JP2017088096A - Electric work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a vehicle body balance and secure a sufficient battery space in an electric work vehicle which comprises a left motor for driving a left rear wheel and a right motor for driving a right rear wheel.SOLUTION: An electric work vehicle comprises: a battery pack 6 which is located between a left rear wheel disposed outside a left frame and a right rear wheel 12R disposed outside a right frame 22, and of which a front end is positioned in the front of an axle center Pr of a rear wheel 12; a left motor which is located above the battery pack 6 and on a periphery of the left rear wheel, to which electric power is supplied from the battery pack 6, and which transmits rotational power to the left rear wheel; and a right motor 4R which is located above the battery pack 6 and on a periphery of the right rear wheel, to which electric power is supplied from the battery pack 6, and which transmits rotational power to the right rear wheel 12R.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric work vehicle that includes a left motor and a right motor that are supplied with power from a battery pack, drives a left rear wheel by the left motor, and drives a right rear wheel by the right motor to travel.

  Patent Document 1 discloses a lawn mower in which a pair of left and right rear wheels are independently driven by a pair of left and right motors. The pair of left and right rear wheels are supported by a rear axle case extending between them. A gear case extends from the center portion of the rear axle case at a right angle to the extending direction of the rear axle case, and further, a left motor on the left side and a right motor on the right side extend from the front end portion of the gear case in the transverse direction of the vehicle body. Yes. Rotational power of each motor is transmitted to an axle built in the rear axle case through a power transmission mechanism built in the gear case. As is clear from FIG. 2 of Patent Document 1, a pair of left and right motors that extend linearly in the vehicle body transverse direction and a rear axle case that extends linearly in the vehicle body transverse direction, They are connected by a gear case extending in the longitudinal direction of the vehicle body. Therefore, the case structure having a mechanism for transmitting power from the motor to the rear wheels has a rather complicated shape, which causes a high cost. Further, since the pair of left and right motors are disposed inside the body frame and the battery is disposed between the pair of left and right motors, there is a problem that a large battery cannot be used.

  In Patent Document 2, a left motor that drives the left rear wheel and a right motor that drives the right rear wheel are attached to the outside of the frame, respectively, and an engine and a battery are disposed between the left motor and the right motor. A hybrid lawn mower is disclosed. The left motor and the right motor are wheel motors, and the rear wheel axis coincides with the motor rotation axis. In this structure, since the engine and the battery pack having a large weight are positioned behind the rear wheel shaft center, the weight balance regarding the rear wheel shaft center is deteriorated. However, since the center of gravity of the left motor and the right motor is substantially on the rear wheel shaft center, the left motor and the right motor cannot improve the deterioration of the weight balance.

International Publication No. 2013/015171 (FIGS. 1 and 2) JP 2008-168869 A

  In view of the above situation, in an electric work vehicle including a left motor for driving the left rear wheel and a right motor for driving the right rear wheel, improvement of the vehicle body balance and securing of sufficient battery space are demanded. .

  An electric work vehicle according to the present invention includes a left frame and a right frame extending in the longitudinal direction of the vehicle body at intervals in the transverse direction of the vehicle body, a left rear wheel disposed on the outer side of the left frame in the vehicle body direction, and the right frame. A rear wheel unit comprising a right rear wheel disposed on the outer side in the vehicle transverse direction of the vehicle, and is disposed between the left rear wheel and the right rear wheel, and a front end portion is forward of an axle of the rear wheel unit. A battery pack that is positioned, and a left motor that is disposed around the left rear wheel above the battery pack and that is supplied with power from the battery pack and transmits rotational power to the left rear wheel, and above the battery pack And a right motor which is arranged around the right rear wheel and which is supplied with power from the battery pack and transmits rotational power to the right rear wheel.

