Electric work vehicle

Abstract

To provide an electric work vehicle such as an electric tractor.SOLUTION: An electric work vehicle comprises: a frame; a rear housing; a first motor for driving a first front wheel, the first motor being supported by the frame; a second motor for driving a second front wheel, the second motor being supported by the frame; a third motor for driving a first rear wheel, the third motor being supported on the rear housing; and a fourth motor for driving a second rear wheel, the fourth motor being supported by the rear housing. The first motor and the second motor are spaced apart from each other by a first distance in a left-right direction of the electric work vehicle, whereas the third motor and the fourth motor are spaced apart from each other by a second distance in the left-right direction of the electric work vehicle. The first distance is shorter than the second distance.SELECTED DRAWING: Figure 32

Description

[Technical field]

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

[0002] Electric utility vehicles (EVs) are becoming more common 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] A preferred embodiment of an electric work vehicle according to the present invention includes a frame, a rear housing, a first motor supported by the frame and driving a first front wheel, a second motor supported by the frame and driving a second front wheel, a third motor supported by the rear housing and driving a first rear wheel, and a fourth motor supported by the rear housing and driving a second rear wheel. The first motor and the second motor are separated from each other by a first distance in the left-right direction of the electric work vehicle. The third motor and the fourth motor are separated from each other by a second distance in the left-right direction of the electric work vehicle. The first distance is shorter than the second distance.

[0006] According to a preferred embodiment of the present disclosure, an electric work vehicle can be provided.

