Work vehicle

Abstract

To simplify a drive system of a lubricating oil pump that circulates lubricating oil in a transmission case for cooling in a work vehicle.SOLUTION: A transmission mechanism that transmits power to a driven portion is housed in a transmission cases 21, 28 to which lubricating oil is supplied. A hydrostatic continuously variable transmission 37 includes a travel pump 38 and a travel motor 39 that is driven with supply of hydraulic oil from the travel pump 38 to drive a travel device 2. A lubricating oil pump 46 circulates lubricating oil such that the lubricating oil is supplied from the transmission cases 21, 28 to a cooling device 19 to be cooled, and then supplied from the cooling device 19 to the transmission cases 21, 28. A common pump drive shaft 26 driven by power of an engine 10 drives the travel pump 38 and the lubricating oil pump 46.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a configuration of a drive system for a hydraulic pump installed in a work vehicle. [Background technology]

[0002] A sugarcane harvester, which is an example of a work vehicle, is disclosed in Patent Document 1. In Patent Document 1, the vehicle is provided with a transmission case for driving a hydraulic pump with engine power and a transmission case in which a traveling device is provided.

[0003] Since the temperature of the lubricating oil in the transmission case is likely to rise due to the operation of the transmission mechanism housed in the transmission case, a configuration for cooling the lubricating oil is sometimes provided. One configuration for cooling the lubricating oil in the transmission case is to circulate the lubricating oil by supplying it from the transmission case to a cooling device using a lubricating oil pump, cooling it in the cooling device, and then supplying it from the cooling device to the transmission case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-101186 Summary of the Invention [Problem to be solved by the invention]

[0005] Since work vehicles are often equipped with multiple hydraulic pumps in addition to the lubricating oil pump, there is a demand for simplification of the drive system for the hydraulic pumps. SUMMARY OF THE INVENTION An object of the present invention is to simplify the drive system of a lubricating oil pump that circulates lubricating oil in a transmission case for cooling in a work vehicle. [Means for solving the problem]

[0006] The work vehicle of the present invention is equipped with a hydrostatic continuously variable transmission having an engine, traveling gear, a cooling device, a transmission case that houses a transmission mechanism that transmits power to the driven parts and to which lubricating oil is supplied, a traveling pump, and a traveling motor that is activated by the supply of hydraulic oil from the traveling pump to drive the traveling gear, and a lubricating oil pump that circulates lubricating oil so that the lubricating oil is supplied from the transmission case to the cooling device, cooled, and then supplied from the cooling device to the transmission case, and the traveling pump and the lubricating oil pump are driven by a common pump drive shaft that is driven by the power of the engine.

[0007] Work vehicles are often equipped with a hydrostatic continuously variable transmission that has a travel pump and a travel motor. The travel pump is driven by the engine, and hydraulic oil from the travel pump is supplied to the travel motor, which then drives the travel device, allowing the work vehicle to travel.

[0008] According to the present invention, the travel pump and the lubricating oil pump are driven by a common pump drive shaft driven by the power of the engine. The lubricating oil pump supplies the lubricating oil from the transmission case to the cooling device, where it is cooled, and then circulates the lubricating oil from the cooling device to the transmission case. As a result, the travel pump of the hydrostatic continuously variable transmission and the lubricating oil pump that circulates the lubricating oil in the transmission case for cooling are driven by a common pump drive shaft, and the pump drive shaft is used for both driving the travel pump and the lubricating oil pump, thereby simplifying the drive system of the lubricating oil pump.

[0009] In the present invention, it is preferable that the transmission case is a drive transmission case that transmits the power of the engine to the transmission mechanism and then from the transmission mechanism to the plurality of driven parts.

[0010] According to the present invention, engine power is transmitted to a transmission mechanism of a drive transmission case, and then transmitted from the transmission mechanism to a plurality of driven parts to drive the plurality of driven parts. A lubricating oil pump supplies lubricating oil from the drive transmission case to a cooling device, where it is cooled, and then circulates the lubricating oil from the cooling device to the drive transmission case. This provides a configuration suitable for a drive transmission case for driving a plurality of driven parts.

[0011] In the present invention, it is preferable that the travel pump and the lubricating oil pump are included in the driven parts, and the pump drive shaft is provided in the drive transmission case and driven by the power of the transmission mechanism.

[0012] According to the present invention, the pump drive shaft is provided in the drive transmission case and is driven by the transmission mechanism, and the travel pump and lubricating oil pump of the hydrostatic continuously variable transmission are driven by the pump drive shaft. This allows the travel pump, lubricating oil pump, and pump drive shaft to be compactly mounted in the drive transmission case, which is advantageous in terms of simplifying the drive system of the lubricating oil pump.

[0013] In the present invention, it is preferable that a plurality of drive supply oil passages are provided that are connected across the cooling device and the drive transmission case and supply lubricating oil from the cooling device to the drive transmission case, and that the plurality of drive supply oil passages are connected to a plurality of different parts of the drive transmission case.

[0014] According to the present invention, the lubricating oil cooled by the cooling device is supplied to a plurality of different portions of the drive transmission case through a plurality of drive supply oil passages. As a result, the lubricating oil cooled by the cooling device is dispersed and supplied to each part of the drive transmission case, thereby improving the efficiency of cooling the lubricating oil in the drive transmission case.

