JP2018198503A - motor - Google Patents

Abstract

To provide a motor capable of suppressing entry of water internally.SOLUTION: A motor 1 includes: a stationary section; a rotation section for rotating with a central shaft being a center; and a bearing unit for rotatably supporting the rotation section against the stationary section. The stationary section includes an annular projection 22 that projects on an end face in a shaft direction at one side toward the shaft direction at one side. The rotation section includes: a shaft 31 that extends in a shaft direction and positioned inside in a radial direction of the bearing unit; and a cover section 33 being fixed onto the shaft at a position separated at one side in the shaft direction from the end face at one side in the shaft direction of the stationary section. The cover section is positioned inside in the radial direction relative to the projection. At least part of an outer peripheral surface of the cover section faces an internal peripheral surface of the projection in the radial direction. The projection includes a groove 221 that sinks toward the other side in the shaft direction. The groove includes a first opening for opening to an inner circumferential surface side of the projection and a second opening for opening to an outer circumferential surface side of the projection. The second opening is arranged at a rotation direction front side of the rotation section relative to the first opening in a circumferential direction.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a motor.

  Japanese Patent Laying-Open No. 2006-116396 discloses a rotating electrical machine having a rotating shaft, a support portion, and a cover portion. The rotating shaft rotates a rotor provided in the rotating electrical machine main body. The support part is provided in the rotating electrical machine main body part and supports the rotating shaft. A cover part is fixed to the site | part which protrudes outside a support part among rotating shafts, and covers a support part. The rotating electrical machine realizes a shaft seal structure by a labyrinth structure portion composed of a support portion and a cover portion. The labyrinth structure portion can prevent water and foreign matter from entering the support portion and the rotating electric machine. The rotating electrical machine includes a radial groove portion that extends along the radial direction of the rotation shaft in the labyrinth structure portion. For this reason, even if water or a foreign substance enters the labyrinth structure, the water or the foreign substance can be discharged from the radial groove.

Japanese Patent Laid-Open No. 2006-116396

  It is desired that water can be efficiently prevented from entering the motor both when the motor is driven and when it is stationary. Thereby, the lifetime of a motor can be extended.

  In view of the above points, an object of the present invention is to provide a motor that can prevent water from entering inside.

  An exemplary motor of the present invention includes a stationary part, a rotating part that rotates about a central axis, and a bearing part that rotatably supports the rotating part with respect to the stationary part. The stationary part has an annular projecting part projecting toward the one side in the axial direction on an end face on one side in the axial direction. The rotating portion extends in the axial direction and is fixed to the shaft at a position spaced from the shaft located on the radially inner side of the bearing portion and the end surface on one axial side of the stationary portion toward one axial side. And a cover portion. The cover portion is located on the radially inner side than the protruding portion. At least a part of the outer peripheral surface of the cover portion faces the inner peripheral surface of the protruding portion in the radial direction. The protrusion has a groove that is recessed toward the other side in the axial direction. The groove includes a first opening that opens to the inner peripheral surface side of the protrusion and a second opening that opens to the outer peripheral surface of the protrusion. The second opening is disposed on the front side in the rotation direction of the rotation unit with respect to the first opening in the circumferential direction.

  According to the exemplary present invention, it is possible to provide a motor capable of suppressing water from entering inside.

FIG. 1 is a perspective view of a motor according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of the motor according to the embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of the cover portion and its periphery. FIG. 4 is an enlarged perspective view of an end portion on one side in the axial direction of the motor. FIG. 5 is a plan view of the motor according to the embodiment of the present invention as viewed from one axial side. FIG. 6 is an enlarged plan view showing the groove and its periphery. FIG. 7 is a view showing a modification of the groove. FIG. 8 is a diagram for explaining the configuration of the groove in more detail. FIG. 9 is a diagram for explaining a preferable configuration of the groove.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In this specification, the direction parallel to the central axis A of the motor 1 is “axial direction”, the direction orthogonal to the central axis A of the motor 1 is “radial direction”, and the arc is centered on the central axis A of the motor 1. Each direction is referred to as a “circumferential direction”. Moreover, in this specification, when the motor 1 is arrange | positioned in the direction shown in FIG. 2, let the surface orthogonal to the central axis A be a vertical surface, and let the surface orthogonal to the said vertical surface be a horizontal surface. The horizontal direction is a direction parallel to the horizontal plane, and the vertical direction is a direction perpendicular to the horizontal plane. However, the definition of these directions is not intended to limit the direction when the motor 1 according to the present invention is used.

