Motor

Abstract

The purpose of this disclosure is to make a motor more compact while making it possible to cool the motor body by air blowing. A motor (1) is provided with a motor body (MB1), a motor housing (6), a drive shaft (51), and a fan. The motor housing (6) has a thin portion (U10) and a thick portion (A10) that is thicker than the thin portion (U10). The thick portion (A10) includes a ventilation path (V1) that extends in the axial direction, and a plurality of openings (OP1) that connect the ventilation path (V1) to the outside of the motor housing (6).

Description

Motor

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

[0002] The motor described in Patent Document 1 includes a motor body, a fan device, and a plurality of plate-shaped fins. The plate-shaped fins are arranged so as to be in contact with the frame of the motor body. The fan device blows air, blowing cooling air between the plate-shaped fins.

[0003] Japanese Patent Application Publication No. 11-313465

[0004] The present disclosure aims to reduce the size of a motor while enabling the motor body to be cooled by blowing air.

[0005] A motor according to one aspect of the present disclosure includes a motor body, a motor housing, a drive shaft, and a fan. 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 motor housing has a thin portion and a thick portion that is thicker than the thin portion. The thick portion includes an air passage extending in the axial direction and a plurality of openings connecting the air passage to the outside of the motor housing.

[0006] The present disclosure has the advantage of being able to reduce the size of the motor while allowing the motor body to be cooled by blowing air.

[0007] FIG. 1 is a perspective view of a motor according to embodiment 1. FIG. 2 is an exploded perspective view of the motor according to embodiment 1. FIG. 3 is a cross-sectional view of the motor according to embodiment 1 as seen from the left. FIG. 4 is a cross-sectional view corresponding to line IV-IV in FIG. 3. FIG. 5 is a distribution diagram of air temperature in a motor according to comparative example 1. FIG. 6 is a distribution diagram of air temperature in a motor according to comparative example 1. FIG. 7 is a distribution diagram of air temperature in a motor according to comparative example 2. FIG. 8 is a distribution diagram of air temperature in a motor according to comparative example 2. FIG. 9 is a distribution diagram of air temperature in a motor according to a reference example. FIG. 10 is a distribution diagram of air temperature in a motor according to a reference example. FIG. 11 is a flow velocity distribution diagram of a motor according to comparative example 1. FIG. 12 is a flow velocity distribution diagram of a motor according to comparative example 1. FIG. 13 is a flow velocity distribution diagram of a motor according to comparative example 2. FIG. 14 is a flow velocity distribution diagram of a motor according to comparative example 2. FIG. 15 is a flow velocity distribution diagram of a motor according to a reference example. FIG. 16 is a flow velocity distribution diagram of a motor according to a reference example. Fig. 17 is a cross-sectional view of a motor according to one modified example, as viewed from the left. Fig. 18 is a cross-sectional view of a motor according to another modified example, as viewed from the left. Fig. 19 is a cross-sectional view of a motor according to yet another modified example, as viewed from the left. Fig. 20 is a perspective view of a motor according to embodiment 2. Fig. 21 is a cross-sectional view of a motor according to embodiment 3. Fig. 22 is a cross-sectional view of a motor according to embodiment 4. Fig. 23 is a cross-sectional view of a motor according to embodiment 5. Fig. 24 is a cross-sectional view of a motor according to embodiment 6. Fig. 25 is a cross-sectional view of a motor according to embodiment 7.

[0008] 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.

[0009] 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.

[0010] (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 corresponding to line IV-IV in FIG. 3. 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 corresponding to line IV-IV refers to a cross-sectional view passing through line IV-IV shown in FIG. 3 and including the rotation axis of the motor 1 (a straight line parallel to the Y axis). The "cross-sectional view seen from the left" is defined for FIGS. 17, 18, and 19, which will be described later, in the same manner as for FIG. 3. The cross-sectional views of FIGS. 21 to 25, which will be described later, are also defined in the same manner as for FIG. 4.

[0011] 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, and a fan 8. 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 motor housing 6 has a thin portion U10 and a thick portion A10 that is thicker than the thin portion U10. The thick portion A10 includes a ventilation passage V1 that extends axially (in the Y-axis direction) and a plurality of openings OP1 that connect the ventilation passage V1 to the outside of the motor housing 6.

