Work vehicle

Abstract

To provide a work vehicle equipped with a hybrid transmission, which adopts high-output motor generators, avoids increase of size of a charging battery, enables a power transmission mechanism to be simplified, and enables an engine and the motor generators to drive a running device while supplying sufficient electric power to the motor generators.SOLUTION: A hybrid transmission 16 comprises an electric, 16A and a gear mission unit 16B. The electric mission unit 16A has a first motor generator 17 and a second motor generator 18. The second motor generator 18 is arranged at a side where the gear mission unit 16B is positioned, with respect to the first motor generator 17. An output transmission mechanism 130 that transmits output of the second motor generator 18 to the gear mission unit 16b is arranged at a side where the gear mission unit 16B is positioned, with respect to the second motor generator 18.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work vehicle equipped with a hybrid transmission. [Background technology]

[0002] An example of the above-mentioned work vehicle is the tractor disclosed in Patent Document 1. The tractor disclosed in Patent Document 1 is equipped with an engine and a hybrid transmission in which an electric transmission unit having a motor generator unit (motor generator) and a gear transmission unit without a motor generator but having a gear transmission mechanism (planetary gear mechanism, forward / reverse switch device, gear transmission device) are arranged side by side in the fore-and-aft direction of the vehicle body, and which changes the speed of power from the engine and outputs it to the traveling device (front wheels, rear wheels). The hybrid transmission is housed in a transmission case provided on the vehicle body and arranged side by side in the fore-and-aft direction of the vehicle body relative to the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-65349 Summary of the Invention [Problem to be solved by the invention]

[0004] In the past, when the motor generator operated as an electric motor to drive the traveling device, a large charging battery with a large charging capacity was required to ensure that the power supplied to the motor generator for driving was sufficient.

[0005] The present invention provides a work vehicle that employs a high-output motor generator, while avoiding the need for a large charging battery, and simplifies the power transmission structure for the gear transmission unit, and is capable of driving the traveling device with an engine and motor generator while adequately supplying power to the motor generator operating as an electric motor. [Means for solving the problem]

[0006] The work vehicle according to the present invention comprises: The vehicle comprises an engine, an electric transmission having a motor generator, and a geared transmission having a gear transmission mechanism but no motor generator, arranged side by side in the longitudinal direction of the vehicle body, a hybrid transmission that changes the speed of power from the engine and outputs it to a traveling device, and a transmission case that is arranged on the vehicle body side by side with respect to the engine along the longitudinal direction of the vehicle body and that houses the hybrid transmission, wherein the electric transmission has a first motor generator and a second motor generator, and is arranged on the side of the geared transmission where the engine is located, the first motor generator is arranged on the side of the second motor generator where the engine is located, the second motor generator is arranged on the side of the first motor generator where the geared transmission is located, and an output transmission mechanism that connects the second motor generator and an input part of the geared transmission part and transmits the output of the second motor generator to the input part is arranged on the side of the second motor generator where the geared transmission is located The output transmission mechanism includes a rotating shaft connected to a rotor of the second motor generator, a first gear interlocking mechanism that transmits power from the rotating shaft to a low-speed planetary transmission unit in the gear transmission unit, and a second gear interlocking mechanism that transmits power from the rotating shaft to a high-speed planetary transmission unit in the gear transmission unit, and the first motor generator and the second motor generator are arranged side by side. There are.

[0007] According to this configuration, the first motor generator and the second motor generator are aligned in the fore-and-aft direction of the vehicle body, so that the outer diameters of the first and second motor generators can be increased while avoiding the transmission case from expanding in the width direction and the vertical direction of the vehicle body.

[0008] When the second motor generator operates as an electric motor that outputs power to the driving device, the first motor generator is operated as a generator, and the electricity generated can be used to drive the second motor generator that operates as an electric motor.Therefore, even if a charging battery with a smaller charging capacity is used compared to when power is supplied from the charging battery when no power is being generated, it is possible to supply enough power to the second motor generator that operates as an electric motor.