[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 perspective view of an electric work vehicle according to a preferred embodiment of the present invention, viewed from the left front. [Figure 1B] 1 is a perspective view of an electric work vehicle according to a preferred embodiment of the present invention, viewed from the right front. [Figure 1C] 1 is a perspective view of an electric work vehicle according to a preferred embodiment of the present invention, as viewed from the left rear. [Figure 1D] 1 is a perspective view of an electric work vehicle according to a preferred embodiment of the present invention, as viewed from the right rear. [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 plan 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 components removed for illustrative purposes. [Diagram 2] 1 is a perspective view of an intermediate frame, a battery housing, a front frame, and a rear frame of an electric work vehicle according to a preferred embodiment of the present invention, as viewed from the rear. FIG. [Diagram 3] 1 is a perspective view of a battery housing and a front frame of an electric work vehicle according to a preferred embodiment of the present invention, as viewed from the rear. FIG. [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 perspective view of a portion of a rear portion of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention, viewed from the upper left. [Figure 7] 1 is a perspective view of a portion of a rear portion of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention, viewed from the lower right side. [Figure 8] 1 is a perspective view of a portion of a rear portion of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention, viewed from the lower left. [Figure 9] 1 is a 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, viewed from above. [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. 1 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. 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 13B] 1 is a perspective view showing the arrangement of a rear motor of an electric work vehicle according to a preferred embodiment of the present invention, as viewed from the rear. FIG. [Figure 13C] 1 is a perspective view showing the arrangement of a rear motor of an electric work vehicle according to a preferred embodiment of the present invention, as viewed from the right rear. FIG. [Figure 14] FIG. 2 is a plan 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 perspective view of a rear frame according to a preferred embodiment of the present invention, as viewed from the right. [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 perspective view of a rear frame according to a preferred embodiment of the present invention, as viewed from the left. [Figure 20] FIG. 2 is a rear view of the rear frame according to the preferred embodiment of the present invention. [Figure 21] FIG. 2 is a plan view of a front axle according to a preferred embodiment of the present invention. [Figure 22] FIG. 2 is a bottom view of a front axle according to a preferred embodiment of the present invention. [Diagram 23] FIG. 2 is a plan view of a partially exploded front axle according to a preferred embodiment of the present invention; [Figure 24] FIG. 2 is a bottom view of a partially exploded front axle according to a preferred embodiment of the present invention. [Diagram 25] FIG. 2 is a front perspective view of a partially exploded front axle according to a preferred embodiment of the present invention; [Figure 26] FIG. 2 is an enlarged rear left perspective view of a portion of a partially disassembled front axle in accordance with a preferred embodiment of the present invention; [Figure 27] FIG. 2 is an enlarged rear right perspective view of a portion of a partially disassembled front axle in accordance with a preferred embodiment of the present invention; [Figure 28] 1 shows an inner end of a first motor according to a preferred embodiment of the present invention. [Figure 29] 1 shows an inner end of a second motor according to a preferred embodiment of the present invention. [Diagram 30]FIG. 1 is a bottom view of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention. [Diagram 31] FIG. 2 is another bottom view of a partially disassembled electric work vehicle in accordance with a preferred embodiment of the present invention. [Diagram 32] FIG. 2 is yet another bottom view of a partially disassembled electric work vehicle in accordance with a preferred embodiment of the present invention. 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 utilized 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 of the vehicle 1 as viewed from the front left and front right, respectively. FIG. 1C is a perspective view of the vehicle 1 as viewed from the rear left. FIG. 1D is a perspective view of the vehicle 1 as viewed from the rear right. FIG. 1E is a front view of the vehicle 1. FIGS. 1F and 1G are side views of the vehicle 1, respectively. FIGS. 1H and 1I are plan 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, a fifth wheel (e.g., an additional wheel aligned with one of the four wheels, or a wheel provided at the front or rear of the vehicle), a pair of central wheels, and the like, for a total of six wheels. In another preferred embodiment, a vehicle may utilize tracks (crawlers) 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 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, the front axle 3 is connected to the left front wheel 2L and the right front wheel 2R, and the front axle 3 is connected and supported by the front frame 10, and similarly, the rear axle 5 is connected to the left rear wheel 4L and the right rear wheel 4R, and the rear axle 5 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 device 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 device 17 to drive the right front wheel 2R. For example, as shown in Fig. 1J, the first electric motor 14, the second electric motor 16, the first gear device 15, and the second gear device 17 are illustrated, and 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 accommodating portion 12-1 accommodating a third electric motor 18 (left rear wheel electric motor) connected to a third gear set 19 to drive the left rear wheel 4L, and a second motor accommodating portion 12-2 accommodating a fourth electric motor 20 (right rear wheel electric motor) connected to a fourth gear set 21 to drive the right rear wheel 4R. Preferably, the rear housing 12 also includes a third motor accommodating portion 12-3 accommodating a fifth electric motor 22 connected to a fifth gear set 23 to drive a first component (e.g., power take-off (PTO)) of the electric work vehicle, and a fourth motor accommodating portion 12-4 accommodating a sixth electric motor 24 connected to a sixth gear set 25 to drive a second component (e.g., a hydraulic device) of the electric work vehicle, as shown in Figs. 1J and 2, for example. 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 FIGURE 1J, with parts removed for illustration purposes, including the rear housing 12. In the bottom view of FIGURE 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 section 26, a second battery housing section 28, a third battery housing section 30, a fourth battery housing section 32, and a fifth battery housing section 34, which are each shown by dashed lines in FIG. 3. In a preferred embodiment, the first battery housing section 26 and the second battery housing section 28 are adjacent to each other in the width direction of the vehicle, and the third battery housing section 30 and the fourth battery housing section 32 are adjacent to each other in the width direction of the vehicle. In a preferred embodiment, the widths 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 in the vehicle width direction are equal or substantially equal to each other. FIGS. 4, 5A, and 5B show the battery housing section 8 with the battery housing section cover removed 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 disposed 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 portion 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 receive a battery module. In a preferred embodiment, each of the third battery housing section 30 and the fourth battery housing section 32 includes a greater number of 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 a fewer number of 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 may be attached to the left cover of the fifth battery accommodating section 34, the first inverter 13-1, the third inverter 13-3 and the sixth inverter 13-6 may be attached to the left cover of the second battery accommodating section 28, 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 accommodating 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 supplies power to the first electric motor 14, the second inverter 13-2 supplies power to the second electric motor 16, the third inverter 13-3 supplies power to the third electric motor 18, the fourth inverter 13-4 supplies power to the fourth electric motor 20, the fifth inverter 13-5 supplies power to the fifth electric motor 22, and the sixth inverter 13-6 supplies power to the sixth electric motor 24. The seventh inverter 13-7 may supply power to other components of the electric work vehicle 1, for example a cooling mechanism 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 to 8 show components attached to the rear housing 12 and housed therein. The components attached to the rear housing 12 and housed therein preferably include, for example, a left hub casing (hub and casing) 4L2, a right hub casing 4R2, the third electric motor to the sixth electric motor 18, 20, 22, 24, the third gear set to the sixth gear set 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 wheel drive gear assembly 540, and the rear wheel drive gear assembly 540 includes components that interact with the third gear set to the sixth gear set 19, 21, 23, 25.

