Patent Publication Number: US-2023135406-A1

Title: Tableware Washing Apparatus and Filtering Device Thereof

Description:
CROSS REFERENCE 
     The present disclosure is a continuation application of International (PCT) Patent Application No. PCT/CN2020/115686, filed on Sep. 16, 2020, the entire contents of which are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the field of kitchen appliances, and in particular to a tableware washing apparatus and a filtering device. 
     BACKGROUND 
     In recent years, more and more consumers choose to use tableware washing apparatus. A filtration system is one of the core systems of a tableware washing apparatus, and the filtration system may ensure the filtering effect while saving energy. 
     In the related art, two means are adopted to improve the filtering effect of the filtration system: increasing the filtering area, and dividing a filtering screen into a coarse filtering screen and a fine filtering screen. Such means may be prone to clogging the filtering screen, resulting in unclean dishes. Therefore, the filtering effect of the filtration system may still not be guaranteed through the above means. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure provides a filtration device and a tableware washing apparatus having a filtration device. 
     A first aspect of the present disclosure provides a filtering device of a tableware washing apparatus, including: a rotary filter, including a columnar filtering screen configured to filter to water from a washing process of the tableware washing apparatus; wherein a diameter of an external circle defined by each mesh of the columnar filtering screen is between 0.2 to 0.5 mm; and a drive assembly, connected to the rotary filter and configured to drive the columnar filtering screen to rotate relative to contents within the columnar filtering screen at a relative speed of 100 to 1000 r/min, for separating at least a portion of residue on the columnar filtering screen from the columnar filtering screen. 
     A second aspect of the present disclosure provides a tableware washing apparatus, including: an inner liner; a spray arm, received in the inner liner; and the filtering device as above, received in the inner liner and communicated with the spray arm. 
     The present disclosure may improve the filtration performance and filtration effect of the filtering device by driving at least a portion of the rotary filter with a drive assembly to rotate the columnar filtering screen relative to the contents of the columnar filtering screen, and by setting the diameter of the outer circle defined by the mesh of the columnar filtering screen to collect the residue at the bottom of the columnar filtering screen and reduce the possibility of blocking the flow of water caused by the residue gathering on the filtering screen in the direction of the flow of to-be-filtered water. In addition, the water volume of the tableware washing apparatus may be increased when the water filtered by the filtering device is pumped to the inner liner, thereby reducing the washing time or the water used for a single washing, and may save energy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following is a brief description of the accompanying drawings to be used in the description of the embodiments. It is obvious that the accompanying drawings in the following description are only some of the embodiments of the present disclosure, and other accompanying drawings may be obtained on the basis of these drawings for those skilled in the art without creative labor. 
         FIG.  1    is a perspective structural schematic view of a filtering device according to an embodiment of the present disclosure. 
         FIG.  2    is an exploded schematic view of the filtering device in  FIG.  1   . 
         FIG.  3    is a perspective schematic view of a partial structure of the filtering device in  FIG.  1    along a viewing angle direction. 
         FIG.  4    is a plan schematic view of the partial structure of the filtering device in  FIG.  3    along a viewing angle direction. 
         FIG.  5    is a perspective schematic view of the partial structure of the filtering device in  FIG.  3    along another viewing angle direction. 
         FIG.  6    is a plan schematic view of the partial structure of the filtering device in  FIG.  3    along another viewing angle direction. 
         FIG.  7    is an enlarged schematic view of area A circumscribed in  FIG.  6   . 
         FIG.  8    is a cross-sectional schematic view of the filtering device along B-B in  FIG.  6   . 
         FIG.  9    is a perspective schematic view of the partial structure of the filtering device in  FIG.  3    along another viewing angle direction. 
         FIG.  10    is an enlarged schematic view of area C circumscribed in  FIG.  9   . 
         FIG.  11    is a cross-sectional schematic view of the filtering device along D-D in  FIG.  6   . 
         FIG.  12    is a cross-sectional schematic view of a partial structure of a filtering device according to an embodiment of the present disclosure. 
         FIG.  13    is a cross-sectional schematic view of a partial structure of a filtering device according to an embodiment of the present disclosure. 
         FIG.  14    is an enlarged schematic view of area E circumscribed in  FIG.  13   . 
         FIG.  15    is a cross-sectional structural schematic view of a filtering device according to an embodiment of the present disclosure. 
         FIG.  16    is a perspective schematic view of a partial structure of a filtering device according to an embodiment of the present disclosure. 
         FIG.  17    is an exploded schematic view of the partial structure of the filtering device in  FIG.  16   . 
         FIG.  18    is a plan schematic view of a filtering device according to an embodiment of the present disclosure. 
         FIG.  19    is a cross-sectional schematic view of the filtering device along F-F in  FIG.  18    according to an embodiment of the present disclosure. 
         FIG.  20    is a perspective structural schematic view of a cleaning element according to an embodiment of the present disclosure. 
         FIG.  21    is a perspective schematic view of a partial structure of a filtering device according to another embodiment of the present disclosure. 
         FIG.  22    is a cross-sectional schematic view of a filtering device according to another embodiment of the present disclosure. 
         FIG.  23    is a perspective structural schematic view of a pulsator in  FIG.  22   . 
         FIG.  24    is an exploded schematic view of a filtering device according to another embodiment of the present disclosure. 
         FIG.  25    is a cross-sectional schematic view of the filtering device along F-F in  FIG.  18    according to another embodiment of the present disclosure. 
         FIG.  26    is a perspective structural schematic view of a rotary filter in  FIG.  24    along a viewing angle direction. 
         FIG.  27    is a perspective structural schematic view of a rotary filter in  FIG.  24    along another viewing angle direction. 
         FIG.  28    is a schematic view of a relationship between residue and water flow direction at a first moment using the filtering device in  FIG.  24   . 
         FIG.  29    is a schematic view of a relationship between residue and water flow direction at a second moment using the filtering device in  FIG.  24   . 
         FIG.  30    is a schematic view of a relationship between residue and water flow direction at a third moment using the filtering device in  FIG.  24   . 
         FIG.  31    is a schematic view of a relationship between residue and water flow direction at a fourth moment using the filtering device in  FIG.  24   . 
         FIG.  32    is a cooperation relationship schematic view between a drive accommodating portion and a drive assembly according to an embodiment of the present disclosure. 
         FIG.  33    is a perspective structural schematic view of a drive accommodating portion according to an embodiment of the present disclosure. 
         FIG.  34    is a plan schematic view of a filtering device according to another embodiment of the present disclosure. 
         FIG.  35    is a cross-sectional schematic view of the filtering device along G-G in  FIG.  34    according to an embodiment of the present disclosure. 
         FIG.  36    is a perspective structural schematic view of a filtering device according to further another embodiment of the present disclosure along a viewing angle direction. 
         FIG.  37    is a perspective structural schematic view of the filtering device in  FIG.  36    along another viewing angle direction. 
         FIG.  38    is a perspective structural schematic view of a filtering device according to further another embodiment of the present disclosure. 
         FIG.  39    is a plan schematic view of a filtering device according to further another embodiment of the present disclosure. 
         FIG.  40    is a cross-sectional schematic view of the filtering device along H-H in  FIG.  39   . 
         FIG.  41    is a cooperation relationship schematic view between a water wheel and a cleaning element according to an embodiment of the present disclosure. 
         FIG.  42    is a schematic view of a partial structure of a tableware washing apparatus according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following will be a clear and complete description of the technical solutions in the embodiments of the present disclosure in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, and not all of them. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present disclosure. 
     The terms “first” and “second” in the present disclosure are intended for descriptive purposes only, and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the present disclosure, “plurality” means at least two, such as two, three, etc., unless otherwise expressly and specifically limited. In addition, the terms “including” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus including a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units that are not listed, or optionally further includes other steps or units that are inherent to the process, method, product, or apparatus. The term “and/or” is simply a description of the associated relationship of associated objects, indicating that three relationships may exist, for example, A and/or B, which may mean: A alone, both A and B, and B alone. In addition, the character “/” in this specification generally indicates that the associated objects before and after “/” is in an “or” relationship. 
     As shown in  FIGS.  1 - 2    and  FIG.  32   , embodiments of the present disclosure provide a filtering device  10  of a tableware washing apparatus. The filtering device  10  includes a water cup assembly  100 , a plane filter  200  arranged on the water cup assembly  100 , a rotary filter  300  at least partially inserted in the water cup assembly  100 , and a drive assembly  400  connected to the rotary filter  300 . Both the plane filter  200  and the rotary filter  300  are configured to filter water from a washing process of the tableware washing apparatus. The rotary filter  300  includes a columnar filtering screen  330 . Therefore, the water can either be filtered by the plane filter  200  and out of the water cup assembly  100 , or enter the columnar filtering screen  330  through an opening on the plane filter  200 , filtered by the columnar filtering screen  330 , and out of the water cup assembly  100 . The drive assembly  400  is configured to drive/cause the columnar filtering screen  330  to rotate at a relative speed of 100 to 1000 r/min relative to contents in the columnar filtering screen  330  (components received in an internal space enclosed by the columnar filtering screen  330 ), for separating at least a portion of residue on the columnar filtering screen from the columnar filtering screen  330 . In some embodiments, the drive assembly  400  may cause the columnar filtering screen  330  to rotate relative to the contents in the columnar filtering screen  330  at a relative speed of 150 to 700 r/min. The columnar filtering screen  330  rotating relative to the contents in the columnar filtering screen  330  herein means that the columnar filtering screen  330  rotates by itself driven by the drive assembly  400 , or the contents in the columnar filtering screen  330  is rotatable driven by the drive assembly  400 . 
