WO2022158927A2

WO2022158927A2 - Washing machine

Info

Publication number: WO2022158927A2
Application number: PCT/KR2022/001220
Authority: WO
Inventors: Ilyoung PARK; Yicheol CHOI; Sanghyun Joo; Jangseok Lee
Original assignee: Lg Electronics Inc.
Priority date: 2021-01-25
Filing date: 2022-01-24
Publication date: 2022-07-28
Also published as: WO2022158927A3; KR20220107557A; KR102472995B1

Abstract

The present disclosure relates to a washing machine comprising a first housing having an opening and a space into which a drum accommodating laundry is inserted, a storage tank configured to store carbon dioxide to be supplied to the drum, and a first compressor and a second compressor, each of which compresses the carbon dioxide discharged after completion of washing in the drum and enables the compressed carbon dioxide to flow into the storage tank. Washing is performed after carbon dioxide is introduced into the drum. After completion of the washing, the first compressor and the second compressor are operated in parallel to compress carbon dioxide. When internal pressure of the drum is lowered by a first preset pressure, a revolutions per minute (rpm) of the second compressor is changed.

Description

WASHING MACHINE

The present disclosure relates to a washing machine, and more particularly to a washing machine for performing laundry treatment such as washing using carbon dioxide (CO2).

In a washing procedure and a rinsing procedure of a washing machine designed to use carbon dioxide (CO2), the inside of a washing tub of the washing machine is filled with gaseous carbon dioxide (CO2) and liquid carbon dioxide (CO2). In order to wash laundry using carbon dioxide (CO2), carbon dioxide (CO2) flows from a storage tub into the washing machine so that the inside of the washing machine can be filled with the carbon dioxide (CO2). After completion of the washing procedure, carbon dioxide (CO2) is drained from the washing tub to a distillation tub and then flows from the distillation tub into the storage tub, so that the carbon dioxide (CO2) can be reused. In addition, the washing tub is generally designed in a manner that a pulley is connected to a drive shaft, and a motor pulley is connected to a drum pulley through a belt, so that a drum can rotate by the washing tub.

According to conventional technology disclosed in US Patent Application Publication No. US20040020510A1, a washing space in which laundry is disposed and a motor space in which a motor is installed are used together without distinction therebetween, so that the motor space is unavoidably filled with carbon dioxide (CO2). As a result, the amount of carbon dioxide (CO2) to be used in the washing procedure of laundry unavoidably increases. Also, due to the large amount of carbon dioxide (CO2), pressure vessels related to carbon dioxide (CO2) unnecessarily increase in size, and the system becomes very large in size and very heavy in weight, so that there are many restrictions on the space in which the system is to be installed. In addition, according to the above-described conventional technology, the drum cannot be taken out of the washing space, so that it is impossible to provide an operator (or a repairman) with an easy repair environment in which the drum can be easily repaired.

The compressor of the washing machine designed to use carbon dioxide as a solvent should lower the pressure of high-pressure gas (about 40 bar) stored in the washing tub close to the atmospheric pressure during the washing tub recovery mode, and then the user can take laundry out of the tub after completion of laundry washing. At this time, a function (i.e., a wash-tub recovery move) for lowering the internal pressure of the washing tub is performed. Whereas the pressure ratio at the start of the washing-tub recovery mode is low, the pressure ratio at the end of the washing-tub recovery mode increases to 20~30, which greatly affects deterioration of compressor durability. In addition, the pressure of the washing tub should be lowered quickly to reduce the overall washing time, so that the user can quickly take laundry out of the washing tub. Thus, there is a need for the compressor to be operated in consideration of the above-described technical limitations.

Accordingly, the present disclosure is directed to a washing machine that substantially obviates one or more problems due to limitations and disadvantages of the related art.

The present disclosure provides a washing machine in which the same compressors are operated in parallel during a flow recovery mode for recovery of a large amount of flow rates to result so as to reduce a washing-tub recovery time, and the compressors are operated in series during an operation mode of a high-pressure ratio so as to prevent degradation of durability caused by the high-pressure ratio.

An object of the present disclosure is to provide a washing machine capable of reducing environmental pollution by reducing the amount of carbon dioxide (CO2) used for laundry treatment such as washing.

Another object of the present disclosure is to provide a washing machine capable of reducing the size of a pressure vessel designed to use carbon dioxide (CO2) by reducing the amount of the carbon dioxide (CO2) to be used.

Another object of the present disclosure is to provide a washing machine capable of providing the environment in which an operator (or a repairman) can repair the drum that rotates while accommodating laundry.

Another object of the present disclosure is to provide a washing machine capable of reducing the size of a space to be occupied by a motor assembly rotating the drum, thereby reducing the size of an overall space to be occupied by the washing machine.

Another object of the present disclosure is to provide a washing machine capable of stably operating by allowing a washing space including the drum and a motor space including the motor to be kept at the same pressure.

The present disclosure defines a mode conversion time point where a parallel operation mode transitions to a serial operation mode, and defines a compressor RPM conversion time point. In order to implement a washing process (e.g., filling, transfer, liquefaction, washing, recovery, rinsing, vaporization, regeneration, etc.) in a washing machine configured to use carbon dioxide as a washing solvent, there is a need for the compressor(s) to be operated according to various pressure conditions. The present disclosure provides technology for efficiently operating two compressors.

The present disclosure relates to technology in which, when the compressors are operated in a parallel mode within a pressure ratio (outlet pressure/suction pressure) where the compressors can be driven and then reach a designed pressure ratio, the compressors transition to a serial mode to prevent degradation of compression efficiency and durability. In addition, when the pressure ratio reaches the designed pressure ratio during the parallel operation mode of two compressors, RPM of a high-pressure compressor from among the two compressors is adjusted (is generally lowered) to be stabilized, conversion of a system-side valve is performed so that the parallel operation mode can transition to the serial mode.

In accordance with one aspect of the present disclosure, a washing machine may include a barrier for dividing the inner space of a washing tub into a washing unit and a motor unit such that liquid carbon dioxide used as a washing solvent is not transferred to the motor unit by the barrier. The barrier may be formed as a detachable (or separable) component. In addition, the motor is directly mounted to a rotary shaft of a washing drum to minimize unnecessary space of the motor unit, so that the amount of carbon dioxide to be used for laundry treatment can be reduced. As a result, a distillation tank and the storage tank can be miniaturized in size, so that the overall size of the washing machine can be reduced.

A through-hole may be installed at an upper portion of the barrier in a manner that the pipe of the heat exchanger disposed at the barrier can penetrate the through-hole. As a result, gaseous carbon dioxide can move to the washing unit and the motor unit, resulting in pressure equilibrium between the washing unit and the motor unit.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing, wherein the barrier is configured to prevent liquid carbon dioxide injected into a space provided by the first housing and the barrier from flowing into a space provided by the second housing and the barrier.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. The opening is larger in size than a cross-section of the drum. Thus, an operator can access the drum through the opening so that the operator can maintain and repair the drum.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. The first housing may include a first flange formed along the opening, and the second housing includes a second flange coupled to the first flange.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. The barrier includes a first through-hole through which a rotary shaft of a motor passes, and a second through-hole through which gaseous carbon dioxide moves.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. The barrier is provided with a heat exchanger through which a refrigerant moves. The heat exchanger is disposed in a space formed by the first housing and the barrier. The washing machine may further include a motor assembly coupled to the barrier. The motor assembly may include a stator, a rotor, and a bearing housing.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. The barrier is provided with a heat exchanger through a refrigerant moves. The heat exchanger is disposed in a space formed by the first housing and the barrier. The washing machine may further include a motor assembly coupled to the barrier. The motor assembly may include a stator, a rotor, and a bearing housing. The bearing housing is formed with a communication hole through which inflow or outflow of external air is possible.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. The barrier is provided with a heat exchanger through a refrigerant moves. The heat exchanger is disposed in a space formed by the first housing and the barrier. The washing machine may further include a motor assembly coupled to the barrier. The motor assembly may include a stator, a rotor, and a bearing housing. An O-ring may be disposed at a portion where the bearing housing is coupled to the barrier. The O-ring may prevent liquid carbon dioxide from flowing into a space opposite to the barrier.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; a second housing configured to seal one surface of the barrier and coupled to the first housing; and a storage tank configured to store carbon dioxide to be supplied to the drum.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; a second housing configured to seal one surface of the barrier and coupled to the first housing; and a distillation chamber configured to distill liquid carbon dioxide used in the drum.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. The first housing and the second housing may be interconnected to form a closed space, wherein the closed space is divided by the barrier.

In the present disclosure, a washing machine may include a first housing configured to include an opening formed therein and a space in which a drum for accommodating laundry is inserted; a barrier configured to seal the opening and coupled to the first housing; and a second housing configured to seal one surface of the barrier and coupled to the first housing. Carbon dioxide may be injected into the drum to perform washing. The barrier may prevent liquid carbon dioxide injected into a space provided by the first housing and the barrier from flowing into a space provided by the second housing and the barrier.

