IMPELLER AND BLOWING APPARATUS INCLUDING THE SAME

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2024-151991, filed on Sep. 4, 2024, the entire contents of which are hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present disclosure relates to impellers and blowing apparatuses including the same.

BACKGROUND

A known impeller includes a body portion having a tubular shape and includes a plurality of blade portions. The body portion is rotatable about a center axis. The plurality of blade portions protrude in a radial direction from an outer circumferential surface of the body portion and are arranged at intervals in a circumferential direction. When the blade portions rotate about the center axis, the impeller blows air in an axial direction. Each of the blade portions extends in the circumferential direction while being inclined toward an upstream side in an air blowing direction toward a rotation direction.

However, in the known impeller, the static pressure may decrease and the air blowing efficiency may decrease.

SUMMARY

An impeller according to an example embodiment of the present disclosure includes a body portion having a tubular shape and including a plurality of blade portions. The body portion is rotatable about a center axis. The plurality of blade portions protrude in a radial direction from an outer circumferential surface of the body portion and are arranged at intervals in a circumferential direction. When the blade portions rotate about the center axis, the impeller blows air in an axial direction. Each of the blade portions extends in the circumferential direction while being inclined to an upstream side in an air blowing direction toward a front side in a rotation direction. Each of the blade portions is curved to be convex toward a downstream side in the air blowing direction at the front side in the rotation direction with respect to a center in the circumferential direction.

The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal cross-sectional view of a blowing apparatus according to an example embodiment of the present disclosure.

FIG. 2 is a perspective view of an impeller of the blowing apparatus according to an example embodiment of the present disclosure.

FIG. 3 is a side view of the impeller of the blowing apparatus according to an example embodiment of the present disclosure.

FIG. 4 is a bottom view of the impeller of the blowing apparatus according to an example embodiment of the present disclosure.

DETAILED DESCRIPTION

Example embodiments of the present disclosure will be described in detail below with reference to the drawings. Herein, a direction in which a center axis J of a blowing apparatus 1 extends is simply referred to as an “axial direction”, a direction orthogonal to the center axis J with the center axis J of the blowing apparatus 1 as a center is simply referred to as a “radial direction”, and a direction along a circular arc with the center axis J of the blowing apparatus 1 as a center is simply referred to as a “circumferential direction”. A cross section parallel to the axial direction is referred to as a “longitudinal cross section”. Furthermore, the term “parallel” does not only refer to parallel in a strict sense, but also includes substantially parallel.

For ease of description, the axial direction is defined as a vertical direction, and the vertical direction in FIG. 1 is defined as a vertical direction of the blowing apparatus 1, to describe the shape and positional relationship of each portion. An “upper side” of the blowing apparatus 1 is an “intake side”, and a “lower side” thereof is an “exhaust side”. Note that the definition of the vertical direction does not limit the orientation and positional relationship of the blowing apparatus during use. Herein, a cross section parallel to the axial direction is referred to as a “longitudinal cross section”.

FIG. 1 is a longitudinal cross-sectional view of an example of the blowing apparatus 1 according to an example embodiment of the present disclosure. The blowing apparatus 1 includes a pair of impellers 101 and 102, a pair of motors 12, and a pair of housings 20, which are each arranged side by side in the axial direction. The blowing apparatus 1 generates an air flow at a lower side X2 in the axial direction along the center axis J. In the present example embodiment, the configurations of each of the motors 12 and each of the housings 20 are the same and will be described by using the same reference numerals.

The impeller 101 and the impeller 102 have different shapes and are coaxially arranged along the center axis J. The impeller 102 is arranged on an intake side X1, and the impeller 101 is arranged on an exhaust side X2. That is, the impeller (upstream impeller) 102 is arranged on an upstream side X1 in an air blowing direction from the impeller 101, and is aligned coaxially with the impeller 101.

