Fan generating medium wind pressure and air supply

Abstract

A fan includes a casing with a small inlet and a wide outlet. A blade unit includes a hub and a plurality of inclined blades extend radially from an outer periphery of the hub. The hub is located close to the inlet and the inclined blades extend toward the outlet. A positioning frame is connected to the casing and has a cone-shaped body. A cone-shaped gap is defined between an outer periphery of the cone-shaped body and an inner periphery of the casing. The cone-shaped body and the fan unit can be manufactured by molding and the motor is enclosed by the cone-shaped body so as to reduce the space that the fan occupies. The fan generates medium wind pressure and air supply.

Description

FIELD OF THE INVENTION

The present invention relates to a fan with compact size and generates medium wind pressure and air supply.

BACKGROUND OF THE INVENTION

There are two types of conventional fans which are axial fans as shown in FIG. 1 and centrifugal fans as shown in FIG. 2. The feature of the axial fan is that the air stream is sucked along the axle of the blade unit and flows out axially from the opposite side of the fan. The blades of the blade unit each include a suction side and a pressure side on the upper and bottom thereof so as to drive the air streams. The axial fan generates high volume of air supply and low wind pressure. The feature of the centrifugal fan is that the air stream enters the fan along the axial direction and flows out from the fan in radial direction which is perpendicular to the axial direction. The centrifugal fan generates lower air supply and high wind pressure. However, there are two inherent shortcomings happened on the two conventional fans, the first one is that the axial fan generates noise during operation although it generates high volume of air supply. The second one is that the centrifugal fan generates less noise but it generates less air supply and cannot bring sufficient heat from the heat source.

In practical use, a fan with mediate air supply and wind pressure is needed for removing heat satisfactorily. A latest fan is developed which includes stators on the axial fan so as to meet the requirement of mediate air supply and wind pressure. Unfortunately, the fan with stators cannot reach the purposes for sufficiently removing heat form the heat source.

As shown in FIG. 3, a fan cooperated with a pump is developed and the fan includes the features of the axial fans and the centrifugal fans. However, the blades of the fan has a specific curvature so that the blades can only be manufactured by four or five-axle machine rather than the conventional 3-axle machine. The specific curvature of the blades cannot be made by way of molding so that the blades are not suitable for mass production. Furthermore, the motor is installed outside of the fan and this increases the space that the fan occupies.

SUMMARY OF THE INVENTION

The present invention relates to a fan which comprises a casing having a narrow inlet and a wide outlet. A blade unit has a hub at a center thereof and a plurality of inclined blades extend radially from an outer periphery of the hub. The hub is located close to the inlet and the inclined blades extend toward the outlet. A positioning frame has a cone-shaped body and a plurality of arms extend from the cone-shaped body. The cone-shaped body has a narrow end which is located close to the inlet and a wide end which is located close to the outlet. The arms are connected to the casing.

The primary object of the present invention is to provide a fan which generates medium air supply and wind pressure so as to obtain higher efficiency for removing heat from the heat source. The fan is compact and can be manufactured by way of molding.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conventional axial fan;

FIG. 2 shows a conventional centrifugal fan;

FIG. 3 shows a pump to be cooperated with a conventional fan;

FIG. 4 is an exploded view to show the fan of the present invention;

FIG. 5 is a perspective view to show the combination of the blade unit and the positioning frame of the fan of the present invention;

FIG. 6 is a perspective view to show the fan of the present invention;

FIG. 7 is a perspective view, partly removed, of the fan of the present invention;

FIG. 8 is a cross sectional view to show the fan of the present invention;

FIG. 9 shows an enlarged cross sectional view to show the reinforcement ring and the casing;

FIG. 10 is an exploded view to show another embodiment of the fan of the present invention, and

FIG. 11 is a cross sectional view to show the fan in FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 4 and 5, the fan “A” of the present invention comprises a casing 1, a blade unit 2 and a positioning frame 3. The casing 1 includes an inlet “A1” and an outlet “A2” which has a diameter larger that a diameter of the inlet “A1”. A stepped annular surface 11 is defined in an inner periphery of the casing 1 and located close to the outlet “A2” and three lugs 12 extend from an outer periphery of the casing 1 and located close to the outlet “A2”. Each lug 12 includes a recess 121 defined in a side thereof.

The blade unit 2 is driven by a motor 4 and has a hub 21 at a center thereof. A plurality of inclined blades 22 extend radially from an outer periphery of the hub 21. The hub 21 is located close to the inlet “A1” and the inclined blades 22 extend toward the outlet “A2”. A connection hole 211 is defined in a center of the hub 21 so that the output shaft 41 of the motor 4 is connected to the connection hole 211 so as to rotate the hub 21. A cover 212 is connected to the hub 21 and located to the inlet “A1”. A reinforcement ring 23 is connected to respective outside of the blades 22 so as to prevent from leakage of the pressure and avoid from shaking of the blades 22.

