Jet structure of fan rotor

The present invention relates to a jet structure of a fan rotor, which comprises a fan wheel and at least one connecting channel. The fan wheel has a hub and plural blades disposed on the circumferential side of the hub. The hub has a top portion and a sidewall. Each of the blades has an upper surface and a lower surface which form a high-pressure zone and a low-pressure zone, respectively. The connecting channel is provided with at least one first inlet disposed in the high-pressure zone and at least one first outlet disposed in the low-pressure zone. The first inlet and the first outlet are a first end and a second end of the connecting channel, respectively. By means of the design of the present invention, the effect of noise reduction can be achieved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a jet structure of a fan rotor and, in particular, to a jet structure of a fan rotor, which can achieve the effect of noise reduction.

2. Description of Prior Art

With the improvements on 5G, AI, and IOT technologies, the computation loads and the amount of data transmission of the telecommunication equipment increase enormously and thus more powerful cooling capacity inside such equipment is required to keep it in normal operating condition. The method of increasing cooling capacity inside the telecommunication equipment is to increase the number of fans, the rotational speed of fans or to modify the design of fans. However, the high-performance fan with improved air flow and pressure always cause louder noise. How to reduce the noise and improve the cooling capacity of fans is always a big challenge for the designers in the industry.

The current method of noise reduction is mainly to design a specific structure placed where eddies occur on the blade or to add extra energy (e.g., a nozzle device) to destroy the eddies to reduce noise. As for the method of addition of extra energy, the air is directed from the frame wall to the blade tip to destroy the eddies to achieve noise reduction.

The prior art uses a fluid source and plural nozzles for generating swirls, which is called active jet method. That is, the nozzles are added on the frame wall of the fan to provide the swirl directed to the blades tips to mitigate the eddies. However, this method incurs another problem; that is, the extra nozzles and external driving power are required, which is not feasible to place a nozzle device in a confined space (e.g., inside a server or communication equipment). Also, the use of the extra nozzle equipment obviously increases the cost. Moreover, as for the traditional method of swirl generation in which the fan structure is equipped with a rotating part (i.e., a rotor), the connecting tube of the nozzle air source cannot be implemented on the rotating part. Thus, the outlet of the nozzle can only be placed on the frame wall or the non-rotating part to generate swirls. As a result, the noise reduction method by generating swirls is restricted by the arrangement of the nozzle itself and thus the extent and effect of noise reduction are limited.

SUMMARY OF THE INVENTION

One objective of the present invention is to provide a jet structure of a fan rotor to achieve the effect of noise reduction.

Another objective of the present invention is to provide a jet structure of a fan rotor, which directs the air flow around the fan rotor to naturally generate jets to restrict the eddies at the fan blades and reduce the cost through a jet structure itself.

To achieve the above objectives, the present invention provides a jet structure of a fan rotor, which comprises a fan wheel and at least one connecting channel. The fan wheel has a hub and a plurality of blades disposed on the circumferential side of the hub. The hub has a top portion and a sidewall axially extending from the edge of the top portion. Each of the blades has an upper surface and a lower surface which form a high-pressure zone and a low-pressure zone, respectively. The connecting channel is provided with at least one first inlet disposed in the high-pressure zone and at least one first outlet disposed in the low-pressure zone; the first inlet and the first outlet are a first end and a second end of the connecting channel, respectively. By means of the present invention, the self-jet generated by the fan rotor can restrict the eddies around the blades to effectively achieve the effects of noise reduction and cost reduction.

DETAILED DESCRIPTION OF THE INVENTION

The above objective, structural and functional characteristics of the present invention will be described according to the preferred embodiments with the accompanying figures.

The present invention relates to a jet structure of a fan rotor. Please refer toFIG. 1Ais a perspective view of the jet structure of a fan rotor according to the first embodiment of the present invention,FIG. 1Bis a cross-sectional view of the jet structure of a fan rotor according to the first embodiment of the present invention,FIG. 1Cis a cross-sectional view of the jet structure of a fan rotor according to a variant of the first embodiment of the present invention,FIG. 2Ais a perspective view of the jet structure of a fan rotor according to another variant of the first embodiment of the present invention,FIG. 2Bis a cross-sectional view of the jet structure of a fan rotor according to another variant of the first embodiment of the present invention,FIG. 3Ais a perspective view of the jet structure of a fan rotor according to yet another variant of the first embodiment of the present invention,FIG. 3Bis a cross-sectional view of the jet structure of a fan rotor according to yet another variant of the first embodiment of the present invention,FIG. 4Ais a schematic view of the assembled fan according to the first embodiment of the present invention, andFIG. 4Bis an assembled cross-sectional view of the assembled fan according to the first embodiment of the present invention. As shown inFIGS. 1A, 1B, 4A, and 4B, the jet structure1of the fan rotor is applied to a fan2(e.g., a centrifugal fan, axial fan, frameless fan, or tandem fan). The jet structure1of the fan rotor of the present invention is installed in the frame21of an axial fan2. The jet structure1of the fan rotor comprises a fan wheel11, at least one connecting channel12, a magnet member14, a yoke15(e.g., an iron shell), and a shaft16. The fan wheel11is integrally formed on the circumferential side of the yoke15by injection molding. The magnet member14such as a magnet is received on the inner side of the circumference of the yoke15corresponding to the stator22of the fan2for magnetic induction. One end of the shaft16is fixed to the center of the fan wheel11(or the yoke15) and the other end is pivoted to the shaft seat211in the frame21. In practice, the yoke15can be omitted and the magnet member14is a Halbach array.