The pair of motors 12 respectively rotate the impellers 101 and 102 about the center axis J. In the present example embodiment, the impeller 101 rotates clockwise (in a Y1 direction) about the center axis J in a top view. On the other hand, the impeller 102 rotates counterclockwise (in a Y2 direction) about the center axis J in a top view. Note that, depending on the shapes of the impellers 101 and 102, the rotation direction of the impeller 101 and the rotation direction of the impeller 102 may be the same.

Each of the pair of housings 20 is a molded resin product (die-molded product), and has an air flow path 21 therein. The air flow path 21 extends along the center axis J inside the housing 20. The pair of housings 20 are coupled to each other in the axial direction, and the air flow paths 21 also communicate with each other in the axial direction. The coupled pair of housings 20 include an intake port 21b at an upper end thereof and an exhaust port 21a at a lower end thereof.

The housing 20 on the exhaust side X2 accommodates the impeller 101, the motor 12, and a circuit board (not illustrated) therein. The housing 20 on the intake side X1 accommodates the impeller 102, the motor 12, and a circuit board (not illustrated) therein. Each of the housings 20 includes a tubular wall portion 22, a base portion 23, a stationary blade portion 24, and a bearing holding portion 25.

The tubular wall portion 22 extends along the center axis J and covers each of the impellers 101 and 102 from the outside in the radial direction. The tubular wall portion 22 has a cylindrical shape extending vertically in the axial direction. The air flow path 21 is arranged inside the tubular wall portion 22 in the radial direction. The exhaust port 21a is arranged at a lower end in the axial direction of the tubular wall portion 22 on the exhaust side X2. The intake port 21b is arranged at an upper end in the axial direction of the tubular wall portion 22 of the intake side X1.

The motor 12 is fixed to the base portion 23. The base portion 23 has a disk shape extending in the radial direction with the center axis J as a center. In the present example embodiment, the base portions 23 are brought into contact with each other to couple the housings 20.

The stationary blade portion 24 extends outward in the radial direction from an outer surface of the base portion 23 in the radial direction and couples the base portion 23 and the tubular wall portion 22. A plurality of stationary blade portions 24 are arranged in the circumferential direction. The air flowing through the air flow path 21 is straightened when passing between adjacent ones of the stationary blade portions 24 and flows to the lower side X2 in the axial direction.

The bearing holding portion 25 is, for example, a metal member made of a metal such as brass, and is integrally molded with the base portion 23. The bearing holding portion 25 protrudes from the base portion 23 in the axial direction and has a cylindrical shape with the center axis J as a center. In the present example embodiment, the bearing holding portion 25 on the intake side X1 protrudes from the upper surface of the base portion 23 toward the intake side X1. The bearing holding portion 25 on the exhaust side X2 protrudes from the lower surface of the base portion 23 toward the exhaust side X2.

The bearing holding portion 25 holds a bearing 126 (described later) therein and constitutes a part of the motor 12. Note that the bearing holding portion 25 may be molded integrally with the base portion 23 by using the same resin member, instead of being molded as a separate member from the base portion 23.

Each of the impellers 101 and 102 is rotatably supported by a corresponding one of the motors 12 on the inner side of the tubular wall portion 22 in the radial direction. Each of the impellers 101 and 102 is a molded resin product (die-molded product) and is rotated about the center axis J by a corresponding one of the motors 12. The shape of the impellers 101 and 102 will be described in detail later.

Each of the motors 12 is fixed to a corresponding one of the base portions 23 and accommodated in a corresponding one of the housings 20. The motor 12 includes a shaft 125, the bearing 126, the bearing holding portion 25, a stator 123, and a rotor 124.

The shaft 125 is arranged along the center axis J. The shaft 125 is made of a metal such as stainless steel and is a columnar member extending vertically in the axial direction. The shaft 125 is supported by the bearing 126 so as to be rotatable about the center axis J.

The bearing 126 is held inside the bearing holding portion 25. For example, the bearing 126 is constituted by a ball bearing, but may be constituted by a sleeve bearing or the like. The pair of bearings 126 positioned vertically in the axial direction support the shaft 125 so as to be rotatable about the center axis J with respect to the housings 20.