  According to this configuration, since the front end portion of the battery pack is positioned further forward than the rear wheel axle, the center of gravity of the battery pack remains on the side surface even when the battery pack is elongated and the rear end portion is positioned rearward. Since it does not deviate greatly from the rear axle, the adverse effect of the weight of the battery pack on the balance of the vehicle body is reduced. Further, by disposing the left motor and the right motor above the battery pack, the upper space of the battery pack is effectively utilized, and the overall length of the vehicle body can be suppressed and downsizing can be achieved.

  At this time, the battery pack is arranged so that the center of gravity of the battery pack enters the rear wheel section defined by the left rear wheel and the right rear wheel in the vehicle longitudinal direction and the vehicle transverse direction in plan view. The negative effects of battery packs on vehicle stability are almost negligible. The rear wheel section here means that the rear wheel diameter is one side length in the longitudinal direction of the vehicle around the rear axle that is the axis of the rear wheel, and the distance between the left rear wheel and the right rear wheel is the other side. A rectangle with a length. More preferably, the center of gravity of the battery pack is on the center line in the longitudinal direction of the vehicle body and within the radius of the rear wheel from the rear axle in the longitudinal direction of the vehicle body. Thereby, the weight of the battery pack contributes to the stability of the vehicle body.

  From the viewpoint of the stability of the vehicle body, it is desirable that the battery pack, which is a heavy object, be arranged low. However, when the ground height of the battery pack is low, the rear end of the battery pack comes into contact with the ground when traveling on a rough road or traveling uphill. In order to eliminate this inconvenience and secure the lowest possible center of gravity of the battery pack, it is desirable to lower the ground height of the front portion of the battery pack and increase the ground height of the rear portion of the battery pack. For this reason, in a preferred embodiment of the present invention, the battery pack includes a front rectangular parallelepiped portion and a rear rectangular parallelepiped portion shifted upward with respect to the front rectangular parallelepiped portion, and the battery pack includes upper and lower surfaces. It is formed as a stepped three-dimensional shape having steps. In particular, in order to suppress contact with the ground when traveling on rough roads or traveling uphill, the rear end of the battery pack is located behind the rear wheel unit in the longitudinal direction of the vehicle body, and the battery pack It is preferable that the ground height of the rear end is higher than the ground height of the rear axle case.

It is a side view which shows typically the relationship between the battery pack mounted in an electrically-driven work vehicle, and a rear wheel. It is a top view which shows typically the relationship between the battery pack mounted in an electrically-driven work vehicle, and a rear wheel. It is a side view of the riding type electric mower which is one of the embodiments of the electric work vehicle. It is a top view of a riding type electric mower. It is a perspective view which shows a vehicle body frame, a battery pack, and the drive mechanism of a rear-wheel unit. It is a perspective view of a battery pack. It is a cross-sectional view of a battery pack. It is an exploded view of a battery case.

  Before describing a specific embodiment of an electric work vehicle related to the present invention, the arrangement of a battery pack mounted on the electric work vehicle will be described with reference to FIGS. 1 and 2. In this specification, the longitudinal direction of the vehicle body is the direction of the vehicle body central axis (also referred to as the vehicle body longitudinal axis) that extends in the horizontal direction along the traveling direction of the vehicle body, and the vehicle body transverse direction (also simply referred to as the lateral direction). , A direction extending in the horizontal direction perpendicular to the center axis of the vehicle body. “Front (front)” means the forward side in the vehicle longitudinal direction, and “rear (back)” means the backward side in the vehicle longitudinal direction. “Left (left side)” means left when facing the vehicle body advance direction, and “Right (right side)” means right when facing the vehicle body advance direction.

