JP2013203232A - Axle case for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axle case for a working vehicle capable of easily making a fixing case and a steering case into oil baths while preventing leakage of lubrication oil from a part between the fixing case and the steering case.SOLUTION: An axle case is provided with a fixing case 24, a steering case 25 which is swingably supported about a vertical-direction shaft at a lower part of the fixing case 24 and supports a front wheel 5, a transmission shaft 26 which is provided in the vertical direction in the fixing case 24 and the steering case 25 and transmits motive power from the fixing case 24 side to the front wheel 5, a first seal member 46 which seals a part between the lower part of the fixing case 24 and the transmission shaft 26, a second seal member 47 which seals a part between an upper part of the steering case 25 and the transmission shaft 26, and an oil path 45b which communicates the fixing case 24 and the steering case 25 to each other.

Description

  The present invention relates to an axle case for a work vehicle, and more specifically, a fixed case, and a steering case that supports a steering wheel supported by a lower portion of the fixed case so as to be swingable around a vertical axis. The present invention relates to a transmission shaft that is provided vertically in the fixed case and the steering case and transmits power from the fixed case side to the steering wheel, and an axle case for a work vehicle.

  For example, in the riding type rice transplanter described in Patent Document 1, a transmission case equipped with left and right front wheels so as to be steerable is connected and fixed to the front portion of the body frame of the traveling body. The transmission case includes a mission case portion and an axle case portion (fixed case). A rotating case (steering case) is supported on the outer end portion of the axle case portion so as to be rotatable around a longitudinal axis. The rotating case is equipped with a longitudinal transmission shaft (transmission shaft) along a longitudinal axis. The transmission case part, the axle case part, and the rotation case are filled with lubricating oil to perform oil bath lubrication.

JP 2009-92169 A

  Here, in the riding type rice transplanter described in Patent Document 1, when the axle case portion and the rotating case are to be oil bathed, in order to prevent leakage of lubricating oil from between the axle case portion and the rotating case. The sealability between the axle case portion and the rotating case is required. In this case, it is conceivable to seal between the axle case portion and the rotating case with a seal member.

  However, when the space between the axle case portion and the rotating case is sealed by the seal member, the communication between the axle case portion and the rotating case is blocked. Therefore, it becomes difficult to achieve the oil bath of the rotating case.

  The present invention has been made in view of the above situation, and it is possible to easily convert the fixed case and the steering case into an oil bath while preventing leakage of lubricating oil from between the fixed case and the steering case. An object of the present invention is to provide an axle case for a working vehicle that can be used.

  A characteristic configuration of an axle case for a work vehicle according to the present invention includes: a fixed case; and a steering case that supports a steering wheel supported by a lower portion of the fixed case so as to be swingable about a vertical axis. A transmission shaft provided in the vertical direction over the inside of the fixed case and the steering case and transmitting power from the fixed case side to the steering wheel; A first seal member that seals, a second seal member that seals between the upper portion of the steering case and the transmission shaft, and an oil passage that communicates the fixed case and the steering case. There is.

  According to this characteristic configuration, the lower portion of the fixed case and the transmission shaft are sealed by the first seal member. The upper portion of the steering case and the transmission shaft are sealed by the second seal member. Thereby, the lubricating oil leakage from between the fixed case and the steering case can be prevented. Moreover, even if communication between the fixed case and the steering case is blocked by the first seal member and the second seal member, the fixed case and the steering case are communicated by the oil passage. Thereby, lubricating oil distribute | circulates via an oil path between a fixed case and a steering case. Therefore, it is possible to easily convert the fixed case and the steering case into an oil bath while preventing leakage of lubricating oil from between the fixed case and the steering case.

  A further characteristic configuration of the axle case for a work vehicle according to the present invention includes a cylindrical member interposed between the first seal member and the second seal member and the transmission shaft, and the oil passage includes: It is formed in the cylindrical member.

