JP7270433B2 - motor unit - Google Patents

Description

The present invention relates to a motor unit.

In recent years, it has been proposed to mount a motor unit in which a motor and a fan are integrated in a vehicle such as a small two-wheeled vehicle. For example, Patent Literature 1 discloses a motor unit in which a fan is installed on the shaft of the motor. The motor unit disclosed in Patent Document 1 cools the inverter by blowing air from a fan onto the inverter.

JP 2017-147919 A

By the way, in the motor unit, not only the inverter but also the motor generates heat, so it is preferable to cool the motor as well. In such a case, it is conceivable to blow air from the above-described fan not only along the inverter but also along the motor housing. However, the cooling effect of the motor by blowing air from the fan is not sufficient, and there is a demand for a proposal that can cool the motor further.

SUMMARY OF THE INVENTION It is an object of the present invention to improve cooling efficiency of a motor in a motor unit including a fan and a motor.

The present invention employs the following configurations as means for solving the above problems.

A first invention is a motor unit that includes a motor, a fan connected to the shaft of the motor, and a fan cover that encloses the fan, and that is mounted on a vehicle capable of traveling, wherein the fan cover comprises: a peripheral wall for guiding the air pressure-fed by the fan along the outer wall surface of the motor housing of the motor; A configuration is adopted in which it has a traveling wind guide section for joining the air.

According to a second aspect of the present invention, in the first aspect, the motor unit is mounted on the vehicle in a posture in which the extension direction of the shaft of the motor is a horizontal direction that intersects the running direction of the vehicle. At least part of the wind guide part is arranged above the motor unit in the mounting posture.

In a third aspect based on the second aspect, the motor housing has a fixed portion fixed to the vehicle, and when viewed from the extension direction of the shaft, the wind guide portion is at least one of the fixed portions. A configuration in which the part is overlapped with the part is adopted.

According to a fourth invention, in the third invention, the fixing portion has a ventilation hole penetrating in the extending direction of the shaft.

In a fifth aspect based on any one of the second to fourth aspects, the traveling wind guide portion is provided with a curved surface for guiding the traveling wind from the traveling direction of the vehicle in a direction along the extending direction of the shaft. and the running wind guide portion has a rectifying rib erected on the curved surface along the running wind guiding direction.

According to the present invention, the peripheral wall portion allows the air that is pressure-fed by the fan to flow along the motor housing, and the traveling wind guide portion causes the traveling wind to flow along the motor housing. According to the present invention, the air guided by the peripheral wall portion and the running wind guided by the running wind guide portion merge to cool the motor housing, so that the cooling efficiency of the motor can be improved. Therefore, according to the present invention, it is possible to further improve the cooling efficiency of the motor in the motor unit including the fan and the motor.

1 is a schematic configuration diagram of a small two-wheeled vehicle in which a motor unit that is an embodiment of the present invention is installed; FIG. 1 is an external perspective view of a motor unit that is an embodiment of the present invention; FIG. 1A is a left side view of a motor unit according to an embodiment of the present invention, and FIG. 1B is a right side view of a motor unit according to an embodiment of the present invention; FIG. FIG. 3B is a schematic cross-sectional view of a motor unit that is an embodiment of the present invention, and is a cross-sectional view taken along the line AA shown in FIG. 3B. FIG. 3B is a schematic cross-sectional view of a motor unit that is an embodiment of the present invention, and is a cross-sectional view taken along the line BB shown in FIG. 3B. FIG. 5 is a schematic cross-sectional view of a modified example of the motor unit that is one embodiment of the present invention;

An embodiment of a motor unit according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a small two-wheeled vehicle 50 (vehicle) on which a motor unit 1 of this embodiment is mounted. As shown in this figure, a small two-wheeled vehicle 50 has a vehicle body frame 51 to which the motor unit 1 and the like are fixed, wheels 52 rotated by the rotational power generated by the motor unit 1, and electric power to be supplied to the motor unit 1. It has a battery 53 and the like. Description of the configuration of the small two-wheeled vehicle 50 excluding the motor unit 1 is omitted.

