Tracked work machine

Abstract

In the present invention, a bulldozer (1) comprises: a first right oil passage (101R), a second right oil passage (102R), and a third right oil passage (103R). The first right oil passage (101R) guides some of lubricating oil discharged from a hydraulic pump (81) to a right steering brake (50R). The second right oil passage (102R) guides some of the lubricating oil discharged from the hydraulic pump (81) to a right planetary gear structure (30R). The third right oil passage (103R) guides at least some of the lubricating oil that has passed through the right planetary gear structure (30R) to the right steering brake (50R). At least a part of the right planetary gear structure (30R) is arranged further inside than the right steering brake (50R) in a radial direction perpendicular to the shaft center of an input shaft (26).

Description

[Technical Field]

[0001] The present disclosure relates to a track-type work machine. [Background technology]

[0002] In a track-type work machine (such as a bulldozer), engine power is transmitted to left and right drive wheels via a transmission, and the left and right drive wheels drive left and right tracks. In such a track-type work machine, left and right turns are performed by hydraulically controlling left and right steering clutches and steering brakes provided corresponding to the left and right drive wheels.

[0003] Patent Document 1 proposes a method for efficiently utilizing lubricating oil by supplying a portion of the lubricating oil supplied from a hydraulic pump to a steering clutch to a steering brake. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-71357 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in order to reduce the size of the steering clutch, it is possible to provide a planetary gear mechanism between the input shaft and the output shaft, but Patent Document 1 does not consider the efficient use of lubricating oil when a planetary gear mechanism is provided.

[0006] An object of the present disclosure is to provide a track-type work machine that can efficiently use lubricating oil. [Means for solving the problem]

[0007] A track-type work machine according to one aspect of the present disclosure includes a planetary gear mechanism, a steering clutch, a steering brake, a hydraulic pump, a first oil passage, a second oil passage, and a third oil passage. The planetary gear mechanism is disposed between an input shaft and an output shaft. The steering clutch switches between transmitting and blocking rotation from the input shaft to the output shaft by the planetary gear mechanism. The steering brake brakes the rotation of the output shaft. The hydraulic pump discharges lubricating oil. The first oil passage guides a portion of the lubricating oil discharged from the hydraulic pump to the steering brake. The second oil passage guides a portion of the lubricating oil discharged from the hydraulic pump to the planetary gear mechanism. The third oil passage guides at least a portion of the lubricating oil that has passed through the planetary gear mechanism to the steering brake. At least a portion of the planetary gear mechanism is disposed inward of the steering brake in a radial direction perpendicular to the axis of the input shaft. [Effects of the Invention]

[0008] According to the track-type work machine according to the present disclosure, lubricating oil can be used efficiently. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a bulldozer, which is an example of a track-type work machine. [Figure 2] FIG. 2 is a cross-sectional view of the power transmission system of the bulldozer. [Figure 3] FIG. 1 is a schematic system configuration diagram of a power transmission system of a bulldozer. [Figure 4] FIG. 3 is a cross-sectional view showing the configuration of the periphery of a lubricating oil passage. [Figure 5] FIG. 2 is a schematic diagram for explaining the flow of lubricating oil. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Bulldozer 1 configuration) Fig. 1 is a perspective view of a bulldozer 1, which is an example of a track-type work machine. Fig. 2 is a cross-sectional configuration diagram of a power transmission system of the bulldozer 1. Fig. 3 is a schematic system configuration diagram of the power transmission system of the bulldozer 1.

[0011] The bulldozer 1 is equipped with left and right traveling devices 4L, 4R having left and right sprockets 2L, 2R and left and right crawler tracks 3L, 3R, a blade 5 provided at the front of the vehicle, and a ripper device 6 provided at the rear of the vehicle.

[0012] The bulldozer 1 can perform work such as pushing earth with the blade 5 and work such as crushing and excavating with the ripper device 6.

[0013] The bulldozer 1 has an engine 10, a power transmission device 20, left and right planetary gear mechanisms 30L, 30R, left and right steering clutches 40L, 40R, left and right steering brakes 50L, 50R, left and right output shafts 60L, 60R, left and right final drive devices 70L, 70R, and a lubricating oil supply unit 80.