The stator 123 is fixed to an outer circumferential surface of the bearing holding portion 25. The stator 123 includes a stator core 1231, an insulator (not illustrated), and a coil 1232.

The stator core 1231 is formed by vertically stacking electromagnetic steel plates such as silicon steel plates. The insulator (not illustrated) is made of a resin having insulating properties. The insulator (not illustrated) is provided on a part of an outer surface of the stator core 1231. The coil 1232 is formed of a conductive wire wound around the stator core 1231, with the insulator interposed therebetween.

The rotor 124 on the intake side X1 is disposed on an upper side in the axial direction and an outer side in the radial direction of the stator 123. The rotor 124 at the exhaust side X2 is arranged on a lower side in the axial direction and on the outer side in the radial direction of the stator 123. The rotor 124 rotates about the center axis J with respect to the stator 123. The rotor 124 includes a rotor yoke 1241 and a magnet 1242.

The rotor yoke 1241 is constituted by a magnetic body. The rotor yoke 1241 on the intake side X1 is a substantially cylindrical member including a lid on an upper side in the axial direction. The rotor yoke 1241 on the exhaust side X2 is a substantially cylindrical member including a lid on a lower side in the axial direction. Each of the rotor yokes 1241 is fixed to the shaft 125. The magnet 1242 has a cylindrical shape and is fixed to an inner circumferential surface of the rotor yoke 1241. The magnet 1242 is arranged outside of the stator 123 in the radial direction.

The circuit board (not illustrated) is arranged between the impeller 101 and the base portion 23 and between the impeller 102 and the base portion 23, for example. The circuit board has a disk shape extending in the radial direction with the center axis J as a center, for example. A lead wire of the coil 1232 is electrically connected to the circuit board. An electronic circuit used for supplying a drive current to the coil 1232 is mounted on the circuit board.

In the blowing apparatus 1 configured as described above, when a drive current is supplied to the coil 1232 of the motor 12 via the circuit board, a magnetic flux in the radial direction is generated in the stator core 1231. A magnetic field generated by the magnetic flux in the stator core 1231 and a magnetic field generated by the magnet 1242 interact to generate torque in the circumferential direction of the rotor 124. This torque causes the impellers 101 and 102 to rotate in opposite directions with the center axis J as a center. When the impellers 101 and 102 rotate, an air flow is generated by a plurality of blade portions 112 and 122. Accordingly, the blowing apparatus 1 can blow air by generating an air flow in which the upper side of the blowing apparatus 1 is the intake side (upstream side in the air blowing direction) X1 and the lower side is the exhaust side (downstream side in the air blowing direction) X2.

FIG. 2 is a perspective view of the impeller 101. FIG. 3 is a side view of the impeller 101. FIG. 4 is a bottom view of the impeller 101. The impeller 101 is arranged outside of the motor 12 in the radial direction and, in the present example embodiment, is rotated clockwise (in the Y1 direction) about the center axis J by the motor 12.

The impeller 101 includes a body portion 111 having a tubular shape and a plurality of blade portions 112. The body portion 111 is a substantially cylindrical member including a lid portion 113 on a lower side in the axial direction. The body portion 111 is fixed to the outer side of the rotor yoke 1241 in the radial direction and is rotatable about the center axis J. The lid portion 113 has a through-hole 113a penetrating in the axial direction along the center axis J. For example, an upper end portion of the shaft 125 is arranged inside the through-hole 113a.

The plurality of blade portions 112 protrude in the radial direction from an outer circumferential surface of the body portion 111 and are arranged at intervals in the circumferential direction. In the present example embodiment, three blade portions 112 are provided and arranged at equal intervals in the circumferential direction. Note that two or four or more blade portions 112 may be provided.