     In some embodiments, the mesh count of meshes of the columnar filtering screen  330  is about 50 to 70 mesh. Specifically, the diameter of an external circle defined by each mesh of the columnar filtering screen  330  is about 0.2 to 0.5 mm, and the mesh spacing ranges from about 0.4 to 0.6 mm. In some embodiments, the diameter of the external circle defined by the mesh of the columnar filtering screen  330  is about 0.2 to 0.4 mm. In some embodiments, the diameter of the external circle defined by the mesh of the columnar filtering screen  330  may be 0.3 to 0.4 mm, and the mesh spacing may range from 0.6 to 1.0 mm. It can be understood that the mesh spacing herein may refer to a spacing between each adjacent meshes. 
     Conventionally, the filtering device  10  of the tableware washing apparatus may filter residues with a minimum particle size of about 0.3 mm. In the related art, a combination of coarse filtration and fine filtration is usually adopted for filtering, for example, a mesh aperture of 0.8 mm may be applied for coarse filtration, followed by a mesh aperture of 0.3 mm for fine filtration to improve the filtering effect. However, in the filtering process, the problem of mesh clogging still easily occurs, which causes a poor filtering effect. 
     To improve the filtering effect, in some embodiments of the present disclosure, the plane filter  200  and the rotary filter  300  are adopted to filter the water, and at least a portion of the rotary filter  300  is driven by the drive assembly  400  to rotate the columnar filtering screen  330  relative to the contents inside the columnar filtering screen  330  at a relative speed of 100 to 1000 r/min. The diameter of the external circle defined by the mesh of the columnar filtering screen  330  (hereinafter referred to as the “mesh aperture”) is about 0.2 to 0.5 mm. 
     It is known from the related art that when the mesh aperture of the filtering screen is larger, more residue will leach out of the filtering screen, and therefore more residue may still be present in the filtered water. Therefore, in order to improve the filtering effect, the mesh aperture of the filtering screen is usually designed to be small. However, if the mesh aperture is too small, it is difficult to form an aggregation of the residue and the residue tends to block the mesh, causing trapped air. In addition, if the rotation speed of the filtering screen is too small when rotating the contents inside the columnar filtering screen  330  relative to the columnar filtering screen  330 , water flow may be subjected to resistance, causing clogging. Therefore, a greater rotation speed of the filtering screen may be required when the mesh aperture is small, to mitigate the problem of difficult aggregation of residue and easy clogging. However, when the rotation speed of the filtering screen is too large, the residue tends to seep out of the filtering screen, resulting in poor filtering effect. 
     Therefore, in some embodiments of the present disclosure, the columnar filtering screen  330  is configured to rotate at a relative speed of 100 to 1000 r/min relative to the contents in the columnar filtering screen  330 , and the mesh aperture diameter of the columnar filtering screen  330  is set to about 0.2-0.5 mm, such that while increasing the filtration area and improving the filtering speed, the residue can be gathered at the bottom of the columnar filtering screen  330 , reducing the possibility of the residue collecting on the filtering screen in the direction of the water flow and blocking the flow of water, and also reducing the possibility of the residue leaking out of the filtering screen due to the excessive rotation speed of the filtering screen, thereby improving the filtering performance and filtering effect of the filtering device  10 . In addition, it is possible to improve the water volume when the water filtered by the filtering device  10  is pumped through a pump to an inner liner of the tableware washing apparatus, thereby reducing the washing time or reducing the water used for a single washing, thus achieving energy saving and consumption reduction. In some embodiments, better filtering effect may be achieved by using the filtering device  10  mentioned in the present disclosure. In some embodiments, for example, a filtering effect of about 100% filtration may even be achieved when the diameter of the external circle defined by the mesh of the columnar filtering screen  330  is 0.3 mm and the columnar filtering screen  330  is rotated relative to the contents inside the columnar filtering screen  330  at a relative speed of 250 r/min. 
     Referring specifically to  FIGS.  1 - 2  and  4 - 5   , in some embodiments, a first opening  250   a  is defined on the plane filter  200 , and the columnar filtering screen  330  of the rotary filter  300  is disposed below the first opening  250   a . A second opening  110   a  is defined on the water cup assembly  100  facing and communicated with the first opening  250   a , and a projection of an inner wall enclosing the first opening  250   a  on the water cup assembly  100  is located in the second opening  110   a , thereby defining a return chamber  123   a  between the water cup assembly  100  and the columnar filtering screen  330  of the rotary filter  300 . In this way, the water after the washing process can be filtered through the plane filter  200  and fall directly into the return chamber  123   a ; also, can fall through the first opening  250   a  into the rotary filter  300  and be filtered through the columnar filtering screen  330  of the rotary filter  300 , and thereafter enter the return chamber  123   a . The filtered water entering the return chamber  123   a  can be subsequently discharged through an outlet pipe  150  of the water cup assembly  100 . 
     Further referring to  FIGS.  1 - 3   , in some embodiments of the present disclosure, the water cup assembly  100  may include a tray  110 , a cup  120  connected to the tray  110 , a spray arm interface  130  arranged on the tray  110 , and a drive accommodating portion  140 , an outlet pipe  150 , a discharge pump accommodating portion  160 , and a water-extraction pump accommodating portion  170 , each connected to the cup  120 . The plane filter  200  is arranged on the tray  110 , and the tray  110  is configured to collect the water filtered by the plane filter  200 . The cup  120  is configured to accommodate the columnar filtering screen  330 , and the drive accommodating portion  140  is configured to accommodate at least the motor  410  of the drive assembly (referring to  FIG.  32   ). The outlet pipe  150  is communicated with the cup  120  such that the filtered water can be discharged through the outlet pipe  150 . The discharge pump accommodating portion  160  is communicated with the cup  120  and is configured to accommodate a discharge pump (not shown) to discharge the residue from the cup  120  by the pumping action of the discharge pump. The water-extraction pump accommodating portion  170  is configured to accommodate a water-extraction pump (not shown). The water-extraction pump accommodating portion  170  is connected to the outlet pipe  150  through a line to transport the water in the cup  120  to the outside of the cup  120 , specifically to the spray arm interface  130  on the tray  110 , after being filtered by the columnar filtering screen  330 , by the pumping action of the water-extraction pump. 
     Referring to  FIGS.  6 ,  9  and  12 - 13   , in some embodiments, the outlet pipe  150 , the water-extraction pump accommodating portion  170 , and the discharge pump accommodating portion  160  are spaced along a circumference of the cup  120 . The water-extraction pump accommodating portion  170  is arranged adjacent to the outlet pipe  150  to reduce the loss of water flow. The discharge pump accommodating portion  160  is arranged on a side of the water-extraction pump accommodating portion  170  away from the outlet pipe  150  and is disposed at a junction position between the drive accommodating portion  140  and the cup  120 , thereby reducing mutual interference between the residue discharge process and the water discharge process, and saving the installation space of each component. The “junction position” herein means that the discharge pump accommodating portion  160  is disposed at a corner position formed by the intersection of the drive accommodating portion  140  and the cup  120 . 
     In some embodiments, the cup  120  may include a top surface and a bottom surface disposed opposite each other along an axial direction of the cup  120 . The drive accommodating portion  140  does not protrude from a bottom surface of the cup  120  along the axial direction of the cup  120 . In some embodiments, the drive accommodating portion  140  may not protrude from the top surface of the cup  120  along the axial direction of the cup  120 . In some embodiments, referring to  FIG.  2    and  FIG.  11   , the drive accommodating portion  140  may neither protrude from the top surface of the cup  120  nor protrude from the top surface of the cup  120  along the axial direction of the cup  120 . With this structure, it is possible to add drive assemblies (e.g., including but not limited to the motor  410 ) without changing the original height of the washing apparatus, thereby saving space in the height direction and reducing the increase in the overall height of the washing apparatus due to installations of drive assemblies. 
     The “not protruding” herein means, in the axial direction, below the top surface, or above the bottom surface, or flush with the top or bottom surface. For example, in some embodiments, the drive accommodating portion  140  may likewise include a top surface and a bottom surface disposed opposite each other along the axial direction of the cup  120 . In this case, the top surface of the drive accommodating portion  140  is disposed between the top surface and the bottom surface of the cup  120  in the height direction, or a bottom surface of the drive accommodating portion  140  is disposed between the top surface and the bottom surface of the cup  120  in the height direction, or the top surface of the drive accommodating portion  140  is flush with the top surface of the cup  120  in the height direction, or the bottom surface of the drive accommodating portion  140  is flush with the bottom surface of the cup  120  in the height direction. 
