Work vehicle

Abstract

To provide a work vehicle equipped with a hybrid transmission, which adopts high-output motor generators, avoids increase in size of a charging battery, enables the motor generators to be easily maintained, and supplies sufficient electric power to the motor generators which operate as electric motors.SOLUTION: A hybrid transmission 16 has a first motor generator 17 and a second motor generator 18. A first rotary shaft center of the first motor generator 17 and a second rotary shaft center of the second motor generator 18 respectively are disposed along a longitudinal direction of a vehicle body. The first rotary shaft center of the first motor generator 17 and the second rotary shaft center of the second motor generator 18 are arranged in parallel. An input shaft 23 of a mission case 13 passes, in the longitudinal direction of the vehicle body, in a space between the first motor generator 17 and 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 Art

[0002] As the above-described work vehicle, for example, there is a tractor shown in Patent Document 1. In the tractor shown in Patent Document 1, an engine is provided, an electric transmission unit having a motor generator unit (motor generator), and a gear transmission unit having a gear transmission mechanism (planetary gear mechanism, forward and reverse switching device, gear shifting device) without a motor generator are provided in a state of being arranged along the vehicle body longitudinal direction, and a hybrid transmission that shifts the power from the engine and outputs it to a traveling device (front wheels, rear wheels) is provided. The hybrid transmission is housed in a transmission case provided in the vehicle body in a state of being arranged along the vehicle body longitudinal direction with respect to the engine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional case, when the motor generator operates as an electric motor that drives the traveling device, a large charging battery with a large charging capacity is required to prevent the power supplied to the motor generator for driving from being insufficient.

[0005] The present invention provides a work vehicle that employs a high-output motor-generator while avoiding the need for a large rechargeable battery, facilitating maintenance of the motor-generator, and supplying sufficient power to the motor-generator operating as an electric motor, thereby enabling the engine and motor-generator to drive the traction device. [Means for solving the problem]

[0006] The work vehicle according to the present invention is The vehicle is equipped with an engine, an electric transmission unit having a motor-generator unit, and a gear transmission unit having a gear transmission mechanism but without a motor-generator unit, arranged in a manner along the longitudinal direction of the vehicle body, and a hybrid transmission that shifts the power from the engine and outputs it to the running gear, and a transmission case that houses the hybrid transmission, which is provided on the vehicle body in a manner aligned with the engine in a manner along the longitudinal direction of the vehicle body, and the electric transmission unit has a first motor-generator and a second motor-generator, and is provided between the engine and the gear transmission unit, and the first motor-generator and the second motor-generator are the first motor The first rotation axis of the motor generator and the second rotation axis of the second motor generator are aligned along the longitudinal direction of the vehicle body, and the first rotation axis and the second rotation axis are arranged in parallel. The input shaft of the transmission case is provided so as to pass between the first motor generator and the second motor generator in the longitudinal direction of the vehicle body. The gear transmission section is provided with a low-speed planetary gear shift unit that combines the engine power from the input shaft and the motor power from the second motor generator to output a combined power on the low-speed side, and a high-speed planetary gear shift unit that combines the engine power from the input shaft and the motor power from the second motor generator to output a combined power on the high-speed side that is faster than the combined power on the low-speed side.

[0007] In this configuration, the first rotation axis of the first motor generator, which is aligned along the longitudinal direction of the vehicle body, and the second rotation axis of the second motor generator, which is aligned along the longitudinal direction of the vehicle body, are parallel to each other. Compared to the case where the first and second rotation axes are aligned along the longitudinal direction of the vehicle body, even if the outer diameters of the first and second motor generators are made smaller so that the first and second motor generators and the input shaft can be housed in the transmission case while avoiding an increase in the outer diameter of the transmission case, the length of the first and second motor generators in the direction along the longitudinal direction of the vehicle body can be increased, making the first and second motor generators high-output motor generators without a decrease in output due to their smaller outer diameter. Furthermore, the engine's power and the second motor-generator's power are combined by the low-speed planetary transmission unit to produce a combined power on the low-speed side, and the engine's power and the second motor-generator's power are combined by the high-speed planetary transmission unit to produce a combined power on the high-speed side that is faster than the combined power on the low-speed side, thus enabling the production of a combined power with a wide transmission range.