  According to this characteristic configuration, the oil passage is formed by processing the cylindrical member. Thereby, it is not necessary to process a large fixed case or a steering case in order to form an oil passage. Therefore, processing for forming the oil passage is facilitated.

  A further characteristic configuration of the axle case for a working vehicle according to the present invention is that the oil passage is formed on the transmission shaft.

  According to this characteristic configuration, the oil passage is formed by processing the transmission shaft. Thereby, it is not necessary to process a large fixed case or a steering case in order to form an oil passage. Therefore, processing for forming the oil passage is facilitated.

  A further characteristic configuration of the axle case for a working vehicle according to the present invention is that the steering case is swingably supported by the fixed case via a bush.

  According to this feature configuration, the fixed case is supported on the fixed case without a gap by the bush. Thereby, rattling between the fixed case and the steering case is reduced. Therefore, leakage of lubricating oil from between the fixed case and the steering case can be prevented.

The side view which shows a riding type rice transplanter. The partial back sectional view which shows a front transmission case. The rear sectional view showing a front axle case. Sectional drawing which shows a cylindrical member. The plane sectional view showing a rear axle case. Side surface sectional drawing which shows a rolling support part. The top view which shows a lubricating oil channel | path typically. The top view which shows a lubricating oil channel | path. The side view which shows a 1st lubricating oil channel | path. The side view which shows a 2nd lubricating oil channel | path. The top view which shows the lubricating oil channel | path which concerns on 2nd embodiment. The side view which shows the 1st lubricating oil channel | path which concerns on 2nd embodiment. The side view which shows the 2nd lubricating oil channel | path which concerns on 2nd embodiment. The rear sectional view showing the front axle case according to another embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  First, the overall configuration of the riding type rice transplanter will be described with reference to FIG.

  As shown in FIG. 1, the riding type rice transplanter includes a traveling machine body 1, a driving unit 7, a fertilizer application device 10, a seedling planting device 11, an engine E, right and left spare seedling platforms 16, I have.

  The traveling machine body 1 is configured as a four-wheel drive type. The traveling machine body 1 includes a machine body frame 2, a front transmission case 3, and a rear transmission case 4.

  The front transmission case 3 is provided at the front portion of the body frame 2. The front transmission case 3 includes right and left front wheels 5 as “steering wheels”. The inside of the front transmission case 3 is made into an oil bath with lubricating oil.

  The rear transmission case 4 is provided at the rear part of the body frame 2. The rear transmission case 4 is provided with right and left rear wheels 6. The rear transmission case 4 is made into an oil bath with lubricating oil.

  In addition, although mentioned later in detail, lubricating oil is circulated by the lubricating oil channel | path 14 between the front transmission case 3 and the rear transmission case 4 (refer FIG. 7).

  The driving unit 7 is provided on the traveling machine body 1. The driving unit 7 includes a steering handle 8 and a driver seat 9.

  The fertilizer application 10 is provided at the rear part of the traveling machine body 1. The fertilizer application 10 includes a blower 12. The blower 12 supplies a conveying wind for conveying the fertilizer.

  The seedling planting device 11 is provided behind the traveling machine body 1. The seedling planting device 11 is connected to the rear part of the traveling machine body 1 through a link mechanism 11a so as to be movable up and down. The link mechanism 11 a is driven by a hydraulic cylinder 13.

  The engine E is provided at the front portion of the traveling machine body 1. The engine E is covered with a bonnet 15.

  The preliminary seedling table 16 is provided at the front portion of the traveling machine body 1.

  Next, the front transmission case 3 will be described with reference to FIGS.

  As shown in FIGS. 2 and 3, the front transmission case 3 includes a continuously variable transmission case 17, a transmission case 18, and right and left front axle cases 19. The right and left front axle cases 19 have a symmetrical configuration. Accordingly, in the following, the left front axle case 19 will be mainly described, and the right front axle case 19 will be described as necessary.