[0009] Since the output transmission mechanism is located on the side where the gear transmission unit is located relative to the second motor generator, there is no need to configure the output transmission mechanism to bypass the second motor generator, which makes it possible to simplify the output transmission mechanism compared to when the output transmission mechanism is located on the side where the first motor generator is located relative to the second motor generator.

[0010] In other words, while employing high-output first and second motor generators, it is possible to avoid increasing the size of the charging battery, simplify the output transmission mechanism that transmits power from the second motor generator to the gear transmission section, and drive the traveling device using the engine and second motor generator while supplying an adequate amount of power to the second motor generator operating as an electric motor.

[0011] In the present invention, An input transmission mechanism is provided that connects the input shaft of the transmission case to the first motor generator and inputs the power of the input shaft to the first motor generator, and it is preferable that the input transmission mechanism is provided on the side of the first motor generator where the engine is located.

[0012] With this configuration, compared to when the input transmission mechanism is provided between the first motor generator and the second motor generator, it is easier to move the first motor generator and the second motor generator closer together, and it is easier to provide a compact arrangement for the electrical systems connected to the first motor generator and the second motor generator. Furthermore, even if the first motor generator is left installed, work such as inspection of the input transmission mechanism can be performed from the side opposite the side where the second motor generator is located relative to the first motor generator, making maintenance of the input transmission mechanism easier.

[0013] In the present invention, The input transmission mechanism is preferably configured to increase the speed of the power of the input shaft and transmit it to the first motor generator.

[0014] With this configuration, the power of the input shaft is accelerated by the input transmission mechanism and transmitted to the first motor-generator to drive the first motor-generator, so the first motor-generator can be made small in outer diameter without reducing the power generation performance of the first motor-generator. Also, even if the structure of the input transmission mechanism becomes complex due to the acceleration function, the input transmission mechanism is located on the opposite side of the first motor-generator from the side where the second motor-generator is located, making it easy to incorporate the input transmission mechanism.

[0015] In the present invention, It is preferable that the rotational axis of the first motor generator, the rotational axis of the second motor generator, and the axis of the input shaft are positioned on the same axis.

[0016] According to this configuration, the first motor generator, the second motor generator, and the input shaft are positioned close together in the width direction and the vertical direction of the vehicle body, so that the electric transmission unit can be made compact so that it does not expand too much in the width direction and the vertical direction of the vehicle body.

[0017] In the present invention, It is preferable that the engine is provided at the front of the vehicle body, and the transmission case is located adjacent to and rear of the engine.

[0018] With this configuration, the load of the engine is applied to the front of the vehicle body, so even when a work implement is connected to the rear of the vehicle body, a hybrid work vehicle can be obtained in which the front and rear weight of the vehicle body can be easily balanced. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a side view showing the entire tractor. [Figure 2] FIG. 2 is a schematic diagram of a driving power transmission device. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. In the following explanation, with respect to the running body of a tractor (an example of a "work vehicle"), the direction of arrow F shown in Figure 1 will be referred to as the "front of the body," the direction of arrow B as the "rear of the body," the direction of arrow U as the "upper side of the body," the direction of arrow D as the "lower side of the body," the direction towards the front of the page as the "left side of the body," and the direction towards the back of the page as the "right side of the body."

[0021] [Overall configuration of the tractor] As shown in FIG. 1, a tractor includes a body frame 1, a traveling body 4 having a pair of left and right front wheels 2 steerably and drivably mounted at the front of the body frame 1, and a pair of left and right rear wheels 3 drivably mounted at the rear of the body frame 1. A driving unit 6 having an engine 5 is mounted at the front of the traveling body 4. A driver's seat 7 and a driver's unit 9 having a steering wheel 8 for steering the front wheels 2 are mounted at the rear of the traveling body 4. The driver's unit 9 is equipped with a cabin 10 that covers the passenger space. A link mechanism (not shown) that connects a work implement such as a rotary tiller (not shown) so that it can be raised and lowered is mounted at the rear of the traveling body 4, and a power take-off shaft 12 that extracts and transmits power from the engine 5 to the connected work implement. The body frame 1 is made up of the engine 5, a transmission case 13 mounted adjacent to the rear of the engine 5, and a front frame 14 connected to the bottom of the engine 5. In this embodiment, the vehicle is provided with front wheels 2 and rear wheels 3, but the travelling device may be a crawler travelling device or a combination of wheels and mini crawlers.