[0008] When one of the motor generators, the first motor generator and the second motor generator, operates as an electric motor outputting to the traction device, the other motor generator can be operated as a generator, and the power generated can be used to drive the motor generator operating as an electric motor. Therefore, even if a rechargeable battery with a smaller charging capacity is used compared to when power is supplied from the rechargeable battery when no power is being generated, sufficient power can be supplied to the motor generator operating as an electric motor.

[0009] Since the first rotation axis of the first motor generator, which is aligned along the longitudinal direction of the vehicle body, and the second rotation axis of the second motor generator, which is aligned along the longitudinal direction of the vehicle body, are parallel to each other, it is possible to inspect the first and second motor generators from the front side in the direction along the rotation axis of the first and second motor generators, even when the first and second motor generators are assembled.

[0010] In other words, it is possible to drive the traction system using the engine and motor generators while employing high-output first and second motor generators, avoiding the need for larger rechargeable batteries, facilitating maintenance of the first and second motor generators, and ensuring sufficient power supply to the motor generators operating as electric motors.

[0011]

[0012]

[0013] Another work vehicle according to the present invention is, The vehicle is equipped with an engine, an electric transmission unit having a motor-generator section, and a gear transmission unit having a gear transmission mechanism but without a motor-generator, arranged in a manner along the longitudinal direction of the vehicle body, and a hybrid transmission that shifts the power from the engine and outputs it to the running gear, and a transmission case that houses the hybrid transmission, which is provided on the vehicle body in a manner aligned with the engine in a manner along the longitudinal direction of the vehicle body, and the electric transmission unit has a first motor-generator and a second motor-generator, and is provided between the engine and the gear transmission unit, and the first motor-generator and the second motor-generator This means that the first rotation axis of the first motor generator and the second rotation axis of the second motor generator are aligned along the longitudinal direction of the vehicle body, and the first rotation axis and the second rotation axis are aligned in parallel, the input shaft of the transmission case is provided so as to pass between the first motor generator and the second motor generator in the longitudinal direction of the vehicle body, the first rotation axis and the second rotation axis are aligned in parallel along the width direction of the vehicle body, the input shaft passes above the first rotation axis and the second rotation axis in the longitudinal direction of the vehicle body, and the upper end of the input shaft is located above the upper end of the first motor generator and the upper end of the second motor generator.

[0014] In this configuration, the input shaft is located in the upper part of the upward-expanding gap between the portion of the first motor generator above the first rotation axis and the portion of the second motor generator above the second rotation axis. This makes it easier to bring the first motor generator and the second motor generator closer together in the width direction of the vehicle body, and allows for a larger outer diameter for both the first and second motor generators. Since the input shaft passes above the first and second rotation axes, it does not need to be positioned too low inside the transmission case, making it easier to install the input shaft.

[0015] In the present invention, it is preferable that the outer diameter of the first motor generator and the outer diameter of the second motor generator are different.

[0016] According to this configuration, for example, even if the outer diameter of the first motor generator, which operates as a power generator, is smaller than the outer diameter of the second motor generator, which operates as an electric motor that drives the traction device, it is possible to supply sufficient power to the second motor generator. In such cases, costs can be reduced compared to the case where the outer diameters of the first and second motor generators are the same.

[0017] In the present invention, It is preferable that the rotation axis of one of the low-speed planetary gear shifting unit and the high-speed planetary gear shifting unit and the first rotation axis of the first motor generator are located on the same axis, and the rotation axis of the other of the low-speed planetary gear shifting unit and the high-speed planetary gear shifting unit and the second rotation axis of the second motor generator are located on the same axis.

[0018] With this configuration, the low-speed planetary gear shifting unit, the high-speed planetary gear shifting unit, the first motor generator, and the second motor generator are positioned close together in the vertical and horizontal directions of the vehicle body. As a result, the gear transmission unit can be made compact without significantly expanding in the vertical and horizontal directions of the vehicle body, while the running gear can be driven by shifting speeds over a wide range of gears.

[0019] In the present invention, The engine is preferably provided at the front part of the vehicle body, and the transmission case is provided adjacent to the rear of the engine.

[0020] According to this configuration, since the load of the engine is applied to the front part of the vehicle body, a hybrid working vehicle can be obtained in a state where it is easy to balance the front and rear weights of the vehicle body even if a working device is connected to the rear part of the vehicle body.

