JP7521371B2 - Drive device for electric vehicle, drive unit and electric vehicle - Google Patents

Description

The present invention relates to an electric vehicle drive device that uses an electric motor as a drive source to rotate and drive wheels, a drive unit that includes the electric vehicle drive device, and an electric vehicle that includes multiple drive units.

In response to the recent trend towards reducing the use of fossil fuels, research into electric vehicles has progressed and some have been implemented. JP 2006-22879 A (Patent Document 1) describes a drive unit for an electric vehicle that transmits the output torque of a single electric motor to a pair of left and right drive wheels via a two-speed transmission and a differential gear.

JP 2006-22879 A

The electric vehicle drive device described in JP 2006-22879 A is configured to drive a pair of left and right drive wheels with a single electric motor. For this reason, it is necessary to use an electric motor, two-speed transmission, and differential gear with appropriate specifications according to the total vehicle weight. In other words, when using the electric vehicle drive device described in JP 2006-22879 A as an electric vehicle drive device, it is necessary to design it specifically for each total vehicle weight, which is disadvantageous in terms of reducing the manufacturing costs of electric vehicles.

In particular, self-driving cars, which can run without human intervention, are equipped with numerous expensive sensors, and there is a strong demand for cost reduction.

In view of the above circumstances, the present invention aims to standardize the drive unit for electric vehicles regardless of the total vehicle weight, thereby reducing the manufacturing costs of electric vehicles.

The electric vehicle drive device of the present invention comprises:
Housing and
a pair of electric motors each having an output shaft and supported relative to the housing;
a pair of drive shafts that are coaxial with each other and rotatably supported on the housing with their respective tip ends, on which wheels are supported, facing in opposite directions;
a pair of torque transmission devices that transmit the rotational torque of each of the output shafts of the pair of electric motors to each of the pair of drive shafts;
Equipped with.

The electric vehicle drive device of the present invention is supported on the vehicle body so as to be rotatable about a pivot axis perpendicular to the road surface.
Furthermore, when an electric vehicle is constructed using the electric vehicle drive device of the present invention, one or more electric vehicle drive devices, for example, four or more, are mounted on the vehicle body.

In the electric vehicle drive device of the present invention, the output shafts of the pair of electric motors and the pair of drive shafts can be disposed in parallel.
In this case, the output shafts of the pair of electric motors can be arranged non-coaxially and parallel to each other.
Furthermore, in this case, the pair of electric motors can be disposed so as to overlap each other in a direction perpendicular to the output shafts of the respective electric motors.

Each of the pair of electric motors can be disposed radially outward from the wheels. Alternatively, each of the pair of electric motors can be disposed between the wheels.

Each of the pair of torque transmission devices can be configured by a gear-type reducer including a plurality of gears.
Alternatively, each of the pair of torque transmission devices may be configured by a reducer using a belt or chain, or by a worm reducer.
Alternatively, each of the pair of torque transmission devices can be configured as a continuously variable transmission or a stepped transmission capable of adjusting the reduction ratio between the output shaft of each of the pair of electric motors and each of the pair of drive shafts.

The drive unit of the present invention comprises:
A drive device for an electric vehicle having a pair of drive shafts;
a pair of wheels supported on each of the pair of drive shafts;
a turning device that supports the electric vehicle drive device with respect to a vehicle body so as to enable the electric vehicle drive device to turn about a turning axis that is perpendicular to a road surface;
Equipped with
The electric vehicle drive device is configured by the electric vehicle drive device of the present invention.

The swivel device may have a stopper mechanism that limits the range of rotation of the electric vehicle drive device around the swivel shaft.

The turning device may have a rotating member supported relative to the electric vehicle drive device so as not to rotate around the turning axis, and a fixed member arranged coaxially with the rotating member so as to be rotatable relative to the rotating member, and supported and fixed to the vehicle body.
In this case, the stopper mechanism may have a rotating side stopper surface provided on the rotating member, facing in a circumferential direction around the rotating axis, and a fixed side stopper surface provided on the fixed member, facing in a circumferential direction around the rotating axis and facing the rotating side stopper surface.

The rotating member is
a rotating member main body having a main body-side facing surface facing a circumferential direction centered on the pivot shaft and supported in such a manner that the rotating member main body cannot rotate about the pivot shaft relative to the electric vehicle drive device;
a rotation side stopper member that faces a circumferential direction about the pivot axis and has a stopper member side opposing surface that abuts or closely faces the main body side opposing surface and the rotation side stopper surface, and is supported and fixed to the rotation member main body;
It can be provided with:

The fixing member is
A fixing member main body that is supported and fixed to the vehicle body;
a fixed-side stopper member having the fixed-side stopper surface and supported and fixed to the fixed member body so that an attachment position thereof in a circumferential direction about the pivot shaft can be adjusted;
It can be provided with:

The drive unit of the present invention can include a support device that presses each of the outer circumferential surfaces of the tires that constitute the wheels against the road surface, while mitigating vibrations transmitted from the road surface to the vehicle body via each of the wheels.

The drive unit of the present invention can include a vehicle height adjustment device that is disposed between each of the electric vehicle drive devices and the vehicle body and adjusts the height of the vehicle body relative to the road surface.

The electric vehicle of the present invention is
The car body and
At least one drive unit;
Equipped with
Each of the drive units is constituted by the drive unit of the present invention.
In the electric vehicle of the present invention, the number of drive units mounted is determined according to the total vehicle weight.

According to the present invention, it is possible to standardize the drive unit for electric vehicles regardless of the total vehicle weight, thereby reducing the manufacturing costs of electric vehicles.

FIG. 1 is a perspective view showing an electric vehicle drive device according to a first embodiment. FIG. 2 is a perspective view showing a part of the electric vehicle drive device according to the first embodiment, in an exploded state. FIG. 3 is a perspective view showing the electric vehicle drive device according to the first embodiment with a pair of hub unit bearings attached. FIG. 4 is a side view showing the electric vehicle drive device according to the first embodiment with a pair of hub unit bearings attached. FIG. 5 is a cross-sectional view taken along line X ₁ -O ₁ -O ₂ -O ₃ -X ₂ of FIG. FIG. 6 is a cross-sectional view taken along line X ₁ -O ₁ -O ₂ -O ₃ -O ₂ -O ₄ -X ₃ of FIG. FIG. 7 is a schematic diagram showing an electric vehicle drive device according to a first embodiment. FIG. 8 is a perspective view showing a drive unit including an electric vehicle drive device according to a first embodiment. FIG. 9 is a perspective view showing the drive unit shown in FIG. 8 with the vehicle height control device removed. FIG. 10 is a side view showing the state shown in FIG. 9 with one of the drive wheels removed. FIG. 11(A) is an oblique view showing a first example of an electric vehicle equipped with a drive unit relating to a first example of an embodiment, FIG. 11(B) is a side view seen from the lower left of FIG. 11(A), and FIG. 11(C) is an end view seen from the left side of FIG. 11(B). Figure 12(A) is an oblique view showing a second example of an electric vehicle equipped with a drive unit relating to the first example of the embodiment, Figure 12(B) is a side view seen from the lower left of Figure 12(A), and Figure 12(C) is an end view seen from the left side of Figure 12(B). Figure 13(A) is an oblique view showing a third example of an electric vehicle equipped with a drive unit relating to the first example of the embodiment, Figure 13(B) is a side view seen from the lower left of Figure 13(A), and Figure 13(C) is an end view seen from the left side of Figure 13(B). Figure 14(A) is an oblique view showing an unmanned guided vehicle (electric vehicle) according to a second example of an embodiment, Figure 14(B) is a side view showing the unmanned guided vehicle according to the second example of an embodiment, and Figure 14(C) is a bottom view seen from below of Figure 14(B). FIG. 15 is a perspective view showing a drive unit according to the second example of the embodiment. FIG. 16 is a side view showing a drive unit according to the second example of the embodiment. FIG. 17 is a front view seen from the left side of FIG. FIG. 18 is a plan view seen from above in FIG. FIG. 19 is a perspective view showing a drive unit according to a second example of the embodiment with the wheels removed. FIG. 20 is a side view showing a drive unit according to a second example of the embodiment with the wheels removed. FIG. 21 is a front view seen from the left side of FIG. FIG. 22 is a plan view seen from above in FIG. FIG. 23 is a cross-sectional view taken along line Y ₁ -O ₅ -O ₆ -O ₇ -O ₈ -O ₉ -O ₁₀ -Y ₂ of FIG. FIG. 24 is a cross-sectional view taken along line Y ₃ -O ₇ -O ₈ -O ₉ -O ₁₀ -Y ₂ of FIG. FIG. 25 is a cross-sectional view taken along line Y ₄ -O ₅ -O ₆ -O ₇ -O ₁₁ -Y ₅ of FIG. FIG. 26 is a schematic diagram showing an electric vehicle driving device according to a second example of the embodiment. Figure 27(A) is an oblique view showing an unmanned guided vehicle according to a third example of an embodiment, Figure 27(B) is a side view showing an unmanned guided vehicle according to the third example of an embodiment, and Figure 27(C) is a bottom view seen from below of Figure 27(B). FIG. 28 is a perspective view showing a drive unit according to a fourth example of the embodiment. 29(A) is a side view showing a state in which only one cylindrical portion is removed from a fixing member and a lid is not yet attached, and FIG. 29(B) is a ZZ cross-sectional view of FIG. 29(A). FIG. 30 is a perspective view showing a drive unit according to a fifth example of the embodiment. FIG. 31 is a schematic diagram showing a state in which an automobile is transported by an automatic guided vehicle according to a sixth embodiment. FIG. 32 is a perspective view showing a drive unit according to a seventh example of the embodiment. FIG. 33 is a plan view showing a drive unit according to a seventh example of the embodiment. FIG. 34 is a plan view showing a drive unit according to a seventh example of an embodiment in a state in which one rotation-side stopper surface and one fixed-side stopper surface are in contact with each other. FIG. 35 is a perspective view showing a state in which the rotation side stopper surface and the fixed side stopper surface are in contact with each other when the swivel device is removed from the drive unit according to the seventh example of the embodiment. FIG. 36 is a partially cutaway perspective view showing a state in which the swivel device has been removed from the drive unit according to the seventh example of the embodiment and before the rotation-side stopper member is supported and fixed to the rotation member main body. Figure 37 is a partially cut-away oblique view, seen from a different direction than Figure 36, showing the state before the rotating device is removed from the drive unit of the seventh example of the embodiment and the rotating side stopper member is supported and fixed to the rotating member main body. FIG. 38 is a perspective view showing a turning device taken out of a drive unit according to an eighth example of the embodiment. FIG. 39 is a partially exploded perspective view of a swivel device taken out of a drive unit according to an eighth example of the embodiment. FIG. FIG. 40 is a perspective view showing a turning device taken out of a drive unit according to a ninth example of the embodiment. FIG. 41 is a partially exploded perspective view of a swivel device taken out of a drive unit according to a ninth embodiment. FIG. FIG. 42 is a perspective view showing a turning device taken out of a drive unit according to a tenth example of the embodiment. FIG. 43 is a partially exploded perspective view of a swivel device taken out of a drive unit according to a tenth example of the embodiment. FIG. FIG. 44 is a partially cut-away perspective view showing a part of a turning device according to a tenth example of the embodiment. FIG. 45 is a perspective view showing a turning device taken out of a drive unit according to an eleventh example of the embodiment. FIG. 46 is a partially exploded perspective view of a swivel device taken out of a drive unit according to an eleventh example of the embodiment. FIG. 47 is a partially cut-away perspective view showing a part of a turning device according to an eleventh example of the embodiment.