[0022] [Traveling power transmission device] As shown in FIGS. 1 and 2, a driving power transmission device 15 that transmits power from the engine 5 to the front wheels 2 and rear wheels 3 includes a transmission case 13 disposed adjacent to the rear of the engine 5. The transmission case 13 is aligned with the engine 5 in a direction along the fore-and-aft direction of the vehicle body and extends along the fore-and-aft direction of the vehicle body. The engine 5 is disposed in the front portion of the vehicle body, and the transmission case 13 is connected to the rear portion of the engine 5. As shown in FIG. 1, the transmission case 13 is connected to the engine 5 by providing a flywheel housing portion 13F in the front portion of the transmission case 13 and connecting the front end portion of the flywheel housing portion 13F to the rear end portion of the engine 5. The flywheel housing portion 13F is configured to cover a flywheel 5a (see FIG. 2) disposed in the rear portion of the engine 5. The outer diameter of the maximum diameter portion of the flywheel housing portion 13F is larger than the outer diameter of a portion 13R of the transmission case 13 rearward of the flywheel housing portion 13F.

[0023] As shown in FIG. 2, the transmission case 13 houses a hybrid transmission 16 that changes the speed of the power from the engine 5 and outputs it to the front wheels 2 and the rear wheels 3.

[0024] [Hybrid Transmission] 2, the hybrid transmission 16 is provided with an input shaft 23 that is provided in the front part of the transmission case 13 and receives power from the output shaft 5b of the engine 5, an electric transmission unit 16A that is located adjacent to the rear of the engine 5, and a gear transmission unit 16B that is located rearward of the electric transmission unit 16A. The axis of the input shaft 23 and the axis of the output shaft 5b are aligned on the same axis.

[0025] As shown in FIG. 2, the electric transmission section 16A is housed in an electric transmission chamber 28 formed in the front part of the transmission case 13. The gear transmission section 16B is housed in a gear transmission chamber 29 formed in the rear part of the transmission case 13. The electric transmission chamber 28 is formed by the peripheral wall of the transmission case 13, a front wall 13a provided inside the front end of the transmission case 13, and a blocking wall 13b provided inside the middle part of the transmission case 13. The gear transmission chamber 29 is formed by the peripheral wall of the transmission case 13, a rear wall 13c located at the rear end of the transmission case 13, and the blocking wall 13b. The electric transmission chamber 28 and the gear transmission chamber 29 are adjacent to each other with the blocking wall 13b sandwiched therebetween. The electric transmission chamber 28 and the gear transmission chamber 29 are separated from each other by the blocking wall 13b to prevent communication between them. The outer peripheral edge of the blocking wall portion 13b is connected to the inside of the peripheral wall portion of the transmission case 13, and a sealing member (not shown) is provided on the blocking wall portion 13b to seal the gap between the blocking wall portion 13b and the rotating shaft 131 in a through hole provided in the blocking wall portion 13b so that the rotating shaft 131 can be inserted therethrough, making it possible for the blocking wall portion 13b to isolate the electric transmission chamber 28 from the gear transmission chamber 29.

[0026] [Electric Transmission] 2, the electric transmission unit 16A is provided between the engine 5 and the gear transmission unit 16B. The electric transmission unit 16A is located adjacent to and rear of the engine 5. The electric transmission unit 16A can be housed in the portion of the transmission case 13 where the flywheel housing portion 13F, which has a large outer diameter, is located.

[0027] 2, the electric transmission unit 16A has a motor generator unit 24. The motor generator unit 24 is provided with two motor generators 17, 18. An inverter device 21 is connected to the two motor generators 17, 18, and a battery 22 is connected to the inverter device 21.

