阅读说明：本技术 马达的结构 (Motor structure ) 是由 小林由幸 于 2019-09-24 设计创作，主要内容包括：在外转子型的马达中,在其内部,将散热板电力控制部(PCU)25安装于固定在不旋转的定子上的散热板26。在散热板26设置有翅片,在对置的马达的壳体29的内表面和侧面也设置有翅片。壳体29与转子一起旋转,在马达内产生空气流,散热板的热传递到壳体,向外部扩散。(In the outer rotor type motor, a heat sink Power Control Unit (PCU)25 is mounted on a heat sink 26 fixed to a non-rotating stator inside the motor. The heat dissipation plate 26 is provided with fins, and the fins are also provided on the inner surface and the side surface of the casing 29 of the motor facing each other. The housing 29 rotates together with the rotor, and generates an air flow in the motor, and the heat of the heat dissipation plate is transferred to the housing and dissipated to the outside.)

1. A structure of a motor (11) characterized in that,

the motor has a structure comprising:

a stator (24);

a rotor (23) rotated by a magnetic force from the stator (24);

a housing (21, 29) of the motor, the housing being coupled to the rotor (23); and

a power control unit (10) disposed inside the housings (21, 29) and configured to drive the stator (24),

the casings (21, 29) are provided with cooling fins (111).

2. The structure of the motor (11) according to claim 1,

the power control unit (10) is mounted on a heat-conducting member (26) fixed to the stator (24),

in the cases (21, 29), the fins (111) are provided on a side surface through which a shaft that rotates together with the rotor (23) passes and on an inner surface facing the heat-conducting member (26).

3. Structure of a motor (11) according to claim 2,

in the heat conducting member (26), cooling fins (111) are provided on a surface facing an inner surface of the housing (21, 29).

4. The structure of the motor (11) according to any one of claims 1 to 3,

the motor (10) further comprises a hollow shaft (112), the shaft (112) being fixed to the stator (24), serving as a shaft of the housing (21, 29) that rotates together with the rotor (23), and being rotatable with respect to the housing (21, 29),

a wire harness connected to the power control unit (10) is inserted through the shaft (112) and routed to the inside of the housings (21, 29).

5. A vehicle characterized by having a driving wheel formed by mounting a tire (12) on an outer periphery of the housing (21, 29) of a motor (11) having the structure of any one of claims 1 to 4.

Technical Field

The present invention relates to a vehicle using, for example, an electric motor as a drive source, and more particularly to a structure of the motor.

Background

In order to make an electric vehicle compact, a configuration in which an electric motor as a driving source is used as an in-wheel motor is effective. A structure has been proposed in which heat generated by an in-wheel motor is dissipated to the outside via a heat pipe (see patent document 1 and the like).

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5169280

Disclosure of Invention

Problems to be solved by the invention

In order to make the in-wheel motor more compact, there is a structure in which the motor and a Power Control Unit (PCU) are integrated. When the PCU is integrated with the motor, the in-wheel motor is housed inside the wheel, and therefore, from the viewpoint of circuit protection, the PCU is preferably provided inside the motor. In such a configuration, heat from the PCU is radiated in addition to heat from the motor, and therefore, in the above-described conventional technique, the heat pipe needs to be thickened accordingly. However, in the prior art, the heat pipe is provided through the axis of the wheel, and the thickness is limited.

The present invention has been made in view of the above conventional example, and an object thereof is to provide a structure of a motor capable of efficiently cooling a motor incorporating a power control unit.

Means for solving the problems

In order to achieve the above object, the present invention has the following configuration. That is, according to an aspect of the present invention, there is provided a structure of a motor (11) characterized in that,

the motor has a structure comprising:

a stator (24);

a rotor (23) rotated by a magnetic force from the stator (24);

a housing (21, 29) of the motor, the housing being coupled to the rotor (23); and

a power control unit (10) disposed inside the housings (21, 29) and configured to drive the stator (24),

the casings (21, 29) are provided with cooling fins (111).

Effects of the invention

According to the present invention, the motor having the power control unit built therein can be efficiently cooled.

Drawings

Fig. 1A is a view showing an appearance and a configuration of a two-wheeled vehicle according to an embodiment.

Fig. 1B is a block diagram of a drive control circuit of the motor.

Fig. 2A is an exploded perspective view of the in-wheel motor of the embodiment.

Fig. 2B is a sectional view of the in-wheel motor of the embodiment.

Fig. 3A is a diagram showing the arrangement of the circuit board in the in-wheel motor according to the embodiment.

Fig. 3B is a diagram showing the arrangement of the circuit board in the in-wheel motor according to the embodiment.

Fig. 3C is a diagram showing the arrangement of the circuit board in the in-wheel motor according to the embodiment.

