Motor

Abstract

The purpose of the present disclosure is to improve cooling efficiency of a motor body. A motor (1) is provided with a motor body (MB1), a motor housing (6), a drive shaft (51), a fan (8), a fan housing (9), and a ventilation path (V1). The fan housing (9) covers the motor housing (6) and the fan (8). The ventilation path (V1) is surrounded by an inner surface of the fan housing (9) and an outer surface of the motor housing (6). The fan housing (9) has a plurality of openings (OP1) in a region facing the motor housing (6). The plurality of openings (OP1) connect the ventilation path (V1) to the outside of the fan housing (9).

Description

motor

[0001] The present disclosure relates generally to motors, and more particularly to motors with fans.

[0002] The power unit (motor) described in Patent Document 1 includes a motor body and a casing. The casing surrounds the motor body and defines at least one cooling passage. Airflow is introduced into the cooling passage through an opening.

[0003] Japanese Patent Application Laid-Open No. 2022-117969

[0004] However, in Patent Document 1, there is a problem in that the air temperature increases toward the downstream side of the cooling flow path, and the cooling efficiency of the motor body decreases.

[0005] An object of the present disclosure is to provide a motor that can improve the cooling efficiency of the motor body.

[0006] A motor according to one aspect of the present disclosure includes a motor body, a motor housing, a drive shaft, a fan, a fan housing, and an air passage. The motor body includes a rotor and a stator. The motor housing covers the motor body. The drive shaft extends axially through the motor housing and rotates with the rotor. The fan is disposed outside the motor housing and attached to the drive shaft. The fan housing covers the motor housing and the fan. The air passage is surrounded by the inner surface of the fan housing and the outer surface of the motor housing. The fan housing has multiple openings in an area facing the motor housing. The multiple openings connect the air passage to the outside of the fan housing.

[0007] The present disclosure has the advantage of being able to improve the cooling efficiency of the motor body.

[0008] FIG. 1 is a perspective view of a motor according to the first embodiment. FIG. 2 is an exploded perspective view of the motor according to the first embodiment. FIG. 3 is a cross-sectional view of the motor according to the first embodiment as seen from the left. FIG. 4 is a cross-sectional view of the motor according to the first embodiment as seen from the front. FIG. 5 is a distribution map of air temperature in a motor according to a first comparative example. FIG. 6 is a distribution map of air temperature in a motor according to a second comparative example. FIG. 7 is a distribution map of air temperature in a motor according to a third comparative example. FIG. 8 is a distribution map of air temperature in a motor according to the first embodiment. FIG. 9 is a flow velocity distribution map of the motor according to the first comparative example. FIG. 10 is a flow velocity distribution map of the motor according to the second comparative example. FIG. 11 is a flow velocity distribution map of the motor according to the third comparative example. FIG. 12 is a flow velocity distribution map of the motor according to the first embodiment. FIG. 13 is a cross-sectional view of the motor according to the second embodiment as seen from the front. FIG. 14 is a plan view of a resistor of the motor according to the second embodiment as seen from the left. FIG. 15 is a distribution map of air temperature in a motor according to the third comparative example. FIG. 16 is a distribution map of air temperature in a motor according to a reference example. Fig. 17 is a distribution diagram of air temperature in a motor according to a reference example. Fig. 18 is a flow velocity distribution diagram of a motor according to comparative example 3. Fig. 19 is a flow velocity distribution diagram of a motor according to a reference example. Fig. 20 is a flow velocity distribution diagram of a motor according to a reference example. Fig. 21 is a cross-sectional view seen from the front of a motor according to embodiment 3. Fig. 22 is a cross-sectional view seen from the front of a motor according to embodiment 4. Fig. 23 is a cross-sectional view seen from the front of a motor according to embodiment 5. Fig. 24 is a cross-sectional view seen from the front of a motor according to embodiment 6. Fig. 25 is a cross-sectional view seen from the front of a motor according to embodiment 7.

[0009] In the following embodiments, the motor of the present disclosure will be described using the drawings. However, the following embodiments are merely a portion of various embodiments of the present disclosure. The following embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Furthermore, the following embodiments, including modified examples, may be realized by combining them as appropriate. Furthermore, the drawings described in the following embodiments are schematic diagrams, and the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.

[0010] The X-axis direction shown in each drawing is defined as the front-to-back direction, the Y-axis direction as the left-to-right direction, and the Z-axis direction as the up-to-down direction. Furthermore, the positive direction of the X-axis direction is defined as the front, the positive direction of the Y-axis direction as the right, and the positive direction of the Z-axis direction as the up. However, these directions are merely examples and are not intended to limit the directions in which the motor may be used. Furthermore, the arrows indicating the various directions in the drawings are merely shown for explanatory purposes and have no substance.

[0011] (Embodiment 1) (Overview) FIG. 1 is a perspective view of a motor 1 according to Embodiment 1. FIG. 2 is an exploded perspective view of the motor 1 according to Embodiment 1. FIG. 3 is a cross-sectional view of the motor 1 according to Embodiment 1 as seen from the left. FIG. 4 is a cross-sectional view of the motor 1 according to Embodiment 1 as seen from the front. Here, the "cross-sectional view seen from the left" refers to a cross-sectional view of the motor 1 cut along a plane perpendicular to the Y axis and viewed from the negative direction of the Y axis. Furthermore, the "cross-sectional view seen from the front" refers to a cross-sectional view of the motor 1 cut along a plane perpendicular to the X axis and viewed from the positive direction of the X axis. Similarly to FIG. 4, the "cross-sectional views seen from the front" in FIGS. 13 and 21 to 25 described below are also defined as cross-sectional views of the motors (1A to 1F) cut along a plane perpendicular to the X axis and viewed from the positive direction of the X axis.

[0012] As shown in FIGS. 1 to 4 , the motor 1 of this embodiment includes a motor main body MB1, a motor housing 6, a drive shaft 51, a fan 8, a fan housing 9, and a ventilation passage V1. The motor main body MB1 includes a rotor 3 and a stator 4. The motor housing 6 covers the motor main body MB1. The drive shaft 51 extends axially (in the Y-axis direction) through the motor housing 6 and rotates with the rotation of the rotor 3. The fan 8 is disposed outside the motor housing 6 and attached to the drive shaft 51. The fan housing 9 covers the motor housing 6 and the fan 8. The ventilation passage V1 is surrounded by the inner surface of the fan housing 9 and the outer surface of the motor housing 6. The fan housing 9 has multiple openings OP1 in an area facing the motor housing 6. The multiple openings OP1 connect the ventilation passage V1 to the outside of the fan housing 9.

