Patent Publication Number: US-11377775-B2

Title: Washing machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority benefit of Korean Application No. 10-2019-0072390, filed on Jun. 18, 2019, and Korean Application No. 10-2018-0074382, filed on Jun. 27, 2018. The disclosures of the prior applications are incorporated by reference in their entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a washing machine and particularly to a washing machine having nozzles that spray water, discharged from a tub and circulated along a circulation pipe, into a drum. 
     2. Description of the Related Art 
     In general, a washing machine is an apparatus for removing a contaminant adhered to clothes, bedding, etc. (hereinafter, referred to as ‘the laundry’) using a chemical disintegration of water and a detergent and a physical operation such as a friction between water and the laundry. The washing machine includes a tub containing water, and a drum rotatably provided in the tub to accommodate laundry. 
     Korean Patent Application Publication No. 10-2011-0040180 (hereinafter, referred to as a “related art”) discloses a washing machine that circulates water, discharged from a tub, using a circulation pump and sprays the circulated water into a drum through a spray nozzle. The washing machine is in a structure in which a distributer is coupled to the circulation pump to distribute wash water and first and second spray paths are connected to the distributer to guide the wash water to first and second spray nozzles, respectively. In addition, the spray nozzles are connected to a gasket by connectors passing through the gasket and are connected to the spray paths. 
     The related art discloses a washing machine having two spray nozzles, but the washing machine is not capable of uniformly wetting laundry since spray directions are limited. In particular, although various new technologies for controlling rotation of the drum have been developed to provide diversity to movement of laundry loaded in the drum, it is hard to expect remarkable improvement in performance using the conventional structure. 
     In addition, the conventional technology has a complex structure because the spray nozzles need to be coupled to the gasket by passing the connectors through the gasket, the spray nozzles connected to the circulation pump need to be in number corresponding to the number of spray nozzles, and a plurality of flow paths and the plurality connectors need to be coupled, respectively. In addition, the manufacturing procedure is bothersome due to the assembling process. 
     In addition, there are many portions for connecting the pump, the spray paths, the connectors, and the spray nozzles, and wash water is likely to leak through the portions. In addition, there is also a hygiene issue because of solidification of detergent in the wash water or pigmentation of a contaminant. 
     In order to solve the problem, efforts are being made to develop a technology for guiding circulating water, discharged from a circulation pipe, to a plurality of nozzles. 
     However, there is a problem that the circulation pipe connecting the circulation pump and a distribution pipe for supplying wash water to the plurality of nozzles can intervene other structures such as a balancer. 
     In addition, in order to efficiently utilize a space inside the casing of the washing machine, the pump may be generally disposed on one side of the left and right sides of the washing machine. Accordingly, a circulating water discharging portion of a circulation pump and a circulation water introducing portion of the distribution pipe for supplying circulating water to the plurality of nozzles may not be disposed vertically, and this could misassembling of the circulation pipe that connects the circulation pump and the distribution pipe. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a washing machine having a plurality of nozzles for uniformly spraying water discharged from a tub to thereby uniformly wet laundry, and simplifying a connection structure and an assembling process between a pump and the plurality of nozzles. 
     Another object of the present invention is to provide a washing machine allowing a distribution pipe for supplying was water to a plurality of nozzles and a circulation pipe connecting the same to be placed at the right position 
     Yet another object of the present invention is to provide a washing machine that prevents the circulation pipe from moving out of the right position due to vibration of a tub. 
     Yet another object of the present invention is to provide a washing machine capable of avoiding intervention of the distribution pipe and the circulation pipe with other structures, such as a balancer and a heater. 
     Objects of the present invention should not be limited to the aforementioned objects and other unmentioned objects will be clearly understood by those skilled in the art from the following description. 
     In order to achieve the above objects, a washing machine according to an embodiment of the present invention includes a plurality of nozzles spraying water into a drum, a distribution pipe supplying water pumped by a pump to the plurality of nozzles, and a circulation pipe connecting the distribution pipe and the pump. 
     The washing machine includes a laundry entry hole formed in a front surface of a casing, an opening formed in a front surface of a tub, and a gasket connecting the laundry entry hole and the opening. 
     The nozzle is provided in an inner circumferential surface of a gasket body defining a passage of the gasket. 
     The distribution pipe includes an inlet port introducing water pumped by the pump. The inlet port is coupled to the circulation pipe. 
     The pump is disposed below the tub. The pump is disposed in one side of left and right sides with reference to the inlet port. 
     The circulation pipe is bent at least once. 
     The inlet port includes a positioning means that guides the right position of the circulation pipe. The inlet port includes an inlet pipe inserted into the circulation pipe and a first positioning protrusion protruding from the inlet pipe. 
     The first positioning protrusion protrudes from an outer circumferential surface of the inlet pipe. 
     A first positioning groove allowing the first positioning protrusion to be inserted thereinto is formed in the circulation pipe. The first positioning groove is formed at one end portion of the circulation pipe, which is coupled to the inlet port. 
     The first positioning groove is formed in a shape corresponding to the first positioning protrusion. 
     The pump may include a circulation port guiding water discharged from the tub to the distribution pipe. The circulation pipe may be coupled to the circulation port. 
     The circulation port may include a tube portion inserted into the circulation pipe, and a second positioning protrusion protruding from an outer circumferential surface of the tube portion. 
     The second positioning groove allowing the second positioning protrusion to be inserted thereinto may be formed at the other end portion of the circulation pipe, which is coupled to the circulation port. The second positioning protrusion may be formed in a shape corresponding to the second positioning protrusion. 
     The circulation pipe may include a first port coupling tube, a second port coupling tube, and a connection tube. 
     The first port coupling tube may include a first coupling portion coupled to the inlet port, and a first coupling tube portion extending downward from the first coupling portion. 
     The connection tube may be bent from the first coupling tube portion, and extend toward one side in which the pump is disposed. 
     The second port coupling tube may be connected to the connection tube and coupled to the circulation port. The second port coupling tube may include a second coupling portion allowing the circulation port to be inserted thereinto, and a corrugated tube portion extending from the second coupling portion toward the connection tube. The second port coupling portion may include a bent tube portion bent from the connection tube in a direction parallel to the coupling portion. 
     The corrugated tube portion may be relatively flexible compared to the first port coupling portion, the connection tube, and the second coupling portion. The corrugated tube portion may connect the bent tube portion and the second coupling portion. 
     The corrugated tube portion may connect the bent tube portion and the second coupling portion. 
     The washing machine may further include a balancer disposed on a front surface of the tub. The balancer may include a first balancer and a second balancer respectively disposed on left and right sides of the gasket on the front surface of the tub. A lower end portion of the first balancer and a lower end portion of the second balancer may be spaced apart from each other in a lower side of the gasket 
     The inlet port and the first port coupling tube may be disposed in a space where the lower end portions of the first and second balancers are spaced apart from each other. 
     The washing machine may include a heater heating water contained in the tub. the heater may be installed below the tub. The heater may be installed at a rear side further than the front surface of the tub. 
     The lower end portions of the first and second balancers may extend downward from a lower end portion of the front surface of the tub. 
     At least a portion of the connection tube may be disposed between one of the first and second balancers, which is disposed on the one side where the pump is disposed, and the heater. 
     The connection tube may include a first connection tube bent from the first coupling tube portion and extending in a direction where the heater is disposed, and a second connection tube bent from the first connection tube and extending toward the one side in which the pump is disposed. The second connection tube may be disposed at a rear side of the one of the first and second balancers. The second connection tube may be disposed at a front side of the tub. 
     The first connection tube may be bent from the first coupling portion and extending rearward. 
     The second connection tube may be bent from the first connection tube and extending toward the one side in which the pump is disposed. 
     The bent tube portion may be bent downward from the second connection tube. 