[0015] In the present invention, it is preferable that the traveling device is included in the driven part, and the transmission case is a traveling transmission case in which the traveling device is provided and the power of the traveling motor is transmitted from the transmission mechanism to the traveling device.

[0016] According to the present invention, the power of the travel motor of the hydrostatic continuously variable transmission is transmitted to the transmission mechanism of the travel transmission case, and then transmitted from the transmission mechanism to the travel device, thereby driving the travel device. The lubricating oil is supplied from the travel transmission case to the cooling device by the lubricating oil pump, cooled by the cooling device, and circulated so that it is supplied from the cooling device to the travel transmission case. This provides a configuration suitable for the travel transmission case for driving the travel device.

[0017] In the present invention, the traveling transmission case preferably has a main body portion in which the transmission mechanism is housed, a right axle portion connected to the right portion of the main body portion and on which the right traveling device is provided, a left axle portion connected to the left portion of the main body portion and on which the left traveling device is provided, and a connecting pipe connected between the right axle portion and the left axle portion and allowing lubricating oil to flow between the right axle portion and the left axle portion, and is preferably provided with a traveling supply oil passage connected between the cooling device and the main body portion and supplying lubricating oil from the cooling device to the traveling transmission case, and a traveling return oil passage connected between the connecting pipe and the lubricating oil pump and supplying lubricating oil from the traveling transmission case to the lubricating oil pump.

[0018] According to the present invention, the travel transmission case has a main body, a right axle, and a left axle, with the right travel device being provided on the right axle and the left travel device being provided on the left axle. The connecting pipe is connected across the right axle section and the left axle section, and the connecting pipe allows lubricating oil to pass between them, so that the lubricating oil of the right axle section and the lubricating oil of the left axle section can easily pass between them through the connecting pipe. According to the present invention, lubricating oil is supplied to the main body of the traveling transmission case through the traveling supply oil passage, passes through the main body, the right axle and the left axle, and enters the connecting pipe. The lubricating oil in the traveling transmission case is supplied to the lubricating oil pump from the connecting pipe through the traveling return oil passage. This allows the lubricating oil cooled by the cooling device to flow through each part of the traveling transmission case, such as the main body of the traveling transmission case, the right axle and left axle parts, and the connecting pipe, thereby making it possible to efficiently cool the lubricating oil in the traveling transmission case.

[0019] In the present invention, it is preferable that a connection part is provided that is connected between the main body part and the connecting pipe and allows lubricating oil to pass between the main body part and the connecting pipe.

[0020] According to the present invention, if it is difficult for the lubricating oil supplied to the main body of the traveling transmission case to enter the connecting pipe from the main body through the right axle and left axle, the lubricating oil can bypass the right axle and left axle and enter the connecting pipe by passing from the main body through the connecting part. This maintains the flow of lubricating oil from the main body of the travel transmission case to the connecting pipe, which is advantageous in terms of improving the efficiency of cooling the lubricating oil in the travel transmission case.

[0021] In the present invention, the traveling device is included in the driven parts, and the transmission case comprises a drive transmission case that transmits the power of the engine to the transmission mechanism and from the transmission mechanism to the plurality of driven parts, and a traveling transmission case that is provided with the traveling device and transmits the power of the traveling motor from the transmission mechanism to the traveling device, and it is preferable that the lubricating oil is discharged from the drive transmission case and the traveling transmission case by the lubricating oil pump, supplied to the cooling device and cooled, and supplied from the cooling device to the drive transmission case and the traveling transmission case, and that a connecting oil passage that connects the drive transmission case and the traveling transmission case and allows the lubricating oil to pass through is provided.

[0022] According to the present invention, engine power is transmitted to a transmission mechanism of a drive transmission case, and then transmitted from the transmission mechanism to a plurality of driven parts to drive the plurality of driven parts. A lubricating oil pump supplies lubricating oil from the drive transmission case to a cooling device, where it is cooled, and then circulates the lubricating oil from the cooling device to the drive transmission case. This provides a configuration suitable for a drive transmission case for driving a plurality of driven parts.

[0023] According to the present invention, the power of the travel motor of the hydrostatic continuously variable transmission is transmitted to the transmission mechanism of the travel transmission case, and then transmitted from the transmission mechanism to the travel device, thereby driving the travel device. The lubricating oil is supplied from the travel transmission case to the cooling device by the lubricating oil pump, cooled by the cooling device, and circulated so that it is supplied from the cooling device to the travel transmission case. This provides a configuration suitable for the travel transmission case for driving the travel device.

[0024] According to the present invention, the connecting oil passage through which the lubricating oil can pass is connected across the drive transmission case and the travel transmission case, and the temperature of the lubricating oil in the drive transmission case and the lubricating oil in the travel transmission case can be equalized. This makes it possible to improve the efficiency of cooling the lubricating oil in the drive transmission case and the lubricating oil in the travel transmission case.

[0025] In the present invention, there are provided a drive supply oil passage that is connected between the cooling device and the drive transmission case and supplies lubricating oil from the cooling device to the drive transmission case, a travel supply oil passage that is connected between the cooling device and the travel transmission case and supplies lubricating oil from the cooling device to the travel transmission case, and a travel return oil passage that is connected between the travel transmission case and the lubricating oil pump and supplies lubricating oil from the travel transmission case to the lubricating oil pump, and it is preferable that the lubricating oil for the drive transmission case is supplied from the drive transmission case to the travel transmission case via the connecting oil passage.

