Patent Publication Number: US-9422656-B2

Title: Drum type washing machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority from Korean Patent Application No. 10-2013-0163094, filed on Dec. 24, 2013, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a washing machine, and more particularly, to a drum type washing machine having a separate sub tub and drum, which is able to wash baby clothes separately from other clothes and laundry, thereby preventing contamination of the baby clothes by adult or other clothes or laundry, or by detergent and/or fabric softener used to wash the adult or other clothes or laundry. 
     BACKGROUND 
     In general, a drum type washing machine is designed to put laundry into the washing machine through a door at a front side of the washing machine, and to wash the laundry using a relatively small amount of water and detergent. The drum type washing machine typically includes single drum that receives and holds laundry for washing. 
     In general, households where the washing machine is used usually own the laundry being washed, including adult clothes and sometimes baby clothes. Thus, it is conventional in a household having a single washing machine that the adult clothes and baby clothes are washed in the single drum. 
     However, in the case where the adult clothes and baby clothes are washed in the single drum of the washing machine, the drum may be contaminated by bacteria, relatively harsh detergents, chemicals in fabric softener and bleach, and the like, as a result of washing the adult clothes. Thus, the baby clothes may be exposed to such contaminants, and become contaminated by the bacteria and the like. 
     In order to prevent this situation, two or more washing machines should be purchased, but it is generally not desirable or economical. 
     SUMMARY 
     Embodiments of the present disclosure provide a drum type washing machine which can prevent baby clothes from becoming contaminated by contaminants resulting from washing adult clothes. 
     Exemplary embodiments of the present disclosure provide a drum type washing machine comprising a main tub having a main drum that rotates to wash main laundry, a sub tub separate from the main tub and having a sub drum that rotates to wash separate laundry, and a clutch unit including a motor configured to provide a rotational force to at least one of the main drum and the sub drum. 
     The clutch unit may comprise a driving part connected to the motor; and a power transfer assembly connected to the driving part and selectively connectable to the main drum and/or the sub drum. When the power transfer assembly is connected to the driving part, the rotational force of the motor is transferred to the drum connected to the power transfer assembly. In some embodiments, the driving part and the power transfer assembly exists in two sets in the clutch unit, in which the two power transfer assemblies may be respectively connected to the main drum and the sub drum. For example, the clutch unit may comprise a first driving part connected to the motor, a first power transfer assembly connected to the main drum and selectively connectable to the first driving part, a second driving part connected to the motor, and a second power transfer assembly connected to the sub drum and selectively connectable to the second driving part. 
     The driving part and the power transfer assembly may be selectively connected by a clutch structure comprising a clutch cover and a clutch disc that selectively engage with each other. In other words, the clutch unit may comprise a clutch cover and a clutch disc that selectively engage or interface with each other, to transfer the rotational power from the motor to one of the main drum and the sub drum. 
     The power transfer assembly may comprise a transfer shaft that is movable in a first direction approaching the driving part and a second direction moving away from the driving part, a pulley shaft selectively connectable to the transfer shaft, an inner pulley connected to the pulley shaft and transferring rotation of the pulley shaft to one of the main drum and the sub drum, and a cylinder configured to move the transfer shaft in the first and second directions. In various embodiments, the pulley shaft is connected to the transfer shaft when the transfer shaft is engaged with the driving part. Conversely, the pulley shaft is disconnected from the transfer shaft when the transfer shaft is disengaged from the driving part. The inner pulley may be at or proximate to an end of the pulley shaft opposite to the driving part. The power transfer assembly may further comprise a connector connected to the transfer shaft and the cylinder, configured to transfer translational power from the cylinder to the transfer shaft, and allow rotation of the transfer shaft. 
     According to embodiments of the present disclosure, since it is possible to wash baby clothes and adult clothes in separate drums, contamination of the baby clothes from contaminants associated with washing the adult clothes may be avoided or prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of an exemplary drum type washing machine according to one or more embodiments of the present disclosure. 
         FIG. 2  is a schematic view illustrating an exemplary connection structure between a motor unit and each of a main tub and a sub tub in the exemplary drum type washing machine of  FIG. 1 . 
         FIG. 3  is a perspective view illustrating an exemplary connection structure of various parts inside an exemplary clutch unit in the exemplary motor unit of  FIG. 2 . 
         FIG. 4  is a schematic and/or side view of the exemplary clutch unit of  FIG. 3 , for explaining operations of various parts in the clutch unit. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. 
     One or more exemplary embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which one or more exemplary embodiments of the disclosure can be easily determined by those skilled in the art. As those skilled in the art will realize, the described exemplary embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure, which is not limited to the exemplary embodiments described herein. 