[0013] According to the above configuration, by providing the ventilation passage V1 between the fan housing 9 and the motor housing 6, air can be sent to a position away from the fan 8 for cooling. Furthermore, because the air passing through the ventilation passage V1 can be cooled via the multiple openings OP1, it is possible to prevent the air temperature from becoming too high at a position away from the fan 8. This improves the cooling efficiency of the motor main body MB1.

[0014] (Details) (1) Overall configuration As shown in Figure 2, the motor 1 comprises a motor body MB1, a motor housing 6, a drive shaft 51, a first bearing 52, a second bearing 53 (see Figure 4), a substrate 54, a side cover 7, a fan 8, and a fan housing 9.

[0015] (2) Drive Shaft The longitudinal direction of the drive shaft 51 is along the Y axis. The shape of the drive shaft 51 is cylindrical with its center aligned with the Y axis.

[0016] The drive shaft 51 has a first tip 511 and a second tip 512. The first tip 511 is the tip of the drive shaft 51 in the Y-axis direction. More specifically, the first tip 511 is the left end of the drive shaft 51. The second tip 512 is the tip of the drive shaft 51 on the opposite side to the first tip 511. More specifically, the second tip 512 is the right end of the drive shaft 51.

[0017] The fan 8 is attached to a side closer to the first tip 511 than the center of the drive shaft 51 in the Y-axis direction. The load is attached to a side closer to the second tip 512 than the center of the drive shaft 51 in the Y-axis direction. As the drive shaft 51 rotates, the fan 8 and the load rotate.

[0018] (3) Motor Main Body As shown in Figures 3 and 4, the motor main body MB1 includes a rotor 3 and a stator 4. The rotor 3 includes a rotor core 31 and a plurality of permanent magnets 32. The stator 4 includes a stator core 41 and a plurality of coils 42.

[0019] The rotor core 31 contains a magnetic material. The rotor core 31 has a cylindrical shape with its center aligned with the Y-axis. A drive shaft 51 is fixed to the rotor core 31. More specifically, the drive shaft 51 is fitted into a through hole 310 provided in the center of the rotor core 31. As the rotor core 31 rotates, the drive shaft 51 rotates.

[0020] A plurality of permanent magnets 32 are embedded in the rotor core 31 .

[0021] The stator core 41 includes a magnetic material and has a cylindrical shape with its center aligned with the Y axis.

[0022] The stator core 41 includes, for example, a plurality of split cores 410. The split cores 410 are connected in an annular shape when viewed in the Y-axis direction. As a result, the stator core 41 is formed in a cylindrical shape that surrounds the rotor core 31.

[0023] The multiple coils 42 correspond one-to-one to the multiple split cores 410. A corresponding coil 42 is wound around each split core 410. More specifically, the coil 42 is wound around the split core 410 via an insulating member having electrical insulation properties.

[0024] Each of the plurality of coils 42 generates a magnetic flux when energized. Electromagnetic interaction between the magnetic flux generated from the plurality of coils 42 and the plurality of permanent magnets 32 causes the rotor 3 to rotate relative to the stator 4.

[0025] (4) First Bearing and Second Bearing The first bearing 52 and the second bearing 53 rotatably support the drive shaft 51 .

[0026] 4, the first bearing 52 is fixed to the side cover 7. The second bearing 53 is fixed to the motor housing 6.

[0027] The first bearing 52 is disposed on the left side of the motor main body MB1, and the second bearing 53 is disposed on the right side of the motor main body MB1.

[0028] (5) Motor Housing The motor housing 6 includes a metal as a material. For example, the motor housing 6 includes aluminum as a material. The thermal conductivity of the motor housing 6 is higher than the thermal conductivity of the fan housing 9.

[0029] The motor housing 6 has a hollow rectangular parallelepiped shape with an opening at the left end, and accommodates the motor main body MB1.

[0030] As shown in FIGS. 2 to 4, the motor housing 6 includes a bottom portion 61 and a side portion 62 .

[0031] The shape of the side portion 62 is cylindrical with its center aligned with the Y axis. When viewed from the Y axis direction, the shape of the outer circumferential surface of the side portion 62 is rectangular. In this disclosure, the term "rectangle" encompasses the concept of a square and a rectangle. More specifically, when viewed from the Y axis direction, the shape of the outer circumferential surface of the side portion 62 is square.

[0032] 3, the outer peripheral surface of the side portion 62 includes four outer surfaces 621, 622, 623, and 624. The outer surfaces 621, 622, 623, and 624 are the upper surface, front surface, lower surface, and rear surface of the motor housing 6, respectively.

[0033] When viewed from the Y-axis direction, the inner peripheral surface of the side portion 62 has a circular shape. The cylindrical stator 4 is fitted inside the side portion 62.

[0034] The side portion 62 has a wire passage hole 620 (see FIG. 2 ). Electric wires for energizing the plurality of coils 42 of the stator 4 are passed through the wire passage hole 620.

[0035] The bottom portion 61 covers the right end of the side portion 62. The bottom portion 61 has a through-hole 610 (see FIG. 4) through which the drive shaft 51 passes.

[0036] (6) Side Cover As shown in Fig. 4, the side cover 7 is attached to the motor housing 6. More specifically, the side cover 7 is attached to the motor housing 6 using, for example, a plurality of bolts 21 (see Fig. 2).

[0037] The side cover 7 covers the left end of the side portion 62 of the motor housing 6 .

[0038] In the space surrounded by the side cover 7 and the motor housing 6, the motor main body MB1, the first bearing 52, and the second bearing 53 are arranged.

[0039] (7) Board As shown in FIG. 4, the board 54 is housed in the motor housing 6. The board 54 includes, for example, a rotary encoder that detects the rotation of the rotor 3.

[0040] (8) Fan As shown in FIG. 2 , the fan 8 includes a fan base 81 , a shaft support 82 , and a plurality of blades 83 .

[0041] The fan base 81 has a plate-like shape with its thickness direction aligned along the Y-axis direction. More specifically, the fan base 81 has a disk-like shape.

[0042] The shaft support portion 82 has a cylindrical shape with its center aligned with the Y axis. The shaft support portion 82 protrudes from the fan base 81 along the Y axis. The drive shaft 51 is fitted inside the shaft support portion 82. In this way, the fan 8 is attached to the drive shaft 51.

[0043] The plurality of blades 83 protrude along the Y axis from the fan base 81. The plurality of blades 83 are arranged radially around the pivot support portion 82.

[0044] The fan 8 rotates in accordance with the rotation of the drive shaft 51, generating airflow to the right.

[0045] (9) Fan Housing The fan housing 9 is made of resin. The fan housing 9 is a hollow rectangular parallelepiped with an opening at the right end. The fan housing 9 houses the motor housing 6, the fan 8, the side cover 7, and the motor main body MB1. The motor 1 also includes, for example, an amplifier that drives the motor main body MB1, and the motor housing 6 houses the amplifier.