[0021] The left hub casing 4L2 and the right hub casing 4R2 are respectively coupled 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 coupled 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 to the inside of 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 portion 12-1 and the second motor housing portion 12-2, respectively, adjacent to the front portion of the rear housing 12. More preferably, the sixth electric motor 24 is configured to drive a hydraulic pump 510 (described later), but is disposed in the fourth motor housing portion 12-4, and the fourth motor housing portion 12-4 is disposed lower than one of the third electric motor 18 and the fourth electric motor 20 in the vertical direction of the electric vehicle (electric work vehicle), so that the sixth electric motor 24 is disposed closer to one of the third electric motor 18 and the fourth electric motor 20 than the other 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 12-3 located at the front of the rear housing 12. The fifth electric motor 22 transmits rotational energy to the PTO 500 via the fifth gear set 23. The fifth gear set 23 preferably includes a PTO motor gear 2302 driven by an output shaft of the fifth electric motor 22 and a PTO input shaft 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 larger torque output and a larger rated output.

[0024] As shown in Figs. 13B and 13C, for example, as shown in Figs. 10 to 12, 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. 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, for example, as shown in Figs. 10 to 13C. 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, for example, as shown in Figs. 10 to 12. The central axes of the third electric motor 18 and the fourth electric motor 20 are preferably aligned with each other and arranged on the same straight line, for example, as shown in Figs. 10 to 12. The central axes of the fifth electric motor 22 and the sixth electric motor 24 are preferably arranged below the third electric motor 18 and the fourth electric motor 20 in the vertical direction of the electric vehicle, for example, as shown in Figs. 10 to 12.

[0025] 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 below with reference to Figs. 9 to 13A, which show a part of the rear part of a partially disassembled electric work vehicle according to a preferred embodiment of the present invention, viewed from different directions. The third gear train 19 preferably includes a left motor driven pinion gear 542L, a left motor transmission gear 506L, a left driving ratio gear 546L, and a left wheel driving gear 4L3. Similarly, the fourth gear train 21 preferably includes a right motor driven pinion gear 542R, a right motor transmission gear 544R, a right driving ratio gear 546R, and a right wheel driving gear 4R3.

[0026] The left motor driven pinion gear 542L and the right motor driven 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 driven pinion gear 542L includes portions with different diameters including low speed gear teeth 5420L and high speed gear teeth 5422L, which are provided at both ends of a dog clutch (a mesh clutch) via a dog ring 5362 (controlled by a speed change fork 536L (details will be described later)) and can be selectively engaged by the dog clutch. Similarly, the right motor driven pinion gear 542R includes portions with different diameters including low speed gear teeth 5420R and high speed gear teeth 5422R, which are provided at both ends of a dog clutch (a mesh clutch) via a dog ring 5362 (controlled by a speed change fork 536R (details will be described later)). The low speed gear teeth are preferably provided outside the high speed gear teeth in the left-right direction of the electric work vehicle.

[0027] The left motor transmission gear 544L is disposed to mesh (engage) with the left motor driven pinion gear 542L, and the right motor transmission gear 544R is disposed to mesh with the right motor driven pinion gear 542R. Specifically, for example, as shown in Fig. 12, the left motor transmission gear 544L preferably includes a plurality of portions having different diameters, i.e., low speed gear teeth 5440L that mesh (engage) with the low speed gear teeth 5420L, high speed gear teeth 5442L that mesh with the high speed gear teeth 5422L, and drive teeth 5444L that mesh with the left drive ratio gear 546L. Similarly, the right motor transmission gear 544R preferably includes multiple portions of different diameters, namely, low speed gear teeth 5440R that mesh (engage) with the low speed gear teeth 5420R, high speed gear teeth 5442R that mesh with the high speed gear teeth 5422R, and drive teeth 5444R that mesh with the right drive ratio gear 546R.

[0028] The left drive ratio gear 546L is arranged to mesh (engage) with the left wheel drive gear 4L3, and the right drive ratio gear 546R is arranged to mesh with the right wheel drive gear 4R3. Specifically, the left drive ratio gear 546L includes a plurality of portions with different diameters, i.e., input teeth 5460L that mesh (engage) with the drive teeth 5444L, and output teeth 5462L that mesh with the left wheel drive gear 4L3. Similarly, the right drive ratio gear 546R includes a plurality of portions with different diameters, i.e., input teeth 5460R that mesh (engage) with the drive teeth 5444R, and output teeth 5462R that mesh with the right wheel drive gear 4R3.

