Patent Publication Number: US-2017353090-A1

Title: Stator unit, motor, and blower

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application No. 2016-113586 filed on Jun. 7, 2016. The entire contents of this application are hereby incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a stator unit, a motor, and a blower. 
     2. Description of the Related Art 
     Conventionally, there is known a molded motor in which a winding wound around a stator core and a bush mounting portion having a leg provided on the stator core are molded and solidified with a thermosetting resin. The molded motor is excellent in waterproof property and vibration proofing/soundproofing property at the time of driving the motor. A conventional molded motor is described in, for example, Japanese Patent Laid-Open Publication No. S59-70163. 
     Further, in a motor used for a communication base station with a high possibility of being exposed to the ambient air or a home electric appliance such as a refrigerator or the like, it is required to satisfy a higher waterproof standard such as a salt spray test or the like. For example, Japanese Patent Laid-Open Publication No. H07-59289 discloses a motor with higher sealability. 
     However, in the structure of Japanese Patent Laid-Open Publication No. H07-59289, it is necessary to further use a separate member such as an O ring or a sealing material. This may make the manufacturing process more complicated and may increase the manufacturing cost. 
     An object of the present invention is to provide a molded motor capable of enjoying high waterproof performance without using a separate member in a stator unit used for the molded motor. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect of the present invention, there is provided a stator, including: a base member including a cylindrical bearing housing extending along a vertically extending rotation axis; a stator fixed to an outer circumferential surface of the bearing housing; and a molding resin part arranged to cover the stator, wherein the stator includes a stator core having a plurality of teeth protruding radially outward, an insulator arranged to cover a part of a surface of the stator core, and a plurality of coils including conductive wires wound around the teeth via the insulator, a non-sealed space connected to an external space of the stator unit and a sealed space connected to an internal space of the stator unit are opposed to each other through a contact location where the bearing housing or the base member makes contact with the molding resin part or the insulator, and an angle α of the non-sealed space and an angle β of the sealed space opposed to each other through the contact location in a cross section including the rotation axis are set to satisfy a relationship of α&gt;β. 
     According to the first exemplary embodiment of the present invention, the non-sealed space connected to the external space of the stator unit and the sealed space connected to the internal space of the stator unit are opposed to each other through the contact location where the bearing housing or the base member makes contact with the molding resin part or the insulator. Thus, if the angle α of the non-sealed space and the angle β of the sealed space opposed to each other through the contact location in the cross section including the rotation axis are set to satisfy a relationship of α&gt;β, it is possible to prevent water droplets from entering the inside. 
     The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a vertical sectional view of a motor according to a first embodiment. 
         FIGS. 2 and 3  are partial vertical sectional views of the motor according to the first embodiment. 
         FIG. 4  is a vertical sectional view of a motor according to a second embodiment. 
         FIG. 5  is a vertical sectional view of a motor according to a third embodiment. 
         FIG. 6  is a partial vertical sectional view of a motor according to a modification. 
         FIG. 7  is a partial vertical sectional view of a motor according to another modification. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Exemplary preferred embodiments of the present invention will now be described with reference to the drawings. In the present invention, the direction parallel to the rotation axis of a motor including a stator unit will be referred to as “axial direction”, the direction orthogonal to the rotation axis of the motor will be referred to as “radial direction”, and the direction along the circular arc about the rotation axis of the motor will be referred to as “circumferential direction”. Furthermore, in the present invention, the shapes and arrangement relationships of the respective parts will be described under the assumption that the axial direction is a vertical direction and the circuit board side with respect to a stator is a lower side. However, the definition of the vertical direction is not intended to limit the orientation of the motor according to the present invention at the time of manufacture and using the same. 
       FIG. 1  is a vertical sectional view of a motor  1 A including a stator unit  2 A according to a first embodiment of the present invention.  FIG. 2  is a partial vertical sectional view of a cross section including a rotation axis  9 A of a motor  1 A. 
     The motor  1 A is used as, for example, a blower for supplying a cooling air flow in a home base electric appliance such as a refrigerator or the like, or a communication base station in which a plurality of electronic devices are arranged. The motor  1 A preferably includes an impeller  6 A having a plurality of blades  62 A. However, the motor  1 A of the present invention may not include the impeller  6 A. 