  The continuously variable transmission case 17 houses a hydraulic continuously variable transmission 20. Hydraulic oil is supplied to the hydraulic continuously variable transmission 20 by a charge pump 21 (see FIG. 7). The hydraulic continuously variable transmission 20 includes a hydraulic pump and a hydraulic motor (not shown).

  The hydraulic pump includes an input shaft (pump shaft) 20a. The power of the engine E is transmitted to the input shaft 20a by a belt (not shown). The input shaft 20a is provided with an input pulley 20b around which the belt is wound.

  The continuously variable transmission case 17 includes an oil supply port 17a and an oil discharge port 17b.

  The lubricating oil in the mission case 18 is supplied to the oil supply port 17a. That is, the continuously variable transmission case 17 is connected to the transmission case 18 via the fuel filler port 17a. The oil filler port 17 a is disposed on the right side surface of the continuously variable transmission case 17.

  The oil discharge port 17 b discharges the lubricating oil in the continuously variable transmission case 17. The oil discharge port 17 b is disposed on the rear surface of the continuously variable transmission case 17. That is, the oil discharge port 17 b is arranged on a different surface from the oil supply port 17 a in the continuously variable transmission case 17.

  The transmission case 18 houses a sub-transmission mechanism, a stock transmission mechanism, a differential device, and the like (not shown). The power of the hydraulic continuously variable transmission 20 is transmitted to the transmission case 18 (the auxiliary transmission mechanism, the inter-company transmission mechanism, the differential device, etc.). The power of the mission case 18 is transmitted to the right and left front wheels 5 via the right and left front axle cases 19. The power of the mission case 18 is transmitted to the seedling planting device 11 via a PTO shaft (not shown). Further, the power of the transmission case 18 is transmitted to the right and left rear wheels 6 via the transmission shaft 22 (see FIG. 1) and the rear axle case 23.

  The front axle case 19 includes a fixed case 24, a steering case 25, and a transmission shaft 26.

  The fixed case 24 is fixed to the mission case 18. Specifically, for example, with respect to the left fixed case 24, the right end surface of the fixed case 24 is fixed to the left side surface of the mission case 18. Further, a front joint portion 19a described later in detail is provided on the rear surface of the right fixed case 24. A front joint portion 19 a is also provided on the front surface of the left fixed case 24. Further, a transmission shaft 27 in the left-right direction of the machine body is rotatably supported inside the fixed case 24 via a bearing 28. The power of the mission case 18 is transmitted to the transmission shaft 27.

  Further, an oil supply port 24 b is provided at the upper part of the fixed case 24. The oil filler opening 24 b is plugged with a bolt 42. By removing the bolt 42 from the oil supply port 24b, it is possible to perform oil supply or oil inspection from the oil supply port 24b.

  The steering case 25 supports the front axle 5a of the front wheel 5 rotatably. The steering case 25 is supported by the lower part of the fixed case 24 so as to be swingable about the vertical axis Y. The steering case 25 is swingably supported by the fixed case 24 via the bush 44. The steering case 25 is connected to the steering handle 8 via a tie rod 29. When the steering handle 8 is operated, the steering case 25 is swung around the axis Y through the tie rod 29. Further, the upper portion of the steering case 25 and the fixed case 24 are sealed by a seal member 64.

  Further, an oil drain port 25 a is provided at the lower portion of the steering case 25. The oil discharge port 25 a is plugged with a bolt 43. By removing the bolt 43 from the oil discharge port 25a, the lubricating oil can be discharged from the oil discharge port 25a.

  The transmission shaft 26 is provided in the vertical direction across the inside of the fixed case 24 and the steering case 25. The transmission shaft 26 transmits power from the fixed case 24 side (power of the transmission shaft 27) to the front wheel 5. Specifically, the power of the transmission shaft 27 is transmitted to the transmission shaft 26 by the bevel gear 30 and the bevel gear 31. The power of the transmission shaft 26 is transmitted to the front wheels 5 by the bevel gear 32, the bevel gear 33, and the front axle 5a.