[0014] The power transmission device 20 transmits power from the engine 10 to the left and right planetary gear mechanisms 30L, 30R. The power transmission device 20 includes a power take-off device 21, a torque converter 22, a transmission 23, a pinion 24, a bevel gear 25, and an input shaft 26.

[0015] The power take-off device 21 distributes power from the engine 10 to the torque converter 22 and the lubricating oil supply unit 80. The torque converter 22 transmits the power of the engine 10 transmitted from the power take-off device 21 to the transmission 23 via a fluid. The transmission 23 changes the speed of the rotational motion transmitted from the torque converter 22. The transmission 23 can be switched between forward and reverse. The transmission 23 is connected to a pinion 24. The power from the transmission 23 is transmitted to an input shaft 26 via the pinion 24 and a bevel gear 25.

[0016] The left and right planetary gear mechanisms 30L, 30R are disposed between the input shaft 26 and the left and right output shafts 60L, 60R. The left and right planetary gear mechanisms 30L, 30R include left and right ring gears 31L, 31R, left and right planetary gears 32L, 32R, left and right sun gears 33L, 33R, and left and right carriers 34L, 34R.

[0017] The left and right ring gears 31L, 31R are connected to the input shaft 26. The left and right planetary gears 32L, 32R are arranged inside the left and right ring gears 31L, 31R in a radial direction perpendicular to the axis of the input shaft 26. The left and right planetary gears 32L, 32R are arranged between the left and right ring gears 31L, 31R and the left and right sun gears 33L, 33R. The left and right planetary gears 32L, 32R mesh with the left and right ring gears 31L, 31R and the left and right sun gears 33L, 33R. The left and right sun gears 33L, 33R are rotatably attached to the input shaft 26. The left and right sun gears 33L, 33R are arranged inside the left and right planetary gears 32L, 32R in the radial direction. The left and right sun gears 33L, 33R are connected to the left and right steering clutches 40L, 40R. The left and right carriers 34L, 34R are connected to the left and right planetary gears 32L, 32R and the left and right output shafts 60L, 60R.

[0018] The left and right steering clutches 40L, 40R are wet multi-plate clutches that can be engaged or disengaged with the left and right sun gears 33L, 33R. The left and right steering clutches 40L, 40R switch between transmitting and cutting off rotational power from the input shaft 26 to the left and right output shafts 60L, 60R by the left and right planetary gear mechanisms 30L, 30R.

[0019] Specifically, when the left steering clutch 40L is engaged and the left sun gear 33L is directly connected to the first clutch gear 91, the first clutch gear 91 is unable to rotate (described below), and therefore the left sun gear 33L is also unable to rotate. Then, rotation of the input shaft 26 is transmitted to the left output shaft 60L via the left ring gear 31L, the left planetary gear 32L, and the left carrier 34L. Furthermore, when the left steering clutch 40L is disengaged and the left sun gear 33L enters a free rotation state, rotation from the input shaft 26 to the left output shaft 60L is cut off. Similarly, the right steering clutch 40R switches between transmitting and cutting off rotation from the input shaft 26 to the right output shaft 60R depending on whether it is engaged or disengaged.

[0020] 3, a first clutch gear 91 is attached to the left steering clutch 40L, and the first clutch gear 91 is connected to an idler gear 93 and a pinion gear 94. A second clutch gear 92 is attached to the right steering clutch 40R, and the second clutch gear 92 is connected to the idler gear 93 and the pinion gear 94 via a first transfer gear 95, a countershaft 96, and a second transfer gear 97. A pinion shaft 94a connected to the pinion gear 94 is fixed by a fixing member 98 and cannot rotate. Therefore, no rotational power is applied from the left and right steering clutches 40L, 40R to the left and right sun gears 33L, 33R.

[0021] Here, the fixing member 98 is detachably fixed to a housing (not shown). When the fixing member 98 is removed from the housing, the fixing member 98 can also be removed from the pinion gear 94. As a result, the fixing of the pinion gear 94 by the fixing member 98 is released.

