Structure for preventing intrusion of foreign objects into a rotating seal part of a work machine equipped with a crawler-type traveling body, and the work machine

Abstract

To suppress infiltration of foreign matters into a rotary seal portion and improve discharge performance of foreign matters to the outside.SOLUTION: A foreign matter infiltration prevention structure of a rotary seal portion of a work machine comprising a crawler type travel body comprises: a fixed housing fixed to a vehicle body side of the crawler type travel body; rotary wheels around which crawlers of the crawler type travel body are stretched and which rotates by driving force from a driving source; and a rotary seal portion provided between the fixed housing and the rotary wheel. The fixed housing includes a cover portion covering at least a part of an upper side space from above. Between the cover portion and the rotary wheel, there is formed a first opening communicating with the upper side space and opening downward in the vertical direction. Between a lower part of the fixed housing and the rotary wheel, there is formed a second opening communicating with a lower side space and opening downward in the vertical direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a structure for preventing intrusion of foreign matter into a rotating seal unit of a work machine equipped with a crawler-type traveling body, and to the work machine. [Background technology]

[0002] Patent Document 1 discloses a device for preventing mud from entering a rotating seal part that rotates in soil and sand, for example, a rotating seal part of a traveling reducer of an excavator. In Patent Document 1, a protector is attached to the outer periphery of the rotating seal part, and a space for mud accumulation is provided between the protector and the rotating seal part. The space for mud accumulation is formed between the protrusion of the protector and a sprocket that rotates via a rotating shaft. Patent Document 2 discloses a housing for a travel reducer that houses a reduction mechanism that reduces the rotational speed of a travel motor. In Patent Document 2, an opening for discharging foreign objects that communicates with a labyrinth passage is provided on the outer periphery of a cylindrical housing main body. A plurality of openings for discharging foreign objects are arranged in a region extending from the lower half of the housing main body to one end in the travel direction. Patent Document 3 discloses a cover body for preventing foreign objects from entering a drive sprocket of a work machine equipped with a crawler-type traveling body. In Patent Document 3, the cover body is divided into an upper half and a lower half, and the connecting parts of the adjacent ends are connected to each other via a connecting bolt. A discharge port is formed by cutting out the lower half of the cover part to discharge foreign objects that have entered the gap between the sprocket housing and the tip of the cover part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 60-43772 [Patent Document 2] JP 2017-215002 A [Patent Document 3] JP 2016-88172 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of Patent Document 1, the protector has the same shape for 360° around the rotation axis. In Patent Document 1, priority is given to preventing the infiltration of soil and sand, which may result in poor soil discharge performance. In the case of Patent Document 2, the range of the openings for discharging foreign matter is narrow, so there is room for improvement in terms of improving the ability to dispose of foreign matter. In the case of Patent Document 3, the outlet formed by the cutout in the lower half of the cover has a labyrinth shape (L-shaped in cross section), which leaves room for improvement in terms of improving the ability to discharge foreign matter from the outlet.

[0005] Therefore, the present disclosure aims to provide a foreign object intrusion prevention structure for a rotating seal part of a work machine equipped with a crawler-type running body that can suppress the intrusion of foreign objects into the rotating seal part and improve the ability to discharge foreign objects to the outside, and to provide a work machine. [Means for solving the problem]

[0006] According to one embodiment of the present disclosure, there is provided a foreign object intrusion prevention structure for a rotating seal unit of a work machine equipped with a crawler-type running body, the rotating wheel on which the crawler of the crawler-type running body is suspended and which rotates by a driving force from a driving source, and a rotating seal unit provided between the fixed housing and the rotating wheel, the rotating seal unit including an upper space having a labyrinth-shaped space formed between an upper part of the fixed housing and the rotating wheel, and a lower space formed between a lower part of the fixed housing and the rotating wheel, the fixed housing including a cover unit covering at least a part of the upper space from above, a first opening connected to the upper space and opening vertically downward is formed between the cover unit and the rotating wheel, and a second opening connected to the lower space and opening vertically downward is formed between the lower part of the fixed housing and the rotating wheel. Effect of the Invention

[0007] According to the above aspect, it is possible to suppress the intrusion of foreign matter into the rotating seal portion and improve the ability to discharge foreign matter to the outside. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of a work machine according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of one end side in the running direction of a lower running body according to the embodiment. [Diagram 3] FIG. 4 is an explanatory diagram showing an example of the behavior of soil and sand on a lower traveling body according to the embodiment. [Figure 4] FIG. 4 is a side view of one end in the running direction of a lower running body according to the embodiment. [Diagram 5] FIG. 5 is a diagram including a VV cross section of FIG. 4 . [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 4. [Figure 7] Enlarged view of Figure 5. [Figure 8] 8 is a cross-sectional view corresponding to FIG. 7 and showing a protrusion according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, a shovel will be described as an example of a work machine (work vehicle).

