Work vehicle

Abstract

To provide a hybrid-type work vehicle that is equipped with a generator and a motor, which is configured to enable the generator and the motor to output highly, while suppressing cores of the generator and the motor from enlarging in a size.SOLUTION: A work vehicle is provided with: generator gear mechanisms 21b and 31 that accelerate power pf an engine 5 and transmit the power to a generator 21; motor gear mechanisms 22b and 32 that decelerate power of a motor 22 and transmit the power; and transmission devices 23 and 24 that combine the power of the engine 5 with the power of the motor 22, decelerated by the motor gear mechanisms 22b and 32 and transmit the power to a running device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a configuration of a transmission system in a work vehicle. [Background technology]

[0002] As disclosed in Patent Document 1, one example of a work vehicle is a hybrid tractor that is provided with an engine and a motor, and is configured so that the power of the engine and the power of the motor are transmitted to a transmission device, where they are combined and transmitted from the transmission device to a traveling device. In this case, it is considered to provide a generator that is driven by the power of the engine in addition to the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-65349 A Summary of the Invention [Problem to be solved by the invention]

[0004] In contrast to ordinary passenger cars, low-revolution, high-torque power is transmitted to the traveling gear of a work vehicle. For this reason, in a hybrid work vehicle equipped with a generator and a motor, when increasing the output of the generator and the motor, it is necessary to enlarge the cores of the generator and the motor.

[0005] However, when the cores of the generator and motor are enlarged, the case that houses the generator and motor also becomes larger, and the costs of the generator and motor also increase, so there is room for improvement.

[0006] The present invention aims to configure a hybrid work vehicle equipped with a generator and a motor so as to enable high output of the generator and motor while preventing the cores of the generator and motor from becoming larger. [Means for solving the problem]

[0007] The work vehicle of the present invention is equipped with a traveling device, an engine, a generator, a motor, a battery, a generator gear mechanism that accelerates the power of the engine and transmits it to the generator, a motor gear mechanism that decelerates the power of the motor and transmits it, and a transmission device that combines the power of the engine and the power of the motor decelerated by the motor gear mechanism and transmits it to the traveling device.

[0008] According to the present invention, the power of the engine is accelerated by the generator gear mechanism and transmitted to the generator, which is rotated at high speed. This makes it possible to increase the output of the generator without increasing the size of the generator core.

[0009] According to the present invention, the power of the motor is reduced by the motor gear mechanism and transmitted to the transmission. By driving the motor to rotate at high speed, the high-speed, low-torque power of the motor is converted to low-speed, high-torque power and transmitted to the transmission, so that the motor can have a high output without increasing the size of the motor core.

[0010] This prevents the case housing the generator and motor from becoming larger and prevents increases in cost for the generator and motor, while enabling the generator and motor to have higher output, thereby improving the driving performance of the work vehicle.

[0011] In the present invention, it is preferable that the generator and the motor are a motor generator.

[0012] According to the present invention, since the generator and the motor are a motor-generator, the generator can be operated as a motor and the motor can be operated as a generator.

[0013] As a result, by operating the generator as a motor, the power of the engine and generator (motor) and the power of the motor can be combined by the transmission device and transmitted to the traveling device. By operating the generator as a motor, the power of the generator (motor) and the power of the motor can be combined by the transmission and transmitted to the traveling gear, without transmitting the power of the engine to the transmission. By operating the motor as a generator, the battery can be charged by the power generated by the generator and the power generated by the motor (generator).

[0014] As described above, by using a motor generator as the generator and the motor, it is possible to respond to various driving conditions, which is advantageous in terms of improving the driving performance of the work vehicle.

[0015] In the present invention, it is preferable that there is provided an engine transmission shaft that transmits the power of the engine, and a cylindrical motor transmission shaft that is attached to the outer periphery of the engine transmission shaft and is rotatable relative to the engine transmission shaft, the motor gear mechanism is attached to an end of the motor transmission shaft, and the generator gear mechanism is attached to a portion of the engine transmission shaft adjacent to the end of the motor transmission shaft, the power of the engine is transmitted to the generator via the generator gear mechanism and to the transmission device via the engine transmission shaft, and the power of the motor is transmitted to the transmission device via the motor gear mechanism and the motor transmission shaft.

[0016] According to the present invention, when a dual-shaft structure consisting of an engine transmission shaft and a cylindrical motor transmission shaft is adopted, the generator gear mechanism and the motor gear mechanism are attached to the engine transmission shaft and the motor transmission shaft so as to be adjacent to each other. This allows the generator gear mechanism and the motor gear mechanism to be arranged compactly, which is advantageous in that it prevents the case that houses the generator and the motor from becoming too large.

[0017] In the present invention, it is preferable that the generator gear mechanism has a first transmission gear arranged coaxially with the generator shaft and interlocking with the generator shaft, and a second transmission gear attached to the engine transmission shaft, meshing with the first transmission gear and having a larger diameter than the first transmission gear, and that the motor gear mechanism has a third transmission gear arranged coaxially with the motor shaft and interlocking with the motor shaft, and a fourth transmission gear attached to the motor transmission shaft, meshing with the third transmission gear and having a larger diameter than the third transmission gear.

[0018] According to the present invention, the generator gear mechanism has a small diameter first transmission gear and a large diameter second transmission gear, so that the generator gear mechanism is compact.The motor gear mechanism has a small diameter third transmission gear and a large diameter fourth transmission gear, so that the motor gear mechanism is compact. This allows the generator gear mechanism and the motor gear mechanism to be configured compactly, which is advantageous in that it prevents the case that houses the generator and the motor from becoming too large.

[0019] In the present invention, it is preferable that the gear ratio between the third transmission gear and the fourth transmission gear, and the gear ratio between the first transmission gear and the second transmission gear are set so that the reduction in speed from the third transmission gear to the fourth transmission gear is smaller than the reduction in speed from the first transmission gear to the second transmission gear.

[0020] According to the present invention, when the power of the motor is reduced by the motor gear mechanism and then transmitted to the transmission device, the power of the motor can be prevented from being reduced more than necessary. This allows the engine power and the motor power reduced by the motor gear mechanism to be smoothly combined in the transmission device, which is advantageous in terms of improving the driving performance of the work vehicle.

[0021] In the present invention, it is preferable that the engine transmission shaft and the motor transmission shaft are arranged along the fore-and-aft direction, the generator is arranged on one side, left or right, of the engine transmission shaft and the motor transmission shaft, and the motor is arranged on the other side, left or right, of the engine transmission shaft and the motor transmission shaft.

[0022] According to the present invention, the generator and motor are arranged on one side of the left and right side and the other side of the left and right side with respect to the engine transmission shaft and the motor transmission shaft arranged along the fore-and-aft direction, so that the engine transmission shaft, the motor transmission shaft, the generator and the motor are arranged in line along the left-right direction. This allows the engine transmission shaft, the motor transmission shaft, the generator, and the motor to be arranged compactly, which is advantageous in that it prevents the case housing the generator and the motor from becoming too large.

[0023] According to the present invention, the generator and the motor are arranged on opposite sides of the engine transmission shaft and the motor transmission shaft, so that the first transmission gear of the generator shaft and the third transmission gear of the motor shaft are arranged on opposite sides of the engine transmission shaft and the motor transmission shaft.

[0024] This makes it possible to bring adjacent generator gear mechanisms and motor gear mechanisms close to each other while avoiding interference between the first transmission gear on the generator shaft and the third transmission gear on the motor shaft, which is advantageous in terms of arranging the generator gear mechanism and motor gear mechanism compactly and in terms of preventing the case housing the generator and motor from becoming larger.

