Filter device and electric motor

Abstract

A filter device (31) comprises a first filtration member (41) having: a plurality of first front surface parts (42); a plurality of first back surface parts (43); and a plurality of first side-surface parts (44). Main surfaces (42a) of the respective first front surface parts (42) intersect the inflow direction of outside air. The first front surface parts (42) are positioned with first gaps (45) sandwiched therebetween. Main surfaces (43a) of the respective first back surface parts (43) each face a corresponding one of the first gaps (45) between two of the first front surface parts (42) adjacent to each other. The first back surface parts (43) are, with intervals therebetween, positioned downstream of the first front surface parts (42). The first side-surface parts (44) connect the first front surface parts (42) and the first back surface parts (43). The interval between the two first side surface parts (44) connected to the same first back surface part (43) on the downstream side in the inflow direction is equal to or greater than that on the upstream side in the inflow direction, and the total surface area of the first side-surface parts (44) is larger than the total surface area of the first front surface parts (42) and the total surface area of the first back surface parts (43).

Description

[Technical Field]

[0001] The present disclosure relates to a filter device and an electric motor. [Background technology]

[0002] Some on-board equipment for railway vehicles uses outside air flowing in through an air intake to cool the interior, specifically electronic components that are installed inside and generate heat when powered on. The on-board equipment is equipped with a filter installed outside the air intake to prevent the electronic components from breaking down due to contact with foreign matter such as dust and moisture contained in the outside air. This type of on-board equipment is disclosed in Patent Document 1.

[0003] The air compressor for a railway vehicle disclosed in Patent Document 1 uses the rotation of a cooling fan to draw outside air into the housing case as cooled air that has filtered through the filter part of the filter unit. The filter part has an uneven shape with alternating convex parts facing outward and concave parts facing inward of the housing case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-153534 Summary of the Invention [Problem to be solved by the invention]

[0005] The filter unit included in the railcar air compressor disclosed in Patent Document 1 has a continuous V-shaped concave and convex shape in horizontal cross section. The plate-shaped filter material forming the V-shape is oriented intersecting the direction of outside air inflow. As the filter unit is used for a long time, foreign matter may adhere to the edges of the ventilation holes in the plate-shaped filter material oriented intersecting the inflow direction, causing the ventilation holes to become clogged. When the ventilation holes become clogged due to aging, the air flow path through the filter unit decreases, causing a sudden decrease in the flow rate of the filter unit and a sudden decline in the cooling performance of the railcar air compressor.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a filter device that can suppress a sudden decrease in flow rate due to aging, and an electric motor that includes the filter device. [Means for solving the problem]

[0007] To achieve the above object, the present disclosure provides a filter device that is attached to on-board equipment of a railway vehicle that cools the interior with outside air taken in through an air intake, covering the air intake from the outside. The filter device removes foreign matter from the incoming outside air and guides the removed outside air to the air intake, and includes a first filtering member having a plurality of first front surfaces, a plurality of first rear surfaces, and a plurality of first side surfaces. The main surfaces of each of the first front surfaces intersect with the direction in which the outside air flows in. Adjacent first front surfaces are positioned with a first gap between them. The main surfaces of each of the first rear surfaces face the first gap between two adjacent first front surfaces. The multiple first rear surfaces are positioned downstream of the first front surfaces in the air intake direction, spaced apart from each other. The first side surfaces connect the first rear surfaces to each of the two first front surfaces that are positioned across the first gap toward which the main surfaces of the first rear surfaces face. The distance between two first side sections connected to the same first rear section is such that the length downstream in the inflow direction is longer than the length upstream in the inflow direction. Greater than The sum of the surface areas of the first side portions is greater than the sum of the surface areas of the first front portion and the first rear portion. [Effects of the Invention]

[0008] The filter device of the present disclosure includes a first filtering member having a plurality of first front face portions whose main surfaces intersect with the inflow direction, a plurality of first rear face portions whose main surfaces face first gaps between the first front face portions, and a plurality of first side face portions connecting the first rear face portions to each of the two first front face portions located on either side of the first gaps to which the main faces of the first rear face portions face. The distance between the two first side face portions connected to the same first rear face portion is such that the length downstream in the inflow direction is equal to or greater than the length upstream in the inflow direction, and the total surface area of ​​the first side face portions is greater than the total surface area of ​​the first front face portions and the first rear face portions. This configuration makes it difficult for foreign matter to clog the first side face portions, resulting in a filter device that suppresses a sudden decrease in flow rate due to aging. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of an electric motor according to a first embodiment; [Figure 2] 1 is a cross-sectional view of an electric motor according to a first embodiment; [Figure 3] 3 is a cross-sectional view of the electric motor according to the first embodiment taken along line III-III in FIG. 2; [Figure 4] 1 is a side view of an electric motor according to a first embodiment; [Figure 5] 5 is a cross-sectional view of the filter device according to the first embodiment taken along line VV in FIG. 4. [Figure 6] 6 is a cross-sectional view of the filter device according to the first embodiment taken along line VI-VI in FIG. 4. [Figure 7] 10 is a cross-sectional view of a filter device according to a second embodiment. [Figure 8] 10 is a cross-sectional view of a filter device according to a second embodiment. [Figure 9] 1 is a cross-sectional view of a first modified example of a filter device according to an embodiment; [Figure 10] 10 is a cross-sectional view of a second modified example of the filter device according to the embodiment; [Figure 11] 10 is a side view of an electric motor including a third modified example of a filter device according to an embodiment. [Figure 12] 10 is a side view of an electric motor provided with a fourth modified example of a filter device according to an embodiment. [Figure 13]10 is a side view of an electric motor including a fifth modified example of a filter device according to an embodiment. [Figure 14] 10 is a cross-sectional view of a sixth modified example of the filter device according to the embodiment; [Figure 15] 13 is a front view of a power conversion device including a seventh modified example of a filter device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a filter device and an electric motor according to an embodiment of the present disclosure will be described in detail with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0011] (Embodiment 1) A filter device and a motor equipped with a filter device according to a first embodiment will be described using an electric motor, which is a type of on-board equipment for a railway vehicle, as an example. The electric motor 1 shown in FIGS. 1 and 2 is an open-type electric motor for driving a railway vehicle. The electric motor 1 is attached to the underfloor of the railway vehicle by means of a mounting member (not shown). The electric motor 1 takes in outside air, which is air outside the electric motor 1, and cools the components of the electric motor 1 by flowing the air inside the electric motor 1. The electric motor 1 is equipped with a filter device 31 to prevent foreign matter such as dust and moisture contained in the outside air from entering the inside.