[0010] <Shovel (working machine)> As shown in FIG. 1, a shovel 1 as a work machine includes a vehicle body 2 and a work implement 3 connected to the vehicle body 2. Hereinafter, the forward direction, reverse direction and vehicle width direction of the shovel 1 will be referred to as the "front of the vehicle (one side in the fore-and-aft direction of the vehicle)", the "rear of the vehicle (the other side in the fore-and-aft direction of the vehicle)" and the "vehicle width direction". The vehicle width direction may also be referred to as the "left side (one side in the vehicle width direction)" or the "right side (the other side in the vehicle width direction)". The right side with respect to the forward direction of the shovel 1 will be referred to as the right side, and the left side with respect to the forward direction of the shovel 1 will be referred to as the left side. The up-down direction, upward and downward when the shovel 1 is arranged on a horizontal plane will be referred to simply as the "up-down direction", "up" and "down".

[0011] <Vehicle body> The vehicle body 2 includes a self-propelled lower traveling body 5 (crawler type traveling body) and an upper rotating body 6 provided on the lower traveling body 5 so as to be able to rotate freely.

[0012] The lower traveling body 5 includes a crawler 7 connected in a belt so as to surround a rotating wheel 32 serving as a drive wheel. The crawler 7 is composed of a pair of left and right tracks 7L, 7R. The lower traveling body 5 includes a motor (drive source, not shown) that drives the tracks 7L, 7R. For example, the motor is a hydraulic motor. The lower traveling body 5 travels by the tracks 7L, 7R being driven by the motor. The excavator 1 moves forward, turns, and reverses by the rotation of the left track 7L and the right track 7R.

[0013] The upper rotating body 6 is provided on the upper part of the lower traveling body 5. The upper rotating body 6 is capable of rotating about an axis extending in the vertical direction relative to the lower traveling body 5. The upper rotating body 6 is provided with a driver's cab 10 where an operator sits and operates and steers the excavator. The driver's cab 10 is provided in the front left part of the upper rotating body 6. The driver's cab 10 is provided with a control device 11 for controlling the excavator 1.

[0014] The work machine 3 is provided so as to be movable relative to the upper rotating body 6 so as to be able to bend and rise and fall freely. The work machine 3 includes a boom 20, an arm 21, a bucket 22 (work implement), and a plurality of (for example, three in this embodiment) cylinders 25-27. The three cylinders 25-27 are a first cylinder 25 that operates the boom 20, a second cylinder 26 that operates the arm 21, and a third cylinder 27 that operates the bucket 22. A base end of the boom 20 is rotatably connected to the upper rotating body 6. A tip end of the boom 20 is rotatably connected to a base end of the arm 21. A tip end of the arm 21 is rotatably connected to the bucket 22.

[0015] <Lower running body> Fig. 2 is a perspective view of one end side in the running direction of a lower traveling body according to the embodiment, as viewed from the inside (the side indicated by the arrow indicated by the two-dot chain line in Fig. 1) of the rear side of the lower traveling body. As shown in Fig. 2, a lower frame 30, which is a skeleton of the lower part of the vehicle, is provided on the lower traveling body 5 of the excavator 1. A fixed housing 31, which serves as a fixed part on the vehicle body side, is fixed to the lower frame 30. A drive shaft that is driven to rotate in both forward and reverse directions by a motor (not shown) is rotatably supported by the fixed housing 31.

[0016] A rotating wheel 32 serving as a drive wheel is rotatably supported by the fixed housing 31 via a bearing (not shown). A sprocket 72 around which the crawler 7 is stretched is provided on the outer periphery of the rotating wheel 32. For example, as the drive shaft rotates due to the drive of the motor, the rotating wheel 32 is rotated at a reduced speed in either forward or reverse direction via a gear reduction mechanism (not shown) in the fixed housing 31. Therefore, the crawler 7 is rotated in either forward or reverse direction via the sprocket 72 on the outer periphery of the rotating wheel 32, and the excavator 1 moves forward or backward.

