JP6686421B2 - Electric motor - Google Patents

Description

The present invention relates to an electric motor including a bushing for drawing a lead wire connected to a circuit board from the inside covered with a motor outer shell and a bracket to the outside.

  2. Description of the Related Art As a conventional electric motor, there is an inner rotor type electric motor in which a rotor including a permanent magnet is rotatably arranged inside a stator that generates a rotating magnetic field. This type of electric motor includes, for example, a brushless DC motor for rotationally driving a blower fan mounted in an outdoor unit of an air conditioner.

Such an electric motor includes, for example, a stator covered with a motor outer shell formed of resin, a rotor, a circuit board, and a bracket, and a lead wire connected to the circuit board is connected to the motor outer shell and the bracket. It is equipped with a bushing for drawing from the inside covered with and to the outside. The motor outer shell has an end surface perpendicular to the axial direction of the rotor and an outer peripheral surface continuously formed on the end surface and parallel to the axial direction of the rotor on the side of the circuit board on which the bushing is arranged.

  This bushing has, for example, a type having a pair of holding pieces for holding the lead wire from both sides (for example, Patent Document 1). Of the pair of holding pieces, one holding piece is formed in a substantially L-shape, and is brought into contact with a first contact portion which is in contact with the end surface of the motor outer shell and an outer peripheral surface of the motor outer shell. The second contact portion is provided.

In electric motor having such a bushing, when water such as dew condensation water in the interior covered with a motor shell and the bracket has occurred outside drainage of generated water from the interior covered with a motor shell and the bracket There is a need to. Therefore, as an internal drainage measures covered by the motor shell and the bracket, for example, the drainage passage communicating inside and outside covered with a motor shell and the bracket, provided on one of the holding pieces of the bushing It is possible to form from the 1st contact part toward the 2nd contact part.

However, for example, in the electric motor mounted in the outdoor unit of the air conditioner, small insects such as ants may be separated from the motor casing and the bracket from the drainage passage depending on the size of the drainage passage formed in one holding piece of the bushing. There is a risk that it may enter the covered interior and cause a short circuit in the wiring or parts provided on the circuit board.

JP, 2013-138551, A

In view of the above problems, the present invention is an electric motor including a bushing of a type having a pair of holding pieces for holding a lead wire from both sides, and in a drainage passage provided in the bushing, a worm is a motor shell and a bracket. It is an object of the present invention to provide an electric motor capable of preventing its entry into a covered interior.

In order to solve the above-mentioned problems, an electric motor of the present invention includes a stator covered with a motor outer shell, a rotor, a circuit board, and a bracket, and a lead wire connected to the circuit board is connected to the motor outer shell and the bracket. It is equipped with a bushing for drawing out from the inside covered with and to the outside, and the motor outer shell is connected to the end surface formed perpendicularly to the axial direction of the rotor on the circuit board side where the bushing is arranged, and to be continuous with this end surface An outer peripheral surface formed parallel to the axial direction of the rotor, the bushing has a pair of holding pieces for holding the lead wire, and one holding piece of the pair of holding pieces is L-shaped. A first contact portion that is formed into a shape and that is formed along the end surface of the motor outer shell and contacts the end surface, and a second contact portion that is formed along the outer peripheral surface of the motor outer shell and contacts the outer peripheral surface. Equipped with the first The contact portion and the second contact portion are formed in the widthwise center of one of the holding pieces from the first contact portion to the second contact portion, so that water generated inside the motor outer shell and the bracket is covered. A drainage passage for draining water is provided, and the drainage passage is recessed from a contact surface between the first contact portion and the end surface of the first contact portion, and a contact surface between the outer peripheral surface of the second contact portion and the first drain passage. A second drainage passage, wherein the depth of the first drainage passage is formed deeper than the depth of the second drainage passage, and the depth of the second drainage passage is set to a minute depth to prevent invasion of small insects. It is characterized by being formed.

According to the electric motor of the present invention, in an electric motor including a bushing of a type having a pair of holding pieces for holding a lead wire, a worm is covered with a motor outer shell and a bracket from a drainage passage provided in the bushing . It is possible to prevent intrusion into the inside.