[0022] When the pinion gear 94 is released from the fixing member 98, a swing motor (not shown) may be connected to the pinion shaft 94a. In this case, when the left and right steering clutches 40L, 40R are engaged and the rotational power of the swing motor is transmitted to the left and right sun gears 33L, 33R via the left and right steering clutches 40L, 40R, the left and right sun gears 33L, 33R rotate in opposite directions at the same rotation speed. This causes a difference in rotation speed between the left and right output shafts 60L, 60R, allowing the bulldozer 1 to make gentle left and right turns.

[0023] The left and right steering brakes 50L, 50R brake the rotation of the left and right output shafts 60L, 60R. The left and right steering brakes 50L, 50R are wet multi-plate clutches that can be engaged with or disengaged from the left and right output shafts 60L, 60R.

[0024] When the left steering brake 50L is engaged, the rotation of the left output shaft 60L is braked, thereby reducing the rotation of the left final reduction gear 70L connected to the left sprocket 2L. When the right steering brake 50R is engaged, the rotation of the right output shaft 60R is braked, thereby reducing the rotation of the right final reduction gear 70R connected to the right sprocket 2R.

[0025] The lubricating oil supply unit 80 includes a hydraulic pump 81 , a lubricating oil passage 82 , and a lubricating oil tank 83 .

[0026] The hydraulic pump 81 is driven by the power of the engine 10 transmitted from the power take-off device 21. The hydraulic pump 81 discharges lubricating oil from a lubricating oil tank 83 to a lubricating oil passage 82. In this embodiment, the hydraulic pump 81 is a fixed displacement pump.

[0027] The lubricating oil passage 82 includes a first supply oil passage 100, a second supply oil passage 110, left and right first oil passages 101L, 101R, left and right second oil passages 102L, 102R, left and right third oil passages 103L, 103R, left and right fourth oil passages 104L, 104R, left and right fifth oil passages 105L, 105R, and left and right discharge oil passages 106L, 106R.

[0028] The first oil supply passage 100 is connected to the second oil supply passage 110, the left and right first oil passages 101L, 101R, and the hydraulic pump 81. The first oil supply passage 100 supplies lubricating oil discharged from the hydraulic pump 81 to the second oil supply passage 110 and the left and right first oil passages 101L, 101R.

[0029] The left and right first oil passages 101L, 101R guide a portion of the lubricating oil discharged from the hydraulic pump 81 to the left and right steering brakes 50L, 50R.

[0030] The second oil supply passage 110 communicates with the first oil supply passage 100 and the interior of the input shaft 26. The second oil supply passage 110 guides a portion of the lubricating oil discharged from the hydraulic pump 81 to the left and right second oil passages 102L, 102R and the left and right fourth oil passages 104L, 104R.

[0031] The left and right second oil passages 102L, 102R guide a portion of the lubricating oil discharged from the hydraulic pump 81 to the left and right planetary gear mechanisms 30L, 30R. The left and right third oil passages 103L, 103R guide at least a portion of the lubricating oil that has passed through the left and right planetary gear mechanisms 30L, 30R to the left and right steering brakes 50L, 50R. In this embodiment, the left and right third oil passages 103L, 103R guide all of the lubricating oil that has passed through the left and right planetary gear mechanisms 30L, 30R to the left and right steering brakes 50L, 50R.

[0032] The left and right fourth oil passages 104L, 104R guide a portion of the lubricating oil discharged from the hydraulic pump 81 to the left and right steering clutches 40L, 40R. The left and right fifth oil passages 105L, 105R guide at least a portion of the lubricating oil that has passed through the left and right steering clutches 40L, 40R to the left and right steering brakes 50L, 50R. Specifically, the left and right fifth oil passages 105L, 105R guide all of the lubricating oil that has passed through the left and right steering clutches 40L, 40R to the left and right steering brakes 50L, 50R via the left and right planetary gear mechanisms 30L, 30R and the left and right third oil passages 103L, 103R.

[0033] In this way, in this embodiment, all of the lubricating oil guided to the left and right planetary gear mechanisms 30L, 30R and the steering clutches 40L, 40R is guided to the left and right steering brakes 50L, 50R via the left and right third oil passages 103L, 103R and the left and right fifth oil passages 105L, 105R.

[0034] The left and right oil discharge passages 106L, 106R guide the lubricating oil that has passed through the left and right steering brakes 50L, 50R to the lubricating oil tank 83.

