Electric crawler vehicle

Abstract

To provide an electric crawler vehicle which can facilitate work for maintenance and assembly to a vehicle of electric motors (a traveling electric motor and a revolving electric motor).SOLUTION: An electric crawler vehicle includes: a pair of left and right traveling crawlers; a traveling electric motor which generates traveling power to be transmitted to the pair of left and right traveling crawlers; and a revolving electric motor which generates revolving power to be transmitted to the pair of left and right traveling crawlers. The traveling electric motor and the revolving electric motor are disposed at one side of the vehicle.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an electric crawler vehicle. [Background technology]

[0002] Conventionally, a technique has been proposed in which left and right traveling crawlers are driven independently by left and right electric motors, respectively (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-271317 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, the left and right electric motors are disposed on both sides (right and left) of the vehicle. In this configuration, when performing maintenance on each electric motor and assembling it to the vehicle, it is necessary to disassemble or remove the traveling crawlers on both sides and perform the work from both sides. For this reason, the maintenance on each electric motor and assembling it to the vehicle are not easy.

[0005] Furthermore, in a configuration in which the electric motors are lined up in the left-right direction, it is necessary to consider at least the axial dimension of each of the two electric motors as the width of the drive unit. In other words, the width of the drive unit includes the width obtained by adding up the axial dimensions of each of the two electric motors. For this reason, in a crawler vehicle equipped with the drive unit, restrictions are imposed on the setting of the center-to-center dimension (tread) of the left and right traveling crawlers. As a result, there is a concern that fewer tasks will be able to be performed. For example, depending on the agricultural work, the tread needs to be set narrow, but in a configuration in which the electric motors are lined up in the left-right direction, the tread may become too wide and it may become impossible to perform certain agricultural work.

[0006] The present invention has been made to solve the above problems, and its object is to provide an electric crawler vehicle that facilitates the maintenance and assembly of multiple electric motors to the vehicle, while also increasing the freedom in setting the tread. [Means for solving the problem]

[0007] An electric crawler vehicle according to one aspect of the present invention comprises a pair of left and right running crawlers, a running electric motor that generates running power which is transmitted to the pair of left and right running crawlers, and a turning electric motor that generates turning power which is transmitted to the pair of left and right running crawlers, the running electric motor and the turning electric motor being arranged on one side of the vehicle. Effect of the Invention

[0008] According to the above configuration, it is possible to facilitate the maintenance of a plurality of electric motors (electric motors for driving, electric motors for turning) and the work of assembling them to a vehicle, and it is also possible to improve the degree of freedom in setting the tread. [Brief description of the drawings]

[0009] [Figure 1] 1 is a left side view showing a schematic configuration of an electric crawler that is an example of an electric crawler vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a right side view showing a schematic configuration of the electric crawler. [Diagram 3] 4 is a perspective view of a first reducer included in the electric crawler. FIG. [Figure 4] FIG. 2 is a perspective view of the inside of the first reducer. [Diagram 5] 3 is an explanatory diagram illustrating a schematic configuration of a differential mechanism included in the electric crawler. FIG. [Figure 6] FIG. 2 is a block diagram illustrating a schematic configuration of a control system for the electric crawler. [Figure 7] 3 is a perspective view showing a positional relationship between a traveling electric motor, a turning electric motor, and a PTO electric motor in the electric crawler. FIG. [Figure 8] FIG. 2 is a bottom view of a main portion of the electric crawler. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The following describes an embodiment of the present invention with reference to the drawings.

[0011] [1. Configuration of the electric crawler vehicle] Fig. 1 is a left side view showing a schematic configuration of an electric crawler 1, which is an example of an electric crawler vehicle according to this embodiment. Fig. 2 is a right side view showing a schematic configuration of the electric crawler 1. In the following, the electric crawler 1 may also be simply referred to as a vehicle.

