Patent Publication Number: US-2006000240-A1

Title: Washing machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 2004-51658, filed on Jul. 2, 2004 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a washing machine, and more particularly, to a washing machine which can prevent vibrations of a drainage pump from being transmitted to an outer case.  
      2. Description of the Related Art  
      In general, a washing machine includes a water tub for containing wash water, a rotating tub installed in the water tub having, and formed at a peripheral surface thereof with, a plurality of through-holes for use in a dry cycle, and a driving device for driving the rotating tub. In addition, the washing machine includes a water supply device supplying the wash water into the water tub, and a drainage device draining the wash water from the water tub.  
      In such a washing machine, the drainage device is adapted to forcibly drain the wash water from the water tub and conventionally includes a drainage pump, a drainage filter, and a drainage pipe. The drainage pump typically includes a pump casing containing an impeller and a driving motor. The drainage filter is used to filter impurities from the wash water before the wash water enters the drainage pump. The drainage pipe is used to guide the discharge of the wash water. In a conventional drainage device, the drainage pump is fixed to the inner bottom surface of the outer case of the washing machine.  
      However, in the washing machine described above, since a support for the drainage pump is fixed directly to the bottom surface of the outer case by bolts or other fasteners, vibration, generated during operation of the drainage pump, is transmitted along the bottom surface of the outer case, resulting in operational noise.  
      One proposal put forward to solve the operational noise problem related to the drainage pump is Korean Patent No. 10-0238970 (published on Jan. 15, 2000). The 10-0238970 patent discloses a washing machine comprising a damper member which is interposed between a bracket supporting the drainage pump and a frame of the washing machine. The bracket is adapted to attenuate vibration generated by the drainage pump, the damper member and the bracket being fixed to each other by means of bolts penetrating through the frame of the washing machine.  
      Although the above described installation structure of the drainage pump may attenuate the vibration of the drainage pump to some extent through the use of the damper member, vibration of the bracket, used to support the drainage pump, is still transmitted to the frame of the washing machine through the fixing bolts, resulting in an unsatisfactory vibration attenuation effect.  
     SUMMARY OF THE INVENTION  
      The present invention has been made in view of the above mentioned problem. Accordingly, an aspect of the invention is to provide a washing machine which can reduce vibration transmitted from the drainage pump to the outer case of the washing machine, through the use of an improved installation structure for the drainage pump.  
      Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.  
      To achieve the above and/or other aspects and advantages, the present invention provides a washing machine including an outer case, a water tub installed in the outer case, a drainage pump adapted to drain wash water from the water tub, and a fixing device adapted to fix the drainage pump. The fixing device includes: a support member extending from the drainage pump; vibration-proof members arranged to support the outer surface of the support member; and fixture members attached to the outer case that are adapted to support the outer surfaces of the vibration-proof members.  
      The vibration-proof members may include first and second vibration-proof members, which are coupled to oppose each other such that they support opposite sides of the outer surface of the support member. The vibration-proof members surround the outer surface of the support member.  
      The first and second vibration-proof members may have toothed portions formed at their opposite coupling surfaces, in order to enhance a coupling force between both the vibration-proof members.  
      The first and second vibration-proof members may be formed with grooves, and at the outer surface of the support member are formed protruding ribs, in order to enhance a coupling force between the vibration-proof members and the support member.  
      The support member may have a crucial cross section, and the first and second vibration-proof members may have coupling recesses corresponding to the shape of the outer shape of the support member.  
      The vibration-proof members may have a plurality of through-holes.  
      The fixture members may include first and second fixture members enclosing the outer surfaces of the vibration-proof members.  
      The coupling direction of the first and second fixture members may intersect with the coupling direction of the first and second vibration-proof members.  
      The first and second fixture members may have protrusions and receiving holes for the engagement of their contact portions.  
      The first and second fixture members may have respective insertion slots formed at their upper surfaces so that the support member is inserted into the first and second fixture members, the insertion slots being spaced apart from the support member.  
      The fixing device may further include screw-fastening portions provided on the fixture members in order to fix the fixture members to the inner surface of the outer case and fixing screws inserted into the screw-fastening portions.  
      The majority of the drainage pump, except for a portion fixed by the fixing device, may be spaced apart from the outer case.  
