Patent Publication Number: US-9890496-B2

Title: Impeller housing for an appliance

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to impeller housings for appliances, such as dryer appliances. 
     BACKGROUND OF THE INVENTION 
     Dryer appliances generally include a cabinet with a drum rotatably mounted therein. A motor can selectively rotate the drum during operation of the dryer appliance, e.g., to tumble articles located within a chamber defined by the drum. Dryer appliances also generally include a heater assembly that passes heated air through the chamber of the drum in order to dry moisture laden articles disposed within the chamber. 
     To circulate heated air, certain dryer appliances include an impeller positioned within a housing. During operation of the dryer appliance, the impeller urges a flow of heated air into the chamber of the drum. Such heated air absorbs moisture from articles disposed within the chamber. The impeller also urges moisture laden air out of the chamber through a vent. The vent can be connected to household ductwork that directs the moisture laden air outdoors. 
     Performance of a dryer appliance can be affected by the flow of heated air. For example, dryer appliance performance can be improved by generating a large volume of heated air. Conversely, dryer appliance performance can be negatively affected if the heating assembly generates a low volume of heated air. 
     To improve dryer performance, a size of the impeller can be increased. However, space with a dryer appliance is generally limited or constrained. Thus, increasing a size of the impeller can be difficult. To improve dryer performance, certain dryer appliances include a second motor configured to rotate the impeller. However, motors can be expensive, and adding the second motor to the dryer appliance can increase the cost of the dryer appliance. 
     Accordingly, a dryer appliance with features for improving air flow through the dryer appliance would be useful. In particular, a dryer appliance with features for improving air flow through the dryer appliance without requiring a relatively large impeller or adding a second motor to the dryer appliance would be useful. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present subject matter provides a housing for receiving an impeller. The housing includes a transition duct that extends between a volute of the housing and an exhaust exit of the housing. Cross-sections of the transition duct continuously vary from an inlet cross-section of the transition duct to an outlet cross-section of the transition duct along a length of the transition duct. A related dryer appliance is also provided. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In a first exemplary embodiment, a dryer appliance is provided. The dryer appliance includes a cabinet that defines a vent and an exhaust duct. A drum is rotatably mounted within the cabinet. The drum defines a chamber for receipt of articles for drying. The dryer appliance also includes a motor and an impeller in mechanical communication with the motor. The impeller is rotatable with the motor in order to urge a flow of air from the chamber from the drum to the vent of the cabinet. A housing is positioned within the cabinet. The housing has a transition duct that extends between a volute of the housing and an exhaust exit of the housing. The impeller is positioned within the housing at the volute of the housing. The exhaust duct extends between the exhaust exit of the housing and the vent of the cabinet. The transition duct has an inlet cross-section immediately downstream of the volute of the housing and an outlet cross-section at the exhaust exit of the housing. The inlet cross-section has a curvilinear trapezoidal shape. The outlet cross-section has a circular shape. The transition duct continuously varies from the inlet cross-section to the outlet cross-section along a length of the transition duct. 
     In a second exemplary embodiment, a housing for an impeller of a dryer appliance is provided. The housing includes a cylindrical portion configured for receiving the impeller. The cylindrical portion has a volute. A transition duct extends between the volute of the cylindrical portion and an exhaust exit. The transition duct has an inlet cross-section immediately downstream of the volute of the cylindrical portion and an outlet cross-section at the exhaust exit. The inlet cross-section has a curvilinear trapezoidal shape. The outlet cross-section has a circular shape. Cross-sections of the transition duct continuously vary from the inlet cross-section to the outlet cross-section along a length of the transition duct. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. 
         FIG. 1  provides a perspective view of a dryer appliance according to an exemplary embodiment of the present subject matter. 
         FIG. 2  provides a perspective view of the exemplary dryer appliance of  FIG. 1  with a portion of a cabinet of the exemplary dryer appliance removed to reveal certain internal components of the exemplary dryer appliance. 
         FIG. 3  provides a perspective view of an impeller assembly according to an exemplary embodiment of the present subject matter. 
         FIG. 4  provides a perspective view of a housing of the exemplary impeller assembly of  FIG. 3 . 
         FIG. 5  provides a rear, elevation view of the housing of the exemplary impeller assembly of  FIG. 3 . 
