JP5597888B2 - Axle drive - Google Patents

Description

  The present invention provides a first oil sump in which lubricating oil in which at least a part of the gear group of the reduction gear mechanism is immersed is stored at the bottom of a transmission case that houses a reduction gear mechanism for shifting driving of an axle. The present invention relates to an axle drive device that pumps up lubricating oil in the first oil sump by a hydraulic pump of a hydraulic continuously variable transmission and supplies it as hydraulic oil to the hydraulic continuously variable transmission, and more particularly to a lubrication configuration in the axle drive device. .

  Conventionally, in an axle drive device mounted on a work machine such as a combiner, when a reduction gear mechanism including a transmission unit is accommodated in a sealed transmission case, lubrication to a lubricated part such as a gear group or a bearing of the reduction gear mechanism is performed. Is a technique in which a part of the gear group is immersed in an oil reservoir of lubricating oil stored at the bottom of the transmission case, and the lubricating oil is scattered by the rotation of the gear group to lubricate each part of the reduction gear mechanism. It is publicly known (see, for example, Patent Document 1). Further, the axle drive device is configured by attaching a hydraulic continuously variable transmission connected to the input side of the reduction gear mechanism to the upper side surface of the transmission case, and the oil in the oil reservoir Pumped up as hydraulic oil to be replenished to a continuously variable transmission.

JP 2000-318470 A

  The pumped oil is adjusted to a predetermined pressure by a charge relief valve provided in the hydraulic continuously variable transmission and then replenished into the hydraulic continuously variable transmission. At this time, the oil is discharged from the charge relief valve. The surplus oil having a high temperature is discharged into the transmission case through the device case of the hydraulic continuously variable transmission and returned to the oil reservoir. For this reason, the oil temperature of the oil sump tends to rise, and the viscosity of the oil decreases, and when this oil is replenished into the hydraulic continuously variable transmission, the operation of circulating through the hydraulic continuously variable transmission There was a problem that transmission efficiency deteriorates because oil easily leaks. Further, the oil level of the oil reservoir is set high so that the lubricating oil can be sufficiently scattered even at a low speed rotation of the gear group at the start of operation. For this reason, during operation, there has been a problem that the lubricating oil in the oil reservoir is vigorously stirred due to the high-speed rotation of the gear group, and the loss horsepower is increased or the oil temperature is significantly increased due to the stirring resistance.

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
In other words, according to the first aspect, the first oil reservoir in which the lubricating oil in which at least a part of the gear group of the reduction gear mechanism is immersed is stored in the bottom portion of the transmission case that accommodates the reduction gear mechanism for the speed change drive of the axle. In the axle drive device that pumps up the lubricating oil in the first oil sump by the hydraulic pump of the hydraulic continuously variable transmission and supplies it as hydraulic fluid to the hydraulic continuously variable transmission, an upper portion in the transmission case is provided. The second oil sump is provided with a second oil sump, and a partition wall of the second oil sump is provided with an injection port communicating with the space in the transmission case, and the second oil sump and the device case of the hydraulic continuously variable transmission connected via a communication passage between the transmission case is composed of a pair of case halves, upon assembly of the casing halves, the partition walls between which is provided in each case half in contact with each other And by the with a second oil reservoir defining formed from the transmission case in the space, the噴油port, one of the partition walls along the joint surfaces of the partition wall and forms partially offset from the other partition wall is there.
According to a second aspect of the present invention, the communication passage is constituted by an external pipe, and a cooling device for cooling the lubricating oil flowing from the device case to the second oil reservoir is provided in the middle of the external pipe.
According to a third aspect of the present invention, the injection hole of the second oil sump is directed to the lubricated portion of the reduction gear mechanism.
According to a fourth aspect of the present invention, the second oil reservoir is communicated with the lubrication target portion of the reduction gear mechanism via an external pipe.

Since this invention was comprised as mentioned above, there exists an effect shown below.
That is, according to claim 1, the lubricating oil is stored in the second oil reservoir from the first oil reservoir via the hydraulic pump, the hydraulic continuously variable transmission, and the communication path. A reflux oil path is formed in which the oil is gradually returned to the first oil reservoir through the mouth. As a result, the lubricating oil is cooled while it is gradually ejected from the oil outlet of the second oil reservoir, and the viscosity of the lubricating oil can be increased by lowering the oil temperature of the first oil reservoir. The hydraulic fluid that circulates in the step transmission is unlikely to leak, and the transmission efficiency of the hydraulic continuously variable transmission is improved. In addition, during operation, part of the lubricating oil can be stored in the second oil sump, and the oil level of the first oil sump can be lowered, reducing the agitation of the lubricating oil due to the rotation of the gear group. It is possible to suppress an increase in oil temperature due to an increase in loss horsepower and stirring resistance.
In addition, the second oil reservoir and its injection port can be formed with a simple configuration, and the assembly and maintenance of the transmission case can be improved. In addition, the opening area of the injection port can be changed simply by changing the shape of each case punching die and changing the amount of shift between the parts having different shapes, making it easy to set the amount of injection.
According to the second aspect, the lubricating oil cooled while flowing in the external pipe can be cooled more efficiently by the cooling device, and the oil temperature of the first oil sump can be surely lowered. The transmission efficiency is further improved.
According to the third aspect , the lubricating oil can be intensively supplied to a specific portion to be lubricated while cooling, and effective lubrication of the portion to be lubricated or the like having a high frictional heat becomes possible.
According to the fourth aspect of the present invention, the lubricating oil is further cooled while flowing in the external pipe, and effective lubrication can be performed on a portion to be lubricated or the like having a large frictional heat.

It is a side view which shows the whole structure of the combine which mounts an axle drive device in this invention. It is also a plan view. It is a skeleton figure which shows the power transmission structure of an axle shaft drive device. It is a left view of an axle drive device. Similarly, it is a right side view. It is a right view of the left case half. It is a left view of the right case half. It is a plane partial cross section figure of the upper part of a jet nozzle. It is a back surface partial cross section figure of a lower fountain port periphery. It is a partial plane sectional view of the periphery of the third external piping. It is a right view of the suction filter periphery. It is a back surface partial sectional view. It is a figure which shows the oil leak prevention structure in a breather, Comprising: Fig.13 (a) is a side view of the periphery of a breather in the left case half part, FIG.13 (b) is back part sectional drawing similarly. It is a side view of the periphery of the breather in the left case half, showing another form of oil leakage prevention structure in the breather. It is a hydraulic circuit diagram of an axle drive device.

  Hereinafter, embodiments of the present invention will be described in detail. The direction indicated by the arrow F in FIG. 1 is the front direction of the combine 1 that is a work vehicle, and the positions and directions of the members described below are based on this front direction.

  First, the whole structure of the combine 1 which mounts the axle drive device 28 concerning this invention is demonstrated with FIG. 1, FIG. In the combine 1, crawler type traveling devices 4L and 4R are supported on the left and right of the track frame 3, and a machine base 5 is installed on the track frame 3, and a cutting part 6 and a threshing part 7 are provided before and after the machine body. Is provided.

