WO2018105526A1

WO2018105526A1 - Fan motor

Info

Publication number: WO2018105526A1
Application number: PCT/JP2017/043320
Authority: WO
Inventors: 有希雄北邑; 成勝松田
Original assignee: 日本電産株式会社
Priority date: 2016-12-09
Filing date: 2017-12-01
Publication date: 2018-06-14
Also published as: CN109863312A; US20200072241A1; CN109863312B; JPWO2018105526A1

Abstract

This fan motor has a motor, an impeller, and a housing. The motor has: a stationary section having a stator; and a rotating section rotating about a vertically extending center axis. The impeller has a plurality of blades and rotates with the rotating section. The housing contains therein the motor and at least a part of the impeller. The housing has a cylindrical section, a flange section, and one or more ribs. The cylindrical section extends axially and contains therein the motor and at least a part of the impeller. The flange section protrudes radially outward from the upper end or lower end of the cylindrical section. The ribs are column shaped and extend on the outer peripheral surface of the cylindrical section from the flange section. The ribs are tilted relative to the axial direction.

Description

Fan motor

The present invention relates to a fan motor.

Conventionally, an axial-flow fan motor that rotates an impeller using a driving force of a motor to generate an airflow in an axial direction is known. An axial-flow fan motor is mounted on, for example, home appliances, OA equipment, transportation equipment, and the like, and is used for the purpose of cooling electronic components or circulating gas in the equipment housing. A fan motor may be used for gas circulation in a server room where a large number of electronic devices are installed.

Measures such as increasing the size of the impeller have been made to increase the air volume of the fan motor. However, the fan motor becomes large. When the size of the impeller is increased without increasing the size of the fan motor, the thickness of the fan motor housing is reduced. Thereby, the rigidity of the housing is lowered, and there is a risk that unpleasant vibrations and noises may occur. Further, the natural frequency decreases due to a decrease in the rigidity of the housing. As a result, resonance with magnetic excitation occurs when the fan motor is driven, and unpleasant vibration and noise may occur. FIG. 18 is a perspective view showing a result of analyzing a horizontal vibration mode in a housing 5X used in a conventional fan motor. FIG. 19 is a perspective view showing the result of analyzing the axial vibration mode in the housing 5Y used in the conventional fan motor. The housing 5X is formed as a single member by resin injection molding or the like, and the housing 5Y is formed from two upper and lower members.

For example, in the axial fan disclosed in Japanese Patent Application Laid-Open No. 2016-125394, rectangular recesses are formed on two opposite side surfaces of the fan frame. Thereby, when the dimension and position of the said recessed part satisfy | fill a specific condition, the displacement amount of the fan frame when resonance generate | occur | produces at the time of a drive can be restrained small.
JP 2016-125394 A

However, in the structure disclosed in Japanese Patent Application Laid-Open No. 2016-125394, the resin thickness at the corners of the fan frame increases when the recesses are formed, and there is a risk of so-called sinks that cause depression on the surface during resin molding.

An object of the present invention is to provide a fan motor capable of suppressing the occurrence of sink marks, increasing the rigidity of the housing, and suppressing unpleasant vibration and noise during driving.

The exemplary invention of the present application is a fan motor, which includes a motor, an impeller, and a housing. The motor has a stationary part having a stator and a rotating part that rotates around a central axis extending vertically. The impeller has a plurality of blades and rotates together with the rotating unit. The housing accommodates at least a part of the motor and the impeller inside. The housing has a tubular portion, a flange portion, and one or a plurality of ribs. The tubular portion is tubular, extends in the axial direction, and accommodates at least a part of the motor and the impeller inside. A flange part protrudes toward the radial direction outer side from the upper end part or lower end part of a cylindrical part. The rib is columnar and extends from the flange portion on the outer peripheral surface of the cylindrical portion. The rib is inclined with respect to the axial direction.

According to the exemplary invention of the present application, the rigidity of the housing is increased by forming one or more columnar ribs extending from the flange portion and inclined with respect to the axial direction on the outer peripheral surface of the cylindrical portion. Unpleasant vibration and noise at the time can be suppressed. Moreover, since the thickness of the housing in parts other than the rib can be suppressed, the occurrence of sink marks can be suppressed.

