Electric work vehicle
The electric work vehicle addresses the challenge of efficiently powering multiple components by using a configuration with four motors supported by a rear housing, resulting in improved power efficiency and reduced complexity.
Patent Information
- Application Number
- JP2024186339
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-12-07
- Filing Date
- 2024-10-23
- Publication Date
- 2025-06-03
AI Technical Summary
Existing electric work vehicles, such as electric tractors, face challenges in efficiently powering multiple components and wheels, leading to complexity and potential inefficiencies in motor distribution and energy management.
The electric work vehicle employs a configuration with four motors: two for the rear wheels and two for additional components like a power take-off (PTO) and hydraulic systems, all supported by a rear housing, allowing for efficient distribution of power and reduced complexity.
This configuration enhances power efficiency, reduces mechanical complexity, and improves overall performance by ensuring that each component receives dedicated power, thereby optimizing the vehicle's operational capabilities.
Smart Images
Figure 2025084693000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an electric work vehicle (EV) such as an electric tractor.
Background Art
[0002] Electric vehicles (EVs) are becoming increasingly popular as the industry shifts from internal combustion engines to fully electric motors powered by battery systems.
Summary of the Invention
Problems to be Solved by the Invention
[0003] A preferred embodiment of the present invention provides an electric work vehicle such as an EV tractor.
[0004] A preferred embodiment of the present invention provides an electric work vehicle.
Means for Solving the Problems
[0005] The electric work vehicle according to a preferred embodiment of the present invention includes a rear housing, a first motor that drives a first rear wheel and is supported by the rear housing, a second motor that drives a second rear wheel and is supported by the rear housing, a third motor that drives a first electric work vehicle component other than the wheels and is supported by the rear housing, and a fourth motor that drives a second electric work vehicle component other than the wheels and is supported by the rear housing.
[0006] According to a preferred embodiment of the present disclosure, it is possible to provide an electric work vehicle.
[0007] The above and other features, elements, steps, configurations, characteristics, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings.
Brief Description of the Drawings
[0008]
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Mode for Carrying Out the Invention
[0009] The electric work vehicle according to a preferred embodiment of the present invention may be a tractor or other agricultural vehicle, but any desired type of electric work vehicle is applicable to the preferred embodiment of the present invention and can be used together with the preferred embodiment of the present invention.
[0010] Figures 1A to 1I show an electric work vehicle 1 according to a preferred embodiment of the present invention. Figures 1A and 1B are perspective views from the left front end and the right front end of the vehicle 1, respectively. Figure 1C is an isometric view seen from the left rear end of the vehicle 1. Figure 1D is an isometric view seen from the right rear end of the vehicle 1. Figure 1E is a front view of the vehicle 1. Figures 1F and 1G are side views of the vehicle 1. Figures 1H and 1I are a top view and a bottom view of the vehicle 1, respectively.
[0011] In a preferred embodiment of the present invention, as shown in Figures 1A to 1H for example, the vehicle 1 includes a left front wheel 2L, a right front wheel 2R, a left rear wheel 4L, and a right rear wheel 4R. However, the vehicle according to the preferred embodiment of the present invention is not particularly limited to four wheels and can include any appropriate number of wheels. For example, the vehicle according to a preferred embodiment may include only three wheels by removing one of the aforementioned four wheels, or may include a fifth wheel (for example, an additional wheel provided in a straight line with one set of the aforementioned four wheels, or a wheel provided at the front or rear of the vehicle, etc.), or may include a total of six wheels by including a pair of central wheels. In another preferred embodiment, tracks may be used instead of wheels.
[0012] In a preferred embodiment of the present invention, as shown in FIG. 2 for example, the vehicle 1 includes an intermediate frame 6, a battery housing 8 attached to the front portion of the intermediate frame 6, a front frame 10 attached to the battery housing 8, and a rear housing 12 attached to the rear portion of the intermediate frame 6. In a preferred embodiment, as shown in FIG. 1I for example, a front axle 3 connected to the left front wheel 2L and the right front wheel 2R is connected and supported by the front frame 10, and a rear axle 5 connected to the left rear wheel 4L and the right rear wheel 4R is connected and supported by the rear housing 12.
[0013] In a preferred embodiment of the present invention, as shown in FIG. 1I, the front axle 3 includes a left axle housing 3L and a right axle housing 3R. The left axle housing 3L houses a first electric motor 14 (left front wheel electric motor) connected to a first gear device 15 to drive the left front wheel 2L, and the right axle housing 3R houses a second electric motor 16 (right front wheel electric motor) connected to a second gear device 17 to drive the right front wheel 2R. The first electric motor 14, the second electric motor 16, the first gear device 15, and the second gear device 17 are shown in FIG. 1J, for example, in which the left axle housing 3L and the right axle housing 3R are omitted for the sake of explanation.