The opening may be larger in size than a cross-section of the drum.

The opening may be larger in size than a maximum cross-section of the drum.

The opening may be larger in size than a maximum cross-section of a space of the first housing.

The opening may be maintained at the same size until reaching a center portion of the first housing.

The first housing may include a first flange formed along the opening, and the second housing may include a second flange coupled to the first flange.

At least one seating groove coupled to the barrier and formed along the opening may be formed in the first flange.

The first flange may be provided with a first seating surface that extends farther in a radial direction than a circumference of the seating groove. The second flange may be provided with a second seating surface that is coupled to the first seating surface through surface contact with the first seating surface.

The barrier may include a first through-hole through which a rotary shaft of a motor passes, and a second through-hole through which gaseous carbon dioxide moves.

The second through-hole may be disposed higher than the first through-hole.

The washing machine may further include a heat exchanger coupled to the barrier, wherein a refrigerant pipe through which a refrigerant moves in the heat exchanger passes through the second through-hole.

The second through-hole may include two separate holes.

The barrier may be provided with a heat exchanger through a refrigerant moves, wherein the heat exchanger is disposed in a space formed by the first housing and the barrier.

A heat insulation member may be disposed between the heat exchanger and the barrier.

The heat exchanger may include a bracket coupled to the barrier, wherein the bracket is fixed to the barrier by a bolt penetrating the barrier and a cap nut coupled to the bolt.

The washing machine may further include a motor assembly coupled to the barrier, wherein the motor assembly includes a stator, a rotor, and a bearing housing.

The washing machine may further include a rotary shaft disposed in the bearing housing, wherein one end of the rotary shaft is coupled to the rotor, and the other end of the rotary shaft is coupled to the drum.

The washing machine may further include a sealing portion disposed around the rotary shaft, wherein the sealing portion is disposed to be exposed to a space provided by the first housing and the barrier.

The sealing portion may prevent liquid carbon dioxide from flowing into a space opposite to the barrier.

The bearing housing may be formed with a communication hole through which inflow or outflow of external air is possible.

The rotary shaft may be formed with a first flow passage and a second flow passage spaced apart from each other in a manner that inflow or outflow of air is possible through the first flow passage and the second flow passage.

The first flow passage and the second flow passage may be formed in a radial direction from a center portion of the rotary shaft.

The washing machine may further include a connection flow passage formed to interconnect the first flow passage and the second flow passage.

The connection flow passage may be disposed at a center of rotation of the rotary shaft, and is vertically connected to each of the first flow passage and the second flow passage.

An O-ring may be disposed at a portion where the bearing housing is coupled to the barrier. The O-ring may prevent liquid carbon dioxide from flowing into a space opposite to the barrier.

An O-ring cover for preventing separation of the O-ring may be coupled to the O-ring. The washing machine may further include a storage tank configured to store carbon dioxide to be supplied to the drum.

The washing machine may further include a distillation chamber configured to distill liquid carbon dioxide used in the drum.

The washing machine may further include a filter configured to filter contaminants when discharging liquid carbon dioxide used in the drum.

The washing machine may further include a compressor configured to reduce pressure inside the drum.

The first housing and the second housing may be interconnected to form a closed space, wherein the closed space is divided by the barrier.

It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

As is apparent from the above description, the washing machine according to the present disclosure may first change revolutions per minute (rpm) of each of the compressors to another rpm, so that the washing machine can minimize impact that may occur in the compressors when the compressors transition from a parallel operation mode to a serial operation mode.

In addition, the washing machine may increase an operation time at which the compressors are operated in parallel, and may reduce a recovery time for which carbon dioxide is recovered from the washing chamber, resulting in reduction in a total washing time.

The washing machine according to the embodiments of the present disclosure can reduce the amount of carbon dioxide to be used so that the amount of residual carbon dioxide to be reprocessed after use can also be reduced, resulting in improvement in energy efficiency of the entire system. In addition, since the amount of carbon dioxide to be used is reduced, the size of a storage tank that should store carbon dioxide before use can also be reduced, so that the overall size of the washing machine can be reduced.

In particular, the amount of carbon dioxide to be used in the washing machine can be reduced as compared to the prior art, so that the amount of carbon dioxide to be reprocessed after use can also be reduced. As the amount of carbon dioxide to be used is reduced, the overall size of the washing machine for using carbon dioxide as well as the capacity of a storage tank storing carbon dioxide can be reduced. In addition, since the amount of carbon dioxide to be reprocessed after use is reduced, the time required to perform washing or rinsing can also be reduced.

According to the present disclosure, the washing machine is constructed in a manner that various constituent elements can be separated from the washing machine so that an operator (or a repairman) can easily access and repair a necessary constituent component from among the constituent elements. In addition, the washing machine according to the present disclosure provides a structure in which various constituent elements can be combined to produce an actual product, so that the operator can easily manufacture the washing machine designed to use carbon dioxide.

According to the present disclosure, a stator and a rotor are disposed together around a rotary shaft configured to rotate the drum, and the space to be occupied by a motor assembly is reduced in size, so that the overall size of the washing machine can also be reduced. In addition, the coupling relationship of the constituent elements for rotating the drum is simplified, so that noise generated by rotation of the drum can be reduced and the efficiency of power transmission can increase.

According to the present disclosure, whereas liquid carbon dioxide is not introduced into the driving space in which the motor is disposed, gaseous carbon dioxide can flow into the driving space, and the drum can be rotated in a state in which pressure equilibrium between the washing space and the driving space is maintained. Therefore, when the washing machine operates, the drum can stably rotate. In addition, since the driving space is filled with gaseous carbon dioxide, the amount of carbon dioxide to be used for laundry treatment such as washing can be reduced.

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a conceptual diagram illustrating a washing machine according to an embodiment of the present disclosure.

FIG. 2 illustrates the appearance of a washing chamber according to an embodiment of the present disclosure.

FIG. 3 is a front view illustrating the structure shown in FIG. 2.

FIG. 4 is a cross-sectional view illustrating the structure shown in FIG. 2.

FIG. 5 is a diagram illustrating that a second housing is separated from the structure shown in FIG. 2.

FIG. 6 is a diagram illustrating that some parts of a drum shown in FIG. 5 are detached rearward.

FIG. 7 is a diagram illustrating the drum and some constituent elements included in the drum.

FIG. 8 is a cross-sectional view illustrating the structure shown in FIG. 7.

FIG. 9 is an exploded perspective view illustrating the structure shown in FIG. 7.

FIG. 10 is an exploded perspective view illustrating the main constituent elements of the structure shown in FIG. 7.

FIG. 11 is a diagram illustrating a barrier.

FIG. 12 is a diagram illustrating the function of a second through-hole.

FIG. 13 is a diagram illustrating a structure in which a heat exchanger is coupled to a barrier.

FIG. 14 is a diagram illustrating an O-ring and an O-ring cover mounted to the barrier.

FIG. 15 is a diagram illustrating an exemplary state in which the structure of FIG. 14 is coupled to other constituent elements.

FIG. 16 is a diagram illustrating a rotary shaft.

FIG. 17 is a diagram illustrating an exemplary state in which the rotary shaft of FIG. 16 is coupled to other constituent elements.

FIG. 18 is a diagram illustrating the concept of one embodiment.

FIG. 19 is a flowchart illustrating an operation process of the washing machine according to one embodiment.

FIGS. 20 and 21 are diagrams illustrating techniques in which two compressors are operated in parallel.

FIGS. 22 and 23 are diagrams illustrating techniques in which two compressors are operated in series.

FIG. 24 is a diagram illustrating a path through which oil trapped in a storage tank or a washing chamber flows.

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In the drawings, the sizes, shapes, or the like of constituent elements may be exaggerated for clarity and convenience of description. In addition, the terms, which are particularly defined while taking into consideration the configurations and operations of the present disclosure, may be replaced by other terms based on the intentions of users or operators, or customs. Therefore, terms used in the present specification need to be construed based on the substantial meanings of the corresponding terms and the overall matters disclosed in the present specification rather than construed as simple names of the terms.

Referring to FIG. 1, since the washing machine according to the embodiment of the present disclosure performs various laundry treatments (such as washing, rinsing, etc. of laundry) using carbon dioxide (CO2), the washing machine may include constituent elements capable of storing or processing such carbon dioxide (CO2).

The washing machine may include a supply unit for supplying carbon dioxide, a washing unit for processing laundry, and a recycling unit for processing used carbon dioxide. The supply unit may include a tank for storing liquid carbon dioxide therein, and a compressor for liquefying gaseous carbon dioxide. The tank may include a supplementary tank and a storage tank. The washing unit may include a washing chamber into which carbon dioxide and laundry can be put together. The recycling unit may include a filter for separating contaminants dissolved in liquid carbon dioxide after completion of the washing procedure, a cooler for liquefying gaseous carbon dioxide, a distillation chamber for separating contaminants dissolved in the liquid carbon dioxide, and a contamination chamber for storing the separated contaminants after distillation.