The positioning frame 3 has a cone-shaped body 31 and a plurality of arms 33 extend from the cone-shaped body 31. The cone-shaped body 31 has a narrow end which is located close to the inlet “A1” and a wide end which is located close to the outlet “A2”. The cone-shaped body 31 includes a chamber 32 defined therein so as to receive the motor 4 therein as shown in FIGS. 5 and 8. It is noted that the motor 4 can also be installed outside the cone-shaped body 31 to drive the fan unit 2. The arms 33 are connected to the casing 1 by extending bolts 5 through holes in the arms 33 and connected to the lugs 12 of the casing 1 as shown in FIGS. 6 and 7.

The reinforcement ring 23 is located in the area “A4” at the stepped annular surface 11 of the casing 1 so as to reduce the gap “G” between the reinforcement ring 23 and the stepped annular surface 11, and the high pressurized air stream in the outlet “A2” cannot enter into the inlet “A1” which has lower pressure the gap between the blades 22 and the casing 1 as shown in FIGS. 8 and 9. A cone-shaped gap “A3” is defined between an outer periphery of the cone-shaped body 31 and an inner periphery of the casing 1 as shown in FIG. 8.

When the motor 4 drives the blade unit 2, the blades 22 expel the air in the fan “A” from the outlet “A2” and a negative pressure area is defined in the fan “A” and sucks air outside the fan “A” from the inlet “A1”. The air passes through the cone-shaped gap “A3” and out from the outlet “A2”. By this way, a medium air supply and wind pressure are generated with low noise. The fan can more efficiently bring heat from the heat source which is not shown. In this embodiment, the cone-shaped body 31 of the positioning frame 3 is stationary and the blade unit 2 is rotatable.

As shown in FIG. 10 and 11, another embodiment of the fan “A” is disclosed wherein the blade unit 2 and the cone-shaped body 31′ of the positioning frame 3′ are made integrally and co-rotated. The positioning frame 3′ includes a hollow cone-shaped body 31′ and a support frame 32′ at a bottom thereof. The cone-shaped body 31′ includes a space 311′ for receiving the hub 21 of the blade unit 2. The cone-shaped body 31′ is connected to the output shaft 41 of the motor 4 so as to be co-rotated with the blade unit 2. The support frame 32′ includes three arms 321′ which are engaged with the recesses 121 of the three lugs 12 by bolts 5. The support frame 32′ includes a neck 322′ so that the motor 4 can be connected to the positioning frame 3′ directly.

The cone-shaped gap “A3” is defined between the axial and radial directions so as to generate medium air supply and wind pressure, and the noise can be reduced. The fan includes less number of parts wherein the casing, the blade unit, the positioning frame and motor can be manufactured individually and suitable for mass production. The motor is received in the cone-shaped body so that the fan is compact which is cooperated with electronic products. The shape of the casing and the cone-shaped body block the light from reaching the electronic parts in the fan such that the electronic parts do not affected by the light. The blades can be manufactured by conventional 3D CNC and can be easily released from molds. The air stream enters into the fan from the inlet and is pressurized due to centrifugal force so that the wind pressure is higher than that of axial fans. The air streams are guided axially in front of the outlet and meet the requirement of axial wind. The reinforcement ring reinforces the structural strength of the blade unit and also depresses shaking of the blades. The reinforcement ring also prevents the high pressurized air streams from entering into the inlet with lower pressure via the gap between the blades and the casing. The cone-shaped body has a wide diameter at the outlet so that a large sized motor can be used when needed. The blades and the cone-shaped body can be made individually and then are combined to each other, this is benefit for mass production by using 3D CNC. The cone-shaped body and the blades are co-rotated, there is no gap between the blades and the cone-shaped body so that no friction loss happens between the blades and the cone-shaped body and this increases the efficiency of the fan.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.

Claims

1. A fan comprising:

a casing having an inlet and an outlet which has a diameter larger that a diameter of the inlet;

a blade unit having a hub at a center thereof and a plurality of inclined blades extending radially from an outer periphery of the hub, the hub located close to the inlet and the inclined blades extending toward the outlet, and

a positioning frame having a cone-shaped body and a plurality of arms extending from the cone-shaped body, the cone-shaped body having a narrow end which is located close to the inlet and a wide end which is located close to the outlet, the arms connected to the casing.

2. The fan as claimed in claim 1, wherein the blade unit and the cone-shaped body of the positioning frame can be manufactured individually.

3. The fan as claimed in claim 1, wherein the blade unit and the cone-shaped body of the positioning frame are co-rotated.

4. The fan as claimed in claim 1, wherein the cone-shaped body of the positioning frame is stationary and the blade unit is rotatable.

5. The fan as claimed in claim 1, wherein a reinforcement ring is connected to respective outside of the blades.

6. The fan as claimed in claim 1, wherein the cone-shaped body encloses a motor which drives the fan unit.