  The transmission shaft 26 is rotatably supported by the steering case 25 via a bearing 36, a bearing 37, and a bearing 38. A spacer 58 is provided between the bearing 36 and the bearing 37. The transmission shaft 26 is rotatably supported by the fixed case 24 via a bearing 34 and a bearing 35.

  The bearing 34 rotatably supports the upper end portion of the transmission shaft 26. The bearing 34 is prevented from being pulled upward by the bolt 39 and the washer 40. An insertion port 24 a is formed in the upper part of the fixed case 24. The insertion port 24a is disposed so as to face the bolt 39 and the washer 40 from above. The insertion port 24 a is covered with a cap 41. By removing the cap 41 from the insertion port 24a, a tool can be inserted from the insertion port 24a, and the bolt 39 can be tightened or loosened with this tool.

  Further, a cylindrical member 45, which will be described in detail later, is fitted on the transmission shaft 26. The lower portion of the fixed case 24 and the transmission shaft 26 (cylindrical member 45) are sealed with a first seal member 46. The space between the upper portion of the steering case 25 and the transmission shaft 26 (cylindrical member 45) is sealed by a second seal member 47.

  The cylindrical member 45 is interposed between the first seal member 46 and the second seal member 47 and the transmission shaft 26. The cylindrical member 45 is disposed between the bearing 35 and the bearing 36. The upper end surface of the cylindrical member 45 is in contact with the bearing 35. The lower end surface of the cylindrical member 45 is in contact with the bearing 36. That is, the cylindrical member 45 also serves as a spacer between the bearing 35 and the bearing 36.

  The cylindrical member 45 has a fitting hole 45a. The fitting hole 45a penetrates the cylindrical member 45 in the axial direction. The transmission shaft 26 is inserted into the insertion hole 45a.

  In addition, an oil passage 45 b is formed in the cylindrical member 45. The oil passage 45b allows the fixed case 24 and the steering case 25 to communicate with each other. In the present embodiment, four oil passages 45b are formed (see FIG. 4). The four oil passages 45b are arranged at equal intervals (90 degrees) with respect to the center O of the cylindrical member 45 when viewed in the axial direction (axial center Y direction) of the cylindrical member 45. The number of “oil passages” is not limited to the present embodiment. The oil passage 45b includes a vertical oil passage 45c, a first horizontal oil passage 45d, and a second horizontal oil passage 45e.

  The vertical oil passage 45c is formed so as to penetrate the cylindrical member 45 in the axial direction. The vertical oil passage 45c is formed along the outer periphery of the insertion hole 45a.

  The first horizontal oil passage 45 d is formed in the direction perpendicular to the axis of the cylindrical member 45. The first horizontal oil passage 45d communicates the upper end of the vertical oil passage 45c and the fixed case 24 (the space above the first seal member 46).

  The second horizontal oil passage 45 e is formed in the direction perpendicular to the axis of the cylindrical member 45. The second horizontal oil passage 45e allows the lower end portion of the vertical oil passage 45c and the steering case 25 (a space below the second seal member 47) to communicate with each other.

  With such a configuration, the lubricating oil flows between the fixed case 24 and the steering case 25 through the oil passage 45 b of the cylindrical member 45 as follows.

  That is, as shown in FIG. 3, the lubricating oil in the fixed case 24 (specifically, the space above the first seal member 46) flows through the bearing 35, and the first lateral oil passage 45d. To the oil passage 45b. In the oil passage 45b, the lubricating oil flows from the first lateral oil passage 45d through the vertical oil passage 45c and the second lateral oil passage 45e, and from the second transverse oil passage 45e to the steering case 25 (specifically, the second oil passage 45b). It flows out into the space below the seal member 47. Thereafter, the spilled lubricating oil flows through the bearing 36, the bearing 37 and the bearing 38. Note that the lubricating oil flows from the steering case 25 side to the fixed case 24 side along a path opposite to the above.