     With such a structure, the drive accommodating portion  140  does not protrude from the bottom surface of the cup  120  along the axial direction of the cup  120 , such that a motor may be added without changing the original height of the filtering device  10 , and the space along the height direction of the filtering device  10  may be saved, making the entire filtering device  10  more compact. 
     The “bottom surface” herein refers to an outer surface of the cup  120  away from the tray  110 . 
     Of course, in some embodiments, the drive accommodating portion  140  may protrude at least partially from the bottom surface of the cup  120  along the axial direction of the cup  120 . The ratio of the protruding height of the bottom surface of the drive accommodating portion  140  to the height of the motor is less than 1:1. With this structure, the drive accommodating portion  140  protrudes at least partially from the bottom surface of the cup  120  and the ratio of the protruding height to the height of the motor is less than 1:1, which may save space along the height direction of the filtering device  10  and makes the entire filtering device  10  more compact. 
     In some embodiments, the ratio of the protruding height of the bottom surface of the drive accommodating portion  140  relative to the bottom surface of the cup  120  to the height of the motor is less than 1:5 or even less than 1:7. In some embodiments, the ratio of the protruding height of the bottom surface of the drive accommodating portion  140  relative to the bottom surface of the cup  120  to the height of the motor is 1:16 to 1:5, and in other embodiments the ratio may be 1:12 to 1:7. For example, in some embodiments, the height of the motor may be 50 to 80 mm, or in some embodiments the height of the motor may be 70 mm. Accordingly, the protruding height of the drive accommodating portion  140  relative to the bottom surface of the cup  120  may be 5 to 10 mm. In some embodiments, the protruding height of the drive accommodating portion  140  relative to the bottom surface of the cup  120  may be 5 mm. Taking the above range, such as less than 1:5 or 1:7, etc., the protrusion height of the drive accommodating portion  140  and the motor arranged in the drive accommodating portion  140  may be further reduced, thereby further saving space along the height direction of the filtering device  10  and making the entire filtering device  10  more compact. 
     The “protruding height” herein refers to a distance between the bottom surface of the drive accommodating portion  140  and the bottom surface of the cup  120 . 
     In some embodiments of the present disclosure, referring to specifically  FIGS.  3 - 4   , the tray  110  defines the second opening  110   a , and the water collected by the tray  110  after being filtered by the plane filter  200  can fall through the second opening  110   a  to the bottom of the tray  110 . The spray arm interface  130  is arranged on the tray  110 , and the spray arm interface  130  and the second opening  110   a  are disposed at intervals along a first direction X. 
     In some embodiments, the tray  110  may be substantially elliptical in shape and have a long axis  111  and a short axis  112  that intersect with each other, where the long axis  111  may be set along the first direction X, i.e., the first direction X is the direction in which the long axis  111  of the tray  110  is located. The short axis  112  may be set in a second direction Y perpendicular to the first direction X, i.e., the second direction Y is the direction in which the short axis  112  of the tray  110  is located. In some embodiments, the ratio of the length of the long axis  111  and the short axis  112  may be 5:3, which may facilitate the arrangement of the spray arm interface  130  and increase the water-passing area when filtering, such that most of the water after washing can fall into the rotary filter  300  through the first opening  250   a  on the plane filter  200 , and enter the return chamber  123   a  after being filtered by the columnar filtering screen  330 , or enter directly into the return chamber  123   a  filtered by the plane filter  200 . 
     In some embodiments of the present disclosure, the tray  110  is elliptical. Of course, in other embodiments, the tray  110  may be configured in other shapes, such as round, square, rectangular, diamond-shaped, etc., as long as the tray  110  has enough space to arrange the spray arm interface  130  and define the second opening  110   a  and can carry the plane filter  200 . 
     In some embodiments of the present disclosure, the cup  120  is substantially columnar in shape. The columnar filtering screen  330  of the rotary filter  300  may be accommodated in the cup  120 , and a gap exists between an inner surface of the cup  120  and an outer surface of the columnar filtering screen  330 . The ratio of an inner diameter of the cup  120  to an inner diameter of the columnar filtering screen  330  is about 3:4 to 8:9, and the width of the gap between the inner surface of the cup  120  and the outer surface of the columnar filtering screen  330  along a radial direction of the cup  120  is about 10 to 20 mm. In some embodiments, the height of the cup  120  is about 90 to 110 mm, the inner diameter of the cup  120  is about 80 to 100 mm, and the inner diameter of the columnar filtering screen  330  is about 60 to 80 mm. This size design may effectively reduce the problem of air extraction during the water return process, ensure the smooth flow of water such that the water can fill the return chamber  123   a , reduce the possibility of air adulteration in the return chamber  123   a , thereby ensuring the flow of the washing process and improving the filtration performance. 
     Referring further to  FIGS.  3 - 5   , the cup  120  may substantially include a bottom wall  121  and a first peripheral wall  123  and a second peripheral wall  125  that are connected to the bottom wall  121 . The first peripheral wall  123  and the second peripheral wall  125  are connected to opposite sides of the bottom wall  121 , respectively. That is, the first peripheral wall  123  is connected to a side of the bottom wall  121 , and the second peripheral wall  125  is connected to the other side of the bottom wall  121  opposite to the side of the bottom wall  121 . That is, the first peripheral wall  123  extends toward a side of the bottom wall  121 , and the second bottom wall  125  extends toward the other side of the bottom wall  121 . The first peripheral wall  123  encloses a receiving cavity (not shown) for receiving the columnar filtering screen  330 . The columnar filtering screen  330  may be received in the receiving cavity, and the columnar filtering screen  330  may divide the receiving cavity into a filtration chamber for receiving the water inside the columnar filtering screen  330  and the return chamber  123   a  disposed outside the columnar filtering screen  330 . The first peripheral wall  123  further defines a first water outlet  123   b , and the outlet pipe  150  is connected to the return chamber  123   a  through the first water outlet  123   b . The second bottom wall  125  may enclose a discharge cavity  125   a , and the second bottom wall  125  may further define a discharge outlet  125   b . The discharge pump accommodating portion  160  is communicated with the discharge cavity  125   a  through the discharge outlet  125   b . In conjunction with  FIG.  11   , the bottom wall  121  may further define a through hole  121   a , and the receiving cavity and the discharge cavity  125   a  are communicated with each other through the through hole  121   a.    
     In some embodiments, the first peripheral wall  123  and the second peripheral wall  125  may each be an annular peripheral wall. Of course, in other embodiments, the first peripheral wall  123  and the second peripheral wall  125  may also be other shapes. 
     The first peripheral wall  123  and the second peripheral wall  125  may be integrally formed into one part, or separately formed, which is not limited herein. 
     Referring further to  FIGS.  3 - 5   , the cup  120  may further include a support tab  127 , which is connected to the bottom wall  121  and extends from the bottom wall  121  toward the receiving cavity. The support tab  127  is arranged around the through hole  121   a . In some embodiments of the present disclosure, the inner surface of the columnar filtering screen  330  may be abutted against an outer surface of the support tab  127 , to support the columnar filtering screen  330  on the support tab  127 . The support tab  127  may be configured to support the columnar filtering screen  330  and may serve as a retaining wall to prevent the residue falling into the discharge cavity  125   a  from adhering to the columnar filtering screen  330  again by the action of flowing water. 
     The “supported on” herein may be understood to mean that the support tab  127  only serves as a support, not as a fixing part. Therefore, the columnar filtering screen  330  may be fixed to the support tab  127  or not be fixed. For example, the columnar filtering screen  330  may be rotated relative to the support tab  127 . 
     After the filtered water has been filtered through the columnar filtering screen  330 , the water seeps out of the columnar filtering screen  330  into the return chamber  123   a  and is delivered to the outside of the cup  120  through the first water outlet  123   b . In this case, at least a portion of the residue falls into the discharge cavity  125   a  and is discharged through the pumping action of a discharge pump to the outside of the cup  120  through the discharge outlet  125   b.    
     In some embodiments, the discharge outlet  125   b  is defined at the bottom of the cup  120 . In some embodiments, the discharge outlet  125   b  is defined at a lowest position at the bottom of the cup  120  to facilitate the collection and discharge of the residue. In addition, referring to  FIG.  12   , an angle α between a line connecting the center of the discharge outlet  125   b  and the center of the cup  120  and a line connecting the center of the first water outlet  123   b  and the center of the cup  120  is greater than 90 degrees and less than or equal to 180 degrees. In some embodiments, the angle may be 180 degrees, in which case the discharge pump accommodating portion  160  and the outlet pipe  150  are arranged along the radial direction of the cup  120  on opposite sides of the cup  120 . 
