Patent Publication Number: US-10779702-B2

Title: Spraying assembly for dish washing machine and dish washing machine having same

Description:
PRIORITY CLAIM AND RELATED APPLICATION 
     This application is a continuation of PCT Patent Application No. PCT/CN2015/096165, entitled “SPRAYING ASSEMBLY FOR DISH WASHING MACHINE AND DISH WASHING MACHINE HAVING SAME” filed on Dec. 1, 2015, which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a technical field of dish washing machines, and more particularly to a spraying assembly for a dish washing machine and a dish washing machine having the same. 
     BACKGROUND 
     With increasing improvements in people&#39;s living standards, requirements for intelligent household appliances are increasingly higher. For example, a household dish washing machine can replace manual work to wash tableware. The dish washing machine uses a plurality of spraying arms which rotate while jet-washing the tableware, in conjunction with actions of water such as reflection, splashing and flowing, and completes a washing coverage of the tableware in the dish washing machine. However, since an inner tub of the dish washing machine generally is near quadrate, a common rotary spraying arm has a round spraying area and hence it is difficult to reach front and rear regions in the dish washing machine, such that a washing dead zone tends to be caused, thereby causing insufficient washing at the front and rear regions in the dish washing machine, and greatly reducing overall washing and cleaning effects. 
     SUMMARY 
     Embodiments of the present disclosure seek to solve at least one of the problems existing in the related art to at least some extent. For that reason, a spraying assembly for a dish washing machine is provided by the present disclosure, and the spraying assembly of the dish washing machine has a simple structure, a wide washing coverage and a good washing effect. 
     A dish washing machine having the above-mentioned spraying assembly is further provided by the present disclosure. 
     The spraying assembly for the dish washing machine according to embodiments of a first aspect of the present disclosure includes: a bottom shell, the bottom shell defining a water storage chamber therein, the bottom shell having a water inlet in communication with the water storage chamber; a spraying seat, the spraying seat being rotatably disposed on the bottom shell, the spraying seat having a water input passage in communication with the water storage chamber; a sprayer, the sprayer having at least one spraying arm, the sprayer being rotatably disposed on the spraying seat and a rotation center of the sprayer being eccentrically arranged with respect to a rotation center of the spraying seat, the sprayer having a plurality of spraying orifices spaced apart, each spraying orifice being in communication with the water input passage; and an actuator, the actuator being connected to the sprayer and the spraying seat respectively, so as to drive the sprayer and the spraying seat to rotate around their respective rotation centers. 
     In the spraying assembly for the dish washing machine according to embodiments of the present disclosure, the sprayer is rotatably disposed in an eccentric position of the spraying seat rotatable with respect to the bottom shell, such that each spraying orifice of the sprayer has an epicycloid motion track, e.g., a spray-wash area is substantially quadrate, thereby enlarging a washing area of the spraying assembly, and solving a problem that the dish washing machine in the related art cannot wash a dead corner of an inner tub. The spraying assembly for the dish washing machine has a simple structure, a wide washing coverage, a good washing effect and a high user experience. 
     In addition, the spraying assembly for the dish washing machine according to embodiments of the present disclosure can further have the following technical features. 
     According to an embodiment of the present disclosure, the spraying assembly for the dish washing machine further includes: a driving transmission member, the driving transmission member being connected to the actuator and the sprayer, the driving transmission member being driven by the actuator to drive the sprayer to rotate; and a driven transmission member, the driven transmission member being connected to the driving transmission member and the spraying seat, the driven transmission member being driven by the driving transmission member to drive the spraying seat to rotate. 
     According to an embodiment of the present disclosure, the driving transmission member includes a first sun gear and a drive shaft, a first end of the drive shaft is connected to the actuator, the first sun gear is connected to a second end of the drive shaft, the first sun gear is coaxial with the drive shaft and is driven by the drive shaft, and the sprayer is provided with a planetary gear engaged with the first sun gear. 
     According to an embodiment of the present disclosure, a gear ratio of the first sun gear to the planetary gear is 1:3. 
     According to an embodiment of the present disclosure, the gear ratio of the first sun gear to the planetary gear is 1:5. 
     According to an embodiment of the present disclosure, the driven transmission member is configured as a first gear disposed on the bottom shell, the first end of the drive shaft is provided with a second sun gear engaged with the first gear, the spraying seat is provided with a second gear engaged with the first gear, and the second sun gear cooperates with the first gear and the second gear to drive the spraying seat to rotate. 
     According to an embodiment of the present disclosure, the spraying seat has a mounting portion penetrating the bottom shell and extending downwards, the mounting portion is configured as a hollow column coaxial with the drive shaft, an upper end of the drive shaft passes through the mounting portion to be connected to the first sun gear, a lower end of the drive shaft is provided with the second sun gear, the first gear is disposed at a bottom portion of the bottom shell, and a lower end of the mounting portion is provided with the second gear. 
     According to an embodiment of the present disclosure, the upper end of the drive shaft is provided with a plurality of grooves spaced apart, and an inner ring of the first sun gear is provided with a plurality of bulges correspondingly fitted with the grooves. 
     According to an embodiment of the present disclosure, the end of the drive shaft, which is fitted with the first sun gear, is configured as a spline shaft, and the spline shaft is snapped with the first sun gear. 
     According to an embodiment of the present disclosure, the spraying seat is a rotary body, and a central axis of the spraying seat coincides with central axes of the bottom shell and the drive shaft. 
     According to an embodiment of the present disclosure, the spraying seat is provided with a mounting column eccentrically arranged with respect to the rotation center of the spraying seat, the mounting column defines the water input passage therein, and the sprayer is fitted over the mounting column and is rotatable with respect to the mounting column. 
     According to an embodiment of the present disclosure, the mounting column is provided with a plurality of locking tongues spaced apart, and an inner wall of the sprayer is provided with a mounting groove fitted with the locking tongues. 
     According to an embodiment of the present disclosure, the spraying assembly for the dish washing machine further includes a pressing plate, the pressing plate is provided on the bottom shell and connected to the bottom shell, and at least a part of the pressing plate is pressed on the spraying seat. 
     According to an embodiment of the present disclosure, the second sun gear is integrally formed with the drive shaft, the planetary gear is integrally formed with the sprayer, and the second gear is integrally formed with the spraying seat. 