FIG. 1 is a longitudinal sectional view of the fan motor according to the first embodiment. FIG. 2 is a partial longitudinal sectional view of the fan motor according to the first embodiment. FIG. 3 is a perspective view of the housing according to the first embodiment. FIG. 4 is a side view of the housing according to the first embodiment. FIG. 5 is a diagram illustrating a result of analyzing the relationship between the inclination of the rib according to the first embodiment and the natural frequency of the housing. FIG. 6A is a side view of the housing according to the first embodiment. FIG. 6B is a side view of the housing according to the first embodiment. FIG. 6C is a side view of the housing according to the first embodiment. FIG. 6D is a side view of the housing according to the first embodiment. FIG. 7 is a diagram illustrating a result of analyzing the relationship between the thickness of the rib according to the first embodiment and the natural frequency of the housing. FIG. 8A is a side view of the housing according to the first embodiment. FIG. 8C is a side view of the housing according to the first embodiment. FIG. 8E is a side view of the housing according to the first embodiment. FIG. 8F is a side view of the housing according to the first embodiment. FIG. 9 is a diagram illustrating a result of analyzing the relationship between the position of the rib according to the first embodiment and the natural frequency of the housing. FIG. 10A is a top view of the housing according to the first embodiment. FIG. 10G is a top view of the housing according to the first embodiment. FIG. 10H is a top view of the housing according to the first embodiment. FIG. 10I is a top view of the housing according to the first embodiment. FIG. 10C is a top view of the housing according to the first embodiment. FIG. 11 is a diagram illustrating a result of analyzing the relationship between the position of the rib according to the first embodiment and the natural frequency of the housing. FIG. 12A is a top view of the housing according to the first embodiment. FIG. 12J is a top view of the housing according to the first embodiment. FIG. 12K is a top view of the housing according to the first embodiment. FIG. 12L is a top view of the housing according to the first embodiment. FIG. 12C is a top view of the housing according to the first embodiment. FIG. 13 is a longitudinal sectional view of the fan motor according to the second embodiment. FIG. 14 is a perspective view of a housing according to the second embodiment. FIG. 15 is a side view of the housing according to the second embodiment. FIG. 16 is a diagram illustrating a result of analyzing the relationship between the position of the rib according to the second embodiment and the natural frequency of the housing. FIG. 17A is a top view of the housing according to the second embodiment. FIG. 17B is a top view of the housing according to the second embodiment. FIG. 17C is a top view of the housing according to the second embodiment. FIG. 17D is a top view of the housing according to the second embodiment. FIG. 17E is a top view of the housing according to the second embodiment. FIG. 17F is a top view of the housing according to the second embodiment. FIG. 18 is a perspective view showing a result of analyzing a vibration mode in a conventional fan motor housing. FIG. 19 is a perspective view showing a result of analyzing a vibration mode in a conventional fan motor housing.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present application, a direction parallel to the motor central axis, which will be described later, is referred to as an “axial direction”, a direction orthogonal to the motor central axis is referred to as a “radial direction”, and a direction along an arc centered on the motor central axis is referred to as “circumference”. Direction ". Further, in the present application, the axial direction is the vertical direction, the side from which air is taken in is referred to as “intake side” or simply “upper side”, and the side from which air is discharged is referred to as “exhaust side” or simply “lower side”. However, the “upper side” and “lower side” are expressions for convenience of explanation, and are not related to the direction of gravity. The fan motor according to the present invention may be used in any direction.

In the present application, the “parallel direction” includes a substantially parallel direction. Further, in the present application, the “perpendicular direction” includes a substantially orthogonal direction.

<1. First Embodiment>
<1-1. Overall configuration of fan motor>
FIG. 1 is a longitudinal sectional view of a fan motor 10 according to the first embodiment.

The fan motor 10 is used, for example, as a device for supplying a cooling airflow into a room such as a home appliance such as a refrigerator or a server room in which a plurality of electronic devices are arranged. The fan motor 10 may be used alone, or a plurality of fan motors 10 may be used in combination. For example, a plurality of fan motors 10 may be installed in one server room and driven simultaneously.

As shown in FIG. 1, the fan motor 10 includes a motor 1, an impeller 4, and a housing 5. The fan motor 10 is an axial fan that generates an airflow downward along the central axis 9. When the fan motor 10 is driven, air is taken in from the upper side of the fan motor 10 that is the intake side, and is sent out through the wind tunnel 50 in the housing 5 to the lower side of the fan motor 10 that is the exhaust side. .

<1-2. Configuration of motor and impeller>
First, the configuration of the motor 1 and the impeller 4 will be described. FIG. 2 is a partial longitudinal sectional view of the fan motor 10 according to the first embodiment. In the following, FIG. 1 will be referred to as appropriate together with FIG.

The motor 1 has a stationary part 2 and a rotating part 3. The stationary part 2 is relatively stationary with respect to the device where the fan motor 10 is disposed. The rotating part 3 is supported so as to be rotatable with respect to the stationary part 2 around a central axis 9 extending vertically.

2, the stationary portion 2 includes a stator 22, a circuit board 23, and a bearing holder 24. The stator 22 is fixed to the outer peripheral surface of the bearing holder 24. The stator 22 has a stator core 221 and a plurality of coils 222. Stator core 221 has a plurality of teeth. Each tooth extends in the radial direction. Each of the plurality of coils 222 is formed by a conductive wire wound around the teeth. The end of the conducting wire is connected to the circuit board 23.

The bearing holder 24 is a cylindrical member extending along the central axis 9. A lower portion of the bearing holder 24 is fixed to an inner peripheral surface of the base portion 21 described later with an adhesive, for example. A bearing portion 25 is disposed on the radially inner side of the bearing holder 24. For example, a ball bearing is used for the bearing portion 25. The outer ring of the bearing portion 25 is fixed to the inner peripheral surface of the bearing holder 24. The inner ring of the bearing portion 25 is fixed to a shaft 31 described later. Thereby, the shaft 31 is supported rotatably with respect to the stationary part 2. However, the motor 1 may have other types of bearings such as a slide bearing and a fluid bearing instead of the ball bearing.

The rotating unit 3 includes a shaft 31, a rotor holder 32, an annular member 33, and a magnet 34. The shaft 31 is a columnar member disposed along the central axis 9. The shaft 31 is rotatably supported by the bearing portion 25. The upper end portion of the shaft 31 projects upward from the bearing holder 24. When the motor 1 is driven, the shaft 31 rotates around the central axis 9.

The rotor holder 32 is a covered cylindrical member having a rotor lid 321 and a rotor cylinder 322. The rotor lid 321 extends in a disk shape substantially perpendicular to the central axis 9. The rotor cylinder portion 322 extends in the axial direction from the rotor lid portion 321 to the exhaust side. For example, metal or resin is used as the material of the rotor holder 32. A central portion of the rotor lid portion 321 is fixed to the upper end portion of the shaft 31 via an annular member 33. Thereby, the rotor holder 32 rotates together with the shaft 31. The rotor lid 321 is disposed on the intake side of the stationary part 2. The rotor cylinder portion 322 is disposed on the radially outer side of the stator 22. The magnet 34 is fixed to the inner peripheral surface of the rotor cylinder portion 322.