[0026] According to the present invention, lubricating oil is supplied from the cooling device to the traveling transmission case via the traveling supply oil passage, and is supplied from the traveling transmission case to the lubricating oil pump via the traveling return oil passage. According to the present invention, lubricating oil is supplied from the cooling device to the drive transmission case through the drive supply oil passage, from the drive transmission case through the connecting oil passage to the traveling transmission case, and from the traveling transmission case through the traveling return oil passage to the lubricating oil pump. As a result, the travel return oil passage is used both as an oil passage that supplies lubricating oil from the travel transmission case to the lubricating oil pump and as an oil passage that supplies lubricating oil from the drive transmission case to the lubricating oil pump, thereby simplifying the structure by sharing the oil passages.

[0027] In the present invention, the traveling transmission case has a main body portion in which the transmission mechanism is accommodated, a right axle portion connected to the right portion of the main body portion and on which the right traveling device is provided, a left axle portion connected to the left portion of the main body portion and on which the left traveling device is provided, and a connecting pipe connected between the right axle portion and the left axle portion and allowing lubricating oil to flow between the right axle portion and the left axle portion, and it is preferable that the traveling supply oil passage is connected between the cooling device and the main body portion, the traveling return oil passage is connected between the connecting pipe and the lubricating oil pump, and the connecting oil passage is connected between the driving transmission case and the connecting pipe.

[0028] According to the present invention, the travel transmission case has a main body, a right axle, and a left axle, with the right travel device being provided on the right axle and the left travel device being provided on the left axle. The connecting pipe is connected across the right axle section and the left axle section, and the connecting pipe allows lubricating oil to pass between them, so that the lubricating oil of the right axle section and the lubricating oil of the left axle section can easily pass between them through the connecting pipe. According to the present invention, lubricating oil is supplied to the main body of the traveling transmission case through the traveling supply oil passage, passes through the main body, the right axle and the left axle, and enters the connecting pipe. The lubricating oil in the traveling transmission case is supplied to the lubricating oil pump from the connecting pipe through the traveling return oil passage. This allows the lubricating oil cooled by the cooling device to flow through each part of the traveling transmission case, such as the main body of the traveling transmission case, the right axle and left axle parts, and the connecting pipe, which is advantageous in terms of efficient cooling of the lubricating oil in the traveling transmission case.

[0029] According to the present invention, the connecting oil passage is connected across the drive transmission case and the connecting pipe of the traveling transmission case, so that the lubricating oil supplied from the drive transmission case through the connecting oil passage to the connecting pipe immediately enters the traveling return oil passage and is easily supplied to the lubricating oil pump, and is less likely to flow to each part of the traveling transmission case. This means that the lubricating oil supplied from the drive transmission case through the connecting oil passage to the connecting pipe is less likely to hinder the cooling of the lubricating oil in the travel transmission case, which is advantageous in terms of improving the efficiency of cooling the lubricating oil in the travel transmission case. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 2 is a left side view of the sugarcane harvester. [Figure 2] FIG. 2 is a schematic diagram showing hydraulic circuits for a drive case and a transmission case. DETAILED DESCRIPTION OF THE INVENTION

[0031] Figures 1 and 2 show a sugarcane harvester, which is an example of a work vehicle, and in Figures 1 and 2, F indicates the forward direction, B indicates the rearward direction, U indicates the upward direction, and D indicates the downward direction.

[0032] (Overall configuration of sugarcane harvester) As shown in Figure 1, the reaping unit 3 and the first conveying device 4 are connected to form the machine body 8, and the first conveying device 4 extends diagonally upward and rearward from the rear of the reaping unit 3.

[0033] Right and left front wheels 1 are attached to the right and left parts of the reaping unit 3. An upper cutting device 7 is provided on the top of the reaping unit 3 and is positioned above and in front of the reaping unit 3. Right and left rear wheels 2 (corresponding to the traveling device) (corresponding to the driven part) are provided on the lower part of the rear part of the first conveying device 4, and the front wheels 1 and rear wheels 2 support the machine body 8.

[0034] The sorting device 5 is provided in the vertical direction at the rear of the first conveying device 4, and the second conveying device 6 extends diagonally upward from the bottom of the sorting device 5. A driving unit 9 is provided at the top of the reaping unit 3, and an engine 10 is provided at the top of the front part of the first conveying device 4.

[0035] (Sugarcane harvester in operation) As shown in Figure 1, as the machine body 8 moves forward, the upper leaves of the crops in the field are cut by the upper cutting device 7, and the crops in the field are introduced into the reaping unit 3. The crops introduced into the reaping unit 3 are leaned forward, the bases of the plants are cut, and the crops are supplied from the bases to the first conveying device 4. The crops supplied to the first conveying device 4 are transported diagonally upward and rearward along the first conveying device 4, cut to a predetermined length at the rear end of the first conveying device 4, and supplied to the top of the sorting device 5.

[0036] The crops supplied to the top of the sorting device 5 fall into the front part of the second conveying device 6. A sorting fan (not shown) is provided at the top of the sorting device 5, and the sorting fan generates sorting wind directed upward inside the sorting device 5. Inside the sorting device 5, the crops fall into the front part of the second conveying device 6 below, and impurities are separated from the crops by the sorting wind and discharged from the top of the sorting device 5.

[0037] The crops that fall onto the front of the second conveying device 6 are transported diagonally upward by the second conveying device 6. A transport vehicle (not shown) accompanies the sugarcane harvester, and the crops are dumped from the rear of the second conveying device 6 onto the loading platform of the transport vehicle.