  Of these, the cutting unit 6 includes a cutting blade 8, a culm conveying mechanism 9, and the like, and can be moved up and down by a hydraulic cylinder 13 via a cutting frame 14. A feed chain 10 is stretched on the left side of the threshing portion 7, and a handling cylinder 11 and a processing cylinder 12 are built in the right side of the feed chain 10, and a rear end of the waste chain 15 is located behind the feed cylinder 10. The waste disposal processing part 16 which desires is arrange | positioned, and the waste after threshing is discharged | emitted back.

  A grain tank 18 for carrying the grain from the threshing part 7 through the whipping cylinder 17 is provided on the side of the slaughtering part 16. A movable discharge auger 19 is provided, and after the grain cut by the harvesting unit 6 and processed by the threshing unit 7 is stored in the grain tank 18, the grain is passed through the discharge auger 19. It is carried out of the machine.

  In addition, a driving unit 20 is provided between the harvesting unit 6 and the grain tank 18. In the driving unit 20, a round steering handle 22 is supported on a front handle post 21. A driver's seat 23 is disposed behind the handle 22, and a parking brake lever 24, a main transmission pedal 39, a two-stage transmission lever 25, a sub-transmission lever 26, and the like are arranged side by side on the side of the driver's seat 23. .

  And between the left and right crawler type traveling devices 4L and 4R below the driving unit 20, the power from the engine 27 and the engine 27 is changed to drive the left and right crawler type traveling devices 4L and 4R. An axle drive device 28 according to the present invention is disposed.

  Next, the schematic structure and power transmission configuration of the axle drive device 28 will be described with reference to FIGS. 3 to 10 and FIG. 15, particularly with reference to FIG. The axle drive device 28 is configured by mounting axle cases 100L and 100R for housing left and right axles D6L and D6R on both left and right side surfaces of the bottom of the transmission case 29 of the transmission 2, and the transmission case 29 is divided vertically. It consists of left and right case halves 96 and 97. The case halves 96 and 97 are formed of left and right side walls 96a and 97a and left and right peripheral walls 96b and 97b surrounding the outer peripheries of the side walls 96a and 97a, respectively.

  A device case 121 is mounted on the upper outer surface of the right case half 97, and in the device case 121, there are a first hydraulic continuously variable transmission 31 for traveling and a second for turning. The hydraulic continuously variable transmission 32 is accommodated in order from the front.

  In the first hydraulic continuously variable transmission 31, a variable displacement hydraulic pump 35 and a hydraulic motor 36 that are fluidly connected to each other by a hydraulic circuit 122 that will be described in detail later are arranged vertically in the apparatus case 121. Similarly, in the second hydraulic continuously variable transmission 32, a variable displacement hydraulic pump 37 and a fixed displacement hydraulic motor 38 that are fluidly connected to each other by the hydraulic circuit 122 are juxtaposed in the apparatus case 121. Has been. The hydraulic pumps 35 and 37 have pump shafts D1 and S1 extending in the left-right direction, respectively. Of these, a gear 123 fixed to the pump shaft D1 and a gear 124 fixed to the pump shaft S1. Are meshed with input gears 125a and 125b fixed to a common input shaft N, respectively. As shown in FIG. 8, both ends of the input shaft N are rotatably supported by the mission case 29 by left and right bearings 170 and 170, and between the input shaft N and the mission case 29, An oil seal 171 is interposed so as to be oiltight.

  The input shaft N penetrates the side wall 96a of the left case half 96 and protrudes outward from the transmission case 29. An input pulley 42 is fitted to the protruding end of the input shaft N. The input pulley 42 and the engine 27 A belt 43 is wound around an output pulley 34 fitted to the tip of the output shaft 33, and power from the engine 27 is input to the input shaft N by belt transmission by the belt 43. Further, the movable swash plate 35a of the hydraulic pump 35 and the movable swash plate 37a of the hydraulic pump 37 are connected to the main transmission pedal 39 and the steering handle 22 via a traveling servo mechanism 126 and a turning servo mechanism 127, respectively. Has been.

  Accordingly, by depressing the main shift pedal 39, the inclination angle of the movable swash plate 35a of the hydraulic pump 35 is changed, and the discharge amount and discharge direction of the pressure oil from the hydraulic pump 35 to the hydraulic motor 36 are changed. Thus, the power from the engine 27 input to the input shaft N can be steplessly shifted by the first hydraulic continuously variable transmission 31 and output as the main transmission power from the motor shaft D2 of the hydraulic motor 36. . Similarly, by rotating the steering handle 22, the inclination angle of the movable swash plate 37a of the hydraulic pump 37 is changed, and the discharge amount and discharge direction of the pressure oil from the hydraulic pump 37 to the hydraulic motor 38 are changed. The power from the engine 27 input to the pump shaft S1 can be changed steplessly and output as turning power from the motor shaft S2 of the hydraulic motor 38.

  As for the hydraulic motor 36, the movable swash plate 36a is connected to the two-stage transmission lever 25 via a two-stage transmission servo mechanism 44 and the like, and the main transmission power is supplied to the hydraulic motor 36 at a high and low speed. The speed can be changed in two stages so that the main transmission range by the first hydraulic continuously variable transmission 31 can be further expanded.

  Further, the transmission shaft of the auxiliary transmission 57 is arranged in parallel with the input shaft N, the pump shafts D1 and S1, and the motor shafts D2 and S2 from the transmission case 29 to the left and right axle cases 100L and 100R in the axle drive device 28. D3, auxiliary transmission shaft D4, left and right travel drive shafts D5L and D5R, main drive shaft 86 on the same axis as travel drive shafts D5L and D5R, axles D6L and D6R for fixing left and right drive sprockets 54L and 54R, respectively A deceleration shaft S3, a lock shaft S4, an intermediate shaft S5, and a PTO shaft P for taking out PTO power are each supported in a horizontally extending manner.

  A small-diameter gear 62 and a large-diameter gear 63 for auxiliary transmission are fixed on the transmission shaft D3 in this order from the left, and the left end of the motor shaft D2 is a side wall 97a of the right case half 97. The input gear 46 is fixedly provided at the end of the transmission, and the input gear 46 is engaged with the large-diameter gear 63. The signal is input to the transmission shaft D <b> 3 of the auxiliary transmission 57 through 63.

  On the transmission shaft D3, a transmission gear 65 is fixed to the left of the small-diameter gear 62, and the transmission gear 65 is engaged with a connecting gear 73 fixed to the right end of the PTO shaft P. ing. The PTO shaft P passes through the side wall 96a of the left case half 96 and protrudes outward from the transmission case 29. A PTO output pulley 74 is fitted to the protruding end, and the PTO output pulley 74 is The mowing unit 6 and the belt 75 are interlocked and connected to each other, so that the main transmission power can be transmitted to the mowing unit 6.

  A traveling gear 89, a large-diameter low-speed gear 68, and a small-diameter high-speed gear 69 are provided on the auxiliary transmission shaft D4 in this order from the left, and the traveling gear 89 is fixed to the auxiliary transmission shaft D4. On the other hand, the low speed gear 68 and the high speed gear 69 are provided so as to be rotatable relative to the auxiliary transmission shaft D4, and the low speed gear 68 and the high speed gear 69 mesh with the small diameter gear 62 and the large diameter gear 63, respectively. Has been. Accordingly, a two-stage sub-transmission drive train is formed such as a low-speed gear train 62 and 68 composed of a small-diameter gear 62 and a low-speed gear 68 and a high-speed gear train 63 and 69 composed of a large-diameter gear 63 and a high-speed gear 69.

