Air blower

Abstract

To provide an air blower capable of improving PQ characteristics by suppressing occurrence of surging.SOLUTION: An air blower includes an impeller and a housing 20. The impeller rotates around a central axis. The housing houses the impeller. The housing has a cylindrical wall 22. The cylindrical wall extends along the central axis, and covers the impeller from the outside in a radial direction. The cylindrical wall has a groove 22a. The groove is recessed in the radial direction from an inner peripheral surface, and the plurality of grooves are arranged in a circumferential direction. A width W in the circumferential direction of the groove becomes smaller as going from an end on a blow direction upstream side X1 of the impeller toward an end on a blow direction downstream side X2.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a blower device. Regarding. [Background technology]

[0002] A conventional blower device includes an impeller that rotates about a central axis and a housing that accommodates the impeller. The housing extends along the central axis and has a cylindrical wall portion that covers the impeller from the radial outside (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-015576 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional blowers, there is a possibility that surging, in which the air flow is disturbed around the rotating impeller, may occur. When surging occurs, for example, both the pressure difference between the exhaust side (downstream side in the blowing direction) and the intake side (upstream side in the blowing direction) and the air volume may decrease, and the PQ characteristics may decrease.

[0005] An object of the present invention is to provide a blower capable of suppressing the occurrence of surging and improving PQ characteristics. [Means for solving the problem]

[0006] An exemplary blower device of the present invention includes an impeller and a housing. The impeller rotates around a central axis. The housing accommodates the impeller. The housing has a cylindrical wall portion. The cylindrical wall portion extends along the central axis and covers the impeller from the radial outside. The cylindrical wall portion has a groove portion. The groove portion is recessed radially from the inner peripheral surface and is arranged in a plurality of groove portions in the circumferential direction. The circumferential width of the groove portion decreases from the upstream end of the impeller in the air blowing direction toward the downstream end of the impeller in the air blowing direction. Effect of the Invention

[0007] According to an exemplary embodiment of the present invention, it is possible to provide a blower capable of suppressing the occurrence of surging and improving the PQ characteristics. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an overall perspective view of a blower device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the blower according to the embodiment of the present invention. [Diagram 3] FIG. 3 is a vertical sectional perspective view of a housing of the blower according to the embodiment of the present invention. [Figure 4] FIG. 4 is an enlarged perspective view of a part of a housing of the blower according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the drawings. In this document, the direction in which the central axis of the blower extends is simply called the "axial direction", the direction perpendicular to the central axis of the blower is simply called the "radial direction", and the direction along the arc centered on the central axis of the blower is simply called the "circumferential direction". In this document, for convenience of explanation, the axial direction is the up-down direction, and the up-down direction in FIG. 2 is the up-down direction of the blower, and the shape and positional relationship of each part will be described. The "upper side" of the blower is the "intake side", and the "lower side" is the "exhaust side". Note that this definition of the up-down direction does not limit the orientation and positional relationship when the blower is in use. In this document, a cross section parallel to the axial direction is called a "longitudinal cross section". In addition, the term "parallel" used in this document does not mean parallel in the strict sense, but includes approximately parallel.

[0010] <1. Overall configuration of the blower> FIG. 1 is an overall perspective view of an example of a blower device 1 according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of the blower device 1. As shown in FIG.

[0011] The blower 1 includes an impeller 11, a motor 12, and a housing 20.

[0012] The housing 20 has an air flow passage 21 therein. The air flow passage 21 extends along a central axis J inside the housing 20. The air flow passage 21 has an air intake port 211 at an upper end and an air outlet 212 at a lower end.

[0013] The housing 20 is a resin molded product (a molded product) and accommodates the impeller 11, the motor 12, and a circuit board (not shown) therein. The housing 20 has a cylindrical wall portion 22, a base portion 23, a stator blade portion 24, and a bearing holder 25.

[0014] The cylinder wall portion 22 extends along the central axis J and covers the impeller 11 from the radially outer side. The cylinder wall portion 22 has a cylindrical shape extending up and down in the axial direction. An air flow passage 21 is arranged on the radially inner side of the cylinder wall portion 22. An air intake port 211 is arranged at an axially upper end of the cylinder wall portion 22. An air outlet 212 is arranged at an axially lower end of the cylinder wall portion 22.

[0015] The cylindrical wall portion 22 has groove portions 22a. The groove portions 22a are recessed radially from the inner peripheral surface of the cylindrical wall portion 22 and are arranged in a plurality of groove portions 22a in the circumferential direction (see FIG. 3). In this embodiment, the groove portions 22a are provided in 16 locations and are arranged at equal intervals in the circumferential direction. The shape of the groove portions 22a will be described in detail later.