     The first port coupling tube and the second port coupling tube may be disposed in parallel. The first port coupling tube and the second port coupling tube may be disposed to be vertical to a virtual plane including the first and second connection tubes. 
     The circulation pipe may be fixed to the tub. The circulation pipe may be fixed to the tub by a clamp. 
     The clamp may include a first clamp and a second clamp. The first clamp may fix the first port coupling tube to the front surface of the tub. The second clamp may fix the connection tube to a lower surface of the tub. 
     The distribution pipe may include: a transport conduit branching water, introduced through the inlet port, to the left and right sides to be guided upward; and a plurality of outlet ports protruding from the transport conduit toward the gasket, and supplying water to the plurality of nozzles. The inlet port may be disposed at a position lower than the plurality of outlet ports. The inlet port may protrude downward from the transport conduit at a position lower than the plurality of outlet ports. 
     The first positioning protrusion may extend to an upper end of the inlet port. 
     The first positioning protrusion may be formed in a front side of the outer circumferential surface of the inlet pipe. 
     The details of other embodiments are included in the following description and the accompanying drawings. 
     The washing machine of the present invention may have one or more effects, as below. 
     First, a plurality of nozzles is provided on an inner circumferential surface of a gasket, and a distribution pipe connects the pump and the plurality of nozzles so as to supply water pumped by the pump to the plurality of nozzles, and thus, there is an advantageous effect of simplifying a connection structure and an assembling process between the pump and the plurality of nozzles. 
     Second, an inlet port of the distribution pipe include a first positioning protrusion, and a first positioning groove allowing the first positioning protrusion to be inserted thereinto is formed in the circulation pipe, and accordingly, it is possible to assemble the circulation pipe at the right position, thereby preventing any defect caused by misassembling, such as braking of the circulation pipe. Alternatively, the circulation pipe includes a second port coupling tube coupled to a circulation port, and the second port coupling tube includes a corrugated tube portion relatively flexible compared to a first port coupling tube, a connection tube, and a second coupling portion, and accordingly, any defect caused by misassembling, such as braking of the circulation pipe, may be prevented even though the circulation pipe moves out of the right position. 
     Third, as the circulation pipe includes the flexible corrugated tube portion, the circulation pipe may be prevented from moving out of the right position due to vibration of the tub. 
     Fourth, a first balancer and a second balancer are respectively disposed on the left and right sides with reference to the gasket, the inlet port and the first port coupling tube are disposed in a space at a lower side where the first and second balancers are spaced apart from each other. In addition, at least a portion of the connection tube connecting the first port coupling tube and the second coupling tube is disposed between a heater disposed below the tub and the balancers, and accordingly, the distribution pipe and the circulation pipe may avoid intervention with other structures such as the balancers and the heater. 
     Effects of the present invention should not be limited to the aforementioned effects and other unmentioned effects will be clearly understood by those skilled in the art from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
         FIG. 1  is a perspective view of a washing machine according to an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view of the washing machine shown in  FIG. 1 ; 
         FIG. 3  illustrates a portion of the washing machine shown in  FIG. 2 ; 
         FIG. 4  is an exploded perspective view of an assembly shown in  FIG. 3 ; 
         FIG. 5  is a perspective view of a gasket shown in  FIG. 4 ; 
         FIG. 6  is a rear view of an assembly including the gasket and a distribution pipe shown in  FIG. 4 ; 
         FIG. 7  is a front view of the assembly shown in  FIG. 6 ; 
         FIG. 8  is a perspective view of the assembly shown in  FIG. 6 ; 
         FIG. 9  is a cross-sectional view taken along line I-I in  FIG. 7 ; 
         FIG. 10  is a front view of the distribution pipe shown in 
         FIG. 4 ; 
         FIG. 11  is a perspective view of a pump shown in  FIG. 4 ; 
         FIGS. 12A and 12B  are cross-sectional views of a circulation chamber and a drain chamber in the pump shown in  FIG. 4 ; 
         FIG. 13  is a front view of an assembly including a tub, a gasket, a distribution pipe, a circulation pipe, and a pump. 
         FIG. 14  is a front view of an assembly further including a balancer in addition to the configuration shown in  FIG. 13 ; 
         FIG. 15  is a diagram illustrating a circulation pipe shown in  FIG. 4 ; 
         FIG. 16  is an enlarged view of area A shown in  FIG. 13 ; 
       and 
         FIG. 17  is an enlarged view of area B shown in  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Advantages and features of the present disclosure and methods to achieve them will become apparent from the descriptions of exemplary embodiments herein below with reference to the accompanying drawings. However, the present disclosure is not limited to exemplary embodiments disclosed herein but may be implemented in various different ways. The exemplary embodiments are provided for making the disclosure of the present disclosure thorough and for fully conveying the scope of the present disclosure to those skilled in the art. It is to be noted that the scope of the present disclosure is defined only by the claims. Like reference numerals denote like elements throughout the descriptions. 
     Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 
     Referring to  FIGS. 1 and 2 , a washing machine according to the present invention includes a casing  10  forming an exterior appearance of the washing machine, a tub  30  for containing wash water, and a drum  40  rotatably provided in the tub  30  to receive laundry. In addition, the washing machine may include a motor (hereinafter, referred to as a “driving unit”) for rotating the drum  40 . 
     A front panel  11  having a laundry entry hole  12  formed therein is disposed on a front surface of the casing  10 . A door  20  for opening and closing the laundry entry hole  12  is disposed on the front panel  11 , and a dispenser  14  for supplying detergent may be installed on the front panel  11 . 
     In addition, a water supply valve  15 , a water supply pipe  16 , and a water supply hose  17  are installed in the casing  10  so that wash water supplied after passing through the water supply valve  15  and the water supply pipe  16  is mixed with detergent in the dispenser  14  and is then supplied to the tub  30  through the water supply hose  17 . 
     Meanwhile, a direct water supply pipe  18  may be connected to the water supply valve  15  so that wash water is supplied directly to the tub  30  through the direct water supply pipe  18  without being mixed with detergent. 
     In addition, a pump  70  and a distribution pipe  80  may be installed. The pump  70  and the tub  30  may be connected via a discharge hose  72 , and the distribution pipe  80  and the pump  70  may be connected via a circulation pipe  86 . Accordingly, if the pump  70  operates, wash water contained in the tub  30  may be sprayed into the drum  40  through the distribution pipe  80  and circulate. The pump  70  may be connected to a drain pipe  74  and discharge wash water to the outside through the drain pipe  74 . 
     As described above, the pump  70  of the washing machine according to an embodiment of the present invention functions a drain pump for discharging wash water to the outside and as a circulation pump for circulating wash water. On the contrary, a drain pump and a circulation pump may be installed individually, and, in this case, it is obvious that the drain pump is connected to the drain pipe  74  and the circulation pump is connected to the circulation pipe  86 . 
     Meanwhile, the tub  30  may be formed as a single tub body or may be formed as a combination of a first tub body  30   a  and a second tub body  30   b  coupled thereto. In the embodiment of the present invention, an example in which the first tub body  30   a  and the second tub body  30   b  are coupled to form the tub  30  is described. Hereinafter, the first tub body  30   a  is referred to as a “tub”  30 . 
     The tub  30  is disposed in the casing  10 , and an opening  32  (see  FIG. 4 ) is formed at the front of the tub  30  to correspond to the laundry entry hole  12  formed in the front panel  11 . 
     The drum  40  for receiving laundry may be rotatably provided in the tub  30 . The drum  40  receives laundry, and is disposed such that an entrance hole through which laundry is loaded is disposed at a front surface. The drum  40  is rotated about an approximately horizontal rotation center line. In this case, “horizontal” does not refer to the mathematical definition thereof. That is, even in the case where the rotation center line is inclined at a predetermined angle relative to a horizontal state, the axis is more like in the horizontal state than in a vertical state, and thus, it is considered that the rotation center line is substantially horizontal. A plurality of through holes may be formed in the drum  40  so as to introduce water contained in the tub  30  into the drum  40 . 
