Abstract:
A fan system including a volute, a wind wheel, a motor, and a motor controller. The motor controller includes a control box including a plurality of fins for dissipating heat of the motor controller, and controls the operation of the motor to drive the wind wheel. The wind wheel is adapted to suck ambient air to form an air flow which passes through the plurality of fins.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 14/565,363, filed Dec. 9, 2014, now pending, which is a continuation-in-part of International Patent Application No. PCT/CN2013/085760 with an international filing date of Oct. 23, 2013, designating the United States, and further claims foreign priority to Chinese Patent Application No. 201320387505.9 filed Jun. 29, 2013. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P.C., Attn.: Dr. Matthias Scholl Esq., 245 First Street, 18th Floor, Cambridge, Mass. 02142. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The invention relates to a motor controller and a fan system comprising the same. 
       Description of the Related Art 
       [0003]    A typical motor controller includes a control box and a control circuit board. The control box is provided with a cavity, and the control circuit board is disposed in the cavity of the control box. The motor controller is generally disposed at a bottom part of a load box. Limited by the space, the motor controller generally has a small volume, thereby resulting in poor heat dissipation performance; besides, heat quantity produced by the motor is accumulated at the bottom part of the load box. Because the control circuit board is mounted inside the sealed control box, when the temperature therein increases and the heat quantity in the control box is difficult to dissipate, the normal operation of the control circuit board will be seriously affected. Thus, the motor controller of such structure has low reliability and hidden dangers. Some manufacturers have adopted methods of arranging cooling ribs or vent holes on an outer surface of the control box to improve the heat dissipation performance of the motor controller, but such motor controller is troublesome in assembly and the heat dissipation effect thereof is not ideal. 
         [0004]    A typical fan system includes a volute, a wind wheel, a motor, and a motor controller. The volute is provided with an inner cavity. An end face of the volute is provided with an air inlet, and a side face of the volute is provided with an air outlet. The motor is disposed outside the air inlet of the volute; a rotating shaft of the motor is inserted into the inner cavity from the air inlet and connected to the wind wheel; and the motor controller is generally disposed away of the motor. Since the motor is far away from the motor controller, a lead wire demanded for connection is so long that a large space is occupied; furthermore, it is troublesome to connect the long lead wire, faults easily occur, and hidden dangers exist. In some existing motors, the motor controller is disposed near the motor. However, since the motor controller is a sealed structure, poor dissipation performance of the motor controller is resulted. After a long term operation of the motor controller, the temperature inside the motor controller increases, so that the normal operation of the motor controller is affected, and faults easily occur during the operation of the motor under the control of the motor, thereby resulting in low reliability. 
       SUMMARY OF THE INVENTION 
       [0005]    In view of the above-described problems, it is one objective of the invention to provide a motor controller and a fan system comprising the same. The motor controller has a simple structure, convenient installation, excellent heat dissipation performance, high efficiency and reliability. The fan system has a simple and compact structure, convenient installation, good heat dissipation performance, and high reliability. 
         [0006]    To achieve the above objective, in accordance with one embodiment of the invention, there is provided a motor controller. The motor controller comprises: a supporting frame, a control circuit board, and a control box. The control box comprises: a cavity, a base plate, and a plurality of fins for dissipating heat generated in the motor controller. The control circuit board is disposed on the base plate in the cavity. The fins are disposed outside the cavity on an outer side surface of the base plate. Cooling ducts are formed between adjacent fins. The control box is fixed on the supporting frame. 
         [0007]    In a class of this embodiment, the control box comprises: the base plate, an upper plate, and a lower plate. The upper plate and the lower plate are extended from two ends of the base plate to a same side. The upper plate, the base plate, and the lower plate form the cavity, side openings at two sides of the cavity, and an upper opening at a top of the cavity. The supporting frame comprises two supporting plates and a connecting plate connected to the two supporting plates. The connecting plate shields the upper opening of the control box. The supporting plates shield the side openings at two sides of the control box and match with two side surfaces of the base plate, respectively, for mounting the control box on the supporting frame. 
         [0008]    In a class of this embodiment, the supporting frame comprises a plurality of vent holes and a gel inlet. An encapsulating material is filled into the control box via the gel inlet for partially or totally covering the control circuit board. 
         [0009]    In a class of this embodiment, the two supporting plates lock the control box on an upper part of the supporting frame via screws. 