The supplementary tank 20 may store carbon dioxide to be supplied to the washing chamber 10. Of course, the supplementary tank 20 may be a storage tank that can be used when replenishment of carbon dioxide is required, and the supplementary tank 20 may not be installed in the washing machine in a situation where replenishment of such carbon dioxide is not required. The supplementary tank is not provided in a normal situation, the supplementary tank is coupled to supplement carbon dioxide as needed, so that replenishment of carbon dioxide is performed. Preferably, when such replenishment of carbon dioxide is completed, the supplementary tank can be separated from the washing machine.

The storage tank 30 may supply carbon dioxide to the washing chamber 10, and may store the carbon dioxide recovered through the distillation chamber 50.

The cooler 40 may re-liquefy gaseous carbon dioxide, and may store the liquid carbon dioxide in the storage tank 30.

The distillation chamber 50 may distill liquid carbon dioxide used in the washing chamber 10. The distillation chamber 50 may separate contaminants by vaporizing the carbon dioxide through the distillation process, and may remove the separated contaminants.

The compressor 80 may reduce pressure of the inside of the pressurized washing chamber 10 to approximately 1.5 bar.

The contamination chamber 60 may store contaminants filtered through distillation by the distillation chamber 50.

The filter unit 70 may filter out contaminants in the process of discharging liquid carbon dioxide used in the washing chamber 10 into the distillation chamber 50. The filter unit 70 may include a filter having a plurality of fine holes.

Laundry is put in the washing chamber 10, so that washing or rinsing of the laundry is performed. When a valve of the storage tank 30 connected to the washing chamber 10 opens a flow passage, air pressure in the washing chamber 10 becomes similar to air pressure in the storage tank 30. At this time, gaseous carbon dioxide is injected first, and then the inside of the washing chamber 10 is pressurized through equipment such as a pump, so that the inside of the washing chamber 10 can be filled with liquid carbon dioxide. In a situation in which the inside of the washing chamber 10 is maintained at approximately 45~51 bar and 10~15 °C, washing may be performed for 10~15 minutes, and rinsing may be performed for 3~4 minutes. When washing or rinsing is completed, liquid carbon dioxide is discharged from the washing chamber 10 to the distillation chamber 50.

The valve 90 may remove internal air of the washing chamber 10 before starting the washing procedure, thereby preventing moisture from freezing in the washing chamber 10. Because washing performance is deteriorated when moisture in the washing chamber 10 is frozen, moisture in the washing chamber 10 can be prevented from being frozen.

FIG. 2 illustrates the appearance of the washing chamber according to an embodiment of the present disclosure. FIG. 3 is a front view illustrating the structure shown in FIG. 2. FIG. 4 is a cross-sectional view illustrating the structure shown in FIG. 2.

Referring to FIGS. 2 to 4, the washing chamber 10 may include a door 300, a first housing 100, and a second housing. In this case, the washing chamber 10 may refer to a space in which laundry is disposed and various laundry treatments such as washing, rinsing, etc. of laundry can be performed. In addition, the washing chamber 10 may be provided with a motor assembly that supplies driving force capable of rotating the drum to the washing chamber 10.

The door 300 may be provided at one side of the first housing 100 to open and close the inlet 102 provided in the first housing 100. When the door 300 opens the inlet 102, the user can put laundry to be treated into the first housing 100 or can take the completed laundry out of the first housing 100.

The first housing 100 may be formed with a space in which the drum 350 accommodating laundry is inserted. The drum 350 is rotatably provided so that liquid carbon dioxide and laundry are mixed together in a state in which laundry is disposed in the drum 350.

The first housing 100 may be provided with an opening 104 in addition to the inlet 102. The opening 100 may be located opposite to the inlet 102, and may be larger in size than the inlet 102.

The first housing 100 may be formed in an overall cylindrical shape, the inlet 102 formed in a circular shape may be formed at one side of the first housing 102, and the opening 100 formed in a circular shape may be provided at the other side of the first housing 102.

The drum 350 may be formed in a cylindrical shape similar to the shape of the inner space of the first housing 100, so that the drum 350 can rotate clockwise or counterclockwise in the first housing 100.

The opening 104 may be larger in size than the cross-section of the drum 350, so that the operator or user can repair the drum by removing the drum 350 through the opening 104. In this case, the opening 104 may be larger in size than a maximum cross-section of the drum 350. Therefore, the operator or the user can open the opening 104 to remove the drum 350. It is also possible to install the drum 350 in the first housing 100 through the opening 104.

The opening 104 may be larger in size than the maximum cross-section of the space of the first housing 100. In addition, the opening 104 may be maintained at the same size while extending to the center portion of the first housing 100. Thus, when the operator or the user removes the drum 100 from the first housing 100 or inserts the drum 350 into the first housing 100, a space sufficient not to interfere with movement of the drum 350 can be guaranteed.

In one embodiment, the user can put laundry into the first housing 100 using the inlet 102, and maintenance or assembly of the drum 350 may be achieved using the opening 104. The inlet 102 and the opening 104 may be located opposite to each other in the first housing 100.

The first housing 100 may be provided with an inlet pipe 110 through which carbon dioxide flows into the first housing 100. The inlet pipe 110 may be a pipe that is exposed outside the first housing 100, so that the pipe through which carbon dioxide flows may be coupled to the constituent elements described in FIG. 1.

The first housing 100 may be provided with the filter fixing part 130 capable of fixing the filter part 70. The filter fixing part 130 may be formed to radially protrude from the cylindrical shape of the first housing 100, resulting in formation of a space in which the filter can be inserted. The filter fixing part 130 may be provided with a discharge pipe 132 through which carbon dioxide filtered through the filter part 70 can be discharged from the first housing 100. The carbon dioxide used in the first housing 100 may be discharged outside the first housing 100 through the discharge pipe 132.

The first housing 100 may include a first flange 120 formed along the opening 104. The first flange 120 may extend in a radial direction along the outer circumferential surface of the first housing 100 in a similar way to the cylindrical shape of the first housing 100. The first flange 120 may be evenly disposed along the circumference of the first housing 100 in a direction in which the radius of the first housing 100 increases.

The second housing 200 may be coupled to the first housing 100 to form one washing chamber. At this time, the washing chamber may provide a space in which laundry treatment is performed and a space in which a motor assembly for providing driving force required to rotate the drum is installed.

The second housing 200 may include a second flange 220 coupled to the first flange 120. The second housing 200 may be formed to have a size similar to the cross-section of the first housing 100, and may be disposed at the rear of the first housing 100.

The second flange 220 may be coupled to the first flange 120 by a plurality of bolts, so that the internal pressure of the washing chamber can be maintained at pressure greater than the external atmospheric pressure in a state in which the second housing 200 is fixed to the first housing 100.

The first filter fixing part 130 provided in the first housing 200 may be provided with a filter 140 for filtering foreign substances. The filter 140 may include a plurality of small holes not passing foreign substances, but liquid carbon dioxide can pass through the small holes, so that the liquid carbon dioxide can be discharged outside the first housing 100 through the discharge pipe 132.

In one embodiment, a barrier 400 for sealing the opening 104 while coupling to the first housing 100 may be provided. The second housing 200 may seal one surface of the barrier 200.

In the left space on the basis of the barrier 400 in the structure shown in FIG. 4, the drum 350 may be disposed so that laundry and liquid carbon dioxide are mixed together and laundry treatment such as washing or rising can be performed in the drum 350. On the other hand, the motor assembly 500 may be disposed in the right space on the basis of the barrier 400, thereby providing driving force capable of rotating the drum 350. In this case, a portion of the motor assembly 500 may be coupled to the drum 350 after passing through the barrier 400.

The barrier 400 may be larger in size than the opening 104, and may be disposed to be in contact with the opening 104, thereby sealing the opening 104. The barrier 400 and the opening 140 may be formed to have a substantially circular shape similar to the shape of the first housing 100, and the diameter L of the opening 104 may be smaller than the diameter of the barrier 400. The diameter L of the opening 104 may be larger than the diameter of the drum 350. Therefore, the cross-section of the drum 350 may be formed to have the smallest size, the cross-section of the opening 104 may be formed to have a medium size, and the barrier 400 may be formed to have the largest size.

The barrier 400 may be arranged to have a plurality of steps, thereby guaranteeing sufficient strength.

The first flange 102 may be provided with a seating groove 122 coupled to the barrier 400 so that the seating groove 122 may be formed along the opening 104. That is, the seating groove 122 may be provided at a portion extending in a radial direction from the opening 104. The seating groove 122 may be recessed by a thickness of the barrier 400 so that the first flange 120 and the second flange 220 are formed to contact each other. The seating groove 122 may be formed to have the same shape as the outer circumferential surface of the barrier 400. Thus, when the barrier 200 is seated in the seating groove 122, the surface of the first flange 120 becomes flat.