[0012] For the sake of convenience in the following explanation, directions are defined as follows: the direction in which an operator (pilot, driver) seated in the operator's seat 11 of the electric crawler 1 faces forward is defined as the forward direction, and the opposite direction is defined as the rearward direction. Additionally, the left side as viewed from the operator seated in the operator's seat 11 is defined as the "left" and the right side as the "right". Furthermore, the direction of gravity perpendicular to the front-to-rear and left-to-right directions is defined as the up-down direction, with the upstream side of the direction of gravity defined as the "up" and the downstream side defined as the "down". In the drawings, the forward direction is indicated as "F", the rear as "B", the right as "R", the left as "L", the up as "U" and the down as "D" as necessary.

[0013] As shown in FIG. 1 and FIG. 2, the electric crawler 1 is a crawler-type tractor equipped with traveling crawlers 2 on the left and right. Each traveling crawler 2 has a track frame 3 extending in the front-rear direction. A front idler 4a is rotatably supported at the front end of the track frame 3, and a rear idler 4b is rotatably supported at the rear end. A plurality of rollers 5 are rotatably supported between the front idler 4a and the rear idler 4b on the track frame 3. A drive sprocket 6 is disposed as a drive wheel diagonally above and in front of the rear idler 4b. A crawler belt 7 is wound around the drive sprocket 6, the front idler 4a, the rear idler 4b, and the plurality of rollers 5 to form the traveling crawler 2. In this manner, the electric crawler 1 is equipped with a pair of left and right traveling crawlers 2, each of which has a drive wheel (drive sprocket 6).

[0014] The electric crawler 1 has a main body frame 10. The above-mentioned track frame 3 is located below the main body frame 10 and is connected to the main body frame 10. A driver's seat 11 is disposed above the main body frame 10 via a seat mount 11a. A safety frame 12 is erected behind the driver's seat 11. A first battery unit 13a is disposed in the space between the main body frame 10 and the driver's seat 11. A second battery unit 13b is disposed above the main body frame 10 and behind the safety frame 12. Electronic components (not shown) such as a system controller 56 (see FIG. 6) described later are disposed above the second battery unit 13b. The first battery unit 13a and the second battery unit 13b are collectively referred to as the battery unit 13 below.

[0015] A floor (not shown) is provided below and in front of the driver's seat 11. The floor is supported by the main body frame 10. A control section 14 is provided in front of the floor. The control section 14 is provided with a handle 15 for turning the vehicle, a lever for switching the vehicle between forward and reverse travel, a PTO (Power Take Off) switching lever, a brake pedal, etc.

[0016] A first reduction gear 21 is disposed between the pair of left and right traveling crawlers 2. FIG. 3 is a perspective view of the first reduction gear 21. FIG. 4 is a perspective view of the inside of the first reduction gear 21. The first reduction gear 21 is connected to the traveling electric motor M1 and the turning electric motor M2. The traveling electric motor M1 is located forward of the turning electric motor M2. A plurality of gears and a chain or a belt are provided between the drive shaft of the traveling electric motor M1 and the drive shafts of the left and right traveling crawlers 2. The traveling power generated by the traveling electric motor M1 is transmitted to the drive shafts of the left and right traveling crawlers 2 by these plurality of gears and the chain or the belt. In addition, a plurality of gears are provided between the drive shaft of the turning electric motor M2 and the drive shafts of the left and right traveling crawlers 2, and the turning power generated by the turning electric motor M2 is transmitted to the drive shafts of the left and right traveling crawlers 2 by these plurality of gears. The above-mentioned drive sprockets 6 are provided on both left and right ends of the drive shafts of the left and right traveling crawlers 2. The drive sprockets 6 rotate by the traveling power or turning power transmitted to the drive shafts, which causes the left and right traveling crawlers 2 to rotate and the electric crawler 1 to travel or turn. The electric crawler 1 is equipped with a differential mechanism 30 (see FIG. 5), but details of the differential mechanism 30 will be described later.

[0017] From the above, it can be said that the electric crawler 1 of this embodiment is equipped with a running electric motor M1 that generates running power to be transmitted to a pair of left and right running crawlers 2, and a turning electric motor M2 that generates turning power to be transmitted to the pair of left and right running crawlers 2.

