Patent Publication Number: US-10774841-B2

Title: Fan motor assembly and vacuum cleaner having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. patent application Ser. No. 14/578,931, filed on Dec. 22, 2014, which claims the priority benefit of the Korean Patent Application No. 10-2014-0000463, filed on Jan. 2, 2014, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field 
     The following description relates to a fan motor assembly capable of improving efficiency of a motor by minimizing loss in flow, and a vacuum cleaner having the same. 
     2. Description of the Related Art 
     In general, a vacuum cleaner is an apparatus capable of performing cleaning, after suctioning a foreign substance such as dust together with air by generating a suction force, by removing the foreign substance by use of a dust collecting apparatus provided inside a body of the vacuum cleaner. 
     The dust collecting apparatus configured to filter dust from the suctioned air is installed inside the body of the vacuum cleaner, and a fan motor assembly configured to generate a suction force to suction air is mounted at a rear of the dust collecting apparatus. 
     The fan motor assembly, by rotating a motor having a rotor configured to rotate with respect to a stator through an electromagnetic force when an external power is applied and by rotating an impeller installed at an upper portion of a shaft of the motor by a rotational force of the motor, is configured to suction outside air. 
     The fan motor assembly as such is configured to suction air to the inside of the vacuum cleaner at a fast flow speed through the impeller, and the suctioned air is guided to the inside by reducing the flow speed of the suctioned air by a guide fan. 
     Meanwhile, with respect to the guide fan formed by an injection process, an upper collar of a diffuser may have a deformity, such as a burr generated by an injection pressure, and flow loss may occur. 
     In addition, the flow loss may increase a variation in the performance of the motor and decrease the efficiency of the motor. 
     SUMMARY 
     Therefore, it is an aspect of the present disclosure to provide a fan motor assembly capable of improving efficiency of a motor by minimizing flow loss, and a vacuum cleaner having the same. 
     It is an aspect of the present disclosure to provide a fan motor assembly capable of improving the quality thereof by improving efficiency of a motor, and a vacuum cleaner having the same. 
     Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. 
     In accordance with an aspect of the present disclosure, a fan motor assembly includes a case, a motor, an impeller, and a guide fan. The motor may be installed inside the case to form a suction force. The impeller may be rotatably installed at a shaft of the motor. The guide fan may be configured to guide air that is suctioned by the motor. The guide fan may include a first guide unit configured to increase pressure of the suctioned air, and a second guide unit provided at an upper side of the first guide unit to be in contact with the case. 
     The first guide unit may include a panel member having the shape of a circle, and a diffuser provided at the panel member. 
     The second guide unit may include a sealing member provided to prevent air flow from being generated between the second guide unit and the case. 
     The second guide unit may include a ring member having the shape of a ring, and a return vane formed to guide air having the pressure thereof increased by the first guide toward the motor. 
     The sealing member may include at least one rib protruding at an upper surface of the ring member. 
     The case may include a first case provided at an upper portion of the motor, and a second case provided at a lower portion of the motor, wherein the sealing member may be correspondingly formed as to make contact with a circumference of an upper surface of an inner side of the first case. 
     The panel member may be provided with a coupling groove correspondingly formed to be coupled to the second guide unit. 
     In accordance with an aspect of the present disclosure, a vacuum cleaner includes a body, and a fan motor assembly provided inside the body and configured to generate a suction force to suction outside air and dust, wherein the fan motor assembly may include a case, a motor, an impeller, and a guide fan. The motor may be installed inside the case to form a suction force. The impeller may be rotatably installed at a shaft of the motor. The guide fan may be configured to guide air that is suctioned by the motor. The guide fan may include a diffuser configured to increase the pressure of suctioned air, and a sealing member provided to make a line contact with the case at an upper side of the diffuser. 
     At least one rib may protrude from an upper surface of the sealing member. 
     The sealing member may include a return vane to guide air having the pressure thereof increased by the diffuser toward the motor. 
     The sealing member may include a ring member having the shape of a ring, and further include a first rib formed at one side of an upper surface of the ring member and a second rib protruding from the upper surface of the ring member while spaced apart from the first rib. 
     A coupling groove may be formed at an upper surface of the diffuser such that the return vane is coupled to the coupling groove. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a drawing schematically showing a vacuum cleaner in accordance with an embodiment of the present disclosure. 
         FIG. 2  is a drawing schematically showing a fan motor assembly installed at the vacuum cleaner in accordance with an embodiment of the present disclosure. 
         FIG. 3  is an exploded perspective view schematically showing the fan motor assembly in accordance with an embodiment of the present disclosure. 
         FIG. 4  is a perspective view schematically showing a guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure. 