[0012] With the above configuration, the motor 1 can be made smaller than when the motor 1 includes a fan housing 9 that covers the motor housing 6 and a ventilation passage V1 extending in the Y-axis direction is provided between the fan housing 9 and the motor housing 6. Furthermore, because a cavity is provided in the thick portion A10 of the motor housing 6 and is used as the ventilation passage V1, the space occupied by the thick portion A10 can be used effectively.

[0013] Although the motor 1 of this embodiment includes a fan housing 9, the fan housing 9 is not an essential component of the motor 1.

[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 first board 54 (see Figure 4), a board housing 71, a second board 72, a support base 73, a side cover 74, a first terminal block 75, a second terminal block 76, 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 74. 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] 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.

[0033] As described above, the outer peripheral surface of the side portion 62 has a square (quadrilateral) shape. Therefore, as shown in FIG. 3 , the shape of the motor housing 6 in a cross section perpendicular to the axial direction (Y-axis direction) is a quadrangle with four corners. Furthermore, the center of the inner peripheral surface of the side portion 62 coincides with the center of the outer peripheral surface of the side portion 62. Therefore, the thickness of the motor housing 6 is greater at each of the four corners. In other words, the thickness of the motor housing 6 is greater at and near the four vertices.

[0034] As shown in Figure 3, each of the four corners of the motor housing 6 is a thick portion A10. A portion of the motor housing 6 between two adjacent corners is a thin portion U10. The motor housing 6 has four thick portions A10 and four thin portions U10.

[0035] The thickness W1 of the thick portion A10 is greater than the thickness W2 of the thin portion U10. Here, the thickness W1 of the thick portion A10 is the distance between the outer peripheral surface 602 and the inner peripheral surface 603 of the motor housing 6 at the corner. The thickness W1 of the thick portion A10 is the thickness of a region including a hollow portion (ventilation passage V1) provided in the thick portion A10. The thickness W2 of the thin portion U10 is the distance between the outer peripheral surface 602 and the inner peripheral surface 603 of the motor housing 6 between two adjacent corners.

[0036] The motor housing 6 has four ventilation passages V1. The four ventilation passages V1 correspond one-to-one to the four thick-walled portions A10. Each ventilation passage V1 is provided in the corresponding thick-walled portion A10. Each ventilation passage V1 penetrates the corresponding thick-walled portion A10 in the axial direction (Y-axis direction).

[0037] In the following, the rear and upper ventilation passage V1 of the motor housing 6 will be referred to as ventilation passage V11, the front and upper ventilation passage V1 will be referred to as ventilation passage V12, the rear and lower ventilation passage V1 will be referred to as ventilation passage V13, and the front and lower ventilation passage V1 will be referred to as ventilation passage V14.

[0038] The spatial shape of the ventilation passage V1 is a cylinder centered on an axis along the Y axis. The ventilation passage V1 has an intake port V21 (opening) at its left end and an exhaust port V22 (opening) at its right end. The ventilation passage V1 is a space extending in the Y axis direction from the intake port V21 to the exhaust port V22.

[0039] The motor housing 6 also has a plurality of openings OP1 provided in each thick-walled portion A10. Each opening OP1 corresponds to one of the four ventilation passages V1. Each opening OP1 is connected to the corresponding ventilation passage V1. More specifically, one ventilation passage V1 corresponds to two or more openings OP1 (five in FIG. 2 ). Each ventilation passage V1 is connected to the outside of the motor housing 6 through two or more openings OP1 (five in FIG. 2 ).

[0040] In a cross section perpendicular to the axial direction (Y-axis direction), the opening OP1 is provided on a straight line connecting the center 601 (see FIG. 3 ) of the motor housing 6 and the apex of the corner. The opening OP1 penetrates along this straight line.

[0041] 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.

[0042] 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.

[0043] The motor housing 6 further includes four mounting portions 63 (only two are shown in FIG. 4 ). The four mounting portions 63 correspond one-to-one to the four ventilation passages V1. Each mounting portion 63 faces the exhaust port V22 of the corresponding ventilation passage V1. The mounting portions 63 are spaced apart in the Y-axis direction from the exhaust port V22. The mounting portions 63 have mounting holes 630 for mounting the motor housing 6 to a predetermined member. Mounting members such as bolts are passed through the mounting holes 630. Note that line IV-IV in FIG. 3 passes through the center of the mounting holes 630.