When the blade portions 112 rotate about the center axis J, air is blown to the lower side X2 in the axial direction. Each of the blade portions 112 extends in the circumferential direction while being inclined to the upstream side X1 in the air blowing direction toward a front side Y1 in the rotation direction.

Each of the blade portions 112 is curved to be convex toward the downstream side X2 in the air blowing direction at the front side Y1 in the rotation direction with respect to a center T in the circumferential direction. Accordingly, the static pressure of the impeller 101 is improved, and the air blowing efficiency of the impeller 101 and the air blowing apparatus 1 including the impeller 101 is improved. Each of the blade portions 112 is curved to be convex toward the upstream side X1 in the air blowing direction at a rear side Y2 in the rotation direction with respect to the center T in the circumferential direction. Thus, the static pressure of the impeller 101 is further improved.

In each of the blade portions 112, a width W1 in the radial direction at an end portion of the blade portion 112 at the front side Y1 in the rotation direction is smaller than a width W2 in the radial direction at an end portion of the blade portion 112 at the rear side Y2 in the rotation direction (see FIG. 4). Accordingly, it is possible to reduce the rotation load on the impeller 101 generated by the air flow flowing into the end portion of the blade portion 112 at the front side Y1 in the rotation direction. It is also possible to increase the amount of air blown from the end portion of the blade portion 112 at the rear side Y2 in the rotation direction to the downstream side X2 in the air blowing direction. Thus, the air blowing efficiency of the impeller 101 is further improved.

In blade portions 112 adjacent to each other in the circumferential direction, an end portion of one of the blade portions 112 at the front side Y1 in the rotation direction and an end portion of the other blade portion 112 at the rear side Y2 in the rotation direction overlap each other when viewed from the axial direction (see FIG. 4). Thus, the air blowing efficiency of the impeller 101 is further improved.

The outer circumferential surface of the body portion 111 extends parallel to the axial direction, and an end portion of the body portion 111 at the downstream side X2 in the air blowing direction is inclined inward in the radial direction toward the downstream side X2 in the air blowing direction. More specifically, at the downstream side X2 in the air blowing direction, the outer diameter of the body portion 111 decreases toward the downstream side X2 in the air blowing direction with respect to an end P2 of the blade portion 112 at the rear side Y2 in the rotation direction. The outer circumferential surface of the body portion 111 extends in parallel with the axial direction at the upstream side X1 in the air blowing direction with respect to an end P1 of the blade portion 112 at the front side Y1 in the rotation direction (see FIG. 3).

The air flow flowing through the air flow path 21 in the axial direction flows along the outer circumferential surface of the body portion 111 extending parallel to the axial direction in the impeller 101, and smoothly flows along the blade portion 112 from the end P1 of the blade portion 112 at the front side Y1 in the rotation direction. Thus, the static pressure of the impeller 101 is further improved. The air flow flowing in the axial direction from the end P2 of the blade portion 112 at the rear side Y2 in the rotation direction flows to the downstream side X2 in the air blowing direction along the outer circumferential surface of the body portion 111 that is inclined. Thus, the static pressure of the impeller 101 is further improved.

The impeller 102 includes a body portion 121 having a tubular shape and a plurality of blade portions 122. In the present example embodiment, the impeller 102 is rotated counterclockwise (in the Y2 direction) about the center axis J by the motor 12 (see FIG. 1).

Each of the blade portions 122 extends in the circumferential direction while being inclined toward the upstream side X1 in the air blowing direction toward a front side Y2 in the rotation direction. Each of the blade portions 122 may be curved to be convex toward the upstream side X1 in the air blowing direction, or may be formed in a flat plate shape without being curved. Thus, the airflow volume of the impeller 102 is improved. Accordingly, the air blowing efficiency of an air blowing apparatus 200 is further improved by arranging the impeller 101 having improved static pressure on the exhaust side and arranging the impeller 102 having improved airflow volume on the intake side.