The motor 1 further has a lead wire (not shown) electrically connected to the stator 22. One end of the lead wire (not shown) is connected to the circuit board 23. The other end is drawn radially outward from a cylindrical portion 51 to be described later, and is connected to a power source provided outside the fan motor 10, for example.

When a drive current is supplied to the coil 222 of the stator 22 via the lead wire (not shown) and the circuit board 23, magnetic flux is generated in the plurality of teeth. A circumferential torque is generated between the stationary part 2 and the rotating part 3 by the action of the magnetic flux between the teeth and the magnet 34. As a result, the rotating unit 3 rotates about the central axis 9 with respect to the stationary unit 2. Thereby, an impeller 4 to be described later that is directly or indirectly fixed to the rotating unit 3 rotates around the central axis 9 together with the rotating unit 3.

The impeller 4 has a cup portion 41 and a plurality of blades 42. The cup portion 41 covers the rotor lid portion 321 and the rotor cylinder portion 322 of the rotor holder 32. Each blade 42 extends radially outward from the outer peripheral surface of the cup portion 41. The plurality of blades 42 are arranged at substantially equal intervals in the circumferential direction. The number of blades 42 is not particularly limited. The impeller 4 rotates together with the rotating unit 3.

<1-3. Housing configuration>
Next, the configuration of the housing 5 will be described. FIG. 3 is a perspective view of the housing 5 according to the first embodiment. FIG. 4 is a side view of the housing 5 according to the first embodiment.

The housing 5 is a housing that houses at least a part of the motor 1 and the impeller 4 therein. As shown in FIGS. 3 and 4, the housing 5 includes a base portion 21, a cylindrical portion 51, a flange portion 52, one or more base connection portions 53, and one or more ribs 54. The housing 5 has a rectangular solid shape that opens up and down.

The base portion 21 is a disk-shaped portion that is disposed below the stator 22 of the motor 1 and extends from the periphery of the bearing holder 24 toward the radially outer side. As described above, the lower portion of the bearing holder 24 is fixed to the inner peripheral surface of the base portion 21 with, for example, an adhesive. The motor 1 is disposed on the upper portion of the base portion 21. The motor 1 is supported by the base portion 21.

The cylindrical portion 51 is a cylindrical portion that extends in the axial direction from the intake side (upper side) to the exhaust side (lower side) along the central axis 9. The cylindrical portion 51 extends in a substantially cylindrical shape on the radially outer side of the impeller 4. The cylindrical part 51 accommodates at least a part of the motor 1 and the impeller 4 inside.

The flange portion 52 is a portion that protrudes outward in the radial direction at four locations in the circumferential direction of the tubular portion 51. The flange portion 52 includes an upper flange portion 521 and a lower flange portion 522. The upper flange portion 521 protrudes radially outward from the upper end portion of the tubular portion 51. The lower flange portion 522 protrudes radially outward from the lower end portion of the tubular portion 51. The housing 5 has a rectangular shape when viewed from above. The housing 5 has a rectangular shape when viewed from below. That is, the housing 5 has a rectangular solid shape that opens up and down. In the present embodiment, the axial thickness of the upper flange portion 521 and the axial thickness of the lower flange portion 522 are equal to each other. Note that the rigidity of each part of the housing 5 decreases as the distance from the central axis 9 increases in the radial direction, and resonance easily occurs when the fan motor 10 is driven. For example, the radially outer end of the upper flange portion 521 has the lowest rigidity in the housing 5. Further, the end portion on the radially outer side of the lower flange portion 522 is similarly low in rigidity. However, since the base connection portion 53 is provided at the lower portion of the housing 5 as described later, the radially outer side of the lower flange portion 522 is provided. The end portion of the upper flange portion 521 has higher rigidity than the end portion on the radially outer side of the upper flange portion 521. The upper flange portion 521 or the lower flange portion 522 is attached to a frame body such as a device in which the fan motor 10 is installed by, for example, screwing. In addition, the flange part 52 may be comprised only from the upper side flange part 521 or the lower side flange part 522. FIG.

The base connection portion 53 is a columnar portion that extends radially outward from at least a portion of the outer peripheral surface of the base portion 21 and is connected to at least a portion of the inner peripheral surface of the tubular portion 51. Thereby, the position of the stationary part 2 of the motor 1 with respect to the housing 5 is fixed. Further, by providing the base connecting portion 53, the lower portion and the lower flange portion 522 of the tubular portion 51 are more rigid than the upper portion and the upper flange portion 521 of the tubular portion 51. One or a plurality of base connection portions 53 are provided in the lower portion of the housing 5. However, the number of the base connection parts 53 is not limited.

On the outer peripheral surface of the cylindrical portion 51, one or more columnar ribs 54 extending from the flange portion 52 are further provided. Details of the rib 54 will be described later. In the present embodiment, the base portion 21, the cylindrical portion 51, the flange portion 52, the one or more base connecting portions 53, and the one or more ribs 54 are formed by a single injection molding of resin. It is formed as a member. However, these may be separate members.

<1-4. Structure of rib>
Next, the configuration of the rib 54 will be described.

As described above, one or more ribs 54 are located on the outer peripheral surface of the tubular portion 51 and connect the upper flange portion 521 and the lower flange portion 522. This increases the rigidity of the housing 5 and increases the natural frequency of the housing 5 with respect to horizontal vibration. As a result, when the fan motor 10 is driven, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced.