Such a small two-wheeled vehicle 50 can run forward (vehicle running direction) shown in FIG. 1 by the rotational power generated by the motor unit 1 of the present embodiment. In the following description, the rearward direction opposite to the traveling direction of the vehicle, the upper side in the vertical direction is the upper side, the lower side in the vertical direction is the lower side, the left side of the driver of the small two-wheeled vehicle 50 is the left side, and the small The right side of the driver of the two-wheeled vehicle 50 is referred to as the right direction.

FIG. 2 is an external perspective view of the motor unit 1 of this embodiment. FIG. 3(a) is a side view of the motor unit 1 of the present embodiment viewed from the left. FIG. 3(b) is a side view of the motor unit 1 of the present embodiment viewed from the right. 4 is a schematic cross-sectional view of the motor unit 1 of the present embodiment, taken along the line AA shown in FIG. 3(b). FIG. 5 is a schematic cross-sectional view of the motor unit 1 of this embodiment, and is a cross-sectional view taken along the line BB shown in FIG. 3(b).

As shown in FIG. 1, the motor unit 1 of this embodiment is mounted on a small two-wheeled vehicle 50 in such a manner that the extension direction of the shaft 2d (see FIG. 4 or 5) of the motor 2 is parallel to the left-right direction. It is said that In other words, the motor unit 1 of the present embodiment has a mounting posture in which the extension direction of the shaft 2 d of the motor 2 is a horizontal direction that intersects the running direction of the small two-wheeled vehicle 50 .

The motor unit 1 of this embodiment includes a motor 2, an inverter 3, a fan 4, a fan cover 5, and a gear unit 6, as shown in FIGS.

The motor 2 includes a motor housing 2a, a stator core 2b, a rotor core 2c, and a shaft 2d. The motor housing 2a is a housing that accommodates the stator core 2b, the rotor core 2c and the shaft 2d. On the outer wall of the motor housing 2a, a plurality of motor heat radiation ribs 2e extending in the left-right direction are arranged in a circumferential direction around the shaft 2d. As shown in FIGS. 2 and 3, the outer wall of the motor housing 2a includes a frame fixing portion 2f (fixing portion) for fixing the motor unit 1 of the present embodiment to the vehicle body frame 51, and an inverter (to be described later). and an inverter fixing portion 2g for fixing the housing 3a. These frame fixing portion 2f and inverter fixing portion 2g are extended along the horizontal direction.

In addition, as shown in FIG. 3A, the frame fixing portion 2f is provided with two ventilation holes 2f1 penetrating in the left-right direction. These air holes 2f1 are arranged side by side in the circumferential direction around the shaft 2d when viewed from the extending direction of the shaft 2d. Further, in the present embodiment, the frame fixing portion 2f is provided so as to protrude forward from the outer wall surface of the motor housing 2a when viewed from the extending direction of the shaft 2d. Therefore, in the present embodiment, the vent holes 2f1 are arranged vertically as shown in FIG. 3(a). Air pressure-fed from the fan 4 flows through these ventilation holes 2f1.

If any one of the ventilation holes 2f1 is removed due to the strength of the frame fixing portion 2f, it is preferable to remove the lower ventilation hole 2f1 and leave the upper ventilation hole 2f1. Compared to the upper portion, the lower portion of the motor unit 1 is more likely to be exposed to running wind and cooled. Therefore, by leaving the upper ventilation holes 2f1 that are not easily cooled by the running wind, it is possible to improve the strength of the frame fixing portion 2f while suppressing a decrease in the cooling efficiency of the frame fixing portion 2f.