Brief Description of the Drawings

[0021] [Figure 1] It is a side view showing the whole tractor. [Figure 2] It is a schematic diagram of the traveling power transmission device. [Figure 3] It is a front view showing the arrangement of the motor generator.

Embodiments for Carrying out the Invention

[0022] Hereinafter, an embodiment which is an example of the present invention will be described based on the drawings. In the following description, regarding the traveling vehicle body of the tractor (an example of a "working vehicle"), the direction of the arrow F shown in FIG. 1 etc. is the "front of the vehicle body", the direction of the arrow B is the "rear of the vehicle body", the direction of the arrow U is the "upper part of the vehicle body", the direction of the arrow D is the "lower part of the vehicle body", the direction of the arrow L is the "left side of the vehicle body", and the direction of the arrow R is the "right side of the vehicle body".

[0023] 〔Overall Configuration of the Tractor〕 As shown in Figure 1, the tractor comprises a vehicle body 4 having a vehicle frame 1, a pair of left and right front wheels 2 mounted on the front of the vehicle frame 1 in a steerable and drivable manner, and a pair of left and right rear wheels 3 mounted on the rear of the vehicle frame 1 in a drivable manner. A drive unit 6 having an engine 5 is mounted on the front of the vehicle body 4. A driver's compartment 9 having a driver's seat 7 and a steering wheel 8 for steering the front wheels 2 is mounted on the rear of the vehicle body 4. The driver's compartment 9 is equipped with a cabin 10 that covers the passenger space. A link mechanism (not shown) for connecting a working device such as a rotary tiller (not shown) in a liftable and lowerable manner is provided on the rear of the vehicle body 4, and a power take-off shaft 12 for extracting and transmitting power from the engine 5 to the connected working device. The vehicle frame 1 is composed of the engine 5, a transmission case 13 located next to the rear of the engine 5, and a front frame 14 connected to the lower part of the engine 5. In this embodiment, the vehicle is equipped with front wheels 2 and rear wheels 3, but the running gear can be a crawler running gear, or a combination of wheels and mini-crawlers.

[0024] [Power transmission system for traction] The power transmission device 15, which transmits power from the engine 5 to the front wheels 2 and rear wheels 3, includes a transmission case 13 located next to the rear of the engine 5, as shown in Figures 1 and 2. The transmission case 13 is aligned with the engine 5 in the longitudinal direction of the vehicle body and extends along the longitudinal direction of the vehicle body. The engine 5 is located at the front of the vehicle body, and the transmission case 13 is connected to the rear of the engine 5. As shown in Figure 1, the connection of the transmission case 13 to the engine 5 is made by providing a flywheel housing portion 13F at the front of the transmission case 13, and connecting the front end of the flywheel housing portion 13F to the rear end of the engine 5. The flywheel housing portion 13F is configured to cover the flywheel 5a (see Figure 2) located at the rear of the engine 5. The outer diameter of the largest diameter portion of the flywheel housing portion 13F is larger than the outer diameter of the portion 13R of the transmission case 13 that is further rear than the flywheel housing portion 13F.

[0025] As shown in Figure 2, the transmission case 13 houses a hybrid transmission 16 that shifts the power from the engine 5 and outputs it to the front wheels 2 and rear wheels 3.

[0026] [Hybrid transmission] As shown in Figure 2, the hybrid transmission 16 includes an input shaft 23 located at the front of the transmission case 13 to which power from the output shaft 5b of the engine 5 is input, an electric transmission unit 16A located next to the rear of the engine 5, and a gear transmission unit 16B located behind the electric transmission unit 16A. The axis of the input shaft 23 and the axis of the output shaft 5b are located on the same axis.