[0046] As shown in FIG. 2 , the fan housing 9 includes a bottom wall 91 and a side wall 92 .

[0047] The side wall 92 has a cylindrical shape centered on an axis along the Y axis. When viewed from the Y axis direction, the outer circumferential surface of the side wall 92 has a rectangular shape.

[0048] When viewed from the Y-axis direction, the inner circumferential surface of the side wall 92 has a rectangular shape. As shown in Fig. 3, the inner circumferential surface of the side wall 92 includes four inner surfaces 921, 922, 923, and 924. The normal directions of the inner surfaces 921, 922, 923, and 924 are downward, rearward, upward, and forward, respectively. The inner surfaces 921, 922, 923, and 924 face the outer surfaces 621, 622, 623, and 624 of the motor housing 6, respectively.

[0049] An air passage V1 (also referred to as air passage V11) is provided on the motor housing 6 between the outer surface 621 and the inner surface 921. That is, the outer surface 621 and the inner surface 921 each form a boundary of the air passage V11. That is, the outer surface 621 and the inner surface 921 constitute the air passage V11. The inner surface 921 of the fan housing 9 that constitutes the air passage V11 has a shape that follows the outer surface 621 of the motor housing 6 that constitutes the air passage V11. More specifically, the inner surface 921 is parallel to the outer surface 621. In this disclosure, "parallel" is not limited to parallel in the strict sense, but also includes a state in which there is a difference from the strict sense of parallelism within the range of manufacturing tolerance.

[0050] In front of the motor housing 6, an air passage V1 (also referred to as air passage V12) is provided between the outer surface 622 and the inner surface 922. That is, the outer surface 622 and the inner surface 922 each form a boundary of the air passage V12. The inner surface 922 of the fan housing 9, which constitutes the air passage V12, has a shape that follows the outer surface 622 of the motor housing 6, which also constitutes the air passage V12. More specifically, the inner surface 922 is parallel to the outer surface 622.

[0051] Below the motor housing 6, an air passage V1 (also referred to as air passage V13) is provided between the outer surface 623 and the inner surface 923. That is, the outer surface 623 and the inner surface 923 each form a boundary of the air passage V13. The inner surface 923 of the fan housing 9 that forms the air passage V13 has a shape that follows the outer surface 623 of the motor housing 6 that forms the air passage V13. More specifically, the inner surface 923 is parallel to the outer surface 623.

[0052] Behind the motor housing 6, an air passage V1 (also referred to as air passage V14) is provided between the outer surface 624 and the inner surface 924. That is, the outer surface 624 and the inner surface 924 each form a boundary of the air passage V14. The inner surface 924 of the fan housing 9 that constitutes the air passage V14 has a shape that follows the outer surface 624 of the motor housing 6 that also constitutes the air passage V14. More specifically, the inner surface 924 is parallel to the outer surface 624.

[0053] The ventilation passages V11 and V13 are opposed to each other in the up-down direction. The ventilation passages V12 and V14 are opposed to each other in the front-rear direction. The ventilation passages V12 and V14 connect the ventilation passage V11 and the ventilation passage V13.

[0054] Each ventilation passage V1 has an exhaust port V20 (see FIG. 4) at its right end V32. The exhaust port V20 is a gap between the right end of the fan housing 9 and the motor housing 6.

[0055] The fan 8 is disposed to the left of the motor main body MB1. The motor main body MB1 is disposed to the right of the fan 8.

[0056] 4, the length L1 from the left end V31 of the ventilation passage V1 to the right end V32 of the ventilation passage V1 is longer than the length L2 from the left end V31 of the ventilation passage V1 to the left end of the fan housing 9. In addition, the length L1 is longer than twice the length L2.

[0057] The right end V32 of the ventilation passage V1 is located to the right of the center C1 of the rotor 3 in the left-right direction. The right end V32 of the ventilation passage V1 is also located to the right of the center C2 of the motor housing 6 in the left-right direction.

[0058] The fan housing 9 has a plurality of openings OP1 in an area facing the motor housing 6. More specifically, the plurality of openings OP1 are provided so as to penetrate inner surfaces 921, 922, 923, and 924 of the side wall 92 of the fan housing 9. The four ventilation passages V11 to V14 are connected to the outside of the fan housing 9 via the plurality of openings OP1.

[0059] 2, the openings OP1 are aligned in the Y-axis direction. Furthermore, the openings OP1 are aligned in a direction intersecting the Y-axis direction (the X-axis direction or the Z-axis direction). Specifically, on the top and bottom surfaces of the fan housing 9, the openings OP1 are aligned in the X-axis and Y-axis directions. On the front and rear surfaces of the fan housing 9, the openings OP1 are aligned in the Y-axis and Z-axis directions.

[0060] When viewed from the penetrating direction of the openings OP1, the openings OP1 have a circular shape. The internal space of the openings OP1 has a cylindrical shape. The openings OP1 have the same dimensions.

[0061] The fan 8 is disposed in a space SP1 (see FIG. 4) on the left side of the area where the multiple openings OP1 are provided in the motor housing 6. The space SP1 is connected to four ventilation passages V11 to V14.

[0062] No opening OP1 is provided in the areas facing the space SP1 among the top, bottom, front, and rear surfaces of the fan housing 9. This makes it possible to suppress a decrease in the flow rate of air flowing into the ventilation passage V1.

[0063] 2, a bottom wall 91 of the fan housing 9 covers the left end of the side wall 92. The bottom wall 91 has an air vent 910 facing the fan 8. The air vent 910 is an air inlet.

[0064] The fan housing 9 is attached to the motor housing 6. More specifically, the fan housing 9 is attached to the motor housing 6 using, for example, a plurality of bolts 22 (see FIG. 2). The motor housing 6 has a plurality of bolt holes 600 (see FIG. 2) through which the plurality of bolts 22 pass.

[0065] (10) Air-Cooling of the Motor Body When the fan 8 rotates, air is blown to the right inside the fan housing 9. Therefore, air flows from the space SP1 (see FIG. 4 ) in which the fan 8 is disposed into the four ventilation channels V1. Some of the air flowing through the ventilation channel V1 exits the ventilation channel V1 through a plurality of openings OP1, and another part of the air flowing through the ventilation channel V1 exits the ventilation channel V1 through the exhaust port V20 (opening).

[0066] The air flowing through the ventilation passage V1 absorbs heat from the motor main body MB1, causing the temperature to rise. However, the provision of multiple openings OP1 connecting the ventilation passage V1 to the outside of the fan housing 9 suppresses the temperature rise of the air flowing through the ventilation passage V1. Therefore, the air temperature is prevented from becoming excessively high even on the right side of the ventilation passage V1 (near the exhaust port V20). This allows the motor main body MB1 to be effectively cooled even in the right side of the ventilation passage V1 (near the exhaust port V20).