[0018] A PTO electric motor M3 is supported on the rear of the main body frame 10 shown in Figures 1 and 2. The PTO electric motor M3 generates PTO power for driving a work implement 24. The work implement 24 is connected to the rear of the main body frame 10 via a two-point or three-point linkage type lifting device 23. The work implement 24 is, for example, a tilling implement (e.g., a rotary tiller or a plow), but may be another work implement such as a fertilizer applicator.

[0019] The PTO electric motor M3 is connected to a second reduction gear 22 having a plurality of gears therein. That is, the second reduction gear 22 is a PTO reduction gear to which the PTO electric motor M3 is attached. The second reduction gear 22 and the working implement 24 are connected via a PTO power transmission unit 25 (see FIG. 2). The power of the PTO electric motor M3 is transmitted to the working implement 24 via the second reduction gear 22 and the PTO power transmission unit 25, thereby driving the working implement 24.

[0020] [2. Differential mechanism] 5 is an explanatory diagram showing a schematic configuration of a differential mechanism 30 provided in the electric crawler 1. The differential mechanism 30 is disposed in a turning power transmission part P (power transmission path) between the turning electric motor M2 and each of the driving wheels (driving sprockets 6) of the pair of left and right traveling crawlers 2.

[0021] The differential mechanism 30 has a pair of left and right planetary transmission mechanisms 31. The planetary transmission mechanisms 31 are arranged symmetrically. Each planetary transmission mechanism 31 has a planet carrier 32. The left and right planetary carriers 32 are arranged rotatably within the first reduction gear 21 (see FIG. 4) with their central axes (rotation axes) coaxial with a sun shaft 33 extending in the left-right direction. The central axis of the left planetary carrier 32 is connected to the drive shaft 6a of the drive wheel (drive sprocket 6) of the left traveling crawler 2. The central axis of the right planetary carrier 32 is connected to the drive shaft 6b of the drive wheel (drive sprocket 6) of the right traveling crawler 2.

[0022] The left and right planetary transmission mechanisms 31 each have a plurality of planetary gears 34 (for example, three). In the left planetary transmission mechanism 31, the plurality of planetary gears 34 are each rotatably supported by the left planetary carrier 32. In the right planetary transmission mechanism 31, the plurality of planetary gears 34 are each rotatably supported by the right planetary carrier 32. In each planetary transmission mechanism 31, the plurality of planetary gears 34 are positioned at the same radius around the sun shaft 33, and are disposed in mesh with sun gears 35 fixed to both the left and right ends of the sun shaft 33, respectively.

[0023] In the left and right planetary transmission mechanisms 31, a ring gear 36 is disposed concentrically with the sun shaft 33. Each ring gear 36 has internal teeth on its inner circumferential surface and external teeth on its outer circumferential surface. The ring gear 36 of the left planetary transmission mechanism 31 is disposed so that its internal teeth mesh with the multiple left planetary gears 34. The ring gear 36 of the right planetary transmission mechanism 31 is disposed so that its internal teeth mesh with the multiple right planetary gears 34. Each ring gear 36 is rotatably supported on the sun shaft 33 or the drive shafts 6a, 6b via bearings.

[0024] When the electric motor M2 for turning is rotated, the rotational power (power for turning) of the electric motor M2 for turning is transmitted to the left drive shaft 6a and the right drive shaft 6b via the power transmission part P for turning. More specifically, the power for turning of the electric motor M2 for turning is transmitted to transmission gears 37a and 37b attached to both the left and right ends of the motor output shaft 37.

[0025] Here, the left transmission gear 37a is disposed so as to directly mesh with the external teeth of the left ring gear 36. Meanwhile, the right transmission gear 37b is disposed so as to mesh with a reversing gear 39 attached to a reversing shaft 38. This reversing gear 39 is disposed so as to mesh with the external teeth of the right ring gear 36.