     In order to facilitate the discharge of the residue, in some embodiments of the present disclosure, further referring to  FIG.  5   , at least one guiding element  125   c  may be arranged inside the discharge cavity  125   a . The at least one guiding element  125   c  is arranged adjacent to the discharge outlet  125   b  for guiding the residue during the discharge of the residue from the cup  120 . 
     Referring further to  FIG.  3    and  FIGS.  9 - 10   , in some embodiments, a recess  129  is defined on the bottom wall  121  toward the receiving cavity, and the recess  129  is arranged adjacent to and communicated with the first water outlet  123   b . The recess  129  is further communicated with the return chamber  123   a . The provision of such a recess  129  at a position adjacent to the first water outlet  123   b  may effectively solve the problem of pumping air when pumping water through the pump subsequently, such that the water can adequately fill an outlet region of the cup  120  without mixing with air and ensuring the flow of water during the subsequent washing process. 
     In some embodiments, in conjunction with  FIGS.  13 - 14   , the recess  129  may be disposed between the first peripheral wall  123  and the support tab  127 . 
     In some embodiments, referring to  FIG.  12   , the recess  129  may extend along a circumference of the cup  120  for a length greater than the length of the first water outlet  123   b  along the circumference of the cup  120 , thereby ensuring that filtered water can sink to the recess  129  and flow out of the cup  120  in a timely manner through the first water outlet  123   b . In this way, the filtered water can fill the outlet region of the cup without air in the process of pumping water through the pump, which can effectively reduce the probability of trapped air in the pump. 
     In some embodiments of the present disclosure, referring to  FIG.  6    and  FIGS.  13 - 14   , the recess  129  may include a first recess portion  129   a  and a second recess portion  129   d  that are from inside to outside sequentially arranged along the radial direction of the cup  120 . The first recess portion  129   a  has a first bottom surface  129   b  and the second recess portion  129   d  has a second bottom surface  129   e . A recessed depth of the second bottom surface  129   e  relative to the bottom wall  121  is greater than a recessed depth of the first bottom surface  129   b  relative to the bottom wall  121 . The “recessed depth” herein means a vertical distance (i.e., the distance along the axial direction of the cup  120 ) between the bottom surface (i.e., the first bottom surface  129   b  or the second bottom surface  129   e ) of the corresponding recess portion (first recess portion  129   a  or second recess portion  129   d ) and the bottom wall  121 . In some embodiments, the difference between the recessed depth of the first recess portion  129   a  and the recessed depth of the second recess portion  129   d  is about 5 to 8 mm. The design of two levels of recess portions to form the recess  129  may facilitate the injection molding process of the cup  120  and reduce the possibility of shrinkage and deformation of the recess  129  during the injection molding process of the cup  120 . 
     Further referring to  FIGS.  13 - 14   , in some embodiments, the recessed depth of the second bottom surface  129   e  relative to the bottom wall  121  may be further less than a recessed depth of a lowest point of an inner wall of the outlet pipe  150  at the first water outlet  123   b  relative to the bottom wall  121 , thereby reducing the probability of trapped air during subsequent pumping, such that the water can adequately fill the outlet region of the cup  120  without mixing with air, ensuring the water flow of the washing process. 
     In addition, in some embodiments, the first recess portion  129   a  has an inclined surface  129   c  connecting the bottom wall  121  and the first bottom surface  129   b . In some embodiments, an angle between the inclined surface  129   c  and the first bottom surface  129   b  is about 158.9° to 162.7°. The first recess portion  129   a  is set with an inclined surface, which allows the filtered water to smoothly transitioned into the recess  129  through the inclined surface  129   c  and flow into the outlet pipe  150  through the first water outlet  123   b  and then out of the cup  120 . 
     In some embodiments, referring to  FIGS.  7 ,  9  and  12   , an end of the outlet pipe  150  is connected to the cup  120  and communicated with the return chamber  123   a  through the first water outlet  123   b . The other end of the outlet pipe  150  is arranged with a second water outlet  151 , and the outlet pipe  150  defines an outlet channel  150   a  between the first water outlet  123   b  and the second water outlet  151 . The cross-sectional area of the outlet channel  150   a  decreases in a direction from the first water outlet  123   b  to the second water outlet  151 , in conjunction with  FIGS.  7  and  12   . The design of this structure of the outlet pipe  150  may effectively solve the problem of pumping air at the outlet location caused by the pump during the pumping process, such that the water adequately fills the outlet region without mixing with air, ensuring the flow of water during the washing process. 
     In some embodiments, the ratio of the cross-sectional area of the outlet channel  150   a  at the first water outlet  123   b  to the cross-sectional area of the outlet channel  150   a  at the second water outlet  151  is about 1.63 to 1.99. The ratio setting may more effectively solve the problem of pumping air at the outlet location caused by the pump during the pumping process, thereby improving the flow rate during the washing process. Herein, the cross-sectional area is the area of the cross-section dissected parallel to the axial direction of the columnar filtering screen  330 . 
     In some embodiments, referring to  FIG.  8   , the cross-section of the outlet channel  150   a  at the first water outlet  123   b  is substantially elliptical in shape and the ratio of the lengths of the long and short axes of the elliptical is substantially 5:3. The elliptical design allows more filtered water to enter the outlet tube  150  at the same time as the water is being discharged, ensuring that the water fills the outlet region sufficiently without air admixture. 
     In other embodiments, the cross-section of the outlet channel  150   a  at the first water outlet  123   b  may also be round, square, etc. In some embodiments, when a circular cross-section is adopted, the diameter of the circular cross-section is about 35 mm, i.e., the inner diameter of the outlet pipe  150  at that first water outlet  123   b  is about 35 mm. 
     In some embodiments, the outlet channel  150   a  has a substantially circular cross-section at the second water outlet  151 . In some embodiments, the diameter of the circular cross-section of the outlet channel  150   a  at the second water outlet  151  is about 26 mm. The circular cross-section of the outlet channel  150   a  at the second water outlet  151  facilitates connection to external pipeline and thus to the pump. 
     Of course, in other embodiments, the shape of the cross-section of the outlet channel  150   a  at the first water outlet  123   b  and the second water outlet  151  and the size of the inner diameter of the outlet pipe  150  at the first water outlet  123   b  and the second water outlet  151  may be selected according to actual needs. The present disclosure is not limited herein specifically. 
     Referring to  FIG.  7    and  FIG.  13   , the outlet pipe  150  includes a diameter-inconsistent portion  153  and a diameter-consistent portion  155  connected from the inside to the outside in the radial direction of the cup  120 , and the diameter-inconsistent portion  153  and the diameter-consistent portion  155  are communicated with each other. By setting the diameter-inconsistent portion  153  and the diameter-consistent portion  155 , it may be ensured that the water adequately fills the outlet region without mixing air, and the connection with the external pipeline may be facilitated. In some embodiments of the present disclosure, the length of the diameter-consistent portion  155  may be greater than or equal to 15 mm. In other embodiments, the length of the diameter-consistent portion  155  may be greater than or equal to 20 mm. 
     In conjunction with  FIG.  13    and  FIG.  15   , the diameter-inconsistent portion  153  is connected to the first peripheral wall  123  and defines a first sub outlet channel  153   a  connected to the return chamber  123   a  of the receiving cavity through the first water outlet  123   b . The cross-sectional area of the first sub outlet channel  153   a  gradually decreases in the direction from the first water outlet  123   b  to the second water outlet  151 . 
     The diameter-consistent portion  155  is arranged on a side of the outlet pipe  150  away from the return chamber  123   a  of the receiving cavity and defines a second sub outlet channel  155   a  communicated with the first sub outlet channel  153   a , and the second water outlet  151  is arranged on the diameter-consistent portion  155 . The first sub outlet channel  153   a  and the second sub outlet channel  155   a  form the aforementioned outlet channel  150   a , and the cross-sectional area of the second sub outlet channel  155   a  remains constant along the direction from the first water outlet  123   b  toward the second water outlet  151 . 
     In some embodiments, further referring to  FIG.  13   , the diameter-inconsistent portion  153  has a first side  153   b  and a second side  153   c  in a cross-section perpendicular to the axial direction of the cup  120  and over the geometric center of the first water outlet  123   b . The first side  153   b  is near the water-extraction pump accommodating portion  170  and the second side  153   c  is away from the water-extraction pump accommodating portion  170 . The diameter-inconsistent portion  153  has a cross-sectional area between the first side  153   b  and the first peripheral wall  123 . The diameter-inconsistent portion  153  forms a first intersection  153   d  at the connection of the first side  153   b  with the first peripheral wall  123  and a second intersection  153   e  at the connection with the diameter-consistent portion  155 , while the diameter-inconsistent portion  153  forms a third intersection  153   f  at the connection of the second side  153   c  with the first peripheral wall  123  and a fourth intersection  153   g  at the connection with the diameter-consistent portion  155 . In some embodiments, the length of a line between the first intersection  153   d  and the second intersection  153   e  is less than the length of a line between the third intersection  153   f  and the fourth intersection  153   g , and the angle between the line between the first intersection  153   d  and the second intersection  153   e  and a tangent line of the first peripheral wall  123  at the first intersection  153   d  is greater than the angle between the line between the third intersection  153   f  and the fourth intersection  153   g  and a tangent line of the first peripheral wall  123  at the third intersection  153   f . In addition, the angle between the diameter-inconsistent portion  153  on the first side  153   b  and the diameter-consistent portion  155  may be less than the angle between the diameter-inconsistent portion  153  on the second side  153   c  and the diameter-consistent portion  155 . With this structure, the connection between the outlet pipe  150  and the pump accommodated in the water-extraction pump accommodating portion  170  may be facilitated through the pipeline, and the stability and reliability of the connection or communication between the outlet pipe  150  and the pump may be ensured. 
