Abstract:
A fan defines a plurality of fixing holes and includes a plurality of protrusions. The plurality of protrusions is located on sides of the plurality of fixing holes. Each protrusion includes a guiding surface. The plurality of guiding surface extends in the plurality of fixing holes. A fan assembly is also provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Chinese Patent Application No. 201510146970.7 filed on Mar. 31, 2015, the contents of which are incorporated by reference herein. 
       FIELD 
       [0002]    The subject matter herein generally relates to a fan and a fan assembly. 
       BACKGROUND 
       [0003]    When electronic devices are in a working state, microprocessors can generate heat. If the heat is not dissipated in time, the electronic devices will be damaged. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
           [0005]      FIG. 1  is an isometric view of a first embodiment of a fan. 
           [0006]      FIG. 2  is an assembly view of the fan of  FIG. 1  being installed on a circuit board. 
           [0007]      FIG. 3  is an isometric view of the fan of  FIG. 1  being mounted to the circuit board. 
           [0008]      FIG. 4  is a top plan view of a second embodiment of a fan. 
           [0009]      FIG. 5  is a top plan view of a third embodiment of a fan. 
           [0010]      FIG. 6  is an isometric view of a forth embodiment of a fan. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. 
         [0012]    Several definitions that apply throughout this disclosure will now be presented. 
         [0013]    The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need not be exact. For example, “substantially cylindrical” means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
         [0014]    The present disclosure is described in relation to a fan 
         [0015]      FIGS. 1-3  illustrate a first embodiment of a fan  10 . The fan  10  is used to dissipate heat from a component  24 . 
         [0016]    The fan  10  includes a bottom plane  11 , and four protrusions  12 . Four fixing holes  14 , an air inlet  16 , and an air outlet  18  are defined in the fan  10 . The four protrusions  12  extend up from the bottom plane  11 . The four fixing holes  14  and the air inlet  16  are defined on the bottom plane  11 . The four protrusions  12  are located on sides of the four fixing holes  14 . Each protrusion  12  includes a guiding surface  120  and a chamfer  122 . The chamfer  122  extends from the guiding surface  120  into an edge of the protrusion  12 . The guiding surface  120  extends into the fixing hole  14 . In one embodiment, the bottom plane  11  can be substantially rectangular. The four protrusions  12  can be substantially located on four corners of the bottom plane  11 . The air inlet  16  is defined in the centre of the bottom plane  11 . The air outlet  18  is defined in a sidewall of the fan  10 . The sidewall can be substantially perpendicular to the bottom plane  11 . In one embodiment, each protrusion  12  can be substantially a half ring. The guiding surface  120  can be arc-shaped. A diameter of the guiding surface  120  is greater than a diameter of the fixing hole  14 . The four guiding surfaces  120  curve toward a same direction. 
         [0017]    A circuit board  20  includes four fixing posts  22 . The component  24  is located on a central portion of the four fixing posts  22 . 
         [0018]    The fan  10  is moved to the circuit board  20  until the four fixing posts  22  engaged with the four guiding surfaces  120 . The four fixing posts  22  are slid into the four fixing holes  14  guided by the four guiding surfaces  120 . The fan  10  is fixed to the circuit board  20 . When the component  24  is in a working state, heat produced by the component  24  can be dissipated by the fan  10  via the air outlet  18 . 
         [0019]      FIG. 4  illustrates a second embodiment of a fan  10 . The four protrusions  12  can be substantially located on four corners of the bottom plane  11 . The air inlet  16  is located on a centre of the bottom plane  11 . The guiding surface  120  can be arc-shaped. At least two arcuate directions of the four guiding surfaces  120  are opposite. 
         [0020]      FIG. 5  illustrates a third embodiment of a fan  10 . The four protrusions  12  can be substantially located on four corners of the bottom plane  11 . The air inlet  16  is located on a centre of the bottom plane  11 . The guiding surface  120  can be arc-shaped. At least two guiding surfaces  120  face each other. 
         [0021]      FIG. 6  illustrates a forth embodiment of a fan  10 . Each protrusion  12  can be substantially a ring. The guiding surface  120  can be circular. 
         [0022]    The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a fan. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the details, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.