Patent Publication Number: US-8113019-B2

Title: Drum type washing machine for preventing water from penetrating into a bearing

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a drum type washing machine. 
     2. Description of the Related Art 
     In general, a drum type washing machine serves to wash laundry by using a friction force between a rotating drum and the laundry and the laundry dropping from a top to a bottom in the rotating drum. Accordingly, in the drum type washing machine, the laundry is little damaged and is not entangled. 
     The drum type washing machine includes a tub for holding water therein, a drum rotatably installed in the tub and receiving laundry therein, a driving motor is installed at a rear side of the drum so as to rotate the drum, a rotation shaft for transferring a driving force from the driving motor to the drum, a bearing for supporting the rotation shaft, and a sealing member installed on an outer circumferential surface of the rotation shaft in front of the bearing so as to prevent water between the tub and the drum from penetrating into the bearing. 
     Even though the sealing member is provided in front of the bearing, it is impossible to perfectly prevent the water between the tub and the drum from penetrating into the bearing through a gap between the sealing member and the rotation shaft. 
     Once the water penetrates into the bearing, the bearing is corroded. Then the corroded bearing cannot stably support the rotation shaft, which results in shaking of the rotation shaft and the drum. As a result, vibration and noise generated while the drum type washing machine is operated, which causes the drum type washing machine to be out of order. 
     SUMMARY OF THE INVENTION 
     To solve the aforementioned problems, in accordance with one aspect of the present invention, there is provided a drum type washing machine comprising: a tub; a drum rotatably installed in the tub; a driving motor for rotating the drum; a rotation shaft for transferring a rotational force from the driving motor to the drum; a bearing for supporting the rotation shaft; a sealing member for preventing water from penetrating into the bearing; and a water penetration preventing unit for preventing the water from penetrating into the sealing member. 
     Preferably, the water penetration preventing unit is implemented as a rib formed at a spider connecting the rotation shaft and the drum to each other or a is rib formed at the sealing member. 
     Alternately the water penetration preventing unit is implemented as a first rib formed at a spider connecting the rotation shaft and the drum to each other and a second rib formed at the sealing member, preferably. Here, an external diameter of the first rib is larger than that of the second rib, and the first rib and the second rib are overlapped with each other in a length direction, preferably. 
     In accordance with another aspect of the present invention, there is provided a drum type washing machine comprising: a tub; a drum rotatably installed in the tub; a driving motor for rotating the drum; a rotation shaft for transferring a rotational force from the driving motor to the drum; front and rear bearings for supporting the rotation shaft; a sealing member insertedly installed on an outer circumferential surface of the rotation shaft in front of the front bearing; and a rib formed at a spider connecting the rotation shaft and the drum to each other or formed at the sealing member. Here, it may be doubly prevented that water between the tub and the drum penetrates into the front and rear bearings by the sealing member and the rib. 
     Here, the rib is formed at the spider in a cylindrical shape, and is extended toward the sealing member with a length so as to form a gap between the rib and the sealing member, preferably. 
     Alternately the rib is formed at the sealing member in a cylindrical shape, and is extended toward the spider with a length so as to form a gap between the rib and the spider, preferably. 
     In accordance with still another aspect of the present invention, there is provided a drum type washing machine comprising: a tub; a drum rotatably installed in the tub; a driving motor for rotating the drum; a rotation shaft for transferring a rotational force from the driving motor to the drum; front and rear bearings for supporting the rotation shaft; a sealing member insertedly installed on an outer circumferential surface of the rotation shaft in front of the front bearing; a first rib formed at a spider connecting the rotation shaft and the drum to each other; and a second rib formed at the sealing member. Here, an external diameter of the first rib may be larger than that of the second rib, and the first rib and the second rib may be overlapped with each other in a length direction. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the description serve to explain the principles of the invention. 
       In the drawings: 
         FIG. 1  is a schematic view showing a drum type washing machine in accordance with one embodiment of the present invention; 
         FIG. 2  is an enlarged view of “A” portion in  FIG. 1 ; 
         FIG. 3  is a diagram showing a variation of a water penetration preventing unit of  FIG. 2 ; and 
         FIG. 4  is a diagram showing another variation of the water penetration preventing unit of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Description will now be given in detail of the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     Hereafter, a drum type washing machine in accordance with one embodiment of the present invention will be described in detail.  FIG. 1  is a schematic view showing the drum type washing machine in accordance with the one embodiment of the present invention, and  FIG. 2  is an enlarged view of “A” portion in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , the drum type washing machine in accordance with the one embodiment of the present invention includes a cabinet  5  forming an external appearance, a tub  3  installed in the cabinet  5  so as to hold water therein, a drum  9  rotatably installed in the tub  3  and receiving laundry therein, driving motors  7 ,  8  for rotating the drum  9 , a rotation shaft  17  for transferring a rotational force from the driving motors  7 ,  8  to the drum  9 , a bearing  11  for supporting the rotation shaft  17 , a sealing member  13  for preventing water between the tub  3  and the drum  9  from penetrating into the bearing  11 , and a water penetration preventing unit  100  for preventing the water between the tub  3  and the drum  9  from penetrating into the sealing member  13 . 