     As shown in  FIG. 1 , the motor  1 A preferably includes a stator unit  2 A and a rotor unit  3 A. The rotor unit  3 A is rotatably supported with respect to the stator unit  2 A. In addition, the rotor unit  3 A rotates about a rotation axis  9 A extending in a vertical direction. 
     The stator unit  2 A preferably includes a stator  21 A, a base member  22 A, a circuit board  24 A, and a molding resin part  25 A. The base member  22 A preferably includes a bearing housing  23 A, a base protruding portion  221 A, and a base bottom plate portion  222 A. The inner circumferential surface of the base protruding portion  221 A extends in a cylindrical shape along the rotation axis  9 A. The base bottom plate portion  222 A extends radially outward from the lower end of the base protruding portion  221 A. The stator  21 A is an armature fixed to the outer circumferential surface of the bearing housing  23 A. 
     The bearing housing  23 A of the present embodiment is a cylindrical member extending along the vertically-extending rotation axis  9 A. The lower portion of the bearing housing  23 A is fixed to the inner circumferential surface of the base member  22 A by, for example, an adhesive agent. A bearing unit  231 A is disposed radially inward of the bearing housing  23 A. For example, a ball bearing is used for the bearing unit  231 A. The outer ring of the bearing unit  231 A is fixed to the inner circumferential surface of the bearing housing  23 A. The inner race of the bearing unit  231 A rotatably supports a below-described shaft  31 A. Thus, the shaft  31 A is rotatably supported with respect to the base member  22 A. However, instead of the ball bearing, the motor  1 A may include another type of bearing unit such as a sliding bearing, a fluid bearing, or the like. In the present embodiment, the bearing housing  23 A is formed of a member different from the base member  22 A. However, the bearing housing  23 A and the base member  22 A may be formed of a single member. 
     The rotor unit  3 A preferably includes a shaft  31 A, a rotor holder  32 A, a plurality of magnets  33 A, and an annular member  34 A. The shaft  31 A is a columnar member arranged along the rotation axis  9 A. At least a part of the shaft  31 A is disposed radially inward of the bearing housing  23 A. The shaft  31 A is rotatably supported by the base member  22 A via the bearing unit  231 A. 
     As the material of the rotor holder  32 A, for example, a metal such as iron or the like which is a magnetic material is used. The rotor holder  32 A preferably includes a holder top plate portion  321 A and a holder cylindrical portion  322 A. The holder top plate portion  321 A extends substantially perpendicularly to the rotation axis  9 A. The central portion of the holder top plate portion  321 A is fixed to the shaft  31 A via the annular member  34 A. As a result, the rotor holder  32 A rotates together with the shaft  31 A. The holder cylindrical portion  322 A extends in a cylindrical shape from the outer peripheral portion of the holder top plate portion  321 A toward the lower side in the axial direction. 
     As shown in  FIG. 1 , the motor  1 A of the present embodiment preferably includes an impeller  6 A for use as a blower that supplies an air flow. The impeller  6 A preferably includes an impeller cup  61 A and a plurality of blades  62 A. The impeller cup  61 A is fixed to the rotor holder  32 A. The blades  62 A extend radially outward from the outer circumferential surface of the impeller cup  61 A. When driving the motor  1 A, the impeller  6 A rotates together with the rotor holder  32 A and the shaft  31 A. The blades  62 A are arranged at substantially equal intervals in the circumferential direction. The number of the blades is not particularly limited. 
     The magnets  33 A are disposed on the inner circumferential surface of the holder cylindrical portion  322 A. The radial inner surfaces of the magnets  33 A are magnetic pole surfaces radially opposed to the radial outer end surfaces of teeth  42 A. The magnets  33 A are arranged at equal intervals in the circumferential direction so that the magnetic pole surfaces having an N pole and the magnetic pole surfaces having an S pole are alternately arranged. 
     Instead of the magnets  33 A, a single annular magnet may be used. When the annular magnet is used, the N pole and the S pole may be alternately magnetized in the circumferential direction on the inner circumferential surface of the annular magnet. Further, the magnets may be embedded in the rotor holder  32 A. In addition, the rotor holder  32 A may be molded with a resin mixed with a magnetic material powder. The rotor holder  32 A may be fixed to the shaft  31 A. 
