JP2007255109A - Rotating shaft support structure for tunnel excavator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating shaft support structure for a tunnel excavator of excellent productivity. <P>SOLUTION: The rotating shaft support structure for the tunnel excavator comprises a cutter head having a cutter for excavating sediment; a rotating shaft provided with the cutter head at one end and rotated together with the cutter head; and a tapered roller bearing built in a fixed member to support the rotating shaft rotatably. The tapered roller bearing comprises an outer ring 32; an inner ring 33; a plurality of tapered rollers arranged between the outer ring 32 and the inner ring 33; a plurality of cage segments 11a, 11d having pockets for holding the tapered rollers and arranged sequentially connected in a circumferential direction between the outer ring 32 and the inner ring 33; and a spacer 26 arranged between the first cage segment 11a and the last cage segment 11d connected in the circumferential direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary shaft support structure for a tunnel excavator, and more particularly to a rotary shaft support structure for a tunnel excavator including a roller bearing having a split cage.

  Conventionally, a tunnel excavator (shield machine) has been used to form a large-scale tunnel. The tunnel excavator has a cutter head at the tip, and advances while excavating the front face by the rotation of the cutter head to form a tunnel. Here, the rotary shaft support structure of the tunnel excavator includes a rotary shaft with a cutter head fixed to one end and a roller bearing that rotatably supports the rotary shaft.

  The roller bearing is generally composed of an outer ring, an inner ring, a plurality of rollers disposed between the outer ring and the inner ring, and a cage that holds the plurality of rollers. There are various types of cages for holding rollers, such as resin cages, press cages, shaving cages, and welded cages, depending on the material and manufacturing method. ing. In addition, the cage is usually composed of a single piece, that is, an annular part.

  Here, in order to form a large-scale tunnel, the roller bearing included in the rotary shaft support structure of the tunnel excavator needs to receive a large thrust load, radial load, moment load, etc., and the roller bearing itself is also large. . If it does so, each structural member which comprises a roller bearing, such as a roller and a holder | retainer, will also become large sized, and production and assembly of a member will become difficult. In addition, race rings such as an inner ring and an outer ring provided in the roller bearing described above may be deformed by a large moment load. When the tunnel is formed, the moment load applied to the roller bearing is particularly large as compared with the case of the main shaft support structure of a wind power generator in which the same large roller bearing is used. In such a case, in the integrated cage, the shape of the cage is difficult to follow the shape of the deformed raceway ring, which may cause various problems. Here, if each member can be divided, production and assembly can be facilitated, and the above-described problems can be reduced.

  A technique related to a split type retainer in which a retainer included in a roller bearing is divided by a parting line extending in a direction along the axis is disclosed in European Patent Publication No. 1408248A2 (Patent Document 1). FIG. 14 is a perspective view showing a cage segment which is a split type cage disclosed in Patent Document 1. FIG. Referring to FIG. 14, the cage segment 101a includes a plurality of pillar portions 103a, 103b, 103c, 103d, 103e extending in a direction along the axis so as to form a plurality of pockets 104 for accommodating rollers, and a plurality of pillars. It has the connection parts 102a and 102b extended in the circumferential direction so that the parts 103a-103e may be connected.

FIG. 15 is a cross-sectional view showing a part of a roller bearing including the cage segment 101a shown in FIG. The configuration of the roller bearing 111 including the cage segment 101a will be described with reference to FIGS. 14 and 15. The roller bearing 111 holds the outer ring 112, the inner ring 113, the plurality of rollers 114, and the plurality of rollers 114. A plurality of cage segments 101a, 101b, 101c and the like. The plurality of rollers 114 are held by a plurality of cage segments 101a and the like in the vicinity of a PCD (Pitch Circle Diameter) 105 where the roller behavior is most stable. The cage segment 101a that holds the plurality of rollers 114 is continuously arranged so that the cage segments 101b and 101c having the same shape adjacent in the circumferential direction and the outermost column portions 103a and 103e abut on each other. ing. A plurality of cage segments 101 a, 101 b, 101 c, etc. are connected to each other and incorporated into the roller bearing 111 to form one annular cage included in the roller bearing 111.
European Patent Publication EP1408248A2

  One annular retainer described above is formed by arranging a plurality of retainer segments in a circumferential direction. In order to form a single annular cage by connecting a plurality of cage segments in the circumferential direction, a circumferential gap in consideration of thermal expansion or the like is required.

  Here, if this circumferential clearance is too wide, the cage segments move greatly in the circumferential direction, and adjacent cage segments collide with each other, so that abnormal noise may be generated or the cage segments may be damaged. In addition, the cage segment thermally expands as the temperature rises, but if this circumferential clearance is narrow, the thermal expansion eliminates the gap between adjacent cage segments, and the adjacent cage segments Will push each other. The circumferential stress caused by this thermal expansion causes friction and wear of the cage segment, which also causes breakage of the cage segment.

