Anti-pressure-relief structure for fan

Abstract

An anti-pressure-relief structure for fan includes a fan rotor and a fan frame. The fan rotor includes a hub, a shaft vertically downward extended from the hub, a plurality of blades extended radially outward from the hub, and an outer ring member connected to radially outer ends of the blades. The fan frame internally includes a vertically upward extended shaft cup for rotatably connecting with the fan rotor via the shaft. The outer ring member is mounted in the fan frame with a gap left between them. Raised sections and recessed sections are provided on an outer wall surface of the outer ring member and an inner wall surface of the fan frame at staggered positions to form an anti-pressure-relief zone in the gap. Air flowing through the anti-pressure-relief zone will swirl and is impeded from flowing smoothly to thereby achieve an effect of preventing pressure relief.

Description

[0001] This application claims the priority benefit of Taiwan patent application number 114102567 filed on Jan. 21, 2025, the disclosure of which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The present invention relates to an anti-pressure-relief structure for fan, and more particularly, to an anti-pressure-relief structure for fan that includes staggered raised sections and recessed sections, such that air flowing through the anti-pressure-relief structure will swirl and be impeded from flowing smoothly to achieve an anti-pressure-relief effect.BACKGROUND OF THE INVENTION

[0003] The currently quickly developed electronic products have high performance, high working frequency, high operating speed, and light and compact volume. These features also make the electronic products produce more and more heat during their operation. The large amount of heat produced during operation would lead to unstable operation and affect the reliability and service life of the products. Thus, heat dissipation has become a very important issue in the field of electronic products. Fan is a common structure used to dissipate the heat produced by the electronic products during operation. Usually, air flowing through blades of the fan in operation would swirl, which tends to reduce an overall performance of the fan, such as reduced volume of air output. An annular fan is therefore developed to overcome this problem. Please refer to FIGS. 1A and 1B. A conventional annular fan 1 includes a frame 10 and an impeller 11. The frame 10 has an air outlet side 101, an air inlet side 102, and a shaft cup 104. The air outlet side 101 and the air inlet side 102 are located opposite to each other and together define a receiving space 12 between them for accommodating the impeller 11 therein. The shaft cup 104 is located at a central area of the receiving space 12, and the impeller 11 is rotatably connected to the shaft cup 104.

[0004] The impeller 11 includes a hub 111 and a plurality of blades 112. The blades 112 are equally spaced along and connected at their radially inner ends to a periphery of the hub 111. A ring member 14 is formed around the blades 112 to connect to free ends of the blades 112. A gap 15 is defined between the ring member 14 and an inner wall surface of the frame 10. When the fan 1 operates, the ring member 14 can effectively reduce the occurrence of swirls among the blades 112 to thereby enable upgraded fan performance and reduced noise produced by the fan 1 during operation.

[0005] While the ring member 14 of the conventional annular fan 1 can effectively reduce the occurrence of swirls, it leads to another problem. When the annular fan 1 operates, air 17 is guided into the fan from the air inlet side 102 and then guided out of the fan from the air outlet side 101. At this point, a negative pressure will be produced at the air outlet side 101, and a part of the guided out air 17 will flow backward into the gap 15 and then flows out of the fan from the gap 15 to cause pressure loss. The backward flowed air and the air guided into the fan at the same time interfere with each other to result in turbulences and unsmooth air flowing and accordingly, lowered fan performance and increased noise. It is therefore tried by the inventor to develop an improved anti-pressure-relief structure for fan in an attempt to solve the disadvantage in the conventional annular fan 1.SUMMARY OF THE INVENTION

[0006] To effectively solve the above problem, it is a primary object of the present invention to provide an anti-pressure-relief structure for fan, which enables upgraded efficiency of water reuse in a vapor chamber and enhanced structural stability of a combined structure of heat pipes and vapor chamber.

[0007] To achieve the above and other objects, the anti-pressure-relief structure for fan according to the present invention includes a fan rotor and a fan frame.