[0029] 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 outermost part in the left-right direction 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 outermost part in the left-right direction of the fourth gear device 21 is located inside the fourth electric motor 20 in the left-right direction of the electric work vehicle. The highest parts of the third gear device 19 and the fourth gear device 21 in the vertical direction of the electric work vehicle are preferably located above the fifth electric motor 22 or the central axis of the fifth electric motor 22 in the vertical direction of the electric work vehicle. Preferably, all parts 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.

[0030] The electric work vehicle according to a preferred embodiment of the present invention preferably includes a parking assembly (e.g., a lock assembly) 520 configured 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 to 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 claws 524L, 524R. The left and right parking claws 524L, 524R abut against parts of the third gear set 19 and the fourth gear set 21, thereby fixing 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, they prevent the wheels of the electric work vehicle from rotating in response to external 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.).

[0031] The left and right parking pawls 524L, 524R are preferably rotatably supported by left and right parking pawl rotary supports 5240L, 5240R which can selectively tilt the left and right parking pawls 524L, 524R toward or away from the left and right motor transmission gears 544L, 544R in response to lateral movement by the parking shaft 522. The parking pawls 524L, 524R preferably provide a biasing force to the parking pawls 524L, 524R that pulls the parking pawls 524L, 524R away from the left and right motor transmission gears 544L, 544R. The parking shaft 522 is preferably biased rightward, for example, by a biasing spring 526, and includes two actuating projections 5220 and a flange 5222. The actuating projection 5220 is provided on each of the left and right parking claws 524L, 524R. The actuating projection 5220 includes an inclined engagement surface, and when the parking shaft 522 is moved, for example, to the right of the electric work vehicle, the inclined engagement surface presses the parking claws 524L, 524R so that the parking claws 524L, 524R engage with the outermost gears of the left and right motor transmission gears 544L, 544R. Therefore, the equilibrium state of the parking assembly 520 is the parking position, and at this time, the left and right parking claws 524L, 524R are preferably in a state of engagement with the left and right motor transmission gears 544L, 544R. The left and right parking pawls 524L, 524R are preferably configured to engage and lock with low speed gear teeth 5440L, 5440R of the left and right motor change gears 544L, 544R.

[0032] The parking actuator 529 preferably includes a motor (e.g., a servo motor, a stepping motor, etc.) and a rotating cam fixed to the output shaft of the motor. The output shaft of the parking actuator 529 preferably has a direction in which the parking shaft 522 extends. The parking actuator 529 is preferably disposed inward of 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, for example. The rotating cam is configured to move 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. Thus, the parking assembly 520 can be engaged and disengaged using either or both of the linkage 528 and the parking actuator 529 (via the parking lever 5284 as shown in FIG. 1D, FIG. 1F, and FIG. 1H). Furthermore, the operation of the parking actuator 529 can be performed without affecting the position of the linkage 528. 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 operating a single parking shaft 522.

[0033] According to a preferred embodiment of the present invention, the third gear train 19 and the fourth gear train 21 each preferably include / constitute both a high speed gear transmission path and a low speed gear transmission path that may be selectively engaged through the use of a gear shifting assembly 530, as shown in Figures 10 and 11. The left and right high speed gear transmission paths are respectively constituted by high speed gear teeth 5422L, 5442L and high speed gear teeth 5422R, 5442R. The left and right low speed gear transmission paths are respectively constituted by low speed gear teeth 5420L, 5440L and low speed gear teeth 5420R, 5440R.

[0034] The transmission assembly 530 preferably includes a transmission actuator 532 that can be driven to generate a pushing force that moves the first transmission rod 534 and the second transmission rod 535 in opposite vector directions in the left-right direction of the electric work vehicle. The first transmission rod 534 and the second transmission rod 535 are connected to a transmission fork 536 that engages with dog rings 5362 of the left motor driven pinion gear 542L and the right motor driven pinion gear 542R. When the transmission fork 536 is moved laterally outward in the left-right direction of the electric work vehicle, the low speed gear teeth 5420L, 5420R mesh with each other and are rotated by the third electric motor 18 and the fourth electric motor 20. When the speed-changing fork 536 is moved laterally inward in the left-right direction of the electric work vehicle, the high-speed gear teeth 5422L, 5422R mesh with each other and are rotated by the third electric motor 18 and the fourth electric motor 20.

[0035] A preferred embodiment of the rear housing 12 of the electric work vehicle according to the present invention is shown in Figs. 14 to 20. The rear housing 12 preferably has a T-shape when viewed from above. The T-shape is preferably asymmetric in the left-right direction of the electric work vehicle. An upper portion of the rear housing 12 preferably includes a recess in which a gear actuator holding portion 1206 is defined. The gear actuator holding portion 1206 is configured to support a shift actuator 532.