In addition, it is desirable that the ribs 54 be inclined with respect to the axial direction in a direction away from the central axis 9 from the lower part to the upper part of the housing 5. FIG. 5 is a diagram showing a result of analyzing the relationship between the inclination of the rib 54 and the natural frequency of the housing 5 with respect to the vibration in the horizontal direction. The vertical axis represents the analysis result of the natural frequency of each housing 5 based on the analysis result of the natural frequency of the housing 5 of A. A is a result of analyzing the natural frequency of the housing 5 with respect to the vibration in the horizontal direction when the ribs 54 are not provided on the housing 5. B is the result of the same analysis when the housing 5 is provided with ribs 54 parallel to the axial direction. C is the result of the same analysis in the case where a rib 54 that is inclined in a direction away from the central axis 9 as it goes from the lower part to the upper part of the housing 5 is provided. D is the result of the same analysis in the case where a rib 54 that is inclined away from the central axis 9 as it goes from the upper part to the lower part of the housing 5 is provided. For reference, FIGS. 6A, 6B, 6C, and 6D show side views of housings 5 for A, B, C, and D, respectively. The BD housing 5 has two ribs 54 on each of the four side surfaces of the rectangular parallelepiped solid shape.

As shown in FIG. 5, when the analysis results A to D are compared, C has the highest natural frequency of the housing 5 with respect to the horizontal vibration. The radially inner portion of the lower flange portion 522 has higher rigidity than the radially outer portion of the upper flange portion 521. In C, the radially outer portion of the upper flange portion 521 is connected to the radially inner portion of the lower flange portion 522. For this reason, the rigidity of the entire housing 5 is increased, and the natural frequency is increased. As a result, when the fan motor 10 is driven, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced.

The thickness of the rib 54 is preferably equal to or less than the thickness of the upper flange portion 521 or the lower flange portion 522 in the axial direction. Moreover, it is desirable that the thicknesses of the plurality of ribs 54 be approximately the same. FIG. 7 is a diagram illustrating a result of analyzing the relationship between the thickness of the rib 54 and the natural frequency of the housing 5 with respect to the vibration in the horizontal direction. The vertical axis represents the analysis result of the natural frequency of each housing 5 based on the analysis result of the natural frequency of the housing 5 of A. In FIG. 7, A is the result of analyzing the natural frequency of the housing 5 with respect to the vibration in the horizontal direction when the rib 54 is not provided on the housing 5. C, E, and F are the same analysis results in the case where the rib 54 that is inclined in the direction away from the central axis 9 as it goes from the lower part to the upper part of the housing 5 is provided. The C, E, and F housings 5 have two ribs 54 on each of the four side surfaces of the rectangular parallelepiped solid shape. However, while the thickness of the C rib 54 is equal to the thickness of the upper flange portion 521 and the lower flange portion 522 in the axial direction, the thickness of the E rib 54 is smaller than the thickness of the C rib 54. The thickness of the F rib 54 is smaller than the thickness of the E rib 54. For reference, FIGS. 8A, 8C, 8E, and 8F show side views of housings 5 for A, C, E, and F, respectively.

As shown in FIG. 7, when the analysis results of A, C, E, and F are compared, C has the highest natural frequency of the housing 5 with respect to the horizontal vibration. The thickness of the rib 54 of C is equal to the axial thickness of the upper flange portion 521 and the lower flange portion 522 and has a sufficient size, so that the rigidity of the housing 5 as a whole is increased and the natural vibration is increased. The number is high. On the other hand, in E and F, when the thickness of the rib 54 is smaller than C, the overall rigidity of the housing 5 is lower than C, and the natural frequency is lower than C. If the thickness of the rib 54 is further larger than the thickness of the upper flange portion 521 and the lower flange portion 522 in the axial direction, so-called sinking occurs, in which the surface of the housing 5 including the rib 54 is depressed during resin molding. There is a risk of doing. Therefore, it is desirable not to make the thickness of the rib 54 too large, but to be about the same as the axial thickness of the upper flange portion 521 and the lower flange portion 522.

It is desirable that two or more ribs 54 are provided on each of the four side surfaces of the rectangular solid shape of the housing 5. FIG. 9 is a diagram showing a result of analyzing the relationship between the position of the rib 54 and the natural frequency of the housing 5 with respect to the vibration in the horizontal direction. The vertical axis represents the analysis result of the natural frequency of each housing 5 based on the analysis result of the natural frequency of the housing 5 of A. In FIG. 9, A is the result of analyzing the natural frequency of the housing 5 with respect to the vibration in the horizontal direction when the rib 54 is not provided on the housing 5. G is the result of the same analysis in the case where two ribs 54 are provided on one of the four side surfaces in the rectangular solid shape of the housing 5. H is a result of the same analysis in the case where two ribs 54 are provided on each of the four side surfaces in the three-dimensional shape of the rectangular parallelepiped of the housing 5 and the side surface facing the one side surface. . I is the result of the same analysis in the case where two ribs 54 are provided on each of the four side surfaces in the three-dimensional shape of the rectangular parallelepiped of the housing 5 and the side surface adjacent to the one side surface. is there. C is the result of the same analysis in the case where two ribs 54 are provided on all four side surfaces of the rectangular solid shape of the housing 5. For reference, FIGS. 10A, 10G, 10H, 10I, and 10C show top views of the respective housings 5 of A, G, H, I, and C. FIG. Ribs 54 are provided at the positions of the black circles in each top view.