Returning to FIGS. 4 and 5, the stator core 2b is fixed to the inner wall of the motor housing 2a and is annularly provided so as to surround the rotor core 2c. The stator core 2b generates a magnetic force that rotates the rotor core 2c when supplied with power. The rotor core 2c is arranged inside the stator core 2b and fixed to the shaft 2d. The rotor core 2c is rotatable by the magnetic force generated by the stator core 2b.

The shaft 2d is fixed with respect to the rotor core 2c and is rotated as the rotor core 2c rotates. In this embodiment, the shaft 2d is rotatably supported by a bearing fixed to the motor housing 2a. is fixed to Such a shaft 2 d transmits the rotational power generated by the stator core 2 b and rotor core 2 c to the fan and gear unit 6 .

The motor 2 is supplied with electric power converted into three-phase alternating current by the inverter 3, generates rotational power from the supplied electric power, and transmits the generated rotational power to the fan 4 and the gear unit 6 through the shaft 2d. do.

The inverter 3 has an inverter housing 3a and a core unit 3b. The inverter housing 3a functions as a cover member that covers the core unit 3b and as a heat sink that absorbs heat from the core unit 3b and releases it to the outside. That is, in the present embodiment, the cover member that covers the core unit 3b and the heat sink that absorbs the heat of the core unit 3b and releases it to the outside are integrated as the inverter housing 3a.

The core unit 3b is housed inside the inverter housing 3a while being fixed to the inverter housing 3a. The core unit 3b converts DC power supplied from a battery (not shown) into three-phase AC power and supplies it to the stator core 2b of the motor 2. As shown in FIG. Such a core unit 3b includes a substrate (not shown) on which switching elements, capacitors, and the like are mounted. The inverter housing 3a is integrally formed of a highly thermally conductive metal (for example, aluminum), and has a surrounding wall 3c, a heat radiating portion 3d, and side wall heat radiating fins 3e.

The surrounding wall 3c is a bowl-shaped portion that accommodates the core unit 3b, and has a ceiling wall facing the fan 4 and a side wall extending leftward from the ceiling wall. The heat radiating portion 3d receives the air flow pressure-fed from the fan 4 and radiates heat to the air flow. The side wall radiating fins 3e are plate-like portions that stand upright on the outer wall surface of the side wall portion of the surrounding wall 3c and extend in the left-right direction. The side wall radiation fins 3e are arranged at substantially equal intervals in the circumferential direction around the shaft 2d.

The fan 4 is arranged facing the heat radiating portion 3 d with a certain gap, and is connected to the shaft 2 d of the motor 2 . The fan 4 is rotated via the shaft 2d to take in air from the opposite side of the heat radiating portion 3d and pump the air toward the heat radiating portion 3d. In other words, the fan 4 forms an air flow toward the heat radiating portion 3d by being rotated by transmission of rotational power from the motor 2 .

The fan cover 5 is made of resin, for example, and fixed to the inverter housing 3a. The fan cover 5 includes a top wall portion 5b provided with an intake opening 5a, a peripheral wall portion 5c extending from the peripheral edge portion of the top wall portion 5b, and a traveling wind guide projecting forward from the peripheral wall portion 5c. and a portion 5d.

The ceiling wall portion 5 b is a portion that covers the fan 4 from the air inflow side, and is arranged on the right side of the fan 4 . Incidentally, the intake opening 5a is provided with a net-like portion or the like for preventing entry of foreign matter, if necessary. The peripheral wall portion 5c is a portion that surrounds the fan 4 from the radial outside. When viewed from the extending direction of the shaft 2d, the peripheral wall portion 5c is arranged to cover the peripheral wall of the inverter housing 3a from the outside in the radial direction with a certain gap therebetween. That is, the peripheral wall portion 5c is arranged with a certain gap from the peripheral wall of the inverter housing 3a. Such a peripheral wall portion 5c guides the air pressure-fed by the fan 4 along the outer wall surface of the motor housing 2a through the gap.

