Crawler-type traveling device for work machine

Abstract

A crawler-type traveling device for a work machine comprises a crawler belt, a track frame, a rotation mechanism, a support mechanism, and a floating seal. The track frame includes a storage section and an attachment section. The attachment section extends from the inner surface of the storage section. The rotation mechanism includes a rotating body around which the crawler belt is wound. The rotation mechanism is disposed outside the attachment section in the axial direction of the rotating body. The support mechanism rotatably supports the rotation mechanism. At least a part of the support mechanism is disposed in the internal space of the storage section. The support mechanism is attached to the attachment section. The floating seal provides sealing between the rotation mechanism and the support mechanism. The support mechanism includes a seal cover. The seal cover covers the floating seal from the inside of the floating seal in the axial direction. The seal cover is disposed inside the attachment section in the axial direction.

Description

Track-type travel device for work machine

[0001] The present disclosure relates to a track-type traveling device for a work machine.

[0002] Some work machines are equipped with a track-type travelling device. For example, in the work machine disclosed in Patent Document 1, the track-type travelling device includes a track, a sprocket, a housing, a reduction gear, a travel motor, and a track frame. The track is wound around the sprocket. The travel motor is connected to the sprocket via the reduction gear. The housing is attached to the track frame. The travel motor and the reduction gear are disposed inside the housing and the track frame and are supported by the housing.

[0003] The track-type travelling device also includes a floating seal. The floating seal is disposed between the sprocket and the housing. The floating seal seals the gap between the sprocket and the housing, thereby preventing foreign matter such as soil and sand from entering the housing.

[0004] Japanese Patent Application Laid-Open No. 2002-178963

[0005] The floating seal described above may be damaged due to wear. In such cases, the tracked traveling device must be disassembled to replace the floating seal. Specifically, the track is first cut and removed from the sprocket. The reducer is then disassembled and removed from the housing. The floating seal is then replaced.

[0006] As described above, in conventional tracked traveling devices, replacing a floating seal requires disassembling the tracked traveling device and removing the tracks, sprockets, reducers, etc., which is a cumbersome process. An object of the present disclosure is to facilitate the replacement of a floating seal in a tracked traveling device.

[0007] A track-type traveling device for a work machine according to one aspect of the present disclosure includes tracks, a track frame, a rotation mechanism, a support mechanism, and a floating seal. The track frame supports the tracks. The track frame includes a storage section and a mounting section. The storage section has an internal space. The mounting section extends from an inner surface of the storage section. The rotation mechanism includes a rotating body around which the tracks are wound. The rotation mechanism is disposed outside the mounting section in the axial direction of the rotating body. The support mechanism rotatably supports the rotation mechanism. At least a portion of the support mechanism is disposed in the internal space. The support mechanism is mounted to the mounting section. The floating seal seals between the rotation mechanism and the support mechanism. The support mechanism includes a seal cover. The seal cover covers the floating seal from inside the floating seal in the axial direction. The seal cover is disposed inside the mounting section in the axial direction.

[0008] In the track-type traveling device according to the present disclosure, the floating seal can be accessed by removing the seal cover from the support mechanism. The seal cover is also disposed inside the mounting portion in the axial direction. Therefore, the seal cover can be removed from inside the mounting portion without removing the rotation mechanism, which is disposed outside the mounting portion. Therefore, the floating seal can be easily replaced by removing the seal cover without disassembling the track and the rotation mechanism.

[0009] According to the present disclosure, replacement of a floating seal in a track-type traveling device becomes easy.

[0010] Fig. 2 is a side view of the work machine. Fig. 3 is a top view of the work machine. Fig. 4 is a cross-sectional view taken along II-II in Fig. 1. Fig. 5 is a perspective view of the tracked traveling device with the inner cover removed, viewed from the inside in the axial direction. Fig. 6 is a side view of the tracked traveling device with the inner cover removed, viewed from the inside in the axial direction. Fig. 7 is an enlarged view showing the structure in the vicinity of the floating seal, and Fig. 8 is a side view of the tracked traveling device with the inner cover and seal cover removed, viewed from the inside in the axial direction.

[0011] A track-type traveling device for a work machine according to an embodiment will now be described with reference to the drawings. Fig. 1 is a side view of a work machine 1 according to an embodiment. Fig. 2 is a top view of the work machine 1. In this embodiment, the work machine 1 is an excavator such as a hydraulic excavator or an electric excavator.