Other Remarks

The above-described example embodiments are merely illustrative of the present disclosure. The configuration of the example embodiment may be appropriately changed without departing from the technical idea of the present disclosure. Furthermore, the example embodiments may be combined with each other within a feasible range. For example, in the present example embodiment, each of the blade portions 112 is curved to be convex toward the upstream side X1 in the air blowing direction at the rear side Y2 in the rotation direction with respect to the center T in the circumferential direction. However, the blade portion 112 may be formed in a flat plate shape without being curved.

In the present example embodiment, the pair of housings 20 are coupled to each other by bringing the base portions 23 into contact with each other. However, the pair of housings 20 may be coupled to each other by causing the base portions 23 to face each other in the axial direction with the pair of motors 12 interposed therebetween. The pair of housings 20 may be coupled to each other by arranging the base portions 23 on one of the intake side X1 and the exhaust side X2. Furthermore, although the pair of housings 20 were coupled to each other, the impellers 101 and 102 may be accommodated in one housing extending in the axial direction.

In the present example embodiment, the blowing apparatus 1 is configured by coaxially aligning the impeller (upstream impeller) 102 and the impeller 101. However, the blowing apparatus 1 may only include the impeller 101.

Supplement

As described above, an impeller (101) according to an example embodiment of the present disclosure includes a body portion (111) having a tubular shape and being rotatable about a center axis (J), and a plurality of blade portions (112) protruding in a radial direction from an outer circumferential surface of the body portion and arranged at intervals in a circumferential direction. When the plurality of blade portions rotate about the center axis, the impeller (101) blows air in an axial direction, and each of the plurality of blade portions extends in the circumferential direction while being inclined to an upstream side (X1) in an air blowing direction toward a front side (Y1) in a rotation direction, and each of the plurality of blade portions is curved to be convex toward a downstream side (X2) in the air blowing direction at the front side (Y1) in the rotation direction with respect to a center (T) in the circumferential direction (first configuration).

In the above-described example embodiment, a configuration may be adopted in which each of the plurality of blade portions is curved to be convex toward the upstream side (X1) in the air blowing direction at a rear side (Y2) in the rotation direction with respect to the center (T) in the circumferential direction (second configuration).

In the above-described example embodiments, a configuration may be adopted in which the outer circumferential surface of the body portion extends parallel or substantially parallel to the center axis on the upstream side (X1) in the air blowing direction with respect to an end (P1) at the front side (Y1) in the rotation direction of each of the plurality of blade portions (third configuration).

In any one of the above-described example embodiments, a configuration may be adopted in which an outer diameter of the body portion decreases toward the downstream side (X2) in the air blowing direction on the downstream side (X2) in the air blowing direction with respect to an end (P2) at the rear side (Y2) in the rotation direction of each of the plurality of blade portions (fourth configuration).

In any one of the above-described example embodiments, a configuration may be adopted in which a width (W1) of each of the plurality of blade portions in the radial direction at an end portion at the front side (Y1) in the rotation direction is smaller than a width (W2) in the radial direction at an end portion at the rear side (Y2) in the rotation direction (fifth configuration).

In any one of the above-described example embodiments, a configuration may be adopted in which, in adjacent ones of the plurality of blade portions in the circumferential direction, an end portion of one of the blade portions at the front side (Y1) in the rotation direction and an end portion of the other of the blade portions at the rear side (Y2) in the rotation direction overlap each other when viewed from the axial direction (sixth configuration).

A blowing apparatus (1) according to an example embodiment of the present disclosure includes the impeller (101) according to any one of the above-described example embodiments, and a motor (12) that rotates the impeller (seventh configuration).

A blowing apparatus (1) according to an example embodiment of the present disclosure includes the impeller (101) according to any one of the above-described example embodiments, an upstream impeller (102) upstream (X1) of the impeller in an air blowing direction and aligned coaxially or substantially coaxially with the impeller, and a motor (12) that rotates each of the impeller and the upstream impeller (eighth configuration).

Example embodiment of the present disclosure can be utilized in a blowing apparatus that cools a server, for example.

Features of the above-described example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.