[0014] In a preferred embodiment of the present invention, the rear housing 12 includes a first motor housing portion 12-1 that houses a third electric motor 18 (left rear wheel electric motor) connected to a third gear device 19 to drive the left rear wheel 4L, and a second motor housing portion 12-2 that houses a fourth electric motor 20 (right rear wheel electric motor) connected to a fourth gear device 21 to drive the right rear wheel 4R. Preferably, the rear housing 12 also includes, as shown in FIGS. 1J and 2 for example, a third motor housing portion 12-3 that houses a fifth electric motor 22 connected to a fifth gear device 23 to drive a first electric work vehicle component (e.g., a power take-off (PTO)), and a fourth motor housing portion 12-4 that houses a sixth electric motor 24 connected to a sixth gear device 25 to drive a second electric work vehicle component (e.g., a hydraulic device). The third electric motor 18, the fourth electric motor 20, the fifth electric motor 22, and the sixth electric motor 24 are shown in FIG. 1J for example, but in this figure, the elements including the rear housing 12 are omitted for the sake of explanation. In the bottom view of FIG. 1J, the sixth electric motor 24 overlaps the third electric motor 18.
[0015] In a preferred embodiment of the present invention, the battery housing 8 includes a first battery housing portion (battery housing part) 26, a second battery housing portion (battery housing part) 28, a third battery housing portion (battery housing part) 30, a fourth battery housing portion (battery housing part) 32, and a fifth battery housing portion (battery housing part) 34, each of which is shown by a dashed line in FIG. 3. In a preferred embodiment, the first battery housing portion 26 and the second battery housing portion 28 are adjacent to each other in the vehicle width direction, and the third battery housing portion 30 and the fourth battery housing portion 32 are adjacent to each other in the vehicle width direction. In a preferred embodiment, the vehicle width direction widths of the first battery housing portion 26, the second battery housing portion 28, the third battery housing portion 30, the fourth battery housing portion 32, and the fifth battery housing portion 34 are equal or substantially equal. FIGS. 4, 5A, and 5B show the battery housing 8 with the battery housing cover omitted for the sake of explanation.
[0016] In a preferred embodiment, as shown in FIG. 3 for example, the first battery housing portion 26 and the second battery housing portion 28 are included in the first battery housing section 8-1 (rear battery housing section), the third battery housing portion 30 and the fourth battery housing portion 32 are included in the second battery housing section 8-2 (front upper battery housing section), and the fifth battery housing portion 34 is included in the third battery housing section 8-3 (front lower battery housing section). In a preferred embodiment, the width of the first battery housing section 8-1 is equal to or substantially equal to the width of the second battery housing section 8-2, and the width of the third battery housing section 8-3 is smaller than the width of the first battery housing section 8-1 and the width of the second battery housing section 8-2. Preferably, the rear surface of the third battery housing section 8-3 is spaced apart from the front surface of the first battery housing section 8-1. In a preferred embodiment, the rear surface of the second battery housing section 8-2 intersects the middle portion of the first battery housing section 8-1 in the front-rear direction of the electric work vehicle in top view and side view.
[0017] As shown in FIGS. 4, 5A and 5B, each of the first battery housing portion 26, the second battery housing portion 28, the third battery housing portion 30, the fourth battery housing portion 32 and the fifth battery housing portion 34 includes a plurality of battery module housing compartments, and these compartments are each adapted to house a battery module. In a preferred embodiment, each of the third battery housing portion 30 and the fourth battery housing portion 32 includes more battery module housing compartments than each of the first battery housing portion 26 and the second battery housing portion 28. Preferably, the fifth battery housing portion 34 includes fewer battery module housing compartments than each of the first battery housing portion 26 and the second battery housing portion 28.
[0018] In a preferred embodiment of the present invention, for example, as shown in FIGS. 5C and 5D, one or more inverters 13 are connected to the battery housing 8, attached to the battery housing 8, or supported by the battery housing 8. For example, the one or more inverters 13 may include a first inverter 13-1, a second inverter 13-2, a third inverter 13-3, a fourth inverter 13-4, a fifth inverter 13-5, a sixth inverter 13-6, and a seventh inverter 13-7. Preferably, as shown in FIG. 5C, the first inverter 13-1, the third inverter 13-3, the sixth inverter 13-6, and the seventh inverter 13-7 are arranged on the left side of the battery housing 8. Preferably, as shown in FIG. 5D, the second inverter 13-2, the fourth inverter 13-4, and the fifth inverter 13-5 are arranged on the right side of the battery housing 8. More specifically, as shown in FIGS. 5C and 5D, the seventh inverter 13-7 is attached to the left cover of the fifth battery housing 34, and each of the first inverter 13-1, the third inverter 13-3, and the sixth inverter 13-6 is attached to the left cover of the second battery housing 28, and each of the second inverter 13-2, the fourth inverter 13-4, and the fifth inverter 13-5 may be attached to the right cover of the first battery housing 26. However, the total number of inverters 13 is not limited, and the inverters 13 may be provided at other positions within the vehicle 1.
[0019] In a preferred embodiment of the present invention, the first inverter 13-1 can supply power to the first electric motor 14, the second inverter 13-2 can supply power to the second electric motor 16, the third inverter 13-3 can supply power to the third electric motor 18, the fourth inverter 13-4 can supply power to the fourth electric motor 20, the fifth inverter 13-5 can supply power to the fifth electric motor 22, and the sixth inverter 13-6 can supply power to the sixth electric motor 24. The seventh inverter 13-7 can supply power to other components of the electric work vehicle 1, such as a cooling structure like a radiator / condenser fan.