[0038] (Overview of hydraulic systems in sugarcane harvesters) 2, there are provided hydraulic pumps 11 (corresponding to the driven part), 12 (corresponding to the driven part), 13 (corresponding to the driven part), 14 (corresponding to the driven part), 15 (corresponding to the driven part), 16 (corresponding to the driven part), and 17 (corresponding to the driven part). The hydraulic pumps 11, 12, 13, 14, 15, 16, and 17 are driven by the engine 10, as will be described later.

[0039] As shown in Figures 1 and 2, hydraulic oil is supplied from hydraulic pump 11 to reaping unit 3, causing reaping unit 3 to operate. Hydraulic oil is supplied from hydraulic pump 12 to first conveying device 4, causing first conveying device 4 to operate. Hydraulic oil is supplied from hydraulic pump 13 to sorting device 5, causing the sorting fan of sorting device 5 to operate.

[0040] A steering device (not shown) is provided to steer the front wheels 1, and the front wheels 1 are steered by the steering device when a control handle (not shown) provided on the driver's section 9 is operated. Hydraulic oil is supplied from a hydraulic pump 14 to the upper cutting device 7 and the steering device, causing the upper cutting device 7 and the steering device to operate.

[0041] A radiator 18 that produces cooling water for the engine 10 and an oil cooler 19 (corresponding to a cooling device) are provided at the upper rear part of the first transfer device 4, at a position higher than the engine 10, and a blower fan 20 that supplies cooling air to the radiator 18 and the oil cooler 19 is provided. Hydraulic oil is supplied from the hydraulic pump 15 to the blower fan 20, causing the blower fan 20 to operate.

[0042] A number of hydraulic cylinders (not shown) are provided to perform lifting and lowering operations and direction change operations for the second transfer device 6, etc., and a control valve unit (not shown) is provided to supply and discharge hydraulic oil to the hydraulic cylinders, and hydraulic oil from a hydraulic pump 17 is supplied to the control valve unit. Hydraulic oil is supplied from the hydraulic pump 16 to the second transfer device 6, causing the second transfer device 6 to operate.

[0043] (Configuration of drive case 21) 1 and 2, a drive case 21 (corresponding to a drive transmission case) is provided at the upper front part of the first conveying device 4 and is connected to the engine 10. The drive case 21 is provided at a position lower than the oil cooler 19.

[0044] As shown in FIG. 2, drive shafts 22, 23, 24, 25, 26 and a relay gear 27 (corresponding to a transmission mechanism) are rotatably provided in a drive case 21, and an output shaft 10a of an engine 10 and the drive shaft 22 are connected.

[0045] Inside the drive case 21, a transmission gear 22a (corresponding to a transmission mechanism) is connected to the drive shaft 22, and a transmission gear 23a (corresponding to a transmission mechanism) is connected to the drive shaft 23, and the transmission gear 22a of the drive shaft 22 and the transmission gear 23a of the drive shaft 23 are engaged with each other.

[0046] A transmission gear 24a (corresponding to a transmission mechanism) is connected to the drive shaft 24, and the transmission gear 23a of the drive shaft 23 and the transmission gear 24a of the drive shaft 24 are in mesh with each other. A transmission gear 25a (corresponding to a transmission mechanism) is connected to the drive shaft 25, and the transmission gear 22a of the drive shaft 22 and the transmission gear 25a of the drive shaft 25 are in mesh with each other.

[0047] The transmission gear 22a of the drive shaft 22 is in mesh with the relay gear 27. The transmission gear 26a (corresponding to a transmission mechanism) is connected to the drive shaft 26, and the transmission gear 26a of the drive shaft 26 is in mesh with the relay gear 27.

[0048] Hydraulic pumps 11 and 12 are connected to a drive shaft 22. Hydraulic pump 13 is connected to a drive shaft 23. Hydraulic pumps 14 and 15 are connected to a drive shaft 24. Hydraulic pumps 16 and 17 are connected to a drive shaft 25.

[0049] The power of the engine 10 is transmitted to the drive shaft 22, driving the drive shaft 22, which in turn drives the hydraulic pumps 11 and 12. The power of the engine 10 is transmitted to the drive shaft 23 via transmission gears 22a and 23a of the drive shafts 22 and 23, driving the drive shaft 23, which in turn drives the hydraulic pump 13.

[0050] The power of the engine 10 is transmitted to the drive shaft 24 via transmission gears 22 a , 23 a , and 24 a of the drive shafts 22 , 23 , and 24 to drive the drive shaft 24 , which in turn drives the hydraulic pumps 14 and 15 .

[0051] The power of the engine 10 is transmitted to the drive shaft 25 via the transmission gears 22 a and 25 a of the drive shafts 22 and 25 to drive the drive shaft 25 , which in turn drives the hydraulic pumps 16 and 17 .

[0052] Drive case 21 is filled with grease and is not an oil bath. As will be described later, drive case 21 is configured so that lubricating oil is supplied to multiple parts inside drive case 21 that particularly require lubrication.

[0053] (Configuration of the 28th transmission case) 1 and 2, a transmission case 28 (corresponding to a travel transmission case) (corresponding to a transmission case) is provided at the lower rear portion of the first conveying device 4. The transmission case 28 is provided at a position rearward of the engine 10 and the drive case 21, and at a position lower than the oil cooler 19, the engine 10, and the drive case 21.