[0026] For example, when the traveling electric motor M1 is stopped, the sun shaft 33 and the sun gears 35 on both the left and right sides are fixed. Therefore, when the turning electric motor M2 (motor output shaft 37) is rotated forward, the left ring gear 36 rotates in the reverse direction by a predetermined number of rotations, and the right ring gear 36 rotates forward at the same number of rotations as the left ring gear 36. Therefore, the left planetary gear 34 and planetary carrier 32 rotate in the reverse direction around the sun shaft 33, while the right planetary gear 34 and planetary carrier 32 rotate forward around the sun shaft 33. Therefore, the drive shaft 6a coaxial with the left planetary carrier 32 rotates in the reverse direction, and the drive shaft 6b coaxial with the right planetary carrier 32 rotates forward. Therefore, the left traveling crawler 2 moves backward, and the right traveling crawler 2 moves forward. In this case, the electric crawler 1 spins to the left on the spot.

[0027] On the other hand, when the traveling electric motor M1 is rotated, the rotational power (traveling power) of the traveling electric motor M1 is transmitted to the sun shaft 33 via the traveling power transmission unit Q. The traveling power transmission unit Q is configured to include a plurality of gears, belts, and the like. Here, for example, if the turning electric motor M2 is stopped, the rotation of the ring gears 36 on both the left and right sides is stopped and fixed. Therefore, the traveling power transmitted to the sun shaft 33 is transmitted equally to the left drive shaft 6a and the right drive shaft 6b via the left and right planetary speed change mechanisms 31 (sun gear 35, planetary gear 34, planetary carrier 32). As a result, the left and right drive sprockets 6 rotate at the same rotational speed in the same rotational direction, and the electric crawler 1 travels. In other words, the electric crawler 1 moves forward or backward depending on the rotational direction of the traveling electric motor M1.

[0028] Based on the above principle, the electric crawler 1 can be turned while traveling by controlling the rotation speed and rotation direction of the traveling electric motor M1 and the turning electric motor M2 in an appropriate combination. The rotation speed and rotation direction of the traveling electric motor M1 can be adjusted by the accelerator pedal and forward / reverse switching lever of the operation unit 14 (see Figs. 1 and 2). The rotation speed and rotation direction of the turning electric motor M2 can be adjusted by the rotation direction and rotation angle of the handle 15 (see Figs. 1 and 2).

[0029] [3. Configuration of the electric crawler control system] Next, the configuration of the control system of the electric crawler 1 will be described. FIG. 6 is a block diagram showing the configuration of the control system of the electric crawler 1. In FIG. 6, solid lines indicate power supply paths, and dashed lines indicate signal paths. In addition to the above-mentioned traveling electric motor M1, turning electric motor M2, and PTO electric motor M3, the electric crawler 1 includes a charger 51, an inverter 52, a relay box 53, a high-voltage branch box 54, a DC-DC converter 55, a system controller 56, a high-voltage battery 57, and a lead battery (12V battery) 58. The system controller 56 is formed by an electronic control unit also called an ECU (Electronic Control Unit), and performs electrical control of each part of the electric crawler 1. The high-voltage battery 57 corresponds to the battery unit 13 shown in FIG. 1 and FIG. 2.

[0030] The electric motor M1 for driving, the electric motor M2 for turning, and the electric motor M3 for PTO (hereinafter also referred to as the electric motor M1 for driving, etc.) are driven by power supplied from a high-voltage battery 57 via a relay box 53, a high-voltage branch box 54, and an inverter 52.

[0031] Charger 51 (also called power supply device) converts AC voltage supplied from a commercial power source (not shown) via a power supply cable into DC voltage. Inverter 52 converts DC voltage supplied from high-voltage battery 57 into AC voltage and supplies it to traveling electric motors M1 and the like. This causes traveling electric motors M1 and the like to rotate. The supply of AC voltage (current) from inverter 52 to traveling electric motors M1 and the like is performed based on a rotation command (command value) output from system controller 56.

[0032] The relay box 53 is a battery control unit that includes a battery relay and a fuse and controls the battery relay to control the input / output of the high-voltage battery 57. The high-voltage branch box 54 includes a charger relay, an inverter relay, a fuse, etc. The voltage output from the charger 51 is supplied to the high-voltage battery 57 via the high-voltage branch box 54 and the relay box 53. This allows the high-voltage battery 57 to be charged. The voltage output from the high-voltage battery 57 is supplied to the inverter 52 via the relay box 53 and the high-voltage branch box 54.