     The dish washing machine according to embodiments of a second aspect of the present disclosure includes the spraying assembly for the dish washing machine according to the above-mentioned embodiments. 
     Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 2  is a sectional view of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 3  is a simplified diagram of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 4  is a schematic view of a bottom shell of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 5  is a schematic view of a spraying seat of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 6  is a schematic view of a sprayer of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 7  is an assembly view of a drive shaft and a second sun gear of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 8  is schematic view of a first sun gear of a spraying assembly for a dish washing machine according to embodiments of the present disclosure. 
         FIG. 9  illustrates motion tracks of respective spraying orifices of a spraying assembly for a dish washing machine according to an embodiment of the present disclosure. 
         FIG. 10  illustrates motion tracks of respective spraying orifices of a spraying assembly for a dish washing machine according to another embodiment of the present disclosure. 
         FIG. 11  illustrates motion tracks of respective spraying orifices of a spraying assembly for a dish washing machine according to a further embodiment of the present disclosure. 
         FIG. 12  illustrates motion tracks of respective spraying orifices of a spraying assembly for a dish washing machine according to an embodiment of the present disclosure. 
         FIG. 13  illustrates motion tracks of respective spraying orifices of a spraying assembly for a dish washing machine according to a further embodiment of the present disclosure. 
         FIG. 14  illustrates motion tracks of respective spraying orifices of a spraying assembly for a dish washing machine according to another embodiment of the present disclosure. 
         FIG. 15  illustrates motion tracks of respective spraying orifices of a spraying assembly for a dish washing machine according to a further embodiment of the present disclosure. 
     
    
    
     REFERENCE NUMERALS 
     spraying assembly  100 ; 
     bottom shell  10 ; water storage chamber  11 ; water inlet  12 ; fixing shaft  13 ; 
     spraying seat  20 ; water input passage  21 ; mounting portion  22 ; mounting column  23 ; locking tongue  231 ; 
     sprayer  30 ; first spraying arm  301   c ; second spraying arm  302   c ; third spraying arm  303   c ; spraying arm  31 ; spraying orifice  311 ; mounting groove  32 ; sleeve  33 ; 
     actuator  40 ; 
     first sun gear  51 ; bulge  511 ; drive shaft  52 ; groove  521 ; first gear  53 ; planetary gear  54 ; second sun gear  55 ; second gear  56 ; 
     pressing plate  60 . 
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure will be described in detail in the following, and examples of the embodiments are illustrated in the drawings. The embodiments described herein with reference to drawings are explanatory and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure. 
     A spraying assembly  100  for a dish washing machine according to embodiments of a first aspect of the present disclosure will be described in detail with reference to  FIGS. 1-8 . 
     As illustrated in  FIGS. 1 and 2 , the spraying assembly  100  for the dish washing machine according to embodiments of the present disclosure includes a bottom shell  10 , a spraying seat  20 , a sprayer  30  and an actuator  40 . Specifically, the bottom shell  10  defines a water storage chamber  11  therein. The bottom shell  10  has a water inlet  12  in communication with the water storage chamber  11 . The spraying seat  20  is rotatably disposed on the bottom shell  10 . The spraying seat  20  has a water input passage  21  in communication with the water storage chamber  11 . The sprayer  30  includes at least one spraying arm  31 . The sprayer  30  is rotatably provided to spraying seat  20  and a rotation center of the sprayer  30  is eccentrically arranged with respect to a rotation center of the spraying seat  20 . The sprayer  30  has a plurality of spraying orifices  311  spaced apart, and each spraying orifice  311  is in communication with the water input passage  21 . The actuator  40  is connected to the sprayer  30  and the spraying seat  20  respectively, so as to drive the sprayer  30  and the spraying seat  20  to rotate around their respective rotation centers. 
     That is to say, the spraying assembly  100  for the dish washing machine is mainly composed of the bottom shell  10 , the spraying seat  20 , the sprayer  30  and the actuator  40 . The water storage chamber  11  having an opening upper end is defined in the bottom shell  10 . A side wall or a bottom wall of the bottom shell  10  is provided with the water inlet  12  in communication with the water storage chamber  11 , thus making it convenient for a system to inject washing water into the water storage chamber  11 . The spraying seat  20  is disposed on the bottom shell  10  to close an opening upper end of the bottom shell  10 , and the spraying seat  20  is rotatable with respect to the bottom shell  10 . The spraying seat  20  has the water input passage  21  extending in a vertical direction (an up and down direction as illustrated in  FIG. 2 ). The water input passage  21  is in communication with the water storage chamber  11 . Advantageously, an inner wall of the bottom shell  10  is provided with the water inlet  12 , and the washing water enters the water storage chamber  11  in a substantially tangential direction, then flows along an annular flow channel in the water storage chamber  11  to fill the whole water storage chamber  11 , finally flows out of the water input passage  21  in the spraying seat  20 , and flows to the respective spraying arms  31 . 
     Furthermore, the actuator  40  is disposed below the bottom shell  10  and is connected to the spraying seat  20 , so as to drive the spraying seat  20  to rotate. The sprayer  30  is disposed in an eccentric position of the spraying seat  20  and is rotatable with respect to the spraying seat  20 . The sprayer  30  has at least one spraying arm  31 . Each spraying arm  31  is provided with the plurality of spraying orifices  311  spaced apart in a length direction of the spraying arm  31 . Each spraying orifice  311  is in communication with the water input passage  21 . 
     During the operations of the spraying assembly  100  for the dish washing machine, the actuator  40  drives the spraying seat  20  to rotate around a central axis of the spraying seat  20 . In this process, since the sprayer  30  is disposed in the eccentric position of the spraying seat  20 , the sprayer  30  has a circular motion with respect to the spraying seat  20 , and also has a motion with a changing rotation center in relative to the bottom shell  10 . The washing water enters the water storage chamber  11  through the water inlet  12  of the bottom shell  10 , then flows to each spraying arm  31  through the water input passage  21 , and jets out of the plurality of spraying orifices  311 , thus reaching the objective of dish washing, and also achieving a wide washing coverage. 
