Electric work vehicle

Abstract

To provide, in preferred embodiments, an electric work vehicle such as an EV tractor.SOLUTION: According to a preferred embodiment, an electric work vehicle comprises: a rear housing; a gear casing; a first motor to drive a first rear wheel, the first motor being supported by the rear housing; a second motor to drive a second rear wheel, the second motor being supported by the rear housing; a third motor to drive a first electric work vehicle component other than wheels, the third motor being supported by the rear housing; and a fourth motor to drive a second electric work vehicle component other than wheels, the fourth motor being supported by the rear housing. The rear housing is wider than the gear casing in the left-right direction of the electric work vehicle. The rear housing houses the first motor, the second motor, the third motor, and the fourth motor. The gear casing houses first gears and second gears.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electric work vehicle (EV) such as an electric tractor. [Background technology]

[0002] Electric vehicles (EVs) are becoming more prevalent as the industry transitions from internal combustion engines to fully electric motors powered by battery systems. Summary of the Invention [Problem 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 problem]

[0005] An electric work vehicle according to a preferred embodiment of the present invention includes a rear housing, a gear casing, 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. The rear housing is wider than the gear casing in the left-right direction of the electric work vehicle. The rear housing accommodates the first motor, the second motor, the third motor, and the fourth motor. The gear casing accommodates a first gear located between the first motor and the first rear wheel, and a second gear located between the second motor and the second rear wheel.

[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 preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0008] [Figure 1A] 1 is a left front perspective view of an electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 1B] 1 is a right front perspective view of an electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 1C] 1 is a left rear perspective view of an electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 1D] 1 is a right rear perspective view of an electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 1E] 1 is a front view of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 1F] 1 is a right side view of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 1G] 1 is a left side view of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 1H] 1 is a top view of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 1I] FIG. 1 is a bottom view of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 1J] FIG. 1 is a bottom view of an electric work vehicle according to a preferred embodiment of the present invention, with certain members omitted for ease of explanation. [Diagram 2] FIG. 2 is a rear perspective view of the intermediate frame, battery housing, front frame, and rear frame of the electric work vehicle according to the preferred embodiment of the present invention. [Diagram 3] FIG. 2 is a rear perspective view of a battery housing and a front frame of the electric work vehicle according to the preferred embodiment of the present invention. [Figure 4] FIG. 2 is a front perspective view of a battery housing according to a preferred embodiment of the present invention. [Figure 5A]FIG. 2 is a left side view of a battery housing according to a preferred embodiment of the present invention. [Figure 5B] FIG. 2 is a right side view of a battery housing according to a preferred embodiment of the present invention. [Figure 5C] FIG. 2 is a left side view of the intermediate frame, battery housing, front frame, and rear frame of the electric work vehicle according to the preferred embodiment of the present invention. [Figure 5D] FIG. 2 is a right side view of the intermediate frame, battery housing, front frame, and rear frame of the electric work vehicle according to the preferred embodiment of the present invention. [Figure 6] 1 is a left upper perspective view showing a portion of a rear portion of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 7] 1 is a right-down perspective view showing a portion of a rear portion of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 8] 1 is a bottom left perspective view showing a portion of a rear portion of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 9] 1 is a top perspective view showing a portion of a rear portion of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention; [Figure 10] FIG. 1 is a top perspective view of a partially disassembled rear gear assembly of an electric work vehicle in accordance with a preferred embodiment of the present invention. [Figure 11] FIG. 2 is a rear perspective view of a partially disassembled rear gear assembly of an electric work vehicle in accordance with a preferred embodiment of the present invention. [Figure 12] FIG. 1 is a top perspective view of a partially disassembled rear gear assembly of an electric work vehicle in accordance with a preferred embodiment of the present invention. [Figure 13A] FIG. 2 is a bottom perspective view of a partially disassembled rear gear assembly of an electric work vehicle in accordance with a preferred embodiment of the present invention. [Figure 13B] FIG. 2 is a rear perspective view showing the arrangement of a rear motor of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 13C] FIG. 2 is a right rear perspective view showing the arrangement of a rear motor of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 14] FIG. 2 is a top view of a rear frame according to a preferred embodiment of the present invention. [Figure 15] FIG. 2 is a bottom view of the rear frame according to the preferred embodiment of the present invention. [Figure 16] FIG. 2 is a front view of a rear frame according to a preferred embodiment of the present invention. [Figure 17A] FIG. 2 is a right side view of a rear frame according to a preferred embodiment of the present invention. [Figure 17B] FIG. 2 is a right perspective view of a rear frame according to a preferred embodiment of the present invention. [Figure 18] FIG. 2 is a left side view of a rear frame according to a preferred embodiment of the present invention. [Figure 19] FIG. 2 is a left perspective view of a rear frame according to a preferred embodiment of the present invention. [Figure 20] FIG. 2 is a rear view of the rear frame according to the preferred embodiment of the present invention. [Figure 21A] FIG. 2 is a bottom perspective view of a hydraulic assembly according to a preferred embodiment of the present invention; [Figure 21B] FIG. 2 is a top left perspective view of a hydraulic assembly according to a preferred embodiment of the present invention; [Figure 22] FIG. 2 is a rear perspective view of the components of the parking assembly and gear shifting assembly according to a preferred embodiment of the present invention. [Figure 23] FIG. 2 is a front perspective view showing the components of the parking assembly and gear shifting assembly according to a preferred embodiment of the present invention. [Figure 24] FIG. 2 is a top perspective view of the components of the parking assembly and gear shifting assembly according to a preferred embodiment of the present invention; [Diagram 25] 1 is a cross-sectional view of components held within a rear frame of an electric work vehicle according to a preferred embodiment of the present invention. FIG. [Figure 26] FIG. 2 is a rear perspective view of a PTO assembly according to a preferred embodiment of the present invention. [Figure 27] 1 is a cross-sectional side view of a rear frame of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 28] 1 is a cross-sectional top view of a rear frame of an electric work vehicle according to a preferred embodiment of the present invention. [Figure 29] 1 is a cross-sectional side view of a rear frame of an electric work vehicle according to a preferred embodiment of the present invention. [Diagram 30] 1 is a cross-sectional front view of a rear frame of an electric work vehicle according to a preferred embodiment of the present invention. [Diagram 31] 2 is a cross-sectional rear view showing some of the components in the rear frame of the electric work vehicle according to the preferred embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The electric work vehicle according to the preferred embodiment of the present invention may be a tractor or other agricultural vehicle, however, any desired type of electric work vehicle is applicable to and can be used with the preferred embodiment of the present invention.