     A plurality of lifter may be provided on an inner surface of the drum  40 . The plurality of liters may be disposed at a predetermined angle relative to the center of the drum  40 . 
     When the drum  40  is rotated, laundry repeatedly goes through an operation of being lifted by the lifter and falling. 
     A driving unit  50  for rotating the drum  40  may be further provided. A driving shaft to be rotated by the driving unit  50  may penetrate the rear of the tub  30  to be coupled to the drum  40 . 
     Preferably, the driving unit  50  includes a direct drive wash motor, and the wash motor may include a stator fixed to a rear side of the tub  30 , and a rotor rotating by a magnetic force acting in relation with the stator. The driving shaft  38   a  may rotate integrally with the rotor. 
     Referring to  FIGS. 3 and 4 , the washing machine according to an embodiment of the present invention includes a gasket  60  for connecting the casing  10  and the tub  30 , a nozzle  66  and  67  (see  FIG. 6 ) for spraying water into the drum  40 , the pump  70  for pumping water discharged from the tub  30 , and a distribution pipe  80  for guiding the water pumped by the pump  70  to the nozzle  66  and  67 , and the circulation pipe  86  for guiding the water pumped by the pump  70  to the distribution pipe  80 . In addition, the washing machine may include a balancer  90  disposed at the front surface  31  of the tub  30 , and a heater  95  installed below the tub  30 . 
     Referring to  FIGS. 3, 4, 5, and 9 , the gasket  60  includes a gasket body  61  and  62  that forms a passage  60 P connecting the laundry entry hole  12  of the casing  10  and the opening  32  of the tub  30 . An inner circumferential surface facing the central direction of the gasket body  61  and  62  of the gasket  60  may be referred to as an inner circumferential surface  62 , and an outer circumferential surface opposite thereto may be referred to the inner circumferential surface  61 . Hereinafter, the outer circumferential surface  61  and the inner circumferential surface  62  of the gasket body  61  and  62  are respectively referred to as an outer circumferential surface  61  and an inner circumferential surface  62  of the gasket  60 . 
     The inner circumferential surface  62  of the gasket  60  may form the passage  60 P connecting the laundry entry hole  12  and the opening  32 . The outer circumferential surface  61  of the gasket  60  may oppose the inner circumferential surface of the balancer  90 . The outer circumferential surface of the gasket  60  may oppose the distribution pipe  80 . 
     The gasket  60  is disposed between an edge defining the entry hole  12  of the front panel  11  and an edge defining the opening  32  of the tub  30 , and accordingly, a leakage of wash water contained in the tub  30  is prevented. 
     More specifically, the gasket  60  is formed of a flexible substance such as rubber and has an approximate cylindrical shape (hereinafter, referred to as an annular shape). For example, the gasket  60  may be formed of a substance such as Ethylene Propylene Diene Monomer (EPDM), Thermo Plastic Elastomer (TPE), or the like, but aspects of the present invention are not limited thereto. 
     As the boundary of the front side of the gasket  60  is connected to the edge of the entry hole  12  of the front panel  11  and the boundary of the rear side of the gasket  60  is connected to the edge of the opening  32  of the tub  30 , the body part  61  and  62  connecting the boundaries of the front and rear sides of the gasket  60  forms the laundry entry passage  60 P. If a space between the tub and the front panel are sealed and the door  20  is closed, the door  20  and the front end of the gasket  60  are tightly brought into contact with each other and the space between the door  20  and the gasket  60  is sealed, and therefore, leakage of wash water is prevented. 
     A front end and a rear end of the gasket  60  are annular, and the gasket  60  has a tubular shape extending from the front end to the rear end. The front end of the gasket  60  is fixed to the casing  10 , and the rear end is fixed to an entrance hole circumference  33  of the tub  30 . The gasket  60  may be formed of a flexible or elastic substance. The gasket  60  may be formed of natural rubber or synthetic resin. 
     The gasket  60  may include a casing coupling part  68   a  coupled to a circumference of the entry hole  12  of the casing  10 , a tub coupling part  68   b  coupled to a circumference of the entrance hole circumference  33  of the tub  30 , and a body part  61  and  62  extending between the casing coupling part  68   a  and the tub coupling part  68   b.    
     The casing coupling part  68   a  and the tub coupling part  68   b  have an annular shape. The gasket body may include an annular front end connected to the casing coupling part  68   a  and an annular rear end connected to the tub coupling part  68   b , and have a tubular shape extending from the front end to the rear end. 
     The circumference of the entry hole  12  of the front panel  11  is rolled outwardly, and the casing coupling part  68  may be fitted into a concave area formed by the outward rolled portion. 
     An annular groove to be wound by a wire may be formed in the casing coupling part  61 . After the wire winds around the groove  61   r , both ends of the wire are bound, and therefore, the casing coupling part  61  is tightly fixed to the circumference of the entrance hole  12   h.    
     The entrance hole circumference  33  of the tub  30 , which defines the opening  32  of the tub  30 , protrudes from the front surface  31  and is rolled outward, and the tub coupling part  68   b  is fitted in a concave area formed by the outward rolled portion. An annular groove to be wound by a clamp, which is formed of a wire, may be formed in the tub coupling part  68   b . The tub coupling part  68   b  of the gasket is coupled to the entrance opening circumference  33  of the tub, the clamp winds around the groove, and both ends of the clamp are bounded, and accordingly, the tub coupling part  68   b  may be tightly fixed to the entrance hole circumference  33  of the tub  30 . 
     While the casing coupling part  68   a  is fixed to the front panel  11 , the tub coupling part  68   b  is displaceable in accordance with movement of the tub  30 . Accordingly, the gasket body needs to be able to transform in accordance with the displacement of the tub coupling part  68   b . In order to allow the gasket body to transform easily, the gasket  60  may include a folding part  61   b  between the casing coupling part  68   a  and the tub coupling part  68   b  (or the body part), and the folding part  61   b  is folded as the tub  30  moves in a direction of eccentricity (or a radial direction). 
     Referring to  FIGS. 6 and 7 , the nozzle  66  and  67  may be provided in plural on the inner circumferential surface  62  of the gasket  60 . The nozzle  66  and  67  may include an upper nozzle  66   a  and  67   a , and a lower nozzle  66   b  and  67   b  disposed lower than the upper nozzle  66   a  and  67   a . The upper nozzle  66   a  and  67   a  may be disposed higher than the center of the gasket  60 , and the lower nozzle  66   b  and  67   b  may be disposed lower than the center of the gasket  60 . 
     A plurality of nozzles  66  and  67  may include a first nozzle  66  and a second nozzle  67  respectively disposed on the left and right sides of the inner circumferential surface  62  of the gasket. The first nozzle  66  may be disposed on the left side of the inner circumferential surface  62  of the gasket, and the second nozzle  67  may be disposed on the right side of the inner circumferential surface  62  of the gasket. 
     Each of the first nozzle  66  and the second nozzle  67  may be provided in plural. In the embodiment of the present invention, two first nozzles  66  and two second nozzles  67  are provided, but aspects of the present invention are not limited thereto. 
     The first nozzle  66  may include a first lower nozzle  66   b  disposed lower than the center of the gasket  60 , and a first upper nozzle disposed higher than the first lower nozzle  66   b . The first upper nozzle  66   a  may be disposed higher than the center of the gasket  60 . 
     The second nozzle  67  may include a second lower nozzle  67   b  disposed lower than the center of the gasket  60 , and a second upper nozzle  67   a  may be disposed higher than the second lower nozzle  67   b . The second upper nozzle  67   a  may be disposed higher than the center of the gasket  60 . 