         [0010]    In a class of this embodiment, steps are arranged in the cavity on the upper plate and the lower plate. The control circuit board is disposed on top surfaces of the steps. A plurality of mounting columns is disposed on the base plate in the cavity. The control circuit board is fixed on top surfaces of the mounting columns via screws. 
         [0011]    In a class of this embodiment, a plurality of wire bushings is disposed on the lower plate of the control box. Lead wires of the control circuit board are led out from the wire bushings. A bottom part of each of the two supporting plates is bent to form a flange. A plurality of mounting holes is disposed on the flange. 
         [0012]    In accordance with another embodiment of the invention, there is provided a fan system. The fan system comprises: a volute, a wind wheel, a motor, and a motor controller. The volute comprises: an inner cavity, an air inlet, and a first air outlet. The motor comprises a rotating shaft. The motor controller comprises: the supporting frame, the control circuit board, and the control box. The control box comprises: the cavity and the base plate, and a plurality of the fins. The inner cavity is disposed inside the volute. The air inlet is disposed on an end face of the volute. The first air outlet is disposed on a side face of the volute. The motor is disposed outside the air inlet of the volute. The rotating shaft of the motor is inserted into the inner cavity and connected to the wind wheel. The motor controller is disposed nearby the motor. The motor controller is in electric connection with the motor and controls operation of the motor. The control circuit board is disposed on the base plate in the cavity. The fins are disposed outside the cavity on the outer side surface of the base plate. Cooling ducts are formed between adjacent fins. The control box is fixed on the supporting frame. 
         [0013]    In a class of this embodiment, the control box comprises: the base plate, an upper plate, and a lower plate. The upper plate and the lower plate are extended from two ends of the base plate to a same side. The upper plate, the base plate, and the lower plate form the cavity, side openings at two sides of the cavity, and an upper opening at a top of the cavity. The supporting frame comprises two supporting plates and a connecting plate connected to the two supporting plates. The connecting plate shields the upper opening of the control box. The supporting plates shield the side openings at two sides of the control box and match with two side faces of the base plate of the control box for mounting the control box on the supporting frame. 
         [0014]    In a class of this embodiment, the volute, the motor, and the motor controller are disposed in a mounting cavity of a load box. A second air outlet is disposed on a sidewall of the mounting cavity. The first air outlet of the volute communicates with the second air outlet of the load box. 
         [0015]    In a class of this embodiment, the motor is disposed on a motor bracket. A base wall of the load box is provided with a mounting bracket. The motor bracket is disposed on the mounting bracket. 
         [0016]    Advantages according to embodiments of the invention are summarized as follows: 
         [0017]    1) The control circuit board is disposed on the base plate in the cavity. The fins are disposed outside the cavity on the outer side surface of the base plate. Cooling ducts are formed between adjacent fins. The structure is simple, the volume of the motor controller is enlarged, and the heat dissipation performance and the reliability of the motor controller are improved. The control box is fixed by the supporting frame, and the installation thereof is simple and convenient. 
         [0018]    2) The upper plate, the base plate, and the lower plate form the cavity, side openings at the two sides of the cavity, and the upper opening at the top of the cavity. The supporting frame comprises two supporting plates and the connecting plate connected to the two supporting plates. The connecting plate shields the upper opening of the control box. The supporting plates shield the side openings at two sides of the control box and match with two side faces of the base plate of the control box, respectively, for mounting the control box on the supporting frame. The structure is simple, the installation of the control box and the supporting frame is very convenient, and meanwhile, materials for producing the control box are reduced, thereby lowering the production cost. 
         [0019]    3) The supporting frame is provided with a plurality of the vent holes. More cooling air flows into the control box to carry out the heat quantity produced by the control circuit board, so that the temperature of the control circuit board is decreased, the control circuit board is ensured to work at a proper ambient temperature, and the reliability of the operation of the motor controller is improved. The encapsulating material is filled into the control box via the gel inlet to partially or totally cover the control circuit board. The structure is simple and is configured to effectively protect the electronic components on the control circuit board and to prevent the electronic components from being polluted or damaged. 
         [0020]    4) The two supporting plates lock the control box on the upper part of the supporting frame via screws, and contact area between the fins of the control box and the air outside is enlarged. As more heat quantity of the motor controller is carried out by the air, the heat dissipation performance of the motor controller is improved. 