Fig. 4 is a diagram illustrating a cooling principle in driving of the in-wheel motor according to the embodiment.

Detailed Description

Hereinafter, embodiments will be described in detail with reference to the drawings. The following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the invention. Two or more of the plurality of features described in the embodiments may be arbitrarily combined. The same or similar components are denoted by the same reference numerals, and redundant description thereof is omitted.

[ first embodiment ] to provide a liquid crystal display device

● Structure of straddle type vehicle

Fig. 1A shows an example of an external appearance of a powered two-wheeled vehicle 1 as a saddle-ride type vehicle according to the present embodiment. The two-wheeled vehicle 1 includes an in-wheel motor (hereinafter, also simply referred to as a motor) 11 as a drive source, and a tire 12 is mounted around the in-wheel motor 11 as a hub. The in-wheel motor 11 is supported by the swing arm 13 through the rotation shaft 112 thereof, and can directly rotate the drive wheel without a reduction mechanism or a transmission mechanism. Cooling fins 111 are provided on both side surfaces of the in-wheel motor 11, and air flows on the surface thereof by rotation, thereby efficiently dissipating heat propagating from the inside. Power is supplied to the in-wheel motor 11 from a power control unit (or power control circuit, PCU)10 (see fig. 1B), and the rotation speed thereof is controlled by the driver operating an accelerator provided at a grip portion of a handlebar.

Fig. 1B shows a block diagram of a control circuit for drive control of the in-wheel motor 11. The in-wheel motor 11 of the present embodiment is structurally an outer rotor type surface magnet synchronous motor (SPMSM), and may be referred to as a brushless dc motor including the PCU 10. The in-wheel motor 11 is driven by a three-phase ac power supply supplied from the PCU 10. Each phase of the ac power supply may be a sine wave or a square wave. The PCU10 is driven by a low voltage power supply (e.g., 12V power supply) 104, including a controller 101 and an inverter 102. An output signal (hall sensor signal) of a hall sensor for detecting the rotational position of the rotor from the motor 103 is input to the controller 101. The motor 103 is a portion obtained by removing the PCU from the in-wheel motor 11. The controller 101 inputs a control signal for controlling switching and the like of a current from a high-voltage power supply (HV battery) 105 to the inverter 102 based on the input hall sensor signal. The controller 101 also adjusts the timing of the control signal to the inverter 102 in order to control the output frequency of the inverter 102 based on the signal indicating the accelerator opening degree. Further, not only the frequency but also the current may be controlled.

The inverter 102 converts the high-voltage power supply 105 into three-phase alternating current U, V, W in accordance with a control signal from the controller 101, and inputs the three-phase alternating current U, V, W to the motor 103. The motor 103 is driven in synchronization with the frequency of the input power. The motor 103 includes a temperature sensor and a hall sensor, and a temperature signal indicating a temperature detected by the temperature sensor and a hall sensor signal indicating a magnetic field detected by the hall sensor are input to the controller 101. The hall sensor signal detects the electrical rotational position of the rotor by detecting the magnetic field of the permanent magnet attached to the surface of the rotor so that the S-pole and the N-pole alternate.

In the present embodiment, the PCU10 is incorporated in the in-wheel motor 11 as will be described later. The in-wheel motor 11 configured as described above can rotate the drive wheel of the two-wheeled vehicle 1, and the two-wheeled vehicle 1 can travel as intended by the driver.

● Structure of in-wheel Motor

Fig. 2A is an exploded perspective view of the in-wheel motor 11. The main components of the in-wheel motor 11 are housed inside a housing formed of a wheel case 21 and a wheel case 29, which are made of metal or the like. The wheel housing 21 is provided at its rotational shaft portion with a hole through which the shaft 112 passes, and has a disk shape with a peripheral portion protruding. Further, fins 111 for heat dissipation are provided on the outer and inner surfaces thereof. In this example, the fins 111 are a plurality of elongated projecting portions arranged in parallel with each other, and are formed integrally with the wheel housing 21. The height and number of the in-wheel motor 11 can be determined according to the amount of heat generated to release the heat generated therein. The wheel case 29 has the same configuration as the wheel case 21, but in this example, the peripheral edge portion provided on the outer peripheral portion has no protruding portion. However, the same structure as the wheel housing 21 may be adopted. The wheel housing 21 and the wheel housing 29 are fixed to each other by bolts or the like, for example, to constitute a housing of the in-wheel motor 11, and are attached to the shaft 112 via the bearings 22 and 28. Therefore, the wheel housings 21 and 29 are rotatable with respect to the shaft 112 fixed to the swing arm 13 so as not to rotate, and the tire 12 is mounted on the outer periphery thereof, which also serves as a hub of the drive wheel.