     The stator  21 A is an armature that generates a magnetic flux in response to a drive current. The stator  21 A preferably includes a stator core  211 A, an insulator  212 A, and a plurality of coils  213 A. The stator core  211 A is formed of a laminated steel plate in which electromagnetic steel plates are laminated in the axial direction. The stator core  211 A preferably includes an annular core back  41 A surrounding the rotation shaft  9 A and a plurality of teeth  42 A protruding radially outward from the core back  41 A. The teeth  42 A are arranged at equal intervals in the circumferential direction. 
     The insulator  212 A covers at least a part of the surface of the stator core  211 A. As the material of the insulator  212 A, a resin of an insulating material is used. The insulator  212 A preferably includes an upper insulator  43 A covering the upper portion of the stator core  211 A and a lower insulator  44 A covering the lower portion of the stator core  211 A. In addition, the coils  213 A preferably include conductive wires wound around the teeth  42 A via the insulator  212 A. 
     The circuit board  24 A is electrically connected to the stator  21 A. The circuit board  24 A is disposed substantially perpendicularly to the rotation axis  9 A on the lower side of the stator  21 A. An electric circuit for supplying a drive current to the coils  213 A is mounted on the circuit board  24 A. The end portions of the conductive wires constituting the coils  213 A are electrically connected to the electric circuit on the circuit board  24 A. A current supplied from an external power source flows to the coils  213 A via the circuit board  24 A. 
     The molding resin part  25 A is a resin-made member covering at least a part of the stator  21 A and the circuit board  24 A. For example, a thermosetting unsaturated polyester resin is used as the material of the molding resin part  25 A. The molding resin part  25 A is obtained by pouring a resin into a cavity of a mold in which the stator  21 A and the circuit board  24 A are accommodated, and curing the resin. 
     As shown in  FIG. 2 , the molding resin part  25 A of the present embodiment preferably includes a molding resin cylindrical portion  251 A and a molding resin bottom portion  252 A. The molding resin cylindrical portion  251 A extends in a substantially cylindrical shape in the axial direction. The stator  21 A is covered with the resin which forms the molding resin cylindrical portion  251 A. However, a part of the stator  21 A including the radial outer end surfaces of the teeth  42 A may be exposed from the molding resin cylindrical portion  251 A. The magnets  33 A of the rotor unit  3 A are disposed radially outward of the molding resin cylindrical portion  251 A. For example, the molding resin bottom portion  252 A bulges radially outward in the lower end portion of the molding resin cylindrical portion  251 A. In the present embodiment, the outer diameter of the circuit board  24 A is larger than the outer diameter of the teeth  42 A. A part of the radial outer portion of the circuit board  24 A axially overlaps with the magnets  33 A. Therefore, when the circuit board  24 A is covered with the molding resin part  25 A, the molding resin bottom portion  252 A is arranged axially lower than the magnets  33 A. 
     As described above, the circuit board  24 A is covered with the molding resin part  25 A. As a result, it is possible to suppress entry of water droplets into the circuit board  24 A. Moreover, it is possible to prevent occurrence of a short circuit between the terminals on the circuit board  24 A. 
     A gap  253 A narrower than the periphery is formed between the radial outer surface of the molding resin bottom portion  252 A and the radial inner surface of a base protrusion  223 A extending axially upward from the base bottom plate portion  222 A. As a result, it is possible to suppress entry of water droplets into the inside of the stator unit  2 A. In addition, a labyrinth structure may be formed by at least a part of the narrow gap  253 A. As used herein, the term “labyrinth structure” refers to a structure in which intricate gaps are provided between two opposing members by forming the two opposing members in a convex shape and a concave shape. This makes it possible to further suppress entry of water droplets through the gap  253 A. 
     In the manufacturing process of the motor  1 A, the molding resin part  25 A is formed by supplying a resin to around the stator  21 A and the circuit board  24 A at once. Thus, it is possible to enhance the productivity. The molding resin part  25 A may further have a structure that covers at least a part of the bearing housing  23 A. 
     At the time of driving the motor  1 A, a drive voltage is supplied from an external power source to the coils  213 A via the circuit board  24 A. As a result, a magnetic flux is generated in the teeth  42 A of the stator core  211 A. Then, a circumferential torque is generated by the action of the magnetic flux between the teeth  42 A and the magnets  33 A. As a result, the rotor unit  3 A rotates about the rotation axis  9 A. 