The fan wheel11has a hub111and a plurality of blades113disposed on the circumferential side of the hub111. The hub111has a top portion1111and a sidewall1112axially extending from the edge of the top portion1111. Each of the blades113has an upper surface1131, a lower surface1132, a front edge1133corresponding to the top end1112aof the sidewall1112, and a rear edge1134corresponding to the bottom end1112bof the sidewall1112in which the upper surface1131and the lower surface1132of each blade113naturally form a low-pressure zone and a high-pressure zone, respectively. The connecting channel12is disposed in the hub111or the connecting channel12extends from the hub111to one of the blades113. In the current embodiment, the connecting channel12is disposed in the sidewall1112of the hub111and does not penetrate into the inner side of the sidewall1112(i.e., the side where the sidewall1112attached to the yoke15). In other words, the connecting channel12is disposed vertically or obliquely on the sidewall1112of the hub111corresponding to the corresponding blade113. In practice, the connecting channel12can be disposed axially in the sidewall1112of the hub111, parallel with the axial line L or can be disposed radially in the sidewall1112of the hub111, vertical to the axial line L.

The connecting channel12is provided with a first inlet121, a first end, a second end, and a first outlet123. The first inlet121and the first outlet123are the first end and the second end of the connecting channel12, respectively, and together form a jet structure. The jet structure is used to restrict the eddies generated by the fan rotor (i.e., the eddies generated on the surface of the blade) to achieve the effect of noise reduction. The first outlet123is disposed on the sidewall1112above the upper surface1131of one of the blades113; the first outlet123is disposed in the low-pressure zone above the upper surface1131of the corresponding blade113. In the current embodiment, the first outlet123is disposed close to and above the junction of the sidewall1112and a side of one of the blades113to jet the air flow to restrict the stall flows on the front edge of the hub111(the junction of the sidewall1112and the corresponding blade113) to mitigate the stall noise and postpone the stall condition of the blade113such that the fan can operate in a condition of higher pressure to enhance the performance of the fan. The first inlet121is disposed on the sidewall1112below the lower surface1132of one of the blades113; the first inlet121is disposed on the hub111in the high-pressure zone below the lower surface1132of the corresponding blade113. The first inlet121is used to direct the air flow3around the hub111into the connecting channel12.

When the fan2is operating, the first inlet121in the high-pressure zone below the corresponding blade113will direct the air flow3around the hub111naturally into the connecting channel12. Because of the pressure difference between the first inlet121in the high-pressure zone and the first outlet123in the low-pressure zone, the air flow3in the connecting channel12will flow naturally towards the first outlet123in the low-pressure zone above the corresponding blade113. Then, the air flow3(or called the jet) is self-jetted from the first outlet123to restrict the eddies generated at the junction of the sidewall1112and the corresponding blade113and generated on the upper surface1131of the corresponding blade113. Therefore, by means of the self-jet of the jet structure, the eddies generated by the blade113(or around the corner between the sidewall1112and the corresponding blade113) can be restricted to effectively achieve noise reduction.

In an embodiment, referring toFIG. 1C, the first inlet121in the high-pressure zone is disposed at the bottom end1112bof the sidewall1112to direct the air flow3around the hub111into the connecting channel12. In another embodiment, a second outlet (not shown) is further disposed to communicate with the connecting channel12and is the third end of the connecting channel12. The second outlet is disposed on the sidewall1112above the upper surface1131of one of the blades113and is close to the first outlet123; also, the second outlet is disposed in the low-pressure zone above the upper surface1131of the corresponding blade113. The first outlet123, the second outlet, and the first inlet121are individually disposed at three ends of the connecting channel12and together form the jet structure such that the connecting channel12has a Y-liked shape, but not limited to this. Any with plural outlets or with a three-ended shape is embraced by the connecting channel12with three ends of the present invention. Through two outlets disposed in the low-pressure zone above the corresponding blade113, the eddies generated at several locations on the upper surface1131of the blade113can be effectively restricted by the jets and thus the jetted area can be extended to reduce the noise.