[0027] As shown in Figure 2, the electric transmission unit 16A is housed in an electric transmission chamber 28 formed in the front of the transmission case 13. The gear transmission unit 16B is housed in a gear transmission chamber 29 formed in the rear of the transmission case 13. The electric transmission chamber 28 is formed by the peripheral wall of the transmission case 13, the front wall 13a provided inside at the front end of the transmission case 13, and the barrier wall 13b provided inside at the middle of the transmission case 13. The gear transmission chamber 29 is formed by the peripheral wall of the transmission case 13, the rear wall 13c located at the rear end of the transmission case 13, and the barrier wall 13b. The electric transmission chamber 28 and the gear transmission chamber 29 are adjacent to each other with the barrier wall 13b in between. The electric transmission chamber 28 and the gear transmission chamber 29 are separated by the barrier wall 13b so that they do not communicate with each other. The outer peripheral edge of the barrier 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 barrier wall portion 13b to close the gap between the barrier wall portion 13b and the input shaft 23, etc., in a through hole provided in the barrier wall portion 13b through which the input shaft 23, etc., is inserted, thereby enabling the barrier wall portion 13b to separate the electric transmission chamber 28 from the gear transmission chamber 29.

[0028] [Electric transmission section] As shown in Figure 2, the electric transmission unit 16A is located between the engine 5 and the gear transmission unit 16B. The electric transmission unit 16A is located next to the rear of the engine 5. The electric transmission unit 16A can be housed in the part of the transmission case 13 where the flywheel housing unit 13F, which has a larger outer diameter, is located.

[0029] As shown in Figure 2, the electric transmission unit 16A has a motor-generator unit 24. The motor-generator unit 24 is equipped with two motor-generators 17 and 18. An inverter device 21 is connected to the two motor-generators 17 and 18, and a battery 22 is connected to the inverter device 21.

[0030] In this embodiment, one of the two motor generators 17 and 18, motor generator 17, will be referred to as the first motor generator 17, and the other motor generator 18, motor generator 18, will be referred to as the second motor generator 18. The first motor generator 17 and the second motor generator 18 are provided such that the first rotation axis 17c of the first motor generator 17 and the second rotation axis 18c of the second motor generator 18 are aligned along the longitudinal direction of the vehicle body, and the first rotation axis 17c and the second rotation axis 18c are parallel to each other. In this embodiment, as shown in Figure 3, the first motor generator 17 and the second motor generator 18 are provided such that the first rotation axis 17c and the second rotation axis 18c are parallel to each other in the direction along the width of the vehicle body. The first motor generator 17 and the second motor generator 18 are arranged in the direction along the width of the vehicle body. As the first motor generator 17 and the second motor generator 18, motor generators with a longer length in the direction along the vehicle's longitudinal direction can be used compared to the case where the two motor generators are aligned in the direction along the vehicle's longitudinal direction. In this embodiment, the outer diameter of the first motor generator 17 and the outer diameter of the second motor generator 18 are set to be the same.

[0031] The input shaft 23 of the transmission case 13 is provided so as to pass between the first motor generator 17 and the second motor generator 18 in the longitudinal direction of the vehicle body. In this embodiment, as shown in Figure 3, the input shaft 23 passes in the longitudinal direction above the first rotation axis 17c of the first motor generator 17 and the second rotation axis 18c of the second motor generator 18. A gap S is formed between the portion of the first motor generator 17 above the first rotation axis 17c and the portion of the second motor generator 18 above the second rotation axis 18c, and the input shaft 23 passes through this gap S. The upper end 23t of the input shaft 23 is located above the upper end 17t of the first motor generator 17 and above the upper end 18t of the second motor generator 18. The input shaft 23 passes over the top of the gap S.

[0032] [Gear Transmission Section] As shown in Figure 2, the gear transmission unit 16B is located on the side opposite to the side where the engine 5 is located relative to the electric transmission unit 16A. The gear transmission unit 16B is located immediately behind the electric transmission unit 16A.

[0033] As shown in Figure 2, the gear transmission unit 16B has a gear transmission mechanism 30 without a motor generator. The gear transmission mechanism 30 includes a transmission mechanism input shaft 99, a gear transmission mechanism 98, a low-speed planetary gear shift unit 100, a low-speed clutch 100C, a high-speed planetary gear shift unit 110, a high-speed clutch 110C, a forward / reverse switching device 25, a sub-transmission device 26, a rear wheel differential mechanism 19, a front wheel transmission device 20, and a gear interlocking mechanism 27.