[0036] 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 driven 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 driven pinion gear 542R.

[0037] 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.

[0038] 14, for example, a portion 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 configured to support the parking actuator 529. A gear casing 1200 is preferably formed at the rear of the rear housing 12 to house the third gear set 19 and the fourth gear set 21. A gear access opening 1202 is preferably provided at the top of the gear casing 1200, and a PTO opening 1210 is preferably provided at the rear of the gear casing 1200.

[0039] In a preferred embodiment of the present invention, the rear housing 12 preferably includes at least a first oil passage and a second oil passage extending through the rear housing 12, for example, to allow oil to circulate back into the rear housing 12 through hydraulic paths / oil passages. As shown in FIG. 14, FIG. 16 and FIG. 17A, the first oil passage 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 preferably includes a front inlet opening 551 and a side inlet opening 552. The front inlet opening 551 is preferably formed in 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 formed in the right side surface of the rear housing 12 adjacent to the second motor housing portion 12-2. The second oil passage preferably includes an upper inlet opening 561, as shown in FIG. 14.

[0040] As shown in Figures 14, 16 and 17A, the front inlet opening 551, the side inlet opening 552 and the upper inlet opening 561 are preferably positioned forward of the third shaft 1802 of the third electric motor 18 and the fourth shaft 2002 of the fourth electric motor 20 in the fore-and-aft direction of the electric work vehicle.

[0041] 21-27 are perspective views of a front axle 3 according to a preferred embodiment of the present invention. As shown in FIG. 21 and FIG. 22, the front axle 3 preferably includes a left axle housing 3L and a right axle housing 3R. The left axle housing 3L preferably houses at least a first electric motor 14 and a first gear set 15. Similarly, the right axle housing 3R preferably houses at least a second electric motor 16 and a second gear set 17. The respective ends of the left axle housing 3L and the right axle housing 3R are connected to a left steering knuckle (joint) 3L-2 and a right steering knuckle (joint) 3R-2, respectively. The left steering knuckle 3L-2 is connected to both the left wheel hub 3L-1 and the left tie rod 3L-3, and the right steering knuckle 3R-2 is connected to both the right wheel hub 3R-1 and the right tie rod 3R-3. The left front wheel 2L is attached to a left wheel hub 3L-1, and the right front wheel 2R is attached to a right wheel hub 3R-1.

[0042] The left tie rod 3L-3 and the right tie rod 3R-3 are connected to opposing ends of a steering cylinder 572. The steering cylinder 572 is preferably connected to a hydraulic assembly that can control the rotation of the left front wheel 2L and the right front wheel 2R in response to a steering device (e.g., a steering wheel, a yoke, a controller, etc.) that can be operated by a driver of the electric work vehicle. The left tie rod 3L-3 and the right tie rod 3R-3 are alternately pushed and pulled by the steering cylinder 572 to rotate the left steering knuckle 3L-2 and the right steering knuckle 3R-2. This allows the left front wheel 2L and the right front wheel 2R to be steered.

[0043] 23 to 25, the left axle housing 3L and the right axle housing 3R are removed to show the details of the first motor 14, the first gear device 15, the second motor 16, and the second gear device 17. The first motor 14 preferably includes a central axis located rearward of the rotation axis of the left wheel hub 3L-1 and the left front wheel 2L in the longitudinal direction of the electric work vehicle when the steering angles of the first wheel and the second wheel are zero. Similarly, the second motor 16 preferably includes a central axis located rearward of the rotation axis of the right wheel hub 3R-1 and the right front wheel 2R in the longitudinal direction of the electric work vehicle when the steering angles of the first wheel and the second wheel are zero.

[0044] 23 and 24, the rearmost ends of the first motor 14 and the second motor 16 in the front-rear direction of the electric work vehicle are preferably located forward of the rearmost ends of the left steering knuckle 3L-2 and the right steering knuckle 3R-2 in the front-rear direction of the electric work vehicle. The first gear device 15 is configured so that the rotation of the first motor 14 can be transmitted to the left front wheel 2L via the left wheel hub 3L-1, and the second gear device 17 is configured so that the rotation of the second motor 16 can be transmitted to the right front wheel 2R via the right wheel hub 3R-1.

[0045] 26 is an enlarged view of a portion of the front axle 3 including the first gear device 15. The first gear device 15 preferably includes a left gear bearing 410L, a left motor driven gear 412L, a left front transmission gear 414L, and a left front wheel drive gear 416L. An inner end of the left gear bearing 410L in the left-right direction of the electric work vehicle is preferably fixed to the first motor 14. The left front transmission gear 414L further preferably includes a large diameter gear portion 4142L and a small diameter gear portion 4144L.