[First Example of the Embodiment]
1 to 13(C), a first embodiment of the present invention will be described. An electric vehicle drive device 1 includes a housing 2, a pair of electric motors 3a, 3b, a pair of drive shafts 4a, 4b, and a pair of torque transmission devices 5a, 5b.

The housing 2 is made of a light alloy such as an aluminum alloy, or synthetic resin, and is constructed by combining multiple parts. In this example, the housing 2 has three cylindrical parts 6a, 6b, and 6c arranged parallel to one another, and an arm part 37 that extends from the lower end toward one side in the traveling direction (the left side in Figures 4 and 10).

The traveling direction refers to the traveling direction (left-right direction in Figs. 4, 10, 11B, 12B, and 13B) of electric vehicles 50a, 50b, and 50c (see Figs. 11A to 13C) when drive unit 48 including electric vehicle drive device 1 is attached to vehicle body 32a, 32b, and 32c (see Figs. 11A to 13C) and wheels 16a and 16b (see Figs. 8 and 9) are oriented in a straight-ahead direction. The width direction refers to the width direction (left-right direction in Figs. 5, 7, 11C, 12C, and 13C) of electric vehicles 50a, 50b, and 50c when drive unit 48 including electric vehicle drive device 1 is attached to vehicle body 32a, 32b, and 32c and wheels 16a and 16b are oriented in a straight-ahead direction.

The housing 2 also has a connector section 54 on the upper part. The connector section 54 is connected by cables to the pair of electric motors 3a, 3b and various sensors that make up the electric vehicle drive device 1. The connector section 54 is also connected by harnesses to the power source and control device mounted on the vehicle bodies 32a, 32b, 32c. This allows power to be supplied to the pair of electric motors 3a, 3b, and output signals from the various sensors to be sent to the control device.

Each of the pair of electric motors 3a, 3b has an output shaft 7a, 7b, and is supported by the housing 2. The output shafts 7a, 7b of the pair of electric motors 3a, 3b are arranged non-coaxially and parallel to each other with their respective tips facing in opposite directions.

To this end, specifically, the output shaft 7a of the first electric motor 3a, which is one of the pair of electric motors 3a, 3b, is rotatably supported inside one of the three cylindrical portions 6a, 6b, 6c of the housing 2 with its tip facing one side in the width direction (the left side in Figs. 5 and 7). That is, the first electric motor 3a has the inner peripheral surface of the stator 8a, which is supported and fixed to the inner peripheral surface of the cylindrical portion 6a, closely facing the outer peripheral surface of the rotor 9a, which is supported and fixed around the middle portion of the output shaft 7a.

In contrast, the output shaft 7b of the second electric motor 3b, which is the other of the pair of electric motors 3a, 3b, is supported rotatably inside another one of the three cylindrical portions 6a, 6b, 6c of the housing 2 with its tip facing the other side in the width direction (the right side in FIG. 7). That is, the second electric motor 3b has the inner peripheral surface of the stator 8b supported and fixed to the inner peripheral surface of the cylindrical portion 6b closely facing the outer peripheral surface of the rotor 9b supported and fixed around the middle portion of the output shaft 7b.

Each of the pair of electric motors 3a, 3b has a driving section 53a, 53b consisting of a stator 8a, 8b and a rotor 9a, 9b, which are arranged so as to overlap in a direction perpendicular to the output shafts 7a, 7b. Specifically, in this example, the positions of the driving sections 53a, 53b in the width direction are the same.

In addition, rotation sensors 10a, 10b are attached to the periphery of the base end of each of the output shafts 7a, 7b of the pair of electric motors 3a, 3b that protrude from the side of the housing 2. This makes it possible to detect the number of rotations (rotation speed) of each of the output shafts 7a, 7b of the pair of electric motors 3a, 3b.

The pair of electric motors 3a, 3b have the same rated output and rated rotational speed, and are configured to be able to independently control the rotational speed and rotation direction of the output shafts 7a, 7b. The rated output and rated rotational speed of the pair of electric motors 3a, 3b are not particularly limited as long as they are the same, but for example, the rated output can be 5 kW or more and 10 kW or less , and the rated rotational speed can be 2400 rpm or more and 4500 rpm or less.

The pair of drive shafts 4a, 4b are supported coaxially with their respective tips facing in opposite directions and rotatably relative to the housing 2. In this example, the pair of drive shafts 4a, 4b are arranged non-coaxially and parallel to the respective output shafts 7a, 7b of the pair of electric motors 3a, 3b.

To this end, specifically, the first drive shaft 4a, which is one of the pair of drive shafts 4a, 4b, has its tip facing one side in the width direction, and its base end is rotatably supported on the end of one width direction side of the remaining one of the three cylindrical portions 6a, 6b, 6c of the housing 2. In contrast, the second drive shaft 4b, which is the other of the pair of drive shafts 4a, 4b, has its tip facing the other side in the width direction, and its base end is rotatably supported on the end of the other width direction side of the cylindrical portion 6c.

In this example, each of the pair of drive shafts 4a, 4b has a splined shaft portion 24 on the outer circumferential surface of the tip portion.

Each of the pair of torque transmission devices 5a, 5b transmits the rotational torque of the output shafts 7a, 7b of the pair of electric motors 3a, 3b to each of the pair of drive shafts 4a, 4b. In this example, each of the pair of torque transmission devices 5a, 5b is configured with a gear-type reducer. That is, the first torque transmission device 5a, which is one of the pair of torque transmission devices 5a, 5b, increases the rotational torque of the output shaft 7a of the first electric motor 3a while transmitting it to the first drive shaft 4a. In contrast, the second torque transmission device 5b, which is the other of the pair of torque transmission devices 5a, 5b, increases the rotational torque of the output shaft 7b of the second electric motor 3b while transmitting it to the second drive shaft 4b.

For this purpose, each of the pair of torque transmission devices 5a, 5b has one intermediate shaft 11 and four gears 12a, 12b, 12c, and 12d.

The intermediate shaft 11 is supported rotatably relative to the housing 2, non-coaxially and parallel to the output shafts 7a, 7b and the drive shafts 4a, 4b.

The first gear 12a rotates together with the output shafts 7a and 7b of the electric motors 3a and 3b. In this example, the first gear 12a is supported and fixed to the tip of the output shafts 7a and 7b of the electric motors 3a and 3b.

The second gear 12b meshes with the first gear 12a. The second gear 12b has a number of teeth _N2 that is greater than the number of teeth _N1 of the first gear 12a ( _N2 > _N1 ). In this example, the second gear 12b is supported and fixed to the intermediate shaft 11.

The third gear 12c rotates in synchronization with the second gear 12b. The third gear 12c has a number of teeth _N3 that is smaller than the number of teeth _N2 of the second gear 12b ( _N3 < _N2 ). In this example, the third gear 12c is supported and fixed to a portion of the intermediate shaft 11 that is axially displaced from the portion to which the second gear 12b is supported and fixed.

The fourth gear 12d meshes with the third gear 12c and rotates together with each of the drive shafts 4a and 4b. The fourth gear 12d has a number of teeth _N4 that is greater than the number of teeth _N3 of the third gear 12c ( _N4 > _N3 ). In this example, the fourth gear 12d is supported and fixed to the base ends (the ends closer to each other) of each of the drive shafts 4a and 4b.

When the output shafts 7a and 7b are rotated by energizing the electric motors 3a and 3b, the rotation of the output shafts 7a and 7b is transmitted to the intermediate shaft 11 through the meshing portion between the first gear 12a and the second gear 12b. Furthermore, the rotation of the intermediate shaft 11 is transmitted to the drive shafts 4a and 4b through the meshing portion between the third gear 12c and the fourth gear 12d. In this way, the rotational torque of the output shafts 7a and 7b of the pair of electric motors 3a and 3b is increased by the torque transmission devices 5a and 5b, respectively, and then transmitted to the pair of drive shafts 4a and 4b, respectively.

Each of the pair of torque transmission devices that transmit the rotational torque of the output shafts of the pair of electric motors to each of the pair of drive shafts is not limited to being a gear-type reducer as in this example, but can also be configured with a reducer using a belt or chain, or with a worm reducer. When each of the pair of torque transmission devices is configured with a worm reducer, the output shafts of the pair of electric motors and each of the pair of drive shafts can be positioned in a twisted position relative to each other. Alternatively, each of the pair of torque transmission devices can be configured with a continuously variable transmission or a stepped transmission that can adjust the reduction ratio between the output shafts of the pair of electric motors and each of the pair of drive shafts.

The reduction ratio between the output shafts 7a, 7b of the pair of electric motors 3a, 3b and the pair of drive shafts 4a, 4b is not particularly limited, but is preferably, for example, 6.0 or more and 8.0 or less.

As shown in Figures 8 to 10, a pair of drive shafts 4a, 4b of the electric vehicle drive unit 1 support a braking rotor 15 constituting the braking device 14 and wheels 17 constituting the wheels 16a, 16b via hub unit bearings 13a, 13b.

In this example, the entire electric vehicle drive device 1 is disposed between the wheels 16a, 16b with the wheels 16a, 16b supported on the pair of drive shafts 4a, 4b, respectively. Therefore, in this example, the pair of electric motors 3a, 3b are disposed between the wheels 16a, 16b, respectively. Also, as shown in FIG. 10, when viewed from the axial direction of the drive shafts 4a, 4b, the electric vehicle drive device 1 is located radially inward from the outer periphery of the tires 33 that constitute the wheels 16a, 16b (it does not have a portion that protrudes radially outward from the outer periphery of the tires 33).

Each of the hub unit bearings 13a and 13b includes an outer ring 18, a hub 19, and a number of rolling elements 20.

The outer ring 18 has a double row outer ring raceway on its inner circumferential surface and a stationary flange 21 that protrudes radially outward. The outer ring 18 is supported and fixed to the housing 2 by support members 49 that are inserted or screwed into support holes provided at multiple locations around the circumference of the stationary flange 21.

The hub 19 is disposed inside the outer ring 18 and coaxially with the outer ring 18. The hub 19 has a double row inner ring raceway on its outer circumferential surface. The hub 19 also has a spline hole 22 that penetrates in the axial direction in the center, and a rotating flange 23 that protrudes radially outward.