[0034] The transmission mechanism input shaft 99 is located behind the input shaft 23 of the transmission case 13, on the same axis as the input shaft 23. The transmission mechanism input shaft 99 and the input shaft 23 are connected, and the power from the input shaft 23 is transmitted to the transmission mechanism input shaft 99. The gear transmission mechanism 98 is provided across the transmission mechanism input shaft 99 and the rotor support shaft 17b of the first motor generator 17, and is configured to transmit the power from the input shaft 23 to the first motor generator 17.

[0035] As shown in Figure 2, the low-speed planetary gear shifting unit 100 comprises a sun gear 101, planetary gears 102, an internal gear 103, and a carrier 104. The low-speed planetary gear shifting unit 100 is located behind the second motor generator 18 such that the rotation axis of the sun gear 101 and the rotor support shaft 18b (second rotation axis 18c) of the second motor generator 18 are located on the same axis. The internal gear 103 and the transmission mechanism input shaft 99 are connected via a gear interlocking mechanism 105. The sun gear 101 is provided with a first input shaft 136, which is connected to the rotor support shaft 18b of the second motor generator 18.

[0036] In the low-speed planetary gear shifting unit 100, the power from the input shaft 23 is transmitted to the internal gear 103 to drive the internal gear 103, the driving force from the second motor generator 18 is transmitted to the sun gear 101 to drive the sun gear 101, the power from the engine 5 and the driving force from the second motor generator 18 are combined to produce a combined low-speed power, and this combined low-speed power is output from the carrier 104.

[0037] The low-speed clutch 100C is provided between the output section of the low-speed planetary gear shift unit 100 and the input shaft 25a of the forward / reverse switching device 25. When switched to the engaged (on) state, it transmits the combined low-speed power output by the low-speed planetary gear shift unit 100 to the forward / reverse switching device 25. When switched to the disengaged (off) state, it cuts off the power transmission from the low-speed planetary gear shift unit 100 to the forward / reverse switching device 25.

[0038] As shown in Figure 2, the high-speed planetary gearbox 110 comprises a sun gear 111, planetary gears 112, an internal gear 113, and a carrier 114. The high-speed planetary gearbox 110 is located behind the first motor generator 17 such that the rotation axis of the sun gear 111 and the rotor support shaft 17b (first rotation axis) of the first motor generator 17 are located on the same axis. The carrier 114 and the transmission mechanism input shaft 99 are connected via a gear interlocking mechanism 115. The sun gear 111 is provided with a second input shaft 137, and the second input shaft 137 and the rotor support shaft 18b of the second motor generator 18 are connected via a gear interlocking mechanism 116 and the first input shaft 136.

[0039] In the high-speed planetary gear shifting unit 110, the power from the input shaft 23 is transmitted to the carrier 114 to drive the planetary gear 112, the driving force from the second motor generator 18 is transmitted to the sun gear 111 to drive the sun gear 111, the engine power from the input shaft 23 and the driving force from the second motor generator 18 are combined to produce a 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 gear shifting unit 100.

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

[0041] In this embodiment, the rotation axis of the sun gear 101, which serves as the rotation axis of the low-speed planetary speed change unit 100, and the second rotation axis 18c of the second motor generator 18 are located on the same axis, and the rotation axis of the sun gear 111, which serves as the rotation axis of the high-speed planetary speed change unit 110, and the first rotation axis 17c of the first motor generator 17 are located on the same axis. However, instead, it is possible to adopt an arrangement in which the rotation axis of the sun gear 101, which serves as the rotation axis of the low-speed planetary speed change unit 100, and the first rotation axis 17c of the first motor generator 17 are located on the same axis, and the rotation axis of the sun gear 111, which serves as the rotation axis of the high-speed planetary speed change unit 110, and the second rotation axis 18c of the second motor generator 18 are located on the same axis.

[0042] As shown in Figure 2, the forward / reverse switching device 25 includes an input shaft 25a located behind the transmission mechanism input shaft 99, and an output shaft 25b parallel to the input shaft 25a. The input shaft 25a and the transmission mechanism input shaft 99 are located on the same axis. A forward clutch 25c and a reverse clutch 25d are provided on the input shaft 25a. A forward gear mechanism 25e is provided extending from the forward clutch 25c to the output shaft 25b. A reverse gear mechanism 25f is provided extending from the reverse clutch 25d to the output shaft 25b.