As shown in FIG. 9, when the analysis results of A, G, H, I, and C are compared, C has the highest natural frequency of the housing 5 with respect to the horizontal vibration. In C, since two ribs 54 are provided on all four side surfaces of the rectangular solid shape of the housing 5, the rigidity of the entire housing 5 is increased and the natural frequency is increased. As a result, when the fan motor 10 is driven, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced.

In FIG. 9, when the analysis results of H and I are compared, the natural frequency of the housing 5 with respect to the horizontal vibration is higher in I. In both H and I, two ribs 54 are provided on each of two of the four side surfaces of the rectangular solid shape of the housing 5. However, in H, the two side surfaces face each other, whereas in I, the two side surfaces are adjacent to each other.

Hereinafter, as shown in FIG. 10A, FIG. 10G, FIG. 10H, FIG. 10I, and FIG. Further, as shown in the top view of the housing 5, two of the four side surfaces of the rectangular solid shape of the housing 5 are parallel to the X axis, and the remaining two side surfaces are parallel to the Y axis. It will be described as being arranged in (1). In H, two ribs 54 are provided on two side surfaces parallel to the X-axis direction among the four side surfaces in the rectangular solid shape of the housing 5. Therefore, in H, the natural frequency of the housing 5 with respect to the vibration in the X-axis direction in the horizontal direction (XY direction) is high. On the other hand, in I, two ribs 54 are provided on one side surface parallel to the X-axis direction and one side surface parallel to the Y-axis direction among the four side surfaces in the rectangular solid shape of the housing 5. Is provided. Therefore, in I, the natural frequency of the housing 5 with respect to vibrations in the X-axis direction and the Y-axis direction in the horizontal direction (XY direction) is high. As a result, I has a higher natural frequency of the housing 5 with respect to the horizontal vibration than H as a whole. That is, when two or more ribs 54 are provided on each of the two side surfaces of the four side surfaces of the rectangular parallelepiped solid shape, the ribs 54 are provided on the two side surfaces adjacent to each other, thereby preventing horizontal vibration. The natural frequency of the housing 5 can be further increased.

FIG. 11 is a diagram showing the result of analyzing the relationship between the position of the rib 54 and the natural frequency of the housing 5 with respect to the vibration in the horizontal direction, as in FIG. The vertical axis represents the analysis result of the natural frequency of each housing 5 based on the analysis result of the natural frequency of the housing 5 of A. In FIG. 11, A is the result of analyzing the natural frequency of the housing 5 with respect to the vibration in the horizontal direction when the ribs 54 are not provided on the housing 5. J is a result of the same analysis in the case where one rib 54 is provided on each of the four side surfaces in the three-dimensional shape of the rectangular parallelepiped of the housing 5 and the side surface adjacent to the one side surface. is there. K is the result of the same analysis when one rib 54 is provided on each of all four side surfaces of the rectangular solid shape of the housing 5. L is provided with two ribs 54 on one side surface parallel to the Y-axis among the four side surfaces in the rectangular solid shape of the housing 5, and on each of the two side surfaces adjacent to the one side surface, It is the result of analyzing similarly when one rib 54 is provided. C is the result of the same analysis in the case where two ribs 54 are provided on all four side surfaces of the rectangular solid shape of the housing 5. For reference, FIGS. 12A, 12J, 12K, 12L, and 12C show top views of the housings A, J, K, L, and C, respectively. Ribs 54 are provided at the positions of the black circles in each top view.

As in the analysis result of FIG. 9, when comparing the analysis results of A, J, K, L, and C as shown in FIG. 11, C has the highest natural frequency of the housing 5 with respect to the horizontal vibration. In C, since two ribs 54 are provided on all four side surfaces of the rectangular solid shape of the housing 5, the rigidity of the housing 5 as a whole is increased and the natural frequency is increased. As a result, when the fan motor 10 is driven, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced.

When the analysis results of K and L in FIG. 11 are compared with H and I in FIG. The number gets higher. All of H, I, K, and L are provided with a total of four ribs 54 on the four side surfaces of the rectangular solid shape of the housing 5. However, the horizontal plane orthogonal to the axial direction is the XY plane, and as shown in the top view of the housing 5, K and L are the X-axis directions of the four side surfaces in the three-dimensional shape of the rectangular parallelepiped of the housing 5. In total, two ribs 54 are provided on the side surface parallel to the Y axis and the side surface parallel to the Y-axis direction. Therefore, the natural frequency of the housing 5 with respect to the horizontal vibration as a whole increases.

<2. Second Embodiment>
<2-1. Fan motor configuration>
Subsequently, a second embodiment of the present invention will be described. FIG. 13 is a longitudinal sectional view of a fan motor 10B according to the second embodiment. FIG. 14 is a perspective view of a housing 5B according to the second embodiment. FIG. 15 is a side view of the housing 5B according to the second embodiment. In the following description, differences from the first embodiment will be mainly described, and redundant description of parts equivalent to those of the first embodiment will be omitted.

As shown in FIG. 13, the fan motor 10B has a motor 1B, an impeller 4B, and a housing 5B. The motor 1B includes a stationary portion 2B having a stator 22B and a rotating portion 3B that rotates about a central axis 9B that extends vertically. The stationary part 2B is relatively stationary with respect to the device or the like where the fan motor 10B is disposed. The rotating part 3B is supported so as to be rotatable with respect to the stationary part 2B around a central axis 9B extending vertically. The impeller 4B has a plurality of blades 42B and rotates together with the rotating portion 3B of the motor 1B. The housing 5B is a housing that houses at least a part of the motor 1B and the impeller 4B. Details of the housing 5B will be described later.