[0025] In the present invention, it is preferable that a shaft portion of the generator and a shaft portion of the motor are disposed at a lower position than a shaft portion of the engine transmission shaft and a shaft portion of the motor transmission shaft.

[0026] According to the present invention, while maintaining a state in which the generator and the motor are disposed on opposite sides of the engine transmission shaft and the motor transmission shaft, the meshing portion between the first transmission gear and the second transmission gear in the generator gear mechanism can be brought closer to the engine transmission shaft and the motor transmission shaft in the left-right direction, and the meshing portion between the third transmission gear and the fourth transmission gear in the motor gear mechanism can be brought closer to the engine transmission shaft and the motor transmission shaft in the left-right direction.

[0027] This makes it possible to place the generator and motor closer to each other in the left-right direction, thereby reducing the overall width of the engine transmission shaft, motor transmission shaft, generator, and motor, which is advantageous in terms of compactly arranging the engine transmission shaft, motor transmission shaft, generator, and motor, and in terms of preventing the case housing the generator and motor from becoming larger.

[0028] In the present invention, there is provided a pump that supplies cooling liquid to an object to be cooled, and a pump gear mechanism that transmits power of the engine transmission shaft to the pump, and it is preferable that the pump gear mechanism is attached to a portion of the engine transmission shaft adjacent to the opposite side of the motor gear mechanism with respect to the generator gear mechanism.

[0029] According to the present invention, when a pump for supplying a cooling liquid to an object to be cooled is provided, the power of the engine transmission shaft is transmitted to the pump via the pump gear mechanism, thereby driving the pump to rotate. In this case, the pump gear mechanism is attached to a portion of the engine transmission shaft adjacent to the opposite side of the motor gear mechanism relative to the generator gear mechanism, so that the generator gear mechanism, the motor gear mechanism, and the pump gear mechanism are attached to the engine transmission shaft and the motor transmission shaft so as to be adjacent to each other. This allows the generator gear mechanism, motor gear mechanism, and pump gear mechanism to be arranged compactly, which is advantageous in that it prevents the case that houses the generator and motor from becoming too large.

[0030] In the present invention, it is preferable that the pump is disposed below the engine transmission shaft and the motor transmission shaft.

[0031] In work vehicles, the coolant reservoir is often located at a low position. According to the present invention, by arranging the pump below the engine transmission shaft and the motor transmission shaft, the pump can be easily arranged close to the coolant storage section, thereby shortening the flow path from the coolant storage section to the pump, which is advantageous in terms of simplifying the structure.

[0032] In the present invention, it is preferable that the engine transmission shaft and the motor transmission shaft are arranged along the fore-and-aft direction, the generator is arranged on one side to the left or right of the engine transmission shaft and the motor transmission shaft, the motor is arranged on the other side to the left or right of the engine transmission shaft and the motor transmission shaft, the generator shaft and the motor shaft are arranged at a lower position than the engine transmission shaft and the motor transmission shaft, and the pump is arranged at a lower position than the generator shaft and the motor shaft.

[0033] According to the present invention, the generator and motor are arranged on one side of the left and right side and the other side of the left and right side with respect to the engine transmission shaft and the motor transmission shaft arranged along the fore-and-aft direction, so that the engine transmission shaft, the motor transmission shaft, the generator and the motor are arranged in line along the left-right direction. This allows the engine transmission shaft, the motor transmission shaft, the generator, and the motor to be arranged compactly, which is advantageous in that it prevents the case housing the generator and the motor from becoming too large.

[0034] According to the present invention, the generator and the motor are arranged on opposite sides of the engine transmission shaft and the motor transmission shaft, so that the first transmission gear of the generator shaft and the third transmission gear of the motor shaft are arranged on opposite sides of the engine transmission shaft and the motor transmission shaft.

[0035] This makes it possible to bring adjacent generator gear mechanisms and motor gear mechanisms close to each other while avoiding interference between the first transmission gear on the generator shaft and the third transmission gear on the motor shaft, which is advantageous in terms of arranging the generator gear mechanism and motor gear mechanism compactly and in terms of preventing the case housing the generator and motor from becoming larger.

[0036] According to the present invention, while maintaining a state in which the generator and the motor are disposed on opposite sides of the engine transmission shaft and the motor transmission shaft, the meshing portion between the first transmission gear and the second transmission gear in the generator gear mechanism can be brought closer to the engine transmission shaft and the motor transmission shaft in the left-right direction, and the meshing portion between the third transmission gear and the fourth transmission gear in the motor gear mechanism can be brought closer to the engine transmission shaft and the motor transmission shaft in the left-right direction.

[0037] This makes it possible to place the generator and motor closer to each other in the left-right direction, thereby reducing the overall width of the engine transmission shaft, motor transmission shaft, generator, and motor, which is advantageous in terms of compactly arranging the engine transmission shaft, motor transmission shaft, generator, and motor, and in terms of preventing the case housing the generator and motor from becoming larger.

[0038] According to the present invention, when the pump is disposed below the engine transmission shaft and the motor transmission shaft, the pump is disposed at a lower position than the generator shaft and the motor shaft, so that the pump is naturally disposed between the generator and the motor in a plan view. This is advantageous in that the engine transmission shaft, motor transmission shaft, generator, motor, and pump can be arranged compactly, and also in that it is advantageous in that it prevents the case that houses the generator and motor from becoming too large.

[0039] In the present invention, it is preferable that the generator gear mechanism, the motor gear mechanism and the pump gear mechanism are arranged in front of the generator and the motor, and the transmission device is arranged in rear of the generator and the motor.

[0040] According to the present invention, the generator gear mechanism, motor gear mechanism, pump gear mechanism, and transmission device are arranged on opposite sides of the generator and motor and are arranged apart from each other, so that they are arranged smoothly with little influence on each other. [Brief description of the drawings]

[0041] [Figure 1] FIG. [Diagram 2] 2 is a schematic view showing the inside of a clutch housing, a gear case, a motor case, and a transmission case. FIG. [Diagram 3] FIG. 2 is a cross-sectional plan view of the clutch housing, the gear case, and the motor case. [Figure 4] FIG. 2 is a vertical sectional left side view of the clutch housing, the gear case, and the motor case. [Diagram 5] FIG. 4 is a left side view of the clutch housing and the motor case. [Figure 6] FIG. 2 is a front view of the clutch housing and the gear case. [Figure 7] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] A hybrid tractor, which is an example of a work vehicle, is shown in Figures 1 to 7. In Figures 1 to 7, F indicates the forward direction, B indicates the backward direction, U indicates the upward direction, D indicates the downward direction, R indicates the rightward direction, and L indicates the leftward direction.

[0043] (Overall configuration of the tractor) As shown in FIG. 1, a vehicle body 3 is supported by right and left front wheels 1 (corresponding to running gear) and right and left rear wheels 2 (corresponding to running gear). A bonnet 6 is provided at the front of the vehicle body 3, and a driver's section 9 is provided at the rear of the vehicle body 3.

[0044] As shown in Figures 1 and 2, the aircraft body 3 has an engine 5, a clutch housing 11 connected to the rear of the engine 5, a motor case 12 connected to the rear of the clutch housing 11, a transmission case 13 connected to the rear of the motor case 12, a front frame 4 connected to the front of the engine 5, etc.