[0043] 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 to the engaged position, the power from the input shaft 25a is switched to forward power by the forward gear mechanism 25e and the forward clutch 25c and transmitted to the output shaft 25b, from which output power is produced. When the reverse clutch 25d is switched to the engaged position, the power from the input shaft 25a is switched to reverse power by the reverse gear mechanism 25f and the reverse clutch 25d and transmitted to the output shaft 25b, from which output power is produced.

[0044] As shown in Figure 2, the sub-transmission 26 comprises an input shaft 26a connected to the output shaft 25b of the forward / reverse switching device 25, and an output shaft 26b located behind the input shaft 26a. The input shaft 26a and the output shaft 26b are located on the same axis. A high-speed clutch 26c is provided between the rear of the input shaft 26a and the front of the output shaft 26b. A low-speed gear mechanism 26f and a low-speed clutch 26d are provided extending from the input shaft 26a to the rear of the output shaft 26b.

[0045] In the sub-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 from the input shaft 26a is transmitted to the output shaft 26b via the high-speed clutch 26c without being shifted, 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 from the input shaft 26a is shifted to low-speed power by the low-speed gear mechanism 26f and the low-speed clutch 26d and transmitted to the output shaft 26b, and output from the output shaft 26b. The low-speed power is lower in speed than the high-speed power output when the high-speed clutch 26c is switched to the engaged position.

[0046] As shown in Figure 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 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 from the output shaft 26b of the auxiliary transmission 26 to the input shaft 20a of the front wheel transmission 20.

[0047] As shown in Figure 2, the front wheel transmission 20 includes an input shaft 20a connected to the second gear interlocking section 27B, and an output shaft 20e running parallel to the input shaft 20a. A constant speed clutch 20b and a speed-increasing clutch 20c are provided on the input shaft 20a. A constant speed gear mechanism 20d is provided across the constant speed clutch 20b and the output shaft 20e. A speed-increasing gear mechanism 20f is provided across the speed-increasing clutch 20c and the output shaft 20e.

[0048] In the front wheel transmission 20, the output of the sub-transmission 26 is transmitted to the input shaft 20a by the gear interlocking mechanism 27. When the constant-speed clutch 20b is switched to engaged, the power of the input shaft 20a is converted to constant-speed power by the constant-speed clutch 20b and the constant-speed gear mechanism 20d and transmitted to the output shaft 20e, from which it is output. Constant-speed power is the power that drives the front wheels 2 at the same speed as the rear wheels 3. When the speed-increasing clutch 20c is switched to engaged, the power of the input shaft 20a is converted to speed-increasing power by the speed-increasing clutch 20c and the speed-increasing gear mechanism 20f and transmitted to the output shaft 20e, from which it is output. Speed-increasing power is the 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.

[0049] In the traction power transmission device 15, when the front wheels 2 and rear wheels 3 are driven, the power from the engine 5 and the driving force from the second motor generator 18 are transmitted to the front wheels 2 and rear wheels 3.

[0050] In other words, the power from the engine 5 transmitted to the input shaft 23 (engine power) and the driving force of the second motor generator 18 (motor power) are combined into a low-speed composite power by the low-speed planetary transmission unit 100. The power from the engine 5 transmitted to the input shaft 23 (engine power) and the driving force of the second motor generator 18 (motor power) are combined into a high-speed composite power by the high-speed planetary transmission unit 110. By switching the low-speed clutch 100C to the engaged state and the high-speed clutch 110C to the disengaged state, the low-speed composite power from the low-speed planetary transmission unit 100 is transmitted to the input shaft 25a of the forward / reverse switching device 25, transmitted from the output shaft 25b of the forward / reverse switching device 25 to the sub-transmission unit 26, and from the sub-transmission unit 26 to the rear wheel differential mechanism 19 and the front wheel transmission unit 20 via the gear interlocking mechanism 27. By switching the high-speed clutch 110C to the engaged state and the low-speed clutch 100C to the disengaged state, the combined high-speed power from the high-speed planetary transmission unit 110 is transmitted to the input shaft 25a of the forward / reverse switching device 25, then from the output shaft 25b of the forward / reverse switching device 25 to the sub-transmission 26, and from the sub-transmission 26 to the rear wheel differential mechanism 19 and the front wheel transmission 20.