[0035] (Configuration of the lubricating oil passage 82 and its surroundings) Fig. 4 is a cross-sectional view showing the configuration around the lubricating oil passage 82. Fig. 4 shows a cross section perpendicular to the axis of the input shaft 26. Since the configuration around the lubricating oil passage 82 is basically symmetrical, the configuration on the right side will be described below.

[0036] The right steering clutch 40R includes a rotating member 41, a clutch housing 42, a plurality of clutch discs 43, a plurality of clutch plates 44, and a clutch piston 45.

[0037] The rotating member 41 is supported by the input shaft 26 and rotates around the axis of the input shaft 26. The clutch housing 42 is installed so as to be rotatable relative to the rotating member 41. The clutch housing 42 surrounds the outside of each clutch disc 43 and each clutch plate 44. Each clutch disc 43 is supported by the rotating member 41. Each clutch plate 44 is supported by the clutch housing 42. Each clutch disc 43 and each clutch plate 44 are arranged alternately in the axial direction parallel to the axis of the input shaft 26. When hydraulic oil is supplied, the clutch piston 45 presses each clutch disc 43 and each clutch plate 44 against each other. This causes the right steering clutch 40R to be engaged.

[0038] The right steering brake 50R includes a rotating member 51, a brake housing 52, a plurality of fixed plates 53, a plurality of brake discs 54, and a brake piston 55.

[0039] The rotating member 51 is fixed to the right output shaft 60R and rotates around the axis of the right output shaft 60R. The brake housing 52 is rotatable relative to the rotating member 51. In this embodiment, the brake housing 52 is fixed and does not rotate itself. The brake housing 52 surrounds the outside of each fixed plate 53 and each brake disc 54. Each fixed plate 53 is attached to the brake housing 52. Each fixed plate 53 may move slightly in the axial direction relative to the brake housing 52. Each brake disc 54 is supported by the rotating member 51. Each brake disc 54 may move slightly in the axial direction relative to the rotating member 51.

[0040] The fixed plates 53 and the brake discs 54 are arranged alternately in the axial direction. The fixed plates 53 and the brake discs 54 are pressed against each other by springs (not shown) (e.g., disc springs, coil springs, etc.). When hydraulic oil is supplied, the brake pistons 55 move the fixed plates 53 and the brake discs 54 away from each other. This puts the right steering brake 50R into a non-braking state.

[0041] Here, at least a portion of the right planetary gear mechanism 30R is disposed radially inward of the right steering brake 50R. Specifically, the right ring gear 31R is disposed radially inward of the respective brake discs 54. The right planetary gear 32R and the right sun gear 33R, which are disposed inside the right ring gear 31R, are also disposed radially inward of the respective brake discs 54. Furthermore, a portion of the right carrier 34R, which is connected to the right planetary gear 32R and the right output shaft 60R, is also disposed radially inward of the respective brake discs 54.

[0042] At least a portion of the right steering clutch 40R is disposed radially inward of the right steering brake 50R. Specifically, the clutch discs 43 and the clutch plates 44 are disposed radially inward of the brake discs 54.

[0043] In this specification, "at least a portion of the X member is disposed radially inward of the Y member" means that, when viewed from an axial direction parallel to the axis of input shaft 26, the shortest distance between the X member and the axis is shorter than the shortest distance between the Y member and the axis. In this case, the position of the X member in the axial direction and the position of the Y member in the axial direction may or may not overlap partially or entirely.

[0044] In this embodiment, the right steering brake 50R, the right planetary gear mechanism 30R, and the right steering clutch 40R are arranged in this order from the right side, but the axial arrangement order can be changed as appropriate.

[0045] Next, the flow of lubricating oil will be described with reference to Fig. 5, which is a schematic diagram for explaining the flow of lubricating oil.

[0046] The lubricating oil discharged from the hydraulic pump 81 is distributed to the first right oil passage 101R, the second right oil passage 102R, and the fourth right oil passage 104R via the first oil supply passage 100 and the second oil supply passage 110. The distribution ratio to each oil passage can be adjusted appropriately by changing the diameter of each oil passage.