[0012] In Figures 1 and 2, the Z-axis direction indicates the vertical direction when the railway vehicle is positioned horizontally. The Y-axis direction indicates the width direction of the railway vehicle. The X-axis direction indicates the direction of travel of the railway vehicle. In other words, the railway vehicle travels in the positive X-axis direction or the negative X-axis direction. The X-axis, Y-axis, and Z-axis are perpendicular to each other. This also applies to subsequent figures.

[0013] 1 and 2, a rotor 15 located radially outward of shaft 14 and rotating integrally with shaft 14, a stator 16 facing rotor 15 at a distance in the radial direction, bearings 17 and 18 that rotatably support shaft 14, and a fan 19 attached to shaft 14 and rotating integrally with shaft 14. The radial direction is a direction perpendicular to rotation axis AX.

[0014] The electric motor 1 further includes a frame 11 that houses the rotor 15, the stator 16, the bearings 17, 18, and the fan 19 with the shaft 14 inserted therethrough; a first bracket 12 that has an intake hole 12a formed in an end face that intersects with the extension direction of the rotation axis AX; a second bracket 13 that faces the first bracket 12 in the extension direction of the rotation axis AX across the rotor 15 and the stator 16 and that has an exhaust hole 13a formed in its outer peripheral surface; and a filter device 31 attached to the first bracket 12.

[0015] In the electric motor 1 having the above configuration, the rotation of the fan 19 causes outside air to flow into the interior of the electric motor 1 through the intake holes 12a formed in the first bracket 12. As shown by the solid arrows in Figure 2, the outside air flows through the gap 20 between the rotor 15 and the stator 16, and then flows out of the electric motor 1 through the exhaust holes 13a formed in the second bracket 13. The above-mentioned flow of outside air cools the components of the electric motor 1, specifically the rotor 15, the stator 16, and the bearings 17 and 18.

[0016] The details of each part of the electric motor 1 will be described. The frame 11 is fixed to the underfloor of the railway vehicle by mounting members. The frame 11 has a cylindrical shape with both ends open. The openings at both ends of the frame 11 are closed by a first bracket 12 and a second bracket 13.

[0017] First bracket 12 is attached to one end of frame 11, specifically the end on the Y-axis negative side. As shown in Fig. 3, which is a cross-sectional view taken along line III-III in Fig. 2, first bracket 12 is formed with air intake hole 12a for letting in outside air. Air intake hole 12a is preferably formed in a flow path for outside air inside electric motor 1, specifically at a position facing air gap 20.

[0018] 1 and 2, second bracket 13 faces first bracket 12 in the Y-axis direction, with rotor 15 and stator 16 sandwiched between them. Second bracket 13 is attached to the other end of frame 11, specifically the end on the Y-axis positive side. Exhaust holes 13a are formed in the outer peripheral surface of second bracket 13, through which outside air that has flowed in through intake holes 12a flows out to the outside.

[0019] One end of the shaft 14 close to the second bracket 13 is connected to an axle of the railway vehicle via a joint and a gear (not shown). The rotation of the shaft 14 provides power to the railway vehicle.

[0020] The rotor 15 has a rotor core 15a attached to the shaft 14, and rotor bars 15b inserted into slots formed in the outer circumferential surface of the rotor core 15a.

[0021] The stator 16 has a stator core 16a attached to the inner circumferential surface of the frame 11 and stator coils 16b inserted into slots formed in the stator core 16a. The stator core 16a faces the rotor core 15a with a gap therebetween in the radial direction.

[0022] The bearing 17 is held by the first bracket 12 and rotatably supports the shaft 14. The bearing 18 is held by the second bracket 13 and rotatably supports the shaft 14.

[0023] Fan 19 is attached to shaft 14 between stator 16 and second bracket 13 and rotates integrally with shaft 14. As shaft 14 rotates, air outside motor 1 flows into motor 1 through intake holes 12a, and the outside air that has flowed in flows out through exhaust holes 13a.

[0024] 4, which is a view of electric motor 1 viewed in the positive direction of the Y-axis, filter device 31 is attached to first bracket 12 in a state where it covers intake holes 12a formed in first bracket 12. In the first embodiment, filter device 31 is attached to first bracket 12 by fastening with fastening members.

[0025] Filter device 31 removes foreign matter from the outside air that flows in, and guides the outside air from which the foreign matter has been removed to air intake port 12a. As a result, the outside air from which the foreign matter has been removed by filter device 31 flows into the interior of electric motor 1 through air intake port 12a. In the first embodiment, the outside air flows in along the positive direction of the Y axis. Filter device 31 removes foreign matter from the outside air that flows in in the positive direction of the Y axis, and guides the outside air from which the foreign matter has been removed to air intake port 12a located on the positive side of filter device 31 in the Y axis direction.

[0026] The filter device 31 has a fixed frame 40 fixed to the first bracket 12, and a first filter member 41 attached to the fixed frame 40 and configured to prevent foreign matter contained in the outside air from flowing into the interior of the electric motor 1. In the first embodiment, the fixed frame 40 and the first filter member 41 have the shape of a partial ring extending in the circumferential direction around the rotation axis AX.

[0027] As shown in FIG. 4 and FIG. 5, which is a cross-sectional view taken along line VV in FIG. 4, the first filtering member 41 has a concave-convex shape extending in a radial direction perpendicular to the rotation axis AX. Specifically, as shown in FIG. 5, the first filtering member 41 includes a plurality of first front surface portions 42 whose main surfaces 42a intersect with the inflow direction of outside air, i.e., the positive direction of the Y axis. Adjacent first front surface portions 42 are positioned with a first gap 45 sandwiched between them. The first filtering member 41 includes a plurality of first back surface portions 43 whose main surfaces 43a face the first gap 45 between adjacent first front surface portions 42 and are spaced apart downstream of the first front surface portions 42 in the inflow direction, and a plurality of first side surface portions 44 connecting the first back surface portion 43 to each of the two first front surface portions 42 positioned with the first gap 45 sandwiched between them, toward which the main surfaces 43a of the first back surface portions 43 face.

[0028] In the first embodiment, the first filter member 41 includes a plurality of first front portions 42 whose main surfaces 42a are perpendicular to the Y-axis direction, and a plurality of first back portions 43 whose main surfaces 43a are perpendicular to the Y-axis direction.

[0029] 4, the first front surface portions 42 are spaced apart in the circumferential direction around the rotation axis AX. In the first embodiment, each first front surface portion 42 extends in the radial direction and the circumferential direction perpendicular to the rotation axis AX.