[0020] In a preferred embodiment of the present invention, the front portion of the rear housing 12 is connected to the rear portion of the intermediate frame 6, and the front portion of the intermediate frame 6 is connected to the rear portion of the battery housing 8. FIGS. 6 to 8 show the components attached to and housed in the rear housing 12. The components attached to and housed in the rear housing 12 preferably include, for example, a left hub casing 4L2, a right hub casing 4R2, third to sixth electric motors 18, 20, 22, 24, third to sixth gear devices 19, 21, 23, 25, a power take-off (PTO) 500, a hydraulic pump 510, a parking assembly 520, a gear shifting assembly (transmission assembly) 530, and components of the third to sixth gear devices 19, 21, 23, 25, and include a rear drive gear assembly 540 that interacts with the third to sixth gear devices 19, 21, 23, 25.
[0021] The left hub casing 4L2 and the right hub casing 4R2 are respectively connected to a left rear wheel rim 4L1 that supports a left rear wheel 4L and a right rear wheel rim 4R1 that supports a right rear wheel 4R. The inner ends of the left hub casing 4L2 and the right hub casing 4R2 are respectively connected to the left and right sides of the gear casing 1200 of the rear housing 12. The gear casing 1200 preferably includes a wheel hub access opening 1208 that allows a drive shaft to extend from the inside of the gear casing 1200 into the left hub casing 4L2 and the right hub casing 4R2.
[0022] In a preferred embodiment of the present invention, the third electric motor 18 and the fourth electric motor 20 are respectively structured to drive the left rear wheel 4L and the right rear wheel 4R. The third electric motor 18 and the fourth electric motor 20 are respectively housed / arranged in a first motor housing portion 12-1 and a second motor housing portion 12-2 adjacent to the front portion of the rear housing 12. Further, preferably, the sixth electric motor 24 configured to drive a hydraulic pump 510 (described later) is positioned below the other of the third electric motor 18 and the fourth electric motor 20 in the vertical direction of the electric vehicle so that the sixth electric motor 24 is closer to the other of the third electric motor 18 and the fourth electric motor 20 than to one of the third electric motor 18 and the fourth electric motor 20, and is arranged in a fourth motor housing portion 12-4.
[0023] In a preferred embodiment of the present invention, the fifth electric motor 22 is structured to drive the PTO 500. The fifth electric motor 22 is preferably attached to a third motor housing portion 12-3 located at the front portion of the rear housing 12. For example, as shown in FIG. 26, the fifth electric motor 22 transmits rotational energy to the PTO 500 via a fifth gear device 23. The fifth gear device 23 preferably includes a PTO motor gear (gear) 2302 driven by the output shaft of the fifth electric motor 22 and a PTO input shaft gear (gear) 2300 driven by the PTO motor gear 2302. The fifth electric motor 22 is preferably larger than each of the third electric motor 18, the fourth electric motor 20, and the sixth electric motor 24, and has a large torque output and a large rated output.
[0024] As shown in FIGS. 13B and 13C, the central axis of the fifth electric motor 22 is preferably positioned below the central axes of the third electric motor 18 and the fourth electric motor 20 (for example (Figs. 10 to 12). The central axis of the fifth electric motor 22 preferably extends perpendicular or substantially perpendicular to the central axes of the third electric motor 18 and the fourth electric motor 20, as shown in Figs. 10 to 13C for example. The central axis of the sixth electric motor 24 preferably extends parallel or substantially parallel to the central axes of the third electric motor 18 and the fourth electric motor 20, as shown in Figs. 10 to 12 for example. The central axes of the third electric motor 18 and the fourth electric motor 20 are preferably arranged in a straight line with each other, as shown in Figs. 10 to 12 for example. The central axes of the fifth electric motor 22 and the sixth electric motor 24 are preferably located below the third electric motor 18 and the fourth electric motor 20 in the vertical direction of the electric vehicle, as shown in Figs. 10 to 12 for example.
[0025] As shown in Figs. 25 and 26, the PTO 500 preferably includes a PTO input shaft 504 fixed to a PTO input shaft gear 2300. The PTO input shaft 504 extends in the longitudinal direction of the electric work vehicle and engages with a PTO output shaft 502 supported by a PTO housing 508. The PTO input shaft 504 preferably includes a rotation transmission portion 5041 that engages with a rotation transmission portion 5021 of the PTO output shaft 502. The rotation transmission portions 5021 and 5041 are preferably gear-shaped portions (the gear teeth of the rotation transmission portions 5021 and 5041 are omitted from Figs. 25 and 26 for clarity). The PTO output shaft 502 has a structure that can engage with a standard PTO agricultural accessory to operate. The PTO housing 508 is preferably connected to the rear end of the gear casing 1200, and a PTO opening 1210 is formed in the gear casing 1200 to allow the PTO input shaft 504 to extend outside the gear casing 1200 from the PTO input shaft gear 2300, as shown in Fig. 17B. The PTO housing 508 is preferably supported by the rear end of the gear casing 1200 and a PTO support bracket 506 provided on the left and right of the electric vehicle, as shown in Fig. 9. The PTO support bracket 506 preferably contacts both a part of the PTO housing 508 and a part of each of the left hub casing 4L2 and the right hub casing 4R2.