The splined shaft portions 24 provided at the respective ends of the pair of drive shafts 4a, 4b are splined into the splined holes 22.

The rotating flange 23 has mounting holes 25 that penetrate the axial direction at multiple locations around the circumference. The braking rotor 15 and the wheel 17 are supported on the rotating flange 23 by screwing hub bolts 26, which pass through holes provided at multiple locations around the circumference of each of them, into the mounting holes 25.

In this example, the braking device 14 is configured as a disk brake device. That is, the braking rotor 15 is configured as a disk-shaped brake rotor. The brake caliper 28 that constitutes the braking device 14 is supported and fixed to the housing 2. However, the braking device can also be configured as a drum brake.

The electric vehicle drive device 1 is supported on the underside of the vehicle bodies 32a, 32b, and 32c that constitute the electric vehicles 50a, 50b, and 50c via a support device 29, a turning device 30, and a vehicle height adjustment device 31.

The support device 29 is disposed between the electric vehicle drive device 1 and the vehicle bodies 32a, 32b, and 32c, and has the function of pressing the outer peripheral surfaces (treads) of the tires 33 constituting each of the wheels 16a and 16b against the road surface while mitigating vibrations transmitted from the road surface to the vehicle bodies 32a, 32b, and 32c via each of the wheels 16a and 16b. In this example, the support device 29 includes a mount member 34, a damper 35, and a connecting member 36.

The mount member 34 is disposed on the upper side of the electric vehicle drive device 1 and is approximately parallel to the road surface. The mount member 34 is supported on the underside of the vehicle bodies 32a, 32b, and 32c via the turning device 30 and the vehicle height adjustment device 31.

The damper 35 is configured so that its entire length can be expanded or contracted. The upper end of the damper 35 is rotatably supported (pivoted) on the end of the mount member 34 on one side in the direction of travel (the left side in Figures 8 to 10), and the lower end is rotatably supported on the arm portion 37 of the housing 2.

The connecting member 36 is composed of a leaf spring having a substantially arc-like or substantially U-like shape. The connecting member 36 is stretched between the end of the mount member 34 on the other side in the traveling direction (the right side in FIGS. 8 to 10 ) and the lower end of the housing 2 in a state in which the connecting member 36 is elastically deformed so that the curvature of the curved portion becomes larger (the radius of curvature becomes smaller). That is, the connecting member 36 has an upper end connected and fixed to the end of the mount member 34 on the other side in the traveling direction (the right side in FIGS. 8 to 10 ), and a lower end connected and fixed to the lower end of the housing 2.

The support device 29 configured as described above presses the outer circumferential surface of the tire 33 against the road surface by the elastic force of the connecting member 36 attempting to return to its original position. In addition, the support device 29 absorbs and reduces vibrations transmitted from the road surface to the vehicle bodies 32a, 32b, and 32c by the elastic deformation of the connecting member 36 and the contraction of the damper 35 to generate a damping force.

The turning device 30 supports the electric vehicle drive device 1 on the vehicle bodies 32a, 32b, 32c via the vehicle height adjustment device 31, allowing the electric vehicle drive device 1 to rotate around a turning axis C (see FIG. 10) perpendicular to the road surface. In other words, by making the rotation speed and/or rotation direction of the output shafts 7a, 7b of the pair of electric motors 3a, 3b different from each other, the electric vehicle drive device 1 turns (rotates) around the turning axis C relative to the vehicle bodies 32a, 32b, 32c.

In this example, the swivel device 30 is configured by combining a fixed member 38 supported and fixed to the lower surface of a lower support member 40 constituting the vehicle height adjustment device 31, and a rotating member 39 supported and fixed to the upper surface of a mount member 34 of the support device 29, which are coaxial with each other and can rotate relative to each other around a swivel axis C. Specifically, the swivel device 30 supports the rotating member 39 on the radially inner side of the fixed member 38 via a plurality of rolling elements so that it can rotate freely.

The fixed member 38 has a fixed flange 84 at its upper end or vertical middle portion that protrudes outward in the radial direction about the pivot axis C. Each fixed flange 84 has a fixed side support hole 85 that penetrates in the vertical direction, and includes a plurality of fixed flange pieces 86 (four in the illustrated example) that are spaced apart in the circumferential direction. Specifically, each fixed flange piece 86 has one fixed side support hole 85. The fixed member 38 is supported and fixed to the lower support member 40 by bolts 87 that are inserted or screwed into the fixed side support holes 85 (see FIG. 8).

The rotating member 39 has, at its lower end, a rotating flange 88 that protrudes outward in the radial direction about the pivot axis C. The rotating flange 88 has a plurality of rotating flange pieces 89 (four in the illustrated example) that are spaced apart in the circumferential direction, each of which has a rotating side support hole (not shown) that penetrates in the vertical direction. Specifically, each of the rotating flange pieces 89 has one of the rotating side support holes. The fixed member 38 is supported and fixed to the mount member 34 by bolts 90 that are inserted or screwed into the rotating side support holes.

The swivel device can also be constructed by supporting a fixed member rotatably on the radially inner side of the rotating member.

In this example, the pivot axis C is disposed in a twisted position relative to the pair of drive shafts 4a, 4b. Specifically, as shown in FIG. 10, the pivot axis C is disposed offset to the other side in the traveling direction relative to the pair of drive shafts 4a, 4b. This positions the pivot axis C on the other side in the traveling direction relative to the contact point of the tire 33 with the road surface, ensuring a caster trail.

The vehicle height adjustment device 31 has the function of adjusting the height of the vehicle bodies 32a, 32b, and 32c relative to the road surface. To this end, the vehicle height adjustment device 31 includes a support frame 41, an adjustment mechanism 42, and a height adjustment motor 43.

The support frame 41 includes a lower support member 40, an upper support member 44, a pair of lower link members 45, a pair of upper link members 46, and a pair of pivots 47. The lower support member 40 is supported and fixed to the upper surface of the fixed member 38 of the swivel device 30. The upper support member 44 is supported and fixed to the lower surface of the vehicle bodies 32a, 32b, and 32c. Each of the pair of lower link members 45 supports a lower end of the lower support member 40 so as to be swingable relative to the ends of the lower support member 40 on both sides in the traveling direction. Each of the pair of upper link members 46 supports an upper end of the upper support member 44 so as to be swingable relative to the ends of the upper support member 44 on both sides in the traveling direction. Each of the pair of pivots 47 swingably connects the upper end of each of the pair of lower link members 45 and the lower end of each of the pair of upper link members 46 to each other.

The adjustment mechanism 42 adjusts the height of the vehicle bodies 32a, 32b, and 32c relative to the road surface by expanding and contracting the gap between the pair of pivots 47 and the gap between the lower support member 40 and the upper support member 44, using the height adjustment motor 43 as a drive source. For this purpose, the adjustment mechanism 42 is equipped with a telescopic shaft formed by combining a pair of shaft members in a telescopic manner, and a linear motion mechanism.

The linear motion mechanism is, for example, a ball screw mechanism. That is, the linear motion mechanism includes a ball screw shaft, which is one of a pair of shaft members, and a ball nut supported and fixed to the other of the pair of shaft members.

The adjustment mechanism 42 rotates the ball screw shaft using the height adjustment motor 43, displacing the ball nut relatively in the axial direction. This displaces the other shaft member in the axial direction and expands and contracts the telescopic shaft, expanding and contracting the gap between the pair of pivots 47, thereby adjusting the height of the vehicle bodies 32a, 32b, and 32c relative to the road surface.

As shown in FIG. 8, the electric vehicle drive device 1 of this example is combined with the hub unit bearings 13a, 13b, the braking device 14, the wheels 16a, 16b, the support device 29, the turning device 30, and the vehicle height adjustment device 31, and can be handled as a single unit as the drive unit 48. The drive unit 48 is equipped with a weight sensor for measuring the weight to be supported, and an angle sensor for measuring the steering angle of the wheels 16a, 16b. The mounting positions of the weight sensor and the angle sensor are not particularly limited, and they can be mounted, for example, on the turning device 30.

The electric vehicle drive device 1 of this example is used as a drive source for the electric vehicle. Specifically, an appropriate number of drive units 48 including the electric vehicle drive device 1 of this example are mounted on the electric vehicle according to the total vehicle weight. The weight supported by each drive unit 48 is not particularly limited, but can be, for example, 300 kg to 650 kg.

An example of an electric vehicle that uses the electric vehicle drive device 1 as a drive source will be described with reference to Figures 11(A) to 13(C).

Figures 11(A) to 11(C) show a first example of an electric vehicle that uses the electric vehicle drive device 1 as a drive source. The electric vehicle 50a has a passenger capacity of about four to five people. The electric vehicle 50a includes a vehicle body 32a and four drive units 48.

The vehicle body 32a comprises a rectangular box-shaped vehicle body main body 51a and a pair of eaves-shaped supported parts 52a1, 52a2 that protrude from the lower parts of both sides of the vehicle body main body 51a in the traveling direction.

Each of the drive units 48 is supported in pairs on the underside of each of the pair of supported parts 52a1, 52a2 so that they all face the same direction. That is, the upper support members 44 of the vehicle height adjustment device 31 constituting each of the drive units 48 are supported and fixed at two locations in the width direction on the underside of each of the pair of supported parts 52a1, 52a2. This makes it possible to ensure a large space (vehicle interior space) inside the vehicle body 51a.

The electric vehicle drive device 1 can rotate each of the wheels 16a, 16b in either direction. However, the pivot axis C of the drive unit 48 is offset to the other side of the traveling direction relative to the pair of drive shafts 4a, 4b. For this reason, except when parking in a parking space or changing direction, it is usually preferable for the electric vehicle 50a to run with the other side of the traveling direction of the electric vehicle drive device 1 (the right side in FIG. 11(B)) facing forward in order to ensure stability in straight-ahead driving.

In addition, a connecting member 36 of the support device 29 is disposed on the other side of the electric vehicle drive device 1 in the direction of travel. Therefore, when the other side of the direction of travel is facing forward, even if pebbles or the like are kicked up by the tires of a vehicle traveling in front, the connecting member 36 can prevent the pebbles or the like from directly colliding with the electric vehicle drive device 1.

The electric vehicle 50a controls the running direction and running speed by controlling the rotation speed and direction of each of the wheels 16a, 16b of the four drive units 48 using a control device (not shown). For example, the electric vehicle 50a can run straight by making the rotation speed and direction of all the wheels 16a, 16b the same. On the other hand, the electric vehicle 50a can turn by adjusting the rotation speed of each of the wheels 16a, 16b to an appropriate value. Specifically, when turning, the rotation speed of the wheels 16a, 16b is made smaller for the wheels located radially inside the turning trajectory. Also, if the rotation direction of one wheel 16a and the rotation direction of the other wheel 16b are made opposite to each other for each of the drive units 48, only the direction of the drive unit 48 can be changed (steered) on the spot.