[0017] <Behavior of soil and sand> FIG. 3 is an explanatory diagram showing an example of the behavior of soil and sand on the lower traveling body according to the embodiment. As shown in Fig. 3, when the rotating wheel 32 rotates in either the forward or reverse direction and the crawler 7 rotates in either the forward or reverse direction, the soil moves along the crawler 7. For example, soil adheres to the crawler 7 due to the running of the vehicle, and the adhered soil moves along the rotation of the crawler 7 (for example, in the direction of arrows A1 to A3 in Fig. 3). Then, some of the soil falls from the crawler 7 onto the upper part of the fixed housing 31 (for example, in the direction of arrow A3 in Fig. 3). The soil that has fallen onto the upper part of the fixed housing 31 moves along the circumferential direction of the rotating wheel 32 (for example, in the direction of arrow B1 or arrow B2 in the figure).

[0018] <Floating seal> Fig. 4 is a side view of one end side in the running direction of a lower running body according to the embodiment. Fig. 4 corresponds to a side view of a fixed housing seen from one side in a direction along the axis of a rotating wheel (axial direction). In Fig. 4, the fixed housing is indicated by dot hatching. Fig. 5 is a view including a VV cross section of Fig. 4. Fig. 6 is a view including a VI-VI cross section of Fig. 4. Fig. 7 is an enlarged view of Fig. 5. 5, an annular floating seal 40 is provided between the fixed housing 31 and the rotating ring 32, coaxially with the rotating ring 32. The floating seal 40 has the function of suppressing leakage of oil that lubricates the bearings and the like (not shown) to the outside, and also prevents foreign matter such as external soil and dust from entering.

[0019] The floating seal 40 comprises a pair of elastic rings 41 attached to the inner ends of the fixed housing 31 and the rotating ring 32, respectively, and a seal ring 42 supported by the elastic rings 41. For example, the elastic ring 41 is made of an elastic material such as rubber. For example, the seal ring 42 is made of a metal material such as special cast iron. The elastic rings 41 urge the seal rings 42 in the pressure contact direction with each other, thereby ensuring the sealing performance between the seal rings 42.

[0020] <Prevention of foreign matter from entering the rotating seal> 5, a rotating seal portion 50 is provided between the fixed housing 31 and the rotating wheel 32. The rotating seal portion 50 is provided so as to surround the outer periphery of the floating seal 40. The rotating seal portion 50 has a function of preventing foreign matter such as soil and sand from entering the floating seal 40 side.

[0021] The rotating seal portion 50 includes an upper space 52 having a labyrinth-shaped space 51 formed between the upper portion 35 of the fixed housing 31 and the rotating wheel 32, and a lower space 53 (see FIG. 6) formed between the lower portion 36 of the fixed housing 31 and the rotating wheel 32. Here, the labyrinth shape means a shape in which the length of the passage is made as long as possible by providing a bent portion in order to prevent foreign matter such as soil and sand from entering the rotating seal portion 50. The labyrinth-shaped space 51 is formed by the fixed housing 31 and the rotating wheel 32.

[0022] As shown in Fig. 4, the upper part 35 of the stationary housing 31 is a portion including a range of 180° above the stationary housing 31 (upper angle D1 shown in Fig. 4). The lower part 36 of the stationary housing 31 is a portion including a range of 180° below the stationary housing 31 (lower angle D2 shown in Fig. 4). As shown in Fig. 5, the upper space 52 is a portion of the space 51 of the rotating seal part 50 that includes a range of 180° above (upper angle D1 shown in Fig. 4). The lower space 53 is a portion of the space 51 of the rotating seal part 50 that includes a range of 180° below (lower angle D2 shown in Fig. 4).

[0023] As shown in Fig. 7, the fixed housing 31 includes a cover portion 61 that covers at least a portion of the upper space 52 from above. In this embodiment, the cover portion 61 is configured to cover the entire upper space 52 from above. The cover portion 61 is provided over the entire portion of the fixed housing 31 including a range of 180° (upper angle D1 shown in Fig. 4) on the upper side. The fixed housing 31 includes a cylindrical housing main body 60 that is coaxial with the rotating wheel 32. The cover portion 61 is detachably attached to the upper portion of the housing main body 60 (upper portion 35 of the fixed housing 31).

[0024] 7, a female threaded portion 62 that opens vertically upward so that the male threaded portion 63a of the bolt 63 can be screwed into the female threaded portion 62 is formed in the upper portion of the housing body 60. The cover portion 61 has a through hole 64 at a position corresponding to the female threaded portion 62, the through hole 64 being open so that the male threaded portion 63a of the bolt 63 can be inserted therethrough.

[0025] In the cross-sectional view of Fig. 7, the cover portion 61 has an L-shape. In the cross-sectional view of Fig. 7, the cover portion 61 includes a first extension portion 65 extending parallel to the axis of the rotating wheel 32 (axial direction of the rotating wheel 32), and a second extension portion 66 extending from one end of the first extension portion 65 toward the axis of the rotating wheel 32 (radial inner side of the rotating wheel 32). For example, the first extension portion 65 and the second extension portion 66 are integrally formed of the same member. The through hole 64 is formed in a portion of the first extension portion 65 that overlaps with the female thread portion 62 at the upper part of the housing main body 60.