[0016] The base portion 23 is disposed axially below the motor 12, and the motor 12 is fixed to the base portion 23. The base portion 23 has a disk shape that extends radially from the central axis J as the center.

[0017] The stator blade sections 24 extend radially outward from the radial outer surface of the base section 23 and connect the base section 23 and the tube wall section 22. A plurality of stator blade sections 24 are arranged in the circumferential direction. That is, a plurality of stator blade sections 24 are arranged in the circumferential direction, extending radially inward from the downstream end of the tube wall section 22 in the air blowing direction. The air flowing through the air flow passage 21 is straightened when passing between adjacent stator blade sections 24 and is blown out to the outside of the housing 20. In this embodiment, eight stator blade sections 24 are provided and arranged at equal intervals in the circumferential direction.

[0018] The bearing retaining portion 25 is a metal member such as brass, and is molded integrally with the base portion 23. The bearing retaining portion 25 protrudes axially upward from the upper surface of the base portion 23 and is cylindrical with the central axis J as its center. The bearing retaining portion 25 holds a bearing 122 therein, which will be described later, and constitutes a part of the motor 12. Note that instead of being molded as a separate member from the base portion 23, the bearing retaining portion 25 may be molded integrally with the base portion 23 from the same resin member.

[0019] The impeller 11 is disposed radially inside the cylindrical wall portion 22, axially above and radially outside the motor 12. The impeller 11 is a resin molded product (a molded product), and is rotated around a central axis J by the motor 12.

[0020] The impeller 11 has an impeller cup 111 and blade portions 112. The impeller cup 111 is fixed to the motor 12. The impeller cup 111 is a substantially cylindrical member having a lid on the axially upper side. The multiple blade portions 112 are arranged in the circumferential direction on the outer surface of the impeller cup 111.

[0021] The motor 12 is fixed to the base portion 23 and accommodated in the housing 20. The motor 12 rotates the impeller 11 around the central axis J (Y1 direction). The motor 12 has a shaft 121, a bearing 122, a bearing holder 25, a stator 123, and a rotor 124.

[0022] The shaft 121 is disposed along the central axis J. The shaft 121 is made of a metal such as stainless steel, and is a columnar member extending up and down in the axial direction. The shaft 121 is supported by a bearing 122 so as to be rotatable around the central axis J.

[0023] The bearings 122 are arranged in at least one pair, one above and one below in the axial direction. The bearings 122 are held inside the bearing holder 25. The bearings 122 are formed of, for example, ball bearings, but may also be formed of sleeve bearings or the like. The pair of bearings 122, one above and one below in the axial direction, support the shaft 121 rotatably around the central axis J with respect to the housing 20.

[0024] The stator 123 is fixed to the outer circumferential surface of the bearing holder 25. The stator 123 includes a stator core 1231, an insulator (not shown), and a coil 1233.

[0025] Stator core 1231 is formed by stacking electromagnetic steel plates such as silicon steel plates one above the other. Insulators (not shown) are made of insulating resin. Insulators (not shown) are provided to surround the outer surface of stator core 1231. Coils 1233 are formed by conductive wires wound around stator core 1231 via insulators 1232.

[0026] The rotor 124 is disposed axially above and radially outward of the stator 123. The rotor 124 rotates about a central axis J relative to the stator 123. The rotor 124 includes a rotor yoke 1241 and a magnet 1242.

[0027] Rotor yoke 1241 is made of a magnetic material and is a substantially cylindrical member having a cover on the axially upper side. Rotor yoke 1241 is fixed to shaft 121. Magnet 1242 is cylindrical and fixed to the inner circumferential surface of rotor yoke 1241. Magnet 1242 is disposed radially outside stator 123.

[0028] The circuit board (not shown) is disposed, for example, below the impeller 11 in the axial direction and above the base portion 23 in the axial direction. The circuit board is, for example, in the shape of a disk extending in the radial direction about the central axis J. The lead wires of the coils 1233 are electrically connected to the circuit board. An electronic circuit for supplying a drive current to the coils 1233 is mounted on the circuit board.

[0029] In the blower 1 having the above configuration, when a driving current is supplied to the coil 1233 of the motor 12 via the circuit board, a radial magnetic flux is generated in the stator core 1231. A magnetic field generated by the magnetic flux of the stator core 1231 and a magnetic field generated by the magnet 1242 act on each other, generating a torque in the circumferential direction of the rotor 124. This torque causes the rotor 124 and the impeller 11 to rotate counterclockwise (Y1 direction) about the central axis J. When the impeller 11 rotates, an airflow is generated by the multiple blades 112. That is, the blower 1 can blow air by generating an airflow with the upper side being the intake side (upstream side in the blowing direction) X1 and the lower side being the exhaust side (downstream side in the blowing direction) X2.