[0044] (6) Side Cover As shown in Fig. 4, the side cover 74 is attached to the motor housing 6. More specifically, the side cover 74 is attached to the motor housing 6 using, for example, a plurality of bolts.

[0045] The side cover 74 covers the left end of the side portion 62 of the motor housing 6 .

[0046] In the space surrounded by the side cover 74 and the motor housing 6, the motor main body MB1, the first bearing 52, and the second bearing 53 are arranged.

[0047] The side cover 74 has four through holes 741. The four through holes 741 correspond one-to-one to the four ventilation passages V1 of the motor housing 6. Each through hole 741 faces the intake port V21 of the corresponding ventilation passage V1.

[0048] The side cover 74 further has a through hole 742 through which the drive shaft 51 passes.

[0049] (7) First Board As shown in FIG. 4, the first board 54 is accommodated in the motor housing 6. The first board 54 includes, for example, a rotary encoder that detects the rotation of the rotor 3.

[0050] 1, 2, and 4, the substrate housing 71 is a hollow rectangular parallelepiped with an opening at the right end. The substrate housing 71 accommodates the second substrate 72 and the support base 73.

[0051] The board housing 71 covers the left side surface of the side cover 74. The board housing 71 is attached to the side cover 74. The board housing 71 is attached to the side cover 74 using, for example, a plurality of bolts.

[0052] The board housing 71 has four through holes 711. The four through holes 711 correspond one-to-one to the four ventilation passages V1 of the motor housing 6. Each through hole 711 faces the intake port V21 of the corresponding ventilation passage V1.

[0053] The board housing 71 further has a through-hole 712 through which the drive shaft 51 passes.

[0054] (9) Second Board and Support Base The second board 72 is attached to the support base 73. The second board 72 includes, for example, an amplifier that drives the motor main body MB1.

[0055] The second substrate 72 and the support base 73 are housed in a substrate housing 71 .

[0056] (10) First Terminal Block and Second Terminal Block The first terminal block 75 is fixed to the board housing 71. A first electric wire 77, which is electrically connected to the second board 72, is electrically and mechanically connected to the first terminal block 75.

[0057] The second terminal block 76 is fixed to the motor housing 6. A second electric wire 78 for supplying electricity to the plurality of coils 42 of the stator 4 is electrically and mechanically connected to the second terminal block 76.

[0058] (11) Fan As shown in FIG. 2 , the fan 8 includes a fan base 81 , a shaft support 82 , and a plurality of blades 83 .

[0059] 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.

[0060] 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.

[0061] 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.

[0062] The fan 8 rotates in accordance with the rotation of the drive shaft 51, generating airflow to the right.

[0063] (12) Fan Housing The fan housing 9 contains resin as a material. The fan housing 9 has a hollow rectangular parallelepiped shape with an opening at the right end. The fan housing 9 covers the fan 8 and also houses the fan 8.

[0064] As shown in FIG. 2 , the fan housing 9 includes a bottom wall 91 and a side wall 92 .

[0065] 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 peripheral surface of the side wall 92 has a rectangular shape. When viewed from the Y axis direction, the inner peripheral surface of the side wall 92 has a rectangular shape.

[0066] The side wall 92 extends from the bottom wall 91 in the axial direction (Y-axis direction) and faces the motor housing 6 in the axial direction (Y-axis direction).

[0067] 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.

[0068] The fan housing 9 has a space SP1 inside. The space SP1 is connected to the four ventilation passages V1. The space SP1 faces the four ventilation passages V1 in the Y-axis direction. When viewed from the Y-axis direction, the space SP1 is larger than each of the ventilation passages V1. Furthermore, when viewed from the Y-axis direction, the space SP1 is larger than the sum of the areas of the ventilation passages V1.

[0069] The fan housing 9 covers the left side surface of the board housing 71. The fan housing 9 is attached to the board housing 71. More specifically, the fan housing 9 is attached to the board housing 71 using, for example, a plurality of bolts.

