Patent Publication Number: US-10758107-B2

Title: Pump and dishwasher comprising the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present disclosure claims the benefit of priority to Korean Application No. 10-2017-0030735, filed on Mar. 10, 2017, which is herein expressly incorporated by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pump and a dishwasher including the same, and more particularly, to a pump for heating and conveying washing water and a dishwasher including the same. 
     2. Description of the Related Art 
     A dishwasher is a household appliance that removes foreign matter remaining in a tableware by spraying washing water to the tableware. The dishwasher includes a tub for providing a washing space, a rack provided in the tub to accommodate the dishware, a spraying arm for spraying the washing water to the rack, a sump for storing the washing water, and a pump for supplying washing water stored in the sump to the spraying arm. 
     Meanwhile, the dishwasher washes the tableware by using heated washing water (hot water) or performs cleaning or sterilization of the tableware by supplying steam to the tableware. In a conventional dishwasher, generally, hot water is generated by heating the washing water stored in the sump through a heater provided inside the sump. In this case, since the heater must be exposed to the inside of the sump to contact the washing water, the water level inside the sump must be controlled so that the heater is not exposed to prevent overheating of the heater. In addition, since the heat can be transmitted only when the heater is in contact with the washing water, foreign matter adhered to the surface of the heater may decrease a heat exchange efficiency, and a corroded surface of the heater may deteriorate durability. 
     To overcome these disadvantages, recently, a dishwasher that installs a heater in a pump has been developed. In this case, the heater contacts a bottom surface of the pump to heat the bottom surface, and the heated bottom surface heats the washing water flowing in the pump. The above problems are overcome as the heater indirectly heats a small amount of washing water temporarily stored in the pump. However, based on a phenomena that the heater intensively heats up a part of the bottom surface or the washing water is collected on a specific part due to a bottom surface structure, lime or other foreign matter contained in the washing water sticks to and piled on the bottom surface of the pump. Accordingly, there is a problem that the heating of the washing water by the heater is not smooth. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above problems, and provides a pump for evenly heating a bottom surface of a pump by a heater and a dishwasher including the pump. 
     The present invention further provides a pump that prevent a heater from heating a portion of the bottom surface of the pump where the washing water is collected and a dishwasher including the pump. 
     In accordance with an aspect of the present invention, a pump includes: a housing having a cylindrical shape to contain water; an rotatable impeller to discharge the water in the housing to an external; a heater cover to form a bottom surface of the housing; a heater plate joined to a lower side of the heater cover; and a heater joined to a lower side of the heater plate to heat the heater plate. The heater is not in directly contact with the heater cover. 
     The heater plate includes: a plate base formed in a circular or circular segment shape; and a plate lip protruding upward from a circumference of the plate base. The heater cover includes: a cover base having a circular shape; a cover holder protruding upward from a circumference of the cover base to form a space in which a part of the heater is accommodated; and a cover rim formed in a circumference of the cover holder and coupled to the housing. The heater includes: a heater body having an arc shape to generate heat; and a terminal to supply power to the heater body. The plate lip is stacked between the cover holder and the heater body. 
     An external side surface of the heater body is spaced apart from an external side surface of the cover holder. 
     The plate base is joined to the cover base, and a side surface of the plate lip is joined to an interior side surface of the cover holder and an upper surface of the plate lip is joined to an upper surface of the cover holder. 
     An upper surface of the heater body is joined to an upper surface of the plate lip and an interior side surface of the heater body is joined to a side surface of the plate lip. 
     An external side surface of the cover holder is spaced apart from a side surface of the housing. 
     The pump further includes a heater shield disposed in a lower side of the plate base and the heater body. 
     In accordance with another aspect of the present invention, a dishwasher includes a tub which accommodates a dishware; a spraying arm which sprays washing water into the tub; a sump which stores the washing water; and a pump which supplies the washing water stored in the sump to the spraying arm, and the pump includes: a housing having a cylindrical shape to contain water; an rotatable impeller to discharge the water in the housing to an external; a heater cover to form a bottom surface of the housing; a heater plate joined to a lower side of the heater cover; and a heater joined to a lower side of the heater plate to heat the heater plate. The heater is not in directly contact with the heater cover. 
     A part of the heater is formed in an arc shape, the heater cover forms an accommodation space for accommodating a part of the heater plate and a portion of the arc shape of the heater. 
     An outer circumference of the portion of the arc shape of the heater is spaced apart from a portion of the heater cover forming the accommodation space. 
