JP2017052312A - Crawler vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crawler vehicle reducing sediment pressure applied to a floating seal provided between a fixed side housing and a rotating side housing.SOLUTION: A drive wheel 8 rotated by a reduction gear 15 is provided on the rear side of a side frame 6 in a longitudinal direction. A floating seal 37 for sealing a gap 36 between a fixed side housing 16 and a rotating side housing 18 of the reduction gear 15 is provided on the radial inner side of the gap 36. A cover 42 covering the gap 36 from the radial outer side is provided in the fixed side housing 16. The cover 42 passes the rotation center of the drive wheel 8 at a meshing part A in which a crawler 10 and the drive wheel 8 mesh with each other in a circumferential direction of the gap 36, and is disposed on the upper side from a virtual line B-B extending in the longitudinal direction of the side frame 6. A portion below the virtual line B-B is open radially outward of the gap 36.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tracked vehicle such as a hydraulic excavator or a hydraulic crane provided with a crawler belt for traveling on rough terrain.

  Generally, a tracked vehicle such as a hydraulic excavator that travels on rough terrain such as a construction site includes a self-propelled lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and the upper turning And a working device provided on the body.

  The lower traveling body is provided with a center frame, left and right side frames provided on both left and right sides of the center frame and extending in the front and rear directions, and on the front and rear sides of the side frames. An idler wheel provided, a drive wheel provided on the other side of the front and rear directions of each side frame, a speed reducer that is driven by a travel motor and decelerates the rotation of the travel motor to rotate the drive wheel; A crawler belt wound between the idler wheel and the drive wheel is provided.

  The reduction gear includes a stationary housing provided with a traveling motor, a rotating housing provided rotatably with respect to the stationary housing, and rotating a driving wheel when driven by the traveling motor, and the rotating housing. It comprises a speed reduction mechanism that is housed and decelerates the rotation of the travel motor, and a floating seal that is provided radially inside the gap to seal the gap between the stationary housing and the rotation housing.

  And the cover which covers a clearance gap from the radial direction outer side is provided in the stationary side housing or the rotation side housing. This cover protects the floating seal by suppressing the intrusion of earth and sand into the gap (see, for example, Patent Document 1).

JP2013-189042A

  By the way, in patent document 1 mentioned above, the cover is provided over the perimeter of the circumferential direction of a clearance gap. Therefore, it is difficult to discharge the earth and sand once inside the cover (gap) unless the cover is removed.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a railroad track in which earth pressure is reduced on a floating seal provided between a stationary housing and a rotating housing. It is to provide a type vehicle.

  In order to solve the above-described problems, the present invention provides a center frame, left and right side frames provided on both left and right ends of the center frame and extending in the rear and rear directions, and front of each side frame. The idler wheel provided on one side of the rear direction, the drive wheel provided on the other side of the front and rear sides of each side frame, and driven by a travel motor, reduce the rotation of the travel motor and A speed reducer for rotating the drive wheel; and a crawler belt wound between the idler wheel and the drive wheel. The speed reducer includes a stationary housing on which the travel motor is provided, and a stationary housing on the stationary housing. A rotation-side housing that is rotatably provided to rotate the drive wheel by being driven by the travel motor, and a speed reduction mechanism that is housed in the rotation-side housing and decelerates the rotation of the travel motor. It applied to the crawler type vehicle comprising a floating seal disposed radially inwardly of the gap to seal the gap between the rotating side housing and the stationary housing.

  The fixed housing is provided with a cover that covers the gap from outside in the radial direction, and the cover is a meshing portion in which the crawler belt and the driving wheel mesh with each other in the circumferential direction of the gap, and It is arranged on the upper side of the imaginary line that passes through the rotation center of the drive wheel and extends in the front and rear directions of the side frame, and the lower part of the imaginary line is open to the outside in the radial direction of the gap. There is.

  ADVANTAGE OF THE INVENTION According to this invention, the lifetime of the floating seal provided between the stationary side housing and the rotation side housing can be improved.