The first flange 120 may include the first seating surface 124 extending in a more radial direction than the circumference of the seating groove 122, and the second flange 220 may include a second seating surface 224 coupled to the first seating surface 124 in surface contact with the first seating surface 124. The first seating surface 124 and the second seating surface 224 may be disposed to be in contact with each other, so that carbon dioxide injected into the inner space of the first housing 100 can be prevented from being disposed outside the first housing 100. The first seating surface 124 and the second seating surface 224 may be in surface contact with each other while being disposed at the outer circumferential surfaces of the first housing 100 and the second housing 200, and at the same time may provide a coupling surface where two housings can be bolted to each other.

A heat exchanger 600 in which refrigerant flows may be disposed at the barrier 400. The heat exchanger 600 may be disposed in a space formed by the first housing 100 and the barrier 400. The heat exchanger 600 may change a temperature of the space formed by the first housing 100. The temperature of the space formed by the first housing 100 may be reduced so that humidity of the inner space of the first housing 100 can be lowered.

A heat insulation member (i.e., an insulation member) 650 may be disposed between the heat exchanger 600 and the barrier 400. The heat insulation member 650 may prevent the temperature of the heat exchanger 600 from being directly transferred to the barrier 400. The heat insulation member 650 may allow the barrier 400 to be less affected by temperature change of the heat exchanger 600. The heat insulation member 650 may be formed similar to the shape of the heat exchanger, thereby covering the entire surface of the heat exchanger 600.

FIG. 5 is a diagram illustrating that the second housing is separated from the structure shown in FIG. 2. FIG. 6 is a diagram illustrating that some parts of the drum shown in FIG. 5 are detached rearward.

Referring to FIGS. 5 and 6, when the second housing 200 is separated from the first housing 100, the barrier 400 may be exposed outside. Since the barrier 400 is coupled to the seating groove of the first housing 100, the inner space of the first housing is not exposed outside even when the second housing 200 is separated from the first housing 100. The barrier 400 may be coupled to the second housing 200 by a plurality of bolts or the like.

A motor assembly 500 may be coupled to the center portion of the barrier 400, and a second through-hole 420 may be formed at an upper side of the motor assembly 500. A refrigerant pipe 610 for circulating a refrigerant in the heat exchanger 600 may be formed to pass through the second through-hole 420.

When the barrier 400 is separated from the first housing 100, the opening 104 may be exposed outside. At this time, the drum 350 may be withdrawn to the outside through the opening 104. As the opening 104 is larger in size than the drum 350, maintenance of the drum 350 is possible through the opening 104.

A gasket 320 may be disposed between the barrier 400 and the seating groove 122. As a result, when the barrier 400 is coupled to the first housing 100, carbon dioxide can be prevented from leaking between the barrier 400 and the first housing 100. When the barrier 400 is seated in the seating groove 122, the barrier 400 can be coupled to the first housing 100 by the plurality of bolts while compressing the gasket 320. A plurality of coupling holes through which the barrier 400 is coupled to the first housing 100 may be evenly disposed along the outer circumferential surface of the barrier 400.

FIG. 7 is a diagram illustrating a drum and some constituent elements of the drum. FIG. 8 is a cross-sectional view illustrating the structure shown in FIG. 7. FIG. 9 is an exploded perspective view illustrating the structure shown in FIG. 7. FIG. 10 is an exploded perspective view illustrating the main constituent elements of the structure shown in FIG. 7.

As can be seen from FIGS. 7 and 8, the first housing 100 is removed so that the drum 350 is exposed outside. The drum 350 may be formed in a cylindrical shape such that laundry put into the drum 350 through the inlet 102 is movable into the drum 350.

In the left side from the barrier 400, the drum 350, the heat exchanger 600, and the heat insulation member 650 may be disposed. In the right side from the barrier 400, the motor assembly 500 may be disposed.

FIG. 9 is an exploded perspective view illustrating that the drum 350 and the barrier 400 are separated from each other. Referring to FIG. 9, the rotary shaft 510 of the motor assembly 500 may be coupled to the drum 350 at the rear of the drum 350. Therefore, when the rotary shaft 510 rotates, the drum 350 can also be rotated thereby. In addition, when the rotational direction of the rotary shaft 510 is changed, the rotational direction of the drum 350 is also changed.

Since the motor assembly 500 is coupled to the barrier 400, the driving force required to rotate the drum 350 is not transmitted to the drum 350 through a separate belt or the like. As a result, rotational force of the motor according to one embodiment is directly transmitted to the drum 350, so that loss of force or occurrence of noise can be reduced.

FIG. 10 is an exploded perspective view illustrating constituent elements installed at the barrier shown in FIG. 9.

Referring to FIG. 10, the heat exchanger 600 may be formed in a doughnut shape similar to the shape of the opening 104. A circular through-hole 602 may be formed at the center of the heat exchanger 600 so that the rotary shaft 510 of the motor can pass through the through-hole 602.

The heat insulation member 650 may be formed in a shape corresponding to the heat exchanger 600, and may prevent the temperature change generated in the heat exchanger 600 from being transferred to the barrier 400. The heat insulation member 650 may be made of a material having low thermal conductivity, and may be disposed between the heat exchanger 600 and the barrier 400. A circular through-hole 652 may be formed at the center of the heat insulation member 650 so that the rotary shaft 510 of the motor can pass through the through-hole 652.

The circular shape of the through-hole 602 of the heat exchanger 600 may be similar in size to the circular shape of the through-hole 652 of the heat insulation member 650. However, the through-hole 652 may be formed with a through-groove 654 through which the refrigerant pipe 610 for supplying refrigerant to the heat exchanger 600 can pass.

The heat exchanger 600 may include a bracket 620 coupled to the barrier 400. The bracket 620 can be fixed to the barrier 400 by both a bolt 624 penetrating the barrier 400 and a cap nut 626 coupled to the bolt 624.

The bracket 620 may be formed in a three-dimensionally stepped shape such that the bracket 620 is disposed at a surface where the heat exchanger 600 has a thin thickness. The bolt 624 may be disposed at the stepped groove portion, and may be coupled to the cap nut 626.

The plurality of brackets 620 may be provided, so that the heat exchanger 600 and the heat insulation member 650 may be coupled to the barrier 400 at a plurality of points. Although FIG. 10 illustrates one embodiment in which three brackets 650 are used for convenience of description, a larger number of brackets or a smaller number of brackets than the three brackets may also be used as necessary. The plurality of brackets may be evenly disposed at various positions of the heat exchanger 600, so that the heat exchanger 600 can be more stably fixed.

The motor assembly 500 may be coupled to the barrier 400. The motor assembly 500 may include a stator 570, a rotor 550, and a bearing housing 520. The bearing housing 520 may include the rotary shaft 510. One end of the rotary shaft 510 may be coupled to the rotor 550, and the other end of the rotary shaft 510 may be coupled to the drum 350. Therefore, as the rotor 550 rotates around the stator 570, the rotary shaft 510 is also rotated.

The stator 570 is fixed to a bearing housing 520, thereby providing the environment in which the rotor 550 can rotate.

When the bearing housing 520 is coupled to the barrier 400, an O-ring 450 may be disposed between the bearing housing 520 and the barrier 400, so that liquid carbon dioxide injected into the first housing 100 is prevented from flowing into a gap between the barrier 400 and the bearing housing 520. At this time, an O-ring cover 460 may be disposed to improve the coupling force of the O-ring 450. The O-ring cover 460 may be formed similar in shape to the O-ring 450. The O-ring cover 460 may reduce the size of one surface where the O-ring 450 is exposed to one side of the barrier 400, thereby more strongly sealing the gap.

FIG. 11 is a diagram illustrating the barrier 400. FIG. 11(a) is a front view of the barrier 400, and FIG. 11(b) is a side cross-sectional view of the center portion of the barrier 400.

As can be seen from the side cross-sectional view of the barrier 400, since the barrier 400 includes a plurality of step differences, the barrier 400 can provide sufficient strength by which the heat exchanger 600 can be fixed to one side of the barrier 400 and the motor assembly 500 can be fixed to the other side of the barrier 400.

A first through-hole 410 through which the rotary shaft 510 of the motor passes may be disposed at the center of the barrier 400. The first through-hole 410 may be formed in a circular shape, so that no contact occurs at the rotary shaft 510 passing through the first through-hole 410.

The barrier 400 may include a second through-hole 420 through which gaseous carbon dioxide moves. The second through-hole 420 may be disposed at a higher position than the first through-hole 410. The second through-hole 420 may be disposed to allow the refrigerant pipe 610 to pass therethrough. The second through-hole 420 may be larger in size than the first through-hole 410.

Here, the second through-hole 420 may be implemented as two separate holes. The second through-holes 420 may be disposed symmetrical to each other with respect to the center point of the barrier 400.

The barrier 400 may be a single component capable of being separated from the first housing 100 or the second housing 200, and may provide a coupling structure between the heat exchanger 600 and the motor assembly 500.

