JP2010022091A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor for efficiently dissipating heat generated in the motor, while preventing water from entering the motor. <P>SOLUTION: The electric motor includes: a stator formed by winding a coil 17 around a plurality of teeth provided on a stator base 4; a rotor formed of a cylindrical bottomed rotor yoke 60 covering the stator from the front face and a neodymium magnet disposed corresponding to the coil 17 of the stator on a peripheral wall 61 of the rotor yoke 60; and a rotating shaft provided on the center portion of the rotor, the rotating shaft being freely rotatably supported on the center portion of the stator base 4 via a first bearing and a second bearing. In the electric motor, a resin material J is filled between the stator base 4 and the coil 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric motor for driving a cooling fan in which a fan blade is fixed to an outer rotor, for example.

Conventionally, an outer rotor type brushless motor may be used as a fan motor used for cooling a radiator of an automobile.
In this type of electric motor, a coil is wound around a plurality of teeth provided on a stator base to form a stator, and a bottomed cylindrical rotor yoke that covers the teeth and a permanent yoke disposed on the inner peripheral surface of the rotor yoke. The rotor is composed of magnets, and the rotating shaft of the rotor yoke is rotatably supported on the stator base. Fan blades are provided on the outer peripheral wall of the rotor yoke, and when a current is supplied to the coil, a magnetic field is formed on the stator teeth, and a magnetic attraction and repulsive force is generated between the rotor yoke and the permanent magnets. The cooling air is generated in the axial direction of the rotation shaft by rotating and fan blades.

In this type of electric motor, since the rotor as a rotor rotates outside the stator as a stator, if an attempt is made to ensure watertightness inside, a separate cover is required and the size is increased. For this reason, in many cases, the rotor yoke is usually an open type in which the rotor yoke is exposed, and as a result, water easily enters from the outside.
For example, in the device described in Patent Document 1, a waterproof wall is provided to prevent water from entering from the air intake port on the front surface of the rotor yoke provided for cooling the inside. It has the structure which provided the drain hole for discharging | emitting to the exterior (for example, refer patent document 1).
JP 2004-40934 A

However, if an air intake hole is formed on the bottom surface of the rotor yoke, the inside of the motor can be cooled. However, a considerable amount of water enters from the air intake port.
Here, the main heat generating part in the motor is a coil wound around the teeth, and the heat generated in the coil is drawn from the teeth to the outside of the motor through the stator, the stator base and the like. Therefore, there is a problem that the heat drawing distance becomes long and the heat dissipation efficiency is deteriorated.

  Therefore, the present invention has been made in view of the above-described circumstances, and an electric motor that can efficiently release the heat generated inside the motor while suppressing the intrusion of water into the motor. It is to provide.

  In order to solve the above-described problem, the invention according to claim 1 is directed to a plurality of teeth (for example, the teeth 13 in the embodiment) provided on the stator base (for example, the stator base 4 in the embodiment) to the coils (for example, the teeth). A coil 17) in the embodiment is wound to form a stator (for example, the stator S in the embodiment), and a bottomed cylindrical rotor yoke (for example, the rotor yoke 60 in the embodiment) that covers the stator from its front surface, and this A permanent magnet (for example, neodymium magnet 62 in the embodiment) disposed on the inner peripheral surface of the rotor yoke (for example, the peripheral wall 61 in the embodiment) constitutes a rotor (for example, the rotor R in the embodiment), and the center of the rotor A rotating shaft (for example, the rotating shaft 6 in the embodiment) is provided in the section, and this rotating shaft is connected to the step An electric motor rotatably supported by a central portion of the base base via bearings (for example, the first bearing 29 and the second bearing 30 in the embodiment), and a filler is provided between the stator base and the coil. (For example, the resin material J in the embodiment) is filled.

  According to a second aspect of the present invention, a ring portion (for example, the ring portion 92 in the embodiment) that rises along the rotating shaft is formed on the outer peripheral side of the stator base, and the ring portion is formed in the rotor yoke. And the tip is provided so as to overlap the coil wound around the teeth when viewed from the side, and the filler is between the stator base and the coil. A portion surrounded by the ring portion is filled.

