of the inner peripheral wall portion 31, and the first seal member transfer mechanism 49 uses the flange portion 55 for a plurality of spacers. It has a plurality of bolt members 57 arranged at appropriate intervals in the circumferential direction and fixed to the front end portion of the inner peripheral wall portion 31 via 56. At the initial stage of excavation, the excavation is carried out with a plurality of spacers 56 installed, and the abrasion amount of the inner peripheral portion of the cutter drum 26 slidingly contacting the first seal member 51 during the excavation is a predetermined value or more in the radial direction. At that stage, the one spacer 56 is removed, and the first ring member 53 is moved rearward along the first seal member 51 by a predetermined small distance in the axial direction, and thereafter, this transfer operation is repeated. Reference numeral 58 indicates a reinforcing diagonal member.

The second seal member transfer mechanism 50 will be described. As shown in FIGS. 4, 7 and 8, a plurality of second seal members 59 and an annular seal pressing member are provided on the outer peripheral portion of the cutter drum 26. A second ring member 61 in which 60 are attached alternately is provided, and the second ring member 61 is configured to be removable together with the second seal member 59 and the seal pressing member 60 rearward in the axial direction by a predetermined small distance. A grease 62 is filled between the second seal member 59 and the seal pressing member 60 and the outer peripheral wall of the partition wall 4.

Each connecting member 25 is a cutter drum 26.
The second seal member transfer mechanism 50 has a plurality of bolt members 64 and a plurality of nut members 65 screwed to the bolt members 64, respectively. That is, a plurality of bolt members 64 are circumferentially fixed to the front end portion of the second ring member 61 by screwing and welding,
Each bolt member 64 is configured to pass through the flange plate 63 and extend forward. Each nut member 65 includes a nut portion 65a at the front end portion and a cylindrical portion 6 connected to the nut portion 65a.
5b, a flange portion 65c externally fitted and fixed to the rear end portion of the cylindrical portion 65b.
Is inserted into the insertion hole 63a, is sandwiched between the nut portion 65a and the flange portion 65c, and is rotatably mounted, and the bolt member 64 is screwed.

Next, the operation of the above-mentioned bearing seal structure for the cutter drum will be described. Shield machine 1
Is subjected to long-distance excavation, the first seal member transfer mechanism 49 is operated at a stage when the wear amount of the inner peripheral portion of the cutter drum 26 slidingly contacting the first seal member 51 during the excavation reaches a predetermined value or more in the radial direction. Thus, the first ring member 53 is moved to the rear side in the axial direction by a predetermined small distance together with the first seal member 51 and the seal pressing member 52. That is, one spacer 56 of the plurality of spacers 56 is removed from each bolt member 57, and the first ring member 53 is moved rearward by the thickness of the one spacer 56.

Then, the sealing function of the first sealing member 51 is restored, and it is possible to prevent the entry of dirt and muddy water into the excavator body from the inner peripheral portion of the cutter drum 26. After the amount of wear of the inner peripheral portion of the cutter drum 26 slidingly contacting the first seal member 51 after the restart of excavation reaches the predetermined value or more again, one spacer 56 is removed from each bolt member 57 in the same manner as described above. The first ring member 53 is moved rearward by the thickness of one spacer 56 to restore the sealing function. If the digging distance becomes longer, the relocation work will be repeated to restore the sealing function.

In the second seal member 59, as shown in FIGS. 7 and 8, the front end of the second ring member 61 is brought into contact with the flange plate 63 of the connecting member 25 at the initial stage of excavation, and during excavation, When the nut portions 65a of the plurality of nut members 65 are synchronously rotated by a predetermined pitch when the amount of wear of the outer peripheral wall portion 32 of the partition wall 4 slidingly contacting the second seal member 59 reaches or exceeds the predetermined value, the second ring Second member 61
The sealing member 59 and the plurality of bolt members 64 can be moved rearward in the axial direction by a predetermined small distance, and the second sealing member moving mechanism 50 can restore the sealing function in the outer peripheral portion of the cutter drum 26. If the digging distance becomes long, the relocation work will be repeated to restore the sealing function.

According to the bearing seal structure for a cutter drum described above, the first seal member transfer mechanism 49 moves the first ring member 53 together with the first seal member 51 axially rearward to restore the seal function. As a result, the structure is simplified, and it is not necessary to disassemble the cutter drum 26 when the first ring member 53 is transferred, and the work load can be reduced. In addition, the first ring member 53 itself serves as a strength member and can be made stronger. Since the first ring member 53 is moved by a predetermined small distance, the number of times of moving can be increased, so that the total life of the sealing function can be extended and the digging distance can be remarkably extended.

Furthermore, the seal function of the outer peripheral portion of the cutter drum 26 is restored by the second seal member transfer mechanism 50, and in parallel with this, the seal of the inner peripheral portion of the cutter drum 26 is performed by the first seal member transfer mechanism 49. Since the function is restored, the sealing function of the entire bearing seal in the cutter drum 26 can be restored. Also, the second
It is not necessary to disassemble the cutter drum 26 when the ring member 61 is transferred, and the work load can be reduced. In addition, the first ring member 53 and the second ring member 61
The first seal member 51 and the second seal member 59 can be exchanged by pulling out to the chamber 4 side.
At that time, the flange plate 63 is to be removed.

