JP7009825B2 - Motor and blower - Google Patents

Description

The present invention relates to a motor and a blower.

In a motor having an armature, the winding heats up in proportion to the magnitude of the current flowing through the armature winding. Therefore, conventionally, motors and fan motors that allow air to flow around the armature as the rotor rotates are known.

Japanese Patent Application Laid-Open No. 2012-246806 provides a plurality of ventilation holes on the bottom surface of the rotor yoke for cooling the inside of the rotor yoke including the coil on the stator side.

Japanese Unexamined Patent Publication No. 2012-246806

However, in the axial fan described in Japanese Patent Application Laid-Open No. 2012-246806, the air flowing from the upper side of the rotor yoke toward the bottom surface portion does not efficiently enter the inside through the ventilation holes. Therefore, for example, in an axial fan having a motor having a high output, it is difficult to enhance the cooling effect.

One aspect of the present invention is to provide a motor having a structure capable of efficiently cooling the inside of the motor, and a blower including such a motor.

The motor of one exemplary embodiment of the present invention has a rotating portion having a magnet and rotating about a central axis extending up and down, a stationary portion having a stator and rotatably supporting the rotating portion, and a stationary portion. The rotating portion includes a shaft extending axially around the central axis, a top surface portion extending radially from the shaft, a tubular tubular portion extending axially from the top surface portion, and the cylinder . The top surface portion has at least one through hole penetrating in the axial direction and an upper surface of the top surface portion forming the through hole. The rotor holder has an upper edge portion and a lower edge portion of the lower surface of the top surface portion forming the through hole, and the rotor holder has a plate portion arranged on the lower side in the axial direction of the top surface portion and the plate portion. The top surface portion has at least one holder hole that penetrates the through hole in the axial direction, and the center axis portion of the top surface portion from the upper edge portion of the through hole toward the lower edge portion of the through hole. Further having a first inclined surface inclined in a direction away from the above, at least a part of the through hole is arranged at a position overlapping the holder hole when viewed from the axial direction, and the through hole is opened more than the holder hole. Includes a first through hole with a large area.

According to one aspect of the present invention, there is provided a motor having a structure for efficiently flowing air near the top surface portion into the motor and cooling the inside of the motor, and a blower including such a motor.

FIG. 1 is a vertical sectional view of a blower having a motor according to an exemplary embodiment of the present invention. FIG. 2 is a partially enlarged view of a top surface portion of a motor according to an exemplary embodiment of the present invention. FIG. 3 is analysis data showing the flow velocity vector of the air near the top surface of the conventional motor. FIG. 4 is a top view of a rotating portion of a motor according to an exemplary embodiment of the present invention. FIG. 5 is a top view of a rotating portion of a motor according to a modification of an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In this specification, the direction in which the central axis J extends when the rotating portion 3 of the motor 2 rotates is referred to as the "axial direction". Further, the direction orthogonal to the central axis J of the motor 2 is referred to as "diameter direction", and the direction along the arc centered on the central axis J of the motor 2 is referred to as "circumferential direction". Further, in the present specification, the shape and positional relationship of each portion will be described with the axial direction as the vertical direction and the direction from the coil 44 toward the top surface portion 31 as the upward direction. However, this definition of the vertical direction does not intend to limit the orientation of the motor 2 according to the present invention when it is used.

FIG. 1 is a schematic cross-sectional view showing the configuration of a blower 1 having a motor 2 according to an embodiment of the present invention. As shown in FIG. 1, the blower 1 has a motor 2 and a casing 20 for accommodating the motor 2. The motor 2 has a rotating portion 3 and a stationary portion 4. A casing hole 20a penetrating in the axial direction is provided at the center of the casing 20. The casing 20 has a base portion 21 on the lower side of the casing hole portion 20a. The base portion 21 supports the stationary portion 4.

The rotating portion 3 has a top surface portion 31, a tubular portion 32, a shaft 33, a magnet 34, and a housing portion 35. The rotating portion 3 has a magnet 31 and rotates about a central axis J extending up and down.

The shaft 33 extends in the axial direction about the central axis J. The shaft 33 is a columnar metal member. However, the shaft 33 may have another shape such as a cylindrical shape.

The top surface portion 31 extends radially from the shaft 33. The top surface portion 31 has at least one through hole 310 penetrating in the axial direction, an upper edge portion 311 and a lower edge portion 312. The upper edge portion 311 is the edge of the upper surface of the top surface portion 31 forming the through hole 310. The lower edge portion 312 is an edge of the lower surface of the top surface portion 31 forming the through hole 310. In the present embodiment, the top surface portion 31 has a plurality of through holes 310.