[0012] 1 and 2 , the work machine 1 includes a work implement 3, a rotating body 4, and a pair of left and right track-type traveling devices 5, 6. The work implement 3 is movably attached to the rotating body 4. The work implement 3 includes a boom 11, an arm 12, and a bucket 13. The boom 11 is rotatably attached to the rotating body 4. The arm 12 is rotatably attached to the boom 11. The bucket 13 is rotatably attached to the arm 12.

[0013] The track-type traveling device 5 includes a first rotation mechanism 21, a second rotation mechanism 22, a track 23, and a track frame 24. The track frame 24 supports the track 23 via a plurality of rollers 25. Note that in the drawings, only one of the plurality of rollers 25 is designated by the reference numeral 25, and the reference numerals of the other rollers 25 are omitted.

[0014] The first rotation mechanism 21 includes a first rotating body 26. The second rotation mechanism 22 includes a second rotating body 27. In this embodiment, the first rotating body 26 is a sprocket, and the second rotating body 27 is an idler. The crawler belt 23 is wound around the first rotating body 26 and the second rotating body 27. Although not shown, the crawler belt 23 includes a plurality of track plates connected to each other. The work machine 1 travels when the crawler belt 23 is driven.

[0015] Figure 3 is a cross-sectional view taken along line III-III in Figure 1. As shown in Figure 3, the first rotation mechanism 21 includes a first hole 28. The first hole 28 extends in the axial direction of the first rotating body 26. As shown in Figure 2, the axis Ax1 of the first rotating body 26 extends in the left-right direction of the work machine 1. In other words, the axial direction of the first rotating body 26 coincides with the left-right direction of the work machine 1. The axial direction of the first rotating body 26 is the same as the axial direction of the left and right track-type traveling devices 5, 6.

[0016] The track-type traveling device 5 includes a support mechanism 30. The support mechanism 30 is fixed to the track frame 24. A portion of the support mechanism 30 is disposed within the first hole 28. The support mechanism 30 rotatably supports the first rotation mechanism 21. The support mechanism 30 includes a support shaft 31, a traveling motor 32, and a seal cover 33. The support shaft 31 is disposed within the first hole 28 of the first rotation mechanism 21. The support shaft 31 extends in the axial direction of the first rotating body 26. The support shaft 31 is disposed coaxially with the first rotating body 26. Bearings 34 and 35 are disposed between the outer circumferential surface of the support shaft 31 and the inner circumferential surface of the first hole 28. The support shaft 31 rotatably supports the first rotation mechanism 21 via the bearings 34 and 35. The support shaft 31 includes a second hole 36. The second hole 36 extends in the axial direction.

[0017] The travel motor 32 is disposed in the second hole 36 of the support shaft 31. The travel motor 32 rotates the first rotation mechanism 21. The travel motor 32 is, for example, an electric motor. Alternatively, the travel motor 32 may be a hydraulic motor. The travel motor 32 includes a drive shaft 37 and a motor housing 38. The drive shaft 37 extends in the axial direction. The drive shaft 37 is disposed coaxially with the first rotating body 26. The drive shaft 37 is connected to the first rotation mechanism 21. The motor housing 38 supports the drive shaft 37. The seal cover 33 will be described in detail later.

[0018] The first rotation mechanism 21 includes a final reduction gear 41, a rotor housing 42, and a boss 43. The final reduction gear 41 is connected to the drive shaft 37. The final reduction gear 41 reduces the rotation of the drive shaft 37 and transmits it to the first rotor 26. The final reduction gear 41 includes a first reduction gear 44, a second reduction gear 45, and a third reduction gear 46. The first reduction gear 44, the second reduction gear 45, and the third reduction gear 46 include, for example, planetary gear mechanisms. However, the first reduction gear 44, the second reduction gear 45, and the third reduction gear 46 may include reduction mechanisms other than planetary gear mechanisms. Note that in FIG. 3, the first reduction gear 44, the second reduction gear 45, and the third reduction gear 46 are illustrated in a simplified manner.

[0019] The first reducer 44 and the second reducer 45 are disposed in the second hole 36 of the support shaft 31. The first reducer 44 is disposed outside the traveling motor 32 in the axial direction. The first reducer 44 is connected to the drive shaft 37. The second reducer 45 is disposed outside the first reducer 44 in the axial direction. The second reducer 45 is connected to the first reducer 44. The third reducer 46 is disposed outside the second reducer 45 in the axial direction. The third reducer 46 is disposed outside the support shaft 31 in the axial direction. The third reducer 46 is connected to the second reducer 45.