  Next, the rear transmission case 4 will be described with reference to FIGS. 5 and 6.

  As shown in FIGS. 5 and 6, the rear transmission case 4 includes a rear axle case 23. The rear axle case 23 is configured to be movable relative to the front transmission case 3. That is, the rear axle case 23 is configured to be able to roll around the axis X in the front-rear direction with respect to the front transmission case 3.

  Further, a right and left rear joint portion 23a, which will be described in detail later, is provided on the front wall of the rear axle case 23. The rear joint portion 23a is disposed on the inner side of the machine body (on the machine body center side) than the side clutch 52 in the left-right direction of the machine body. The rear joint portion 23 a is disposed on the upper portion of the rear axle case 23. (See FIGS. 9 and 10)

  An oil drain port 23 b is provided at the lower part of the rear axle case 23. The oil discharge port 23 b is plugged with a bolt 67. By removing the bolt 67 from the oil discharge port 23b, the lubricating oil can be discharged from the oil discharge port 23b.

  Further, the rear axle case 23 rotatably supports the rear axle 6a of the right and left rear wheels 6. In addition, a transmission shaft 48 in the left-right direction of the machine body is rotatably supported in the rear axle case 23. The power of the transmission shaft 49 in the longitudinal direction of the machine body is transmitted to the transmission shaft 48 by the bevel gear 50 and the bevel gear 51. The power of the transmission shaft 22 (see FIG. 1) is transmitted to the transmission shaft 49.

  The power of the transmission shaft 48 is transmitted to the gear 53 through the side clutch 52. The power of the gear 53 is transmitted to the relay shaft 55 by the gear 54. The power of the relay shaft 55 is transmitted to the rear wheel 6 by the gear 56, the gear 57, and the rear axle 6a. The gear 57 agitates the lubricating oil in the rear axle case 23 by rotating.

  Here, the transmission shaft 49 is rotatably supported by the rolling support portion 59 via the bearing 60 and the bearing 61. The rolling support portion 59 is supported by the boss portion 62 so as to be swingable (rollable) around the axial center X in the front-rear direction. Further, the rolling support portion 59 is configured separately from the rear axle case 23. That is, the rolling support part 59 is detachably attached to the rear axle case 23. Specifically, the rolling support portion 59 is fixed to the front surface of the rear axle case 23 with a bolt 63. Further, the rolling support part 59 is provided with a positioning part 59a and a positioning part 59b. The positioning part 59a positions the bearing 60. Then, the positioning portion 59b positions the bearing 61.

  Thereby, since the rolling support part 59 can be removed from the rear axle case 23, the rolling support part 59 can be easily replaced when the rolling support part 59 is worn. Moreover, since the bearing 60 and the bearing 61 can be positioned by the rolling support part 59, the number of parts can be reduced. That is, it is not necessary to provide a dedicated positioning member for positioning the bearing 60 and the bearing 61.

  Next, the lubricating oil passage 14 will be described with reference to FIGS.

  As shown in FIGS. 7 to 10, the lubricating oil passage 14 circulates the lubricating oil between the front transmission case 3 and the rear transmission case 4. The lubricating oil circulated in the lubricating oil passage 14 is pumped by the charge pump 21. Further, the lower part of the front axle case 19 and the lower part of the rear axle case 23 are arranged lower than the lubricating oil passage 14.

  The lubricating oil passage 14 includes a first lubricating oil passage 65 and a second lubricating oil passage 66. The first lubricating oil passage 65 and the second lubricating oil passage 66 are arranged so as to be distributed to the left outer side and the right outer side of the body frame 2 with respect to the body frame 2 in a plan view. That is, the first lubricating oil passage 65 is arranged on the left side of the body frame 2. The second lubricating oil passage 66 is disposed on the right side of the body frame 2.