In another embodiment, referring toFIGS. 2A and 2B, a second inlet122is disposed to communicate with the connecting channel12and is a third end of the connecting channel12. The second inlet122is disposed on the sidewall1112below the lower surface1132of one of the blades113and is close to the first inlet121. The first outlet123is disposed above the middle of one of the blades113and is used to restrict the eddies caused by the diverged flow around the corner between the sidewall1112and the corresponding blade113. Besides, the first outlet123, the first inlet121, and the second inlet122are individually disposed at three ends of the connecting channel12and together form the jet structure such that the connecting channel12has an h-liked shape, but not limited to this. Therefore, through plural inlets (e.g., two inlets) disposed in the high-pressure zone, the pressure difference between the inlet and the outlets can be effectively increased to further increase the jet flow.

In another embodiment, referringFIGS. 3A and 3B, the first outlet123has a shape corresponding to the shape of the upper surface1131(i.e., like the curved shape of the upper surface1131) of one of the blades113and is disposed on the sidewall1112. In the current embodiment, the first outlet123and the first inlet121have long-bar shapes, but not limited to this. Therefore, through the first outlet123having a long-bar shape, the gain of the jet location can be effectively obtained. Moreover, the connecting channel12can have a shape of gradual contraction or gradual expansion. The connecting channel12gradually contracts (or expands) upwards from the first inlet121to the first outlet123along the sidewall1112of the hub111, which can expand the area distribution to decrease the friction inside the connecting channel12and then to increase the jet flow. In practice, the shape of the connecting channel12can be a large area shaped into a slender bar to reduce the friction inside the channel and increase the jet flow.

Moreover, the locations and numbers of the first outlets123(or the second outlets) and the first inlets121(or the second inlets122) are not limited to those described in the above-mentioned embodiments. In practice, more than two inlets can be disposed on the sidewall112of the hub111to increase the inlet pressure; also, the user can adjust the locations and numbers of the first outlets123(or the second outlets) according to the expected locations where the eddies are generated on the blades113and then are restricted. For example, one or more than two outlets can be disposed on the sidewall1112of the hub111. Alternatively, one or more than two outlets can be disposed on the upper surface1131or the side surface of the blade113. The locations of the above-mentioned first outlets123(or the second outlets) will determine the locations where the eddies are generated on the surface of the corresponding blade113and then are restricted by the jet flow. Therefore, the effect of noise reduction can be achieved. The shape of each of the first outlet123, the second outlet, the first inlet121, the second inlet122, and the interior of the connecting channel12is a geometric shape or an irregular shape; the geometric shape is a long-bar shape, a flat shape, a square shape, a round shape, or a triangular shape. The first outlet123, the second outlet, the first inlet121, the second inlet122, and the interior of the connecting channel12may have the same or different shapes.

In an alternative embodiment, the above-mentioned connecting channel12is plural in number. The connecting channels12are disposed on the sidewall1112of the corresponding blades113along the edge of the hub111axially or radially and are disposed on the sidewall1112of the corresponding blades113with axial symmetry. In this way, the same eddy noises can be greatly restricted. Besides, the connecting channels12can be disposed on the sidewall1112of the blades113without axial symmetry to restrict different eddy noises. The first outlet123, the second outlet, the first inlet121, the second inlet122, and the interior of the connecting channel12for each connecting channel12may have the same or different shapes. The first outlet123, the second outlet, the first inlet121, the second inlet122, and the interior of the connecting channel12for each connecting channel12may have the same or different sizes.

Therefore, by means of the design of the jet structure of the fan rotor of the present invention, the jet outlet (i.e., the first outlet123) on the sidewall1112of the hub111rotates with the corresponding blade113of the fan wheel11such that the jets can be precisely directed to the eddies on the surface of the blade113close to the jet outlet to restrict the diverged eddies. In addition, the inertial force of the jets can be enhanced to destroy the eddies and postpone the air flow to stall, which effectively improves the performance and the operating range of the fan and reduces noise. Furthermore, the traditional extra nozzle equipment and complicated structure design are not used in the present invention and only the jet structure inside the fan rotor is used in the present invention to restrict the eddies on the surfaces of the blades113to solve the problem of characteristic noise.