In this example, the pair of drive shafts 4a, 4b are arranged coaxially with each other, so that by controlling the rotation direction and rotation speed of the pair of drive shafts 4a, 4b, the drive unit 48 can be rotated about a pivot axis C that is perpendicular to the road surface parallel to the drive shafts 4a, 4b, and the vehicle can be steered.

When the electric vehicle 50a stops, the braking device 14 is driven and a pair of pads supported by the brake caliper 28 are pressed against the braking rotor 15 to perform braking. However, regenerative braking can also be performed by using each of the pair of electric motors 3a, 3b that make up the electric vehicle drive device 1 as a generator.

Each drive unit 48 is equipped with a height adjustment device 31. Therefore, the electric vehicle 50a can adjust its height by adjusting the vertical dimensions of the height adjustment devices 31 of each drive unit 48. In particular, by adjusting the vertical dimensions of each height adjustment device 31 based on measurements by the weight sensors of each drive unit 48, the weight of the vehicle body 32a can be supported in a balanced manner by the four drive units 48 regardless of the weight balance in the vehicle interior space. In addition, when passengers get on and off the vehicle or when loading and unloading luggage, the entrance side of the vehicle body 32a can be lowered to facilitate boarding and alighting and loading and unloading operations.

Figures 12(A) to 12(C) show a second example of an electric vehicle that uses the electric vehicle drive device 1 as a drive source. The electric vehicle 50b has a passenger capacity of about 8 to 10 people. The electric vehicle 50b includes a vehicle body 32b and eight drive units 48.

The vehicle body 32b comprises a rectangular box-shaped vehicle body main body 51b and a pair of eaves-shaped supported parts 52b1, 52b2 that protrude from the lower parts of both sides of the vehicle body main body 51b in the traveling direction.

Each of the drive units 48 is supported by four units on the underside of each of the pair of supported parts 52b1, 52b2. That is, the upper support members 44 of the vehicle height adjustment device 31 constituting each of the drive units 48 are supported and fixed to the underside of each of the pair of supported parts 52b1, 52b2 in two rows, with two locations in each row in the width direction. The configuration and effects of the other parts are the same as those of the first example shown in Figures 11(A) to 11(C).

Figures 13(A) to 13(C) show a third example of an electric vehicle that uses the electric vehicle drive device 1 as a drive source. The electric vehicle 50c has a passenger capacity of about 20 to 30 people. The electric vehicle 50c includes a vehicle body 32c and 16 drive units 48.

The vehicle body 32c comprises a rectangular box-shaped vehicle body 51c and a pair of eaves-shaped supported parts 52c1, 52c2 that protrude from the lower parts of both sides of the vehicle body 51c in the traveling direction.

Each of the drive units 48 is supported by eight units on the underside of each of the pair of supported parts 52c1, 52c2. That is, the upper support members 44 of the vehicle height adjustment device 31 constituting each of the drive units 48 are supported and fixed to the underside of each of the pair of supported parts 52c1, 52c2 in two rows, with four locations in each row in the width direction. The configuration and effects of the other parts are the same as those of the first example shown in Figures 11(A) to 11(C).

As described above, the electric vehicle drive device 1 of this example can be commonly used as a drive device for electric vehicles regardless of the total vehicle weight. Therefore, there is no need to design an electric vehicle drive device specifically for each total vehicle weight, and the manufacturing costs of electric vehicles can be reduced. In particular, when the electric vehicle drive device 1 of this example is applied to an autonomous vehicle equipped with a large number of expensive sensors, the cost reduction effect of sharing the electric vehicle drive device 1 can be obtained significantly.

In this example, the pair of electric motors 3a, 3b are configured to be able to independently control the rotation speed and direction of each output shaft 7a, 7b. Therefore, the rotation speed and direction of the wheels 16a, 16b supported by each of the pair of drive shafts 4a, 4b can be independently adjusted. Therefore, even without a separate actuator for steering the drive unit 48, the drive unit 48 can be steered by rotating one wheel 16a in the opposite direction to the other wheel 16b. However, each drive unit 48 can also be provided with a separate actuator for steering about the pivot axis C.

In addition, in the electric vehicle drive device 1 of this example, the drive units 53a, 53b constituting each of the pair of electric motors 3a, 3b are positioned in the same position in the direction perpendicular to the output shafts 7a, 7b. This allows the width dimension of the electric vehicle drive device 1 to be reduced.

In this example, the electric vehicle drive device 1 is configured to drive each of the pair of drive shafts 4a, 4b by a pair of electric motors 3a, 3b via a pair of torque transmission devices 5a, 5b, but when implementing the present invention, each of the drive shafts can also be configured to be driven by two or more electric motors.

The electric vehicle drive device 1, the hub unit bearings 13a, 13b, the brake device 14, the wheels 16a, 16b, the support device 29, the turning device 30, and the vehicle height adjustment device 31 constitute a drive unit 48 that enables the electric vehicles 50a, 50b, and 50c to run, turn, and stop. The electric vehicles 50a, 50b, and 50c each have a plurality of such drive units 48. Therefore, even if one of the drive units 48 fails, the electric vehicles 50a, 50b, and 50c can continue to run to a certain extent (for example, to the extent of retreating to the roadside) using the remaining drive units 48. The electric vehicles 50a, 50b, and 50c also have excellent maintainability because the breakdown can be easily repaired by replacing the failed drive unit 48.

[Second Example of the Embodiment]
A second embodiment of the present invention will be described with reference to Fig. 14(A) to Fig. 26. In this embodiment, the electric vehicle drive device of the present invention is applied to a drive device of an automated guided vehicle (AGV), which is a type of electric vehicle. The automated guided vehicle transports an automobile to a predetermined position. In the following, the overall structure of the automated guided vehicle will be described first, and then the structure of the drive unit of this embodiment will be described.

The automated guided vehicle 55 includes a vehicle body 56, a pair of drive units 48a, and a pair of driven wheels 57.

The vehicle body 56 includes a rectangular box-shaped towing section 58 and a mounting section 59 for mounting an automobile. The mounting section 59 has a generally U-shaped planar shape when viewed from the top-bottom direction. That is, the mounting section 59 has a rectangular plate-shaped base section 60 that extends rearward from the lower end of the rear side of the towing section 58, and rectangular plate-shaped extension sections 61 that extend rearward from two positions spaced apart in the width direction of the rear end section of the base 60. The front and rear wheels of the automobile are placed on each of the extension sections 61.

Each of the drive units 48a is supported on the underside of the towing section 58 at two locations spaced apart in the width direction so as to be able to rotate about a pivot axis C (see FIG. 16) that is perpendicular to the road surface.

Each of the driven wheels 57 has a support shaft 62 supported on the rear portion of the extension 61 and a pair of tires 63 supported rotatably on the support shaft 62.

Next, the structure of the drive unit 48a mounted on the automated guided vehicle 55 of this example will be described. The drive unit 48a of this example differs from the drive unit 48 of the first example of the embodiment in the location where the pair of electric motors 3c, 3d are installed. That is, in the drive unit 48a of this example, each of the pair of electric motors 3c, 3d is disposed at a position radially outwardly offset from the wheels 16c, 16d. More specifically, each of the pair of electric motors 3c, 3d is disposed at a position offset upward from the wheels 16c, 16d.

The pair of electric motors 3c, 3d are arranged so that the driving parts 53c, 53d are overlapped in a direction perpendicular to the output shafts 7c, 7d. Specifically, in this example, the positions of the driving parts 53c, 53d in the width direction are the same.

The drive unit 48a includes an electric vehicle drive device 1a, wheels 16c, 16d, a braking device 14, and a turning device 30a.

The electric vehicle drive unit 1a includes a housing 2a, a pair of electric motors 3c, 3d, a pair of drive shafts 4c, 4d, and a pair of torque transmission devices 5c, 5d.

The housing 2a has a cylindrical portion 6d, a pair of rectangular plate-shaped motor mounting portions 64a, 64b that are provided above the cylindrical portion 6d and are arranged parallel to each other and spaced apart in the direction of travel and width, and a pair of transmission device accommodating portions 65a, 65b that are bridged between the cylindrical portion 6d and the motor mounting portions 64a, 64b, respectively.

The pair of electric motors 3c, 3d each have an output shaft 7c, 7d, and are supported and fixed to the housing 2a. Specifically, the pair of electric motors 3c, 3d each are supported and fixed to the motor mounting parts 64a, 64b of the housing 2a such that the output shafts 7c, 7d are non-coaxial and parallel to each other with the tips of the output shafts 7c, 7d facing in opposite directions.

To this end, specifically, the first electric motor 3c, which is one of the pair of electric motors 3c, 3d, is supported and fixed to the other side in the width direction of the motor mounting portion 64a on one side in the width direction of the pair of motor mounting portions 64a, 64b of the housing 2a, with the tip of the output shaft 7c facing one side in the width direction (the left side in FIG. 26).

In contrast, the second electric motor 3d, which is the other of the pair of electric motors 3c, 3d, is supported and fixed to one side of the motor mounting portion 64b on the other side in the width direction of the pair of motor mounting portions 64a, 64b of the housing 2a, with the tip of the output shaft 7d facing the other side in the width direction (the right side in FIG. 26).

In this example, a pair of electric motors 3c, 3d are each a larger motor with a lower rated voltage than the electric motors 3a, 3b of the electric vehicle drive device 1 according to the first embodiment. Specifically, for example, a motor with a rated voltage of 48 V is used as each of the electric motors 3c, 3d.

The pair of drive shafts 4c, 4d are coaxial with each other, with their respective tips facing in opposite directions, and their base ends (the ends closest to each other) are rotatably supported by the cylindrical portion 6d of the housing 2a. Furthermore, as shown in Figures 23 and 24, the middle portion of each of the pair of drive shafts 4c, 4d is rotatably supported by a pair of tapered roller bearings 77 with a back-to-back (DB) type contact angle on the inside of a cylindrical member 76 supported and fixed to the housing 2a. In this example, the pair of drive shafts 4c, 4d are arranged non-coaxially and parallel to the output shafts 7c, 7d of the pair of electric motors 3c, 3d.

To this end, specifically, the first drive shaft 4c, which is one of the pair of drive shafts 4c, 4d, has its base end rotatably supported on the end of the cylindrical portion 6d of the housing 2a in the other width direction, with its tip end facing the other side in the width direction. In contrast, the second drive shaft 4d, which is the other of the pair of drive shafts 4c, 4d, has its base end rotatably supported on the end of the cylindrical portion 6d in the one width direction, with its tip end facing one side in the width direction.

In this example, as shown in Fig. 16, when wheels 16c, 16d are supported on drive shafts 4c, 4d, respectively, the positional relationship between cylindrical portion 6d and motor mounting portions 64a, 64b constituting housing 2a is regulated so that electric motors 3c, 3d are positioned above tires 33 constituting wheels 16c, 16d when viewed from the width direction (axial direction of drive shafts 4c, 4d). In other words, the positional relationship between cylindrical portion 6d and motor mounting portions 64a, 64b in the vertical direction is regulated based on the size of electric motors 3c, 3d and the outer diameter dimension of tires 33.