<2-2. Housing configuration>
Next, the configuration of the housing 5B will be described.

As shown in FIGS. 14 and 15, the housing 5B has a first housing 55B and a second housing 56B. The second housing 56B is fixed directly or indirectly below the first housing 55B.

The first housing 55B has a rectangular parallelepiped solid shape that opens up and down. The first housing 55B includes a first tubular portion 511B and an upper flange portion 521B.

The first cylindrical portion 511B is a cylindrical portion that extends in the axial direction from the intake side (upper side) to the exhaust side (lower side) along the central axis 9B. The first cylindrical portion 511B accommodates at least a part of the motor 1B and the impeller 4B inside, and surrounds the radially outer side of the impeller 4B in an annular shape. The upper flange portion 521B protrudes radially outward from the upper end portion of the first tubular portion 511B at four locations in the circumferential direction of the first tubular portion 511B.

The second housing 56B has a rectangular parallelepiped solid shape that opens up and down. The second housing 56B includes a base portion 21B, a second cylindrical portion 512B, a lower flange portion 522B, and one or a plurality of base connection portions 53B. The housing 5B may have only the upper flange portion 521B or the lower flange portion 522B of the first housing 55B.

The base portion 21B is a disk-shaped portion that is disposed below the stator 22B of the motor 1B and expands in the radial direction. A motor 1B is disposed on the upper portion of the base portion 21B. The motor 1B is supported by the base portion 21B. The second cylindrical portion 512B is a cylindrical portion that is disposed below the first cylindrical portion 511B and extends in the axial direction from the intake side (upper side) to the exhaust side (lower side) along the central axis 9B. . The second cylindrical portion 512B accommodates at least a part of the motor 1B and the impeller 4B inside, and surrounds the radially outer side of the impeller 4B in an annular shape. The second tubular portion 512B is continuously arranged below the first tubular portion 511B via a contact surface 513B with the first tubular portion 511B. The lower flange portion 522B protrudes radially outward from the lower end portion of the second tubular portion 512B at four locations in the circumferential direction of the second tubular portion 512B.

Note that the upper surface and outer peripheral surface of the upper flange portion 521B of the first housing 55B and the lower surface and outer peripheral surface of the lower flange portion 522B form the outer shape of the housing 5 having a rectangular parallelepiped shape that opens up and down. The In the present embodiment, the axial thickness of the upper flange portion 521B and the axial thickness of the lower flange portion 522B are equal to each other.

The base connection portion 53B is a columnar portion that extends radially outward from at least a portion of the outer peripheral surface of the base portion 21B and is connected to at least a portion of the inner peripheral surface of the second cylindrical portion 512B. Thereby, the position of the stationary part 2B of the motor 1B with respect to the housing 5B is fixed. Further, by providing the base connection portion 53B, the lower portion of the second tubular portion 512B and the lower flange portion 522B are more rigid than the upper portion of the first tubular portion 511B and the upper flange portion 521B. One or a plurality of base connection portions 53B are provided in the lower portion of the housing 5B. However, the number of base connection parts 53B is not limited.

Furthermore, the housing 5B has a columnar first rib 541B and a columnar second rib 542B. The first rib 541B extends downward from the upper flange portion 521B on the outer peripheral surface of the first tubular portion 511B. The second rib 542B extends upward from the lower flange portion 522B on the outer peripheral surface of the second cylindrical portion 512B. One or a plurality of first ribs 541B and second ribs 542B are provided. Details of the first rib 541B and the second rib 542B will be described later. The housing 5B may have a structure having only at least one of the first rib 541B and the second rib 542B. In the present embodiment, the first tubular portion 511B, the upper flange portion 521B, and the one or more first ribs 541B are formed as a single member by resin injection molding. However, these may be separate members. In the present embodiment, the base portion 21B, the second cylindrical portion 512B, the lower flange portion 522B, the one or more base connection portions 53B, and the one or more second ribs 542B are made of resin. It is formed as a single member by injection molding. However, these may be separate members.

<2-3. Configuration of first rib and second rib>
Next, the configuration of the first rib 541B and the second rib 542B will be described.

Each of the one or more columnar first ribs 541B is located on the outer peripheral surface of the first tubular portion 511B, and extends downward from the upper flange portion 521B in a direction inclined with respect to the axial direction. The one or more columnar second ribs 542B are located on the outer peripheral surface of the second tubular portion 512B, respectively, and extend upward from the lower flange portion 522B in a direction inclined with respect to the axial direction. By having the first rib 541B and the second rib 542B, the rigidity of the housing 5B is increased, and the natural frequency of the housing 5B with respect to the vibration in the horizontal direction is increased. As a result, when driving the fan motor 10B, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced.

In the present embodiment, the first rib 541B is inclined in a direction away from the central axis 9B as it goes to the upper surface of the housing 5B. The second rib 542B is inclined in a direction away from the central axis 9B as it goes to the lower surface of the housing 5B. As in the first embodiment, the rigidity of each part of the housing 5B decreases as the distance from the central axis 9B increases outward in the radial direction. For example, the radially outer end of the upper flange portion 521B and the radially outer end of the lower flange portion 522B have particularly low rigidity in the housing 5B. By providing the first rib 541B and the second rib 542B, these portions are connected to a portion having a high radial inner rigidity in the housing 5B. As a result, the rigidity of the housing 5B as a whole increases, and the natural frequency increases. As a result, when driving the fan motor 10B, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced.