     Of course, in other embodiments, the diameter-inconsistent portion section  153  may be arranged symmetrically about the centerline of the outlet pipe  150 . That is, the length of the line between the first intersection  153   d  and the second intersection  153   e  is equal to the length of the line between the third intersection  153   f  and the fourth intersection  153   g , and the angle between the line between the first intersection  153   d  and the second intersection  153   e  and the tangent line of the first peripheral wall  123  at the first intersection  153   d  is equal to the angle between the line between the third intersection  153   f  and the fourth intersection  153   g  and the tangent line of the first peripheral wall  123  at the third intersection  153   f . The present disclosure is not specifically limited herein. 
     In some embodiments, a side of the outlet pipe  150  away from the water-extraction pump accommodating portion  170  (i.e., the second side  153   c  of the diameter-inconsistent portion  153 ) may be tangential to an outer peripheral wall of the cup  120  (specifically, the outer surface of the first peripheral wall  123 ), such that filtered water may enter the outlet pipe  150  more smoothly, thereby reducing the resistance to the water generated by the outlet pipe  150 . 
     Referring to  FIG.  15   , in some embodiments of the present disclosure, the height of the outlet channel  150   a  along the axis of the columnar filtering screen  330  remains constant in the direction from the first water outlet  123   b  to the second water outlet  151 , thereby reducing the installation height along the axis of the columnar filtering screen  330  and saving space in that direction, resulting in a lower installation height and more compact structure of the entire filtering device  10 . 
     Further referring to  FIGS.  1 - 2   , in some embodiments, the filtering device  10  further includes a spray arm adapter  500  arranged on the plane filter  200 , which is connected to and communicated with the spray arm adapter  130  on the tray  110 , for spraying the filtered water of the filtering device  10  into the inner liner of the tableware washing apparatus through the spray arm adapter  500 . 
     The plane filter  200  may include a face-shaped screen holder  250 , and a first face-shaped screen  210  and a second face-shaped screen  230  arranged side by side in the first direction X. The first opening  250   a  is defined on the face-shaped screen holder  250 . The columnar filtering screen  330  is disposed below the face-shaped screen holder  250  and facing the first opening  250   a . Therefore, the water can fall from the first opening  250   a  into the columnar filtering screen  330  below the face-shaped screen holder  250 . The spray arm adapter  500  is arranged on the face-shaped screen holder  250  and is spaced apart from the first opening  250   a  along the first direction X. 
     In some embodiments, the first face-shaped screen  210  and the second face-shaped screen  230  may both be plane screens. In other embodiments, the first face-shaped screen  210  and the second face-shaped screen  230  may be curved screens with curves, or one of the first face-shaped screen  210  and the second face-shaped screen  230  may be a plane screen and the other a curved screen. The present disclosure does not limit the shape of the first face-shaped screen  210  and the second face-shaped screen  230 . 
     In some embodiments, referring to  FIGS.  1 - 2  and  12   , the second face-shaped screen  230  is away from the spray arm adapter  500  along the first direction X compared to the first face-shaped screen  210 . The area of the first face-shaped screen  210  is greater than the area of the second face-shaped screen  230 . In conjunction with  FIG.  16   , a first angle ( 31  may be formed between the first face-shaped screen  210  and a reference plane perpendicular to the axial direction of the first opening  250   a , and a second angle ( 32  may be formed between the second face-shaped screen  230  and the reference plane, the first angle ( 31  being less than the second angle ( 32 . 
     The above is embodiments in which the first face-shaped screen  210  and the second face-shaped screen  230  are separate structures, i.e., the first face-shaped screen  210  and the second face-shaped screen  230  are separately machined and stitched together. However, in other embodiments, the first face-shaped screen  210  and the second face-shaped screen  230  may each be of a one-piece structure; for example, the first face-shaped screen  210  and the second face-shaped screen  230  may be formed by bending the entire screen at a predetermined location. The present disclosure does not limit the way of forming and combining the first face-shaped screen  210  and the second face-shaped screen  230 . 
     With the above structure design, the plane filter  200  is divided into a plurality of different face-shaped screens and spliced with each other through the face-shaped screen holder  250 , which may increase the filtration area, improve the filtering speed, reduce the probability of empty pumping caused by untimely water return, and facilitate the manufacture of the plane filter  200 . Moreover, because the inclination angles of the first face-shaped screen and the second face-shaped screen with different areas are not the same with respect to the reference plane, the distances between the first face-shaped screen and the second face-shaped screen at corresponding positions and the reference plane may be approximately equal, such that the water falls more smoothly into the tray  110  through the different positions of the plane filter  200  or into the columnar filtering screen  330  through the first opening  250   a.    
     In some embodiments, the ratio of the first angle β1 to the second angle β2 may be 1:5 to 1:2. In some embodiments, the ratio of the first angle β1 to the second angle β2 is about 1:3. 
     Referring further to  FIG.  16   , in some embodiments of the present disclosure, the first angle β1 and the second angle β2 are set such that a distance from an outer edge of the first face-shaped screen  210  away from the second face-shaped screen  230  along the first direction X and/or the second direction Y perpendicular to the first direction X to the reference plane along the axial direction of the first opening  250   a  is the same as a distance from an outer edge of the second face-shaped screen  230  away from the first face-shaped screen  210  along the first direction X and/or the second direction Y to the reference plane along the axial direction of the first opening  250   a , thereby allowing the water to fall more smoothly into the tray  110  through the different positions of the plane filter  200  or into the columnar filtering screen  330  through the first opening  250   a.    
     Specifically, in some embodiments, the opposing outer edges of the first face-shaped screen  210  and the second face-shaped screen  230  along the first direction X may be set at equal distances from the reference plane along the axial direction of the first opening  250   a . For example, referring to  FIG.  16   , the first face-shaped screen  210  has a first outer edge  211  in the first direction, a projection of which in the reference plane is at a maximum distance h1 from the center of the first opening  250   a , and a first angle β1 exists between the first face-shaped screen  210  and the reference plane. In a similar manner, the second face-shaped screen  230  has a second outer edge  231  in the first direction, and the second outer edge  231  and the first outer edge  211  are disposed on opposite sides of the first opening  250   a , respectively. A projection of the second outer edge  231  in the reference plane is at a maximum distance h2 from the center of the first opening  250   a , and a first angle β2 exists between the second face-shaped screen  230  and the reference plane. Therefore, the first face-shaped screen  210  and the second face-shaped screen  230  satisfy the following relationship: tan β1*h1=tan β2*h2. 
     Of course, in other embodiments, the opposing outer edges of the first face-shaped screen  210  and the second face-shaped screen  230  along the second direction Y may be set at equal distances from the reference plane along the axial direction of the first opening  250   a . Specifically, in the embodiments shown in  FIG.  16   , the entire plane filter  200  is arranged symmetrically about the first direction X. The first face-shaped screen  210  has two opposing third outer edges  213  in the second direction Y, and the two third outer edges  213  are equidistant from the reference plane along the axial direction of the first opening  250   a . Similarly, the second face-shaped screen  230  has two opposing fourth outer edges  233  in the second direction Y, and the two fourth outer edges  233  are equidistant from the reference plane along the axial direction of the first opening  250   a.    
     In other embodiments, the first angle β1 and the second angle β2 are set such that the opposing outer edges of the first face-shaped screen  210  and the second face-shaped screen  230  along the first direction X are at equal distances from the reference plane along the axial direction of the first opening  250   a , and the opposing outer edges of the first face-shaped screen  210  and the second face-shaped screen  230  along the second direction Y are at equal distances from the reference plane along the axial direction of the first opening  250   a.    
     Referring further to  FIG.  16   , in some embodiments, a dividing line  220  of the first face-shaped screen  210  and the second face-shaped screen  230  is disposed on a side of the center of the first opening  250   a  away from the spray arm adapter  500  and intersecting with the first opening  250   a . In other words, the dividing line  220  is off-center from the center of the first opening  250   a . The eccentric arrangement of the dividing line  220  facilitates the arrangement of the spray arm adapter  500  while allowing the water to fall smoothly into the columnar filtering screen  330 . 
