Patent Publication Number: US-11649832-B2

Title: Fan impeller

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This Non-provisional application is a Divisional Application (DA) of an earlier filed, pending application, having application Ser. No. 16/591,687 and filed on Oct. 3, 2019, which claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 201811433443.4 filed in People&#39;s Republic of China on Nov. 28, 2018, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     Field of Disclosure 
     The present disclosure relates to a fan impeller and, in particular, to a fan impeller that has a low manufacturing cost and a strengthened structure and can maintain the operation performance. 
     Related Art 
     As the performance of electronic devices continuously increases, the current electronic devices generate a large amount of waste heat during operation. If the heat cannot be immediately removed from the electronic device, the temperature of the electronic device will rise, thereby causing damage to internal components and reducing the performance and lifetime of the electronic device. Fans are the heat-dissipation devices that are widely used in electronic devices. At present, those skilled in the art have developed a mixed flow fan with the blades and hub having two or more unequal diameters. However, the top surface of the blade of the conventional mixed flow fan is usually a large planar surface, and the rotating elements (e.g. the housing, magnetic tape and shaft) are disposed therein. Herein, the top surface of the housing is also a planar surface. Although the structure of non-planar top surface has been developed, it is needed to use much plastic material on the housing during the molding process, thereby increasing the manufacturing cost and decreasing the available space thereof. In addition, in the conventional mixed flow fan, no enhancement element is provided at the shaft, so the entire structure of the mixed flow fan is not stable, which can affect the performance and safety of the fan. 
     Therefore, it is desired to provide a fan impeller that has a low manufacturing cost and a strengthened structure and can maintain the operation performance. 
     SUMMARY OF THE DISCLOSURE 
     An objective of this disclosure is to provide a fan impeller of a mixed flow fan. Compared with the conventional fan impeller, the fan impeller of this disclosure has a low manufacturing cost and a strengthened structure and can maintain the operation performance. 
     The present disclosure provides a fan impeller, comprising a hub, a shaft, a metal housing, and a plurality of blades. The outer periphery of the hub has a curved surface, and the slopes of straight lines connecting any two points on the curved surface are not equal. The shaft is disposed in the hub and connected to the hub. The metal housing has an annular shape and is disposed in the hub. The blades are disposed around the outer periphery of the hub. 
     In one embodiment, the hub and the blades are projected along an extension direction toward the shaft to define projection areas thereof, and the projection area of each of the blades is partially overlapped with the projection area of the hub. 
     In one embodiment, the hub defines a top portion and a bottom portion, so that the top portion is located at a center of the projection area of the hub, and the bottom portion is located an edge of that of the hub. 
     In one embodiment, an annular extension portion is formed in the hub, the extension portion extends from an inner side of the hub to an axis of the shaft, and the metal housing is connected with the hub by the extension portion. 
     In one embodiment, a plurality of spacers are disposed between the bottom portion of the hub and the extension portion, and any adjacent two of the spacers form an accommodating space therebetween. 
     In one embodiment, the fan impeller further comprises at least a rib disposed inside the hub, and the rib covers the shaft. 
     In one embodiment, the fan impeller further comprises a magnetic ring or an annular magnet disposed inside the metal housing. 
     In one embodiment, the metal housing extends toward the extension portion of the hub, and the metal housing protrudes beyond the extension portion or aligns with the extension portion. 
     The present disclosure also provides a fan impeller comprising a hub, a shaft, a metal housing and a plurality of blades. The outer periphery of the hub has a curved surface, and slopes of straight lines connecting any two points on the curved surface are not equal. The shaft is disposed in the hub. The metal housing is disposed in the hub and has a top surface, and the shaft is connected with the top surface. The blades are disposed around the outer periphery of the hub. 
     In one embodiment, the top surface of the metal housing is formed with at least a through hole, and when the hub is formed by injection molding, a heat stake is formed in the through hole for connecting the hub and the metal housing. 
     In one embodiment, the shaft is connected with the metal housing by welding. 
     In one embodiment, the top surface of the metal housing is formed with a heat-dissipation hole. 
     In one embodiment, the hub and the blades are projected along an extension direction toward the shaft to define projection areas thereof, and the projection area of each of the blades is partially overlapped with that of the hub. 
     In one embodiment, the hub defines a top portion and a bottom portion, the top portion is located at a center of that of the hub, and the bottom portion is located an edge of that of the hub. 
     In one embodiment, an annular extension portion is formed in the hub, the extension portion extends from an inner side of the hub to an axis of the shaft, and the metal housing is connected with the hub by the extension portion. 
     In one embodiment, the fan impeller further comprises a magnetic ring disposed inside the metal housing. 
     In one embodiment, the metal housing extends toward the extension portion of the hub, and the metal housing protrudes beyond the extension portion or aligns with the extension portion. 