     The first and second lower nozzles  66   b  and  67   b  may spray circulating water into the drum  40  in an upward direction. The first and second upper nozzles  66   a  and  67   a  may spray circulating water into the drum  40  in a downward direction. The circulating water refers to water that is discharged from the tub  30 , pumped by the pump  70 , guided to the distribution pipe  80 , and sprayed into the drum  40  through the nozzle  66  and  67 . 
     In the gasket  60 , there may be provided a direct nozzle for spraying water into the drum  40 , and a direct water supply pipe  18  for guiding water supplied through a water supply unit to the direct nozzle. The direct nozzle may be a whirl nozzle or a spray nozzle, but aspects of the present invention are not necessarily limited thereto. When viewed from the front, the direct nozzle may be disposed on a vertical line OV. A window  22  may protrude toward the drum  40  further than the direct nozzle. A water stream sprayed through the direct nozzle may touch the window  22 , and, in this case, the effect of cleaning the window  22  may be achieved. 
     Referring to  FIGS. 5 and 6 , the gasket  60  includes a port receiving pipe  63  and  64  having a hole formed therein to communicate with the nozzle  66  and  67 . The port receiving pipe  63  and  64  may be formed to protrude from the outer circumferential surface  61  of the gasket  60 . An outlet ports  83  and  84  described in the following are inserted into the port receiving pipe  63  and  64 , and the port receiving pipe  63  and  64  are formed to protrude from the outer circumferential surface  61  of the gasket  60 , and accordingly, it is possible to prevent that water supplied from the distribution pipe  80  to the nozzles  66  and  67  leaks through between the port receiving pipe  62  and  63  and the outlet port  83  and  84 . 
     The port receiving pipe  63  and  64  may be provided in plural, as does the above-described nozzles  66  and  67 . A plurality of port receiving pipes  63  and  64  may provide in number corresponding to the number of nozzles  66  and  67 . The port receiving pipe  63  and  64  include a first port receiving pipe  63  disposed on the left side of the outer circumferential surface  61  of the gasket, and a second port receiving pipe  64  disposed on the right side of the outer circumferential surface  61  of the gasket. 
     The first port receiving pipe  63  may include a first lower port receiving pipe  63   b  disposed lower than the center of the gasket  60 , and a first upper port receiving pipe  63   a  disposed higher than the first lower port receiving pipe  63   b . The first upper port receiving pipe  63   a  may be disposed higher than the center of the gasket  60 . The first lower port receiving pipe  63   b  communicates with the first lower nozzle  66   b , and the first upper port receiving pipe  63   a  communicates with the first upper nozzle  66   a . The first upper port receiving pipe  63   a  and the first lower port receiving pipe  63   b  may protrude in directions parallel with each other. 
     The second port receiving pipe  64  may include a second lower port receiving pipe  64   b  disposed lower than the center of the gasket  60 , and a second upper port receiving pipe  64   a  disposed higher than the second lower port receiving pipe  6   b . The second upper port receiving pipe  64   a  may be disposed higher than the center of the gasket  60 . The second lower port receiving pipe  64   b  communicates with the second lower nozzle  67   b , and the second upper port receiving pipe  64   a  communicates with the second upper nozzle  67   a . The second upper port receiving pipe  64   a  and the second lower port receiving pipe  64   b  may protrude in directions parallel with each other. 
     Referring to  FIGS. 6 and 7 , a protruding part  65  may be formed in the inner circumferential surface  62  of the gasket at a portion corresponding to the port receiving pipe  63  and  64  to protrude inward, and the nozzle  66  may be formed at the protruding part  65 . 
     The protruding part  65  may include a first protruding part  65   a , a second protruding part  65   b , a third protruding part  65   c , and a fourth protruding part  65   d  protruding inwardly at portions that respectively correspond to the first upper and lower port receiving pipes  63   a  and  63   b  and the second upper and lower port receiving pipes  64   a  and  64   b . The first upper and lower nozzles  66   a  and  66   b  and the second upper and lower nozzles  67   a  and  67   b  may be respectively formed at the first protruding part  65   a , the second protruding part  65   b , the third protruding part  65   c , and the fourth protruding part  65   d.    
     Referring to  FIGS. 8 and 9 , the gasket  60  includes a recessed portion  610  that is recessed inward further than a portion adjacent to the outer circumferential surface  61 . At least a portion of the distribution pipe  80  is disposed in the recessed portion  610 . At least a portion of a transport pipe  81  and  82  may be disposed in the recessed portion  610 . 
     The recessed portion  610  is formed to be recessed inward further than a portion adjacent to the front of the recessed portion  610 . The recessed portion  610  may be formed as a portion of the outer circumferential surface  61  of the gasket body is recessed inwardly. A riser portion  61   d  protruding outward further than the surrounding area may be formed on the outer circumferential surface  61  of the gasket body, and the recessed portion  610  may be formed on one side (a rear side) of the riser portion  61   d.    
     A rib  615  may be formed in the outer circumferential surface  61  of the gasket  60 . The rib  615  may protrude from the outer circumferential surface  61  of the gasket  60  in a radial direction of the gasket  60 . That is, the rib  615  may extend in a direction that is orthogonal to a tangent line of the outer circumferential surface  61  of the gasket  60 . 
     The distribution pipe  80  may be disposed to allow at least a portion thereof to be brought into contact with the rib  615 . At least a portion of the transport conduit  81  and  82  in the distribution pipe  80  may be brought into contact with the rib  615 . Since at least a portion of the distribution pipe  80  is disposed in the recessed portion  610 , the rib  615  may be formed in the recessed portion  610 . 
     Referring to  FIGS. 6 to 10 , the distribution pipe  80  includes the transport conduit  81  and  82  for guiding water pumped by the pump  70 , and the outlet port  83  and  84  protruding from the transport conduit  81  and  82  toward the gasket  60  and coupled to the port receiving pipe  63  and  64 . In addition, the distribution pipe  80  may include an inlet port  85  introducing water discharged from the pump  70 , and the transport conduit  82  may guide the water introduced through the inlet port  85  to the port receiving pipes  63  and  64 . 
     The transport conduit  81  and  82  of the distribution pipe  80  is disposed on the outer circumferential surface  61  of the gasket body. The distribution pipe  80  may be inserted into the gasket  60  as the outlet port  83  and  84  are inserted into the port receiving pipes  63  and  64 . The transport conduit  81  and  82  of the distribution pipe  80  may be disposed between the outer circumferential surface  61  of the gasket body and the balancer  90 . Accordingly, the distribution pipe  80  may be installed without a need for an additional space. 
     The distribution pipe  80  may be formed of synthetic resin that is harder or stiffer than the gasket  60 . The distribution pipe  80  maintains a predetermined shape in spite of vibration occurring during operation of the washing machine, and the distribution pipe  80  is relatively rigid compared to the gasket  60  that transforms in response to vibration of the tub  30 . 
     In addition, the circulation pipe  86  may be flexible to transform in response to vibration of the tub  30 . In this case, the distribution pipe  80  may be formed of synthetic resin harder or stiffer than the circulation pipe  86 . 
     The distribution pipe  80  may have an upper side  88  that is in an open ring shape. That is, the distribution pipe  80  may include an inlet port  85  through which water pumped by the pump  70  is introduced, one or more outlet ports  83  and  84  discharging the introduced water to be spayed into the drum  40 , and a transport conduit  81  and  82  connecting the inlet ports  85  and the outlet ports  83  and  84 . One end of a left conduit  81  of the transport conduit  81  and  82  and one end of a right conduit  82  of the transport conduit  81  and  82  may be connected to each other at a point where the inlet port  85  is disposed, whereas the other end of the left conduit  81  and the other end of the right conduit  82  may be separated from each other. 