[0030] <2. Detailed configuration of the housing> FIG. 3 is a vertical cross-sectional perspective view of the housing 20, and FIG. 4 is an enlarged perspective view of the groove 22a of the housing 20. As shown in FIG.

[0031] In this embodiment, the groove 22a is formed in a substantially triangular shape when the inner peripheral surface of the tube wall portion 22 is developed in the circumferential direction. In detail, the groove 22a has a wall surface L1 in the forward direction Y1 of the rotation direction of the impeller 11 extending in the axial direction (X1-X2 direction). The wall surface L2 in the rearward direction Y2 of the rotation direction of the impeller 11 inclines toward the forward direction Y1 of the rotation direction as it approaches the downstream side X2 in the air blowing direction. The wall surface L1 in the forward direction Y1 of the rotation direction of the impeller 11 and the wall surface L2 in the rearward direction Y2 of the rotation direction intersect at an end P of the downstream side X2 in the air blowing direction.

[0032] As a result, the circumferential width W of the groove 22a becomes smaller from the end of the impeller 11 on the upstream side X1 in the airflow direction toward the end of the impeller 11 on the downstream side X2 in the airflow direction. Therefore, the groove 22a is formed such that the circumferential width W gradually narrows over the entire length in the airflow direction (X1-X2). As a result, the airflow flows smoothly along the groove 22a on the inner circumferential surface of the cylindrical wall 22 toward the downstream side X2 in the airflow direction. Therefore, the PQ characteristic can be improved while suppressing the occurrence of surging. Furthermore, since the airflow flows smoothly along the inner circumferential surface of the cylindrical wall 22, noise reduction is also improved.

[0033] In addition, the airflow flowing along the groove 22a flows smoothly toward the downstream side X2 in the air blowing direction while rotating forward Y1 in the rotation direction of the impeller 11 along the inclined wall surface L2 of the groove 22a. Therefore, the occurrence of surging can be further suppressed.

[0034] Moreover, the air current flowing along the groove portion 22a flows smoothly from the end P toward the downstream side X2 in the air blowing direction. Therefore, the occurrence of surging can be further suppressed.

[0035] Moreover, the radial depth D of the groove 22a decreases toward the downstream side X2 in the airflow direction. This allows the airflow flowing along the groove 22a to flow smoothly toward the downstream side X2 in the airflow direction. This makes it possible to further suppress the occurrence of surging.

[0036] Moreover, the radial depth D of the groove 22a becomes smaller toward the front Y1 in the rotation direction of the impeller 11. This allows the airflow flowing along the groove 22a to flow smoothly toward the front Y1 in the rotation direction of the impeller 11. This makes it possible to further suppress the occurrence of surging.

[0037] Also, the end of groove 22a on upstream side X1 in the airflow direction is located further upstream in the airflow direction X1 than the end of blade 112 on upstream side X1 in the airflow direction (see FIGS. 1 and 2). This allows the airflow to smoothly flow into housing 20 along groove 22a. Also, end P of groove 22a on downstream side X2 in the airflow direction is located further upstream in the airflow direction X1 than the end of blade 112 on downstream side X2 in the airflow direction. This allows the airflow to flow along tube wall 22 where groove 22a is not yet formed, at downstream side X2 in the airflow direction than blade 112. This makes it possible to reduce noise generated near the end of housing 20 on downstream side X2 in the airflow direction, thereby further improving quietness.

[0038] Moreover, the groove portion 22a is disposed corresponding to the stator blade portion 24. Specifically, an end P of the groove portion 22a on the downstream side X2 in the airflow direction is located further upstream in the airflow direction X1 than an end of the stator blade portion 24 on the upstream side X1 in the airflow direction (see FIG. 5). Moreover, in this embodiment, the end P of the groove portion 22a on the downstream side X2 in the airflow direction faces an end N of the base portion of the stator blade portion 24 on the tube wall portion 22 side rearward in the rotation direction Y2 of the impeller 11 in the axial direction. This allows the airflow that flows along the groove portion 22a to flow smoothly toward the stator blade portion 24. Therefore, the occurrence of surging can be further suppressed.

[0039] (4. Other) The above embodiment is merely an example of the present invention. The configuration of the embodiment may be appropriately changed without departing from the technical spirit of the present invention. The embodiments may be combined as far as possible. For example, in the present embodiment, the grooves 22a are provided in 16 places, but they may be provided in 17 places or more. Also, the grooves 22a may be provided in 15 places or less.