  Here, according to Patent Document 1, when the cage segments are brought into contact with each other and arranged in the circumferential direction, the dimension of the last gap generated between the first cage segment and the last cage segment is determined. A technique is disclosed in which the circumferential clearance is made appropriate by defining the circumference of the circle passing through the center of the cage segment as 0.15% or more and less than 1%.

  However, since each cage segment is manufactured independently, each cage segment has a dimensional error in the circumferential direction. When the cage segments having such dimensional errors are arranged in the circumferential direction, the dimensional errors are also accumulated. Therefore, in order to make the circumferential clearance within the above-described predetermined range, each cage segment must be manufactured with high accuracy, and the productivity of the cage segment is deteriorated. If it does so, the productivity of the roller bearing provided with a cage segment will also deteriorate, and the productivity of the rotating shaft support structure of the tunnel excavator including such a roller bearing will also deteriorate.

  An object of the present invention is to provide a rotary shaft support structure for a tunnel excavator with good productivity.

  The rotary shaft support structure of the tunnel excavator according to the present invention includes a cutter head provided with a cutter for excavating earth and sand, a cutter head provided at one end, a rotary shaft that rotates together with the cutter head, and a fixed member, And a roller bearing that rotatably supports the rotating shaft. The roller bearing has an outer ring, an inner ring, a plurality of rollers arranged between the outer ring and the inner ring, and a pocket for holding the roller, and is arranged sequentially in the circumferential direction between the outer ring and the inner ring. A plurality of retainer segments and a spacer disposed between the first retainer segment and the last retainer segment connected in the circumferential direction.

  By comprising in this way, a spacer can be arrange | positioned in the clearance gap between the 1st retainer segment and the last retainer segment among the roller bearings contained in the rotating shaft support structure of a tunnel excavator. Then, regardless of the circumferential dimension error of each cage segment, the dimension between the first cage segment and the last cage segment can be set within a set range. Therefore, it is not necessary to manufacture each cage segment with high accuracy, and the productivity of the cage segment is improved. As a result, the productivity of the roller bearing is also improved. As a result, the productivity of the rotary shaft support structure of the tunnel excavator including such a roller bearing is also improved. In this case, rollers and spacers may be arranged.

  Here, the cage segment is a unit body obtained by dividing one annular cage by a dividing line extending in a direction along the axis so as to have at least one pocket for accommodating the rollers. The first cage segment is the cage segment that is placed first when the cage segments are sequentially arranged in the circumferential direction, and the last cage segment is the adjacent cage segment. The cage segments are arranged last when they are brought into contact with each other and sequentially arranged in the circumferential direction. A plurality of cage segments are connected to the roller bearing in a circumferential direction to form one annular cage. The cage segment has at least one pocket that accommodates the roller, and is different from a spacer that does not have a pocket that accommodates the roller.

  Preferably, the roller bearing is provided with a seal. By comprising in this way, the penetration | invasion in the roller bearing which excavated earth and sand and muddy water can be prevented. Therefore, it is possible to realize a long life of the roller bearing, and thus the rotating shaft support structure of the tunnel excavator.

  More preferably, the cage segment is provided with a pair of protrusions located at both ends in the axial direction and projecting in the circumferential direction, and the spacer is a pair of projections provided in the first cage segment. And the circumferential end surfaces of the pair of protrusions provided in the last cage segment. By comprising in this way, the circumferential load from a spacer can be received by a pair of protrusion part. If it does so, a load will not be applied to the pillar part which forms the pocket contained in a cage segment from the spacer in the peripheral direction. Therefore, it is possible to prevent deformation and breakage of the column portion and locking of the rollers held in the pocket.

  More preferably, the spacer is located at both ends in the axial direction, and has an end portion sandwiched between the protrusions of the first and last retainer segments, and a central portion located between the both end portions. With this configuration, both end portions included in the spacer come into contact with the pair of protrusions of the first and last cage segments. If it does so, the pillar part of a holder | retainer segment and the edge part of a spacer will not contact | abut. Therefore, a load is not applied to the column portion from the spacer.

  More preferably, the central portion of the spacer has a circumferential bulge that bulges in the circumferential direction and is received between the pair of protrusions of the cage segment. With this configuration, the movement of the spacer in the axial direction is restricted by the pair of protrusions, and the movement in the axial direction is restricted. Therefore, the displacement of the spacer in the axial direction can be suppressed.