[0030] The first back portions 43 are spaced apart in the circumferential direction around the rotation axis AX. In the first embodiment, each first back portion 43 extends in the radial direction and the circumferential direction perpendicular to the rotation axis AX.

[0031] Each first side surface portion 44 smoothly connects the first front surface portion 42 and the first rear surface portion 43. In the first embodiment, each first side surface portion 44 has a main portion extending in the extension direction of the rotation axis AX and in the radial direction, and an end portion connecting the main portion to the first front surface portion 42 or the first rear surface portion 43.

[0032] The distance between two first side surface portions 44 connected to the same first back surface portion 43 is such that the length W11 downstream in the inflow direction is equal to or greater than the length W12 upstream in the inflow direction. Specifically, the circumferential length W11 of the gap between two circumferentially adjacent first side surface portions 44 downstream in the inflow direction is equal to or greater than the circumferential length W12 of the gap between two circumferentially adjacent first side surface portions 44 upstream in the inflow direction. In other words, the angle formed between the flat portion of the main surface 42a of the first front surface portion 42 and the flat portion of the main surface 44a of the first side surface portion 44 is equal to or greater than 90 degrees. In the first embodiment, the length W11 downstream in the inflow direction is equal to the length W12 upstream in the inflow direction. Therefore, the first side surface portion 44 is provided with the main surface 44a oriented along the inflow direction.

[0033] The total surface area of ​​the first side portion 44 is greater than the total surface area of ​​the first front portion 42 and the first back portion 43. Specifically, the total surface area of ​​the main surface 44a of the first side portion 44 is greater than the total surface area of ​​the main surface 42a of the first front portion 42 and the main surface 43a of the first back portion 43.

[0034] The main surface 42a of the first front surface portion 42, the main surface 43a of the first rear surface portion 43, and the main surface 44a of the first side surface portion 44 shown in FIG. 5 are each the surface on the upstream side of the outside air passing through the filter device 31. As an example, the main surface 42a of the first front surface portion 42 is the surface on the negative Y-axis direction side of the first front surface portion 42. Similarly, the main surface 43a of the first rear surface portion 43 is the surface on the negative Y-axis direction side of the first rear surface portion 43. The main surface 44a of the first side surface portion 44 located at the right end in FIG. 5 is the surface on the positive X-axis direction side of the first side surface portion 44. The main surface 44a of the first side surface portion 44 located at the left end in FIG. 5 is the surface on the negative X-axis direction side of the first side surface portion 44.

[0035] In the first embodiment, the first filtering member 41 is formed by repeatedly bending a mesh-like first metal member into a U-shape while alternating the folding direction to form a bellows shape. The first metal member is made of, for example, stainless steel. Specifically, the first filtering member 41 is formed by repeatedly bending a stainless steel mesh into a U-shape.

[0036] The first filtering member 41, which has been repeatedly bent into a U-shape, is then bent into an arc shape so that the bending lines formed when bending into a U-shape coincide with the radial direction, and attached to the inner surface of the fixing frame 40, thereby obtaining the filter device 31. Protrusions are formed on the inner surface of the fixing frame 40, and the mesh of the first filtering member 41 is engaged with the protrusions. As a result, the first filtering member 41 is attached to the fixing frame 40.

[0037] By forming the first filter member 41 from a mesh-like first metal member, ventilation holes 42b, 43b, and 44b are formed in the first front portion 42, the first back portion 43, and the first side portion 44, respectively, as shown in Figure 6, which is a cross-sectional view taken along line VI-VI in Figure 4.

[0038] As shown by the solid arrows in Figure 6, outside air passes through one of the ventilation holes 42b, 43b, or 44b, passes through the filter device 31, and then flows into the interior of the motor 1 through the intake hole 12a as shown in Figure 2, passes through the gap 20, and then flows out to the outside through the exhaust hole 13a.

[0039] As the filter is used for a long time, foreign matter may become clogged in the ventilation holes through which outside air passes. In the filter device 31, the main surface 42a of the first front portion 42 and the main surface 43a of the first rear portion 43 are positioned perpendicular to the inflow direction, and the first side portion 44 is provided with the main surface 44a oriented along the inflow direction. More outside air flows through the ventilation holes 42b formed in the main surface 42a of the first front portion 42, which are perpendicular to the inflow direction of outside air, and the ventilation holes 43b formed in the main surface 43a of the first rear portion 43. Therefore, as the filter device 31 is used for a long time, foreign matter is less likely to become clogged in the ventilation holes 44b formed in the first side portion 44, whose main surface 44a is oriented along the inflow direction, compared to the ventilation holes 42b formed in the first front portion 42 and the ventilation holes 43b formed in the first rear portion 43.

[0040] As described above, the filter device 31 according to the first embodiment includes a first filtering member 41 having a plurality of first front surfaces 42, a plurality of first rear surfaces 43, and a plurality of first side surfaces 44 connecting the first rear surfaces 43 to each of the two first front surfaces 42 positioned on either side of a first gap 45 toward which the main surfaces of the first rear surfaces 43 face. The distance between the two first side surfaces 44 connected to the same first rear surface 43 is such that the length downstream in the inflow direction is equal to or greater than the length upstream in the inflow direction, and the total surface area of ​​the first side surfaces 44 is greater than the total surface area of ​​the first front surfaces 42 and the first rear surfaces 43.

[0041] The distance between two first side portions 44 connected to the same first rear portion 43 is such that the length downstream in the inflow direction is equal to or greater than the length upstream in the inflow direction, and the total surface area of ​​the first side portions 44, which are less likely to become clogged with foreign matter, is greater than the total surface area of ​​the first front portion 42 and the first rear portion 43. This makes the filter device 31 less likely to become clogged with foreign matter than a filter with a continuous V-shaped uneven shape. This results in a filter device 31 in which a sudden decrease in flow rate due to aging is suppressed. As a result, a motor 1 in which a sudden decrease in cooling performance due to aging is suppressed is obtained.

[0042] As described above, foreign matter is less likely to clog the first side surface portion 44, and a sudden decrease in flow rate due to aging is suppressed, so the period from when the filter device 31 starts to be used until the filter device 31 needs to be cleaned to remove foreign matter is extended. As a result, the maintenance cycle of the filter device 31 is extended, and maintainability is improved.

[0043] Since the first front surface portion 42, the first back surface portion 43, and the first side surface portion 44 form an uneven shape, the surface area of ​​the first filter member 41 is larger than that of a flat filter member, and the total area of ​​the ventilation holes is therefore larger, resulting in a larger flow rate.

