Work vehicle

Abstract

To provide a compact pump which supplies cooling liquid to a cooling object in a hybrid type work vehicle equipped with an engine and a motor.SOLUTION: A work vehicle includes a travel device, an engine 5, motors 21, 22 and transmission devices 23, 24 that combine power of the engine 5 with power of the motors 21, 22 to transmit to the travel device. The work vehicle includes a first case 12 which houses the motors 21, 22 and a second case 11 which is provided between the engine 5 and the first case 12. A pump 34 which supplies cooling liquid to cooling objects 21 and 22, is housed in the second case 11.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cooling configuration in a work vehicle.

Background Art

[0002] In a tractor which is an example of a work vehicle, as disclosed in Patent Document 1, an engine and a motor are provided, and the power of the engine and the power of the motor are transmitted to a transmission, and the power of the engine and the power of the motor are combined by the transmission and transmitted from the transmission to a traveling device. There is a hybrid tractor configured as such.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a hybrid work vehicle provided with an engine and a motor as in Patent Document 1, it is necessary to cool cooling targets such as the motor and an inverter that operates the motor. In this case, it is necessary to provide a pump that supplies a coolant to the cooling targets. An object of the present invention is to provide a pump that supplies a coolant to a cooling target in a compact manner in a hybrid work vehicle provided with an engine and a motor.

Means for Solving the Problems

[0005] The work vehicle of the present invention includes a traveling device, an engine, a motor, a transmission that combines the power of the engine and the power of the motor and transmits it to the traveling device, a first case that houses the motor inside, and a second case that is provided across the engine and the first case, and a pump that supplies a coolant to a cooling target is housed inside the second case 、 A gear case is provided which houses a pump gear mechanism for transmitting power to the pump and a motor gear mechanism for transmitting power to the motor, the gear case is housed inside the second case, and the pump is supported by the gear case. It is.

[0006] According to the present invention, when a first case for housing a motor is provided, a second case is provided spanning the engine and the first case, thereby connecting the engine and the motor (first case). According to the present invention, a pump that supplies coolant to the object to be cooled is housed inside the second case, and the pump can be compactly installed by effectively utilizing the inside of the second case.

[0007] According to the present invention, in a configuration in which the power of the engine and the power of the motor are transmitted to a transmission device and combined, the pump and the transmission device are separated, so the pump is less affected by the transmission device, can be easily installed inside the second case, improves the ease of assembling the pump, and can reduce production costs.

[0008]

[0009] According to the present invention, when a pump gear mechanism is provided to transmit power for driving the pump, the pump gear mechanism can be housed inside the second case, allowing the pump gear mechanism to be provided compactly, similar to the case of the pump. According to the present invention, similar to the case of a pump, the pump gear mechanism can be easily installed inside the second case with less influence from the transmission device, improving the ease of assembly of the pump gear mechanism and offering advantages in terms of reducing production costs. According to the present invention, the pump is supported by a gear case, and the pump gear mechanism housed inside the gear case can be easily linked with the pump, thereby improving the ease of assembly of the pump and offering advantages in terms of reducing production costs.

[0010] In the present invention , Mo The transmission shaft extends from the motor gear mechanism through the inside of the first case and exits from the first case to the opposite side of the second case. The engine transmission shaft that transmits power to the engine passes through the inside of the first case from inside the second case and exits from the first case to the opposite side of the second case. It is preferable that the transmission device is provided on the opposite side of the second case from the first case.

[0011] According to the present invention, when a motor gear mechanism for transmitting power from a motor is provided, the motor gear mechanism can be housed inside a second case, allowing it to be provided compactly, similar to the case of a pump. According to the present invention, similar to the case of a pump, the motor gear mechanism can be easily installed inside the second case with less influence from the transmission device, improving the ease of assembly of the motor gear mechanism and offering advantages in terms of reducing production costs.

[0012] According to the present invention, the transmission device is provided on the opposite side of the second case from the first case. A motor transmission shaft that transmits power from the motor passes through the inside of the first case from the motor gear mechanism and exits from the first case on the opposite side of the second case, and the power from the motor is transmitted to the transmission device via the motor gear mechanism and the motor transmission shaft. The engine drive shaft, which transmits power from the engine, passes through the inside of the first case from the inside of the second case and emerges from the first case on the opposite side of the second case, and the engine power is transmitted to the transmission device via the engine drive shaft.

[0013] According to the present invention, the transmission device and the pump (pump gear mechanism and motor gear mechanism) can be installed with a first case in between, spaced sufficiently apart from each other. This improves the ease of assembly of the pump, pump gear mechanism, and motor gear mechanism, which is advantageous in terms of reducing production costs.

[0014] According to the present invention, as described above, even if the transmission device and the pump (pump gear mechanism and motor gear mechanism) are installed sufficiently far apart from each other with the first case in between, the engine power and the motor power can be transmitted to the transmission device without difficulty by the engine transmission shaft and motor transmission shaft that pass through the first case.

[0015] In the present invention, it is preferable that the motor is a motor generator, and a generator gear mechanism that transmits the power of the engine to the motor generator to cause the motor generator to generate electricity is housed inside the second case.

[0016] According to the present invention, when providing a generator gear mechanism that transmits the power of the engine to a motor generator to cause the motor generator to generate electricity, by housing the generator gear mechanism inside the second case, similar to the case of the pump, the generator gear mechanism can be provided in a compact manner. According to the present invention, similar to the case of the pump, it is less affected by the transmission device, the generator gear mechanism can be easily provided inside the second case, the assemblability of the generator gear mechanism can be improved, and it is advantageous in terms of reducing production costs.

[0017] The work vehicle of the present invention comprises a running gear, an engine, a motor, a transmission device that combines the power of the engine and the power of the motor and transmits it to the running gear, a first case that houses the motor, and a second case that extends between the engine and the first case, with a pump that supplies coolant to the object to be cooled housed inside the second case. A pump gear mechanism for transmitting power to the pump is housed inside the second case, a motor gear mechanism for transmitting power to the motor is housed inside the second case, a motor transmission shaft passes through the inside of the first case from the motor gear mechanism and exits from the first case on the opposite side of the second case, an engine transmission shaft for transmitting power to the engine passes through the inside of the first case from the inside of the second case and exits from the first case on the opposite side of the second case, the transmission device is provided on the opposite side of the second case from the first case, the motor is a motor generator, and a generator gear mechanism for transmitting power from the engine to the motor generator and operating the motor generator is housed inside the second case. A gear case that houses the pump gear mechanism, the motor gear mechanism, and the generator gear mechanism inside is provided. The gear case is housed inside the second case. ru.