         FIG. 6  provides a section view of the housing of the exemplary impeller assembly of  FIG. 5  taken along the  6 - 6  line of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
     As used herein, the term “article” may refer to but need not be limited to fabrics, textiles, garments (or clothing), and linens. Furthermore, the term “load” or “laundry load” refers to the combination of articles that may be washed together in a washing machine or dried together in a laundry dryer (i.e., a clothes dryer) and may include a mixture of different or similar articles of different or similar types and kinds of fabrics, textiles, garments and linens within a particular laundering process. 
       FIGS. 1 and 2  illustrate a dryer appliance  10  according to an exemplary embodiment of the present subject matter. While described in the context of a specific embodiment of dryer appliance  10 , using the teachings disclosed herein it will be understood that dryer appliance  10  is provided by way of example only. Other dryer appliances having different appearances and different features may also be utilized with the present subject matter as well. For example, dryer appliance  10  illustrated in  FIGS. 1 and 2  is a gas dryer appliance with a combustion chamber  36 . In alternative exemplary embodiments, dryer appliance  10  may be an electric dryer appliance with electric heating elements replacing combustion chamber  36 . 
     Dryer appliance  10  includes a cabinet  12  having a front panel  14 , a rear panel  16 , a pair of side panels  18  and  20  spaced apart from each other by front and rear panels  14  and  16 , a bottom panel  22 , and a top cover  24 . Within cabinet  12  is a drum or container  26  mounted for rotation about a substantially horizontal axis. Drum  26  is generally cylindrical in shape and defines a chamber  27  for receipt of articles for drying. 
     Drum  26  also defines an opening  29  for permitting access to the chamber  27  of drum  26 . Opening  29  of drum  26 , e.g., permits loading and unloading of clothing articles and other fabrics from chamber  27  of drum  26 . A door  33  is rotatably mounted at opening  29  and selectively hinders access to chamber  27  of drum  26  through opening  29 . 
     Drum  26  includes a rear wall  25  rotatably supported within cabinet  12  by a suitable fixed bearing. Rear wall  25  can be fixed or can be rotatable. A motor  28  rotates the drum  26  about the horizontal axis through a pulley  30  and a belt  31 . Motor  28  is also in mechanical communication with a fan or air handler  42  such that motor  28  rotates an impeller  43 , e.g., a centrifugal impeller, of air handler  42 . Air handler  42  is configured for drawing air through chamber  27  of drum  26 , e.g., in order to dry articles located therein as discussed in greater detail below. In alternative exemplary embodiments, dryer appliance  10  may include an additional motor (not shown) for rotating impeller  43  of air handler  42  independently of drum  26 . 
     Drum  26  is configured to receive heated air that has been heated by a heater assembly  34 , e.g., in order to dry damp articles disposed within chamber  27  of drum  26 . Heater assembly  34  includes a combustion chamber  36 . As discussed above, during operation of dryer appliance  10 , motor  28  rotates drum  26  and impeller  43  of air handler  42  such that air handler  42  draws air through chamber  27  of drum  26  when motor  28  rotates impeller  43 . In particular, ambient air, shown with arrow A a , enters combustion chamber  36  via an inlet  38  due to air handler  42  urging such ambient air A a  into inlet  38 . Such ambient air A a  is heated within combustion chamber  36  and exits combustion chamber  36  as heated air, shown with arrow A h . Air handler  42  draws such heated air A h  through a back duct  40  to drum  26 . The heated air A h  enters drum  26  through a plurality of holes  32  defined in rear wall  25  of drum  26 . 
     Within chamber  27 , the heated air A h  can accumulates moisture, e.g., from damp articles disposed within chamber  27 . In turn, air handler  42  draws moisture laden air, shown as arrow A m , through a screen filter  44  which traps lint particles. Such moisture laden air A m  then enters a front duct  46  and is passed through air handler  42  to an exhaust duct  48 . From exhaust duct  48 , such moisture laden air A m  passes out of clothes dryer  10  through a vent  49  defined by cabinet  12 . 
     Front duct  46  and exhaust duct  48  form a conduit  47  that extends between and connects chamber  27  of drum  26  and vent  49 . Conduit  47  places chamber  27  of drum  26  and vent  49  in fluid communication in order to permit moisture laden air A m  to exit dryer appliance  10 . Air handler  42  is in fluid communication with conduit  47 , and impeller  43  of air handler  42  is positioned within conduit  47 . 
     A cycle selector knob  50  is mounted on a cabinet backsplash  52  and is in communication with a controller  54 . Signals generated in controller  54  operate motor  28  and heater assembly  34  in response to a position of selector knob  50 . Alternatively, a touch screen type interface may be provided. As used herein, “processing device” or “controller” may refer to one or more microprocessors or semiconductor devices and is not restricted necessarily to a single element. The processing device can be programmed to operate dryer appliance  10 . The processing device may include, or be associated with, one or memory elements such as e.g., electrically erasable, programmable read only memory (EEPROM). 