  According to this invention, a spacer can be arrange | positioned among the roller bearings contained in the rotating shaft support structure of a tunnel excavator between the first cage segment and the last cage segment. Then, regardless of the circumferential dimension error of each cage segment, the dimension between the first cage segment and the last cage segment can be set within a set range. Therefore, it is not necessary to manufacture each cage segment with high accuracy, and the productivity of the cage segment is improved. As a result, the productivity of the roller bearing is also improved. As a result, the productivity of the rotary shaft support structure of the tunnel excavator including such a roller bearing is also improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a perspective view showing a cage segment 11a provided in a tapered roller bearing included in the rotary shaft support structure of the tunnel excavator according to the embodiment of the present invention. 3 is a cross-sectional view of the cage segment 11a shown in FIG. 2 taken along a plane that includes the line III-III in FIG. 2 and is perpendicular to the axis. FIG. 4 is a cross-sectional view of the cage segment 11a shown in FIG. 2 cut along a plane that passes through the center of the column 14a and is orthogonal to the circumferential direction. From the viewpoint of easy understanding, in FIGS. 3 and 4, the plurality of tapered rollers 12a, 12b, 12c held by the cage segment 11a are indicated by dotted lines. Moreover, PCD22 is shown with a dashed-dotted line.

  With reference to FIG. 2, FIG. 3, and FIG. 4, first, the structure of the cage segment 11a provided in the tapered roller bearing will be described. The cage segment 11a includes four column portions 14a, 14b, 14c, 14d extending in the direction along the axis so as to form pockets 13a, 13b, 13c for receiving the tapered rollers 12a, 12b, 12c, A pair of connecting portions 15a and 15b extending in the circumferential direction so as to connect the four pillar portions 14a, 14b, 14c and 14d, and a pair of protrusions positioned in both ends in the axial direction and projecting in the circumferential direction Parts 16a and 16b.

  The pair of projecting portions 16a and 16b are provided so as to project in the circumferential direction from the column portions 14a and 14d located on the outermost side in the circumferential direction, in continuation with the pair of connecting portions 15a and 15b. That is, the pair of protrusions 16a and 16b has a shape in which the connecting portions 15a and 15b extend in the circumferential direction more than the column portions 14a and 14d in the circumferential direction.

  The pair of connecting portions 15a and 15b and the pair of protrusions 16a and 16b are connected in the circumferential direction to form one annular cage when the plurality of cage segments 11a and the like are incorporated in the tapered roller bearing. Furthermore, it has a predetermined radius of curvature in the circumferential direction. Of the pair of connecting portions 15a and 15b and the pair of projecting portions 16a and 16b, the connecting portion 15a located on the small diameter side of the tapered roller 12a and the like, and the curvature radius of the projecting portion 16a is located on the large diameter side of the tapered roller 12a and the like. It is comprised smaller than the curvature radius of the connection part 15b and the protrusion 16b to perform. The circumferential ends of the pair of protrusions 16a and 16b have end surfaces 21a and 21b that come into contact with adjacent cage segments when a plurality of cage segments 11a and the like are arranged in the circumferential direction.

  The pair of protrusions 16a and 16b accommodate the tapered rollers between the cage segment 11a and the other cage segment when the other cage segments and the end faces 21a and 21b are arranged in contact with each other. Form a pocket.

  Guides for restricting movement of the cage segment 11a radially outward on the inner diameter side of the pillars 14a, 14b located on both sides in the circumferential direction of the pocket 13a and the pillars 14c, 14d located on both sides in the circumferential direction of the pocket 13c. Surfaces 17a, 17b, 17c, and 17d are provided. In addition, guide surfaces 18b and 18c for restricting the movement of the cage segment 11a inward in the radial direction are provided on the outer diameter side of the column portions 14b and 14c located on both sides in the circumferential direction of the pocket 13b. With such a configuration, the cage segment 11a becomes a so-called roller guide, and the radial position of the cage segment 11a can be stably arranged.

  Also, guide surfaces 18a and 18d are provided on the outer diameter side of the outer circumferential direction of the column portions 14a and 14d located on the outermost circumferential direction. The guide rollers 18a and 18d allow the tapered rollers disposed between the adjacent cage segments to guide the cage segments.

  Here, since the cage segment 11a is independent, there is a possibility that the cage segment 11a may be inclined with respect to the PCD 22 when arranged in the tapered roller bearing. However, the cage segment 11a has a total of three pockets, specifically, two inner diameter guiding pockets 13a and 13c at both ends of the cage segment 11a and one outer diameter guiding pocket 13b at the center of the cage segment 11a. Therefore, the possibility that the cage segment 11a is inclined with respect to the PCD 22 is reduced, and the stability is good.