[0018] According to the present invention, since the pump gear mechanism, the motor gear mechanism, and the generator gear mechanism are housed inside the gear case, it is advantageous in terms of protecting the pump gear mechanism, the motor gear mechanism, and the generator gear mechanism.

[0019]

[0020]

[0021] In the present invention, it is preferable that the coolant is lubricating oil, and the pump supplies the lubricating oil to the object to be cooled and supplies it inside the gear case.

[0022] According to the present invention, lubricating oil is used as the coolant, and the lubricating oil is supplied to the object to be cooled and the inside of the gear case by a pump. As a result, in addition to cooling the object to be cooled, the pump gear mechanism, motor gear mechanism and generator gear mechanism inside the gear case are lubricated, thereby improving the smooth operation and durability of the pump gear mechanism, motor gear mechanism and generator gear mechanism.

[0023] In the present invention, it is preferable that a clutch capable of transmitting and disconnecting the power of the engine to the engine transmission shaft is housed inside the second case, and that the gear case is attached to the opposite side of the interior of the first case at the wall separating the interior of the first case from the interior of the second case.

[0024] According to the present invention, in the wall portion separating the interior of the first case from the interior of the second case, the gear case is attached to the portion of the wall portion opposite to the interior of the first case, which is advantageous in terms of simplifying the support structure of the gear case.

[0025] According to the present invention, the gear case is attached to the wall separating the interior of the first case from the interior of the second case, so that the clutch is located in an area within the second case that is biased toward the first case. This configuration provides a relatively large area between the engine and the gear case within the second case. This allows the clutch, which transmits engine power to the engine transmission shaft, to be housed inside the second case, to be easily installed in the relatively large area between the engine and the gear case. [Brief explanation of the drawing]

[0026] [Figure 1] This is a left side view of the tractor. [Figure 2] This is a schematic diagram showing the interior of the clutch housing, gear case, motor case, and transmission case. [Figure 3]This is a cross-sectional plan view of the clutch housing, gear case, and motor case. [Figure 4] This is a longitudinal cross-sectional left side view of the clutch housing, gear case, and motor case. [Figure 5] This is a left side view of the clutch housing and motor case. [Figure 6] This is a front view of the clutch housing and gear case. [Figure 7] This is a rear view of the motor case. [Modes for carrying out the invention]

[0027] Figures 1 to 7 show a hybrid tractor, which is an example of a work vehicle. In Figures 1 to 7, F indicates forward, B indicates backward, U indicates upward, D indicates downward, R indicates right, and L indicates left.

[0028] (Overall configuration of the tractor) As shown in Figure 1, the machine body 3 is supported by the right and left front wheels 1 (corresponding to the running gear) and the right and left rear wheels 2 (corresponding to the running gear). A bonnet 6 is provided at the front of the machine body 3, and a driver's unit 9 is provided at the rear of the machine body 3.

[0029] As shown in Figures 1 and 2, the aircraft body 3 includes an engine 5, a clutch housing 11 (corresponding to the second case) connected to the rear of the engine 5, a motor case 12 (corresponding to the case) (corresponding to the first case) connected to the rear of the clutch housing 11, a transmission case 13 (corresponding to the transmission case) connected to the rear of the motor case 12, a front frame 4 connected to the front of the engine 5, and the like.

[0030] The front wheels 1 are supported by the front frame 4, and the rear wheels 2 are supported at the rear of the transmission case 13. The engine 5 is covered by the bonnet 6. The driver's compartment 9 is covered by the cabin 10, and the driver's seat 7 and the steering wheel 8 for steering the front wheels 1 are provided in the driver's compartment 9.

[0031] (Configuration of the transmission system to the front and rear wheels) As shown in Figure 2, the first motor generator 21 (corresponding to a motor) and the second motor generator 22 (corresponding to a motor) are housed inside the motor case 12.

[0032] The first planetary gear 23 (corresponding to a transmission), the second planetary gear 24 (corresponding to a transmission), the first clutch 25, the second clutch 26, the forward / reverse gear selector 27, the auxiliary transmission 28, the rear differential 29, the front transmission 30, etc., are housed inside the transmission case 13.

[0033] The engine 5 primarily generates electricity in the first motor generator 21, and primarily outputs power in the second motor generator 22. The power from engine 5 and the power from the second motor generator 22 are transmitted to the first planetary gear 23 and the second planetary gear 24, and are combined in each of them. The first planetary gear 23 outputs the combined low-speed power, and the second planetary gear 24 outputs the combined high-speed power.

[0034] When the first clutch 25 is operated to the transmission state, the low-speed combined power of the first planetary gear 23 is transmitted to the forward / reverse switching device 27 via the first clutch 25. When the second clutch 26 is operated to the transmission state, the high-speed combined power of the second planetary gear 24 is transmitted to the forward / reverse switching device 27 via the second clutch 26.

[0035] The combined low and high-speed power is operated by the forward / reverse selector 27 to switch between forward and reverse. The power from the forward / reverse selector 27 is transmitted to the auxiliary transmission 28, and from the auxiliary transmission 28 to the rear wheels 2 via the rear differential 29. The power branched off from between the auxiliary transmission 28 and the rear differential 29 is transmitted to the front transmission 30, and from the front transmission 30 to the front wheels 1 via the front differential 20.

[0036] (Correspondence between the configuration of the transmission system to the front and rear wheels and the claims) As shown in Figure 2, the system is equipped with a first motor generator 21 (motor) and a second motor generator 22 (motor) capable of supplying power to the front wheels 1 (running gear) and the rear wheels 2 (running gear).

[0037] In addition to the first motor generator 21 (motor) and the second motor generator 22 (motor), an engine 5 is provided. The power from engine 5 and the power from the second motor generator 22 (motor) are combined and transmitted to the front wheels 1 (running gear) and rear wheels 2 (running gear).

[0038] The vehicle is equipped with a first planetary gear 23 (transmission device) and a second planetary gear 24 (transmission device) that combine the power of the engine 5 and the power of the second motor generator 22 (motor) and transmit it to the front wheel 1 (running gear) and the rear wheel 2 (running gear). The first planetary gear 23 (transmission device) and the second planetary gear 24 (transmission device) are installed on the opposite side of the clutch housing 11 (second case) from the motor case 12 (case, first case).

