Patent Publication Number: US-9903067-B2

Title: Laundry machine

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a U.S. National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/KR2014/006936, filed Jul. 29, 2014, which claims priority to Korean Patent Application No. 10-2013-0136079, filed Nov. 11, 2013, whose entire disclosures are hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to a laundry machine. More specifically, the present invention relates to a laundry machine which is provided with a heat pump and is capable of preventing the heat pump from overheating. 
     BACKGROUND ART 
     Examples of laundry machines generally includes a washing machine having only a washing function of washing clothing, and a machine having both washing and drying functions. The washing machine having only a washing function is a product that removes various contaminants from clothing and bedding using the softening effect of a detergent, friction of water streams and shock applied to the laundry to according to rotation of a pulsator or a drum. A recently introduced automatic washing machine automatically performs a series of operations including a washing operation, a rinsing operation and a spin-drying operation, without requiring user intervention. 
     The laundry machine capable of drying clothes is a type of laundry machines that has not only the function of the washing machine dedicated to washing but also the function of drying the laundry after washing. 
     Laundry machines capable of drying laundry supply high-temperature air (hot air) to the laundry, and can be classified into an exhaust type and a circulation (or condensation) type depending on how air flows through the machine. 
     The exhaust type laundry machine supplies heated air to the laundry accommodating part, but discharges the air coming out of the laundry accommodating part from the laundry machine instead of circulating the air. 
     The circulation type laundry machine circulates air in a laundry accommodating part storing the laundry by removing moisture from the air (i.e., dehumidifying the air) discharged from the laundry accommodating part, heating the air, and then resupplying the air to the accommodation part. 
     Hereinafter, a conventional circulation type laundry machine having the drying function will be briefly described with reference to  FIG. 1 . As shown in  FIG. 1 , the circulation type laundry machine  1  having the drying function  1  includes a cabinet  10  provided with an introduction port  12  defining an accommodation space therein and allowing laundry to be introduced therethrough and an a door  14  to open and close the introduction port  12 , a tub  20  to accommodate the cabinet  10 , a drum  40  rotatably installed in the tub  20  to accommodate laundry to be dried, and an air supply unit  50  to supply the drying air to the tub  20  to dry the laundry. 
     Herein, the air supply unit  50  includes a condensation duct  51  formed at the exterior of the tub  20  to condense the air containing moisture produced in the tube  20 , a heating duct  54  connected to the downstream side of the condensation duct  51  in the flow direction of the air to heat the air through a heater  56  and to supply the heated air into the tub, and an air-blowing fan  53  causing the air in the tub  20  to circulate along the condensation duct  51  and the heating duct  54 . 
     In drying the laundry in the laundry machine  1  configured as above, the air moved by the air-blowing fan  53  is heated by the heater  56  provided to the heating duct  54 , and the heated air is supplied into the tub  20 . Thereby, the laundry is dried by rotation of the drum  40  and the hot air. Thereafter, the heated air having dried the laundry changes to humid air as the laundry is dried. The humid air flows from the tub  20  into the condensation duct  51 , and the moisture is removed from the air in the condensation duct  51 . 
     Herein, separate cooling water is supplied to the condensation duct  51  to condense the humid air. The air introduced into the condensation duct  51  is supplied back to the heating duct  54  by the air-blowing fan  53 , thereby circulating through the process described above. 
     The condensation duct  51  is formed in the shape of a pipe in consideration of the volumetric capacity of the air-blowing fan  53  and smooth air flow, and the inner surface of the condensation duct  51  condenses moisture contained in the humid air through exchange of heat with the humid air to remove the moisture from the air. To condense the moisture in the humid air introduced into the condensation duct  51 , a large amount of cooling water needs to be consistently supplied during the laundry drying process. 
     Meanwhile, the air supply unit  50  provided to the conventional laundry machine having the function of drying includes an air-blowing fan  53  to discharge the air from the laundry accommodating part and a heating duct  54  to heat the air caused to flow by the air-blowing fan  53 . 
     That is, in the conventional laundry machine  1 , the air-blowing fan  53  is positioned before the heating duct  54  with respect to the air flow direction, and thus the air flowing out of the laundry accommodation part (i.e., the tub  20 ) sequentially passes through the air-blowing fan  53  and heating duct  54 , and is then supplied back to the laundry accommodation part. 
     The conventional laundry machine as described above uses a heater which is configured to heat the air to supply high temperature air (hot air) to the laundry. 
     Such heaters include a gas heater to burn a gas to heat the air and an electric heater to heat the air through electric resistance. Recently, the electric heater is widely used as it is easily installable and has a simple structure. 
     However, when the air is heated by the electric heater, the high-temperature heat of the heater may be directly transferred to the laundry, damaging the laundry and even leading to fire in the laundry machine. 
     In addition, since the electric heater heats the air using electricity, heating the air to a desired temperature may consume a large amount of electricity, thereby increasing maintenance expenses. 
     Moreover, removing moisture from the air having dried the laundry disadvantageously requires injection of a large amount of cooling water into the condensation duct. 
     In this regard, a laundry machine capable of generating hot air through a heat pump having an evaporator, a compressor, a condenser and an expander through which a refrigerant circulates, and an air blower has recently been developed and is increasingly widely used. 
     In the case of such laundry machine with a heat pump, the evaporator may remove moisture contained in the air, and the condenser may heat the air and supply and circulate the heated air to the tub to dry the laundry. 
     That is, a typical heat pump has a circulation cycle in which a refrigerant supplied from the compressor condenses moisture contained in the air and heats the air through heat exchange occurring in the evaporator and the condenser, and then returns to the compressor. 
     The circulation cycle of the refrigerant may be smoothly implemented by the compressor only when heat exchange consistently occurs in the evaporator and the condenser during the circulation cycle. That is, for the laundry machine having the function of drying and employing a heat pump, it is important to maintain constant heat exchange during operation of the heat pump. 