[0044] (Embodiment 2) The configuration of the filter device is not limited to the above example. A filter device including multiple filter members will be described in Embodiment 2, focusing on differences from Embodiment 1. Filter device 32 shown in FIG. 7 includes a second filter member 51 in addition to the configuration of filter device 31 according to Embodiment 1. Filter device 32 removes foreign matter from the incoming outside air using first filter member 41 and second filter member 51, and guides the outside air from which the foreign matter has been removed to air intake hole 12a. As with Embodiment 1, the positive direction of the Y axis is the direction in which outside air flows in.

[0045] Similar to the first filtering member 41, the second filtering member 51 has an uneven shape extending in a radial direction perpendicular to the rotation axis AX. Specifically, the second filtering member 51 includes a plurality of second front surface portions 52 whose main surfaces 52a face different first front surface portions 42. Adjacent second front surface portions 52 are positioned with a second gap 55 sandwiched between them. The second filtering member 51 has a plurality of second back surface portions 53 whose main surfaces 53a face the second gap 55 between adjacent second front surface portions 52 and are positioned downstream of the second front surface portions 52 in the inflow direction and spaced apart from each other, and a plurality of second side surface portions 54 connecting the second back surface portions 53 to each of the two second front surface portions 52 positioned with the second gap 55 sandwiched between them, toward which the main surfaces 53a of the second back surface portions 53 face.

[0046] In the second embodiment, the second filtering member 51 includes a plurality of second front portions 52 whose main surfaces 52a are perpendicular to the Y-axis direction, and a plurality of second back portions 53 whose main surfaces 53a are perpendicular to the Y-axis direction.

[0047] The convex portions of the second filtering member 51 are located downstream in the inflow direction of the convex portions of the first filtering member 41. The concave portions of the second filtering member 51 are located downstream in the inflow direction of the concave portions of the first filtering member 41. Specifically, the main surfaces 52a of the second front surface portions 52 face toward different first front surface portions 42, and the main surfaces 53a of the second back surface portions 53 face toward different first back surface portions 43.

[0048] The second front surface portions 52 are spaced apart in the circumferential direction around the rotation axis AX. In the second embodiment, each second front surface portion 52 extends in a radial direction and a circumferential direction perpendicular to the rotation axis AX.

[0049] The second back portions 53 are spaced apart in the circumferential direction around the rotation axis AX. In the second embodiment, each second back portion 53 extends in the radial direction and the circumferential direction perpendicular to the rotation axis AX.

[0050] Each second side surface portion 54 smoothly connects the second front surface portion 52 and the second rear surface portion 53. In the second embodiment, each second side surface portion 54 has a main portion extending in the extension direction of the rotation axis AX and in the radial direction, and an end portion connecting the main portion to the second front surface portion 52 or the second rear surface portion 53.

[0051] The distance between two second side surface portions 54 connected to the same second back surface portion 53 is such that the length W21 downstream in the inflow direction is equal to or greater than the length W22 upstream in the inflow direction. Specifically, the circumferential length W21 of the gap between two circumferentially adjacent second side surface portions 54 downstream in the inflow direction is equal to or greater than the circumferential length W22 of the gap between two circumferentially adjacent second side surface portions 54 upstream in the inflow direction. In other words, the angle formed between the flat portion of the main surface 52a of the second front surface portion 52 and the flat portion of the main surface 54a of the second side surface portion 54 is equal to or greater than 90 degrees. In the second embodiment, the length W21 downstream in the inflow direction is equal to the length W22 upstream in the inflow direction. Therefore, the second side surface portion 54 is provided with the main surface 54a oriented along the inflow direction.

[0052] The total surface area of ​​the second side portions 54 is greater than the total surface area of ​​the second front portion 52 and the second back portion 53. In particular, the total surface area of ​​the main surfaces 54a of the second side portions 54 is greater than the total surface area of ​​the main surfaces 52a of the second front portion 52 and the main surfaces 53a of the second back portion 53.

[0053] The main surface 52a of the second front surface portion 52, the main surface 53a of the second rear surface portion 53, and the main surface 54a of the second side surface portion 54 are each the surface on the upstream side of the outside air passing through the filter device 32, of the two main surfaces. As an example, the main surface 52a of the second front surface portion 52 is the surface on the negative Y-axis direction side of the second front surface portion 52. Similarly, the main surface 53a of the second rear surface portion 53 is the surface on the negative Y-axis direction side of the second rear surface portion 53. The main surface 54a of the second side surface portion 54 located at the right end in FIG. 7 is the surface on the positive X-axis direction side of the first side surface portion 54. The main surface 54a of the second side surface portion 54 located at the left end in FIG. 7 is the surface on the negative X-axis direction of the second side surface portion 54.

[0054] In the second embodiment, the second filter member 51 is formed by repeatedly bending a mesh-like second metal member into a U-shape while alternating the direction of the bending to form a bellows shape. The second metal member is made of the same material as the first metal member, such as stainless steel. Specifically, the second filter member 51 is formed by repeatedly bending a stainless steel mesh into a U-shape.

[0055] The entire first filtering member 41 and the entire second filtering member 51, which have been repeatedly bent into a U-shape, are bent into an arc shape with the bending lines of the U-shape aligned in the radial direction, and then attached to the inner surface of the fixing frame 40, thereby obtaining the filter device 32. Protrusions are formed on the inner surface of the fixing frame 40, and the meshes of the first filtering member 41 and the second filtering member 51 are engaged with the protrusions. As a result, the first filtering member 41 and the second filtering member 51 are attached to the fixing frame 40.

[0056] By forming the second filter member 51 using a mesh-like second metal member, ventilation holes 52b, 53b, and 54b are formed in the second front portion 52, the second back portion 53, and the second side portion 54, respectively, as shown in Figure 8.

[0057] 8, the outside air passes through one of ventilation holes 42b, 43b, or 44b, and then passes through one of ventilation holes 52b, 53b, or 54b, and then passes through filter device 32. The outside air that has passed through filter device 32 flows into the interior of electric motor 1 through intake hole 12a, passes through gap 20, and then flows out to the outside through exhaust hole 13a.

[0058] The mesh size of the first filter member 41 is preferably larger than that of the second filter member 51. Specifically, the sizes of the ventilation holes 42b, 43b, and 44b are preferably larger than the sizes of the ventilation holes 52b, 53b, and 54b, respectively.

[0059] The mesh spacing of the first filter member 41 is preferably wider than the mesh spacing of the second filter member 51. Specifically, the spacing between adjacent ventilation holes 42b is wider than the spacing between adjacent ventilation holes 52b. Similarly, the spacing between adjacent ventilation holes 43b is wider than the spacing between adjacent ventilation holes 53b. Similarly, the spacing between adjacent ventilation holes 44b is wider than the spacing between adjacent ventilation holes 54b.