[0067] In addition, the wind generated by the rotation of the fan 8 causes air to flow from the space SP1 in which the fan 8 is located through the gaps between the balls of the first bearing 52 (ball bearing) and into the inside of the motor main body MB1, thereby air-cooling the motor main body MB1.

[0068] 5 to 7 are diagrams showing the results of a simulation of the air temperature distribution in the motors according to Comparative Examples 1 to 3, respectively. Fig. 8 is a diagram showing the results of a simulation of the air temperature distribution in motor 1 of this embodiment (also referred to as Basic Example 1). In the diagrams showing the air temperature distribution in Figs. 5 to 8, "high" indicates a region where the temperature is higher than the surroundings and than "medium," "medium" indicates an intermediate temperature region, and "low" indicates a region where the temperature is lower than the surroundings and than "medium."

[0069] 9 to 11 are diagrams showing the simulation results of the flow velocity distribution of the motors according to Comparative Examples 1 to 3, respectively. Fig. 12 is a diagram showing the simulation results of the flow velocity distribution of the motor 1 of Basic Example 1.

[0070] In the motor according to Comparative Example 1 (see FIGS. 5 and 9), the right end of the fan housing 9a is closed, preventing air from leaking from the fan housing 9a to the periphery of the motor housing 6. As a result, the temperature rise in the motor main body MB1 is greater than in Basic Example 1. In the diagrams showing the results of the flow velocity distribution in FIGS. 9 to 12, "high" represents a region where the flow velocity is higher than the surroundings and than "medium," "medium" represents an intermediate temperature region, and "low" represents a region where the flow velocity is lower than "medium" and than the surroundings.

[0071] In the motor of Comparative Example 2 (see FIGS. 6 and 10), the length of the fan housing 9b in the left-right direction is shorter than that of the fan housing 9 of Basic Example 1, and the right end of the fan housing 9b is located to the left of the motor housing 6. The air leaves the fan housing 9b and flows to the right around the motor housing 6, but the further away from the fan housing 9b to the right, the slower the flow speed becomes, and the less effective it is at suppressing the temperature rise of the motor main body MB1.

[0072] The motor according to Comparative Example 3 (see FIGS. 7 and 11) differs from the motor 1 of Basic Example 1 in that the fan housing 9c does not have an opening OP1. Air leaves the fan housing 9c and flows to the right through the ventilation passage V1 around the motor housing 6, but the air temperature rises the further to the right it is from the fan housing 9c, and the effect of suppressing the temperature rise of the motor body MB1 decreases.

[0073] In the motor 1 of Basic Example 1 (see FIGS. 8 and 12), the fan housing 9 is provided with an opening OP1, so the flow velocity of the air flowing through the ventilation passage V1 decreases the further to the right from the fan housing 9. However, a certain level of flow velocity is maintained. Furthermore, compared to Comparative Examples 1 to 3, the temperature rise in the area farther to the right from the fan housing 9 (the downstream portion of the ventilation passage V1) is suppressed.

[0074] In this way, in the motor 1 of the basic example 1, the cooling efficiency of the motor main body MB1 can be improved compared to the motors of the comparative examples 1 to 3.

[0075] The simulation results for the temperature of the coil 42 and the temperature of the rotor core 31 are shown in Table 1.

[0076]

[0077] (Variation of First Embodiment) The above description has been given on the assumption that air flows from left to right through the ventilation channel V1. However, air may also flow from right to left through the ventilation channel V1. For example, air may flow from right to left through the ventilation channel V1 by rotating the fan 8 in the opposite direction. When air flows from right to left through the ventilation channel V1, the exhaust port V20 serves as an air inlet, and the ventilation hole 910 serves as an air outlet. The flow velocity of the air from the exhaust port V20 is greater than the flow velocity of the air from the multiple openings OP1.

[0078] Even when air flows from right to left through the ventilation passage V1, the provision of a plurality of openings OP1 suppresses a rise in temperature on the downstream side (left side).

[0079] Second Embodiment A motor 1A according to a second embodiment will be described below with reference to Figures 13 to 20. Components similar to those in the first embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0080] Fig. 13 is a cross-sectional view of the motor 1A according to the second embodiment as seen from the front. Fig. 14 is a plan view of the resistor 23 of the motor 1A according to the second embodiment as seen from the left.

[0081] The motor 1A differs from the motor 1 of the first embodiment in that it further includes a resistor 23. The resistor 23 restricts the inflow of air into the ventilation passage V1.

[0082] The resistor 23 includes a metal as a material, for example, aluminum as a material.

[0083] 13 and 14, the resistor 23 has a plate shape with its thickness direction along the Y-axis direction. More specifically, the resistor 23 has a rectangular plate shape.

[0084] The resistor 23 is disposed between the fan 8 and the motor main body MB1. More specifically, the resistor 23 is attached to the side cover 7 so as to cover the left side surface of the side cover 7.

[0085] The resistor 23 has a plurality of sixth openings 231 facing the ventilation passage V1 and a seventh opening 232 facing the motor main body MB1. The seventh opening 232 is provided at the center of the resistor 23. The plurality of sixth openings 231 are provided around the seventh opening 232. The peripheral edge of each sixth opening 231 blocks the air passage between the space SP1 and the ventilation passage V1.

[0086] The aperture ratio of the plurality of sixth openings 231 is smaller than the aperture ratio of the seventh opening 232. In this disclosure, the "aperture ratio" of an opening means the proportion of the area (opening area) occupied by the openings per unit area. In other words, the total area of ​​one or more openings present per unit area corresponds to the aperture ratio.

[0087] The total opening area of ​​the sixth openings 231 is smaller than the opening area of ​​the seventh opening 232 .

[0088] Air flows from the space SP1 inside the fan housing 9 to the ventilation passage V1 through the sixth openings 231. Air also flows from the space SP1 through the seventh opening 232 into the interior of the motor main body MB1.

[0089] According to this embodiment, the flow rate of air flowing through the ventilation passage V1 is restricted by the resistor 23, thereby increasing the flow rate of air flowing inside the motor main body MB1. This enhances the effect of suppressing the temperature rise of the motor main body MB1.

[0090] The number of seventh openings 232 may be plural. In this case, the aperture ratio of the plurality of sixth openings 231 is preferably smaller than the aperture ratio of the plurality of seventh openings 232. The sum of the aperture areas of the plurality of sixth openings 231 is preferably smaller than the sum of the aperture areas of the plurality of seventh openings 232. The aperture area of ​​each of the plurality of sixth openings 231 is preferably smaller than the aperture area of ​​each of the plurality of seventh openings 232. The number of the plurality of sixth openings 231 is preferably smaller than the number of the plurality of seventh openings 232.