In addition, when the barrier 400 is separated from the first housing 100, the environment in which the user or operator can separate the drum 350 from the first housing 100 can be provided.

The barrier 400 may be formed to have a plurality of step differences in a forward or backward direction, and may sufficiently increase the strength. In addition, the barrier 400 may be formed to have a curved surface within some sections, so that the barrier 400 can be formed to withstand force generated in various directions. The outermost portion of the barrier 400 may be coupled to the seating groove 122 of the first housing 100.

Referring to the direction from the outermost part of the barrier 400 to the center part of the barrier 400 as shown in FIG. 11(b), the barrier 400 may be formed to have step differences in various directions (e.g., the barrier first protrudes to the left side, protrudes to the right side, and again protrudes to the left side) by various lengths, thereby increasing strength.

FIG. 12 is a diagram illustrating the function of the second through-hole.

Referring to FIG. 12, carbon dioxide may be injected into the drum 350 to perform washing of laundry. In this case, the carbon dioxide may be a mixture of liquid carbon dioxide and gaseous carbon dioxide. Since the liquid carbon dioxide is heavier than the gaseous carbon dioxide, the liquid carbon dioxide may be located below the gaseous carbon dioxide, and the gaseous carbon dioxide may be present in the empty space located over the liquid carbon dioxide.

By rotation of the drum 350, laundry disposed in the drum 350 may be mixed with liquid carbon dioxide.

The barrier 400 may prevent liquid carbon dioxide injected into the space formed by both the first housing 100 and the barrier 400 from flowing into the other space formed by both the second housing 200 and the barrier 400. That is, since the barrier 400 seals the opening 104, liquid carbon dioxide cannot move to the opposite side of the barrier 400.

During laundry treatment such as washing, the space formed by the first housing 100 and the barrier 400 is separated from the space formed by the second housing 200 and the barrier 400. In this case, the space formed by the first housing 100 and the barrier 400 may be filled with liquid carbon dioxide and gaseous carbon dioxide at a higher pressure than atmospheric pressure. Therefore, in order to stably maintain the pressure of the washing chamber, only gaseous carbon dioxide rather than liquid carbon dioxide may move into the space formed by the second housing 200 and the barrier 400, resulting in implementation of pressure equilibrium.

At this time, gaseous carbon dioxide may pass through the barrier 400 through the second through-hole 420 provided at the barrier 400. However, since the second through-hole 420 is located higher in height than the liquid carbon dioxide, the gaseous carbon dioxide cannot move through the second through-hole 420.

Typically, the amount of liquid carbon dioxide used in washing or rising of laundry may not exceed half of the total capacity of the drum 350. In other words, the amount of liquid carbon dioxide does not exceed the height of the rotary shaft 510 coupled to the drum 350.

Therefore, if the second through-hole 420 is located higher than the rotary shaft 510, gaseous carbon dioxide may not move through the second through-hole 420. However, since the space formed by the first housing 100 and the barrier 400 is filled with gaseous carbon dioxide, the gaseous carbon dioxide can freely flow into the space formed by the second housing 200 and the barrier 400, resulting in implementation of pressure equilibrium.

That is, during laundry treatment such as washing or rinsing, gaseous carbon dioxide and liquid carbon dioxide may be mixed with each other in the space partitioned by the first housing 100 and the barrier 400. On the other hand, whereas liquid carbon dioxide is not present in the space partitioned by the second housing 200 and the barrier 400, only gaseous carbon dioxide may be present in the space partitioned by the second housing 200 and the barrier 400. Since two spaces are in a pressure equilibrium state therebetween, liquid carbon dioxide need not be present in the space formed by the second housing 200 and the barrier 400, and the amount of used liquid carbon dioxide may be reduced in the space formed by the second housing 200 and the barrier 400. Therefore, the total amount of carbon dioxide to be used in washing or rinsing of laundry may be reduced, so that the amount of carbon dioxide to be used can be greatly reduced compared to the prior art. As a result, the amount of carbon dioxide to be reprocessed after use can also be reduced. As described above, the amount of carbon dioxide to be used can be reduced, so that a storage capacity of the tank configured to store carbon dioxide and the overall size of the washing machine configured to use carbon dioxide can also be reduced. In addition, since the amount of carbon dioxide to be reprocessed after use is reduced, the time required to perform washing or rinsing can also be reduced.

FIG. 13 is a diagram illustrating a structure in which the heat exchanger is coupled to the barrier.

FIG. 13 is a cross-sectional view of a portion in which the bracket 620 is in contact with the heat exchanger 600.

The bracket 620 may be formed in a stepped shape, and the stepped portion is in contact with the heat exchanger 600, so that the heat exchanger 600 can be fixed. The protruding portion may be disposed to contact the heat insulation member 650.

The bolt 624 may be fixed to the protruding portion, and the bolt 624 may pass through the heat insulation member 650 and the barrier 400. A cap nut 626 may be provided at the opposite side of the bolt 624, so that the bolt 624 can be fixed by the cap nut 626. The cap nut 626 may be in contact with the plurality of points of the barrier 400, so that the fixing force at the barrier 400 can be guaranteed.

The cap nut 626 may be formed in a rectangular parallelepiped shape, and a coupling groove may be formed at a portion contacting the barrier 400. A sealing 627 may be disposed in the coupling groove to seal a gap when the cap nut 626 is coupled to the barrier 400. That is, when the cap nut 626 is coupled to the bolt 624, the sealing 627 is pressed so that the bolt 624 can be fixed while being strongly pressurized by the cap nut 626. At this time, the barrier 400 is also pressed together, a hole through which the bolt 624 passes can be sealed.

The bracket 620 may be implemented as a plurality of brackets, so that the heat exchanger 600 can be fixed at various positions. Although the shape of the brackets 620 may be changed when viewed from each direction, the same method for coupling the bracket 620 by the bolt and the cap nut can be applied to the brackets 620.

FIG. 14 is a diagram illustrating the O-ring and the O-ring cover mounted to the barrier. FIG. 15 is a diagram illustrating an exemplary state in which the structure of FIG. 14 is coupled to other constituent elements.

The O-ring 450 may be disposed at a portion where the bearing housing 520 is coupled to the barrier 400. The O-ring 450 may prevent liquid carbon dioxide from flowing into the space opposite to the barrier 400.

That is, since the rotary shaft 510 is disposed to penetrate the first through-hole 410 of the barrier 400, the gap should exist in the first through-hole 410. Since the rotary shaft 510 rotates, the rotary shaft 510 should be spaced apart from the through-hole 410 by a predetermined gap, and this predetermined gap cannot be sealed. Therefore, the bearing housing 520 is coupled to the barrier 400, and the gap between the bearing housing 520 and the barrier 400 is sealed by the O-ring 450, so that carbon dioxide can be prevented from moving through the gap sealed by the O-ring 450.

The O-ring 450 may be coupled to the O-ring cover 460 preventing separation of the O-ring 450. The O-ring cover 460 may surround one surface of the O-ring 450, so that the O-ring cover 460 can prevent the O-ring 450 from being exposed to a space provided by the first housing 100. Therefore, the O-ring cover 460 may prevent the O-ring 450 from being separated by back pressure.

FIG. 16 is a diagram illustrating the rotary shaft. FIG. 17 is a diagram illustrating an exemplary state in which the rotary shaft of FIG. 16 is coupled to other constituent elements.

A rotary shaft 510 having one side coupled to the drum 350 and the other side coupled to the rotor 550 may be provided at the center of the bearing housing 520. The rotary shaft 510 may be disposed to pass through the center of the bearing housing 520.

The rotary shaft 510 may be supported by the bearing housing 520 through the first bearing 521 and the second bearing 522. The rotary shaft 510 may be supported to be rotatable by the two bearings. In this case, the two bearings may be implemented as various shapes of bearings as long as they are rotatably supported components.

Meanwhile, the first bearing 521 and the second bearing 522 may have different sizes, so that the first bearing 521 and the second bearing 522 can stably support the rotary shaft 510. On the other hand, the shape of the rotary shaft 510 corresponding to a portion supported by the first bearing 521 may be formed differently from the shape of the rotary shaft 510 corresponding to a portion supported by the second bearing 522 as needed.

A sealing portion 540 may be provided at one side of the first bearing 521. The sealing portion 540 may be disposed along the circumferential surface of the rotary shaft 510. The sealing portion 540 may be disposed to be exposed to the space formed by the first housing 100 and the barrier 400, so that carbon dioxide can be prevented from moving through a gap between the rotary shaft 510 and the bearing housing 520. Specifically, the sealing portion 540 can prevent liquid carbon dioxide from moving into the space opposite to the barrier 400.

The sealing portion 540 may include a shaft-seal housing 542 that is disposed between the rotary shaft 510 and a hole through which the rotary shaft 510 passes, so that the shaft-seal housing 542 can seal a gap between the rotary shaft 510 and the hole. A shaft seal 544 may be disposed at a portion where the shaft-seal housing 542 and the rotary shaft 510 meet each other, thereby improving sealing force. The shaft seal 544 may be disposed to surround the circumferential surface of the rotary shaft 510.