A rotor 23 is connected or fixed to the inside of the protruding portion along the peripheral edge portion of the wheel housing 21. The rotor 23 is configured by arranging a plurality of permanent magnets, for example, 16 or 32 magnets, with alternately reversed polarities. This is the same as a general outer rotor type motor. On the other hand, the circuit case 26 is fixed to the shaft 112. The circuit case 26 is a disk-shaped member made of, for example, metal, centering on the shaft 112. A part of a surface of the circuit case 26 facing the wheel case 29 is preferably provided with a heat radiation fin formed integrally with the circuit case 26. Further, a hall element substrate 27 provided with a hall sensor is mounted on a part of the same surface. A PCU substrate 25 provided with PCU10 is attached to a surface of circuit case 26 opposite to hall element substrate 27. The PCU substrate 25 and the hall element substrate 27 are connected by necessary signal lines and electric wires through holes passing through the circuit case 26. In this example, no fins are provided on the surface of circuit case 26 on the PCU substrate 25 side, but fins may be provided.

The stator 24 is mounted on the circuit case 26 so as to surround the periphery thereof. That is, the stator 24 is fixed to the shaft 112 via the circuit case 26. The stator 24 includes windings connected to the three-phase alternating-current power supplies UVW from the inverter 102, respectively. The stator 24 is fixed to the shaft 112, and the rotor 23 on the outer side thereof rotates.

Fig. 2B is a cross-sectional view showing a cross section parallel to the rotation axis of the in-wheel motor 11. The rotor 23, the stator 24, the substrate case 26, and the like are accommodated in a housing constituted by the wheel cases 21, 29 with the shaft 112 as an axis. Here, the board case 26 is a heat conductive member having high heat conductivity such as metal, and is a member to which boards are mounted, and also functions as a heat dissipation plate. Therefore, the PCU substrate 25 can be mounted on the substrate case 26 in such a manner that the heat generating components mounted therein are in contact with the substrate case 26 directly or via a heat conductive material having high heat conductivity. Further, the stator 24 is also in contact with the substrate housing 26, and its heat is propagated toward the substrate housing 26. As a result of this structure, heat of stator 24 and PCU substrate 25 is easily transmitted to substrate case 26. The surface of the base plate case 26 on which the fins are provided faces the wheel case 29, and the rotation of the wheel case 29 causes air to flow in the space between the base plate case 26 and the wheel case 29. The air flow contacts the fins of the base housing 26 to effectively cool it. On the other hand, although the hall element substrate 27 is mounted on the substrate case 26, it is preferably mounted so that heat from the substrate case 26 is less likely to propagate to the hall elements.

Fig. 4 shows this situation. Fig. 4 shows the upper portions of the base plate case 26 and the wheel case 29 from the shaft 112 in the cross section of fig. 2B. The rotation of the wheel housing 29 generates an air flow toward the outer peripheral side along the wheel housing 29, and the air flow hits the outer edge of the wheel housing 21 and is directed toward the space on the substrate housing 26 side. This airflow passes through the substrate case 26 and goes to the shaft 112 side, and collides with an airflow generated also on the opposite side across the shaft 112, thereby causing a convection in a vortex as shown by an arrow in fig. 4. By this flow of air, the heat generated by the PCU substrate 25, the hall element substrate 27, the stator 24, and the like and transferred to the substrate case 26 is further propagated to the wheel case 29. Also, heat is efficiently radiated from the fins provided on the outer side surface of the wheel housing 29. This effect is similarly exerted also on the wheel house 21, and the heat generated inside can be efficiently diffused to the outside of the in-wheel motor 11.

Fig. 3A to 3C show details of mounting PCU substrate 25 and hall element substrate 27 to substrate case 26. Fig. 3A shows the PCU substrate 25 side of the substrate case 26, fig. 3B shows the hall element substrate 27 side thereof on the opposite side, and fig. 3C shows a cross section. PCU substrate 25 and hall element substrate 27 are mounted on the facing surfaces of substrate case 26 at positions that do not overlap each other. PCU substrate 25 is mounted such that power element 251 such as an FET of inverter 102 provided thereon is in direct contact with substrate case 26. Thereby, heat from the power element 251 is efficiently propagated to the substrate case 26. The hall elements 271 on the hall element substrate 27 are provided at the end on the rotor side to detect the rotational position of the rotor 23. The substrate case 26 is surrounded by the stator 243 at its outer periphery and coupled to the shaft 112 at its center. Both ends of shaft 112 are formed as open hollow portions, and holes 41 and 42 are provided to communicate with the side of the wheel housing interior surface on which PCU base plate 25 is mounted. A power supply cable or other cables (or wire harnesses) 40, which are guided from a power supply mounted on the body of the two-wheeled vehicle 1 and are inserted from the end of the shaft 112 into the hollow shaft, are guided to the PCU substrate 25 via the holes 41 and 42, and are connected to predetermined terminals. The cables connecting the PCU substrate 25 and the hall element substrate 27 are routed through the opening 43 of the substrate case 26. In this way, PCU substrate 25 and hall element substrate 27 are mounted on the surfaces of substrate case 26 that are opposite to each other.