[0054] The transmission case 28 has a main body 29, a right axle 30, a left axle 31, and a connecting pipe 32. A gear-type sub-transmission device 33 (corresponding to a transmission mechanism) that can be shifted between high and low speeds, and a differential device 34 (corresponding to a transmission mechanism) are provided inside the main body 29.

[0055] The right axle 30 is connected to the right part of the front of the main body 29, and the right rear wheel 2 is provided on the right axle 30. The left axle 31 is connected to the left part of the front of the main body 29, and the left rear wheel 2 is provided on the left axle 31. Right and left planetary reduction gears 35 (corresponding to transmission mechanisms) and right and left brakes 36 are provided inside the right axle 30 and left axle 31. A connecting pipe 32 is connected across the front of the right axle 30 and the front of the left axle 31 , and the right axle 30 and the left axle 31 are reinforced by the connecting pipe 32 .

[0056] The transmission case 28 (main body 29, right axle 30, left axle 31, connecting pipe 32) stores lubricating oil inside, forming an oil bath. The lubricating oil can flow between the main body 29, right axle 30, and left axle 31, and can also flow between the right axle 30 and left axle 31 by passing through the connecting pipe 32.

[0057] An oil passage 54 (corresponding to a connection part) connects the lower front part of the right part of the main body 29 to the right part of the connecting pipe 32. An oil passage 55 (corresponding to a connection part) connects the lower rear part of the left part of the main body 29 to the left part of the connecting pipe 32. By passing through the oil passages 54, 55, the lubricating oil can travel between the main body 29 and the connecting pipe 32 without passing through the right axle 30 and the left axle 31.

[0058] (Configuration of hydrostatic continuously variable transmission 37) 2, a hydrostatic continuously variable transmission 37 is provided across the drive case 21 and the transmission case 28. The continuously variable transmission 37 has a travel pump 38 (corresponding to the driven part), a travel motor 39, a charge pump 40 (corresponding to the driven part), and oil passages 41 and 42.

[0059] A travel pump 38 and a charge pump 40 are provided in the drive case 21 and connected to a drive shaft 26 (corresponding to a pump drive shaft). The power of the engine 10 is transmitted to the drive shaft 26 via a transmission gear 22a of the drive shaft 22 and a relay gear 27, driving the drive shaft 26, which in turn drives the travel pump 38 and the charge pump 40.

[0060] A travel motor 39 is provided in the main body 29 of the transmission case 28, and power from the travel motor 39 is transmitted to the auxiliary transmission 33. A pair of oil passages 41 are connected between the travel pump 38 and the travel motor 39.

[0061] The travel pump 38 can change the amount of hydraulic oil discharged in a stepless manner in the forward and reverse directions, and the hydraulic oil from the travel pump 38 is supplied to the travel motor 39 via an oil passage 41, so that the travel motor 39 is driven in a stepless manner in the forward and reverse directions at a speed that can be changed in a stepless manner.

[0062] Power is transmitted from the travel motor 39 to the auxiliary transmission 33, and from the auxiliary transmission 33 to the differential 34 and the right and left planetary reduction gears 35, and then to the right and left rear wheels 2, which are driven forward and backward. The right and left rear wheels 2 can be braked by the brakes 36.

[0063] An oil passage 42 is connected across a pair of oil passages 41, and hydraulic oil from a hydraulic oil tank 43 is sucked into the charge pump 40 through an oil passage 44 and is supplied from the charge pump 40 through the oil passage 42 to the oil passage 41. Hydraulic oil leaking from the travel pump 38 and the travel motor 39 returns to the hydraulic oil tank 43 through an oil passage 45.

[0064] (Configuration of the cooling system for the lubricating oil of the drive case 21 and the transmission case 28) 2, a lubricating oil pump 46 (corresponding to a driven part) is provided in the drive case 21 and connected to the drive shaft 26. The drive shaft 26 drives the travel pump 38, the charge pump 40, and the lubricating oil pump 46.

[0065] An oil passage 47 extends from the lubricating oil pump 46 and is connected to the oil cooler 19 (see FIG. 1). An oil passage 48 extends from the oil cooler 19 and branches into two oil passages 49 (corresponding to drive supply oil passages) and one oil passage 50 (corresponding to a travel supply oil passage).

[0066] Two oil passages 49 are connected to different portions of drive case 21. The portions where oil passages 49 are connected to drive case 21 are located above portions of drive case 21 that particularly require lubrication. Oil passage 50 is connected to the upper rear portion of main body 29 of transmission case 28.

[0067] An oil passage 51 (corresponding to a connecting oil passage) is connected between the drive case 21 and the connecting pipe 32 of the transmission case 28. An oil passage 52 (corresponding to a travel return oil passage) is connected between the connecting pipe 32 of the transmission case 28 and the lubricating oil pump 46, and a filter 53 is provided in the oil passage 52.

[0068] (Circulation of lubricating oil in the drive case 21 and the transmission case 28) As shown in FIG. 2, when the lubricating oil pump 46 is driven, the lubricating oil is cooled and circulated as described below.

[0069] Lubricating oil is supplied from lubricating oil pump 46 through oil passage 47 to oil cooler 19 where it is cooled. The lubricating oil cooled in oil cooler 19 is supplied to drive case 21 through oil passages 48 and 49, and is then supplied to main body 29 of transmission case 28 through oil passages 48 and 50.

