JPH0775994B2 - Electric wheel of electric vehicle and three-wheel electric vehicle using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an electric wheel of a direct drive type electric vehicle that directly rotates a wheel and a three-wheel electric vehicle including the electric wheel.

(Prior Art) In recent years, electric vehicles using battery power as a power source and a motor as a drive source have been drawing attention because of advantages such as low pollution, low noise, and easy control.

Conventional electric vehicles are of the two-axis drive type in which the wheels and the motor are mounted independently of each other, so that the rotation of the motor is transmitted to the wheels, or the rotation speed of the left and right wheels is changed. When turning a corner, a power transmission device such as a speed reducer and an operating device (see, for example, Japanese Utility Model Laid-Open No. 47-18,010), or this device and wheels, should be used in order to smoothly and reliably perform the operation. There is a need for an auxiliary device (see, for example, Japanese Utility Model Laid-Open No. 48-38,506) including a drive shaft and the like to be connected.

However, such a power transmission device and an auxiliary device are accompanied by a decrease in power mechanical loss and an increase in the weight of the vehicle body,
As a result, there is a possibility that disadvantages such as an increase in power consumption and a decrease in a traveling distance (hereinafter referred to as a range) per battery charging may occur. In particular, in an electric vehicle, it is well known that the short mileage per battery charge is a major factor that hinders the generalization of the electric vehicle.

Therefore, in recent years, in order to reduce the vehicle body weight by abolishing the power transmission devices such as the speed reducer, the differential gear, the drive shaft, etc., and reducing the weight of the vehicle body, some vehicles have direct drive type electric wheels. is there.

This direct drive type electric wheel directly transmits the torque of the motor to the wheel, and includes a motor and the wheel that are mechanically connected (for example, Japanese Utility Model Laid-Open No. 54-21,312).
JP, No. 3,937,293, etc.), and one in which a motor is incorporated in the wheel (JP-A-52-22,214, USP).
See No. 4,021,690).

(Problems to be Solved by the Invention) However, in the former system in which a motor and a wheel are connected, the axial dimension of the electric wheel is enlarged, and a thick solid motor rotation shaft is provided as the wheel shaft. As a result, the weight of the vehicle body increases and the traveling distance per battery charge may decrease. In addition, a mechanism for supporting the rotating shaft or a power line for supplying electric power to the motor is complicated, and the entire structure of the electric wheel is complicated, cooling of the motor is difficult, workability of assembling the electric wheel, maintenance and inspection, etc. There is a problem in maintainability.

Also in the latter method of attaching a motor to the wheel disk, the thick solid motor rotation shaft is the axle,
The structure of the electric wheel becomes complicated and has the same problem as the former.In addition to this, since the motor is installed inside the wheel, dust etc. will enter the inside of the motor when the motor is cooled. However, there is a problem that the durability of the electric wheel is deteriorated due to the dust and the like.

A dust seal is provided at a predetermined position in order to prevent such intrusion of dust and the like, but since this dust seal usually slides on the hub side, it has a drawback that the mechanical loss of the motor is reduced. . Further, in the conventionally used electric wheel having a disc brake, the disc and the pad are always in contact with each other, which is also disadvantageous to the mechanical loss of the motor.

Therefore, as a result of diligent efforts to eliminate such drawbacks, the present inventors have achieved the advantages of the direct drive method in developing a motor that is lightweight, compact, and capable of exhibiting a large output and is optimal for an electric vehicle. In addition to facilitating simplification of the power transmission system, weight reduction of the entire vehicle, etc., an electric wheel that can eliminate the decrease of mechanical loss of the motor due to the increase of rolling friction resistance, which is its drawback, and this electric wheel We have developed a three-wheeled electric vehicle equipped with it.

The present invention has been made in view of the above problems of the prior art, and a direct drive type electric machine that achieves simplification of a power transmission system, weight reduction of an entire vehicle, and improvement of mechanical loss of a motor. An object is to provide an electric wheel of a vehicle and a three-wheel electric vehicle equipped with the electric wheel.

[Structure of the Invention] (Means for Solving the Problem) In a first invention for achieving the above object, a wheel disc is rotatably attached to the outer periphery of a hub, and a wheel is attached to the outer periphery of the wheel disc. At the same time, the rotor portion of the motor is fixed to the outside of the wheel disc from the outside of the wheel by wheel fastening, and the motor cover is fixed to the outside of the roller portion from the outside of the wheel by bolting, so that the rotor portion and the rotor portion are small. A stator portion, which is opposed to the hub via a clearance, is fixed to the hub from the outside of the wheel by bolting, while a brake drum of a drum type brake is bolted from the inside of the wheel to the inside of the wheel disc. In addition, a space in which the stator portion is accommodated by interposing a dust seal between the brake drum and the hub. A motor-driven wheel of the electric vehicle, characterized in that sealed.