  Further, a clutch slider 71 is provided between the low-speed gear 68 and the high-speed gear 69 on the auxiliary transmission shaft D4 so as to be axially slidable and relatively non-rotatable. It is possible to select an engaged state engaged with any one of 69 or a neutral state in which neither is engaged. The clutch slider 71 is connected to the auxiliary transmission lever 26 via a link mechanism (not shown).

  Thus, by tilting the auxiliary transmission lever 26, the low-speed gear 68 and the high-speed gear 69 can be engaged with the auxiliary transmission shaft D4 in a relatively non-rotatable manner. Sub-shifting is performed via any one of the gear trains of the sub-transmission drive train, and then output from the traveling gear 89 of the sub-transmission shaft D4 as sub-transmission power.

  The auxiliary transmission shaft D4 passes through the side wall 96a of the left case half 96 and protrudes outward from the transmission case 29, and a traveling rotation detection gear 64 for main transmission power control is fixed to the protruding end. On the other hand, it penetrates the side wall 97a of the right case half 97 and protrudes outward from the transmission case 29, and a parking brake device 72 such as a hydraulic multi-plate type is provided at the protruding end. The parking brake device 72 is connected to the parking brake lever 24, and by tilting the parking brake lever 24, the auxiliary transmission shaft D4 is locked so that the combine 1 can be reliably stopped even on a slope. .

  Further, as shown in FIG. 9, both ends of the auxiliary transmission shaft D4 are rotatably supported by the transmission case 29 by left and right bearings 170 and 170, and between the auxiliary transmission shaft D4 and the transmission case 29, The oil seal 171 is interposed so as to be oiltight.

  A large-diameter drive center gear 87 is fixed substantially at the center in the left-right direction of the main drive shaft 86. The drive center gear 87 is always meshed with the travel gear 89, and the sub-transmission power is transmitted to the travel gear. The signal is input to the differential device 58 via 89.

  The differential device 58 includes left and right planetary gear devices 59 and 60, and the planetary gear devices 59 and 60 are arranged on the same axis between the traveling drive shafts D5L and D5R. The sun gears 90, 90 engraved on the shaft 86, a plurality of planetary gears 91, 91... Meshed with the outer periphery of the sun gears 90, 90, and the ring gears 84, 85 are integrated with the planetary gears 91, 91, The internal gears 92 and 93 meshing with the traveling drive shafts D5L and D5R and the carriers 94 and 95 that pivotally support the planetary gears 91, 91,.

  The planetary gears 91, 91,... Are evenly arranged radially from the traveling drive shafts D5L, D5R, and are rotatably supported by the left and right carriers 94, 95, respectively. The carriers 94, 95 sandwich the sun gear 90. The internal gears 92 and 93 are arranged on the same axis as the main drive shaft 86, and are rotatably supported on the inner ends of the travel drive shafts D5L and D5R, respectively. Has been.

  The sun gears 90 and 90 are integrally engraved on a common main drive shaft 86 as a sun gear common to the left and right planetary gear devices 59 and 60. The auxiliary transmission power from the first hydraulic continuously variable transmission 31 is input to the sun gears 90 and 90 through the drive center gear 87 that is locked to the sun gear 90.

  Further, the motor shaft S2 of the second hydraulic continuously variable transmission 32 penetrates the side wall 97a of the right case half 97 and enters the transmission case 29, and a small diameter gear 76 is fixed, and the small diameter gear 76 is fixed. 76 is meshed with a large-diameter gear 77 fixed on the reduction shaft S3. A wide small-diameter gear 78 is fixed to the left of the large-diameter gear 77, and the small-diameter gear 78 meshes with the large-diameter gears 79 and 79 on the lock shaft S4. Accordingly, a first reduction gear train comprising a small diameter gear 76 and a large diameter gear 77 and a plurality of reduction drive trains comprising a second reduction gear train comprising a small diameter gear 78 and large diameter gears 79 and 79 are formed. The turning power from S2 is decelerated and input to the lock shaft S4.

  A turning brake 45, which will be described later in detail, is provided on the left side of the small-diameter gear 76 on the motor shaft S2, and the hydraulic motor 38 is braked when the second hydraulic continuously variable transmission 32 is in a neutral state. I can do it. Further, a turning rotation detection gear 47 for turning power control is fixed to the left end of the deceleration shaft S3.

  On the lock shaft S4, swivel input gears 80 and 81 are fixed to the left and right with the large-diameter gear 79 interposed therebetween, and the swivel input gear 80 is circularly mounted on the intermediate shaft S5 so as to be relatively rotatable. The intermediate gear 83 meshes with the ring gear 84 of the left planetary gear device 59, while the swivel input gear 81 meshes directly with the ring gear 85 of the right planetary gear device 60. Yes. Further, the reduction ratio of the turning input gear 80, the intermediate gear 83, and the ring gear 84 in the left planetary gear device 59 and the reduction ratio of the turning input gear 81 and the ring gear 85 in the right planetary gear device 60 are set to be the same. Has been.

  Thereby, in the gear transmission 61 arranged from the motor shaft S2 of the second hydraulic continuously variable transmission 32 to the ring gears 84 and 85 of the left and right planetary gear devices 59 and 60, the rotation of the motor shaft S2 is performed. Is transmitted to the left and right ring gears 84 and 85 with their rotational directions reversed.

  When the hydraulic pump 37 of the second hydraulic continuously variable transmission 32 is in a neutral state and no turning power is output from the motor shaft S2, the left and right ring gears 84 and 85 rotate at the same speed in the same direction. When trying to do so, the rotational force is transmitted to the lock shaft S4 at the same speed in opposite directions, so the lock shaft S4 does not rotate in any direction. The ring gears 84 and 85 are locked so as not to rotate.

  In the above configuration, in the combine 1, according to the traveling condition, first, the auxiliary transmission lever 26 is tilted to engage the clutch slider 71 of the auxiliary transmission 57 with any gear, When driving on the road, a high speed stage by the high-speed gear trains 63 and 69 is selected and a low speed stage by the low-speed gear trains 62 and 68 is selected and set. Then, the main shift pedal 39 is depressed, The movable swash plate 35a in the hydraulic continuously variable transmission 31 is tilted to change and control the vehicle speed continuously, including the control of the traveling direction of the machine body, thereby causing the combine 1 to travel. At this time, the two-speed shift lever 25 is tilted to shift the two-speed on the hydraulic motor 36 side so that the main shift range can be expanded.

  During straight travel, the tilting operation of the movable swash plate 37a of the second hydraulic continuously variable transmission 32 by the steering handle 22 is not performed, and the second hydraulic continuously variable transmission 32 is maintained in a neutral state. As described above, the left and right ring gears 84 and 85 are locked so as not to rotate by the lock shaft S4, and the planetary gears 91, 91... Integrally formed with the ring gears 84 and 85 are also locked so as not to rotate. On the other hand, the main transmission power from the first hydraulic continuously variable transmission 31 is transmitted to the sun gears 90 and 90 from the drive center gear 87 after being sub-shifted, and the sun gears 90 and 90 are rotationally driven.

