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EP-4742508-A1 - AXIAL GAP MOTOR, BLOWER DEVICE, AND AIR CONDITIONER

EP4742508A1EP 4742508 A1EP4742508 A1EP 4742508A1EP-4742508-A1

Abstract

During driving of an axial gap-type motor, an abnormal noise having a peak of a sound pressure level at a frequency near a natural frequency of an air gap between a rotor and a stator is generated by minute vibration in an axial direction of the rotor. A motor (40) includes a rotor (50, 60) and a stator (70). The rotor (50, 60) has a disk shape. The stator (70) faces the rotor (50, 60) across an air gap (G1, G2) in the axial direction of the rotor (50, 60). The stator (70) includes a plurality of stator cores (71) and a coil (72) wound around each of the stator cores (71). A plurality of the stator cores (71) is annularly arranged when viewed from the axial direction of the rotor (50, 60). The rotor (50, 60) has a plurality of through holes (54, 64) penetrating in the axial direction of the rotor (50, 60). The plurality of through holes (54, 64) is provided on a radially inner side of the rotor (50, 60) with respect to the coils (72) when viewed from the axial direction of the rotor (50, 60).

Inventors

  • TSUCHIYAMA, Kohei
  • TAKAYAMA, YOSHINORI
  • ISHIMARU, Jun

Assignees

  • Daikin Industries, Ltd.

Dates

Publication Date
20260513
Application Date
20240523

Claims (10)

  1. An axial gap-type motor (40) comprising: a rotor (50, 60) having a disk shape; and a stator (70) facing the rotor across an air gap (G1, G2) in an axial direction (X) of the rotor, wherein the stator includes a plurality of stator cores (71) arranged in an annular shape when viewed from the axial direction, and a coil (72) wound around each of the stator cores, the rotor has a plurality of through holes (54, 64) penetrating in the axial direction, and the plurality of through holes is provided on a radially inner side of the rotor with respect to the coil when viewed from the axial direction.
  2. The axial gap-type motor according to claim 1, wherein the plurality of through holes is provided in a first region (R1) having a circular shape centered on an axis of the rotor when viewed from the axial direction, and a radius of the first region is 40% or less of a radius of the rotor.
  3. The axial gap-type motor according to claim 1 or 2, wherein a first ratio that is a ratio of a total area of the plurality of through holes to an opening area of an outer edge portion of the air gap is 3% or more.
  4. The axial gap-type motor according to claim 3, wherein the first ratio is 10% or more.
  5. The axial gap-type motor according to claim 3, wherein the first ratio is 20% or more.
  6. The axial gap-type motor according to any one of claims 3 to 5, wherein the first ratio is 40% or less.
  7. The axial gap-type motor according to any one of claims 1 to 6, wherein the plurality of through holes is arranged along a circumference of a first circle such that a center of each of the through holes is located on the circumference of the first circle centered on the axis of the rotor when viewed from the axial direction.
  8. The axial gap-type motor according to any one of claims 1 to 7, further comprising a pair of the rotors and the stator sandwiched between the pair of the rotors.
  9. A blower (100) comprising: the axial gap-type motor (40) according to any one of claims 1 to 8; and a fan (20, 30) driven by the axial gap-type motor.
  10. An air conditioner comprising the blower (100) according to claim 9.

Description

TECHNICAL FIELD The present disclosure relates to an axial gap-type motor, a blower, and an air conditioner. BACKGROUND ART Conventionally, as disclosed in Patent Literature 1 (JP 2006-353078 A), an axial gap-type motor including a rotor and a stator facing the rotor across an air gap in an axial direction of the rotor is known. SUMMARY OF THE INVENTION <Technical Problem> In the axial gap-type motor, a space (air gap) between the rotor and the stator has a natural frequency. Therefore, during driving of the motor, due to minute vibration in the axial direction of the rotors, abnormal noise having a peak of a sound pressure level may occur at frequencies near the natural frequencies of the air gaps. <Solution to Problem> An axial gap-type motor according to a first aspect includes a rotor and a stator. The rotor has a disk shape. The stator faces the rotor across an air gap in an axial direction of the rotor. The stator includes a plurality of stator cores and a coil wound around each of the stator cores. A plurality of the stator cores is annularly arranged when viewed from the axial direction of the rotor. The rotor has a plurality of through holes penetrating in the axial direction of the rotor. The plurality of through holes is provided on a radially inner side of the rotor with respect to the coil when viewed from the axial direction of the rotor. In the axial gap-type motor according to the first aspect, the through holes are provided in a central portion of the rotor to make a natural frequency of the air gap larger than a predetermined frequency and decrease a sound pressure level at a frequency near the natural frequency in a case where the through holes are not provided. As a result, abnormal noise generated from the motor is reduced. An axial gap-type motor according to a second aspect is the axial gap-type motor according to the first aspect, in which the plurality of through holes is provided in a first region having a circular shape centered on an axis of the rotor when viewed from the axial direction of the rotor. A radius of the first region is 40% or less of a radius of the rotor. An axial gap-type motor according to a third aspect is the axial gap-type motor according to the first or second aspect, in which a first ratio that is a ratio of a total area of the plurality of through holes to an opening area of an outer edge portion of the air gap is 3% or more. An axial gap-type motor according to a fourth aspect is the axial gap-type motor according to the third aspect, in which the first ratio is 10% or more. An axial gap-type motor according to a fifth aspect is the axial gap-type motor according to the third aspect, in which the first ratio is 20% or more. An axial gap-type motor according to a sixth aspect is the axial gap-type motor according to any one of the third to fifth aspects, in which the first ratio is 40% or less. An axial gap-type motor according to a seventh aspect is the axial gap-type motor according to any one of the first to sixth aspects, in which the plurality of through holes is arranged along a circumference of a first circle such that a center of each of the through holes is located on the circumference of the first circle centered on the axis of the rotor when viewed from the axial direction of the rotor. An axial gap-type motor according to an eighth aspect is the axial gap-type motor according to any one of the first to seventh aspects, and includes a pair of rotors and a stator sandwiched between the pair of rotors. A blower according to a ninth aspect includes the axial gap-type motor according to any one of the first to eighth aspects and a fan driven by the axial gap-type motor. An air conditioner according to a tenth aspect includes the blower according to the ninth aspect. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of a blower 100 according to a first embodiment.FIG. 2 is an external perspective view of a first fan 20, a second fan 30, and a motor 40 according to the first embodiment.FIG. 3 is a side view of the first fan 20, the second fan 30, and the motor 40 according to the first embodiment.FIG. 4 is an exploded perspective view of the first fan 20, the second fan 30, and the motor 40 according to the first embodiment.FIG. 5 is a plan view of a first rotor 50 according to the first embodiment.FIG. 6 is an external perspective view of the first rotor 50 according to the first embodiment.FIG. 7 is a plan view of a second rotor 60 according to the first embodiment.FIG. 8 is an external perspective view of the second rotor 60 according to the first embodiment.FIG. 9 is a plan view of a stator 70 according to the first embodiment.FIG. 10 is an external perspective view of the stator 70 according to the first embodiment.FIG. 11 is a sectional view of the motor 40 according to the first embodiment.FIG. 12 is a diagram for describing a stationary wave having a natural frequency of a first air gap G1. FIG. 12 is a diagram showing a