1 is a front view showing a hydraulic excavator provided with a tracked vehicle according to an embodiment of the present invention. It is sectional drawing which looked at the deceleration device of a lower traveling body from the arrow II-II direction in FIG. FIG. 3 is an enlarged cross-sectional view of a main part illustrating an enlarged gap, a floating seal, a cover, and the like between a stationary housing and a rotating housing in FIG. 2. FIG. 4 is a cross-sectional view of the drive wheel, crawler belt, cover, and the like in FIG. 2 as viewed from the direction of arrows IV-IV. It is a perspective view which shows a cover alone.

  Hereinafter, an embodiment of a tracked vehicle according to the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where it is applied to a hydraulic excavator.

  A hydraulic excavator 1 shown in FIG. 1 includes a self-propelled track-type (crawler-type) lower traveling body 2, an upper revolving body 3 that is turnably mounted on the lower traveling body 2, and the upper revolving body. 3 is provided so as to be movable up and down, and includes a working device 4 that performs excavation work such as earth and sand.

  Here, the lower traveling body 2 includes a center frame 5 and left and right side frames 6 provided on both left and right ends of the center frame 5 and extending in the front and rear directions (only the left side is shown in FIG. 1). And idler wheels 7 provided on the front side in the front and rear directions of the side frames 6, driving wheels 8 provided on the rear side in the front and rear directions of the side frames 6, and a travel motor 9. A speed reduction device 15 described later for rotating the driving wheel 8 by decelerating the rotation of the traveling motor 9 and a crawler belt 10 wound between the idler wheel 7 and the driving wheel 8 are provided.

  The crawler belt 10 rotates around the idler wheel 7 and the drive wheel 8 when the drive wheel 8 is rotationally driven. As shown in FIGS. 2 and 4, the crawler belt 10 is press-fitted into the left and right track links 12 connected endlessly by pins 11 and the left and right track links 12 at both ends, and the pins 11 are inserted therein. And a shoe 14 attached to the left and right track links 12. In this case, the crawler belt 10 performs a revolving operation when the bush 13 is engaged with the driving wheel 8 and guided. A range indicated by a dotted line in FIG. 4 is a meshing portion A where the crawler belt 10 and the drive wheel 8 mesh.

  The reduction gear 15 is attached to a reduction gear bracket 6 </ b> A provided on the rear side of the side frame 6. The reduction gear 15 drives the excavator 1 by rotating the drive wheels 8 to drive the crawler belt 10 around. The speed reduction device 15 includes a stationary housing 16, a rotation side housing 18, planetary gear speed reduction mechanisms 26 and 31, a floating seal 37, and the like.

  The stationary housing 16 is attached to the speed reducer bracket 6A. The stationary housing 16 is provided with a travel motor 9 as a rotation source. Here, the fixed-side housing 16 includes a cylindrical portion 16A that houses the traveling motor 9 therein, and an annular flange portion 16B that protrudes radially outward from the cylindrical portion 16A. A plurality of female screw holes 16B1 are formed in the flange portion 16B so as to be spaced apart from each other in the circumferential direction. The stationary housing 16 is fixed to the reduction gear bracket 6A by a plurality of bolts 17 screwed into the female screw holes 16B1 of the flange portion 16B. In this case, some of the bolts 17 constitute a fastening member of the present invention, and are also used to attach a cover 42 described later to the flange portion 16 </ b> B of the stationary housing 16.

  Further, a male spline portion to which a housing support portion 16C for supporting a rotation side housing 18 to be described later and a carrier 35 of a planetary gear speed reduction mechanism 31 to be described later is coupled to the distal end side of the cylindrical portion 16A protruding from the speed reduction device bracket 6A. 16D. Between the flange portion 16B and the housing support portion 16C, a cylindrical seal mounting portion 16E to which a fixed-side seal ring 38 described later is attached is provided. As shown in FIGS. 2 and 3, the outer peripheral side of the seal mounting portion 16 </ b> E is an annular inclined portion 16 </ b> F that is inclined toward the radially inner side of the stationary housing 16. Since the opening on the radially outer side of the gap 36, which will be described later, can be widened by the inclined portion 16F, it is possible to improve the discharge performance of the earth and sand that has entered the gap 36.