The bearing housing 520 may be formed with a communication hole 526 through which inflow or outflow of external air is possible. The communication hole 526 of the bearing housing 520 may be exposed to the space partitioned by the second housing 200 and the barrier 400.

The rotary shaft 510 may be provided with a first flow passage 512 and a second flow passage 514 spaced apart from each other such that inflow or outflow of air is possible through the first flow passage 512 and the second flow passage 514. At this time, the first flow passage 512 and the second flow passage 514 may be formed in a radial direction from the center of the rotary shaft 510.

Air in the space partitioned by the second housing 200 and the barrier 400 may flow into the rotary shaft 510 through the first flow passage 512 and the second flow passage 514.

In particular, a connection flow passage 516 for connecting the first flow passage 512 to the second flow passage 514 may be formed. The connection flow passage 516 may be disposed at the center of rotation of the rotary shaft 510, and may be vertically connected to each of the first flow passage 512 and the second flow passage 514.

If the connection flow passage 516 does not exist, each of the first flow passage 512 and the second flow passage 514 is perforated on the outer surface of the rotary shaft 510, but the opposite side of each of the first flow passage 512 and the second flow passage 514 is closed. Therefore, it is difficult for air to substantially flow into the first passage 512 or the second flow passage 514. To this end, the connection flow passage 516 for interconnecting two flow passages may be formed. Thus, when the internal pressure of the rotary shaft 510 is changed, air can more easily flow into the first flow passage 512, the second flow passage 514, and the connection flow passage 516, so that pressure of the rotary shaft 510 can be maintained in the same manner as the external pressure change.

The rotary shaft 510 may rotate in a state in which one side of the rotary shaft 10 is fixed to the drum 350 and the other side of the rotary shaft 10 is fixed to the rotor 550. Therefore, noise or vibration may occur in the rotary shaft 510. If the rotary shaft 510 rotates at a place where there occurs a pressure deviation, noise or vibration may unavoidably increase. Therefore, the rotary shaft 510 according to one embodiment may be formed with a communication hole 526 through which air can flow into the bearing housing 520. The bearing housing 520 is a relatively large component and has a space for allowing air to enter and circulate therein, so that air can be introduced without distinction between the air inlet and the air outlet. On the other hand, the rotary shaft 510 may be made of a material having high rigidity, but the strength of the rotary shaft 510 is reduced so that it is difficult to secure the space in which air can easily flow, thereby increasing the size of the air passage. Therefore, the plurality of flow passages may be coupled to each other, resulting in formation of a path through which the introduced air can be discharged through the opposite flow passage.

In one embodiment, the washing chamber 10 may be coupled to the first housing 100 and the second housing 200, resulting in formation of a sealed space. At this time, the sealed space may be divided into two spaces by the barrier 400. Based on the barrier 400, one space may be a space for laundry treatment, and the other space may be a space for installation of the motor or the like.

FIG. 18 is a diagram illustrating the concept of one embodiment.

Referring to FIG. 18, the compressor unit 80 may include two compressors. The compressor unit 80 may include a first compressor 82 and a second compressor 84, each of which compresses carbon dioxide (CO2) discharged after completion of washing in the drum so that the compressed carbon dioxide (CO2) flows into the storage tank 10. The carbon dioxide (CO2) generated after completion of washing in the washing chamber 10 may be guided to the storage tank 30 by the first compressor 82 and the second compressor 84. In an initial stage, there is performed a parallel operation in which carbon dioxide (CO2) is compressed by each of the two compressors. In the latter stage, there is performed a serial operation in which two compressors compress carbon dioxide (CO2) through multistage compression so that carbon dioxide (CO2) flows into the storage tank 30.

When a current pressure of the washing tub reaches a preset pressure during a recovery mode operation of the washing tub of the washing machine in which a reciprocating compressor (based on the piston~cylinder volume compression scheme) compressor is used in two stages, after a parallel operation mode transitions to a serial operation mode by switching of the system-side valve, the RPM (revolutions per minute) of each compressor is adjusted after lapse of a predetermined time (△t), so that a serial operation mode of a high-pressure ratio region can be implemented.

However, when the system is operated as described above, there are three kinds of vulnerabilities. In the first vulnerability, a (low-speed + serial) operation is performed for a preset time (△t) so that there occurs a section where the recovery flow rate decreases, resulting in an increase in the total washing time. In the second vulnerability, a mechanical behavior (= RPM) of the compressor is changed after high load caused by chemical change of carbon dioxide (CO2) fluid has occurred, so that sudden RPM change generated in the high-pressure ratio operation may reduce durability of a frictional surface of the compressor unit. In this case, when technology (e.g., hardening of frictional material, heat treatment of a bearing, etc.) for preventing degradation of the durability of the compressor is used, the cost of materials may unavoidably increase. In the third vulnerability, since the design (fixed) compression ratio of the compressor should be considered, the mode conversion pressure setting range is limited, load may be inevitably concentrated on a specific compression stage (1-stage or 2-stage) without accurate load distribution. Accordingly, the system for use in the present embodiment may be implemented in other ways in consideration of the above-described technical disadvantages.

In the embodiment of FIG. 19, when using a plurality of compressors (or multistage compressors) with the same capacity is used, it is assumed that total load is divided equally into the compressors (compression stages). In this case, load of a single compressor is represented by shaft torque. In addition, if the same amount of fluid passes through the respective compressors during the serial operation mode, torque may be proportional to the compressor pressure ratio (= discharge pressure / inlet pressure). That is, in order to maximize the operation efficiency of the compressor in the system designed to use a volumetric compressor, it is very important for the compression ratio of the first compressor and the compression ratio of the second compressor to be implemented in the same operation condition. However, it is practically impossible for the compressor having a fixed design compression ratio to have the same compression ratio in real time under all available situations. Therefore, from the viewpoint of compressor protection, the use of the first criterion in which the pressure ratio is equally selected as the worst condition, and the use of the second criterion in which the compressor pressure ratio designed to increase to a higher-temperature level is set to a lower pressure ratio may be considered advantageous in terms of durability guarantee. In other words, lowering the pressure ratio of the compressor located at a high-pressure stage may be considered advantageous in terms of durability lifespan.

In most washing machines each having a limited intercooler size, a discharge temperature of the high-pressure stage compressor (i.e., second compressor 84) in a two-stage compression mode is higher than the discharge temperature of the low-pressure stage compressor (i.e., first compressor 82) in the two-stage compression mode. For example, the pressure ratio of the second compressor 84 is set to 4.9 and the second compressor 84 is driven at the pressure ratio of 4.9, and the pressure ratio of the first compressor 82 is set to 5.2 and the first compressor 82 is driven at the pressure ratio of 5.2. As a result, a relatively smaller load is applied to the second compressor 84 located at the high-pressure stage, so that durability of the compressor can be guaranteed.

Referring to FIG. 19, when washing is finished, the first compressor 82 and the second compressor 84 are arranged in parallel to compress carbon dioxide, so that the compressed carbon dioxide can be guided to the storage tank 30 (S10). In this case, two compressors have the same capacity, and the compression efficiency is high, so that a time taken to perform such compression can be shortened.

Washing chamber pressure (barA)	Operation mode	RPM of First Compressor [rpm]	RPM of Second Compressor [rpm]
40 → 14(=P1(First setting pressure))	Parallel	6500	6500
14 → 13(=P2(Second setting pressure)	Parallel	6500	2500
13 → 2.5	Serial	6500	2500

Since the washing chamber pressure is the same as the internal pressure of the drum, the terms "washing chamber pressure" and "drum internal pressure" will be used interchangeably. The drum is disposed in the washing chamber because portions where the two components are disposed have the same pressure.

When the washing chamber pressure, i.e., the drum internal pressure, is lowered by a first setting pressure P1, the rpm of the second compressor 84 may be changed (S20, S30). Two compressors are operated in parallel until the drum internal pressure drops to the first setting pressure (e.g., 14), but the two compressors are kept at the same rpm.

Since the carbon dioxide of the washing chamber 10 is continuously compressed during operation of the two compressors, the internal pressure of the washing chamber may be continuously reduced.

When the drum internal pressure is reduced by a second setting pressure (P2, for example 13), the first compressor 82 and the second compressor 84 are arranged in series to compress carbon dioxide (S50). At this time, whereas the rpm of the first compressor 82 is identical to the initial rpm, the rpm of the first compressor 84 may be kept low.

That is, in the present embodiment, the two compressors are operated in parallel at the same rpm until the drum internal pressure drops to the first setting pressure.

When the drum internal pressure reaches the first setting pressure, the rpm of the second compressor 84 is lowered compared to the conventional rpm in a situation where the parallel operation is maintained.