[0010] 1A to 1I show an electric work vehicle 1 according to a preferred embodiment of the present invention. FIGS. 1A and 1B are perspective views from the left front end and the right front end of the vehicle 1, respectively. FIG. 1C is an isometric view from the left rear end of the vehicle 1. FIG. 1D is an isometric view from the right rear end of the vehicle 1. FIG. 1E is a front view of the vehicle 1. FIGS. 1F and 1G are side views of the vehicle 1. FIGS. 1H and 1I are top and bottom views of the vehicle 1, respectively.

[0011] In a preferred embodiment of the present invention, as shown in, for example, FIG. 1A to FIG. 1H, a 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, a vehicle according to a preferred embodiment of the present invention is not particularly limited to four wheels, and may include any suitable number of wheels. For example, a vehicle according to a preferred embodiment may include only three wheels by removing one of the four wheels described above, include a fifth wheel (e.g., an additional wheel aligned with one pair of the four wheels described above, or a wheel provided at the front or rear of the vehicle), or include a pair of central wheels to provide a total of six wheels. In another preferred embodiment, tracks may be used instead of the 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 of the intermediate frame 6, a front frame 10 attached to the battery housing 8, and a rear housing 12 attached to the rear of the intermediate frame 6. In a preferred embodiment, as shown in Fig. 1I for example, a front axle 3 connected to a left front wheel 2L and a right front wheel 2R is connected and supported by the front frame 10, and a rear axle 5 connected to a left rear wheel 4L and a right rear wheel 4R is connected and supported by the rear housing 12.