[0047] The lubricating oil distributed to the right fourth oil passage 104R lubricates the right steering clutch 40R, and then is guided by centrifugal force from the right fifth oil passage 105R to the right planetary gear mechanism 30R.

[0048] The lubricating oil distributed to the right second oil passage 102R lubricates the right planetary gear mechanism 30R, and then, together with the lubricating oil guided to the right planetary gear mechanism 30R from the right fifth oil passage 105R, is guided by centrifugal force from the right third oil passage 103R to the right steering brake 50R.

[0049] The lubricating oil distributed to the right first oil passage 101R lubricates the right steering brake 50R together with the lubricating oil led from the right third oil passage 103R to the right steering brake 50R, and is then led by centrifugal force from the right discharge oil passage 106R to the lubricating oil tank 83.

[0050] (Features) (1) The bulldozer 1 is equipped with a right first oil passage 101R, a right second oil passage 102R, and a right third oil passage 103R. The right first oil passage 101R guides a portion of the lubricating oil discharged from the hydraulic pump 81 to the right steering brake 50R. The right second oil passage 102R guides a portion of the lubricating oil discharged from the hydraulic pump 81 to the right planetary gear mechanism 30R. The right third oil passage 103R guides at least a portion of the lubricating oil that has passed through the right planetary gear mechanism 30R to the right steering brake 50R. At least a portion of the right planetary gear mechanism 30R is disposed inward of the right steering brake 50R in a radial direction perpendicular to the axis of the input shaft 26.

[0051] Therefore, the lubricating oil can be guided from the right planetary gear mechanism 30R to the right steering brake 50R by centrifugal force via the third oil passage 103R, so that the lubricating oil used to lubricate the right planetary gear mechanism 30R can also be used to lubricate the right steering brake 50R. As a result, the lubricating oil supplied from the hydraulic pump 81 can be used efficiently, and the capacity of the hydraulic pump 81 can be reduced. This effect can also be obtained in the left steering brake 50R.

[0052] (2) The bulldozer 1 is provided with a right fourth oil passage 104R and a right fifth oil passage 105R. The right fourth oil passage 104R guides a portion of the lubricating oil discharged from the hydraulic pump 81 to the right steering clutch 40R. The right fifth oil passage 105R guides at least a portion of the lubricating oil that has passed through the right steering clutch 40R to the right steering brake 50R. At least a portion of the right steering clutch 40R is disposed radially inward of the right steering brake 50R.

[0053] Therefore, the lubricating oil can be guided from the right steering clutch 40R to the right steering brake 50R by centrifugal force via the fifth oil passage 105R, so that the lubricating oil used to lubricate the right steering clutch 40R can also be used to lubricate the right steering brake 50R. This allows the lubricating oil supplied from the hydraulic pump 81 to be used more efficiently, thereby further reducing the capacity of the hydraulic pump 81. This effect can also be obtained in the left steering brake 50R.

[0054] (Modification of the embodiment) The present invention is not limited to the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the present invention.

[0055] (Variation 1) In the above embodiment, the left and right third oil passages 103L, 103R are configured to guide all of the lubricating oil that has passed through the left and right planetary gear mechanisms 30L, 30R to the left and right steering brakes 50L, 50R, but this is not limited to this. The left and right third oil passages 103L, 103R may also guide only a portion of the lubricating oil that has passed through the left and right planetary gear mechanisms 30L, 30R to the left and right steering brakes 50L, 50R. In this case, the remainder of the lubricating oil that has passed through the left and right planetary gear mechanisms 30L, 30R may be directly collected in the lubricating oil tank 83.

[0056] (Variation 2) In the above embodiment, the left and right fifth oil passages 105L, 105R are configured to guide all of the lubricating oil that has passed through the left and right steering clutches 40L, 40R to the left and right steering brakes 50L, 50R, but this is not limited to this. The left and right fifth oil passages 105L, 105R may also guide only a portion of the lubricating oil that has passed through the left and right steering clutches 40L, 40R to the left and right steering brakes 50L, 50R. In this case, the remainder of the lubricating oil that has passed through the left and right steering clutches 40L, 40R may be directly collected in the lubricating oil tank 83.