[0091] Next, Figures 7 and 15 are diagrams showing the results of a simulation of air temperature distribution in the motor according to Comparative Example 3. Figures 16 and 17 are diagrams showing the results of a simulation of air temperature distribution in the motor according to the Reference Example. In the diagrams showing air temperature distribution in Figures 15 to 17, "high" indicates a region where the temperature is higher than the surroundings and than "medium," "medium" indicates an intermediate temperature region, and "low" indicates a region where the temperature is lower than the surroundings and than "medium."

[0092] 11 and 18 are diagrams showing the results of a simulation of the flow velocity distribution of the motor according to Comparative Example 3. Figures 19 and 20 are diagrams showing the results of a simulation of the flow velocity distribution of the motor according to the Reference Example. In the diagrams showing the results of the flow velocity distribution in Figures 18 to 20, "high" represents a region where the flow velocity is higher than the surroundings and than "medium," "medium" represents an intermediate temperature region, and "low" represents a region where the flow velocity is lower than "medium" and than the surroundings.

[0093] The motor according to the reference example (see FIGS. 16 and 17) includes the resistor 23, similar to the motor 1A. The only difference between the comparative example 3 and the reference example is whether or not the resistor 23 is present.

[0094] In the reference example, the air flow velocity inside the motor main body MB1 is higher than in the comparative example 3. As a result, the temperature rise inside the motor main body MB1 is suppressed compared to the comparative example 3. Similarly, in the motor 1A of this embodiment, the temperature rise inside the motor main body MB1 can be suppressed.

[0095] (Embodiment 3) A motor 1B according to embodiment 3 will be described below with reference to Fig. 21. Fig. 21 is a cross-sectional view of the motor 1B according to embodiment 3 as seen from the front. Components similar to those in embodiment 1 are given the same reference numerals and descriptions thereof will be omitted.

[0096] The motor 1B of this embodiment differs from the motor 1 of the first embodiment in the shape of the opening OP1. The opening OP1 of the motor 1B is tapered such that the opening area is larger on the side farther from the motor housing 6 (outside) than on the side closer to the motor housing 6 (inside). In other words, the opening OP1 is tapered such that the opening area on the outside of the fan housing 9 is larger than the opening area on the ventilation passage V1 side. The opening OP1 is inclined so that the opening area gradually increases the farther away from the ventilation passage V1. The shape of the internal space of the opening OP1 is a truncated cone.

[0097] The right side of the inner surface of the opening OP1 is inclined so that the farther the area from the ventilation passage V1, the more to the right the area is. The left side of the inner surface of the opening OP1 is inclined so that the farther the area from the ventilation passage V1, the more to the left the area is.

[0098] Because the opening OP1 has a tapered shape, whether the air flows rightward or leftward through the ventilation passage V1, the air can easily flow from the ventilation passage V1 through the opening OP1 to the outside of the fan housing 9. This improves the heat dissipation effect in the ventilation passage V1.

[0099] (Embodiment 4) A motor 1C according to embodiment 4 will be described below with reference to Fig. 22. Fig. 22 is a cross-sectional view of the motor 1C according to embodiment 4 as seen from the front. Components similar to those of embodiment 3 are given the same reference numerals and descriptions thereof will be omitted.

[0100] The motor 1C of this embodiment differs from the motor 1B of the third embodiment in the arrangement of the plurality of openings OP1.

[0101] Hereinafter, each of the openings OP1 connected to the ventilation passage V11 will also be referred to as a first opening OP11. Also, each of the openings OP1 connected to the ventilation passage V13 will also be referred to as a second opening OP12.

[0102] The fan housing 9 includes a first region having a plurality of first openings OP11 and a second region having a plurality of second openings OP12. Specifically, the inner surface 921 is the first region, and the inner surface 923 is the second region.

[0103] When viewed from the axial direction (Y-axis direction), the drive shaft 51 is disposed between the first region and the second region. In other words, the first region and the second region face each other in a direction perpendicular to the axial direction, with the drive shaft 51 interposed therebetween.

[0104] The aperture ratio of the plurality of first openings OP11 is different from the aperture ratio of the plurality of second openings OP12. In this embodiment, the number of the plurality of first openings OP11 is different from the number of the plurality of second openings OP12, thereby providing a difference between the aperture ratio of the plurality of first openings OP11 and the aperture ratio of the plurality of second openings OP12.

[0105] More specifically, the aperture ratio of the plurality of first openings OP11 is greater than the aperture ratio of the plurality of second openings OP12. Furthermore, the number of the plurality of first openings OP11 is greater than the number of the plurality of second openings OP12.

[0106] The motor 1C is preferably used with the first region having the plurality of first openings OP11 oriented higher in the direction of gravity than the second region having the plurality of second openings OP12. In this case, warm air passing through the ventilation passage V11 is likely to flow upward through the plurality of first openings OP11 due to the density difference between the warm air and the cold air. The relatively large opening ratio of the plurality of first openings OP11 enhances the effect of causing the warm air to flow out through the plurality of first openings OP11.

[0107] Furthermore, when the first region is higher than the second region in the direction of gravity, warm air is less likely to flow out of the ventilation passage V13 through the second openings OP12. The relatively small aperture ratio of the second openings OP12 makes it easier for air to flow to the exhaust port V20, enhancing the heat dissipation effect. In other words, priority is given to making it easier for air to flow to the exhaust port V20 over allowing warm air to flow out of the second openings OP12.

[0108] Fifth Embodiment A motor 1D according to a fifth embodiment will be described below with reference to Fig. 23. Fig. 23 is a cross-sectional view of the motor 1D according to the fifth embodiment as seen from the front. The same components as those in the third embodiment will be assigned the same reference numerals and will not be described again.

[0109] The motor 1D of this embodiment differs from the motor 1B of the third embodiment in the opening area of ​​some of the openings OP1 among the plurality of openings OP1.

[0110] As in the fourth embodiment, each of the openings OP1 connected to the ventilation passage V11 is also referred to as a first opening OP11. Also, each of the openings OP1 connected to the ventilation passage V13 is also referred to as a second opening OP12. Also, as in the fourth embodiment, a first region and a second region are defined.

[0111] The aperture ratio of the plurality of first openings OP11 is different from the aperture ratio of the plurality of second openings OP12. In this embodiment, the aperture area of ​​each of the plurality of first openings OP11 is different from the aperture area of ​​each of the plurality of second openings OP12, thereby providing a difference between the aperture ratio of the plurality of first openings OP11 and the aperture ratio of the plurality of second openings OP12.

