Abstract:
A washing machine using a BLDG motor is disclosed. The washing machine having a brushless DC motor for rotating a tub includes a case, a dynamic braking resistor, mounted with respect the case, producing heat energy when the brushless DC motor is braked, and a mount, coupled to the case and the dynamic braking resistor, for impeding a transfer of the heat energy of the dynamic braking resistor to the case.

Description:
[0001]     This application claims the benefit of Korean Application No. P2003-090700, filed on Dec. 12, 2003, which is hereby incorporated by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a washing machine using a BLDC motor, and more particularly, to a mount fixing a dynamic braking resistor of a washing machine.  
         [0004]     2. Discussion of the Related Art  
         [0005]     Generally, a washing machine as a representative one of home appliances is an apparatus for removing filth or dirt attached to a laundry using interaction between water and detergent. Such a washing machine is categorized into various types according to a laundry-impacting system. A washing machine using a BLDC (brushless direct current) motor removes the dirt attached to the laundry by rotating a tub at a different speed during washing or dewatering by regulating the speed of the BLDC motor. The washing machine is explained in detail by referring to  FIG. 1  as follows.  
         [0006]      FIG. 1  is a cross-sectional diagram of a washing machine using BLDC motor according to a related art. Referring to  FIG. 1 , a case  10  forms an exterior of a washing machine  1 . A tub  20  is rotatably provided within the case  10 . A pulsator  30  enabling to independently rotate regardless of the tub  20  is provided within the tub  20 . A BLDC motor  40  is provided under the tub  20  to transfer a dynamic force to the tub  20  or pulsator  30 . A dynamic braking resistor  50  is provided to a topside of the case  10 . The dynamic braking resistor  50  is a device for transforming braking energy generated from sudden stop of the BLDC motor into thermal energy to dissipate.  
         [0007]     Specifically, when the BLDC motor  40  is suddenly stopped, a counter electromotive force is generated from the BLDC motor  40  to provide high voltage. The provided high voltage causes damage to the BLDC motor  40 . Hence, a voltage detecting circuit detects the provided high voltage and excessive energy is then dissipated into heat by the dynamic braking resistor  50  that is an energy dissipater. However, the heat generated from the dynamic braking resistor transforms a topside of the case while the dynamic braking resistor thermally dissipates electricity. Moreover, the heat generated from the dynamic braking resistor is transferred to other devices of the washing machine to cause thermal transformation of the corresponding devices.  
       SUMMARY OF THE INVENTION  
       [0008]     Accordingly, the present invention is directed to a washing machine using a BLDC motor that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.  
         [0009]     An object of the present invention, which has been devised to solve the foregoing problem, lies in providing a heat-transfer preventing mount, by which heat generated from a dynamic braking resistor is prevented from being transferred to a case or other devices of a washing machine.  
         [0010]     Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from a practice of the invention. The objectives and other advantages of the invention will be realized and attained by the subject matter particularly pointed out in the specification and claims hereof as well as in the appended drawings.  
         [0011]     To achieve these objects and other advantages in accordance with the present invention, as embodied and broadly described herein, a washing machine having a brushless DC motor for rotating a tub includes a case, a dynamic braking resistor, mounted with respect the case, producing heat energy when the brushless DC motor is braked, and a mount, coupled to the case and the dynamic braking resistor, for impeding a transfer of the heat energy of the dynamic braking resistor to the case.  
         [0012]     The mount may include a first mounting member for fixing the dynamic braking resistor, and a second mounting member for separating the fixed dynamic braking resistor from the case. The first and second mounting members are integrally formed as one body. The first mounting member may include a flange fixed to the dynamic braking resistor, and a frame, connected to the second mounting member, for supporting the flange. The frame may have at least one aperture for facilitating air circulation with respect to the dynamic braking resistor. The frame may include a bent perimeter for imparting the frame with rigidity.  
         [0013]     The second mounting member may establish a predetermined distance between the frame and the case, based on the height of the dynamic braking resistor. The second mounting member may have a length greater than the height of the dynamic braking resistor. The flange may extend from the frame to separate the fixed dynamic braking resistor from the frame. The second-mounting member has a length greater than the height of the dynamic braking resistor plus the separation between the fixed dynamic braking resistor and the frame. The second mounting member may be secured to an upper surface of the case.  
         [0014]     The dynamic braking resistor may be disposed between the first mounting member and the upper surface of the case. The dynamic braking resistor may be fixed to the first mounting member using at least one screw. The dynamic braking resistor may be fixed to the first mounting member using two screws. The second mounting member may be secured to the case using at least one screw. And, the second mounting member may be secured to the case using four screws.  