     In some embodiments, the number of first face-shaped screens  210  and the number of second face-shaped screens  230  are each two. The two first face-shaped screens  210  are arranged side by side in the second direction perpendicular to the first direction X, and the two second face-shaped screens  230  are arranged side by side in the second direction perpendicular to the first direction X. Moreover, the dividing line between one first face-shaped screen  210  and one second face-shaped screen  230  and the dividing line between the other first face-shaped screen  210  and the other second face-shaped screen  230  are symmetrically arranged about a line connecting the center of the first opening  250   a  and the center of the spray arm adapter  500 . That is, the two first plane screens  210  are arranged symmetrically about the line connecting the center of the first opening  250   a  and the center of the spray arm adaptor, and the two second plane screens  230  are arranged symmetrically about the line connecting the center of the first opening  250   a  and the center of the spray arm adaptor. 
     In some embodiments of the present disclosure, the mesh count of meshes of each of the first face-shaped screen  210  and the second face-shaped screen  230  is about 50 to 70 mesh. Specifically, in some embodiments, the diameter of an external circle defined by each mesh of each of the first face-shaped screen  210  and the second face-shaped screen  230  is about 0.2 to 0.5 mm, and the mesh spacing ranges from about 0.4 to 0.6 mm. In some embodiments, the diameter of the external circle defined by each mesh of each of the first face-shaped screen  210  and the second face-shaped screen  230  is about 0.2 to 0.4 mm. With this design, the residue in the water can be effectively filtered. In some embodiments, the diameter of the external circle defined by each mesh of each of the first face-shaped screen  210  and the second face-shaped screen  230  may be 0.3 to 0.4 mm, and the mesh spacing ranges from 0.6 to 1.0 mm. 
     Referring to  FIG.  17   , in some embodiments, the face-shaped screen holder  250  may include an outer frame  251 , an inner frame  253  embedded within the outer frame  251  and facing the first opening  250   a , and at least one support rib  255  connected between the outer frame  251  and the inner frame  253 . The outer frame  251  and the inner frame  253  enclose a receiving region for the first face-shaped screen  210  and the second face-shaped screen  230 , and the at least one support rib  255  divides the receiving region into regions for receiving the first face-shaped screen  210  and the second face-shaped screen  230 . Edges of the first face-shaped screen  210  and the second face-shaped screen  230  abut against the outer frame  251 , the inner frame  253 , and the at least one support rib  255 , respectively, such that the first face-shaped screen  210  and the second face-shaped screen  230  are supported on the face-shaped screen holder  250 . 
     In the embodiments shown in  FIG.  17   , the number of first face-shaped screens  210  and the number of second face-shaped screens  230  are each two, and the number of support ribs  255  is four. The inner frame  253  is generally circular in shape and the four support ribs  255  are arranged around a circumference of the inner frame  253 , thereby dividing the receiving region into four regions (corresponding to the two first face-shaped screens  210  and two second face-shaped screens  230 ), such that the first face-shaped screens  210  and the second face-shaped screens  230  are firmly supported on the face-shaped screen holder  250 . Moreover, the support ribs  255  are adopted to divide the receiving region to facilitate the processing and shaping of the filtering screens. 
     As further shown in  FIG.  17   , in some embodiments, the face-shaped screen holder  250  may further include a support platform  257  connected between the outer frame  251  and the inner frame  253  and arranged adjacent to the first face-shaped screen  210 . The spray arm adapter  500  is arranged on the support platform  257 . 
     Continuing with  FIG.  2    and  FIGS.  18 - 19   , in some embodiments, the rotary filter  300  may include a columnar screen holder  310  and the columnar filtering screen  330 . The columnar screen holder  310  is inserted within the cup  120 . The columnar filtering screen  330  is supported on the columnar screen holder  310  and is arranged facing the first opening  250   a  for filtering the water. The columnar filtering screen  330  is rotatable relative to the contents of the columnar filtering screen  330 . 
     In some embodiments, the columnar screen holder  310  may be integrally molded with the inner frame  253 , which may make the whole filtering device better integrated and sealed, and may reduce the possibility of residue leaking out to the return chamber  123   a  through the seams or fits of the inner frame  253  and the columnar screen holder  310 . Of course, in other embodiments, the columnar screen holder  310  may be separated from the inner frame  253  and may be rotatably connected to the inner frame  253 , thereby facilitating the rotation of the columnar screen holder  310  and the columnar filtering screen  330  supported thereon relative to the plane filter  200 . 
     In some embodiments, the contents of the columnar filtering screen  330  are rotatable by the drive assembly  400 , thereby allowing the columnar filtering screen  330  to rotate relative to the contents. For example, in the embodiments shown in  FIG.  2   , the rotary filter  300  includes the columnar filtering screen  330 , the columnar screen holder  310 , and a cleaning element  350 , where the specific design of the columnar screen holder  310  and the columnar filtering screen  330  is as previously described and will not be repeated herein. In the embodiments, the columnar screen holder  310  may be integrally formed with the inner frame  253 . The cleaning element  350  is accommodated within the columnar filtering screen  330  and is in contact with, or abutting against, an inner wall (or inner surface) of the columnar filtering screen  330 . In some embodiments, a bottom of the cleaning element  350  may further be in contact with and supported on the support tab  127 . Of course, in other embodiments, the cleaning element  350  may not be in contact with the support tab  127 . 
     Referring further to  FIGS.  18 - 19   , the drive assembly  400  may be connected to the cleaning element  350  to drive the cleaning element  350  to rotate for separating at least a portion of the residue from the columnar filtering screen  330  by the cleaning element  350 . In some embodiments, the drive assembly  400  may drive the cleaning element  350  to rotate relative to the columnar filtering screen  330  at a speed of about 150 to 400 r/min. Using the cleaning element  350  to rotate at this speed reduces the probability of failure to form a residue collection caused by residue being thrown out of the columnar filtering screen  330  due to excessive rotation speed, and also reduces the probability that resistance to the flow of water will be formed due to too little rotation speed. Referring to  FIG.  20   , in some embodiments, the cleaning element  350  may include a mounting bracket  351  and a contact portion  353  arranged on the mounting bracket  351 . The mounting bracket  351  may be connected to the drive assembly  400  and rotatable under the drive of the drive assembly  400 , thereby driving the entire cleaning element  350  to rotate. The contact portion  353 , in turn, contacts the inner wall of the columnar filtering screen  330  such that at least a portion of the residue on the columnar filtering screen  330  can be scraped off to separate at least a portion of the residue from the columnar filtering screen  330 . 
     In some embodiments, referring to  FIG.  20   , the mounting bracket  351  may include a connection portion  3511  and a shelf portion  3513 . The connection portion  3511  is coaxially disposed with a motor of the drive assembly  400  and is rotatable under the drive of the motor. A side of the shelf portion  3513  is connected to the connection portion  3511 , and the contact portion  353  may be arranged on another side of the shelf portion  3513  away from the connection portion  3511 . The number of contact portions  353  is the same as the number of shelf portions  3513 , or to say, the contact portions  353  are in one-to-one correspondence with the shelf portions  3513 . 
     In some embodiments, the shelf portion  3513  may be integrally formed with the connection portion  3511 . Of course, in other embodiments, the shelf portion  3513  may be molded separately from the connection portion  3511 . Moreover, the shape of the shelf portion  3513  is not limited to the frame structure with a hollow portion shown in the drawings, and in some embodiments, the shelf portion  3513  may be a solid (not hollow) structure. 
     In some embodiments, the cleaning element  350  may include at least two shelf portions  3513 , and each shelf portion  3513  is arranged with a contact portion  353 . When the cleaning element  350  includes two shelf portions  3513 , the number of contact portions  353  is also two, and the two shelf portions  3513  may be arranged symmetrically about an axial direction of the connection portion  3511 , as shown in  FIGS.  19 - 20   . Of course, in other embodiments, three or more shelf portions  3513  and three or more contact portions  353  may be arranged. For example, in the embodiments shown in  FIG.  21   , the number of the shelf portions  3513  and the number of the contact portions  353  are each three, and the three shelf portions  3513  are evenly distributed at equal distances along the circumference of the connection portion  3511 . In some embodiments, the number of the shelf portion  3513  and the number of the contact portion  353  are each one. The present disclosure does not limit the number, material, and size of such shelf portion  3513  and contact portion  353 . 
     In some embodiments, the contact portion  353  may be a scraper, and the contact portion  353  may be made of, for example, silicone, rubber, and other materials. In addition, the contact portion  353  has a height of about 40 to 60 mm and a width of about 0.9 to 1.1 mm. During rotation of the cleaning element  350 , the contact portion  353  may generate a torque of about 0.4 to 0.6 N*m to cause as much residue as possible to fall off or be separated from the columnar filtering screen  330 . 