     The heater plate is stacked between the heater cover and the heater in the accommodation space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects, features and advantages of the present invention will be more apparent from the following detailed description in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a sectional view of a dishwasher according to an embodiment of the present invention; 
         FIG. 2  is an exploded perspective view of a pump according to an embodiment of the present invention; 
         FIG. 3  is an exploded perspective view of a heater assembly of a pump according to an embodiment of the present invention; and 
         FIG. 4  is a partial vertical cross-sectional view of a pump according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention are described with reference to the accompanying drawings in detail. The same reference numbers are used throughout the drawings to refer to the same or like parts. Detailed descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present invention. 
     Hereinafter, the present invention will be described with reference to the drawings for explaining a pump and a dishwasher including the same according to embodiments of the present invention. 
       FIG. 1  is a sectional view of a dishwasher according to an embodiment of the present invention. 
     A dishwasher  100  according to an embodiment of the present invention may include a cabinet  1  forming an outer appearance, a tub  11  provided inside the cabinet  1  to accommodate a dishware, a plurality of spraying arms  3  and  5  for spraying washing water into the tub  11 , a sump  13  for storing washing water, and a pump  8  for supplying the washing water stored in the sump  13  to the plurality of spraying arms  3  and  5 . 
     A plurality of racks  191  and  193  for storing dishware may be provided in the tub  11 . The plurality of racks  191  and  193  may include an upper rack  191  provided in the upper area of the tub  11  and a lower rack  193  provided in the lower area of the tub  11 . 
     The tub  11  may be opened and closed by a door  16  provided on one side of the cabinet. A user may take out the plurality of racks  191  and  193  from the tub  11  after opening the door  16 . 
     The plurality of spraying arms  3  and  5  may include an upper arm  3  for spraying washing water to the upper rack  191  and a lower arm  5  for spraying washing water to the lower rack  193 . The washing water sprayed from the plurality of spraying arms  3  and  5  may be collected into the sump  13 . 
     The sump  13  may be provided in a lower portion of the tub  11  to store wash water. A sump cover  15  may be disposed in an upper portion of the sump  13 . The sump cover  15  may be provided with a recovery hole  151  so that washing water in the tub  11  can pass through the recovery hole  151  and flow into the sump  13 . 
     The sump  13  may be connected to an external water source through a water supply channel  135 . The water supply channel  135  may be opened and closed by a water supply valve  136 . The washing water stored in the sump  13  may be discharged to the outside of the dishwasher  100  through a drainage path  137  and a drainage pump  139 . 
     The washing water stored in the sump  13  may be supplied to the plurality of spraying arms  3  and  5  through the pump  8  and a supply passage  7 . The supply passage  7  may include a connection passage  77  connected to the pump  8 , a first supply passage  71  connecting the connection passage  77  and the upper arm  3 , and a second supply passage  73  connecting the connection passage  77  and the lower arm  5 . 
     The first supply passage  71  and the second supply passage  73  may be branched from the connection passage  77 , and a switching valve  75  for controlling the opening and closing of the first supply passage  71  and the second supply passage  73  may be provided in a branch point of the first supply passage  71  and the second supply passage  73 . 
     The pump  8  may transmit the washing water stored in the sump  13  to the supply passage  7 . The pump  8  may heat the washing water transmitted to the supply passage  7 . The pump  8  may suck and heat the washing water stored in the sump  13  and supply the heated washing water to the plurality of spraying arms  3  and  5  through the supply passage  7 . The pump  8  will be described in detail with reference to  FIG. 2 . 
       FIG. 2  is an exploded perspective view of a pump according to an embodiment of the present invention. 
     The pump  8  according to an embodiment of the present invention may include a housing  82  fixed inside the cabinet  1 , a partition wall  84  dividing a space inside the housing  82  into upper and lower spaces and defining a first chamber C 1  and a second chamber C 2  in the housing  82 , a communication hole  86  formed in the partition wall  84  to communicate the first chamber C 1  and the second chamber C 2 , an inlet  841  connecting the sump  13  and the first chamber C 1 , an outlet  849  connecting the second chamber C 2  and the connection passage  77 , an impeller  85  provided inside the second chamber, and a heater assembly H provided at the lower end of the housing  82  to heat the washing water. 