[0026] Next, regarding the components of the third gear device 19, the fourth gear device 21, the fifth gear device 23, and the sixth gear device 25, reference will be made to FIGS. 9 to 13A, which are a plurality of types of views of a part of the rear portion of the electric work vehicle in a partially disassembled state according to a preferred embodiment of the present invention. The third gear device 19 preferably includes a left motor drive pinion gear (gear) 542L, a left motor transmission gear (gear) (transmission gear) 544L, a left drive ratio gear (gear) 546L, and a left wheel drive gear (gear) 4L3. Similarly, the fourth gear device 21 preferably includes a right motor drive pinion gear (gear) 542R, a right motor transmission gear (gear) (transmission gear) 544R, a right drive ratio gear (gear) 546R, and a right wheel drive gear (gear) 4R3.
[0027] The left motor drive pinion gear 542L and the right motor drive pinion gear 542R are preferably directly connected to the rotation shafts of the third electric motor 18 and the fourth electric motor 20, respectively. The left motor drive pinion gear 542L includes a plurality of diameter portions with different diameters including low-speed gear teeth 5420L and high-speed gear teeth 5422L, and these are provided at both ends of the engagement clutch via an engagement ring 536 (details will be described later) controlled by a shift fork 536 and can be selectively engaged by the engagement clutch. Similarly, the right motor drive pinion gear 542R includes a plurality of diameter portions with different diameters including low-speed gear teeth 5420R and high-speed gear teeth 5422R provided at both ends of engagement rings 5362L and 5362R controlled by respective shift forks 536L and 536R.
[0028] The left motor transmission gear 544L and the right motor transmission gear 544R are arranged to mesh with the left motor drive pinion gear 542L and the right motor drive pinion gear 542R, respectively. Specifically, for example, as shown in FIG. 12, the left motor transmission gear 544L has a low-speed gear tooth 5440L that meshes with the low-speed gear tooth 5420L, a high-speed gear tooth 5442L that meshes with the high-speed gear tooth 5422L, and a drive tooth 5444L that meshes with the left drive ratio gear 546L, and a diameter It is preferable to include a plurality of different diameter portions. Similarly, the right motor transmission gear 544R preferably includes a plurality of different diameter portions having a low-speed gear tooth 5440R that meshes with the low-speed gear tooth 5420R, a high-speed gear tooth 5442R that meshes with the high-speed gear tooth 5422R, and a drive tooth 5444R that meshes with the right drive ratio gear 546R.
[0029] The left drive ratio gear 546L and the right drive ratio gear 546R are respectively arranged to mesh with the left wheel drive gear 4L3 and the right wheel drive gear 4R3. Specifically, the left drive ratio gear 546L includes a plurality of different diameter portions having an input tooth 5460L that meshes with the drive tooth 5444L and an output tooth 5462L that meshes with the left wheel drive gear 4L3. Similarly, the right drive ratio gear 546R includes a plurality of different diameter portions having an input tooth 5460R that meshes with the drive tooth 5444R and an output tooth 5462R that meshes with the right wheel drive gear 4R3.
[0030] The left wheel drive gear 4L3 and the right wheel drive gear 4R3 are preferably arranged such that their central axes are located between (i) the third electric motor 18 and the fourth electric motor 20 and (ii) the sixth electric motor 24 in the vertical direction of the electric work vehicle. The outermost lateral portions of the third gear device 19 in the left-right direction are located inside the electric work vehicle in the left-right direction relative to the third electric motor 18, and the outermost lateral portions of the fourth gear device 21 in the left-right direction are located inside the electric work vehicle in the left-right direction relative to the fourth electric motor 20. At least the highest portions of the third gear device 19 and the fourth gear device 21 are preferably located above the axis of the fifth electric motor 22, that is, above the central axis of the fifth electric motor 22, in the vertical direction of the electric work vehicle. Preferably, all portions of the third gear device 19, the fourth gear device 21, the fifth gear device 23, and the sixth gear device 25 are arranged between the third electric motor 18 and the fourth electric motor 20 in the left-right direction of the electric work vehicle.
[0031] The electric work vehicle according to a preferred embodiment of the present invention preferably includes a parking assembly (for example, a lock assembly) 520 structured to stop the electric work vehicle when the electric work vehicle is not actively driven by a user, as shown in FIGS. 10, 11, and 22 to 24. The parking assembly 520 preferably includes a parking shaft 522 operable in the left-right direction of the electric work vehicle so as to engage with left and right parking claws (stoppers) 524L and 524R. The left and right parking claws 524L and 524R abut against a part of the third gear device 19 and the fourth gear device 21, so that the third electric motor 18 and the fourth electric motor 20 cannot drive the left rear wheel 4L and the right rear wheel 4R, and the rotational positions of the third gear device 19 and the fourth gear device 21 can be fixed. Further, when the left and right parking claws 524L and 524R fix the rotational positions of the third gear device 19 and the fourth gear device 21, rotation of the wheels of the electric work vehicle is prevented in response to an externally applied force (for example, the inclination or tilt of the ground on which the electric work vehicle may be located, the pushing or pulling force applied by another vehicle, the pushing or pulling force applied by a human or an animal, etc.).