  This electric work vehicle includes a left frame 21 and a right frame 22 that extend in the longitudinal direction of the vehicle body at intervals in the transverse direction of the vehicle body, and a vehicle body that includes at least one cross beam 23 that connects the left frame 21 and the right frame 22. A frame 20 is provided. The left front wheel 11 </ b> L and the right front wheel 11 </ b> R constituting the front wheel unit 11 are disposed in the front portion of the vehicle body frame 20. The left rear wheel 12L and the right rear wheel 12R constituting the rear wheel unit 12 are disposed rearward from the center of the vehicle body frame 20. In the following, unless it is particularly necessary to distinguish between the left front wheel 11L and the right front wheel 11R, the term front wheel unit 11 is used as a generic term, and the left rear wheel 12L and the right rear wheel 12R are generically used as a rear wheel. The term unit 12 is used. The rear axle center Pr extends in the vehicle body transverse direction.

  The battery pack 6 is disposed in the rear half region of the vehicle body frame 20 between the left frame 21 and the right frame 22, and the front end portion of the battery pack 6 is forward and substantially rearward of the rear axle Pr when viewed from the side. It is located near the front end of the wheel unit 12. The rear end of the battery pack 6 is located substantially at the rear end of the vehicle body frame 20. As apparent from FIG. 2, the battery pack 6 has a width that fits almost exactly between the left frame 21 and the right frame 22, and extends in the longitudinal direction of the vehicle body with an equal width. Further, the front half of the battery pack 6 enters the axle space of the rear wheel unit 12. A particularly preferable arrangement of the battery pack 6 is that the center of gravity of the battery pack 6 is located in a region between the front end and the rear end of the rear wheel unit 12 on the vehicle longitudinal center line, that is, from the rear axle to the rear wheel in the vehicle longitudinal direction. It is within the length of the radius. Thereby, the weight of the battery pack 6 does not deteriorate the vehicle body balance.

  Further, the battery pack 6 has a shape in which the rear half is shifted upward in the vertical direction with respect to the front half of the rectangular parallelepiped. That is, the battery pack 6 has a three-dimensional shape composed of the front rectangular parallelepiped portion 6F and the rear rectangular parallelepiped portion 6B, and the rear rectangular parallelepiped portion 6B protrudes upward with respect to the front rectangular parallelepiped portion 6F. That is, upward steps are formed on the upper and lower surfaces of the battery pack 6. Therefore, the ground height Hb of the rear half of the battery pack 6 is higher than the ground height Hf of the front half of the battery pack 6. In the example shown in FIG. 1, the ground height Hf of the front half of the battery pack 6 is substantially the same as the ground height of the lower end of the rear axle case 31 of the rear wheel unit 12. The ground height Hb of the rear half of the battery pack 6 is higher than the ground height of the rear axle case 31 and is substantially the same as the ground height of the rear axle center Pr. The minimum ground height of the vehicle body frame 20 at the portion supporting the battery pack 6 is substantially equal to the minimum ground height of the battery pack 6. Since the ground height Hf of the front half of the battery pack 6 is set low, the center of gravity of the battery pack 6 is lowered, and the running stability is improved. In addition, since the ground height Hb of the rear half of the battery pack 6 is set high, the rear end of the battery pack 6 or the vehicle body frame 20 may come into contact with the ground or stones when climbing or traveling on a rough road. Is low.

  As shown in FIG. 2, the left motor 4L that transmits rotational power to the left rear wheel 12L is disposed around the left rear wheel 12L above the front rectangular parallelepiped portion 6F that is the front half of the battery pack. The right motor 4R that transmits rotational power to the right rear wheel 12R is disposed around the right rear wheel 12R above the front rectangular parallelepiped portion 6F that is the front half of the battery pack. The left motor 4L and the right rear wheel 12R are arranged at symmetrical positions. The left motor 4L and the left rear axle case 31L are connected by a left transmission case 30L, and the right motor 4R and the right rear axle case 31R are connected to each other. Are connected by a right transmission case 30R. The left transmission case 30L is disposed outside the left frame 21, and the right transmission case 30R is disposed outside the right frame 22. The left motor 4L and the right motor 4R are collectively referred to as the motor 4. The left transmission case 30L and the right transmission case 30R are collectively referred to as the transmission case 30. The left rear axle case 31L and the right rear axle case 31R are collectively referred to as the rear axle case 31. A driver's seat 16 is disposed above the motor 4 to effectively use the space.