[0026] 7 shows one female thread portion 62 on the upper part of the fixed housing 31 and one through hole 64 on the cover part 61, but is not limited thereto. For example, a plurality of female thread portions 62 may be provided on the upper part of the fixed housing 31, and a plurality of through holes 64 may be provided on the cover part 61. For example, the number of female thread portions 62 and through holes 64 provided can be changed according to the required specifications.

[0027] As shown in Fig. 5, a first opening 55 that communicates with the upper space 52 and opens vertically downward is formed between the cover portion 61 and the rotating wheel 32. As shown in Fig. 6, a second opening 56 that communicates with the lower space 53 and opens vertically downward is formed between the lower portion 36 of the fixed housing 31 and the rotating wheel 32.

[0028] 5 (a cross-sectional view including the axis and vertical plane of the rotating wheel 32), the rotating wheel 32 includes a foreign matter accumulation portion 70 in which foreign matter can accumulate, and a protrusion 71 that stands up from the foreign matter accumulation portion 70 and extends vertically above the first opening 55. In the cross-sectional view of FIG. 5, the foreign matter accumulation portion 70 corresponds to the lower end of the protrusion 71 in the vertical direction.

[0029] In the cross-sectional view of Fig. 5, the rotating wheel 32 is provided between the sprocket 72 and the foreign matter accumulation portion 70, and has a curved surface 73 that extends while curving so as to approach the foreign matter accumulation portion 70 toward the axial side of the rotating wheel 32 (the radially inner side of the rotating wheel 32). In the cross-sectional view of Fig. 5, the curved surface 73 is curved in an arc shape in the opposite direction to the cover portion 61. A gap is formed between the cover portion 61 and the curved surface 73.

[0030] In the cross-sectional view of FIG. 7, in the rotating wheel 32, the vertical distance L2 from the foreign matter accumulation portion 70 to the upper end of the protrusion 71 is greater than the vertical distance L1 from the foreign matter accumulation portion 70 to the first opening 55 (L1 <L2)。

[0031] In the cross-sectional view of Fig. 5, the upper space 52 has a labyrinth shape (inverted J shape) extending from the first opening 55 to the upper side of the floating seal 40. In the cross-sectional view of Fig. 7, the upper space 52 includes a first gap 52a formed between the protrusion 71 and the cover part 61 and extending vertically upward from the first opening 55, a second gap 52b formed on the opposite side of the protrusion 71 to the first gap 52a and extending vertically, and a third gap 52c extending to connect the vertical upper end of the first gap 52a and the vertical upper end of the second gap 52b. In the cross-sectional view of Fig. 7, the interval (horizontal length) of the first gap 52a, the interval (horizontal length) of the second gap 52b, and the interval (vertical length) of the third gap 52c are all the same size. The interval (horizontal length) of the first gap 52a, the interval (horizontal length) of the second gap 52b, and the interval (vertical length) of the third gap 52c may each have a different size.

[0032] In the cross-sectional view of FIG. 7, the protrusion 71 is formed in a rectangular shape having a longitudinal direction perpendicular to the axis of the rotating wheel 32 (the radial direction of the rotating wheel 32). In the cross-sectional view of FIG. 7, the protrusion 71 has a first protrusion side surface 71a that faces the first gap 52a and has a linear shape along the vertical direction, a second protrusion side surface 71b that faces the second gap 52b and has a linear shape parallel to the first protrusion side surface 71a, and a third protrusion side surface 71c that faces the third gap 52c and has a linear shape along the horizontal direction. In the cross-sectional view of FIG. 7, the first protrusion side surface 71a and the second protrusion side surface 71b have the same length in the vertical direction. Note that the range of the second protrusion side surface 71b of the rotating wheel 32 facing the fixed housing 31 is longer in the vertical direction than the first protrusion side surface 71a. In the cross-sectional view of FIG. 7, the length (horizontal length) of the third protrusion side surface 71c is shorter than the length (vertical length) of the first protrusion side surface 71a.

[0033] In the cross-sectional view of Figure 7, the upper part 35 of the fixed housing 31 (including the cover part 61 attached to the housing main body 60) has a first fixed side 35a that faces the first gap 52a and has a linear shape along the vertical direction, a second fixed side 35a that faces the second gap 52b and has a linear shape parallel to the first fixed side 35a, and a third fixed side 35c that faces the third gap 52c and has a linear shape along the horizontal direction.