     However, when the drying cycle is performed in the laundry machine having the function of drying and employing the heat pump, the heat pump may overheat. That is, at the initial start and final start of the heat pump, heat exchange in the evaporator or the condenser is not balanced with that in the condenser or the evaporator, and thus the discharge pressure of the compressor increases, overloading the compressor. 
     In this case, the operational temperature of the heat pump excessively increases, and the pressure of the refrigerant discharged from the compressor excessively increase. Thereby, the efficiency of the heat pump may not be normally exhibited. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     An object of the present invention devised to solve the problem lies in a laundry machine provided with an air supply unit for supply of heated air for drying of laundry having an improved structure to increase drying efficiency. 
     Another object of the present invention devised to solve the problem lies in a laundry machine allowing the air moved by an air-blowing fan to pass through the entire area of heat exchange to increase heat exchange efficiency. 
     Another object of the present invention devised to solve the problem lies in a laundry machine having a heat exchanger with an improved structure provided to a drying duct of an air supply unit to increase heat exchange efficiency of the air passing through the drying duct and to simplify the structure of the heat exchanger. 
     Another object of the present invention devised to solve the problem lies in a laundry machine that improves the installation position of an air supply unit for supply of heated air to reduce the overall volume of the laundry machine. 
     A further object of the present invention devised to solve the problem lies in a laundry machine that may prevent temperature of a compressor of a heat pump for heating of the air from rising due to overloading of the compressor so as to maintain a constant efficiency of the heat pump. 
     Solution to Problem 
     The object of the present invention can be achieved by providing a laundry machine including a tub, an air supply unit configured to circulate air in the tub, a heat pump including a compressor, an evaporator, an expansion valve, and a condenser, the heat pump being configured to dehumidify and heat the air from the air supply unit, and a cooling unit installed at the compressor to cool the compressor using a supplied fluid. 
     Preferably, the air supply unit includes a suction duct to suction the air in the tub, a connection duct connected to the inlet duct, the evaporator and condenser of the heat pump being installed at the connection duct, an air-blowing fan connected to the connection duct, and a discharge duct to supply air to the tub. 
     The air supply unit preferably further includes a heat exchanger provided to a predetermined part of the connection duct, the evaporator and the condenser being installed at the heat exchanger to correspond to a shape of an outer circumferential surface of the tub. 
     The laundry machine according to claim  3 , wherein a lower portion of the heat exchanger is provided with a condensed water sump to collect condensed water produced in the evaporator. 
     Preferably, the fluid is the condensed water collected in the condensed water sump, and the cooling unit cools the compressor using the condensed water. 
     The cooling unit preferably includes a supply pipe connected to the condensed water sump, a water jacket allowing the condensed water supplied to the supply pipe to pass therethrough to cool the compressor, and a discharge pipe to discharge the condensed water having passed through the water jacket. 
     The supply pipe is preferably provided with a condensed water pump to forcibly move the condensed water. 
     The supply pipe is preferably provided with a 3-way valve to switch a flow passage of the condensed water to the water jacket or the tub. 
     The heat exchanger is preferably provided with a washing nozzle to wash the evaporator or the condenser, and the discharge pipe supplies the condensed water to the washing nozzle. 
     The discharge pipe is preferably provided with a 3-way valve to switch a flow passage of the discharge pipe to the washing nozzle or the tub. 
     Preferably, supply of the condensed water to the washing nozzle and cooling of the compressor are simultaneously performed. 
     Preferably, the cooling unit is selectively provided to an upper portion or lower portion of the compressor. 
     The cooling unit is preferably provided to upper and lower portions of the compressor. 
     The fluid is preferably supplied from a water supply source configured to supply wash water to the tub. 
     Advantageous Effects of Invention 
     According to one embodiment of the present invention, a laundry machine using an air supply unit employing a heat pump according to one embodiment of the present invention may have a reduced volume and a compact size. 
     In addition, in a laundry machine using an air supply unit employing a heat pump according to one embodiment of the present invention, the air supply structure and the air heating structure may be improved. 
     In addition, in a laundry machine using an air supply unit employing a heat pump according to one embodiment of the present invention, the air movement path in a heat exchanger of the heat pump may be improved, thereby increasing heat exchange efficiency. 
     In a laundry machine using an air supply unit employing a heat pump according to one embodiment of the present invention, a heat exchanger is integrated with the air supply unit, thereby increasing the heat exchange efficiency of the heat exchanger. 
     In a laundry machine according to one embodiment of the present invention, when the heat pump overheats during operation, it is directly cooled using cooling water. Therefore, the efficiency of operation of the heat pump may be held constant. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. 
       In the drawings: 
         FIG. 1  is a perspective view illustrating a conventional laundry machine; 
         FIG. 2  is a perspective view illustrating a laundry machine according to the present invention; 
         FIG. 3  is a cross-sectional view schematically illustrating the laundry machine according to the present invention; 
         FIG. 4  is a perspective view illustrating main elements of the laundry machine according to the present invention; 
         FIG. 5  is a plan view illustrating main elements of the laundry machine according to the present invention; 
         FIG. 6  is a view schematically illustrating an air supply unit of the laundry machine according to the present invention; 
         FIG. 7  is a view schematically illustrating a cooling structure of a compressor according to a first embodiment of the present invention; 
         FIG. 8  is a view schematically illustrating a cooling structure of a compressor according to a second embodiment of the present invention; and 
         FIG. 9  is a view schematically illustrating a cooling structure of a compressor according to a third embodiment of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     In describing the present invention, terms used herein for the elements are defined based on the functions of the elements. Accordingly, the terms should not be understood as limiting the technical elements. In addition, the terms for respective elements may be replaced with other terms used in the art. 