[0112] More specifically, the aperture ratio of the first openings OP11 is greater than the aperture ratio of the second openings OP12. Furthermore, the opening area of ​​each of the first openings OP11 is greater than the opening area of ​​each of the second openings OP12.

[0113] By providing a difference between the aperture ratio of the plurality of first openings OP11 and the aperture ratio of the plurality of second openings OP12, the present embodiment also provides the same effects as the fourth embodiment.

[0114] Sixth Embodiment A motor 1E according to a sixth embodiment will be described below with reference to Fig. 24. Fig. 24 is a cross-sectional view of the motor 1E according to the sixth embodiment as seen from the front. The same components as those in the third embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0115] The motor 1E of this embodiment differs from the motor 1B of the third embodiment in the arrangement of the multiple openings OP1.

[0116] Hereinafter, among the regions of the inner surface of the fan housing 9 facing the ventilation passage V1, the region relatively close to the fan 8 will be referred to as the third region, the region relatively far from the fan 8 as the fifth region, and the region between the third and fifth regions as the fourth region. More specifically, the distance L4 in the axial direction (Y-axis direction) between the fourth region and the fan 8 is longer than the distance L3 in the axial direction between the third region and the fan 8 and shorter than the distance L5 in the axial direction between the fifth region and the fan 8.

[0117] Hereinafter, each of the openings OP1 provided in the third region will also be referred to as a third opening OP13. Also, each of the openings OP1 provided in the fourth region will also be referred to as a fourth opening OP14. Also, each of the openings OP1 provided in the fifth region will also be referred to as a fifth opening OP15.

[0118] The aperture ratio of the plurality of fourth openings OP14 is smaller than the aperture ratio of the plurality of third openings OP13 and smaller than the aperture ratio of the plurality of fifth openings OP15. In this embodiment, the number of the plurality of fourth openings OP14 is smaller than the number of the plurality of third openings OP13 and smaller than the number of the plurality of fifth openings OP15, thereby providing a difference in aperture ratio.

[0119] The advantages of this embodiment will be described assuming that the air flows through the ventilation passage V1 to the right. On the left side (inlet side) of the ventilation passage V1, the air is strongly directed to the right and weakly directed in the Z-axis direction. Therefore, even if the aperture ratio of the multiple third openings OP13 is relatively large, the amount of air flowing out from the multiple third openings OP13 is small, and the air flow to the right is less likely to be obstructed. On the other hand, on the right side (outlet side) of the ventilation passage V1, the air is weakly directed to the right, and the amount of heat dissipation from the exhaust port V20 tends to be insufficient. Therefore, by relatively increasing the aperture ratio of the multiple fifth openings OP15, a sufficient amount of heat dissipation can be ensured.

[0120] The advantages of this embodiment will be described assuming that the air flows through the ventilation passage V1 to the left. On the right side (inlet side) of the ventilation passage V1, the air is strongly directed leftward and weakly directed in the Z-axis direction. Therefore, even if the aperture ratio of the plurality of fifth openings OP15 is relatively large, the amount of air flowing out from the plurality of fifth openings OP15 is small, and the air flow to the left is less likely to be obstructed. On the other hand, on the left side (outlet side) of the ventilation passage V1, the air is weakly directed leftward, and the amount of heat dissipated from the ventilation holes 910 tends to be insufficient. Therefore, by relatively increasing the aperture ratio of the plurality of third openings OP13, a sufficient amount of heat dissipation can be ensured.

[0121] (Seventh embodiment) A motor 1F according to a seventh embodiment will be described below with reference to Fig. 25. Fig. 25 is a cross-sectional view of the motor 1F according to the seventh embodiment as seen from the front. The same components as those in the third embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

[0122] The motor 1F of this embodiment differs from the motor 1B of the third embodiment in the opening area of ​​some of the openings OP1 among the plurality of openings OP1.

[0123] A third region, a fourth region, and a fifth region are defined in the same manner as in embodiment 6. Also, as in embodiment 6, each of the plurality of openings OP1 provided in the third region is also referred to as a third opening OP13, each of the plurality of openings OP1 provided in the fourth region is also referred to as a fourth opening OP14, and each of the plurality of openings OP1 provided in the fifth region is also referred to as a fifth opening OP15.

[0124] The aperture ratio of the plurality of fourth openings OP14 is smaller than the aperture ratio of the plurality of third openings OP13 and smaller than the aperture ratio of the plurality of fifth openings OP15. Therefore, in this embodiment, the same effects as in the sixth embodiment can be obtained.

[0125] In this embodiment, the opening areas of the openings OP1 are made different, thereby making the opening ratios different. More specifically, the opening area of ​​each of the plurality of fourth openings OP14 is smaller than the opening area of ​​each of the plurality of third openings OP13 and smaller than the opening area of ​​each of the plurality of fifth openings OP15.

[0126] (Modifications) The following are modifications of the first to seventh embodiments. The following modifications may be implemented in appropriate combinations.

[0127] The external shape of each of the plurality of openings OP1 is not limited to a circle, and may be, for example, an ellipse or a polygon.

[0128] The plurality of openings OP1 may have a honeycomb structure, which increases the strength of the fan housing 9.

[0129] The number of ventilation passages V1 is not limited to four, but may be one to three, or five or more.

[0130] It is not essential that the multiple ventilation channels V1 are connected to each other.

[0131] It is not essential that the fan housing 9 be made up of a single member, but the fan housing 9 may include multiple members connected to each other.

[0132] When viewed from a direction perpendicular to the Y-axis direction, the fan housing 9 may cover the entire motor housing 6, or may cover only a portion of the motor housing 6. When viewed from a direction perpendicular to the Y-axis direction, the length in the Y-axis direction of the portion of the fan housing 9 that covers the motor housing 6 may be, for example, equal to or greater than half the length of the fan housing 9 in the Y-axis direction (L1 + L2 in FIG. 4).

[0133] The space in which the motor main body MB1 is disposed may be sealed. For example, the space may be sealed by the motor housing 6 and the side cover 7. This configuration prevents outside air from entering the space in which the motor main body MB1 is disposed, thereby suppressing poor insulation due to dust, etc., and deterioration due to wear of the stator 4 (deterioration of motor characteristics).

[0134] (Summary) The above-described embodiments and the like disclose the following aspects.