[0013] In a preferred embodiment of the present invention, the front axle 3 includes a left axle housing 3L and a right axle housing 3R, as shown in Fig. 1I. The left axle housing 3L accommodates a first electric motor 14 (left front wheel electric motor) connected to a first gear train 15 to drive the left front wheel 2L, and the right axle housing 3R accommodates a second electric motor 16 (right front wheel electric motor) connected to a second gear train 17 to drive the right front wheel 2R. The first electric motor 14, the second electric motor 16, the first gear train 15 and the second gear train 17 are shown, for example, in Fig. 1J, in which the left axle housing 3L and the right axle housing 3R are omitted for illustrative purposes.

[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) that is connected to a third gear set 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) that is connected to a fourth gear set 21 to drive the right rear wheel 4R. Preferably, the rear housing 12 also includes a third motor housing portion 12-3 that houses a fifth electric motor 22 that is connected to a fifth gear set 23 to drive a first electric work vehicle component (e.g., power take-off (PTO)), as shown in, for example, FIG. 1J and FIG. 2. and a fourth motor housing 12-4 housing a sixth electric motor 24 coupled to a sixth gear set 25 to drive a moving 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, for example, in FIG. 1J, which omits elements including the rear housing 12 for purposes of illustration. 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 portion) 26, a second battery housing portion (battery housing portion) 28, a third battery housing portion (battery housing portion) 30, a fourth battery housing portion (battery housing portion) 32, and a fifth battery housing portion (battery housing portion) 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 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 in the vehicle width direction are equal or substantially equal to each other. FIGS. 4, 5A, and 5B show the battery housing 8 in a state where the battery housing portion cover is omitted for the purpose of explanation.

[0016] In a preferred embodiment, as shown in FIG. 3, for example, the first battery accommodating section 26 and the second battery accommodating section 28 are included in the first battery accommodating section 8-1 (rear battery accommodating section), the third battery accommodating section 30 and the fourth battery accommodating section 32 are included in the second battery accommodating section 8-2 (front upper battery accommodating section), and the fifth battery accommodating section 34 is included in the third battery accommodating section 8-3 (front lower battery accommodating section). In a preferred embodiment, the width of the first battery accommodating section 8-1 is equal to or substantially equal to the width of the second battery accommodating section 8-2, and the width of the third battery accommodating section 8-3 is smaller than the width of the first battery accommodating section 8-1 and the width of the second battery accommodating section 8-2. Preferably, the rear surface of the third battery accommodating section 8-3 is spaced apart from the front surface of the first battery accommodating section 8-1. In a preferred embodiment, the rear surface of the second battery accommodating section 8-2 intersects with the middle part of the first battery accommodating section 8-1 in the front-rear direction of the electric work vehicle in a top view and a side view.

[0017] As shown in Figures 4, 5A and 5B, each of the first battery housing section 26, the second battery housing section 28, the third battery housing section 30, the fourth battery housing section 32 and the fifth battery housing section 34 includes a plurality of battery module housing compartments, each adapted to house a battery module. In a preferred embodiment, each of the third battery housing section 30 and the fourth battery housing section 32 includes more battery module housing compartments than each of the first battery housing section 26 and the second battery housing section 28. Preferably, the fifth battery housing section 34 includes fewer battery module housing compartments than each of the first battery housing section 26 and the second battery housing section 28.

[0018] In a preferred embodiment of the present invention, one or more inverters 13 are connected to, attached to, or supported by the battery housing 8, as shown, for example, in Figures 5C and 5D. 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, the first inverter 13-1, the third inverter 13-3, the sixth inverter 13-6, and the seventh inverter 13-7 are disposed on the left side of the battery housing 8, as shown in Figure 5C. Preferably, the second inverter 13-2, the fourth inverter 13-4, and the fifth inverter 13-5 are disposed on the right side of the battery housing 8, as shown in Figure 5D. More specifically, as shown in FIGS. 5C and 5D, the seventh inverter 13-7 is attached to the left cover of the fifth battery accommodating section 34, and the first inverter 13-1, the third inverter 13-3, and the sixth inverter 13-6 are attached to the left cover of the second battery accommodating section 2. Alternatively, the first inverter 13-1 may be attached to the left cover of the vehicle 10, and 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 section 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, for example cooling structures such as a radiator / condenser fan.