[0045] The front wheels 1 are supported by a front frame 4, and the rear wheels 2 are supported at the rear of a transmission case 13. An engine 5 is covered by a bonnet 6. A driver's section 9 is covered by a cabin 10, and is provided with a driver's seat 7 and a steering wheel 8 for steering the front wheels 1.

[0046] (Configuration of transmission system to front and rear wheels) As shown in FIG. 2, a first motor generator 21 (corresponding to a generator) and a second motor generator 22 (corresponding to a motor) are accommodated inside the motor case 12.

[0047] A first planetary device 23 (corresponding to a transmission device), a second planetary device 24 (corresponding to a transmission device), a first clutch 25, a second clutch 26, a forward / reverse switching device 27, an auxiliary transmission device 28, a rear wheel differential device 29, a front wheel transmission device 30, etc. are housed inside the transmission case 13.

[0048] Power is generated mainly in the first motor generator 21 by the power of the engine 5, and power is mainly outputted from the second motor generator 22. The power of the engine 5 and the power of the second motor generator 22 are transmitted to the first planetary device 23 and the second planetary device 24, and are combined in each of the first planetary device 23 and the second planetary device 24. The first planetary device 23 outputs a low-speed combined power, and the second planetary device 24 outputs a high-speed combined power.

[0049] When the first clutch 25 is operated to a transmission state, the low-speed combined power of the first planetary device 23 is transmitted to the forward / reverse switching device 27 via the first clutch 25. When the second clutch 26 is operated to a transmission state, the high-speed combined power of the second planetary device 24 is transmitted to the forward / reverse switching device 27 via the second clutch 26.

[0050] The combined low-speed and high-speed power is operated to a forward state and a reverse state in the forward / reverse switching device 27. The power of the forward / reverse switching device 27 is transmitted to the auxiliary transmission 28, and then transmitted from the auxiliary transmission 28 to the rear wheels 2 via the rear wheel differential device 29. The power branched between the auxiliary transmission 28 and the rear wheel differential device 29 is transmitted to the front wheel transmission 30, and then transmitted from the front wheel transmission 30 to the front wheels 1 via the front wheel differential device 20.

[0051] (Configuration of clutch housing and motor case) As shown in FIGS. 2, 3, and 4, the clutch housing 11 and the motor case 12 are integrally formed, and the rear part of the clutch housing 11 and the front part of the motor case 12 are connected to each other.

[0052] A wall 14 of the motor case 12 separates the interior of the clutch housing 11 from the interior of the motor case 12. An open portion at the front of the clutch housing 11 is closed by being connected to the engine 5. A wall 15 is connected to the rear of the motor case 12, and the wall 15 separates the interior of the motor case 12 from the interior of the transmission case 13.

[0053] A dry clutch 16 and a gear case 17 are housed inside the clutch housing 11, and the clutch 16 is connected to the output shaft 5a of the engine 5. A transmission shaft 18 (corresponding to an engine transmission shaft) is connected to the clutch 16 and provided along the front-rear direction, and extends from inside the clutch housing 11, through inside the gear case 17 and inside the motor case 12, and into the inside of the transmission case 13. The power of the engine 5 is transmitted via the clutch 16 and the transmission shaft 18 to a first planetary device 23 and a second planetary device 24 as described below.

[0054] A gear case 17 is attached to the wall 14 of the motor case 12 at the opposite side of the interior of the motor case 12. The interior of the gear case 17 is separated from the area inside the clutch housing 11 where the clutch 16 is present, and is separated from the interior of the motor case 12 by the wall 14 of the motor case 12.

[0055] (Internal structure of gear case and motor case) As shown in Figures 2, 3, and 4, a cylindrical transmission shaft 19 (corresponding to the motor transmission shaft) is arranged along the fore-and-aft direction and is rotatably supported relative to the transmission shaft 18, and extends through the inside of the gear case 17 and the inside of the motor case 12 into the inside of the transmission case 13.

[0056] Inside the motor case 12, a first motor generator 21 and a second motor generator 22 are arranged side by side in the left-right direction and supported by a wall portion 14 of the motor case 12. Transmission shafts 18, 19 are provided between the first motor generator 21 and the second motor generator 22, with the first motor generator 21 provided on the right side of the transmission shafts 18, 19 and the second motor generator 22 provided on the left side of the transmission shafts 18, 19.

[0057] The first motor generator 21 and the second motor generator 22 are provided so that the shaft portion 21a of the first motor generator 21 and the shaft portion 22a of the second motor generator 22 are aligned in the front-rear direction and are positioned lower than the transmission shafts 18, 19 (see FIGS. 5 and 7). The shaft portion 21a of the first motor generator 21 and the shaft portion 22a of the second motor generator 22 extend forward and enter the inside of the gear case 17.

[0058] (Configuration of generator gear mechanism) 2, 3 and 4, inside the gear case 17, a transmission gear 31 (corresponding to a generator gear mechanism) (corresponding to a second transmission gear) is connected to a portion of the transmission shaft 18 adjacent to the front side of the front end of the transmission shaft 19. A transmission gear 21b (corresponding to a generator gear mechanism) (corresponding to a first transmission gear) is connected to a shaft portion 21a of the first motor generator 21.

[0059] The transmission gear 31 and the transmission gear 21b of the first motor generator 21 are in mesh with each other, and the transmission gear 31 is configured to have a larger diameter than the transmission gear 21b of the first motor generator 21. The power of the engine 5 is accelerated from the transmission shaft 18 via the transmission gear 31 and the transmission gear 21b of the first motor generator 21, and is transmitted to the first motor generator 21, causing the first motor generator 21 to generate electricity.

[0060] (Motor gear mechanism configuration) 2, 3, and 4, inside the gear case 17, a transmission gear 32 (corresponding to the motor gear mechanism) (corresponding to the fourth transmission gear) is connected to the front end of the transmission shaft 19. A transmission gear 22b (corresponding to the motor gear mechanism) (corresponding to the third transmission gear) is connected to a shaft portion 22a of the second motor generator 22.

[0061] The transmission gear 32 and the transmission gear 22b of the second motor generator 22 are in mesh with each other, and the transmission gear 32 is configured to have a larger diameter than the transmission gear 22b of the second motor generator 22. The power of the second motor generator 22 is reduced in speed via the transmission gear 22b of the second motor generator 22 and the transmission gear 32, and is transmitted to the transmission shaft 19 and then to the first planetary device 23 and the second planetary device 24 as described below.

[0062] (Correspondence to claims regarding generator gear mechanism and motor gear mechanism) With the above configuration, the vehicle is equipped with a traveling device (front wheels 1 and rear wheels 2), an engine 5, a generator (first motor generator 21), a motor (second motor generator 22), and a battery 73 (see FIG. 2). A generator gear mechanism (transmission gears 21b, 31) is provided which accelerates the power of the engine 5 and transmits it to a generator (first motor generator 21). A motor gear mechanism (transmission gears 22b, 32) is provided to reduce the power of the motor (second motor generator 22) and transmit it. The vehicle is provided with a transmission device (first planetary device 23 and second planetary device 24) that combines the power of the engine 5 and the power of the motor (second motor generator 22) reduced by a motor gear mechanism (transmission gears 22b, 32) and transmits the combined power to the running device (front wheels 1 and rear wheels 2).

[0063] The generator (first motor generator 21) and the motor (second motor generator 22) are motor generators (first motor generator 21 and second motor generator 22).