         [0021]    5) Steps are arranged in the cavity on the upper plate and the lower plate. The control circuit board is disposed on top surfaces of the steps. A plurality of mounting columns is disposed on the base plate in the cavity. The control circuit board is fixed on top surfaces of the mounting columns via screws. The structure is simple, and the installation of the control circuit board is simple and convenient. 
         [0022]    6) A bottom part of each of the two supporting plates is bent to form a flange. A plurality of mounting holes is disposed on the flange. The motor controller is mounted on other loads via mounting holes of the flanges, thereby realizing simple structure and convenient and firm installation. 
         [0023]    7) The motor is disposed outside the air inlet of the volute. The rotating shaft of the motor is inserted into the inner cavity and connected to the wind wheel. The motor controller is disposed nearby the motor. The connection is simple and convenient, less lead wires are demanded, so that the production cost is lowered and the connection is not prone to failure. The motor controller comprises: the supporting frame, the control circuit board, and the control box. The control circuit board is disposed on the base plate in the cavity. The fins are disposed outside the cavity on the outer side surface of the base plate. Cooling ducts are formed between adjacent fins. When the motor works, the wind wheel rotates to suck the air from the mounting cavity of the load box into the air inlet so as to form an air flow, the fins of the motor controller are disposed in the air flow. Heat quantity produced in the operation of the motor controller is carried away by the air flow. Thus, the structure is simple, the heat dissipation performance is excellent, and the reliability of the operation of the motor controller is improved. 
         [0024]    8) The motor is disposed on the motor bracket. The base wall of the load box is provided with the mounting bracket. The motor bracket is disposed on the mounting bracket. The structure is simple and the installation is convenient and firm. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The invention is described hereinbelow with reference to the accompanying drawings, in which: 
           [0026]      FIG. 1  is a stereogram of a motor controller from one perspective in accordance with one embodiment of the invention; 
           [0027]      FIG. 2  is a stereogram of a motor controller from another perspective in accordance with one embodiment of the invention; 
           [0028]      FIG. 3  is an exploded view of a motor controller in accordance with one embodiment of the invention; 
           [0029]      FIG. 4  is a top view of a motor controller in accordance with one embodiment of the invention; 
           [0030]      FIG. 5  is a cross sectional view taken from line A-A of  FIG. 4 ; 
           [0031]      FIG. 6  is cross sectional view taken from line B-B of  FIG. 4 ; 
           [0032]      FIG. 7  is a stereogram of a fan system in accordance with one embodiment of the invention; and 
           [0033]      FIG. 8  is a partial assembly diagram of a fan system in accordance with one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0034]    For further illustrating the invention, experiments detailing a motor controller and a fan system comprising the same are described below. It should be noted that the following examples are intended to describe and not to limit the invention. 
       Example 1 
       [0035]    As shown in  FIGS. 1-6 , a motor controller comprises: a supporting frame  1 , a control circuit board  2 , and a control box  3 . The control box  3  is provided with a cavity  31 . The control circuit board  2  is disposed on a base plate  32  in the cavity  31 . A plurality of fins  33  is disposed outside the cavity  31  on an outer side surface of the base plate  32 . Cooling ducts  330  are formed between adjacent fins  33 . The control box  3  is fixed on the supporting frame  1 . 
         [0036]    The control box  3  comprises: the base plate  32 , and an upper plate  34  and a lower plate  35  extended from two ends of the base plate  32  to a same side. The upper plate  34 , the base plate  32 , and the lower plate  35  form the cavity  31 , side openings at two sides of the cavity  31 , and an upper opening  31  at a top of the cavity  31 . The supporting frame  1  comprises two supporting plates  11  and a connecting plate  12  connected to the two supporting plates  11 . The connecting plate  12  shields the upper opening  31  of the control box  3 . The supporting plates  11  shield the side openings at two sides of the control box  3  and match with two side faces of the base plate  32  of the control box  3 , respectively, for mounting the control box  3  on the supporting frame  1 . 
         [0037]    The supporting frame  1  is provided with a plurality of vent holes  13 . The supporting frame  1  is also provided with a gel inlet  14 . An encapsulating material is filled into the control box via the gel inlet  14  for partially or totally covering the control circuit board  2 . 
         [0038]    The two supporting plates  11  lock the control box  3  on an upper part of the supporting frame  1  via screws  4 . 
         [0039]    Steps  36  are arranged in the cavity  31  on the upper plate  34  and the lower plate  35 . The control circuit board  2  is disposed on top surfaces of the steps  36 . A plurality of mounting columns  5  is disposed on the base plate  32  in the cavity  31 . The control circuit board  2  is fixed on top surfaces of the mounting columns  5  via screws  4 . 