     A door  1  is disposed at a front side of the cabinet  5 , and a gasket  2  is installed between the door  1  and the tub  3 . A locking spring  4  for supporting the tub  3  is installed between an upper inner surface of the cabinet  5  and an outer upper surface of the tub  3 . A friction damper  10  for reducing vibration of the tub  3  is installed between a lower inner surface of the cabinet  5  and an outer lower surface of the tub  3 . 
     A detergent supply device  30  for supplying detergent to the tub  3  is disposed at a front upper side of the cabinet  5 . The detergent supply device  30  serves to mix the detergent with water and to supply the mixture to the tub  5  through a supply pipe  31 . 
     A water supply device  20  consisted of a plurality of valves for supplying water to the detergent supply device  30  is disposed at a rear upper side of the cabinet  5 . And, a supply pipe  21  connected to an external water supply source and a connection pipe  22  connected to the detergent supply device  30  are respectively installed at the water supply device  20 . 
     A drain pump  41  for draining the water stored in the tub  3  by outwardly pumping it is installed at a rear lower side of the cabinet  5 . And, a drain pipe  41  connected to the lower side of the tub  3  and a connection pipe  42  connected to an external drain are respectively installed at the drain pump  40 . 
     A plurality of lifters  9   a  for moving the laundry up and down are disposed in the drum  9 . 
     The driving motors  7 ,  8  consist of a stator  7  implemented as a direct drive type motor and provided with a coil wound at a slot, and a rotor  8  rotated at an outer circumferential surface of the stator  7  and provided with a permanent magnet  12  therein. 
     The stator  7  is coupled to a rear wall of the tub  3  by a plurality of coupling member  19 . 
     The rotor  8  is coupled to a rear end of the rotation shaft  17  by a coupling member  18 . 
     With such configuration, once the coil of the stator  7  receives a power and thus to become electromagnetic, the rotor  8  is rotated by an interaction between the coil of the stator  7  and the permanent magnet  12  attached in the rotor  8 . A rotational force of the rotor  8  is transferred to the drum  9  through the rotation shaft  17 . 
     The bearing  11  is installed in a bearing housing  15  and includes a front bearing  11   a  positioned at a front side of the rotation shaft  17  and a rear bearing  11   b  positioned at a rear side of the rotation shaft  17 . 
     The sealing member  13  installed on the outer circumferential surface of the rotation shaft  17  in front of the front bearing  11   a , thereby preventing water B between the tub  3  and the drum  9  from penetrating into the bearing  11 . 
     The water penetration preventing unit  100  includes a first rib  110  having a cylindrical shape and formed at a spider  6  connecting the rotation shaft  17  and the drum  9  to each other, and a second rib  120  having a cylindrical shape and formed at the sealing member  13 . 
     Here, an external diameter D 1  of the first rib  110  is larger than an external diameter D 2  of the second rib  120 . Alternately, the external diameter D 1  of the first rib  110  may be smaller than the external diameter D 2  of the second rib  120 . Even in the second case, the external diameter D 1  of the first rib  110  should not be larger than an external diameter D 3  of the sealing member  13 . In other words, the external diameter D 1  of the first rib  110  should be same as or smaller than the external diameter D 3  of the sealing member  13 . 
     If the external diameter D 2  of the first rib  110  is larger than the external diameter D 3  of the sealing member  13 , the first rib  110  is positioned out of a central portion of the spider  6 . Then, due to a structure of the spider  6 , a gap through which water can penetrate is generated between the spider  6  and the first rib  110 , accordingly an effect with respect to preventing of water penetration may is be deteriorated. 
     In the meantime, the first rib  110  is extended toward the sealing member  13  and the second rib  120  is extended toward the spider  6  so that a length W 1  of the first rib  110  and a length W 2  of the second rib  120  may be overlapped with each other in a length direction. 
     By the first rib  110  and the second rib  120 , it is capable of preventing water dropping to the first rib  110  or the second rib  120  from approaching the sealing member  13 . 
     Hereafter, an operation principle of the water penetration preventing unit will be described. 
     While washing, rinsing or dehydrating, water kept in the drum  9  or at the lower portion of the tub  3  is splashed to an upper inner wall of the tub  3  by the rotational force of the drum  9 . Some of the water drops through an interval S between the tub  3  and the drum  9 . The water B dropping through the interval S between the tub  3  and the drum  9  drops to the first rib  110  or the second rib  120  in a direction of dotted line arrow. 
     The water dropping to the first rib  110  is splashed from the outer circumferential surface of the first rib  110  in a direction of solid line arrow by the rotational force of the rotating drum  9 . 
     The water dropping to the second rib  120  flows down along the outer circumferential surface of the second rib  120  in the direction of solid line arrow. 
     By the first rib  110  and the second rib  120 , it is capable of preventing the water from approaching the sealing member  13 . 
     Thus, by the first rib  110  and the second rib  120  and the sealing member  13 , it is capable of doubly preventing the water between the tub  3  and the drum  9  from penetrating into the bearing  11 . 