[0064] The vehicle is provided with an engine transmission shaft (transmission shaft 18) that transmits the power of the engine 5, and a cylindrical motor transmission shaft (transmission shaft 19) that is attached to the outer periphery of the engine transmission shaft (transmission shaft 18) and is rotatable relative to the engine transmission shaft (transmission shaft 18). The motor gear mechanism (transmission gears 22b, 32) is attached to an end of the motor transmission shaft (transmission shaft 19). The generator gear mechanism (transmission gears 21b, 31) is attached to a portion of the engine transmission shaft (transmission shaft 18) adjacent to the end of the motor transmission shaft (transmission shaft 19).

[0065] The power of the engine 5 is transmitted to the generator (first motor generator 21) via a generator gear mechanism (transmission gears 21b, 31), and is also transmitted to the transmission device (first planetary device 23 and second planetary device 24) via an engine transmission shaft (transmission shaft 18). The power of the motor (second motor generator 22) is transmitted to the transmission device (first planetary device 23 and second planetary device 24) via the motor gear mechanism (transmission gears 22b, 32) and the motor transmission shaft (transmission shaft 19).

[0066] The generator gear mechanism (transmission gears 21b, 31) has a first transmission gear (transmission gear 21b) that is arranged on the same axis as the shaft portion 21a of the generator (first motor generator 21) and that interlocks with the shaft portion 21a of the generator (first motor generator 21), and a second transmission gear (transmission gear 31) that is attached to the engine transmission shaft (transmission shaft 18), meshes with the first transmission gear (transmission gear 21b), and has a larger diameter than the first transmission gear (transmission gear 21b).

[0067] The motor gear mechanism (transmission gears 22b, 32) has a third transmission gear (transmission gear 22b) that is arranged on the same axis as the shaft portion 22a of the motor (second motor generator 22) and that interlocks with the shaft portion 22a of the motor (second motor generator 22), and a fourth transmission gear (transmission gear 32) that is attached to the motor transmission shaft (transmission shaft 19), engages with the third transmission gear (transmission gear 22b), and has a larger diameter than the third transmission gear (transmission gear 22b).

[0068] (Correspondence to claims regarding the first motor generator and the second motor generator) With the above-mentioned configuration, the engine transmission shaft (transmission shaft 18) and the motor transmission shaft (transmission shaft 19) are arranged along the front-rear direction.

[0069] A generator (first motor generator 21) is arranged on the left or right side of the engine transmission shaft (transmission shaft 18) and the motor transmission shaft (transmission shaft 19), and a motor (second motor generator 22) is arranged on the other left or right side of the engine transmission shaft (transmission shaft 18) and the motor transmission shaft (transmission shaft 19).

[0070] A shaft portion 21a of the generator (first motor generator 21) and a shaft portion 22a of the motor (second motor generator 22) are disposed at a lower position than the engine transmission shaft (transmission shaft 18) and the motor transmission shaft (transmission shaft 19).

[0071] (Configuration of the first motor generator and the second motor generator) As shown in FIG. 2, a first inverter 71 is provided for the first motor generator 21, a second inverter 72 is provided for the second motor generator 22, and a battery 73 is provided.

[0072] When the first motor generator 21 (second motor generator 22) operates as a motor to provide power to the transmission shaft 18 (transmission shaft 19), the DC power of the battery 73 is converted to AC power by the first inverter 71 (second inverter 72) and supplied to the first motor generator 21 (second motor generator 22), causing the first motor generator 21 (second motor generator 22) to operate as a motor (drive mode).

[0073] When the first motor generator 21 (second motor generator 22) is driven to operate as a generator, AC power generated by the first motor generator 21 (second motor generator 22) is converted to DC power by the first inverter 71 (second inverter 72) and charged into the battery 73 (regeneration mode). Note that a capacitor (not shown) may be used as the battery 73.

[0074] A control device (not shown) sets the regeneration mode and drive mode of the first motor generator 21 and the regeneration mode and drive mode of the second motor generator 22 based on the state of the working device (not shown) attached to the machine body 3 and the running state of the machine body 3, etc.

[0075] The basic running state is when the first motor generator 21 is set to the regenerative mode and the second motor generator 22 is set to the drive mode. In a basic running state, the power of the engine 5 is transmitted to the first planetary device 23 and the second planetary device 24, as described below, and the power of the second motor generator 22 is transmitted to the first planetary device 23 and the second planetary device 24.

[0076] By operating the clutch 16 into the disengaged state, it is also possible to stop the engine 5 and run the vehicle in the drive mode of the first motor generator 21 and the drive mode of the second motor generator 22.

[0077] (Configuration regarding gear ratio of generator gear mechanism and gear ratio of motor gear mechanism) As shown in Figures 2 and 3, the gear ratio between the transmission gear 21b of the first motor generator 21 and the transmission gear 31, and the gear ratio between the transmission gear 22b of the second motor generator 22 and the transmission gear 32 are set so that the reduction in speed from the transmission gear 22b of the second motor generator 22 to the transmission gear 32 is smaller than the reduction in speed from the transmission gear 21b of the first motor generator 21 to the transmission gear 31.

[0078] As a result, in the drive mode of the first motor generator 21 and the drive mode of the second motor generator 22, the transmission shaft 19 is rotated at a speed slightly faster than that of the transmission shaft 18. Similarly, in the regeneration mode of the first motor generator 21 (a state in which the power of the engine 5 is transmitted to the transmission shaft 18) and the drive mode of the second motor generator 22, a state in which the transmission shaft 19 is rotated and driven slightly faster than the transmission shaft 18 is obtained.

[0079] (Correspondence of the gear ratio of the generator gear mechanism and the gear ratio of the motor gear mechanism to the claims) With the above configuration, the gear ratio between the third transmission gear (transmission gear 22b) and the fourth transmission gear (transmission gear 32), and the gear ratio between the first transmission gear (transmission gear 21b) and the second transmission gear (transmission gear 31) are set so that the reduction in speed from the third transmission gear (transmission gear 22b) to the fourth transmission gear (transmission gear 32) is smaller than the reduction in speed from the first transmission gear (transmission gear 21b) to the second transmission gear (transmission gear 31).

[0080] (Configuration of the first planetary device) As shown in FIG. 2, the first planetary device 23 includes a sun gear 23a, a plurality of planetary gears 23b, a carrier 23c, a ring gear 23d, and transmission gears 23e and 23f.

[0081] In the first planetary device 23, the transmission gear 23e is connected to the ring gear 23d, and the transmission gear 23f is connected to the sun gear 23a. The planetary gear 23b is rotatably supported by the carrier 23c, the sun gear 23a and the planetary gear 23b mesh, and the ring gear 23d and the planetary gear 23b mesh.

[0082] Inside the transmission case 13, a transmission gear 48 is connected to the transmission shaft 18, and a transmission gear 23e of the first planetary device 23 meshes with the transmission gear 48. Inside the transmission case 13, a transmission gear 49 is connected to the transmission shaft 19, and a transmission gear 23f of the first planetary device 23 meshes with the transmission gear 49.

[0083] The power of the engine 5 (or the power of the first motor generator 21) is transmitted to the ring gear 23d of the first planetary device 23 via the transmission shaft 18 and the transmission gear 48. The power of the second motor generator 22 is transmitted to the sun gear 23a of the first planetary device 23 via the transmission gear 32, the transmission shaft 19, and the transmission gear 49.

[0084] In the first planetary gear 23, the power of the engine 5 (or the power of the first motor generator 21) and the power of the second motor generator 22 are combined and changed in speed, and then output as a low-speed combined power from the carrier 23c of the first planetary gear 23 to the first clutch 25.

