JP2003111355A - Structure for cooling motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for cooling a motor incorporated in a washing machine, etc. SOLUTION: A row of wings 4 is formed on the inner surface of a circular cover shaped housing 3 of a rotor 2 and air inlets 5, through which air outside the housing 3 is introduced into the housing 3, are provided in the circular cover shaped housing 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor cooling structure for introducing cooling air into an electric motor.

[0002]

Conventionally, as a cooling structure of an electric motor, the centrifugal force of an impeller rotating together with the electric motor guides the air near the center of the air to the peripheral edge of the impeller, and this air further surrounds the impeller. There is known a technique in which the above-mentioned impeller is housed in an outer case whose air outlet is opened toward the electric motor so as to reach the electric motor without being diffused into the electric motor.

However, in the above-mentioned structure, the outer case, which is a separate component from the impeller, is indispensable in addition to the impeller. Further, since both the impeller and the outer case are added to the electric motor, not only is it difficult to reduce the size of a washing machine or the like into which they are incorporated, but it is also difficult to reduce the manufacturing cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling structure for an electric motor which can blow cooling air efficiently into the electric motor at a very low cost.

[0005]

In a cooling structure for an electric motor according to the present invention, a blade row is formed on an inner surface of a circular lid-shaped housing of a rotor of an electric motor, and air on the outer surface side of the blade row is formed in the circular lid-shaped housing. It is formed with an introduction port for introducing into the space.

Further, the cooling structure for the electric motor according to the present invention is
The blade row is composed of a plurality of plate blades extending from the vicinity of the inlet to the peripheral edge of the circular lid-shaped housing.

Further, the cooling structure for an electric motor according to the present invention is
The blade row consists of spiral blades.

Further, the cooling structure for an electric motor according to the present invention is
A recess recessed toward the rotor is formed near the center of the circular lid-shaped housing, and an inlet is formed on the side wall surface.

Further, the cooling structure for the electric motor according to the present invention is
A bowl-shaped recess that is recessed toward the rotor is formed near the center of the dome-shaped housing, and an inlet is formed on the inclined surface of this side wall.

Further, the cooling structure for an electric motor according to the present invention is
In an outer rotor type electric motor in which the rotor rotates around the stator, the air flowing along the blade rows due to the centrifugal force caused by the rotation of the rotor causes the air gap between the stator of the electric motor and the slots formed in the stator. It flows into the gap.

Further, the cooling structure for an electric motor according to the present invention is
The dome-shaped housing is integrally formed by injection molding of synthetic resin.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIGS. 1 and 2, a cooling structure for an electric motor according to a first embodiment of the present invention has a blade row on the inner surface of a fork-shaped housing 3 of a rotor 2 of the electric motor 1. 4 is formed, and an inlet port 5 for introducing the air on the outer surface side between the blade rows 4 is formed in the circular lid-shaped housing 3. The electric motor 1 is an outer rotor type in which a ring-shaped rotor 2 rotates around a stator 7 provided with an exciting coil 6, but the invention is not limited to this structure. For example, although not shown, in the case of an electric motor in which an inner rotor rotates inside a ring-shaped stator, the circular lid-shaped housing 3 configured as described above may be provided on one side of the inner rotor.

The inner peripheral surface of the rotor 2 is provided with a magnetic pole surface 21 in which permanent magnets 22 are arranged so that the N / S poles are exchanged at predetermined intervals in the circumferential direction. The circular lid-shaped housing 3 does not have to be circular in shape, and may be any member that can form the blade row 4 and the inlet 5 as described above. As shown in FIG. 3, the stator 7 has a magnetic pole surface 21 of the rotor 2.
Radial tooth portions 71 facing each other through a gap 8 are formed on the outer periphery of the slot 7, and the slots 7 that are spaces between the tooth portions 71 are formed.
In 2, the exciting coil 6 is wound around these tooth portions 71,
Further, a gap 9 is formed between the adjacent exciting coils 6.