[0051] In the traction power transmission device 15, when the front wheels 2 and rear wheels 3 are driven, power from the engine 5 transmitted to the input shaft 23 is input to the first motor generator 17 via the transmission mechanism input shaft 99 and the gear transmission mechanism 98. The first motor generator 17 is driven to generate electricity, and the electricity generated can be supplied to the second motor generator 18 for driving. The power to the second motor generator 18 is supplied either by charging the battery 22 with the electricity generated and using the battery 22, or by not charging the battery 22 with the electricity generated and using the battery 22.

[0052] As shown in Figure 2, a clutch 45 is provided across 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 the clutch 45 is switched to the engaged state, it transmits power from the engine 5 to the electric transmission unit 16A and the gear transmission unit 16B, switching the hybrid transmission 16 to a hybrid mode in which the engine 5's power and the second motor generator 18's driving force drive the front wheels 2 and rear wheels 3, and the first motor generator 17 generates electricity. When the clutch 45 is switched to the disengaged state, it cuts off the transmission of power from the engine 5 to the electric transmission unit 16A and the gear transmission unit 16B, switching the hybrid transmission 16 to an electric mode in which the second motor generator 18's driving force drives the front wheels 2 and rear wheels 3. A dry clutch can be used as the clutch 45.

[0053] As shown in Figure 2, a trochoid pump 81 is provided on the input shaft 23 to supply lubricating oil to the motor generator unit 24 and the gear transmission mechanism 30.

[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 power transmission device 40 that transmits power from the engine 5 to the power take-off shaft 12 is housed in the transmission case 13.

[0055] As shown in Figure 2, the power transmission device 40 includes a transmission mechanism input shaft 99 connected to the input shaft 23, a rotating shaft 41 provided behind the transmission mechanism input shaft 99 and extending along the longitudinal direction of the vehicle body, with its front end connected to the rear of the transmission mechanism input shaft 99, a work clutch 42 connected to the rear of the rotating shaft 41, and a power take-off shaft transmission device 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 located on the same axis. The input shaft 23 and the rotating shaft 41 are linked together directly or via a joint.

[0056] In the work power transmission device 40, power from the input shaft 23 is transmitted to the rotating shaft 41, and from the rotating shaft 41 to the power take-off shaft 12 via the work clutch 42 and the power take-off shaft transmission 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 an "off" state, in which power transmission from the engine 5 to the power take-off shaft 12 is cut off.

[0057] [Another example] (1) In the embodiment described above, an example was shown in which the outer diameter of the first motor generator 17 and the outer diameter of the second motor generator 18 are the same, but the outer diameters of the first motor generator 17 and the outer diameter of the second motor generator 18 may be different.

[0058] (2) In the above embodiment, an example was shown in which the first rotation axis 17c of the first motor generator 17 and the second rotation axis 18c of the second motor generator 18 are aligned along the width direction of the vehicle body. However, the embodiment is not limited to this, and it is acceptable as long as the first rotation axis 17c and the second rotation axis 18c are aligned along the radial direction of the transmission case 13, such as along the vertical direction of the vehicle body.

[0059] (3) In the above-described embodiment, an example was shown in which the input shaft 23 passes between the first motor generator 17 and the second motor generator 18 above the first rotation axis 17c and the second rotation axis 18c. However, the input shaft 23 may also pass between the first motor generator 17 and the second motor generator 18 below the first rotation axis 17c and the second rotation axis 18c.

[0060] (4) In the above-described embodiment, an example was shown in which a low-speed planetary gear shifting section 100 and a high-speed planetary gear shifting section 110 were provided in the gear transmission mechanism 30. However, the invention is not limited to this, and a gear shifting mechanism that changes speed by changing shift gears, or a gear shifting mechanism employing a continuously variable transmission, may also be employed.

[0061] (5) In the above-described embodiment, an example was shown in which the engine 5 is located at the front of the vehicle body and the transmission case 13 is located next to the rear of the engine 5. However, the engine 5 may also be located at the rear of the vehicle body and the transmission case 13 may be located next to the front of the engine 5.

[0062] (6) In the embodiment described above, the engine 5 and the transmission case 13 are shown to be connected, but the engine 5 and the transmission case 13 may be separate and not connected.