The tubular portion 32 is a tubular member extending in the axial direction from the top surface portion 31. In the present embodiment, a rotor holder 36, which will be described later, is arranged inside the tubular portion 32 in the radial direction. However, the tubular portion 32 and the rotor holder 36 may be a single member. The rotor holder 36 has a cup shape that opens downward. The rotor holder 36 is arranged inside the tubular portion 32 and the top surface portion 31 to hold the magnet 34. The rotor holder 36 is made of a magnetic material such as carbon steel.

The magnet 34 is arranged on the inner peripheral surface of the rotor holder 36. In this embodiment, the magnet 34 is a single annular magnet. N poles and S poles are alternately magnetized in the circumferential direction on the inner surface of the magnet 34 in the radial direction. Instead of a single annular magnet, a plurality of magnets 34 may be arranged on the inner peripheral surface of the rotor holder 36. In this case, the plurality of magnets 34 are arranged at equal intervals in the circumferential direction. In the plurality of magnets 34, the magnetic pole surfaces of the N pole and the magnetic pole surfaces of the S pole are alternately arranged in the circumferential direction. The rotor holder 36 and the magnet 34 may be configured as a single member by a resin containing magnetic powder.

The housing portion 35 supports the shaft 33. The housing portion 35 has a housing hole portion 35a extending in the axial direction in the central portion. The shaft 33 is inserted into the housing hole 35a. The housing portion 35 is located above the shaft 33. The upper portion of the shaft 33 is fixed to the housing hole 35a. The housing portion 35 is made of, for example, metal.

In the present embodiment, the tubular portion 32 of the rotating portion 3 has a plurality of blades 37 in the circumferential direction on the outer side in the radial direction. The plurality of blades 37 rotate around the central axis J together with the rotating portion 3. As a result, an air flow is generated in the casing hole 20a. In the present embodiment, the blower 1 having the motor 2 is an axial flow type blower in which an air flow from the upper side to the lower side in the axial direction is generated. That is, due to the air flow passing through the casing hole portion 20a, the air near the top surface portion 31 also goes from the upper side in the axial direction to the lower side in the axial direction. Therefore, more air can pass through the through hole 310 described later, and a larger cooling effect can be obtained.

The stationary portion 4 has a stator 41. The stator 41 has a stator core 42. The stator core 42 is composed of, for example, a laminated steel plate in which electromagnetic steel plates are laminated in the axial direction. The stator core 42 has an annular core back 42a and a plurality of teeth 42b extending radially outward from the core back 42a. A coil 44 is formed by winding a conducting wire around each tooth 42b via an insulator 43. That is, the stator 41 has a plurality of coils 44. One end of the lead wire drawn from the coil 44 is electrically connected to the circuit board 45 arranged under the stator 41. Electric power is supplied to the circuit board 45 from the outside.

The stationary portion 4 has a bearing holder 46. The bearing holder 46 is arranged inside the stator 41 in the radial direction. The bearing holder 46 extends axially and is fixed to the stator 41. The bearing holder 46 has a bearing 5 inside in the radial direction. Two bearings 5 are arranged at the upper part and the lower part. The upper and lower bearings 5 rotatably support the rotating portion 3 with respect to the stationary portion 4. The bearing 5 is fixed to the outer periphery of the shaft 33. In this embodiment, the bearing 5 is a ball bearing.

In the motor 2 having the above configuration, when electric power is supplied to the coil 44, a magnetic flux is generated in the teeth 42b. Then, torque in the circumferential direction is generated by the action of the magnetic flux between the teeth 42b and the magnet 34. As a result, the rotating portion 3 rotates with respect to the stationary portion 4 about the central axis J, and the rotational operation of the motor 2 is started. The rotation of the rotating portion 3 includes the rotation of the blade 37, and an air flow is generated. When the supply of electric power to the coil 44 is stopped, the rotation of the rotating portion 3 is stopped. As a result, the rotational operation of the motor 2 is completed.

FIG. 2 is a partially enlarged view of a top surface portion 31 of a motor 2 according to an exemplary embodiment of the present invention. FIG. 3 is a diagram showing a flow velocity vector of air near the top surface portion 31 of the conventional motor 2. After hitting the top surface portion 31, the air near the top surface portion 31 flows outward in the radial direction due to the centrifugal force generated by the rotation of the motor 2. As shown in FIG. 2, inside the radial inside of the through hole 310, the top surface portion 31 is a first inclined surface that is inclined in a direction away from the central axis J from the upper edge portion 311 of the through hole 310 toward the lower edge portion 312. It has 313. Therefore, when the air near the top surface portion 31 flows outward in the radial direction, the air flows downward in the axial direction along the first inclined surface 313 and flows into the motor 2. As a result, the inside of the motor 2 can be efficiently cooled. Further, since the first inclined surface 313 is formed by being recessed from the top surface portion 31, it is easy to arrange parts outside the motor 2. That is, the first inclined surface 313 is arranged in the axial thickness of the top surface portion 31. The first inclined surface 313 may be arranged so as to extend to the lower side in the axial direction from the lower surface of the top surface portion 31.