  In the battery pack 6 illustrated in FIG. 1 and FIG. 2, the front rectangular parallelepiped portion 6 </ b> F of the battery pack 6 has a form in which the upper right portion and the upper left portion thereof are lacked in order to further effectively use the space. A convex central portion 6Fc extending in the direction is created. For this reason, spaces are created on the left and right of the central portion 6Fc. The left motor 4L enters the space on the left side of the central portion 6Fc of the front rectangular parallelepiped portion 6F, and the right motor 4R enters the space on the right side of the central portion 6Fc.

  Next, one specific embodiment of the electric work vehicle will be described with reference to the drawings. FIG. 3 is a side view of a riding electric mower as an example of an electric work vehicle, and FIG. 4 is a plan view of the riding electric mower.

  As shown in FIGS. 3 and 4, the riding electric mower (hereinafter simply referred to as a mower) includes a vehicle body 10, and the vehicle body 10 includes a caster type including a left front wheel 11 </ b> L and a right front wheel 11 </ b> R. The front wheel unit 11 and a rear wheel unit 12 including a left rear wheel 12L and a right rear wheel 12R that are rotationally driven are supported on the ground. The vehicle body 10 has a vehicle body frame 20 as a base frame. The body frame 20 includes a left frame 21, a right frame 22, and a cross beam 23 that connects the left frame 21 and the right frame 22. A mower unit 13 is suspended from the vehicle body frame 20 via a link mechanism 14 between the front wheel unit 11 and the rear wheel unit 12. The mower unit 13 includes a blade transmission mechanism 131 and a blade 132 that is rotated by the blade transmission mechanism 131. A driver's seat 16 is disposed in the center region of the vehicle body 10 in the longitudinal direction of the vehicle body. The basic structure of the battery pack 6 and the basic arrangement in the vehicle body frame 20 adopt the contents described with reference to FIGS. 1 and 2.

  FIG. 5 is a perspective view showing the vehicle body frame 20, the battery pack 6, and the drive mechanism of the rear wheel unit 12. The drive mechanism that supplies rotational power to the rear wheel unit 12 includes a motor 4, a transmission case 30, and a rear axle case 31. As shown in FIG. 5, the left frame 21 and the right frame 22 branch up and down from the middle region and are connected again in the rear region. That is, the left frame 21 is a rear half region and includes an upper frame portion 21a and a lower frame portion 21b. Similarly, the right frame 22 is a rear half region, and includes an upper frame portion 22a and a lower frame portion 22b. In a side view, the left transmission case 30L is disposed in the region between the upper frame portion 21a and the lower frame portion 21b of the left frame 21, and in the region between the upper frame portion 22a and the lower frame portion 22b of the right frame 22. A right transmission case 30R is disposed. A left rear axle case 31L is connected to the left transmission case 30L, and the left rear wheel 12L is supported by the left rear axle case 31L. A right rear axle case 31R is connected to the right transmission case 30R, and the right rear wheel 12R is supported by the right rear axle case 31R. The left rear axle case 31L is a cylindrical body that supports and supports the left rear axle 41 of the left rear wheel 12L, and the outer shape thereof is a truncated cone shape. Similarly, the right rear axle case 31R is a cylindrical body that supports and supports the right rear axle 42 of the right rear wheel 12R, and its outer shape is a truncated cone shape. The battery pack 6 is such that the center of gravity of the battery pack 6 is located substantially on the center line in the longitudinal direction of the vehicle body in a plan view and is within the length of the rear wheel radius on the front side and the rear side from the rear axle axis Pr. Has been placed.