Also, the thicknesses of the first rib 541B and the second rib 542B are preferably equal to or less than the axial thickness of the upper flange portion 521B or the lower flange portion 522B. Further, it is desirable that the thicknesses of the plurality of first ribs 541B and the plurality of second ribs 542B are approximately the same. Thus, as in the first embodiment, during resin molding of the housing 5B including the first rib 541B and the second rib 542B, the rigidity of the housing 5B is enhanced while suppressing the occurrence of sink marks, and the fan motor 10B is driven. Noise can be suppressed.

In addition, each lower end part of 1 or several 1st rib 541B and each upper end part of 1 or several 2nd rib 542B are contact surfaces of 1st cylindrical part 511B and 2nd cylindrical part 512B. In 513B, it is desirable to arrange them consecutively. Thereby, the rigidity of the 1st rib 541B and the 2nd rib 542B becomes high, and the rigidity as the whole of the housing 5B can further be improved.

Further, similarly to the first embodiment, when two or more first ribs 541B are provided on each of two side surfaces of the four side surfaces of the rectangular parallelepiped solid shape of the first housing 55B, they are adjacent to each other. It is desirable to provide the first rib 541B on one side surface. Thereby, the natural frequency of the 1st housing 55B with respect to the vibration of a horizontal direction can be raised more. Further, when two or more second ribs 542B are provided on each of the two side surfaces of the four side surfaces of the rectangular parallelepiped solid shape of the second housing 56B, the second ribs 542B are provided on the two adjacent side surfaces. It is desirable to provide it. Thereby, the natural frequency of the 2nd housing 56B with respect to the vibration of a horizontal direction can be raised more.

FIG. 16 is a diagram illustrating a result of analyzing the relationship between the positions of the first rib 541B and the second rib 542B and the natural frequency of the housing 5B with respect to the vibration in the horizontal direction. The vertical axis represents the analysis result of the natural frequency of each housing 5B based on the analysis result of the natural frequency of the A housing 5B. In FIG. 16, A analyzes the natural frequency of the housing 5B with respect to the horizontal vibration in the case where the first rib 541B is not provided in the first housing 55B and the second rib 542B is not provided in the second housing 56B. It is the result. B is the result of the same analysis in the case where two first ribs 541B are provided on each of the four side surfaces of the rectangular parallelepiped solid shape of the first housing 55B. The second ribs 542B are not provided in the second housing 56B. C is the result of the same analysis in the case where two second ribs 542B are provided on each of the four side surfaces of the rectangular solid shape of the second housing 56B. The first housing 55B is not provided with the first rib 541B. D and E are each provided with one first rib 541B on each of the four side surfaces of the rectangular parallelepiped solid shape of the first housing 55B, and one on each of the four side surfaces of the solid rectangular solid shape of the second housing 56B. It is the result of analyzing similarly when two second ribs 542B are provided. However, as for D, the lower end part of the 1st rib 541B and the upper end part of the 2nd rib 542B are continuing in the contact surface 513B. E is provided at a position where the first rib 541B and the second rib 542B are not continuous on the contact surface 513B. F is provided with two first ribs 541B on all four side surfaces of the rectangular parallelepiped solid shape of the first housing 55B, and on all four side surfaces of the rectangular solid shape of the second housing 56B, It is the result of the same analysis when two second ribs 542B are provided. For reference, FIGS. 17A, 17B, 17C, 17D, 17E, and 17F show top views of housings 5B of A, B, C, D, E, and F, respectively. A first rib 541B is provided at a black circle in the top view of each first housing 55B. Further, a second rib 542B is provided at a position indicated by a black circle in the top view of each second housing 56B.

16, when the analysis results of A, B, C, D, E, and F are compared, the natural frequency of the housing 5 with respect to the vibration in the horizontal direction is the highest in F. In F, two first ribs 541B are provided on all four side surfaces in the rectangular solid shape of the first housing 55B, respectively, and on all four side surfaces in the rectangular solid shape of the second housing 56B, Since each of the two second ribs 542B is provided, the rigidity of the entire housing 5B is increased and the natural frequency is increased. As a result, when driving the fan motor 10B, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced. That is, two or more first ribs 541B are provided on each of the four side surfaces of the rectangular solid shape of the first housing 55B, and the second ribs 542B are four shapes of the rectangular solid shape of the second housing 56B. It is desirable that two or more are provided on each side surface.

When comparing the analysis results of B and C in FIG. 16, B has a higher natural frequency of the housing 5B with respect to vibration in the horizontal direction than C. In B, since the portion on the radially outer side of the upper flange portion 521B having particularly low rigidity in the housing 5B is connected to the portion on the radially inner side of the contact surface 513B having high rigidity by the first rib 541B, the entire housing 5B is formed. The rigidity is increased and the natural frequency is increased. As a result, when driving the fan motor 10B, the resonance amplitude at the time of resonance with the magnetic excitation can be reduced, and noise can be reduced. That is, in the case where a rib (first rib 541B or second rib 542B) is provided on one of the first housing 55B and the second housing 56B, on each of the four side surfaces of the rectangular solid shape of the first housing 55B, It is desirable to have only the first rib 541B.

<3. Modification>
As mentioned above, although exemplary embodiment of this invention was described, this invention is not limited to said embodiment.

The thickness of each rib does not necessarily have to be constant. For example, the thickness of the rib may change depending on the position in the axial direction. Further, two or more ribs may be provided on each of the four side surfaces of the solid rectangular solid shape of the housing. Moreover, each rib does not necessarily need to be linear.

Also, the detailed shape of each part may be different from the shape shown in each drawing of the present application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

The present invention can be used for a fan motor, for example.