The blade row 4 is composed of a plurality of blades 41 and long blades 42 radially arranged on the inner surface of the circular lid-shaped housing 3. The plate blade 41 extends from the vicinity of the introduction port 5 to the peripheral edge of the circular lid-shaped housing 3. The long blades 42 are arranged between the blades 41 and extend further toward the center of the circular lid-shaped housing 3 from the plate blades 41, and are formed of reinforcing ribs for ensuring the rigidity of the circular lid-shaped housing 3. It also has a role. The plate blade 41 and the long plate blade 42 are thin plates integrally formed on the inner surface of the circular lid-shaped housing 3 in a posture in which air strikes a surface that crosses the rotation direction of the circular lid-shaped housing 3. The position of the root end 43 of the plate blade 41 substantially coincides with the vicinity of the center of the edge of the introduction port 5. This is because the air that has flowed in from the inlet port 5 is directly wasted without being wasted.
The reason for this is to reach 3.

A spline boss 31 connecting the pivots is formed at the center of the circular lid-shaped housing 3. The pivot is, for example, a shaft whose one end is rotatably supported by a frame or the like of a washing machine via bearings and the other end is meshed with the spline boss 31.
Any axis can be used as long as it rotates. Further, near the center of the circular lid-shaped housing 3 (around the spline boss 31), there is formed a bowl-shaped recess 10 that is recessed to the inner surface side (the inner side of the electric motor 1). The inlet 51 is opened.

When the electric motor 1 is started, the air in the vicinity of the bowl-shaped recess 10 is rotated by the centrifugal force associated with the rotation of the blade row 4 so that the blades 41 and the long blades of the blade row 4 are moved as shown by an arrow i in FIG. Four
2 to reach the inner peripheral edge of the dome-shaped housing 3, and as shown by the arrow o, the direction is changed substantially at a right angle along the inner peripheral surface of the rotor 2, and a gap 8 between the stator 7 and the outer rotor 2, And the gap 9 of the slot 72 formed in the stator 7.
Flow into. On the other hand, a relative negative pressure is generated in the vicinity of the bowl-shaped recess 10 due to the action of the centrifugal force described above, so that the air on the outer surface side of the circular lid-shaped housing 3 is sucked into the inlet port 5 and the inner inlet port 51, and It flows between the blades 41 and the long blades 42 of the row 4.

In particular, the air in the bowl-shaped recess 10 sucked from the inner introduction port 51 has the blades 41 along a straight streamline.
The air on the outer surface side of the circular lid-shaped housing 3 is efficiently introduced into the electric motor 1 with almost no resistance, because the air flows between the long blades 42 and the long blades 42. By thus forming the bowl-shaped recess 10 by immersing the vicinity of the center of the circular lid-shaped housing 3 toward the rotor 2 side, when the rotor 2 is fixedly attached to the screw portion formed on the pivot shaft, the fastening for that is performed. Since the nut can be fixed to the inside of the outer end surface of the circular lid-shaped housing 3 (that is, the nut can be kept in the bowl-shaped recess 10), the overall length of the electric motor 1 can be shortened and the electric motor 1 can be made thin.

Further, by maintaining the rotation of the electric motor 1,
A continuous air flow is formed as shown by arrows i and o. The above-described actions and effects are exhibited regardless of the rotation direction of the rotor 2.

Next, in a cooling structure for an electric motor according to a second embodiment of the present invention, as shown in the outline of the main part of FIG. The magnetic pole surface 21 is formed on the raised portion. The cross-sectional shape is a substantially U-shape as well shown in FIG. The blade row 4 is formed by arranging four plate blades 41 in a cross shape. The introduction port 5 is four fan-shaped openings formed around the spline boss 31 of the circular lid-shaped housing 3 through which the pivot is inserted so as to be located near the root end 43 of each plate blade 41. The other configurations are similar to those of the first embodiment, and therefore, the same reference numerals are given and the description thereof is omitted.

FIG. 5 shows a cross section of a modified example of the cooling structure for an electric motor according to the second embodiment. This is one in which a recess 32 is provided near the center of the dome-shaped housing 3. Specifically, the concave portion 32 having a shape in which a portion corresponding to the root ends 43 of the plate blades 41 opposed to each other is recessed into the inner surface side of the circular lid-shaped housing 3 (inside the electric motor 1) is provided. An inlet 5 is formed on the peripheral surface of the recess 32.