  In the first lubricating oil passage 65, lubricating oil flows from the front transmission case 3 side to the rear transmission case 4 side. The first lubricating oil passage 65 includes a first pipe 68 and a first rubber hose 69. The first lubricating oil passage 65 is connected to the oil outlet 17 b of the continuously variable transmission case 17 and the rear axle case 23. Specifically, the front end portion of the first pipe 68 is connected to the oil discharge port 17 b of the continuously variable transmission case 17. The rear end portion of the first rubber hose 69 is connected to the left rear joint portion 23 a of the rear axle case 23. The rear end portion of the first pipe 68 and the front end portion of the first rubber hose 69 are connected.

  The first pipe 68 is disposed on the front transmission case 3 side in the first lubricating oil passage 65. The first pipe 68 is, for example, a metallic tubular member. The rear end side of the first pipe 68 is supported on the body frame 2 side by the left support tool 70.

  The first rubber hose 69 is disposed on the rear transmission case 4 side in the first lubricating oil passage 65. The first rubber hose 69 is a flexible tubular member (for example, a rubber tubular member). The first rubber hose 69 allows the rear axle case 23 to move relative to the front transmission case 3. The first rubber hose 69 constitutes a part of the first lubricating oil passage 65. That is, the first lubricating oil passage 65 is not entirely constituted by a flexible tubular member (first rubber hose 69). The first rubber hose 69 is formed in a straight line in plan view.

  In the second lubricating oil passage 66, the lubricating oil flows from the rear transmission case 4 side to the front transmission case 3 side. The second lubricating oil passage 66 includes a second pipe 71 and a second rubber hose 72. The second lubricating oil passage 66 is connected to the front axle case 19 and the rear axle case 23. Specifically, the front end portion of the second pipe 71 is connected to the front joint portion 19 a of the right front axle case 19. The rear end portion of the second rubber hose 72 is connected to the right rear joint portion 23 a of the rear axle case 23. The rear end portion of the second pipe 71 and the front end portion of the second rubber hose 72 are connected.

  The second pipe 71 is disposed on the front transmission case 3 side in the second lubricating oil passage 66. The second pipe 71 is, for example, a metal tubular member. The rear end side of the second pipe 71 is supported on the body frame 2 side by the right support tool 70.

  The second rubber hose 72 is disposed on the rear transmission case 4 side in the second lubricating oil passage 66. The second rubber hose 72 is a flexible tubular member (for example, a rubber tubular member). The second rubber hose 72 allows the rear axle case 23 to move relative to the front transmission case 3. The second rubber hose 72 constitutes a part of the second lubricating oil passage 66. That is, the second lubricating oil passage 66 is not entirely constituted by a flexible tubular member (second rubber hose 72). The second rubber hose 72 is formed in a straight line in plan view.

  With such a configuration, the lubricating oil is circulated between the front transmission case 3 and the rear transmission case 4 through the lubricating oil passage 14 as follows.

  That is, the lubricating oil in the transmission case 18 is supplied to the continuously variable transmission case 17 from the oil supply port 17a. Then, the lubricating oil in the continuously variable transmission case 17 is discharged from the oil discharge port 17b to the first lubricating oil passage 65.

  In the first lubricating oil passage 65, the lubricating oil flows from the first pipe 68 to the first rubber hose 69. Then, the lubricating oil in the first rubber hose 69 flows into the rear axle case 23 from the left rear joint portion 23a. Then, the lubricating oil in the rear axle case 23 flows into the second lubricating oil passage 66 from the right rear joint portion 23a.

  In the second lubricating oil passage 66, the lubricating oil flows from the second rubber hose 72 to the second pipe 71. Then, the lubricating oil in the second pipe 71 flows into the right front axle case 19 from the right front joint portion 19a. Then, the lubricating oil in the right front axle case 19 is supplied to the continuously variable transmission case 17 from the oil supply port 17a again via the transmission case 18.