It is explanatory drawing which shows the electric motor provided with the bushing of this invention, (a) is sectional drawing, (b) is a partial perspective view. It is explanatory drawing which shows the position of the motor outline in which the bushing of the electric motor of this invention is arrange | positioned, (a) is a partial front view, (b) is a partial top view. It is an external appearance perspective view which shows the bushing of the electric motor of this invention. It is explanatory drawing explaining the attachment aspect of the electric motor of this invention, (a) is a partial external appearance perspective view, (b) is a partial top view. It is explanatory drawing which shows the state which made the bushing of the electric motor of this invention contact | abut to the motor outline, (a) is a partial sectional view, (b) is a partial front view.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 5 are diagrams illustrating the electric motor according to the present embodiment. As shown in FIGS. 1 to 5, the electric motor 1 is an inner rotor type electric motor in which a rotor 3 is rotatably arranged inside a stator 2. For example, a blower fan mounted in an outdoor unit of an air conditioner. Is a brushless DC motor for rotationally driving.

  As shown in FIG. 1, this electric motor 1 has a cylindrical stator 2 and a rotor 3 arranged coaxially with the stator 2 on the inner diameter side of the stator 2, and the stator 2 is combined in a mold. By integrally molding the resin with the stator core 21, the whole of the stator core 21 is covered with a motor outer shell 40 formed of synthetic resin, except for the teeth surface 22.

  A first bracket 41 that accommodates a bearing 33 that supports a shaft 32, which will be described later, provided in the rotor 3 is provided in a motor outer shell 40 that covers one end surface side (lower surface in FIG. 1) of the stator 2. A circuit board 5 having a control unit for driving the electric motor 1 is mounted on a motor outer casing 40 that covers the other end surface side (upper surface in FIG. 1) of the stator 2, and the shaft 32 is supported so as to cover the circuit board 5. A second bracket 42 for accommodating another bearing 34 is provided.

  The rotor 3 includes a shaft 32 rotatably supported by bearings 33 and 34, a disk-shaped back yoke 35 coaxially attached to the shaft 32, and a plurality of rotors arranged on the outer diameter side of the back yoke 35. And a plate-shaped rotor magnet 31. At both ends of the stator 2 and the rotor 3, the first bracket 41 is integrally formed with the motor outer shell 40, the second bracket 42 is press-fitted into the motor outer shell 40, and the inside of the motor outer shell 40 is closed to form a waterproof structure. .

A bushing 6 is provided between the motor shell 40 and the second bracket 42 to draw out the lead wire 51 connected to the circuit board 5 from the inside covered with the motor shell 40 and the second bracket 42 to the outside. ing. In describing the bushing 6, first, the structure of the motor outer shell 40 with which the bushing 6 is brought into contact will be described.

  As shown in FIGS. 1, 2, and 4, the motor outer shell 40 is formed continuously on the end surface 401, which is formed on the output side (the bearing 34 side) of the shaft 32 and is perpendicular to the axial direction of the shaft 32. An outer peripheral surface 402 that is parallel to the axial direction of the shaft 32 is formed. On the outer peripheral side of the end surface 401 (upper surface in FIG. 1) of the motor outer shell 40, an outer peripheral convex portion 407 continuously formed on the end surface 401 and protruding in the axial direction of the shaft 32 is provided. The circuit board 5 is placed on the outer peripheral protrusion 407, and a notch 403 is provided at a position where the bushing 6 is arranged. The notch portion 403 is notched so as to have an opening width corresponding to the width of the bushing 6 from the outer circumference of the motor outer shell 40 toward the inner side.

  An outer peripheral recess 404 is formed on the outer peripheral side of the cutout portion 403 for forming an outer peripheral surface 402, which is in contact with a second contact portion 68 of the bushing 6 described later, at a location recessed from the outermost periphery of the motor outer shell 40. Has been. The outer peripheral recess 404 supports the bushing 6 by locking the second contact portion 68 of the bushing 6. The bushings 6 are supported by fitting the notches 69, 69 formed at both ends of the bushing 6 to the side walls 405, 405 formed on both sides of the notch 403.