[0028] The two motor generators 17, 18 are aligned in the longitudinal direction of the vehicle body. The first motor generator 17, which is the front of the two motor generators 17, 18, is provided on the side where the engine 5 is located relative to the second motor generator 18, which is the rear of the two motor generators 17, 18. The second motor generator 18 is provided on the side where the gear transmission unit 16B is located relative to the first motor generator 17. The rotational axes of the first motor generator 17, the second motor generator 18, and the input shaft 23 of the transmission case 13 are aligned on the same axis.

[0029] An input transmission mechanism 120 is provided on the side of the first motor generator 17 where the engine 5 is located. The input transmission mechanism 120 connects the first motor generator 17 and the input shaft 23 of the transmission case 13, and is configured to input the power of the input shaft 23 to the first motor generator 17.

[0030] 2, the input transmission mechanism 120 has a sun gear 121, planetary gears 122, an internal gear 123, and a carrier 124. The sun gear 121 is connected to the rotor 17a of the first motor generator 17 so as to rotate around a rotation axis that is located on the axis of the input shaft 23. The sun gear 121 and the rotor 17a are connected via a rotation shaft 125. The carrier 124 is connected to the input shaft 23. The internal gear 123 is fixed to the transmission case 13.

[0031] The input transmission mechanism 120 is configured with a planetary gear mechanism, and increases the speed of the power from the engine 5 transmitted to the input shaft 23 and inputs it to the rotor 17a of the first motor generator 17. In this embodiment, the input transmission mechanism 120 is configured with a planetary gear mechanism, but a gear interlocking mechanism other than a planetary gear mechanism can be used as the input transmission mechanism 120. Also, a transmission mechanism that transmits the power of the input shaft 23 to the first motor generator 17 without increasing (changing) the speed can be used as the input transmission mechanism 120.

[0032] [Gear Transmission Section] 2, the gear transmission unit 16B is provided on the opposite side of the electric transmission unit 16A from the side on which the engine 5 is located. The gear transmission unit 16B is located adjacent to and behind the electric transmission unit 16A.

[0033] 2, the gear transmission unit 16B does not have a motor generator but has a gear transmission mechanism 30. The gear transmission mechanism 30 is provided with a low-speed planetary transmission unit 100, a low-speed clutch 100C, a high-speed planetary transmission unit 110, a high-speed clutch 110C, a forward / reverse switching device 25, an auxiliary transmission device 26, a rear wheel differential mechanism 19, a front wheel transmission device 20, and a gear interlocking mechanism 27.

[0034] 2, the low-speed planetary transmission unit 100 includes a sun gear 101, planet gears 102, an internal gear 103, and a carrier 104. The internal gear 103 of the low-speed planetary transmission unit 100 is connected to the input shaft 23 by a first interlocking mechanism 126. The high-speed planetary transmission unit 110 includes a sun gear 111, planet gears 112, an internal gear 113, and a carrier 114. The carrier 114 of the high-speed planetary transmission unit 110 is connected to the input shaft 23 by a second interlocking mechanism 127.

[0035] An output transmission mechanism 130 is provided on the side of the second motor generator 18 where the gear transmission unit 16B is located. The output transmission mechanism 130 connects the second motor generator 18 to an input unit 135 located in front of the gear transmission unit 16B, and is configured to transmit the driving force of the second motor generator 18 to the input unit 135.

[0036] 2, the input portion 135 of the gear transmission unit 16B includes a first input shaft 136 connected to the sun gear 101 of the low-speed planetary transmission unit 100, and a second input shaft 137 connected to the sun gear 111 of the high-speed planetary transmission unit 110. The output transmission mechanism 130 includes a rotating shaft 131 connected to the rotor 18a of the second motor generator 18, a first gear interlocking mechanism 132 that connects the rotating shaft 131 to the first input shaft 136, and a second gear interlocking mechanism 133 that connects the rotating shaft 131 to the second input shaft 137. In this embodiment, the output transmission mechanism 130 of the second motor generator 18 is provided in the gear transmission chamber 29, but it may also be provided in the electric transmission chamber .