  According to a third aspect of the present invention, a terminal for supplying power to the coil (for example, the terminal 24 in the embodiment) is provided between the stator base and the coil and surrounded by the ring portion. ) And the coil (for example, the terminal unit 22 in the embodiment) is arranged, and the filler is filled so as to cover at least the terminal unit.

  According to the first aspect of the present invention, by filling the filler between the coil and the stator base, the heat generated from the coil is directly drawn to the stator base via the filler. . Therefore, since the heat drawing distance can be shortened, the heat dissipation efficiency can be improved and the inside of the motor can be reliably cooled.

  According to the second aspect of the present invention, since the tip of the ring portion of the stator base is formed so as to overlap the coil as viewed from the side, when the filler is filled, the ring portion causes the filler to flow out. Can be blocked. As a result, since the filler can be filled without gaps in the portion surrounded by the ring portion between the coil and the stator base, the heat radiation efficiency between the coil and the stator base is further improved, and the interior of the motor is Cooling can be ensured.

  According to the invention described in claim 3, by filling the filler so as to cover the terminal unit, the waterproofing and vibration resistance of the connecting part between the terminal unit and the coil and the connecting part between the terminal unit and the terminal are improved. It is possible to insulate between the coil and the terminal unit or between the terminal unit and the terminal. Further, the heat generated in the coil is efficiently drawn from the filler to the stator base through the terminal unit and the terminal. Therefore, the inside of the motor can be reliably cooled.

Next, embodiments of the present invention will be described with reference to the drawings. In the following description, the left side of FIG. 1 is the front side, and the right side of FIG. 1 is the rear side.
1 to 3, reference numeral 1 denotes a fan motor. The fan motor 1 is for cooling an automobile radiator. The fan motor 1 includes a brushless type electric motor M and a fan blade 3 supported by a rotor R of the electric motor M. The rotor R is an outer rotor type, and a stator S is provided in the rotor R. The stator base 4 of the stator S is attached to the fan shroud 91.
The stator base 4 is made of aluminum and includes three mounting pieces 5 attached to the fan shroud 91 around the stator base 4. In the central portion of the rear surface of the stator base 4, a housing portion 9 for the sensor unit 8 is formed around the rotating shaft 6 of the rotor R and surrounded by the vertical wall 7. The housing portion 9 has four screws. 10 is closed by the lid 2.

A boss portion 11 is provided at the center of the front surface of the stator base 4. A stepped portion 12 is formed around the boss portion 11, and a stator core 14 having twelve teeth 13 in the radial direction is disposed on the stepped portion 12. The stator core 14 is attached to the boss portion 11 from the axial direction of the rotary shaft 6 by three fixing bolts 15. The stator core 14 is formed by laminating metal plates made of a magnetic material in the axial direction of the rotary shaft 6, and a coil 17 is wound around each tooth 13 via an insulator 16 having a U-shaped cross section as an insulating material. It is disguised. The coil 17 is protected by being covered with a coating material (not shown).
Here, on the inner wall 18 of each insulator 16, ring-shaped insulator rings 19 and 20 that rise in the axial direction of the rotary shaft 6 along the inner wall 18 are locked to the root portion of the insulator 16. A pair of front and rear sides of S are mounted. At the lower part of each insulator ring 19, 20, a cutout portion 37 is provided for reducing the height within an angle range of 90 degrees in order to enhance drainage (see FIG. 2). The stator S is composed of the stator base 4 and the stator core 14 around which the coil 17 is wound.

A recess 21 is formed around the boss 11 on the front surface of the stator base 4, and an annular terminal unit 22 is disposed in the recess 21. The terminal unit 22 is connected to the coils 17 corresponding to the U-phase, V-phase, and W-phase, and is fixed in a state where the U-phase, V-phase, and W-phase terminals 24 are pressed by a double nut 23.
As shown in FIG. 4, a cable 25 is connected to each terminal 24. This cable 25 is for supplying electric power to the coil 17 (terminal unit 22) via each terminal 24, and the terminal part of the terminal 24 and the terminal part of the cable 25 are covered with a waterproof tube 26. In the waterproof tube 26, a connection portion between the terminal portion of the cable 25 and the terminal portion of the terminal 24 is configured as a power feeding unit 120 for supplying power from the cable 25 to the terminal 24.