1, 1B motor, 2, 2B stationary part, 3, 3B rotating part, 4, 4B impeller, 5, 5B, 5X, 5Y housing, 9, 9B central axis, 10, 10B fan motor, 21, 21B base part, 22 , 22B stator, 23 circuit board, 24 bearing holder, 25 bearing part, 31 shaft, 32 rotor holder, 33 annular member, 34 magnet, 41 cup part, 42, 42B blade, 50 wind tunnel, 51 cylindrical part, 52 flange part, 53, 53B base connection, 54 rib, 55B first housing, 56B second housing, 221 stator core, 222 coil, 321 rotor lid, 322 rotor cylinder, 511B first cylinder, 512B second cylinder, 513B contact surface, 521, 521B upper flange, 22,522B lower flange portion, 541B first rib, 542B second rib

Claims

A fan motor,
A motor having a stationary part having a stator and a rotating part rotating around a central axis extending vertically;
An impeller having a plurality of blades and rotating together with the rotating part;
A housing that houses at least a part of the motor and the impeller;
Have
The housing is
A cylindrical tubular portion extending in the axial direction and accommodating at least a part of the motor and the impeller inside;
A flange portion projecting radially outward from an upper end portion or a lower end portion of the tubular portion;
On the outer peripheral surface of the cylindrical portion, one or more columnar ribs extending from the flange portion;
Have
The fan motor is inclined with respect to the axial direction.
The fan motor according to claim 1,
The housing further includes a base portion that supports the motor;
In the lower part of the housing, one or a plurality of columnar base connecting portions that connect the outer peripheral surface of the base portion and the inner peripheral surface of the cylindrical portion;
Have
The fan motor, wherein the rib is inclined in a direction away from the central axis from the lower part to the upper part of the housing.
The fan motor according to claim 1 or 2,
The housing has a cuboid solid shape that opens up and down,
Two or more ribs are provided on each of the four side surfaces of the rectangular parallelepiped solid shape.
The fan motor according to claim 1 or 2,
The housing has a cuboid solid shape that opens up and down,
Two or more ribs are provided on each of two side surfaces of the four side surfaces of the rectangular parallelepiped solid shape,
The fan motor in which the side surface in which the said rib in the three-dimensional shape of the said rectangular parallelepiped shape is provided is adjacent to each other.
The fan motor according to any one of claims 1 to 4, wherein
The flange portion is
An upper flange portion projecting radially outward from the upper end portion of the tubular portion;
A lower flange portion projecting radially outward from a lower end portion of the cylindrical portion;
Have
The thickness of the said rib is a fan motor which is below the axial thickness of the said upper side flange part or the said lower side flange part.
A fan motor,
A motor having a stationary part having a stator and a rotating part rotating around a central axis extending vertically;
An impeller having a plurality of blades and rotating together with the rotating part;
A housing that houses at least a part of the motor and the impeller;
Have
The housing is
A first housing;
A second housing fixed directly or indirectly below the first housing;
Have
The first housing is
A cylindrical first cylindrical portion extending in the axial direction and accommodating at least a part of the motor and the impeller inside;
An upper flange portion projecting radially outward from an upper end portion of the first tubular portion;
Have
The second housing is
A cylindrical second cylindrical portion disposed below the first cylindrical portion, extending in the axial direction, and accommodating at least a part of the motor and the impeller;
A lower flange portion projecting radially outward from a lower end portion of the second tubular portion;
Have
The housing further includes one or more columnar first ribs extending in a direction inclined with respect to the axial direction downward from the upper flange portion on the outer peripheral surface of the first cylindrical portion,
and,
One or more columnar second ribs extending in a direction inclined with respect to the axial direction upward from the lower flange portion on the outer peripheral surface of the second cylindrical portion;
A fan motor having at least one of the following.
The fan motor according to claim 6,
The second housing further includes a base portion that supports the motor;
One or more columnar base connecting portions that connect the outer peripheral surface of the base portion and the inner peripheral surface of the second tubular portion;
Have
The first rib is a fan motor that inclines in a direction away from the central axis toward the top of the housing.
The fan motor according to claim 6 or 7,
The housing is a fan motor having only the first rib of the first rib and the second rib.
The fan motor according to any one of claims 6 to 8,
Each of the first housing and the second housing has a rectangular parallelepiped solid shape that opens up and down,
Two or more said 1st ribs or said 2nd ribs are each provided in each of the four side surfaces in the said rectangular parallelepiped solid shape.
The fan motor according to any one of claims 6 to 8,
Each of the first housing and the second housing has a rectangular parallelepiped solid shape that opens up and down,
Two or more of the first ribs or the second ribs are provided on each of two side surfaces of the four side surfaces in the rectangular solid shape.
The fan motor in which the side surface in which the said 1st rib or the said 2nd rib is provided in the three-dimensional shape of the said rectangular parallelepiped is adjacent to each other.
The fan motor according to any one of claims 6 to 10, wherein
The fan motor, wherein a thickness of the first rib and the second rib is equal to or less than an axial thickness of the upper flange portion or the lower flange portion.
A fan motor according to claim 6 or any one of claims 8 to 11,
The second housing further includes a base portion that supports the motor;
One or more columnar base connecting portions that connect the outer peripheral surface of the base portion and the inner peripheral surface of the second tubular portion;
Have
The first rib is inclined in a direction away from the central axis toward the upper portion of the housing,
The second rib is inclined in a direction away from the central axis toward the lower portion of the housing,
The fan motor, wherein a lower end portion of the first rib and an upper end portion of the second rib are disposed in contact with each other.