     Meanwhile, the construction and control method of an apparatus described below are simply illustrative of embodiments of the present invention, and are not intended to limit the scope of the present invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     In addition, the laundry mentioned in this specification includes not only clothes and costumes, but also objects such as shoes, socks, gloves, and hats which a person can wear. The laundry may treat all objects which can be washed. 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  FIG. 2  is a perspective view illustrating a laundry machine according to the present invention, and  FIG. 3  is a cross-sectional view schematically illustrating the internal structure of the laundry machine according to the present invention. 
     As shown in  FIGS. 2 and 3 , the laundry machine  100  includes a cabinet  1  defining an external appearance of the laundry machine  100 , a laundry accommodation part provided in the cabinet  110  to store laundry, and an air supply unit  160  to supply hot air to the laundry accommodation part. 
     The cabinet  110  includes an introduction port  114  for introduction of laundry and a door  115  rotatably provided to the cabinet  110  to open and close the introduction port  114 . Provided to the upper portion of the introduction port  114  are a control panel  111  including at least one of an input unit  112  for input of a control command for operation of the laundry machine  100  and a display unit  113  to display details of control of the laundry machine, and a controller (not shown) to control the above constituent parts according to the control command input through the input unit  112 . 
     Herein, the input unit  112  provided to the control panel  111  takes the form of a button or a rotary knob, and serves as a means to input, to the controller, control commands such as, for example, a program (a washing course or a drying course) for washing or drying set in the laundry machine, washing time, the amount of wash water, and hot air supply time. 
     The display unit  113  displays a control command (such as a course name) input through the input unit and information (such as remaining time) generated as the laundry machine  100  operates according to the input control command. 
     In the case in which the laundry machine  100  is provided as a dryer only for drying of laundry, the laundry accommodation part may be provided only with a drum  150  rotatably provided in the cabinet  110 . 
     On the other hand, in the case in which the laundry machine  100  is provided as an apparatus capable of both washing and drying of the laundry, the laundry accommodation part may include a tub  120  provided in the cabinet to store wash water and a drum  150  rotatably provided in the tub to store the laundry, as shown in  FIG. 2 . 
     For simplicity of description, it will be assumed in the following description that the laundry accommodation part is provided with both the tub  120  and the drum  150 . 
     As shown in  FIG. 3 , the tub  120  has the shape of a hollow cylinder and is supported on or fixed to the interior of the cabinet  110  by a separate suspension (not shown). In addition, the front of the tub  120  is provided with a tub opening  122  for introduction and retrieval of laundry at a position corresponding to the position of the introduction port  114  of the cabinet  110 . 
     Herein, a gasket  130  is provided between the tub opening  122  and the introduction port  114 . The gasket  130  not only serves to prevent the wash water stored in the tub  120  from leaking from the tub  120 , but also serves to prevent vibration generated in the tub  120  during rotation of the drum  150  from being transferred to the cabinet  110 . Accordingly, the gasket  130  may be provided with a vibration isolation material such as rubber. 
     Meanwhile, the tub  120  may be arranged parallel with the ground by which the cabinet  110  is supported as shown in  FIG. 3 , or may be inclined at a predetermined angle with respect to the ground. In the case in which the tub  120  is inclined at a predetermined angle with respect to the ground, the inclination angle of the tub  120  is preferably less than 90 degrees. 
     Herein, the upper circumferential portion of the tub  120  is provided with an air discharge hole  123  for discharge of air from the tub  120 , and the lower portion of the tub  120  is provided with a drainage sump  124  for draining wash water stored in the tub  120 . Herein, the drainage sump  124  is formed in a recessed shape at the lower portion of the tub  120  to collect the wash water in the tub  120 . 
     A drainage unit  126  to drain the wash water collected in the drainage sump is connected to the outer lower portion of the drainage sump  124 . Herein, the drainage unit  126  discharges the wash water collected in the drainage sump using a drainage pipe and a drainage pump. 
     Meanwhile, the air discharge hole  123  is arranged in the longitudinal direction of the tub  120 . Preferably, the air discharge hole  123  is preferably spaced a predetermined distance from a line passing through the center of the tub  120 . Herein, the air discharge hole  123  is positioned so as to facilitate discharge of air from the tub  120  through the air discharge hole  123  when the drum  150  rotates. 
     The drum  150 , which has the shape of a hollow cylinder, is positioned in the tub  120  and is rotated in the tub  120  by a motor  140  provided to the exterior of the tub  120 . 
     Herein, the motor  140  may include a stator  141  fixed to the rear surface of the tub  120 , a rotor  142  to rotate through electromagnetic interaction with the stator  141 , and a rotating shaft  152  connecting the rear surface of the drum  150  and the rotor  142  by penetrating the rear surface of the tub  120 . 
     The drum  150  is provided with a drum opening  151  communicating with the introduction port  114  and the tub opening  122 , and accordingly the user can introduce laundry into the drum  150  through the introduction port  114  or take the laundry stored in the drum  150  out of the cabinet  110 . 
     In the case in which the laundry machine  100  is capable of both washing and drying laundry, the interior of the cabinet  110  may be further provided with a detergent supply unit  180  to store a detergent to be supplied to the tub  120 . 
     The detergent supply unit  180  may include a storage unit  181  (see  FIG. 5 ) provided in the form of a drawer withdrawable from the cabinet  110 , a detergent supply pipe  182  (see  FIG. 5 ) to guide the detergent stored in the storage unit  181  into the tub  120 , and a storage unit handle  183  positioned at one side of the control panel  111  to allow the user to withdraw the storage unit  181  from the cabinet  110 . 
     The storage unit  181  receives water from a water supply source (not shown) arranged outside of the laundry machine  100 . When water is supplied to the storage unit  181  through the water supply source, the detergent in the storage unit  181  and water are supplied together to the tub  120  through the detergent supply pipe  182 . 
     The air supply unit  160  includes, as shown in  FIG. 4 , circulation flow passages  162 ,  163  and  168  to guide air discharged from the tub  120  to the front surface of the tub  120  (i.e., one surface of the tub formed on the side where the introduction port  114  is positioned), an air supply unit  160  provided in the circulation flow passages  162 ,  163  and  168 , and an air-blowing fan  167  to circulate the air in the tub  120 . 