     Thus, in the spraying assembly  100  for the dish washing machine according to embodiments of the present disclosure, the sprayer  30  is rotatably disposed in the eccentric position of the spraying seat  20  which is rotatable with respect to the bottom shell  10 , such that each spraying orifice  311  of the sprayer  30  has an epicycloid motion track, e.g., a spray-wash area is substantially quadrate, thereby enlarging the washing area of the spraying assembly  100 , and hence solving the problem that the dish washing machine in the related art cannot wash a dead corner of an inner tub. The spraying assembly  100  for the dish washing machine has a simple structure, a wide washing coverage, a good washing effect and a high user experience. 
     According to an embodiment of the present disclosure, the spraying assembly  100  for the dish washing machine further includes a driving transmission member and a driven transmission member. Specifically, the driving transmission member is connected to the actuator  40  and the sprayer  30 , the driving transmission member is driven by the actuator  40  and drives the sprayer  30  to rotate, the driven transmission member is connected to the driving transmission member and the spraying seat  20 , and the driven transmission member is driven by the driving transmission member and drives the spraying seat  20  to rotate. 
     In other words, the spraying assembly  100  for the dish washing machine is mainly composed of the bottom shell  10 , the spraying seat  20 , the sprayer  30 , the driving transmission member, the driven transmission member and the actuator  40 . The driving transmission member is connected to the actuator  40  and the sprayer  30  respectively. The driven transmission member is connected to the spraying seat  20 , and the driving transmission member is fitted with the driven transmission member. When the spraying assembly  100  for the dish washing machine starts operating, the actuator  40  drives the driving transmission member to move, such that the driving transmission member drives the sprayer  30  to rotate with respect to the spraying seat  20 , and the driving transmission member also drives the driven transmission member to move, so as to drive the spraying seat  20  to rotate with respect to the bottom shell  10 . Thus, by arranging the driving transmission member and the driven transmission member to the spraying seat  20  and the bottom shell  10  respectively, a washing rotation speed required by a system of the dish washing machine is satisfied and transmissions of motion and power are facilitated. 
     Optionally, according to an embodiment of the present disclosure, the driving transmission member includes a first sun gear  51  and a drive shaft  52 . A first end of the drive shaft  52  is connected to the actuator  40 , and the first sun gear  51  is connected to a second end of the drive shaft  52 . The first sun gear  51  is coaxial with the drive shaft  52  and is driven by the drive shaft  52 . The sprayer  30  is provided with a planetary gear  54  engaged with the first sun gear  51 . 
     Specifically, as illustrated in  FIG. 2 , the driving transmission member is mainly composed of the first sun gear  51  and the drive shaft  52 . The drive shaft  52  extends in the vertical direction (the up and down direction illustrated in  FIG. 2 ), and the drive shaft  52  is mounted to the spraying seat  20  and is rotatable with respect to the spraying seat  20 . The first end (a lower end as illustrated in  FIG. 2 ) of the drive shaft  52  is connected to the actuator  40 , and the second end (an upper end as illustrated in  FIG. 2 ) of the drive shaft  52  is connected to the first sun gear  51 . A lower end of the sprayer  30  is provided with the planetary gear  54 , and the planetary gear  54  is engaged with the first sun gear  51 . 
     When the actuator  40  is started, the actuator  40  drives the drive shaft  52  to rotate around a central axis of the drive shaft  52 , and the upper end of the drive shaft  52  drives the first sun gear  51  to rotate around the central axis of the drive shaft  52 , such that the spraying seat  20  drives the sprayer  30  to rotate around the central axis of the drive shaft  52  (a revolution of the sprayer  30 ). In the meantime, the first sun gear  51  is engaged with the planetary gear  54 , such that the sprayer  30  rotates around a central axis of the planetary gear  54  (a rotation of the sprayer  30 ). The lower end of the drive shaft  52  is fitted with the driven transmission member, so as to drive the spraying seat  20  to rotate around the central axis of the drive shaft  52 . Since the planetary gear  54  is located in the eccentric position of the spraying seat  20 , when the spraying assembly  100  for the dish washing machine starts operating, the sprayer  30  rotates with respect to the spraying seat  20 , and the spraying seat  20  rotates with respect to the bottom shell  10 . 
     In some specific embodiments of the present disclosure, a gear ratio of the first sun gear  51  to the planetary gear  54  is 1:3. Since the first sun gear  51  is externally engaged with the planetary gear  54 , the rotation and the revolution of the planetary gear  54  have the same direction. Optionally, the gear ratio of the first sun gear  51  to the planetary gear  54  is 1:3. For example, the first sun gear  51  has 30 teeth, and the planetary gear  54  has 90 teeth. Thus, a ratio of a pitch radius R 1  of the first sun gear  51  to a pitch radius R 2  of the planetary gear  54  is 1:3 as well, and a radius R 3  of a revolution trajectory of the planetary gear  54  is equal to a sum of R 1  and R 2 . 
     Furthermore, due to the gear ratio and the external engagement between the first sun gear  51  and the planetary gear  54 , ends of the respective spraying arms  31  present a prolate epicycloid motion track, thus covering a rectangle area better. Moreover, an angle of a phase difference between motion tracks of two spraying arms  31  is equal to 3/2 times of an angle of a phase difference between the two spraying arms  31 . 
     For a single spraying arm  31 , each spraying orifice  311  of the single spraying arm  31  has a characteristic epicycloid motion track. For the relatively outer spraying orifice  311 , a distance from the spraying orifice  311  to a center of the planetary gear  54  is larger than four times of the pitch radius R 2  of the planetary gear  54 , and the motion track of such spraying orifice  311  is a prolate epicycloid. The curve does not cross itself, front and rear parts of the curve are curved outwards, and left and right parts of the curve are slightly curved inwards. With the position of the spraying orifice  311  moving inwards, the inwards curved portion of the prolate epicycloid motion track gradually gets obvious, a radius of a transition rounded corner is gradually reduced, and four corners gradually become sharp. When the distance from the spraying orifice  311  to the center of the planetary gear  54  is equal to four times of the pitch radius R 2  of the planetary gear  54 , the transition rounded corner at the inwards curved portion is just disappeared, the overall prolate epicycloid motion track of the spraying orifice  311  is a kidney-shaped curve with the front and rear parts thereof being curved outwards. Then, for the relatively inner spraying orifice  311 , the distance from such spraying orifice  311  to the center of the planetary gear  54  is less than four times of the pitch radius R 2  of the planetary gear  54 , the inwards curved portion of the prolate epicycloid motion track has a crossed shape. Finally, for the spraying orifice  311  which is located at the center of the planetary gear  54 , the motion track of such spraying orifice  311  is a revolution trajectory, i.e., a circle of radius R 3 . 