[0032] The left and right parking claws 524L and 524R are preferably rotatably supported by left and right parking claw rotating supports 5240L and 5240R. These rotating supports 5240L and 5240R can selectively tilt the left and right parking claws 524L and 524R towards and away from the left motor transmission gear 544L and the right motor transmission gear 544R in response to the lateral movement by the parking shaft 522. The parking claws 524L, 524R preferably apply a biasing force that acts on the left parking claw 524L and the right parking claw 524R to pull them away from the left motor transmission gear 544L and the right motor transmission gear 544R. The parking shaft 522 is preferably biased (urged) to the right, for example, by a bias spring 526, and includes two operating protrusions 5220 and a flange 5222. The operating protrusions 5220 are provided one by one on the left and right parking claws 524L, 524R respectively. When the parking shaft 522 is moved, for example, to the right of the electric work vehicle , the operating protrusions 5220 include angled engagement surfaces that press the parking claws 524L and 524R to engage with the outermost gears (gears) of the left motor transmission gear 544L and the right motor transmission gear 544R. Therefore, the equilibrium state of the parking assembly 520 is preferably the parking position where the left and right parking claws 524L and 524R are engaged with the left motor transmission gear 544L and the right motor transmission gear 544R. The left and right parking claws 524L, 524R preferably have a structure that meshes and locks with the low-speed gear teeth 5440L, 5440R of the left motor transmission gear 544L and the right motor transmission gear 544R simultaneously.
[0033] The parking shaft 522 preferably includes flanges 5222 provided at each end of the parking shaft 522, as shown, for example, in FIG. 23. Since the parking shaft 522 extends through the parking shaft opening 1211 of the rear housing 12, one of the flanges 5222 that may extend to a position outside the rear housing 12 is arranged to engage with the connecting portion 528 via the pull fork 5282. The connecting portion 528 is connected to a parking lever 5284 (shown in FIGS. 1D, 1F, and 1H) that can be manually operated by the driver of the electric work vehicle to pull the parking shaft 522 through the engagement between the flange 5222 and the pull fork 5282. Therefore, the driver of the electric work vehicle can manually engage and disengage the parking assembly 520 through the operation of the connecting portion 528. The other of the flanges 5222 is arranged to be locked by a parking actuator 529 fixed to a parking actuator holding portion 1204 provided in the rear housing 12. The parking actuator 529 is shown, for example, in FIG. 23.
[0034] The parking actuator 529 preferably includes a motor (e.g., a servo motor, a stepping motor, etc.) and a rotary cam fixed to the output shaft of the motor, and can be controlled by a controller (e.g., a CPU, a vehicle ECU, a travel control device, etc.). The output shaft of the parking actuator 529 preferably intersects the extending direction of the parking shaft 522. The parking actuator 529 is arranged, for example, inside the third electric motor 18 and the fourth electric motor 20 in the left-right direction of the electric work vehicle as shown in FIG. 9, and is preferably provided on the side opposite to the connecting portion 528 in the left-right direction of the electric work vehicle. More specifically, the parking actuator 529 is preferably arranged on the left side of the rear housing 12 and the parking shaft 522, while the connecting portion 528 is provided on the right side of the rear housing 12 and the parking shaft 522. The rotary cam has a structure that operates the parking shaft 522 in the left-right direction of the electric work vehicle by pressing or releasing the flange 5222. The operation of the parking actuator 529 can be controlled by a travel computer configured or programmed to control the motor, by a button on the dashboard of the electric work vehicle, and by any other desired method. Therefore, the engagement and disengagement of the parking assembly 520 can be performed using either or both of the connecting portion 528 and the parking actuator 529. Further, the operation of the parking actuator 529 can be performed without affecting the positional relationship (arrangement) between the connecting portion 528 and the parking lever 5284. In the structure of a preferred embodiment of the present invention, it is possible to lock the rotations of both the left rear wheel 4L and the right rear wheel 4R by operating a single parking shaft 522.
[0035] According to a preferred embodiment of the present invention, the third gear device 19 and the fourth gear device 21 each preferably include and / or form both a high-speed gear transmission path and a low-speed gear transmission path that can be selectively engaged using a gear shifting assembly 530, as shown in FIGS. 10, 11, and 22-24. The high-speed gear transmission path is formed by high-speed gear teeth 5422L and 5442L, and high-speed gear teeth 5422R and 5442R, respectively. The low-speed gear transmission path is formed by low-speed gear teeth 5420L, 5440L and low-speed gear teeth 5420R, 5440R, respectively.
[0036] The gear shifting assembly 530 preferably includes a shift actuator (shift actuator) 532 that can be energized to generate a pressing force for moving the first shift rod 534 and the second shift rod 535 in vectors facing each other within the left-right direction of the electric work vehicle. The first shift rod 534 and the second shift rod 535 are connected to respective shift forks 536 that engage with the meshing ring 5362 of the left motor-driven pinion gear 542L and the right motor-driven pinion gear 542R. When the shift fork 536 is laterally moved outward in the left-right direction of the electric work vehicle, the low-speed gear teeth 5420L, 5420R mesh and are rotated by the third electric motor 18 and the fourth electric motor 20. When the shift fork 536 is laterally moved inward in the left-right direction of the electric work vehicle, the high-speed gear teeth 5422L, 5422R mesh and are rotated by the third electric motor 18 and the fourth electric motor 20.
