FAN APPARATUS
There is provided a fan apparatus having a high-strength structure for supporting an impeller and a motor with good air quantity characteristics. The fan apparatus has a motor, an impeller, a motor base portion, a frame and a plurality of spoke portions. The impeller has a plurality of blades and are arranged to be rotated by the motor. The motor base portion supports the motor. The frame has an annular inner peripheral wall formed to surround the impeller as viewed from a rotation axis direction. The spoke portions connect the motor base portion and the frame. An end portion of the blade in the side of the frame is inside the inner peripheral wall and a blade portion having a length not less than half the length of the blade in the rotation axis direction is exposed, as viewed from a direction perpendicular to the rotation axis direction.
This application claims the benefit of Japanese Patent Application No. 2016-194408, filed Sep. 30, 2016, which is hereby incorporated by reference in its entirety.
BACKGROUND Technical FieldThe present disclosure relates to a fan apparatus and, more particularly, to a fan apparatus not provided with an air channel portion surrounding a whole of an outer peripheral portion of an impeller.
BackgroundFan apparatuses are widely used as air blowers for cooling, ventilation, and air conditioning of household electrical appliances, office automation equipment, and industrial equipment, and vehicular air conditioning and air blowing. For example, a fan apparatus is attached to a heat-generating component, such as an MPU (micro processing unit) of an electronic apparatus, and used to improve cooling capability of a heat sink.
Japanese Patent Laid-Open No. 2001-304188 describes a cooling fan having a structure without a casing portion surrounding an impeller, to save both space and weight.
Japanese Patent Laid-Open No. 2002-159155 describes a structure of a fan motor with a heat sink configured such that the heat sink is attached to a fan.
Japanese Patent Laid-Open No. 2014-056792 describes a structure using a heat radiating unit including a heat sink and a fan as an air blowing apparatus to release heat generated by a light-emitting element in a lighting fixture to be mounted on a vehicle. The fan is stored in a storage portion provided in the heat sink.
SUMMARYIn the cooling fan illustrated in Japanese Patent Laid-Open No. 2001-304188, a motor attaching portion in a circular shape having a plurality of spoke portions is provided at a central portion of an impeller. If the spoke portions have large width dimensions, ventilation resistance when the cooling fan is driven is largely affected, and air quantity characteristics of the cooling fan deteriorates. To enhance the characteristics of the cooling fan, the width of each spoke portion needs to be set as small. For this reason, strength of the spoke portion tends to be low. The spoke portions are highly likely to break at the time of, for example, attaching the cooling fan to a piece of equipment or the like.
A solution to the above-described problem is not disclosed in Japanese Patent Laid-Open No. 2002-159155 and No. 2014-056792.
It is an object of the present disclosure to solve the above-described problem and to provide a fan apparatus having a high-strength structure for supporting an impeller and a motor with good air quantity characteristics.
In accordance with one aspect of the present disclosure, a fan apparatus includes a motor base portion, a motor arranged on an upper side of the motor base portion, an impeller having a plurality of blades and arranged to be rotated by the motor, a frame having an annular inner peripheral wall formed to surround the impeller as viewed from a rotation axis direction, and a plurality of spoke portions connecting the motor base portion and the frame. A lower end portion of each of the blades is inside the inner peripheral wall, and a blade portion having a length not less than half the length of the blade in the rotation axis direction is exposed, as viewed from a direction perpendicular to the rotation axis direction.
Preferably, a value obtained by dividing a distance between an upper end portion of the inner peripheral wall and the lower end portion of the blade by a dimension of the frame in a vertical direction is not less than 0.35, and the lower end portion of the blade is above a position in contact with the spoke portion.
The present disclosure allows provision of a fan apparatus having a high-strength structure for supporting an impeller and a motor with good air quantity characteristics.
A fan apparatus according to an embodiment of the present disclosure will be described below.
The fan apparatus is, for example, an axial fan having an impeller rotating about a rotation axis and a motor arranged with the impeller along the rotation axis. The fan apparatus does not have an air channel portion surrounding a whole side peripheral portion of the impeller and has a support structure in the shape of a plate. The support structure comprises a motor base portion supporting the motor and the motor base portion is joined to a surrounding frame via a plurality of spoke portions. The support structure is attached to a housing or the like of a different apparatus, and the fan apparatus is used for air blowing or the like in the apparatus.
In the description below, a direction about the rotation axis may be referred to as a circumferential direction, and a direction toward and away from the rotation axis may be referred to as a radial direction. A rotation axis direction may be referred to as a vertical direction. A direction from the motor toward the impeller along the rotation axis direction may be referred to as up (upward), and the opposite direction may be referred to as down (downward). Note that the terms “up” and “down” here are expressions with a focus only on the fan apparatus itself and are not expressions relating to a posture of the fan apparatus attached to the different apparatus.
EmbodimentFor illustrative purposes, spoke portions 10 of a support member 2 are not shown in
As shown in
The impeller 3 has a hub 4 and a plurality of blades 5. The hub 4 has a generally cylindrical shape. The hub 4 is connected to the motor 100. The plurality of blades 5 are attached to an outer peripheral surface of the hub 4. The hub 4 and the blades 5 are integrally molded through injection molding using resin. Note that the present disclosure is not limited to this and a whole or a part of each portion may be molded separately from a different portion. The hub 4 and the blades 5 may not be made of resin and may be made using a different material. The number of blades 5 is, for example, 9 and is not limited to this.
The fan apparatus 1 is configured to, for example, rotate the impeller 3 with the motor 100 such that gas, such as air, flows upward. Note that the fan apparatus 1 may be configured such that gas flows downward.
As shown in
The support member 2 has a frame 9, a motor base portion 6, two attaching portions 7 and 8, and the spoke portions 10 (10a to 10d).
The frame 9, the motor base portion 6, the attaching portions 7 and 8, and the spoke portions 10 are a one-piece molded article integrally molded through injection molding using resin. Note that the present disclosure is not limited to this and that a whole or a part of each portion may be molded separately from a different portion. The portions may not be made of resin but may be made using a different material.
The support member 2 is formed in the shape of a plate as a whole. In the present embodiment, the support member 2 is configured such that a dimension (thickness) of each portion in a vertical direction is identical to or smaller than a thickness of the frame 9. The support member 2 may be formed by machining a plate-like resin plate.
As shown in
As shown in
As shown in
Note that a lead wire 25 is wired to one spoke portion 10d of the four spoke portions 10 along the spoke portion 10d. The lead wire 25 is intended to supply power to the motor 100.
As shown in
The lead wire 25 is electrically connected to a terminal portion of a circuit board 20 of the motor 100 (to be described later). The lead wire 25 is sheathed with a tube 26 and protected. The lead wire 25 is put on a hook 27 molded integrally with the annular frame 9 and is led out to outside the fan apparatus 1.
The motor 100 is a brushless DC motor of an outer rotor type. As shown in
The stator portion 102 has a bearing holder 16, bearings 21 and 22, and a stator 11. The stator 11 has a stator core 17, an insulator 18 (an upper insulator 18a and a lower insulator 18b), and coils 19.
The bearing holder 16 is fixed to the motor base portion 6 while being fit in an opening of a projecting portion 6b formed to project upward at a center of the motor base portion 6. The stator 11 is attached to an outer peripheral surface of the bearing holder 16.
The stator 11 has the stator core 17 mounted while being fit on an outer periphery of the bearing holder 16, the upper insulator 18a mounted to the stator core 17 from above, the lower insulator 18b mounted to the stator core 17 from below, and the coils 19.
The stator core 17 is composed of a predetermined number of cores, each having a plurality of salient poles extending radially outward from an annular yoke portion, stacked in the rotation axis direction. The insulator 18 composed of the upper insulator 18a and the lower insulator 18b is mounted to the stator core 17. The coil 19 is attached to each of the salient poles of the stator core 17 while being wound around the salient pole via the insulator 18.
Note that the circuit board 20 populated with electronic components is mounted to an outer peripheral portion of the bearing holder 16 on a lower side of the lower insulator 18b. The circuit board 20 is connected to the lead wire 25.
The rotor 12 has a rotor yoke 13, a magnet 14, and a shaft 15.
The rotor yoke 13 is a member in a cup shape opening downward made of a soft magnetic material, such as iron. The magnet 14 has a ring shape. The magnet 14 is fixedly attached to an inner peripheral surface of the rotor yoke 13. The shaft 15 is made of, for example, iron. The shaft 15 is attached to an upper surface of the rotor yoke 13 to project downward. The shaft 15 is coupled to the rotor yoke 13 while an upper end portion of the shaft 15 is pressed in a projecting portion 13b formed at a center of the rotor yoke 13. The projecting portion 13b of the rotor yoke 13 is formed through drawing.
The hub 4 of the impeller 3 is fixed to an outer peripheral surface of the rotor yoke 13. For example, the hub 4 is bonded using an adhesive. Note that the rotor yoke 13 may be formed through insert molding and that the impeller 3 including the rotor yoke 13 may be manufactured.