[0020] In a preferred embodiment of the present invention, the front of the rear housing 12 is connected to the rear of the intermediate frame 6, and the front of the intermediate frame 6 is connected to the rear of the battery housing 8. FIGS. 6-8 show components attached to and housed within the rear housing 12. The components attached to and housed within the rear housing 12 preferably include, for example, a left hub casing 4L2, a right hub casing 4R2, the third to sixth electric motors 18, 20, 22, 24, the third to sixth gear sets 19, 21, 23, 25, a power take-off (PTO) 500, a hydraulic pump 510, a parking assembly 520, a gear shifting assembly 530, and a rear drive gear assembly 540 that includes components of the third to sixth gear sets 19, 21, 23, 25 and interacts with the third to sixth gear sets 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 supporting the left rear wheel 4L and a right rear wheel rim 4R1 supporting the 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 a 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 configured to drive the left rear wheel 4L and the right rear wheel 4R, respectively. The third electric motor 18 and the fourth electric motor 20 are accommodated / disposed in the first motor housing 12-1 and the second motor housing 12-2, respectively, adjacent to the front part of the rear housing 12. Furthermore, the sixth electric motor 24, which is preferably configured to drive a hydraulic pump 510 (described later), is disposed in the fourth motor housing 12-4, which is located 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.

[0023] In a preferred embodiment of the present invention, the fifth electric motor 22 is configured to drive the PTO 500. The fifth electric motor 22 is preferably attached to the third motor housing portion 12-3 located at the front 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 set 23. The fifth gear set 23 preferably includes a PTO motor gear (gear) 2302 driven by an 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 larger than each of the third electric motor 18, the fourth electric motor 20, and the sixth electric motor 24, and has a larger torque output and rated output. It is preferable.

[0024] As shown in Figs. 13B and 13C, the central axis of the fifth electric motor 22 is preferably located below the central axes of the third electric motor 18 and the fourth electric motor 20 (e.g., 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 on 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 Figures 25 and 26, the PTO 500 preferably includes a PTO input shaft 504 fixed to the PTO input shaft gear 2300. The PTO input shaft 504 extends in the front-rear direction of the electric work vehicle and is engaged 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 Figures 25 and 26 for clarity). The PTO output shaft 502 is configured to be able to engage and operate with a standard PTO agricultural attachment. 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 from the PTO input shaft gear 2300 to the outside of the gear casing 1200, as shown in FIG. 17B. The PTO housing 508 is preferably supported by the rear end of the gear casing 1200 and PTO support brackets 506 provided on the left and right sides of the electric vehicle, as shown in FIG. 9. The PTO support brackets 506 preferably contact both a portion of the PTO housing 508 and a portion of each of the left hub casing 4L2 and the right hub casing 4R2.

[0026] Next, components of the third gear train 19, the fourth gear train 21, the fifth gear train 23, and the sixth gear train 25 will be described with reference to Figs. 9-13A, which are various views of a part of a partially disassembled rear portion of an electric work vehicle according to a preferred embodiment of the present invention. The third gear train 19 preferably includes a left motor drive pinion gear (gear) 542L, a left motor transmission gear (gear) (speed change gear) 544L, a left drive ratio gear (gear) 546L, and a left wheel drive gear (gear) 4L3. Similarly, the fourth gear train 21 preferably includes a right motor drive pinion gear (gear) 542R, a right motor transmission gear (gear) (speed change 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 rotating 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 having different diameters including low speed gear teeth 5420L and high speed gear teeth 5422L, which are provided at both ends of a mesh clutch via a mesh ring 5362 controlled by a shift fork 536 (described in detail below), and are selectively engageable by the mesh clutch. Similarly, the right motor drive pinion gear 542R includes a plurality of diameter portions having different diameters including low speed gear teeth 5420R and high speed gear teeth 5422R, which are provided at both ends of mesh 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 respectively connected to the left motor drive pin. The left motor transmission gear 544L is arranged to mesh with the right motor driving pinion gear 542L and the right motor driving pinion gear 542R. Specifically, as shown in FIG. 12, the left motor transmission gear 544L preferably includes a plurality of diameter portions having different diameters, the low-speed gear teeth 5440L meshing with the low-speed gear teeth 5420L, the high-speed gear teeth 5442L meshing with the high-speed gear teeth 5422L, and the driving teeth 5444L meshing with the left driving ratio gear 546L. Similarly, the right motor transmission gear 544R preferably includes a plurality of diameter portions having different diameters, the low-speed gear teeth 5440R meshing with the low-speed gear teeth 5420R, the high-speed gear teeth 5442R meshing with the high-speed gear teeth 5422R, and the driving teeth 5444R meshing with the right driving ratio gear 546R.