<1. General configuration of motor>
First, a schematic configuration of a motor according to an exemplary embodiment of the present invention will be described. FIG. 1 is a perspective view of a motor 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of the motor 1 according to the embodiment of the present invention. In FIG. 2, the lower half is a sectional view and the upper half is a side view. As shown in FIGS. 1 and 2, the motor 1 includes a stationary part 2, a rotating part 3, and a bearing part 4.

  The stationary part 2 has a casing 20 and a stator 21. The casing 20 accommodates the stator 21 therein. The stator 21 is fixed to the casing 20.

  More specifically, the casing 20 includes a casing body 201 and a casing lid 202. The casing body 201 has a bottomed cylindrical shape having an end wall 201a on one side in the axial direction and opening on the other side in the axial direction. A stator and a rotor, which will be described later, are put into the casing body 201 from the opening side. The end wall 201a may be a separate member from the casing body 201. The casing lid 202 has a disk shape. The casing lid 202 is disposed on the other axial side of the casing body 201 and closes the opening of the casing body 201. The casing lid 202 is fixed to the casing body 201. The method for fixing the casing lid 202 to the casing body 201 is not particularly limited, and for example, a screw, a rivet or the like is used. In the present embodiment, the casing 20 is made of metal. The casing 20 is not limited to metal but may be made of resin, for example.

  The stator 21 is an armature of the motor 1. The stator 21 is substantially annular. The center of the stator 21 coincides with the central axis A of the motor 1. The stator 21 includes a stator core 211, a coil 212, and an insulator 213.

  The stator core 211 is configured by stacking, for example, magnetic steel plates in the axial direction. Specifically, the stator core 211 has an annular core back 211a and a plurality of teeth 211b protruding radially inward from the core back 211a. For example, the stator core 211 may be configured by joining a plurality of core pieces having a core back and teeth in the circumferential direction.

  The coil 212 is configured by winding a conductive wire around each tooth 211b via an insulator 213. A plurality of coils 212 are arranged in the circumferential direction.

  The insulator 213 is an insulating resin member that electrically insulates the stator core 211 and the coil 212. The insulator 213 covers at least a part of the stator core 211. The insulator 213 may be configured to be integrated with the stator core 211 by insert molding, for example. The insulator 213 may be a separate member from the stator core 211. In this case, the insulator 213 may be composed of, for example, two members that are placed on the stator core 211 from above and below.

  The rotating unit 3 rotates about the central axis A. The rotating part 3 includes a shaft 31, a rotor 32, and a cover part 33. The rotating part 3 is located on the radially inner side of the stator 21.

  The shaft 31 extends in the axial direction and is located on the radially inner side of the bearing portion 4. In the present embodiment, the shaft 11 is a cylindrical metal member. A part of the shaft 31 protrudes from the casing 20 to the outside on one axial side. However, a part of the shaft 31 may protrude outside from the casing 20 on the other side in the axial direction in addition to the one side in the axial direction. In this case, for example, a cover portion 33 and a protruding portion 22 described later may be provided on the end surface on the other side in the axial direction.

  The rotor 32 is disposed on the radially outer side of the shaft 31. The rotor 32 is housed inside the casing 20 and is located on the radially inner side of the stator 21. Specifically, the rotor 32 includes a rotor core 321 and a magnet portion 322.

  The cylindrical rotor core 321 is configured, for example, by laminating magnetic steel plates in the axial direction. However, the rotor core 321 may be formed by processing a cylindrical or columnar magnetic material, for example. The shaft 31 is press-fitted into the center of the rotor core 321. The rotor core 321 rotates with the shaft 31.

  In the present embodiment, the magnet portion 322 is fixedly disposed on the radially outer side of the rotor core 321. The magnet portion 322 is configured such that the N pole and the S pole are aligned in the circumferential direction. The magnet part 322 may be comprised by the some permanent magnet arranged in the circumferential direction, for example, and may be comprised by one cylindrical permanent magnet.