     Subsequently, the structure of the contact location between the base member  22 A and the molding resin part  25 A according to the present embodiment will be described.  FIGS. 2 and 3  are partial vertical sectional views of a cross section including the rotation axis  9 A of the motor  1 A. 
     As shown in  FIG. 2 , the base protruding portion  221 A of the base member  22 A preferably includes a conical inclined surface inclined with respect to the radial direction and extending away from the stator core  211 A as going radially outward. The molding resin bottom portion  252 A of the molding resin part  25 A is bent in the radial direction by coming into contact with the inclined surface  50 A. A non-sealed space  52 A connected to the external space of the stator unit  2 A and a sealed space  53 A connected to the internal space of the stator unit  2 A are opposed to each other through a contact location  51 A. Instead of the molding resin part  25 A or in addition to the molding resin part  25 A, the insulator  212 A may make contact with the inclined surface  50 A of the base protruding portion  221 A. The term “sealed space” includes a case where the sealed space is completely sealed and not connected to the external space at all and a case where the sealed space is slightly connected to the external space via a minute gap described later or the like. A space which does not correspond to the “sealed space”, namely a space which is completely connected to the external space, is defined as “non-sealed space”. 
     As shown in  FIG. 3 , at the contact location  51 A, a minute gap may be generated between the molding resin bottom portion  252 A and the base protruding portion  221 A. In the present embodiment, not only a case where a gap is not formed due to complete contact but also a case where such a small gap is formed will be referred to as “contact”. In  FIG. 3 , an angle α of the non-sealed space  52 A and an angle β of the sealed space  53 A opposed to each other through the contact location  51 A satisfy a relationship of α&gt;β. Specifically, the angle α is an angle formed between the molding resin bottom portion  252 A and the base protruding portion  221 A in a portion of the non-sealed space  52 A adjacent to the contact location  51 A. Specifically, the angle β is an angle formed between the molding resin bottom portion  252 A and the base protruding portion  221 A in a portion of the sealed space  53 A adjacent to the contact location  51 A. 
     In this situation, description will be made on a phenomenon occurring when water droplets intrude from the external space of the stator unit  2 A through the contact location  51 A, namely when water droplets  55 A intrude from the side of the non-sealed space  52 A connected to the external space of the stator unit  2 A into the sealed space  53 A connected to the internal space of the stator unit  2 A, via the gap of the contact location  51 A. 
     In  FIG. 3 , among the intruding water droplets  55 A, a water droplet  551 A existing on the side of the non-sealed space  52 A and a water droplet  552 A existing on the side of the sealed space  53 A are respectively applied with a force Fα and a force Fβ that draw the water droplet  551 A and the water droplet  552 A toward the minute gap of the contact location  51 A. These forces are forces generated due to the so-called “capillary phenomenon”. 
     The force Fα is a force by which the water droplet  551 A existing on the side of the non-sealed space  52 A tries to climb up the gap of the contact location  51 A. The force Fβ is a force by which the water droplet  552 A existing on the side of the sealed space  53 A tries to go down along the gap of the contact location  51 A. The forces Fα and Fβ act in the opposite directions with respect to the water droplet  552 A. 
     The “capillary phenomenon” is influenced by the surface tension, the density, the size of a gap, and the like. The water droplet  551 A existing on the side of the non-sealed space  52 A and the water droplet  552 A existing on the side of the sealed space  53 A are not different in physical properties, are arranged in substantially the same manner and are opposed to each other via the common gap of the contact location  51 A. Therefore, in addition to the angles α and β opposed to each other via the gap of the contact location  51 A, the numerical values that affect the force Fα and the force Fβ are equal to each other. In general, the smaller the size of the gap, the larger the force of drawing the water droplet into the gap by the “capillary phenomenon”. Since the angle α of the non-sealed space  52 A is larger than the angle β of the sealed space  53 A, the size of the gap is smaller on the side of the sealed space  53 A than on the side of the non-sealed space  52 A. 