[0070] In this case, most of the lubricating oil cooled by the oil cooler 19 is supplied from the oil passage 50 to the main body 29 of the transmission case 28, and only a small amount of lubricating oil is supplied from the oil passage 49 to the drive case 21.

[0071] The lubricating oil supplied to the drive case 21 from the oil passages 48, 49 is supplied (dripped) to parts inside the drive case 21 that particularly require lubrication, and is supplied from the drive case 21 through the oil passage 51 to the connecting pipe 32 of the transmission case 28.

[0072] In this case, since drive case 21 is located higher than transmission case 28 (see FIG. 1), lubricating oil for drive case 21 is smoothly supplied from oil passage 51 to connecting pipe 32 of transmission case 28.

[0073] The lubricating oil supplied from oil passages 48 and 50 to the main body 29 of the transmission case 28 flows from the main body 29 through the right axle 30, the left axle 31, and oil passages 54 and 55 into the connecting pipe 32. When the lubricating oil in the drive case 21 is supplied to the connecting pipe 32 of the transmission case 28, the lubricating oil in the drive case 21 and the lubricating oil in the transmission case 28 join together at the connecting pipe 32 of the transmission case 28 and are supplied to the lubricating oil pump 46 through the oil passage 52 and the filter 53.

[0074] (First Alternative Embodiment of the Invention) Three or four oil passages 49 may be provided, and each oil passage 49 may be connected to a different portion of drive case 21 .

[0075] (Second Alternative Embodiment of the Invention) If the inside of drive case 21 is filled with grease and drive case 21 does not serve as an oil bath, oil passages 49 and 51 may be omitted. With this configuration, the lubricating oil pump 46 and the oil cooler 19 only have the function of cooling and circulating the lubricating oil in the transmission case 28.

[0076] (Third Alternative Embodiment of the Invention) Drive case 21 may serve as an oil bath by storing lubricating oil therein, similar to transmission case 28. According to this configuration, only one oil passage 49 may be required.

[0077] (Fourth Alternative Embodiment of the Invention) When lubricating oil is stored inside the drive case 21 and the drive case 21 serves as an oil bath, first and second lubricating oil pumps 46 may be connected to the drive shaft 26, and first and second oil coolers 19 may be provided.

[0078] According to the above-described configuration, the first lubricating oil pump 46 and the first oil cooler 19 preferably have the function of cooling and circulating the lubricating oil in the drive case 21, and the second lubricating oil pump 46 and the second oil cooler 19 preferably have the function of cooling and circulating the lubricating oil in the transmission case 28. In this configuration, the oil passage 51 may be provided or may be eliminated.

[0079] (Fifth Alternative Embodiment of the Invention) Instead of the rear wheels 2, crawler-type right and left traveling devices (not shown) may be provided on the transmission case 28. According to this configuration, the front wheels 1 and the rear crawler type traveling devices may be provided, or the front wheels 1 may be eliminated and only the right and left crawler type traveling devices may be provided.

[0080] (Sixth Alternative Embodiment of the Invention) All or some of the hydraulic pumps 11 to 17 may be eliminated. For example, if the hydraulic pumps 11 and 12 are eliminated, it is preferable to configure the system so that the power of the drive shaft 22 is transmitted to the reaping unit 3 and the first conveying device 4 by a transmission belt (not shown) or a transmission chain (not shown). In this configuration, the reaping unit 3 and the first conveying device 4 become the driven parts.

[0081] For example, if the hydraulic pumps 13 and 16 are eliminated, it is preferable to configure the system so that the power of the drive shafts 23 and 25 is transmitted to the sorting device 5 and the second conveying device 6 by a transmission belt (not shown) or a transmission chain (not shown). In this configuration, the sorting device 5 and the second conveying device 6 become the driven parts.

[0082] (Correspondence to claims)-1 The vehicle is equipped with an engine 10, a driving device (rear wheels 2), and a cooling device (oil cooler 19). A transmission case (drive case 21) (transmission case 28) is provided which houses a transmission mechanism (transmission gears 22a, 23a, 24a, 25a, 26a, relay gear 27) (auxiliary transmission 33, differential device 34, planetary reduction device 35) that transmits power to the driven parts (hydraulic pumps 11, 12, 13, 14, 15, 16, 17, travel pump 38, charge pump 40, lubricating oil pump 46) (rear wheels 2), and through which lubricating oil is supplied. The vehicle is provided with a hydrostatic continuously variable transmission 37 having a travel pump 38 and a travel motor 39 that is actuated by the supply of hydraulic oil from the travel pump 38 to drive the travel device (rear wheels 2).

[0083] A lubricating oil pump 46 is provided to circulate the lubricating oil so that the lubricating oil is supplied from the transmission case (drive case 21) (transmission case 28) to the cooling device (oil cooler 19) where it is cooled, and then supplied from the cooling device (oil cooler 19) to the transmission case (drive case 21) (transmission case 28). A common pump drive shaft (drive shaft 26) driven by the power of the engine 10 drives the travel pump 38 and the lubricating oil pump 46.

[0084] (Correspondence to claims)-2 The transmission case (drive case 21) is a drive transmission case (drive case 21) that transmits the power of the engine 10 to the transmission mechanism (transmission gears 22a to 26a, relay gear 27) and from the transmission mechanism (transmission gears 22a to 26a, relay gear 27) to multiple driven parts (hydraulic pumps 11 to 17, travel pump 38, charge pump 40, lubricating oil pump 46).