[0070] 4, the space SP1 inside the fan housing 9 (i.e., the space in which the fan 8 is disposed) is connected to the ventilation passage V1 of the motor housing 6. More specifically, the space SP1 inside the fan housing 9 is connected to the ventilation passage V1 of the motor housing 6 via the through-hole 711 of the board housing 71 and the through-hole 741 of the side cover 74.

[0071] The board housing 71 is disposed to the left of the motor housing 6. The fan housing 9 is disposed to the left of the board housing 71. The side wall 92 of the fan housing 9, the board housing 71 (intermediate member), and the motor housing 6 are aligned in the axial direction (Y-axis direction), and the board housing 71 (intermediate member) is interposed between the side wall 92 and the motor housing 6 in the axial direction (Y-axis direction). In other words, the fan housing 9 is attached to the motor housing 6 via the board housing 71 (intermediate member).

[0072] (13) Air-Cooling of the Motor Body When the fan 8 rotates, air is generated inside the fan housing 9 to the right. 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 V22 (opening).

[0073] 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 motor housing 6 suppresses the temperature rise of the air flowing through the ventilation passage V1. Therefore, the air temperature on the right side of the ventilation passage V1 (near the exhaust port V22) is also suppressed from becoming excessively high. 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 V22).

[0074] 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.

[0075] Figures 5 and 6 are diagrams showing the results of a simulation of air temperature distribution in the motor of Comparative Example 1. Figures 7 and 8 are diagrams showing the results of a simulation of air temperature distribution in the motor of Comparative Example 2. Figures 9 and 10 are diagrams showing the results of a simulation of air temperature distribution in the motor of the Reference Example. In the diagrams showing air temperature distribution in Figures 5 to 10, "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."

[0076] 11 and 12 are diagrams showing the simulation results of the flow velocity distribution of the motor according to Comparative Example 1. FIGS. 13 and 14 are diagrams showing the simulation results of the flow velocity distribution of the motor according to Comparative Example 2. FIGS. 15 and 16 are diagrams showing the simulation results of the flow velocity distribution of the motor according to the Reference Example. In the diagrams showing the flow velocity distribution results of FIGS. 11 to 16, "high" represents a region where the flow velocity is higher than that of the surroundings and than that of "medium," "medium" represents an intermediate temperature region, and "low" represents a region where the flow velocity is lower than that of "medium" and than that of the surroundings.

[0077] The motor of Comparative Example 1 (see Figures 5, 6, 11, and 12) differs from the motor 1 of Basic Example 1 in that it does not have a ventilation passage V1 and does not have a fan 8.

[0078] The motor of Comparative Example 2 (see Figures 7, 8, 13, and 14) differs from the motor 1 of Basic Example 1 in that it does not have a ventilation passage V1 and uses the gap between the fan housing 9b, which extends around the motor housing 6, and the motor housing 6 as a ventilation passage to air-cool the motor main body MB1.

[0079] The motor of the reference example (see Figures 9, 10, 15, and 16) differs from the motor 1 of the basic example 1 in that, when viewed from the Y-axis direction, multiple ventilation passages V1 are provided at each corner of the motor housing 6.

[0080] In the reference example, the temperature rise of the motor body MB1 is suppressed compared to the comparative examples 1 and 2. Furthermore, in the motor 1 of the above-described embodiment 1, the temperature rise of the motor body MB1 can also be suppressed, similar to the reference example.

[0081] The simulation results for the temperature of the coil 42 and the temperature of the rotor core 31 are shown in Table 1.

[0082]

[0083] Furthermore, in the first embodiment and the reference example, unlike the second comparative example, the fan housing 9 does not extend around the motor housing 6, and therefore the motor can be made smaller than in the second comparative example.

[0084] (First Modification of First Embodiment) As in the reference example, a plurality of ventilation passages V1 may be provided at one corner of the motor housing 6 when viewed from the Y-axis direction.

[0085] (Second Modification of First Embodiment) In the above, the 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 V22 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 V22 is greater than the flow velocity of the air from the multiple openings OP1.

[0086] 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).