In the present embodiment, the top surface portion 31 has a second inclined surface portion 314 inclined in a direction away from the central axis J from the upper edge portion 311 toward the lower edge portion 312 on the radial outer side of the through hole 310. A part of the air flowing along the first inclined surface 313 may flow further outward in the radial direction from the upper edge portion 311 located on the outer side in the radial direction. By providing the second inclined surface 314, it is possible to prevent the flowing air from flowing out more radially outward than the upper edge portion 311 located on the radial outer side. Therefore, air can be flowed into the motor 2 more efficiently.

In the present embodiment, the angle θ1 formed by the surface parallel to the central axis J through the upper edge portion 311 and the first inclined surface 313 is the surface parallel to the central axis J passing through the upper edge portion 311 and the second inclined surface 314. The degree of formation is greater than θ2. The first inclined surface 313 directs the direction of the airflow flowing in the radial direction downward in the axial direction. Therefore, it is preferable that the inclination angle θ1 is gentler than the inclination angle θ2. The second inclined surface 314 suppresses the flow of the changed airflow upward in the axial direction. Therefore, the tilt angle θ2 is preferably smaller than the tilt angle θ1.

In the present embodiment, the radial outer end portion of the first inclined surface 313 is located at the same position in the radial direction or in the radial direction as the radial inner end portion of the second inclined surface 314. In this way, when the top surface portion 31 is molded using the mold, the mold can be pulled out in the axial direction. Therefore, the through hole 310 can be easily created in the top surface portion 31.

FIG. 4 is a top view of the rotating portion 3 as viewed from above. In the present embodiment, the through hole 310 has a rectangular shape having a long side in a direction perpendicular to the radial direction in a plan view. Therefore, the first inclined surface 313 and the second inclined surface 314 can be formed along the long side of the through hole 310. That is, the length of the first inclined surface 313 and the second inclined surface 314 in the direction perpendicular to the radial direction can be increased. On the upper surface of the top surface portion 31, the air flowing in the radial direction due to the centrifugal force due to the rotation of the motor 2 tends to flow into the inside of the through hole 310 having a large opening in the direction perpendicular to the radial direction. Air near the top surface portion 31 can be efficiently flowed from the through hole 310 along the first inclined surface 313 and the second inclined surface 314, and the cooling effect inside the motor 2 is improved. However, the through hole 310 may be, for example, a circle, a triangle, a square, or the like in a plan view.

In this embodiment, the rotor holder 36 has a plate portion 361 and at least one holder hole 362. The plate portion 361 is arranged on the lower side in the axial direction of the top surface portion 31. The plate portion 361 is provided with a holder hole 362 that penetrates the plate portion 361 in the axial direction. At least a part of the through hole 310 is arranged at a position overlapping the holder hole 362 when viewed from the axial direction. Air flows from the upper side in the axial direction to the lower side in the axial direction through the through hole 310 and the holder hole 362 into the inside of the motor. As a result, the inside of the rotor holder 36 is cooled, and the cooling effect of the motor 2 can be further obtained.

In the present embodiment, the through hole 310 includes a first through hole 3101 having a larger opening area than the holder hole 362. When the rotating portion 3 is combined, the positions of the through hole 310 and the holder hole 362 in the circumferential direction may be displaced. In that case, the area of the portion where both the through hole 310 and the holder hole 362 overlap when viewed from the axial direction is reduced, and the amount of air passing through both the through hole 310 and the holder hole 362 is reduced. However, when the opening area of the through hole 310 is larger than the opening area of the holder hole 362, even if the positions of the through hole 310 and the holder hole 362 in the circumferential direction are displaced, the opening area corresponding to the size of the holder hole 362 is used. Since air is taken in, it is possible to suppress a decrease in the cooling effect.

In the present embodiment, the through hole 310 further includes a second through hole 3102 having an opening area equivalent to that of the holder hole 362. That is, the through hole 310 includes a first through hole 3101 having a larger opening area than the holder hole 362 and a second through hole 3102 having an opening area equivalent to that of the holder hole 362. When assembling the rotating portion 3, first, a pin having a cross-sectional area equivalent to the opening area of the holder hole 362 is passed through and fixed to the holder hole 362. Then, from above the holder hole 362, the through hole 310 is also passed through the pin that has passed through the holder hole 362 and combined. At this time, if the pin is passed through the first through hole 3101 having an opening area larger than that of the holder hole 362, the rotating portion 3 may move due to the difference in the opening area. However, by passing the pin through the second through hole 3102 having an opening area equivalent to that of the holder hole 362 and combining the pin and the through hole 310, it is possible to suppress the rotation portion 3 from moving due to the difference in the opening area.