A mounting hole 28 for the bearing holder 27 is formed at the center of the boss portion 11 of the stator base 4, and the bearing holder 27 is inserted therein.
As shown in FIGS. 5 and 6, the bearing holder 27 is an iron-made cylindrical member, and the first bearing 29 and the second bearing 30 are fitted and fixed to the front end portion and the rear end portion, respectively. The part 31 and the second holding part 32 are stepped. Thus, by forming the bearing holder 27 with an iron member equivalent to the first bearing 29 and the second bearing 30, the degree of expansion and contraction due to the relative heat between the bearing holder 27 and the first and second bearings 29 and 30. Are equivalent.
Therefore, compared with the case where the bearing holder 27 is made of aluminum, the change in the internal gap due to the expansion and contraction of the first bearing 29 and the second bearing 30 due to heat is greatly reduced, and the sound of the first bearing 29 and the second bearing 30 is reduced. The vibration performance can be improved and the life can be extended.

  Three flange portions 33 are formed around the neck portion of the first holding portion 31 of the bearing holder 27, and the flange portions 33 are fixed to the boss portion 11 of the stator base 4 by screws 34. Further, a water shield ring portion 35 extending outward is formed on the periphery of the front end portion of the first holding portion 31, and the water shield ring portion 35 is a cut portion in which a lower portion is cut in an angle range of 90 degrees in order to improve drainage. 38. An insertion hole 36 through which the rotary shaft 6 is loosely inserted is formed in the center portion of the bearing holder 27 on the first holding portion 31 side.

A reduced diameter portion 40 is formed on the outer peripheral portion of the bearing holder 27 over the entire circumference, and an annular gap portion 41 is formed between the mounting hole 28 of the boss portion 11 and the reduced diameter portion. A communication hole 42 communicating with the inside of the bearing holder 27 is formed in the lower portion of 40. The reduced diameter portion 40 is formed in the storage portion 9 of the sensor unit 8 located on the rear end side of the mounting hole 28 of the boss portion 11 through the communication grooves 43 formed at three locations in the circumferential direction on the rear end portion of the bearing holder 27. Communicate.
As shown in FIG. 1, a communication hole 44 is formed in a lower portion of the boss portion 11 of the stator base 4 at a position communicating with the gap portion 41 toward the lower portion, and this communication hole 44 is an outer peripheral wall of the boss portion 11. The terminal unit 22 is opened to the arrangement site.

The mounting hole 28 of the boss portion 11 is formed as a storage portion 9 of the sensor unit 8 at a portion rearward of the rear end portion of the bearing holder 27. A ring-shaped sensor magnet 47 that is fixed to the rear end screw portion 45 of the rotating shaft 6 by a nut 46 and rotates together with the rotating shaft 6 is accommodated in the accommodating portion 9. As shown in FIG. 4, a fan-shaped sensor case 49 is fixed to the screw hole 48 of the stator base 4 with a screw 50 corresponding to the sensor magnet 47. The sensor magnet 47 and the sensor case 49 constitute a sensor unit 8.
The sensor case 49 is a member in which a circuit component 56 is housed. As shown in FIG. 7, the sensor case 49 has a vertical wall 58 on the both ends of the sensor case 49 and a screw hole 48 in the screw hole 48 of the stator base 4. A pair of attachment pieces 51 are formed which are tightened by (see FIGS. 3 and 4). A long mounting hole 52 for positioning is provided in the mounting piece 51 so that the sensor case 49 can be moved along the rotational peripheral surface of the sensor magnet 47.

  As shown in FIGS. 1 and 3, a rib portion 53 extending in the radial direction from the vertical wall 7 of the storage portion 9 is provided in the lower portion of the stator base 4, and a drainage passage 54 is formed in the rib portion 53. . The upper end of the drainage passage 54 communicates with the storage portion 9, the lower end of the drainage passage 54 is not opened linearly, is closed with screws, and the opening end 55 is bent forward and opened at the front surface of the stator base 4. A harness 57 is connected to the circuit component 56 in the sensor case 49.