  The left transmission case 30L is a hollow body that extends from the left rear axle case 31L forward in the vehicle longitudinal direction so as to be orthogonal to the rear axle Pr that is also the center axis of the left rear axle case 31L, and has a gear transmission mechanism therein. The left transmission consisting of A mounting surface for the left motor 4L is formed on the power input portion 32f of the left transmission case 30L. Similarly, it is a hollow body that extends forward from the right rear axle case 31R in the front-rear direction of the vehicle body so as to be orthogonal to the rear axle center Pr that is also the center axis of the right rear axle case 31R. The transmission is built in. The gear transmission mechanism generally decelerates input power, but may be increased or may not increase or decrease. A mounting surface for the right motor 4R is formed on the power input portion 32f of the right transmission. In this embodiment, the left transmission case 30L and the left rear axle case 31L are integrally configured, and the right transmission case 30R and the right rear axle case 31R are integrally configured. As the left transmission and the right transmission, a chain electric mechanism, a transmission shaft mechanism, or the like may be employed instead of the gear transmission mechanism.

  The speed change operation for the left motor 4L and the right motor 4R is performed by a pair of left and right speed change levers 18 (see FIGS. 3 and 4) disposed on both sides of the driver seat 16. When the speed change lever 18 is held in the front-rear neutral position, the corresponding motor 4 is stopped, and by operating the speed change lever 18 forward from the neutral position, the corresponding motor 4 is driven to rotate forward to realize forward shift, and to the rear. By operating, the corresponding motor 4 is driven backward to realize reverse gear shifting. The left motor 4L and the right motor 4R are independently controlled at variable speeds by independent operation of the pair of left and right transmission levers 18 respectively. For example, when the pair of left and right shift levers 18 are operated from the neutral position in the forward direction with substantially the same operation amount, both the left rear wheel 12L and the right rear wheel 12R are driven at substantially the same speed, and the vehicle body 10 advances straight forward. . When the pair of left and right speed change levers 18 are operated from the neutral position in the rearward direction with substantially the same operation amount, the left rear wheel 12L and the right rear wheel 12R are driven in the reverse direction at substantially the same speed, and the vehicle body 10 travels straight and reverse. . Further, when the pair of left and right speed change levers 18 are operated with different operation amounts, the left rear wheel 12L and the right rear wheel 12R are driven at different speeds, and the vehicle body 10 turns. At that time, one of the left rear wheel 12L and the right rear wheel 12R is turned to a low speed close to zero speed, and the other is operated at a high speed to the forward side or the reverse side, thereby making a small turn. Further, by driving the left rear wheel 12L and the right rear wheel 12R in opposite directions, the vehicle body 10 can be spin-turned with the substantially central portion of the rear wheel unit 12 as the turning center.

  Hereinafter, the battery pack 6 will be described with reference to FIGS. 5, 6, 7, and 8. The battery pack 6 includes a plurality of battery modules 6 </ b> A housed in a battery case 60. In the description of the battery pack 6 using FIG. 1 and FIG. 2, the battery pack 6 is handled as an integrated battery case 60 and battery module 6A, and the front half of the battery pack 6 is a front rectangular parallelepiped portion. The rear half of the battery pack 6 was defined as the rear rectangular parallelepiped portion 6B. Further, a convex central portion 6Fc is formed in the upper half of the front rectangular parallelepiped portion 6F, the left motor 4L is disposed in the left space of the central portion 6Fc, and the right motor 4R is disposed in the right space of the central portion 6Fc. It has entered. Such an arrangement structure is also adopted in this embodiment. However, in the description of the battery pack 6 here, the structure of the battery case 60 and the battery module 6A, which are originally separate bodies, will be described separately.

  The battery case 60 is a molded product that is split into two vertically and includes an upper case 60a and a lower case 60b. However, in order to facilitate the description of the internal structure, the battery case 60 will be described by being divided into a front case portion 61 and a rear case portion 62.