[0033] The DC-DC converter 55 steps down a high-voltage (e.g., 300 V) direct current voltage supplied from the high-voltage battery 57 via the high-voltage branch box 54 to a low voltage (e.g., 12 V). The voltage output from the DC-DC converter 55 is supplied to the system controller 56 and the like, similar to the output from the lead battery 58.

[0034] [4. Placement of each electric motor] FIG. 7 is a perspective view showing the positional relationship of the traveling electric motor M1, the turning electric motor M2, and the PTO electric motor M3 in the electric crawler 1. FIG. 8 is a bottom view of the main part (including each electric motor) of the electric crawler 1. As shown in FIG. 7 and FIG. 8, the traveling electric motor M1 and the turning electric motor M2 are disposed on one side of the vehicle. Specifically, the traveling electric motor M1 and the turning electric motor M2 are positioned shifted to one side (right side in FIG. 8) from the center line C0 in the width direction (left-right direction) of the vehicle. The traveling electric motor M1 and the turning electric motor M2 are positioned side by side in a direction perpendicular to the width direction of the vehicle (front-rear direction of the electric crawler 1). In this embodiment, the traveling electric motor M1 and the turning electric motor M2 are positioned side by side in the front-rear direction of the vehicle.

[0035] In such an arrangement of the traveling electric motor M1 and the slewing electric motor M2, when servicing (maintenance) the traveling electric motor M1 and the slewing electric motor M2, it is only necessary to disassemble the traveling crawler 2 arranged on one side (the right side in FIG. 8 ) out of the left and right traveling crawlers 2. For example, it is only necessary to remove the crawler belt 7 and the drive sprocket 6, which are components, of the right traveling crawler 2 from the vehicle. This allows easy access to both the traveling electric motor M1 and the slewing electric motor M2 from the same side (from one side). Furthermore, when assembling the traveling electric motor M1 and the slewing electric motor M2 to the vehicle during the manufacture of the electric crawler 1, both the traveling electric motor M1 and the slewing electric motor M2 can be assembled from the same side of the vehicle.

[0036] In this way, when performing maintenance or assembly work on the traveling electric motor M1 and the turning electric motor M2, the maintenance or assembly can be performed by accessing only from either the left or right side. Therefore, compared to a conventional configuration in which the traveling motors are arranged independently on the left and right, that is, a configuration in which the motors are arranged side by side in the left-right direction and access is required from both the left and right sides, it is possible to facilitate the maintenance of multiple electric motors and the assembly work to the vehicle.

[0037] In addition, if the traveling electric motor M1, the turning electric motor M2, and the first reduction gear 21 are considered as one driving part DP (mechanism), as shown in FIG. 8, the width dimension of the driving part DP is the axial dimension of the traveling electric motor M1 + the thickness of the first reduction gear 21, or the axial dimension of the turning electric motor M2 + the thickness of the first reduction gear 21. In other words, the electric motor that contributes to the width dimension of the driving part DP is either the traveling electric motor M1 or the turning electric motor M2. In other words, of the two electric motors, only one electric motor contributes to the width dimension of the driving part DP. This makes the driving part DP compact in the width direction. As a result, the degree of freedom in setting the center-to-center dimension (tread) of the left and right traveling crawlers 2 is improved, and more work can be handled.

[0038] In addition, the traveling electric motor M1 and the turning electric motor M2 are disposed on one side (offset) with respect to the center line C0 of the vehicle, and the first reduction gear 21 is disposed on the other side (offset) with respect to the center line C0, and the traveling electric motor M1, the turning electric motor M2, and the first reduction gear 21 are assembled on the center line C0 of the vehicle (or in the vicinity of the center line C0). This makes it possible to move the position of the center of gravity of the traveling electric motor M1, the turning electric motor M2, and the first reduction gear 21 together closer to the center in the width direction of the vehicle. This also makes it possible to maintain a good weight balance in the width direction of the vehicle.