[0057] (Variation 3) In the above embodiment, the left and right fifth oil passages 105L, 105R connect the left and right steering clutches 40L, 40R to the left and right planetary gear mechanisms 30L, 30R, but this is not limited to this. For example, the left and right fifth oil passages 105L, 105R may directly connect the left and right steering clutches 40L, 40R to the left and right steering brakes 50L, 50R. Alternatively, the left and right fifth oil passages 105L, 105R may directly connect the left and right steering clutches 40L, 40R to the lubricating oil tank 83. [Explanation of symbols]

[0058] 1. Bulldozer 10 Engine 20 Power transmission device 26 Input shaft 30L, 30R left and right planetary gear mechanism 40L, 40R left and right steering clutches 50L, 50R left and right steering brakes 60L, 60R Left and right output shafts 70L, 70R Left and right final drive units 80 Lubricating oil supply section 81 Hydraulic pump 82 Lubricating oil path 100 Oil supply line 101L, 101R Left and right first oil passages 102L, 102R Left and right second oil passages 103L, 103R Left and right third oil passages 104L, 104R Left and right fourth oil passages 105L, 105R Left and right fifth oil passages 106L, 106R Left and right oil drain passages

Claims

1. The engine and a transmission that changes the speed of the power of the engine; an input shaft to which power is transmitted from the transmission; a planetary gear mechanism disposed between the input shaft and the output shaft; a steering clutch that switches between transmission and interruption of rotational power from the input shaft to the output shaft by the planetary gear mechanism; a steering brake that brakes the rotation of the output shaft; a hydraulic pump that discharges lubricating oil; a first oil passage that guides a portion of the lubricating oil discharged from the hydraulic pump to the steering brake; a second oil passage that guides a portion of the lubricating oil discharged from the hydraulic pump to the planetary gear mechanism; a third oil passage that guides at least a portion of the lubricating oil that has passed through the planetary gear mechanism to the steering brake; a fourth oil passage that guides a portion of the lubricating oil discharged from the hydraulic pump to the steering clutch; a fifth oil passage that directly guides at least a portion of the lubricating oil that has passed through the steering clutch to the steering brake; Equipped with At least a portion of the planetary gear mechanism is disposed inward of the steering brake in a radial direction perpendicular to the axis of the input shaft. Tracked work machine.

2. An engine; a transmission that changes the speed of the power of the engine; an input shaft to which power is transmitted from the transmission; a planetary gear mechanism disposed between the input shaft and the output shaft; a steering clutch that switches between transmission and interruption of rotational power from the input shaft to the output shaft by the planetary gear mechanism; a steering brake that brakes the rotation of the output shaft; a hydraulic pump that discharges lubricating oil; a first oil passage that guides a portion of the lubricating oil discharged from the hydraulic pump to the steering brake; a second oil passage that guides a portion of the lubricating oil discharged from the hydraulic pump to the planetary gear mechanism; a third oil passage that guides at least a portion of the lubricating oil that has passed through the planetary gear mechanism to the steering brake; a fourth oil passage that guides a portion of the lubricating oil discharged from the hydraulic pump to the steering clutch; a fifth oil passage that guides at least a portion of the lubricating oil that has passed through the steering clutch to the steering brake; Equipped with At least a portion of the planetary gear mechanism is disposed inward of the steering brake in a radial direction perpendicular to an axis of the input shaft, The steering brake, the planetary gear mechanism, and the steering clutch are arranged in this order in an axial direction parallel to the input shaft. Tracked work machine.

3. The planetary gear mechanism includes: a ring gear connected to the input shaft; a planetary gear disposed inside the ring gear in the radial direction; a sun gear disposed radially inside the planetary gears and connected to the steering clutch; a carrier connected to the planetary gear and the output shaft; and The steering brake a rotating member that rotates together with the output shaft; a brake housing rotatable relative to the rotating member; a plurality of fixing plates attached to the brake housing; a plurality of brake discs attached to the rotating member; and The ring gear is disposed radially inward of the plurality of brake discs.

3. A track-type working machine according to claim 1 or 2.

4. At least a portion of the steering clutch is disposed radially inward of the steering brake.

3. A track-type working machine according to claim 1 or 2.

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