     Thus, the gear ratio of the first sun gear  51  to the planetary gear  54  is set as 1:3, such that each spraying orifice  311  of the sprayer  30  has the epicycloid motion track, e.g., the spray-wash area is substantially rectangle, thereby enlarging the washing area of the spraying assembly  100 , and hence solving the problem that the dish washing machine in the related art cannot wash the dead corner of the inner tub. The spraying assembly  100  for the dish washing machine has a simple structure, a wide washing coverage, a good washing effect and a high user experience. 
     In other specific embodiments of the present disclosure, the gear ratio of the first sun gear  51  and the planetary gear  54  is 1:5. For example, the first sun gear  51  has 20 teeth, and the planetary gear  54  has 100 teeth. Thus, the ratio of the pitch radius R 1  of the first sun gear  51  to the pitch radius R 2  of the planetary gear  54  is 1:5 as well, and the radius R 3  of the revolution trajectory of the planetary gear  54  is equal to the sum of R 1  and R 2 . Furthermore, due to the gear ratio and the external engagement between the first sun gear  51  and the planetary gear  54 , the ends of the respective spraying arms  31  each present the prolate epicycloid motion track, thus covering a square area better. Moreover, an angle of a phase difference between motion tracks of two spraying arms  31  is equal to 5/4 times of an angle of a phase difference between the two spraying arms  31 . 
     For a single spraying arm  31 , each spraying orifice  311  of the single spraying arm  31  has a characteristic epicycloid motion track. For the relatively outer spraying orifice  311 , the distance from such spraying orifice  311  to the center of the planetary gear  54  is larger than six times of the pitch radius R 2  of the planetary gear  54 , the motion track of the spraying orifice  311  is a four-leaved prolate epicycloid. The curve does not cross itself, and four corners of the curve are curved outwards. With the position of the spraying orifice  311  moving inwards, the four inwards curved portions of the motion track gradually get obvious, the radius of the transition rounded corner is gradually reduced, and hence the corner gradually becomes sharp. When the distance from the spraying orifice  311  to the center of the planetary gear  54  is equal to six times of the pitch radius R 2  of the planetary gear  54 , i.e., five times of the revolution radius R 3 , the transition rounded corners at the four inwards curved portions are just disappeared and become into four pointed corners. Then, for the relatively inner spraying orifice  311 , the distance from the spraying orifice  311  to the center of the planetary gear  54  is less than six times of the pitch radius R 2  of the planetary gear  54 , the inwards curved portion of the prolate epicycloid motion track defines has a crossed shape. Finally, for the spraying orifice  311  which is located at the center of the planetary gear  54 , the motion track of such spraying orifice  311  is a revolution trajectory, i.e., a circle of radius R 3 . 
     During the operation of the spraying assembly  100  for the dish washing machine, the actuator  40  drives the spraying seat  20  to rotate around the central axis of the spraying seat  20 . In this process, since the sprayer  30  is disposed in the eccentric position of the spraying seat  20 , the sprayer  30  has a circular motion with respect to the spraying seat  20 , and also has a motion with a changing rotation center with respect to the bottom shell  10 . The washing water enters the water storage chamber  11  through the water inlet  12  of the bottom shell  10 , then flows to each spraying arm  31  through the water input passage  21 , and jets out of the plurality of spraying orifices  311 , thus reaching the objective of dish washing, and also achieving a wide washing coverage. 
     Thus, the sprayer  30  is rotatably disposed in the eccentric position of the spraying seat  20  which is rotatable with respect to the bottom shell  10 , and the gear ratio of the first sun gear  51  to the planetary gear  54  is set as 1:5, such that each spraying orifice  311  of the sprayer  30  has an epicycloid motion track, e.g., the spray-wash area is substantially square, thereby enlarging the washing area of the spraying assembly  100 , solving the problem that the dish washing machine in the related art cannot wash the dead corner of the inner tub. The spraying assembly  100  for the dish washing machine has a simple structure, a wide washing coverage, a good washing effect and a high user experience. 
     Optionally, the driven transmission member is configured as a first gear  53  provided to the bottom shell  10 , the first end of the drive shaft  52  is provided with a second sun gear  55  engaged with the first gear  53 , the spraying seat  20  is provided with a second gear  56  engaged with the first gear  53 , the second sun gear  55  cooperates with the first gear  53  and the second gear  56  to drive the spraying seat  20  to rotate. 
     Specifically, as illustrated in  FIG. 2 , the second sun gear  55  is fixedly provided to the lower end of the drive shaft  52 , the bottom shell  10  is provided with the first gear  53  which is rotatable, and the lower end of the spraying seat  20  is provided with the second gear  56 . The first gear  53  includes two toothed parts having different amounts of teeth and the two toothed parts are engaged with the second gear  56  and the second sun gear  55  correspondingly. When the spraying assembly  100  for the dish washing machine starts operating, the drive shaft  52  drives the first sun gear  51  and the second sun gear  55  to rotate around the central axis of the drive shaft  52 . The second sun gear  55  on the drive shaft  52  is engaged with the first gear  53 , such that the first gear  53  drives the spraying seat  20  to rotate around the central axis of the drive shaft  52  by the engagement with the second gear  56 . The first sun gear  51  on the drive shaft  52  drives the sprayer  30  to rotate around the central axis of the planetary gear  54  by the engagement with the planetary gear  54 . Thus, the spraying assembly  100  for the dish washing machine has a transmission system which is simple in structure, easy to dismount and mount, effortless to operate, low in cost and also can transmit motions accurately. 
     Optionally, as illustrated in  FIG. 4 , a lower end of the bottom shell  10  is provided with a fixing shaft  13 , the first gear  53  is mounted to the fixing shaft  13  and is rotatable with respect to the fixing shaft  13 , thus facilitating the mounting of the first gear  53 , and thereby achieving functional requirements of the spraying assembly  100  for the dish washing machine. 