  Therefore, the planetary gears 91, 91 ... meshing with the sun gear 90 are also driven to rotate, but the internal gears 92, 93 meshing with the planetary gears 91, 91 ... radially outwardly cannot rotate as described above. The planetary gears 91, 91... Revolve in the same direction as the rotation direction of the sun gear 90 while rotating. For this reason, the left and right carriers 94 and 95 that pivotally support the planetary gears 91 and 91 are also rotated in the same direction as the sun gear 90 and at the same speed between the left and right carriers 94 and 95, As a result, the left and right traveling drive shafts D5L and D5R fixed to the carriers 94 and 95 rotate at the same direction and at the same speed.

  Here, a small-diameter gear 110 is fixed to the outer end of the left travel drive shaft D5L, and a large-diameter gear 111 is fixed to the inner end of the axle D6L. Is meshed with the small-diameter gear 110 to form the left final reduction gear train 104. On the other hand, a small-diameter gear 116 is fixed to the outer end portion of the right traveling drive shaft D5R, and a large-diameter gear 117 is fixed to the inner end portion of the axle D6R. A right final reduction gear train 105 is formed by meshing with the small-diameter gear 116.

  Therefore, the power from the left and right traveling drive shafts D5L and D5R rotating in the same direction and at the same speed is decelerated by the left and right final reduction gear trains 104 and 105, respectively, and then transmitted to the left and right axles D6L and D6R. As a result, the aircraft travels straight ahead.

  On the other hand, the steering handle 22 is rotated during straight traveling, and the movable swash plate 37a of the second hydraulic continuously variable transmission 32 is tilted. As described above, the left and right ring gears 84 and 85 are moved. When rotations in opposite directions are given, the revolution speeds of the planetary gears 91, 91... Meshed with the internal gears 92, 93 of the ring gears 84, 85, that is, the rotation speeds of the carriers 94, 95 are The speed of the carrier is increased and the speed of the other carrier is decreased.

  Therefore, a difference in rotation speed is given to the left and right traveling drive shafts D5L and D5R rotating in the same direction and the same speed, thereby generating a rotation speed difference between the left and right sprockets 54L and 54R. Is able to turn.

  Next, the hydraulic operation configuration of the hydraulic continuously variable transmissions 31 and 32 will be described with reference to FIGS. 4 to 7 and FIG. In the hydraulic circuit 122, the traveling hydraulic pump 35 and the hydraulic motor 36 are fluidly connected by hydraulic oil through a closed circuit including a pair of first main oil passages 40 and 40, and the swiveling hydraulic pump 36 and the hydraulic motor 36. The hydraulic pump 37 and the hydraulic motor 38 are also fluidly connected by hydraulic oil through a closed circuit including a pair of second main oil passages 41 and 41.

  As a result, when the power from the engine 27 is input to the traveling pump shaft D1 and the hydraulic pump 35 is driven, the hydraulic oil discharged by driving the hydraulic pump 35 is discharged from the first main oil passage 40. The hydraulic motor 36 is supplied to the hydraulic motor 36 through 40, and the hydraulic motor 36 is driven by the supply and discharge of the hydraulic oil, and the driving force is output from the motor shaft D2 as speed change power. Similarly, when power from the engine 27 is input to the turning pump shaft S1 and the hydraulic pump 37 is driven, the hydraulic oil discharged by driving the hydraulic pump 37 is discharged into the second main oil passage 41. The hydraulic motor 38 is supplied to the hydraulic motor 38 via 41, and the hydraulic motor 38 is driven by the supply and discharge of the hydraulic oil, and the driving force is output from the motor shaft S2 as transmission power.

  Further, a charge pump 48 is provided on the turning pump shaft S1. A suction filter 49, which will be described later in detail, is connected to the inlet side of the charge pump 48 via a first external pipe 56. The suction filter 49 is connected to the first oil sump 51 at the bottom of the transmission case 29. Soaked. On the other hand, a charge oil passage 53 having an external filter 55 interposed in the middle is connected to the outlet side of the charge pump 48, and a check is made between the charge oil passage 53 and the first main oil passages 40 and 40. Valves 66 and 66 are interposed, and check valves 67 and 67 are interposed between the charge oil passage 53 and the second main oil passages 41 and 41.

  As a result, when the charge pump 48 is rotationally driven together with the turning hydraulic pump 37, the lubricating oil in the first oil reservoir 51 is sucked up as working oil from the suction filter 49, and the first external pipe 56. The hydraulic oil is supplied to the first main oil passages 40 and 40 and the second main oil passages 41 and 41 through the charge oil passage 53 and the external filter 55. At this time, the charge pressure of the hydraulic oil from the charge pump 48 is adjusted to a predetermined pressure by the charge relief valve 70 connected to the middle portion of the charge oil passage 53.

  Further, the servo mechanisms 126, 127 and 44 are operated by the hydraulic oil from the charge oil passage 53. Of these, the travel servo mechanism 126 tilts the movable swash plate 35a of the travel hydraulic pump 35. The piston 130 is connected to the movable swash plate 35a and contains a spool 131, and the piston 130 is slid back and forth. A manual travel control valve 128 that manually controls the hydraulic oil to be moved and an electromagnetic automatic travel control valve 129 that automatically controls the hydraulic oil that slides the piston 130 back and forth. The travel operation tool 138 of the manual travel control valve 128 is connected to the main transmission pedal 39, and the oil passage is switched in conjunction with the depression operation of the main transmission pedal 39, and the piston 130 moves. The tilt angle of the movable swash plate 35a is changed. The solenoid 129a of the automatic travel control valve 129 is connected to a controller (not shown) so that the oil passage can be switched so that automatic travel at a predetermined speed is possible.

  The turning servo mechanism 127 tilts the movable swash plate 37a of the turning hydraulic pump 37. The piston 134 is connected to the movable swash plate 37a and contains a spool 135, and slides the piston 134 back and forth. A manual swing control valve 132 that manually controls the hydraulic oil and an electromagnetic automatic swing control valve 133 that automatically controls the hydraulic oil that slides the piston 134 back and forth. Then, the turning operation tool 139 of the manual turning control valve 132 is connected to the steering handle 22, the oil passage is switched in conjunction with the turning operation of the steering handle 22, and the piston 134 moves. Thus, the tilt angle of the movable swash plate 37a is changed. Solenoids 133a and 133a of the automatic turning control valve 133 are also connected to a controller (not shown) so that the oil passage can be switched so that automatic turning with a predetermined radius is possible.

  The two-speed gearshift servo mechanism 44 tilts the movable swash plate 36a of the traveling hydraulic motor 36. The piston 137 connected to the movable swash plate 36a and the hydraulic oil that slides the piston 137 back and forth. And an electromagnetic automatic two-stage shift control valve 136 that automatically controls the motor. The solenoid 136a of the automatic two-stage shift control valve 136 is connected to a controller (not shown) so that the oil path can be switched so that the gear can be automatically shifted to two stages at high and low speeds according to the traveling load. I have to.