[0135] A motor (1; 1A-1F) according to a first aspect includes a motor body (MB1), a motor housing (6), a drive shaft (51), a fan (8), a fan housing (9), and a ventilation passage (V1). The motor body (MB1) includes a rotor (3) and a stator (4). The motor housing (6) covers the motor body (MB1). The drive shaft (51) extends axially, penetrates the motor housing (6), and rotates with the rotation of the rotor (3). The fan (8) is disposed outside the motor housing (6) and attached to the drive shaft (51). The fan housing (9) covers the motor housing (6) and the fan (8). The ventilation passage (V1) is surrounded by the inner surface of the fan housing (9) and the outer surface of the motor housing (6). The fan housing (9) has a plurality of openings (OP1) in an area facing the motor housing (6). A plurality of openings (OP1) connect the ventilation passage (V1) to the outside of the fan housing (9).

[0136] According to the above configuration, by providing the ventilation passage (V1) between the fan housing (9) and the motor housing (6), air can be sent to a position away from the fan (8) for cooling. Furthermore, since the air passing through the ventilation passage (V1) can be cooled via the multiple openings (OP1), it is possible to prevent the air temperature from becoming too high at a position away from the fan (8). Therefore, the cooling efficiency of the motor body (MB1) can be improved.

[0137] In the motor (1C; 1D) according to the second aspect, in the first aspect, the fan housing (9) includes a first region having a plurality of first openings (OP11) among the plurality of openings (OP1), and a second region having a plurality of second openings (OP12) among the plurality of openings (OP1). The aperture ratio of the plurality of first openings (OP11) is different from the aperture ratio of the plurality of second openings (OP12).

[0138] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0139] In addition, in the motor (1C; 1D) according to the third aspect, in the second aspect, a drive shaft (51) is arranged between the first region and the second region when viewed in the axial direction.

[0140] According to the above configuration, the motor (1C; 1D) can be used with the first region positioned higher than the second region in the direction of gravity, thereby improving the cooling effect of the motor main body (MB1).

[0141] In addition, in the motor (1D) according to the fourth aspect, in the second or third aspect, the opening area of ​​each of the plurality of first openings (OP11) is different from the opening area of ​​each of the plurality of second openings (OP12).

[0142] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0143] In addition, in the motor (1C) according to the fifth aspect, in any one of the second to fourth aspects, the number of the plurality of first openings (OP11) is different from the number of the plurality of second openings (OP12).

[0144] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0145] In a motor (1E; 1F) according to a sixth aspect, in any one of the first to fifth aspects, the fan housing (9) includes a third region having a plurality of third openings (OP13) among the plurality of openings (OP1), a fourth region having a plurality of fourth openings (OP14) among the plurality of openings (OP1), and a fifth region having a plurality of fifth openings (OP15) among the plurality of openings (OP1). The axial distance (L4) between the fourth region and the fan (8) is longer than the axial distance (L3) between the third region and the fan (8) and shorter than the axial distance (L5) between the fifth region and the fan (8). The aperture ratio of the plurality of fourth openings (OP14) is smaller than the aperture ratio of the plurality of third openings (OP13) and smaller than the aperture ratio of the plurality of fifth openings (OP15).

[0146] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0147] In addition, in the motor (1F) relating to the seventh aspect, in the sixth aspect, the opening area of ​​each of the multiple fourth openings (OP14) is smaller than the opening area of ​​each of the multiple third openings (OP13) and smaller than the opening area of ​​each of the multiple fifth openings (OP15).

[0148] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0149] In addition, in the motor (1E) relating to the eighth aspect, in the sixth or seventh aspect, the number of the multiple fourth openings (OP14) is less than the number of the multiple third openings (OP13) and less than the number of the multiple fifth openings (OP15).

[0150] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0151] In addition, in the motor (1B to 1F) according to the ninth aspect, in any one of the first to eighth aspects, the shape of at least one of the openings (OP1) is tapered, with the opening area on the side farther from the motor housing (6) being larger than that on the side closer to the motor housing (6).

[0152] According to the above configuration, air is likely to flow out of the fan housing (9) from the ventilation passage (V1) through at least one opening (OP1) regardless of the direction in which the air flows through the ventilation passage (V1).

[0153] In addition, in a motor (1; 1A to 1F) according to a tenth aspect, in any one of the first to ninth aspects, the external shape of each of the multiple openings (OP1) is circular, elliptical, or polygonal.

[0154] According to the above configuration, the opening area of ​​the opening (OP1) can be easily increased.

[0155] In addition, in the motor (1; 1A to 1F) according to an eleventh aspect, in any one of the first to tenth aspects, the motor housing (6) contains metal as a material.

[0156] According to the above configuration, the thermal conductivity of the motor housing (6) can be increased, and the heat dissipation efficiency can be improved.

[0157] In addition, in a motor (1; 1A to 1F) according to a twelfth aspect, in any one of the first to eleventh aspects, the fan housing (9) contains resin as a material.

[0158] According to the above configuration, the weight of the fan housing (9) can be reduced.

[0159] In addition, the motor (1A) according to a thirteenth aspect is any one of the first to twelfth aspects, further comprising a resistor (23) arranged between the fan (8) and the motor body (MB1). The resistor (23) has a plurality of sixth openings (231) facing the ventilation passage (V1) and at least one seventh opening (232) facing the motor body (MB1).

[0160] According to the above configuration, the flow rate to the ventilation passage (V1) and the flow rate to the motor body (MB1) can be adjusted to flow rates according to the respective opening rates of the multiple sixth openings (231) and at least one seventh opening (232).

[0161] In addition, in the motor (1A) according to the fourteenth aspect, in the thirteenth aspect, the aperture ratio of the plurality of sixth openings (231) is smaller than the aperture ratio of at least one seventh opening (232).

[0162] According to the above configuration, the flow rate to the motor main body (MB1) can be increased, thereby enhancing the effect of suppressing the temperature rise of the motor main body (MB1).

[0163] In addition, in the motor (1; 1A to 1F) according to the fifteenth aspect, in any one of the first to fourteenth aspects, the inner surface of the fan housing (9) forming the ventilation passage (V1) is shaped to follow the outer surface of the motor housing (6) forming the ventilation passage (V1).

[0164] According to the above configuration, air easily passes through the ventilation passage (V1).

[0165] In addition, in a motor (1; 1A to 1F) according to a sixteenth aspect, in any one of the first to fifteenth aspects, the side on which the fan (8) is disposed as viewed from the motor body (MB1) is defined as the left, and the side on which the motor body (MB1) is disposed as viewed from the fan (8) is defined as the right. The length (L1) from the left end (V31) of the ventilation passage (V1) to the right end (V32) of the ventilation passage (V1) is longer than the length (L2) from the left end (V31) of the ventilation passage (V1) to the left end of the fan housing (9).

[0166] According to the above configuration, the ventilation passage (V1), which is a space through which heat from the motor body (MB1) is transferred, is relatively long, so that the cooling efficiency of the motor body (MB1) can be improved.