[0029] The left drive ratio gear 546L and the right drive ratio gear 546R are arranged to mesh with the left wheel drive gear 4L3 and the right wheel drive gear 4R3, respectively. Specifically, the left drive ratio gear 546L includes a plurality of different diameter portions, each of which has 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, each of which has 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 so 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 left-right outermost portion of the third gear device 19 is located inside the third electric motor 18 in the left-right direction of the electric work vehicle, and the left-right outermost portion of the fourth gear device 21 is located inside the fourth electric motor 20 in the left-right direction of the electric work vehicle. 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, i.e., the central axis of the fifth electric motor 22, in the vertical direction of the electric work vehicle. Preferably, all 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 the preferred embodiment of the present invention preferably includes a parking assembly (e.g., a lock assembly) 520 structured to stop the electric work vehicle when the electric work vehicle is not being actively driven by a user, as shown in Figures 10, 11, and 22-24. The parking assembly 520 preferably includes a parking shaft 522 operable in the left-right direction of the electric work vehicle to engage with left and right parking pawls (pawls) 524L, 524R. The left and right parking pawls 524L, 524R can abut against parts of the third gear set 19 and the fourth gear set 21 to fix the rotational positions of the third gear set 19 and the fourth gear set 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. Furthermore, when the left and right parking claws 524L, 524R fix the rotational positions of the third gear unit 19 and the fourth gear unit 21, the wheels of the electric work vehicle are prevented from rotating in response to externally applied forces (for example, the inclination or tilt of the ground on which the electric work vehicle may be positioned, pushing and pulling forces applied by other vehicles, pushing and pulling forces applied by humans or animals, etc.).

[0032] The left and right parking pawls 524L and 524R are preferably rotatably supported by left and right parking pawl rotary supports 5240L and 5240R that permit the left and right parking pawls 524L and 524R to be selectively tilted toward and away from the left motor transfer gear 544L and right motor transfer gear 544R in response to lateral movement by the parking shaft 522. The parking pawls 524L, 524R preferably provide a biasing force acting on the left and right parking pawls 524L and 524R to pull them away from the left and right motor transfer gears 544L and 544R. The parking shaft 522 is preferably biased rightward, for example, by a bias spring 526, and includes two actuating projections 5220 and a flange 5222. The actuating projections 5220 are provided on each of the left and right parking pawls 524L, 524R. The actuating projections 5220 include angled engagement surfaces that urge the parking pawls 524L and 524R to engage with the outermost gears (gears) of the left motor transmission gear 544L and the outermost gears (gears) of the right motor transmission gear 544R when the parking shaft 522 is moved, for example, to the right of the electric work vehicle. Thus, the equilibrium state of the parking assembly 520 is preferably a parking position in which the left and right parking pawls 524L and 524R are engaged with the left motor transmission gear 544L and the right motor transmission gear 544R. The left and right parking pawls 524L, 524R are preferably constructed to simultaneously mesh and lock with the low speed gear teeth 5440L, 5440R of the left motor transfer gear 544L and the right motor transfer gear 544R.

[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. One of the flanges 5222, which may extend to a position outside the rear housing 12 because the parking shaft 522 extends through the parking shaft opening 1211 of the rear housing 12, is arranged to be engaged with a coupling 528 via a pull fork 5282. The coupling 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. Thus, the driver of the electric work vehicle can manually engage and disengage the parking assembly 520 through the operation of the coupling 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 on the rear housing 12. A parking actuator 529 is shown, for example, in FIG.