      The fixing device may include, a support member extending from the pump, vibration-proof members arranged to support an outer surface of the support member, and fixture members adapted to support outer surfaces of the vibration-proof members and fixed to an inner surface of the outer case. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is a perspective view illustrating a washing machine in according to the present invention;  
       FIG. 2  is an exploded perspective view illustrating a drainage pump and a fixing device for use in the fixing of the drainage pump according to the present invention;  
       FIG. 3  is a partial cross-sectional view taken along the line III-III′ shown in  FIG. 2 ; and  
       FIG. 4  is a perspective view illustrating the installation structure of a filter case according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. Although the present invention is applicable to both a pulsator-type washing machine and a drum-type washing machine, hereinafter only the drum-type washing machine will be explained for the convenience of explanation.  
      Referring to  FIG. 1 , the washing machine according to the present invention includes a drum-type water tub  11  installed in an outer case  10  and adapted to contain wash water, a rotating drum  12  rotatably installed in the water tub  11 , and a driving motor  13  installed below the water tub  11  and adapted to rotate the rotating drum  12  installed in the water tub  11 . In addition, the washing machine includes a water supply device  14  installed above the water tub  11  and adapted to supply the wash water into the water tub  11 , a detergent supply device  15  adapted to supply detergent in a water supply cycle, and a drainage device  20  installed below the water tub  11  and adapted to forcibly drain the wash water from the water tub  11 .  
      Openings are provided at respective corresponding front ends of the outer case  10 , water tub  11 , and rotating drum  12  for putting laundry into the rotating drum  12  or taking the laundry out of the rotating drum  12  through the openings. In order to open or close the openings, a door  16  is installed at the front end of the outer case  10 .  
      Although not shown, the rear end of the rotating drum  12  is centrally coupled to a rotating shaft. The rotating shaft is rotatably supported at the center of the rear end of the water tub  11  such that the rotating drum  12  is rotatably installed in the water tub  11 . Such a rotating shaft, extending rearward from the water tub  11 , is coupled to a pulley, and in turn, the pulley is connected to another pulley, coupled with a rotating shaft of the driving motor  13 , by means of a belt  17 . In this manner, according to the rotation of the shaft of the driving motor  13 , the rotating drum  12  rotates. The rotating drum  12  includes a plurality of through-holes formed throughout the peripheral surface thereof. The rotating drum  12  also includes a plurality of lifters  12   a  arranged around the inner peripheral surface thereof and adapted to allow easy lifting and dropping of the laundry when the rotating drum  12  rotates.  
      The detergent supply device  15  includes a detergent case  15   a  installed near the front end of the outer case  10 , and a detergent container  15   b  taking the form of a drawer so that it can be inserted into or retracted from the detergent case  15   a , thereby allowing an appropriate amount of detergent to be placed in the detergent container  15   b  when the detergent container  15   b  is retracted from the detergent case  15   a , as shown in  FIG. 1 .  
      The water supply device  14  includes a pair of external water supply pipes  14   a , a pair of first water supply pipes  14   b  connected between the external water supply pipes  14   a  and the rear end of the detergent case  15   a , a second water supply pipe  14   c  connected between the detergent case  15   a  and the water tub  11 , and a pair of water supply valves  14   d  installed at the inlet side of the first water supply pipes  14   b  for controlling the supply of water. When the water supply valves  14   d  are opened to supply the water, the water is supplied into the water tub  11  via the detergent supply device  15 , such that the detergent filled in the detergent supply device  15  can be supplied into the water tub  11  along with the water.  
      The drainage device  20 , installed below the water tub  11 , includes a drainage pump  30  adapted to forcibly drain the wash water contained in the water tub  11  to the outside, a first drainage pipe  21  connected between the water tub  11  and the drainage pump  30 , and a second drainage pipe  22  extending from the drainage pump  30  to the outside of the outer case  10 .  
      Referring to  FIGS. 2 and 3 , the drainage pump  30  includes a drainage casing  35 , which is an integral combination of a filter case  31  and a pump case  33 . Here, the filter case  31  internally defines a filter chamber  32 , and the pump case  33  internally defines a pump chamber  34 , such that the filter chamber  32  and the pump chamber  34  form separate spaces sectionalized from each other. The drainage pump  30  further includes a filter  36  which is received in the filter chamber  32  and is adapted to filter impurities contained in the wash water to be drained, an impeller  37  rotatably installed in the pump chamber  34 , and a motor  38  mounted at one side of the pump case  33  and adapted to drive the impeller  37 . The drainage pump  30  is fixed to an inner bottom surface  10   b  of the outer case  10  by means of a fixing device  50 .  