When the drum internal pressure reaches a second setting pressure, the parallel mode switches to the serial operation. At this time, the rpm of the first compressor 82 and the rpm of the second compressor 84 are maintained at previous rpms of the first compressor 82 and the second compressor 84, so that each of the first compressor 82 and the second compressor 84 can be prevented from being overloaded when the parallel operation switches to the serial operation.

The first setting pressure P1 may be greater than the second setting pressure P2. This is because, as the compressor is driven, carbon dioxide of the washing chamber moves from one place to another place, so that the internal pressure of the washing chamber can also be reduced.

On the other hand, according to the present embodiment, during the process of moving the carbon dioxide from the washing chamber to the storage tank after completion of laundry washing, the rpm of the first compressor 82 from among two compressors is maintained at the same rpm, so that operation stability can be guaranteed in the process of driving the first compressor 82.

Until the drum internal pressure is reduced by the second setting pressure P2, the first compressor and the second compressor are operated in parallel to prevent the amount of compression of carbon dioxide from decreasing. For reference, when two compressors are operated in series, whereas carbon dioxide can be compressed at a high pressure, but the amount of compressed carbon dioxide can decrease.

When the drum internal pressure is reduced by the first setting pressure P1, the rpm of the second compressor is reduced so that the risk of high load generated by serial arrangement of two compressors can be reduced.

FIGS. 20 and 21 are diagrams illustrating techniques in which two compressors are operated in parallel. FIGS. 22 and 23 are diagrams illustrating techniques in which two compressors are operated in series.

FIGS. 20 and 22 are conceptual diagrams illustrating a path through which carbon dioxide flows, and FIGS. 21 and 23 are diagrams illustrating actual implementation states.

The two

compressors

82 and 84 are disposed separately from each other, and manual valves (also called hand valves) 802, 810, 818, 820 are disposed. The manual valves may allow the user to open or close a flow passage.

Valves

804, 806, 808, 814, and 816 capable of opening or closing the flow passage according to a system state may be installed.

Oil separators

830 and 840 and the oil reservoir may be installed on the path through which carbon dioxide flows. The oil separators and the oil reservoir may separate oil to be discharged with carbon dioxide from the compressor, and may temporarily store the separated oil.

On the other hand, when the valve 818 installed in the flow passage through which oil is drained from the oil reservoir is opened, or when the

valves

814 and 816 installed in the flow passage through which oil is drained within the oil separators are opened, the stored oil may return to the compressor. At this time, the stored oil may also pass through a metering valve 812 as needed.

The flow passage through which carbon dioxide compressed by the first compressor 82 and the second compressor 84 is discharged may include a flow passage 818 in which a safety valve is installed, so that the carbon dioxide is prevented from being excessively compressed and excessive increase of such pressure can also be prevented.

In addition, the intercooler 86 is disposed to lower a temperature of the compressed carbon dioxide when a multistage compression mode is performed. In addition, when the parallel operation is performed, the temperature of carbon dioxide introduced into the second compressor 84 can be lowered, so that the second compressor 84 can be prevented from heating up to a high temperature.

A method for performing the parallel operation will hereinafter be described with reference to FIGS. 20 and 21. Carbon dioxide of the washing chamber 10 may be provided after passing through the manual valve 802. At this time, the flow passage through which carbon dioxide is supplied based on the manual valve 802 and the other flow passage formed to pass through the manual valve 802 can be separated from each other.

Meanwhile, carbon dioxide passing through the manual valve 802 is guided to the suction passage of the first compressor 82, and is discharged to the outlet passage. Since the valve 802 is in a state where the flow passage is opened, carbon dioxide having penetrated the manual valve 802 passes through the intercooler 86 and is compressed by the second compressor 84, so that the compressed carbon dioxide can be discharged.

Since the valve 808 is in a state where the flow passage is opened, carbon dioxide compressed by the first compressor 82 and carbon dioxide compressed by the second compressor 84 may simultaneously move toward the flow passage opened by the valve 818.

Meanwhile, the valve 806 is in a state where the flow passage is closed, so that it is impossible for carbon dioxide to move after passing through the valve 806.

Carbon dioxide having penetrated the manual valve 810 may sequentially pass through the first oil separator 830, the second oil separator 840, and the oil reservoir 850, so that oil mixed with the carbon dioxide can be separated (or isolated).

During the compression process by the

compressors

82 and 84, oil used in the

compressors

82 and 84 may be mixed with carbon dioxide. If the oil is mixed with carbon dioxide, there is a possibility that laundry is contaminated with oil during washing of the laundry, so that there is a need for oil to be separated from carbon dioxide to be reused.

The carbon dioxide having passed through both the oil separator and the oil reservoir may flow into the storage tank 30 after passing through the manual valve 820, so that the resultant carbon dioxide may be stored in the storage tank 30. In this case, the upper side and the lower side of the washing machine can be separated from each other based on the manual valve 820, so that the upper portion and the lower portion of the washing machine can be separated from each other based on the manual valve 820 for facilitation of user manipulation.

The oil stored in the oil reservoir 850 may return to the compressor when the flow passage is opened by the manual valve 818.

In addition, oil separated by the first oil separator 830 may open the flow passage in the valve 814, and oil separated by the second oil separator 840 may flow into two compressors when the flow passage is opened by the valve 816.

In FIGS. 20 and 21, whereas each of the valve 804 and the valve 808 opens the flow passage, the valve 806 may block the flow passage through which carbon dioxide moves, so that two compressors can be operated in parallel.

Technology for operating two compressors in series will hereinafter be described with reference to FIGS. 21 and 22.

Whereas the valve 804 and the valve 808 shown in FIGS. 20 and 21 block the flow passage, the valve 806 opens the flow passage through which carbon dioxide moves, so that two compressors can be operated in series.

Carbon dioxide guided from the washing chamber is compressed by the first compressor 82 after passing through the valve 802. At this time, since the valve 804 blocks the flow passage, all carbon dioxide may be guided to the first compressor 82 without passing through the valve 804.

Since the valve 808 blocks the flow passage and the valve 806 opens the flow passage, the carbon dioxide compressed in the first compressor 82 may flow into the flow passage passing through the valve 806 and may be cooled after passing through the intercooler 86. Subsequently, after the carbon dioxide is compressed by the second compressor 84, the carbon dioxide may move after passing through the manual valve 818.

The process for controlling two compressors to switch from the parallel operation to the serial operation can be implemented by opening/closing the flow passage in the

valves

804, 806, and 808. When the operation condition is changed, the serial operation may switch to the parallel operation and the parallel operation may then switch to the serial operation by activation of the flow passage that is opened or closed by the respective valves. When the drum internal pressure is lowered by the second setting pressure P2, the flow passage of the carbon dioxide can be adjusted in a manner that the first compressor and the second compressor are arranged in series.

A process for returning oil from the oil separator and the oil reservoir will hereinafter be described with reference to FIGS. 20 to 23.

The present disclosure relates to a method for separating oil having leaked from the compressor and mixed with a washing solvent from the compressor and re-supplying the separated oil to the compressor, when the oil-supply-type compressor is used as a fluid machine capable of recovering and regenerating the carbon dioxide after completion of the washing course in the washing machine in which the carbon dioxide is used as a washing solvent. Also, the present disclosure relates to a method for completely removing oil mixed with the washing solvent so that laundry can be washed only using the washing solvent formed of pure carbon dioxide.

When recovery of the carbon dioxide is performed, one or more compressors may be operated in parallel or in series so as to form a high flow rate and a differential pressure. In this case, the oil can be smoothly supplied to the respective compressors through oil return valve control. In addition, the oil accumulated in the storage tank is bypassed without being separated from the oil separator, so that the oil can be removed from the washing solvent.

The present embodiment provides the oil-supply-type scroll compressor for implementation of a compact and economical carbon dioxide (CO2) washing machine. That is, in order to form a high flow rate and differential pressure, one or more oil-supply-type scroll compressors are operated in series or in parallel. In this case, one or more oil separators may be used to increase separation efficiency of oil having leaked from the compressor.

In the present embodiment, the oil-supply-type scroll compressor is used so that volume can be reduced by about 60% as compared to the other case in which the oil-less compressor is used.

In the present embodiment, in order to supply oil to one or more compressors, a plurality of oil separators is installed, and the separated oil is recirculated using the compressor(s). The plurality of oil separators may be arranged in series, and carbon dioxide including the oil may sequentially pass through the plurality of oil separators, resulting in an increase in oil separation efficiency.

On the other hand, the oil filtered by the respective oil separators is collected into a reservoir so that the collected oil is then returned to the compressor. In this case, the amount of returned oil can be measured by calculating the flow rate using oil flowmeter installation or pressure sensing. The amount of oil leakage in the compressor may be measured by the OCR meter or the L-CO2 extraction method. The amount of returned oil can also be determined in a manner that the appropriate amount of oil can be maintained in the oil separator (or the oil reservoir).

The oil separated in the oil separator is supplied to the carbon dioxide suction line of each compressor through a valve. In order to uniformly supply oil to the respective compressors in the system to which one or more compressors are applied, an oil return pipe may be connected to an inlet of a main pipe through which carbon dioxide flows or may be disposed among the compressor, the washing tub, and a distillation tank. Of course, the oil supply line may also be installed in each compressor as needed.