[0008] The fan rotor includes a hub, a shaft vertically downward extended from the hub, a plurality of blades radially outward extended from an outer wall surface of the hub, and an outer ring member connected to radially outer ends of the blades. The fan frame has an air inlet side and an opposite air outlet side, and a passage defined between and communicable with the air inlet and outlet sides. The fan frame internally includes a base located adjacent to the air outlet side; and a shaft cup vertically upward extended from the base. The base is connected to the fan frame via a plurality of connecting members.

[0009] A stator assembly is externally fitted around the shaft cup and at least one bearing is provided in the shaft cup. The fan rotor is rotatably connected to the bearing via the shaft. The outer ring member of the fan rotor is mounted in the passage of the fan frame with a gap flow passage left between the outer ring member and the fan frame. Staggered or corresponding raised sections and recessed sections are provided on an outer wall surface of the outer ring member and an inner wall surface of the fan frame to form an anti-pressure-relief zone. When air flows through the gap flow passage, it swirls due to the anti-pressure-relief zone with staggered raised and recessed sections, and is impeded from flowing smoothly to thereby achieve an effect of preventing pressure relief.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

[0011] FIG. 1A is an exploded perspective view of a conventional annular fan structure;

[0012] FIG. 1B is a sectional side view showing the manner in which air flows through the conventional annular fan structure of FIG. 1A;

[0013] FIG. 2 is an exploded perspective view of an anti-pressure-relief structure for fan according to a first embodiment of the present invention; and

[0014] FIG. 3 is an assembled sectional side view of the anti-pressure-relief structure for fan according to the first embodiment of the present invention.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention will now be described with some preferred embodiments thereof and by referring to the accompanying drawings. For the purpose of easy to understand, elements that are the same in the preferred embodiments are denoted by the same reference numerals.

[0016] Please refer to FIGS. 2 and 3, which are exploded perspective view and assembled sectional side view, respectively, of an anti-pressure-relief structure for fan according to a first embodiment of the present invention. For the purpose of conciseness and clarity, the present invention is also briefly referred to as the anti-pressure-relief structure herein and generally denoted by reference numeral 2. As shown, the anti-pressure-relief structure 2 includes a fan rotor 21 and a fan frame 22.

[0017] The fan rotor 21 includes a hub 211 and a shaft 212 vertically downward extended from a center of the hub 211. A magnetic element 213 is provided on an inner wall surface of the hub 211. A plurality of blades 214 is radially outward extended from an outer wall surface of the hub 211 to connect at their radially outer ends to an outer ring member 215.

[0018] The fan frame 22 has an upper and a lower end serving as an air inlet side 221 and an air outlet side 222, respectively. A passage 223 is defined between and communicable with the air inlet side 221 and the air outlet side 222. The end of the fan frame 22 located adjacent to the air outlet side 222 is provided with a base, and a shaft cup 224 is vertically upward extended from a center of the base. The base has a radially outer periphery connected to an inner wall surface of the fan frame 22 via a plurality of connecting members 225 radially extended between the base and the fan frame 222. The connecting members 225 may be stationary blades or ribs. A stator assembly 226 is externally fitted around the shaft cup 224, and at least one bearing 227 is provided in the shaft cup 224. The fan rotor 21 is rotatably connected to the bearing 227 via the shaft 212. The outer ring member 215 of the fan rotor 21 is correspondingly mounted in the passage 223 of the fan frame 22 with a gap left between them, such that a gap flow passage 228 is formed between the outer ring member 215 and the fan frame 22.

[0019] The inner wall surface of the fan frame 22 and the outer wall surface of the outer ring member 215 are not smooth surfaces but provided with a plurality of staggered raised sections and recessed sections, such that an anti-pressure-relief zone 220 is formed in the gap flow passage 228. When air flows through the gap flow passage 228, it will swirl in the anti-pressure-relief zone 220 and is impeded from flowing smoothly to thereby achieve an anti-pressure-relief effect.

[0020] To provide the anti-pressure-relief zone 220, portions of the gap flow passage 228 corresponding to the inner wall surface of the fan frame 2 may be provided with a plurality of non-continuous recessed section 220A, and portions of the gap flow passage 228 corresponding to the outer wall surface of the outer ring member 215 may be provided with a plurality of non-continuous raised sections 220B facing toward the recessed sections 220A. Alternatively, the inner wall surface of the fan frame 22 is provided with continuous sawtooth sections (not shown), and the outer wall surface of the outer ring member 215 is correspondingly provided with continuous sawtooth sections (not shown) staggered from the sawtooth sections on the fan frame 22. Further, the outer wall surface of the outer ring member 215 is axially extended in parallel with the inner wall surface of the fan frame 22.

