Patent Publication Number: US-2018045219-A1

Title: Blower

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Application No. 201610670064.1 filed in The People&#39;s Republic of China on Aug. 12, 2016. 
     FIELD OF THE INVENTION 
     The present invention relates to the field of blowers. 
     BACKGROUND OF THE INVENTION 
       FIG. 1  illustrates a conventional blower including a mounting base  11 , a motor  12  mounted to the mounting base  11 , an impeller  3  fixed to a shaft of the motor  12  via an interference fit, and an electronic control unit  14  mounted to one side of the mounting base  11  away from the impeller  13 . A heat dissipating device  15  is disposed between the electronic control unit  14  and the mounting base  11 . Air enters via an air entrance  111  on the mounting base  11 , flows through the heat dissipating device  15 , and is then discharged via an exit of the mounting base. A first issue of such blower  10  is that, the heat dissipating device  15  has a large distance from the air entrance  111 , which leads to a poor heat dissipating result. A second issue is that, in some situations where the impeller  13  is mounted as the last element, because the electronic control unit  14  is disposed at an outside of the shaft of the motor  12 , a mounting tool cannot resist the end of the shaft of the motor  12  so as to support the shaft or exert a force on the shaft toward the other end thereof at which the impeller  13  is to be mounted and, a result, the impeller  13  cannot be mounted to the shaft. In some other situations, the electronic control unit  14  may be provided with an opening for allowing the mounting tool to resist the end of the shaft. However, this requires the opening to be defined through a PCB in the electronic control unit  14 , which may increase the difficulties and cost in the PCB design. 
     SUMMARY OF THE INVENTION 
     Accordingly, a blower is provided which includes a mounting base, a motor, an impeller, and an electronic control unit. The motor is mounted to an upper side of the mounting base and includes a motor shaft. The impeller is mounted on the motor. The electronic control unit is mounted to a lower side of the mounting base. The mounting base defines a through hole. The through hole is axially aligned with a motor shaft to expose an axial end of the motor shaft opposite from the impeller. The electronic control unit includes a printed circuit board disposed offset from the through hole. 
     Preferably, the blower further includes a heat dissipating device configured to dissipate heat of the electronic control unit. 
     Preferably, the mounting base defines an air entrance, and the heat dissipating device is disposed adjacent the air entrance. 
     Preferably, the blower further includes a control box, and the electronic control unit and the heat dissipating device are both disposed in the control box. 
     Preferably, the control box is mounted to the lower side of the mounting base, and the control box is disposed offset from the through hole. 
     Preferably, the electronic control unit is mounted in the control box, and is mounted to the mounting base through the control box. 
     Preferably, the mounting base comprises a mounting plate and an accommodating portion, the mounting plate is disposed at a bottom of the accommodating portion, the motor is mounted on the mounting plate and accommodated in the accommodating portion, the motor shaft of the motor extends out of the accommodating portion for mounting the impeller, and the through hole is defined in the mounting plate. 
     Preferably, the mounting base further includes a ledge disposed along an outer periphery of the accommodating portion, and the air entrance is disposed on the ledge. 
     Preferably, the ledge further defines an air passage in communication with the air entrance and adapted to guide the air flow into the control box. 
     Preferably, the mounting plate defines a heat dissipating opening, such that the air introduced into the control box via the air entrance is discharged via the heat dissipating opening of the mounting plate. 
     Preferably, the heat dissipating device is disposed between the printed circuit board and the mounting base. 
     Preferably, the impeller is mounted to the motor shaft of the motor via an interference fit. 
     In situations where it is desired to mount the impeller to the mounting base after the mounting of the control box, defining the hole through the control box and the PCB therein can be avoided by implementing the present invention. In addition, the control box is disposed adjacent the air entrance on the mounting base, which enhances the heat dissipating efficiency of the heat dissipating device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described below in greater detail with reference to the drawings and embodiments. 
         FIG. 1  is a sectional view of a conventional blower. 
         FIG. 2  is a perspective view of a blower according to one embodiment of the present invention. 
         FIG. 3  is a perspective view of the blower of  FIG. 2 , viewed from another aspect. 
         FIG. 4  is an exploded view of the blower of  FIG. 2 . 
         FIG. 5  is an exploded view of the blower of  FIG. 2 , viewed from another aspect. 
         FIG. 6  is a sectional view of the blower of  FIG. 2 . 
         FIG. 7  is an assembled view of the blower of  FIG. 6 , showing the impeller being mounted. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Below, embodiments of the present invention will be described in greater detail with reference to the drawings. Elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It should be noted that the figures are illustrative rather than limiting. The figures are not drawn to scale, do not illustrate every aspect of the described embodiments, and do not limit the scope of the present disclosure. Unless otherwise specified, all technical and scientific terms used in this disclosure have the ordinary meaning as commonly understood by people skilled in the art. 
     It is noted that, when a component is described to be “fixed” or “mounted” to another component, it can be directly fixed or mounted to the another component or there may be an intermediate component. When a component is described to be “connected” to another component, it can be directly connected to the another component or there may be an intermediate component. When a component is described to be “disposed” on another component, it can be directly disposed on the another component or there may be an intermediate component. 