     As illustrated in  FIG. 5 , according to an embodiment of the present disclosure, the spraying seat  20  has a mounting portion  22  penetrating the bottom shell  10  and extending downwards, and the mounting portion  22  is configured as a hollow column coaxial with the drive shaft  52 . The upper end of the drive shaft  52  passes through the mounting portion  22  to be connected to the first sun gear  51 , and the lower end of the drive shaft  52  is provided with the second sun gear  55 . The first gear  53  is disposed at a bottom portion of the bottom shell  10 , and a lower end of the mounting portion  22  is provided with the second gear  56 . 
     Specifically, the mounting portion  22  is located in the center of the spraying seat  20  and extends downwards in an axial direction (an up and down direction as illustrated in  FIG. 5 ) of the spraying seat  20 . The mounting portion  22  defines a cavity therein for mounting the drive shaft  52 , and the drive shaft  52  penetrates the cavity and is rotatable with respect to the mounting portion  22 . The upper and lower ends of the drive shaft  52  extend out of the cavity, so as to be provided with the first sun gear  51  and the second sun gear  55  correspondingly. The second sun gear  55  is engaged with the first gear  53  on the fixing shaft  13  of the bottom shell  10 , and the first sun gear  51  is engaged with the planetary gear  54  of the sprayer  30 . 
     Furthermore, the spraying seat  20  is provided with a mounting column  23  eccentrically provided with respect to a rotation center of the spraying seat  20 , the mounting column  23  defines the water input passage  21  therein, and the sprayer  30  is fitted over the mounting column  23  and is rotatable with respect to the mounting column  23 . Specifically, the sprayer  30  includes a sleeve  33  extending in the vertical direction, and the planetary gear  54  is provided at a lower end of the sleeve  33 . When the sprayer  30  is mounted to the spraying seat  20 , the spraying seat  20  serves as a planetary gear carrier for the planetary gear  54 , so as to ensure the revolution trajectory of the planetary gear  54 . At an upper end of the sleeve  33  of the sprayer  30 , one or more spraying arms  31  extend outwards from the center of the planetary gear  54 , and each spraying arm  31  is provided with a plurality of spraying orifices  311 . Advantageously, a part of the spraying orifices  311  is used for washing, and other spraying orifices  311  are mostly used for forcing a horizontal rotation of the spraying arm  31  as well as the planetary gear  54 , thereby providing power for the rotation of the sprayer  30 . 
     Optionally, as illustrated in  FIGS. 5 and 6 , the mounting column  23  is provided with a plurality of locking tongues  231  spaced apart, and an inner wall of the sprayer  30  is provided with a mounting groove  32  fitted with the locking tongues  231 . Thus, it is ensured that the sprayer  30  can be snapped with the spraying seat  20 , so as to avoid the sprayer  30  from being disengaged with the spraying seat  20  during operations, and also, the relative rotation between the sprayer  30  and the spraying seat  20  is ensured, such that rotations of the sprayer  30  and the planetary gear  54  can be achieved. 
     According to an embodiment of the present disclosure, the upper end of the drive shaft  52  is provided with a plurality of grooves  521  spaced apart, and an inner ring of the first sun gear  51  is provided with a plurality of bulges  511  correspondingly fitted with the grooves  521 . Specifically, as illustrated in  FIG. 7 , a side wall of the upper end of the drive shaft  52  is provided with the plurality of grooves  521  spaced apart in its circumferential direction, and an inner wall of the first sun gear  51  is provided with the plurality of bulges  511  correspondingly fitted with the grooves  521 , thus ensuring the first sun gear  51  to be fixedly connected to the drive shaft  52 , and hence improving the connection reliability of the spraying assembly  100  for the dish washing machine. 
     In some specific embodiments of the present disclosure, the end of the drive shaft  52  which is fitted with the first sun gear  51  is configured as a spline shaft, and the spline shaft is snapped with the first sun gear  51 . 
     Specifically, an inner wall of the first sun gear  51  is provided with a splined hole, and four bulges  511  are provided in the splined hole. When mounted, the first sun gear  51  is sleeved onto the spline shaft of the drive shaft  52 , till the four bulges  511  are correspondingly locked in four grooves  521  of the spline shaft, thereby achieving the fixation of the first sun gear  51 . Such connection structure can achieve the fit between the drive shaft  52  and the first sun gear  51 , and is simple in structure, easy to produce and high in efficiency of mounting and dismounting. 
     Preferably, according to an embodiment of the present disclosure, the spraying seat  20  is a rotary body, and a central axis of the spraying seat  20  coincides with the central axes of the bottom shell  10  and the drive shaft  52 . In addition, the spraying assembly  100  for the dish washing machine further includes a pressing plate  60 , the pressing plate  60  is provided on the bottom shell  10  and is connected to the bottom shell  10 , and at least a part of the pressing plate  60  is pressed on the spraying seat  20 . 
     Specifically, as illustrated in  FIG. 2 , the spraying seat  20  is located between the first sun gear  51  and the bottom shell  10 , the central axes of the spraying seat  20 , the first sun gear  51  and the bottom shell  10  coincide with one another, and a main body of the spraying seat  20  is a round rotary disk. When mounted, the water storage chamber  11  of the bottom shell  10  is covered by the spraying seat  20  first, and the mounting portion  22  of the spraying seat  20  extends into the water storage chamber  11 . Then, an outer ring of the spraying seat  20  is pressed by the pressing plate  60 . At this time, the drive shaft  52  is inserted into the mounting portion  22  and extends out of the spraying seat  20 , and then the first sun gear  51  is fitted with the upper end of the drive shaft  52 . Finally, the sprayer  30  is mounted to the mounting column  23  of the spraying seat  20 , and the planetary gear  54  on the sprayer  30  is engaged with the first sun gear  51  on the drive shaft  52 . Therefore, the spraying seat  20  is embedded between the pressing plate  60  and the bottom shell  10 , and can rotate with respect to the pressing plate  60  and the bottom shell  10 . 