The running wind guide portion 5d is a portion that guides the running wind generated by the running of the small two-wheeled vehicle 50 and joins the running wind with the air guided by the peripheral wall portion 5c. That is, the running wind guide portion 5d joins the running wind with the air that has been pumped by the fan 4 and then guided by the peripheral wall portion 5c and discharged from the fan cover 5 along the outer wall portion of the motor housing 2a. is.

As shown in FIG. 4, the running wind guide portion 5d has a base portion 5e provided with a curved surface 5e1 and vertical wall portions 5f arranged to sandwich the curved surface 5e1 from above and below. The curved surface 5e1 is arranged so as to be exposed when viewed from the front, and receives the running wind that flows in from the front in a direction along the extending direction (horizontal direction) of the shaft 2d from the running direction of the small two-wheeled vehicle 50. invite. The vertical wall portion 5f prevents the running wind guided by the curved surface 5e1 from scattering in the vertical direction.

As shown in FIGS. 3(a) and 3(b), when viewed from the extending direction (horizontal direction) of the shaft 2d, the traveling wind guide portion 5d is arranged so as to overlap the upper portion of the frame fixing portion 2f. ing. In other words, when viewed from the extending direction of the shaft 2d, the wind guide portion 5d is arranged so as to partially overlap the frame fixing portion 2f. Therefore, the running wind guided by the running wind guide portion 5d is directly blown against the frame fixing portion 2f.

The gear unit 6 is arranged on the left side of the motor 2, adjusts the rotational speed of the rotational power transmitted from the motor 2, and outputs it. Such a gear unit 6 has the same diameter as the motor 2, as shown in FIGS. By making the gear unit 6 have the same diameter as or a smaller diameter than the motor 2, the air flow along the motor housing 2a is not obstructed by the gear unit 6, and the air flows smoothly along the motor housing 2a. becomes possible. For example, in order to make the gear unit 6 have the same diameter as the motor 2 or a smaller diameter, the gear unit 6 has a structure using a planetary gear mechanism.

In the motor unit 1 of this embodiment having such a configuration, when power is supplied to the motor 2 through the inverter 3, the motor 2 generates rotational power, and the motor 2 drives the wheels 52 through the gear unit 6 and the like. power is transmitted to Also, part of the rotational power generated by the motor 2 is transmitted to the fan 4 through the shaft 2d, and the fan 4 is rotationally driven.

When the fan 4 is driven to rotate, air is drawn into the fan cover 5 through the intake opening 5a of the fan cover 5, forming an air flow toward the heat radiating portion 3d of the inverter housing 3a. The airflow generated by the fan 4 spreads radially around the shaft 2d after hitting the heat radiating portion 3d, and is then discharged to the outside of the fan cover 5 through the gap between the inverter housing 3a and the fan cover 5. be done. At this time, the peripheral wall portion 5c of the fan cover 5 guides the discharged air to the outer wall surface of the motor housing 2a along the extending direction of the shaft 2d.

Further, in the motor unit 1 of the present embodiment, running wind generated by running of the small two-wheeled vehicle 50 is guided by the running wind guide portion 5d and joins the air guided to the peripheral wall portion 5c. That is, according to the motor unit 1 of the present embodiment, the motor 2 is cooled not only by the air guided by the peripheral wall portion 5c but also by the running wind guided by the running wind guide portion 5d.

In the motor unit 1 of the present embodiment as described above, the fan cover 5 includes the peripheral wall portion 5c that guides the air pumped by the fan 4 along the outer wall surface of the motor housing 2a provided in the motor 2, A running wind guide portion 5d is provided to guide the running wind generated by the running of the automobile 50 and join the running wind to the air guided by the peripheral wall portion 5c.