[0046] 27 is an enlarged view of a portion of the front axle 3 including the second gear device 17. The second gear device 17 preferably includes a right gear bearing 410R, a right motor driven gear 412R, a right front transmission gear 414R, and a right front wheel drive gear 416R. An inner end of the right gear bearing 410R in the left-right direction of the electric work vehicle is preferably fixed to the second motor 16. The right front transmission gear 414R further preferably includes a large diameter gear portion 4142R and a small diameter gear portion 4144R.

[0047] FIG. 28 shows an inner end of the first motor 14 according to a preferred embodiment of the present invention. The first motor 14 preferably includes a first motor base plate (first motor board) 420 attached to the inner side of the first motor 14 in the left-right direction of the electric work vehicle. Preferably, the first motor base plate 420 is disposed adjacent to a plurality of first motor power supply terminals 432, and each of the plurality of first motor power supply terminals 432 is connected to each of the first motor power receiving terminals 434 of the first motor 14. Preferably, the first motor base plate 420 includes a plurality of openings 4202, which allow a conductor (wiring) extending from the inside of the first motor 14 to be connected to the first motor power receiving terminals 434, and also allow a cooling conduit connected to the cooling connector 1411 to extend through the first motor base plate 420. Preferably, the first motor 14 is a three-phase motor and includes three first motor power receiving terminals 434, each connected to a respective one of the three first motor power connection lines 430. Each of the three first motor power connection lines 430 is preferably connected to a respective one of the three first motor power supply terminals 432.

[0048] 29 shows an inner end portion of the second motor 16 according to a preferred embodiment of the present invention. The second motor 16 preferably includes a second motor base plate (second motor board) 422 attached to the inner side of the second motor 16 in the left-right direction of the electric work vehicle. Preferably, the second motor base plate 422 is disposed adjacent to a plurality of second motor power supply terminals 442, Each of the plurality of second motor power supply terminals 442 is connected to each of the second motor power receiving terminals 444 of the second motor 16. Preferably, the second motor base plate 422 includes a plurality of openings 4222, which allow a conductor (wiring) extending from the inside of the second motor 16 to be connected to the second motor power receiving terminals 444 and also allow a cooling conduit connected to the cooling connector 1411 to extend through the second motor base plate 422. Preferably, the second motor 16 is a three-phase motor and includes three second motor power receiving terminals 444, each of which is connected to each of the three second motor power connection lines 440. Each of the three second motor power connection lines 440 is preferably connected to each of the three second motor power supply terminals 442. The first motor power supply terminal 432 is preferably connected to the first inverter 13-1, and the second motor power supply terminal 442 is preferably connected to the second inverter 13-2.

[0049] As shown in Figs. 23 to 25, 28, 29 and 32, the first motor 14 and the second motor 16 are disposed in the left axle housing 3L and the right axle housing 3R, and at this time, the first motor base plate 420 and the second motor base plate 422 face each other in the left-right direction of the electric vehicle. The first motor base plate 420 and the second motor base plate 422 are disposed at a distance from each other to define a space between the first motor base plate 420 and the second motor base plate 422. Preferably, at least a part of the first motor power connection line 430 and at least a part of the second motor power connection line 440 are disposed in the space between the first motor base plate 420 and the second motor base plate 422. The first motor power receiving terminal 434 is preferably disposed at a rear portion of the first motor 14 in the front-rear direction of the electric work vehicle. The second motor power receiving terminal 444 is preferably disposed at a front portion of the second motor 16 in the front-rear direction of the electric work vehicle. The first motor power supply terminal 432 and the second motor power supply terminal 442 are preferably disposed at the same position in the fore-and-aft direction of the electric work vehicle. Furthermore, the first motor power receiving terminal 434 is preferably disposed at a position closer to both the first motor power supply terminal 432 and the second motor power supply terminal 442 than the second motor power receiving terminal 444.