Furthermore, in this example, as shown in FIG. 18, the distance between the pair of electric motors 3c, 3d in the traveling direction is regulated so that all members constituting the drive unit 48a are located inside the turning circle α of the pair of wheels 16c, 16d (a circle centered on the turning axis C described below and passing through the outer end in the width direction of the outer peripheral surface of the tire 33 constituting the wheels 16c, 16d). In other words, the positional relationship of the motor mounting parts 64a, 64b in the traveling direction is regulated based on the size of the electric motors 3c, 3d and the width dimension of the tire 33.

Each of the pair of torque transmission devices 5c, 5d transmits the rotational torque of the output shaft 7c, 7d of the pair of electric motors 3c, 3d to each of the pair of drive shafts 4c, 4d. In this example, each of the pair of torque transmission devices 5c, 5d is configured with a gear-type reducer. That is, the first torque transmission device 5c, which is one of the pair of torque transmission devices 5c, 5d, increases the rotational torque of the output shaft 7c of the first electric motor 3c while transmitting it to the first drive shaft 4c. In contrast, the second torque transmission device 5d, which is the other of the pair of torque transmission devices 5c, 5d, increases the rotational torque of the output shaft 7d of the second electric motor 3d while transmitting it to the second drive shaft 4d.

For this reason, each of the pair of torque transmission devices 5c, 5d has four intermediate shafts 66a-66d, all of which are made up of spur gears, and eight gears 67a-67h.

The intermediate shafts 66a to 66d are supported non-coaxially and in parallel to each other so as to be freely rotatable inside the transmission device accommodating portions 65a and 65b of the housing 2a.

The first intermediate shaft 66a is rotatably supported at a position on the inner side of the transmission device housing 65a, 65b closer to the drive shafts 4c, 4d than the output shafts 7c, 7d of the electric motors 3c, 3d in the direction of travel. The second intermediate shaft 66b is rotatably supported at a position on the inner side of the transmission device housing 65a, 65b closer to the drive shafts 4c, 4d than the first intermediate shaft 66a in the direction of travel and above the first intermediate shaft 66a. The third intermediate shaft 66c is rotatably supported at a position on the inner side of the transmission device housing 65a, 65b lower than the second intermediate shaft 66b and closer to the drive shafts 4c, 4d than the first intermediate shaft 66a in the direction of travel. The fourth intermediate shaft 66d is rotatably supported in the inner portion of the transmission device accommodating portion 65a, 65b, at a position lower than the third intermediate shaft 66c and closer to the drive shafts 4c, 4d than the third intermediate shaft 66c in the direction of travel.

The first gear 67a rotates together with the output shafts 7c and 7d of the electric motors 3c and 3d. In this example, the first gear 67a is fitted and fixed to the tip of the output shafts 7c and 7d of the electric motors 3c and 3d.

The second gear 67b meshes with the first gear 67a and is provided around the first intermediate shaft 66a. In this example, the second gear 67b is integrally formed with the first intermediate shaft 66a. The second gear 67b has a greater number of teeth than the first gear 67a.

The third gear 67c meshes with the second gear 67b and is supported and fixed to the second intermediate shaft 66b. In this example, the third gear 67c has a greater number of teeth than the second gear 67b.

The fourth gear 67d is provided around a portion of the second intermediate shaft 66b that is axially displaced from the portion where the third gear 67c is supported and fixed, and rotates in synchronization with the third gear 67c. In this example, the fourth gear 67d is integrally formed with the second intermediate shaft 66b. The fourth gear 67d has a smaller number of teeth than the third gear 67c.

The fifth gear 67e meshes with the fourth gear 67d and is supported and fixed to the third intermediate shaft 66c. In this example, the fifth gear 67e has a greater number of teeth than the fourth gear 67d.

The sixth gear 67f is provided around a portion of the third intermediate shaft 66c that is axially displaced from the portion where the fifth gear 67e is supported and fixed, and rotates in synchronization with the fifth gear 67e. In this example, the sixth gear 67f is integrally formed with the third intermediate shaft 66c. The sixth gear 67f has a smaller number of teeth than the fifth gear 67e.

The seventh gear 67g meshes with the sixth gear 67f and is provided around the fourth intermediate shaft 66d. In this example, the seventh gear 67g is integrally formed with the fourth intermediate shaft 66d. The seventh gear 67g has a greater number of teeth than the sixth gear 67f.

The eighth gear 67h meshes with the seventh gear 67g and rotates with each of the drive shafts 4c and 4d. The eighth gear 67h has a greater number of teeth than the seventh gear 67g. In this example, the eighth gear 67h is supported and fixed to the base end (the end closest to each other) of each of the drive shafts 4c and 4d.

The pair of torque transmission devices 5c, 5d are not limited to the above configuration, and can be modified as appropriate as long as the rotational torque of the output shafts 7c, 7d of the electric motors 3c, 3d can be increased and transmitted to the drive shafts 4c, 4d. Specifically, for example, the relationship between the number of teeth of the gears 67a to 67h can be changed from the above relationship, or the number of gears (and intermediate shafts) can be changed. In this example, the gears 67a to 67h are all spur gears, but some or all of the gears can be helical gears. A worm reducer in which the central axis of the worm and the central axis of the worm wheel that mesh with each other are in a twisted position can also be incorporated into the torque transmission device. Furthermore, the torque transmission device can be configured with a reducer that uses a belt or chain.

As shown in Figures 23 and 24, a pair of drive shafts 4c, 4d are supported by mounting members 78 on each of which are a braking rotor 15 constituting the braking device 14 and wheels 17 constituting the wheels 16c, 16d.

The mounting member 78 has a spline hole 79 that penetrates axially in the center, and a rotating flange 80 that protrudes radially outward.

The splined shaft portions 24 provided at the respective ends of the pair of drive shafts 4c, 4d are splined into the splined holes 79.

The rotating flange 80 has mounting holes 81 at multiple locations in the circumferential direction. The braking rotor 15 and the wheel 17 are supported on the rotating flange 80 by threading the hub bolts 26, which pass through holes provided at multiple locations in the circumferential direction of each of them, into the mounting holes 81.

The mounting member 78 is prevented from falling off the drive shafts 4c and 4d by nuts 82 that are screwed onto the ends of the pair of drive shafts 4c and 4d.

The electric vehicle drive unit 1a is supported on the underside of the towing section 58 of the vehicle body 56 via the turning device 30a.

The swivel device 30a is a combination of a fixed member 38a supported and fixed to the underside of the towing section 58 of the vehicle body 56 and a rotating member 39a supported and fixed to the upper end of the housing 2a, which are coaxial with each other and can rotate relative to each other around the swivel axis C. Specifically, the swivel device 30a supports the rotating member 39a on the radially inner side of the fixed member 38a via a plurality of rolling elements 91 so that it can rotate freely.

The fixed member 38a has a double row of fixed side tracks 92 on its inner circumferential surface, and a fixed flange 84 at the vertical middle that protrudes outward in the radial direction centered on the pivot axis C. Each fixed flange 84 has a fixed side support hole 85 that penetrates in the vertical direction, and includes a plurality of fixed flange pieces 86 (four in the illustrated example) that are spaced apart in the circumferential direction. That is, each fixed flange piece 86 has one fixed side support hole 85. The fixed member 38 is supported and fixed to the towing section 58 by bolts that are inserted or screwed into the fixed side support holes 85.

The rotating member 39a has a double row rotating side raceway 93 on its outer circumferential surface, and a rotating flange 88 at its lower end that protrudes outward in the radial direction centered on the rotation axis C. Each rotating flange 88 has a rotating side support hole (not shown) that penetrates in the vertical direction, and has a plurality of rotating flange pieces 89 (four in the illustrated example) that are spaced apart in the circumferential direction. Specifically, each rotating flange piece 89 has one of the rotating side support holes. The rotating member 39a is supported and fixed to the upper end of the housing 2a by bolts 90 that are inserted or screwed into the rotating side support holes.

Each of the rolling elements 91 is held by a cage between a double row fixed side raceway 92 and a double row rotating side raceway 93, and is arranged to roll freely, and is given a back-to-back combination type contact angle. In this example, balls are used as the rolling elements 91, but tapered rollers can also be used.

In this example, the drive unit 48a can rotate the wheels 16c, 16d (and the electric vehicle drive unit 1a) around the pivot axis C by controlling the direction and speed of rotation of the drive shafts 4c, 4d.

In this example, as shown in FIG. 24, a double row fixed side raceway 92 is provided on the inner peripheral surface of the fixed member 38a via an outer ring 94, and a double row rotating side raceway 93 is provided on the outer peripheral surface of the rotating member 39a via an inner ring 95. In other words, the rotating member 39a is rotatably supported on the radially inner side of the fixed member 38a via a pair of angular ball bearings with a back-to-back contact angle. However, when implementing the present invention, one or both of the double row fixed side raceways can be provided directly on the inner peripheral surface of the fixed member, and/or one or both of the double row rotating side raceways can be provided directly on the outer peripheral surface of the rotating member.

In this example, the pivot axis C, which is the central axis of the rotating member 39a, is perpendicular to the central axes of the pair of drive shafts 4c and 4d. However, the caster trail can also be ensured by offsetting the pivot axis C in the direction of travel with respect to the central axes of the pair of drive shafts 4c and 4d (positioning it in a twisted position).

In this example, the automated guided vehicle 55 controls each of the pair of drive units 48a using a control device mounted on the towing unit 58 based on signals from various sensors, etc. In other words, the control device controls the rotation direction and number of rotations (rotational speed) of each of the drive shafts 4c, 4d of the pair of drive units 48a, and controls the rotation direction and number of rotations of the wheels 16c, 16d supported by the drive shafts 4c, 4d, thereby controlling the travel direction and travel speed of the automated guided vehicle 55.

For example, by making the rotation speed and direction of all the wheels 16c, 16d the same, the automated guided vehicle 55 can travel straight. Also, by making the rotation speed of the wheels 16c, 16d smaller for the wheels located radially inwards of the turning trajectory, the automated guided vehicle 55 can travel in turns. Furthermore, by making the rotation direction of one wheel 16c and the rotation direction of the other wheel 16d opposite each other for each of the drive units 48a, it is possible to change (steer) only the direction of the drive unit 48a on the spot.

In this example, the pair of electric motors 3c, 3d are arranged at a position radially outward from the wheels 16c, 16d (the tires 33 that constitute them). Therefore, compared to the structure in which the pair of electric motors 3a, 3b are arranged between the pair of wheels 16a, 16b as in the first example of the embodiment, it is easier to shorten the distance between the wheels 16c, 16d (the distance in the axial direction of the wheels 16c, 16d). In other words, it is easier to keep the width dimension of the entire drive unit 48a small. In short, even if general-purpose and large electric motors 3c, 3d are used instead of small ones specially designed for the electric motors 3c, 3d, the width dimension of the contact surface (tread) of the tire 33 can be sufficiently secured while suppressing an increase in the width dimension of the entire drive unit 48a.