  The rotation side housing 18 is provided so as to be rotatable with respect to the fixed side housing 16. The rotation-side housing 18 is formed in a covered cylindrical shape as a whole, and accommodates planetary gear reduction mechanisms 26 and 31 described later therein. The rotation-side housing 18 is fixed to the inner peripheral side of the annular flange portion 19 disposed on the outer peripheral side of the housing support portion 16C provided in the fixed-side housing 16 and the flange portion 19 using bolts 20. A cylindrical drum 21 in which inner teeth 21 </ b> A are formed and a disc-like lid body 22 that covers the drum 21 are roughly configured.

  Here, the inner peripheral side of the flange portion 19 is rotatably attached to the housing support portion 16C of the fixed side housing 16 via a bearing 23, and a plurality of bolts 24 are used on the outer peripheral side of the flange portion 19 to drive wheels. (Sprocket) 8 is fixed. The flange portion 19 is provided with a cylindrical seal mounting portion 19A to which a rotation side seal ring 39 described later is attached.

  The rotating shaft 25 derives the rotational output of the traveling motor 9. The base end side of the rotating shaft 25 is connected to the output shaft of the traveling motor 9 and extends in the rotating side housing 18 in the axial direction. A sun gear 27 described later is integrally formed at the tip of the rotary shaft 25 located in the vicinity of the lid 22.

  The first stage planetary gear speed reduction mechanism 26 is housed on the lid 22 side in the rotation side housing 18. This planetary gear reduction mechanism 26 reduces the rotation of the traveling motor 9 in cooperation with a second-stage planetary gear reduction mechanism 31 described later, and makes the drive wheel 8 fixed to the flange portion 19 of the rotation side housing 18 large. It rotates with torque. The planetary gear reduction mechanism 26 constitutes the reduction mechanism of the present invention.

  Here, the planetary gear speed reduction mechanism 26 meshes with the sun gear 27 integrally formed at the tip of the rotating shaft 25 and the sun gear 27 and the inner teeth 21A of the drum 21, and rotates around the sun gear 27. A plurality of planetary gears 28 (only one is shown) that revolves while revolving, and a carrier 30 that rotatably supports the planetary gears 28 via pins 29. Then, the planetary gear reduction mechanism 26 decelerates the rotation of the sun gear 27 and transmits the revolution of the planetary gear 28 to the second-stage sun gear 32 described later via the carrier 30.

  The second-stage planetary gear speed reduction mechanism 31 is accommodated on the fixed-side housing 16 side in the rotation-side housing 18 and is spline-coupled to the first-stage carrier 30 while being loosely fitted to the rotation shaft 25. The planetary gear reduction mechanism 31 constitutes the reduction mechanism of the present invention together with the planetary gear reduction mechanism 26. The planetary gear speed reduction mechanism 31 meshes with the sun gear 32 to which only the revolution of the first stage planetary gear 28 is transmitted via the carrier 30, and the sun gear 32 and the internal teeth 21A of the drum 21. A plurality of planetary gears 33 (only one is shown) that revolves while rotating around the gear 32 and a carrier 35 that rotatably supports the planetary gear 33 via a pin 34.

  The carrier 35 is splined to the male spline portion 16D of the stationary housing 16. Thereby, the revolution of the planetary gear 33 supported by the carrier 35 is transmitted to the rotation side housing 18 via the inner teeth 21 </ b> A of the drum 21. The rotation-side housing 18 is configured to rotate with respect to the fixed-side housing 16 in a state where the rotation-side housing 18 is decelerated by two stages by the planetary gear reduction mechanisms 26 and 31.