A second invention for achieving the above object is a three-wheel electric vehicle in which the above-mentioned electric wheels are disposed on the left and right rear portions of a vehicle body, and a battery for supplying electric power to the electric wheels in the vicinity of the electric wheels. And a control device for the electric wheels.

(Operation) According to this structure, the direct drive system is adopted, and the hollow shaft constitutes the axle and the rotation shaft of the motor, so that the power transmission device such as the speed reducer, the differential device, the drive shaft, etc. is not required, and the axle The structure of the part is simplified, and the weight and compactness of the vehicle body can be achieved, which also extends the mileage per battery charge, and also when assembling the electric wheels of an electric vehicle, Since the rotor can be fixed to the wheel disk from the side and the stator part to the hub by bolting, it can be done easily from the outside without lifting the car body during maintenance and inspection of the car, and the parts can be stacked one after another. Since it is possible to adopt an assembling work method, the assembling of the vehicle body becomes extremely easy.

Further, in the space where the stator portion is housed, the motor cover, the rotor portion, the wheel disc, and the hub are bolted together, and the dust seal is interposed only between the hub and the brake drum, so the rolling friction resistance of the wheel is reduced. This results in an increase in the mechanical loss of the motor output. Moreover, since it has a drum-type brake, the brake drum and the shoe do not come into contact with each other when the brake is not operating, which also reduces the rolling friction resistance of the wheels and improves the mechanical loss of the motor. To do.

(Example) Hereinafter, the electric vehicle of the present invention will be described in detail based on examples.

FIG. 1 is a sectional view of an essential part showing an electric wheel according to an embodiment of the first invention, FIG. 2 is an exploded perspective view of the same electric wheel, and FIG. 3 is an embodiment of the second invention. FIG. 4 is a plan view showing the three-wheel electric vehicle according to FIG. 4, and FIG. 4 is a side view of the three-wheel electric vehicle.

First, the electric wheels shown in FIGS. 1 to 2 are arranged on the left and right rear portions of the three-wheel electric vehicle shown in FIGS. 3 to 4 via suspensions, knuckles, etc. Each has a similar structure. The front wheels 17 shown in FIGS. 3 to 4 are steerable wheels rotatably attached to a handle shaft 19 via a shock absorber 18.

The electric wheel 14 is of an outer rotor type in which a wheel 3 to be described later is mounted on the outer periphery of the wheel disc 2 and a motor M is attached to the outer side of the wheel disc 2, and the wheel disc 2 is rotated by the motor M. It is a direct drive system.

The electric wheel 14 has a knuckle (not shown) in the center thereof, and the vehicle body 15 is provided via a suspension mechanism 20 (see FIG. 3).
It is attached so that it can move up and down.

The knuckle is hollow and is coaxially connected to the hub 1 by a bolt. The wheel disc 2 is rotatably attached to the outer periphery of the hub 1 via two bearings 21 and 22. ing. This hub 1 is a motor M
It also serves as both the rotating shaft and the axle.

The wheel 3 mounted on the outer periphery of the wheel disc 2 has a wheel rim 24 fixed by bolts 23,
It is composed of tires 25.

Further, the rotor portion 4 of the motor M and the rotor collar 26 are fastened together from the outside by a plurality of bolts 5 at the outer peripheral end portion of the wheel disk 2, and further the rotor collar 26 is fixed to the rotor collar 26. A motor cover 6 covering the outside of the motor M is fixed by bolts 7.

By doing so, the motor cover 6 can be attached and detached from the outside side, so that the assembling property and the maintainability are improved. The rotor collar 26 is eliminated and the rotor portion 4
The motor cover 6 and the motor cover 6 may be fastened together with the wheel disc 2 from the outside of the wheel 3.

The rotor portion 4 is composed of an annular yoke 27 and a rare-earth permanent magnet 28 that generates a strong magnetic field with a thin wall fixed to the inner peripheral surface of the yoke 27 with an adhesive or bolts.

The rare earth permanent magnet 28 not only has a large magnetic flux density but also exhibits a large crystal magnetic anisotropy at room temperature and thus exhibits a large coercive force. The motor can be made thin, the motor can be made compact, and a large output can be produced.