[0060] Specifically, the filter device 32 is obtained by attaching to the fixed frame 40 a first filter member 41 formed by repeatedly bending a stainless steel mesh with large mesh and thick wire diameter into a U-shape, and a second filter member 51 formed by bending a stainless steel mesh with small mesh and thin wire diameter into a U-shape.

[0061] With the above configuration, the rigidity of the first filtering member 41 is higher than the rigidity of the second filtering member 51. Furthermore, the second filtering member 51 is a filter with a finer mesh than the first filtering member 41. Increasing the rigidity of the first filtering member 41 prevents the filter device 32 from being damaged by hard foreign matter such as stones or sand. By making the second filtering member 51 a filter with a finer mesh than the first filtering member 41, small foreign matter contained in the outside air that has passed through the first filtering member 41, such as iron powder, pollen, and PM (Particulate Matter) 2.5, can be removed by the second filtering member 51.

[0062] As the filter is used for a long time, foreign matter may become clogged in the ventilation holes through which outside air passes. In the filter device 32, the main surface 52a of the second front portion 52 and the main surface 53a of the second back portion 53 are positioned perpendicular to the inflow direction, and the second side portion 54 is provided with the main surface 54a oriented along the inflow direction. More outside air flows through the ventilation holes 52b formed in the main surface 52a of the second front portion 52, which is perpendicular to the inflow direction of outside air, and the ventilation holes 53b formed in the main surface 53a of the second back portion 53. Therefore, as the filter device 32 is used for a long time, foreign matter is less likely to become clogged in the ventilation holes 54b formed in the second side portion 54, whose main surface 54a is oriented along the inflow direction, compared to the ventilation holes 52b formed in the second front portion 52 and the ventilation holes 53b formed in the second back portion 53.

[0063] As described above, the filter device 32 of embodiment 2 comprises a first filter member 41 having a plurality of first front surface portions 42, a plurality of first rear surface portions 43, and a plurality of first side surface portions 44 connecting the first rear surface portion 43 to each of the two first front surface portions 42 located on either side of the first cavity 45 toward which the main surface of the first rear surface portion faces, and a second filter member 51 having a plurality of second front surface portions 52, a plurality of second rear surface portions 53, and a plurality of second side surface portions 54 connecting the second rear surface portion 53 to each of the two second front surface portions 52 located on either side of the second cavity 55 toward which the main surface of the second rear surface portion 53 faces.

[0064] The distance between two first side portions 44 connected to the same first rear portion 43 is such that the length downstream in the inflow direction is equal to or greater than the length upstream in the inflow direction, and the total surface area of ​​the first side portions 44 is greater than the total surface area of ​​the first front portion 42 and the first rear portion 43. The distance between two second side portions 54 connected to the same second rear portion 53 is such that the length downstream in the inflow direction is equal to or greater than the length upstream in the inflow direction, and the total surface area of ​​the second side portions 54 is greater than the total surface area of ​​the second front portion 52 and the second rear portion 53.

[0065] The distance between two first side portions 44 connected to the same first rear portion 43 and the distance between two second side portions 54 connected to the same second rear portion 53 are such that the distance downstream in the inflow direction is equal to or greater than the distance upstream in the inflow direction. The total surface area of ​​the first side portions 44, which are less susceptible to clogging, is greater than the total surface area of ​​the first front portion 42 and the first rear portion 43. The total surface area of ​​the second side portions 54, which are less susceptible to clogging, is greater than the total surface area of ​​the second front portion 52 and the second rear portion 53. Therefore, the filter device 32 is less susceptible to clogging than a filter with a continuous V-shaped concave-convex shape. This results in a filter device 32 in which a rapid decrease in flow rate due to aging is suppressed. As a result, a motor 1 in which a rapid decrease in cooling performance due to aging is suppressed is obtained.

[0066] As described above, foreign matter is less likely to clog the first side surface portion 44 and the second side surface portion 54, and a sudden decrease in flow rate due to aging is suppressed, so the period from when the filter device 32 starts to be used until the filter device 32 needs to be cleaned to remove foreign matter is extended. As a result, the maintenance cycle of the filter device 32 is extended, improving maintainability.

[0067] By making the rigidity of the first filtering member 41 higher than that of the second filtering member 51 and making the second filtering member 51 a filter with a finer mesh than the first filtering member 41, a filter device 32 is obtained that prevents the inflow of small foreign matter such as iron powder, pollen, and PM2.5 while suppressing damage from large foreign matter such as stones and sand.

[0068] Since the convex portion of the second filter member 51 is located downstream of the convex portion of the first filter member 41 in the inflow direction, and the concave portion of the second filter member 51 is located downstream of the concave portion of the first filter member 41 in the inflow direction, the width of the filter device 32 equipped with the first filter member 41 and the second filter member 51 in the inflow direction is prevented from increasing significantly compared to the filter device 31.

[0069] The present disclosure is not limited to the above-described embodiment. The structure and shape of the filter device may be any structure and shape that can prevent foreign matter from entering the electric motor 1 and that can prevent a sudden decrease in the flow rate over time.

[0070] 9 includes a first filtering member 41, in which the distance between two first side surfaces 44 connected to the same first rear surface 43 is such that the length W31 downstream in the inflow direction is greater than the length W32 upstream in the inflow direction. The length W31 downstream in the inflow direction can be greater than the length W32 upstream in the inflow direction, as long as the two first side surfaces 44 connected to the same first front surface 42 do not abut on each other. The filtering device 33 may further include a second filtering member 51 formed in the same manner as the first filtering member 41.

[0071] 10 includes a plurality of filtration units each having a first filtration member 41 and a second filtration member 51. Specifically, the filter device 34 includes a filtration unit 61 having the first filtration member 41 and the second filtration member 51, and a filtration unit 62 having the first filtration member 41 and the second filtration member 51. The filtration units 61 and 62 are aligned in the inflow direction, in other words, in the positive direction of the Y axis.

[0072] The first filtering member 41 of the filtering unit 62 located downstream in the inflow direction preferably has a finer mesh than the second filtering member 51 of the filtering unit 61 located upstream in the inflow direction. Specifically, the size of the ventilation holes 42b formed in the first front surface portion 42 of the first filtering member 41 of the filtering unit 62 is preferably smaller than the ventilation holes 52b formed in the second front surface portion 52 of the second filtering member 51 of the filtering unit 61. The spacing between the ventilation holes 42b formed in the first front surface portion 42 of the first filtering member 41 of the filtering unit 62 is preferably narrower than the spacing between the ventilation holes 52b formed in the second front surface portion 52 of the second filtering member 51 of the filtering unit 61.