[0020] The rotor housing 42 is disposed outside the first rotor 26 in the axial direction. The rotor housing 42 is connected to the first rotor 26. The third reducer 46 is disposed within the rotor housing 42. The third reducer 46 is supported by the rotor housing 42. The final reducer 41 transmits the rotation of the drive shaft 37 to the rotor housing 42. The rotor housing 42 is connected to the first rotor 26. The rotor housing 42 rotates integrally with the first rotor 26. The rotation of the rotor housing 42 causes the first rotor 26 to rotate.

[0021] The boss 43 is disposed inside the first rotor 26 in the axial direction. The boss 43 is connected to the first rotor 26. The boss 43 rotates integrally with the first rotor 26. The first hole 28 described above is provided inside the first rotor 26, the rotor housing 42, and the boss 43. The first hole 28 is filled with lubricating oil.

[0022] The track frame 24 includes a storage section 51 and an attachment section 52. The storage section 51 is disposed inside the first rotating body 26 in the axial direction. The storage section 51 has an internal space S1. A portion of the support mechanism 30 is disposed in the internal space S1 of the storage section 51. At least a portion of the travel motor 32 is disposed in the internal space S1 of the storage section 51. The storage section 51 includes a wall section 53 and an inner cover 54. FIG. 4 is a perspective view of the tracked traveling device 5 with the inner cover 54 removed, as seen from the inside in the axial direction. FIG. 5 is a side view of the tracked traveling device 5 with the inner cover 54 removed, as seen from the inside in the axial direction.

[0023] As shown in Figures 4 and 5, the wall portion 53 covers the internal space S1 in the front-rear and top-bottom directions. The wall portion 53 includes a first wall portion 55 and a second wall portion 56. The first wall portion 55 has a curved plate-like shape. The first wall portion 55 is disposed at the rear, top, and bottom of the internal space S1. The second wall portion 56 is disposed at the front of the internal space S1. The second wall portion 56 includes a hole 57. A cable 58 connected to the travel motor 32 is passed through the hole 57.

[0024] As shown in Figure 3, the inner cover 54 is disposed inside the internal space S1 in the axial direction. The inner cover 54 has a plate-like shape that extends in the up-down and front-rear directions. The inner cover 54 is detachably attached to the wall portion 53. For example, the inner cover 54 is attached to the wall portion 53 with bolts 59 and 60.

[0025] The mounting portion 52 extends in the up-down and front-rear directions from the inner surface of the wall portion 53. The mounting portion 52 has a plate-like shape. The mounting portion 52 is fixed to the wall portion 53. For example, the mounting portion 52 is fixed to the wall portion 53 by welding. The mounting portion 52 is disposed inside the first rotating body 26 in the axial direction. In other words, the first rotating body 26 is disposed outside the mounting portion 52 in the axial direction. The mounting portion 52 includes a first opening 61. The support mechanism 30 and the boss 43 of the first rotating mechanism 21 described above extend through the first opening 61. The support mechanism 30 is attached to the mounting portion 52.

[0026] The track-type traveling device 5 includes a floating seal 62. The floating seal 62 is disposed between the first rotating mechanism 21 and the support mechanism 30 in the axial direction. The floating seal 62 seals the gap between the first rotating mechanism 21 and the support mechanism 30. Specifically, the floating seal 62 is disposed between the boss 43 and the seal cover 33. The floating seal 62 has an outer diameter smaller than the first opening 61 of the mounting portion 52. At least a portion of the floating seal 62 is located inside the mounting portion 52 in the axial direction. The support shaft 31 has an outer diameter smaller than the floating seal 62. The support shaft 31 is disposed radially inside the floating seal 62.

[0027] Figure 6 is an enlarged view showing the structure near the floating seal 62. As shown in Figure 6, the floating seal 62 includes a first seal 63 and a second seal 64. The first seal 63 is attached to the boss 43. The second seal 64 is attached to the seal cover 33. More specifically, a first recess 65 is provided at the end of the boss 43 on the inside in the axial direction. The first seal 63 is attached to the first recess 65. The seal cover 33 is provided with a second recess 66. The second seal 64 is attached to the second recess 66.