Therefore, the drive unit 48a of this example can be easily installed in a vehicle with limited installation space in the width direction. Alternatively, since the distance between the wheels 16c, 16d can be reduced, the pair of electric motors 3c, 3d can be made larger (upsized), and the rated output of the electric motors 3c, 3d can be increased, thereby reducing the number of drive units 48a mounted on an electric vehicle (automated guided vehicle 55). In addition, the degree of freedom in the layout of the parts arranged between the wheels 16c, 16d can be improved. Specifically, for example, it is easy to make changes such as making the brake device 14 larger to obtain a large braking force, or increasing the width dimension of the tire 33 to increase the load capacity.

Even if large electric motors 3c, 3d are used, all of the members constituting the drive unit 48a can be easily accommodated inside the turning circle α of the pair of wheels 16c, 16d. Furthermore, the electric motors 3c, 3d can be replaced without removing the wheels 16c, 16d, which improves maintainability.
The configuration and the effects of the other parts are the same as those of the first embodiment.

[Third Example of the Embodiment]
27(A) to 27(C) show a third embodiment. An automated guided vehicle 55a in this embodiment has only one drive unit 48a. Specifically, the drive unit 48a is supported at the center position in the width direction of the underside of a towing section 58 of a vehicle body 56 so as to be rotatable about a rotation axis C (see FIG. 16) perpendicular to the road surface.

In the present example of the automated guided vehicle 55a, the number of drive units 48a is kept to a minimum, thereby reducing costs. The configuration and effects of the other parts are the same as those of the first and second examples of the embodiment.

[Fourth Example of the Embodiment]
Fig. 28 shows a fourth example of the embodiment. A drive unit 48b in this example has a function of reducing vibrations transmitted from the road surface to a vehicle body 56 (see Figs. 14(A) to 14(C)) via each of the wheels 16c and 16d.

For this purpose, the fixed member 38b of the swivel device 30b has two cylindrical portions 68 at positions opposite to the traveling direction. In this example, the central axis of the cylindrical portion 68 is arranged in the width direction. That is, the central axis of the cylindrical portion 68 is arranged parallel to the output shafts 7c, 7d and drive shafts 4c, 4d of the electric motors 3c, 3d (see Figures 23, 24, and 26). Furthermore, the fixed member 38b has a sleeve 70 supported on the inside of each cylindrical portion 68 via an elastic member 69 made of an elastomer such as rubber, and has a hollow circular plate-shaped cover body 83 that closes the opening on one axial side (the left side in Figures 29(A) and 29(B)) of the cylindrical space between the inner peripheral surface of the cylindrical portion 68 and the outer peripheral surface of the sleeve 70.

The fixing member 38b is supported and fixed to the mounting portion provided on the underside of the towing part 58 of the vehicle body 56, for example, by screwing a nut onto a bolt inserted through the sleeve 70 and the lid body 83 from the other axial side. In other words, when the fixing member 38b is supported and fixed to the vehicle body 56, the lid body 83 and the mounting portion close the openings on both axial sides of the cylindrical space between the inner circumferential surface of the cylindrical part 68 and the outer circumferential surface of the sleeve 70.

According to this example, even if the wheels 16c, 16d vibrate in the axial direction (width direction) or radial direction (travel direction and/or up-down direction) of the wheels 16c, 16d due to unevenness of the road surface, the elastic member 69 of the turning device 30b can absorb this vibration by elastic deformation. In other words, the vibration transmitted from the road surface to the vehicle body 56 via each of the wheels 16c, 16d can be mitigated. In particular, in this example, the central axis of the cylindrical portion 68 is arranged in the width direction, so that the absorption performance of the vertical vibration from the wheels 16c, 16d can be improved.

Furthermore, in this example, the lid 83 and the mounting portion close the openings on both axial sides of the cylindrical space between the inner circumferential surface of the cylindrical portion 68 and the outer circumferential surface of the sleeve 70, so that excessive deformation of the elastic member 69 due to vibration of the wheels 16c, 16d can be prevented. In addition, the pair of lids can close the openings on both axial sides of the cylindrical space between the inner circumferential surface of the cylindrical portion 68 and the outer circumferential surface of the sleeve 70, and a flange facing radially inward can be provided at one axial end of the cylindrical portion 68 to prevent excessive deformation of the elastic member 69 to one axial side.

In addition, when implementing the present invention, instead of or in addition to the configuration in which the drive unit 48b is supported on the vehicle body 56 via the elastic member 69 as in this example, the drive unit can also be supported on the vehicle body via a cushioning mechanism such as a gas damper or air spring.
The other configurations and effects are similar to those of the first and second embodiments.

[Fifth Example of the Embodiment]
Fig. 30 shows a fifth example of the embodiment. Similar to the drive unit 48b according to the fourth example of the embodiment shown in Fig. 29, the drive unit 48c of this example also has a function of reducing vibrations transmitted from the road surface to the vehicle body 56 (see Figs. 14(A) to 14(C)) via each of the wheels 16c and 16d.

For this purpose, the fixed member 38c of the swivel device 30c has cylindrical portions 68a at multiple locations in the circumferential direction. In this example, the cylindrical portions 68a are provided at four locations on the fixed member 38c at equal intervals in the circumferential direction. The central axes of the cylindrical portions 68a are arranged in the vertical direction. The fixed member 38c has a sleeve 70a supported on the inside of each cylindrical portion 68a via an elastic member 69a made of an elastomer such as rubber. Furthermore, the fixed member 38c has a hollow circular plate-shaped cover body 83 (see Figures 29(A) and 29(B)) that closes an opening on one axial side (lower opening) of the cylindrical space between the inner peripheral surface of the cylindrical portion 68a and the outer peripheral surface of the sleeve 70a.

The fixing member 38c is supported and fixed to the mounting portion provided on the underside of the towing part 58 of the vehicle body 56, for example, by screwing a nut onto a bolt inserted from the other axial side (upper side) through the sleeve 70a and the lid body 83. In other words, when the fixing member 38c is supported and fixed to the vehicle body 56, the lid body 83 and the mounting portion close the openings on both axial sides (openings on both vertical sides) of the cylindrical space between the inner circumferential surface of the cylindrical part 68a and the outer circumferential surface of the sleeve 70a.

According to this example, even if the wheels 16c, 16d vibrate in the axial direction (width direction) or radial direction (travel direction and/or width direction) of the wheels 16c, 16d due to unevenness of the road surface, the elastic member 69a of the turning device 30c can absorb this vibration by elastic deformation. In other words, the vibration transmitted from the road surface to the vehicle body 56 via each of the wheels 16c, 16d can be mitigated. In particular, in this example, the central axis of the cylindrical portion 68a is arranged in the vertical direction, so that the vibration absorption performance in the width direction from the wheels 16c, 16d can be improved.

Furthermore, in this example, the lid 83 and the mounting portion close the openings on both axial sides of the cylindrical space between the inner circumferential surface of the cylindrical portion 68a and the outer circumferential surface of the sleeve 70a, preventing excessive deformation of the elastic member 69a due to vibration of the wheels 16c, 16d.

In this embodiment as well, the drive unit may be supported on the vehicle body via a shock-absorbing mechanism such as a gas damper or an air spring.
The other configurations and effects are similar to those of the first, second and fourth embodiments.

[Sixth Example of the Embodiment]
31 shows a sixth embodiment. An automated guided vehicle 55b of this embodiment includes a rectangular box-shaped vehicle body 71, a drive unit 48a, a plurality of auxiliary wheels 72 (four in the illustrated example), and a fork 73.

The drive unit 48a is supported in the center of the underside of the vehicle body 71 so as to be able to rotate about a pivot axis C (see FIG. 16) that is perpendicular to the road surface.

The auxiliary wheels 72 are supported at corners of the underside of the vehicle body 71 so that they can rotate about a central axis perpendicular to the road surface.

The fork 73 is supported on the front of the vehicle body 71 so that it can move up and down.

When the automated guided vehicles 55b of this example are used to transport the automobile 74, the automobile 74 is transported by using multiple automated guided vehicles 55b as a group. Specifically, each wheel 75 of the automobile 74 is lifted by the fork 73 of each automated guided vehicle 55b and transported. In the example shown in the figure, each of the four wheels 75 is transported by one automated guided vehicle 55b in total, four in number.

The automated guided vehicle 55b of this example can transport many types of automobiles 74. That is, in the automated guided vehicle 55 according to the second example of the embodiment and the automated guided vehicle 55a according to the third example of the embodiment, it may be necessary to change the width dimension and overall length of the placement unit 59 depending on the width and overall length of the automobile to be transported. In contrast, the automated guided vehicle 55b of this example transports the automobile 74 by lifting each of the wheels 75 with the forks 73 of the automated guided vehicle 55b, so that the automobile 74 can be transported regardless of the width and overall length of the automobile 74.
The configuration and the effects of the other parts are similar to those of the second embodiment.

[Seventh Example of the Embodiment]
32 to 37 show a seventh example of the embodiment. The turning device 30d constituting the drive unit 48d of this example has a stopper mechanism 96 that restricts the rotatable range of the electric vehicle drive device 1a around the turning axis C. That is, the turning device 30d of this example has a mechanical stopper. The stopper mechanism 96 has a pair of fixed side stopper surfaces 97 facing the circumferential direction and provided on the fixed member 38d, and a pair of rotating side stopper surfaces 98 facing the circumferential direction and facing the pair of fixed side stopper surfaces 97 and provided on the rotating member 39a. Note that, with respect to the turning device 30d, the circumferential direction, the radial direction, and the axial direction refer to the circumferential direction, the radial direction, and the axial direction around the turning axis C.

The fixed member 38d has a fixed flange 84 protruding radially outward at the axial middle. The fixed flange 84 has four fixed flange pieces 86 in a substantially triangular shape that protrude radially outward from the adjacent parts on both sides in the circumferential direction at four circumferentially spaced locations. The fixed member 38d has a pair of bent plate portions 99 bent downward from the ends of a pair of fixed flange pieces 86 adjacent in the circumferential direction, which are far from each other in the circumferential direction, among the four fixed flange pieces 86 that constitute the fixed flange 84. In other words, each of the two fixed flange pieces 86 adjacent in the circumferential direction has a bent plate portion 99. The radially inner ends of each of the bent plate portions 99 are connected to the portion of the outer circumferential surface of the fixed member 38d that is adjacent to the lower side of the fixed flange 84. That is, the fixed member 38d is configured as a whole, including the four fixed flange pieces 86 and the fixed flange 84 having a pair of bent plate portions 99. The pair of fixed stopper surfaces 97 are provided on the side surfaces of the pair of bent plate portions 99 that are farther from each other in the circumferential direction.