      The filter case  31  of the drainage casing  35  includes an inlet port  39  formed at the lateral upper portion thereof, through which the wash water to be drained is introduced. To the inlet port  39  is provided an inlet pipe  40  for use in the connection of the first drainage pipe  21 . At a lower position on the filter case  31  opposite to the inlet port  39  is formed an outlet port  41  communicating with the interior of the pump chamber  34 , thereby allowing the wash water to flow from the filter chamber  32  to the pump chamber  34 .  
      The filter case  31  is further formed at the front end thereof with an opening  31  a for use in the removal of the filter  36  received in the filter chamber  32 . One end of the filter  36  is provided with a cap  42 , which is used to mount the filter  36  in the filter chamber  32 . The cap  42  is also used to close the opening  31   a  of the filter case  31 . For this, throughout the outer periphery of the cap  42  and the inner periphery of the opening  31  a formed at the filter case  31 , threads  42   a  and  31   b  are provided. The cap  42  is rotatably coupled to the end of the filter  36 . In this way, in a state wherein the filter  36  is completely inserted in the filter chamber  32 , the cap  42  is rotated such that it can be fastened to the opening  31   a  of the filter case  31 , thereby closing the opening  31   a.    
      Referring to  FIG. 4 , the filter case  31  is installed in such a fashion that the opening  31   a  of the filter case  31  and the cap  42  are exposed to the outside through an opening  10   c  formed in the outer case  10 , such that a user can separate the filter  36  from the filter case  31  at the outside of the outer case  10  in order to wash the filter  36 . The opening  10   c  of the outer case  10 , for exposing the cap  42  to the outside, is larger than the filter case  31 , such that the filter case  31  is radially spaced apart from the outer case  10 . This has the effect of preventing vibration generated during the operation of the drainage pump  30  from being transmitted to the outer case  10 .  
      Referring again to  FIG. 3 , the pump case  33 , defining the pump chamber  34 , is opened at one side thereof, and the open side of the pump case  33  is closed as the motor  38  is mounted to the pump case  33 . The pump case  33  has an outlet port  43  for discharging the wash water from the pump chamber  34  to the outside when the impeller  37  is driven. The outlet port  43  is connected to an outlet pipe  44  to which the second drainage pipe  22  is attached.  
      With such a configuration of the drainage pump  30 , first, the wash water introduced from the water tub  11  to the filter chamber  32  is filtered while passing through the filter  36  received in the filter chamber  32 , and then, the filtered wash water flows into the pump chamber  34 . In the pump chamber  34 , the impeller  37 , rotated by the motor  38 , discharges the wash water from the pump chamber  34  to the outside through the outlet port  43 , thereby draining the wash water from the water tub  11  to the outside.  
      The fixing device  50 , used to fix the drainage pump  30  to the bottom surface  10   b  of the outer case  10 , includes a support member  51  extending downward for a predetermined length from the lower surface of the drainage casing  35 , vibration-proof members  52  and  53  installed to surround the lower portion of the support member  51  to support it, and fixture members  54  and  55  fixed to the bottom surface  10   b  of the outer case  10  such that they enclose the outer surfaces of the vibration-proof members  52  and  53  to support them.  
      The support member  51  is integrally formed with the drainage casing  35  through injection molding of a conventional resin material. The support member  51  extends downward from the lower surface of the drainage casing  35 . The support member  51  is positioned to correspond to the center of gravity of the drainage pump  30 , such that it can attenuate the vibration of the drainage pump  30  and stably support the drainage pump  30 . Further, the support member  51  has a crucial cross section, such that it can secure strength thereof sufficient to support the drainage pump  30 , and can be firmly coupled with the vibration-proof members  52  and  53  without shaking.  
      The vibration-proof members are made of an elastic rubber material, and include first and second vibration-proof members  52  and  53 , which are coupled to oppose each other such that they can support opposite sides of the support member  51 . In such a coupled state, the first and second vibration-proof members  52  and  53  define a width larger than the maximum width of the support member  51 , such that they can completely surround the lower portion of the support member  51 . The first and second vibration-proof members  52  and  53  are provided with toothed portions  52   a  and  53   a  along edge areas of their-opposite surfaces to be coupled with each other in order to enhance a coupling force therebetween. The first and second vibration-proof members  52  and  53  are further provided with coupling recesses  52   b  and  53   b  corresponding to the shape of an outer surface of the support member  51  having the crucial cross section, such that they can support the outer surface of the support member  51  in a close contact state. In this way, the support member  51  can be stably supported by the two vibration-proof members  52  and  53 .  