  The cover part 33 is fixed to the shaft 31 at a position separated from the end face on one side in the axial direction of the stationary part 2 toward one side in the axial direction. In the present embodiment, the cover portion 33 is fixed to a portion of the shaft 31 that protrudes outside from one axial side of the casing 20. That is, the cover part 33 is located outside the casing 20. The cover part 33 is spaced apart from the end surface on one side in the axial direction of the end wall 201a toward one side in the axial direction. The cover part 33 is preferably composed of a member having high elasticity such as synthetic rubber or natural rubber. The cover part 33 rotates together with the shaft 31. The cover portion 33 prevents water and dust from entering the motor 1. The cover portion 33 is located on one axial side of the bearing portion 4 and prevents water and dust from entering the bearing portion 4. The detailed structure of the cover part 33 will be described later.

  The bearing portion 4 supports the rotating portion 3 to be rotatable with respect to the stationary portion 2. The bearing portion 4 is positioned on the radially outer side of the shaft 31 and is fixed to the shaft 31. In the present embodiment, the bearing portion 4 includes a first bearing 41 and a second bearing 42. The first bearing 41 and the second bearing 42 are ball bearings. However, these may be other types of bearings such as sleeve bearings.

  The first bearing 41 is held by a first holding portion 43 provided on the inner surface side of the end wall 201a on one axial side of the casing body 201. The first holding portion 43 is a cylindrical portion extending from the inner surface of the end wall 201a to the other side in the axial direction. In the present embodiment, the casing body 201 and the first holding portion 43 are a single member.

  The second bearing 42 is held by a second holding portion 44 provided on the inner surface side of the casing lid 202. The second holding portion 44 is a cylindrical portion that extends from the inner surface of the casing lid 201 to one side in the axial direction. In the present embodiment, the second holding portion 44 and the casing lid 202 are a single member.

  In the motor 1, when a current is supplied to the coil 212, a radial magnetic flux is generated in the tooth 211b. A magnetic field formed by the magnetic flux and a magnetic field formed by the magnet portion 322 act to generate torque in the circumferential direction of the rotor 32. Due to this torque, the rotating part 3 rotates about the central axis A. When the supply of current to the coil 212 is stopped, the rotation of the rotating unit 3 is stopped.

<2. Detailed configuration of the cover and its surroundings>
FIG. 3 is an enlarged cross-sectional view of the cover portion 33 and its periphery. FIG. 4 is an enlarged perspective view showing an end portion on one axial side of the motor 1. In FIG. 4, the cover 33 is removed.

  As shown in FIGS. 1 to 4, the stationary portion 2 has an annular projecting portion 22 that projects toward the one axial side on the end surface on the one axial side. Specifically, the protrusion 22 has an annular shape. The protruding portion 22 protrudes from the outer surface of the end wall 201a toward the one side in the axial direction. The center of the protrusion 22 coincides with the central axis A. In the present embodiment, the protrusion 22 and the casing body 201 are a single member. However, the protrusion 22 may be a separate member from the casing body 201. The cover part 33 is located on the radially inner side than the protruding part 22.

  The protrusion 22 is located on the radially outer side than the shaft 31. For this reason, the protrusion part 22 can prevent the water which exists radially outside the protrusion part 22 from reaching the shaft 31 along the radial direction. In the present embodiment, the central axis A of the motor 1 extends in the horizontal direction. For this reason, water falls along the annular outer surface of the protrusion 22. Accordingly, it is possible to prevent water from reaching the shaft 31, and it is possible to make it difficult for water to enter the bearing portion 4 through the shaft 31.

  As shown in FIGS. 3 and 4, the stationary portion 2 has a first annular convex portion 23 that protrudes toward the one axial side on the end surface on the one axial side. The first annular convex portion 23 is disposed radially inward of the protruding portion 22 and radially outward of the shaft 31. Specifically, the first annular convex portion 23 has an annular shape. The 1st annular convex part 23 protrudes toward the axial direction one side from the outer surface of the edge part wall 201a. The center of the first annular convex portion 23 coincides with the central axis A. In the present embodiment, the first annular protrusion 23 and the casing body 201 are a single member. However, the first annular convex portion 23 may be a separate member from the casing body 201. The shaft 31 protrudes outside the casing 20 through the central through hole of the first annular convex portion 23.