8 and 9, R represents a rotor, and this rotor R is mainly composed of a bottomed cylindrical rotor yoke 60 that covers the stator S from the front surface and a neodymium magnet 62 disposed on the inner surface of the peripheral wall 61 of the rotor yoke 60. ing.
A boss 64 protruding forward is formed at the center of the bottom wall 63 of the rotor yoke 60, and the rotating shaft 6 is inserted into the boss 64. The distal end portion of the rotating shaft 6 protrudes from the end face of the boss 64, and this protruding portion is a screw portion 65, and a nut 66 is tightened here to fix the rotating shaft 6 to the boss 64 of the rotor yoke 60. The rotary shaft 6 is formed with a flange portion 67 that comes into contact with the bottom wall 63 of the rotor yoke 60 from the back side, and the first bearing 29 is press-fitted and fixed from the rear end side of the rotary shaft 6 so as to come into contact with the flange portion 67. . A plurality of drain holes 68 are formed in the bottom wall 63 of the rotor yoke 60 in the vicinity of the connection portion of the peripheral wall 61 along the circumferential direction.

  The peripheral wall 61 of the rotor yoke 60 is formed thicker than the bottom wall 63, and a magnet cover 69 is press-fitted and fixed to the inner surface of the peripheral wall 61. The opening edge 70 of the peripheral wall 61 of the rotor yoke 60 is disposed so as to face the front surface of the stator base 4 and extends to a position close to form a gap 71 between the front surface of the stator base 4 (see FIG. 1).

  As shown in FIGS. 10 and 11, the magnet cover 69 is formed by forming a plate material into a cylindrical shape, and the opening edge of the rear portion is enlarged to form a diameter-expanded portion 72, and the diameter-expanded portion 72 is formed on the rotor yoke 60. It is press-fitted and fixed to the inner surface of the peripheral wall 61. An inner flange portion 73 directed inward is formed at the opening edge of the front portion. A peripheral wall 74 extending from the enlarged diameter portion 72 to the inner flange portion 73 has a slightly smaller diameter than the inner surface of the peripheral wall 61 of the rotor yoke 60. The neodymium magnets 62 are mounted at eight locations partitioned in the housing portion 75 via the magnet holder 76 (see FIGS. 1 and 8).

  In the magnet cover 69, a plurality of drain holes 59 are formed in the circumferential direction at the ridge line portion between the inner flange portion 73 and the peripheral wall 74. Here, the drain hole 59 of the magnet cover 69 is located slightly inward in the radial direction with respect to the drain hole 68 of the rotor yoke 60, and the drain hole 68 of the rotor yoke 60 is positioned rearward in the axial direction of the rotating shaft 6. The neodymium magnet 62 can be effectively used as an inlet for the filler Z to be filled.

As shown in FIGS. 1, 8, and 9, three attachment holes 77 are formed around the boss 64 of the bottom wall 63 of the rotor yoke 60, and the water shield ring 80 is formed in the attachment hole 77 from the back surface of the bottom wall 63. Rivet 81 is fixed.
As shown in FIG. 12, the water shield ring 80 is an annular member composed of an inner ring portion 82, an outer ring portion 83, and a bottom portion 84, and the outer ring portion 83 is formed so as to increase in diameter toward the outside. The inner ring portion 82 is formed to rise along the axial direction of the rotary shaft 6. The peripheral portion of the outer ring portion 83 is inside the peripheral wall of the insulator ring 19 and close to the midway portion in the height direction, and the inner ring portion 82 is close to the outside of the water shield ring portion 35 of the bearing holder 27, and the water shield ring It stands up to a position that blocks the periphery of the portion 35.

  Accordingly, as shown in FIG. 13, a labyrinth portion 98 that is meandering and is a long path (see an arrow) is formed between the outer ring portion 83 of the water shield ring 80 and the peripheral wall of the insulator ring 19. The labyrinth portion 99 that meanders and is a long path (see arrow) is also formed between the inner ring portion 82 and the water shield ring portion 35 of the bearing holder 27.