      In order to enhance a coupling force between the two vibration-proof members  52  and  53  and the lower outer surface of the support member  51 , the support member  51  is formed at the lower outer surface thereof with protruding ribs  51   a , and the two vibration-proof members  52  and  53  are formed with retaining grooves  53   d  at the inner surfaces of the coupling recesses  52   b  and  53   b  thereof, such that the protruding ribs  51   a  are fitted in the retaining grooves  53   d , respectively. Further, the first and second vibration-proof members  52  and  53  are perforated with a plurality of through-holes  52   c  and  53   c  in order to increase the attenuation of vibration transmitted to the support member  51 .  
      The fixture members include first and second fixture members  54  and  55 , which are configured to enclose the outer surfaces of the first and second vibration-proof members  52  and  53  to support them. The first and second fixture members  54  and  55  are coupled laterally to the vibration-proof members  52  and  53  in such a fashion that they come into close contact with the outer surfaces of the vibration-proof members  52  and  53 . In this way, the first and second fixture members  54  and  55  can support the overall periphery and upper surfaces of the two vibration-proof members  52  and  53 . For the engagement of the two fixture members  54  and  55 , the fixture members  54  and  55  are formed at their contact portions with protrusions  54   a  and  55   a , and receiving holes  54   b  and  55   b . In an engaged state, as fixing screws  56  are fastened to screw-fastening portions  54   d ,  54   e  and  55   d  provided at the fixture members  54  and  55 , the two fixture members  54  and  55  are fixed to the inner bottom surface  10   b  of the outer case  10 . It should be understood that the coupling direction of the first and second vibration-proof members  52  and  53  intersects with the coupling direction of the first and second fixture members  54  and  55 , such that the vibration-proof members  52  and  53  can be more firmly coupled to each other by the fixture members  54  and  55 .  
      The first and second fixture members  54  and  55  are spaced, at their upper surfaces, apart from the support member  51 , thereby being insulated from the support member  51 . For this, the first and second fixture members  54  and  55  are formed at their upper surfaces with insertion slots  54   c  and  55   c , such that the insertion slots  54   c  and  55   c  are spaced apart from the support member  51 . This has the effect of preventing the vibration, transmitted from the drainage pump  30  to the support member  51 , from being transmitted to the fixture members  54  and  55 , thereby preventing the vibration of the drainage pump  30  from being transmitted to the outer case  10 .  
      When it is desired to fix the drainage pump  30  using the above described fixing device  50 , the first and second vibration-proof members  52  and  53  are first coupled to opposite sides of the lower portion of the support member  51 . Then the first and second fixture members  54  and  55  are coupled to the vibration-proof members  52  and  53  such that the coupling direction of the fixture members  54  and  55  intersects with the coupling direction of the vibration-proof members  52  and  53 . Finally, as the fixing screws  56  are fastened, the two fixture members  54  and  55  are fixed to the bottom surface  10   b  of the outer case  10 .  
      When the drainage pump  30  is fixed as stated above, the majority of the drainage pump  30 , except for a portion fixed by the fixing device  50 , is spaced apart from the outer case  10  so the transmission of vibration from the drainage pump  30  to the outer case  10  is minimized. Further, when the drainage is fixed as stated above, since the support member  51  is spaced apart from the fixture members  54  and  55  by interposing the vibration-proof members  52  and  53 , and the support member  51  is supported only by the vibration-proof members  52  and  53 , the vibrations of the drainage pump  30  transmitted to the support member  51  can be minimized. This minimizes vibration of the outer case  10  due to the vibration of the drainage pump  30 , resulting in a reduction in operational noise of the washing machine.  
      As is apparent from the above description, a washing machine according to the present invention is configured in such a fashion that a drainage pump is supported only by a support member, and in turn, the support member is supported only by vibration-proof members, which are supported by fixture members spaced apart therefrom, thereby achieving a remarkable decrease in vibration transmitted from the drainage pump to the outer case of the washing machine, resulting in a reduction in operational noise of the washing machine.  
      Although an embodiment of the present invention has been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.