     As mentioned above, the fan impeller of this disclosure can be manufactured with less plastic material, the internal space of the hub can be effectively utilized, the structure can be strengthened, and the operation performance can be maintained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the subsequent detailed description and accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present disclosure, and wherein: 
         FIG.  1    is a schematic diagram showing the fan impeller according to a first embodiment of this disclosure; 
         FIG.  2    is a top view of the fan impeller according to the first embodiment of this disclosure; 
         FIG.  3    is a schematic diagram showing the outer periphery of the hub of the fan impeller according to the first embodiment of this disclosure; 
         FIG.  4    is a sectional view of the fan impeller according to the first embodiment of this disclosure; 
         FIG.  5    is a sectional view of the fan impeller according to a second embodiment of this disclosure; 
         FIG.  6    is a bottom view of the fan impeller according to the second embodiment of this disclosure; 
         FIG.  7 A  is a sectional side view of the fan impeller according to a third embodiment of this disclosure; 
         FIG.  7 B  is a sectional view of the fan impeller according to the third embodiment of this disclosure; and 
         FIG.  8    is a sectional view of the fan impeller according to a fourth embodiment of this disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     The present disclosure will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements. 
       FIGS.  1  and  2    are a schematic diagram and a top view of a fan impeller according to a first embodiment of this disclosure. As shown in  FIGS.  1  and  2    the fan impeller  1   a  comprises a hub  11 , a shaft  12 , and a plurality of blades  14  disposed around the hub  11 . The hub  11  has a curved surface  111 , and the blades  14  substantially extend outwardly from the curved surface  111 . Referring to  FIG.  2   , the hub  11  forms a projection area. The center of the projection area is a top portion  113  of the hub  11 , and the edge of the projection area is a bottom portion  112  of the hub  12 . The blades  14  also form corresponding projection areas. The projection areas of the blades  14  are partially overlapped with that of the hub  11 . 
       FIG.  3    is a schematic diagram showing the outer periphery of the hub  11  of the fan impeller  1   a  according to the first embodiment of this disclosure. The feature of the curved surface  111  on the outer periphery of the hub  11  of the fan impeller  1   a  will be described hereinafter with reference to  FIG.  3   . To be noted,  FIG.  3    only shows the curved surface  11  of the outer periphery of the hub  11 . As shown in  FIG.  3   , a straight line A connects two points a and a′ on the curved surface  111 , and a straight line B connects two points b and b′ on the curved surface  111 . In this embodiment, the slope of the straight line A and the slope of the straight line B are unequal to each other. That is, the slopes of straight lines connecting any two points on the curved surface  111  are not equal. In all fan impellers of this disclosure, the curved surfaces of the hubs all have the above-mentioned feature. 
       FIG.  4    is a sectional view of the fan impeller  1   a  according to the first embodiment of this disclosure. As shown in  FIG.  4   , the fan impeller  1   a  comprises a hub  11 , a shaft  12 , a metal housing  13   a , and a plurality of blades  14 . The shaft  12  is disposed in the hub  11  and connected to the hub  11 . The metal housing  13   a  has an annular shape and is disposed in the hub  11 . The blades  14  are disposed around the outer periphery of the hub  11 . 
     The fan impeller  1   a  of this embodiment further comprises at least one rib  15  disposed in the hub  11 . The at least one rib  15  covers the shaft  12  for enhancing the connection strength between the shaft  12  and the hub  11 . 
     In this embodiment, a space is formed in the hub  11 , and the shaft  12  is disposed in the hub  11  and connected to the hub  11 . The metal housing  13   a  has an annular shape and is disposed in the space of the hub  11 . As shown in the figure, an annular extension portion  114  is formed in the hub  11 . The extension portion  114  extends from the space of the hub  11  to an axis of the shaft  12 , and the metal housing  13   a  is connected with the hub  11  by the extension portion  114 . 
     In this embodiment, the metal housing  13   a  can be made of, for example, a magnetic material containing iron. 
     The fan impeller  1   a  of this embodiment further comprises a magnetic ring  133   a  disposed inside the metal housing  13   a . The material of the magnetic ring  133   a  can be a magnetic rubber or a magnet. 
     In this embodiment, the metal housing  13   a  extends toward the extension portion  114 , and the metal housing  13   a  protrudes beyond the extension portion  114 , so that the magnetic ring  133   a  inside the metal housing  13  can protrude beyond the bottom portion  112  of the hub  11 . Accordingly, the magnetic ring  133   a  can have a larger size for increasing the magnetic force. 
       FIG.  5    is a sectional view of a fan impeller  1   b  according to a second embodiment of this disclosure. The structure of the fan impeller  1   b  as shown in  FIG.  5    is mostly the same as that shown in  FIG.  4   . Different from the embodiment of  FIG.  4   , as shown in  FIG.  5   , the metal housing  13   b  and the magnetic ring  133   b  are aligned with the extension portion  114 . 