For example, a normal permanent magnet such as an alnico type or a ferrite type has a coercive force of about 50 to 270 kA / m, while a rare earth cobalt type (RCo ₅ ) type has a coercive force. Since the magnetic force is as high as 680 to 800 kA / m, it is clear that the rare earth magnet is effective.

Further, the motor cover 6 is made of a lightweight metal such as aluminum alloy, and in order to improve the heat dissipation of the motor M, heat dissipation fins f ₁ are projected on the inner peripheral surface and the outer peripheral surface.

The rotor portion 4 and the stator portion 8 that is provided oppositely with a small gap G are fixed to the flange portion 1a of the hub 1 with the bolt 9 at the inner peripheral portion of the armature core 28 around which the coil C is wound. However, upon fixing, the armature holder 29 is also tightened.

This armature holder 29 has an L-shaped half-section as is apparent from FIG. 2, and a tooth portion is formed on the ring-shaped protrusion 29a, and this tooth portion and the end portion of the hub 1 are formed. The formed tooth portions are adapted to mesh with each other.

Further, the coil C and a power line (not shown) inserted through the hub 1 are connected via a plate-shaped terminal 20, and this connection is a tubular connector 31 at the end of the power line. Is fixed by crimping, the connector 31 is inserted into the insulating block 32, and the terminal 30 is interposed when the stud bolt 33 is screwed to the end of the connector 31.

Further, a timing grid 42 for detecting the rotation state of the motor M is provided on the inner surface of the motor cover 6. The timing grid 42 is provided corresponding to the magnetic poles of the permanent magnet 28 attached to the rotor portion 4, and receives an optical signal from a photosensor 43 attached to one end of the armature holder 29, which is not shown. It reflects toward the element.

As shown in FIG. 2, a brake drum 11 of a drum type brake 10 is attached to the inner end surface of the wheel disc 5 by bolts 12. This drum type brake 10
Is equipped with a brake shoe 35 which is expanded and brought into contact with the inner peripheral surface of the brake drum 11 by operating the cam mechanism 34. When the cam mechanism 34 is returned to the brake released position, the return spring 36 is used. The brake shoe 35 and the brake drum 11 are no longer in contact with each other. Therefore, if such a drum-type brake 10 is applied to an electric vehicle, there is no frictional resistance between the brake drum 11 and the brake shoe 35 during normal traveling, so that the disc brake in which the brake pad is always in contact with the brake disc is used. In comparison, the mechanical loss of the motor M is improved.
In addition, "37" in FIG. 1 is a brake back plate.

As described above, the space S accommodating the stator portion 8 constituting the motor M is the hub 1, the wheel disc 2,
Since the rotor portion 4, the rotor collar 26, the motor cover 6, and the brake drum 11 are formed by bolting, respectively, dust and the like do not enter the space S from the outside of the wheel 3. However, the motor M
A ring-shaped dust seal 13 is attached to the gap between the outer peripheral surface of the hub 1 rotating by and the brake drum 11. Therefore, in the electric wheel 14 according to the present embodiment,
Compared with the conventional one that uses a plurality of dust seals, the frictional resistance caused by the contact between the dust seal 13 and the rotating body (in this embodiment, the hub 1) can be reduced as much as possible. It is possible to improve the mechanical loss of the motor output.

A relatively large communication passage 38 as shown in FIG. 1 is formed in the knuckle that rotatably supports the wheel disc 2 and the hub 1. Electric power is supplied to the motor M using this communication passage 38. It is possible to insert a power line to connect the motor cooling air. That is, since the large communication passage 38 is formed in the center, wiring of the power line becomes extremely easy when the power line is inserted, and the communication line 38 is simply connected to the power line. Instead, the air can be circulated inside, so that the motor M can be cooled.

In order to further enhance the cooling effect due to the natural circulation of air, an air cooling means such as an axial fan device which introduces the communication passage 38 into the outside air, for example, which is rotated by a small motor may be provided.

As shown in FIGS. 3 to 4, the upper arm and the lower arm are swingably attached to the top and the lower part of the knuckle via a bracket by ball bearings. The other ends of the upper arm and the lower arm are Car body 15
Is mounted rotatably on a Nighthart 39 mounted on the vehicle, and a shock absorber 40 is provided between the Nighthart 39 and the vehicle body 15. One end of the Knighthart 39 is rotatably attached to the vehicle body 15, and by the suspension mechanism 20 including the Nighthart 39, the upper arm, the lower arm, and the shock absorber 40,
The electric wheels 14 and 14 can swing on the vehicle body 15.