[0039] A motor case 12 (case, first case) is provided, which houses the first motor generator 21 (motor) and the second motor generator 22 (motor) inside. A mission case 13 (transmission case) that houses the first planetary gear 23 (transmission device) and the second planetary gear 24 (transmission device) is connected to a motor case 12 (case, first case).

[0040] The power from the first motor generator 21 (motor) and the second motor generator 22 (motor) is transmitted to the first planetary gear 23 (transmission device) and the second planetary gear 24 (transmission device), and then transmitted from the first planetary gear 23 (transmission device) and the second planetary gear 24 (transmission device) to the front wheel 1 (running gear) and the rear wheel 2 (running gear).

[0041] (Configuration of clutch housing and motor case) As shown in Figures 2, 3, and 4, the clutch housing 11 and the motor case 12 are integrally formed, and the rear of the clutch housing 11 and the front of the motor case 12 are connected.

[0042] The wall portion 14 of the motor case 12 separates the interior of the clutch housing 11 from the interior of the motor case 12. The open front portion of the clutch housing 11 is closed by being connected to the engine 5. A wall portion 15 is connected to the rear of the motor case 12, and the wall portion 15 separates the interior of the motor case 12 from the interior of the transmission case 13.

[0043] 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 the engine transmission shaft) is connected to the clutch 16 and is provided along the front-rear direction, extending from inside the clutch housing 11, through inside the gear case 17 and the motor case 12, into the transmission case 13. The power from engine 5 is transmitted to the first planetary gear 23 and the second planetary gear 24 via the clutch 16 and the transmission shaft 18, as described later.

[0044] The gear case 17 is attached to the opposite side of the inside of the motor case 12 at the wall portion 14 of the motor case 12. The inside of the gear case 17 is separated from the area where the clutch 16 is located inside the clutch housing 11, and is separated from the inside of the motor case 12 by the wall portion 14 of the motor case 12.

[0045] (Correspondence between the configuration of the clutch housing and motor case and the claims) As shown in Figures 2, 3, and 4, a clutch housing 11 (second case) is provided, extending across the engine 5 and the motor case 12 (case, first case).

[0046] A clutch 16 capable of transmitting and disconnecting power from engine 5 to the transmission shaft 18 (engine transmission shaft) is housed inside the clutch housing 11 (second case). The transmission shaft 18 (engine transmission shaft) that transmits power from engine 5 passes through the inside of the motor case 12 (case, first case) from inside the clutch housing 11 (second case), and exits from the motor case 12 (case, first case) to the opposite side of the clutch housing 11 (second case).

[0047] The gear case 17 is housed inside the clutch housing 11 (second case). The gear case 17 is attached to the opposite side of the inside of the motor case 12 (case, first case) at the wall portion 14 that separates the inside of the motor case 12 (case, first case) from the inside of the clutch housing 11 (second case).

[0048] (Internal configuration of the 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 provided along the front-rear direction and is rotatably supported relative to the transmission shaft 18, extending through the inside of the gear case 17 and the motor case 12 into the inside of the transmission case 13.

[0049] Inside the motor case 12, the first motor generator 21 and the second motor generator 22 are arranged side by side along the left-right direction and supported by the wall portion 14 of the motor case 12. Transmission shafts 18 and 19 are provided between the first motor generator 21 and the second motor generator 22, with the first motor generator 21 positioned to the right of the transmission shafts 18 and 19, and the second motor generator 22 positioned to the left of the transmission shafts 18 and 19.

[0050] The first motor generator 21 and the second motor generator 22 are positioned such 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 lower than the transmission shafts 18 and 19 (see Figures 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.

[0051] Inside the gear case 17, a transmission gear 31 (corresponding to the generator gear mechanism) is connected to the transmission shaft 18, and a transmission gear 21b (corresponding to the generator gear mechanism) is connected to the shaft portion 21a of the first motor generator 21. The transmission gear 31 and the transmission gear 21b of the first motor generator 21 are meshed. Power from the engine 5 is transmitted to the first motor generator 21 via the transmission shaft 18 and the transmission gear 31, causing the first motor generator 21 to generate electricity.

[0052] Inside the gear case 17, a transmission gear 32 (corresponding to the motor gear mechanism) is connected to the transmission shaft 19, and a transmission gear 22b (corresponding to the motor gear mechanism) is connected to the shaft portion 22a of the second motor generator 22. The transmission gear 32 and the transmission gear 22b of the second motor generator 22 are meshed together. The power from the second motor generator 22 is transmitted to the first planetary gear 23 and the second planetary gear 24 via the transmission gear 32 and the transmission shaft 19, as described later.

[0053] (Correspondence between the internal configuration of the gear case and motor case and the claims) As shown in Figures 2, 3, and 4, the system is equipped with a transmission gear 31 (generator gear mechanism) that transmits power from the engine 5 to the first motor generator 21 (motor generator) and operates the first motor generator 21 (motor generator) to generate electricity, and a transmission gear 21b (generator gear mechanism) for the first motor generator 21.

[0054] The transmission gear 31 (generator gear mechanism) and the transmission gear 21b (generator gear mechanism) of the first motor generator 21 are housed inside the clutch housing 11 (second case).

[0055] The transmission gear 32 (motor gear mechanism) that transmits power to the second motor generator 22 (motor) and the transmission gear 22b (motor gear mechanism) of the second motor generator 22 are housed inside the clutch housing 11 (second case).

[0056] The transmission shaft 19 (motor transmission shaft) passes through the inside of the motor case 12 (case, first case) from the transmission gear 32 (motor gear mechanism) and exits the motor case 12 (case, first case) on the opposite side of the clutch housing 11 (second case).

[0057] (Configuration of the first motor generator and the second motor generator) As shown in Figure 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.

[0058] When the first motor generator 21 (second motor generator 22) operates as a motor and supplies power to the transmission shaft 18 (transmission shaft 19), the DC power from 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).

[0059] When the first motor generator 21 (second motor generator 22) is driven and operates as a generator, the AC power generated by the first motor generator 21 (second motor generator 22) is converted into DC power by the first inverter 71 (second inverter 72) and charged to the battery 73 (regenerative mode). A capacitor (not shown) may be used instead of the battery 73.