     It is noted that the drawings are schematic and may not be necessarily dimensionally illustrated or accurate. Relative sizes and proportions of parts in the drawings may be exaggerated or reduced in their sizes, and a predetermined size is exemplary, and not limiting. The same reference numerals designate the same structures, elements, or parts illustrated in two or more drawings in order to exhibit the same or similar characteristics. 
     The disclosed embodiments illustrate idealized exemplary embodiments of the present disclosure in detail. As a result, various modifications of the drawings are expected. Accordingly, the exemplary embodiments are not limited to a specific form or illustrated region, and for example, include modifications of form by manufacturing. 
     Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a front view of an exemplary drum type washing machine according to one or more embodiments of the present disclosure, and  FIG. 2  is a schematic view illustrating an exemplary connection structure between a motor unit and each of a main tub and a sub tub in the exemplary drum type washing machine of  FIG. 1 . 
     Referring to  FIG. 1  and  FIG. 2 , a drum type washing machine  1  according to exemplary embodiment(s) of the present disclosure includes two tubs  100 ,  200  inside a cabinet  10  forming an exterior of the washing machine  1 , and the two tubs  100 ,  200  are opened and closed by a main door  12  and a sub door  14 , respectively. 
     Laundry washed by the drum type washing machine  1  may be classified into a first or main laundry, such as adult clothes having a relatively large amount of bacteria and that are washed with relatively strong detergents and fabric softener, and a second or sub laundry, such as baby clothes having a relatively small amount of bacteria and that are washed with relatively mild detergent and generally no fabric softener. However, the above classification is only one example, and the present disclosure is not limited by the kinds of clothing or laundry washed by the drum type washing machine  1 . 
     A main tub  100  connected to the main door  12  may be used in washing the first or main laundry, and the sub tub  200  connected to the sub door  14  may be used in washing the second or sub laundry. Operations of the drum type washing machine  1  may be controlled by a control panel  16 , which may be connected to a controller (not illustrated) inside the cabinet  10 . One or more washing operations using at least one of the main tub  100  and the sub tub  200  can be performed by manipulating the control panel  16 . In general, the control panel  16  controls (e.g., allows the user to select) multiple washing operations (e.g., washing, rinsing, spin-drying, and/or drying) and/or settings thereof (e.g., default settings for laundry types such as regular laundry, delicate laundry, permanent press or wool clothing, etc., or selectable settings such as time, temperature and/or rotation rate for a particular operation) for each of the main tub  100  and the sub tub  200 . 
     Each of the main tub  100  and the sub tub  200  includes a drum (not illustrated) in which the laundry is placed. The washing operation is performed by rotating the drum. The drums inside each of the tubs  100  and  200  may be selectively rotated by a motor controlled by the controller. In the present embodiment, the drum inside the main tub  100  is called a ‘main drum’ and the drum inside the sub tub  200  is called a ‘sub drum’. 
     The main drum is connected to a main shaft  112  supported by a main supporting member  114  fixed or attached to the main tub  100 . The main shaft  112  extends or protrudes from a rear surface  102  of the main tub  100 , and a main pulley  110  is connected to the protruding end of the main shaft  112 . The main supporting member  114  may be connected to the main shaft  112  through a bearing or the like to allow the main shaft  112  to rotate in the main supporting member  114 , and the main drum connected to the main shaft  112  also rotates in the main tub  100 . 
     Like the main drum, the sub drum is also connected to a sub shaft  212  supported by a sub supporting member  214 . The sub shaft  212  extends or protrudes from a rear surface  202  of the sub tub  200 , and a sub pulley  210  is connected to the protruding end of the sub shaft  212 . The sub supporting member  214  may be connected to the sub shaft  212  through a bearing or the like to allow the sub shaft  212  to rotate in the sub supporting member  214 , and the sub drum connected to the sub shaft  212  also rotates in the sub tub  200 . 
     A clutch unit  300  is behind and/or at a rear side of the main tub  100  and the sub tub  200 , and the main pulley  110  and the sub pulley  210  are respectively connected to two inner pulleys (see  337  in  FIG. 3 ) inside the clutch unit  300  by a main belt  116  and a sub belt  216 . When the inner pulley  337  of the clutch unit  300  rotates, the main pulley  110  or the sub pulley  210  connected to the rotating inner pulley  337  rotates too. Holes or openings  302  allowing the main belt  116  and the sub belt  216  to pass through are in surfaces (e.g., top and bottom surfaces) of the housing of the clutch unit  300 . 
     The clutch unit  300  is electrically connected to the controller, and may be operated to rotate one or both of the main pulley  110  and the sub pulley  210  according to a control signal from the controller. 
     An exemplary detailed configuration of the clutch unit  300  is illustrated in  FIGS. 3 and 4 . 
       FIG. 3  is a perspective view illustrating an exemplary connection structure of various parts inside an exemplary clutch unit suitable for use in the exemplary main tub-sub tub-motor unit of  FIG. 2 , and  FIG. 4  is a schematic and/or side view for explaining operations of various parts in the exemplary clutch unit of  FIG. 3 . 