         FIG. 5  is a cross-sectional view schematically showing the guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure. 
         FIG. 6  is an enlarged view of a portion ‘A’ of  FIG. 5 . 
         FIG. 7  is a graph showing vacuum level according to flow change when the guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure is applied. 
         FIG. 8  is a graph showing efficiencies according to flow change when the guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure is applied. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
       FIG. 1  is a drawing schematically showing a vacuum cleaner in accordance with an embodiment of the present disclosure,  FIG. 2  is a drawing schematically showing a fan motor assembly installed at the vacuum cleaner in accordance with an embodiment of the present disclosure, and  FIG. 3  is an exploded perspective view schematically showing the fan motor assembly in accordance with an embodiment of the present disclosure. 
     As illustrated on  FIG. 1  to  FIG. 3 , a vacuum cleaner  1  includes a suction unit  11  provided to suction a foreign substance on a surface, such as a floor, to be cleaned, by use of a suction force, and a body  10  provided to collect the foreign substance that is taken in at the suction unit  11 . 
     A connecting hose  13  and a connecting pipe  12  are connected between the body  10  and the suction unit  11  so that the suction force generated from the body  10  is delivered to the suction unit  11 , and a handle  12   a  for a user may be provided between the connecting hose  13  and the connecting pipe  12 . 
     The connecting hose  13  may be formed in the shape of a wrinkled pipe having flexibility, with one end thereof connected to the body  10  while the other end thereof is connected to the handle  12   a , so that the suction unit  11  may be provided to freely move within a predetermined radius while having the body  10  as a center. The connecting pipe  12  is formed to have a predetermined length, with one end thereof connected to the suction unit  11  while the other end thereof is connected to the handle  12   a , so that a user may be able to clean a foreign substance on a floor by moving the suction unit  11  while grabbing the handle  12   a.    
     Driving wheels  14  symmetrically disposed at each sides of a lower surface of the body  10  may be provided. The driving wheels  14  are provided in a way that a user may be able to smoothly move the body  10 . 
     The connecting hose  13  is connected to a front of the body  10  so that the suction air may be delivered, and an exhaust port  10   a  may be formed at a rear of the body  10  so that the air from which a foreign substance is filtered by use of an inside dust connecting unit  20  may be exhausted outside the body  10 . 
     The dust connecting unit  20 , and a fan motor assembly  30  provided to generate a suction force may be provided inside the body  10 . 
     The fan motor assembly  30  includes a motor  32  installed inside a case  31  and provided to generate a suction force, an impeller  33  configured to rotate while installed on a shaft of the motor  32 , and a guide fan  40  configured to guide the air that is suctioned by the motor  32 . 
     The fan motor assembly  30  may be installed in a way that a rotational shaft is positioned vertically inside the body  10 . 
     Meanwhile, an exhaust filter  15  configured to filter a foreign substance that is not filtered at the dust collecting unit  20  may be installed at a lower portion of the fan motor assembly  30 . 
     In addition, a suction side  34  of the fan motor assembly  30  is connected to an exhaust side of the dust collecting unit  20  by a connecting pipe  21  to generate a suction force at the dust collecting unit  20 . 
     The impeller  33  applied to the present disclosure is formed with a centrifugal fan configured to suction air toward an axis direction of the centrifugal fan and exhaust the suctioned air in a radial direction, and the air that is exhausted from the impeller  33  is exhausted to an outer side of the motor  32  after cooling the motor  32 . 
     The case  31  includes a first case  31   a  provided at an upper portion of the motor  32 , and a second case  31   b  provided at a lower portion of the motor  32  while coupled at a lower side of the first case  31   a.    
     The motor  32  is provided with a rotor (not shown) and a stator (not shown), and the rotor is rotated in a case when a current is applied, while the rotation of the rotor is delivered to a motor shaft (not shown) to rotate the motor  32 . 
     The rotation of the motor  32  is delivered to the impeller  33  that is fastened at an upper portion of the motor shaft. 
     The rotational motion of the impeller  33  is configured to provide a centrifugal force to the surroundings of the impeller  33 , and by use of the centrifugal force, while air at the center of the impeller  33  is exhausted to an edge, or an outer side, of the impeller  33 , the outside air of the suction side  34  may be taken in. 
     The impeller  33  is composed of an upper panel  33   a  and a lower panel  33   b  that are spaced apart from each other by a predetermined space while having the motor shaft as a concentric axis, and blades  33   c  are provided between the upper panel  33   a  and the lower panel  33   b . The blades  33   c  are disposed between the upper panel  33   a  and the lower panel  33   b  in a radial direction while having a predetermined distance with respect to each other, and each blade  33   c  is formed in the shape of a curve having a predetermined curvature. 