[0028] The first seal 63 includes a first O-ring 67 and a first metal seal ring 68. The second seal 64 includes a second O-ring 69 and a second metal seal ring 70. The first metal seal ring 68 and the second metal seal ring 70 are in close contact with each other due to the elastic force of the first O-ring 67 and the second O-ring 69. Therefore, when the first rotating body 26 rotates, the first metal seal ring 68 and the second metal seal ring 70 slide in close contact with each other in the floating seal 62. This allows the support mechanism 30 to rotatably support the first rotating mechanism 21, and prevents foreign matter such as soil and sand from entering between the support mechanism 30 and the first rotating mechanism 21.

[0029] The first rotation mechanism 21 includes a flange portion 71. The flange portion 71 extends from the boss 43 toward the outside in the radial direction of the first rotation mechanism 21. The flange portion 71 faces the mounting portion 52 from the outside of the mounting portion 52 in the axial direction. The flange portion 71 forms a labyrinth structure between the boss 43 and the mounting portion 52. This further prevents foreign matter such as soil and sand from entering between the support mechanism 30 and the first rotation mechanism 21.

[0030] The above-mentioned seal cover 33 is disposed inside the floating seal 62 in the axial direction. The floating seal 62 is disposed between the boss 43 and the seal cover 33 in the axial direction. The seal cover 33 covers the floating seal 62 from inside the floating seal 62 in the axial direction. The seal cover 33 has an outer diameter larger than the first opening 61 of the mounting portion 52. The seal cover 33 is disposed inside the mounting portion 52 in the axial direction. The seal cover 33 is detachably attached to the mounting portion 52. The seal cover 33 is attached to the mounting portion 52 by a plurality of first bolts 72. Note that in the drawings, only one of the plurality of first bolts 72 is denoted by the reference numeral 72, and the reference numerals of the other first bolts 72 are omitted.

[0031] The seal cover 33 is separate from the support shaft 31. The seal cover 33 is disposed inside the support shaft 31 in the axial direction. The seal cover 33 is removably attached to the support shaft 31. The seal cover 33 is disposed inside the motor housing 38 in the axial direction. The seal cover 33 is removably attached to the motor housing 38. The seal cover 33 is attached to the support shaft 31 and the motor housing 38 by a common plurality of second bolts 73. Note that in the drawings, only one of the plurality of second bolts 73 is denoted by the reference numeral 73, and the reference numerals of the other second bolts 73 are omitted.

[0032] As shown in Fig. 5, the seal cover 33 has an annular shape. The seal cover 33 includes a second opening 74. As shown in Fig. 3, the travel motor 32 is exposed to the internal space S1 of the truck frame 24 through the second opening 74. As shown in Figs. 5 and 6, the seal cover 33 includes an outer diameter portion 75, an inner diameter portion 76, and an intermediate portion 77. The outer diameter portion 75 is located radially outward from the floating seal 62. The inner diameter portion 76 is located radially inward from the floating seal 62. The intermediate portion 77 is located radially between the outer diameter portion 75 and the inner diameter portion 76.

[0033] The seal cover 33 is attached to the mounting portion 52 at its outer diameter portion 75. As shown in Fig. 6, a bolt hole 78 is formed in the outer diameter portion 75. A bolt hole 79 is formed in the mounting portion 52. The outer diameter portion 75 is attached to the mounting portion 52 by a first bolt 72 that is passed through the bolt hole 78 in the outer diameter portion 75 and the bolt hole 79 in the mounting portion 52. The first bolt 72 is inserted into the bolt hole 78 in the outer diameter portion 75 and the bolt hole 79 in the mounting portion 52 from the inside of the seal cover 33 in the axial direction.

[0034] The seal cover 33 is attached to the support shaft 31 at its inner diameter portion 76. A bolt hole 81 is formed in the inner diameter portion 76. A bolt hole 82 is formed in the support shaft 31. A bolt hole 83 is formed in the motor housing 38. The inner diameter portion 76 is attached to the support shaft 31 by a second bolt 73 that is passed through the bolt hole 81 in the inner diameter portion 76, the bolt hole 83 in the motor housing 38, and the bolt hole 82 in the support shaft 31. The second bolt 73 is inserted from the inside of the seal cover 33 in the axial direction into the bolt hole 81 in the inner diameter portion 76, the bolt hole 83 in the motor housing 38, and the bolt hole 82 in the support shaft 31.