  As a result, the movable swash plates 35a, 36a, 37a in the traveling hydraulic pump 35, the hydraulic motor 36, and the turning hydraulic pump 37 are tilted manually or automatically so that they can travel straight or turn so that they can be shifted. Yes.

  In the device case 121 that accommodates such hydraulic continuously variable transmissions 31 and 32, excess oil discharged by the operation of the charge relief valve 70, various control valves 128, 129, 132, 133, The hydraulic oil after being used for 136 and hydraulic oil leaking from the rotary sliding contact portions of the hydraulic pumps 35 and 37 and the hydraulic motors 36 and 38 flow in.

  Next, the lubrication structure of the axle drive device 28 will be described with reference to FIGS. 4 to 10 and FIG. As shown in FIG. 4 to FIG. 7 and FIG. 15, in addition to the first oil sump 51 provided at the bottom of the mission case 29, a second oil sump 52 according to the present invention is provided at the upper front portion of the mission case 29. Is provided.

  In the second oil reservoir 52, one end of the second external pipe 99 is connected to the upper opening 101, while the other end of the second external pipe 99 is communicated with the inside of the device case 121. As described above, after the hydraulic oil sucked up from the first oil reservoir 51 by the charge pump 48 is used in the hydraulic continuously variable transmissions 31 and 32 and flows into the device case 121, the second external pipe 99. Flows into the second oil reservoir 52 and is stored as lubricating oil.

  Therefore, as shown in FIGS. 6 and 7, when the engine 27 is stopped and the charge pump 48 is not driven, the initial oil level height of the first oil reservoir 51 is at the position 51a. When the engine 27 is in an operating state and the charge pump 48 is driven, a part of the lubricating oil is stored in the second oil reservoir 52, and the lubricating oil in the first oil reservoir 51 is reduced correspondingly, and the oil level height is increased. The position decreases from the position 51a to the position 51b. Then, when the oil level is at the position 51a, the gear group on the axes D4, D5L, D5R, S4, and S5 and the axes D3 and S3 near the oil level is immersed, whereas the oil level is at the position. In the case of 51b, the gear group on the shaft D5L / D5R or on the shaft D4 / S4 / S5 near the oil surface is only immersed, and the number of gears immersed in the first oil reservoir 51 is reduced.

  Thereby, when the engine 27 is in an operating state, gears immersed in the lubricating oil in the first oil sump 51 can be reduced, agitation of the lubricating oil due to rotation of the gear group is reduced, and loss horsepower is reduced. At the same time, a significant increase in the oil temperature of the lubricating oil accompanying the stirring resistance can be suppressed.

  Further, an oil cooler 102 having a bypass circuit is also provided in the middle of the second external pipe 99. Accordingly, the hydraulic oil is cooled more efficiently by the oil cooler 102 in addition to being cooled to some extent by the surrounding air through the pipe wall while flowing in the second external pipe 99.

  As a result, the hydraulic oil flowing through the second external pipe 99 is sufficiently cooled to lower the oil temperature of the second oil sump 52, and as a result, the oil temperature of the first oil sump 51 can be reliably lowered. it can.

  Further, as shown in FIGS. 4 to 9 and FIG. 15, a left partition wall 106 that protrudes from the side wall 96a of the left case half 96 toward the joint 30 and divides the front upper portion from the internal space of the case half 96; The right partition wall 107 that protrudes from the side wall 97a of the right case half 97 toward the joining surface 30 and that separates the front upper portion from the inner space of the case half 97 is brought into contact with each other in the joined state of both case halves 96 and 97. By making contact, the second oil reservoir 52 is partitioned from the inner space of the mission case 29.

  As a result, the second oil sump 52 includes the left and right partition walls 106 and 107, a part of the left and right peripheral walls 96b and 97b facing the partition wall 106 and 107, and a part of the left and right side walls 96a and 97a. Composed. The upper opening 101 is perforated in the vertical direction at the front upper part of the left peripheral wall 96b, and is opened outside the mission case 29.

  A convex portion 107a inclined in the front-rear direction in a side view is formed between the upper rear edge of the right partition 107 and the peripheral wall 97b, while the left partition 106 facing the convex portion 107a A vertical portion 106a is formed at a position in front of the rear edge of the convex portion 107a at the upper rear edge portion, and the convex portion along the joint surface 30 in the joined state of both case halves 96 and 97. When the portion 107a is displaced rearward from the vertical portion 106a, the first injection port 108 having a predetermined opening area is formed.

  Similarly, the lower edge of the left partition wall 106 is formed with a convex portion 106b partially bulging downward in a side view, while the lower edge portion of the right partition wall 107 facing the convex portion 106b. The horizontal portion 107b is formed at a position higher than the lower edge of the convex portion 106b. When the two case halves 96 and 97 are joined, the convex portion 106b is located along the joint surface 30 in the horizontal portion. By deviating downward from 107b, a second injection hole 109 having a predetermined opening area is formed.

  As a result, the second oil reservoir 52 and its injection holes 108 and 109 can be easily formed by the punching dies of both case halves 96 and 97 without providing a complicated structure separately, and the amount of injection oil is determined. The opening area can be easily set by the shape of each case punching die according to the amount of deviation between the vertical portion 106a and the convex portion 107a and the amount of deviation between the convex portion 106b and the horizontal portion 107b. The lubricating oil can be jetted substantially accurately toward the lubricated part such as a gear group provided in the mission case 29 through the jetting ports 108 and 109.

  In the first jet port 108, the input shaft N is disposed immediately behind the first jet port 108 as shown in FIG. 8, and the input gear 125a on the input shaft N extends from the first jet port 108.・ To 125b, the lubricating oil is ejected little by little while being cooled by the outside air. The lubricating oil is distributed to the meshing portion of the input gear 125a and the gear 123 on the pump shaft D1 and the meshing portion of the input gear 125b and the gear 124 on the pump shaft S1 along the input gears 125a and 125b. Is done.

  The shafts D2, P, D3, and D4 are arranged in order from the top, substantially below the pump shaft D1 and above the position 51b. The gears on the shafts D2, P, D3, and D4 are arranged in the gear group. Is mainly sprayed with lubricating oil flowing down from the pump shaft D1. Similarly, shafts S2, S3, S4, and S5 are arranged in order from the top, substantially below the pump shaft S1 and above the position 51b, on the shafts S2, S3, S4, and S5. Lubricating oil flowing mainly from the pump shaft S1 is sprayed on the gear group.

  That is, as long as the engine 27 is not stopped, the oil 27 is always rotated and the lubricating oil is directly supplied from the second oil reservoir 52 to the input shaft N at the uppermost position. The oil always flows down through the gears and is always sprayed to the gear group below the input shaft N so that the lubricating oil is evenly distributed to the gear group in the mission case 29.