[0034] The parking actuator 529 preferably includes a motor (e.g., a servo motor, a stepping motor, etc.) and a rotating cam fixed to an output shaft of the motor, and can be controlled by a controller (e.g., a CPU, a vehicle ECU, a driving control device, etc.). The output shaft of the parking actuator 529 preferably intersects with the extending direction of the parking shaft 522. As shown in FIG. 9, for example, the parking actuator 529 is preferably disposed on the inside of the third electric motor 18 and the fourth electric motor 20 in the left-right direction of the electric work vehicle, and is preferably provided on the opposite side of the connecting portion 528 in the left-right direction of the electric work vehicle. More specifically, the parking actuator 529 is preferably disposed 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 rotating cam is structured to operate 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 driving 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. Thus, engagement and disengagement of the parking assembly 520 can be achieved using either or both of the linkage 528 and the parking actuator 529. Furthermore, operation of the parking actuator 529 can be achieved without affecting the relative position (arrangement) of the linkage 528 and the parking lever 5284. In the structure of the preferred embodiment of the present invention, it is possible to lock the rotation of both the left rear wheel 4L and the right rear wheel 4R by actuating a single parking shaft 522.

[0035] In accordance with a preferred embodiment of the present invention, the third gear train 19 and the fourth gear train 21 each preferably comprise high speed and low speed gear transmission paths that can be selectively engaged using a gear shifting assembly 530, as shown in Figures 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 transmission actuator (shift actuator) 532 that can be energized to generate a pushing force that moves the first shift rod 534 and the second shift rod 535 in opposite vectors in the left-right direction of the electric work vehicle. The first shift rod 534 and the second shift rod 535 are coupled to respective shift forks 536 that engage with meshing rings 5362 of the left motor drive pinion gear 542L and the right motor drive pinion gear 542R. When the shift fork 536 is moved laterally 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 moved laterally 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 (inward) toward the center of the electric work vehicle in the left-right direction of the electric work vehicle by a shift rod bias spring 537. The shift actuator 532 is preferably attached to the gear actuator holding portion 1206 of the rear housing 12 such that a portion of the shift actuator 532 is located outside the rear housing 12. The shift actuator 532 preferably includes a shift cam 538 that moves from a first cam position to a second cam position to apply a pressing force that moves the first shift rod 534 and the second shift rod 535. As shown in FIG. 23 and FIG. 24, the shift cam 538 preferably has point symmetry centered on the rotation axis of the shift cam 538. More specifically, the shift cam 538 may be an S-shaped cam. The shift actuator 532 is preferably arranged to rotate the shift cam 538 between the first cam position and the second cam position to change the gear engagement of the high range and the low range. The first and second shift rods 534, 535 are preferably biased inwardly by a shift cam 538. In the first cam position, the high speed gear teeth 5422L and 5422R are engaged for rotation by the third and fourth electric motors 18, 20, and in the second cam position, the low speed gear teeth 5420L and 5420R are engaged for rotation by the third and fourth electric motors 18, 20. Position sensors and / or encoders are preferably provided on the ends of the first and second shift rods 534, 535 and on the shift actuator 532 to determine when the shift actuator 532 has pushed the first and second shift rods 534, 535 far enough to reach the second cam position, thereby engaging the low speed gear.

[0038] 21A and 21B show a preferred embodiment of a hydraulic assembly of an electric work vehicle according to a preferred embodiment of the present invention. A control lever 509 and a coupling 599 for controlling the hydraulic assembly are preferably disposed on the right side of the electric work vehicle as shown in FIG. 1B, FIG. 1D, and FIG. 1H. The hydraulic assembly preferably includes a hydraulic pump 510 driven by the sixth electric motor 24 via a hydraulic motor drive gear 518 meshing with a hydraulic pump input gear 516 of the hydraulic pump 510. The hydraulic pump 510 is preferably mounted on the lower surface of the rear housing 12 as shown in FIG. 8, for example. The hydraulic pump 510 is preferably connected to a hydraulic pump coupling 511 which is connected to a hydraulic line (not numbered) 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 which is further connected to a return pipe 519 configured to collect lubricating oil / hydraulic oil from the inside of the rear housing 12. Filter Base 512 0 is preferably connected to a hydraulic pump 510 via a hydraulic connecting tube 514, as shown in Figures 7, 8, and 13A.