With this configuration, the wiring between PCU substrate 25 and hall element substrate 27 can be simplified, and the structure of in-wheel motor 11 can be made compact. Further, the wiring to the inside of the in-wheel motor 11 by the hollow shaft 112 contributes to the compactness of the in-wheel motor 11. Further, since PCU substrate 25 and hall element substrate 27 are provided at positions not overlapping each other, the influence of heat generated from PCU substrate 25, particularly from inverter 102, on hall element circuit 27 can be reduced.

In the present embodiment, the fins provided in the casing are arranged in parallel in a fixed direction, but the present invention is not limited to this. For example, the substrates may be arranged radially about an axis. The shape may be not only a straight line but also a curved line. Further, the shape may be determined in consideration of not only the efficiency of heat dissipation but also wind noise and the like.

In the present embodiment, the vehicle using the in-wheel motor 11 as power is a two-wheeled vehicle, but may be a three-wheeled vehicle or a four-wheeled vehicle. The drive wheels are not limited to the rear wheels, and may be front wheels, or may be all wheels provided in the vehicle. In addition, the two-wheeled vehicle is not limited to a vehicle having wheels on the front and rear sides, and may be a vehicle having wheels arranged on the left and right sides with respect to the traveling direction, such as a wheelchair. In this case, the two wheels serve as driving wheels and are driven by the in-wheel motor 11. In the case of such a two-wheeled vehicle or four-wheeled vehicle, the in-wheel motor 11 may be configured to be capable of rotating in the reverse direction (i.e., backward) under the control of the controller 101. The in-wheel motor 11 according to the present embodiment may be used as a power source for rotating an object, not limited to the drive wheels of the vehicle. Further, in the case where the in-wheel motor 11 is used as the driving wheel of the vehicle, a member that efficiently guides the traveling wind to the hub portion of the driving wheel can be attached to the vehicle.

● summary of the embodiments

The above-described embodiment is summarized as follows.

(1) According to a first aspect of the present invention, there is provided a motor (11) structure characterized in that,

the motor has a structure comprising:

a stator (24);

a rotor (23) rotated by a magnetic force from the stator (24);

a housing (21, 29) of the motor, the housing being coupled to the rotor (23); and

a power control unit (10) disposed inside the housings (21, 29) and configured to drive the stator (24),

the casings (21, 29) are provided with cooling fins (111).

This makes the housing rotate with the rotation of the rotor, and the air flow is easily caused, so that the cooling efficiency of the motor can be further improved.

(2) According to a second aspect of the present invention, there is provided a motor structure (1) of a motor (11),

the power control unit (10) is mounted on a heat-conducting member (26) fixed to the stator (24),

in the cases (21, 29), the fins (111) are provided on a side surface through which a shaft that rotates together with the rotor (23) passes and on an inner surface facing the heat-conducting member (26).

This can provide cooling fins also inside the casing, thereby further improving the cooling effect.

(3) According to a third aspect of the present invention, there is provided a motor structure (2) of the motor (11),

in the heat conducting member (26), cooling fins (111) are provided on a surface facing an inner surface of the housing (21, 29).

Thus, the cooling effect can be further improved by providing the heat conductive member with the cooling fin.

(4) According to a third aspect of the present invention, there is provided a motor structure, in addition to the motor (10) structure according to any one of the aspects (1) to (3),

the motor (10) further comprises a hollow shaft (112), the shaft (112) being fixed to the stator (24), serving as a shaft of the housing (21, 29) that rotates together with the rotor (23), and being rotatable with respect to the housing (21, 29),

a wire harness connected to the power control unit (10) is inserted through the shaft (112) and routed to the inside of the housings (21, 29).

This can improve the wiring efficiency inside the motor, and can reduce the size of the motor.

(5) According to a third aspect of the present invention, there is provided a vehicle characterized in that,

the vehicle has a drive wheel formed by mounting a tire (12) on the outer periphery of the housing (21, 29) of a motor (11) having any one of the structures (1) to (4).

This makes the housing rotate with the travel of the vehicle, and the air flow is easily caused, so that the cooling efficiency can be further improved.

The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention.

This application claims priority based on Japanese patent application laid-open at 2018, 9, 28, and 2018-184939, the entire disclosure of which is incorporated herein by reference.