As shown in the schematic plan view and the schematic side view of the electric vehicle of FIGS. 3 to 4, the electric wheel 14 of the electric vehicle 15 is of a direct drive type using an outer rotor type motor, so Since various auxiliary devices are unnecessary, a considerable empty space can be secured in the vehicle body 15.

Therefore, the battery B that supplies electric power to the electric wheels 14 is
As shown, it can be installed in this empty space with even weight distribution. In the present embodiment, two batteries B, B are conveniently mounted in the central portions of the front and rear wheels 14, 17 of the chassis frame 41 constituting the vehicle body 15.

Further, the control device 16 for controlling the torque of the electric wheel 14 has a power supply between the electrode (+ terminal, − terminal) of the battery B and the control device 16 in the vicinity of the electric wheel 14 and at the upper position of the battery B. The wiring distance of the line and the wiring distance of the power line between the control device 16 and the electric wheel 14 are both arranged at the shortest position. Further, like the battery B, the control device 16 is also placed at a position where the loads applied to the respective electric wheels 14 are equalized.

The control device 16 includes a control signal for driving the electric vehicle 15, for example, a control calculated from a depression amount of an accelerator pedal or a brake pedal, a running torque, a charge amount of a battery, a heat generation amount of electric wheels, and the like. A control signal input device to which a signal is input is connected.

In this way, when the battery B and the control device 16 are mounted by selecting the positions as described above, the control device 16 causes the electric wheels 14 to be mounted.
If the required distance of the power line up to and the required distance of the power line from the battery B to the control device 16 are both set to the necessary minimum, it is extremely advantageous in terms of weight saving.

As is well known, it is said that the battery has the largest element that influences the performance of the electric vehicle 15. However, the lack of performance of this battery is caused by studying the vehicle shape.
This can be compensated for by making various small improvements such as making C _d extremely small, reducing the weight, and reducing the power loss in the wiring path from the Vanteri to the motor.

Therefore, the technique of the present embodiment in which the weight of the power system wiring is reduced by shortening the required electric wire length, and the power loss in the power system is reduced by shortening the required electric wire length,
In an electric vehicle, this is one of the effective measures for compensating for the lack of battery performance.

Next, the operation will be described.

First, to assemble the electric wheel 14, the knuckle, hub 1,
Install the brake back plate 37 and brake drum 11. Then, after the stator portion 8 is externally tightened to the hub 1 with the bolt 9, the power line and the stator portion 8 are
And the coil C of. Finally, the rotor portion 4 and the rotor collar 26 are attached to the wheel disk 2 from the outside by bolts 5, and then the rotor collar 26 and the motor cover 6 are attached.
Are tightened with bolts 7.

When the electric wheel 14 is assembled in this manner, the hub 1, the drum brake 10, the stator portion 8, the rotor portion 4 and the like may be mounted from the outside in a stacking system, so to speak. The assembly procedure is good and can be done easily. Therefore, the work becomes easy even at the time of maintenance and inspection for disassembling it, and the maintainability is also improved.

Next, when a guidance switch (not shown) is turned on, a predetermined current from the battery B is guided to the power line via the control device 16, and from this power line to the coil C via the connector 31, the stud bolt 33, and the terminal 30. Be guided. This current is controlled by the light receiving element detecting the reflected light from the photo sensor 43 by the timing grid 42.

As a result, the current crosses the magnetic field formed by the rare-earth magnet 28 on the rotor section 4 side, whereby the rotor section 4 rotates. This rotation is carried out by the bolt 5 through the wheel disc 2
And the wheels 3 rotate.

That is, since the electric wheels 14 are of the direct drive type in which the linear rotor portion 4 is rotated by the stator portion 8, the electric wheels 14 do not need a power transmission device such as a speed reducer, a differential device, or a drive shaft. The desired operation can be performed, which simplifies the structure of the axle portion. Moreover, this makes it possible to reduce the weight and size of the vehicle body 15 as a whole, to extend the mileage per battery charge, and also to improve the assembly and maintenance of the electric wheel 14.

Further, the space S accommodating the stator portion 8 has a motor cover 6, a rotor portion 4, a wheel disc 2 and a hub 1.
Are bolted to each other, and the dust seal 13 is interposed only between the hub 1 and the brake drum 11. Therefore, the rolling friction resistance of the wheel 3 is reduced, which improves the mechanical loss of the motor M. Moreover, since the drum-type brake 10 is provided, the brake drum 11 and the brake shoe 35 are not in contact with each other when the brake is not operated, and this also reduces the rolling frictional resistance of the wheel 3 and the motor. The mechanical loss of output is improved.