As shown in FIG. 1, a resin fan boss 86 constituting a part of the rotor R is attached to the front surface of the bottom wall 63 of the rotor yoke 60 via six screws 85. The fan boss 86 includes a shoulder portion 87 that rises around the boss 64 of the bottom wall 63 of the rotor yoke 60, a bottom wall portion 88 that covers the bottom wall 63 of the rotor yoke 60, and a peripheral wall portion 89 that covers the peripheral wall 61 of the rotor yoke 60 to the middle portion. The fan blade 3 is integrally formed on the peripheral wall portion 89. Here, the outer peripheral portion of the bottom wall portion 88 of the fan boss 86 is formed in a stepped manner so as to be separated from the bottom wall 63 of the rotor yoke 60, so as not to close the drain hole 68 of the rotor yoke 60.
In the vicinity of the opening edge of the peripheral wall portion 89 of the fan boss 86, an annular waterproof ring 90 having a U-shaped cross section is fixed to a fan shroud 91 provided on the mounting piece 5. The waterproof ring 90 is disposed at a position that covers the gap 71 formed between the opening edge 70 of the peripheral wall 61 of the rotor yoke 60 and the front surface of the stator base 4 from the outside.
Therefore, a narrow gap 97 is formed between the opening edge of the fan boss 86 and the front flange portion 90 a of the waterproof ring 90.

  Here, as shown in FIG. 14, the front surface of the stator base 4 is close to the inner surface of the peripheral wall 61 of the rotor yoke 60, and extends to the front side in the axial direction of the rotating shaft 6 from the opening edge 70 of the rotor yoke 60. A ring portion 92 is formed so as to be overlapped. An end edge of the ring portion 92 located at the height H extends to the front side of the rear end edge located at the height K of the coil 17 and is disposed so as to overlap in a side view. 13 is formed in an intricate labyrinth shape. A protrusion 93 is provided at the end portion of the ring portion 92 so as to go to the vicinity of the inner surface of the peripheral wall 61 of the rotor yoke 60. The lower part of the protrusion 93 is cut off at an angle range of 90 degrees (see FIG. 2), and the portion between the peripheral wall 61 of the rotor yoke 60 and the ring part 92 is configured as a drain part 100 in this part.

Therefore, between the opening edge 70 of the rotor yoke 60 and the front surface of the stator base 4, in order to ensure the length of the water intrusion path, the gap between the opening edge 70 of the peripheral wall 61 of the rotor yoke 60 and the front surface of the stator base 4. A labyrinth portion 94 communicating with the gap 71 is formed.
Here, the labyrinth portion 94 wraps further outward from the space between the ring portion 92 and the inner surface of the peripheral wall 61 of the rotor yoke 60 by the protrusion 93, and meanders to form a long path (see arrow).

  As shown in FIG. 1, a resin material (filler) J excellent in heat transfer is filled between the rear end edge of the coil 17 and the recess 21 formed around the boss portion 11 of the stator base 4. Has been. This resin material J is the same material as the coating material of the coil 17 described above, and after the terminal unit 22 is arranged on the stator base 4, the resin material J is filled in the concave portion 21 of the stator base 4 simultaneously with the coating process of the coil 17. . Specifically, the periphery of the terminal unit 22 and the terminal 24 and the periphery of the coil 17 and the terminal unit 22 are filled without a gap.

  Here, the end edge (height H) of the ring portion 92 of the stator base 4 extends forward from the rear end edge (height K) of the coil 17 wound around the teeth 13. The front end of the ring portion 92 is formed so as to overlap the rear end side of the coil 17 when viewed from the side. That is, it is formed in a labyrinth shape that is complicated between the stator base 4 and the teeth 13. Therefore, when filling the forming material of the resin material J, the forming material is blocked by the ring portion 92 even if it overflows from the recess 21. Therefore, since the forming material of the resin material J does not flow out between the stator base 4 and the coil 17, the resin material J is formed around the terminal unit 22 and the terminal 24 and around the coil 17 and the terminal unit 22. The forming material can be filled in a predetermined position without a gap.

Therefore, according to the present embodiment, by filling the resin material J between the coil 17 and the stator base 4, the heat generated from the coil 17 when the electric motor M is operated directly passes through the resin material J. The heat is drawn by the stator base 4. As a result, compared to the conventional case where the heat generated in the coil is transferred from the teeth to the outside of the motor through the stator, stator base, etc., the heat drawing distance can be shortened, improving the heat dissipation efficiency. Thus, the inside of the electric motor M can be reliably cooled.
Further, as described above, the ring portion 92 can block the outflow of the resin material J, and the portion surrounded by the ring portion 92 between the coil 17 and the stator base 4 is filled with the resin material J without a gap. Therefore, the heat radiation efficiency between the coil 17 and the stator base 4 can be further improved, and the interior of the electric motor M can be reliably cooled.
Here, since the electric motor M of the present embodiment does not have an inlet for cooling air in front of the rotor R, the cooling air cannot be taken into the fan motor 1, but the heat generated in the coil 17 is heat. Since heat is drawn by the stator base 4 through the resin material J having high conductivity, it is possible to effectively cool the coil 17 by suppressing the overheating of the coil 17 while eliminating room for water from the front of the rotor R to enter. Can do.