         [0040]    A plurality of wire bushings  6  is disposed on the lower plate  35  of the control box  3 . Lead wires of the control circuit board  2  are led out from the wire bushings  6 . A bottom part of each of the two supporting plates  11  is bent to form a flange  111 . A plurality of mounting holes  1110  is disposed on the flange  111 . 
         [0041]    The control box  3  is made of aluminum, and a surface of the supporting frame  1  is coated with white zinc. 
         [0042]    Working principle of the motor controller is as follows: the control circuit board  2  is disposed on the base plate  32  in the cavity  31  of the control box  3 . The connecting plate  12  shields the upper opening  31  of the control box  3 . The supporting plates  11  shield the side openings at two sides of the control box  3  and match with two side faces of the base plate  32  of the control box  3 , respectively, for mounting the control box  3  on the supporting frame  1 . Heat dissipation of the control box  3  is realized by arranging the fins  33  on the base plate  31  and by arranging the vent holes  13  on the supporting frame  1 . The structure is simple and convenient, and the motor controller has good heat dissipation performance and high efficiency and reliability. 
       Example 2 
       [0043]    As shown in  FIGS. 7-8 , a fan system comprises: a volute  7 , a wind wheel, a motor  8 , and a motor controller  9 . An inner cavity  71  is disposed in the volute  7 . An end face of the volute  7  is provided with an air inlet  72 . A side face of the volute  7  is provided with a first air outlet  73 . The motor  8  is disposed outside the air inlet  72  of the volute  7 . A rotating shaft  81  of the motor  8  is inserted into the inner cavity  71  and connected to the wind wheel. The motor controller  9  is disposed nearby the motor  8 . The motor controller  9  is in electric connection with the motor  8  and controls operation of the motor  8 . The motor controller  9  comprises: a supporting frame  1 , a control circuit board  2 , and a control box  3 . The control box  3  is provided with a cavity  31 . The control circuit board  2  is disposed on a base plate  32  in the cavity  31 . A plurality of fins is disposed outside the cavity  31  on an outer side surface of the base plate  32 . Cooling ducts  330  are formed between adjacent fins  33 . The control box  3  is fixed on the supporting frame  1 . 
         [0044]    The control box  3  comprises: the base plate  32 , and an upper plate  34  and a lower plate  35  extended from two ends of the base plate  32  to a same side. The upper plate  34 , the base plate  32 , and the lower plate  35  form the cavity  31 , side openings at two sides of the cavity  31 , and an upper opening  31  at a top of the cavity  31 . The supporting frame  1  comprises two supporting plates  11  and a connecting plate  12  connected to the two supporting plates  11 . The connecting plate  12  shields the upper opening  31  of the control box  3 . The supporting plates  11  shield the side openings at two sides of the control box  3  and match with two side faces of the base plate  32  of the control box  3 , respectively, for mounting the control box  3  on the supporting frame  1 . 
         [0045]    The volute  7 , the motor  8 , and the motor controller  9  are disposed in a mounting cavity of a load box  10 . A second air outlet  102  is disposed on a sidewall of the mounting cavity. The first air outlet  73  of the volute  7  communicates with the second air outlet  102  of the load box  10 . 
         [0046]    The motor  8  is disposed on a motor bracket  82 . A base wall of the load box  10  is provided with a mounting bracket  103 . The motor bracket  82  is disposed on the mounting bracket  103 . 
         [0047]    Principle of the above fan system is as follows: the motor  8  is disposed outside the air inlet  72  of the volute  7 . The rotating shaft  81  of the motor  8  is inserted into the inner cavity  71  and connected to the wind wheel. The motor controller  9  is disposed nearby the motor  8 . The fins are disposed outside the cavity on the outer side surface of the base plate  32 . The fins  33  are adapted to dissipate heat of the motor controller. Cooling ducts  330  are formed between adjacent fins  33 . When the motor works, the wind wheel rotates to suck the air from the mounting cavity of the load box into the air inlet so as to form an air flow, the fins of the motor controller are disposed in the air flow. Heat quantity produced in the operation of the motor controller is carried away by the air flow. Thus, the structure is simple, the heat dissipation performance is excellent, and the reliability of the operation of the motor controller is improved. 
         [0048]    While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.