  A groove 19 penetrating in the circumferential direction is provided on the outer diameter surface side of the pillar portions 14a, 14b, 14c, and 14d, and a groove 20 penetrating in the circumferential direction is provided on the inner diameter surface side. The groove 19 has a shape recessed toward the inner diameter side from the outer diameter surface of the column portions 14a to 14d in the central portion in the axial direction, and the groove 20 extends from the inner diameter surface of the column portions 14a to 14d in the central portion in the axial direction. The shape is recessed on the outer diameter side. By comprising in this way, a lubricant can be smoothly flowed in the circumferential direction.

  Next, the spacer 26 provided in the tapered roller bearing included in the rotary shaft support structure of the tunnel excavator according to the embodiment of the present invention will be described. FIG. 5 is a perspective view of a spacer 26 provided in the tapered roller bearing. The structure of the spacer 26 will be described with reference to FIG. 5. The spacer 26 includes end portions 27 a and 27 b located at both ends in the axial direction and a central portion 28 located between the end portions 27 a and 27 b. . The distance between the ends 27a and 27b in the axial direction is the same as the distance between the pair of protrusions 16a and 16b included in the cage segment 11a.

  The circumferential dimension of the central portion 28 is configured to be smaller than the circumferential dimension of the end portions 27a and 27b. The dimension of the central portion 28 in the radial direction is slightly smaller than the dimension between the raceway surfaces when incorporated in the tapered roller bearing. By doing so, when the spacer 26 is incorporated in the tapered roller bearing, it becomes a raceway guide, and the radial position can be stabilized. End surfaces 29a and 29b are provided on the outer sides in the circumferential direction of the end portions 27a and 27b. Grooves 30 a and 30 b that penetrate in the circumferential direction are provided on the inner diameter surface side and the outer diameter surface side of the central portion 28. By configuring in this way, the lubricant can be smoothly flowed in the circumferential direction as in the grooves 19 and 20 provided in the cage segment 11a.

  Next, the configuration of the tapered roller bearing including the cage segment 11a and the spacer 26 described above will be described. FIG. 6 is a schematic cross-sectional view of a tapered roller bearing 31 in which a plurality of cage segments 11a, 11b, 11c, 11d and the like and a spacer 26 are arranged in the circumferential direction as seen from the axial direction. Here, since the cage segments 11b, 11c, 11d and the like have the same shape as the cage segment 11a, description thereof is omitted. In FIG. 6, the tapered rollers 34 held by the cage segment 11a and the like are omitted. Here, among the plurality of cage segments 11a to 11d and the like, the cage segment arranged first is the cage segment 11a, and the cage segment arranged last is the cage segment 11d.

  Referring to FIG. 6, the tapered roller bearing 31 includes an outer ring 32, an inner ring 33, a plurality of cage segments 11 a to 11 d, and a spacer 26. The cage segments 11a to 11d and the like are sequentially arranged in the circumferential direction. Here, first, the cage segment 11a is disposed first, and then the cage segment 11b is disposed so as to contact the cage segment 11a. Thereafter, the cage segment 11c is arranged so as to contact the cage segment 11b, the cage segments are sequentially arranged, and finally the cage segment 11d is arranged. Here, a tapered roller 34 is disposed between two adjacent cage segments 11a, 11b, etc., except between the first cage segment 11a and the last cage segment 11d.

  Next, details of the cage segment 11b adjacent to the cage segments 11a and 11c will be described. FIG. 7 is an enlarged cross-sectional view of a portion indicated by VII in FIG. Referring to FIG. 7, the retainer segment 11b is configured such that the end surface 21c of the protrusion 16c of the retainer segment 11b abuts on the end surface 21a of the protrusion 16a of the retainer segment 11a, and the protrusion 16d of the retainer segment 11b It arrange | positions so that the end surface 21d and the end surface 21e of the protrusion 16e of the holder | retainer segment 11c may contact | abut.

  A pocket 35a for accommodating the tapered roller 34 is formed between the two adjacent cage segments 11b and 11c. The pocket 35a holds a tapered roller 34 disposed between adjacent cage segments 11b and 11c. Here, the pocket 35a is formed, for example, by defining the protruding amount of the protrusion 16d of the cage segment 11b and the protrusion 16e of the cage segment 11c according to the diameter of the tapered roller 34 to be held. The

  With this configuration, the tapered roller bearing 31 is provided by the tapered rollers 34 disposed between the cage segments 11b and 11c in addition to the tapered rollers 34 held by the cage segments 11a to 11d. Can also receive loads. Then, the tapered roller bearing 31 can receive a larger load. In particular, when the number of cage segments 11a to 11d and the like included in the tapered roller bearing 31 is large, the number of tapered rollers 34 disposed between the cage segments 11b and 11c and the like is also large, and the effect is remarkable. It is.