[0034] The first fixed side surface 35a faces the first protrusion side surface 71a across the first gap 52a. The first fixed side surface 35a corresponds to a portion of the second extending portion 66 of the cover portion 61 that faces the first gap 52a. The second fixed side surface 35b faces the second protrusion side surface 71b across the second gap 52b. The second fixed side surface 35b corresponds to a portion of the upper part of the housing main body 60 of the fixed housing 31 that faces the second gap 52b. The third fixed side surface 35c faces the third protrusion side surface 71c across the third gap 52c. The third fixed side surface 35c corresponds to a portion of the first extending portion 65 of the cover portion 61 that faces the third gap 52c.

[0035] In the cross-sectional view of FIG. 6 (cross-sectional view including the axis and vertical plane of the rotating wheel 32), the lower space 53 extends from the lower side of the floating seal 40 to the second opening 56 along the arrow E2 in FIG. 6. The lower space 53 has a straight line portion 53a extending in a straight line shape along the vertical direction. In the cross-sectional view of FIG. 6, the straight line portion 53a is formed on an extension line of the second gap 52b (see FIG. 5) of the upper space 52. For example, in the cross-sectional view of FIG. 6, the interval (horizontal length) of the straight line portion 53a has the same size as the interval (horizontal length) of the second gap 52b. The second opening 56 is formed at the vertical lower end of the straight line portion 53a.

[0036] In the cross-sectional view of Fig. 6, the rotating wheel 32 has a downward extension 75 that extends in the vertical direction opposite (vertically downward) to the protrusion 71 (see Fig. 5). The downward extension 75 corresponds to the protrusion 71 that is displaced vertically downward due to the rotation of the rotating wheel 32. The difference between the protrusion 71 and the downward extension 75 is whether it is located on the vertically upper side or the vertically lower side of the rotating wheel 32. In the cross-sectional view of Fig. 6, the downward extension 75 faces the straight portion 53a and has a downward extension side surface 75a that is a straight line along the vertical direction.

[0037] In the cross-sectional view of Fig. 6, the lower portion 36 of the fixed housing 31 faces the straight portion 53a and has a straight lower fixed side surface 36a that is shaped like a straight line along the vertical direction. The lower fixed side surface 36a faces the downwardly extending side surface 75a via the straight portion 53a. In the cross-sectional view of Fig. 6, the lower fixed side surface 36a and the downwardly extending side surface 75a extend parallel to each other. The second opening 56 is formed by the lower end of the lower fixed side surface 36a and the lower end of the downwardly extending side surface 75a.

[0038] <Action and effect> As described above, the foreign object intrusion prevention structure 49 of the rotating seal unit 50 of this embodiment includes the fixed housing 31 fixed to the vehicle body side of the lower traveling body 5, the rotating wheel 32 around which the crawler 7 of the lower traveling body 5 is stretched and which rotates by the driving force from the driving source, and the rotating seal unit 50 provided between the fixed housing 31 and the rotating wheel 32. The rotating seal unit 50 includes an upper space 52 having a labyrinth-shaped space 51 formed between the upper part 35 of the fixed housing 31 and the rotating wheel 32, and a lower space 53 formed between the lower part 36 of the fixed housing 31 and the rotating wheel 32. The fixed housing 31 includes a cover part 61 that covers at least a part of the upper space 52 from above. A first opening 55 that is connected to the upper space 52 and opens vertically downward is formed between the cover part 61 and the rotating wheel 32. A second opening 56 that communicates with the lower space 53 and opens vertically downward is formed between the lower portion 36 of the fixed housing 31 and the rotating wheel 32. According to this configuration, the first opening 55 opens vertically downward between the cover portion 61 and the rotating wheel 32, so that the intrusion of foreign matter from the first opening 55 into the upper space 52 can be suppressed by the action of gravity. In addition, the second opening 56 opens vertically downward between the lower portion 36 of the fixed housing 31 and the rotating wheel 32, so that the intrusion of foreign matter from the second opening 56 into the lower space 53 can be suppressed by the action of gravity. For example, even if a foreign matter invades the upper space 52 or the lower space 53, the invaded foreign matter can be discharged vertically downward from the second opening 56 by the action of gravity. Therefore, the intrusion of foreign matter into the rotating seal portion 50 can be suppressed, and the discharge of foreign matter to the outside can be improved.

[0039] In this embodiment, the rotating wheel 32 includes a foreign matter accumulation portion 70 in which foreign matter can accumulate, and a protrusion 71 that stands up from the foreign matter accumulation portion 70 and extends vertically above the first opening 55. According to this configuration, since the protrusion 71 extends from the foreign matter accumulation part 70 above the first opening 55 in the vertical direction, even if foreign matter enters the first opening 55, for example, the protrusion 71 can prevent the foreign matter from entering deep into the upper space 52. Therefore, the intrusion of foreign matter into the rotary seal part 50 can be more effectively suppressed.