     Therefore, the force Fβ applied to the water droplet  552 A existing on the side of the sealed space  53 A is larger than the force Fα applied to the water droplet  551 A existing on the side of the non-sealed space  52 A. Accordingly, even if the water droplet  55 A tries to enter the sealed space  53 A from the side of the non-sealed space  52 A, the water droplet  55 A is pushed back. This makes it possible to suppress the entry of water droplets into the sealed space  53 A from the outside of the stator unit  2 A, namely the entry of water droplets into the inside of the motor  1 A including the stator unit  2 A. 
     When the molding resin bottom portion  252 A and the base protruding portion  221 A make complete contact with each other at the contact location  51 A so that no minute gap is generated, needless to say, it is possible to prevent the entry of water droplets from the outside of the stator unit  2 A, namely the entry of water droplets into the motor  1 A. 
     At the contact location  51 A, the molding resin bottom portion  252 A of the molding resin part  25 A and the base protruding portion  221 A of the base member  22 A make surface-to-surface contact with each other over the entire circumference around the rotation axis  9 A. This makes it possible to further stabilize the contact state. Instead of the molding resin part  25 A, the insulator  212 A may make surface-to-surface contact with the base member  22 A. 
     In addition, the molding resin part  25 A and the insulator  212 A are made of a resin having elasticity. Thus, it is easy to maintain the contact state with the base member  22 A, whereby the waterproofness is enhanced. 
     Furthermore, the motor  1 A of the present embodiment preferably includes an annular labyrinth structure  60 A disposed in at least a part of the space surrounded by the bearing housing  23 A, the rotor holder  32 A and the molding resin part  25 A. By providing the labyrinth structure  60 A, it is possible to suppress the radially inward entry of water droplets in the space between the rotor unit  3 A and the stator unit  2 A. Accordingly, it is possible to suppress the entry of water droplets into the rotor unit  3 A and to further enhance the waterproofness of the motor  1 A. 
     Moreover, as described above, the rotor unit  3 A of the present embodiment preferably includes an annular member  34 A arranged to connect the shaft  31 A and the rotor holder  32 A. The labyrinth structure  60 A is provided in at least a part of the space surrounded by the annular member  34 A, the bearing housing  23 A, the rotor holder  32 A and the molding resin part  25 A. More specifically, an intricate gap is provided between the protrusions provided in the annular member  34 A and the recesses provided in the molding resin part  25 A. As a result, it is possible to suppress the entry of water droplets into the rotor unit  3 A and to enhance the waterproofness of the motor  1 A. 
     Subsequently, a second embodiment of the present invention will be described.  FIG. 4  is a vertical sectional view of a motor  1 B including a stator unit  2 B according to the second embodiment. In the following description, differences from the first embodiment will be mainly described. Redundant description will be omitted for the parts equivalent to those of the first embodiment and the parts already described in the first embodiment. 
     As shown in  FIG. 4 , the base member  22 B preferably includes a base protruding portion  221 B protruding in the axial direction and a base bottom plate portion  222 B. The base protruding portion  221 B extends in a cylindrical shape along the rotation axis  9 B. The base bottom plate portion  222 B extends radially outward from the lower end portion of the base protruding portion  221 B. 
     Furthermore, the base bottom plate portion  222 B of the base member  22 B preferably includes a planar surface  50 B extending perpendicularly to the rotation axis  9 B. The molding resin bottom portion  252 B of the molding resin part  25 B makes contact with the planar surface  50 B. Moreover, a non-sealed space  52 B connected to the external space of the stator unit  2 B and a sealed space  53 B connected to the internal space of the stator unit  2 B are opposed to each other through a contact location  51 B. Similar to the first embodiment, the angle of the non-sealed space  52 B opposed to the sealed space  53 B through the contact location  51 B is made larger than the angle of the sealed space  53 B. Thus, it is possible to suppress the entry of water droplets into the sealed space  53 B from the outside of the stator unit  2 B, namely the entry of water droplets into the motor  1 B including the stator unit  2 B. Instead of the molding resin part  25 B, an insulator  212 B may make contact with the planar surface  50 B. 
     Subsequently, a third embodiment of the present invention will be described.  FIG. 5  is a vertical sectional view of a motor  1 C including a stator unit  2 C according to the third embodiment. In the following description, differences from the above-described embodiments will be mainly described. Redundant description will be omitted for the parts equivalent to those of the above-described embodiments and the parts already described in the above-described embodiments. 