Next, a modified form in which this embodiment is partially modified will be described. 1) The shield machine may be provided with only one of the first seal member transfer mechanism and the second seal member transfer mechanism. 2) Spacer 5 to be overlapped in the initial stage of excavation
It is also possible to increase the number of sheets of 6 more than that of the embodiment. In this case, each bolt member 57 to be fixed must be long. Besides, it is also possible to carry out the embodiment in which various modifications are added to the embodiment without departing from the spirit of the invention.

[0035]

According to the invention of claim 1, the first seal member moving mechanism can move the first ring member together with the first seal member rearward in the axial direction to restore the sealing function. Moreover, the structure is simplified and the first
It is not necessary to dismantle the cutter drum when moving the ring member, and the work load can be reduced. In addition, the ring member itself serves as a strength member to increase the strength. Since the first ring member is moved by a predetermined small distance, it is possible to increase the number of times of moving, so that the life of the sealing function can be extended and the excavation distance can be remarkably extended. Especially in the initial stage of excavation
In the case of the
The front end of the inner wall with a bolt.
Since it is kept, a series of transfer work is repeated for the number of spacers
Is it possible to increase the number of relocations?
It is possible to extend the life of the sealing function and
The separation can be greatly extended.

According to the second aspect of the invention, the seal function of the outer peripheral portion of the cutter drum is restored by the second seal member transfer mechanism, and in parallel with this, the inner periphery of the cutter drum is transferred by the first seal member transfer mechanism. Since the seal function of the portion is restored, the seal function of the entire bearing seal in the cutter drum can be restored. Other claim 1
Has the same effect as.

[0037]

According to the third aspect of the present invention, for example, the front end of the second ring member is brought into contact with the flange plate of the cutter drum, and the amount of wear of the outer peripheral wall of the partition wall slidingly contacting the second seal member has a predetermined value. When the plurality of nut members are rotated by a predetermined pitch at the stage reached above, the second ring member together with the second seal member and the plurality of bolt members can be moved rearward in the axial direction by a predetermined small distance. The two-seal member transfer mechanism can restore the sealing function in the outer peripheral portion of the cutter drum. In addition, the same effect as in claim 2 is obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a shield machine according to an embodiment of the present invention.

FIG. 2 is a front view of a cutter disk.

FIG. 3 is a vertical cross-sectional view showing an erector, a perfect circle holding device, and the like.

FIG. 4 is a vertical cross-sectional view of a main part of a bearing seal structure for a cutter drum.

FIG. 5 is an enlarged cross-sectional view of the first seal member transfer mechanism before the transfer of the first ring member.

FIG. 6 is a view corresponding to FIG. 5 after the transfer of the first ring member.

FIG. 7 is an enlarged cross-sectional view of the second seal member transfer mechanism before the transfer of the second ring member.

FIG. 8 is a view corresponding to FIG. 7 after the transfer of the second ring member.

[Explanation of symbols]

1 shield machine 2 cutter disk 3 chambers 4 partitions 24 annular recess 25 Connection member 31 Inner wall 32 outer peripheral wall 26 cutter drum 49 First seal member transfer mechanism 50 Second seal member transfer mechanism 51 First Seal Member 53 first ring member 55 Flange 56 spacer 57 bolt members 59 Second seal member 61 Second Ring Member 63 Flange plate 64 bolt member 65 Nut member

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukazu Kukihara 8th Niijima, Harima-cho, Kako-gun, Hyogo Prefecture Kawasaki Heavy Industries Ltd. Harima Plant (56) References JP-A-8-21192 (JP, A) Actual Kohei 4-157 (JP, Y2) S. 62-4619 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) E21D 9/08 F16J 15/32 311 F16J 15/18

Claims (3)

(57) [Claims] 1. A cutter disk, a partition wall defining a chamber on the rear side thereof, an annular recess formed in the partition wall for accommodating a cutter drum, and a plurality of first sealing members for sealing an inner peripheral portion of the cutter drum, In a shield machine having a plurality of second sealing members for sealing the outer peripheral portion of the cutter drum, a first ring member having a plurality of first sealing members attached to the inner peripheral portion of the annular recess is provided to provide a sealing function. In order to recover, the first ring member can be moved together with the first seal member rearward in the axial direction by a predetermined small distance.
Only set the sealing member relocation mechanism, it said septum inner wall portion forming the inner peripheral portion of the annular recess and the annular
An outer peripheral wall portion forming an outer peripheral portion of the recess, and a first ring
The member is fixed to the front end of the member and faces the front end of the inner peripheral wall.
The first seal member transfer mechanism has a flange portion
To the front end of the inner wall through multiple spacers.
A bearing seal structure for a cutter drum of a shield machine, comprising a plurality of bolt members to be fixed . 2. A second ring member having a plurality of second seal members attached to the outer peripheral portion of the cutter drum, and the second ring member together with the plurality of second seal members in the axial direction in order to restore the sealing function. The second that can be moved to the rear for a predetermined small distance
2. A seal member transfer mechanism is provided.
Bearing seal structure for the cutter drum of the shield machine as described in. 3. The cutter drum is connected to a cutter disk via a plurality of connecting members, each connecting member has a flange plate fixed to a front end of the cutter drum, and the second seal member transfer mechanism is A plurality of bolt members that are fixed to the front end of the second ring member and extend forward through the flange plate, and a plurality of nut members that are respectively screwed into these bolt members and rotatably mounted on the flange plate. The bearing seal structure for a cutter drum of a shield machine according to claim 2 , further comprising: