Fan assembly and fan frame thereof

Description

BACKGROUND

[0001] The invention relates to a fan assembly, and in particular to a fan assembly and fan frame thereof.

[0002] Electronic devices generally produce heat during operation, and thus a demand exists for effective heat-dissipation devices. If a heat-dissipation device cannot effectively dissipate excess heat generated by the electronic device, performance can suffer, and more seriously, the electronic device may be burned out at high temperature. Moreover, since the number of transistors per unit area in an electronic device increases to improve performance, available internal space is reduced, and high temperature is concentrated therein such that performance deteriorates. Thus, an effective heat-dissipation device is an important component in micro-electronic devices such as integrated circuits (ICs).

[0003] The most popular heat-dissipation system is a fan assembly. A fan assembly comprises a fan frame, hub, blades and motor. As shown in Figs. 1A and 1B, conventional fan frames 11a and 11b are connected to motor bases 12a and 12b via a plurality of ribs 13a and 13b, respectively. The ribs 13a and 13b support the motor bases 12a and 12b. The ribs 13a and 13b can be cylindrical, curved, or streamlined. For example, the cross section of the rib 13a along line A-A of Fig.1A is triangular , as shown in Fig. 1A-1; the cross section of the rib 13b along line B-B of FIG. 1B is circular, as shown in Fig. 1B-1, or is rectangular, as shown in Fig. 1B-2. Regardless of the shape of rib cross section, however, the ribs 13a and 13b have an identical linear shape extending from the motor bases 12a and 12b toward the fan frame 11a and 11b, respectively.

[0004] As shown in Fig. 1C, if the ribs 13 connected to the motor base 12 and the fan frame 11 are curved, the cross section thereof is not continuous. The side view of the rib 13, however, is fully shown in the figure for clear explanation of the fan frame 11a or 11b. The blades 14 of the fan 10 are radially arranged on an outer periphery of the hub 15 with a motor (not shown) disposed therein.

[0005] When the blades 14 rotate, since the ribs 13 with the same cross section extend linearly along the motor base 12 toward the fan frame 11, the lower edge of the blades 14 are parallel to the ribs 13. As the size of the fan assembly is reduced, noise is produced due to airflow resistance between the lower edge of the blades 14 and the ribs 13. Additionally, the noise level increases with the fan speed.

[0006] US 2003/063987 discloses a fan having a supercharging structure comprising a casing having an air passage hole with an air inlet at a first end thereof and an air outlet at a second end thereof. A base is mounted to the air outlet end of the casing. A supporting plate is mounted in the air passage hole of the casing or an air outlet in the base for engaging with a stator bobbin that pivotally holds a fan wheel to be driven. Plural supercharging plates are mounted between the supporting plate and the base.

[0007] US 2003/091435 discloses a housing structure of a fan including a housing having multiple support bars supporting a seat plate with which a stator is combined. An impeller has a rotation shaft rotatably mounted in the stator. Each of the support bars has two ends respectively connected to the housing and the seat plate. The cross-section of each of the support bars has a highest point, and has an air guide face and an air facing face respectively extended from the highest point, and aSR Draft Response (by ying) bottom face connecting the air guide face and the air facing face. The air guide face of each of the support bars is formed with an inclined face, and an acute included angle is formed between the inclined face and a vertical line that is vertical to a horizontal line of a bottom face of the seat plate.

[0008] The problem to be solved is to reduce the noise of the fan assembly by a design of the ribs.

SUMMARY

[0009] Embodiments of the invention as claimed provide a fan frame comprising ribs with varied cross sections according to claim 1 such that the noise level between the blades and fan frame can be reduced.

[0010] Also provided is a fan frame comprising a housing, a motor base, and a plurality of ribs. The housing comprises an opening. The motor base is disposed in the housing. The ribs are disposed between the opening and the motor base for supporting the motor base. The cross section of each rib is varied from the motor base to the housing according to claim 1. The width and thickness of each rib also vary from the motor base to the housing according to claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Embodiments of the invention can be more fully understood by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein:

Fig. 1A is a schematic plan view of a conventional fan frame;

Fig. 1A-1 is a cross section of the rib along line A-A of Fig. 1A;

Fig. 1B is a schematic plan view of another conventional fan frame;

Figs. 1B-1 and 1B-2 are cross sections of the rib along line B-B of Fig. 1B;

Fig. 1C is a cross section of a conventional fan assembly;

Fig. 2A is a schematic view of a fan frame according to an embodiment of the invention for a better understanding of a not claimed design;

Fig. 2B is a schematic view of another fan frame according to another embodiment of the invention; and

Figs. 3A-1, 3A-2, are cross sections of various fan assemblies according to an embodiment of the invention;

Figs. 3B-1, 3B-2, and 3C are cross sections of various fan assemblies according to an example which does not form part of the invention as claimed;

DETAILED DESCRIPTION

[0012] Figs. 2A and 2B are schematic views of two fan frames according to embodiments of the invention. The fan frame 21 comprises a housing 27, a motor base 22, and a plurality of ribs 23. The housing 27 has an opening 26, and the motor base 22 is disposed in the opening 26. The ribs 23, for supporting the motor base 22, are disposed in the opening 26 and between the housing 27 and the motor base 22. The ribs 23 connecting the housing 27 and the motor base 22 are arranged radially or axially, similar to arrangement of axial blades. The ribs can be cylindrical, curved, or streamlined.

[0013] Each rib 23 has a width varying from the motor base 22 to the housing 27. For example, as shown in Fig. 2A, the width of the rib 23a connecting to the motor base 22 is greater than the width of the rib 23 connecting to the housing 27 of the fan frame 21A. That is, the width of the rib 23a decreases from the motor base 22 to the housing 27. The variation in width can be a linear or non-linear (quadratic) variation. Moreover, as shown in Fig. 2B, another fan frame 21B has different ribs 23b from the ribs 23a. The width of the rib 23b connecting to the housing 27 is greater than the width of the rib 23b connecting to the motor base 22. That is, the width of the rib 23b increases linearly or non-linearly from the motor base 22 to the housing 27.

[0014] Furthermore, Figs. 3A-1, 3A-2, 3B-1, 3B-2, and 3C are cross sections of various fan assemblies. Note that, when the arrangement of the ribs 23 is non-linear between the motor base 22 and the housing 27, the cross sectional view of the ribs 23 is not continuous and cannot be entirely seen in these figures. However, for clarity purpose, the ribs 23 are completely depicted in the figures. Also, the blades 24 are also clearly depicted but the actual cross section thereof cannot be entirely seen in the figures.

[0015] The fan assembly 20 comprises the fan frame 21, a hub 25, the blades 24 and a motor. The opening 26 of the housing 27 forms an inlet 211 and an outlet 212 on both ends of the fan frame 21. The motor base 22 is preferably located at a center of the opening 26 near the outlet 212.

[0016] The blades 24 of the fan 20 are radially connected to an outer periphery of the hub 25. The motor (not shown) is disposed in the hub 25. Each rib 23 has a varied thickness from the motor base 22 to the housing 27. For example, a thickness of the rib 23 connecting to the motor base 22 is greater than that of the rib 23 connecting to the housing 27. Or, the thickness of the rib 23 gradually decreases from the motor base 22 to the housing 27, as shown in Figs. 3A-1 and 3A-2.

[0017] Alternatively, as shown in Figs. 3B-1 and 3B-2, the thickness of the ribs 23 connecting to the motor base 22 is less than that of the ribs 23 connecting to the housing 27. Or, the thickness of the ribs 23 gradually increases from the motor base 22 to the housing 27.

[0018] In Figs. 3A-1 and 3A-2, the thickness of the ribs respectively increases linearly or non-linearly; In Figs. 3B-1, and 3B-2, the thickness of ribs respectively decreases linearly or non-linearly.

[0019] Furthermore, the thickness of ribs can be varied non-linearly. That is, each rib 23 has a maximum or minimum thickness at a portion of the rib 23 connecting to the housing 27, a portion of the rib 23 connecting to the motor base 22, or a location therebetween. For example, in Fig. 3C, each rib 23 with a concave cross section has a maximum thickness near the housing 27 and the motor base 22.

[0020] During rotation of the blades 24, airflow speed increases outwardly from the blades 24. That is, the flow speed near the housing 27 is faster than the speed near the motor base 22. Since each rib 23 has a varied width from the motor base 22 to the housing 27 in the blade rotational direction, flow resistance at the rib 23 near the housing 27 can be reduced, thereby reducing noise. Moreover, since each rib 23 has a varied thickness, the distance between the ribs 23 and the lower edge of the blades 24 can be varied. This reduces interference between the ribs 23 and the blades 24 during rotation, reducing flow resistance and reducing noise level.

[0021] The width of each rib 23 is designed according to the rotational direction of the blades 24. The thickness of the narrower portion of the rib 23 can be increased, ensuring the strength of the ribs 23. For example, as shown in Fig. 2A, the width of each rib 23a connecting to the motor base 22 is greater than that of each rib 23a connecting to the housing 27. Additionally, varied thickness design is applied to each rib 23a so that the rib 23a connecting to the housing 27 is thicker than the rib 23a connecting to the motor base 22, as shown in Fig. 3B-1 or Fig. 3B-2.

[0022] In another embodiment of the invention, as shown in Fig. 2B, the width of each rib 23b connecting to the housing 27 is greater than that of each rib 23b connecting to the motor base 22. Additionally, varied thickness design is applied to each rib 23b so that the rib 23b connecting to the motor base 22 is thicker than the rib 23b connecting to the housing 27, as shown in Fig. 3A-1 or Fig. 3A-2.

[0023] Variation in width and thickness of the ribs 23 can be linear or non-linear. Thus, each rib 23 has a varied cross section from the motor base 22 to the housing 27, preventing noise due to flow resistance between the lower edge of the blades and the ribs. The housing 27 can be substantially rectangular, circular, elliptical, rhomboid, or similar.

[0024] A noise test, comparing a conventional fan with a fan assembly according to an embodiment of the invention, was performed. The experiments revealed in a noise frequency range produced by the blades of the invention, a relative prominent noise ratio can be lowered. In one of the experimental results, in a noise frequency range of 200-2000Hz, the relative prominent noise ratio of a conventional fan was 20dB, while the relative prominent noise ratio of an embodiment of the invention can be reduced to 5 dB. Thus, noise can be effectively lowered because of the varied cross section of the ribs, further reducing the noise produced between the blades and the fan frame.

[0025] The invention is not limited to the disclosed embodiments, but the scope of the invention is defined by the appended claims.

Claims

1. A fan frame (21), comprising:

a housing (27) comprising an opening (26);

a motor base (22), disposed in the housing; and

a plurality of ribs (23), disposed in the opening and between the housing and the motor base for supporting the motor base, wherein each rib has a varied cross section from the motor base to the housing, wherein a width of each rib connecting to the motor base is less than that of each rib connecting to the housing, and a thickness of each rib connecting to the motor base is greater than that of each rib connecting to the housing.

2. The fan frame as claimed in claim 1, wherein a width of each rib is varied from the motor base to the housing.

3. The fan frame as claimed in one or more of the claims 1 to 2, wherein thickness of each rib is varied from the motor base to the housing.

4. The fan frame as claimed in one or more of the claims 1 to 3, wherein a width of each rib connecting to the motor base is greater than that of each rib connecting to the housing, and a thickness of each rib connecting to the motor base is less than that of each rib connecting to the housing.

Ansprüche

1. Lüfterrahmen (21), umfassend:

ein Gehäuse (27) mit einer Öffnung (26);

einen Motorsockel (22), der in dem Gehäuse angeordnet ist; und -

eine Vielzahl von Rippen (23), die in der Öffnung und zwischen dem Gehäuse und dem Motorsockel zum Tragen des Motorsockels angeordnet sind, wobei jede Rippe einen unterschiedlichen Querschnitt von dem Motorsockel zu dem Gehäuse aufweist, wobei eine Breite jeder Rippe, die mit dem Motorsockel verbunden ist, geringer ist als die jeder Rippe, die mit dem Gehäuse verbunden ist, und eine Dicke jeder Rippe, die mit dem Motorsockel verbunden ist, größer Ist als die jeder Rippe, die mit dem Gehäuse verbunden ist.

2. Der Lüfterrahmen nach Anspruch 1, wobei die Breite jeder Rippe vom Motorsockel bis zum Gehäuse variiert wird.

3. Der Lüfterrahmen nach einem oder mehreren der Ansprüche 1 bis 2, wobei die Dicke jeder Rippe vom Motorsockel bis zum Gehäuse variiert wird.

4. Der Lüfterrahmen nach einem oder mehreren der Ansprüche 1 bis 3, wobei eine Breite jeder Rippe, die mit dem Motorsockel verbunden ist, größer ist als die jeder Rippe, die mit dem Gehäuse verbunden ist, und eine Dicke jeder Rippe, die mit dem Motorsockel verbunden ist, geringer ist als die jeder Rippe, die mit dem Gehäuse verbunden ist.

Revendications

1. Une structure de ventilateur (21) comprenant:

un boîtier (27) comprenant une ouverture (26);

une base de moteur (22), disposée dans le boîtier; et

une pluralité de nervures (23), disposées dans l'ouverture et entre le boîtier et la base du moteur pour supporter la base du moteur, dans lequel chaque nervure présente une section transversale variable de la base du moteur vers le boîtier, dans laquelle une largeur de chaque nervure reliant à la base de moteur est inférieure à celle de chaque nervure reliée au boîtier, et une épaisseur de chaque nervure connectée à la base de moteur est supérieure à celle de chaque nervure reliée au boîtier.

2. La structure de ventilateur telle que revendiquée dans la revendication 1, dans lequel une épaisseur de chaque nervure varie de la base du moteur vers le boîtier.

3. La structure de ventilateur telle que revendiquée dans l'une ou plusieurs des revendications 1 à 2, dans lequel la largeur de chaque nervure varie de la base du moteur vers le boîtier.

4. La structure de ventilateur telle que revendiquée dans l'une ou plusieurs des revendications 1 à 3, dans lequel une largeur de chaque nervure reliée à la baes de moteur est supérieure à celle de chaque nervure reliée au boîtier, et une épaisseur de chaque nervure reliée à la base de moteur est inférieure à celle de chaque nervure reliant au boîtier.

Drawing