  Here, the rotation-side housing 18 is filled with a lubricating oil L for lubricating the planetary gear speed reduction mechanisms 26 and 31, the bearing 23, and the like. It is configured to be sealed inside.

  The gap 36 is formed between the stationary housing 16 and the rotating housing 18. As shown in FIGS. 2 and 3, the gap 36 is formed in an annular shape over the entire circumference between the seal mounting portion 16 </ b> E of the fixed-side housing 16 and the seal mounting portion 19 </ b> A of the rotation-side housing 18. In this case, the gap 36 forms a labyrinth structure by the seal mounting portion 16E and the seal mounting portion 19A. This makes it difficult for earth and sand to enter the floating seal 37. Further, the gap 36 has a wide opening at the radially outer side by the inclined portion 16 </ b> F of the stationary housing 16. Thereby, the discharge property of the earth and sand which penetrate | invaded in the clearance gap 36 is improved.

  The floating seal 37 is provided on the radially inner side of the gap 36 between the stationary housing 16 and the rotating housing 18. The floating seal 37 seals the gap 36 to prevent foreign matters such as muddy water and earth and sand from entering the rotary housing 18 and seals the lubricating oil L in the rotary housing 18. As shown in FIG. 3, the floating seal 37 includes a fixed side seal ring 38, a rotation side seal ring 39, a fixed side O ring 40, and a rotation side O ring 41 which will be described later.

  The fixed side seal ring 38 is provided on the inner peripheral side of the seal mounting portion 16 </ b> E of the fixed side housing 16. The fixed-side seal ring 38 is paired with a rotation-side seal ring 39 which will be described later, and is formed in a cylindrical shape using a metal material having excellent wear resistance and corrosion resistance, for example. Here, the fixed-side seal ring 38 is provided with a large-diameter flange portion 38A, and the axial end surface of the large-diameter flange portion 38A is an annular sliding contact surface 38B. Further, the outer peripheral surface of the fixed seal ring 38 facing the inner peripheral surface of the seal mounting portion 16E gradually increases in diameter toward the large-diameter flange portion 38A, and this outer peripheral surface and the inner peripheral surface of the seal mounting portion 16E A fixed-side O-ring 40 described later is provided between the two.

  The rotation-side seal ring 39 is provided on the inner peripheral side of the seal mounting portion 19 </ b> A of the rotation-side housing 18. The rotating side seal ring 39 is the same component as the fixed side seal ring 38. Here, the rotation-side seal ring 39 is provided with a large-diameter flange portion 39A, and the end surface in the axial direction of the large-diameter flange portion 39A is an annular shape that is in fluid-tight sliding contact with the sliding contact surface 38B of the fixed-side seal ring 38. This is a sliding surface 39B. In addition, the outer peripheral surface of the rotation-side seal ring 39 facing the inner peripheral surface of the seal mounting portion 19A gradually increases in diameter toward the large-diameter flange portion 39A, and this outer peripheral surface and the inner peripheral surface of the seal mounting portion 19A Between these, a rotation side O-ring 41 described later is provided.

  The fixed-side O-ring 40 is provided between the inner peripheral surface of the seal mounting portion 16 </ b> E of the fixed-side housing 16 and the outer peripheral surface of the fixed-side seal ring 38. The stationary O-ring 40 is paired with a later-described rotating O-ring 41, and is formed in an annular shape using, for example, a rubber material having oil resistance and elasticity such as butadiene rubber. The fixed-side O-ring 40 seals between the seal mounting portion 16E of the fixed-side housing 16 and the fixed-side seal ring 38, and always has the fixed-side seal ring 38 facing the rotation-side seal ring 39 in the axial direction. Press.