Moreover, the battery B for supplying electric power to the electric wheel 14 and the control device 16 for the electric wheel 14 are arranged near the electric wheel 14, and the battery B, the control device 16 and the electric wheel 14 are arranged.
If the required distance of the power line connecting each of the above is set to the shortest, the weight distribution of the vehicle can be improved, the distribution loss and the wiring weight can be reduced, and the one-charge traveling distance can be improved.

[Advantages of the Invention] As described above, according to the present invention, since the electric wheels are of the direct drive type and the outer rotor type,
A power transmission device such as a speed reducer, a differential device, and a drive shaft is not required, the structure of the axle part is simplified, the weight and size of the vehicle body can be reduced, and the mileage per battery charge is extended. Assembling and maintenance of the electric wheel will also be improved.

Further, in the space where the stator portion is housed, the motor cover, the rotor portion, the wheel disc, and the hub are bolted together, and the dust seal is interposed only between the hub and the brake drum, so the rolling friction resistance of the wheel is reduced. Will be reduced, which will improve the mechanical loss of the motor. Moreover, since it has a drum type brake, the brake drum and brake shoe do not come into contact with each other when the brake is not operating, and this also reduces the rolling resistance of the wheels and the mechanical loss of the motor. improves.

Moreover, a battery for supplying electric power to the electric wheels and a control device for the electric wheels are arranged in the vicinity of the electric wheels, and the required distance of the power line connecting the battery, the control device and the electric wheels is minimized. If so, the weight distribution of the vehicle can be improved, the distribution loss and the wiring weight can be reduced, and the one-charge traveling distance can be improved.

If such electric wheels are arranged on the left and right of the rear part of the vehicle body to form a three-wheeled electric vehicle, a power transmission device such as a reducer, a differential device, and a drive shaft becomes unnecessary, and a large empty space can be secured in a small vehicle body. Therefore, the battery can be installed in a desired weight distribution here.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an electric wheel according to an embodiment of the first invention, FIG. 2 is an exploded perspective view of the same electric wheel, and FIG. 3 is an embodiment of the second invention. FIG. 4 is a plan view showing the three-wheel electric vehicle according to FIG. 4, and FIG. 4 is a side view of the three-wheel electric vehicle. 1 ... Hub, 2 ... Wheel disc, 3 ... Wheel, 4 ... Rotor part, 5,7,9,12 ... Bolt, 6 ... Motor cover, 8 ... Stator part, 10 ... Drum type Brake, 11 ... Brake drum, 13 ... Dust seal, 14 ... Electric wheel, 15 ... Car body, 16 ... Control device, B ... Battery, G ... Gap, S ... Space, M ... Motor.

Front page continuation (72) Inventor Atsushi Mamiya 4428 Shinyoshida-cho, Kohoku-ku, Yokohama-shi, Kanagawa Tokyo R & D Development Laboratory Co., Ltd. (56) References Japanese Patent Publication No. 51-20103 (JP, B2)

Claims (2)

[Claims] 1. An electric vehicle having an electric wheel (14) supported on a side portion of a vehicle body (15) so as to be rotatable about the hub (1), wherein the electric wheel (14) is the hub. A wheel disc (2) is rotatably attached to the outer periphery of (1), a wheel (3) is attached to the outer periphery of the wheel disc (2), and a rotor portion (4) of an annular motor (M) is fixed. Then, by covering the rotor portion (4) from the outside with the motor cover (6), a stator housing space (S) is formed inside, and the outer peripheral surface of the stator portion (8) is formed in the stator housing space (S). The inner peripheral portion of the stator portion (8) is fixed to the hub (1) so as to face the rotor portion (4) with a small gap (G), while the wheel disc (2) is fixed.
Inside the drum type brake (10) brake drum (1
1) is provided, and a dust seal (13) is interposed between the brake drum (11) and the hub (1) to seal the stator housing space (S), and the rotor portion (4), The motor cover (6) and the stator part (8) are fixed to each other by tightening bolts (5, 7, 9) from the outside of the vehicle body (15), and the brake drum (1).
1) is an electric wheel (14) of an electric vehicle characterized in that it is fixed by tightening bolts (12) from the inside. 2. A vehicle body (15) comprising the electric wheel (14) according to claim 1.
A three-wheel electric vehicle disposed on the left and right of the rear part of the vehicle, wherein a battery (B) for supplying electric power to the electric wheel (14) near the electric wheel (14) and a control device for the electric wheel (14) ( 16)
A three-wheeled electric vehicle characterized by having and.