     The inlet port  85  may be formed in a lower side of the transport conduit  81  and  82  to protrude downward, and the outlet port  83  and  84  may be formed at each of the left and right parts of the distribution pipe  80  to protrude inwardly (or toward the gasket). The circulation pipe  86  may be disposed between the inlet port  85  and a circulation port  87  formed in the pump  70 , so that wash water in the tub is introduced into the inlet port  85  through the circulation pipe  86 . 
     A plurality of outlet ports  83  and  84  may include an upper outlet port  83   a  and  84   a  coupled to the upper port receiving pipe  63   a  and  64   a  of the gasket  60 , and a lower outlet ports  83   b  and  84   b  coupled to the lower port receiving pipe  63   b  and  64   b  of the gasket  60 . The upper outlet port  83   a  and  84   a  and the lower outlet port  83   b  and  84   b  may protrude from the transport conduit  81  and  82  toward the gasket body  61  and  62  in directions parallel to each other (which is in other words parallel directions). The upper outlet port  83   a  and  84   a  and the lower outlet port  83   b  and  84   b  may protrude in parallel with a horizontal line passing through the center of the gasket. 
     The outlet port  83  and  84  protrudes from an inner surface of the transport conduit  81  and  82  (that is, a surface facing the outer circumferential surface  61  of the gasket) toward the center of the gasket  60 , and is inserted into the port receiving pipe  62  and  64 . The outlet port  83  and  84  may guide circulating water, flowing along the transport conduit  81  and  82 , to the nozzle  55  and  67 , so that the circulation water is sprayed into the drum  40 . 
     The outlet port  83  and  84  may be formed with a diameter a bit greater than an inner diameter of the port receiving pipe  63  and  64 , so that the outlet port  83  and  84  can be press-fitted into the port receiving pipe  63  and  64 . When the circulating water flows from the outlet port  83  and  84  toward the nozzle  66  and  67 , a reaction force in a direction against the gasket  60  may be applied to a section where the outlet port  83  and  84  is disposed in the transport conduit  81  and  82 . In order to prevent separation of the distribution pipe  80  from the gasket  60  by the reaction force, the port receiving pipe  63  and  64  may be formed to protrude outward from the outer circumferential surface  61  of the gasket, and the outlet port  83  and  84  may be formed with a diameter a bit greater than the inner diameter of the port receiving pipe  63  and  64 . 
     The outlet port  83  and  84  includes a first outlet port  83  protruding from the left conduit part  81  of the transport conduit  81  and  82  toward a vertical line OV passing through the center of the gasket  60 , and a second outlet port  84  protruding from the right conduit part  82  of the transport conduit  81  and  82  toward the vertical line OV passing through the center of the gasket  60 . The first outlet port  83  is inserted into the first port receiving pipe  63  to guide circulating water to the first nozzle  66 , and the second outlet port  84  is inserted into the second port receiving pipe  64  to guide circulating water to the second nozzle  67 . 
     The first outlet port  83  may include a first lower outlet port  83   b  inserted into the first lower port receiving pipe  63   b , and a first upper outlet port  83   a  disposed higher than the first lower outlet port  83   b  and inserted into the first upper port receiving pipe  63   a . The second outlet port  84  may include a second lower outlet port  84   b  inserted into the second lower port receiving pipe  64   b , and a second upper outlet port  84   a  disposed higher than the second lower outlet port  84   b  and inserted into the second upper port receiving pipe  64   a.    
     The inlet port  85  may be connected to the transport conduit  81  and  82  at a position lower than any of the plurality of outlet ports  83  and  84 . The inlet port  85  is connected to the transport conduit  81  and  82  at a position lower than the lower outlet ports  83  and  84 . 
     The transport conduit  81  and  82  may include a first conduit part  81  forming the left side of the transport conduit  81  and  82  with reference to the inlet port  85 , and a second conduit part  82  forming the right side of the transport conduit  81  and  82  with reference to the inlet port  85 . The first conduit part  81  and the second conduit part  82  may be connected to each other at a lower side, and the inlet port  85  may protrude downward from a point where the first and second conduit parts are connected to each other. 
     The transport conduit  81  and  82  may be formed in an arc shape of which the central angle is equal to or greater than 180°, and which has an open top side. The transport conduit  81  and  81  may be bilaterally symmetrical. The transport conduit  81  and  82  may include the first conduit part  81  disposed on the left side and the second conduit part  82  disposed on the right side. The first conduit part  81  and the second conduit part  82  may be bilaterally symmetrical about the vertical line OV passing through the center of the gasket  60 . 
     The transport conduit  81  and  82  may branch water, introduced through the inlet port  85 , to the left and right sides to guide upwardly. By branching the circulating water introduced through the inlet port, the transport conduit  81  and  82  may form a first sub-flow (water flowing along the first conduit part  81 ) and a second sub-flow (water flowing along the second conduit part  82 ). The first sub-flow may be sprayed into the drum  40  through the first nozzle  66 , and the second sub-flow may be sprayed into the drum  40  through the second nozzle  67 . 
     The transport conduit  81  and  82  may be disposed between the gasket  60  and the balancer  90 . The transport conduit  81  and  82  may be disposed in a manner in which the inner surface of the transport conduit  81  and  82  opposes the gasket  60  and the outer surface of the transport conduit  81  and  82  opposes the balancer  90 . 
     The port receiving pipe  63  and  64 , the protruding part  65 , the nozzle  66  and  67 , and the outlet port  83  and  84  may vary in number and arrangement. In addition, it may be configured to omit the protruding part  65  and the nozzle  66  and  67  and spray water from the outlet port  83  and  84  into the drum  40 . In addition, the nozzle  66  and  67  may be formed separately from the gasket  60  such that the nozzle  66  and  67  is coupled to the gasket or spaced apart from the gasket  60 . 
     Referring to  FIGS. 3 and 4 , the washing machine according to an embodiment of the present invention includes the balancer  90  disposed at the front surface  31  of the tub  30 . The balancer  90  may be fastened to the front surface  31  of the tub  30 . The balancer  90  is a weight body having a predetermined weight to reduce vibration of the tub  30 . The balancer  90  may include one or more balancers  90  disposed along a circumference of the front surface  31  of the tub  30 . 
     The balancer  90  may include a first balancer  91  and a second balancer  92  respectively disposed on the left and right sides of the front surface  31  of the tub  30 . The first balancer  91  may be disposed on the left side of the gasket  60 , and the second balancer  92  may be disposed on the right side of the gasket  60 . 
     A lower end portion of the first balancer  91  and a lower end portion of the second balancer  92  may be spaced apart from each other in a lower side of the gasket  60 . An upper end portion of the first balancer  91  and an upper end portion of the second balancer  92  may be spaced apart from each other in an upper side of the gasket  60 . 
     The respective lower end portions of the first and second balancers  91  and  92  may extend downward further than a lower portion of the front surface  31  of the tub  30 . A connection tube  86   c  described in the following may have at least a portion disposed at a rear side further than the lower end portions of the balancers. 
     The first and second balancers  91  and  92  may be in a shape bilaterally symmetrical about the vertical line OV passing through the center of the gasket  60 , and may be at positions bilaterally symmetrical about the vertical line OV. 
     Referring to  FIGS. 13 and 14 , the washing machine according to an embodiment of the present invention may include the heater  95  that heats water contained in the tub  30 . The heater  95  may be installed below the tub  30 . The heater  95  may be installed at a rear side further than the front surface  31  of the tub  30 . Accordingly, the heater  95  may be spaced apart from the balancer  90  in a front-and-back direction. At least a portion of the connection pipe  86   c  may be disposed in front of the heater  95 . That is, at least a portion of the connection pipe  86   c  may be disposed between the balancer  90  and the heater  95 . 
       FIG. 11  is a perspective view of the pump  11 .  FIG. 12A  is a cross-sectional view of a circulation chamber  714  (hereinafter, referred to as a “first chamber”) seen from the right side of the pump  70 .  FIG. 12B  is a cross-sectional view of a drain chamber  716  (hereinafter, referred to as a “second chamber”) seen from the left side of the pump  70 . 