  The rotation-side O-ring 41 is provided to be separated from the fixed-side O-ring 40 in the axial direction. The rotation-side O-ring 41 is between the inner peripheral surface of the seal mounting portion 19 </ b> A of the rotation-side housing 18 and the outer peripheral surface of the rotation-side seal ring 39 with a gap 36 interposed between the rotation-side O-ring 40 and the rotation-side seal ring 39. Is provided. The rotation-side O-ring 41 is composed of the same parts as the fixed-side O-ring 40, and seals between the seal mounting portion 19A of the flange portion 19 and the rotation-side seal ring 39, and the rotation-side seal ring 39 is fixed to the fixed side. It is always pressed in the axial direction toward the seal ring 38.

  Thus, the sliding contact surface 38B of the fixed side seal ring 38 and the sliding contact surface 39B of the rotation side seal ring 39 are pressed in the axial direction from the fixed side O ring 40 and the rotation side O ring 41, respectively. When the rotary housing 18 rotates relative to the fixed housing 16, the lubricating oil L is sealed in the rotary housing 18 by sealing the liquid-tight seal between the two. Yes.

  Next, the cover 42 will be described.

  The cover 42 is provided on the flange portion 16 </ b> B of the fixed side housing 16. The cover 42 is formed in an arc shape along the gap 36, and covers the gap 36 from the outside in the radial direction to prevent foreign matters such as earth and sand from entering the gap 36. In this case, the cover 42 is formed, for example, by dividing the cylindrical shape into approximately three parts, and partially covers the circumferential direction of the gap 36. That is, the gap 36 is partially covered with the cover 42 in the circumferential direction, and the other part is open. The portion where the cover 42 covers the gap 36 will be described later. The cover 42 is formed by a mounting plate 43, an extension plate 44, and an inclined plate 45 in a substantially L-shaped cross section.

  The attachment plate 43 is attached to the flange portion 16 </ b> B of the fixed side housing 16. As shown in FIGS. 3 to 5, the mounting plate 43 is formed in an arc shape along the flange portion 16B, and a bolt insertion hole 43A is formed at a position corresponding to the female screw hole 16B1 of the flange portion 16B. The cover 42 is attached to the flange portion 16B of the stationary housing 16 by the bolt 17 inserted through the bolt insertion hole 43A.

  In this case, the bolt 17 attaches the stationary side housing 16 to the speed reducer bracket 6A. That is, the stationary housing 16 and the cover 42 are fastened together with the reduction gear bracket 6 </ b> A using the common bolt 17. Thereby, the cover 42 can be easily attached to the stationary housing 16 without changing the structure of the existing reduction gear 15.

  The extension plate 44 extends from the inside in the radial direction of the mounting plate 43 toward the rotation side housing 18. The extension plate 44 is formed in a curved shape along the gap 36 and covers the radially outer side of the gap 36. An inclined plate 45 that is bent outward in the radial direction is provided on the distal end side of the extension plate 44. That is, the diameter of the cover 42 is increased toward the outer side in the radial direction. Thereby, since the earth and sand deposited on the inclined plate 45 are guided to the extending plate 44 side, it is possible to reduce the earth and sand from flowing from the space 46 between the inclined plate 45 and the rotation side housing 18 toward the gap 36. be able to.

  Next, the attachment position of the cover 42 will be described with reference to FIG.

  The cover 42 is a meshing portion A in which the bush 13 of the crawler belt 10 and the drive wheel 8 mesh with each other in the circumferential direction of the gap 36, and extends in the front and rear directions of the side frame 6 through the rotation center of the drive wheel 8. It is arranged on the upper side of the phantom line BB (the chain line in FIG. 4). And the lower part of the imaginary line BB is open to the radially outer side of the gap 36. That is, the cover 42 covers only the rear upper part (upper right part in FIG. 4) in the circumferential direction of the gap 36.

  In this case, the cover 42 covers the overlapping part E between the sediment accumulation part C and the sediment compaction part D. Sediment deposition site C is a site in which the sediment deposited by the circumferential drive of crawler belt 10 is deposited in the circumferential direction of gap 36. That is, the sediment accumulation site C can be experimentally determined in advance on the upper side of the imaginary line BB in consideration of the viscosity of the sediment and the water content.