[0037] In the low-speed planetary transmission unit 100, the power of the input shaft 23 is transmitted to the internal gear 103 via the first interlocking mechanism 126 to drive the internal gear 103, the driving force of the second motor generator 18 is transmitted to the sun gear 101 via the output transmission mechanism 130 and the first input shaft 136 to drive the sun gear 101, the power from the engine 5 and the driving force of the second motor generator 18 are combined to produce a low-speed combined power, and the low-speed combined power is output from the carrier 104.

[0038] The low-speed clutch 100C is provided between the output section of the low-speed planetary transmission unit 100 and the input shaft 25a of the forward / reverse switching device 25, and is configured so that when switched to an engaged state (on state), it transmits the low-speed combined power output by the low-speed planetary transmission unit 100 to the forward / reverse switching device 25, and when switched to a disengaged state (off state), it cuts off the power transmission from the low-speed planetary transmission unit 100 to the forward / reverse switching device 25.

[0039] In the high-speed planetary transmission unit 110, the power of the input shaft 23 is transmitted to the carrier 114 via the second interlocking mechanism 127 to drive the planetary gear 112, the driving force of the second motor-generator 18 is transmitted to the sun gear 111 via the output transmission mechanism 130 and the second input shaft 137 to drive the sun gear 111, and the engine power from the input shaft 23 and the driving force of the second motor-generator 18 are combined to produce high-speed combined power, which is output from the internal gear 113. The high-speed combined power is a higher-speed combined power than the low-speed combined power produced by the low-speed planetary transmission unit 100.

[0040] The high-speed clutch 110C is provided between the output section of the high-speed planetary transmission section 110 and the input shaft 25a of the forward / reverse switching device 25, and is configured so that when switched to an engaged state (on state), it transmits the high-speed combined power output by the high-speed planetary transmission section 110 to the forward / reverse switching device 25, and when switched to a disengaged state (off state), it cuts off the power transmission from the high-speed planetary transmission section 110 to the forward / reverse switching device 25.

[0041] As shown in Fig. 2, the forward / reverse switching device 25 includes an input shaft 25a located rearward of the low-speed planetary transmission unit 100 and the high-speed planetary transmission unit 110, and an output shaft 25b arranged parallel to the input shaft 25a. The axis of the input shaft 25a is aligned with the axis of the input shaft 23. A forward clutch 25c and a reverse clutch 25d are provided on the input shaft 25a. A forward gear mechanism 25e is provided between the forward clutch 25c and the output shaft 25b. A reverse gear mechanism 25f is provided between the reverse clutch 25d and the output shaft 25b.

[0042] In the forward / reverse switching device 25, the outputs of the low-speed clutch 100C and the high-speed clutch 110C are input to the input shaft 25a. When the forward clutch 25c is switched on, the power of the input shaft 25a is switched to forward power by the forward gear mechanism 25e and the forward clutch 25c, transmitted to the output shaft 25b, and output from the output shaft 25b. When the reverse clutch 25d is switched on, the power of the input shaft 25a is switched to reverse power by the reverse gear mechanism 25f and the reverse clutch 25d, transmitted to the output shaft 25b, and output from the output shaft 25b.

[0043] As shown in Fig. 2, the auxiliary transmission 26 includes an input shaft 26a connected to the output shaft 25b of the forward / reverse switching device 25, and an output shaft 26b provided rearward of the input shaft 26a. The input shaft 26a and the output shaft 26b are positioned on the same axis. A high-speed clutch 26c is provided between the rear portion of the input shaft 26a and the front portion of the output shaft 26b. A low-speed gear mechanism 26f and a low-speed clutch 26d are provided between the input shaft 26a and the rear portion of the output shaft 26b.