     In some embodiments, a wave wheel may be applied in place of the above cleaning element  350 . Referring to specifically  FIGS.  22 - 23   , in the embodiments, the rotary filter  300  may include the columnar screen holder  310 , the columnar filtering screen  330 , and a wave wheel  370 . The specific design of the columnar screen holder  310  and the columnar filtering screen  330  is as previously described and will not be repeated herein. In the embodiments, the columnar screen holder  310  may be integrally formed with the inner frame  253 . The wave wheel  370  is rotatably accommodated in the columnar filtering screen  330  and is disposed at a bottom of the columnar filtering screen  330 , i.e., on a side away from the plane filter  200 . The drive assembly  400  is connected to the wave wheel  370  to drive the wave wheel  370  to rotate relative to the columnar filtering screen  330  at a speed of about 500 to 700 r/min for stirring the water within the columnar filtering screen  330 , such that at least a portion of the residue cannot adhere to the columnar filtering screen  330 , thereby allowing at least a portion of the residue to be separated from the columnar filtering screen  330  and facilitating water penetration through the mesh of the columnar filtering screen  330  to the return chamber  123   a  to achieve effective filtration. The use of the wave wheel  370  rotating at this speed reduces probability of failure to form a residue collection caused by residue being thrown out of the columnar filtering screen  330  due to excessive rotation speed, and also reduces the probability that resistance to the flow of water will be formed due to too little rotation speed. 
     In some embodiments, the wave wheel  370  may have three blades, as shown in  FIG.  23   . Of course, in other embodiments, the wave wheel  370  may include five or more blades. The present disclosure does not limit the number of blades of the wave wheel  370  herein. Moreover, the shape of the wave wheel  370  is not limited to the shape shown in  FIG.  23   , and may take any suitable shape, as long as the wave wheel can stir the water in the columnar filtering screen  330 . 
     The above is embodiments in which the contents of the columnar filtering screen  330  (e.g., the cleaning element  350  and the wave wheel  370 ) can be rotated relative to the columnar filtering screen  330  such that at least a portion of the residue can be separated from the columnar filtering screen  330 . However, in other embodiments, it is also possible to separate at least a portion of the residue from the columnar filtering screen  330  by rotating the columnar filtering screen  330 . By rotating the columnar filtering screen  330 , a portion of the columnar filtering screen  330  adjacent to the first water outlet  123   b  can be changed such that the residue can be dispersed to different positions of the columnar filtering screen  330 , thereby effectively reducing the possibility of local blockage caused by the residue collecting at a certain position of the columnar filtering screen  330 , facilitating the stripping and cleaning of at least a portion of the residue from the columnar filtering screen  330 , and improving the filtration performance of the filtering device  10  and improving the overall tableware washing apparatus. 
     For example, referring to  FIGS.  24 - 25   , in some embodiments of the present disclosure, the rotary filter  300  may include a columnar screen holder  310  and a columnar filtering screen  330 , and the columnar filtering screen  330  is supported on the columnar screen holder  310 . The drive assembly  400  is connected to the columnar screen holder  310  and drives the columnar screen holder  310  to rotate, and the columnar screen holder  310  drives the columnar filtering screen  330  to rotate relative to the water in the columnar filtering screen  330 , such that at least a portion of the residue can be separated from the columnar filtering screen  330  by the rotation of the columnar filtering screen  330 . The rotation speed of the columnar filtering screen  330  is about 500 to 700 r/min. In addition, the height of the cup  120  is about 90 to 110 mm, the inner diameter of the cup  120  is about 80 to 100 mm, and the inner diameter of the columnar filtering screen  330  is about 60 to 80 mm. Driving the columnar filtering screen  330  to rotate at this speed, while matching the inner diameter of the cup  120  and the inner diameter of the columnar filtering screen  330 , may reduce the probability of failure to form a residue collection caused by residue being thrown out of the columnar filtering screen  330  due to excessive rotation speed, and also reduces the probability that resistance to the flow of water will be formed due to too little rotation speed, thereby effectively reducing the problem of pumping air in the water return process, ensuring smooth water flow and filling the return chamber, reducing the possibility of the air being mixed in the return chamber  123   a , thus ensuring the washing process flow, improving the filtration performance, and achieving better filtering effect. In the embodiments, the outlet channel  150   a  may be of the cross-section-inconsistent design shown in  FIG.  13   . 
     In the embodiments, further referring to  FIGS.  26 - 27   , the columnar screen holder  310  includes a main part  311 , a positioning post  315 , and at least one connecting rib  313  connecting the main part  311  and the positioning post  315 . The main part  311  has a columnar frame structure and the columnar filtering screen  330  may be hung or supported on the main part  311 . The positioning post  315  is disposed at a position substantially at a central axis of the main part  311  to be connected to an output shaft of the drive assembly  400  (e.g., the output shaft  438  of the second spur gear  437  shown in  FIG.  25   ) and the inner frame  253  of the plane filter  200 . The positioning post  315  may define an assembly hole  317  at an end connected to the drive assembly  400 , and the output shaft of the drive assembly  400  may be inserted in the assembly hole  317 , thereby driving the positioning post  315  to rotate the columnar screen holder  310 , which in turn rotates the columnar filtering screen  330  arranged on the columnar screen holder  310 . 
     In some embodiments, the number of the connecting ribs  313  is two or more. In the embodiments shown in  FIGS.  26 - 27   , the columnar screen holder  310  includes three connecting ribs  313 , and the three connecting ribs  313  may be evenly distributed around a circumference of the positioning post  315 . 
       FIGS.  28 - 31    illustrate a relative position of the residue in relation to the direction of water flow in the return chamber  123   a  at different moments when filtering with the rotatable columnar filtering screen  330 . In this case, the filtered water flows out of the return chamber through the first outlet. As shown in  FIG.  28   , at a first moment, after the filtration of the columnar filtering screen  330 , the residue is disposed at a first position P1. At this time, the residue adheres to the inner surface of the columnar filtering screen  330  due to the suction force near the first water outlet  123   b  (suction force is generated by the pump). As shown in  FIG.  29   , at a second moment, the columnar filtering screen  330  is rotated at an angle driven by the drive assembly  400  such that the residue is disposed at a second position P2. At this time, the water disposed in the return chamber reacts to the residue on the columnar filtering screen  330  due to the suction force of the pump, such that the residue begins to separate from the columnar filtering screen  330 . Subsequently, as shown in  FIG.  30   , the columnar filtering screen  330  continues to rotate and at a third moment the residue reaches a third position P3 and is completely separated from the columnar filtering screen  330 . And at a fourth moment, as shown in  FIG.  31   , the columnar filtering screen  330  is rotated to a predetermined position such that the residue is disposed in a fourth position P4, at which time the residue has been completely separated from the columnar filtering screen  330  without adhering to the inner surface of the columnar filtering screen  330 , and the residue further approaches the axial direction of the columnar filtering screen  330  and can fall into the discharge cavity  125   a . Therefore, by rotating the columnar filtering screen  330 , the portion of the columnar filtering screen  330  adjacent to the first water outlet  123   b  can be changed such that the residue can be dispersed to different positions of the columnar filtering screen  330 , thereby effectively reducing the possibility of local blockage caused by the residue collecting at a certain position of the columnar filtering screen  330 , facilitating the stripping and cleaning of at least a portion of the residue from the columnar filtering screen  330 , thus allowing the water to smoothly penetrate into the return chamber  123   a  and flow into the outlet pipe  150 . In this way, the filtration performance of the filtering device  10  and the overall stability of the tableware washing apparatus can be improved. 
     In the embodiments, the rotation of the columnar filtering screen  330  is driven by an external drive assembly  400 . Of course, in other embodiments, it is possible to drive the rotation of the columnar filtering screen  330  without an external drive, for example by the force of the water flow itself. The present disclosure does not limit the driving force of the columnar filtering screen  330  herein. 
     Referring further to  FIGS.  32  and  33   , in some embodiments, the drive assembly  400  may include a motor  410  and a reduction mechanism  430 . The motor  410  is arranged horizontally, i.e., an output shaft  411  of the motor  410  is perpendicular to the axial direction of the cup  120 , thereby saving space in the height direction and making the entire filtering device  10  more compact. 
     In some embodiments, the reduction mechanism  430  may be a reduction gear mechanism, which may include a first bevel gear  431 , a second bevel gear  433 , a first straight gear  435 , and a second spur gear  437 . The first bevel gear  431  and the first straight gear  435  are arranged coaxially. The second bevel gear  433  is connected to the output shaft  411  of the motor  410  and engages with the first bevel gear  431 . The second spur gear  437  engages the first spur gear  435 , and an output shaft  438  of the second spur gear  437  is inserted into the cup  120  from an outer surface (bottom surface) of the bottom of the cup  120  and is connected to a portion of the rotary filter  300  (e.g., the aforementioned columnar screen holder  310 , cleaning element  350 , or wave wheel  370 ), thereby driving the columnar filtering screen  330  to rotate relative to the contents. In some embodiments of the present disclosure, the reduction mechanism  430  may further include a cantilever assembly  439 , and the cantilever assembly  439  is configured to hold down the first bevel gear  431  and the first spur gear  435 . 
     In some embodiments, the motor  410  has a mounting height along the axial direction of the cup  120  of substantially about 80 to 100 mm, and the motor  410  may be accommodated within the drive accommodating portion  140 . In some embodiments, the top of the motor  410  does not protrude from the top surface of the cup  120 , and the bottom of the motor  410  does not protrude from the bottom surface of the cup  120 . 