  Further, the earth and sand compaction part D is a part where the earth and sand accumulated in the earth and sand accumulation part C by the circular drive of the crawler belt 10 is compacted toward the gap 36. That is, when the crawler belt 10 is driven to rotate, the state in which the protrusion of the drive wheel 8 pulls the bush 13 (pin 11) of the crawler belt 10 and the state in which the protrusion engages with the bush 13 are repeated. Accordingly, the crawler belt 10 vibrates due to a change in tension. As a result, the rear side portion (the right side portion in FIG. 4) of the circumferential direction of the gap 36 is a sand compaction portion where the earth and sand are pressed toward the gap 36 by vibration of the crawler belt 10 and the crawler belt 10 being wound. D.

  That is, the overlapping portion E between the sediment depositing portion C and the sediment compacting portion D is a portion where the sediment easily enters the gap 36. When earth and sand enters the gap 36 and presses the floating seal 37, the rotation-side O-ring 41 rotates, so that sand pressure is applied relatively uniformly in the circumferential direction, but the fixed-side O-ring 40 is partially Sediment pressure is applied. Therefore, the life of the fixed side seal ring 38 and the fixed side O ring 40 may be shorter than that of the rotation side seal ring 39 and the rotation side O ring 41.

  Therefore, the cover 42 is disposed at a position that covers the overlapping portion E where earth and sand easily enter the gap 36. Thus, sediment accumulation at the overlapping portion E can be reduced, and soil compaction by the crawler belt 10 can be suppressed. The cover 42 covers about 1/3 of the entire circumference of the gap 36, and the other portions are open. Thereby, since the space between the clearance gap 36 and the crawler belt 10 can be enlarged, the discharge property of earth and sand can be improved.

  The hydraulic excavator 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  When the operator operates a travel lever (not shown) to rotate the travel motor 9, the rotation of the travel motor 9 is reduced by two stages by the planetary gear speed reduction mechanisms 26 and 31 of the speed reducer 15 and transmitted to the rotation side housing 18. . As a result, the rotation-side housing 18 rotates with a large torque, the drive wheel 8 fixed to the rotation-side housing 18 rotates, and the crawler belt 10 wound around the idler wheel 7 and the drive wheel 8 is driven to rotate. As a result, the excavator 1 travels.

  In this case, the rotation-side seal ring 39 of the floating seal 37 rotates integrally with the rotation-side housing 18. The rotation-side seal ring 39 seals the space between the rotation-side housing 18 and the fixed-side housing 16 in a liquid-tight manner by bringing the slide-contact surface 39B into sliding contact with the slide-contact surface 38B of the fixed-side seal ring 38. As a result, the lubricating oil L is held in the rotating housing 18, and the bearing 23, the planetary gear reduction mechanisms 26, 31 and the like can be properly lubricated by the lubricating oil L, so that the rotating housing 18 rotates smoothly. Can be made.

  By the way, since a tracked vehicle such as the hydraulic excavator 1 travels on rough terrain such as muddy ground, foreign matter such as earth and sand caught by the crawler belt 10 accumulates between the stationary housing 16 and the rotating housing 18. May enter the gap 36. And when the earth and sand etc. which penetrate | invaded the clearance gap 36 press the floating seal 37, there exists a problem that the lifetime of the floating seal 37 will fall.

  In this case, in the above-described conventional technology, a cover that covers the radially outer side of the gap is provided. However, since the cover is provided over the entire circumference of the gap, it is difficult to discharge the earth and sand once entering the inside (gap) of the cover unless the cover is removed. Further, since the cover is provided over the entire circumference of the gap, the space between the crawler belt and the cover is narrowed, and earth and sand are easily deposited on the cover. As a result, the sediment pressure applied to the cover increases, and there is a problem that the discharge of sediment on the cover decreases and the life of the cover decreases.