  Further, since the guide surface 36 is provided on the outer diameter side of the column portion 37 positioned on the outer side in the circumferential direction of the cage segment 11b, the cage segment 11b is also guided by the guide surface 36. Then, the radial position of the cage segment 11b can be further stabilized.

  Here, a load may be applied from the protrusion 16e of the adjacent cage segment 11c to the cage segment 11b in the circumferential direction, that is, in the direction indicated by the arrow D in FIG. Even in such a case, the protrusion 16e of the cage segment 11c and the projection 16d of the cage segment 11b come into contact with each other, so that no load is applied to the column portion 37 forming the pockets 35a and 35b. Then, deformation and breakage of the column portion 37 and locking of the tapered rollers 34 held in the pocket 35b can be prevented.

  Next, the arrangement state of the spacer 26 arranged between the first cage segment 11a and the last cage segment 11d will be described. FIG. 1 is an enlarged cross-sectional view of a portion indicated by I in FIG. FIG. 8 is a schematic view of the portion shown in FIG. 1 as viewed from the outside in the radial direction, that is, from the outer ring 32 side. With reference to FIG. 1 and FIG. 8, when the cage segments 11a and the like are successively arranged so as to contact each other, a gap 39 is generated between the cage segment 11a and the cage segment 11d.

  The dimension in the circumferential direction of the gap 39 is set within a certain range in consideration of the thermal expansion of the cage segments 11a to 11d and the like accompanying the temperature rise. However, in the dimension of the gap 39, circumferential dimension errors of the cage segments 11a to 11d and the like are accumulated. Therefore, it is very difficult to set the dimension of the gap 39 within the set range.

  Here, the spacer 26 is disposed so that the end faces 21f, 21g on the protrusions 16f, 16g side of the cage segment 11d abut on the end faces 29a, 29b on one side of the ends 27a, 27b of the spacer 26. Let In this case, the end portions 27a and 27b of the spacer 26 are sandwiched between the protrusions 16a and 16b of the cage segment 11a and the projections 16f and 16g of the cage segment 11d.

  By comprising in this way, the dimension of the last clearance 40 of the circumferential direction produced between the holder | retainer segment 11a and the spacer 26 can be easily set as the range. Here, the last clearance is the first when the cage segments 11a to 11d and the like are arranged without a gap on the circumference, and the last cage segment 11d and the spacer 26 are arranged without a gap. This is the maximum clearance between the cage segment 11a and the spacer 26 disposed between the first cage segment 11a and the last cage segment 11d. Of the circles passing through the connecting portion 15a of the cage segment 11a, if the dimension of the gap 39 on the circle with the smallest diameter is C, the dimension of the end 27a is A, and the dimension of the last gap 40 is B, The dimension A of the portion 27a is arbitrarily determined so that the dimension B of the last gap 40 falls within the set range when the spacer 26 is disposed between the cage segment 11a and the cage segment 11d. It is done. Here, in order to make the dimension B within the set range, for example, the end 27a may be cut in the circumferential direction according to the dimension C, or the spacers 26 having various dimensions A are manufactured in advance. The spacer 26 may be selected and arranged in accordance with the dimension C.

  With this configuration, the tapered roller bearing 31 in which the spacer 26 is disposed between the first cage segment 11a and the last cage segment 11d has a circumferential dimension such as the cage segments 11a to 11d. Regardless of the error, the last gap 40 between the cage segments 11a and 11d can be within a set range. If it does so, it will become unnecessary to manufacture cage segments 11a-11d etc. with high precision, and productivity of cage segments 11a-11d etc. will improve. Along with this, the productivity of the tapered roller bearing 31 is also improved.

  Here, the optimal circumferential dimension of the last clearance 40 is 0.15% or more of the circumference of the circle passing through the connecting portion 15a of the cage segment 11a, and less than the maximum roller diameter in the axial direction of the tapered roller 34. To do.

  When the circumferential dimension of the last gap is 0.15% or less of the circumference, the cage segments 11a to 11d are provided between the cage segment 11a and the spacer 26 when thermally expanded. This is because the last gap 40 is eliminated and a great amount of circumferential stress may occur in the cage segments 11a to 11d. Further, when the circumferential dimension of the last clearance is equal to or larger than the maximum roller diameter in the axial direction of the tapered roller 34, the axial arrangement of the tapered rollers 34 held between the adjacent cage segments 11a to 11d is not good. This is because it may become stable and cause poor guidance.

  Here, the circumferential dimension of the central portion 28 included in the spacer 26 described above is configured to be smaller than the circumferential dimension of the end portions 27a and 27b. The size in the circumferential direction of the central portion 28 may be larger than the size in the circumferential direction of the end portions 27a and 27b.