       FIG. 3  provides a perspective view of an impeller assembly  100  according to an exemplary embodiment of the present subject matter. Impeller assembly  100  may be used in any suitable dryer appliance. For example, impeller assembly  100  may be used in dryer appliance  10 , e.g., as air handler  42  ( FIG. 2 ). Thus, impeller assembly  100  may be positioned within cabinet  12 , e.g., at front duct  46 , such that impeller assembly  100  draws and receives moisture laden air A m  from chamber  27  of drum  26 . As discussed in greater detail below, impeller assembly  100  includes features for limiting a pressure reduction or drop for a flow of air F through impeller assembly  100 . Performance of dryer appliance  10  may be improved by limiting the pressure drop for the flow of air F through impeller assembly  100 , as will be understood by those skilled in the art. 
     As may be seen in  FIG. 3 , impeller assembly  100  includes an impeller  110 , a cover plate  120  and a housing  130 . Impeller  110  is positioned within housing  130 . Impeller  110  may be placed in mechanical communication with a motor, such as motor  28 , that selectively rotates impeller  110  about an axis of rotation  152  within housing  130 . For example, impeller  110  may be fixed to a shaft of motor  28  such that impeller  110  rotates about the axis of rotation  152  within housing  130  with motor  28 . 
     Cover plate  120  is mounted to housing  130 . Cover plate  120  defines an entrance  122  for receiving the flow of air F into housing  130 . Housing  130  also defines an exhaust exit  136  for directing the flow of air F out of housing  130 . As an example, during operation of impeller assembly  100 , impeller  110  may rotate on the axis of rotation  152  within housing  130  such that impeller  110  draws the flow of air F into housing  130  via entrance  122  of cover plate  120 . In addition, impeller  110  may urge the flow of air F through housing  130  to exhaust exit  136  of housing  130  during operation of impeller assembly  100 . In such a manner, impeller  110  may urge or draw the flow of air F through housing  130  during operation of impeller assembly  100 . 
       FIG. 4  provides a perspective view of housing  130 .  FIG. 5  provides a rear, elevation view of housing  130 .  FIG. 6  provides a section view of impeller assembly  100  taken along the  6 - 6  line of  FIG. 5 . As may be seen in  FIG. 4 , housing  130  includes a cylindrical portion  132  and a transition duct  140 . Cylindrical portion  132  defines a volute  134  of housing  130  that is sized and configured for receiving impeller  110 . Thus, impeller  110  may be positioned within cylindrical portion  132 , e.g., at volute  134  of cylindrical portion  132 . Transition duct  140  extends between volute  134  of cylindrical portion  132  and exhaust exit  136 , e.g., in an L-shape. Exhaust exit  136  defines an exit axis  154 . The flow of air F exits housing  130  at exhaust conduit  136  flowing along a direction that is parallel to exit axis  154 . As may be seen in  FIG. 4 , exit axis  154  may be substantially parallel to the axis of rotation  152 . The flow of air F may flow into housing  130  flowing along a direction that is parallel to the axis of rotation  152 . Within volute  134  of cylindrical portion  132 , the flow of air F may be urges radially outward from the axis of rotation  152 , e.g., along directions that are perpendicular to the axis of rotation  152 . Transition duct  140  may redirect or turn the flow of air F within housing  130 , e.g., such that the flow of air F enters and exits housing  130  along directions that are parallel to each other. 
     As discussed above, housing  130  may be positioned within cabinet  12  of dryer appliance  10 . As an example, housing  130  may be positioned within cabinet  12  at front duct  42 . Entrance  122  of cover plate  120  may be positioned for receiving moisture laden air A m  from front duct  42 . In addition, cover plate  120  ( FIG. 3 ) may be mounted to cylindrical portion  132  and positioned over volute  134  of cylindrical portion  132 . Entrance  122  of cover plate  120  may also be positioned for directing the flow of air F into volute  134  of cylindrical portion  132 . The flow of air F flows through housing  130  from volute  134  of cylindrical portion  132  to exhaust exit  136 . From exhaust exit  136 , the flow of air F exits housing  130 . In dryer appliance  10 , exhaust duct  48  may extend between and fluidly couple exhaust exit  136  of housing  130  and vent  49  of cabinet  12 . 