[0044] In the auxiliary transmission 26, the output of the forward / reverse switching device 25 is input to the input shaft 26a. When the high-speed clutch 26c is switched to the engaged position, the power of the input shaft 26a is transmitted to the output shaft 26b via the high-speed clutch 26c without being changed in speed, and high-speed power is output from the output shaft 26b. When the low-speed clutch 26d is switched to the engaged position, the power of the input shaft 26a is changed in speed to low-speed power by the low-speed gear mechanism 26f and the low-speed clutch 26d, transmitted to the output shaft 26b, and output from the output shaft 26b. The low-speed power is slower than the high-speed power that is output when the high-speed clutch 26c is switched to the engaged position.

[0045] 2, the rear wheel differential mechanism 19 includes an input shaft 19a to which the output of the auxiliary transmission 26 is input. The input shaft 19a is connected to the rear portion of the output shaft 26b of the auxiliary transmission 26. The gear interlocking mechanism 27 is provided across the output shaft 26b of the auxiliary transmission 26 and the input shaft 20a of the front wheel transmission 20, and is configured to transmit the power of the output shaft 26b of the auxiliary transmission 26 to the input shaft 20a of the front wheel transmission 20.

[0046] As shown in Fig. 2, the front wheel transmission 20 includes an input shaft 20a connected to the second gear interlocking portion 27B, and an output shaft 20e arranged parallel to the input shaft 20a. A constant speed clutch 20b and an accelerating clutch 20c are provided on the input shaft 20a. A constant speed gear mechanism 20d is provided between the constant speed clutch 20b and the output shaft 20e. A accelerating gear mechanism 20f is provided between the accelerating clutch 20c and the output shaft 20e.

[0047] In the front wheel transmission 20, the output of the auxiliary transmission 26 is transmitted to the input shaft 20a by the gear interlocking mechanism 27. When the constant speed clutch 20b is switched to the engaged position, the power of the input shaft 20a is changed to constant speed power by the constant speed clutch 20b and the constant speed gear mechanism 20d, transmitted to the output shaft 20e, and output from the output shaft 20e. The constant speed power is power that drives the front wheels 2 at the same speed as the rear wheels 3. When the speed-up clutch 20c is switched to the engaged position, the power of the input shaft 20a is changed to increased speed power by the speed-up clutch 20c and the speed-up gear mechanism 20f, transmitted to the output shaft 20e, and output from the output shaft 20e. The increased speed power is power that drives the front wheels 2 at a higher speed than the rear wheels 3. The power of the output shaft 20e of the front wheel transmission 20 is transmitted to the front wheel differential mechanism 39 via the rotating shaft 38.

[0048] In the traveling power transmission device 15, when the front wheels 2 and the rear wheels 3 are driven, the power of the engine 5 and the driving force of the second motor generator 18 are transmitted to the front wheels 2 and the rear wheels 3.

[0049] That is, the power of the input shaft 23 is transmitted to the internal gear 103 of the low-speed planetary transmission unit 100 via the first interlocking mechanism 126, and the driving force of the second motor generator 18 is transmitted to the sun gear 101 of the low-speed planetary transmission unit 100 via the output transmission mechanism 130 and the first input shaft 136, and the power from the engine 5 (engine power) and the driving force (motor power) of the second motor generator 18 are combined into a low-speed combined power by the low-speed planetary transmission unit 100, and the low-speed combined power is output to the low-speed clutch 100C. The power of the input shaft 23 is transmitted to the carrier 114 of the high-speed planetary transmission unit 110 via the second interlocking mechanism 127, the driving force of the second motor generator 18 is transmitted to the sun gear 111 of the high-speed planetary transmission unit 110 via the output transmission mechanism 130 and the second input shaft 137, the power from the engine 5 (engine power) and the driving force (motor power) of the second motor generator 18 are combined into a high-speed combined power by the high-speed planetary transmission unit 110, and the high-speed combined power is output to the high-speed clutch 110C. When the low-speed clutch 100C is switched to an engaged state (ON state) and the high-speed clutch 110C is switched to a disengaged state (OFF state), the low-speed combined power from the low-speed clutch 100C is transmitted to the auxiliary transmission unit 26 via the forward / reverse switching device 25, and then transmitted from the auxiliary transmission unit 26 to the rear wheel differential mechanism 19 and the front wheel transmission unit 20.