  The 1st annular convex part 23 and the protrusion part 22 are arrange | positioned at intervals at radial direction. That is, a recess that is recessed toward the other side in the axial direction is formed between the first annular protrusion 23 and the protrusion 22. By providing the first annular convex portion 23 in addition to the protruding portion 22, the distance until the water existing radially outward from the protruding portion 22 reaches the shaft 31 existing radially inward is increased. Infiltration of water into the portion 4 can be suppressed. In the present embodiment, since the central axis A of the motor 1 extends in the horizontal direction, water can be dropped along the outer surface of the first annular convex portion 23, and the water to the bearing portion 4 can be dropped. Infiltration can be prevented. In the present embodiment, the end surface on the one axial side of the first annular protrusion 23 is located on the one axial side relative to the end surface on the one axial side of the protrusion 22. For this reason, the distance until the water which exists radially outside the protrusion 22 reaches the shaft 31 which exists radially inside can be further increased.

  The bearing portion 4 is located on the other side in the axial direction from the first annular convex portion 23. Specifically, the first annular convex portion 23 covers at least a part of the bearing portion 4 in a plan view from one axial side. Thereby, the protection performance of the bearing part 4 can be improved.

  The first annular convex portion 23 is provided with a second annular convex portion 24 that is disposed radially inward from the outer peripheral surface of the first annular convex portion 23 and projects toward one side in the axial direction. In detail, the 2nd annular convex part 24 is annular. The center of the second annular convex portion 24 coincides with the central axis A. In the present embodiment, the second annular convex portion 24 and the casing body 201 are a single member. However, the second annular convex portion 24 may be a separate member from the casing body 201. The shaft 31 protrudes outside the casing 20 through the central through hole of the second annular convex portion 24.

  By providing the second annular convex portion 24 in addition to the first annular convex portion 23, the distance until the water existing on the radially outer side from the projecting portion 22 reaches the shaft 31 existing on the radially inner side is further increased. Thus, water can be prevented from entering the bearing portion 4. In this embodiment, since the central axis A of the motor 1 extends in the horizontal direction, water can be dropped along the outer surface of the second annular convex portion 24, and water to the bearing portion 4 can be dropped. Infiltration can be suppressed.

  In addition, the 2nd annular convex part 24 is good also as a structure arrange | positioned at intervals in the radial inside rather than the 1st annular convex part 23. FIG. That is, a recess that is recessed toward the other side in the axial direction may be provided between the first annular convex portion 23 and the second annular convex portion 24 in the radial direction. Moreover, in this embodiment, although the number of the convex parts provided in the radial inside of the protrusion part 22 is two, the number of convex parts may be one or three or more. Moreover, it is good also as a structure by which a convex part is not provided in the radial inside of the protrusion part 22. FIG.

  As shown in FIGS. 1 to 3, the cover portion 33 has a cup shape that opens to the other side in the axial direction. Specifically, the cover part 33 includes a cover end wall 331 and a cover side wall 332. The cover end wall 331 has an annular shape in plan view from the axial direction. The cover side wall 332 has a cylindrical shape extending from the cover end wall 331 to the other side in the axial direction.

  The shaft 31 is inserted into the central through hole 331 a of the cover end wall 331. A part of the shaft 31 is provided with a shaft groove 31 a that is recessed inward in the radial direction and goes around the outer periphery of the shaft 31. A part of the inner peripheral side of the annular cover end wall 331 is elastically deformed and fitted into the shaft groove 31 a, and the cover portion 33 is fixed to the shaft 31. Since water present on one axial side of the cover portion 31 is obstructed by the sealing function of the cover portion 33, it is difficult to reach the bearing portion 4 through the shaft 31.

  At least a part of the outer peripheral surface of the cover portion 33 faces the inner peripheral surface of the protruding portion 22 in the radial direction. In the present embodiment, a part of the outer peripheral surface of the cover portion 33 faces the inner peripheral surface of the protruding portion 22 in the radial direction. The cover end wall 331 is located on the one axial side with respect to the end on the one axial side of the protrusion 33.