[0085] (Configuration of the second planetary device) As shown in FIG. 2, the second planetary device 24 includes a sun gear 24a, a plurality of planetary gears 24b, a carrier 24c, a ring gear 24d, and transmission gears 24e and 24f.

[0086] In the second planetary device 24, the transmission gear 24e is connected to the carrier 24c, and the transmission gear 24f is connected to the sun gear 24a. The planetary gear 24b is rotatably supported by the carrier 24c, and the sun gear 24a and the planetary gear 24b mesh with each other, and the ring gear 24d and the planetary gear 24b mesh with each other. Inside the transmission case 13, the transmission gear 24e of the second planetary device 24 meshes with the transmission gear 48, and the transmission gear 24f of the second planetary device 24 meshes with the transmission gear 49.

[0087] The power of the engine 5 (or the power of the first motor generator 21) is transmitted to the carrier 24c of the second planetary device 24 via the transmission shaft 18 and the transmission gear 48. The power of the second motor generator 22 is transmitted to the sun gear 24a of the second planetary device 24 via the transmission gear 32, the transmission shaft 19, and the transmission gear 49.

[0088] In the second planetary device 24, the power of the engine 5 (or the power of the first motor generator 21) and the power of the second motor generator 22 are combined and shifted, and the high-speed combined power is output from the ring gear 24d of the second planetary device 24 to the second clutch 26.

[0089] (Configuration of the transmission system to the PTO shaft) As shown in Fig. 2, inside the transmission case 13, a transmission shaft 45 is coupled to the transmission shaft 18, and a PTO clutch 46 is connected to the transmission shaft 45. A PTO speed change device 47 is provided, and a PTO shaft 44 is provided at the rear of the transmission case 13 (see Fig. 1).

[0090] The power of the engine 5 is transmitted to the PTO transmission 47 via the clutch 16, the transmission shafts 18 and 45, and the PTO clutch 46, and then transmitted from the PTO transmission 47 to the PTO shaft 44. When a working device (not shown) is coupled to the rear of the machine body 3, a transmission shaft (not shown) is connected between the PTO shaft 44 and the working device, and the power of the PTO shaft 44 is transmitted to the working device.

[0091] (Configuration of forward / reverse switching device) As shown in FIG. 2, the forward / reverse switching device 27 includes a cylindrical shaft 50, a forward clutch 51, a reverse clutch 52, a transmission shaft 53, an intermediate gear 54, and the like.

[0092] The cylindrical shaft 50 is rotatably supported on the transmission shaft 45, and the transmission gear 55 is connected to the cylindrical shaft 50. The transmission gear 55 meshes with the transmission gear 25a of the first clutch 25, and the transmission gear 55 meshes with the transmission gear 26a of the second clutch 26.

[0093] A forward clutch 51 and a reverse clutch 52 are attached to a cylindrical shaft 50. Transmission gears 53a and 53b are connected to a transmission shaft 53, and an output gear of the forward clutch 51 meshes with the transmission gear 53a of the transmission shaft 53. An output gear of the reverse clutch 52 meshes with an intermediate gear 54, and the intermediate gear 54 meshes with the transmission gear 53b of the transmission shaft 53.

[0094] When the first clutch 25 is operated to a transmission state, the low-speed combined power of the first planetary device 23 is transmitted to the cylindrical shaft 50 via the first clutch 25. When the second clutch 26 is operated to a transmission state, the high-speed combined power of the second planetary device 24 is transmitted to the cylindrical shaft 50 via the second clutch 26.

[0095] In the forward / reverse switching device 27, when the forward clutch 51 is operated to the transmission state, the power of the cylindrical shaft 50 is transmitted to the transmission shaft 53 in the forward state via the forward clutch 51. When the reverse clutch 52 is operated to the transmission state, the power of the cylindrical shaft 50 is transmitted to the transmission shaft 53 in the reverse state via the reverse clutch 52 and the relay gear 54.

[0096] (Configuration of the auxiliary transmission) As shown in FIG. 2, the sub-transmission device 28 includes a high-speed gear 56, a low-speed gear 57, a transmission shaft 58, a rear wheel output shaft 59, a shift member 60, and the like.

[0097] The high-speed gear 56 is connected to the transmission shaft 53, and a transmission gear 58a of the transmission shaft 58 meshes with the high-speed gear 56. A rear-wheel output shaft 59 is supported concentrically with the transmission shaft 53, and a shift member 60 is provided on the rear-wheel output shaft 59 so as to be slidable. The low-speed gear 57 is rotatably supported on the rear-wheel output shaft 59, and a transmission gear 58b of the transmission shaft 58 meshes with the low-speed gear 57.

[0098] When the shift member 60 is engaged with the high-speed gear 56, the transmission shaft 53 and the rear wheel output shaft 59 are connected, and the power of the transmission shaft 53 is transmitted to the rear wheel output shaft 59 at high speed, and then from the rear wheel output shaft 59 to the rear wheels 2 via the rear wheel differential device 29.

[0099] When the shift member 60 is engaged with the low-speed gear 57, the power of the transmission shaft 53 is transmitted at low speed via the high-speed gear 56, the transmission shaft 58 and the low-speed gear 57 to the rear wheel output shaft 59, and then from the rear wheel output shaft 59 to the rear wheels 2 via the rear wheel differential device 29.

[0100] (Front wheel transmission configuration) As shown in FIG. 2, the front wheel transmission 30 includes a standard clutch 61, a speed increasing clutch 62, a transmission shaft 63, a front wheel output shaft 64, and the like.

[0101] A standard clutch 61 and an accelerating clutch 62 are attached to a transmission shaft 63, and the power of the rear wheel output shaft 59 is transmitted to the transmission shaft 63. The output gear of the standard clutch 61 meshes with a transmission gear 64a of the front wheel output shaft 64, and the output gear of the accelerating clutch 62 meshes with a transmission gear 64b of the front wheel output shaft 64.

[0102] When the front wheel 1 is operated within a range of a set angle to the right or left from a straight ahead position, the standard clutch 61 in the front wheel transmission 30 is operated to a transmission state. The power of the rear wheel output shaft 59 is transmitted to the front wheel output shaft 64 via the transmission shaft 63 and the standard clutch 61, and then transmitted to the front wheels 1 via the transmission shaft 65 and the front wheel differential device 20, so that the front wheels 1 and rear wheels 2 are driven at the same speed.

[0103] When the front wheels 1 are steered to the right or left beyond the right and left set angles, the speed increasing clutch 62 in the front wheel transmission 30 is operated to a transmission state. The power of the rear wheel output shaft 59 is transmitted to the front wheel output shaft 64 via the transmission shaft 63 and the speed-increasing clutch 62, and then transmitted to the front wheels 1 via the transmission shaft 65 and the front wheel differential device 20, so that the front wheels 1 are driven at a higher speed than the rear wheels 2.

[0104] (Configuration of the First Inverter and the Second Inverter) 1 , right and left steps 68 for getting on and off are provided on the right and left parts of a floor 67 of the driver's section 9. Right and left support members 69 are connected to the right and left parts of the front part of the transmission case 13, and a first inverter 71 is attached to the right support member 69, and a second inverter 72 is attached to the left support member 69.

[0105] The first inverter 71 is provided between the transmission case 13 and the right step 68 in a plan view, and is provided below the right part of the floor 67. The second inverter 72 is provided between the transmission case 13 and the left step 68 in a plan view, and is provided below the left part of the floor 67.

[0106] As shown in FIGS. 3 and 5, a first relay terminal 75 is provided on the outer periphery of the motor case 12 at a portion laterally outside to the right of the first motor-generator 21. A second relay terminal 76 is provided on the outer periphery of the motor case 12 at a portion laterally outside the second motor-generator 22 to the left.