As shown in FIG. 6, in the cooling structure for an electric motor according to the third embodiment, four plate blades 41 constituting the blade row 4 are each curved in a spiral shape, and these are covered with a circular lid. It is arranged radially on the inner surface of 3. The direction in which the four plate blades 41 are curved is downward with respect to the rotation direction of the rotor 2 indicated by the arrow r, that is, the end portions of the four plate blades 41 on the peripheral side are curved in a direction that goes back in the rotation direction. It is a thing. By curving in this way, the amount of intake air is increased, and it becomes difficult for dust and the like to adhere to the plate blades 41 of the blade row 4. Since other configurations are similar to those of the second embodiment,
The same reference numerals are given and the description is omitted.

FIG. 7 shows a cooling structure for an electric motor according to the fourth embodiment. The blade row 4 is composed of four pairs of plate blades 41 in which a pair of plate blades 41 arranged in parallel at a distance are arranged in a cross shape. The arrow r1 is attached to one of the pair of plate blades 41.
A normal rotation flange 44 extending in the normal rotation direction of the rotor 2 is formed, and a reverse rotation flange 45 extending in the reverse rotation direction of the rotor 2 indicated by the arrow r2 is formed on the other side. Further, the electric motor according to the present embodiment has the forward rotation flange 44 and the reverse rotation flange 45 of the circular lid-shaped housing 3.
Introducing ports 5 are formed at positions facing each other.

The cross-sectional shape of each blade 41 is substantially L-shaped as well shown in FIG. The introduction port 5 is a square or circular opening arranged near the root end of the plate blade 41. The forward rotation flange 44 and the reverse rotation flange 45 prevent dust, rainwater, and the like from entering the inside of the electric motor 1 via the inlet 5. Further, since these extending directions are the normal rotation direction and the reverse rotation direction of the rotor 2, no matter which direction the rotor 2 is rotated, the air that has flowed into the vicinity of the plate blade 41 from the introduction port 5 is substantially the same. Along the streamline, the inner peripheral edge of the circular lid-shaped housing 3 is reached, and further, the gap 8 between the stator 7 and the outer rotor 2 and the gap 9 of the slot 72 formed in the stator 7 are reached. Therefore, even when the electric motor 1 is incorporated in a device such as a washing machine in which normal rotation and reverse rotation are repeated, the electric motor 1 is cooled uniformly regardless of the rotation direction of the rotor 2.

A cruciform ridge 33 may be provided on the inner surface of the dome-shaped housing 3. Further, another plate blade 411 shown by a broken line in the figure may be additionally provided on the inner surface of the circular lid-shaped housing 3 so as to correspond to the plate blade 41 provided on the outer surface of the circular lid-shaped housing 3. The other configurations are similar to those of the third embodiment, and therefore, the same reference numerals are given and the description thereof is omitted.
The peripheral edge of the rotor 2 is omitted in FIG.

The method of manufacturing the rotor 2 described above can be arbitrarily selected, but the shape of the circular lid-shaped housing 3 of the rotor 2 is in consideration of injection molding. In order to achieve a dramatic reduction in the manufacturing process and a drastic reduction in the manufacturing cost as an effect of the present invention, it is preferable to integrally form the resin by injection molding.

That is, a well-known screw type injection molding machine often uses a separate type mold composed of a fixed mold and a movable mold. For example, in order to manufacture the rotor 2 of the electric motor 1 according to the first embodiment, since the inner introduction port 51 of the circular lid-shaped housing 3 is formed on the inclined surface 11 of the bowl-shaped recess 10, the inner introduction is performed. The core of the movable mold for forming the mouth 51 can be pulled out straight from this portion in the direction of arrow b in FIG. That is, the dome shaped housing 3 is
Since there is no part that has a shape that appears and disappears in a direction orthogonal to the moving direction of the movable mold, the mold can be released by simply advancing and retracting the protruding bar provided on the movable mold. Can be easy.

Therefore, when the rotor 2 which constitutes the cooling structure of the electric motor according to the present invention is injection-molded, the manufacturing cost of the mold to be prepared for each product is reduced, the malfunction of the mold is eliminated, and The operation cycle of the injection molding machine can be shortened all at once. Incidentally, the injection molding machine is not limited to the above-mentioned one, and the same action and effect can be obtained with a torpedo type.