     Accordingly, it is capable of preventing vibration and noise caused by corrosion of the bearing  11 , and of stably supporting the rotation shaft  17  with maintaining its initial performance of the bearing  11 , thereby being capable of preventing the drum type washing machine from being out of order. 
       FIG. 3  is a diagram showing a variation of a water penetration preventing unit of  FIG. 2 . 
     Referring to  FIG. 3 , a water penetration preventing unit  200  is a cylindrical rib formed at the spider  6 . Here, the rib is extended toward the sealing member  13  as long as the rib does not come into contact with the sealing member  13 . That is, the rib has a length W 3  so that an interval between the rib and the sealing member  13  may be a minimum gap g 1 . Accordingly, the water penetration preventing unit  200  has a length W 3  longer than the length W 1  (refer to  FIG. 2 ) of the first rib  110  (refer to  FIG. 2 ). 
     When the water penetration preventing unit  200  is formed only at the spider  6 , even though water may penetrate into the bearing  11  through the gap g 1 , it is capable of simplifying the configuration and of reducing a cost, in comparison with the ribs formed both at the spider  6  and the sealing member  13 . 
     Hereafter, an operation principle of the water penetration preventing unit will be described. 
     While washing, rinsing or dehydrating, water kept in the drum  9  or at the lower portion of the tub  3  is splashed to an upper inner wall of the tub  3  by the rotational force of the drum  9 . Some of the water drops through an interval S between the tub  3  and the drum  9 . The water B dropping through the interval S between the tub  3  and the drum  9  drops to the rib  200  in a direction of dotted line arrow. 
     The water dropping to the rib  200  is splashed from the outer circumferential surface of the rib  200  in a direction of solid line arrow by the rotational force of the rotating drum  9 . 
     By the rib  200 , it is capable of preventing the water from approaching the sealing member  13 . 
     Thus, by the rib  200  and the sealing member  13 , it is capable of doubly preventing the water between the tub  3  and the drum  9  from penetrating into the bearing  11 . 
     Accordingly, it is capable of preventing vibration and noise caused by corrosion of the bearing  11 , and of stably supporting the rotation shaft  17  with maintaining its initial performance of the bearing  11 , thereby being capable of preventing the drum type washing machine from being out of order. 
       FIG. 4  is a diagram showing another variation of a water penetration preventing unit of  FIG. 2 . 
     Referring to  FIG. 4 , a water penetration preventing unit  300  is a cylindrical rib formed at the sealing member  13 . Here, the rib is extended toward the spider  6  as long as the rib does not come into contact with the spider  6 . That is, the rib has a length W 4  so that an interval between the rib and the sealing member  13  may be a minimum gap g 2 . Accordingly, the water penetration preventing unit  300  has the length W 4  longer than the length W 2  (refer to  FIG. 2 ) of the second rib  120  (refer to  FIG. 2 ). 
     When the water penetration preventing unit  300  is formed only at the sealing member  13 , even though water may penetrate into the bearing  11  through the gap g 2 , it is capable of simplifying the configuration and of reducing a cost, in comparison with the ribs formed both at the spider  6  and the sealing member  13 . 
     Hereafter, an operation principle of the water penetration preventing unit will be described. 
     While washing, rinsing or dehydrating, water kept in the drum  9  or at the lower portion of the tub  3  is splashed to an upper inner wall of the tub  3  by the rotational force of the drum  9 . Some of the water drops through an interval S between the tub  3  and the drum  9 . The water B dropping through the interval S between the tub  3  and the drum  9  drops to the rib  300  in a direction of dotted line arrow. 
     The water dropping to the rib  300  flows down along the outer circumferential surface of the rib  300  in a direction of solid line arrow. 
     By the rib  300 , it is capable of preventing the water from approaching the sealing member  13 . 
     Thus, by the rib  300  and the sealing member  13 , it is capable of doubly preventing the water between the tub  3  and the drum  9  from penetrating into the bearing  11 . 
     Accordingly, it is capable of preventing vibration and noise caused by corrosion of the bearing  11 , and of stably supporting the rotation shaft  17  with maintaining its initial performance of the bearing  11 , thereby being capable of preventing the drum type washing machine from being out of order. 
     Meanwhile, the drum type washing machine in the aforementioned embodiment is provided with a horizontal drum, however the present invention can be applied to a drum type washing machine having a drum inclined in a specific angle. 
     The drum type washing machine in accordance with the one embodiment of the present invention includes the sealing member for preventing water between the tub and the drum from penetrating into the bearing for supporting the rotation shaft, and the water penetration preventing unit for preventing the water between the tub and the drum from penetrating into the sealing member. Accordingly, it is capable of doubly preventing the water between the tub and the drum from penetrating into the bearing and thus to prevent corrosion of the bearing due to the water. Accordingly, it is capable of vibration and noise caused by the corrosion of the bearing, and of stably supporting the rotation shaft with maintaining the initial performance of the bearing, thereby preventing the drum type washing machine from being out of order. 
     The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments. 
     As the present inventive features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.