     The housing  82  may be formed in a cylindrical shape having open top and bottom. A housing cover  823  may be coupled to the upper end of the housing  82 , and the heater assembly H may be coupled to the lower end. A housing projection  827  protruding in the radial direction may be formed on the lower circumferential surface of the housing  82 . The housing cover  823  may cover the upper portion of the housing  82 , and the housing cover  823  may be provided with a motor  87  for generating rotation to rotate the impeller  85 . 
     The impeller  85  may discharge the water in the housing  82  to the outside. The impeller  85  may be rotatably disposed in the first chamber C 1  of the housing  82 . The impeller  85  may rotate to transmit the washing water flowing from the first chamber C 1  to the second chamber C 2  through the communication hole  86  to the outlet  849 . The impeller  85  may be rotated by the motor  87 . 
     The heater assembly H may form the bottom surface of the housing  82  so that the pump  8  simultaneously provides a washing water heating function and a washing water circulation function. A detailed description of the heater assembly H will be given later with reference to  FIG. 3  and  FIG. 4 . 
       FIG. 3  is an exploded perspective view of a heater assembly of a pump according to an embodiment of the present invention, and  FIG. 4  is a partial vertical cross-sectional view of a pump according to an embodiment of the present invention. 
     The heater assembly H according to the embodiment of the present invention may include a heater cover  81  forming a bottom surface of the housing  82 , a heater plate  88  joined to the lower side of the heater cover  81 , a heater  83  connected to the lower side of the plate  88  to heat the heater plate  88 , a thermostat  816  for supplying power to the heater  83  and controlling the temperature of the heater  83 , a wire  817  for electrically connecting the heater  83  and the thermostat  816 , and a heater shield  815  for covering a part of the heater  83  from the lower side. 
     The heater cover  81  is coupled to the lower end of the housing  82  to form the bottom surface of the pump  8 . The washing water may flow on the upper side of the heater cover  81 . The heater plate  88  may be joined to the lower side of the heater cover  81 . The heater cover  81  may be heated by the heater plate  88  to heat the washing water. 
     The circumference of the heater cover  81  may be formed in a circular shape, and a plurality of upward and downward bends may be formed in a concentric position. The heater cover  81  may include a cover base  811  in the form of a disk, a cover holder  812  protruding upward from the circumference of the cover base  811 , and a cover rim  813  formed in the circumference of the cover holder  812  and coupled with the housing  82   
     The cover base  811  may be formed of a circular plate to form a central portion of the heater cover  81 . A plate base  881  of the heater plate  88 , which will be described later, may be joined to the lower side of the cover base  811 . The cover base  811  and the plate base  881  may be joined by brazing. 
     The cover holder  812  may be formed in a ring shape protruding upward. The cover holder  812  may form an accommodation space  812   a  in which a part of the heater plate  88  and a part of the heater  83  are accommodated. A plate lip  882  of the heater plate  88  and a heater body  831  of the heater  83 , which will be described later, may be accommodated in the accommodation space  812   a  of the cover holder  812 . The plate lip  882  may be joined to the lower side of the cover holder  812 . The cover holder  812  and the plate lip  882  may be joined by brazing. 
     The longitudinal section of the cover holder  812  in the radial direction from the center may be formed in an open curve whose lower side is opened. At least a part of the cover holder  812  may correspond to at least a part of the shape of the heater  83  accommodated in the accommodation space  812   a  of the cover holder  812 . The cover holder  812  may accommodate a part of the heater  83 , but may not be in directly contact with a part of the heater  83  accommodated in the accommodation space  812   a  of the cover holder  812 . The outer circumference of the cover holder  812  may be spaced apart from a part of the heater  83  accommodated in the accommodation space  812   a  of the cover holder  812 . 
     In the present embodiment, the cover holder  812  may be formed with three surfaces whose lower side is open. Referring to  FIG. 4 , the cover holder  812  may include a cover holder interior side surface  8123  which is bent obliquely upward from the cover base  811  to form an interior side surface of the cover holder  812 , a cover holder upper surface  8121  which is horizontally bent in the radial direction from the cover holder interior side surface  8123  to form an upper surface of the cover holder  812 , and a cover holder external side surface  8124  bent perpendicularly downward from the cover holder upper surface  8121  to form an outer side surface of the cover holder  812 . 
     The cover rim  813  may be formed in a rim shape. The cover rim  813  may be formed to surround the lower end of the housing  82 . The circumference edge of the cover rim  813  may protrude upward and may be coupled with the housing  82 . Since the cover rim  813  is not in contact with the heater plate  88  and the heater  83 , it is heated at a relatively low temperature. 