[0060] Based on the status of the work device (not shown) attached to the machine body 3 and the running status of the machine body 3, the control device (not shown) sets the regenerative mode and drive mode of the first motor generator 21 and the regenerative mode and drive mode of the second motor generator 22.

[0061] The basic driving state is when the first motor generator 21 is set to regenerative mode and the second motor generator 22 is set to drive mode. In the basic driving conditions, the power of the engine 5 is transmitted to the first planetary gear 23 and the second planetary gear 24 as described later, and the power of the second motor generator 22 is transmitted to the first planetary gear 23 and the second planetary gear 24.

[0062] By operating the clutch 16 to the disengaged state, the engine 5 can be stopped, and the vehicle can be driven using the first motor generator 21 drive mode and the second motor generator 22 drive mode.

[0063] (Configuration of the first planetary device) As shown in Figure 2, the first planetary gear 23 includes a sun gear 23a, a plurality of planetary gears 23b and carrier 23c, a ring gear 23d, transmission gears 23e, 23f, etc.

[0064] In the first planetary gear 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 on the carrier 23c, and the sun gear 23a and the planetary gear 23b mesh together, as do the ring gear 23d and the planetary gear 23b.

[0065] Inside the mission case 13, a transmission gear 48 is connected to a transmission shaft 18, and the transmission gear 48 meshes with the transmission gear 23e of the first planetary gear 23. Inside the mission case 13, a transmission gear 49 is connected to a transmission shaft 19, and the transmission gear 49 meshes with the transmission gear 23f of the first planetary gear 23.

[0066] The power from engine 5 (or the power from 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 from 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.

[0067] In the first planetary gear 23, the power from the engine 5 (or the power from the first motor generator 21) and the power from the second motor generator 22 are combined and shifted to output a low-speed combined power from the carrier 23c of the first planetary gear 23 to the first clutch 25.

[0068] (Configuration of the second planetary device) As shown in Figure 2, the second planetary gear 24 includes a sun gear 24a, a plurality of planetary gears 24b and carrier 24c, a ring gear 24d, transmission gears 24e, 24f, etc.

[0069] In the second planetary gear 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 on the carrier 24c, and the sun gear 24a and the planetary gear 24b mesh together, as does the ring gear 24d and the planetary gear 24b. Inside the mission case 13, the transmission gear 24e and the transmission gear 48 of the second planetary gear 24 mesh together, and the transmission gear 24f and the transmission gear 49 of the second planetary gear 24 mesh together.

[0070] The power from engine 5 (or the power from 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 from 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.

[0071] In the second planetary gear 24, the power from engine 5 (or the power from the first motor generator 21) and the power from the second motor generator 22 are combined and shifted to produce a high-speed combined power output from the ring gear 24d of the second planetary gear 24 to the second clutch 26.

[0072] (Configuration of the power transmission system to the PTO shaft) As shown in Figure 2, inside the transmission case 13, the transmission shaft 45 is connected to the transmission shaft 18, and the PTO clutch 46 is connected to the transmission shaft 45. A PTO transmission device 47 is provided, and the PTO shaft 44 is located at the rear of the transmission case 13 (see Figure 1).

[0073] The power from engine 5 is transmitted to the PTO transmission 47 via clutch 16, transmission shafts 18, 45 and PTO clutch 46, and then transmitted from the PTO transmission 47 to the PTO shaft 44. When a working device (not shown) is connected 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 from the PTO shaft 44 is transmitted to the working device.

[0074] (Configuration of the forward / reverse switching device) As shown in Figure 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.

[0075] A cylindrical shaft 50 is rotatably supported relative to a transmission shaft 45, and a 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.

[0076] A forward clutch 51 and a reverse clutch 52 are mounted on a cylindrical shaft 50. Transmission gears 53a and 53b are connected to a transmission shaft 53, with the output gear of the forward clutch 51 meshing with the transmission gear 53a of the transmission shaft 53. The 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.

[0077] When the first clutch 25 is operated to the transmission state, the low-speed combined power of the first planetary gear 23 is transmitted to the cylindrical shaft 50 via the first clutch 25. When the second clutch 26 is operated to the transmission state, the high-speed combined power of the second planetary gear 24 is transmitted to the cylindrical shaft 50 via the second clutch 26.

[0078] 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 intermediate gear 54.

[0079] (Configuration of the auxiliary transmission) As shown in Figure 2, the sub-transmission 28 includes a high-speed gear 56, a low-speed gear 57, a transmission shaft 58, a rear wheel output shaft 59, and a shift member 60, etc.

[0080] A high-speed gear 56 is connected to the transmission shaft 53, and the transmission gear 58a of the transmission shaft 58 meshes with the high-speed gear 56. The rear wheel output shaft 59 is supported concentrically with the transmission shaft 53, and a shift member 60 is slidably mounted on the rear wheel output shaft 59. A low-speed gear 57 is rotatably supported on the rear wheel output shaft 59, and the transmission gear 58b of the transmission shaft 58 meshes with the low-speed gear 57.

[0081] 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 from the transmission shaft 53 is transmitted to the rear wheel output shaft 59 at high speed, and then transmitted from the rear wheel output shaft 59 to the rear wheels 2 via the rear wheel differential device 29.

[0082] When the shift member 60 is engaged with the low-speed gear 57, the power from the transmission shaft 53 is transmitted to the rear wheel output shaft 59 at a low speed via the high-speed gear 56, the transmission shaft 58, and the low-speed gear 57, and then transmitted from the rear wheel output shaft 59 to the rear wheels 2 via the rear wheel differential device 29.

[0083] (Configuration of the front wheel transmission) As shown in Figure 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.

[0084] A standard clutch 61 and a speed-increasing clutch 62 are mounted on the transmission shaft 63, and power from the rear wheel output shaft 59 is transmitted to the transmission shaft 63. The output gear of the standard clutch 61 meshes with the transmission gear 64a of the front wheel output shaft 64, and the output gear of the speed-increasing clutch 62 meshes with the transmission gear 64b of the front wheel output shaft 64.

[0085] When the front wheel 1 is moved within the set angle range to the right and left from the straight position, the standard clutch 61 in the front wheel transmission 30 is operated to the transmission state. The power from the rear output shaft 59 is transmitted to the front output shaft 64 via the transmission shaft 63 and standard clutch 61, and then to the front wheels 1 via the transmission shaft 65 and front differential device 20, so that the front wheels 1 and rear wheels 2 are driven at the same speed.