  The cover side wall 332 extending in the axial direction of the cover portion 33 is located between the protruding portion 22 and the first annular convex portion 23. The cover part 33 covers the first annular convex part 23. Specifically, the end of the cover side wall 332 on the other side in the axial direction enters a recessed portion that is recessed toward the other side in the axial direction formed between the protruding portion 22 and the first annular convex portion 23. A gap in the radial direction between the cover side wall 322 and the protrusion 22 and a gap in the radial direction between the cover side wall 322 and the first annular protrusion 23 are formed small. The protruding portion 22, the cover side wall 332, and the first annular convex portion 23 are arranged in this order toward the radially inner side to form a labyrinth structure. Water is difficult to pass through the labyrinth structure. Further, in this embodiment, since the central axis A of the motor 1 extends in the horizontal direction, water can be dropped along the outer surface of the cover portion 33. Therefore, according to the present embodiment, the water existing on the radially outer side of the protruding portion 22 does not easily reach the shaft 31 existing on the radially inner side, and the water enters the bearing portion 4 through the shaft 31. Can be suppressed.

  An annular recess 333 that is recessed toward one side in the axial direction and faces the second annular protrusion 24 is provided inside the cover portion 33. Specifically, two annular cover convex portions 334 and 335 projecting toward the other axial side are provided on the surface on the other axial side of the cover end wall 331. The first cover convex part 334 is located on the radially inner side with respect to the second cover convex part 335. The 1st cover convex part 334 and the 2nd cover convex part 335 are arrange | positioned at intervals at radial direction. The annular recess 333 is provided between the two cover protrusions 334 and 335.

  A part of the second annular convex portion 24 enters the annular concave portion 333 with a slight gap. That is, in this embodiment, a labyrinth structure is formed by the second annular convex portion 24 and the annular concave portion 333, and it is difficult for water to pass through. According to this embodiment, the water existing on the radially outer side of the protrusion 22 is unlikely to reach the shaft 31 existing on the radially inner side, and the water is prevented from entering the bearing portion 4 through the shaft 31. Can do.

  FIG. 5 is a plan view of the motor 1 according to the embodiment of the present invention as viewed from one side in the axial direction. In addition, the thick arrow shown in FIG. 5 shows the rotation direction of the rotation part 3 when the motor 1 is driven. Moreover, the dashed-dotted line S in FIG. 5 shows a horizontal surface. The horizontal plane S includes a central axis A. As shown in FIGS. 1, 4, and 5, the protrusion 22 has a groove 221 that is recessed toward the other side in the axial direction. FIG. 6 is an enlarged plan view showing the groove 221 and its periphery.

  As shown in FIG. 6, the groove 221 has a first opening 2211 and a second opening 2212. The first opening 2211 opens on the inner peripheral surface side of the protrusion 22. The second opening 2212 opens on the outer peripheral surface side of the protrusion 22. The first opening 2211 and the second opening 2212 are connected by a space forming the groove 221.

  The second opening 2212 is arranged on the front side in the rotation direction with respect to the first opening 2211 in the circumferential direction. In other words, the groove part 221 extends in a direction inclined along the rotation direction of the rotary part 3 with respect to the radial direction. According to this configuration, the cover 33 is rotated together with the shaft 31 by driving the motor 1. The protrusion 22 has a groove 221 that can discharge water existing between the protrusion 22 and the cover 33 to the outside. Since the groove portion 221 has an inclination along the rotation direction of the cover portion 33, the water existing between the protruding portion 22 and the cover portion 33 is efficiently discharged to the outside by the groove portion 221 when the motor 1 is driven. Can do.

  In addition, the magnitude | size of the inclination with respect to radial direction of the groove part 221 inclined with respect to radial direction is not specifically limited. For example, the magnitude of the inclination may be changed in consideration of at least one of the size, shape, and rotation speed of the motor 1. When the rotation direction of the motor 1 is opposite to that of this embodiment, the direction in which the groove 221 is inclined with respect to the radial direction is opposite to that of this embodiment.

  As shown in FIG. 6, the groove part 221 has a pair of side walls 2213a and 2213b which oppose the circumferential direction. Of the pair of side walls 2213a and 2213b, at least the side wall 2213a located on the rear side in the rotational direction preferably has a plane P. In the present embodiment, each of the pair of side walls 2213a and 2213b has a plane P. The planes P included in the pair of side walls 2213a and 2213b are parallel to each other. However, the planes P included in the pair of side walls 2213a and 2213b may not be parallel to each other. Even when each of the side walls 2213a and 2213b has a plane P, a curved surface may be provided on a part of each of the side walls 2213a and 2213b. For example, a curved surface may be provided in the vicinity of the openings 2211 and 2122.