     In the present embodiment, the cover rim  813  may be formed in two surfaces, and the longitudinal section in the radial direction from the center may be formed in a “┘” shape. Referring to  FIG. 4 , the cover rim  813  may include a cover rim bottom surface  8132  which is bent horizontally in the radial direction from the cover holder external side surface  8124  to form the bottom surface of the cover rim  813 , and a cover rim side surface  8134  which is bent vertically upward from the cover rim bottom surface  8132  to form a side surface of the cover rim  813 . The upper end of the cover rim side surface  8134  may be curled in the center direction so as to surround the housing projection  827  so that the heater cover  81  is coupled to the housing  82 . 
     The heater plate  88  may be heated by the heater  83  to heat the heater cover  81 . The heater plate  88  may be a medium for transmitting the heat of the heater  83  to the heater cover  81 . Since the heater  83  may not generate heat evenly, the heater plate  88  may uniformly disperse the heat transmitted from the heater  83  to uniformly heat the heater cover  81 . 
     The circumference of the heater plate  88  may be formed in a circular or circular segment shape and have an edge protruding upward. The heater cover  81  may be joined to the upper side of the heater plate  88  by brazing, and the heater  83  may be joined to the lower side of the heater plate  88  by brazing. The heater plate  88  may be stacked between the heater cover  81  and the heater  83  in the accommodation space  812   a.    
     The heater plate  88  may include the plate base  881  whose circumference has a circular or circular segment shape, and the plate lip  882  protruding upward from the plate base  881 . 
     The plate base  881  may be formed in a disk or bow plate shape. On the upper side of the plate base  881 , the cover base  811  may be joined by brazing. The heater shield  815  may be disposed in the lower side of the plate base  881 . 
     The plate lip  882  may be formed in a ring or arc shape protruding upward. The plate lip  882  may be inserted into the accommodation space  812   a  of the cover holder  812 . The cover holder  812  may be joined to the upper side of the plate lip  882  by brazing, and the heater body  831  of the heater  83  described later may be joined to the lower side of the plate lip  882  by brazing. The plate lip  882  may be stacked between the cover holder  812  and the heater body  831 . The plate lip  882  may correspond to a part of the shape of the heater  83  accommodated in the accommodation space  812   a  of the cover holder  812 . 
     In the present embodiment, the plate lip  882  may be formed in two surfaces, and the longitudinal section in the radial direction from the center may be formed in a “┌” shape. Referring to  FIG. 4 , the plate lip  882  may include a plate lip side surface  8824  which is bent obliquely upward from the plate base  881  to form a side surface of the plate lip  882 , and a plate lip upper surface  8821  which is bent horizontally in the radial direction from the plate lip side surface  8824  to form an upper surface of the plate lip  882 . 
     The plate lip side surface  8824  which is a side surface of the plate lip  882  may be joined, by brazing, to the cover holder interior side surface  8123  which is an interior side surface of the cover holder  812 , and the plate lip upper surface  8821  which is an upper surface of the plate lip  882  may be joined, by brazing, to the cover holder upper surface  8121  which is an upper surface of the cover holder  812 . 
     The heater  83  may receive power from the thermostat  816  through the wire  817  to generate heat. The heater  83  may heat the heater plate  88 . Since the heater  83  is not directly in contact with the heater cover  81 , it may not directly heat the heater cover  81 . On the upper side of the heater  83 , the heater plate  88  may be joined by brazing. A part of the outer circumference of the heater  83  may be spaced apart from a portion of the heater cover  81  that forms the accommodation space  812   a.    
     The heater  83  may include the heater body  831  having an arc shape for generating heat, and a heater terminal  832  for supplying power to the heater body  831 . 
     The heater terminal  832  may receive power from the thermostat  816  through the wire  817  and transmit it to the heater body  831 . A plurality of heater terminals  832  may be provided at both ends of the heater body  831 . The plurality of heater terminals  832  may extend from both ends of the heater body  831  and be inclined downward. That is, the plurality of heater terminals  832  may protrude downward from a plane formed by the lower end of the heater body  831 . 
     The heater body  831  may be formed in an arc shape whose central angle is larger than 180 degrees. The heater body  831  may include a heating element that generates heat. The heater plate  88  may be joined, by brazing, to the inner and upper sides of the heater body  831 . The heater shield  815  may be disposed in the lower side of the heater body  831 . The heater body  831  may be inserted into the accommodation space  812   a  of the cover holder  812 , but may not be in directly contact with the cover holder  812 . The outer circumference of the heater body  831  may be spaced apart from the outer circumference of the cover holder  812 . 