[0040] (5. Notes) As described above, the air blower (1) according to one embodiment of the present disclosure comprises an impeller (11) rotating around a central axis (J) and a housing (20) that accommodates the impeller, the housing having a cylindrical wall portion (22) extending along the central axis and covering the impeller from the radial outside, the impeller having a plurality of blade portions (112) arranged in the circumferential direction, the cylindrical wall portion having a plurality of groove portions (22a) that are recessed radially from the inner circumferential surface and arranged in the circumferential direction, and the circumferential width (W) of the groove portions decreasing from the end of the impeller on the upstream side (X1) in the air blowing direction toward the end on the downstream side (X2) in the air blowing direction (first configuration).

[0041] In the first configuration, the radial depth (D) of the groove portion decreases toward the downstream side in the air blowing direction (second configuration).

[0042] In the first or second configuration, the radial depth (D) of the groove decreases toward the front in the rotation direction of the impeller (third configuration).

[0043] In addition, in any of the above first to third configurations, the groove portion has an end face (L1) at the front (Y1) of the impeller in the rotation direction extending axially, and an end face (L2) at the rear (Y2) of the impeller in the rotation direction extending at an incline toward the front in the rotation direction as it approaches the downstream side in the air blowing direction (fourth configuration).

[0044] In any of the first to fourth configurations, the groove portion has a front end face in the rotational direction and a rear end face in the rotational direction that intersect at an end (P) downstream in the air blowing direction (fifth configuration).

[0045] In addition, in any of the above first to fifth configurations, the impeller has a plurality of blade portions (112) arranged circumferentially, and the upstream end of the groove portion in the air blowing direction is located upstream of the upstream end of the blade portion in the air blowing direction (sixth configuration).

[0046] In addition, in any of the above first to sixth configurations, the downstream end of the groove portion in the air blowing direction is located upstream in the air blowing direction relative to the downstream end of the blade portion in the air blowing direction (seventh configuration).

[0047] In addition, in any of the above first to seventh configurations, the housing has a plurality of stator blade portions (24) arranged circumferentially and extending radially inward from the downstream end of the cylindrical wall portion in the air blowing direction, and the groove portions are arranged corresponding to the stator blade portions (seventh configuration). [Industrial Applicability]

[0048] The present invention can be used, for example, in a blower device for cooling a server. [Explanation of symbols]

[0049] 1. Blower 11 Impeller 12 Motor 20. Housing 21 Air flow path 22 Cylinder wall 22a Groove 23 Base 24 Stator blade section 25 Bearing holder 111 Impeller cup 112 Wing 121 Shaft 122 Bearings 123 Stator 124 Rotor 211 Air intake 212 Air outlet 1231 Stator core 1232 Insulator 1233 Coil 1241 Rotor Yoke 1242 Magnet D Depth J center axis L1 Wall L2 Wall N end P end W width X1 Air blowing direction upstream side X2 Air blowing direction downstream Y1 Rotation direction forward Y2 Rotation direction rear

Claims

1. An impeller that rotates around a central axis; A housing that accommodates the impeller, The housing includes: a cylindrical wall portion extending along the central axis and covering the impeller from a radially outer side, The cylindrical wall portion is The groove portion is recessed radially from the inner peripheral surface and is arranged in the circumferential direction. A blower device, wherein a circumferential width of the groove portion decreases from an upstream end of the impeller in a blowing direction to a downstream end of the impeller in a blowing direction.

2. The air blower according to claim 1 , wherein a radial depth of the groove portion decreases toward a downstream side in the air blowing direction.

3. The blower device according to claim 1 or 2, wherein a radial depth of the groove portion decreases toward the front in a rotation direction of the impeller.

4. 3. The blower device according to claim 1, wherein a wall surface of the groove portion at the front in the rotation direction of the impeller extends in the axial direction, and a wall surface at the rear in the rotation direction of the impeller inclines forward in the rotation direction as it approaches downstream in the air blowing direction.

5. The blower device according to claim 4 , wherein the groove has a front wall surface in the rotational direction and a rear wall surface in the rotational direction that intersect at an end downstream in the air blowing direction.

6. The impeller is A plurality of blades arranged in a circumferential direction, The air blower according to claim 1 or 2, wherein an upstream end of the groove in the air blowing direction is located further upstream in the air blowing direction than an upstream end of the blade in the air blowing direction.

7. The air blower according to claim 6 , wherein a downstream end of the groove in the air blowing direction is located upstream in the air blowing direction relative to a downstream end of the blade in the air blowing direction.

8. The housing includes: a plurality of stator blade portions extending radially inward from a downstream end portion of the cylindrical wall portion in the air blowing direction and arranged in a circumferential direction; The blower device according to claim 1 or 2, wherein the groove portion is disposed corresponding to the stationary blade portion.

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