According to the motor unit 1 of this embodiment, the air pressure-fed by the fan 4 is caused to flow along the motor housing 2a by the peripheral wall portion 5c, and the running wind is directed along the motor housing 2a by the running wind guide portion 5d. be swept away. Therefore, according to the motor unit 1 of the present embodiment, the air guided by the peripheral wall portion 5c and the running wind guided by the running wind guide portion 5d join to cool the motor housing 2a. Cooling efficiency can be improved. Therefore, according to the motor unit 1 of this embodiment, in the motor unit 1 including the fan 4 and the motor 2, the cooling efficiency of the motor 2 can be improved.

Further, in the motor unit 1 of the present embodiment, the extension direction of the shaft 2d provided in the motor 2 is a horizontal direction orthogonal (crossing) to the traveling direction of the small two-wheeled vehicle 50. , and the running wind guide portion 5d is arranged above the motor unit 1 in the mounting posture. Compared to the upper portion, the lower portion of the motor unit 1 is more likely to be exposed to running wind and cooled. On the contrary, the upper part of the motor unit 1 is likely to retain heat and become high in temperature. Therefore, it is possible to efficiently cool the motor 2 by directing the running wind through the running wind guide portion 5d to the upper portion of the motor unit 1 where the temperature tends to be relatively high.

Further, in the motor unit 1 of the present embodiment, the motor housing 2a has the frame fixing portion 2f fixed to the small two-wheeled vehicle 50, and when viewed from the extension direction of the shaft 2d, the traveling wind guide portion 5d is the frame fixing portion. 2f and at least a portion thereof. The frame fixing portion 2f is a portion having a large heat capacity compared to surrounding portions and is a portion that is difficult to be cooled. According to the motor unit 1 of the present embodiment, the running wind guided by the running wind guide part 5d hits the frame fixing part 2f directly, so that the motor 2 can be efficiently cooled.

In addition, in the motor unit 1 of the present embodiment, the frame fixing portion 2f is provided with a ventilation hole 2f1 penetrating in the extending direction of the shaft 2d. Therefore, air can be passed through the inside of the frame fixing portion 2f for cooling, and the motor 2 can be efficiently cooled.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above embodiments. The various shapes, combinations, and the like of the constituent members shown in the above-described embodiment are examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.

For example, as shown in the cross-sectional view of FIG. 6, it is possible to employ a configuration in which the airflow guide portion 5d has straightening ribs 5g erected on the curved surface 5e1 along the airflow guide direction. Such a straightening rib 5g may be one sheet, or may be arranged in the vertical direction and provided in a plurality of sheets. The rectifying ribs 5g rectify the running wind guided to the running wind guide portion 5d, thereby improving straightness, and the motor 2 can be cooled up to the portion on the far side when viewed from the running wind guide portion 5d. It becomes possible to further improve the cooling efficiency of the motor 2 . In addition, the flow direction of the air guided by the peripheral wall portion 5c and the flow direction of the traveling air guided by the traveling air guide portion 5d can be easily matched by the rectifying ribs 5g, thereby suppressing the turbulence of the flows due to confluence. can do.

Further, in the above-described embodiment, the configuration in which only one running wind guide portion 5d is provided has been described. However, the invention is not limited to this. For example, two or more wind guides 5d may be installed.

Further, in the above-described embodiment, the configuration in which the traveling wind guide portion 5d is arranged above the motor unit 1 has been described. However, the present invention is not limited to this, and it is also possible to employ a configuration in which the running wind guide portion 5d is arranged under the motor unit 1. FIG.

Further, in the above-described embodiment, the wind guide portion 5d is arranged so as to partially overlap the frame fixing portion 2f when viewed from the extending direction of the shaft 2d. However, the present invention is not limited to this. It is also possible to employ a configuration in which the entirety of 2f does not overlap the running wind guide portion 5d. In addition, it is preferable that the wind guide portion 5d overlaps the upper portion of the frame fixing portion 2f when viewed from the extension direction of the shaft 2d. Since heat tends to accumulate above the frame fixing portion 2f, the motor 2 is efficiently cooled by arranging the wind guide portion 5d so as to overlap the upper portion of the frame fixing portion 2f when viewed from the extension direction of the shaft 2d. be able to.