  As shown in FIGS. 3 and 4, the bushing 6 has a pair of a first holding piece 61 and a second holding piece 62 that sandwich and hold the lead wire 51, and the first holding piece 61 and the second holding piece 62. Each of 62 is made of an insulating synthetic resin. Each of the first holding piece 61 and the second holding piece 62 has a first facing surface 63 and a second facing surface 64 that face each other and abut. A first guide portion 65 and a second guide portion in which the lead wire 51 is guided by being recessed from the first facing surface 63 and the second facing surface 64, respectively, in the first facing surface 63 and the second facing surface 64. Equipped with 66.

The first holding piece 61 is formed in an L shape and has a first contact portion 67 that contacts the end surface 401 of the motor outer casing 40 and a second contact portion that contacts the outer peripheral surface 402 of the motor outer casing 40. The contact portion 68 is provided. The first contact portion 67 and the second contact portion 68 are formed in the widthwise center of the first holding piece 61 from the first contact portion 67 to the second contact portion 68, and the motor outer shell 40 and the second contact portion 68 are formed . A drainage passage 7 for draining water such as dew condensation water generated inside which is covered with the bracket 42 is provided.

  As shown in FIGS. 4 and 5, the drainage passage 7 includes a first drainage passage 71 that is recessed in a rectangular shape from a contact surface 671 that contacts the end surface 401 of the first contact portion 67, and a second contact portion 68. The second drainage passage 72, which is recessed in a rectangular shape from the contact surface 681 with the outer peripheral surface 402, is provided. Here, when the electric motor 1 is mounted on the outdoor unit of the air conditioner, the shaft 32 extends horizontally and the bushing 6 extends downward from the motor outer shell 40 in the vertical direction in the installed state of the electric motor 1. . In the drainage passage 7 provided in the first holding piece 61 of the bushing 6 at this time, the first drainage passage 71 extends vertically downward and the second drainage passage 72 extends horizontally.

  Therefore, as the drainage passage 7, the first drainage passage 71 has a role of storing water, and the second drainage passage 72 has a role of draining the stored water. The depth D1 of the drainage passage 71 is formed deeper than the depth D2 of the second drainage passage 72. The depth D1 of the first drainage passage 71 is set to 1 mm, for example. Further, the depth D2 of the second drainage passage 72 is formed to be a minute depth so that small insects such as ants do not enter. The depth D2 of the second drainage passage 72 is set to 0.1 mm with respect to the size and type of the worm, for example, based on a small ant (total length 2 mm, head (vertical width 0.15 mm, horizontal width 0.5 mm)). Has been done. As shown in FIG. 5, when the second contact portion 68 of the bushing 6 is in contact with the second drain passage 72, the depth D2 of the second drain passage 72 is equal to that of the second drain passage 72 and the outer peripheral surface 402 of the motor outer shell 40. Corresponds to the gap of the cross section, and the head of the primrose (vertical width 0.15 mm) does not enter this gap.

  The outlet 721 of the second drainage passage 72 is connected to the outside of the motor casing 40 between the outer peripheral recess 404 of the motor casing 40 and the second contact portion 68 of the first holding piece 61. A slit 406 for discharging water is formed. The gap L of the slit 406 is set to 0.1 mm so that small insects such as ants do not enter, like the depth D2 of the second drainage passage 72.

According to the electric motor 1 according to the present embodiment has been described above, the first contact portion 67 second contact portion 68, the center in the width direction of the first holding piece 61, the second person from the first contact portion 67 It is formed over the contact portion 68, provided with a water discharge passage 7 for draining water generated inside covered with a motor shell 40 and the second bracket 42, the drain passage 7, an end face of the first contact portion 67 401 with those from the tangent plane 671 and the first drain passage 71 which is recessed in a rectangular shape, and a second drain passage 72 which is recessed in a rectangular shape from the abutment surface 681 and the outer circumferential surface 402 of the second contact portion 68 with, The depth D1 of the first drainage passage 71 is formed deeper than the depth D2 of the second drainage passage 72, and the depth D2 of the second drainage passage 72 is formed to be a minute depth to prevent entry of small insects. Has been done.
As a result, in the electric motor 1 including the bushing 6 of the type having the pair of the first holding piece 61 and the second holding piece 62 that hold the lead wire 51 in between, worms are discharged from the drainage passage 7 provided in the bushing 6. It is possible to prevent the motor casing 40 and the second bracket 42 from entering the inside.