[0086] When the front wheel 1 is steered to the right or left beyond the set angles for the right and left, the speed-increasing clutch 62 in the front wheel transmission 30 is operated to the transmission state. The power from the rear output shaft 59 is transmitted to the front 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 differential device 20, so that the front wheels 1 are driven at a higher speed than the rear wheels 2.

[0087] (Configuration of the first and second inverters) As shown in Figure 1, right and left steps 68 for boarding and alighting are provided on the right and left sides of the floor 67 of the driver's compartment 9. Right and left support members 69 are connected to the right and left sides of the front of the transmission case 13, with the first inverter 71 attached to the right support member 69 and the second inverter 72 attached to the left support member 69.

[0088] The first inverter 71 is located between the transmission case 13 and the right step 68 in a plan view, and is situated below the right side of the floor 67. The second inverter 72 is located between the transmission case 13 and the left step 68 in a plan view, and is situated below the left side of the floor 67.

[0089] As shown in Figures 3 and 5, the first relay terminal 75 (corresponding to the right relay terminal) is provided on the outer periphery of the motor case 12, on the right lateral outward portion of the first motor generator 21 (corresponding to the right motor). The second relay terminal 76 (corresponding to the left relay terminal) is provided on the outer periphery of the motor case 12, on the left lateral outward portion of the second motor generator 22 (corresponding to the left motor).

[0090] As shown in Figures 2 and 7, a harness 77 is connected outside the motor case 12, spanning from the first inverter 71 to the first relay terminal 75. Inside the motor case 12, a flat power line 70 (corresponding to a current-transmitting member) is connected from a terminal provided at the right end 21c of the first motor generator 21 to the first relay terminal 75. Thus, 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.

[0091] Outside the motor case 12, a harness 77 is connected from the second inverter 72 to the second relay terminal 76. Inside the motor case 12, a flat power line 70 (corresponding to a current-transmitting member) is connected from a terminal provided on the left end 22c of the second motor generator 22 to the second relay terminal 76. Thus, 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.

[0092] As shown in Figures 3 and 7, the shaft portion 21a of the first motor generator 21 is aligned in the front-rear direction, and the shaft portion 22a of the second motor generator 22 is aligned in the front-rear direction. Therefore, the radial direction of the shaft portion 21a of the first motor generator 21 is in the left-right direction and the up-down direction, and the radial direction of the shaft portion 22a of the second motor generator 22 is in the left-right direction and the up-down direction.

[0093] When viewed from the left and right, 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 and right, the second motor generator 22, the second relay terminal 76, the second inverter 72, and the left power line 70 overlap.

[0094] (Correspondence between the configuration of the first and second inverters and the claims) The battery 73 is provided in the configuration shown in Figures 2, 3, 5, and 7. A first inverter 71 is provided on the outside of the motor case 12 (case, first case) and operates the first motor generator 21 (motor). A second inverter 72 is provided on the outside of the motor case 12 (case, first case) and operates the second motor generator 22 (motor).

[0095] A first relay terminal 75 is provided on the outer circumference of the motor case 12 (case, first case), connected to the first motor generator 21 (motor) and also connected to the first inverter 71, thereby connecting the first motor generator 21 (motor) and the first inverter 71.

[0096] A second relay terminal 76 is provided on the outer circumference of the motor case 12 (case, first case), connected to the second motor generator 22 (motor) and the second inverter 72, thereby connecting the second motor generator 22 (motor) and the second inverter 72.

[0097] A power line 70 (current-transmitting member) is provided inside the motor case 12 (case, first case) and is connected to the first motor generator 21 (motor) and the first relay terminal 75.

[0098] A power line 70 (current-transmitting member) is provided inside the motor case 12 (case, first case) and is connected to the second motor generator 22 (motor) and the second relay terminal 76.

[0099] The first relay terminal 75 is provided on the outer circumference of the motor case 12 (case, first case) in the radial direction of the shaft portion 21a of the first motor generator 21 (motor), on the portion facing the first motor generator 21 (motor).

[0100] The second relay terminal 76 is provided on the outer circumference of the motor case 12 (case, first case) in the radial direction of the shaft portion 22a of the second motor generator 22 (motor), on the portion facing the second motor generator 22 (motor).

[0101] The first relay terminal 75 is provided on the outer periphery of the motor case 12 (case, first case) in the portion that is outward along the horizontal direction of the first motor generator 21 (motor). The second relay terminal 76 is provided on the outer periphery of the motor case 12 (case, first case) on the outer portion aligned horizontally with the second motor generator 22 (motor).

[0102] The first motor generator 21 (motor) is provided such that its shaft portion 21a is aligned in the front-rear direction. The second motor generator 22 (motor) is provided such that its shaft portion 22a is aligned in the front-rear direction.

[0103] The first relay terminal 75 is provided on the outer periphery of the motor case 12 (case, first case) on the side of the first motor generator 21 (motor). The second relay terminal 76 is provided on the outer periphery of the motor case 12 (case, first case) on the side of the second motor generator 22 (motor).

[0104] When viewed from the radial direction of the shaft portion 21a of the first motor generator 21 (motor), the first motor generator 21 (motor) and the first relay terminal 75 overlap. When viewed from the radial direction of the shaft portion 22a of the second motor generator 22 (motor), the second motor generator 22 (motor) and the second relay terminal 76 overlap.

[0105] The first motor generator 21 (right motor) and the second motor generator 22 (left motor) are arranged side by side along the left-right direction. The first relay terminal 75 (right relay terminal), which is connected to the first motor generator 21 (right motor), is provided on the outer circumference of the motor case 12 (case, first case), on the right lateral side of the first motor generator 21 (right motor). The second relay terminal 76 (left relay terminal), which is connected to the second motor generator 22 (left motor), is provided on the outer circumference of the motor case 12 (case, first case), on the left lateral side of the second motor generator 22 (left motor).

[0106] (Configuration of the oil pumps that cool the first motor generator and the second motor generator) As shown in Figures 4 and 7, the lower part of the inside of the motor case 12 is formed in a recessed shape when viewed from the front (or rear), forming a storage section 33, in which a relatively low-viscosity lubricating oil A (corresponding to a coolant) is stored.