     The circulation flow passages  162 ,  163  and  168  may be arranged such that the air discharged from the back of the tub  120  moves into the tub  120  through the front surfaced of the tub  120 .  FIG. 4  shows an example of the circulation flow passages  162 ,  163  and  168  allowing the air to be withdrawn from the upper rear portion of the circumferential surface of the tub  120  and to be discharged into the tub  120  through the upper front portion of the circumferential surface of the tub  120 . 
     The circulation flow passages  162 ,  163  and  168  may include a suction duct  162  fixed to the air discharge hole  123  provided to the tub  120 , a connection duct  163  connecting the suction duct  162  with the air-blowing fan  167  and allowing the air supply unit  160  to be fixed thereto, and a discharge duct  168  connecting the air-blowing fan  167  with the gasket  130 . The circulation flow passages  162 ,  163  and  168  may be diagonally arranged with respect to the upper surface of the tub  120 . 
     The suction duct  162  is a flow passage into which the air in the tub  120  is withdrawn through the air discharge hole  123  positioned at the rear portion of the circumferential surface of the tub  120 . Preferably, the suction duct  162  is formed of a vibration isolation member (such as rubber, not shown). The vibration isolation member serves to prevent vibration transferred to the tub  120  during rotation of the drum  150  from being transferred to the connection duct  163  and the air supply unit  160  through the suction duct  162 . 
     To more efficiently prevent the vibration transferred to the tub  120  from being transferred to the connection duct  163  and the air supply unit  160 , the suction duct  162  may further be provided with a bellows. Herein, the bellows may be provided to the entire section of the suction duct  162 , or may be provided to only a portion of the section of the suction duct  162  (e.g., a portion coupled to the connection duct  163 ). 
     The discharge duct  168  serves to guide the air discharged from the connection duct  163  through the air-blowing fan  167  into the tub  120 . One end of the discharge duct  168  is fixed to the air-blowing fan  167 , and the other end thereof is connected to a duct connection hole  131  provided to the gasket  130 . 
     To prevent vibration transferred to the tub  120  from being transferred to the air-blowing fan  167  or the connection duct  163  through the discharge duct  168  during rotation of the drum  150 , at least one of the gasket  130  and the discharge duct  168  is preferably formed of a vibration isolation member (or an elastic member). 
     Meanwhile, since the air-blowing fan  167  is provided between the air supply unit  160  and the discharge duct  168 , the air-blowing fan  167  allows the air to pass through the air supply unit  160  by generating negative pressure at the back of the air supply unit  160  rather than generating positive pressure at the front of the air supply unit  160 . 
     In the case in which the air-blowing fan  167  allows the air to pass through the air supply unit  160  by generating positive pressure at the front of the air supply unit  160 , part of the air in the connection duct  163  may easily move to the air supply unit  160 , but the other part of the air may not easily move to the air supply unit  160 . 
     That is, most of the air discharged from the air-blowing fan  167  readily moves toward the air supply unit  160 , but a part of the air discharged from the air-blowing fan  167  may not rapidly move to the air supply unit  160  depending on the shape of the connection duct  163  or the structure of the air-blowing fan. 
     Therefore, in the case of positioning the air-blowing fan  167  before the air supply unit  160  to forcibly move the air toward the air supply unit  160  (i.e., to create positive pressure at the front of the air supply unit  160 ), the amount of air passing through a cross section of the connection duct  163  may vary depending upon the position of the connection duct  163 , and accordingly the heat exchange efficiency may be lowered. 
     On the contrary, the air-blowing fan  167  provided to the laundry machine  100  according to this embodiment is positioned between the air supply unit  160  and the discharge duct  168  connected to the front surface of the tub (namely, the air sequentially passes through the air supply unit  160  and the air-blowing fan  167 ), and therefore the aforementioned problem may be addressed. 
     As such, in the air supply unit  160  of the present invention, the air-blowing fan is positioned between the air supply unit  160  and the discharge duct  168  to generate negative pressure at the back of the air supply unit  160 , as shown in  FIG. 6 . 
     That is, when the negative pressure is generated at the back of the air supply unit  160 , the amount of air moving to the air supply unit  160  along the connection duct  163  is held constant at all cross sections of the connection duct  163 . Thereby, the efficiency of heat exchange between air and the air supply unit  160  is higher than in the case of positioning the air-blowing fan  167  at the front end of the air supply unit  160 , and thus the drying efficiency of the laundry machine may be increased. 
     Meanwhile, the air supply unit  160  may be provided to heat air through the heat pump to supply the heated air. The heat pump further includes a heat exchanger  200  (including a condenser  240  and an evaporator  220 ) to exchange heat with moving air and a compressor  165  to supply a refrigerant to the heat exchanger  200 . Herein, the compressor  165  is provided with cooling units  300 ,  400  and  500  to cool the compressor  165  when the compressor  165  is overheated or overloaded. 
     Herein, the heat exchanger  200  (including the condenser  240  and the evaporator  220 ) is positioned between the connection duct  163  and the air-blowing fan  167  and inside the connection duct  163 , and the compressor  165  of the heat pump is provided to the exterior of the connection duct  163 . Such heat pump dehumidifies and heats the air through heat exchange between the air and a refrigerant driven by the compressor  165  to circulate along the condenser  240 , an expansion valve, and the evaporator  220 . 
     The heat exchanger  200  of the connection duct  163  that is provided with the evaporator  220  and the condenser  240  is positioned at the upper portion of the circumferential surface of the tub  120 , while the evaporator  220  and the condenser  240  are disposed in the heat exchanger  200  such that the evaporator  220  and the condenser  240  are parallel with the axial direction of the tub  120 . 