     Referring to  FIG. 3  and  FIG. 4 , the clutch unit  300  may include a driving part  320  including a motor  310  electrically connected to the controller and configured to generate rotational force and/or power, a driving gear  312  connected to a shaft of the motor  310 , driven gears  322  engaged with the driving gear  312 , and a power transfer assembly  330  selectively connectable to the driving part  320  to transfer the rotational force from the driving part  320  to the main pulley  110  through the main belt  116  and/or to the sub pulley  210  through the sub belt  216 . 
     While the embodiment shown in  FIGS. 3-4  shows all parts including the motor  310  inside the clutch unit  300  (which may have a box-shaped case or housing), some of the parts, such as the motor  310 , may be outside the case or housing of the clutch unit  300 . In some cases, the case or housing of the clutch unit  300  may be omitted. 
     Some or all of the driving part  320  and generally the entire power transfer assembly  330  exist in two sets in the clutch unit  300 . The two power transfer assemblies  330  may be respectively connected to the main pulley  110  and the sub pulley  210 . 
     While specifically disclosed embodiment(s) include two drums in the washing machine, the present disclosure is not limited thereto, and three or more drums can be present. In such a case, each the number of (partial or whole) driving parts  320  and power transfer assemblies  330  in the clutch unit  300  may equal the number of drums. 
     The driving part  320  may include a driven shaft  324  connected to the driven gear  322 , and a clutch cover  326  at an end of the driven shaft  324  (e.g., opposite to that of the gear  322 ). 
     As the shaft of the motor  310  rotates, the driving gear  312  rotates together, and as the driving gear  312  rotates, the driven gears  322  engaged with the driving gear  312  rotate together. In this regard, the driven gear  322  associated with the main pulley  110  and the driven gear  322  associated with the sub pulley  210  may engage with the driving gear  312 , at different locations on the driving gear  312 . Also, in such an embodiment, the driven gears  322  associated with the main pulley  110  and the sub pulley  210  may rotate is different rotational directions (e.g., clockwise vs. counterclockwise). 
     As the driven gear  322  rotates, the driven shaft  324  and the clutch cover  326  rotate together. The clutch cover  326  constitutes a clutch structure together with a clutch disc  331  of the power transfer assembly  330 , and the clutch disc  331  is provided in a form engaged with the clutch cover  326 . For example, each of the clutch cover  326  and the clutch disc  331  may comprise a disc having a plane perpendicular to the axis of the corresponding shaft, with a plurality of teeth extending from the disc. The teeth on one disc are configured to fit in or mate with openings or spaces between adjacent teeth on the other disc. 
     While the specifically disclosed embodiment(s) include the clutch cover  326  connected to the motor  310  and the clutch disc  331  connected to the power transfer assembly  330 , it is also possible that the clutch disc  331  is connected to the driving part  320  or motor  310 , and the clutch cover  326  is connected to the power transfer assembly  330 . 
     When the clutch cover  326  is engaged with the clutch disc  331 , the rotational force of the driven shaft  324  is transferred to the power transfer assembly  330 , and when the clutch cover  326  is released from the clutch disc  331 , the rotational force of the driven shaft  324  is not transferred to the power transfer assembly  330 . 
     The power transfer assembly  330  may include a transfer shaft  332  connected to the clutch disc  331  to move the clutch disc  331  within a predetermined distance or translational range, a connector  333  connected to the transfer shaft  332  configured to allow the transfer shaft  332  to rotate, a cylinder  334  (e.g., including a piston) connected to the connector  333  to cause and reciprocate the translational movement of the connector  333 , and an inner pulley  337  transferring power to the main pulley  116  (in one case) or the sub pulley  216  (in the other case). 
     The cylinder  334  is a general cylinder configured such that a piston or other mechanism therein causes and reciprocates movement along an axis, and may be or comprise, for example, a hydraulic cylinder. Alternatively, the cylinder  334  may be directly attached or fixed to (e.g., surrounding) the transfer shaft  332 , in which case the connector  333  is not necessary. The cylinder  334  may be connected to a cylinder driving part  338  through a cylinder driving line  335 . The cylinder driving part  338  is configured to control the movement of the piston of the cylinder  334 , and when the cylinder  334  is or comprises a hydraulic cylinder, the cylinder driving part  338  may be configured to control the movement of the piston of the cylinder  335  by supplying or withdrawing working fluid thereto or therefrom. The cylinder driving part  338  is connected to the controller, which controls operations of the cylinder  334  according to a control signal (e.g., a drum selection signal) transmitted from the controller. 