     Preferably, according to an embodiment, the second sun gear  55  is integrally formed with the drive shaft  52 , the planetary gear  54  is integrally formed with the sprayer  30 , and the second gear  56  is integrally formed with the spraying seat  20 . Thus, an integrally formed structure ensures stability of the structure and property of the spraying assembly  100  for the dish washing machine, is convenient to mold and easy to produce, and also omits needless assembly parts and connecting processes, thus greatly improving the assembly efficiency of the spraying assembly  100  for the dish washing machine, and ensuring the connection reliability of the spraying assembly  100  for the dish washing machine. Moreover, the integrally formed structure has high overall strength and stability, is easy to assemble and provides a long service life. 
     The spraying assembly  100  for the dish washing machine according to embodiments of the present disclosure will be described with reference to specific embodiments illustrated in  FIGS. 1-15 . 
     Embodiment One 
     As illustrated in  FIGS. 1-9 , in the present embodiment, the first sun gear  51  is fixed in a center position at the bottom of the inner tub of the dish washing machine, the inner wall of the first sun gear  51  is provided with the splined hole, and the four bulges  511  are provided in the splined hole defines. When mounted, the first sun gear  51  is sleeved onto the spline shaft of the drive shaft  52 , till the four bulges  511  are correspondingly locked in four grooves  521  of the spline shaft, thereby achieving the fixed connection of the first sun gear  51  with the drive shaft  52 . The water storage chamber  11  in the bottom shell  10  is an annular flow channel, and the side wall of the bottom shell  10  is provided with the water inlet  12 , such that the washing water enters the water storage chamber  11  in the substantially tangential direction, then flows along the annular flow channel to fill the whole water storage chamber  11 , finally flows out of the water input passage  21  of the spraying seat  20 , and flows to the spraying arm  31 . 
     As illustrated in  FIG. 9 , in the present embodiment, the gear ratio of the first sun gear  51  to the planetary gear  54  is 1:3, in which the spraying assembly  100  for the dish washing machine includes one spraying arm  31 . According to the gear ratio and the external engagement between the first sun gear  51  and the planetary gear  54 , the end of the spraying arm  31  presents the prolate epicycloid motion track which is substantially rectangle, thus achieving a great coverage of a rectangle spraying area. Specifically, a curvilinear equation of the prolate epicycloid motion track includes:
 
 x =( R 1+ R 2)*cos(ang)− D *cos[( R 1*ang/ R 2]
 
 y =−( R 1+ R 2)*sin(ang)+ D *sin[( R 1*ang/ R 2].
 
     D denotes a distance between the spraying orifice  311  and the center of the planetary gear  54 , R 1  denotes a pitch radius of the first sun gear  51 , and R 2  denotes a pitch radius of the planetary gear  54 . 
     For example, modules of the first sun gear  51  and the planetary gear  54  are set as 0.5, the first sun gear  51  has 30 teeth, and the planetary gear  54  has 90 teeth. It can be seen that, a ratio of the pitch radius R 1  of the first sun gear  51  to the pitch radius R 2  of the planetary gear  54  is also 1:3. Specifically, R 1  is equal to 7.5 mm, R 2  is equal to 22.5 mm, and a radius R 3  of a revolution trajectory of the planetary gear  54  is equal to a sum of R 1  and R 2 , i.e. 30 mm. 
     Furthermore, the distance from the relatively outer spraying orifice  311  in the spraying arm  31  to the center of the planetary gear  54  is larger than four times of the pitch radius R 2  of the planetary gear  54 , i.e. 90 mm, and the motion track of such spraying orifice  311  is the prolate epicycloid. The curve does not cross itself, front and rear parts of the curve are curved outwards, and left and right parts of the curve are slightly curved inwards. With the position of the spraying orifice  311  moving inwards, the inwards curved portion of the prolate epicycloid motion track gradually gets obvious, a radius of a transition rounded corner is gradually reduced, and four corners gradually become sharp. When the distance from the spraying orifice  311  to the center of the planetary gear  54  is equal to 90 mm, the transition rounded corner at the inwards curved portion is just disappeared, the overall prolate epicycloid motion track of the spraying orifice  311  is a kidney-shaped curve with the front and rear parts thereof being curved outwards. Then, for the relatively inner spraying orifice  311 , the distance from such spraying orifice  311  to the center of the planetary gear  54  is less than 90 mm, and the inwards curved portion of the prolate epicycloid motion track has a crossed shape. Finally, for the spraying orifice  311  which is located in the center of the planetary gear  54 , the motion track of such spraying orifice  311  is the revolution trajectory, i.e., a circle of radius 30 mm. 
     When the spraying assembly  100  for the dish washing machine operates, due to a recoiling action of water spraying by a part of the spraying orifices  311  in the spraying arm, the spraying arm  31  along with the planetary gear  54  are driven to rotate. Due to the gear engagement, the spraying arm  31  along with the planetary gear  54  orbit the first sun gear  51  while rotating. The rotation and the revolution have the same direction, and a rotation speed ratio of the rotation to the revolution is 1:3. 
     Embodiment Two 
     As illustrated in  FIG. 10 , in the present embodiment, the gear ratio of the first sun gear  51  to the planetary gear  54  is 1:3, and the sprayer  30  has two spraying arms  31 . That is, two spraying arms  31  extend outwards from the center of the planetary gear  54 , and the two spraying arms  31  are diagonally arranged with a phase difference of 180° therebetween. The two spraying arms  31  each are provided with a group of spraying orifices  311 . According to the gear ratio 1:3 and the external engagement between the first sun gear  51  and the planetary gear  54 , motion tracks of two spraying arms  31  have a phase difference, which is equal to 3/2 times of the phase difference between the two spraying arms  31 , and specifically is 270°. That is, the two motion tracks are perpendicular to each other. 
     The spraying orifices  311  in the two spraying arms  31  have a characteristic prolate epicycloid motion track respectively, whose features are consistent with descriptions of Embodiment One, and will not be elaborated herein. Moreover, since the motion tracks of the two groups of spraying orifices  311  in the two spraying arms  31  has the phase difference of 270°, the two groups of motion tracks are crossed while being perpendicular to each other, thus obtaining a great washing coverage effect within the rectangle central area. 