[0040] In the present embodiment, in the rotating ring 32, the vertical distance L2 from the foreign matter accumulation part 70 to the upper end of the protrusion 71 is larger than the vertical distance L1 from the foreign matter accumulation part 70 to the first opening 55 (L1 < L2). According to this configuration, even if foreign matter enters the first opening 55, for example, due to the relationship of L1 < L2, the foreign matter can be prevented from entering deep into the upper space 52. Therefore, the intrusion of foreign matter into the rotary seal part 50 can be more effectively suppressed.

[0041] In the present embodiment, the upper space 52 is formed between the protrusion 71 and the cover part 61, and includes a first gap 52a extending upward in the vertical direction from the first opening 55, a second gap 52b formed on the opposite side of the first gap 52a with the protrusion 71 interposed therebetween and extending in the vertical direction, and a third gap 52c extending so as to connect the upper end in the vertical direction of the first gap 52a and the upper end in the vertical direction of the second gap 52b. The protrusion 71 has a first protrusion side surface 71a facing the first gap 52a and having a linear shape along the vertical direction, a second protrusion side surface 71b facing the second gap 52b and having a linear shape parallel to the first protrusion side surface 71a, and a third protrusion side surface 71c facing the third gap 52c and having a linear shape along the horizontal direction. The fixed housing 31 has a first fixed side surface 35a facing the first gap 52a and having a linear shape along the vertical direction, a second fixed side surface 35b facing the second gap 52b and having a linear shape parallel to the first fixed side surface 35a, and a third fixed side surface 35c facing the third gap 52c and having a linear shape along the horizontal direction. According to this configuration, the upper space 52 has a labyrinth shape (inverted J shape) formed by the first gap 52a, the second gap 52b, and the third gap 52c. Therefore, even if a foreign object enters the first opening 55, the labyrinth shape can prevent the foreign object from entering the depths of the upper space 52 (for example, the third gap 52c). Therefore, the intrusion of foreign objects into the rotating seal portion 50 can be more effectively prevented.

[0042] In this embodiment, the lower space 53 has a straight portion 53a that extends linearly along the vertical direction. The second opening 56 is formed at the lower end of the straight portion 53a in the vertical direction. According to this configuration, the lower space 53 has a straight shape along the vertical direction. Therefore, compared to when the lower space 53 has a labyrinth shape, foreign matter that has entered is more easily discharged vertically downward from the second opening 56. This further improves the dischargeability of foreign matter to the outside. For example, even if a foreign matter enters the depth of the upper space 52 (e.g., the second gap 52b) (e.g., moves along the direction of arrow E1 in FIG. 5), the straight shape allows the foreign matter that has entered the depth of the upper space 52 to be discharged to the outside along the straight shape (e.g., the direction of arrow E2 in FIG. 6).

[0043] In this embodiment, the cover portion 61 is detachably attached to the upper portion 35 of the fixed housing 31 . According to this configuration, foreign matter that has entered the upper space 52 can be cleaned away by removing the cover portion 61, which provides excellent maintainability.

[0044] In this embodiment, a female threaded portion 62 that opens vertically upward so that the male threaded portion 63a of the bolt 63 can be screwed into is formed on the upper portion 35 of the fixed housing 31. The cover portion 61 has a through hole 64 at a position corresponding to the female threaded portion 62, the through hole 64 opening so that the male threaded portion 63a of the bolt 63 can be inserted therethrough. According to this configuration, a working space for fastening the bolts can be secured above the cover portion 61, resulting in excellent workability.

[0045] In this embodiment, the shovel 1 includes a vehicle body 2 and a work machine 3 connected to the vehicle body 2. The vehicle body 2 includes the foreign matter intrusion prevention structure 49 of the rotating seal portion 50 described above. Therefore, it is possible to provide a shovel 1 that can suppress the intrusion of foreign matter into the rotating seal portion 50 and improve the ability to discharge foreign matter to the outside.

[0046] <Other embodiments> In the above-described embodiment, the rotating wheel is provided with a foreign matter accumulation portion on which foreign matter can accumulate, and a protrusion portion that rises from the foreign matter accumulation portion and extends vertically above the first opening, but the present invention is not limited to this. For example, the protrusion portion may extend vertically below the first opening. For example, the rotating wheel does not need to have a protrusion portion that rises from the foreign matter accumulation portion. For example, it is sufficient that a first opening portion that is connected to the upper space and opens vertically downward is formed between the cover portion and the rotating wheel. For example, the configuration of the protrusion portion can be changed according to the required specifications.