There is no resin on the upper surface (top surface) of the rotor yoke 13 and therefore, the rotor yoke 13 made of metal is exposed upward. With this configuration, a height in the vertical direction (rotation axis direction) of the fan apparatus 1 can be reduced by an amount corresponding to resin of the hub 4, and the fan apparatus 1 can be thinned. Additionally, since the rotor yoke 13 is exposed, heat inside the motor 100 is likely to be released to the outside through the rotor yoke 13, and stable operation can be expected.
As shown in
As described above, the fan apparatus 1 does not include an air channel portion surrounding the impeller 3 in a circumferential direction over an entire length of the impeller 3 in the vertical direction. In other words, in the fan apparatus 1, only a part of a lower end portion of the impeller 3 is hidden by the frame 9 in side view, and a portion having a length not less than half the length of the impeller 3 in the vertical direction is exposed in the radial direction in side view. That is, a dimension of each spoke portion 10 in the vertical direction can be increased and therefore, even if a width dimension of the spoke portion 10 as viewed from below is reduced, high rigidity and strength are ensured. Under the condition that the width dimension of each spoke portion 10 remains the same, the spoke portion 10 has higher rigidity and strength. Thus, the support member 2 supporting the impeller 3 and the motor 100 can be made higher in strength and less prone to breakage. The spoke portion 10 is connected to the frame 9 having a diameter larger than an outer diameter of the impeller 3 and therefore, as compared with a fan apparatus having only spoke portions as described in, for example, Japanese Patent Laid-Open No. 2001-304188, the rigidity and strength of the spoke portion 10 can be improved.
[Concerning Air Quantity Characteristics (P-Q Characteristics) of Fan Apparatus 1]A positional relationship between the annular frame 9 as described above and the blade 5 of the impeller 3 was examined. Specifically, assuming that a displacement amount X is zero when the lower end portion of the blade 5 is at a position in contact with an upper end portion of the annular frame 9 (i.e., an upper end portion of the inner peripheral wall 9a), that the displacement amount X is a plus when the lower end of the blade 5 is below the upper end portion of the annular frame 9 (at a position inside the annular frame 9), and that the displacement amount X is a minus when the lower end of the blade 5 is above the upper end portion of the annular frame 9 (at a position outside the annular frame 9), the ratio X/L of the displacement amount X (in millimeters) to the frame dimension L (in millimeters) is expressed. A dimension of the spoke portion 10 is denoted by Y (in millimeters). In
A maximum static pressure (Pa) and a maximum air quantity (m3/min) of the fan apparatus 1 at a position corresponding to the lower end portion of the blade 5 were measured in the case of forward rotation of the impeller 3. Air quantity characteristics (P-Q characteristics) at respective positions were also measured.
Results of measuring the characteristics at the respective positions (positions with values of −0.31, −0.07, 0.35, 0.45, and 0.55 of X/L) are shown in
As can be seen from
The shape of the support member is not limited to the above-described one. For example, the number of attaching portions is not limited to two. More than two attaching portions may be provided or only one attaching portion may be provided.
A motor may be of an inner rotor type.
The above-described embodiment is to be considered as illustrative in all respects and not limitative. The scope of the present disclosure is defined not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all changes within the scope.
Claims
1. A fan apparatus comprising:
- a motor base portion;
- a motor arranged on an upper side of the motor base portion;
- an impeller having a plurality of blades and arranged to be rotated by the motor;
- a frame having an annular inner peripheral wall formed to surround the impeller as viewed from a rotation axis direction; and
- a plurality of spoke portions connecting the motor base portion and the frame, wherein a lower end portion of each of the blades is inside the inner peripheral wall, and a blade portion having a length not less than half the length of the blade in the rotation axis direction is exposed, as viewed from a direction perpendicular to the rotation axis direction.
2. The fan apparatus according to claim 1, wherein a value obtained by dividing a distance between an upper end portion of the inner peripheral wall and the lower end portion of the blade by a dimension of the frame in a vertical direction is not less than 0.35, and the lower end portion of the blade is above a position in contact with the spoke portion.
Type: Application
Filed: Sep 26, 2017
Publication Date: Apr 5, 2018
Inventors: Haruomi MOROHASHI (Hamamatsu-shi), Koichi TAMAI (Kakegawa-shi), Toshiaki SEIMA (Fukuroi-shi), Yukihiro HIGUCHI (Fukuroi-shi)
Application Number: 15/715,615