[0039] In this embodiment, as shown in Figures 3, 4, 7, and 8, the traveling electric motor M1 and the turning electric motor M2 are assembled to the same first reduction gear 21. In this configuration, when the traveling electric motor M1 and the turning electric motor M2 are assembled to the vehicle, they can be assembled to the vehicle in a state in which the traveling electric motor M1 and the turning electric motor M2 are assembled to the first reduction gear 21. In other words, the traveling electric motor M1, the turning electric motor M2, and the first reduction gear 21 can be assembled to the vehicle simultaneously from one side as one set.

[0040] Therefore, from the standpoint of improving workability (work efficiency) when assembling the traveling electric motor M1, the turning electric motor M2, and the first reduction gear 21, it is desirable for the electric crawler 1 of this embodiment to be equipped with a single first reduction gear 21 to which the traveling electric motor M1 and the turning electric motor M2 are assembled.

[0041] 3, 4, 7, and 8, the traveling electric motor M1 and the turning electric motor M2 are disposed and assembled on the right side of the first reduction gear 21. In this case, when performing maintenance on the traveling electric motor M1 and the turning electric motor M2, by removing some parts of the right traveling crawler 2 (the right crawler belt 7, the drive sprocket 6, etc.) from the vehicle, it becomes possible to access both the traveling electric motor M1 and the turning electric motor M2 without being obstructed by the first reduction gear 21 and perform maintenance work.

[0042] In this way, from the viewpoint of avoiding access to the electric motor M1 for running and the electric motor M2 for turning from one side being obstructed by the first reduction gear 21, it is desirable to arrange the electric motor M1 for running and the electric motor M2 for turning on one side of the first reduction gear 21.

[0043] Since the traveling electric motor M1 and the turning electric motor M2 are heavy objects, it is desirable to place them at a low position in the vehicle in order to lower the center of gravity of the vehicle and improve the running stability. In this embodiment, as shown in FIG. 1, the electric crawler 1 has a driver's seat 11 where an operator sits. The above-mentioned first reduction gear 21 is placed below the driver's seat 11. In this case, the heavy objects assembled to the first reduction gear 21, that is, the traveling electric motor M1 and the turning electric motor M2, can be placed below the driver's seat 11 together with the first reduction gear 21 to lower the center of gravity of the vehicle. This is therefore advantageous for improving the running stability of the vehicle.

[0044] As shown in Fig. 7 and Fig. 8, the PTO electric motor M3 is assembled to the second reduction gear 22 as a PTO reduction gear. The second reduction gear 22 is disposed at the rear upper part of the first reduction gear 21. When assembling the PTO electric motor M3 to the vehicle, it is desirable from the viewpoint of workability that the PTO electric motor M3 can be assembled to the vehicle from one side (for example, the right side) of the vehicle in a state where the PTO electric motor M3 is assembled to the second reduction gear 22, similarly to the case where the traveling electric motor M1 and the turning electric motor M2 are assembled to the vehicle. In other words, it is desirable that the PTO electric motor M3 and the second reduction gear 22 can be assembled to the vehicle from one side at the same time as one set.

[0045] Thus, from the viewpoint of improving workability (work efficiency) when assembling the PTO electric motor M3 and the second reduction gear 22, it is desirable that the electric crawler 1 of this embodiment be equipped with the PTO electric motor M3, as well as the second reduction gear 22 (PTO reduction gear) to which the PTO electric motor M3 is assembled.

[0046] 7 and 8, the PTO electric motor M3 is disposed and assembled on the right side of the second reduction gear 22. In this case, when servicing the PTO electric motor M3, by removing some of the components of the right traveling crawler 2 (the right crawler belt 7, the drive sprocket 6, etc.) from the vehicle, it becomes possible to access the PTO electric motor M3 without being obstructed by the second reduction gear 22 and perform the maintenance work.

[0047] In this way, in order to avoid access to the PTO electric motor M3 from one side being obstructed by the second reduction gear 22, it is desirable to position the PTO electric motor M3 on one side relative to the second reduction gear 22.