[0047] In the above-mentioned embodiment, the upper space includes a first gap formed between the protrusion and the cover and extending vertically upward from the first opening, a second gap formed on the opposite side of the protrusion from the first gap and extending vertically, and a third gap extending so as to connect the vertical upper end of the first gap and the vertical upper end of the second gap. However, the present invention is not limited to this. For example, the upper space does not need to have a third gap. For example, the upper space may be formed by the first gap extending vertically upward from the first opening and the second gap extending vertically downward from the vertical upper end of the first gap. For example, the configuration of the upper space can be changed according to the required specifications.

[0048] In the above-mentioned embodiment, the protrusion has a first protrusion side surface facing the first gap and having a linear shape along the vertical direction, a second protrusion side surface facing the second gap and having a linear shape parallel to the first protrusion side surface, and a third protrusion side surface facing the third gap and having a linear shape along the horizontal direction. However, the shape is not limited to this. For example, the shape of the protrusion does not have to be a rectangular shape having the first protrusion side surface, the second protrusion side surface, and the third protrusion side surface. For example, the shape of the protrusion can be changed according to the required specifications.

[0049] 8, in a cross-sectional view including the axis and vertical plane of the rotating wheel 32, the protrusion 171 may have a triangular shape protruding vertically upward. With this configuration, even if a foreign object penetrates deep into the upper space 52 (e.g., the third gap 52c), the triangular shape can prevent the foreign object from stagnating in the third gap 52c. In other words, the foreign object that penetrates deep into the upper space 52 can be discharged toward the lower space 53 along the inclination of the triangular shape. Therefore, the dischargeability of the foreign object to the outside can be further improved.

[0050] In the above-mentioned embodiment, the fixed housing has a first fixed side surface facing the first gap and having a linear shape along the vertical direction, a second fixed side surface facing the second gap and having a linear shape parallel to the first fixed side surface, and a third fixed side surface facing the third gap and having a linear shape along the horizontal direction. However, the present invention is not limited to this. For example, the shape of the fixed housing does not have to be a rectangular concave shape (a rectangular concave shape that follows the shape of the protrusion) having the first fixed side surface, the second fixed side surface, and the third fixed side surface. For example, when the protrusion has the above-mentioned triangular shape, the shape of the fixed housing may be a triangular concave shape that follows the shape of the protrusion. For example, the shape of the fixed housing can be changed according to the required specifications.

[0051] In the above-described embodiment, the lower space has a straight portion extending in a straight line shape along the vertical direction, and the second opening is formed at the lower end of the straight portion in the vertical direction, but this is not limited to the above. For example, the shape of the lower space does not have to be a straight shape along the vertical direction. For example, the shape of the lower space may be a labyrinth shape. For example, the shape of the lower space can be changed according to the required specifications.

[0052] In the above-described embodiment, the cover portion is detachably attached to the upper portion of the fixed housing, but the present invention is not limited thereto. For example, the cover portion may be non-detachably connected to the upper portion of the fixed housing. For example, the cover portion may be integrally formed with the housing body of the fixed housing using the same material. For example, the configuration of the cover portion may be changed according to the required specifications.

[0053] In the above-described embodiment, an example has been described in which the upper part of the fixed housing is formed with a female threaded portion that opens vertically upward so that the male threaded portion of the bolt can be screwed therein, and the cover part has a through hole that opens so that the male threaded portion of the bolt can be inserted at a position corresponding to the female threaded portion, but this is not limited to the above. A bolt may be connected to the upper part of the fixed housing, and the cover part may have a through hole that opens so that the male threaded portion of the bolt can be inserted therein, and a nut may be screwed onto the male threaded portion of the bolt that has passed through the through hole of the cover part. For example, the manner in which the cover part is attached to the upper part of the fixed housing can be changed according to the required specifications.

[0054] In the above-mentioned embodiment, the cover part is configured to cover the entire upper space from above, but the present invention is not limited thereto. For example, the cover part does not have to be provided over the entire portion including the range of 180° above the fixed housing. For example, the cover part may be configured to cover only a portion of the upper space from above. For example, the cover part may be provided only on the portion including the range of 90° to 180° above the fixed housing. For example, the cover part may be configured to cover the entire upper space from above and to cover a portion of the lower space from below. For example, the cover part may be provided on the portion including the range of 10° to 90° below the fixed housing in addition to the range of 180° above the fixed housing. For example, the installation mode (installation range) of the cover part with respect to the fixed housing can be changed according to the required specifications.