     Accordingly, the space in which the evaporator  220  is positioned may have a different size than the space in which the condenser  240  is positioned due to a difference between the portions of the circumferential surface of the tub  120 . That is, the position of a portion of the heat exchanger  200  to which the evaporator  220  is fixed may be lower than the position of another portion of the heat exchanger  200  to which the condenser  240  is fixed. 
     In the case in which the connection duct  163  formed in the longitudinal direction of the tub  120  has a constant width, and there is a difference in height between the spaces in which the evaporator  220  and the condenser  240  are placed, a heat exchange capacity of one of the evaporator  220  and the condenser  240  may limit the heat exchange capacity of the other one of the evaporator  220  and the condenser  240 . To prevent this problem, an area ratio between the evaporator  220  and the condenser  240  is preferably between 1:1.3 and 1:1.6. 
     Meanwhile, as the air-blowing fan  167  of the air supply unit  160  operates with operation of the heat pump, the air in the tub  120  circulates through the circulation flow passage (including the suction duct  162 , the connection duct  163 , the air supply unit  160  and the discharge duct  168 ). 
     Herein, the refrigerant is compressed in the compressor  165  and supplied to the condenser  240  of the air supply unit  160 , thereby heating the circulating air. After passing through the condenser  240 , the refrigerant moves to the evaporator  220  and removes moisture from the air in the evaporator  220 . 
     Herein, in the movement path of the air, the evaporator  220  is positioned before the condenser  240 . Accordingly, in the movement path of the air circulating along the tub  120  and the air supply unit  160 , the moisture of the air suctioned from the tub  120  is first removed in the evaporator  220 , and the dehumidified air is heated during movement through the condenser  240  and is then supplied back to the tub  120 . 
     If condensed water produced in the evaporator  220  remains in the connection duct  163 , it may corrode constituents in the connection duct  163  or the heat exchanger  200 , or may be mixed with the moving air and supplied to the laundry subjected to the drying operation. Accordingly, provided to the lower portion of the heat exchanger  200  are a condensed water sump  201  to collect and drain the condensed water produced in the evaporator  220  and a drainage pipe  202  connected to the lower portion of the condensed water sump  201  to guide the condensed water collected in the condensed water sump  201 . 
     Herein, the drainage pipe  202  is connected to the drainage sump  124  of the tub  120  or the cooling units  300 ,  400  and  500  configured to cool the compressor  165 . The condensed water collected in the condensed water sump  201  may be moved to the tub  120  through the drainage pipe  202  and drained through the drainage unit  126  of the tub  120 , or may be supplied to the cooling units  300 ,  400  and  500  through the drainage pipe  202  to be used as a refrigerant to cool the compressor  165 . A detailed description of the cooling units  300 ,  400  and  500  will be given later with reference to the drawings. 
     Meanwhile, a separate temperature sensor  161  configured to sense temperature of the air having passed through the heat exchanger  200  may be provided inside the heat exchanger  200 . Herein, the temperature sensor  161  is preferably provided to the front end or rear end of the evaporator  220  provided to the heat exchanger. The internal temperature of the air supply unit  160  and dryness of the laundry subjected to the drying operation may be sensed through sensing of temperature by the temperature sensor  161 . 
     Preferably, the compressor  165  is positioned in a space defined between the circulation flow passages  162 ,  163  and  168  and the cabinet  110  at the upper portion of the tub  120 . That is, since the circulation flow passages  162 ,  163  and  168  extend diagonally with respect to the upper surface of the tub  120 , and therefore the compressor  165  is preferably installed in the space between one side of the circulation flow passages  162 ,  163  and  168  and the cabinet to prevent the compressor  165  from overlapping the circulation flow passages  162 ,  163  and  168 . 
     The compressor  165  is provided with cooling units  300 ,  400  and  500  to cool the compressor in the case of overloading or overheating of the compressor. Herein, the cooling units  300 ,  400  and  500  may directly cool the compressor  165  by contacting the upper surface or lower surface of the compressor  165 , or indirectly cool the compressor  165 . The cooling units  300 ,  400  and  500  will be described in detail with reference to the drawings after description of the air supply unit  160 . 
     The air supply unit  160  may further include a filter unit  170  configured to filter the air to prevent accumulation of foreign substances such as lint in the air supply unit  160 . 
     As shown in  FIGS. 4 and 5 , the filter unit  170  is preferably detachably attached to the connection duct  163  through the cabinet  110 . To this end, the connection duct  163  is provided with a filter guide  164  to guide movement of the filter unit  170 . The cabinet  110  may be provided with a filter mounting hole (not shown) allowing the filter unit  170  to pass therethrough. 
     In the case in which the laundry machine  100  is not provided with the detergent supply unit  180 , a filter mounting part  119  may be arranged to pass through the cabinet  110  or the control panel  111 . 
     In the case in which the laundry machine  100  is not provided with the detergent supply unit  180 , the filter mounting part  119  may be positioned in a space between the detergent supply unit  180  (which is preferably positioned to be parallel with the control panel  111 ) and the control panel  111  such that it penetrates the cabinet  110 . 
     In addition, the filter mounting part  119  is preferably provided to the upper portion of the laundry machine  100 . This configuration allows the user to remove the filter unit  170  from the laundry machine  100  without bending over, contrary to the case in which the filter unit  170  is positioned at the lower portion of the laundry machine  100 . Accordingly, this configuration may enhance user convenience. 
     The filter guide  164  is provided to connect the filter mounting part  119  to the connection duct  163  such that the filter unit  170  inserted into the filter mounting part  119  is positioned between the suction duct  162  and the air supply unit  160 . 
     The filter unit  170  includes a filter frame  171  provided with a filter and a handle  172  for withdrawal/introduction of the filter unit. The filter unit  170  may further include an elastic part provided between the filter frame  171  and the handle  172  and formed of an elastic member or elastic material to allow movement of the filter frame  171  relative to the handle. The elastic part  173  allows the filter frame  171  to be detachably mounted to the connection duct  163  in the case in which the filter mounting part and the connection duct  163  are not arranged parallel to a line perpendicular to the front surface of the cabinet  110 . 