[0063] (7) In the above-described embodiment, an example was shown in which the front wheels 2 and rear wheels 3 were provided as the running gear. However, the vehicle is not limited to this, and a crawler running gear or a combination of wheels and mini-crawlers may also be used as the running gear.

[0064] (8) In the above-described embodiment, an example with a power take-off shaft 12 was shown, but an embodiment without a power take-off shaft 12 is also possible. [Industrial applicability]

[0065] The present invention can be applied to a work vehicle equipped with a hybrid transmission that has an engine, an electric transmission unit having a motor-generator unit, and a gear transmission unit having a gear transmission mechanism but without a motor-generator unit, arranged in a manner along the front-rear direction of the vehicle body, and which changes the speed of power from the engine and outputs it to the running gear. [Explanation of symbols]

[0066] 2. Front wheels (running gear) 3. Rear wheels (running gear) 5 Engine 13 Mission Case 16 Hybrid Transmission 16A Electric Transmission Unit 16B Gear Transmission Section 17. First Motor Generator 17c First rotation axis 18. Second Motor Generator 18c Second rotation axis 24 Motor Generator Section 30 Gear-driven motorized mechanism 100 Low-speed planetary gear shifting unit 110 High-speed planetary gearbox S Gap

Claims

1. The engine and A hybrid transmission comprising an electric transmission unit having a motor-generator unit and a gear transmission unit having a gear transmission mechanism but without a motor-generator unit, arranged in a manner along the longitudinal direction of the vehicle body, which changes the speed of the power from the engine and outputs it to the running gear, A transmission case for housing the hybrid transmission is provided, which is mounted on the vehicle body in a position aligned with the engine along the longitudinal direction of the vehicle body, The electric transmission unit has a first motor generator and a second motor generator, and is provided between the engine and the gear transmission unit. The first motor generator and the second motor generator are arranged such that the first rotation axis of the first motor generator and the second rotation axis of the second motor generator are aligned along the longitudinal direction of the vehicle body, and the first rotation axis and the second rotation axis are parallel to each other. The input shaft of the transmission case is provided so as to pass between the first motor generator and the second motor generator in the longitudinal direction of the vehicle body. A work vehicle comprising a gear transmission unit, a low-speed planetary gear shift unit that combines engine power from the input shaft and motor power from the second motor generator to output a low-speed combined power, and a high-speed planetary gear shift unit that combines engine power from the input shaft and motor power from the second motor generator to output a high-speed combined power that is faster than the low-speed combined power.

2. The engine and A hybrid transmission comprising an electric transmission unit having a motor-generator unit and a gear transmission unit having a gear transmission mechanism but without a motor-generator unit, arranged in a manner along the longitudinal direction of the vehicle body, which changes the speed of the power from the engine and outputs it to the running gear, A transmission case for housing the hybrid transmission is provided, which is mounted on the vehicle body in a position aligned with the engine along the longitudinal direction of the vehicle body, The electric transmission unit has a first motor generator and a second motor generator, and is provided between the engine and the gear transmission unit. The first motor generator and the second motor generator are arranged such that the first rotation axis of the first motor generator and the second rotation axis of the second motor generator are aligned along the longitudinal direction of the vehicle body, and the first rotation axis and the second rotation axis are parallel to each other. The input shaft of the transmission case is provided so as to pass between the first motor generator and the second motor generator in the longitudinal direction of the vehicle body. The first rotation axis and the second rotation axis are aligned parallel to each other in a direction along the width of the vehicle body. The input shaft passes through a location above the first and second rotational axes in the longitudinal direction of the vehicle body. A work vehicle in which the upper end of the input shaft is located above the upper end of the first motor generator and the upper end of the second motor generator.

3. The work vehicle according to claim 1 or 2, wherein the outer diameter of the first motor generator and the outer diameter of the second motor generator are different.

4. The rotation axis of one of the low-speed planetary gear shifting unit and the high-speed planetary gear shifting unit and the first rotation axis of the first motor generator are located on the same axis. The work vehicle according to claim 1, wherein the rotation axis of the other of the low-speed planetary gear shifting unit and the high-speed planetary gear shifting unit and the second rotation axis of the second motor generator are located on the same axis.

5. The aforementioned engine is located at the front of the vehicle body. The work vehicle according to any one of claims 1 to 4, wherein the transmission case is located next to the rear of the engine.

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