When the plurality of compressors is operated in parallel, only the oil stored in the first oil separator 830 may be returned as needed. Since the first oil separator 830 is an oil separator at which oil having passed through the compressor first arrives, there are a large amount of flowing carbon dioxide, so that the large amount of oil leakage may also occur.

When the plurality of compressors is operated in series, only oil stored in the second oil separator 840 can be returned as needed. A serial operation time is shorter than a parallel operation time, so that the use of the oil of the second oil separator 840 is considered sufficient.

In addition, after several washing processes are completed, the oil accumulated in the oil reservoir 850 may be returned through the third valve 818. Unlike the first valve 814 or the second valve 816, the third valve 818 may be designed in a manner that the flow passage is not opened or closed according to a specific condition, the flow passage is opened or closed by the user so that the stored oil can return to the compressor.

The first oil separator 830 may separate the oil from the carbon dioxide compressed by the first compressor and the second compressor. The oil separated by the oil separator 830 may flow into the compressor through the first valve 814 for opening or closing the flow passage through which the oil is guided to the first compressor or the second compressor.

The second oil separator 840 may separate oil from the carbon dioxide having passed through the first oil separator 830. The oil separated by the second oil separator 840 may be guided to the compressor through the second valve 818 for opening/closing the flow passage through which the separated oil is guided to the first compressor or the second compressor.

The oil reservoir 850 may separate oil from the carbon dioxide having passed through the second oil separator 840, and may store the separated oil therein. The oil stored in the oil reservoir 850 may be returned to the compressor through the third valve 818 that opens and closes a flow path through which the oil stored in the oil reservoir 850 is guided to the first compressor or the second compressor.

Meanwhile, the first valve 814 may open the flow passage while the first compressor and the second compressor are operated in parallel, so that the oil can return to the compressor. On the other hand, the first valve 814 may close the flow passage while the first compressor and the second compressor are operated in series, so that the oil is not returned to the compressor.

While the first compressor and the second compressor are operated in parallel, the second valve 816 closes the flow passage to prevent returning of the oil. In contrast, while the first compressor and the second compressor are operated in series, the second valve 816 opens the flow passage so that the oil can be returned to the compressor.

The amount of oil filtered by the first oil separator 830 is greater than that of the second oil separator 840. This is because the carbon dioxide having passed through the compressor passes through the first oil separator before being guided to the second oil separator.

Therefore, since parallel operation is conducted for a longer period of time than serial operation, the oil filtered by the first oil separator 830 is guided to the compressor, so that the sufficient amount of oil can be supplied to the compressor.

Meanwhile, the oil separators to be used for oil returning are used in different ways according to the serial operation and the parallel operation, so that the oil can be relatively evenly returned.

The third valve 818 may be constructed in a manner that the washing cycle is continuously performed two or more times and the flow passage is opened after completion of such washing cycle so that the oil can be returned to the compressor.

When each of the first valve, the second valve, and the third valve opens the flow passage, the other valves may not open the flow passage so that the oil can be individually supplied to each of the compressors. That is, when oil is returned from the first valve, the second valve and the third valve may prevent returning of the oil. As the other valves operate similarly, the oil can be evenly returned to the compressors.

FIG. 24 is a diagram illustrating a path through which oil trapped in the storage tank or the washing chamber flows.

The storage tank may store carbon dioxide. As the storage time increases, oil having a relatively large specific gravity may sink. Therefore, the oil accumulated at the bottom may be guided to a gap between the first oil separator 830 and the second oil separator 840, so that the oil can be filtered through the second oil separator 840.

At this time, the valve 864 is provided, so that the flow passage can be opened by the valve 864 only when there is a need to filter the oil stored in the storage tank 30.

On the other hand, the valve 864 and the valve 862 are simultaneously used to open the flow passage, so that the oil stored in the washing chamber 10 can be filtered by the second oil separator 840.

The oil collected in the storage tank 30 sinks under the storage tank 30 due to a specific gravity (density) difference and is then bypassed to a third space rather than the washing chamber during a short period of time. Thus, t oil mixed with the carbon dioxide washing solvent supplied to the washing chamber can be recovered.

Meanwhile, the storage tank 30 is disposed to be inclined toward one side, so that the oil stored in the storage tank 30 may be collected at the inclined lower portion. The oil moved in a relatively downward direction is separated from the carbon dioxide, so that laundry can be prevented from being contaminated by the oil during washing.

It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the spirit and essential characteristics of the disclosure. Thus, the above embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the disclosure should be determined by reasonable interpretation of the appended claims and all change which comes within the equivalent scope of the disclosure are included in the scope of the disclosure.

Claims

A washing machine comprising:

a first housing including an opening and defining a space in the washing machine into which a drum accommodating laundry is inserted;

a barrier coupled to the first housing and configured to seal the opening;

a second housing coupled to the first housing and configured to seal one surface of the barrier;

a storage tank configured to store in the storate tank and supply carbon dioxide to the drum; and

a first compressor and a second compressor, each of which compresses the carbon dioxide discharged after completion of washing in the drum and moves the compressed carbon dioxide into the storage tank,

wherein

washing that rotates the drum is performed after carbon dioxide is introduced into the drum,

after completion of the washing, the first compressor and the second compressor are operated in parallel to compress carbon dioxide, and

when internal pressure of the drum is lowered by a first preset pressure, revolutions per minute (rpm) of the second compressor is changed.
The washing machine according to claim 1, wherein:

after the rpm of the second compressor is changed,

when the drum internal pressure is lowered by a second preset pressure, the first compressor and the second compressor are operated in series to compress carbon dioxide.
The washing machine according to claim 2, wherein:

the first preset pressure is greater than the second preset pressure.
The washing machine according to claim 1, wherein:

the rpm of the first compressor is not changed.
The washing machine according to claim 1, wherein:

the first compressor and the second compressor are operated in parallel until the drum internal pressure is lowered by a second preset pressure.
The washing machine according to claim 1, wherein:

liquid carbon dioxide injected into a space formed by the first housing and the barrier is prevented from flowing into a space formed by the second housing and the barrier.
A method for controlling a washing machine comprising a first housing having including an opening and defining a space in the washing machine into which a drum accommodating laundry is inserted; a barrier formed to seal the opening and coupled to the first housing and configured to seal the opening; a second housing formed to seal one surface of the barrier and coupled to the first housing and configured to seal one surface of the barrier; and a storage tank configured to store in the storage tank and supply carbon dioxide to be supplied to the drum, the method comprising:

after completion of washing, compressing carbon dioxide by operating a first compressor and a second compressor in parallel, and guiding the compressed carbon dioxide to the storage tank, wherein each compressor compresses the carbon dioxide discharged after completion of washing in the drum and moves the compressed carbon dioxide into the storage tank ; and

when the drum internal pressure is lowered by a first preset pressure, changing revolutions per minute (rpm) of the second compressor to another rpm.
The method according to claim 7, wherein:

after the rpm of the second compressor is changed,

when the drum internal pressure is lowered by a second preset pressure, the first compressor and the second compressor are operated in series to compress carbon dioxide.
The method according to claim 8, wherein:

the first preset pressure is greater than the second preset pressure.
The method according to claim 7, wherein:

the rpm of the first compressor is not changed.
The method according to claim 7, wherein:

the first compressor and the second compressor are operated in parallel until the drum internal pressure is lowered by a second preset pressure.
The method according to claim 7, wherein:

when the drum internal pressure is lowered by a first preset pressure, the rpm of the second compressor is lowered.
The method according to claim 7, wherein:

the first compressor and the second compressor are driven at the same revolutions per minute (rpm) until the drum internal pressure is lowered by a first preset pressure.
The method according to claim 7, wherein:

the opening is larger in size than a cross-section of the drum.
The method according to claim 1, wherein the barrier includes:

a first through-hole through which a rotary shaft of a motor passes; and

a second through-hole through which liquid carbon dioxide flows.
The method according to claim 15, wherein:

the motor is located in a direction opposite to a direction in which the drum is located with respect to the barrier.
The method according to claim 15, wherein:

the second through-hole is located higher than the first through-hole.
The washing machine according to claim 1, further comprising:

a motor assembly coupled to the barrier,

wherein the motor assembly includes:

a rotary shaft;

a rotor coupled to one end of the rotary shaft and rotated by a rotational magnetic field;

a stator configured to generate the rotational magnetic field; and

a bearing housing configured to support the rotary shaft,

wherein the other end of the rotary shaft is coupled to the drum.
The washing machine according to claim 18, wherein:

a sealing portion is disposed around the rotary shaft,

wherein the sealing portion is disposed to be exposed to a space formed by the first housing and the barrier.
The washing machine according to claim 19, wherein:

the sealing portion is configured to prevent liquid carbon dioxide from flowing into a space located opposite to the barrier.