[0050] As shown in Figures 24 and 28, preferably three first motor power connection lines 430 are routed from the first motor supply terminal 432 to the first motor receiving terminal 434. The first motor power connection lines 430 preferably extend no more than about half the circumference of the first motor base plate 420. More preferably, the first motor power connection lines 430 extend no more than about one-quarter of the circumference of the first motor base plate 420. As shown in Figures 24 and 29, preferably three second motor power connection lines 440 are routed from the second motor supply terminal 442 to the second motor receiving terminal 444. The second motor power connection lines 440 preferably extend no less than about one-half of the circumference of the second motor base plate 422. More preferably, the second motor power connection lines 440 extend no more than about three-quarters of the circumference of the second motor base plate 422. According to this arrangement, the second motor power connection line 440 preferably extends above and around the second motor base plate 422 to avoid any openings 4202 through which the cooling conduits connected to the cooling connector 1411 extend.

[0051] As shown in FIG. 29, at least one cable guide 450 is provided to hold a portion of the second motor power connection line 440 to the second motor base plate 422. The at least one cable guide 450 is disposed in the space between the first motor base plate 420 and the second motor base plate 422. The at least one cable guide 450 is preferably attached to a portion of the second power supply motor connection line 440 that is remote from the second motor power receiving terminal 444. As shown in FIG. 28, the length of the first motor power connection line 430 between the first motor power receiving terminal 434 and the first motor power supply terminal 432 is approximately 100 mm. Being much shorter in length than the connection line 440, the first motor power connection line 430 preferably does not require substantial cable guiding.

[0052] 30 to 32 are bottom views of a partially disassembled electric vehicle according to a preferred embodiment of the present invention, showing a preferred relative arrangement position of the motor in the electric work vehicle. The front axle 3 is preferably attached to the underside of the front frame 10 at a position overlapping a part of the battery housing 8 in the vertical direction of the electric work vehicle. As shown in FIG. 32, the outermost part of the first gear device 15 in the left-right direction of the electric work vehicle is preferably located outside the front frame 10 in the left-right direction of the electric work vehicle. Furthermore, the outermost part of the second gear device 17 in the left-right direction of the electric work vehicle is preferably located outside the front frame 10 in the left-right direction of the electric work vehicle. Both the first gear device 15 and the second gear device 17 preferably include a part that overlaps with the front frame 10 in the left-right direction of the electric work vehicle in a plan view.

[0053] The battery housing 8 is at least partially supported by the upper surface of the front frame 10. The outermost part of the first gear device 15 in the left-right direction of the electric work vehicle is preferably located outside the outer surface of the third battery accommodating section 8-3 and inside the outer surface of the second battery accommodating section 8-2 in the left-right direction of the electric work vehicle in a plan view. As shown in Figs. 30 and 32, a straight line extending parallel to the front-rear direction of the electric work vehicle may intersect both the third motor 18 and the side surface of the third battery accommodating section 8-3. Furthermore, the outermost part of the second gear device 17 is preferably located outside the outer surface of the third battery accommodating section 8-3 and inside the outer surface of the second battery accommodating section 8-2 in the left-right direction of the electric work vehicle in a plan view.

[0054] As shown in Figures 9-12, 23-25 ​​and 32, the first motor 14 and the second motor 16 are preferably spaced apart from each other by a first distance X in the left-right direction of the electric work vehicle, while the third motor 18 and the fourth motor 20 are preferably spaced apart from each other by a second distance Y in the left-right direction of the electric vehicle. The first distance X is preferably shorter than the second distance Y. The distance X must be sufficient to allow the first motor harness and cooling components (including the first motor power connection line 430, the first motor power receiving terminal 434, and the cooling conduit connected to the cooling connector 1411) and the second motor harness and cooling components (including the second motor power connection line 440, the second motor power receiving terminals 444, 450, and the cooling conduit connected to the cooling connector 1411) to be provided between the first motor base plate 420 and the second motor base plate 422. Furthermore, the distance Y must be sufficient to allow the third gear set 19, the fourth gear set 21 and the fifth gear set to be provided in the rear casing 12 between the third electric motor 18 and the fourth electric motor 20.

[0055] Although the preferred embodiments of the present invention have been described above, it should be understood that variations and modifications may 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]

[0056] 1 vehicle 2 Front wheels 3 Front Axle 4 Rear Wheel 5 Rear Axle 6 Intermediate Frame 8 Battery Housing 10 Front Frame 12 Rear housing 13 Inverter 14,16,18,20,22,24 Electric motor 15,17,19,21,23,25 Gearing 26, 28, 30, 32, 34 Battery compartment

Claims

1. A frame, A rear housing; a first motor supported by the frame and configured to drive a first front wheel; a second motor supported by the frame and configured to drive a second front wheel; a third motor supported by the rear housing and configured to drive a first rear wheel; a fourth motor supported by the rear housing and configured to drive a second rear wheel; the first motor and the second motor are spaced apart from each other by a first distance in a left-right direction of the electric work vehicle, the third motor and the fourth motor are spaced apart from each other by a second distance in the left-right direction of the electric work vehicle, An electric work vehicle, wherein the first distance is shorter than the second distance.