  Here, as shown in FIG. 3, the front axle case 19 is provided with a blocking portion 73. The interruption | blocking part 73 is comprised by the sealing member, for example. The blocking part 73 forms a blocking chamber 19 b in the front axle case 19. The shutoff chamber 19b is blocked from communicating with the lubricating oil passage 14. That is, the inside of the front axle case 19 is divided into two chambers of the communication chamber 19c and the blocking chamber 19b by the blocking portion 73. The communication chamber 19 c communicates with the lubricating oil passage 14.

  Thereby, as described above, the lubricating oil is circulated by the lubricating oil passage 14 between the front transmission case 3 and the rear transmission case 4, but in the front axle case 19, the lubricating oil in the communication chamber 19c is removed. The lubricating oil in the shutoff chamber 19b (particularly, the lubricating oil in the steering case 25) is not circulated by the lubricating oil passage 14 only by being lubricated by the lubricating oil passage 14.

  Lubricating oil can be supplied into the shutoff chamber 19b from the oil supply port 24b. The lubricating oil in the blocking chamber 19b can be drained from the oil drain port 25a.

  Further, as shown in FIG. 2, the front joint portion 19a is provided on the rear surface of the right fixed case 24 as described above. A front joint portion 19 a is also provided on the front surface of the left fixed case 24.

  That is, in plan view, when the left and right front axle case 19 is rotated by 180 degrees, the shape matches that of the left and right other front axle case 19. In other words, the right and left front axle cases 19 have a point-symmetric configuration in plan view. As a result, the right and left front axle cases 19 are shared between the left and right sides. The unused front joint portion 19a (in this embodiment, the front joint portion 19a of the left front axle case 19) is closed with a cap (not shown).

  Hereinafter, a second embodiment according to the present invention will be described.

  As shown in FIGS. 11 to 13, the lubricating oil passage 114 includes a first lubricating oil passage 165 and a second lubricating oil passage 166. Regarding the first lubricating oil passage 165 and the second lubricating oil passage 166, the intermediate portion in the longitudinal direction of the machine body is offset to the inside of the machine body from the front end part and the rear end part.

  The first lubricating oil passage 165 includes a first pipe 168 and a first rubber hose 169.

  The first pipe 168 is disposed so as to overlap the body frame 2 in plan view. The first pipe 168 is formed in a substantially crank shape in plan view. Specifically, the first pipe 168 includes a straight portion 168a. The straight portion 168a extends linearly in the longitudinal direction of the body along the lower surface of the body frame 2. Further, the first rubber hose 169 is curved so that its front end is close to the inside of the machine body in plan view.

  The second lubricating oil passage 166 includes a second pipe 171 and a second rubber hose 172.

  The second pipe 171 is arranged so as to overlap with the body frame 2 in plan view. The second pipe 171 is formed in a substantially crank shape in plan view. Specifically, the second pipe 171 includes a straight portion 171a. The straight portion 171a extends linearly in the longitudinal direction of the aircraft along the lower surface of the aircraft frame 2. Further, the second rubber hose 172 is curved so that its front end is close to the inside of the machine body in plan view.

  Here, right and left rear joint portions 123 a are provided on the front wall of the rear axle case 23. The right rear joint portion 123 a is connected to the second lubricating oil passage 166. The left rear joint portion 123a is connected to the first lubricating oil passage 165.

  At least a part of the rear joint portion 123a overlaps with the rear axle case 23 in plan view. That is, the front end face of the rear joint portion 123a is aligned with the front end face of the rear axle case 23 in the front-rear direction of the machine body (see FIGS. 12 and 13). Thereby, the part which the rear joint part 123a protrudes from the rear-axle case 23 is decreased.

  Hereinafter, another embodiment according to the present invention will be described.