     Hereinafter, a description will be given of the process of drying operation of the laundry machine as discussed above. 
     Hereinafter, operation of the heat pump during the drying cycle of the laundry machine  100  according to one embodiment of the present invention will be described, and description of the washing cycle, rinsing cycle and spin-drying cycle will be omitted. 
     When the drying cycle is executed, the controller drives the compressor  165  of the heat pump of the air supply unit to start the drying cycle. 
     Operation of the heat pump is briefly described below. First, a refrigerant is caused, by the compressor  165  of the heat pump, to circulate along the condenser  240 , the expansion valve (not shown), and the evaporator  220 . As the air-blowing fan  167  of the air supply unit  160  begins to operate at the same time, the air in the tub  120  circulates through the circulation flow passages (the suction duct  162 , the connection duct  163 , the air supply unit  160 , and the discharge duct  168 ). 
     The refrigerant is compressed in the compressor  165  and supplied to the condenser  240  of the air supply unit  160  to heat the circulating air. After passing through the condenser  240 , the refrigerant moves to the evaporator  220  and removes moisture from the air in the evaporator  220 . 
     In the movement path of the air, the evaporator  220  is positioned before the condenser  240 . Accordingly, in the movement path of the air circulating along the tub  120  and the air supply unit  160 , the moisture of the air suctioned from the tub  120  is first removed in the evaporator  220 , and the dehumidified air is heated while moving through the condenser  240  and is then supplied back to the tub  120  so as to dry objects in the tub  120 . 
     If the moisture in the air is reduced as the laundry is dried or the circulation flow passage of the air is blocked in the above process, heat exchange in the evaporator  220  and the condenser  240  may be smoothly performed. As the heat exchange is not smoothly performed in the evaporator  220  and the condenser  240 , the compressor  165  to circulate the refrigerant may be overloaded. 
     Herein, the cooling units  300 ,  400  and  500  is provided to keep the temperature of the compressor  165  constant to prevent overload to the compressor  165  from causing damage to the compressor  165 . Hereinafter, a detailed description will be given of the cooling units  300 ,  400  and  500  and operation thereof according to one embodiment of the present invention with reference to the drawings. 
     First, a first cooling unit  300  according to a first embodiment will be described.  FIG. 7  is a view schematically illustrating a cooling structure of a compressor according to the first embodiment of the present invention. 
     As shown in  FIG. 7 , the first cooling unit  300  according to the first embodiment is provided with a first water jacket  310  defining, on the upper surface of the compressor, a space allowing a fluid (specifically, condensed water produced in the evaporator of the heat exchanger, which is hereinafter simply referred to as ‘condensed water’) to flow therethrough such that the compressor  165  is cooled by the supplied condensed water. 
     The first water jacket  310  includes a first water inlet  312  connected to the condensed water sump  201  of the heat exchanger  200  to receive the condensed water collected in the condensed water sump  201  and a first water outlet  314  to discharge the condensed water having cooled the compressor  165  by passing through the first water jacket  310 . 
     Herein, the first water inlet  312  is provided with a first supply pipe  316  connected to the condensed water sump  201  to guide the condensed water collected in the condensed water sump  201  to the first water inlet  312 . The first water outlet  314  is provided with a first discharge pipe (not shown) to guide, to the tube  120 , the condensed water having cooled the compressor  165  by passing through the first water jacket  310 . 
     Meanwhile, the first supply pipe  316  is provided with a first condensed water pump  330  to forcibly move the condensed water stored in the condensed water sump  201  of the heat exchanger  200  to the first water jacket  310 . In addition, provided between the first condensed water pump  330  and the first water inlet  312  is a first 3-way valve  320  to supply the condensed water stored in the condensed water sump  201  to the first water jacket  310  or to guide the condensed water to the tub  120  to discharge the condensed water. 
     Herein, the first 3-way valve  320  is provided with a separate solenoid (not shown) that is controlled by the controller (not shown) of the laundry machine  100 . The first 3-way valve  320  selectively controls the movement path of the condensed water to be switched to the first water jacket  310  or the tub  120  through operation of the solenoid. 
     Hereinafter, operation of the first cooling unit  300  according to the first embodiment will be described. As described above, as the heat pump operates to implement the drying operation of the laundry machine  100 , the compressor  165  of the heat pump operates, and the laundry is dried with. At the same time, the moisture produced through drying of the laundry is condensed in the evaporator  220  of the heat pump, and the condensed water is collected in the condensed water sump  201  which is at the lower portion of the heat exchanger  200  where the evaporator  220  is positioned. 
     In this process, the controller determines whether the compressor  165  is overheated by sensing the temperature of the temperature sensor  161  of the air supply unit  160  or the discharge temperature sensor  161  of the heat pump. If overheating of the compressor  165  is sensed, the condensed water is supplied to the first cooling unit  300  to cool the compressor  165 . 
     Specifically, when it is sensed that the compressor  165  is overheated, the controller controls the solenoid driving the first 3-way valve  320  to open the flow passage of the first 3-way valve  320  such that the condensed water sump  201  communicates with the first water inlet  312  of the first water jacket  310 . 
     Thereafter, the first condensed water pump  330  is operated to supply the condensed water collected in the condensed water sump  201  of the heat exchanger  200  to the first water jacket  310  through the first water inlet  312 . As the condensed water supplied by the first condensed water pump  330  passes through the first water jacket  310 , it cools the upper portion of the compressor  165 . 
     Herein, the condensed water having cooled the compressor  165  by passing through the first water jacket  310  is discharged to the tub  120  through the first discharge pipe. The condensed water discharged to the tub  120  is drained by the drainage sump  124  and the drainage unit  126  provided to the tub  120 . 