[0073] Similarly, the size of the ventilation holes 43b formed in the first rear surface portion 43 of the first filtering member 41 of the filtering unit 62 is preferably smaller than the ventilation holes 53b formed in the second rear surface portion 53 of the second filtering member 51 of the filtering unit 61. The spacing between the ventilation holes 43b formed in the first rear surface portion 43 of the first filtering member 41 of the filtering unit 62 is preferably narrower than the spacing between the ventilation holes 53b formed in the second rear surface portion 53 of the second filtering member 51 of the filtering unit 61.

[0074] In the filter device 34, outside air passes through the first filter member 41 and the second filter member 51 of the filter unit 61 and the first filter member 41 and the second filter member 51 of the filter unit 62 in that order before being led to the air intake hole 12a. By passing through the two first filter members 41 and the two second filter members 51, foreign matter can be more reliably removed from the outside air.

[0075] The shapes of the first filtering member 41 and the second filtering member 51 included in the filtering device 34 may be the same as the shape of the first filtering member 41 included in the filtering device 33.

[0076] The electric motor 1 may include any number of filter devices. As an example, the electric motor 1 shown in FIG. 11 includes a plurality of filter devices 35 arranged in the circumferential direction. Specifically, the electric motor 1 includes four filter devices 35 each having a partial ring-like outer shape when viewed in the positive direction of the Y axis. The four filter devices 35 are spaced apart in the circumferential direction. The structure of each filter device 35 is the same as that of the filter device 31, but the circumferential length of each filter device 35 is different from that of the filter device 31. The structure of each filter device 35 is the same as that of the filter device 31.

[0077] The shape of the filter device is not limited to the above example, and may be any shape that can remove foreign matter, such as an annular shape, a circular shape, or a polygonal shape. As an example, the electric motor 1 shown in Fig. 12 is equipped with a filter device 36 that extends in the circumferential direction around the rotation axis AX and has an annular shape with a polygonal outer edge that is partially missing. The structure of the filter device 36 is similar to that of the filter device 31, but the shape of the outer edge when viewed in the positive direction of the Y axis differs from that of the filter device 31.

[0078] As another example, the electric motor 1 shown in FIG. 13 includes a filter device 37 having a ring shape extending in the circumferential direction around the rotation axis AX. The structure of the filter device 37 is similar to that of the filter device 31. The filter device 37 differs from the filter device 31 in that the outer shape of the filter device 37 when viewed in the positive direction of the Y axis is a ring. The outer edge of the filter device 37 may be polygonal. That is, the filter device 37 may be annular in shape with a polygonal outer edge.

[0079] The shapes of the first filtering member 41 and the second filtering member 51 are not limited to the above examples and may be any shape that can remove foreign matter. As an example, a filter device 38 shown in FIG. 14 includes a first filtering member 41 formed by molding a first metal member into a shape in which the angle between the first front surface portion 42 and the first side surface portion 44 can be considered to be 90 degrees or greater. In the example shown in FIG. 14, the first filtering member 41 is formed by molding the first metal member into an angle in which the angle between the first front surface portion 42 and the first side surface portion 44 can be considered to be 90 degrees. In the example shown in FIG. 14, the distance between two first side surface portions 44 connected to the same first rear surface portion 43 can be considered to be such that the length W41 downstream in the inflow direction is equal to the length W42 upstream in the inflow direction. The molding method of the first metal member is arbitrary.

[0080] As another example, the first front surface portion 42, the first rear surface portion 43, the second front surface portion 52, and the second rear surface portion 53 are not limited to being flat plate-like members, and may have the shape of a plate-like member having a curved surface. Furthermore, the shape of the main surface 44a of the first side surface portion 44 and the main surface 54a of the second side surface portion 54 may be a curved shape.

[0081] In the filter devices 32 and 34, the distance between the first filtering member 41 and the second filtering member 51 may be arbitrary. As an example, the first filtering member 41 and the second filtering member 51 may be provided at a position where a portion of the first filtering member 41 and a portion of the second filtering member 51 abut against each other.

[0082] The extension direction of the first front surface portion 42 and the first rear surface portion 43 of the first filtering member 41 is not limited to the above example. As an example, the first front surface portion 42 and the first rear surface portion 43 may extend in the vertical direction and the horizontal direction. In this case, the first front surface portion 42 and the first rear surface portion 43 are positioned with a gap between them in the vertical direction or the horizontal direction.

[0083] The structure of the electric motor 1 is not limited to the above example, and may be any open-type electric motor that takes in outside air to cool the inside. As an example, the electric motor 1 may be a frameless type electric motor that does not have a frame 11. As another example, the electric motor 1 is not limited to the inner rotor shown in the above embodiment, and may be an outer rotor.

[0084] Rotor core 15a may be formed with rotor ventilation passages, which are through-holes that open to both ends in the extension direction of rotation axis AX. By allowing outside air to flow through the rotor ventilation passages, rotor core 15a is cooled more efficiently. In this case, air intake hole 12a is preferably formed in a position facing gap 20 and the rotor ventilation passages.

[0085] Stator core 16a may have a stator ventilation passage formed therein. By allowing outside air to flow through the stator ventilation passage, stator core 16a can be cooled more efficiently. In this case, air intake hole 12a is preferably formed at a position facing gap 20 and the stator ventilation passage.

[0086] The method for attaching the filter devices 31-38 to the electric motor 1 is not limited to the above example. The filter devices 31-38 can be attached to the electric motor 1 by any method such as adhesion, fitting, welding, or the like.

[0087] The on-vehicle equipment to which the filter device is attached is not limited to an electric motor. As an example, a power conversion device 2 shown in FIG. 15 includes a housing 3 that houses electronic components such as a converter circuit, an inverter circuit, and a reactor, and a filter device 39 that is attached to the housing 3 and blocks an air intake hole 3a formed in the housing 3. The filter device 39 has a rectangular outer shape when viewed in the negative Y-axis direction. The filter device 39 includes, for example, a first filter member 41 having an uneven shape extending in the Z-axis direction. In other words, the first filter member 41 has a shape in which protruding portions in the Y-axis direction and recessed portions in the Y-axis direction are alternately arranged. The air that flows into the housing 3 through the filter device 39 flows along electronic components, such as a reactor, housed in an open portion through which outside air flows in, cooling the electronic components before flowing out of the housing 3.