[0107] As shown in Figures 2 and 4, the oil pump 34 (corresponding to a pump) is located in the lower front part of the inside of the gear case 17, below the transmission shafts 18 and 19, and the oil pump 34 is supported by the wall portion 14 of the motor case 12 via the gear case 17. Inside the gear case 17, the drive shaft 34a of the oil pump 34 is provided along the front-rear direction, and the transmission gear 34b (corresponding to a pump gear mechanism) is connected to the drive shaft 34a of the oil pump 34.

[0108] Inside the gear case 17, a transmission gear 35 (corresponding to the pump gear mechanism) is connected to a transmission shaft 18, and the transmission gear 35 meshes with the transmission gear 34b of the oil pump 34. Power from the engine 5 is transmitted to the oil pump 34 via the transmission shaft 18 and the transmission gear 35, driving the oil pump 34.

[0109] As shown in Figures 5, 6, and 7, the filter 36 is located on the lower left side 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. Oil passage 37 extends from the filter 36 toward the left and right center of the motor case 12, oil passage 38 extends upward from the end of oil passage 37, and oil passage 39 extends from the upper end of oil passage 38 toward the left and right center of the motor case 12.

[0110] Oil passages 40, 41, and 43 are formed in the gear case 17, and an oil cooler 42 is provided outside the clutch housing 11 and motor case 12. Oil passage 40 is connected to oil passage 39 in the wall portion 14 of the motor case 12 and to the oil pump 34. Oil passage 41 extends from the oil pump 34, and oil passage 78 connects from oil passage 41 to the oil cooler 42. Oil passage 79 connects from the oil cooler 42 to oil passage 43, and oil passage 43 extends along the left-right direction.

[0111] When the oil pump 34 is driven, lubricating oil A from the storage section 33 is supplied to the oil pump 34 from the filter 36 through oil passages 37, 38, 39, and 40. The lubricating oil A discharged from the oil pump 34 is supplied to oil passage 43 through oil passages 41 and 78, the oil cooler 42, and oil passage 79.

[0112] 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.

[0113] The supplied lubricating oil A cools the first motor generator 21 and the second motor generator 22, and the lubricating oil A returns from the first motor generator 21 and the second motor generator 22 to the storage unit 33.

[0114] 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 21a and transmission gear 21b of the first motor generator 21, the shaft 22a and transmission gear 22b of the second motor generator 22, the drive shaft 34a and transmission gear 34b of the oil pump 34, and transmission gears 31, 32, 35, etc., and the lubricating oil A returns from the gear case 17 to the storage section 33.

[0115] (The configuration of the oil pumps that cool the first motor generator and the second motor generator, and their correspondence with the claims) As shown in Figures 4 and 6, an oil pump 34 (pump) is provided to supply lubricating oil A (coolant) to the first motor generator 21 (object to be cooled) and the second motor generator 22 (object to be cooled).

[0116] The oil pump 34 (pump) is housed inside the clutch housing 11 (second case) and is supported by the gear case 17. The coolant is lubricating oil A, and the oil pump 34 (pump) supplies lubricating oil A to the first motor generator 21 (object to be cooled) and the second motor generator 22 (object to be cooled), and also supplies it to the inside of the gear case 17.

[0117] The transmission gears 34b (pump gear mechanism) and 35 (pump gear mechanism) of the oil pump 34 (pump), which transmit power for driving the oil pump 34 (pump), are housed inside the clutch housing 11 (second case).

[0118] A gear case 17 is provided that houses the transmission gears 34b (pump gear mechanism) and 35 (pump gear mechanism) of the oil pump 34 (pump), the transmission gears 22b (motor gear mechanism) and 32 (motor gear mechanism) of the second motor generator 22 (motor), and the transmission gears 31b (generator gear mechanism) and 31 (generator gear mechanism) of the first motor generator 21 (motor).

[0119] A storage section 33 for storing lubricating oil A (coolant) is provided inside the motor case 12 (case, first case) below the first motor generator 21 (motor) and the second motor generator 22 (motor).

[0120] (Configuration of the storage unit) As shown in Figure 7, in the storage section 33 formed in the lower part of the inside of the motor case 12, the left-right center of the storage section 33 is located in the left-right center of the motor case 12. The gap W1 spanning the right end 33a and the left end 33b of the storage section 33 is narrower than the gap W2 spanning the right end 21c of the first motor generator 21 and the left end 22c of the second motor generator 22.

[0121] As a result, the right end 33a of the storage section 33 is located 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 section 33 is located closer to the left-right center of the motor case 12 than the left end 22c of the second motor generator 22.

[0122] The region B1 between the first relay terminal 75 and the right end portion 33a of the storage portion 33 extends diagonally upward and outward from the right end portion 33a of the storage portion 33 when viewed from the front-rear direction (rear view). The region B2 between the second relay terminal 76 and the left end portion 33b of the storage portion 33 extends diagonally upward and outward from the left end portion 33b of the storage portion 33 when viewed from the front-rear direction (rear view).

[0123] (Correspondence between the configuration of the storage unit and the claims) As shown in Figure 7, the right end 33a of the storage unit 33, which is the end closest to the first relay terminal 75, is located further inward of the motor case 12 (case, first case) than the right end 21c of the first motor generator 21 (motor), which is the end closest to the first relay terminal 75.

[0124] The left end 33b of the storage section 33, which is the end closest to the second relay terminal 76, is located further inward of the motor case 12 (case, first case) than the left end 22c of the second motor generator 22 (motor), which is the end closest to the second relay terminal 76.

[0125] (Configuration related to the front wheel output axle) As shown in Figures 2, 4, 6, and 7, a cylindrical partition 66 is connected to the walls 14 and 15 of the motor case 12 inside the motor case 12. The partition 66 penetrates the lower part of the left and right central part of the storage section 33 (below the transmission shafts 18 and 19), and a gap is formed between the partition 66 and the bottom of the motor case 12 (the bottom of the storage section 33).

[0126] The partition 66 is submerged in the lubricating oil A of the storage section 33 and is located below the liquid level A1 of the lubricating oil A. The lubricating oil A in the right region of the storage section 33 and the lubricating oil A in the left region can pass through the region above the partition 66 and the region below the partition 66 (the gap between the partition 66 and the bottom of the motor case 12 (the bottom of the storage section 33)).