[0087] (Third Modification of First Embodiment) The shape of the ventilation passage V1 in a cross section perpendicular to the Y axis is not limited to a circular shape. For example, the shape of the ventilation passage V1 in the cross section may be a triangle, as shown in FIG. 17 . FIG. 17 is a cross-sectional view of a motor according to a third modification, viewed from the left. In the example shown in FIG. 17 , one of the three vertices of the triangle, vertex T1, faces vertex T2 at a corner of the motor housing 6. Furthermore, two sides S1 and S2 extending from this vertex are aligned along the outer peripheral surface 602 of the motor housing 6. More specifically, the two sides S1 and S2 are parallel to the outer peripheral surface 602. In the present disclosure, "parallel" is not limited to being 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.

[0088] In the example shown in FIG. 17, the cross-sectional area of ​​the ventilation passage V1 can be made relatively large.

[0089] Furthermore, the shape of the ventilation passage V1 in a cross section perpendicular to the Y axis may be, for example, a square, as shown in Fig. 18. Fig. 18 is a cross-sectional view of a motor 1 according to another modified example, as seen from the left. In the example shown in Fig. 18, the shape of the ventilation passage V1 in the cross section is, more specifically, rectangular.

[0090] (Fourth Modification of First Embodiment) In the first embodiment described above (see FIG. 3 ), the shape of the outer peripheral surface 602 of the motor housing 6 in a cross section perpendicular to the Y axis is rectangular. Furthermore, the four corners of the motor housing 6 in this cross section are curved. In other words, the four corners of the motor housing 6 in this cross section are rounded. However, each corner does not have to be rounded.

[0091] Figure 19 is a cross-sectional view of a motor 1 according to yet another modified example, as viewed from the left. As shown in Figure 19, the shape of the outer peripheral surface 602 of the motor housing 6 in a cross section perpendicular to the Y axis may be octagonal. In the example shown in Figure 19, the shape of the outer peripheral surface 602 is a quadrangle with four chamfered corners.

[0092] Furthermore, N is a natural number equal to or greater than 4. The shape of the outer peripheral surface 602 of the motor housing 6 in a cross section perpendicular to the axial direction (Y-axis direction) may be an N-sided polygon having N corners. Furthermore, the thick-walled portion A10 (the portion where the ventilation passage V1 is provided) may be at least one of the N corners of the motor housing 6.

[0093] Second Embodiment A motor 1A according to a second embodiment will be described below with reference to Fig. 20. Components similar to those in the first embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0094] Fig. 20 is a perspective view of a motor 1A according to the second embodiment. As shown in Fig. 20, a plurality of openings OP1 are arranged in a direction perpendicular to the Y axis. In Fig. 20, a plurality (three) of opening groups G1, each of which is made up of two or more (four) openings OP1 whose longitudinal direction is along the Y axis, are provided in each thick portion A10. The plurality of opening groups G1 are arranged along the Y axis direction.

[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 motor 1B according to embodiment 3. The same components as those in embodiment 1 are denoted by the same reference numerals, and description 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 (outside) farther from the center 601 of the motor housing 6 (the central axis along the Y axis) than on the side (inside) closer to the center 601. In other words, the opening OP1 is tapered such that the opening area on the outside of the motor housing 6 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 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 is 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 is 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 motor housing 6. 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. The same components as those in embodiment 3 are denoted by the same reference numerals, and description 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 or V12 will also be referred to as a first opening OP11. Also, each of the openings OP1 connected to the ventilation passage V13 or V14 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 first region is a region including an upper, front corner of the motor housing 6 and a region including an upper, rear corner. The second region is a region including a lower, front corner of the motor housing 6 and a region including a lower, rear corner. In other words, the first region is provided on one side (upper side) in a predetermined direction (Z-axis direction) perpendicular to the axial direction (Y-axis direction), and the second region is provided on the other side (lower side) in the predetermined direction. In other words, the first region and the second region face each other in a direction perpendicular to the Y-axis direction.

[0103] 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 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.