  The front case part 61 is a solid body in which a convex center part 611 is formed at the upper part by denting the upper left part and the upper right part from a rectangular parallelepiped. In other words, the length in the transverse direction of the fuselage is shortened so that a motor storage space into which the left motor 4L and the right motor 4R enter is formed on both sides of the central portion 611 in the transverse direction of the fuselage. The rear case part 62 is a rectangular parallelepiped connected to the front case part 61 in the front-rear direction. The front case portion 61 and the rear case portion 62 are connected in a posture in which the rear case portion 62 is displaced upward, and the battery case 60 has a three-dimensional shape having a vertical difference between the front side and the rear side. The central portion 611 has an enlarged portion 612 that is enlarged leftward and rightward and upward in a connection region between the front case portion 61 and the rear case portion 62, and the internal space of the enlarged portion 612 is expanded.

  The rear case part 62 has a rectangular parallelepiped shape having the same lateral width (length in the vehicle body transverse direction) as the front case part 61. The rear case portion 62 is displaced upward with respect to the front case portion 61, and thus the battery case 60 has a stepped cubic shape having a step between the front case portion 61 and the rear case portion 62. .

  As shown in FIGS. 7 and 8, the battery case 60 divided into an upper case 60 a and a lower case 60 b has a horizontal partition that divides the inside vertically into a front case portion 61 and a rear case portion 62. A wall 63 is provided. By the horizontal partition wall 63, the inside of the front case portion 61 is divided into an upper first space S1 and a lower second space S2, and the interior of the rear case portion 62 is separated from the upper third space S3 and the lower side space S2. It is divided into the fourth space S4. The horizontal partition wall 63 is a plate material, and is formed so as to have an upper and lower step similar to that of the battery case 60 through bending, and the second space S2, the third space S3, and the fourth space S4 have substantially the same shape and volume. It has become. The first space S1 is smaller in width and height than other spaces. A vertical partition wall 64 is provided between the first space S1 and the third space S3.

  Battery modules 6A having the same specifications are accommodated in the second space S2, the third space S3, and the fourth space S4. As shown in FIG. 8, the battery module 6 </ b> A is a rectangular parallelepiped having a lower height than the vertical dimension and the horizontal dimension. A large number of battery cells 6a are accommodated in the battery module 6A.

  In the first space S1, an electrical unit 68 composed of a relay, a fuse, or the like provided on a power line connecting the battery module 6A and the outside is housed. The vertical partition wall 64 is equipped with a circulation fan 69 that sucks air from the first space S1 and sends it to the third space S3. The electrical system of the circulation fan 69 is incorporated in the electrical unit 68. The horizontal partition wall 63 has a front end gap G1 formed between the front end 63a and the front case portion 61, and a rear end gap G2 formed between the rear end 63b and the rear case portion 62. Furthermore, the battery case 60 has a sealed structure to such an extent that grass and dust do not enter the internal space from the outside, or air flow between the internal space and the outside is suppressed. As a result, the circulating air flow exits from the circulation fan 69, passes through the third space S3, the fourth space S4, and the second space S2 to reach the first space S1 and returns to the circulation fan 69. A path (indicated by an arrow in FIG. 7) is formed. The temperature of the four spaces of the battery case 60 is equalized by the circulating air flowing through the circulating air flow path. Further, the electrical unit 68 is cooled by such circulating air. In order to enhance this cooling effect, fins 60 f are formed on the wall surface of the battery case 60, although only partially illustrated. The fins 60f can be formed on the inner wall surface, the outer wall surface, or both of the battery case 60.

  An opening for maintenance and inspection of the electrical unit 68 is provided in the upper wall of the front case portion 61 and is normally closed by a lid 613.

  As shown in FIG. 3, in this embodiment, a work motor 4W that provides power to the mower unit 13 as a work device is disposed at the rear of the mower unit 13, and the power from the work motor 4W is transmitted to the blade via a belt. It is transmitted to the transmission mechanism 131. Instead, the work motor 4W can be arranged on the front side of the battery pack 6. At that time, the PTO shaft including the output shaft and the relay shaft from the work motor 4W is extended forward in the longitudinal direction of the vehicle body, and the power from the work motor 4W is transmitted to the mower unit 13 via the PTO shaft. It is transmitted to the blade transmission mechanism 131.