     Embodiment Three 
     As illustrated in  FIG. 11 , in the present embodiment, the gear ratio of the first sun gear  51  is the planetary gear  54  is 1:3, and the sprayer  30  has three spraying arms  31 , that is, three spraying arms  31  extend outwards from the center of the planetary gear  54 . Each two of the three spraying arms  31  are spaced apart from each other by an interval of 120°. Each spraying arm  31  is provided with a group of spraying orifices  311 . According to the gear ratio 1:3 and the external engagement between the first sun gear  51  and the planetary gear  54 , motion tracks of three spraying arms  31  have a phase difference, which is equal to 3/2 times of a phase difference between the three spraying arms  31 , i.e., 180° and 360°. 
     Each group of spraying orifices  311  in the three spraying arms  31  has a characteristic prolate epicycloid motion track, whose features are consistent with the descriptions of Embodiment One, and will not be elaborated herein. Moreover, since the motion tracks of the three groups of spraying orifices  311  have the phase difference of 180° or 360°, the three motion tracks have a same orientation, and are superimposed to form denser motion tracks of the spraying orifices  311 , thus achieve a better washing coverage effect within the rectangle spraying area. 
     Thus, the spraying assembly  100  for the dish washing machine can achieve a great washing coverage effect by adjusting the amount of the spraying arms  31  and the amount of the spraying orifices  311 , such that it is ensured the rectangle spraying area of the spraying assembly  100  for the dish washing machine is matched with the rectangle inner tub of the dish washing machine, thereby ensuring an all-around and multi-angle cleaning rate. 
     Embodiment Four 
     As illustrated in  FIG. 12 , in the present embodiment, the gear ratio of the first sun gear  51  to the planetary gear  54  is 1:5, and the spraying assembly  100  for the dish washing machine includes one spraying arm  31 . According to the gear ratio and the external engagement between the first sun gear  51  and the planetary gear  54 , the end of the spraying arm  31  presents a prolate epicycloid motion track which is substantially square, thus achieving a great coverage of a square spraying area. Specifically, a curvilinear equation of the prolate epicycloid motion track includes:
 
 x =( R 1+ R 2)*cos(ang)− D *cos[( R 1*ang/ R 2]
 
 y =−( R 1+ R 2)*sin(ang)+ D *sin[( R 1*ang/ R 2].
 
     D denotes a distance from the spraying orifice  311  to the center of the planetary gear  54 , R 1  denotes a pitch radius of the first sun gear  51 , and R 2  denotes a pitch radius of the planetary gear  54 . 
     For example, modules of the first sun gear  51  and the planetary gear  54  both are 0.5, the first sun gear  51  has 20 teeth, and the planetary gear  54  has 100 teeth. It can be seen that, a ratio of the pitch radius R 1  of the first sun gear  51  to the pitch radius R 2  of the planetary gear  54  is also 1:5. Specifically, R 1  is equal to 5 mm, R 2  is equal to 25 mm, and a radius R 3  of a revolution trajectory of the planetary gear  54  is equal to a sum of R 1  and R 2 , i.e. 30 mm. 
     Furthermore, according to the gear ratio 1:5 and the external engagement between the first sun gear  51  and the planetary gear  54 , as well as a rotation speed ratio 5:1 of the first sun gear  51  to the spraying seat  20  achieved by a speed-setting gear train mechanism, it can be seen that, a rotation speed of the planetary gear  54  is ⅕ of a rotation speed of the spraying seat  20 . That is, it is can be further seen that the spraying orifice  311  in the spraying arm  31  presents a special prolate epicycloid motion track. For the relatively outer spraying orifice  311 , a distance from such spraying orifice  311  to the center of the planetary gear  54  is larger than six times (i.e., 150 mm) of the pitch radius R 2  of the planetary gear  54 , and the motion track of such spraying orifice  311  is a four-leaved prolate epicycloid. The curve does not cross itself, and four corners of the curve are curved outwards. With the position of the spraying orifice  311  moving inwards, four inwards curved portions of the motion track gradually get obvious, a radius of the transition rounded corner is gradually reduced, and hence the corner gradually becomes sharp. When the distance from the spraying orifice  311  to the center of the planetary gear  54  is equal to 150 mm, i.e., five times of a revolution radius R 3 , the transition rounded corners at the four inwards curved portions are just disappeared and become into four pointed corners. Then, for the relatively inner spraying orifice  311 , the distance from such spraying orifice  311  to the center of the planetary gear  54  is less than 150 mm, and the prolate epicycloid motion track of such spraying orifice  311  has a crossed shape at the inwards curved portion. Finally, for the spraying orifice  311  located in the center of the planetary gear  54 , the motion track of such spraying orifice  311  is a revolution trajectory, i.e., a circle of radius 30 mm. 
     When the spraying assembly  100  for the dish washing machine operates, due to a recoiling action of water spraying by a part of the spraying orifices  311  in the spraying arm  31 , the spraying arm  31  along with the planetary gear  54  are driven to rotate. Due to the gear engagement, the spraying arm  31  along with the planetary gear  54  orbit the first sun gear  51  while rotating. The rotation and the revolution have the same direction, and a rotation speed ratio of the rotation to the revolution is 1:5. 
     Embodiment Five 
     As illustrated in  FIG. 13 , in the present embodiment, the gear ratio of the first sun gear  51  to the planetary gear  54  is 1:5, and the sprayer  30  has two spraying arms  31 . That is, two spraying arms  31  extend outwards from the center of the planetary gear  54 , and the two spraying arms  31  are diagonally arranged with a phase difference of 180° therebetween. The two spraying arms  31  each are provided with a group of spraying orifices  311 . According to the gear ratio 1:5 and the external engagement between the first sun gear  51  and the planetary gear  54 , motion tracks of the two spraying arms  31  have a phase difference, which is equal to 5/4 times of a phase difference between the two spraying arms  31 , and specifically is 225°. In this case, the inwards curved portion in the motion track of one of the spraying arms  31  is corresponding to the outwards curved portion in the motion track of the other one of the spraying arms  31 . 
     The spraying orifices  311  in the two spraying arms  31  have the characteristic prolate epicycloid motion tracks respectively, whose features are consistent with the descriptions of Embodiment Four, and will not be elaborated herein. Moreover, since the motion tracks of the two groups of spraying orifices  311  in the two spraying arms  31  has the phase difference of 225°, the two motion tracks are interwoven into a net in a central spraying area, thus reaching a great washing coverage effect. 