[0104] In this embodiment, the number of the multiple first openings OP11 is different from the number of the multiple second openings OP12, thereby creating a difference between the aperture ratio of the multiple first openings OP11 and the aperture ratio of the multiple 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 passages V11 and V12 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 passages V13, V14 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 V22, enhancing the heat dissipation effect. In other words, priority is given to making it easier for air to flow to the exhaust port V22 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. The same components as those in the third embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[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 channels V11 and V12 is also referred to as a first opening OP11. Also, each of the openings OP1 connected to the ventilation channels V13 and V14 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. 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, the region of the motor housing 6 that is relatively close to the fan 8 will be referred to as the third region, the region that is 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 V22 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 to the left 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 to the left, and the amount of heat dissipated from the intake port V21 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 a motor 1F according to the seventh embodiment. The same components as those in the third embodiment are denoted by the same reference numerals, and the description 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] The board housing 71 is not an essential component. Therefore, the space SP1 in which the fan 8 is disposed may be connected to the ventilation passage V1 of the motor housing 6 without going through the through-hole 711 of the board housing 71.

[0131] The side cover 74 is not an essential component. Therefore, the space SP1 in which the fan 8 is disposed may be connected to the ventilation passage V1 of the motor housing 6 without going through the through-hole 741 of the side cover 74.

[0132] (Summary) The above-described embodiments and the like disclose the following aspects.

[0133] A motor (1; 1A-1F) according to a first aspect includes a motor body (MB1), a motor housing (6), a drive shaft (51), and a fan (8). 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 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 motor housing (6) has a thin-walled portion (U10) and a thick-walled portion (A10) that is thicker than the thin-walled portion (U10). The thick-walled portion (A10) includes an air passage (V1) extending axially and a plurality of openings (OP1) connecting the air passage (V1) to the outside of the motor housing (6).

[0134] According to the above configuration, the motor (1; 1A-1F) can be made smaller than when the motor (1; 1A-1F) is provided with a fan housing (9) that covers the motor housing (6) and an air passage extending in the axial direction is provided between the fan housing (9) and the motor housing (6). In addition, since a cavity is provided in the thick portion (A10) of the motor housing (6) and used as the air passage (V1), the space occupied by the thick portion (A10) can be effectively utilized.

[0135] In the motor (1; 1A to 1F) according to the second aspect, the outer peripheral surface (602) of the motor housing (6) in a cross section perpendicular to the axial direction has an N-sided polygonal shape having N corners, where N is a natural number equal to or greater than 4. The thick-walled portion (A10) is at least one of the N corners of the motor housing (6).

[0136] According to the above configuration, the size of the motor housing (6) can be prevented from increasing compared to when the thick-walled portion (A10) is provided at a location other than the corner portion.

[0137] In addition, in the motor (1; 1A to 1F) according to the third aspect, in the second aspect, the shape of the outer surface (602) of the motor housing (6) in a cross section perpendicular to the axial direction is rectangular or octagonal.

[0138] According to the above configuration, a motor housing (6) that is easy to use can be provided.

[0139] In a motor (1C; 1D) according to a fourth aspect, in any one of the first to third aspects, the motor housing (6) 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).

[0140] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0141] In addition, in the motor (1C; 1D) according to the fifth aspect, in the fourth aspect, a first region is provided on one side of a predetermined direction perpendicular to the axial direction, and a second region is provided on the other side of the predetermined direction.

[0142] 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).

[0143] In addition, in the motor (1D) according to the sixth aspect, in the fourth or fifth 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).

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

[0145] In addition, in the motor (1C) according to the seventh aspect, in any one of the fourth to sixth aspects, the number of the plurality of first openings (OP11) is different from the number of the plurality of second openings (OP12).

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

[0147] In a motor (1E; 1F) according to an eighth aspect, in any one of the first to seventh aspects, the motor housing (6) 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).

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

[0149] In addition, in the motor (1F) according to the ninth aspect, in the eighth aspect, 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).

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

[0151] In addition, in the motor (1E) relating to the 10th aspect, in the 8th or 9th 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).

[0152] According to the above configuration, the cooling effect of the motor main body (MB1) can be improved.

[0153] In addition, in the motor (1B to 1F) according to the eleventh aspect, in any one of the first to tenth aspects, the shape of at least one of the openings (OP1) is tapered, with the opening area being larger on the side farther from the center of the motor housing (6) than on the side closer to the center of the motor housing (6).

[0154] 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).