         [0015]     The mount may include a plurality of substantially flat surfaces formed of a rigid material, and a channel, formed in the flat surfaces, for increasing the rigidity of the flat surfaces. Herein, the first mounting member may include parallel sides joined by a central strut, the parallel sides being supported on the second mounting member. The first mounting member may also include a plurality of channels, respectively formed in the parallel sides and the central strut. The second mounting member may include four legs, each leg supporting the first mounting member at a separate point. The second mounting member may also include comprises a plurality of channels, respectively formed in each leg. The dynamic braking resistor may be disposed above the case. And, the mount may be secured to an upper surface of the case. The mount may be formed of a material having a low heat transfer coefficient.  
         [0016]     In another aspect of the present invention, a washing machine having a brushless DC motor for rotating a tub includes a case, a dynamic braking resistor, mounted with respect the case, producing heat energy when the brushless DC motor is braked, a flange fixed to the dynamic braking resistor, a frame, connected to the second mounting member and separated from the flange, for supporting the flange, and at least one leg, having one end connected to the frame and the other end secured to the case, the at least one leg having a length greater than a height of the dynamic braking resistor plus the separation of the flange from the frame.  
         [0017]     Herein, the frame may have at least one aperture for facilitating air circulation with respect to the dynamic braking resistor. And, the flange, the frame, and the at least one leg may be formed as substantially flat surfaces of a rigid material, at least one surface comprising a channel for increasing the rigidity of the flat surfaces. At least one of the flange, the frame, and the at least one leg is formed of a material having a low heat transfer coefficient.  
         [0018]     It is to be understood that both the foregoing explanation and the following detailed description of the present invention are exemplary and illustrative and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     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 embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
         [0020]      FIG. 1  is a cross-sectional diagram of a washing machine according to a related art;  
         [0021]      FIG. 2  is a cross-sectional diagram of a washing machine according to the present invention;  
         [0022]      FIG. 3  is a cross-sectional diagram of a mount according to the present invention; and  
         [0023]      FIG. 4  is a perspective diagram of a mount according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Throughout the drawings, like elements are indicated using the same or similar reference designations where possible.  
         [0025]      FIG. 2  is a cross-sectional diagram of a washing machine using a BLDC motor according to the present invention. Referring to  FIG. 2 , an exterior of a washing machine using a BLDC motor is configured by a case. A washing machine  100  according to the present invention includes a case  110 , a tub  120 , a motor  130 , a dynamic braking resistor  150 , and a mount  200  preventing heat transfer. The case  110  forms an exterior of the washing machine  100  and the tub  120  is rotatably provided within the case  110 . And, a pulsator may be rotatably provided within the tub  120 . Besides, a cover  160  may be further provided to a topside of the tub  120  to open/close the tub  120 . A motor  130  is provided beneath the tub  120  to rotate the tub  120 . In the present invention, the motor  130  is a BLDC (brushless direct current) motor  130 .  
         [0026]     Meanwhile, in the washing machine  100  using the BLDC motor  130  enabling electrical braking without a mechanical braking device, if a user opens the cover  160  in the course of high-speed dewatering, a safety device (not shown in the drawing) makes a sudden stop of the motor  130 . In doing so, the motor  130  plays a role of generator or dynamo to generate a counter electromotive force, whereby high voltage is produced. In order to prevent various devices of the washing machine  100  from being broken, a dynamic braking resistor  150 , which transforms electricity of high voltage into heat to dissipate, is provided within the washing machine  100 . Although the dynamic braking resistor  150  fails to be clearly shown in the drawing, a nicrome wire emitting heat at high temperature is loaded within a glass tube and a space between the nicrome wire and the glass tube is filled with an insulating material.  
         [0027]     And, the mount  200  fixes the dynamic braking resistor  150  to an inside of the washing machine  100  and prevents the heat generated from the dynamic braking resistor  150  from being transferred to other devices of the washing machine  100 . The mount  200  is explained in detail by referring to  FIG. 3  and  FIG. 4  as follows. Referring to  FIG. 3  and  FIG. 4 , the mount  200  includes a first mounting member  210  and a second mounting member  250 . The first mounting member  210  is coupled to the dynamic braking resistor  150 . And, the second mounting member  250  extends from the first mounting member  210  to separate the dynamic braking resistor  150  from a device of the washing machine  100 .  