  FIG. 9 is a perspective view of the spacer 41 in this case. Referring to FIG. 9, the spacer 41 has end portions 42a and 42b positioned at both ends in the axial direction, and a central portion 43 positioned between both end portions 42a and 42b. The central portion 43 bulges in the circumferential direction from both sides in the circumferential direction, and has a shape that is received between the pair of protrusions 16a and 16b of the cage segment 11a and the pair of projections 16f and 16g of the cage segment 11d. A bulging portion 44 is provided. Further, grooves 45a and 45b penetrating in the circumferential direction are provided on the radially outer and inner diameter surfaces.

  FIG. 10 is a view from the radially outer side when the spacer 41 is disposed between the cage segments 11a and 11d. Referring to FIG. 10, the spacer 41 is disposed between the first cage segment 11a and the last cage segment 11d. Here, the circumferential bulging portion 44 provided in the spacer 41 is received between the protrusions 16a and 16b of the cage segment 11a and the pair of projections 16f and 16g of the cage segment 11d.

  Even if the spacer 41 having such a configuration tries to move in the axial direction, the circumferential bulging portion 44 is restrained by the pair of protrusions 16a and 16b and the pair of protrusions 16f and 16g, so that the axial movement is prevented. Be regulated. Therefore, the axial displacement of the spacer 41 can be suppressed.

  Here, the circumferential bulging portion 44 has a shape that bulges from both sides of the central portion 43 in the circumferential direction, but is not limited thereto, and bulges from one side of the central portion 43 in the circumferential direction. You may make it into a shape.

  In the above embodiment, the cage segment 11a and the like have three pockets for accommodating the rollers. However, the present invention is not limited to this and may have four or more pockets. FIG. 11A and FIG. 11B are radial cross-sectional views of the cage segment in this case. Referring to FIG. 11A, the cage segment 51 connects the pillars 53 and a plurality of pillars 53 extending in the direction along the axis so as to form four pockets 52a, 52b, 52c, and 52d. The pair of connecting portions 54 extending in the circumferential direction as described above and the pair of projecting portions 55a and 55b that are located at both ends in the axial direction and project from the connecting portion 54 in the circumferential direction are included. Guide surfaces 56 for guiding the cage segments 51 are provided on the inner diameter side and the outer diameter side of the column portion 53. Further, referring to FIG. 11B, the cage segment 61 includes a plurality of pillar portions 63 extending in the direction along the axis, and pillars so as to form five pockets 62a, 62b, 62c, 62d, 62e. A pair of connecting portions 64 extending in the circumferential direction so as to connect the portion 63 and a pair of projecting portions 65 a and 65 b that are located at both ends in the axial direction and that continue from the connecting portion 54 and protrude in the circumferential direction are included. A guide surface 66 for guiding the cage segment 61 is provided on the inner diameter side and the outer diameter side of the column part 63. Since the cage segments 51 and 61 having such a configuration have many pockets 52a provided with guide surfaces 56 and 66, the cage segments 51 and 61 are more stably arranged in the radial direction.

  In the above-described embodiment, the grooves 30a and 30b that penetrate in the circumferential direction are provided on the outer diameter surface and inner diameter surface of the spacer 26 and the like. A groove 30a or the like may be provided on any one of the upper surfaces, or a central portion in the radial direction such as the central portion 28 may be penetrated in the circumferential direction. In this case, the lubricant can flow more efficiently by matching the radial positions of the grooves 19 and 20 provided in the cage segments 11a and 11d with the grooves 30a provided in the spacer 26 and the like. Can do.

  FIG. 12 is a schematic view showing a rotary shaft support structure of a tunnel excavator according to one embodiment of the present invention. Referring to FIG. 12, the rotary shaft support structure 71 of the tunnel excavator includes a cutter head 73 provided with a cutter 72 for excavating earth and sand, and a rotary shaft that is provided with the cutter head 73 at one end and rotates together with the cutter head 73. 74 and a double-row tapered roller bearing 81 that is incorporated in the fixing member 77 and rotatably supports the rotating shaft 74 via the ring member 78. The double-row tapered roller bearing 81 that supports the rotating shaft 74 has a configuration in which the above-described tapered roller bearing is double-rowed. The cutter head 73 and the rotary shaft 74 are also supported by the cutter head support portion 75 as a whole.

  The rotation shaft 74 is rotated by the motor 76, and the cutter head 73 provided at one end thereof rotates. Then, the plurality of cutters 72 provided at the tip of the cutter head 73 excavate the front face. In this way, while excavating the front face, the tunnel excavator is advanced to form a tunnel. The excavated earth and sand are carried backward with respect to the traveling direction and removed.