     The connector  333  is connected to an end (e.g., of the piston or piston rod) of the cylinder  334 , and moves in the moving direction of the piston as the piston reciprocates. The transfer shaft  332  is inserted into and/or through the connector  333 , and the connector  333  and the transfer shaft  332  are connected to each other by one or more bearings (e.g., roller bearings, needle roller bearings, ball bearings in which the balls rotate or roll in a groove or slot in or on the transfer shaft, etc.). While the transfer shaft  332  rotates, the connector  333  does not rotate. However, as the connector  333  moved or translates, the transfer shaft  332  is also moves or translated by the connector  333 . 
     As the transfer shaft  332  moves, the clutch disc  331  may be connected to (e.g., engage with) or released from (e.g., disengage from) the clutch cover  326 . By controlling when the clutch disc  331  is connected to or engaged with the clutch cover  326 , it is possible to selectively transfer the rotational force of the driven shaft  324  to the transfer shaft  332 . 
     The inner pulley  337  is connected to a pulley shaft  336 , and the pulley shaft  336  may have an end inside the transfer shaft  332 . An inner clutch disc  336   a  is in or on the end of the pulley shaft  336  in the transfer shaft  332 , and an inner clutch cover  332   a  is on an inner wall of the transfer shaft  332  (e.g., at an end opposite to the clutch disc  331 ), facing the inner clutch disc  336   a . The inner clutch cover  332   a  is configured to mate or engage with the inner clutch disc  336   a.    
     While the specifically described embodiments include the inner clutch disc  336   a  at the end of the pulley shaft  336 , and the inner clutch cover  332   a  in the transfer shaft  332 , it is possible that the inner clutch cover  332   a  is in or on the end of the pulley shaft  336 , and the inner clutch disc  336   a  is in the transfer shaft  332 . 
     A distance that the piston of the cylinder  334  reciprocates is preset, and thus, a connection position where the clutch disc  331  connects to the clutch cover  326  and a maximum separation position by which the clutch disc  331  separates from the clutch cover  326  are set or predetermined. 
     Also, when the clutch disc  331  is at the connection position, the inner clutch disc  336   a  and the inner clutch cover  332   a  are connected, and when the clutch disc  331  is at the maximum separation position, the inner clutch disc  336   a  and the inner clutch cover  332   a  are separated to the maximum extent. 
     Therefore, although the pulley shaft  336  does not move, since the transfer shaft  332  moves to connect the inner clutch disc  336   a  and the inner clutch cover  332   a , the inner pulley  337  rotates at a fixed position. Since the inner pulley  337  rotates in place, the positions of the main belt  116  and the sub belt  216  do not change, and only the rotational force of the inner pulley  337  may be transferred to the main drum and the sub drum. 
     Now, operations and effects of the drum type washing machine  1  having the above configuration will be described. 
     In an initial state in which washing is not performed, the clutch disc  331  and the clutch cover  326  may be separated. 
     When a user uses or manipulates the control panel  16  in the initial state to select a washing operation in the drum type washing machine  1 , a washing start command is transmitted to the controller connected to the control panel  16 . The controller drives the motor  310  according to the received command and may transmit a control signal to the cylinder driving part  338 . 
     At this time, the user may select either or both of the main tub  100  and the sub tub  200  to perform washing, so that a control signal is transmitted to the cylinder driving part  338  of the power transfer assembly  330  connected to the selected tub. 
     When the control signal is received by the cylinder driving part  338 , the cylinder  334  is driven to move or position the clutch disc  331  at the connection position. At this time, since the motor  310  is in a driving state, the rotational force of the motor  310  is transferred to the driven gears  322  via the driving gear  312  to rotate the driving part  320 , and when the clutch disc  331  is connected to the clutch cover  326 , the rotational force of the driving part  320  is transferred to the drum inside the selected tub via the power transfer assembly  330 . Thus, the drum inside the selected tub rotates to wash laundry therein. 
     According to the drum type washing machine  1  having the above described configurations, since two tubs each having a drum are in one washing machine to wash the first (main) laundry and the second (sub) laundry with separate drums, contamination of the second (sub) laundry with contaminants associated with the first (main) laundry can be avoided or prevented. In other words, contamination of baby clothes with contaminants in or associated with washing adult clothes can be avoided or prevented. 
     Although exemplary embodiments of the present disclosure are described above with reference to the accompanying drawings, those skilled in the art will understand that the present disclosure may be implemented in various ways without changing the necessary features or the spirit of the present disclosure. 
     Therefore, it should be understood that the exemplary embodiments described above are not limiting, but only an example in all respects. The scope of the present disclosure is expressed by claims below, not the detailed description, and it should be construed that all changes and modifications achieved from the meanings and scope of claims and equivalent concepts are included in the scope of the present disclosure. 
     From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. The exemplary embodiments disclosed in the specification of the present disclosure do not limit the present disclosure. The scope of the present disclosure will be interpreted by the claims below, and it will be construed that all techniques within the scope equivalent thereto belong to the scope of the present disclosure.