  Moreover, since the resin material J is filled between the stator base 4 and the coil 17 without a gap, water can be prevented from entering between them, and rusting inside the electric motor M can also be prevented. In particular, the resin material J is filled between the coil 17 and the terminal unit 22 and between the terminal 24 and the terminal unit 22, so that the terminal unit 22 is covered with the resin material J. Thereby, the waterproofing and vibration resistance of the connection part between the terminal unit 22 and the coil 17 and the connection part between the terminal unit 22 and the terminal 24 can be improved, and between the coil 17 and the terminal unit 22 or between the terminal unit. It is possible to insulate between the terminal 22 and the terminal 24. Further, the heat generated in the coil 17 is efficiently drawn from the resin material J to the stator base 4 through the terminal unit 22 and the terminal 24. Furthermore, since the forming material of the resin material J does not overflow, the material loss can be reduced, the manufacturing cost can be reduced, and it is not necessary to remove the overflowing material. Can be improved.

Further, as shown in FIG. 15, even when water is splashed on the outer peripheral portion of the fan boss 86, a narrow gap 97 between the opening edge of the fan boss 86 and the front flange portion 90 a of the waterproof ring 90. Therefore, it is difficult for water to enter from here, which is advantageous for waterproofing.
Even if the air flows into the gap 97 (hereinafter, the flow of water is indicated by an arrow) and enters the gap 71 between the opening edge 70 of the peripheral wall 61 of the rotor yoke 60 and the front surface of the stator base 4, the gap 71 The water is discharged to the outside by centrifugal force due to the rotational operation of the rotor yoke 60, and even if it is not discharged, the labyrinth portion 94 that is continuous with the gap 71 as an entrance is meandering, so that it is difficult for water to enter inside. Infiltration of water into the interior is suppressed. Accordingly, since it is possible to prevent the intruded water from reaching the first bearing 29 and the second bearing 30, the outflow of the lubricant in the first bearing 29 and the second bearing 30 is suppressed, and the first bearing 29 and the second bearing 30 are suppressed. The lubricating performance can be maintained.

  By the way, in the labyrinth portion 94, the water whose momentum has been weakened is divided into one that flows downward from here and one that flows to the front side of the stator S, but most of the water flows to the first bearing from the front side by flowing downward. 29 and the second bearing 30 are reduced in amount of water, which is advantageous for the first bearing 29 and the second bearing 30 in terms of water. Here, most of the water that has flowed downward is guided to the lower side along the ring portion 92 as it is, and the water drainage portion between the ring portion 92 from which the protrusion 93 is cut off and the peripheral wall 61 of the rotor yoke 60. The water is quickly drained from 100 through a gap 71 through a gap 97 between the opening edge of the fan boss 86 and the front flange portion 90a of the waterproof ring 90.

  The water flowing forward from the labyrinth portion 94 is prevented from entering further by the labyrinth portion 98 between the outer ring portion 83 of the water shield ring 80 and the peripheral wall of the insulator ring 19, and along the peripheral wall of the insulator ring 19. It is guided to the lower part, moves from the cut portion 37 of the insulator ring 19 through the drain hole 59 of the magnet cover 69 to the drain hole 68 provided on the outer peripheral side of the bottom wall 63 of the rotor yoke 60, and from here the fan boss 86 The inside of the peripheral wall portion 89 is guided downward, and is quickly drained through a gap 97 between the opening edge of the fan boss 86 and the front flange portion 90 a of the waterproof ring 90. Therefore, the labyrinth portion 94 and the labyrinth portion 98 can prevent water from entering twice, so that the first bearing 29 and the second bearing 30 can be reliably prevented from getting wet.