  As shown in FIG. 9, the sub-transmission shaft D4 is disposed below the second injection port 109, and the gears 89, 68, 69 on the sub-transmission shaft D4 from the second injection port 109 The lubricating oil is ejected little by little toward the clutch slider 71 while being cooled by the outside air. The lubricating oil is transmitted to the gears 89, 68, and 69 through the engagement portion between the clutch slider 71 and the gears 68 and 69, the meshing portion between the low speed gear 68 and the small diameter gear 62, and the high speed gear 69. It is sprayed on the meshing portion with the diameter gear 63 and the meshing portion between the traveling gear 89 and the drive center gear 87.

  As described above, the lubricating oil in the first oil sump 51 is pumped and stored in the upper second oil sump 52 via the first external pipe 56, the second external pipe 99, and the like. Lubricating oil is sprayed from the jet nozzles 108 and 109 to the gear group in the mission case 29 and then returned to the first oil reservoir 51, thereby forming a reflux oil passage 172 for the lubricating oil.

  As described above, the lubricating oil flowing in the reflux oil passage 172 is constantly cooled by the external pipes 56 and 99 and the oil cooler 102 on the way, and is ejected little by little from the injection ports 108 and 109. In addition, since the lubricating configuration is also cooled, the oil temperature of the first oil sump 51 is lowered and the viscosity of the lubricating oil is increased. As a result, the hydraulic oil circulating in the hydraulic continuously variable transmissions 31 and 32 is less likely to leak and transmission efficiency is improved.

  In order to prevent the internal pressure in the mission case 29 from fluctuating greatly even if the oil level height of the first oil reservoir 51 fluctuates up and down, a breather 82 that communicates the space in the mission case 29 to the outside is provided on the left side. The upper half of the case half 96 is provided.

  Further, as shown in FIGS. 4 to 7 and 10, the left side wall 96 a is located substantially in the center of the lower half of the second oil reservoir 52 in the side view in the left-right direction, outside the mission case 29. A discharge port 112 is formed. Further, a port member 113 is fastened and fixed to the left side wall 96a by a pipe joint 115, and an introduction port 113a is formed in the port member 113. Between the introduction port 113a and the discharge port 112, The third external pipe 114 communicates.

  An oil passage 115a is bored in the pipe joint 115 on the same axis as the motor shaft S2, and the oil passage 115a communicates with the introduction port 113a through a lateral hole 115b in the pipe joint 115. Thus, a part of the lubricating oil in the second oil reservoir 52 flows into the oil passage 115a in the pipe joint 115 from the discharge port 112, the third external pipe 114, and the introduction port 113a through the lateral hole 115b. .

Here, as described above, the turning brake 45 is provided on the motor shaft S2.
In the turning brake 45, as shown in FIG. 10, a cylindrical brake housing 163 opened to the right side of the paper is inserted into the mounting hole 96g drilled in the left side wall 96a from the left side of the paper. It is fastened and fixed by 162 (FIG. 4), and a bearing 164 is mounted on the inner periphery of the left end of the brake housing 163. A bearing 165 is also mounted on the right side wall 97a, and the brake shaft 118 of the motor shaft S2 is supported between the left and right bearings 164 and 165.

  The small-diameter gear 76 is fixed to the right side of the brake shaft 118 in the drawing, and the rotary friction body 119 is slidable in the axial direction on the brake shaft 118 on the left side of the small-diameter gear 76 in the axial direction. Friction plates 119a, 119a,... Are supported on the outer peripheral surface of the rotating friction body 119. The friction plates 163a, 163a,... Which alternately overlap with the friction plates 119a, 119a,... Are supported on the inner peripheral surface of the brake housing 163. Is formed. The turning brake 45 is configured as a torque cam actuated type, and when the output of the hydraulic motor 38 is equal to or lower than a predetermined torque, the friction plates 119a and 163a are engaged by the elastic force of the spring 166, and the braking operation is performed. Like to get.

  The brake shaft 118 has a cylindrical shape, and an axial center oil passage 118a whose right end is closed, and horizontal holes 118b and 118c that are communicated with the shaft center oil passage 118a in a radial direction. The horizontal holes 118b and 118c are opened in the spline portion of the rotating friction body 119. On the other hand, the left end of the axial oil passage 118 a in the brake shaft 118 is communicated with the right end of the oil passage 115 a in the pipe joint 115 through an oil chamber 120 provided in the left end portion of the brake housing 163. .

  Thus, the lubricating oil in the second oil reservoir 52 flows into the oil chamber 120 from the third external pipe 114 through the oil passage 115a in the pipe joint 115, and further, the shaft center oil in the brake shaft 118. The air is concentratedly supplied from the path 118a through the horizontal holes 118b and 118c to the friction plate 119a and 163a having a large frictional heat from the spline portion of the rotating friction body 119. At this time, the lubricating oil is further cooled by ambient air through the pipe wall while flowing in the third external pipe 114.

  That is, in the configuration as described above, the device 57 is disposed at the bottom of the transmission case 29 that houses the sub-transmission device 57, the differential device 58, and the gear transmission 61, which are speed reduction gear mechanisms for driving the axles D6L and D6R. A first oil sump 51 in which lubricating oil in which at least a part of the gear groups 58 and 61 is immersed is provided, and the lubricating oil in the first oil sump 51 is supplied to the hydraulic continuously variable transmissions 31 and 32. In the axle drive device 28 that is pumped up by a charge pump 48 that is a hydraulic pump and replenished as hydraulic oil to the hydraulic continuously variable transmissions 31 and 32, a second oil sump 52 is provided in the upper portion of the transmission case 29, and The partition wall of the two oil sump 52 is opened with jet holes 108 and 109 communicating with the space inside the mission case 29, and the second oil sump 52 is connected to the hydraulic non-reactor 52. Since the transmission cases 31 and 32 are connected to the device case 121 via the second external pipe 99 which is a communication path, the lubricating oil is supplied from the first oil reservoir 51 to the charge pump 48 and the hydraulic continuously variable transmission 31. 32, stored in the second oil reservoir 52 through the second external pipe 99, and gradually returned to the first oil reservoir 51 from the second oil reservoir 52 through the jet ports 108 and 109. A reflux oil passage 172 shown in FIG. 15 is configured. As a result, the lubricating oil is cooled while it is gradually ejected from the nozzle holes 108 and 109 of the second oil reservoir 52, and the oil temperature of the first oil reservoir 51 is lowered to increase the viscosity of the lubricating oil. This makes it difficult for the hydraulic oil circulating in the hydraulic continuously variable transmissions 31 and 32 to leak, and the transmission efficiency of the hydraulic continuously variable transmissions 31 and 32 is improved. Furthermore, during operation, a part of the lubricating oil can be stored in the second oil reservoir 52, and the oil level height of the first oil reservoir 51 can be lowered, and the lubricating oil can be agitated by the rotation of the gear group. This can reduce the increase in loss horsepower and increase in oil temperature due to stirring resistance.

  Further, the communication path is constituted by a second external pipe 99 that is an external pipe, and a cooling device that cools the lubricating oil flowing from the device case 121 to the second oil reservoir 52 in the middle of the second external pipe 99. Since the oil cooler 102 is provided, the lubricating oil cooled while flowing in the second external pipe 99 is more efficiently cooled by the oil cooler 102, and the oil temperature of the first oil reservoir 51 is reliably lowered. Thus, the transmission efficiency of the hydraulic continuously variable transmissions 31 and 32 is further improved.