     Referring to  FIGS. 2, 11, and 12 , the pump  70  may selectively perform a function of pumping water drained through the discharge hose  72  to the drain pipe  74 , and a function of pumping water drained through the discharge hose  72  to the circulation pipe  86 . The pump  70  may pump water discharged from the tub  30 . As described above, water pumped by the pump  70 , guided to the distribution pipe  70  along the circulation pipe  86 , and sprayed into the drum  40  is referred to as circulating water. 
     The pump  70  may be disposed below the tub  30 . The pump  70  may be disposed on any one of the left and right sides with respect to the center of the tub  30 . More specifically, the pump  50  may be disposed on any one of the left and right sides with respect to the inlet port  85 . In the drawings showing an embodiment of the present invention, an example in which the pump  70  is disposed on the left side with respect to the inlet port  85  is illustrated. However, the pump  70  may be disposed on the right side with respect to the inlet port  85 . 
     The pump  70  may include a pump housing  71 , a first pump motor  73 , a first impeller  75 , a second pump motor  75 , and a second impeller  717 . The pump  70  may include a circulation port  78  and a drain port  76 , which protrude from the pump housing  71  and discharge water discharged from the tub  30 . 
     A pump inlet port  711  may be formed in the pump housing  71 . The pump housing  71  may include a first chamber  714  to house the first impeller  715 , and a second chamber  716  to house the second impeller  717 . The first impeller  715  is rotated by the first motor  73 , and the second impeller  717  may be rotated by the second pump motor  75 . 
     The first chamber  716  and the circulation port  78  form a flow path in a volute shape that is rolled in a direction of rotation of the first impeller  715 . The second chamber  716  and the drain port  76  form a flow path in a volute shape that is rolled in a direction of rotation of the second impeller  716 . Here, the direction of rotation of each impeller  715  and  717  is controllable and predetermined. The pump inlet port  711  is connected to the discharge hose  72 , and the first chamber  714  and the second chamber  716  communicate with the pump inlet port  711 . Water discharged from the tub  30  through the discharge hose  72  is supplied to the first chamber  714  and the second chamber  716  through the pump inlet port  711 . 
     The first chamber  714  communicate with the circulation port  78 , and the second chamber  716  communicate with the drain port  76 . Accordingly, if the first impeller  715  is rotated upon operation of the first pump motor  73 , water contained in the first chamber  714  is discharged through the circulation port  78 . In addition, if the second pump motor  75  operates, the second impeller  717  is rotated, and, in turn, water contained in the second chamber  716  is discharged through the drain port  76 . The circulation port  78  is connected to the circulation pipe  86 , and the drain port  76  is connected to the drain pipe  74 . 
     A an amount of water to be discharged from (or discharge pressure) of the pump  70  is variable. To this end, the pump motors  73  and  75  are speed-variable motors of which speeds or rotation is controllable. Each of the pump motors  73  and  75  is preferably, but not limited to, a Brushless Direct current Motor (BLDC). A driver for controlling speeds of the pump motors  73  and  75  may be further provided, and the driver may be an inverter driver. The inverter driver inverts AC power into DC power, and inputs the DC power to the motors at a target frequency. 
     A controller for controlling the pump motors  73  and  75  may be further provided. The controller may include a Proportional-Integral (PI) controller, a Proportional-Integral-Derivative (PID) controller), and the like. The controller may receive an output value (e.g., an output current) of a pump motor, and control an output value of the driver based on the received output value of the pump motor so that the number of times of rotation of the pump motor follows a preset target number of times of rotation. 
     The controller is capable of controlling not just speeds of rotation of the pump motors  73  and  75 , but also directions of rotation thereof. In particular, an induction motor applied in a conventional pump is not capable of controlling a direction of rotation in a driving operation, and thus, it is difficult to control rotation of each impeller in a predetermined direction, as shown in  FIGS. 12A and 12B , which causes a problem that the amount of water to be discharged from the drain or circulation port  76  or  78  differs depending on directions of rotation of the impellers. On the contrary, the present invention prevents such a problem because a direction of rotation in a driving operation of the pump motors  73  and  75  is controllable, and an amount of water to be discharged through the drain or circulation port  76  or  78  may be maintained at a constant level. 
     Meanwhile, the controller is capable of controlling not just the pump motors  73  and  75 , but also overall operations of the washing machine. It is understood that each component described in the following is controlled by the controller. 
     Referring to  FIGS. 13 and 14 , the circulation pipe  76  connects the distribution pipe  80  and the pump  70 , and guide water pumped by the pump  70  to the distribution pipe  60 . One end portion  86   a   1  of the circulation pipe  86  is coupled to the inlet port  85 . The other end portion of the circulation pipe  86 , which is the opposite to one end portion  86   a   1  of the circulation pipe  86 , is coupled to the circulation port  78  of the pump  70 . 
     One end portion  86   a   1  of the circulation pipe  86  may have an inner diameter smaller than an outer diameter of the inlet port. The other end portion of the circulation pipe  86  may have an inner diameter smaller than an outer diameter of the circulation port  78 . The circulation pipe  86  may be press-fitted into the inlet port  85  of the distribution pipe  80  and the circulation port  78  of the pump  70 . Accordingly, it is possible to guide water pumped by the pump  70  to the distribution pipe  80  and prevent separation of the distribution pipe  80  from the pump  70 . 
     If the circulation port  74  is disposed at a position to face the inlet port  81  along a straight line, the circulation pipe  86  may be in the shape of a straight pipe. Yet, the pump  70  and the circulation port  78  included in the washing machine according to an embodiment of the present invention are disposed on one of the left and right sides with reference to the inlet port  85 . 
     In order to connect the inlet port  85  and the circulation port  78 , connecting the inlet port  85  and the circulation port  78  in a straight line may be considered. However, if the circulation pump  86  is configured in a straight line shape to connect the inlet port  85  and the pump  70 , this may cause intervention with the heater  95  installed below the tub  30  or with any other component. 
     For this reason, the circulation pipe  86  may be provided as a hose formed of a flexible substance and may be bent once or more. If the circulation pipe  86  is bent once or more, it is possible to efficiently utilize a space between the pump  70  and the distribution pipe  80 . 
     The circulation pipe  86  may be formed of a substance that is flexible and capable of maintaining in shape. In the embodiment of the present invention, the circulation pipe  86  may be formed of Ethylene Propylene Diene Monomer (EPDM) rubber. 
     As described above, the inlet port  84  of the distribution pipe  80  and the circulation port  78  of the pump are not aligned on a straight line, and the circulation pipe  86  is formed of a flexible substance capable of maintaining in shape. If the circulation pipe  80  moves out of the right position, a portion of the circulation pipe  80  may be bent. As a result, a flow path in the circulation pipe  80  may be narrowed or blocked. 
     In the case where the flow path in the circulation pipe  86  is narrowed or blocked, it is not possible to supply a sufficient amount of circulating water to the plurality of nozzles  66  and  67  even though the pump  70  operates normally. Further, the circulation pipe  86  may be separated or damaged by consistent use of the washing machine 
     In order to solve the problem, the inlet port may include a positioning mean that guides the right position of the circulation pipe. On the contrary, to solve the problem, the circulation pipe may include a corrugated tube portion  86   b   2 . Further, the inlet port  85  may include the positioning mean and the circulation pipe  86  may include the corrugated tube portion  86   b   2 . 
     Referring to  FIG. 16 , the inlet port  85  includes an inlet pipe  85   b  coupled to the circulation pipe  86 , and a first positioning protrusion  85   a  protruding from an outer circumferential surface of the inlet pipe  85   b . The inlet port  85  may be coupled to the circulation pipe  86  as the inlet pipe  85   b  is inserted into one end portion  86   a   1  of the circulation pipe. At one end portion  86   a   1  of the circulation pipe, a first positioning groove into which the first positioning protrusion  85   a  is inserted is formed. 