  As shown in FIG. 14, an oil passage 26 a may be formed in the transmission shaft 26. Thereby, the total cross-sectional area of the oil passage can be increased by the oil passage 45 b of the cylindrical member 45 and the oil passage 26 a of the transmission shaft 26. The cylindrical member 45 (oil passage 45b) may be eliminated and only the oil passage 26a of the transmission shaft 26 may be used.

  Further, at least a part of the front joint portion 19a may overlap with the front axle case 19 in a plan view.

  Further, the “continuously variable transmission” may be a hydraulic mechanical continuously variable transmission (HMT).

  Further, the continuously variable transmission case 17 and the transmission case 18 may be provided in the rear axle case 23. In this case, the first lubricating oil passage 65 (165) is connected to the oil outlet 17 b of the continuously variable transmission case 17 and the front joint portion 19 a of the front axle case 19.

  Further, the front transmission case 3 may be configured to be movable relative to the rear transmission case 4. That is, the front transmission case 3 may be configured to be rollable with respect to the rear transmission case 4.

  Further, in place of the rolling suspension, a five-link suspension provided with a lateral rod may be used.

  Further, the “lubricating oil passage” is constituted by a single tubular member, and the tubular member is partitioned by a partition member to provide a “first lubricating oil passage” and a “second lubricating oil passage”. Good.

  Further, the rear transmission case 4 may be provided with a blocking portion 73.

  In addition, the “lubricating oil passage” is configured in such a manner that a metal tube, a rubber tube, and a metal tube are connected in order from the front so that the rubber tube is not disposed in the vicinity of the wheels (front wheel 5 and rear wheel 6) that are susceptible to mud. May be.

  Further, when the rear wheel 6 is a rigid (rigid axle suspension), the “lubricating oil passage” may be entirely composed of a metal pipe.

  Further, with respect to the “lubricating oil passage”, a rubber hose may be disposed on the front transmission case 3 side. In this case, the blocking portion 73 is eliminated and the entire front axle case 19 is made the communication chamber 19c, and the lubricating oil can be circulated throughout the entire front axle case 19 including the steering case 25.

  The machine body frame 2 itself may be a “lubricating oil passage”.

  Alternatively, the intake port of the blower 12 may face a route (lubricant passage 14 (114), etc.) through which the lubricating oil circulates, and hot air around the route through which the lubricating oil circulates may be taken into the fertilizer application apparatus 10. .

  The present invention includes a fixed case, a steering case supported on a lower portion of the fixed case so as to be swingable around an axis in the vertical direction, and supporting a steering wheel, and a vertical direction extending between the fixed case and the steering case. It can be used for a transmission shaft that is provided in a direction and transmits power from a fixed case side to a steering wheel, and an axle case for a work vehicle.

5 Front wheels (steering wheels)
Reference Signs List 24 Fixed case 25 Steering case 26 Transmission shaft 26a Oil passage 44 Bush 45 Cylinder member 45b Oil passage 46 First seal member 47 Second seal member

Claims (4)

A fixed case;
A steering case that is supported by a lower part of the fixed case so as to be swingable around an axis in the vertical direction and supports the steering wheel;
A transmission shaft that is provided in the vertical direction across the inside of the fixed case and the steering case, and transmits power from the fixed case side to the steering wheel;
A first seal member for sealing between a lower portion of the fixed case and the transmission shaft;
A second seal member for sealing between the upper part of the steering case and the transmission shaft;
An axle case for a work vehicle, comprising: an oil passage that communicates the fixed case and the steering case. A cylindrical member interposed between the first seal member and the second seal member and the transmission shaft;
The axle case for a work vehicle according to claim 1, wherein the oil passage is formed in the cylindrical member.   The axle case for a work vehicle according to claim 1, wherein the oil passage is formed in the transmission shaft.   The axle case for a work vehicle according to any one of claims 1 to 3, wherein the steering case is swingably supported by the fixed case via a bush.

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