[0050] When the low-speed clutch 100C is switched to a disengaged state (off state) and the high-speed clutch 110C is switched to an engaged state (on state), the high-speed combined power from the high-speed clutch 110C is transmitted to the auxiliary transmission 26 via the forward / reverse switching device 25, and then transmitted from the auxiliary transmission 26 to the rear wheel differential mechanism 19 and the front wheel transmission 20 via the gear interlocking mechanism 27.

[0051] The second motor generator 18 mainly functions as an electric motor that drives the front wheels 2 and rear wheels 3, but also functions as a generator during deceleration.

[0052] In the traveling power transmission device 15, when the front wheels 2 and the rear wheels 3 are driven, power from the engine 5 transmitted to the input shaft 23 is input to the first motor generator 17 by the input transmission mechanism 120, driving the first motor generator 17 to generate electricity. The generated electric power can be supplied to the second motor generator 18 for driving. The supply of electric power to the second motor generator 18 is performed either via the battery 22, with the generated electric power being charged into the battery 22, or without the battery 22, with the generated electric power not being charged into the battery 22.

[0053] As shown in FIG. 2 , a clutch 45 is provided between the output shaft 5b and the input shaft 23. The clutch 45 is configured to be switched between an engaged state (ON state) and a disengaged state (OFF state) by a hydraulic solenoid valve or the like. When switched to the engaged state, the clutch 45 transmits power from the engine 5 to the electric transmission unit 16A and the geared transmission unit 16B, switching the hybrid transmission 16 to a hybrid mode in which the front wheels 2 and the rear wheels 3 are driven by the power of the engine 5 and the driving force of the second motor generator 18 and electricity is generated by the first motor generator 17. When switched to the disengaged state, the clutch 45 cuts off the power transmission from the engine 5 to the electric transmission unit 16A and the geared transmission unit 16B, switching the hybrid transmission 16 to an electric mode in which the front wheels 2 and the rear wheels 3 are driven only by the driving force of the second motor generator 18. A dry clutch may be used as the clutch 45.

[0054] [Work power transmission device] As shown in Figure 1, the power take-off shaft 12 is supported at the rear of the transmission case 13. As shown in Figure 2, a work power transmission device 40 that transmits the power of the engine 5 to the power take-off shaft 12 is housed in the transmission case 13.

[0055] 2, the work power transmission device 40 is provided behind the input shaft 23, extending in the longitudinal direction of the vehicle body, and includes a rotating shaft 41 whose front portion is connected to the input shaft 23, a work clutch 42 connected to the rear portion of the rotating shaft 41, and a power take-off shaft transmission 43 that changes the speed of the output of the work clutch 42 and transmits it to the power take-off shaft 12. The axis of the rotating shaft 41 and the axis of the input shaft 23 are aligned on the same axis. The input shaft 23 and the rotating shaft 41 are interlocked and connected directly or via a joint.

[0056] In the work power transmission device 40, the power of the input shaft 23 is transmitted to the rotating shaft 41, and then transmitted from the rotating shaft 41 to the power take-off shaft 12 via the work clutch 42 and the power take-off shaft speed change device 43. The work clutch 42 switches between an ON state in which power from the engine 5 is transmitted to the power take-off shaft 12, and a OFF state in which power transmission from the engine 5 to the power take-off shaft 12 is cut off.

[0057] [Another embodiment] (1) In the above embodiment, an example in which the input transmission mechanism 120 is provided is shown, but the input transmission mechanism 120 may not be provided and the first motor generator 17 may be directly connected to the input shaft 23.

[0058] (2) The above-described input transmission mechanism 120 is an example configured to increase the speed of the power of the input shaft 23 and transmit it to the first motor-generator 17, but this is not limiting. The input transmission mechanism 120 may also be configured to transmit the power of the input shaft 23 to the first motor-generator 17 without changing the speed.