     In the case in which the temperature sensor  161  of the air supply unit  160  or the discharge temperature sensor  161  of the heat pump does not senses that the compressor  165  is overheated in the above process, the controller controls the solenoid to maintain the flow passage of the first 3-way valve  320  such that the condensed water sump  201  communicates with the tub  120 . Thereby, the condensed water collected in the condensed water sump  201  of the heat exchanger  200  may be discharged to the tub  120 . 
     Hereinafter, a detailed description will be given of a second cooling unit  400  according to a second embodiment of the invention.  FIG. 8  is a view schematically illustrating a cooling structure of a compressor according to the second embodiment of the present invention. 
     As shown in  FIG. 8 , the second cooling unit  400  according to the second embodiment is provided with a second water jacket  410  defining, on the lower surface of the compressor  165 , a space allowing the condensed water to flow therethrough such that the compressor  165  is cooled by the supplied condensed water. 
     The second water jacket  410  includes a second water inlet  412  connected to the condensed water sump  201  of the heat exchanger  200  to receive the condensed water collected in the condensed water sump  201  and a second water outlet  414  to discharge the condensed water having cooled the compressor  165  by passing through the second water jacket  410 . 
     Herein, the second water inlet  412  is provided with a second supply pipe  416  connected to the condensed water sump  201  to guide the condensed water collected in the condensed water sump  201  to the second water inlet  412 . The second water outlet  414  is provided with a second discharge pipe (not shown) to guide, to the tube  120 , the condensed water having cooled the compressor  165  by passing through the second water jacket  410 . 
     Meanwhile, the second supply pipe  416  is provided with a second condensed water pump  430  to forcibly move the condensed water stored in the condensed water sump  201  of the heat exchanger  200  to the second water jacket  410 . In addition, provided between the second condensed water pump  430  and the second water inlet  412  is a second 3-way valve  420  to supply the condensed water stored in the condensed water sump  201  to the second water jacket  410  or to guide the condensed water to the tub  120  to discharge the condensed water. 
     Herein, the second 3-way valve  420  is provided with a separate solenoid (not shown) that is controlled by the controller (not shown) of the laundry machine  100 . The second 3-way valve  420  selectively controls the movement path of the condensed water to be switched to the first water jacket  310  or the tub  120  through operation of the solenoid 
     The controller determines whether the compressor  165  is overheated by sensing the temperature of the temperature sensor  161  of the air supply unit  160  or the discharge temperature sensor  161  of the heat pump. If it is sensed that the compressor  165  is overheated, the condensed water is supplied to the second cooling unit  400  to cool the compressor  165 . 
     Hereinafter, operation of the second cooling unit  400  according to the second embodiment will be described. As described above, as the heat pump operates to implement the drying operation of the laundry machine  100 , the compressor  165  of the heat pump operates, and the laundry is dried with. At the same time, the moisture produced through drying of the laundry is condensed in the evaporator  220  of the heat pump, and the condensed water is collected in the condensed water sump  201  which is at the lower portion of the heat exchanger  200  where the evaporator  220  is positioned. 
     In this process, the controller determines whether the compressor  165  is overheated by sensing the temperature of the temperature sensor  161  of the air supply unit  160  or the discharge temperature sensor  161  of the heat pump. If overheating of the compressor  165  is sensed, the condensed water is supplied to the second cooling unit  400  to cool the compressor  165 . 
     Specifically, when it is sensed that the compressor  165  is overheated, the controller controls the solenoid driving the second 3-way valve  420  to open the flow passage of the second 3-way valve  420  such that the condensed water sump  201  communicates with the second water inlet  412  of the second water jacket  410 . 
     Thereafter, the second condensed water pump  430  is operated to supply the condensed water collected in the condensed water sump  201  of the heat exchanger  200  to the second water jacket  410  through the second water inlet  412 . As the condensed water supplied by the second condensed water pump  430  passes through the second water jacket  410 , it cools the compressor  165 . 
     Herein, the condensed water having cooled the compressor  165  by passing through the second water jacket  410  is discharged to the tub  120  through the second discharge pipe. The condensed water discharged to the tub  120  is drained by the drainage sump  124  and the drainage unit  126  provided to the tub  120 . 
     In the case in which the temperature sensor  161  of the air supply unit  160  or the discharge temperature sensor  161  of the heat pump does not senses that the compressor  165  is overheated in the above process, the controller controls the solenoid to maintain the flow passage of the second 3-way valve  420  such that the condensed water sump  201  communicates with the tub  120 . Thereby, the condensed water collected in the condensed water sump  201  of the heat exchanger  200  may be discharged to the tub  120 . 
     Hereinafter, a detailed description will be given of a third cooling unit  500  according to a third embodiment of the invention with reference to  FIG. 9 .  FIG. 9  is a view schematically illustrating a cooling structure of a compressor according to the third embodiment of the present invention. 
     As shown in  FIG. 9 , the third cooling unit  500  according to the third embodiment is provided with a third water jacket  510  defining, on the lower surface of the compressor  165 , a space allowing the condensed water to flow therethrough such that the compressor  165  is cooled by the supplied condensed water, and a washing nozzle  515  to wash the evaporator  220  of the heat pump using the condensed water having passed through the third water jacket  510 . 
     The third water jacket  510  includes a third water inlet  512  connected to the condensed water sump  201  of the heat exchanger  200  to receive the condensed water collected in the condensed water sump  201  and a third flow outlet  514  to discharge the condensed water having cooled the compressor  165  by passing through the third water jacket  510 . 
     Herein, the third water inlet  512  is provided with a third supply pipe  516  connected to the condensed water sump  201  to guide the condensed water collected in the condensed water sump  201  to the third water inlet  512 . The third flow outlet  514  is provided with a third discharge pipe  518  to discharge the condensed water having cooled the compressor  165  by passing through the third water jacket  510 . 