[0039] Further, in a preferred embodiment of the present invention, a power steering controller 570, a brake master cylinder 580, and a heat exchanger 590 are also connected to the hydraulic lines of the hydraulic assembly, as shown in FIG. 21B for example. The power steering controller is preferably electrically connected to a control computer of the electric work vehicle or mechanically operated in response to steering wheel operation by the driver. The power steering controller 570 is connected to and controls a steering cylinder 572 capable of rotating the left front wheel 2L and the right front wheel 2R. The heat exchanger 590 is configured to remove heat from the lubricating oil / hydraulic oil passing through the hydraulic assembly.

[0040] FIG. 25 is a cross-sectional view of components arranged / held in 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 gear of the third gear set 19 and the gear of the fourth gear set 21 in the left-right direction of the electric work vehicle. Furthermore, the PTO input shaft 504 is preferably located above the central axes of the left motor drive pinion gear 542L and the left motor drive pinion gear 542R in the up-down direction of the electric work vehicle. FIG. 26 shows that the PTO motor gear 2302 is preferably located 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 shaft center of the fifth electric motor 22 is preferably offset in the left-right direction of the electric work vehicle from the shaft center of the PTO input shaft 504 when the electric work vehicle is viewed from above. Furthermore, it is preferable that the axis of the PTO output shaft 502 is located lower than the axis of the PTO input shaft 504 in the vertical direction of the electric work vehicle.

[0041] In a preferred embodiment of the present invention, the rear housing 12 contains lubricating oil, preferably having an oil top surface when stationary. The recovery pipe 519 and the hydraulic filter 512 are disposed below the oil top surface in the vertical direction of the electric work vehicle, as shown in, for example, FIG. 13A and FIG. 25. Specifically, it is preferable that the oil top surface is located above the lower part of the PTO motor gear 2302 or below the lower part of the PTO input shaft 504 in the vertical direction of the electric work vehicle. In another preferred embodiment of the present invention, the oil top surface is at least as high as the shaft center of the PTO output shaft 502 in the vertical direction of the electric work vehicle. The lubricating oil may be, for example, gear oil, transmission fluid, hydraulic oil, etc. The PTO motor gear 2302 is preferably disposed below the oil top surface and / or below the PTO output shaft 502 in the vertical direction of the electric work vehicle. With this arrangement, at least two of the third gear arrangement 19 through the sixth gear arrangement 25 include gear teeth that rotate below a top surface of the oil to provide lubrication to the gears of the third gear arrangement 19 through the sixth gear arrangement 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 housing 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 housing section 12-2 preferably includes a motor shaft passage 12-15 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 portion 12-27 that supports the right motor drive pinion gear 542R.

[0044] The third motor accommodating portion 12-3 preferably includes a motor shaft passage 12-35 that allows the shaft of the fifth electric motor 22 to pass through the 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 the central portion of the rear housing 12, and a pump support portion 12-47 that supports the hydraulic pump 510.

[0045] 14, for example, a portion of the upper surface of the rear frame adjacent the fourth motor housing portion 12-4 preferably includes a parking actuator retainer 1204 configured to support the parking actuator 529. The rear of the rear housing 12 preferably defines a gear casing 1200 that houses the third gear set 19 and the fourth gear set 21. An upper portion of the gear casing 1200 preferably includes a gear access opening 1202, and a 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 passing through the rear housing 12, for example, to allow oil to circulate back into the rear housing 12 through hydraulic / oil passages. As shown in Figures 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 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 side of the rear housing 12 between the second motor housing 12-2 and the third motor housing 12-3. The side inlet opening 552 is preferably defined on the right side of the rear housing 12 adjacent to the second motor housing 12-2. The first flow path 553 preferably extends horizontally in the fore-aft 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 fore-aft direction of the electric vehicle. The front inlet opening 551 is preferably connected to an oil return from the brake master cylinder 580, while the side inlet opening 552 is preferably connected to a main oil return line. A first outlet opening 554 is preferably provided at the rear end of the first flow path 553 and supplies oil to a central reservoir in the rear housing 12. The first outlet opening 554 is preferably located above the right motor drive pinion gear 542R and is most preferably configured to drop oil onto the low speed gear teeth 5420R.