  FIG. 7 is a view showing a modification of the groove 221. As shown in FIG. 7, the side wall 2213 a located on the rear side in the rotation direction of the groove 221 may have a curved surface C. The curved surface C may be a concave surface C1 as shown by a solid line in FIG. 7, or may be a convex surface C2 as shown by a one-dot chain line in FIG. However, when the curved surface C is the concave surface C1, water may accumulate on the curved surface C. When the curved surface C is the convex surface C2, the width of the first opening 2211 in the circumferential direction is narrowed, and there is a possibility that the water discharge efficiency is lowered. If at least the side wall 2213a on the rear side in the rotational direction has a flat surface as in this embodiment, water can be discharged efficiently. Moreover, according to the structure of this embodiment, possibility that water will accumulate in the groove part 221 can be reduced.

  FIG. 8 is a diagram for explaining the configuration of the groove portion 221 in more detail. As shown in FIG. 8, the circumferential width W <b> 1 of the first opening 2211 is larger than the circumferential width W <b> 2 of the second opening 2212. According to this, the water which exists in the radial inside of the protrusion part 22 can be easily discharged into the groove part 221 from the first opening part 2211. Moreover, according to this, possibility that external water will enter into the groove part 221 through the 2nd opening part 2212, and also may enter into the radial inside of the protrusion part 22 can be reduced.

  The circumferential widths of the two openings 2211 and 2122 may be different from the configuration of the present embodiment. For example, the circumferential width W1 of the first opening 2211 and the circumferential width W2 of the second opening 2212 may be the same.

  As shown in FIG. 8, the circumferential width W <b> 1 of the first opening 2211 is preferably larger than the radial distance R between the outer peripheral surface of the cover portion 33 and the inner peripheral surface of the protruding portion 22. According to this, the radial distance R between the outer peripheral surface of the cover portion 33 and the inner peripheral surface of the protruding portion 22 can be reduced. For this reason, even when water is applied to the motor 1 from the axial direction, it is possible to prevent water from entering between the cover portion 33 and the protruding portion 22. Moreover, according to this, the width | variety of the 1st opening part 2211 can be enlarged, and the water which entered between the cover part 22 and the protrusion part 33 can be easily discharged | emitted outside.

  As shown in FIG. 5, in the present embodiment, a plurality of groove portions 221 are provided at intervals in the circumferential direction. In the present embodiment, the number of the groove portions 221 is three, but the number is not particularly limited. By providing the plurality of groove portions 221, water existing between the cover portion 33 and the protruding portion 22 can be discharged to the outside from a plurality of locations when the motor 1 is driven. For this reason, water can be made difficult to enter the motor 1. The number of the groove portions 221 may be one.

  In the present embodiment, the central axis A of the motor 1 extends in the horizontal direction. The groove portion 221 is disposed on the lower side in the vertical direction than the horizontal plane S including the central axis A. In the present embodiment, a plurality of groove portions 221 are provided, but all of the plurality of groove portions 221 are arranged below the horizontal plane S in the vertical direction. According to this embodiment, even when the motor 1 is stationary, the water falling from the upper side in the vertical direction due to the action of gravity can be discharged to the outside by the groove portion 221.

  The plurality of groove portions 221 and all of them need not be arranged vertically below the horizontal plane S. For example, some of the plurality of groove portions 221 may be disposed on the upper side in the vertical direction from the horizontal plane S. Moreover, when the number of the groove parts 221 is one, it is preferable that the said groove part 221 is provided below the horizontal surface S. FIG. In this case, in the groove part 221, it is preferable that the 2nd opening part 2212 is located in the direction which goes to the perpendicular direction downward from the 1st opening part 2211. Thereby, even when the motor 1 is stationary, water can be discharged through the groove portion 221 by the action of gravity.