[0035] In the track-type traveling device 5 according to the present embodiment described above, when replacing the floating seal 62, first, as shown in FIGS. 4 and 5 , the inner cover 54 is removed from the track frame 24. This allows access to the seal cover 33 from inside the track frame 24. Next, the seal cover 33 is removed from the mounting portion 52 and the support shaft 31. This exposes the floating seal 62, allowing access to the floating seal 62 from inside the track frame 24, as shown in FIG. 7 . Therefore, the floating seal 62 can be easily replaced without cutting the track 23 or removing the first rotation mechanism 21 from outside the track frame 24. Note that the configuration of the track-type traveling device 6 is similar to that of the track-type traveling device 5, and therefore a detailed description thereof will be omitted.

[0036] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

[0037] The work machine 1 is not limited to an excavator, but may be other machines such as a bulldozer or a dump truck. The structure of the first rotation mechanism 21 is not limited to that of the above-described embodiment and may be modified. For example, the number of reducers is not limited to three. The number of reducers may be less than three or more than three. The first rotating body 26 is not limited to a sprocket and may be an idler. The structure of the floating seal 62 and seal cover 33 described above may be applied to the second rotation mechanism 22.

[0038] According to the present disclosure, replacement of a floating seal in a track-type traveling device becomes easy.

[0039] 1: Work machine, 5: Track-type traveling device, 21: First rotating mechanism, 23: Track, 26: First rotating body, 24: Track frame, 30: Support mechanism, 31: Support shaft, 32: Travel motor, 33: Seal cover, 37: Drive shaft, 38: Motor housing, 43: Boss, 51: Storage section, 52: Mounting section, 61: First opening, 62: Floating seal, 71: Flange section, 75: Outer diameter section, 76: Inner diameter section, Ax1: Axis

Claims

1. A crawler travel device for a work machine, comprising a crawler, a storage portion having an internal space, and a mounting portion extending from an inner surface of the storage portion, a track frame that supports the crawler, a rotating body around which the crawler is wound, a rotating mechanism disposed outside the mounting portion in the axial direction of the rotating body, a support mechanism at least partially disposed in the internal space, attached to the mounting portion, and rotatably supporting the rotating mechanism, and a floating seal that seals between the rotating mechanism and the support mechanism, wherein the support mechanism includes a seal cover that covers the floating seal from the inside in the axial direction, and the seal cover is disposed inside the mounting portion in the axial direction, the crawler travel device.

2. The crawler travel device according to claim 1, wherein the seal cover is detachably attached to the mounting portion.

3. The mounting portion includes an opening, and the rotating mechanism includes a boss extending from the rotating body inward in the axial direction through the opening, the crawler travel device according to claim 1.

4. The floating seal is disposed between the boss and the seal cover, the crawler travel device according to claim 3.

5. The seal cover has an outer diameter larger than that of the opening, the crawler travel device according to claim 3.

6. The floating seal has an outer diameter smaller than that of the opening, the crawler travel device according to claim 3.

7. The rotating mechanism includes a flange portion extending radially from the boss of the rotating mechanism, and the flange portion faces the mounting portion from the outside of the mounting portion in the axial direction, the crawler travel device according to claim 3.

8. The support mechanism includes a support shaft disposed in the rotating mechanism and rotatably supporting the rotating mechanism, and the seal cover is disposed inside the support shaft in the axial direction, the crawler travel device according to claim 1.

9. The seal cover is detachably attached to the support shaft, the crawler travel device according to claim 8.

10. The support shaft has an outer diameter smaller than that of the floating seal, the crawler travel device according to claim 8.

11. The seal cover includes an outer diameter portion located radially outside the floating seal and an inner diameter portion located radially inside the floating seal. The seal cover is attached to the attachment portion at the outer diameter portion and attached to the support shaft at the inner diameter portion. The crawler travel device according to claim 8.

12. The support mechanism includes a travel motor disposed in the internal space of the storage portion. The travel motor includes a drive shaft connected to the rotation mechanism and a motor housing that supports the drive shaft. The seal cover is disposed inside the motor housing in the axial direction. The crawler travel device according to claim 8.

13. The seal cover is detachably attached to the motor housing. The crawler travel device according to claim 12.

14. The seal cover connects the support shaft and the motor housing with bolts and is attached to the support shaft and the motor housing. The crawler travel device according to claim 13.

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