  Therefore, in the present embodiment, a part of the gap 36 in the circumferential direction is covered with the cover 42 and the other part is opened to the outside in the radial direction of the gap 36. Specifically, as shown in FIG. 4, the cover 42 is a meshing portion A in which the crawler belt 10 and the drive wheel 8 mesh with each other in the circumferential direction of the gap 36, and passes through the rotation center of the drive wheel 8. It is disposed on the upper side of the imaginary line BB extending in the front and rear direction of the side frame 6. And the lower part of the imaginary line BB is configured to open outward in the radial direction of the gap 36.

  In this case, the cover 42 is pressed toward the gap 36 by the vibration, entanglement, etc. of the earth and sand accumulation portion C where the earth and sand caught by the crawler belt 10 easily accumulate and the earth and sand accumulated in the earth and sand accumulation portion C. The overlapping part E with the earth and sand compaction part D is covered. In other words, in the gap 36 other than the overlapping portion E, the gap 36 has a labyrinth structure, so that it is difficult for soil and sand to enter the floating seal 37. However, in the overlap portion E, earth and sand are likely to accumulate, and the accumulated earth and sand are pressed toward the gap 36 due to vibration of the crawler belt 10 and the like, so that there is a possibility that earth and sand will enter the gap 36 and press the floating seal 37. is there. Therefore, the cover 42 covers a part of the gap 36 including the overlapping portion E in the circumferential direction and opens the other part to the outside of the gap 36 in the radial direction.

  Accordingly, the cover 42 can reduce sediment accumulation at the overlapping portion E, and can suppress the compaction of the sediment by the crawler belt 10, and thus can prevent the sediment from entering the gap 36. Accordingly, it is possible to reduce the sediment pressure applied to the floating seal 37 (particularly, the fixed-side seal ring 38 and the fixed-side O-ring 40), so that the life of the floating seal 37 can be improved.

  Further, the lower part of the imaginary line BB is configured to open to the outside in the radial direction of the gap 36. Thereby, since the space between the crawler belt 10 and the clearance gap 36 can be enlarged, the earth and sand wound by the crawler belt 10 can be discharged | emitted efficiently. Further, the gap 36 is widely opened on the outer side in the radial direction by the inclined portion 16 </ b> F of the stationary housing 16. Thereby, since the discharge property of the earth and sand which penetrate | invaded in the clearance gap 36 can be improved, clogging of the earth and sand in the clearance gap 36 can be reduced.

  Further, the cover 42 and the fixed housing 16 are fastened together with the reduction gear bracket 6 </ b> A using the bolts 17. That is, the cover 42 is attached to the flange portion 16B of the fixed side housing 16 using the bolts 17 for attaching the fixed side housing 16 to the speed reducer bracket 6A. As a result, the cover 42 can be easily attached to the existing reduction gear 15 and the cover 42 can be easily replaced.

  Further, the cover 42 is enlarged in diameter by the inclined plate 45 toward the radially outer side. Thereby, since the earth and sand deposited on the inclined plate 45 are guided to the extending plate 44 side, it is possible to reduce the earth and sand from flowing from the space 46 between the inclined plate 45 and the rotation side housing 18 toward the gap 36. be able to. Accordingly, it is possible to reduce the intrusion of earth and sand between the cover 42 and the gap 36, and consequently to reduce the intrusion of earth and sand into the gap 36.

  Further, since the cover 42 is configured to cover a portion of the gap 36 in the circumferential direction, for example, a plurality of covers 42 can be manufactured by dividing the cylindrical shape, and the cost can be reduced.

  In the above-described embodiment, the cover 42 is the meshing portion A in which the crawler belt 10 and the driving wheel 8 mesh with each other in the circumferential direction of the gap 36, and passes through the rotation center of the driving wheel 8. When it is arranged on the upper side of the imaginary line BB extending in the front and rear directions to cover the overlapping part E, and the lower part of the imaginary line BB is opened to the outside in the radial direction of the gap 36 Was described as an example. However, the present invention is not limited to this. For example, only the overlapping portion E may be covered with a cover, and the other portions may be open to the outside in the radial direction of the gap 36.