[0037] The first shift rod 534 and the second shift rod 535 are preferably biased inward (toward the center) in the left-right direction of the electric work vehicle by a shift rod bias spring 537. The transmission actuator 532 is preferably attached to the gear actuator holding portion 1206 of the rear housing 12 such that a part of the transmission actuator 532 is located outside the rear housing 12. The transmission actuator 532 preferably includes a shift cam 538 that moves from a first cam position to a second cam position and applies a pressing force to move the first shift rod 534 and the second shift rod 535. As shown in FIGS. 23 and 24, the shift cam 538 preferably has point symmetry about the axis of rotation of the shift cam 538. More specifically, the shift cam 538 may be an S-shaped cam. The transmission actuator 532 is preferably arranged to rotate the shift cam 538 between the first cam position and the second cam position in order to change the gear engagement of the high range and the low range. The first shift rod 534 and the second shift rod 535 are preferably biased inside the shift cam 538. In the first cam position, the high-speed gear teeth 5422L and 5422R are meshed so as to be rotated by the third electric motor 18 and the fourth electric motor 20, and in the second cam position, the low-speed gear teeth 5420L and 5420R are meshed so as to be rotated by the third electric motor 18 and the fourth electric motor 20. A position sensor and / or an encoder are preferably provided at the ends of the first shift rod 534 and the second shift rod 535 and the shift actuator 532 to identify that the shift actuator 532 has pushed the first shift rod 534 and the second shift rod 535 to a sufficient distance to reach the second cam position, thereby engaging the low-speed gear (gear).
[0038] Figures 21A and 21B show a preferred embodiment of the hydraulic assembly of an electric work vehicle according to a preferred embodiment of the present invention. The control lever (control lever) 509 for controlling the hydraulic assembly and the connecting portion 599 are preferably arranged on the right side of the electric work vehicle as shown in FIGS. 1B, 1D, and 1H. The hydraulic assembly preferably includes a hydraulic pump 510 that is driven by a sixth electric motor 24 via a hydraulic motor drive gear 518 that meshes with a hydraulic pump input gear 516 of the hydraulic pump 510. The hydraulic pump 510 is preferably attached to the lower surface of the rear housing 12, for example, as shown in FIG. 8. The hydraulic pump 510 is preferably connected to a hydraulic pump coupling 511 that is connected to a hydraulic line (not labeled) of the electric work vehicle. The hydraulic line connects the hydraulic pump 510 to a hydraulic filter 512 as shown in FIG. 13A. The hydraulic filter 512 preferably includes a filter base 5120, and this filter base 5120 is further connected to a recovery pipe 519 having a structure for collecting lubricating oil / working oil from the inside of the rear housing 12. The filter base 5120 is preferably connected to the hydraulic pump 510 via a hydraulic connection tube 514 as shown in FIGS. 7, 8, and 13A.
[0039] Furthermore, in a preferred embodiment of the present invention, as shown in FIG. 21B for example, a power steering controller 570, a brake master cylinder 580, and a heat exchanger 590 are also connected to the hydraulic line of the hydraulic assembly. The power steering controller is preferably electrically connected to the control computer of the electric work vehicle or mechanically operated according to the driver's steering wheel operation. The power steering controller 570 is connected to and controls a steering cylinder 572 that can rotate the left front wheel 2L and the right front wheel 2R. The heat exchanger 590 is structured to remove heat from the lubricating oil / working oil passing through the hydraulic assembly.
[0040] FIG. 25 is a cross-sectional view of components disposed / held within the rear housing 12 of an electric work vehicle according to a preferred embodiment of the present invention. The PTO input shaft 504 preferably extends between the gears of the third gear device 19 and the gears of the fourth gear device 21 in the left-right direction of the electric work vehicle. Further, the PTO input shaft 504 is preferably positioned above the central axes of the left motor drive pinion gears 542L and 542R in the up-down direction of the electric work vehicle. FIG. 26 shows that it is preferable that the PTO motor gear 2302 is disposed below the PTO input shaft 504 and the PTO input shaft gear 2300 of the PTO input shaft 504 in the up-down direction of the electric work vehicle. The diameter of the PTO input shaft gear 2300 is preferably smaller than the diameter of the fifth electric motor 22. The axis of the fifth electric motor 22 is preferably offset in the left-right direction of the electric work vehicle from the axis of the PTO input shaft 504 when the electric work vehicle is viewed from above. Further, the axis of the PTO output shaft 502 is preferably positioned below the axis of the PTO input shaft 504 in the up-down direction of the electric work vehicle.