  The double row tapered roller bearing 81 that supports the rotating shaft 74 needs to receive a large thrust load or moment load generated when crushing hard rock or the like. Then, it is necessary to make the double row tapered roller bearing 81 large. Here, by configuring the double row tapered roller bearing 81 from the above-described tapered roller bearing, the productivity, handleability, and assembly of the cage are improved. Therefore, the productivity of the double row tapered roller bearing 81 is improved, and the productivity of the rotary shaft support structure of the tunnel excavator including such a double row tapered roller bearing 81 is improved. In addition, since the cage is divided, it is possible to follow the deformation of the race such as the outer ring.

  Here, in order to prevent intrusion of excavated earth and sand into the double row tapered roller bearing 81, the double row tapered roller bearing 81 may be provided with a seal. FIG. 13 is a cross-sectional view showing a part of the double-row tapered roller bearing 81 described above. Referring to FIG. 13, double row tapered roller bearing 81 is disposed between outer ring 82, left and right inner rings 83 a and 83 b disposed so that the end surfaces on the small diameter side face each other, and left and right inner rings 83 a and 83 b. An inner ring spacer 86; a plurality of tapered rollers 84a, 84b disposed between the outer ring 82 and the left and right inner rings 83a, 83b; and a pocket for holding the plurality of tapered rollers 84a, 84b in the left and right rows. A plurality of cage segments 85a and 85b sequentially arranged in the circumferential direction between the outer ring 82 and the left and right inner races 83a and 83b, and the first cage segment and the last in the left and right rows. And a spacer (not shown) disposed between the cage segments. Between the outer ring 82 and the left and right inner rings 83a and 83b, a seal 91 is provided to prevent intrusion of earth and sand into the double row tapered roller bearing 81. Here, the seal 91 provided on the inner ring 83a side will be described. However, since the seal 91 provided on the inner ring 83b side has the same configuration, the description thereof is omitted.

  The seal 91 is annular, has a substantially L-shaped cross section, and has a rigid core metal part 92; a rubber part 93 that is attached to the core metal part 92 and has elasticity; and a spring 94 that can contract toward the inner diameter side; Is provided. The rubber portion 93 is provided with a lip portion 95 that nips with one inner ring 83 a with an appropriate pressure, and the spring 94 is disposed on the outer diameter side of the lip portion 95. The metal core portion 92 is attached to the inner diameter surface 90 of the one end portion 89 of the outer ring 82 so that the lip portion 95 provided in the rubber portion 93 nips with the outer diameter surface 88 on the large collar 87 side of the inner ring 83a. . The lip portion 95 is maintained in a nip state with the inner ring 83 a by the spring 94. In this way, the double row tapered roller bearing 81 is sealed by the seal 91.

  By comprising in this way, the penetration | invasion in the double row tapered roller bearing 81, such as earth and sand and muddy water excavated by the cutter 72 and conveyed back, can be prevented. If it does so, since the damage of the bearing member by the penetration | invasion of earth and sand, muddy water, etc. can be prevented, the double row tapered roller bearing 81 can be made long life. Therefore, a long service life can also be realized for the rotary shaft support structure of a tunnel excavator provided with such a double-row tapered roller bearing 81.

  The seal for preventing the entry of earth and sand into the double row tapered roller bearing may be provided on the outer side of the double row tapered roller bearing, or provided on only one of the left and right inner rings. Also good. Further, a plurality of seals may be arranged to prevent the intrusion of earth and sand etc. more efficiently.

  In the above embodiment, the double-row tapered roller bearing is a double-row tapered roller bearing configured so that the small-diameter side end faces of the inner ring face each other. The structure which opposes may be sufficient and two or more rows may be sufficient. Further, it may be a single row tapered roller bearing.

  In the above embodiment, the cage segment has a protrusion protruding in the circumferential direction. However, the present invention is not limited to this, and a type having no protrusion, that is, a column part on the outer side in the circumferential direction. The present invention is also applied to a cage segment having a configuration in which is arranged.

  The spacers etc. included in the tapered roller bearing described above are small and have a simple shape. Therefore, the material is made of resin such as engineer plastic and can be easily manufactured by injection molding or the like. Can do. By doing so, productivity is further improved.

  In the above embodiment, the tapered roller is used as the roller accommodated in the cage segment or the like. However, the present invention is not limited to this, and a cylindrical roller, a needle roller, a rod roller, or the like may be used.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  Since the rotary shaft support structure for a tunnel excavator according to the present invention can improve the productivity of the roller bearing, it can be effectively used when good productivity is required.