In the present embodiment, the through hole 310 has a plurality of first through holes 3101 and a plurality of second through holes 3102. The first through hole 3101 and the second through hole 3102 are alternately arranged in the circumferential direction. However, the through hole 310 may have one first through hole 3101 and one second through hole 3102.

FIG. 5 is a diagram for explaining a modified example. In this modification, unlike the above-described embodiment, the top surface portion 31A, the cylinder portion 32A, and the rotor holder 36 are composed of a single member. As shown in FIG. 5, in this modification as well, the top surface portion 31A is inclined in the radial direction of the through hole 310A in the direction away from the central axis J from the upper edge portion 311A of the through hole 310A toward the lower edge portion 312A. Further has a first inclined surface 313A. However, in this case, the magnet 34A is arranged on the inner peripheral surface of the tubular portion 32A. That is, the motor 2A is an outer rotor type motor in which a plurality of blades 37 are not arranged in the circumferential direction on the radial outer side of the tubular portion 32A.

The various technical features disclosed herein can be modified in various ways without departing from the gist of the technical creation. In addition, a plurality of embodiments and modifications shown in the present specification may be combined and implemented to the extent possible.

The present invention can be used for motors, blowers and the like.

1 ... Blower 2 ... Motor 3, 3A ... Rotating part 31, 31A ... Top surface part 310, 310A ... Through hole 3101 ... First through hole 3102 ... Second through hole 311 311A ... Upper edge 312, 312A ... Lower edge 313, 313A ... First inclined surface 314 ... Second inclined surface 32, 32A ... Cylinder 33 ... Shaft 34・ ・ ・ Magnet 35 ・ ・ ・ Housing part 36 ・ ・ ・ Rotor holder 37 ・ ・ ・ Bearing 4 ・ ・ ・ Static part 41 ・ ・ ・ Stator 42 ・ ・ ・ Stator core 42a ・ ・ ・ Core back 42b ・ ・ ・ Teeth 43 ・ ・・ Insulator 44 ・ ・ ・ Coil 45 ・ ・ ・ Circuit board 46 ・ ・ ・ Bearing holder 5 ・ ・ ・ Bearing J ・ ・ ・ Central axis

Claims (7)

It ’s a motor,
A rotating part that has a magnet and rotates around a central axis that extends vertically,
A stationary portion having a stator and rotatably supporting the rotating portion,
Have,
The rotating part is
A shaft extending in the axial direction around the central axis and
The top surface extending radially from the shaft and
A cylindrical tubular portion extending in the axial direction from the top surface portion and
A rotor holder arranged inside the cylinder portion and the top surface portion to hold the magnet, and
Have,
The top surface is
At least one through hole that penetrates in the axial direction,
The upper edge of the upper surface of the top surface that forms the through hole, and
The lower edge of the lower surface of the top surface that forms the through hole, and
Have,
The rotor holder is
A plate portion arranged on the lower side in the axial direction of the top surface portion and a plate portion
At least one holder hole that penetrates the plate portion in the axial direction,
Have,
The top surface is
Further inside the radial inside of the through hole is a first inclined surface that inclines in a direction away from the central axis from the upper edge portion of the through hole toward the lower edge portion .
At least a part of the through hole is arranged at a position overlapping the holder hole when viewed from the axial direction.
The through hole is a motor including a first through hole having a larger opening area than the holder hole . The top surface is
The motor according to claim 1, further comprising a second inclined surface that is inclined in a direction away from the central axis from the upper edge portion toward the lower edge portion on the radial outer side of the through hole. The angle θ1 formed by the surface parallel to the central axis passing through the upper edge portion and the first inclined surface is the degree θ2 formed between the surface parallel to the central axis passing through the upper edge portion and the second inclined surface. The motor according to claim 1 or 2, which is larger than the above. The motor according to claim 2 or 3, wherein the radial outer end portion of the first inclined surface is located at the same position in the radial direction or radially inward as the radial inner end portion of the second inclined surface. The motor according to any one of claims 1 to 4, wherein the through hole has a rectangular shape having a long side in a direction perpendicular to the radial direction in a plan view. A blower having the motor according to any one of claims 1 to 5.
The tubular portion is a blower having a plurality of blades in the circumferential direction on the outer side in the radial direction. The blower according to claim 6, wherein the through hole further includes a second through hole having an opening area equivalent to that of the holder hole.

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