[0167] In addition, in a motor (1; 1A to 1F) according to a seventeenth aspect, in any one of the first to sixteenth aspects, the side on which the fan (8) is disposed as viewed from the motor body (MB1) is defined as the left, and the side on which the motor body (MB1) is disposed as viewed from the fan (8) is defined as the right. The length (L1) from the left end (V31) of the ventilation passage (V1) to the right end (V32) of the ventilation passage (V1) is longer than twice the length (L2) from the left end (V31) of the ventilation passage (V1) to the left end of the fan housing (9).

[0168] According to the above configuration, the ventilation passage (V1), which is a space through which heat from the motor body (MB1) is transferred, is relatively long, so that the cooling efficiency of the motor body (MB1) can be improved.

[0169] In the motor (1; 1A-1F) according to an eighteenth aspect, in any one of the first to seventeenth aspects, the side on which the fan (8) is disposed as viewed from the motor body (MB1) is defined as the left, and the side on which the motor body (MB1) is disposed as viewed from the fan (8) is defined as the right. The right end (V32) of the ventilation passage (V1) is located to the right of the center (C1) of the rotor (3) in the left-right direction.

[0170] According to the above configuration, the ventilation passage (V1), which is a space through which heat from the motor body (MB1) is transferred, is relatively long, so that the cooling efficiency of the motor body (MB1) can be improved.

[0171] In addition, in the motor (1; 1A to 1F) according to a 19th aspect, in any one of the first to eighteenth aspects, the side on which the fan (8) is disposed as viewed from the motor body (MB1) is defined as the left, and the side on which the motor body (MB1) is disposed as viewed from the fan (8) is defined as the right. The right end (V32) of the ventilation passage (V1) is located to the right of the center (C2) of the motor housing (6) in the left-right direction.

[0172] According to the above configuration, the ventilation passage (V1), which is a space through which heat from the motor body (MB1) is transferred, is relatively long, so that the cooling efficiency of the motor body (MB1) can be improved.

[0173] The configurations other than those of the first aspect are not essential for the motor (1; 1A to 1F) and can be omitted as appropriate.

[0174] According to the motor of the present disclosure, the cooling efficiency of the motor body is improved, and thus the motor of the present disclosure is industrially useful.

[0175] 1; 1A to 1F Motor 3 Rotor 4 Stator 6 Motor housing 8 Fan 9 Fan housing 23 Resistor 51 Drive shaft 231 Sixth opening 232 Seventh opening C1, C2 Center L1, L2 Length L3 to L5 Distance MB1 Motor body OP1 Opening OP11 First opening OP12 Second opening OP13 Third opening OP14 Fourth opening OP15 Fifth opening V1 Ventilation path V31 Left end V32 Right end

Claims

1. A motor comprising: a motor body including a rotor and a stator; a motor housing covering the motor body; a drive shaft extending axially and penetrating the motor housing and rotating as the rotor rotates; a fan disposed outside the motor housing and attached to the drive shaft; a fan housing covering the motor housing and the fan; and an air passage surrounded by the inner surface of the fan housing and the outer surface of the motor housing, wherein the fan housing has a plurality of openings in an area facing the motor housing that connect the air passage to the outside of the fan housing.

2. The motor according to claim 1, wherein the fan housing includes a first region having a plurality of first openings among the plurality of openings, and a second region having a plurality of second openings among the plurality of openings, and the aperture ratio of the plurality of first openings is different from the aperture ratio of the plurality of second openings.

3. The motor according to claim 2, wherein the drive shaft is disposed between the first region and the second region when viewed from the axial direction.

4. The motor according to claim 2, wherein the opening area of each of the plurality of first openings is different from the opening area of each of the plurality of second openings.

5. The motor according to claim 2, wherein the number of the plurality of first openings is different from the number of the plurality of second openings.

6. The motor described in claim 1, wherein the fan housing includes a third region having a plurality of third openings among the plurality of openings, a fourth region having a plurality of fourth openings among the plurality of openings, and a fifth region having a plurality of fifth openings among the plurality of openings, wherein the distance in the axial direction between the fourth region and the fan is longer than the distance in the axial direction between the third region and the fan and shorter than the distance in the axial direction between the fifth region and the fan, and the aperture ratio of the plurality of fourth openings is smaller than the aperture ratio of the plurality of third openings and smaller than the aperture ratio of the plurality of fifth openings.

7. The motor according to claim 6, wherein the opening area of each of the plurality of fourth openings is smaller than the opening area of each of the plurality of third openings and smaller than the opening area of each of the plurality of fifth openings.

8. The motor according to claim 6, wherein the number of the plurality of fourth openings is less than the number of the plurality of third openings and less than the number of the plurality of fifth openings.

9. The motor according to claim 1, wherein at least one of the plurality of openings has a tapered shape in which the opening area is larger on the side farther from the motor housing than on the side closer to the motor housing.

10. The motor according to claim 1, wherein the outer shape of each of the plurality of openings is circular, elliptical, or polygonal.

11. The motor of claim 1, wherein the motor housing comprises a metal as a material.

12. The motor according to claim 1, wherein the fan housing includes a resin as a material.

13. The motor according to claim 1, further comprising a resistor disposed between the fan and the motor body, the resistor having a plurality of sixth openings facing the ventilation passage and at least one seventh opening facing the motor body.

14. The motor according to claim 13, wherein the aperture ratio of the plurality of sixth openings is smaller than the aperture ratio of the at least one seventh opening.

15. The motor according to claim 1, wherein the inner surface of the fan housing that forms the ventilation passage is shaped to follow the outer surface of the motor housing that forms the ventilation passage.

16. The motor according to claim 1, wherein the side on which the fan is located as viewed from the motor body is defined as the left, and the side on which the motor body is located as viewed from the fan is defined as the right, and the length from the left end of the ventilation path to the right end of the ventilation path is longer than the length from the left end of the ventilation path to the left end of the fan housing.

17. The motor according to claim 1, wherein the side on which the fan is located as viewed from the motor body is defined as the left, and the side on which the motor body is located as viewed from the fan is defined as the right, and the length from the left end of the ventilation path to the right end of the ventilation path is more than twice the length from the left end of the ventilation path to the left end of the fan housing.

18. The motor according to claim 1, wherein the side on which the fan is located as viewed from the motor body is defined as the left, and the side on which the motor body is located as viewed from the fan is defined as the right, and the right end of the ventilation passage is located to the right of the center of the rotor in the left-right direction.

19. The motor according to claim 1, wherein the side on which the fan is located as viewed from the motor body is defined as the left, and the side on which the motor body is located as viewed from the fan is defined as the right, and the right end of the ventilation passage is located to the right of the center of the motor housing in the left-right direction.

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