     Thus, when the distribution pipe  80  and the circulation pipe  86  are assembled, the right position of the circulation pipe  86  may be guided. In addition, the circulation pipe  86  may remain in the right position even though the tub  30  vibrates in the use of the washing machine. 
     Not just the inlet port  85  but also the circulation port  78  mat include a positioning means for guiding the right position of the circulation pipe  86 . The circulation port  78  may include a tube portion inserted into the circulation pipe  86 , and a second positioning protrusion  78   a  protruding from an outer circumferential surface of the tube portion. The circulation port  78  may be inserted into the other end portion  86   b   1  of the circulation pipe, which corresponds to the opposite to one end portion  86   a   1 , to be thereby coupled to the circulation pipe  86 . In the other end portion  86   b   1  of the circulation pipe, a second positioning groove into which the second positioning protrusion  78   a  is inserted may be formed. 
     Referring to  FIG. 15 , the circulation pipe  86  may include a first port coupling tube  86   a  coupled to the inlet port  85  of the distribution pipe  80 , a second port coupling tube  86   b  coupled to the circulation port  78  of the pump  70 , and a connection tube  86   c  connecting the first port coupling tube  86   a  and the second port coupling tube  86   b.    
     The first port coupling tube  86   a  may include a first coupling portion  86   a   1  coupled to the inlet port  85 , and a first coupling tube portion  86   a   2  extending downward from the first coupling portion  86   a   1 . The inlet port  85  may be inserted into the first coupling portion  86   a   1 . One end portion  86   a   1  of the circulation pipe described above refers to the first coupling portion  86   a   1 . The first coupling tube portion  86   a   2  may vertically extend downward from the first coupling portion  86   a   1 . 
     The first coupling portion  86   a   1  may have a diameter greater than a diameter of the first coupling tube portion  86   a   2 . Accordingly, the distribution pipe  80  and the circulation pipe  86  may be inserted in a manner in which an upper end portion of the circulation pipe  86  is inserted up to a point where the upper end portion can meet a lower end portion of the transport conduit  81  and  82  or in a manner in which a lower end portion of the inlet port  85  is inserted up to a point where the lower end portion can meet the first coupling tube portion  86   a   2 . 
     On both sides of the first port coupling tube  86   a  and the inlet port  85 , the first and second balancers  91  and  92  are spaced apart each other. In a lower side of the space between the two balancers  91  and  92 , the port coupling tube  86   a  and the inlet port  85  may be installed. The inlet port  85  is preferably formed vertically to avoid interference with the balancer  90 . Likewise, the first port coupling tube  86   a  coupled to the inlet port  85  is preferably formed vertically as well. 
     The connection tube  86   c  may connect the first port coupling tube  86   a  and the second port coupling tube  86   b , and at least a portion of the connection tube  86   c  may be disposed between the heater  95  and the balancer  90 . The connection tube  86   c  may be bent from the lower end of the first coupling tube portion  86   a   2  and extend toward one side in which the tub  70  is disposed. The connection tube  86   c  may extend toward the second port coupling tube  86   b.    
     The connection tube  86   c  may include a first connection tube  86   c   1  bent from the first coupling tube portion  86   a   2  and extending in a direction in which the heater  95  is disposed, and a second connection tube  86   c   2  bent from the first connection tube  86   c   1  and extending toward one side in which the pump  70  is disposed. 
     The first connection tube  86   c   1  may be bent from the first coupling tube portion  86   a   1  and extend to the rear. Here, the term “rear” means not just a rear side in the front-rear direction, but also a state rearwardly biased to one side of the left and right sides. 
     The first connection tube  86   c  may be bent at 90° from a lower side of the first coupling tube portion  86   a   2 . However, the bending angle is not necessarily limited to 90°. 
     The second connection tube  86   c   2  may be bent from an end portion of the rear side of the first connection tube  86   c   1  and extend toward one side of the left and right sides, where the pump  70  is disposed, with reference to the inlet port  85 . For example, if the pump  70  is disposed close to the left side of the tub  30  (or the inlet port  85 ), the second connection tube  86   c   2  may be bent to the left from the first connection tube  86   c   1 . If the pump  70  is disposed close to the right side from the tube  30  (or the inlet port  85 ), the second connection tube  86   c   2  may be bent to the right from the first connection tube  86   c   1 . 
     In front of the second connection tube  86   c   2 , one of the first and second balancers, which is disposed in one side in which the pump  70  is disposed, may be positioned. For example, as shown in  FIG. 14 , if the pump  70  is disposed on the left side and the first balancer is disposed on the left side of the gasket, the second connection tube is disposed at a rear side of the first balancer. 
     The second connection tube  86   c   2  may be disposed at a front side of the heater  95 . 
     The second connection tube  86   c   2  may extend from the first connection tube  86   c   1  to a vertical upper side of the circulation port  78 . 
     Since the pump  70  is disposed below the tub  30 , the circulation port  78  is preferably formed vertically upward from the pump housing  71 . In addition, since the circulation port  78  is formed vertically upward, the second port coupling tube  86   b  is preferably formed vertically as well. 
     The second port coupling tube  86   b  may include a second coupling portion  86   b   1  into which the circulation port is inserted, and a corrugated tube portion  86   b   2  extending from the second coupling portion  86   b   1  toward a second connection tube  86   c   2 . The other end portion  86   b   1  of the circulation pipe described above refers to the second coupling portion  86   b   1 . 
     The corrugated tube portion  86   b   2  may be connected directly to the second connection tube portion  86   b   2 , or the second port coupling tube  86   b  may include a bent tube portion  86   b   3  bent from the second connection tube  86   c   2  in a direction parallel to the second coupling portion  86   b   1 , and the corrugated tube portion  86   b   2  may connect the second coupling portion  86   b   1  and the bent tube portion  86   b   3 . 
     The corrugated tube portion  86   b   2  may be flexible relatively compared to the first port coupling tube  86   a , the connection tube  86   c , the second coupling portion  86   b   1 , and the bent tube portion  86   b   3 . 
     The second port coupling tube  86   b  is a portion adjacent to the tube  70  and may be most greatly affected by vibration occurring in driving of the pump  70 . As the second port coupling tube  86   b  includes the corrugated tube portion  86   b   2 , the second port coupling tube  86   b  may prevent delivery of the vibration of the pump  70  to the distribution pipe  80  and delivery of the vibration of the tub  30  to the pump. 
     Therefore, it is possible to prevent damage to the circulation pipe  86  in advance and reduce noise caused by vibration. 
     A bending angle of the bent tube portion  86   b   3  may be, but not limited to, 90°. 
     The first connection tube  86   c   1  and the second connection tube  86   c   2  may be disposed on the same plane, and the same plane may be a horizontal surface (a surface parallel to the bottom surface of the washing machine). The first port coupling tube  86   a  and the second port coupling tube  86   b  may be disposed to be vertical to the horizontal plane. The port coupling tube  86   a  may be disposed on the upper side of the horizontal surface, and the second port coupling tube  86   b  may be disposed on the lower side of the horizontal surface. 
     The first and second port coupling tubes  86   a  and  86   b  and the first and second connection tubes  86   c   1  and  86   c   2  may be formed separately and coupled or may be formed integrally. 
     The circulation pipe  86  may be fixed to the tub  30  by a clamp  87 . The clamp  87  may fix the circulation pipe  86  to the tub  30 , thereby preventing separation, deformation, and distortion of the circulation pipe  86  upon a supply of circulating water. The clamp  87  may include a first clamp  87   a  coupled to the front surface of the tub  30 , and a second clamp  87   b  coupled to the bottom surface of the tub  30 . 