     Meanwhile, an inlet path  33   d  of the air that is to be introduced by the rotational motion of the impeller  33  may be formed at a central portion of the upper panel  33   a.    
     An example of the blades  33   c  of the impeller  33  that is applied to the present disclosure is illustrated in a way that the blades  33   c  are provided with a blade pattern that is spread in the radial shape of a spiral from a rotational center of the lower panel  33   b  toward an outer side direction, but the present disclosure is not limited hereto. The number and the curvature of the blades may be changed and formed in various ways as appropriate. 
     The guide fan  40  provided to guide the air that is taken in by the impeller  33  is arranged at an outer side of the impeller  33  while spaced apart from the impeller  33  by a predetermined distance, so that the impeller  33  may be rotated. 
     The guide fan  40  may include a first guide unit  41  configured to increase the pressure of suctioned air, and a second guide unit  42  provided at an upper side of the first guide unit  41 . 
       FIG. 4  is a perspective view schematically showing the guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure,  FIG. 5  is a cross-sectional view schematically showing the guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure, and  FIG. 6  is an enlarged view of a portion ‘A’ of  FIG. 5 . 
     As illustrated on  FIG. 4  to  FIG. 6 , the guide fan  40  of the fan motor assembly  30  includes the first guide unit  41  and the second guide unit  42  provided at an upper side of the first guide unit  41 . 
     The case  31  may include a first case  31   a  provided at an upper portion of the motor  32 , and a second case  31   b  provided at a lower portion of the motor  32  at a lower side of the first case  31   a.    
     The first guide unit  41  may include a panel member  45  having the shape of a circle, and a diffuser  46  provided at a lower side of the panel member  45 . 
     The diffuser  46  is provided to guide the air, which is suctioned through the suction side  34  at a fast speed by the rotation of the impeller  33 , toward the motor  32 . 
     The second guide unit  42  includes a ring member  43  having the shape of a ring, and a return vane  44  formed to guide the air provided with the pressure that is increased by the diffuser  46  of the first guide unit  41  toward the motor  32 . 
     In addition, the second guide unit  42  includes a sealing member  50  configured to make a line contact with respect to the case  31  to prevent an air flow from occurring in between the second guide unit  42  and the case  31 . 
     The sealing member  50  may include ribs  51  and  52  protruding from an upper surface of the ring member  43 . The ribs  51  and  52  may be formed in a way to make contact with a circumference of an upper side of an inner side surface of the first case  31   a  forming an upper portion of the case  31 . 
     The ribs  51  and  52  may include the first rib  51  formed around a circumference of an inner side of the ring member  43 , and the second rib  52  formed around a circumference of an outer side of the ring member  43 . 
     An example of the ribs  51  and  52  of the present disclosure is illustrated in a way that the ribs  51  and  52  are disposed at an inner side portion and an outer side portion of an upper surface of the ring member  42 , respectively, but the present disclosure is not limited hereto. For example, the number of the ribs may be formed in a variable manner according to the size of the ring member and the shape of the case. 
     The first guide unit  41  is coupled to the second guide unit  42  to be separated through coupling grooves  47  that are formed in a recessed manner on an upper surface of the panel member  45  of the first guide unit  41 . 
     Thus, when an external power is supplied to the motor  32 , a rotational force is delivered to the impeller  33  by the rotational motion of the motor  32 , and the impeller  33  suctions outside air at the surroundings of the suction side  34  while the impeller  33  is rotated, and then the air is suctioned through a centrifugal force of the impeller  33  and is exhausted toward an edge of the impeller  33 . The air being exhausted from the impeller  33  is guided toward the motor  32  through the diffuser  46  of the first guide unit  41 . 
     At this time, the sealing member  50  of the second guide unit  42  may be able to prevent flow loss of air by making a line contact with an inner side of the first case  31 . 
       FIG. 7  is a graph showing vacuum level according to flow change when the guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure is applied, and  FIG. 8  is a graph showing efficiencies according to flow change when the guide fan of the fan motor assembly in accordance with an embodiment of the present disclosure is applied. 
     According to the result of a simulation test on the vacuum level and the efficiencies with respect to the structure (A) to which the guide fan  40  of the fan motor assembly  30  in accordance with the an embodiment of the present disclosure is applied, and the structure (B) to which the guide fan  40  not provided with the sealing member  50  is applied, the structure (A) applied with the guide fan  40  of the present disclosure is confirmed to be provided with higher vacuum level and the efficiency when compared to the structure (B). 
     As is apparent from the above, the efficiency of a motor can be improved by minimizing air flow loss. 
     In addition, the quality of a vacuum cleaner can be improved by improving the efficiency of a motor. 
     Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.