[0088] The shape of the first filtering member 41 included in the filtering device 35-39 may be the same as the shape of the first filtering member 41 included in the filtering device 33. The filtering device 35-39 may further include a second filtering member 51. Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A filter device is attached to an on-board device of a railway vehicle that cools the interior with outside air taken in through an air intake hole, covering the air intake hole from the outside, removes foreign matter from the outside air flowing in, and guides the outside air from which the foreign matter has been removed to the air intake hole, a plurality of first front surface portions, each of whose main surfaces intersects with the inflow direction of the outside air, and adjacent first front surface portions are positioned with a first gap between them; a plurality of first back surface portions, each of whose main surfaces faces the first gap between two adjacent first front surface portions, and which are located downstream of the first front surface portions in the inflow direction and spaced apart from one another; a first filtering member having a plurality of first side portions connecting the first rear surface portion to each of the two first front surface portions positioned on either side of the first gap to which the main surface of the first rear surface portion is directed; a distance between the two first side surface portions connected to the same first rear surface portion such that the length downstream in the inflow direction is greater than the length upstream in the inflow direction; The sum of the surface areas of the first side portions is greater than the sum of the surface areas of the first front portion and the first rear portion. Filter device. (Appendix 2) Further provided is a second filter member located downstream of the first filter member in the inflow direction, The second filter member is a plurality of second front surface portions, each of whose main surfaces faces a different first front surface portion, and adjacent second front surface portions are positioned with a second gap therebetween; a plurality of second back surface portions, each of whose main surfaces faces a second gap between two adjacent second front surface portions, and which are located downstream of the second front surface portions in the inflow direction and spaced apart from one another; and a plurality of second side portions connecting the second rear surface portion to each of the two second front surfaces located on either side of the second gap to which the main surface of the second rear surface portion faces. 2. The filter device of claim 1. (Appendix 3) a distance between two of the second side surface portions connected to the same second rear surface portion such that the length downstream in the inflow direction is equal to or greater than the length upstream in the inflow direction; The sum of the surface areas of the second side portions is greater than the sum of the surface areas of the second front portion and the second rear portion. 3. The filter device of claim 2. (Appendix 4) The first filter member is formed of a mesh-like first metal member. 4. The filter device of claim 2 or 3. (Appendix 5) The second filter member is formed of a mesh-like second metal member, The mesh size of the first filtering member is larger than the mesh size of the second filtering member, The mesh spacing of the first filter member is wider than the mesh spacing of the second filter member. 5. The filter device of claim 4. (Appendix 6) a fixing frame having a protrusion on an inner surface, the first filtering member being attached to the inner surface by engaging with the protrusion, and the fixing frame being fixed to the in-vehicle device; 6. A filter device according to any one of claims 2 to 5. (Appendix 7) The first filter member and the second filter member are engaged with the protrusions, whereby the first filter member and the second filter member are attached to the inner surface of the fixing frame. 7. The filter device of claim 6. (Appendix 8) a plurality of filtration units each having the first filtration member and the second filtration member; The plurality of filtration units are arranged in the inflow direction. 8. A filter device according to any one of claims 2 to 7. (Appendix 9) a shaft supported rotatably around a rotation axis; a rotor located radially outside the shaft and rotating integrally with the shaft; a stator facing the rotor with a gap in the radial direction; a first bracket having an intake hole formed in an end surface intersecting the extension direction of the rotary shaft to allow outside air to flow in; a second bracket facing the first bracket in the extension direction of the rotary shaft with the rotor and the stator interposed therebetween, the second bracket having an exhaust hole formed in an outer peripheral surface thereof through which the outside air flowing in from the intake hole flows out; the filter device according to claim 1 attached to the first bracket in a state of covering the intake hole from the outside; An electric motor comprising: (Appendix 10) a shaft supported rotatably around a rotation axis; a rotor located radially outside the shaft and rotating integrally with the shaft; a stator facing the rotor with a gap in the radial direction; a first bracket having an intake hole formed in an end surface intersecting the extension direction of the rotary shaft to allow outside air to flow in; a second bracket facing the first bracket in the extension direction of the rotary shaft with the rotor and the stator interposed therebetween, the second bracket having an exhaust hole formed in an outer peripheral surface thereof through which the outside air flowing in from the intake hole flows out; The filter device according to any one of claims 2 to 8, which is attached to the first bracket in a state of covering the intake hole from the outside; An electric motor comprising: (Appendix 11) The first filter member has a circular or partial circular shape extending in a circumferential direction around the rotation axis, an annular shape extending in the circumferential direction and having a polygonal outer edge, or an annular shape extending in the circumferential direction and having a polygonal outer edge with a portion missing. 11. The electric motor according to claim 9 or 10. (Appendix 12) The first front surface portion and the first rear surface portion of the first filter member extend in the radial direction and in the circumferential direction around the rotation axis, respectively. 12. The electric motor according to any one of appendixes 9 to 11. (Appendix 13) a plurality of filter devices each having the first filtering member having a partial ring shape extending in a circumferential direction around the rotation axis, or an annular shape extending in the circumferential direction and having a polygonal outer edge with a portion missing, The plurality of filter devices are arranged side by side in the circumferential direction. 11. The electric motor according to claim 9 or 10. (Appendix 14) The second filter member has a circular or partial circular shape extending in a circumferential direction around the rotation axis, an annular shape extending in the circumferential direction and having a polygonal outer edge, or an annular shape extending in the circumferential direction and having a polygonal outer edge with a portion missing. 11. The electric motor of claim 10. (Appendix 15) The second front surface portion and the second rear surface portion of the second filter member extend in the radial direction and in the circumferential direction around the rotation axis, respectively. 15. The electric motor of claim 10 or 14. (Appendix 16) a plurality of filter devices each having the first filter member having a partial ring shape extending in a circumferential direction around the rotation axis, or an annular shape extending in the circumferential direction with a polygonal outer edge and a missing portion, and a second filter member having a partial ring shape extending in a circumferential direction around the rotation axis, or an annular shape extending in the circumferential direction with a polygonal outer edge and a missing portion, The plurality of filter devices are arranged side by side in the circumferential direction. 11. The electric motor of claim 10.