[0048] In particular, the electric crawler 1 of this embodiment is configured such that the traveling electric motor M1 and the turning electric motor M2 are disposed on one side relative to the first reduction gear 21, and the PTO electric motor M3 is disposed on the same side relative to the second reduction gear 22 (located behind the first reduction gear 21). In this configuration, by removing some of the components of the traveling crawler 2 disposed on one side from the vehicle, it becomes possible to perform maintenance work on all of the traveling electric motor M1, the turning electric motor M2, and the PTO electric motor M3 by accessing them from the same side without being hindered by the first reduction gear 21 and the second reduction gear 22. Therefore, from the viewpoint of preventing access to all the electric motors from being hindered by the first reduction gear 21 and the second reduction gear 22, it is preferable that the PTO electric motor M3 be disposed on one side relative to the second reduction gear 22, that is, on the same side as the traveling electric motor M1 and the turning electric motor M2 are disposed on the first reduction gear 21.

[0049] In order to improve the weight balance of the vehicle, it is desirable to arrange the three heavy electric motors, i.e., the traveling electric motor M1, the turning electric motor M2, and the PTO electric motor M3, together in a compact manner. In this embodiment, as shown in Fig. 7 and Fig. 8, the PTO electric motor M3 is arranged in the vicinity of the traveling electric motor M1 and the turning electric motor M2 (for example, in a position close to the rear). This allows for a compact layout of the heavy objects, improving the weight balance of the vehicle.

[0050] In order to efficiently transmit the power generated by the PTO electric motor M3 to the working implement 24 through a short power transmission path (for example, with a small number of gears), it is desirable to arrange the PTO electric motor M3 at a position close to the working implement 24 attached to the rear of the vehicle. In this regard, as shown in FIG. 7, if the PTO electric motor M3 is arranged rearward of the traveling electric motor M1 and the swing electric motor M2, the PTO electric motor M3 can be arranged at a position close to the front of the working implement 24. Then, the power of the PTO electric motor M3 can be efficiently transmitted to the working implement 24 via the second reduction gear 22 and the PTO power transmission section 25. Therefore, in this regard, it is desirable to arrange the PTO electric motor M3 rearward of the traveling electric motor M1 and the swing electric motor M2.

[0051] In the above, an example has been described in which the traveling electric motor M1 and the turning electric motor M2 are positioned to the right of the center in the width direction of the vehicle, but they may be positioned to the left of the center in the width direction. In this case, the "one side" described in this embodiment can be read as the left side when arranging the various members, thereby achieving the electric crawler 1 that achieves the effects of this embodiment.

[0052] In the above, an example has been described in which the traveling electric motor M1 and the turning electric motor M2 are positioned side by side in the front-rear direction of the vehicle between the left and right traveling crawlers 2, but they may be positioned side by side in the up-down direction. In this case, although there is a possibility that the total center of gravity position of the heavy objects (traveling electric motor M1, turning electric motor M2, PTO electric motor M3) may become higher, it is possible to obtain advantages such as making the vehicle smaller by compactly consolidating the heavy objects, and simplifying the configuration of the first reduction gear 21 by eliminating redundant configurations for traveling and turning (reducing the number of gears). Therefore, in this embodiment, it can be said that it is sufficient that the traveling electric motor M1 and the turning electric motor M2 are positioned side by side in the direction perpendicular to the width direction of the vehicle.

[0053] [5. Supplementary Information] In this embodiment, the electric crawler 1 is described as a type in which the crawler belt 7 is wrapped in a triangular shape around one driving wheel (driving sprocket) and two driven wheels (idlers), but it may also be a type in which the crawler belt 7 is wrapped around one driving wheel and one driven wheel arranged in the fore-and-aft direction.

[0054] In this embodiment, the electric crawler 1 is a crawler-type tractor, but the configuration of this embodiment can also be applied to other crawler vehicles such as snowplows.

[0055] [6. Notes] The electric crawler 1 described in this embodiment can also be expressed as an electric crawler vehicle as described in the following supplementary notes.

[0056] The electric crawler vehicle in Appendix (1) is A pair of left and right crawlers; a traveling electric motor that generates traveling power to be transmitted to the pair of left and right traveling crawlers; a turning electric motor that generates turning power to be transmitted to the pair of left and right traveling crawlers, The electric motor for traveling and the electric motor for turning are disposed on one lateral side of the vehicle.