  In addition, the transmission case 29 is composed of a pair of case halves 96 and 97. When the case halves 96 and 97 are assembled, the partition walls 106 and 107 provided in the case halves 96 and 97 are mutually connected. By abutting, the second oil reservoir 52 is partitioned from the inner space of the mission case 29, and the jet ports 108 and 109 are configured so that one partition wall is disposed along the joint surface 30 of both partition walls 106 and 107. Therefore, the second oil reservoir 52 and the jet holes 108 and 109 can be formed with a simple configuration, and the assembly and maintenance of the mission case 29 can be improved. be able to. In addition, by changing the shape of each case punching die and changing the amount of deviation between the vertical portion 106a and the convex portion 107a and the amount of deviation between the convex portion 106b and the horizontal portion 107b, the opening area of the nozzle is changed. This makes it easy to set the fountain amount.

  Further, the oil injection holes 108 and 109 of the second oil reservoir 52 are directed to the gears 125 a, 125 b, 89, 68, and 69 and the clutch slider 71 that are lubricated parts of the auxiliary transmission 57 that is the reduction gear mechanism. Therefore, the lubricating oil can be intensively supplied to a specific lubrication site while cooling, and effective lubrication of the lubrication site having a large frictional heat becomes possible.

  In addition, the second oil reservoir 52 communicates with the turning brake 45, which is a lubricated part of the gear transmission 61, which is the reduction gear mechanism, via the third external pipe 114, which is an external pipe. Lubricating oil is further cooled while flowing in the pipe 114, and effective lubrication can be performed on a lubricated portion having a large frictional heat.

  As shown in FIGS. 4 and 6, an oil filling port 167 for supplying lubricating oil into the mission case 29 is opened in the vicinity of the second oil injection port 109 on the left side wall 96 a. The oiling lid 168 is detachably mounted from the outside. Further, an oil inspection window 169 is provided at a position in contact with the position 51 a so that the oil level position in the first oil reservoir 51 can be visually recognized. The initial oil level height in the first oil reservoir 51 can be accurately set at the position 51a.

  Next, the suction filter 49 will be described with reference to FIGS. 4 to 7, 11, 12, and 15. The suction filter 49 includes a cylindrical suction portion 141 that filters the lubricating oil in the first oil reservoir 51 with a mesh, and a cylindrical communication portion 142 that is connected to the right end of the suction portion 141 via a joint member 143. The communication portion 142 has a smaller diameter than the suction portion 141 and is disposed on the same axis as the suction portion 141 in the left-right direction.

  Further, the communication part 142 extends to the right so as to cross the vicinity of the bottom part of the first oil sump 51, and at the front part thereof, a reduced insertion part 142a is formed. The portion 142a is inserted and fixed to the cylindrical body 144 protruding from the side wall 97a toward the joining surface 30 at the bottom of the right case half 97.

  A base portion of the cylindrical body 144 is opened to the outside of the case half 97, and a joint 147 is fastened and fixed to the opening portion 144a by a plurality of bolts 146. The left and right inverted L-shaped oil passages 147a in the joint 147 are connected to the right end of the insertion portion 142a and the upper end of the oil passage 147a is connected to the first external portion. The pipe 56 is connected in communication with the lower end.

  As a result, the lubricating oil filtered by the suction part 141 of the suction filter 49 passes through the joint 147 from the communication part 142 and flows into the first external pipe 56 without stagnation, and by the cylindrical body 144, the suction filter 49 is surely supported by the right case half 97 through its right end.

  In addition, a filter housing portion 149 that opens toward the joint surface 30 is formed at the bottom of the left case half 96. The filter storage portion 149 is formed by partitioning a part of the bottom of the left case half 96 with a partition wall 96d, and the suction portion 141 of the suction filter 49 at a substantially central portion in a side view of the filter storage portion 149. However, it is inserted deeply until the whole suction part 141 is completely accommodated.

  On the other hand, the right case half 97 has no partition at the portion facing the partition 96d. When the case halves 96 and 97 are joined, the right end of the partition 96d and the side wall 97a of the right case half 97 A right opening 149b is formed between the first oil sump 51 and the gears such as the travel drive shafts D5L and D5R above the communication portion 142 of the suction filter 49 via the right opening 149b. It is open to the part where the group is immersed (hereinafter referred to as “gear immersion part”).

  That is, the entire suction portion 141 of the suction filter 49 is accommodated in the filter storage portion 149, and at least the upper side of the communication portion 142 located laterally away from the suction portion 141 is disposed in the first oil reservoir 51. The oil level of the first oil sump 51 is lowered from the position 51a to the position 51b as the engine 27 is shifted from the stopped state to the operating state, and the gear group is stirred. Even if the generated bubbles try to approach the suction portion 141 of the suction filter 49, the bubbles need to move a long distance to the suction portion 141 in the back while bypassing the front portion of the partition wall 96 d, and the bubbles to the suction portion 141 Is blocked by the partition wall 96d, and the suction of bubbles from the suction portion 141 can be greatly suppressed.

  As a result, when the lubricating oil is sucked from the first oil reservoir 51 as hydraulic oil, bubbles mixed in the hydraulic oil can be greatly reduced, and the hydraulic continuously variable transmissions 31 and 32 and the servo mechanism included therein can be reduced. With respect to 126, 127, 44, etc., the operation accuracy and device life can be improved.

  A concave portion 149a that opens downward in a side view is formed in the upper portion of the filter storage portion 149, and even when a minute bubble enters the filter storage portion 149 from the first oil reservoir 51, Since the invading bubbles are trapped in the concave portion 149a while rising, the approach of the bubbles to the suction portion 141 is further prevented, and the suction of the bubbles from the suction portion 141 can be further suppressed.

  Further, a left opening 149c is formed in the left side wall 96a of the suction part 141 accommodated in the filter accommodating part 149, and a lid 150 is provided over the left opening 149c. A plurality of bolts 151 are detachably fastened and fixed to the outer surface of the side wall 96 a of the left case half 96.

  Further, the left end 141a of the suction portion 141 is fitted into the left opening portion 149c, and the suction portion 141 is disposed such that its axial center is decentered downward in the left opening portion 149c.

  Thus, the upper outer surface of the left end 141a of the suction portion 141 can be separated from the upper inner surface of the left opening 149c, and a working gap 152 can be provided in the space between them. After removing 150, a tool is inserted into the working gap 152 to grip the suction filter 49, and the suction filter 49 can be easily removed from the filter housing portion 149, improving the maintainability of the suction filter 49. it can.

  Next, the oil leakage prevention structure 153 from the breather 82 will be described with reference to FIGS. 4 to 7, 13, and 14. As shown in FIGS. 4 to 7 and FIG. 13, the oil leakage prevention structure 153 includes a pocket 154 communicating with the cylindrical breather 82 via an upper air passage 96e, and a lower air passage communicating with the pocket 154. The cover wall 155 covers the lower end opening of 96f from below. The upper and lower air passages 96e and 96f are arranged on the same axis as the breather 82 in the vertical direction, and constitute a breather passage 156 that communicates the space in the mission case 29 with the breather 82.