[0041] In a preferred embodiment of the present invention, the rear housing 12 preferably contains lubricating oil having an oil upper surface at rest. The recovery pipe 519 and the hydraulic filter 512 are disposed below the oil upper surface in the up-down direction of the electric work vehicle, as shown in FIGS. 13A and 25, for example. Specifically, the oil upper surface is preferably positioned above the lower part of the PTO motor gear 2302 or below the lower part of the PTO input shaft 504 in the up-down direction of the electric work vehicle. In another preferred embodiment of the present invention, the oil upper surface is at least at the same height as the axis of the PTO output shaft 502 in the up-down direction of the electric work vehicle. The lubricating oil may be, for example, gear oil, transmission fluid, hydraulic oil, or the like. The PTO motor gear 2302 is preferably disposed below the upper surface of the oil and / or below the PTO output shaft 502 in the up-down direction of the electric work vehicle. With this arrangement, at least two of the third gear device 19 to the sixth gear device 25 include the teeth of the gears that rotate below the upper surface of the oil to provide lubrication to the gears from the third gear device 19 to the sixth gear device 25.
[0042] A preferred embodiment of the rear housing 12 of the electric work vehicle corresponding to the present invention is shown in Figs. 14 to 20. The rear housing 12 is preferably T-shaped when viewed from above. The T-shape is preferably asymmetric in the left-right direction of the electric work vehicle. The upper part of the rear housing 12 preferably includes a recessed portion in which a gear actuator holding portion 1206 is defined. The gear actuator holding portion 1206 is structured to support the shift actuator 532.
[0043] In a preferred embodiment of the present invention, the first motor accommodating section 12-1 preferably includes a motor shaft passage 12-15 that allows the shaft of the third electric motor 18 to pass through the central portion of the rear housing 12, and a gear shaft support section 12-17 that supports the left motor drive pinion gear 542L. As shown in Fig. 17A, the second motor accommodating section 12-2 preferably includes a motor shaft passage 12-25 that allows the shaft of the fourth electric motor 20 to pass through the central portion of the rear housing 12, and a gear shaft support section 12-27 that supports the right motor drive pinion gear 542R.
[0044] The third motor housing portion 12-3 is preferably configured such that the shaft of the fifth electric motor 22 is disposed in the rear housing. The fourth motor accommodating portion 12-4 preferably includes a motor shaft passage 12-35 that allows the shaft of the sixth electric motor 24 to pass through a central portion of the rear housing 12, and a PTO input shaft support portion 12-37 that supports the PTO input shaft gear 2300 and the PTO input shaft 504. The fourth motor accommodating portion 12-4 preferably includes a motor shaft passage 12-45 that allows the shaft of the sixth electric motor 24 to pass through a central portion of the rear housing 12, and a pump support portion 12-47 that supports the hydraulic pump 510.
[0045] As shown in FIG. 14, for example, a part of the upper surface of the rear frame adjacent to the fourth motor housing portion 12-4 preferably includes a parking actuator holding portion 1204 having a structure for supporting the parking actuator 529. The rear portion of the rear housing 12 preferably defines a gear casing 1200 that houses the third gear device 19 and the fourth gear device 21. The upper portion of the gear casing 1200 preferably includes a gear access opening 1202, and the rear portion of the gear casing 1200 preferably includes a PTO opening 1210.
[0046] In a preferred embodiment of the present invention, the rear housing 12 preferably includes at least a first oil passage 550 and a second oil passage 560 that penetrate the rear housing 12, for example, enabling oil to circulate back into the rear housing 12 through a hydraulic passage / oil passage. As shown in FIGS. 14, 16, 17A, 27, and 28, the first oil passage 550 is preferably provided on the right side of the rear housing 12 adjacent to the second motor housing portion 12-2. The first oil passage 550 preferably includes a front inlet opening 551, a side inlet opening 552, a first flow path 553, and a first outlet opening 554. The front inlet opening 551 is preferably defined on the front surface of the rear housing 12 between the second motor housing portion 12-2 and the third motor housing portion 12-3. The side inlet opening 552 is preferably defined on the right side surface of the rear housing 12 adjacent to the second motor housing portion 12-2. The first flow path 553 preferably extends horizontally in the front-rear direction of the electric vehicle.
[0047] The front inlet opening 551 and the side inlet opening 552 preferably extend perpendicular to each other and are connected to a first flow path 553 that extends in the longitudinal direction of the electric vehicle. The front inlet opening 551 is preferably connected to the oil return port from the brake master cylinder 580, while the side inlet opening 552 is preferably connected to the main oil return line. The first outlet opening 554 is preferably provided at the rear end of the first flow path 553 and supplies oil to the central reservoir of the rear housing 12. The first outlet opening 554 is preferably located above the right motor-driven pinion gear 542R, and most preferably has a structure that drops oil onto the low-speed gear teeth 5420R.
[0048] The second oil path 560 preferably includes an upper inlet opening 561, a second flow path 562, and a second outlet 563, as shown in FIGS. 14 and 28 to 31, for example. The second oil path 560 preferably lubricates the third shaft (axis) 1802 and the fourth shaft (axis) 2002 of the third electric motor 18 and the fourth electric motor 20 connected to the left and right motor-driven pinion gears 542L, 542R. The third and fourth shafts 1802 and 2002 are preferably at least partially hollow. The upper inlet opening 561 is preferably provided at the central portion of the upper surface of the rear housing 12 and is connected to a low-pressure oil supply source. The second flow path 562 preferably extends vertically downward from the upper inlet opening 561 to the central portion of the rear housing 12. The second outlet 563 is provided at the axial bottom of the second flow path 562 and guides the oil input through the upper inlet opening 561 to the components within the rear housing 12.