[0107] 2 and 7, outside the motor case 12, a harness 77 is connected between the first inverter 71 and the first relay terminal 75. Inside the motor case 12, a flat power line 70 is connected between a terminal provided at the right end portion 21c of the first motor generator 21 and the first relay terminal 75. In this way, the first motor generator 21 and the first inverter 71 are connected via the harness 77, the first relay terminal 75, and the power line 70.

[0108] Outside the motor case 12, a harness 77 is connected between the second inverter 72 and the second relay terminal 76. Inside the motor case 12, a flat-plate-shaped power line 70 is connected between a terminal provided at the left end portion 22c of the second motor generator 22 and the second relay terminal 76. In this way, the second motor generator 22 and the second inverter 72 are connected via the harness 77, the second relay terminal 76, and the power line 70.

[0109] As shown in Figures 3 and 7, the shaft portion 21a of the first motor generator 21 is aligned in the front-to-rear direction, and the shaft portion 22a of the second motor generator 22 is aligned in the front-to-rear direction, so that the radial direction of the shaft portion 21a of the first motor generator 21 is the left-to-right and up-to-down direction, and the radial direction of the shaft portion 22a of the second motor generator 22 is the left-to-right and up-to-down direction.

[0110] When viewed from the left-right direction, the first motor generator 21, the first relay terminal 75, the first inverter 71, and the right power line 70 overlap. When viewed from the left-right direction, the second motor generator 22, the second relay terminal 76, the second inverter 72, and the left power line 70 overlap.

[0111] (Configuration of oil pump for cooling first motor generator and second motor generator) As shown in Figures 4 and 7, the lower part of the interior of the motor case 12 is formed in a recessed shape when viewed from the front (rear), forming a storage section 33, and lubricating oil A (corresponding to a coolant) having a relatively low viscosity is stored in the storage section 33.

[0112] 2 and 4, the oil pump 34 (corresponding to a pump) is provided in the lower front part inside the gear case 17 so as to be located below the transmission shafts 18, 19, and the oil pump 34 is supported by the wall part 14 of the motor case 12 via the gear case 17. Inside the gear case 17, a drive shaft 34a of the oil pump 34 is provided along the front-rear direction, and a transmission gear 34b (corresponding to a pump gear mechanism) is connected to the drive shaft 34a of the oil pump 34.

[0113] The oil pump 34 is provided at a position lower than the shaft portion 21a of the first motor generator 21 and the shaft portion 22a of the second motor generator 22. The oil pump 34 is provided between the shaft portion 21a of the first motor generator 21 and the shaft portion 22a of the second motor generator 22 in a plan view.

[0114] Inside the gear case 17, a transmission gear 35 (corresponding to a pump gear mechanism) is connected to a portion of the transmission shaft 18 in front of the transmission gear 31, and the transmission gear 35 meshes with a transmission gear 34b of the oil pump 34. The power of the engine 5 is transmitted to the oil pump 34 via the transmission shaft 18 and the transmission gear 35, thereby driving the oil pump 34.

[0115] As shown in Figures 5, 6 and 7, a filter 36 is provided on the left side of the lower part of the motor case 12. As shown in Figure 6, oil passages 37, 38 and 39 are formed in the wall portion 14 of the motor case 12. The oil passage 37 extends from the filter 36 toward the left-right center of the motor case 12, the oil passage 38 extends upward from the end portion of the oil passage 37, and the oil passage 39 extends from the upper end portion of the oil passage 38 toward the left-right center of the motor case 12.

[0116] Oil passages 40, 41, 43 are formed in the gear case 17, and an oil cooler 42 is provided outside the clutch housing 11 and the motor case 12. The oil passage 40 is connected to the oil passage 39 in the wall portion 14 of the motor case 12, and is connected to the oil pump 34. The oil passage 41 extends from the oil pump 34, and an oil passage 78 connects the oil passage 41 to the oil cooler 42. The oil passage 79 is connected from the oil cooler 42 to the oil passage 43, and the oil passage 43 extends along the left-right direction.

[0117] When the oil pump 34 is driven, the lubricating oil A in the reservoir 33 is supplied to the oil pump 34 from the filter 36 through the oil passages 37, 38, 39, and 40. The lubricating oil A discharged from the oil pump 34 is supplied to the oil passage 43 through the oil passages 41 and 78, the oil cooler 42, and the oil passage 79.

[0118] The lubricating oil A supplied to the oil passage 43 is supplied to the inside of the casing of the first motor generator 21 (corresponding to the object to be cooled) through an oil passage (not shown) formed in the shaft portion 21a of the first motor generator 21, and is supplied to the inside of the casing of the second motor generator 22 (corresponding to the object to be cooled) through an oil passage (not shown) formed in the shaft portion 22a of the second motor generator 22.

[0119] The supplied lubricating oil A cools the first motor generator 21 and the second motor generator 22 , and the lubricating oil A returns to the reservoir 33 from the first motor generator 21 and the second motor generator 22 .

[0120] The lubricating oil A supplied to the oil passage 43 is supplied to the inside of the gear case 17 through an oil passage (not shown) formed in the transmission shaft 18. The supplied lubricating oil A lubricates and cools the shaft portion 21a and the transmission gear 21b of the first motor generator 21, the shaft portion 22a and the transmission gear 22b of the second motor generator 22, the drive shaft 34a and the transmission gear 34b of the oil pump 34, the transmission gears 31, 32, 35, etc., and then returns from the gear case 17 to the reservoir 33.

[0121] (Correspondence to claims regarding oil pumps) With the above configuration, a pump (oil pump 34) is provided that supplies the cooling liquid (lubricating oil A) to the objects to be cooled (first motor generator 21 and second motor generator 22).

[0122] A pump gear mechanism (transmission gears 34b, 35) is provided to transmit the power of the engine transmission shaft (transmission shaft 18) to the pump (oil pump 34). The pump gear mechanism (transmission gears 34b, 35) is attached to a portion of the engine transmission shaft (transmission shaft 18) adjacent to the generator gear mechanism (transmission gears 21b, 31) on the opposite side of the motor gear mechanism (transmission gears 22b, 32).

[0123] A pump (oil pump 34) is disposed below the engine transmission shaft (transmission shaft 18) and the motor transmission shaft (transmission shaft 19). The pump (oil pump 34) is disposed at a position lower than the shaft portion 21a of the generator (first motor generator 21) and the shaft portion 22a of the motor (second motor generator 22).

[0124] The generator gear mechanism (transmission gears 21b, 31), the motor gear mechanism (transmission gears 22b, 32), and the pump gear mechanism (transmission gears 34b, 35) are disposed forward of the generator (first motor generator 21) and the motor (second motor generator 22). The transmission (first planetary device 23 and second planetary device 24) is disposed rearward of the generator (first motor generator 21) and the motor (second motor generator 22).

[0125] (Configuration of storage section) 7, the storage portion 33 is formed in the lower part inside the motor case 12, and the left-right center of the storage portion 33 is located in the left-right center of the motor case 12. A gap W1 between the right end 33a and the left end 33b of the storage portion 33 and a gap W2 between the right end 21c of the first motor generator 21 and the left end 22c of the second motor generator 22 are narrower than the gap W2.

[0126] As a result, the right end 33a of the storage portion 33 is provided closer to the left-right center of the motor case 12 than the right end 21c of the first motor generator 21. The left end 33b of the storage portion 33 is provided closer to the left-right center of the motor case 12 than the left end 22c of the second motor generator 22.