  In addition, in the electric motor 1 according to the present embodiment, the drainage passage 7 has a structure in which the first drainage passage 71 and the second drainage passage 72, which are recessed in a rectangular shape, are provided, but the present invention is not limited to this, and the shape is triangular or circular. You may make it the structure provided with the 1st drainage passage 71 and the 2nd drainage passage 72 which were recessed in shape. In this case, the depth D1 of the first drainage passage 71 and the depth D2 of the second drainage passage 72 are, for example, D1 = 1 mm and D2 = 0 at the deepest recessed portion of a triangular shape or a circular shape, as described above. It is set to 0.1 mm.

  Further, in the electric motor 1 according to the present embodiment, as the motor outer shell 40, the outer peripheral surface 402 on which the second contact portion 68 of the bushing 6 abuts is provided on the outer peripheral side of the cutout portion 403 from the outermost periphery of the motor outer shell 40. Although the structure is provided with the outer peripheral recess 404 for forming in the recessed portion, the present invention is not limited to this, and the outer peripheral recess 404 is omitted, and the second contact portion 68 of the bushing 6 is provided on the outermost periphery of the motor outer shell 40. You may make it contact | abut.

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Stator 21 Stator core 22 Teeth surface 3 Rotor 31 Rotor magnet 32 Shaft 33, 34 Bearing 35 Back yoke 40 Motor outer shell 401 End surface 402 Outer peripheral surface 403 Notch portion 404 Outer peripheral recess 405 Both side walls 406 Slit 407 Outer peripheral convex portion 41 First bracket 42 second bracket 5 circuit board 51 lead wire 6 bushing 61 first holding piece 62 second holding piece 63 first facing surface 64 second facing surface 65 first guide portion 66 second guide portion 67 first contact portion 671 contact surface 68 second contact portion 681 contact surface 69 notch 7 drainage passage 71 first drainage passage 72 second drainage passage 721 outlet D1 depth of first drainage passage 71 D2 depth of second drainage passage 72 Gap of L slit 406

Claims (2)

A stator, a rotor, a circuit board, and a bracket, which are covered with the motor outer shell, are provided, and lead wires connected to the circuit board are drawn out from the inside covered with the motor outer shell and the bracket to the outside. Equipped with a bushing
The motor outer shell is formed parallel to the axial direction of the rotor so as to be continuous with the end surface formed perpendicular to the axial direction of the rotor on the circuit board side where the bushing is arranged. With an outer peripheral surface,
The bushing has a pair of holding pieces that hold the lead wire therebetween.
One holding piece of the pair of holding pieces is formed in an L shape, and has a first contact portion formed along the end surface of the motor outer shell and contacting the end surface, and the motor outer shell. A second contact portion that is formed along the outer peripheral surface and contacts the outer peripheral surface,
The first abutment portion and the second abutment portion are formed in the widthwise center of the one holding piece from the first abutment portion to the second abutment portion, and include the motor outer shell and the bracket. Equipped with a drainage passage for draining the water generated inside the covered,
The drainage passage has a first drainage passage recessed from a contact surface of the first contact portion with the end surface, and a second drainage passage recessed from a contact surface of the second contact portion with the outer peripheral surface. With and
The depth of the first drainage passage is formed deeper than the depth of the second drainage passage,
The electric motor, wherein the second drainage passage is formed to have a minute depth so as to prevent invasion of small insects. The motor outer shell is provided with an outer peripheral recess for forming the outer peripheral surface at a location recessed from the outermost periphery of the motor outer shell,
A minute gap having the same depth as the depth of the second drain passage connecting the outlet of the second drain passage to the outside of the motor shell is formed between the outer peripheral recess and the second contact portion. The electric motor according to claim 1.

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