  The present invention can be applied to an electric work vehicle equipped with a battery that supplies power to the left motor and the right motor, the left rear wheel being driven by the left motor, and the right rear wheel being driven by the right motor.

4: Motor 4L: Left motor 4R: Right motor 10: Car body 11: Front wheel unit 12L: Left rear wheel 12R: Right rear wheel 13: Mower unit 14: Link mechanism 16: Driver's seat 18: Shift lever 20: Body frame 21: Left frame 22: Right frame 30L: Left transmission case 30R: Right transmission case 31L: Left rear axle case 31R: Right rear axle case 41: Left rear axle 42: Right rear axle 6: Battery pack 6B: Rear cuboid 6F: Front rectangular parallelepiped part 6Fc: Center part 6A: Battery module 6a: Battery cell 60: Battery case 60a: Upper case 60b: Lower case 60f: Fin 611: Center part 612: Enlarged part 613: Lid 61: Front case part 62: Rear case Part 63: Horizontal partition wall 64: Vertical partition wall 68: Electric Unit 69: circulation fan

Claims (8)

A left frame and a right frame extending in the longitudinal direction of the vehicle body at intervals in the transverse direction of the vehicle body,
A rear wheel unit comprising a left rear wheel disposed on the outer side in the vehicle transverse direction of the left frame and a right rear wheel disposed on the outer side in the vehicle body transverse direction of the right frame;
A battery pack disposed between the left rear wheel and the right rear wheel, the front end portion of which is located forward of the axle of the rear wheel unit;
A left motor that is disposed around the left rear wheel above the battery pack and that is powered from the battery pack and transmits rotational power to the left rear wheel;
A right motor that is disposed around the right rear wheel above the battery pack and that is powered from the battery pack and transmits rotational power to the right rear wheel;
Electric working vehicle equipped with.   2. The electric vehicle according to claim 1, wherein the center of gravity of the battery pack is in a rear wheel section defined by the left rear wheel and the right rear wheel in the longitudinal direction of the vehicle body and in the transverse direction of the vehicle body in a plan view. Work vehicle.   The battery pack includes a front rectangular parallelepiped portion and a rear rectangular parallelepiped portion shifted upward with respect to the front rectangular parallelepiped portion, and has a three-dimensional shape having a step between an upper surface and a lower surface of the battery pack. Or an electric work vehicle according to 2;   The rear end of the battery pack is located rearward of the rear wheel unit in the longitudinal direction of the vehicle body, and the ground height of the rear end of the battery pack is higher than the ground height of the rear axle case. The electric work vehicle according to any one of the above.   A front wheel unit comprising a left front wheel disposed outside the left frame in the vehicle transverse direction and a right front wheel disposed outside the right frame in the vehicle transverse direction; and the front wheel unit and the rear wheel The electric work vehicle according to any one of claims 1 to 4, wherein a mower unit is disposed between the units.   The electric work vehicle according to claim 5, wherein a work motor that supplies power to the mower unit is disposed in front of the front end portion of the battery pack. A left transmission case is disposed outside the left frame in the vehicle transverse direction, and the left transmission case houses a left transmission that transmits rotational power from the output shaft of the left motor to the axle of the left rear wheel,
A right transmission case is disposed outside the right frame in the transverse direction of the vehicle body, and the right transmission case houses a right transmission that transmits rotational power from an output shaft of the right motor to an axle of the right rear wheel. The electric work vehicle according to any one of Items 1 to 6.   The electric transmission according to claim 7, wherein the left transmission case is connected to the left frame along the longitudinal direction of the vehicle body, and the right transmission case is connected to the right frame along the longitudinal direction of the vehicle body. Work vehicle.

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