[0021] The provision of the anti-pressure-relief zone 220 gives the gap flow passage 228 non-smooth and uneven inner wall surfaces, and air flows through the anti-pressure-relief zone 220 will swirl and is subjected to flow resistance without flowing through the gap flow passage smoothly. In this way, it is able to achieve the purpose of preventing pressure relief.

[0022] An anti-pressure-relief structure for fan according to a second embodiment of the present invention is generally structurally similar to the first embodiment but includes a gap flow passage 228 having a diameter tapered from the air inlet side 221 toward the air outlet side 222, so that the fan frame 22 has a conical inner wall surface (not shown). The outer ring member 215 of the fan rotor 21 has an outer diameter tapered from one end corresponding to the air inlet side 221 toward another end corresponding to the air outlet side 222 (not shown). In the second embodiment, the conical outer wall surface of the outer ring member 215 is still extended parallel to the conical inner wall surface of the fan frame 22.

[0023] An anti-pressure-relief structure for fan according to a third embodiment of the present invention is generally structurally similar to the first embodiment but includes a fan frame 22 having an inner diameter expanded from the air inlet side 221 toward the air outlet side 222. Alternatively, the fan frame 22 may have a radially outward slant inner wall surface, and the outer ring member 215 of the fan rotor 21 has an outer diameter expanded gradually from one end corresponding to the air inlet side 221 toward another end corresponding to the air outlet side 222 of the fan frame 22. In the third embodiment, the slant outer wall surface of the outer ring member 215 is also extended in parallel with the slant inner wall surface of the fan frame 22.

[0024] The present invention is characterized in that the inner wall surface of the fan frame 22 and the outer wall surface of the outer ring member 215 are spaced to form a gap flow passage 228 between them and are located face to face and correspondingly provided with staggered raised sections and recessed sections in the gap flow passage 228. The gap flow passage 228 with the staggered raised sections and recessed sections provides an anti-pressure-relief zone. Air flowing through the anti-pressure-relief zone is subjected to flow resistance and swirls, so that the air is impeded from flowing smoothly to thereby achieve an anti-pressure-relief effect.

[0025] The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.

Claims

1. An anti-pressure-relief structure for a fan comprising:a fan rotor including a hub, a shaft vertically downward extended from the hub, a plurality of blades radially outward extended from an outer wall surface of the hub, and an outer ring member connected to radially outer ends of the blades anda fan frame having an air inlet side, an opposite air outlet side, a passage defined between the air inlet and outlet sides, a base located in the fan frame at one end adjacent to the air outlet side and connected to an inner wall surface of the fan frame via a plurality of connecting members, a shaft cup vertically extended upward from the base, a stator assembly externally fitted around the shaft cup, and at least one bearing provided in the shaft cup; the fan rotor being rotatably connected to the bearing via the shaft, and the outer ring member of the fan rotor being mounted in the passage of the fan frame with a gap flow passage formed between the outer ring member and the fan frame; the outer ring member having an outer wall surface and the fan frame having a first inner wall surface extending axially parallel to the outer wall surface of the outer ring member and a second inner wall surface conically tapered from the air inlet side to the air outlet side; the outer wall surface of the outer ring member having a plurality of non-continuous raised sections provided thereon, and the first inner wall surface of the fan frame being provided with a plurality of non-continuous recessed sections that are staggered from those the plurality of non-continuous raised sections on the outer wall surface of the outer ring member wherein the non-continuous raised sections of the outer ring member correspond to and radially face the non-continuous recessed sections of the fan frame respectively to define a concave-convex complementary arrangement and so as to form an anti-pressure-relief zone; air flowing through the anti-pressure-relief zone being subject to swirls and impeded from flowing smoothly to achieve an anti-pressure relief effect.2-4. (canceled)5. The anti-pressure-relief structure as claimed in claim 1, wherein the connecting members are selected from the group consisting of stationary blades and ribs.

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