     Embodiment Six 
     As illustrated in  FIG. 14 , in the present embodiment, the gear ratio of the first sun gear  51  to the planetary gear  54  is 1:5, and the sprayer  30  has three spraying arms  31 . That is, three spraying arms  31  extend outwards from a center of the planetary gear  54 . A first spraying arm  301   c  is spaced apart from a second spraying arm  302   c  by an angle of 144°, and the first spraying arm  301   c  is spaced apart from a third spraying arm  303   c  by an angle of 144°. That is, an included angle between the second spraying arm  302   c  and the third spraying arm  303   c  is 72°. Lengths of the second spraying arm  302   c  and the third spraying arm  303   c  are about 0.618 times of a length of the first spraying arm  301   c , thereby ensuring a balance of the overall sprayer  30 . Each spraying arm  31  is provided with a group of spraying orifices  311 . Three motion tracks of the first spraying arm  301   c , the second spraying arm  302   c  and the third spraying arm  303   c  have phase differences therebetween, which are equal to 5/4 times of the phase differences of 72° and 144° among the spraying arms  31 , i.e., 90° and 180°, and therefore the three motion tracks have the same shape and orientation. 
     Each group of spraying orifices  311  in the three spraying arms  31  has a characteristic prolate epicycloid motion track, whose features are consistent with the descriptions of Embodiment Four, and will not be elaborated herein. Moreover, since the phase differences among the motion tracks of the three groups of spraying orifices  311  are 90° and 180° correspondingly, the three motion tracks have the same shape and orientation, and are superimposed to form dense motion tracks of the spraying orifices  311 , thus achieving a great washing coverage effect in a square spraying area. 
     Embodiment Seven 
     As illustrated in  FIG. 15 , in the present embodiment, the gear ratio of the first sun gear  51  to the planetary gear  54  is 1:5, and the sprayer  30  has five spraying arms  31 . That is, five spraying arms  31  extend outwards from a center of the planetary gear  54 . Two adjacent spraying arms  31  are spaced apart from each other by an angle of 72°. Each spraying arm  31  is provided with a group of spraying orifices  311 . According to the gear ratio 1:5 and the external engagement between the first sun gear  51  and the planetary gear  54 , motion tracks of the five spraying arms  31  have phase differences therebetween, which are equal to 5/4 times of the phase differences of 72° among the three spraying arms  31 , i.e., 90°, and therefore the five motion tracks have the same shape and orientation. 
     Each group of spraying orifices  311  in the five spraying arms  31  has a characteristic prolate epicycloid motion track, whose features are consistent with the descriptions of Embodiment Four, and will not be elaborated herein. Moreover, since the motion tracks of the five groups of spraying orifices  311  have the phase differences of 90°, the five motion tracks have the same shape and orientation, and finally are superimposed to form dense motion tracks of the spraying orifices  311 , thus achieving a great washing coverage effect in a square spraying area. 
     Thus, the spraying assembly  100  for the dish washing machine can achieve a better washing coverage effect by adjusting the amount of the spraying arms  31  and the amount of the spraying orifices  311 , so as to ensure that the square spraying area of the spraying assembly  100  for the dish washing machine is matched with the square inner tub of the dish washing machine, thereby achieving an all-around and multi-angle cleaning rate. 
     A dish washing machine according to embodiments of a second aspect of the present disclosure includes the spraying assembly  100  for the dish washing machine according to the above-mentioned embodiments. Since the spraying assembly  100  for the dish washing machine according to embodiments of the present disclosure has the above-mentioned technical effects, the dish washing machine according to embodiments of the present disclosure has the above-mentioned effects as well. That is, the dish washing machine has a simple structure and a wide washing coverage, and provides a quadrate (such as square and rectangle) spraying area matched with a quadrate inner tub of the dish washing machine, thereby solving the problem that the dish washing machine in the related art cannot wash a dead corner of the inner tub. Thus, the dish washing machine has a great washing effect and a high user experience. 
     Other components and operations of the dish washing machine according to embodiments of the present disclosure are known to those skilled in the art, and will not be elaborated herein. 
     In the specification, it is to be understood that terms such as “central,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial” and “circumferential” should be construed to refer to the orientation as then described or as illustrated in the drawings under discussion. These relative terms are for convenience of description and do not require that the present disclosure be constructed or operated in a particular orientation. 
     In addition, terms such as “first” and “second” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance or to imply the number of indicated technical features. Thus, the feature defined with “first” and “second” may comprise one or more of this feature. In the description of the present disclosure, “a plurality of” means two or more than two, unless specified otherwise. 
     In the present disclosure, unless specified or limited otherwise, the terms “mounted,” “connected,” “coupled,” “fixed” and the like are used broadly, and may be, for example, fixed connections, detachable connections, or integral connections; may also be mechanical or electrical connections; may also be direct connections or indirect connections via intervening structures; may also be inner communications of two elements, which can be understood by those skilled in the art according to specific situations. 
     In the present disclosure, unless specified or limited otherwise, a structure in which a first feature is “on” or “below” a second feature may include an embodiment in which the first feature is in direct contact with the second feature, and may also include an embodiment in which the first feature and the second feature are not in direct contact with each other, but are contacted via an additional feature formed therebetween. Furthermore, a first feature “on,” “above,” or “on top of” a second feature may include an embodiment in which the first feature is right or obliquely “on,” “above,” or “on top of” the second feature, or just means that the first feature is at a height higher than that of the second feature; while a first feature “below,” “under,” or “on bottom of” a second feature may include an embodiment in which the first feature is right or obliquely “below,” “under,” or “on bottom of” the second feature, or just means that the first feature is at a height lower than that of the second feature. 
     Reference throughout this specification to “an embodiment,” “some embodiments,” “one embodiment”, “another example,” “an example,” “a specific example,” or “some examples,” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases such as “in some embodiments,” “in one embodiment”, “in an embodiment”, “in another example,” “in an example,” “in a specific example,” or “in some examples,” in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples. 
     Although explanatory embodiments have been illustrated and described, it would be appreciated by those skilled in the art that the above embodiments cannot be construed to limit the present disclosure, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present disclosure.