     In the present embodiment, the heater body  831  has a rectangular longitudinal section in the radial direction from the center. Referring to  FIG. 4 , the heater body  831  may include a heater body upper surface  8311  which is formed horizontally to form an upper surface of the heater body  831 , a heater body external side surface  8314  which is formed vertically to form an external side surface of the heater body  831 , a heater body interior side surface  8313  which is formed to be inclined to form an interior side surface, and a heater body bottom surface  8312  which is formed horizontally to form a bottom surface of the heater body  831 . 
     The heater body upper surface  8311  which is an upper surface of the heater body  831  may be joined, by brazing, to the plate lip upper surface  8821  which is an upper surface of the plate lip  882 . The heater body interior side surface  8313  which is an interior side surface of the heater body  831  may be joined, by brazing, to the plate lip side surface  8824  which is a side surface of the plate lip  882 . 
     The heater body external side surface  8314  which is an external side surface of the heater body  831  may be spaced apart from the cover holder external side surface  8124  which is an external side surface of the cover holder  812 . In addition, the cover holder external side surface  8124  which is an external side surface of the cover holder  812  may be spaced apart from the housing  82 . Thus, since the cover holder external side surface  8124  is not in contact with the heater plate  88  and the heater  83 , it is heated at a relatively low temperature. 
     Hereinafter, the operation of the pump and the dishwasher including the pump according to the present invention will be described. 
     When the motor  87  operates to rotate the impeller  85 , the washing water stored in the sump  13  may flow into the first chamber C 1  inside the housing  82  of the pump  8  through the inlet  841 . 
     In addition, when the thermostat  816  operates to supply power to the heater terminal  832  of the heater  83  via the wire  817 , the heater body  831  may generate heat. The heat generated in the heater body  831  may be transmitted to the plate lip upper surface  8821  and plate lip side surface  8824  of the plate lip  882  in contact with the heater body  831 . The heat transmitted to the plate lip upper surface  8821  and the plate lip side surface  8824  may be transmitted to the plate base  881  so that the heater plate  88  is evenly heated. The heat of the heater plate  88  may be transmitted to the cover base  811  in contact with the heater plate  88 , and the cover holder interior side surface  8123  and cover holder upper surface  8121  of the cover holder  812  so that the cover base  811 , and the cover holder interior side surface  8123  and cover holder upper surface  8121  of the cover holder  812  are evenly heated. Thus, the heater cover  81  may heat the washing water accommodated in the first chamber C 1  inside the housing  82  of the pump  8 . 
     The washing water heated inside the first chamber C 1  may flow into the second chamber C 2  through the communication hole  86  by the rotation of the impeller  85  and then flow into the connection passage  77  through the outlet  849 . The heated washing water flowing into the connection passage  77  may be sprayed from the upper arm  3  and/or the lower arm  5  through the first supply passage  71  and/or the second supply passage  73  depending on the operation of the switching valve  75 . The washing water sprayed from the upper arm  3  and/or the lower arm  5  may be supplied to the tableware housed in the upper rack  191  and/or lower rack  193  to clean the tableware, and may be returned to the sump  13 . 
     Meanwhile, since the cover holder external side surface  8124  of the cover holder  812  and the cover rim  813  are not in contact with the heater plate  88  and the heater  83 , they are heated at a relatively low temperature. Thus, the washing water accommodated in the space  813   a  surrounded by the cover holder external side surface  8124 , the cover rim bottom surface  8132 , and the housing  82  may maintain a relatively low temperature so that the lime of washing water or other foreign matter does not stick to and piled in the space  813   a.    
     According to the pump of the present invention and the dishwasher including the same, one or more of the following effects can be obtained. 
     First, the heater does not directly heat the heater cover forming the bottom surface of the pump but heats the heater plate, so that the heated heater plate uniformly heats the heater cover and concentration of heat generation does not occur in the heater cover. 
     Second, since the portion where the washing water is collected in the heater cover is not heated, the lime in the washing water or other foreign matter does not stick to the heater cover. 
     Third, the heater, the heater cover, and the heater plate can be firmly coupled. 
     Hereinabove, although the present invention has been described with reference to embodiments and the accompanying drawings, the present invention is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention claimed in the following claims.