     Therefore, when this type of reduction mechanism is applied, the rotational motion can be converted into a right angle change of direction by means of multiple stages of gears (two bevel gears and two spur gears), and together with the motor being set horizontally, it is thus possible to incorporate the drive assembly  400  without changing the original height of the filtering device  10 , thereby saving space along the height direction of the filtering device  10  and making the entire filtering device  10  more compact. 
     Of course, in other embodiments, as described above, the bottom of the motor  410  may partially protrude from the bottom surface of the cup  120 , as long as the ratio of the protruding height of the bottom surface of the drive accommodating portion  140  to the height of the motor is less than 1:1, thereby saving space along the height of the filtering device  10  and making the entire filtering device  10  more compact. 
     Referring further to  FIGS.  32  and  33   , the drive accommodating section  140  is arranged facing the reduction mechanism  430 . Specifically, in some embodiments, the drive accommodating portion  140  may include a motor mounting part  141 , a first fixing part  143 , a second fixing part  145 , and a third fixing part  147 . The motor  410  may be arranged on the motor mounting part  141 . The first fixing part  143  has a generally circular outer profile and is intersected with the motor mounting portion  141 , for arranging the coaxially fixed first bevel gear  431  and the first spur gear  435 . The second fixing part  145  has a generally circular outer profile and is intersected with the first fixing part  143 . The second fixing part  145  is disposed below the cup  120  and is configured to arrange the second spur gear  437 . The third fixing part  147  has a generally circular outer contour and is intersected with both the motor mounting portion  141  and the first fixing part  143 , for arranging the cantilever assembly  439 . In the embodiments, the cantilever assembly  439  may extend from the third fixing part  147  to the first fixing part  143 . 
     Of course, in some embodiments, the third fixing portion  147  and the cantilever assembly  439  may be omitted or arranged in another manner, as long as the proper operation of the drive assembly is ensured. In some embodiments, referring to  FIG.  19   , an oil seal  600  may be arranged between the output shaft  438  of the second spur gear  437  and the cup  120 . The oil seal  600  may ensure the rotation of the output shaft  438  and reduce the possibility of failure of the reduction mechanism  430  caused by water in the cup  120  seeping into the reduction mechanism  430 . 
     In the above embodiments, the reduction mechanism is implemented by a reduction gear mechanism. However, in other embodiments, the reduction mechanism may be implemented using other reduction mechanisms, such as a belt drive mechanism. 
     For example, referring to  FIGS.  34 - 37   , in some embodiments of the present disclosure, the drive assembly  400  may include a motor  410   a , an active wheel  431   a , a driven wheel  433   a , and a belt  435   a  connecting the active wheel  431   a  and the driven wheel  433   a . In the embodiments, the motor  410   a  is accommodated in the drive accommodating portion  140 , and an output shaft  411   a  of the motor  410   a  is arranged along the axial direction of the cup  120  and extends to the outside of the drive accommodating portion  140 . The active wheel  431   a  is arranged on the outside of the drive accommodating portion  140  and is connected to the output shaft  411   a  of the motor  410   a . The driven wheel  433   a  is arranged on the outside of the drive accommodating portion  140  and is in transmission connection with the main wheel  431   a  through the belt  435   a . In addition, an output shaft  438   a  of the driven wheel  433   a  is inserted inside the cup  120  from the outer surface of the bottom of the cup  120  and is connected to a portion of the rotary filter  300  (e.g., the aforementioned columnar screen holder  310 , the cleaning element  350 , or the wave wheel  370 ), thereby driving the columnar filtering screen  330  to rotate relative to the contents. This type of reduction mechanism  430   a  has a relatively simple structure and is easy to machine and manufacture. 
     In the embodiments shown in  FIGS.  34 - 37   , the drive accommodating portion  140  accommodates only the motor  410   a , and the active wheel  431   a , driven wheel  433   a , and belt  435   a  are arranged on the outside of the drive accommodating portion  140 . Of course, in other embodiments, the motor  410   a , the active wheel  431   a , the driven wheel  433   a , and the belt  435   a  may all be accommodated inside the drive accommodating portion  140 . The present disclosure is not specifically limited in this regard. 
     In some embodiments, referring to  FIG.  35   , an oil seal  600  may be arranged between the output shaft  438   a  of the driven wheel  433   a  and the cup  120 . The oil seal  600  may ensure the rotation of the output shaft  438   a  and reduce the possibility of failure of the reduction mechanism  430   a  caused by water in the cup  120  seeping into the reduction mechanism  430   a.    
     Both of the above embodiments employ a motor to drive the rotation. However, in other embodiments, other drive methods may be used, such as pneumatic drive, liquid drive, etc. 
     For example, in the embodiments shown in  FIGS.  38 - 40   , a liquid drive may be applied. Referring specifically to  FIGS.  38 - 40   , the drive assembly  400  may be implemented by a water wheel housing mechanism  430   b . The water wheel housing mechanism  430   b  may include a water wheel housing  431   b , a water wheel  433   b , and a drain pipe  435   b . The water wheel housing  431   b  is arranged on the tray  110 . The water wheel housing  431   b  is substantially annular in structure, and the water wheel housing  431   b  may enclose a drive fluid cavity  437   b . The number of the spray arm adapters  500  is at least two, and the drive fluid cavity  437   b  is communicated with one of the at least two spray arm adapters  500  such that water delivered to one of the at least two spray arm adapters  500  (i.e., the spray arm adapter  500  connected to the drive fluid cavity  437   b ) may further enter the drive fluid cavity  437   b.    
     The water wheel  433   b  may be accommodated in the drive fluid cavity  437   b , and the water wheel  433   b  may be driven to rotate by the force exerted on the water wheel  433   b  by the water entering the drive fluid cavity  437   b . In conjunction with  FIG.  41   , the water wheel  433   b  is also connected to at least a portion of the rotary filter  300  (e.g., the aforementioned columnar screen holder  310 , cleaning element  350 , or wave wheel  370 ), thereby driving the columnar filtering screen  330  to rotate relative to the contents within the columnar filtering screen  330 . 
     Referring further to  FIGS.  39 - 40   , the drain pipe  435   b  may be communicated with the drive fluid cavity  437   b  and may further be communicated with the plane filter  200  or the columnar filtering screen  330  for discharging water from the drive fluid cavity  437   b  onto the plane filter  200  or into the columnar filtering screen  330 . The water wheel housing mechanism  430   b  to drive the rotation may save the energy consumption of the filtering device  10 . 
     In the above embodiments, the filtering device  10  includes both a plane filter  200  and a rotary filter  300  to filter the water through the plane filter  200  and the rotary filter  300 . However, in other embodiments, it may be possible to provide only the plane filter  200 , or only the rotary filter  300 , as long as the filtration performance requirements can be met. 
     Embodiments of the present disclosure further provide a tableware washing apparatus. Referring to  FIG.  42   , the tableware washing apparatus substantially includes a filtering device  10 , an inner liner  20 , and a spray arm as described in any of the above embodiments. In particular, the inner liner  20  is configured to define a washing chamber for receiving the dishes to be washed. Both the filtering device  10  and the spray arm are accommodated in the inner liner  20 , and a spray arm adapter  500  of the filtering device  10  is further connected to the spray arm. The filtering device  10  is arranged on an outer surface of the bottom of the inner liner  20  for collecting the washing water flowing from the washing chamber, filtering the washing water, and after filtering, delivering the filtered water to the inner liner again through the pumping action of a pump through the spray arm. 
     Specifically, when the washing water (to-be-filtered water) falls into the filtering device  10  from the inner liner, it first enters the plane filter  200 . A portion of the water falls directly into the return chamber  123   a  between the cup  120  and the columnar filtering screen  330  through the tray  110 . The rest of the water falls into the columnar filtering screen  330  through the first opening  250   a  in the middle of the plane filter  200 , and discharged into the return chamber  123   a  after filtered by the columnar filtering screen  330 . The filtered water in the return chamber  123   a  is discharged through the outlet pipe  150  and transported to the spray arm interface  113  by the pumping action of the pump, and enters the spray arm adapter  500 , which can be sprayed into the inner liner again by the action of the spray arm. 
     With the filtering device  10  and the tableware washing apparatus of the present disclosure, while increasing the filtration area and the filtering speed, it is possible to reduce the possibility of blocking the flow of water caused by the residue gathering on the filtering screen in the direction of the flow of water, and thus increase the water volume of the tableware washing apparatus when the water filtered by the filtration system is pumped out to the inner liner. Therefore, the performance and filtering effect of the filtering device  10  can be improved, thus reducing the washing time or the water used for a single washing, and achieving energy saving and consumption reduction. 
     The above is only some embodiments of the present disclosure, not to limit the scope of the present disclosure. Any equivalent structure or equivalent process transformation made by using the content of the specification and the attached drawings of the present disclosure, or applied directly or indirectly in other related technical fields, are included in the scope of the present disclosure.