The rotating member 39a is made by connecting and fixing a rotating member main body 100 and a rotating side stopper member 101 with a bolt 102.

The rotating member body 100 has a double row rotating side track 93 on its outer circumferential surface, and a circular rotating flange 88a at its lower end that protrudes radially outward. The rotating flange 88a has a rectangular notch 103 at one circumferential position. The notch 103 has a screw hole 104 that opens to the bottom surface, and has a pair of main body-side opposing surfaces 105 that are parallel to each other on both inner circumferential surfaces.

The rotation side stopper member 101 has a rectangular plate-shaped engagement plate portion 106 and a columnar portion 107 that protrudes upward from the upper surface of the engagement plate portion 106. The engagement plate portion 106 has a through hole 108 that penetrates in the radial direction, and has a pair of stopper member side opposing surfaces 109 that are parallel to each other on both circumferential side surfaces. A pair of rotation side stopper surfaces 98 are provided on both circumferential side surfaces of the columnar portion 107. The pair of rotation side stopper surfaces 98 are inclined in a direction that approaches each other as they move radially inward.

The rotating member 39a is constructed by engaging the engagement plate portion 106 with the notch 103, and by screwing the bolt 102, which has passed through the through hole 108, into the screw hole 104 and further tightening it, thereby connecting and fixing the rotating member main body 100 and the rotating side stopper member 101. When the rotating member main body 100 and the rotating side stopper member 101 are connected and fixed, the pair of main body side opposing surfaces 105 and the pair of stopper member side opposing surfaces 109 are in contact or close to each other.

As shown in FIG. 33, in a neutral state with the wheels 16c, 16d facing in a straight-ahead direction, the phase of the rotating member 39a in the circumferential direction relative to the fixed member 38d is regulated so that the rotating side stopper member 101 is located at the circumferential center position between a pair of fixed side stopper surfaces 97. In the neutral state, the allowable limit turning angle θ (see FIG. 33), which is the angle between the fixed side stopper surface 97 and the rotating side stopper surface 98 that face each other in the circumferential direction, can be set appropriately according to the application of the electric vehicle to which the drive unit 48d is attached. However, the allowable limit turning angle θ is equal to or greater than the control limit angle, which is the maximum value of the turning angle when the electric vehicle drive unit 1a turns around the turning axis C relative to the vehicle bodies 32a, 32b, 32c (see FIG. 11(A) to FIG. 13(C)) in accordance with instructions from the control device. A control limit angle of about 135 degrees at most is sufficient. Therefore, for example, the allowable limit turning angle θ can be greater than or equal to 90 degrees and less than 180 degrees, preferably greater than 90 degrees and less than or equal to 150 degrees, and in the illustrated example, is approximately 120 degrees.

The drive unit 48d of this example can prevent the electric vehicle drive device 1a from turning excessively with respect to the vehicle bodies 32a, 32b, and 32c around the turning axis C. In other words, if the electric vehicle drive device 1a is turned close to the control limit angle and travels on a rough road or runs over a curb, a force that tries to turn the electric vehicle drive device 1a beyond the control limit angle may be applied based on the external force applied to the wheels 16c and 16d.

In the drive unit 48d of this example, when the electric vehicle drive device 1a attempts to rotate beyond the control limit angle, one of the pair of rotation side stopper surfaces 98 abuts (collides) against one of the fixed side stopper surfaces 97 that faces the one rotation side stopper surface 98. This makes it possible to prevent further rotation of the rotating member 39a relative to the fixed member 38d. This prevents excessive rotation of the electric vehicle drive device 1a around the rotation axis C, and prevents the drive unit 48a from breaking down or causing control problems.

In addition, in this example, when the rotating member 39a is formed by connecting and fixing the rotating member main body 100 and the rotating side stopper member 101, the pair of main body side opposing surfaces 105 of the rotating member main body 100 and the pair of stopper member side opposing surfaces 109 of the rotating side stopper member 101 are in contact or in close contact with each other. Therefore, when a reaction force is applied to the rotating side stopper member 101 as the rotating side stopper surface 98 abuts against the fixed side stopper surface 97, this reaction force is transmitted from the stopper member side opposing surface 109 to the main body side opposing surface 105. Therefore, even when the fixed side stopper surface 97 and the rotating side stopper surface 98 abut, it is possible to prevent a large load from being applied to the bolt 102 for connecting and fixing the rotating side stopper member 101 to the rotating member main body 100. Therefore, it is not necessary to use a bolt 102 with an excessively large diameter.

In addition, according to this example, the rotation side stopper member 101 can be positioned in the circumferential direction relative to the rotation member main body 100 by engaging the engagement plate portion 106 with the notch 103. Therefore, there is no need to prepare a separate part just for positioning the rotation side stopper member 101 in the circumferential direction relative to the rotation member main body 100, and an unnecessary increase in the number of parts can be prevented.

Furthermore, the rotating side stopper member 101 is attached to the radial outside of the rotating member body 100 by threading the bolt 102 inserted through the through hole 108 into the screw hole 104 and further tightening it. Therefore, even if the pair of rotating side stopper surfaces 98 wears, it is easy to replace only the rotating side stopper member 101, which provides excellent maintainability.

In this example, the pair of fixed side stopper surfaces 97 are provided on the circumferential side surfaces of the pair of bent plate portions 99. The bent plate portions 99 bend downward from the circumferential end portions of the fixed flange pieces 86, and the radially inner end portions are connected to the portion of the outer circumferential surface of the fixed member 38d adjacent to the lower side of the fixed flange 84. In short, the fixed member 38d is constructed as a whole, including the four fixed flange pieces 86 and the fixed flange 84 having the pair of bent plate portions 99. Therefore, the force applied to the bent plate portions 99 as the rotating side stopper surface 98 abuts against the fixed side stopper surface 97 can be effectively distributed and supported by the radially inner portion of the fixed member 38d.

In addition, in this example, the pair of fixed side stopper surfaces 97 are provided on the circumferential side surfaces of a pair of bent plate portions 99 provided on the radially outer portion of the fixed member 38d. Therefore, even if the pair of fixed side stopper surfaces 97 become worn, maintenance of the fixed side stopper surfaces 97 can be easily performed. The configuration and effects of the other parts are the same as those of the first and second examples of the embodiment.

[Eighth Example of the Embodiment]
38 and 39 show an eighth embodiment of the present invention. In this example, a pair of fixed stopper surfaces 97a constituting the stopper mechanism 96a are provided on the tip surface of an elastic member 110 made of an elastic material such as an elastomer like rubber, which is supported and fixed to each of a pair of bent plate portions 99a. For this reason, each of the bent plate portions 99a has a through hole 111 penetrating in the plate thickness direction at the center. The elastic member 110 is formed in a cylindrical shape, has the fixed stopper surface 97a on the tip surface, and has a screw hole opening on the base end surface. The elastic member 110 is supported and fixed to the bent plate portion 99a by inserting a bolt (not shown) through the through hole 111 of the bent plate portion 99a, screwing it into the screw hole of the elastic member 110, and further tightening it.

In this example, the fixed-side stopper surface 97a that abuts (collides with) the rotating-side stopper surface 98 is provided on the tip surface of an elastic member 110 made of an elastic material. This makes it possible to reduce the impact when the fixed-side stopper surface 97a and the rotating-side stopper surface 98 abut, and to keep abnormal noise to a minimum.

The distance between the fixed stopper surface 97a and the rotating stopper surface 98 in the neutral state may be adjusted by sandwiching a shim plate between the bent plate portion 99a and the base end surface of the elastic member 110. The configuration and effects of the other parts are the same as those of the first, second and seventh examples of the embodiment.

[Ninth Example of the Embodiment]
40 and 41 show a ninth embodiment of the present invention. A fixed member 38e constituting a swivel device 30e of this example is formed by connecting and fixing a fixed member main body 112 supported and fixed to the vehicle body and a pair of fixed side stopper members 113 with a plurality of bolts 114 for each fixed side stopper member 113 (two for each, a total of four in the illustrated example).

The fixed member main body 112 has a double row of fixed side raceways 92 (see Figures 36 and 37) on its inner peripheral surface, and has a fixed flange 84a protruding radially outward at an axially intermediate portion. The fixed flange 84a has a plurality of fixed flange pieces 86 spaced apart in the circumferential direction, and has screw holes 115 that penetrate vertically at a plurality of equally spaced circumferential positions on the radially inner portion. In other words , the fixed flange 84a is composed of a circular ring-shaped flange base 127 and substantially triangular fixed flange pieces 86 that protrude radially outward from a plurality of circumferential positions on the outer peripheral surface of the flange base 127, and the flange base 127 has screw holes 115 at a plurality of circumferential positions.

The pair of fixed side stopper members 113 have a partially cylindrical shape. Each of the fixed side stopper members 113 has a fixed side stopper surface 97 on one of the two circumferential side surfaces, and has a pair of through holes 116 that penetrate in the vertical direction.

The fixed member 38e is configured by connecting the fixed member body 112 and the pair of fixed side stopper members 113 by screwing a pair of bolts 114, which are inserted through a pair of through holes 116 of the fixed side stopper member 113, into any pair of screw holes 115 of the fixed member body 112 that are adjacent in the circumferential direction and further tightening them. That is, in the swivel device 30e of this example, the pair of fixed side stopper members 113 are supported and fixed to the fixed member body 112 so that the mounting position in the circumferential direction around the swivel axis C can be adjusted in stages. Therefore, according to the swivel device 30e of this example, the allowable limit swivel angle, which is the angle between the fixed side stopper surface 97 and the rotating side stopper surface 98 in the neutral state, can be adjusted in stages according to the use of the electric vehicle.

In the illustrated example, each of the pair of fixed side stopper members 113 is connected and fixed to the fixed member body 112 by a pair of bolts 114, but the number of bolts for connecting and fixing the fixed side stopper members to the fixed member body can be one or three or more. The configuration and effects of the other parts are the same as those of the first, second, and seventh examples of the embodiment.

[Tenth Example of the Embodiment]
42 to 44 show a tenth embodiment of the present invention. A fixing member 38f constituting a swivel device 30f of this example is formed by connecting and fixing a fixing member main body 112a and a pair of fixed side stopper members 113a with each pair of nuts 124 and bolts 125.

The fixing member body 112a includes a mounting portion 117 and a guide rail 118.

The mount portion 117 has a double row fixed side track 92 (see Figures 36 and 37) on its inner circumferential surface, and a fixed flange 84 protruding radially outward at the middle portion in the vertical direction.

The guide rail 118 has a rail groove 119 with a T-shaped cross section on its outer periphery, and is fixed to the outside of the lower part of the mount portion 117 so that it cannot rotate relative to the mount portion 117.