Please refer toFIG. 5Awhich is perspective view of the jet structure of a fan rotor according to the second embodiment of the present invention,FIG. 5Bwhich is a cross-sectional view of the jet structure of a fan rotor according to the second embodiment of the present invention,FIG. 5Cwhich is a cross-sectional view of the jet structure of a fan rotor according to a variant of the second embodiment of the present invention,FIG. 5Dwhich is a cross-sectional view of the jet structure of a fan rotor according to another variant of the second embodiment of the present invention,FIG. 5Eis a cross-sectional view of the jet structure of a fan rotor according to yet another variant of the second embodiment of the present invention,FIG. 6Awhich is a perspective view of the jet structure of a fan rotor according to still another variant of the second embodiment of the present invention, andFIG. 6BAwhich is a cross-sectional view of the jet structure of a fan rotor according to still another variant of the second embodiment of the present invention. As shown inFIGS. 5A and 5B, the jet structure1of the fan rotor, the configuration, and the function of the current embodiment are roughly similar to those in the first embodiment and will not be repeated hereinafter. The difference is that in the current embodiment, the connecting channel12extends from the hub111to one of the blades113; the first outlet123is disposed on an upper surface1131of one of the blades113and disposed in the low-pressure zone. The first inlet121is disposed on the sidewall1112below a lower side1132of one of the blades113and disposed in the high-pressure zone. The connecting channel12extends upwards from the first inlet121along and inside the sidewall1112of the hub111to the first outlet123on the upper surface131of one of the blades113through the interior of the one of the blades113. In this way, by means of the first outlet123disposed on the corresponding blade113, the diverged eddies and the secondary eddies above the surface of the blades113can be directly restricted to achieve the effect of noise reduction.

In an embodiment, referring toFIG. 5C, the second outlet124is disposed to communicate with the connecting channel12and is a third end of the connecting channel12; the second outlet124is disposed on the upper surface1131of one of the blades113and is close to the first outlet123. The connecting channel12continues to extend from the interior of the blade113corresponding to the first outlet123to the upper surface1131of the blade113corresponding to the second outlet124and then communicates with the second outlet124. By means of two outlets (i.e., the first outlet123and the second outlet124) individually disposed at different locations on the upper surface1131of the corresponding blade113, the eddy noises generated at different locations on the upper surface1131of the blade113can be effectively restricted by the jets to reduce the noises. In another embodiment, referring toFIG. 5D, the first outlet123is disposed on an upper surface1131of one of the blades113; the second outlet124is disposed on the sidewall1112above the upper surface1131of one of the blades113and is corresponding to the first outlet123on the upper surface1131of the corresponding blade113. By means of the design of two outlets individually disposed on the upper surface1131of the corresponding blade113and disposed on the sidewall1112in the low-pressure zone, the eddies above the surfaces of the blades113and the eddies around the corner between the sidewall1112and the corresponding blade113can be restricted to achieve the effect of multi-eddies reduction to reduce noise significantly.

In another embodiment, referring toFIG. 5E, the first outlet123is disposed on the side edge1135of one of the blades113; the second outlet124is disposed on the sidewall1112above the upper surface1131of one of the blades113and the connecting channel12extends upwards from the first inlet121along and inside the sidewall1112to the first outlet123on side edge1135of the blade113through the interior of the blade113. By means of the design of two outlets (i.e., the first outlet123and the second outlet124) individually disposed on the side edge1135of the corresponding blade113and disposed on the sidewall1112in the low-pressure zone, the eddies around the side edge1135of the blade113and the eddies around the corner between the sidewall1112and the corresponding blade113can be restricted to achieve the effect of multi-eddies reduction to reduce noise significantly.

In another embodiment, referring toFIGS. 6A and 6B, the first outlet123is disposed on the rear edge1134of one of the blades113; a second inlet122is disposed to communicate with the connecting channel12and is a third end of the connecting channel12. The first inlet121and the second inlet122are individually disposed on the sidewall1112below the low surface1132of one of the blades113; the first inlet121disposed in the high-pressure zone is next to the second inlet122. Because of the high pressure at the first outlet123on the rear edge1134, the inlet pressure can be increased by arranging plural inlets (e.g., the first and the second inlets) such that a pressure difference naturally occurs in the connecting channel12. Consequently, due to the pressure difference, the air flows3individually directed into the first inlet and the second inlet and inside the connecting channel12will naturally flow to the first outlet123on the rear edge1134of the blade113and spurts out. In this way, the eddies around the rear edge1134of the blade113can be restricted to reduce noise.

The shapes of the first outlet123, the second outlet124, the first inlet121, the second inlet122, and the interior of the connecting channel12in the previous variants of the second embodiment are the same as those of the first outlet123, the second outlet124, the first inlet121, the second inlet122, and the interior of the connecting channel12in the first embodiment and will not be repeated.

In alternative embodiment, the at least one connecting channel12is plural in number. The connecting channels12extend from the sidewall1112of the hub111to the corresponding blade113along the edge of the hub111axially or radially. Besides, the connecting channels12can be disposed with axial symmetry between the sidewall1112and the corresponding blades113. In this way, the same eddy noises can be further restricted. Alternatively, the connecting channels12can be disposed without axial symmetry between the sidewall1112and the corresponding blades113. In this way, the different eddy noises can be effectively restricted.