     As shown in  FIG. 5 , the base member  22 C preferably includes a base protruding portion  221 C protruding in the axial direction and a base bottom plate portion  222 C. The base protruding portion  221 C extends in a cylindrical shape along the rotation axis  9 C. The base bottom plate portion  222 C extends radially outward from the lower end portion of the base protruding portion  221 C. 
     Furthermore, the base bottom plate portion  222 C of the base member  22 C preferably includes a conical inclined surface  50 C inclined with respect to the radial direction and extending away from the stator core  211 C as going radially inward. The molding resin bottom portion  252 C of the molding resin part  25 C makes contact with the inclined surface  50 C. Moreover, a non-sealed space  52 C connected to the external space of the stator unit  2 C and a sealed space  53 C connected to the internal space of the stator unit  2 C are opposed to each other through a contact location  51 C. As in the first embodiment, the angle of the non-sealed space  52 C opposed to the sealed space  53 C through the contact location  51 C is made larger than the angle of the sealed space  53 . Thus, it is possible to suppress the entry of water droplets into the sealed space  53 C from the outside of the stator unit  2 C, namely the entry of water droplets into the motor  1 C including the stator unit  2 C. Instead of the molding resin part  25 C, an insulator  212 C may make contact with the inclined surface  50 C. 
     While exemplary embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. 
       FIG. 6  is a partial vertical sectional view of a cross section including a rotation shaft  9 D of a motor  1 D according to a modification. In the example of  FIG. 6 , the molding resin part  25 D and the base member  22 D make line-to-line contact with each other over the entire circumference around the rotation axis  9 D at the contact location  51 D. Thus, even if the thin molding resin part  25 D is used, a contact structure can be formed and the cost can be reduced. In  FIG. 6 , the base member  22 D preferably includes a conical inclined surface  50 D inclined with respect to the radial direction and extending away from the stator core  211 D as going radially outward. The molding resin part  25 D comes into contact with the inclined surface  50 D in a radially deflected state. A non-sealed space  52 D connected to the external space of the stator unit  2 D and a sealed space  53 D connected to the internal space of the stator unit  2 D are opposed to each other through the contact location  51 D. 
     The molding resin part or the insulator may make contact with the bearing housing. For example, the non-sealed space connected to the external space of the stator unit and the sealed space connected to the internal space of the stator unit are opposed to each other through the contact location between the molding resin part or the insulator and the bearing housing. The angle α of the non-sealed space and the angle β of the sealed space opposed to each other may satisfy a relationship of α&gt;β. Even with such a structure, it is possible to suppress the entry of water droplets into the motor including the stator unit. 
     Furthermore, the molding resin part or the insulator and the bearing housing may make surface-to-surface contact or line-to-line contact with each other over the entire circumference around the rotation axis. 
     Moreover, in the bearing housing, an inclined surface inclined with respect to the radial direction or a planar surface extending perpendicularly to the rotation axis may be provided. The molding resin part or the insulator may come into contact with the inclined surface or the planar surface. The non-sealed space connected to the external space of the stator unit and the sealed space connected to the internal space of the stator unit may be opposed to each other through the contact location. 
       FIG. 7  is a partial vertical sectional view of a cross section including a rotation axis  9 E of a motor  1 E according to another modification. In  FIG. 7 , the base member  22 E preferably includes a base protruding portion  221 E protruding in the axial direction and a base bottom plate portion  222 E extending radially outward from the lower end portion of the base protruding portion  221 E. At the contact location  51 E, the molding resin part  25 E makes contact with the base protruding portion  221 E of the base member  22 E. Instead of the molding resin part  25 E, the insulator  212 E may make contact with the base protruding portion  221 E. In addition, it may be possible to employ a structure in which the molding resin part  25 E or the insulator  212 E makes contact with a protruding portion provided in the bearing housing  23 E. 
     The bearing housing or the base member may be made of a metal or a resin. It is possible to secure high strength when the bearing housing or the base member made of a metal makes contact with the molding resin part or the insulator made of a resin at the aforementioned contact location. In addition, when the bearing housing or the base member made of a resin makes contact with the molding resin part or the insulator made of a resin, the contact state can be maintained with ease, and the waterproofness can be enhanced. 
     The present invention can be applied to, for example, a stator unit, a motor, and a blower. 
     Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises. 
     While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.