[0059] (3) In the above embodiment, an example was shown in which the gear transmission mechanism 30 was provided with the low-speed planetary transmission unit 100 and the high-speed planetary transmission unit 110. However, the present invention is not limited to this. A transmission mechanism that changes speed by switching shift gears, or a transmission mechanism that employs a continuously variable transmission, etc. may also be used.

[0060] (4) In each of the above-described embodiments, the engine 5 is provided at the front of the vehicle body and the transmission case 13 is provided adjacent to the rear of the engine 5, but the engine 5 may also be provided at the rear of the vehicle body and the transmission case 13 may be provided adjacent to the front of the engine 5.

[0061] (5) In the above embodiment, the engine 5 and the transmission case 13 are connected to each other. However, the engine 5 and the transmission case 13 may be separated from each other and not connected to each other.

[0062] (6) In the above embodiment, an example was shown in which the front wheels 2 and rear wheels 3 were used as running devices, but this is not limited to this. The running devices may also be crawler running devices or a combination of wheels and mini crawlers.

[0063] (7) In the above embodiment, an example was shown in which the power take-off shaft 12 was provided, but the power take-off shaft 12 may not be provided. [Industrial Applicability]

[0064] The present invention can be applied to a work vehicle equipped with a hybrid transmission that changes the speed of power from the engine and outputs it to the traveling device, and that has an engine, an electric transmission unit having a motor-generator unit, and a gear transmission unit having no motor-generator but a gear transmission mechanism, all arranged in a row along the fore-and-aft direction of the vehicle body. [Explanation of symbols]

[0065] 2 Front wheels (running gear) 3 Rear wheels (running gear) 5 Engine 13 Mission case 16 Hybrid Transmission 16A Electric Transmission 16B Gear transmission section 17 First motor generator 18 Second motor generator 24 Motor generator section 30 Geared Electric Mechanism 100 Low-speed planetary transmission 110 High-speed planetary transmission 120 Input transmission mechanism 130 Output Transmission Mechanism 131 Rotation axis 132 First gear interlocking mechanism 133 Second gear interlocking mechanism 135 Input section

Claims

1. The engine and a hybrid transmission in which an electric transmission unit having a motor generator unit and a gear transmission unit having a gear transmission mechanism but no motor generator are arranged side by side in the longitudinal direction of the vehicle body, the hybrid transmission changing the speed of power from the engine and outputting it to a traveling device; a transmission case that is provided on the vehicle body and positioned alongside the engine in the vehicle body longitudinal direction, and that houses the hybrid transmission; the electric transmission unit has a first motor generator and a second motor generator, and is provided on a side of the gear transmission unit where the engine is located, the first motor generator is provided on a side of the second motor generator where the engine is located, the second motor generator is provided on a side of the first motor generator where the gear transmission unit is located, and an output transmission mechanism that connects the second motor generator and an input unit of the gear transmission unit and transmits an output of the second motor generator to the input unit is provided on the side of the second motor generator where the gear transmission unit is located, the output transmission mechanism includes a rotating shaft connected to a rotor of the second motor generator, a first gear interlocking mechanism that transmits power from the rotating shaft to a low-speed planetary transmission unit in the gear transmission unit, and a second gear interlocking mechanism that transmits power from the rotating shaft to a high-speed planetary transmission unit in the gear transmission unit, The first motor generator and the second motor generator are arranged side by side in the work vehicle.

2. an input transmission mechanism that connects the input shaft of the transmission case and the first motor generator and inputs power of the input shaft to the first motor generator; 2. The work vehicle according to claim 1, wherein the input transmission mechanism is provided on a side of the first motor generator where the engine is located.

3. The work vehicle according to claim 2, wherein the input transmission mechanism is configured to increase the speed of the power of the input shaft and transmit it to the first motor generator.

4. 4. The work vehicle according to claim 2, wherein the rotational axis of the first motor-generator, the rotational axis of the second motor-generator, and the axis of the input shaft are aligned on the same axis.

5. The engine is provided at the front of the vehicle body, 5. The work vehicle according to claim 1, wherein the transmission case is located adjacent to and rear of the engine.

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