     Meanwhile, the third supply pipe  516  is provided with a third condensed water pump  530  to forcibly move the condensed water stored in the condensed water sump  201  of the heat exchanger  200  to the third water jacket  510 . 
     In addition, the third discharge pipe  518  is provided with a third 3-way valve  520  to control the path of the condensed water to discharge the condensed water having passed through the third water jacket  510  or to wash the evaporator  220  of the heat exchanger  200  using the condensed water. 
     Herein, the third 3-way valve  520  is provided with a separate solenoid (not shown) that is controlled by the controller (not shown) of the laundry machine  100 . The third 3-way valve  520  selectively controls the movement path of the condensed water to be switched to the washing nozzle  515  or the tub  120  through operation of the solenoid. 
     In addition, the washing nozzle  515  is provided to the interior of the heat exchanger  200  and is connected to the third discharge pipe  518  passing through the heat exchanger  200 . The washing nozzle  515  is positioned at the front end or rear end of the evaporator  200  or the condenser  240  to spray the condensed water to the evaporator  220  or the condenser  240 . 
     Herein, the washing nozzle  515  is preferably positioned at the front end or rear end of the evaporator  220  or the condenser  240  and arranged to spray the condensed water toward the heat dissipation fins of the evaporator  220  or the condenser  240  to wash the heat dissipation fins of the evaporator  220  and the condenser  240 . 
     The controller of the laundry machine  100  determines whether the compressor  165  is overheated by sensing the temperature of the temperature sensor  161  of the air supply unit  160  or the discharge temperature sensor  161  of the heat pump. If overheating of the compressor  165  is sensed, the controller supplies the condensed water to the third cooling unit  500  to cool the compressor  165 . In addition, the controller controls the third 3-way valve  520  to wash the evaporator  220  or the condenser  240  with the washing nozzle  515  using the condensed water at the time of cooling of the compressor  165  or according to a set time to discharge the condensed water having cooled the compressor  165 . 
     Hereinafter, operation of the third cooling unit  500  according to the third embodiment will be described. As described above, as the heat pump operates to implement the drying operation of the laundry machine  100 , the compressor  165  of the heat pump operates, and the laundry is dried with. At the same time, the moisture produced through drying of the laundry is condensed in the evaporator  220  of the heat pump, and the condensed water is collected in the condensed water sump  201  which is at the lower portion of the heat exchanger  200  where the evaporator  220  is positioned 
     In addition, the evaporator  220  and the condenser  240  of the heat pump are provided with multiple overlapping heat dissipation fins, and the air moved by the air supply unit  160  contains fine lint. Accordingly, when the air moved by the air supply unit  160  passes through the evaporator  220  and the condenser  240 , the lint contained in the air may attach to the heat dissipation fins of the evaporator  220  and condenser  240 . To maintain the efficiency of the evaporator  220  and condenser  240 , the heat dissipation fins of the evaporator  220  and condenser  240  need to be periodically washed. 
     While the laundry is dried, the controller determines whether the compressor  165  is overheated by sensing the temperature of the temperature sensor  161  of the air supply unit  160  or the discharge temperature sensor  161  of the heat pump. If overheating of the compressor  165  is sensed, the condensed water is supplied to the third cooling unit  500  to cool the compressor  165 . 
     Specifically, when it is sensed that the compressor  165  is overheated, the controller drives the third condensed water pump  530  to supply the condensed water collected in the condensed water sump  201  of the heat exchanger  200  to the third water jacket  510 . Thereby, the condensed water cools the compressor  165  while passing through the third water jacket  510 , and is then discharged to the third flow outlet  514 . 
     Herein, the third discharge pipe  518  connected to the third flow outlet  514  is provided with a third 3-way valve  52 . The third 3-way valve  520  controls the flow passage of the condensed water to be switched to the washing nozzle  515  or the tub  120  according to control of the solenoid by the controller. 
     That is, the controller may control the third 3-way valve  520  to connect the third flow outlet  514  and the tub  120  such that the condensed water having passed through the third water jacket  510  is discharged to the tub  120 . In addition, in the case in which the evaporator  220  or the condenser  240  needs to be washed, the controller may control the third 3-way valve  520  to connect the third flow outlet  514  and the washing nozzle  515  such that the condensed water is supplied to the washing nozzle  515 . Thereby, the evaporator  220  or the condenser  240  may be washed. 
     In the first to third embodiments, each water jacket  300 ,  400 ,  500  is selectively provided to the upper or lower portion of the compressor  165  to cool the compressor  165 . In another embodiment, however, a separate water jacket may be additionally provided to the lower or upper portion of the compressor to cool the upper and lower portions of the compressor simultaneously. 
     In addition, while the compressor  165  is illustrated in the embodiments of the present invention as being cooled using the condensed water produced in the evaporator  220  of the heat pump, the compressor  165  may also be cooled by supplying the cooling water to the respective water jackets  300 ,  400  and  500  through a separate cooling water supply source (e.g., a wash water supply source). 
     Various embodiments have been described in the best mode for carrying out the invention. 
     INDUSTRIAL APPLICABILITY 
     According to one embodiment of the present invention, a laundry machine using an air supply unit employing a heat pump may have a reduced volume and a compact size. 
     In addition, with a laundry machine using an air supply unit employing a heat pump according to one embodiment of the present invention, the air supply structure and the air heating structure may be improved. 
     In addition, with a laundry machine using an air supply unit employing a heat pump according to one embodiment of the present invention, the air movement path in a heat exchanger of the heat pump may be improved, thereby increasing heat exchange efficiency. 
     With a laundry machine using an air supply unit employing a heat pump according to one embodiment of the present invention, a heat exchanger is integrated with the air supply unit, thereby increasing the heat exchange efficiency of the heat exchanger. 
     In a laundry machine according to one embodiment of the present invention, when the heat pump overheats during operation, it is directly cooled using cooling water. Therefore, the efficiency of operation of the heat pump may be held constant. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.