[0127] A region B1 between the first relay terminal 75 and the right end 33a of the storage portion 33 extends laterally outwardly and obliquely upward from the right end 33a of the storage portion 33 when viewed from the front-rear direction (rear view). A region B2 between the second relay terminal 76 and the left end 33b of the storage portion 33 extends laterally outwardly and obliquely upward from the left end 33b of the storage portion 33 when viewed from the front-rear direction (rear view).

[0128] (Configuration regarding front wheel output shaft) 2, 4, 6, and 7, inside the motor case 12, a cylindrical partition 66 is connected across the wall 14 and the wall 15 of the motor case 12. The partition 66 penetrates the lower part of the left-right center of the storage part 33 (below the transmission shafts 18, 19), and a gap is formed between the partition 66 and the bottom of the motor case 12 (the bottom of the storage part 33).

[0129] Partition 66 is submerged in lubricating oil A in reservoir 33 and is located below the liquid level A1 of lubricating oil A. Lubricating oil A in the right region and lubricating oil A in the left region of reservoir 33 can move between each other through the region above partition 66 and the region below partition 66 (the gap between partition 66 and the bottom of motor case 12 (the bottom of reservoir 33)).

[0130] The area inside the partition 66 is separated from the inside of the motor case 12. A front wheel output shaft 64 from the front wheel transmission 30 passes through the area inside the partition 66 and protrudes forward from the motor case 12, and a transmission shaft 65 is connected to the front end of the front wheel output shaft 64 (see FIG. 2).

[0131] Lubricating oil is also stored in the transmission case 13. The first planetary device 23, the second planetary device 24, the first clutch 25, the second clutch 26, the forward / reverse switching device 27, the auxiliary transmission 28, the rear wheel differential device 29, the front wheel transmission 30, the PTO clutch 46, and the PTO transmission 47 are lubricated by the lubricating oil in the transmission case 13.

[0132] As described above, the lubricating oil A having a relatively low viscosity is stored in the reservoir 33 of the motor case 12, and the lubricating oil A of the motor case 12 and the lubricating oil of the transmission case 13 are set to be different from each other.

[0133] As shown in Figures 2 and 4, wall portion 15 of motor case 12 separates the interior of motor case 12 from the interior of transmission case 13, and the area inside partition portion 66 is separated from the interior of motor case 12, so that lubricating oil A in storage portion 33 (motor case 12) and lubricating oil in the transmission case 13 do not mix with each other.

[0134] (Configuration for preventing lubricating oil from splashing from the reservoir to the power lines) As shown in Figure 7, right and left protrusions 74 are integrally formed on the upper end of the right end 33a and the upper end of the left end 33b of the storage section 33 on the inner surface of the outer periphery of the motor case 12 so as to protrude toward the left-right center of the storage section 33.

[0135] In this case, the amount of lubricating oil A stored in storage portion 33 is set so that liquid level A1 of lubricating oil A stored in storage portion 33 is lower than convex portion 74. Convex portion 74 may not be provided integrally with the inner surface of the outer periphery of motor case 12, but may be a separate body from motor case 12 that is attached to the inner surface of the outer periphery of motor case 12.

[0136] A plurality of mounting portions 21d, 21e are formed on the outer periphery of the first motor generator 21. The mounting portions 21d, 21e are formed so as to protrude outward from the outer periphery of the first motor generator 21 along the radial direction of the shaft portion 21a of the first motor generator 21, and are formed in a direction along the shaft portion 21a of the first motor generator 21.

[0137] A plurality of mounting portions 22d, 22e are formed on the outer periphery of the second motor generator 22. The mounting portions 22d, 22e are formed so as to protrude outward from the outer periphery of the second motor generator 22 along the radial direction of the shaft portion 22a of the second motor generator 22, and are formed in a direction along the shaft portion 22a of the second motor generator 22.

[0138] Bosses (not shown) are formed on the inner surface of the wall 14 of the motor case 12, and mounting portions 21d, 21e of the first motor generator 21 are bolted to the bosses of the motor case 12, thereby connecting the first motor generator 21 to the wall 14 of the motor case 12. Mounting portions 22d, 22e of the second motor generator 22 are bolted to the bosses of the motor case 12, thereby connecting the second motor generator 22 to the wall 14 of the motor case 12.

[0139] One of the mounting portions 21d, 21e of the first motor generator 21 is located above the right protrusion 74 when viewed from the front-to-rear direction, and extends from above into the area B1 between the first relay terminal 75 and the right end portion 33a of the storage portion 33.

[0140] One of the mounting portions 22d, 22e of the second motor generator 22 is located above the left protrusion 74 when viewed from the front-to-rear direction, and extends from above into the area B2 between the second relay terminal 76 and the left end portion 33b of the storage portion 33.

[0141] As a result, if lubricating oil A splashes out of the storage section 33 toward the power line 70, the lubricating oil A will hit the lower part of the first motor generator 21 and the lower part of the second motor generator 22, the right and left protrusions 74, and the mounting part 21d of the first motor generator 21 and the mounting part 22d of the second motor generator 22, thereby preventing the lubricating oil A from adhering to the power line 70.

[0142] Since lubricating oil A from the oil pump 34 is supplied to the inside of the casing of the first motor generator 21 and the inside of the casing of the second motor generator 22, the lubricating oil A from the oil pump 34 does not adhere to the power line 70 when it is supplied to the first motor generator 21 and the second motor generator 22.

[0143] (First Alternative Embodiment of the Invention) The first motor-generator 21 may be provided on the left side of the transmission shafts 18 and 19, and the second motor-generator 22 may be provided on the right side of the transmission shafts 18 and 19. The first motor generator 21 and the second motor generator 22 may be disposed so that the shaft portion 21 a of the first motor generator 21 and the shaft portion 22 a of the second motor generator 22 are positioned at the same height as the transmission shafts 18 , 19 .

[0144] (Second Alternative Embodiment of the Invention) The first motor generator 21 and the second motor generator 22 may be provided such that the shaft portion 21a of the first motor generator 21 faces in the left-right direction, and the shaft portion 22a of the second motor generator 22 faces in the left-right direction.

[0145] (Third Alternative Embodiment of the Invention) In Figures 2 and 3, the gear ratio between the transmission gear 21b of the first motor generator 21 and the transmission gear 31, and the gear ratio between the transmission gear 22b of the second motor generator 22 and the transmission gear 32 may be set to be the same so that the reduction in speed from the transmission gear 22b of the second motor generator 22 to the transmission gear 32 is the same as the reduction in speed from the transmission gear 21b of the first motor generator 21 to the transmission gear 31.

[0146] (Fourth Alternative Embodiment of the Invention) 2 and 3, the gear ratio between the transmission gear 21b of the first motor generator 21 and the transmission gear 31, and the gear ratio between the transmission gear 22b of the second motor generator 22 and the transmission gear 32 may be set so that the reduction in speed from the transmission gear 22b of the second motor generator 22 to the transmission gear 32 is greater than the reduction in speed from the transmission gear 21b of the first motor generator 21 to the transmission gear 31.

[0147] (Fifth Alternative Embodiment of the Invention) An oil pump 34 may be disposed above the transmission shafts 18, 19.

[0148] (Sixth Alternative Embodiment of the Invention) The oil pump 34 may be disposed at the same height as the transmission shafts 18,19. In this case, a portion of the oil pump 34 and a portion of the transmission shafts 18, 19 may be disposed at approximately the same height. The oil pump 34 may be disposed so that a portion of the oil pump 34 overlaps a portion of the transmission shafts 18, 19 when viewed in the longitudinal direction of the transmission shafts 18, 19.