2. a battery housing including a wide battery accommodating portion and a narrow battery accommodating portion and supported by the frame; The electric work vehicle according to claim 1 , wherein a straight line extending parallel to a front-rear direction of the electric work vehicle intersects with both the third motor and a side surface of the narrow battery housing portion.

3. 3. The electric work vehicle according to claim 2, wherein the outermost portion of the first gear device driven by the first motor is located outside the outer surface of the narrow battery accommodating section and inside the outer surface of the wide battery accommodating section in the left-right direction of the electric work vehicle.

4. a front gear device that drives the first front wheel by connecting the first motor to the first front wheel and drives the second front wheel by connecting the second motor to the second front wheel; a plurality of front electrical harnesses electrically connected to the first motor and the second motor; a rear gear device that drives the first rear wheel by connecting the third motor to the first rear wheel, and drives the second rear wheel by connecting the fourth motor to the second rear wheel, the front gear device is disposed outboard of the first motor and the second motor in a left-right direction of the electric work vehicle, the plurality of front electric harnesses are disposed inward of the first motor and the second motor in a left-right direction of the electric work vehicle, The electric work vehicle according to claim 1 , wherein the rear gear unit is disposed more inward than the third motor and the fourth motor in the left-right direction of the electric work vehicle.

5. a fifth motor supported by the rear housing and configured to drive a first electric work vehicle component other than wheels; a sixth motor supported by the rear housing and configured to drive a second electric work vehicle component other than wheels; At least a portion of the rear gear device is located above the fifth motor in the vertical direction of the electric work vehicle, The electric work vehicle according to claim 4 , wherein the fifth motor is supported by the rear housing at a position between the third motor and the fourth motor.

6. The electric work vehicle according to claim 4 , wherein the first electric work vehicle component includes a power take-off (PTO).

7. The electric work vehicle according to claim 4 , wherein the second electric work vehicle component includes a hydraulic system.

8. The electric work vehicle according to claim 4 , wherein the shaft of the sixth motor extends parallel or substantially parallel to the shaft of the third motor and the shaft of the fourth motor.

9. The electric work vehicle according to claim 4 , wherein the shaft of the fifth motor extends perpendicular or substantially perpendicular to the shaft of the third motor and the shaft of the fourth motor.

10. The electric work vehicle according to claim 4 , wherein the shaft of the fifth motor is located lower than the shafts of the third motor and the fourth motor in the vertical direction of the electric work vehicle.

11. The electric work vehicle according to claim 4 , wherein the shaft of the sixth motor is located lower than the shafts of the third motor and the fourth motor in the vertical direction of the electric work vehicle.

12. The electric work vehicle according to claim 4 , wherein the shaft of the fourth motor is collinear with the shaft of the third motor.

13. The electric work vehicle according to claim 4 , wherein the fifth motor is disposed closer to one of the third motor and the fourth motor and farther away from the other of the third motor and the fourth motor.

14. The electric work vehicle according to claim 4 , wherein the fifth motor is larger than each of the first motor, the second motor, the third motor, the fourth motor, and the sixth motor.

15. a gear casing fixed to a portion of the rear housing; The electric work vehicle according to claim 1 , wherein a portion of the rear gear unit is disposed within the gear casing.

16. The electric work vehicle according to claim 15, wherein a width of the gear casing in the left-right direction of the electric work vehicle is narrower than a width of the rear housing in the left-right direction of the electric work vehicle.

17. the first rear wheel and the second rear wheel are connected to respective rear wheel hubs; The electric work vehicle of claim 15 , wherein the rear wheel hub is attached to the gear casing.

18. 16. The electric work vehicle of claim 15, wherein the rear gearing includes a plurality of linked gears extending from the rear housing to the gear casing.

19. the third motor is disposed on the left side of the rear housing, the fourth motor is disposed on the right side of the rear housing, the fifth motor is disposed on the front side of the rear housing, The electric work vehicle according to claim 4 , wherein the sixth motor is disposed on the left side of the rear housing.

20. the power take-off includes a PTO shaft connected to the fifth motor via at least one PTO gear; The electric work vehicle according to claim 6 , wherein the PTO shaft is disposed lower than an output shaft of the PTO in a vertical direction of the electric work vehicle.

Images