[0028]

According to the cooling structure for an electric motor and the cooling structure for an electric motor of the present invention, the amount of air blown at low speed rotation can be increased as compared with the case where an axial fan for cooling is added to the electric motor. It is possible to efficiently cool the electric motor incorporated in the above. Moreover, since there is no need for a housing or the like for accommodating the impeller as in the conventional case, when the cooling structure of the electric motor is incorporated into a washing machine or the like, the number of parts is small, and the washing machine It will contribute to the further miniaturization of such things as.

Further, according to the cooling structure of the electric motor of the present invention, since it is integrally formed by injection molding of synthetic resin, the manufacturing cost of the mold to be prepared for each of various products can be reduced, and the mold can be manufactured. It is possible to eradicate the malfunction of the above and shorten the operation cycle of the injection molding machine all at once.

[Brief description of drawings]

FIG. 1 is an external view of a rotor side of an electric motor according to the present invention.

FIG. 2 is a sectional view showing a cooling structure for an electric motor according to the present invention.

FIG. 3 is an external view of a stator of an electric motor according to the present invention.

FIG. 4A is an external view of a rotor of an electric motor according to a second embodiment of the present invention, and FIG. 4B is a sectional view taken along the arrow A-O-B.

FIG. 5 is a sectional view of a modified example of the rotor of the electric motor according to the second embodiment of the invention.

FIG. 6A is an external view of a rotor of an electric motor according to a third embodiment of the present invention, and FIG. 6B is a sectional view taken along the arrow AB and a sectional view of a stator.

FIG. 7A is an external view of a rotor of an electric motor according to a fourth embodiment of the present invention, and FIG. 7B is a sectional view taken along the arrow A-O-B.

[Explanation of symbols]

1: Electric motor 2: rotor 3: Ford-shaped housing 4: Cascade 5: Inlet 6: Excitation coil 7: Stator 8: Void 9: Gap 10: Pot-shaped recess 11: inclined surface 72: Slot

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihiro Minobe             Kusatsu, 2-3-3 Higashi Kusatsu, Kusatsu City, Shiga Prefecture             Electric Co., Ltd. (72) Inventor Hideaki Kunimatsu             Kusatsu, 2-3-3 Higashi Kusatsu, Kusatsu City, Shiga Prefecture             Electric Co., Ltd. (72) Inventor Hideaki Nakanishi             Kusatsu, 2-3-3 Higashi Kusatsu, Kusatsu City, Shiga Prefecture             Electric Co., Ltd. F term (reference) 5H609 BB18 PP02 PP06 PP07 PP08                       PP09 PP10 QQ02 QQ12 QQ14                       RR11 RR27 RR69                 5H621 AA00 GA04 HH01 JK11                 5H622 AA06 CA02 CB01 PP03

Claims (7)

[Claims] 1. A blade row is formed on an inner surface of a circular lid-shaped housing of an electric motor rotor, and an inlet port for introducing air on the outer surface side between the blade rows is formed in the circular lid-shaped housing. And a cooling structure for the electric motor. 2. The cooling structure for an electric motor according to claim 1, wherein the blade row is composed of a plurality of plate blades extending from the vicinity of the inlet to the peripheral edge of the circular housing. 3. The cooling structure for an electric motor according to claim 1, wherein the blade row is formed of spiral plate blades. 4. A cooling structure for an electric motor according to claim 1, wherein a concave portion that is recessed inside the electric motor is formed in the vicinity of the center of the circular lid-shaped housing, and the introduction port is formed on a side wall surface of the concave portion. . 5. A pot-shaped recess that is recessed inside the electric motor is formed near the center of the circular lid-shaped housing, and the introduction port is formed on the inclined surface of the side wall. The cooling structure of the described motor. 6. In an outer rotor type electric motor in which a rotor rotates around a stator, air flowing along the blade rows due to centrifugal force caused by the rotation of the rotor causes a gap between the stator and the rotor of the electric motor, And flowing into a gap of a slot formed in the stator,
3. A cooling structure for an electric motor according to 3, 4 or 5. 7. The circular lid-shaped housing is integrally formed by injection molding of synthetic resin.
5. A cooling structure for an electric motor according to 5 or 6.