Further, in the above-described embodiment, the configuration in which the frame fixing portion 2f is provided with the ventilation holes 2f1 has been described. However, the present invention is not limited to this, and it is also possible to employ a configuration in which the frame fixing portion 2f is not provided with the ventilation holes 2f1.

Reference Signs List 1 Motor unit 2 Motor 2a Motor housing 2b Stator core 2c Rotor core 2d Shaft 2e Motor radiation rib 2f Frame fixing part (fixing part) 2f1 Ventilation hole 2g Inverter fixing part 3 Inverter 3a Inverter housing 3b Core unit 3c Surrounding wall 3d Radiation part 3e Side wall radiation fin 4 Fan 5 Fan cover 5a Suction opening 5b Ceiling wall 5c Peripheral wall 5d Running wind guide 5e Base 5e1 Curved surface 5f Vertical wall portion, 5g...Rectification rib, 6...Gear unit, 50...Small two-wheeled vehicle (vehicle), 51...Body frame, 52...Wheel, 53...Battery

Claims (9)

A motor unit comprising a motor, a fan connected to the shaft of the motor, and a fan cover surrounding the fan, and mounted on a vehicle capable of running,
The fan cover is
a peripheral wall portion that guides air pumped by the fan along an outer wall surface of a motor housing of the motor;
a running wind guide part that guides the running wind generated by running of the vehicle and joins the running wind to the air guided by the peripheral wall part ;
The path along which the air pressure-fed by the fan passes and the path along which the air guided by the wind guide section passes are from the point where the air pressure-fed by the fan and the air guided by the wind guide section join. On the upstream side, it exists as a separate and independent pathway
A motor unit characterized by: The mounting posture of the motor unit to the vehicle is a posture in which the extension direction of the shaft of the motor is a horizontal direction that intersects the running direction of the vehicle,
2. The motor unit according to claim 1, wherein at least a part of said traveling wind guide portion is arranged above said motor unit in said mounting posture. The motor housing has a fixing portion fixed to the vehicle,
3. The motor unit according to claim 2, wherein the wind guide portion overlaps at least a portion of the fixed portion when viewed from the extension direction of the shaft. 4. The motor unit according to claim 3, wherein the fixing portion has a vent hole penetrating in the extending direction of the shaft. The traveling wind guide portion is provided with a curved surface that guides the traveling wind from the traveling direction of the vehicle in a direction along the extending direction of the shaft,
The motor unit according to any one of claims 2 to 4, wherein the airflow guide portion has a straightening rib erected on the curved surface along the direction in which the airflow is guided. A motor unit comprising a motor, a fan connected to the shaft of the motor, and a fan cover surrounding the fan, and mounted on a vehicle capable of running,
The fan cover is
a peripheral wall portion that guides air pumped by the fan along an outer wall surface of a motor housing of the motor;
a running wind guide portion that guides the running wind generated by running of the vehicle and joins the running wind to the air guided by the peripheral wall portion;
has
The mounting posture of the motor unit to the vehicle is a posture in which the extension direction of the shaft of the motor is a horizontal direction that intersects the running direction of the vehicle,
The motor housing has a fixing portion fixed to the vehicle,
A motor unit according to claim 1, wherein the wind guide portion overlaps at least a portion of the fixed portion when viewed from the extending direction of the shaft. 7. The motor unit according to claim 6, wherein at least a part of said traveling wind guide portion is arranged above said motor unit in said mounting posture. 8. The motor unit according to claim 6, wherein the fixed portion has a vent hole penetrating in the extension direction of the shaft. The traveling wind guide portion is provided with a curved surface that guides the traveling wind from the traveling direction of the vehicle in a direction along the extending direction of the shaft,
The running wind guide part has a straightening rib erected along the guiding direction of the running wind on the curved surface.
The motor unit according to any one of claims 6 to 8, characterized in that:

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