It is an expanded sectional view at the time of arrange | positioning a spacer between the 1st retainer segment and the last retainer segment. It is a perspective view of the cage segment with which the tapered roller bearing included in the rotary shaft support structure of the tunnel excavator according to one embodiment of the present invention is provided. It is sectional drawing at the time of cut | disconnecting the holder | retainer segment shown in FIG. 2 by the plane orthogonal to an axis | shaft including line III-III in FIG. It is sectional drawing at the time of cut | disconnecting the holder | retainer segment shown in FIG. 2 with the plane which passes along the center of a pillar part and is orthogonal to the circumferential direction. It is a perspective view which shows the spacer contained in a tapered roller bearing. It is a schematic sectional drawing of a tapered roller bearing at the time of arranging a plurality of cage segments and spacers in the circumferential direction. It is an expanded sectional view which shows the adjacent retainer segment. It is the schematic which looked at the part shown in FIG. 1 from the radial direction outer side. It is a perspective view of the spacer containing a circumferential bulge part. It is the figure which looked at the spacer shown in FIG. 9 from the radial direction outer side. FIG. 4 is a cross-sectional view of another embodiment of a cage segment included in a tapered roller bearing, (A) a cage segment having four pockets, and (B) a cage segment having five pockets. It is a figure which shows an example of the rotating shaft support structure of the tunnel excavator which concerns on this invention. It is sectional drawing which shows a part of double row tapered roller bearing contained in the rotating shaft support structure of the tunnel excavator shown in FIG. It is a perspective view of the retainer segment in the past. It is sectional drawing at the time of cut | disconnecting the holder | retainer segment shown in FIG. 14 in the plane containing a pillar part and orthogonal to an axis | shaft.

Explanation of symbols

  11a, 11b, 11c, 11d, 51, 61, 85a, 85b Cage segment, 12a, 12b, 12c, 34, 84a, 84b Tapered rollers, 13a, 13b, 13c, 35a, 35b, 52a, 52b, 52c, 52d , 62a, 62b, 62c, 62d, 62e Pocket, 14a, 14b, 14c, 14d, 37, 53, 63 Column part, 15a, 15b, 15c, 15d, 54, 64 Connecting part, 16a, 16b, 16c, 16d, 16e, 16f, 16g, 55a, 55b, 65a, 65b Projection, 17a, 17b, 17c, 17d, 18a, 18b, 18c, 18d, 36, 56, 66 Guide surface, 19, 20, 30a, 30b, 45a, 45b groove, 21a, 21b, 21c, 21d, 21e, 21f, 21g, 29a, 29b end face 22 PCD, 26, 41 spacer, 27a, 27b, 42a, 42b end, 28, 43 center, 31 tapered roller bearing, 32, 82 outer ring, 33, 83a, 83b inner ring, 39 clearance, 40 last clearance, 44 Circumferential bulging part, 71 Rotary shaft support structure of tunnel excavator, 72 cutter, 73 cutter head, 74 rotary shaft, 75 cutter head support part, 76 motor, 77 fixing member, 78 ring member, 81 double row conical roller bearing 86, inner ring spacer, 87 large collar, 88 outer diameter surface, 89 one end, 90 inner diameter surface, 91 seal, 92 cored bar portion, 93 rubber portion, 94 spring, 95 lip portion.

Claims (5)

A cutter head equipped with a cutter for excavating earth and sand;
The cutter head is provided at one end, and a rotating shaft that rotates together with the cutter head;
A rotary shaft support structure for a tunnel excavator including a roller bearing incorporated in a fixed member and rotatably supporting the rotary shaft,
The roller bearing has an outer ring, an inner ring, a plurality of rollers disposed between the outer ring and the inner ring, and a pocket for holding the roller, and is arranged in a circumferential direction between the outer ring and the inner ring. A rotary shaft support structure for a tunnel excavator comprising a plurality of cage segments arranged in series and a spacer arranged between a first cage segment and a last cage segment arranged in a circumferential direction. . The rotary shaft support structure for a tunnel excavator according to claim 1, wherein the roller bearing is provided with a seal. The cage segment is provided with a pair of protrusions located at both ends in the axial direction and protruding in the circumferential direction,
The spacer is in contact with a circumferential end surface of a pair of protrusions provided on the first cage segment and a circumferential end surface of a pair of projections provided on the last cage segment. 3. A rotary shaft support structure for a tunnel excavator according to 1 or 2. The said spacer is located in the both ends of an axial direction, and has the edge part pinched | interposed into the protrusion of the said 1st and last cage | basket segment, and the center part located between this both edge parts. Rotating shaft support structure for tunnel excavator. The rotary shaft support structure for a tunnel excavator according to claim 4, wherein a central portion of the spacer has a circumferential bulge that bulges in the circumferential direction and is received between a pair of protrusions of the cage segment. .

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