[0055] In the above embodiment, a shovel has been described as an example of a work machine (work vehicle), but the present invention is not limited to this. For example, the present invention may be applied to other work vehicles such as a dump truck, a bulldozer, a wheel loader, etc.

[0056] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention, and the above-described embodiments can also be combined as appropriate. [Explanation of symbols]

[0057] 1... Shovel (working machine), 2... Vehicle body, 3... Work machine, 5... Lower traveling body (crawler type traveling body), 7... Crawler, 31... Fixed housing, 32... Rotating wheel, 35... Upper part of fixed housing, 35a... First fixed side, 35b... Second fixed side, 35c... Third fixed side, 36... Lower part of fixed housing, 49... Foreign object intrusion prevention structure, 50... Rotating seal part, 51... Space, 52... Upper space space, 52a...first gap, 52b...second gap, 52c...third gap, 53...lower space, 53a...straight portion, 55...first opening, 56...second opening, 61...cover portion, 70...foreign matter accumulation portion, 71...projection portion, 71a...first projection side surface, 71b...second projection side surface, 71c...third projection side surface, L1...distance from foreign matter accumulation portion to first opening, L2...distance from foreign matter accumulation portion to upper end of projection portion

Claims

1. a fixed housing fixed to a vehicle body side of the crawler-type traveling body; a rotating wheel on which the crawler of the crawler-type traveling body is stretched and which rotates by a driving force from a driving source; a rotary seal portion provided between the stationary housing and the rotary wheel, The rotary seal portion is an upper space having a labyrinth shape formed between an upper portion of the fixed housing and the rotating wheel; a lower space formed between a lower portion of the fixed housing and the rotating wheel, the fixed housing includes a cover portion that covers at least a portion of the upper space from above, A first opening portion is formed between the cover portion and the rotating wheel, the first opening portion being connected to the upper space and opening vertically downward, A second opening portion is formed between the lower portion of the fixed housing and the rotating wheel, the second opening portion being connected to the lower space and opening vertically downward. A structure for preventing intrusion of foreign matter into a rotating seal part of a work machine equipped with a crawler-type traveling body.

2. The rotating wheel is a foreign matter accumulation section provided so that foreign matter can accumulate; a protrusion portion that stands from the foreign matter accumulation portion and extends vertically above the first opening portion. A structure for preventing intrusion of foreign matter into a rotating seal portion of a working machine equipped with the crawler-type traveling body according to claim 1.

3. In the rotating wheel, The vertical distance from the foreign matter accumulation portion to the upper end of the protrusion is greater than the vertical distance from the foreign matter accumulation portion to the first opening. A structure for preventing intrusion of foreign matter into a rotating seal portion of a working machine equipped with the crawler-type traveling body according to claim 2.

4. The upper space is a first gap formed between the protrusion and the cover and extending vertically upward from the first opening; a second gap formed on an opposite side of the protrusion from the first gap and extending in a vertical direction; a third gap extending to connect a vertical upper end of the first gap and a vertical upper end of the second gap. A structure for preventing intrusion of foreign matter into a rotating seal portion of a working machine equipped with the crawler-type traveling body according to claim 2 or 3.

5. The protrusion is A first protrusion side surface facing the first gap and having a linear shape along a vertical direction; a second protrusion side surface facing the second gap and having a linear shape parallel to the first protrusion side surface; a third protrusion side surface facing the third gap and having a linear shape along a horizontal direction; A structure for preventing intrusion of foreign matter into a rotating seal portion of a working machine equipped with the crawler-type traveling body according to claim 4.

6. The stationary housing includes: A first fixed side surface facing the first gap and having a linear shape along a vertical direction; A second fixed side surface facing the second gap and having a linear shape parallel to the first fixed side surface; a third fixed side surface facing the third gap and having a linear shape along a horizontal direction; A structure for preventing intrusion of foreign matter into a rotating seal portion of a working machine equipped with the crawler-type traveling body according to claim 5.

7. The lower space has a straight portion extending linearly along a vertical direction, The second opening is formed at a vertical lower end of the straight portion. A structure for preventing intrusion of foreign matter into a rotating seal portion of a working machine comprising the crawler-type traveling body according to any one of claims 1 to 6.

8. The cover portion is detachably attached to the upper portion of the fixed housing. A structure for preventing intrusion of foreign matter into a rotating seal portion of a working machine comprising the crawler-type traveling body according to any one of claims 1 to 7.

9. A vehicle body, A working machine connected to the vehicle body, The vehicle body is provided with a foreign object intrusion prevention structure for a rotating seal part of a working machine equipped with a crawler-type traveling body according to any one of claims 1 to 8. Working machinery.

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