[0057] The electric crawler vehicle of supplementary note (2) is the electric crawler vehicle according to supplementary note (1), The electric vehicle further includes a single reduction gear to which the traveling electric motor and the turning electric motor are assembled.

[0058] The electric crawler vehicle of supplementary note (3) is the electric crawler vehicle according to supplementary note (2), The traveling electric motor and the turning electric motor are disposed on the one lateral side with respect to the reduction gear.

[0059] The electric crawler vehicle of supplementary note (4) is an electric crawler vehicle according to supplementary note (2) or (3), Further comprising a cockpit in which a pilot sits, The reduction gear is disposed below the cockpit.

[0060] The electric crawler vehicle of supplementary note (5) is an electric crawler vehicle according to any one of supplementary notes (2) to (4), Further, a PTO electric motor is provided to generate power for a PTO for driving the working machine. When the reduction gear is a first reduction gear, the vehicle further includes a PTO reduction gear to which the PTO electric motor is attached as a second reduction gear.

[0061] The electric crawler vehicle of supplementary note (6) is the electric crawler vehicle according to supplementary note (5), The PTO electric motor is disposed on the one lateral side with respect to the second reduction gear.

[0062] The electric crawler vehicle of supplementary note (7) is an electric crawler vehicle according to supplementary note (5) or (6), The PTO electric motor is disposed near the traveling electric motor and the turning electric motor.

[0063] The electric crawler vehicle of supplementary note (8) is an electric crawler vehicle according to any one of supplementary notes (5) to (7), The PTO electric motor is disposed rearward of the traveling electric motor and the turning electric motor.

[0064] The electric crawler vehicle of supplementary note (9) is an electric crawler vehicle according to any one of supplementary notes (1) to (8), The traveling electric motor and the turning electric motor are arranged side by side in a direction perpendicular to a width direction of the vehicle.

[0065] Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and the invention can be expanded or modified without departing from the spirit of the invention. [Industrial Applicability]

[0066] The present invention can be used in crawler vehicles used as work machines such as agricultural machines and construction machines. [Explanation of symbols]

[0067] 1 Electric crawler (electric crawler vehicle) 2 Traveling crawler 11. Cockpit 21 1st reducer 22 2nd reducer 24 Work equipment M1 Electric motor for driving M2 Electric motor for turning M3 PTO electric motor

Claims

1. A pair of left and right crawlers; a traveling electric motor that generates traveling power to be transmitted to the pair of left and right traveling crawlers; a turning electric motor that generates turning power to be transmitted to the pair of left and right traveling crawlers, The electric crawler vehicle, wherein the electric motor for traveling and the electric motor for turning are disposed on one lateral side of the vehicle.

2. The electric crawler vehicle according to claim 1 , further comprising a single reduction gear to which the traveling electric motor and the turning electric motor are assembled.

3. The electric crawler vehicle according to claim 2 , wherein the electric motor for traveling and the electric motor for turning are disposed on the one lateral side with respect to the reduction gear.

4. Further comprising a cockpit in which a pilot sits, The electric crawler vehicle according to claim 2 , wherein the reduction gear is disposed below the driver's seat.

5. The vehicle further includes an electric motor for PTO that generates power for PTO to drive the working machine, The electric crawler vehicle according to claim 2 , further comprising a PTO reducer to which the PTO electric motor is attached as a second reducer when the reducer is a first reducer.

6. The electric crawler vehicle according to claim 5 , wherein the PTO electric motor is disposed on the one lateral side with respect to the second reduction gear.

7. The electric crawler vehicle according to claim 5 , wherein the PTO electric motor is disposed near the travel electric motor and the turning electric motor.

8. The electric crawler vehicle according to claim 5 , wherein the PTO electric motor is disposed rearward of the travel electric motor and the turning electric motor.

9. 9. The electric crawler vehicle according to claim 1, wherein the traveling electric motor and the turning electric motor are arranged side by side in a direction perpendicular to a width direction of the vehicle.

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