Electric fan

Abstract

An electric fan includes a motor, two blade units, and two engaging units. The motor has a motor shaft that defines an axis and that has two axially opposite end segments. Each of the end segments has an engaging region. The engaging regions of the end segments are disposed at angularly opposite positions relative to the axis. Each of the blade units includes a hub that is sleeved on a respective one of the end segments. Each of the engaging units includes a first engaging member provided on the engaging region of a respective one of the end segments, and a second engaging member provided on the hub of a respective one of the blade units and engaging the first engaging member.

1 . An electric fan comprising: 
 a motor with a motor shaft defining an axis and having two end segments that are axially opposite to each other, each of said end segments having an engaging region, said engaging regions of said end segments being disposed at angularly opposite positions relative to said axis;    a pair of blade units coupled respectively to and driven by said end segments of said motor shaft, each of said blade units including a hub that is sleeved on the respective one of said end segments, and a plurality of blades that extend from said hub; and    a pair of engaging units, each of which includes a first engaging member that is provided on said engaging region of a respective one of said end segments of said motor shaft, and a second engaging member that is provided on said hub of a respective one of said blade units and that engages said first engaging member, thereby securing said blade units to said end segments of said motor shaft, respectively.    
   
   
       2 . The electric fan as claimed in  claim 1 , wherein each of said end segments of said motor shaft has a free end portion with a non-circular cross-section, said free end portion of each of said end segments having a flat surface that defines said first engaging member of the respective one of said engaging units, said hub of each of said blade units including a sleeve part that is sleeved on the respective one of said end segments and that has a free end portion with a non-circular cross-section, said free end portion of said sleeve part of said hub of each of said blade units having a flat surface that defines said second engaging member and that conforms to and that contacts said flat surface of said free end portion of the respective one of said end segments of said motor shaft.  
   
   
       3 . The electric fan as claimed in  claim 1 , wherein each of said end segments of said motor shaft is formed with an engaging hole that defines said first engaging member of the respective one of said engaging units, said hub of each of said blade units including a sleeve part that is sleeved on the respective one of said end segments and that is formed with a threaded hole, said second engaging member of each of said engaging units being in the form of a screw that engages threadedly and that extends through said threaded hole in said sleeve part of said hub of the respective one of said blade units and that engages said engaging hole in the respective one of said end segments.  
   
   
       4 . The electric fan as claimed in  claim 1 , wherein each of said end segments of said motor shaft is formed with an engaging protrusion that defines said first engaging member of the respective one of said engaging units, said hub of each of said blade units including a sleeve part that is sleeved on the respective one of said end segments and that has a free end portion formed with an engaging groove which extends axially, which opens in a direction toward said motor, and which defines said second engaging member of the respective one of said engaging units, said engaging protrusion of each of said end segments extending through said engaging groove in said free end portion of said sleeve part of said hub of the respective one of said blade units.  
   
   
       5 . The electric fan as claimed in  claim 2 , wherein said hub of each of said blade units further includes a hub base and an outer annular wall that extends axially from a periphery of said hub base and that surrounds said sleeve part, said hub base having an inner side and an outer side that is opposite to said inner side, said sleeve part of said hub of each of said blade units further having an open outer end that is opposite to said free end portion of said sleeve part, each of said end segments of said motor shaft having a threaded portion that extends axially and outwardly through said open outer end of said sleeve part of said hub of the respective one of said blade units, said electric fan further comprising a pair of screw nuts, each of which is disposed at said outer side of said hub base of a respective one of said blade units and each of which engages threadedly said threaded portion of a respective one of said end segments of said motor shaft.