     Housing  130  may be constructed of or with any suitable material. For example, housing  130  may be constructed of or with a single continuous or integral piece of plastic. In particular, cylindrical portion  132  of housing  130  and transition duct  140  of housing  130  may be constructed of a single continuous or integral piece of plastic. Cover plate  120  may also be constructed of or with any suitable material. For example, cover plate  120  may be constructed of a metal, such as steel. 
     As discussed above, transition duct  140  extends between volute  134  of cylindrical portion  132  and exhaust exit  136 . Turning now to  FIG. 6 , transition duct  140  has an inlet cross-section  142 . Inlet cross-section  142  is positioned immediately downstream of volute  134  of cylindrical portion  132 . Thus, the flow of air F may enter transition duct  140  at inlet cross-section  142 . Turning back to  FIG. 5 , transition duct  140  also has an outlet cross-section  144 . Outlet cross-section  144  is positioned at or adjacent exhaust exit  136  of housing  130 . The flow of air F may exit transition duct  140  at outlet cross-section  144 . 
     As may be seen in  FIG. 6 , inlet cross-section  142  has a curvilinear trapezoidal shape. Inlet cross-section  142  is defined by at least at least three (or four) walls of transition duct  140 , and at least one of the three walls is curved or non-linear. In the exemplary embodiment shown in  FIG. 6 , inlet cross-section  142  is defined by a curved upper wall  146 , a linear bottom wall  148  and a linear sidewall  150  (or pair of linear sidewalls  150 ) of transition duct  140 . Curved upper wall  146  is positioned at a top of transition duct  140 , and linear bottom wall  148  is positioned below curved upper wall  146  at a bottom of transition duct  140 . Linear sidewall  150  extends, e.g., vertically between curved upper wall  146  and linear bottom wall  148 . In particular, linear sidewall  150  connects and/or couples curved upper wall  146  and linear bottom wall  148  together. Cover plate  120  may form the other side of inlet cross-section  142  opposite linear sidewall  150 . 
     As may be seen in  FIG. 5 , outlet cross-section  144  has a circular shape, e.g., having a diameter of about (e.g., within ten percent of) four inches. Thus, inlet cross-section  142  and outlet cross-section  144  have different shapes. Transition duct  140  is shaped to transition from inlet cross-section  142  and outlet cross-section  144  along a length L ( FIG. 4 ) of transition duct  140 . In particular, transition duct  140  continuously varies from inlet cross-section  142  to outlet cross-section  144  along the length L of transition duct  140 . Thus, cross-sections of transition duct  140  continuously taper or shift from inlet cross-section  142  to outlet cross-section  144  along the length of transition duct  140 , e.g., such that each cross-section of transition duct  140  along the length L of transition duct  140  is dissimilar to or different than an adjacent cross-section of transition duct  140 , such as an immediately upstream or downstream cross-section of transition duct  140 . As an example, an area or perimeter of each cross-section of transition duct  140  along the length L of transition duct  140  may be less than five percent or less than three percent different than the adjacent cross-section of transition duct  140  per each millimeter or centimeter of the length L of transition duct  140 . 
     By gradually or continuously shifting from inlet cross-section  142  to outlet cross-section  144  in an iterative or smooth manner along the length L of transition duct  140 , transition duct  140  redirects the flow of air F, e.g., to the exit axis  154 , without a significant or drastic pressure reduction within transition duct  140 . Thus, an efficiency of drier appliance  10  may be improved with impeller assembly  100 . In particular, the efficiency of drier appliance  10  may be improved without increasing the size of impeller  110  and/or increasing the speed of impeller  110 . 
     As discussed above, the flow of air F may be redirected ninety degrees within transition duct  140 . Turning back to  FIG. 4 , transition duct  140  defines an inner radius of curvature IR and an outer radius of curvature OR, e.g., between inlet cross-section  142  to outlet cross-section  144 . The inner radius of curvature IR may be any suitable radius. For example, the inner radius of curvature IR may be greater than two inches, greater than four inches, etc. The outer radius of curvature OR may also be any suitable radius. For example, the outer radius of curvature OR may be greater than four inches, greater than six inches, greater than eight inches, etc. The inner radius of curvature IR and outer radius of curvature OR may be defined by opposite sidewalls of transition duct  140 , e.g., as transition duct  140  turns ninety degrees between inlet cross-section  142  and outlet cross-section  144 . The inner radius of curvature IR and the outer radius of curvature OR may also assist with redirecting the flow of air F, e.g., to the exit axis  154 , without a significant or drastic pressure reduction within transition duct  140 , as discussed above. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.