         [0028]     The first mounting member  210  includes a coupling part  220  coupled to the dynamic braking resistor  150  and a support part  230  supporting the coupling part  220 . In order to reduce a contact area between the dynamic braking resistor  150  and the mount  200 , the coupling part  220  protrudes from the support part  230  to have a predetermined height. Namely, the coupling part  220  protrudes upward or downward from the support part  230  to have the predetermined height different from that of the support part  230 . The coupling part  220  protrudes upward if the dynamic braking resistor  150  is coupled to a topside of the support part  230 . Alternatively, the coupling part  220  protrudes downward if the dynamic braking resistor  150  is coupled to a bottom side of the support part  230 .  
         [0029]     The coupling part  220  includes a hole  221  penetrated by a screw  170  to be coupled to the dynamic braking resistor  150 . Hence, the dynamic braking resistor  150  is coupled to the first mounting member  210 , i.e., the coupling part  220  by the screw  170 . And, the support part  230  includes an opening  221  facilitating the dynamic braking resistor  150  to be smoothly contacted with air to activate cooling. The opening  231  is formed across an overall area of the support part  230 . In order to reinforce rigidity of the support part  230 , a rim  232  of the support part  230  is bent downward.  
         [0030]     As mentioned in the foregoing description, the second mounting member  250  extends from the first mounting member  210 , and more particularly, from the support part  230  to be coupled to a device of the washing machine. Specifically, the second mounting member  250  includes at least one or more legs. One side of each of the legs is connected to the support part  230  and the other side of each of the legs is coupled to a topside of the case  110 .  
         [0031]     In order not to occupy a space excessively, the dynamic braking resistor  150  is coupled to a bottom side of the first mounting member  210 . In doing so, the second mounting member  250  is formed longer than a height of the dynamic braking resistor  150  to separate the dynamic braking resistor  150  from the device of the washing machine  100 . And, the second mounting member  250  is coupled to the device of the washing machine  100  by another screw  170 . Specifically, a tip of the second mounting member  250  is bent parallel to a topside of the device of the washing machine  100 , and more particularly, to the topside of the case  110 . A hole  251  is formed in the bent portion of the second mounting member  250  so that the second mounting member  250  can be coupled to the topside of the case  110 .  
         [0032]     Meanwhile, the mount  200  may be bent by the weight of the dynamic braking resistor  150 . In order to prevent the bending of the mount  200 , the mount  200  further includes a bead  260  reinforcing rigidity. Specifically, at least one of the coupling part  220 , support part  230 , and second mounting member  250 , i.e., a plurality of the legs, should further include the bead  260 . In order to facilitate the coupling to the washing machine  100 , the mount  200  is preferably provided to the topside of the case  110 . Moreover, in order to prevent the heat generated from the dynamic braking resistor  150  from being transferred to the case  110  and the device of the washing machine  100 , the mount  200  is formed of a material having a low heat transfer coefficient. Specifically, at least one of the coupling part  220 , support part  230 , and second mounting member  250 , i.e., a plurality of the legs, is formed of a material having a low heat transfer coefficient.  
         [0033]     An operation of the washing machine  100  using the BLDC motor  130  according to the present invention is explained as follows.  
         [0034]     First of all, the mount  200  having the dynamic braking resistor  150  coupled thereto is fixed to the topside of the case  110 . When the dynamic braking resistor  150  emits heat, the mount  200  prevents the heat from being transferred to the topside of the case  110  and the device of the washing machine  100 . Hence, the topside of the case  100  and the device of the washing machine enable to avoid being transformed by the heat.  
         [0035]     Namely, while the dynamic braking resistor  150  is coupled to the first mounting member  210 , the second mounting member  250  extending from the first mounting member  210  is coupled to the topside of the case  110  or the device of the washing machine. In this case, as the second mounting member  250  has the length greater than the height of the dynamic braking resistor  150 , the dynamic braking resistor  150  is separated from the topside of the case  110  or the device of the washing machine to leave a predetermined distance from each other.  
         [0036]     Accordingly, the present invention has the following advantages or effects.  
         [0037]     First of all, the mount prevents the heat emitted from the dynamic braking resistor from being transferred to the case, whereby the case is not transformed by the heat. Secondly, the mount prevents the heat emitted from the dynamic braking resistor from being transferred to the device of the washing machine, whereby the device of the washing machine enables to avoid being transformed by the heat.  
         [0038]     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover such modifications and variations, provided they come within the scope of the appended claims and their equivalents.