[0149] (Seventh Alternative Embodiment of the Invention) An oil pump 34 may be disposed coaxially with the transmission shafts 18, 19. In this configuration, the oil pump 34 may be directly attached to the transmission shaft 18 or the transmission shaft 19 and driven by the transmission shafts 18,19.

[0150] (Eighth Alternative Embodiment of the Invention) 2, 3 and 4, the generator gear mechanism (transmission gears 21b, 31), the pump gear mechanism (transmission gears 34b, 35), and the motor gear mechanism (transmission gears 22b, 32) may be arranged in this order from the front side. According to this configuration, the pump gear mechanism (transmission gears 34b, 35) is disposed between the generator gear mechanism (transmission gears 21b, 31) and the motor gear mechanism (transmission gears 22b, 32).

[0151] (Ninth Alternative Embodiment of the Invention) 2, 3 and 4, the motor gear mechanism (transmission gears 22b, 32) may be disposed on the rear side, which is the same side as the transmission device (first planetary device 23 and second planetary device 24) relative to the first motor generator 21 and the second motor generator 22. In this configuration, the generator gear mechanism (transmission gears 21b, 31) may be disposed forward of the pump gear mechanism (transmission gears 34b, 35).

[0152] (Tenth Alternative Embodiment of the Invention) Instead of the transmission gear 21b being directly connected to the shaft portion 21a of the first motor generator 21, another transmission shaft (not shown) may be concentrically connected to the shaft portion 21a of the first motor generator 21, and the transmission gear 21b may be connected to this other transmission shaft. The transmission gear 21b is not limited to being attached to the shaft portion 21a of the first motor generator 21; it is sufficient that the transmission gear 21b is arranged on the same axis as the shaft portion 21a of the first motor generator 21 and rotates in conjunction with the shaft portion 21a of the first motor generator 21.

[0153] (Eleventh Alternative Embodiment of the Invention) Instead of the transmission gear 22b being directly connected to the shaft portion 22a of the second motor generator 22, another transmission shaft (not shown) may be concentrically connected to the shaft portion 22a of the second motor generator 22, and the transmission gear 22b may be connected to this other transmission shaft. The transmission gear 22b is not limited to being attached to the shaft portion 22a of the second motor generator 22, but it is sufficient that the transmission gear 22b is arranged on the same axis as the shaft portion 22a of the second motor generator 22 and rotates in conjunction with the shaft portion 22a of the second motor generator 22. [Industrial Applicability]

[0154] The present invention can be applied not only to tractors, but also to work vehicles that carry and transport cargo, work vehicles that tow carts, etc., and construction work vehicles such as wheel loaders, and can also be applied to work vehicles equipped with crawler-type running devices instead of front and rear wheels. [Explanation of symbols]

[0155] 1 Front wheel (running gear) 2 Rear wheels (running gear) 5 Engine 18 Transmission shaft (engine transmission shaft) 19 Transmission shaft (motor transmission shaft) 21 First motor generator (generator) (motor generator) (object to be cooled) 21a Shaft part 21b Transmission gear (generator gear mechanism) (first transmission gear) 22 Second motor generator (motor) (motor generator) (cooling object) 22a Shaft 22b Transmission gear (motor gear mechanism) (third transmission gear) 23 First planetary gear (transmission gear) 24 Second planetary gear (transmission gear) 31 Transmission gear (generator gear mechanism) (second transmission gear) 32 Transmission gear (motor gear mechanism) (4th transmission gear) 34 Oil pump (pump) 34b Transmission gear (pump gear mechanism) 35 Transmission gear (pump gear mechanism) 73 Battery A Lubricating oil (cooling fluid)

Claims

1. A running device, an engine, a generator, a motor, a battery, a generator gear mechanism that accelerates the power of the engine and transmits the power to the generator; a motor gear mechanism that reduces the power of the motor and transmits it; the work vehicle is provided with a transmission device which combines the power of the engine and the power of the motor reduced by the motor gear mechanism and transmits the combined power to the traveling device.

2. 2. The work vehicle according to claim 1, wherein the generator and the motor are a motor generator.

3. an engine transmission shaft that transmits power of the engine; a cylindrical motor transmission shaft attached to an outer periphery of the engine transmission shaft so as to be rotatable relative to the engine transmission shaft, the motor gear mechanism is attached to an end of the motor transmission shaft; the generator gear mechanism is attached to a portion of the engine transmission shaft adjacent to an end of the motor transmission shaft, power of the engine is transmitted to the generator via the generator gear mechanism and to the transmission device via the engine transmission shaft; 2. The work vehicle according to claim 1, wherein the power of the motor is transmitted to the transmission device via the motor gear mechanism and the motor transmission shaft.

4. the generator gear mechanism includes a first transmission gear that is provided coaxially with a shaft portion of the generator and that moves in conjunction with the shaft portion of the generator, and a second transmission gear that is attached to the engine transmission shaft, that meshes with the first transmission gear, and that has a larger diameter than the first transmission gear, The work vehicle described in claim 3, wherein the motor gear mechanism has a third transmission gear that is arranged on the same axis as the motor shaft and that moves in conjunction with the motor shaft, and a fourth transmission gear that is attached to the motor transmission shaft, engages with the third transmission gear, and has a larger diameter than the third transmission gear.

5. 5. A work vehicle as described in claim 4, wherein the gear ratio between the third transmission gear and the fourth transmission gear and the gear ratio between the first transmission gear and the second transmission gear are set so that the reduction in speed from the third transmission gear to the fourth transmission gear is smaller than the reduction in speed from the first transmission gear to the second transmission gear.

6. The engine transmission shaft and the motor transmission shaft are disposed along a front-rear direction, the generator is disposed on one of the left and right sides of the engine transmission shaft and the motor transmission shaft, 6. The work vehicle according to claim 4, wherein the motor is disposed on the other of the left and right sides of the engine transmission shaft and the motor transmission shaft.

7. 7. The work vehicle according to claim 6, wherein a shaft portion of the generator and a shaft portion of the motor are disposed at a lower position than a shaft portion of the engine transmission shaft and a shaft portion of the motor transmission shaft.

8. A pump that supplies a cooling liquid to an object to be cooled; a pump gear mechanism that transmits power of the engine transmission shaft to the pump, 4. The work vehicle according to claim 3, wherein the pump gear mechanism is attached to a portion of the engine transmission shaft adjacent to the opposite side of the generator gear mechanism from the motor gear mechanism.

9. 9. The work vehicle according to claim 8, wherein the pump is disposed below the engine transmission shaft and the motor transmission shaft.

10. The engine transmission shaft and the motor transmission shaft are disposed along a front-rear direction, the generator is disposed on one of the left and right sides of the engine transmission shaft and the motor transmission shaft, the motor is disposed on the other of the left and right sides of the engine transmission shaft and the motor transmission shaft, a shaft portion of the generator and a shaft portion of the motor are disposed at a lower position than the engine transmission shaft and the motor transmission shaft, 10. The work vehicle according to claim 9, wherein the pump is disposed at a lower position than a shaft portion of the generator and a shaft portion of the motor.

11. the generator gear mechanism, the motor gear mechanism, and the pump gear mechanism are disposed forward with respect to the generator and the motor; 9. The work vehicle according to claim 8, wherein the transmission device is disposed rearward relative to the generator and the motor.

Images