[0048] The second oil passage 560 preferably includes an upper inlet opening 561, a second flow passage 562, and a second outlet 563, as shown in, for example, FIG. 14 and FIG. 28 to FIG. 31. The second oil passage 560 preferably lubricates the third shaft (shaft) 1802 and the fourth shaft (shaft) 2002 of the third electric motor 18 and the fourth electric motor 20 connected to the left and right motor drive 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 in a central portion of the upper surface of the rear housing 12 and is connected to a low-pressure oil supply source. The second flow passage 562 preferably extends vertically downward from the upper inlet opening 561 to a central portion of the rear housing 12. The second outlet 563 is provided in an axial bottom portion of the second flow passage 562 and guides the oil input to the upper inlet opening 561 to components in the rear housing 12.

[0049] As shown in FIGS. 14, 16, 17A, and 27 to 31, a front inlet opening 551, The side inlet opening 552 and the upper inlet opening 561 are preferably disposed forward of the third shaft 1802 and the fourth shaft 2002 of the third electric motor 18 and the fourth electric motor 20 in the front-rear direction of the electric work vehicle. Furthermore, the oil output from the first oil passage 550 is preferably introduced above the fourth shaft 2002, and the oil output from the second oil passage 560 is preferably introduced into or between the third shaft 1802 and the fourth shaft 2002, as shown in FIG.

[0050] As shown in Figures 30 and 31, the rear housing 12 preferably includes a tank breather 400 that allows air to escape from inside the rear housing 12 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 an inner portion of the rear housing 12, allowing air to flow from inside the rear housing 12 into the second opening 404 and then flow out from the first opening 402. The tank breather 400 is preferably disposed 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] Although the preferred embodiments of the present invention have been described above, it should be understood that modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the invention, and therefore the scope of the invention is to be determined solely by the claims which follow. [Explanation of symbols]

[0052] 1 Electric work vehicle 12 Rear housing 500 Power Take Off (PTO) 1200 Gear casing

Claims

1. An electric work vehicle, A rear housing and A gear casing; 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; a fourth motor that drives components of the second electric work vehicle other than the wheels, the fourth motor being supported by the rear housing; the rear housing is wider than the gear casing in the left-right direction of the electric work vehicle, the rear housing accommodates the first motor, the second motor, the third motor, and the fourth motor, The gear casing accommodates a first gear positioned between the first motor and the first rear wheel, and a second gear positioned between the second motor and the second rear wheel.

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 upper surface of the rear housing includes a pair of protruding portions that form an hourglass or dumbbell shape when viewed from above or below the electric work vehicle.

5. 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.

6. The electric work vehicle according to claim 1 , wherein an axis of the third motor extends in a direction perpendicular or substantially 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 lower than 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 lower than 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 or the second motor and farther from the other of the first motor or 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 unit to drive the first rear wheel; the second motor is connected to a second gear unit to drive the second rear wheel; an outermost portion of the first gear device is located inside the first motor in the left-right direction of the electric work 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 electric work vehicle.

13. The electric work vehicle according to claim 12 , wherein an axis of the fourth motor extends parallel or substantially parallel to an axis of the first motor and an axis of the second motor.

14. The electric work vehicle according to claim 1 , wherein the gear casing is attached to a rear portion of the rear housing in the front-rear direction of the electric work vehicle.

15. The electric work vehicle according to claim 1 , 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 of claim 13 , wherein each of the first gear set and the second gear set 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); 18. The electric work vehicle according to claim 17, wherein the third motor is connected to the PTO via a PTO input shaft, the PTO input shaft extending from the front side of the rear housing through an opening in a rear side of the rear housing.

19. The electric work vehicle of claim 18 , wherein the PTO input 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 input shaft is located above the PTO output shaft in the up-down direction of the electric work vehicle.

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