  Of these, the upper air passage 96e is formed by perforating the peripheral wall 96b above the pump shaft S1 with the left case half 96 in the vertical direction, and the breather 82 is disposed above the upper air passage 96e. The screw portion 82a is fixed by screwing.

  The pocket 154 includes a partition wall 96c projecting from the side wall 96a of the left case half 96 toward the joining surface 30, and a periphery projecting from the side wall 97a of the right case half 97 toward the joining surface 30. The closed partition wall 97c is formed by abutting each other in the joined state of the two case halves 96 and 97. The lower end of the upper air passage 96e is opened on the ceiling surface in the pocket 154, and the upper end of the lower air passage 96f is opened on the bottom surface of the pocket 154. The lower air passage 96f is formed by perforating the partition wall 96c in the vertical direction.

  The cover wall 155 protrudes from the side wall 96 a toward the joint surface 30 at the left case half 96. In the side view, the cover wall 155 is hung from the front lower end of the partition wall 96c by a predetermined distance 157 and then bent rearward until it covers the lower end opening of the breather passage 156 until it covers the lower surface of the partition wall 96c. Along the parallel direction, it extends rearward toward the peripheral wall 96b.

  As a result, a gear group such as the gear 124 of the pump shaft S1 is arranged immediately below the breather 82. Even if the lubricating oil splashes violently due to the stirring of the gear group, the splash is blocked by the covering wall 155. The breather passage 156 is prevented from entering the lower end opening.

  That is, a pocket 154 capable of storing lubricating oil is provided in the middle of the breather passage 156 between the space in the mission case 29 and the breather 82, and the lower end opening of the breather passage 156 is separated by a predetermined interval 157. Since the cover wall 155 is provided, the cover wall 155 prevents the splashing of the lubricating oil that is violently scattered by the stirring of the gear group from entering the breather passage 156 and bypasses the cover wall 155 even if it bypasses the breather. Even if it penetrates into the passage 156, most of the entered lubricating oil can be retained in the pocket 154, and it is possible to reliably prevent the lubricating oil from leaking outside through the breather 82.

  Further, the cover wall 155 extends from the lower end of the partition wall 96c constituting the pocket 154 toward the peripheral wall 96b, thereby covering the lower end opening of the breather passage 156. Therefore, the cover wall 155 is the same as the extending direction of the cover wall 155. The lubricating oil splashing in the direction, in the present embodiment, the lubricating oil splashing in the direction of the arrow 158 is particularly excellent in the protective effect of the lower end opening of the breather passage 156 by the cover wall 155, and from the breather 82 of the lubricating oil. Leakage can be prevented more reliably.

  Further, another type of oil leakage prevention structure 153A will be described with reference to FIG. The oil leakage prevention structure 153A more reliably prevents the lubricating oil from entering the lower end opening of the breather passage 156 by changing the shape of the cover wall 155 in the oil leakage prevention structure 153.

  The side wall 160 of the oil leakage prevention structure 153A is drooped from the front lower end of the partition wall 96c by a predetermined distance 157 and bent backward in a side view, and then rearward in parallel along the lower surface of the partition wall 96c. The first parallel portion 160a that extends, and the second parallel portion 160b that is continuous with the first parallel portion 160a and extends in a rearward and obliquely downward direction along the peripheral wall 96b. The first parallel portion 160 a extends to cover the lower end opening of the breather passage 156, similarly to the cover wall 155.

  Thereby, a gear group such as the gear 124 of the pump shaft S1 is disposed immediately below the breather 82, and when the lubricating oil scatters vigorously due to the stirring of the gear group, the rotation direction of the gear group is not the arrow 158, Even in the direction of the reverse arrow 158, the splash is blocked by the second parallel portion 160b and does not enter the lower end opening of the breather passage 156.

  That is, the cover wall 160 extends rearward and obliquely downward in parallel to the tip of the first parallel portion 160a along the peripheral wall 96b in addition to the first parallel portion 160a covering the lower end opening of the breather passage 156. Since the two parallel portions 160b are provided, the distance to the lower end opening of the breather passage 156 can be increased, and even if the rotation direction of the gear group is switched, the splash of lubricating oil splashed violently by the stirring of the gear group is generated. Intrusion into the passage 156 can be more reliably prevented, and leakage of the lubricating oil to the outside through the breather 82 can be further reliably prevented.

  The present invention provides a first oil sump in which lubricating oil in which at least a part of the gear group of the reduction gear mechanism is immersed is stored at the bottom of a transmission case that houses a reduction gear mechanism for shifting driving of an axle. If the lubricating oil in the first oil sump is pumped up by a hydraulic pump of a hydraulic continuously variable transmission and is supplied to the hydraulic continuously variable transmission as hydraulic oil, only the agricultural combine shown in the embodiment can be used. The present invention can be applied to an axle drive device for various industrial vehicles such as a transport vehicle and a forklift.

28 Axle drive device 29 Mission case 31/32 Hydraulic continuously variable transmission 45 Turning brake (lubricated part)
48 Charge pump (hydraulic pump)
51 First Oil Reservoir 52 Second Oil Reservoir 57 Subtransmission (Reduction Gear Mechanism)
58 Differential (Reduction gear mechanism)
61 Gear transmission (reduction gear mechanism)
68, 69, 89, 125a, 125b Gear (lubricated part)
71 Clutch slider (lubricated part)
96/97 Case half 99 Second external piping (communication path)
102 Oil cooler (cooling device)
106/107 Bulkhead 108/109 Blow hole 114 Third external piping (external piping)
121 Equipment Case D6L / D6R Axle

Claims (4)

A first oil sump is provided at the bottom of a transmission case that houses a reduction gear mechanism for speed change driving of an axle, in which lubricating oil in which at least a part of the gear group of the reduction gear mechanism is immersed is stored. In the axle drive device that pumps up the lubricating oil in the reservoir by the hydraulic pump of the hydraulic continuously variable transmission and replenishes the hydraulic continuously variable transmission as hydraulic oil, a second oil reservoir is provided at the upper part in the transmission case, The partition wall of the second oil sump opens a jet port that communicates with the space inside the transmission case, and the second oil sump and the device case of the hydraulic continuously variable transmission are connected via a communication passage. And
The transmission case is composed of a pair of case halves, and when the case halves are assembled, the partition walls provided in the case halves are brought into contact with each other, whereby the second oil sump is placed in the space inside the transmission case. The axle drive device is characterized in that the jet port is formed by partially shifting one partition wall from the other partition wall along the joint surface of both partition walls .   2. The axle according to claim 1, wherein the communication path is configured by an external pipe, and a cooling device for cooling the lubricating oil flowing from the device case to the second oil reservoir is provided in the middle of the external pipe. Drive device.   The axle drive device according to claim 1 or 2, wherein an oil outlet of the second oil reservoir is directed to a lubricated portion of the reduction gear mechanism.   The axle drive unit according to any one of claims 1 to 3, wherein the second oil reservoir is communicated with a lubrication target portion of the reduction gear mechanism via an external pipe.

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