  Further, even if water reaches between the outer ring portion 83 and the inner ring portion 82 of the water shield ring 80 from the labyrinth portion 98, most of the water that has lost its momentum is in contact with the inner ring portion 82 and the bearing of the water shield ring 80. Further intrusion is prevented by a labyrinth portion 99 formed between the holder 27 and the water shield ring portion 35, guided downward along the peripheral wall of the bearing holder 27, and from the cut portion 38 of the water shield ring portion 35. Guided to the outer ring portion 83 of the water shield ring 80 and reaches the drain hole 59 of the magnet cover 69. And it moves to the drain hole 68 in the same manner as described above, and is guided downward in the peripheral wall portion 89 of the fan boss 86 from here, and the gap between the opening edge of the fan boss 86 and the front flange portion 90a of the waterproof ring 90 It is quickly drained through 97. Therefore, in addition to the labyrinth portion 94 and the labyrinth portion 98, the labyrinth portion 99 is also added to prevent water from entering in triplicate. In particular, the first bearing 29 is exposed to water by the labyrinth portion 99 provided immediately before the first bearing 29. This can be surely prevented.

Even if the air inside the bearing holder 27 expands and contracts due to a temperature change, the air passes through the communication hole 42 and the gap 41 and escapes from the communication hole 44, the drainage part 100 and the gap 71, or communicates therewith. It can escape from the drainage passage 54, the open end 55, and the gap 71 through the hole 42, the gap 41, the communication groove 43, and the storage portion 9. Therefore, as in the case where the insides of the first bearing 29 and the second bearing 30 are hermetically sealed, the grease does not flow to the outside due to a change in internal pressure, thereby preventing deterioration of sound vibration performance and deterioration of durability due to lack of lubrication. be able to.
And since the internal space of the bearing holder 27 communicates with the outside in this way, even if the fan motor 1 is submerged or submerged, the internal water can be quickly removed from the path described above. It drains from the gap 71.

  The present invention is not limited to the above-described embodiment. For example, the case where the fan blade 3 is provided on the fan boss 86 has been described. However, the fan blade 3 is not directly provided on the peripheral wall 61 of the rotor yoke 60 without the fan boss 86 being provided. It may be provided. Moreover, although the case where the neodymium magnet 62 was used was demonstrated, if it is a permanent magnet, a ferrite magnet may be sufficient.

It is sectional drawing of the fan motor of embodiment of this invention. It is a front view of the stator of FIG. It is a rear view of FIG. 2 which abbreviate | omitted the sensor unit. It is a rear view of FIG. It is an expanded sectional view of the bracket of FIG. FIG. 6 is a front view of FIG. 5. It is a front view of a sensor case. It is sectional drawing of the rotor yoke of FIG. It is a front view of FIG. It is a side view of the magnet cover of FIG. It is a front view of FIG. It is sectional drawing of the water shield ring of FIG. It is a principal part enlarged view of FIG. It is a principal part enlarged view of FIG. It is sectional drawing which shows the flow of water.

Explanation of symbols

3 Fan blade 4 Stator base 6 Rotating shaft 13 Teeth 17 Coil 29 First bearing (bearing)
30 Second bearing (bearing)
60 rotor yoke 61 peripheral wall (inner peripheral wall)
62 Neodymium magnet (permanent magnet)
70 Opening edge 92 Ring part J Resin material (filler)
S Stator R Rotor

Claims (3)

A stator is formed by winding a coil around a plurality of teeth provided on the stator base, and a bottomed cylindrical rotor yoke that covers the stator from its front surface and a permanent magnet disposed on the inner peripheral surface of the rotor yoke. An electric motor comprising a rotor, provided with a rotation shaft at a central portion of the rotor, and rotatably supporting the rotation shaft at a central portion of the stator base via a bearing,
An electric motor, wherein a filler is filled between the stator base and the coil. A ring portion that rises along the rotating shaft is formed on the outer peripheral side of the stator base, and the ring portion is arranged so as to face the rotor yoke, and a tip thereof is wound around the teeth. Provided to overlap the coil as viewed from the side,
The electric motor according to claim 1, wherein the filler is filled in a portion between the stator base and the coil and surrounded by the ring portion. A terminal unit for connecting the coil and a terminal for supplying power to the coil is disposed between the stator base and the coil and surrounded by the ring portion.
The electric motor according to claim 2, wherein the filler is filled so as to cover at least the terminal unit.

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