[0085] The travel pump 38 and the lubricating oil pump 46 are included in the driven parts (hydraulic pumps 11 to 17, travel pump 38, charge pump 40, lubricating oil pump 46). A pump drive shaft (drive shaft 26) is provided in a drive transmission case (drive case 21) and is driven by the power of a transmission mechanism (transmission gears 22a to 26a, relay gear 27).

[0086] A plurality of drive supply oil passages (oil passages 49) are provided which connect the cooling device (oil cooler 19) and the drive transmission case (drive case 21) and supply lubricating oil from the cooling device (oil cooler 19) to the drive transmission case (drive case 21). A plurality of drive supply oil passages (oil passages 49) are connected to a plurality of different portions of the drive transmission case (drive case 21).

[0087] (Correspondence to claims) - 3 The running gear (rear wheels 2) is included in the driven part. The transmission case (transmission case 28) is a traveling transmission case (transmission case 28) in which a traveling device (rear wheels 2) is provided and which transmits the power of the traveling motor 39 from the transmission mechanism (auxiliary transmission device 33, differential device 34, planetary reduction device 35) to the traveling device (rear wheels 2).

[0088] The traveling transmission case (transmission case 28) has a main body 29 in which the transmission mechanism (auxiliary transmission 33, differential device 34) is housed, a right axle 30 connected to the right part of the main body 29 and on which the right traveling device (rear wheel 2) is mounted, a left axle 31 connected to the left part of the main body 29 and on which the left traveling device (rear wheel 2) is mounted, and a connecting pipe 32 connected between the right axle 30 and the left axle 31 and allowing lubricating oil to flow between the right axle 30 and the left axle 31.

[0089] A travel supply oil passage (oil passage 50) is provided which connects the cooling device (oil cooler 19) and the main body 29 and supplies lubricating oil from the cooling device (oil cooler 19) to the travel transmission case (transmission case 28). A travel return oil passage (oil passage 52) is provided which is connected between the connecting pipe 32 and the lubricating oil pump 46 and supplies lubricating oil from the travel transmission case (transmission case 28) to the lubricating oil pump 46. The main body 29 and the connecting pipe 32 are connected to each other via connecting parts (oil passages 54, 55) that allow lubricating oil to travel between the main body 29 and the connecting pipe 32.

[0090] (Correspondence to claims)-4 The running gear (rear wheels 2) is included in the driven part. The transmission case (drive case 21) (mission case 28) is a drive transmission case (drive case 21) that transmits the power of the engine 10 to the transmission mechanism (transmission gears 22a to 26a, relay gear 27) and from the transmission mechanism (transmission gears 22a to 26a, relay gear 27) to multiple driven parts (hydraulic pumps 11 to 17, travel pump 38, charge pump 40, lubricating oil pump 46), and a travel transmission case (mission case 28) that has a travel device (rear wheels 2) and transmits the power of the travel motor 39 from the transmission mechanism (auxiliary transmission device 33, differential device 34, planetary reduction device 35) to the travel device (rear wheels 2).

[0091] The lubricating oil pump 46 pumps lubricating oil from the drive transmission case (drive case 21) and the traveling transmission case (transmission case 28) to the cooling device (oil cooler 19) where it is cooled, and then the lubricating oil is supplied from the cooling device (oil cooler 19) to the drive transmission case (drive case 21) and the traveling transmission case (transmission case 28). A connecting oil passage (oil passage 51) is provided which connects the drive transmission case (drive case 21) and the travel transmission case (transmission case 28) and through which lubricating oil can pass.

[0092] A drive supply oil passage (oil passage 49) is provided which connects the cooling device (oil cooler 19) and the drive transmission case (drive case 21) and supplies lubricating oil from the cooling device (oil cooler 19) to the drive transmission case (drive case 21).

[0093] A traveling supply oil passage (oil passage 50) is provided which connects the cooling device (oil cooler 19) and the traveling transmission case (transmission case 28) and supplies lubricating oil from the cooling device (oil cooler 19) to the traveling transmission case (transmission case 28). A travel supply oil passage (oil passage 50) is connected between the cooling device (oil cooler 19) and the main body 29.

[0094] A travel return oil passage (oil passage 52) is provided which connects between the travel transmission case (mission case 28) and the lubricating oil pump 46 and supplies lubricating oil from the travel transmission case (mission case 28) to the lubricating oil pump 46. A travel return oil passage (oil passage 52) is connected between the connecting pipe 32 and the lubricating oil pump 46.