       FIG.  6    is a bottom view of the fan impeller  1   b  according to the second embodiment of this disclosure. Referring to  FIGS.  5  and  6   , in the fan impeller  1   b  of this embodiment, a plurality of spacers f are formed between the bottom portion  112  and the extension portion  114  of the hub  11 , and any two adjacent spacers f form an accommodating space s therebetween. In general, the fan impeller  1   b  of this embodiment is usually applied to the high speed fan, which has the rotation speed of 10,000 RPM or higher. The accommodating space s can be used to fill the balance material (e.g. clay) for calibrating the weight balance of the fan impeller  1   b . This configuration can increase the stability in high speed rotation. In addition, the configuration of the accommodating space s can be also realized as removing a part material of the hub  11 , which can decrease the total weight of the fan impeller  1   b . In other words, the accommodating spaces s between the spacers f are not filled with the material of the hub  11 , so that the total amount of material can be reduced, thereby saving the manufacturing cost of the hub  11 . 
     As shown in  FIG.  6   , a plurality of ribs  15  can be formed at the connection of the hub  11  and the shaft  12  for enhancing the structural stability. The numbers of the ribs  15  can be adjusted according the actual requirement of the user, and this disclosure is not limited. The space between two adjacent ribs  15  can also be filled with the balance material (e.g. clay) for calibrating the weight balance of the fan impeller  1   b.    
     The spacers f and the accommodating spaces s of the fan impeller  1   b  of the second embodiment as shown in  FIG.  6    are for illustrations only. Of course, the fan impeller  1   a  of the first embodiment can also be configured with the spacers f and the accommodating spaces s. 
       FIG.  7 A  is a sectional side view of a fan impeller  1   c  according to a third embodiment of this disclosure, and  FIG.  7 B  is a sectional view of the fan impeller  1   c  according to the third embodiment of this disclosure. In this embodiment, the fan impeller  1   c  comprises a hub  11 , a shaft  12 , a metal housing  13   c , and a plurality of blades  14 . The outer periphery of the hub  11  has a curved surface, and the slopes of straight lines connecting any two points on the curved surface  111  are not equal. The shaft  12  is disposed in the hub  11 . The metal housing  13   c  is disposed in the hub  11  and has a top surface  131 , and the shaft  12  is connected with the top surface  131 . The blades  14  are disposed around the outer periphery of the hub  11 . 
     In this embodiment, the metal housing  13   c  is disposed in the hub  11 , and the top surface  131  of the metal housing  13   c  is connected with the shaft  12 . Accordingly, when the shaft  12  rotates, the hub  11  can be driven by the shaft  12  to rotate. The shaft  12  can be connected with the metal housing  13   c  by, for example but not limited to, welding (e.g. laser welding). 
     In this embodiment, the top surface  131  of the metal housing  13   c  is formed with at least one through hole  132 . When the hub  11  is formed by injection molding, a heat stake can be formed in the through hole  132  for connecting the hub  11  and the metal housing  13   c . The numbers of the through holes  132  can be adjusted based on the actual requirement of the user, and this disclosure is not limited thereto. 
     In this embodiment, the top surface  131  of the metal housing  13   c  can be formed with a plurality of heat-dissipation holes g. After the fan impeller  1   c  connects with the motor, the configured heat-dissipation holes g can help to dissipate the internal heat of the fan impeller  1   c  during high-speed rotation. 
     In this embodiment, the metal housing  13   c  can be formed by punching, and the material of the metal housing  13   c  is iron. In this embodiment, a magnetic ring  133   c  can be provided on the inner side of the metal housing  13   c . The material of the magnetic ring  133   c  can be a magnetic rubber or a magnet. 
     In this embodiment, the hub  11  and the blades  14  are projected along an extension direction toward the shaft  12  to define projection areas thereof, and the projection area of each of the blades  14  is partially overlapped with the projection area of the hub  11 . 
     In this embodiment, an annular extension portion  114   c  is formed in the hub  11 . The extension portion  114   c  extends from an inner space of the hub  11  to an axis of the shaft  12 . The metal housing  13   c  is connected with the hub  11  by the extension portion  114   c . The metal housing  13   c  protrudes beyond the extension portion  114   c , so that the magnetic ring  133   c  inside the metal housing  13   c  can protrude beyond the bottom portion  112  of the hub  11 . Accordingly, the magnetic ring  133   c  can have a larger size for increasing the magnetic force. 
       FIG.  8    is a sectional view of a fan impeller  1   d  according to a fourth embodiment of this disclosure. The features of the fan impeller  1   d  as shown in  FIG.  8    are mostly the same as those of the third embodiment. Different from the third embodiment, as shown in  FIG.  8   , the metal housing  13   d  and the magnetic ring  133   d  are aligned with the extension portion  114 . 
     Although the present disclosure has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the present disclosure.