       FIG. 2  to  FIG. 4  illustrate a blower  20  according to one embodiment of the present invention. The blower  20  includes a mounting base  21 , a motor  22  mounted on the mounting base  21 , an impeller  23  mounted on the motor  22 , an electronic control unit  24 , and a heat dissipating device  25  for dissipating heat of the electronic control unit  24 . The mounting base  21  includes a mounting plate  211 , and a housing  221  of the motor  22  is mounted to the mounting plate  211  through fasteners such as bolts. In the illustrated embodiment, the mounting base  21  further includes an accommodating portion  212 , and the mounting base  211  is disposed at a bottom of the accommodating portion  212 . A motor body of the motor  22  is accommodated in the accommodating portion  212 . A side of the accommodating portion  212  opposite from the mounting plate  211  defines an opening  213 , and one end of a motor shaft  222  of the motor  22  extends to an outside of the accommodating portion  212  through the opening  213 . The impeller  23  defines a shaft hole  231  in a center thereof. The impeller  23  is fixed to the end of the motor shaft  222  through an interference fit between the shaft hole  231  and the motor shaft  222 , and rotates along with the motor shaft  222  to perform work on the air. 
     In the illustrated embodiment, the mounting base  21  further includes a ledge  214 . The ledge  214  is disposed along an outer periphery of the accommodating portion  212  surrounding the accommodating portion  212 . The ledge  214  defines at an upper side thereof an air entrance  215 , and defines an air passage  216  therein in communication with the air entrance  215 . Another end of the air passage  216  extends to within a control box  26  that receives the electronic control unit  24 . The control box  26  is mounted below the mounting base  21 , at a side of the mounting base  21  adjacent the air entrance  215 . The electronic control unit  24  includes a circuit board  241 . The circuit board  241  on one hand receives power and/or control command from an external environment via an interface  242  disposed at an outer side of the control box  26  and, on the other hand, controls rotation of the impeller  23  by connecting to the motor  22  to control rotation of the motor  22 . A heat dissipating device  25  is disposed within the control box  26  above the circuit board  241  to dissipate heat of the circuit board  241 . 
     In the illustrated embodiment, the mounting plate  211  of the mounting base  21  defines a plurality of heat dissipating openings  2111 . The heat dissipating openings  2111  are located in correspondence with the control box  26 . Air enters via the air entrance  215  of the ledge  214 , enters the control box  26  to contact the heat dissipating device  25  after passing through the air passage  216  below the ledge  214 , and finally is discharged via the heat dissipating openings  2111  of the mounting plate  211 , so as to dissipate heat of the circuit board  241 . 
     Referring to  FIG. 4  to  FIG. 6 , the mounting plate  211  of the mounting base  21  defines a through hole  2112 . The through hole  2112  is axially aligned with the motor shaft  222  to expose an axial end of the motor shaft  222  opposite from the impeller  23 . In one embodiment, the motor shaft  222  passes through the through hole  2112  to an outside of the mounting base  21 . In another embodiment, the motor shaft  222  does not pass through the through hole  2112  to the outside of the mounting base  21 . However, no matter in which embodiment, as shown in  FIG. 7 , the motor shaft  222  can be accessed by a tool from the outside through the through hole  2112 , and can be axially supported. As such, the impeller  23  can be press-fit onto the motor shaft  222  at an opposite end, thus forming an interference fit with the motor shaft  222 . 
     After the control box  26  is mounted below the mounting base  21 , the through hole is located at one side of the circuit board  261 . That is, the control box  26  is disposed offset from the through hole  2112 . As such, the control box  26  and the circuit board  261  are no longer required to define holes for allowing the external tool to resist the motor shaft  222 . The control box  26  and the heat dissipating device  25  are disposed below the mounting base  21  at a side thereof adjacent the air entrance  215 , which avoids the poor heat dissipating issue resulted from a too long path of the airflow introduced via the air entrance. 
     In summary, in the blower of the embodiment of the present invention, the motor is mounted to one side of the mounting base, and the electronic control unit is mounted to an opposite side of the mounting base. The mounting plate defines a through hole. The through hole is axially aligned with the motor shaft and disposed adjacent or at an axial end of the motor shaft opposite from the impeller. A PCB is disposed in the electronic control unit and offset from the through hole. As such, after the motor and the electronic control unit have been mounted to the mounting base, in mounting the impeller to the other axial end of the motor, a mounting tool can resist the motor shaft through the through hole of the mounting base to thereby axially support the motor shaft, such that the impeller can be press-fit onto the motor shaft at the other axial end. In addition, the mounting base includes the air entrance, and the heat dissipating device is disposed adjacent the air entrance, which enhances the heat dissipating efficiency of the heat dissipating device. 
     Although the invention is described with reference to one or more embodiments, the above description of the embodiments is used only to enable people skilled in the art to practice or use the invention. It should be appreciated by those skilled in the art that various modifications are possible without departing from the spirit or scope of the present invention. The embodiments illustrated herein should not be interpreted as limits to the present invention, and the scope of the invention is to be determined by reference to the claims that follow.