[0095] Lubricating oil for the drive transmission case (drive case 21) is supplied from the drive transmission case (drive case 21) to the travel transmission case (transmission case 28) via a connecting oil passage (oil passage 51). A connecting oil passage (oil passage 51) is connected between the drive transmission case (drive case 21) and the connecting pipe 32. [Industrial Applicability]

[0096] The present invention can be applied not only to sugarcane harvesters, but also to other agricultural work vehicles such as head-feeding combine harvesters and conventional combine harvesters, and also to construction work vehicles such as backhoes and front loaders. [Explanation of symbols]

[0097] 2 Rear wheels (running gear) (driven part) 10 Engine 11 Hydraulic pump (driven part) 12 Hydraulic pump (driven part) 13 Hydraulic pump (driven part) 14 Hydraulic pump (driven part) 15 Hydraulic pump (driven part) 16 Hydraulic pump (driven part) 17 Hydraulic pump (driven part) 19 Oil cooler (cooling device) 21 Drive case (drive transmission case) (transmission case) 22a Transmission gear (transmission mechanism) 23a Transmission gear (transmission mechanism) 24a Transmission gear (transmission mechanism) 25a Transmission gear (transmission mechanism) 26 Drive shaft (pump drive shaft) 26a Transmission gear (transmission mechanism) 27 Relay gear (transmission mechanism) 28 Transmission case (travel transmission case) (transmission case) 29 Main body 30 Right axle 31 Left axle 32 Connecting pipe 33 Sub-transmission device (transmission mechanism) 34 Differential device (transmission mechanism) 35 Planetary reduction gear (transmission mechanism) 37 Continuously variable transmission 38 Travel pump (driven part) 39 Travel motor 40 Charge pump (driven part) 46 Lubricating oil pump (driven part) 49 Oil passage (drive supply oil passage) 50 Oilway (Traveling supply oilway) 51 Oil line (connection oil line) 52 Oil passage (travel return oil passage) 54 Oil passage (connection) 55 Oil passage (connection)

Claims

1. The engine and Running gear and A cooling device; a transmission case that houses a transmission mechanism that transmits power to a driven part and to which lubricating oil is supplied; a hydrostatic continuously variable transmission including a travel pump and a travel motor that is actuated by the supply of hydraulic oil from the travel pump to drive the travel device; a lubricating oil pump that circulates the lubricating oil so that the lubricating oil is supplied from the transmission case to the cooling device, where it is cooled, and then supplied from the cooling device to the transmission case; A work vehicle in which the traveling pump and the lubricating oil pump are driven by a common pump drive shaft driven by the power of the engine.

2. 2. The work vehicle according to claim 1, wherein the transmission case is a drive transmission case that transmits the power of the engine to the transmission mechanism and then from the transmission mechanism to the plurality of driven parts.

3. the travel pump and the lubricating oil pump are included in the driven part, 3. The work vehicle according to claim 2, wherein the pump drive shaft is provided in the drive transmission case and is driven by the power of the transmission mechanism.

4. a plurality of drive supply oil passages are provided, which are connected across the cooling device and the drive transmission case and supply lubricating oil from the cooling device to the drive transmission case; 3. The work vehicle according to claim 2, wherein a plurality of the drive oil supply passages are connected to a plurality of different portions of the drive transmission case.

5. the traveling device is included in the driven part, 2. The work vehicle according to claim 1, wherein the transmission case is a travel transmission case in which the travel device is provided and in which power from the travel motor is transmitted from the transmission mechanism to the travel device.

6. the travel transmission case has a main body portion in which the transmission mechanism is housed, a right axle portion connected to the right portion of the main body portion and on which the right travel device is provided, a left axle portion connected to the left portion of the main body portion and on which the left travel device is provided, and a connecting pipe connected between the right axle portion and the left axle portion and enabling the flow of lubricating oil between the right axle portion and the left axle portion, a travel supply oil passage connected between the cooling device and the main body and supplying lubricating oil from the cooling device to the travel transmission case; 6. A work vehicle according to claim 5, further comprising a travel return oil passage connected between the connecting pipe and the lubricating oil pump, for supplying lubricating oil from the travel transmission case to the lubricating oil pump.

7. 7. The work vehicle according to claim 6, further comprising a connection portion that is connected between the main body portion and the connecting pipe and allows lubricating oil to pass between the main body portion and the connecting pipe.

8. the traveling device is included in the driven part, the transmission case includes a drive transmission case in which power of the engine is transmitted to the transmission mechanism and transmitted from the transmission mechanism to the plurality of driven parts, and a travel transmission case in which the travel device is provided and in which power of the travel motor is transmitted from the transmission mechanism to the travel device, The lubricating oil pump supplies lubricating oil from the drive transmission case and the traveling transmission case to the cooling device, where it is cooled, and then supplies it to the drive transmission case and the traveling transmission case from the cooling device.

2. The work vehicle according to claim 1, further comprising a connecting oil passage that connects the drive transmission case and the travel transmission case and allows lubricating oil to pass through.

9. a drive supply oil passage connected between the cooling device and the drive transmission case, for supplying lubricating oil from the cooling device to the drive transmission case; a travel supply oil passage connected between the cooling device and the travel transmission case and supplying lubricating oil from the cooling device to the travel transmission case; a travel return oil passage connected between the travel transmission case and the lubricating oil pump and supplying lubricating oil from the travel transmission case to the lubricating oil pump; 9. The work vehicle according to claim 8, wherein lubricating oil for the drive transmission case is supplied from the drive transmission case to the travel transmission case via the connecting oil passage.

10. the travel transmission case has a main body portion in which the transmission mechanism is housed, a right axle portion connected to the right portion of the main body portion and on which the right travel device is provided, a left axle portion connected to the left portion of the main body portion and on which the left travel device is provided, and a connecting pipe connected between the right axle portion and the left axle portion and enabling the flow of lubricating oil between the right axle portion and the left axle portion, The travel oil supply passage is connected across the cooling device and the main body portion, The travel return oil passage is connected between the connecting pipe and the lubricating oil pump, 10. A work vehicle according to claim 9, wherein the connecting oil passage is connected between the drive transmission case and the connecting pipe.

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