     The first clamp  87   a  may be formed to be longer than a circumference of the first port coupling tube  86   a . The first clamp  87   a  may be disposed to surround the circumference of the first port coupling tube  86   a , and then the remaining part of the first clamp  87   a  after surrounding the circumference of the first port coupling tube  86   a  may be screw-connected to the tub  30  to fix a connecting tube portion  86   b  to the lower surface of the tub  30 . 
     Referring to  FIGS. 16 and 17 , the circulation pipe  86  is coupled to the distribution pipe  80 . The positioning protrusion  85   a  and the positioning groove  86   h   1  are formed in the distribution pipe  80  and the circulation pipe  86  to be engaged with each other. The inlet port  85  of the distribution pipe  80  includes the first positioning protrusion  85   a , and the first positioning groove  86   h   1  is formed in the first coupling portion  86   a   1  of the first port coupling tube  86   a . The circulation pipe  86  may be coupled to the inlet port  85  so that the first positioning protrusion  85   a  is inserted into the first positioning groove  86   h   1 . 
     The first positioning protrusion  85   a  protrudes from the outer circumferential surface of the inlet pipe  85   b  of the inlet port  85 . The first positioning protrusion  85   a  may extend to at least a lower side of the transport conduit  81  and  82 . That is, the first positioning protrusion  85   a  may extend to the upper end portion of the inlet pipe  85   b.    
     Meanwhile, the distribution pipe  80  may be fabricated by press-fitting a molten raw material of the transport conduit  81  and  82  in a state in which the pre-prepared outlet port  83  and  84  and the inlet port  85  are inserted into a mold. In this fabricating process, a diameter of the inlet port  85  may be smaller than a front-rear width of a portion at which the inlet port  83  protrudes from the transport conduit  81  and  82 . As a result, a step may be formed between the transport conduit  81  and  82  and the inlet port  85 . 
     The inlet port  85  may be disposed in the lower side of the transport conduit  81  and  82  and disposed at the center in the front-rear direction of the transport conduit  81  and  82 . The first positioning protrusion  85   a  may protrude from the outer circumferential surface of the inlet pipe  85   b  and may protrude by half a difference between the rear-front width of the transport conduit  81  and  82  and the diameter of the inlet pipe  85   b . That is, the first positioning protrusion  85   a  may protrude to a height corresponding to a height of the step formed between the transport conduit  81  and  82  and the inlet pipe  85   b.    
     Alternatively, as shown in  FIG. 16 , the first positioning protrusion  85   a  may have a height greater than the height of the step formed between the transport conduit  81  and  82  and the inlet pipe  85   b . In this case, the first positioning protrusion  85   a  may further protrude from one surface of the transport conduit  81  and  82 . The first positioning protrusion  85   a  may protrude from the outer circumferential surface of the inlet pipe  85   b . The first positioning protrusion  85   a  may extend to at least a lower end portion of the transport conduit  81  and  82 , which meets the inlet port  85 , and may extend in a straight line to an upper end portion of the transport conduit  81  and  82  where the inlet port  85  is disposed. 
     The first positioning protrusion  85   a  is configured to guide the right position of the circulation pipe  86  and the distribution pipe  80  to assemble, and the first positioning protrusion  85   a  is provided with a width and a length sufficient to easily assemble the circulation pipe  86  and the distribution pipe  80  in the right position. The sufficient width and length may indicate a size that allows an assembling person to notice the positions of the first positioning protrusion  85   a  and the first positioning groove  86   h   1  at a glance to thereby engage the first positioning protrusion  85   a  and the first positioning groove  86   h   1 . For example, the first positioning protrusion  85   a  may have a length equal to or greater than 1 mm or equal to or smaller than 10 mm from the lower end portion of the transport conduit  81  and  82 , and may have a width equal to or greater than 1 mm or equal to or smaller than 10 mm along the outer circumferential surface of the inlet pipe  85   b . In addition, the length and width of the first positioning protrusion  85   a  may have a size relative to inlet port  85  and the circulation pipe  86 . 
     A first guide protrusion  85   a  may be formed at the front side of the outer circumferential surface of the inlet pipe  85   b . That is, the first positioning protrusion  85   a  may be formed in the front side of the distribution pipe  80 . Accordingly, even when the distribution pipe  80  is assembled to the gasket  60 , it is possible to easily figure out the position of the first positioning protrusion  85   a  and easily assemble the circulation pipe  86  at the right position. 
     The first positioning groove  86   h   1  may be formed in the first coupling portion  86   a   1  and in a shape corresponding to the first positioning protrusion  85   a . The first positioning groove  86   h   1  may be in a shape corresponding a portion of the first positioning protrusion  85   a  which extends downward from the lower end portion of the transport conduit  81  and  82 . That is, the first positioning groove  86   h   1  may be formed to have the same width and the same length of the first positioning protrusion  85   a . Alternatively, the first positioning groove  86   h   1  may have a width and a size a bit greater than those of the first positioning protrusion  85   a , so that the first positioning groove  86   h   1  and the first positioning protrusion  85   a  are engaged easily. 
     The first positioning groove  86   h   1  may be formed on the front side of the first coupling portion  86   a   1  to correspond to the first positioning protrusion  85   a . The first positioning groove  86   h   1  may be formed to allow the inner surface and the outer surface of the first coupling portion  86   a   1  to pass therethrough. For example, the first positioning groove  86   h  may be formed by punching at an end of the first coupling portion  86   a   1 . 
     Similarly to the first positioning protrusion  85   a  and the first positioning grove  86   h   1 , the circulation port  78  may include a second positioning protrusion  78   a , and a second positioning groove  86   h   2  may be formed in the second coupling portion  86   b   1  of the circulation pipe  86 . The circulation pipe  86  may be coupled to the circulation port  78  so that the second positioning protrusion  78   a  and the second positioning groove  86   h   2  are engaged with each other. 
     Meanwhile, the circulation port  78  may have a tube portion hook portion protruding from the first chamber  714  and inserted into the circulation pipe  86 , and a hook portion disposed below the tube portion. The tube portion may have an outer diameter equal to or a bit greater than an inner diameter of the second coupling portion  86   b   1  to be thereby press-fitted into the circulation pipe  86 , and an end portion of the circulation pipe  86  may be coupled up to a point where to the end portion can meet the hook portion. 
     The second positioning protrusion  78   a  protrudes from the outer circumferential surface of the circulation port  78 . The circulation port  78  may protrude from the pump housing  71 , and the second positioning protrusion  78   a  may extend to a point where the circulation port  78  and the first chamber  714  meets each other. 
     More specifically, the second positioning protrusion  78   a  may protrude from the outer circumferential surface of the tube portion of the circulation port  78 , and partially extend at least to a point where the tube portion meets the hook portion. The second positioning protrusion  78   a  may protrude from the outer circumferential surface of the tube portion of the circulation port  78  to extend to a point where the hook portion and the first chamber  714  meets. 
     The second positioning groove  86   h   2  may be in a shape corresponding to a portion of the second positioning protrusion  78   a  which protrudes from the coupling portion of the circulation port  78 . 
     The second positioning groove  86   h   2  may be formed with the same width and the same length of the second positioning protrusion  78   a . Alternatively, the second positioning groove  86   h   2  may be formed with a length and a width that are slightly greater than a length and a width of the second positioning protrusion  78   a  so that the second positioning protrusion  78   a  and the second positioning groove  86   h   2  are easily engaged in an assembling process. 
     Unmentioned configurations about the second positioning protrusion  78   a  and the second positioning groove  86   h   2  may be identical or similar to configurations of the first positioning protrusion  85   a  and the first positioning groove  86   h   1 , respectively. 
     Although some embodiments have been described above, it should be understood that the present invention is not limited to these embodiments, and that various modifications, changes, alterations and variations can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, it should be understood that the above embodiments are provided for illustration only and are not to be construed in any way as limiting the present invention.