[0089] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Furthermore, the above-described embodiments are intended to illustrate the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of equivalent disclosures are considered to be within the scope of the present disclosure. [Explanation of symbols]

[0090] REFERENCE SIGNS LIST 1 electric motor, 2 power conversion device, 3 housing, 3a intake hole, 11 frame, 12 first bracket, 12a intake hole, 13 second bracket, 13a exhaust hole, 14 shaft, 15 rotor, 15a rotor core, 15b rotor bar, 16 stator, 16a stator core, 16b stator coil, 17, 18 bearing, 19 fan, 20 air gap, 31, 32, 33, 34, 35, 36, 37, 38, 39 filter device, 40 fixing frame, 41 first filtering member, 42 first front surface portion, 42a, 43a, 44a, 52a, 53a, 54a main surface, 42b, 43b, 44b, 52b, 53b, 54b ventilation hole, 43 first rear surface portion, 44 first side surface portion, 45 First gap, 51 second filtering member, 52 second front portion, 53 second rear portion, 54 second side portion, 55 second gap, 61, 62 filtering unit, AX rotating shaft, W11, W12, W21, W22, W31, W32, W41, W42 length.

Claims

1. A filter device is attached to an on-board device of a railway vehicle that cools the interior with outside air taken in through an air intake hole, covering the air intake hole from the outside, removes foreign matter from the outside air flowing in, and guides the outside air from which the foreign matter has been removed to the air intake hole, a plurality of first front surface portions, each of whose main surfaces intersects with the inflow direction of the outside air, and adjacent first front surface portions are positioned with a first gap between them; a plurality of first back surface portions, each of whose main surfaces faces the first gap between two adjacent first front surface portions, and which are located downstream of the first front surface portions in the inflow direction and spaced apart from one another; a first filtering member having a plurality of first side portions connecting the first rear surface portion to each of the two first front surfaces positioned on either side of the first gap to which the main surface of the first rear surface portion is directed; a distance between the two first side surface portions connected to the same first rear surface portion such that the distance downstream in the inflow direction is greater than the distance upstream in the inflow direction; The sum of the surface areas of the first side portions is greater than the sum of the surface areas of the first front portion and the first rear portion. Filter device.

2. Further provided is a second filter member located downstream of the first filter member in the inflow direction, The second filter member is a plurality of second front surface portions, each of whose main surfaces faces one of the first front surface portions different from the other, and adjacent second front surface portions are positioned with a second gap therebetween; a plurality of second back surface portions, each of whose main surfaces faces a second gap between two adjacent second front surface portions, and which are located downstream of the second front surface portions in the inflow direction and spaced apart from one another; a plurality of second side surfaces connecting the second rear surface portion to each of the two second front surfaces positioned across the second gap to which the main surface of the second rear surface portion faces; The filter device according to claim 1 .

3. a distance between two of the second side surface portions connected to the same second rear surface portion such that a length thereof on the downstream side in the inflow direction is equal to or greater than a length thereof on the upstream side in the inflow direction; The sum of the surface areas of the second side portions is greater than the sum of the surface areas of the second front portion and the second rear portion. The filter device according to claim 2 .

4. The first filter member is formed of a mesh-like first metal member.

4. The filter device according to claim 2 or 3.

5. the second filter member is formed of a mesh-like second metal member, The mesh size of the first filter member is larger than the mesh size of the second filter member, The mesh spacing of the first filter member is wider than the mesh spacing of the second filter member.

5. The filter device according to claim 4.

6. a fixing frame having a protrusion on an inner surface, the first filtering member being attached to the inner surface by engaging with the protrusion, and the fixing frame being fixed to the in-vehicle device; 4. The filter device according to claim 2 or 3.

7. The first filter member and the second filter member are engaged with the protrusions, whereby the first filter member and the second filter member are attached to the inner surface of the fixing frame.

7. The filter device according to claim 6.

8. a plurality of filtration units each having the first filtration member and the second filtration member; The plurality of filtration units are arranged in the inflow direction.

4. The filter device according to claim 2 or 3.

9. a shaft supported rotatably around a rotation axis; a rotor located radially outside the shaft and rotating integrally with the shaft; a stator facing the rotor with a gap in the radial direction; a first bracket having an intake hole formed in an end surface intersecting the extension direction of the rotary shaft to allow outside air to flow in; a second bracket facing the first bracket in the extension direction of the rotation shaft with the rotor and the stator interposed therebetween, the second bracket having an exhaust hole formed in an outer peripheral surface thereof through which the outside air flowing in from the intake hole flows out; the filter device according to claim 1 being attached to the first bracket in a state of covering the intake hole from the outside; An electric motor comprising:

10. a shaft supported rotatably around a rotation axis; a rotor located radially outside the shaft and rotating integrally with the shaft; a stator facing the rotor with a gap in the radial direction; a first bracket having an intake hole formed in an end surface intersecting the extension direction of the rotary shaft to allow outside air to flow in; a second bracket facing the first bracket in the extension direction of the rotation shaft with the rotor and the stator interposed therebetween, the second bracket having an exhaust hole formed in an outer peripheral surface thereof through which the outside air flowing in from the intake hole flows out; the filter device according to claim 2 or 3, which is attached to the first bracket in a state of covering the intake hole from the outside; An electric motor comprising:

11. The first filter member has a circular or partial circular shape extending in a circumferential direction around the rotation axis, an annular shape extending in the circumferential direction and having a polygonal outer edge, or an annular shape extending in the circumferential direction and having a polygonal outer edge with a portion missing.

10. The electric motor according to claim 9.

12. The first front surface portion and the first rear surface portion of the first filter member extend in the radial direction and in the circumferential direction around the rotation axis, respectively.

10. The electric motor according to claim 9.

13. a plurality of filter devices each having the first filtering member having a partial ring shape extending in a circumferential direction around the rotation axis, or an annular shape extending in the circumferential direction and having a polygonal outer edge with a portion missing, The plurality of filter devices are arranged side by side in the circumferential direction.

10. The electric motor according to claim 9.

14. The second filter member has a circular or partial circular shape extending in a circumferential direction around the rotation axis, an annular shape extending in the circumferential direction and having a polygonal outer edge, or an annular shape extending in the circumferential direction and having a polygonal outer edge with a portion missing.

11. The electric motor according to claim 10.

15. the second front surface portion and the second rear surface portion of the second filter member extend in the radial direction and in the circumferential direction around the rotation axis, respectively; 11. The electric motor according to claim 10.

16. a plurality of filter devices each having the first filter member having a partial ring shape extending in a circumferential direction around the rotation axis, or an annular shape extending in the circumferential direction with a polygonal outer edge and a missing portion, and a second filter member having a partial ring shape extending in a circumferential direction around the rotation axis, or an annular shape extending in the circumferential direction with a polygonal outer edge and a missing portion, The plurality of filter devices are arranged side by side in the circumferential direction.

11. The electric motor according to claim 10.

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