  In the above-described embodiment, the case where the radially outer side of the gap 36 is widely opened by forming the inclined portion 16F on the outer peripheral side of the seal mounting portion 16E of the fixed housing 16 has been described as an example. However, the present invention is not limited to this, and the radially outer side of the gap 36 may be widely opened by, for example, forming an inclined portion on the outer peripheral side of the seal mounting portion 19 </ b> A of the rotation side housing 18.

  Moreover, in embodiment mentioned above, the hydraulic excavator 1 was mentioned as an example and demonstrated as a tracked vehicle. However, the present invention is not limited to this, and can be widely applied to other tracked vehicles such as a hydraulic crane.

1 Hydraulic excavator (tracked vehicle)
DESCRIPTION OF SYMBOLS 5 Center frame 6 Side frame 6A Reduction gear bracket 7 Idle wheel 8 Drive wheel 9 Traveling motor 10 Crawler belt 15 Reduction gear 16 Fixed side housing 16A Cylindrical part 16B Flange part 17 Bolt (fastening member)
18 Rotating side housing 26 First stage planetary gear speed reduction mechanism (speed reduction mechanism)
31 Second stage planetary gear speed reduction mechanism (speed reduction mechanism)
36 Clearance 37 Floating seal 42 Cover 43 Mounting plate 44 Extension plate 45 Inclined plate A Engagement part BB Virtual line C Sediment deposition site D Sediment compaction site E Overlapping site

Claims (4)

Center frame, left and right side frames provided on both left and right ends of the center frame and extending in the front and rear directions, and idler wheels provided on one side of the front and rear directions of the side frames A driving wheel provided on the other side of the front and rear directions of each side frame, a reduction gear that is driven by a traveling motor and decelerates the rotation of the traveling motor to rotate the driving wheel, and the idler wheel And a crawler belt wound between the drive wheels,
The speed reducer includes a stationary housing provided with the traveling motor, a rotating housing provided rotatably with respect to the stationary housing and rotating the driving wheel by being driven by the traveling motor, A speed reducing mechanism that is housed in the rotation side housing and decelerates the rotation of the travel motor; and a floating seal that is provided radially inside the gap to seal the gap between the fixed side housing and the rotation side housing. In a tracked vehicle consisting of
The fixed housing is provided with a cover that covers the gap from the outside in the radial direction,
The cover is a meshing portion in which the crawler belt and the driving wheel mesh with each other in the circumferential direction of the gap, and passes through a rotation center of the driving wheel and extends from a virtual line extending in the front and rear directions of the side frame. Also placed on the upper side,
A tracked vehicle characterized in that a lower part than the imaginary line is configured to open radially outward of the gap. On the other side of the side frame, a reduction gear bracket for mounting the fixed side housing of the reduction gear is provided,
The tracked vehicle according to claim 1, wherein the cover and the stationary housing are configured to be fastened together with the reduction gear bracket using a fastening member. The fixed-side housing includes a cylindrical portion that houses the traveling motor therein, and an annular flange portion that protrudes radially outward from the cylindrical portion,
The cover includes a mounting plate attached to the flange portion of the stationary housing, an extending plate extending toward the rotating housing so as to cover the gap from a radially inner side of the mounting plate, and the extending plate The track-type vehicle according to claim 1, wherein the track-type vehicle is configured by an inclined plate that is bent toward the radially outer side from the tip of the rail.   In the circumferential direction of the gap, the cover is configured to deposit an earth and sand accumulation portion on which the earth and sand wound by the crawler belt driving is deposited, and the earth and sand accumulated on the earth and sand accumulation portion by the crawler belt driving is pushed toward the gap. The tracked vehicle according to claim 1, 2 or 3, wherein the tracked vehicle is configured to cover an overlapping portion with the earth and sand compaction portion to be hardened.

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