[0049] As shown in FIGS. 14, 16, 17A, and 27 to 31, the front inlet opening 551, the side inlet opening 552, and the upper inlet opening 561 are preferably arranged in front of the third shaft 1802 and the fourth shaft 2002 of the third electric motor 18 and the fourth electric motor 20 in the longitudinal direction of the electric work vehicle. Further, the oil output from the first oil path 550 is preferably introduced above the fourth shaft 2002 and the second oil path 560 The oil output from [the relevant part] is preferably introduced to a position inside or between the third shaft 1802 and the fourth shaft 2002, as shown in FIG. 31.
[0050] As shown in FIGS. 30 and 31, the rear housing 12 preferably includes a tank breather 400 that allows air to escape from the inside to the outside of the rear housing 12. The tank breather 400 preferably includes a first opening 402 and a second opening 404. The first opening 402 preferably opens upward from the upper surface of the rear housing 12. The second opening 404 preferably opens to the inner part of the rear housing 12, allowing air to flow from the inside of the rear housing 12 into the second opening 404 and then flow out from the first opening 402. The tank breather 400 is preferably arranged on the opposite side of the rear housing 12 with respect to the first oil passage 550 in the left - right direction of the electric work vehicle.
[0051] As described above, the preferred embodiments of the present invention have been explained. It should be understood that modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. Therefore, the scope of the present invention is determined only by the following claims.
Explanation of Reference Numerals
[0052] 1 Electric work vehicle 12 Rear housing 500 Power take - off (PTO) 1200 Gear casing
Claims
1. A rear housing; a first motor for driving a first rear wheel, the first motor being supported by the rear housing; a second motor for driving a second rear wheel, the second motor being supported by the rear housing; a third motor that drives components of the first electric work vehicle other than the wheels, the third motor being supported by the rear housing; an electric work vehicle including a fourth motor that drives second electric work vehicle components other than wheels, the fourth motor being supported by the rear housing;
2. The electric work vehicle of claim 1 , wherein the first electric work vehicle component includes a power take off (PTO).
3. The electric work vehicle of claim 1 , wherein the second electric work vehicle component includes a hydraulic system.
4. The electric work vehicle according to claim 1 , wherein an axis of the third motor extends through a position between the first motor and the second motor.
5. The electric work vehicle according to claim 1 , wherein an axis of the fourth motor extends parallel or approximately parallel to an axis of the first motor and an axis of the second motor.
6. The electric work vehicle according to claim 1 , wherein an axis of the third motor extends perpendicular or approximately perpendicular to an axis of the first motor and an axis of the second motor.
7. The electric work vehicle according to claim 1 , wherein an axial center of the third motor is located below an axial center of the first motor and an axial center of the second motor in a vertical direction of the electric work vehicle.
8. The electric work vehicle according to claim 1 , wherein an axial center of the fourth motor is located below an axial center of the first motor and an axial center of the second motor in a vertical direction of the electric work vehicle.
9. The electric work vehicle according to claim 1 , wherein an axis of the second motor is collinear with an axis of the first motor.
10. The electric work vehicle according to claim 1 , wherein the third motor is located closer to one of the first motor and the second motor and farther from the other of the first motor and the second motor.
11. The electric work vehicle according to claim 1 , wherein the third motor is larger than each of the first motor, the second motor, and the fourth motor.
12. the first motor is connected to a first gear set to drive the first rear wheel; the second motor is connected to a second gear set to drive the second rear wheel; an outermost portion of the first gear device is located inside the first motor in a left-right direction of the vehicle, The electric work vehicle according to claim 1 , wherein an outermost portion of the second gear device is located inside the second motor in the left-right direction of the vehicle.
13. a gear casing attached to a portion of the rear housing; The electric work vehicle of claim 12 , wherein a portion of the first gear set and a portion of the second gear set are located within the gear casing.
14. The electric work vehicle according to claim 13 , wherein a width of the gear casing in the left-right direction of the vehicle is smaller than a width of the rear housing in the left-right direction.
15. The electric work vehicle according to claim 13 , wherein the first rear wheel and the second rear wheel are connected to respective rear wheel hubs attached to the gear casing.
16. The electric work vehicle according to claim 13 , wherein each of the first gear set and the second gear set includes a plurality of connecting gears and extends from the rear housing into the gear casing.
17. the first motor is located on the left side of the rear housing, the second motor is located on the right side of the rear housing, the third motor is located on the front side of the rear housing, The electric work vehicle according to claim 1 , wherein the fourth motor is located on the left side of the rear housing.
18. the first electric work vehicle component includes a power take-off (PTO); The electric work vehicle according to claim 17, wherein the third motor is connected to the PTO via a PTO shaft extending from a front side of the rear housing through an opening on a rear side of the rear housing.
19. The electric work vehicle of claim 18 , wherein the PTO shaft is connected to the third motor via at least one PTO gear.
20. The electric work vehicle according to claim 19, wherein the PTO shaft is located lower than an output shaft of the PTO in a vertical direction of the electric work vehicle.