  FIG. 9 is a diagram for explaining a preferable configuration of the groove. In FIG. 9, a broken line arrow B points downward in the vertical direction. A central axis A of the motor 1 extends in the horizontal direction. For this reason, as shown in FIG. 9, in at least one of the groove portions 221, it is preferable that the second opening portion 2212 is located in a direction downward from the first opening portion 2211 in the vertical direction. According to this, water can be dropped downward in the vertical direction by the at least one groove portion 221, and water existing on the radially inner side of the protruding portion 22 can be discharged to the outside. For this reason, even when the motor 1 is stationary, the groove portion 221 can efficiently drain water to the outside.

<3. Points to remember>
The configurations of the embodiment and the modification described above are merely examples of the present invention. The configuration of the embodiment and the modification may be changed as appropriate without departing from the technical idea of the present invention. In addition, the above-described embodiment and a plurality of modification examples may be combined and implemented within a possible range.

  Further, the present invention may be applied to other than the motor 1 in which the central axis A extends in the horizontal direction. For example, the present invention may be applied to a motor whose central axis A extends in the vertical direction.

  The present invention can be widely applied to, for example, a motor disposed in an environment where water is easily applied, such as outdoors. The present invention can be used for, for example, a motor applied to a railway air conditioner.

DESCRIPTION OF SYMBOLS 1 ... Motor 2 ... Static part 3 ... Rotation part 4 ... Bearing part 22 ... Protrusion part 23 ... 1st cyclic | annular convex part 24 ... 2nd cyclic | annular convex part 31 ... · Shaft 33 ··· Cover portion 221 ··· Groove portion 333 ··· Circular recess 2211 · · · First opening portion 2212 · · · 2nd opening portions 2213a and 2213b · · · A pair of side walls

Claims (10)

A motor,
A stationary part;
A rotating part that rotates about a central axis;
A bearing portion that rotatably supports the rotating portion with respect to the stationary portion;
Have
The stationary part has an annular projecting part projecting toward the one side in the axial direction on the end face on one side in the axial direction,
The rotating part is
A shaft extending in the axial direction and positioned radially inside the bearing portion;
A cover portion fixed to the shaft at a position separated from the end surface on one axial side of the stationary portion on one axial side;
Have
The cover portion is located on the radially inner side than the protruding portion,
At least a part of the outer peripheral surface of the cover portion is opposed to the inner peripheral surface of the protruding portion in the radial direction,
The protrusion has a groove that is recessed toward the other side in the axial direction,
The groove has a first opening that opens to the inner peripheral surface side of the protrusion, and a second opening that opens to the outer peripheral surface of the protrusion,
The said 2nd opening part is a motor arrange | positioned in the rotation direction front side of the said rotation part rather than the said 1st opening part in the circumferential direction.   The motor according to claim 1, wherein a circumferential width of the first opening is larger than a circumferential width of the second opening.   3. The motor according to claim 1, wherein a width of the first opening in a circumferential direction is larger than a radial distance between an outer peripheral surface of the cover portion and an inner peripheral surface of the protruding portion.   4. The motor according to claim 1, wherein, of the pair of side walls opposed to each other in the circumferential direction of the groove portion, at least the side wall located on the rear side in the rotational direction has a flat surface.   The motor according to claim 1, wherein a plurality of the groove portions are provided at intervals in the circumferential direction. The central axis extends in a horizontal direction;
The motor according to any one of claims 1 to 5, wherein the groove is disposed on a lower side in a vertical direction than a horizontal plane including the central axis.   The motor according to claim 6, wherein in at least one of the groove portions, the second opening portion is located in a downward direction from the first opening portion in the vertical direction. The stationary portion has a first annular convex portion that is disposed radially inward of the protruding portion and radially outward of the shaft and protrudes toward the axially one side on the end surface on one axial side. And
The bearing portion is located on the other side in the axial direction from the first annular convex portion,
The cover portion has a cup shape that opens to the other side in the axial direction,
The motor according to any one of claims 1 to 7, wherein a cover side wall extending in the axial direction of the cover part is located between the protruding part and the first annular convex part.   9. The motor according to claim 8, wherein an end surface on one axial side of the first annular convex portion is positioned on one axial side than an end surface on one axial side of the protruding portion. The first annular convex portion is provided with a second annular convex portion arranged radially inward from the outer peripheral surface of the first annular convex portion and projecting toward one side in the axial direction.
10. The motor according to claim 8, wherein an inner side of the cover part is provided with an annular recess that is recessed toward one side in the axial direction and faces the second annular protrusion.

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