[0127] The area inside the partition 66 is separated from the inside of the motor case 12. The front wheel output shaft 64 from the front wheel transmission 30 (corresponding to the transmission shaft that transmits power from the transmission to the front running gear) protrudes forward from the motor case 12 through the area inside the partition 66, and the transmission shaft 65 is connected to the front end of the front wheel output shaft 64 (see Figure 2).

[0128] Lubricating oil is also stored in the transmission case 13. The first planetary gear 23, the second planetary gear 24, the first clutch 25, the second clutch 26, the forward / reverse gear selector 27, the auxiliary transmission 28, the rear differential 29, the front transmission 30, the PTO clutch 46, and the PTO transmission 47 are lubricated by the lubricating oil in the transmission case 13.

[0129] As mentioned above, a relatively low-viscosity lubricating oil A is stored in the reservoir 33 of the motor case 12, and the lubricating oil A in the motor case 12 and the lubricating oil in the transmission case 13 are set to be different.

[0130] As shown in Figures 2 and 4, the wall portion 15 of the motor case 12 separates the inside of the motor case 12 from the inside of the transmission case 13, and the area inside the partition portion 66 is separated from the inside of the motor case 12, so that the lubricating oil A in the storage portion 33 (motor case 12) and the lubricating oil in the transmission case 13 do not mix.

[0131] (Correspondence between the configuration of the front wheel output shaft and the claims) As shown in Figures 2, 4, 6, and 7, the wall portion 15 of the motor case 12 (case, first case) separates the interior of the motor case 12 (case, first case) from the interior of the transmission case 13 (transmission case).

[0132] A partition portion 66 is provided that penetrates the storage portion 33 in the motor case 12 (case, first case) and forms a region separated from the interior of the motor case 12 (case, first case). The front wheel output shaft 64 (transmission shaft), which transmits power from the first planetary gear 23 (transmission device) and the second planetary gear 24 (transmission device) to the front wheel 1 (front running gear), passes through the area inside the partition 66.

[0133] (Configuration for preventing the scattering of lubricating oil from the storage unit to the power lines) As shown in Figure 7, on the inner surface of the outer periphery of the motor case 12, right and left protrusions 74 (corresponding to splash prevention parts) are integrally provided on the motor case 12 so as to protrude toward the left and right center of the storage section 33, at the upper end of the right end 33a and the upper end of the left end 33b of the storage section 33.

[0134] In this case, the amount of lubricating oil A stored in the storage section 33 is set such that the liquid level A1 of the lubricating oil A stored in the storage section 33 is lower than the protrusion 74. Rather than the protrusion 74 being integrally provided on the inner surface of the outer circumference of the motor case 12, a separate protrusion 74 may be attached to the inner surface of the outer circumference of the motor case 12.

[0135] Multiple mounting portions 21d and 21e are formed on the outer circumference of the first motor generator 21. The mounting portions 21d and 21e are formed to protrude outward from the outer circumference 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.

[0136] Multiple mounting portions 22d and 22e are formed on the outer circumference of the second motor generator 22. The mounting portions 22d and 22e are formed to protrude outward from the outer circumference 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.

[0137] A boss portion (not shown) is formed on the inner surface of the wall portion 14 of the motor case 12, and the mounting portions 21d and 21e of the first motor generator 21 are bolted to the boss portion of the motor case 12, thereby connecting the first motor generator 21 to the wall portion 14 of the motor case 12. The mounting portions 22d and 22e of the second motor generator 22 are bolted to the boss portion of the motor case 12, thereby connecting the second motor generator 22 to the wall portion 14 of the motor case 12.

[0138] One of the mounting portions 21d and 21e of the first motor generator 21, mounting portion 21d (corresponding to the scattering prevention portion), is positioned above the right protrusion 74 when viewed from the front-rear direction, and extends from above into the region B1 between the first relay terminal 75 and the right end portion 33a of the storage portion 33.

[0139] One of the mounting portions 22d and 22e of the second motor generator 22, mounting portion 22d (corresponding to the splash prevention portion), is positioned above the left protrusion 74 when viewed from the front-to-back direction, and extends from above into the region B2 between the second relay terminal 76 and the left end portion 33b of the storage portion 33.

[0140] As a result, if lubricating oil A is scattered from 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, the mounting section 21d of the first motor generator 21 and the mounting section 22d of the second motor generator 22, thereby preventing the lubricating oil A from adhering to the power line 70.

[0141] Since the 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 lines 70 when it is supplied to the first motor generator 21 and the second motor generator 22.

[0142] (Correspondence between the configuration and claims regarding the prevention of lubricating oil splashing from the storage section to the power lines) As shown in Figure 7, a protrusion 74 (scatter prevention part) that prevents the scattering of lubricating oil A (coolant) from the storage section 33 to the power line 70 (current-transmitting member), a mounting section 21d (scatter prevention part) for the first motor generator 21, and a mounting section 22d (scatter prevention part) for the second motor generator 22 are provided inside the motor case 12 (case, first case).

[0143] A protrusion 74 is provided that extends inward from the inner surface of the outer periphery of the motor case 12 (case, first case), and the protrusion 74 is included in the splash prevention part.

[0144] Multiple mounting portions 21d and 21e are provided on the outer circumference of the first motor generator 21 (motor), projecting outward from the first motor generator 21 (motor) along the radial direction of the shaft portion 21a of the first motor generator 21 (motor).

[0145] The first motor generator 21 (motor) is attached to the outer circumference of the motor case 12 (case) by mounting parts 21d and 21e, in the longitudinal direction of the shaft portion 21a of the first motor generator 21 (motor) and to the portion (wall portion 14 of the motor case 12) facing the first motor generator 21 (motor).

[0146] Multiple mounting portions 22d and 22e are provided on the outer circumference of the second motor generator 22 (motor), projecting outward from the second motor generator 22 (motor) along the radial direction of the shaft portion 22a of the second motor generator 22 (motor).

[0147] The second motor generator 22 (motor) is attached to the outer circumference of the motor case 12 (case) by mounting parts 22d and 22e, in the longitudinal direction of the shaft portion 22a of the second motor generator 22 (motor), to the portion (wall portion 14 of the motor case 12) facing the second motor generator 22 (motor).

[0148] Viewed from the longitudinal direction of the shaft portion 21a of the first motor generator 21 (motor), the mounting portion 21d of the first motor generator 21 (motor) that enters the region B1 between the first relay terminal 75 and the storage portion 33 is included in the scattering prevention portion.