Each of the pair of fixed side stopper members 113a includes a flat or partially cylindrical base 120, a bent plate portion 121 that is bent radially outward from one circumferential end of the base 120, an engaging protrusion 122 that protrudes radially inward from a vertical middle portion of the radial inner surface of the base 120 and extends circumferentially, and a through hole 123 that penetrates the base 120 in the radial direction. Each of the pair of fixed side stopper surfaces 97 is provided on one circumferential side of the bent plate portion 121.

Each of the pair of nuts 124 is partially cylindrical and has a screw hole 126 that penetrates radially through the center, and the ends on both the upper and lower sides are engaged with the rail groove 119 of the guide rail 118 to allow relative circumferential displacement (sliding).

The fixed member 38f is configured by engaging the respective engagement protrusions 122 of the pair of fixed side stopper members 113a with the rail grooves 119 of the guide rail 118, and by screwing the bolts 125 inserted through the respective through holes 123 of the pair of fixed side stopper members 113a into the respective screw holes 126 of the pair of nuts 124 and further tightening them, thereby connecting the fixed member main body 112a and the pair of fixed side stopper members 113a. That is, in the swivel device 30f of this example, the pair of fixed side stopper members 113a are supported and fixed to the fixed member main body 112a so that the mounting position in the circumferential direction can be adjusted steplessly (continuously). Therefore, according to the swivel device 30f of this example, the allowable limit swivel angle, which is the angle between the fixed side stopper surface 97 and the rotating side stopper surface 98 in the neutral state, can be adjusted steplessly. The configuration and effects of other parts are the same as those of the first, second, seventh, and ninth examples of the embodiment.

[Eleventh Example of the Embodiment]
45 to 47 show an eleventh embodiment of the present invention. Similar to the fixing member 38f according to the tenth embodiment, the fixing member 38g constituting the swivel device 30g of this example is formed by connecting and fixing a fixing member main body 112b and a pair of fixed side stopper members 113b with a pair of nuts 124 and bolts 125.

The fixing member body 112b includes a mounting portion 117 and a guide rail 118a.

The guide rail 118a has a rail groove 119 having a T-shaped cross-sectional shape on its entire outer surface, and has engagement recesses 128 formed at multiple equally spaced locations on the outer surface in the circumferential direction so as to extend axially across the rail groove 119.

Each of the pair of fixed side stopper members 113b includes a flat or partially cylindrical base 120, a bent plate portion 121 bent radially outward from one circumferential end of the base 120, an engaging protrusion 122a protruding axially radially inward from one circumferential end of the radial inner surface of the base 120, and a through hole 123 that penetrates the base 120 in the radial direction. Each of the fixed side stopper surfaces 97 is provided on one circumferential side of the bent plate portion 121.

The fixed member 38g is configured by engaging the respective engagement protrusions 122a of the pair of fixed side stopper members 113b with any one of the multiple engagement recesses 128 of the guide rail 118, and screwing a bolt 125 inserted through each through hole 123 of the pair of fixed side stopper members 113b into each screw hole 126 of the pair of nuts 124 and further tightening the bolt 125 to connect the fixed member main body 112b and the pair of fixed side stopper members 113b. That is, in the swivel device 30g of this example, the pair of fixed side stopper members 113b are supported and fixed to the fixed member main body 112b so that the mounting position in the circumferential direction can be adjusted in stages. Therefore, according to the swivel device 30g of this example, the allowable limit swivel angle, which is the angle between the fixed side stopper surface 97 and the rotating side stopper surface 98 in the neutral state, can be adjusted in stages.

In this example, the engaging protrusions 122a of the pair of fixed-side stopper members 113b are engaged with the engaging recesses 128 formed on the outer peripheral surface of the guide rail 118a so as to extend in the axial direction. This prevents the fixed-side stopper members 113b from rotating relative to the fixed member main body 112b when the fixed-side stopper surface 97 and the rotating-side stopper surface 98 collide. The configurations and effects of the other parts are similar to those of the first, second, seventh, ninth and tenth examples of the embodiment.

The first to eleventh examples of the above-mentioned embodiment can be implemented in any suitable combination as long as no contradictions arise.

REFERENCE SIGNS LIST 1, 1a Electric vehicle drive device 2, 2a Housing 3a, 3c First electric motor 3b, 3d Second electric motor 4a, 4c First drive shaft 4b, 4d Second drive shaft 5a, 5c First torque transmission device 5b, 5d Second torque transmission device 6a, 6b, 6c, 6d Cylindrical portion 7a, 7b, 7c, 7d Output shaft 8a, 8b Stator 9a, 9b Rotor 10a, 10b Rotation sensor 11 Intermediate shaft 12a First gear 12b Second gear 12c Third gear 12d Fourth gear 13a, 13b, 13c, 13d Hub unit bearing 14 Brake device 15 Brake rotor 16a, 16b, 16c, 16d Wheel 17 Wheel 18 Description of the Reference Numerals 19 Outer ring 20 Rolling element 21 Stationary flange 22 Spline hole 23 Rotating flange 24 Spline shaft portion 25 Mounting hole 26 Hub bolt 28 Brake caliper 29 Support device 30, 30a, 30b, 30c, 30d, 30e, 30f, 30g Swivel device 31 Height adjustment device 32a, 32b, 32c Vehicle body 33 Tire 34 Mount member 35 Damper 36 Connecting member 37 Arm portion 38, 38a, 38b, 38c, 38d, 38e, 38f, 38g Fixed member 39, 39a, 39b Rotating member 40 Lower support member 41 Support frame 42 Adjustment mechanism 43 Height adjustment motor 44 Upper support member 45 Lower link member 46 Upper link member 47 Pivot 48, 48a, 48b, 48c, 48d Drive unit 49 Support member 50a, 50b, 50c Electric vehicle 51a, 51b, 51c Vehicle body 52a1, 52a2, 52b1, 52b2, 52c1, 52c2 Supported portion 53a, 53b, 53c, 53d Drive portion 54 Connector portion 55, 55a, 55b Automatic guided vehicle 56 Vehicle body 57 Driven wheel 58 Traction portion 59 Placement portion 60 Base portion 61 Extension portion 62 Support shaft 63 Tire 64a, 64b Motor attachment portion 65a, 65b Transmission device accommodating portion 66a First intermediate shaft 66b Second intermediate shaft [0033] 66c Third intermediate shaft 66d Fourth intermediate shaft 67a First gear 67b Second gear 67c Third gear 67d Fourth gear 67e Fifth gear 67f Sixth gear 67g Seventh gear 67h Eighth gear 68, 68a Cylindrical portion 69, 69a Elastic member 70, 70a Sleeve 71 Vehicle body 72 Auxiliary wheel 73 Fork 74 Automobile 75 Wheel 76 Cylindrical member 77 Tapered roller bearing 78 Mounting member 79 Spline hole 80 Rotating flange 81 Mounting hole 82 Nut 83 Cover 84 Fixed flange 85 Fixed side support hole 86 Fixed flange piece 87 Bolt 88 Rotating flange 89 Rotating flange piece 90 Bolt 91 Rolling element 92 Fixed side raceway 93 Rotating side raceway 94 Outer ring 95 Inner ring 96 Stopper mechanism 97 Fixed side stopper surface 98 Rotating side stopper surface 99 Bent plate portion 100 Rotating member main body 101 Rotating side stopper member 102 Bolt 103 Notch 104 Screw hole 105 Main body side facing surface 106 Engagement plate portion 107 Column-shaped portion 108 Through hole 109 Stopper member side facing surface 110 Elastic member 111 Through holes 112, 112a, 112b Fixed member main body 113, 113a, 113b Fixed side stopper member 114 Bolt 115 Screw hole 116 Through hole 117 Mount portion 118 Guide rail 119 Rail groove 120 Base portion 121 Bent plate portion 122 Engagement protrusion 123 Through hole 124 Nut 125 Bolt 126 Screw hole 127 Flange base
128 Engagement recess

Claims (10)

a pair of electric motors each having an output shaft and supported by the housing; a pair of drive shafts coaxially supported by the housing with their respective tips, on which wheels are supported, facing in opposite directions; and a pair of torque transmission devices that transmit rotational torque of the output shafts of the pair of electric motors to each of the pair of drive shafts ;
a pair of wheels supported on each of the pair of drive shafts;
a turning device that supports the electric vehicle drive device with respect to a vehicle body so as to be capable of turning about a turning axis perpendicular to a road surface;
Equipped with
the turning device has a stopper mechanism that restricts a rotatable range of the electric vehicle drive device around the turning shaft,
the turning device includes a fixed member that is supported and fixed to the vehicle body, and a rotating member that is arranged coaxially with the fixed member and capable of rotating relative to the fixed member, and is supported in the electric vehicle drive device so as not to rotate about the turning axis,
the stopper mechanism has a fixed-side stopper surface that faces a circumferential direction about the pivot shaft and is provided on the fixed member, and a rotating-side stopper surface that faces a circumferential direction about the pivot shaft and faces the fixed-side stopper surface and is provided on the rotating member,
the fixed member includes a fixed member main body that is supported and fixed to the vehicle body, and a fixed side stopper member that has the fixed side stopper surface and is supported and fixed to the fixed member main body so that an attachment position in a circumferential direction around the pivot shaft can be adjusted.
Drive unit. The output shafts of the pair of electric motors and the pair of drive shafts are arranged in parallel.
2. A drive unit according to claim 1. The output shafts of the pair of electric motors are arranged non-coaxially and parallel to each other.
A drive unit according to claim 2. The pair of electric motors are arranged to overlap each other in a direction perpendicular to the output shafts of the pair of electric motors.
A drive unit according to claim 3. Each of the pair of electric motors is disposed at a position radially outwardly offset from the wheel.
A drive unit according to any one of claims 1 to 4. Each of the pair of torque transmission devices is constituted by a gear type reducer having a plurality of gears.
A drive unit according to any one of claims 1 to 5. The rotating member is
a rotating member main body having a main body-side facing surface facing a circumferential direction centered on the pivot shaft and supported in such a manner that the rotating member main body cannot rotate about the pivot shaft relative to the electric vehicle drive device;
a rotation side stopper member that faces a circumferential direction about the pivot axis and has a stopper member side opposing surface that abuts or closely faces the main body side opposing surface and the rotation side stopper surface, and is supported and fixed to the rotation member main body;
Equipped with
A drive unit according to any one of claims 1 to 6 . a support device that presses each of the outer circumferential surfaces of the tires constituting the wheels against the road surface and absorbs vibrations transmitted from the road surface to the vehicle body via each of the wheels;
A drive unit according to any one of claims 1 to 7 . a vehicle height adjustment device disposed between each of the electric vehicle drive devices and the vehicle body, the vehicle height adjustment device adjusting the height of the vehicle body relative to the road surface;
A drive unit according to any one of claims 1 to 8 . The car body and
At least one drive unit;
Equipped with
An electric vehicle, wherein each of the drive units is a drive unit according to any one of claims 1 to 9 .

Images