[0155] In addition, in the motor (1; 1A to 1F) according to the twelfth aspect, in any one of the first to eleventh aspects, the external shape of each of the multiple openings (OP1) is circular, elliptical, or polygonal.

[0156] According to the above configuration, the opening area of ​​the opening (OP1) can be easily increased.

[0157] In addition, in the motor (1; 1A to 1F) according to a thirteenth aspect, in any one of the first to twelfth aspects, the motor housing (6) contains metal as a material.

[0158] According to the above configuration, the thermal conductivity of the motor housing (6) can be increased, and the heat dissipation efficiency can be improved.

[0159] A motor (1; 1A to 1F) according to a fourteenth aspect is any one of the first to thirteenth aspects, further comprising a fan housing (9) covering the fan (8). The fan housing (9) has a bottom wall (91) and a side wall (92) extending axially from the bottom wall (91) and facing the motor housing (6) in the axial direction.

[0160] According to the above configuration, the fan (8) can be protected.

[0161] The motor (1; 1A to 1F) according to a fifteenth aspect is the motor (1; 1A to 1F) of the fourteenth aspect, further including an intermediate member (board housing 71). The side wall (92) of the fan housing (9), the intermediate member (board housing 71), and the motor housing (6) are aligned in the axial direction, and the intermediate member (board housing 71) is interposed between the side wall (92) and the motor housing (6) in the axial direction.

[0162] According to the above configuration, the fan housing (9) can be attached to the motor housing (6) via the intermediate member (substrate housing 71).

[0163] In addition, in the motor (1; 1A to 1F) according to the sixteenth aspect, in the fourteenth or fifteenth aspect, the fan housing (9) contains resin as a material.

[0164] According to the above configuration, the weight of the fan housing (9) can be reduced.

[0165] 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.

[0166] The motor of the present disclosure has the advantage that the motor body can be cooled by blowing air while the motor can be made smaller. In this way, the motor of the present disclosure is industrially useful.

[0167] 1; 1A to 1F Motor 3 Rotor 4 Stator 6 Motor housing 8 Fan 9 Fan housing 51 Drive shaft 71 Base housing (intermediate member) 91 Bottom wall 92 Side wall 602 Outer circumferential surface A10 Thick portion L3 to L5 Distance MB1 Motor body OP1 Opening OP11 First opening OP12 Second opening OP13 Third opening OP14 Fourth opening OP15 Fifth opening U10 Thin portion V1 Ventilation path

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; and a fan disposed outside the motor housing and attached to the drive shaft, wherein the motor housing has a thin portion and a thick portion that is thicker than the thin portion, and the thick portion includes an air passage extending in the axial direction and a plurality of openings connecting the air passage to the outside of the motor housing.

2. The motor according to claim 1, wherein N is a natural number equal to or greater than 4, the shape of the outer peripheral surface of the motor housing in a cross section perpendicular to the axial direction is an N-sided polygon having N corners, and the thick-walled portion is at least one of the N corners of the motor housing.

3. The motor according to claim 2, wherein the shape of the outer peripheral surface of the motor housing in the cross section perpendicular to the axial direction is a square or octagon.

4. The motor according to claim 1, wherein the motor 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.

5. The motor according to claim 4, wherein the first region is provided on one side in a predetermined direction perpendicular to the axial direction, and the second region is provided on the other side in the predetermined direction.

6. The motor according to claim 4, 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.

7. The motor according to claim 4, wherein the number of the plurality of first openings is different from the number of the plurality of second openings.

8. The motor described in claim 1, wherein the motor 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.

9. The motor according to claim 8, 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.

10. The motor according to claim 8, 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.

11. 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 center of the motor housing than on the side closer to the center of the motor housing.

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

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

14. The motor according to claim 1, further comprising a fan housing that encases the fan, the fan housing having a bottom wall and a side wall that extends from the bottom wall in the axial direction and faces the motor housing in the axial direction.

15. The motor according to claim 14, further comprising an intermediate member, wherein the side wall of the fan housing, the intermediate member, and the motor housing are aligned in the axial direction, and the intermediate member is interposed between the side wall and the motor housing in the axial direction.

16. The motor according to claim 14, wherein the fan housing includes a resin as a material.

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