[0149] Viewed from the longitudinal direction of the shaft portion 22a of the second motor generator 22 (motor), the mounting portion 22d of the second motor generator 22 (motor) that enters the region B2 between the second relay terminal 76 and the storage portion 33 is included in the scattering prevention portion.

[0150] (First alternative embodiment of the invention) The lubricating oil A from the oil pump 34 may be supplied to the first inverter 71 (corresponding to an object to be cooled) and the second inverter 72 (corresponding to an object to be cooled) instead of supplying it to the first motor generator 21 and the second motor generator 22, thereby cooling the first inverter 71 and the second inverter 72. Alternatively, the lubricating oil A from the oil pump 34 may be supplied to other objects to be cooled besides the first inverter 71 and the second inverter 72.

[0151] (Second alternative embodiment of the invention) Instead of forming the clutch housing 11 and the motor case 12 as a single unit, the clutch housing 11 and the motor case 12 may be formed separately and connected to each other by bolts.

[0152] (Third alternative embodiment of the invention) Instead of storing the lubricating oil A in the storage section 33 of the motor case 12, an oil tank (not shown) for storing the lubricating oil A may be provided separately from the motor case 12. In this case, an oil cooler (not shown) for cooling the lubricating oil A may be provided.

[0153] (Fourth alternative embodiment of the invention) Instead of using lubricating oil A as the coolant, coolant water may be used as the coolant. According to the above configuration, cooling water from a cooling water pump (not shown) can be supplied to the first motor generator 21 and the second motor generator 22, and the first inverter 71 and the second inverter 72, but not to the inside of the gear case 17. In this case, the lubricating oil for the transmission case 13 may be supplied to the inside of the gear case 17 by another pump (not shown).

[0154] When using cooling water, instead of directly spraying the cooling water onto the first motor generator 21 and the second motor generator 22, or the first inverter 71 and the second inverter 72, it is sufficient to provide cooling water channels (not shown) for the first motor generator 21 and the second motor generator 22, and cooling water channels (not shown) for the first inverter 71 and the second inverter 72, and to supply cooling water to these channels to cool the first motor generator 21 and the second motor generator 22, or the first inverter 71 and the second inverter 72.

[0155] (Fifth alternative embodiment of the invention) Instead of providing a first motor generator 21 and a second motor generator 22, the system may be configured to provide one motor generator (not shown) in the motor case 12, along with one relay terminal (not shown) and one inverter (not shown).

[0156] (Sixth alternative embodiment of the invention) Instead of providing a first motor generator 21 and a second motor generator 22, the first motor generator 21 may be eliminated and the second motor generator 22 may be replaced with a motor (not shown). In this case, a dedicated generator (not shown) and battery (not shown) for supplying power to the motor may be provided. [Industrial applicability]

[0157] This invention can be applied not only to tractors, but also to work vehicles that load and transport cargo, work vehicles that tow carts, and construction work vehicles such as wheel loaders, and can also be applied to work vehicles equipped with crawler-type running gear instead of front and rear wheels. [Explanation of symbols]

[0158] 1. Front wheels (running gear) 2. Rear wheels (running gear) 5 Engine 11. Clutch housing (second case) 12 Motor case (first case) 14 Wall 16 Clutch 17 Gear Case 18. Transmission shaft (engine transmission shaft) 19. Transmission shaft (motor transmission shaft) 21. First motor generator (motor generator) (motor) (object to be cooled) 21b Transmission gear (generator gear mechanism) 22. Second motor generator (motor generator) (motor) (object to be cooled) 22b Transmission gear (motor gear mechanism) 23. First planetary device (transmission device) 24. Second planetary device (transmission device) 31. Transmission gear (generator gear mechanism) 34. Pump (oil pump) 32. Transmission gears (motor gear mechanism) 34b Transmission gear (pump gear mechanism) 35. Transmission gears (pump gear mechanism) A. Lubricating oil (coolant)

Claims

1. The running gear, the engine, the motor, A transmission device that combines the power of the engine and the power of the motor and transmits them to the traction device, A first case housing the motor inside, A second case is provided that extends over the engine and the first case. A pump that supplies coolant to the object to be cooled is housed inside the second case. A work vehicle comprising a gear case that houses a pump gear mechanism for transmitting power to the pump and a motor gear mechanism for transmitting power to the motor, the gear case being housed inside the second case, and the pump being supported by the gear case.

2. The motor transmission shaft extends from the motor gear mechanism through the inside of the first case and exits from the first case on the opposite side of the second case, The engine transmission shaft that transmits power to the engine passes through the inside of the first case from inside the second case and exits from the first case to the opposite side of the second case. The work vehicle according to claim 1, wherein the transmission device is provided on the opposite side of the second case relative to the first case.

3. The motor is a motor generator, The work vehicle according to claim 2, wherein a generator gear mechanism that transmits power from the engine to the motor generator and causes the motor generator to generate electricity is housed inside the second case.

4. A traveling device, an engine, a motor, A transmission device that combines the power of the engine and the power of the motor and transmits them to the traction device, A first case housing the motor inside, A second case is provided that extends over the engine and the first case. A pump that supplies coolant to the object to be cooled is housed inside the second case. A pump gear mechanism for transmitting power to the pump is housed inside the second case. The motor gear mechanism that transmits power from the motor is housed inside the second case. The motor transmission shaft extends from the motor gear mechanism through the inside of the first case and exits from the first case to the opposite side of the second case. The engine transmission shaft that transmits power to the engine passes through the inside of the first case from inside the second case and exits from the first case to the opposite side of the second case. The transmission device is provided on the opposite side of the second case from the first case, The motor is a motor generator, A generator gear mechanism, which transmits the power of the engine to the motor generator to operate the motor generator, is housed inside the second case. A gear case is provided that houses the pump gear mechanism, the motor gear mechanism, and the generator gear mechanism inside. A work vehicle in which the gear case is housed inside the second case.

5. The aforementioned coolant is a lubricating oil, The work vehicle according to claim 4, wherein the pump supplies the lubricating oil to the object to be cooled and also supplies it to the inside of the gear case.

6. A clutch capable of transmitting and disconnecting the power of the engine to the engine transmission shaft is housed inside the second case. The work vehicle according to any one of claims 3 to 5, wherein the gear case is attached to the opposite side of the interior of the first case in the wall portion that separates the interior of the first case from the interior of the second case.

Images