Patent Publication Number: US-11396724-B2

Title: Bearing assembly and clothes dryer having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2018-0137635, filed on Nov. 9, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety 
     BACKGROUND 
     1. Field 
     The disclosure relates to a clothes dryer, and more particularly, to a bearing assembly capable of supporting a shaft of a drum and a clothes dryer having the same. 
     2. Description of Related Art 
     A clothes dryer is a device for drying objects to be dried such as wet clothes, and the clothes dryer is configured to dry objects to be dried by allowing hot air to pass through the inside of a drum while rotating the drum, in which the objects to be dried are placed, at a low speed. 
     The clothes dryer includes a housing forming an exterior thereof, a drum rotatably installed inside the housing, a driver for driving the drum, and a hot air supplier for supplying hot air into the rotating drum. 
     When operating the clothes dryer after putting objects to be dried into the drum, the drum is rotated by the operation of the driver and the hot air is supplied to the drum through the hot air supplier, thereby drying the object to be dried in the drum. 
     The drum includes a shaft installed at the center of the rear side of the housing, and at the rear wall of the housing, a bearing assembly configured to rotatably support the shaft is installed. Therefore, the drum is installed to be rotatable in the housing through the bearing assembly. 
     SUMMARY 
     Therefore, it is an aspect of the disclosure to provide a clothes dryer including a bearing assembly capable of allowing a shaft to move in the front, rear, left, and right directions in accordance with a movement of a drum. 
     Additional aspects of the disclosure 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 disclosure. 
     In accordance with an aspect of the disclosure, a clothes dryer includes a housing, a drum configured to be rotatable in the housing, a shaft connected to drum to rotate the drum and installed at the center of a rear wall of the drum, and a bearing assembly configured to rotatably support the shaft, and the bearing assembly includes a bearing configured to rotatably support the shaft, and a centering guide formed in an annular shape and in which the bearing is installed, the centering guide allows an inclination of the shaft to be varied in front, rear, left, and right directions, and the centering guide includes an outer circumferential surface formed with a spherical surface. 
     The bearing is one of a pair of bearings may be provided in the bearing assembly and the pair of bearings is to be fixed to opposite inner sides of the centering guide. 
     The centering guide may include a fixing member formed in an annular shape and to which the bearing is fixed, and a guide member formed in an annular shape to allow the fixing member to be fixed therein and provided with an outer circumferential surface formed with a spherical surface. 
     The fixing member may be formed of a metal material, and the guide member may be formed of a resin material on outside of the fixing member through the insert injection molding method. 
     The fixing member may include at least one chamfered portion formed by processing a portion of an outer circumferential surface to be a plane. 
     The fixing member may include a pair of stepped portions formed in a concave shape at axial opposite ends of the outer circumferential surface of the fixing member, and the guide member includes a pair of catching portions formed in a convex shape at axial opposite ends in an inner circumferential surface of the guided member to be caught by the pair of stepped portions. 
     The bearing assembly may further include a first centering housing and a second centering housing coupled to each other in a front-rear direction and having the centering guide between the first centering housing and the second centering housing so that the centering guide is rotatable inside the coupled first and second centering housings. 
     The first centering housing may include a first guide portion including an inner circumferential surface formed with a spherical surface corresponding to a front outer circumferential surface of the centering guide, and the second centering housing may include a second guide portion including an inner circumferential surface formed with a spherical surface corresponding to a rear outer circumferential surface of the centering guide. 
     The first centering housing may include a first flange formed with an annular plate and in which the first guide portion extends from an inner end thereof, and the second centering housing may include a second flange formed with an annular plate and in which the second guide portion extends from an inner end thereof. 
     The first centering housing may include a first through hole provided in the first flange and a fixing rib extending from an inner end of the first through hole, and the second centering housing may include a second through hole provided on the second flange to correspond to the fixing rib, and the second through hole may be formed to have a diameter larger than that of the fixing rib, and a rear end of the fixing rib may be curled after passing through the second through hole, so as to be supported on the second flange. 
     The clothes dryer may further include an elastic member arranged between the first and second centering housings to elastically support the centering guide. 
     The elastic member may include a base portion formed with an annular plate and fitted between the first and second centering housings, and a plurality of elastic portions extending from an inner end of the base portion and spaced apart from each other in the circumferential direction. 
     The centering guide may include a plurality of locking grooves formed on the outer circumferential surface in the axial direction and spaced apart from each other in the circumferential direction, and the elastic member may further include a plurality of locking portions extending from the inner end of the base portion to be locked by the plurality of locking grooves. 
     In accordance with another aspect of the disclosure, a bearing assembly includes a bearing configured to rotatably support a shaft, a centering guide formed in an annular shape and in which the bearing is installed, and a first centering housing and a second centering housing coupled to each other in a front-rear direction to receive the centering guide therein and the centering guide being configured to be rotatable therein so that the centering guide allows an inclination of the shaft to be varied in front, rear, left, and right directions, and the centering guide includes an outer circumferential surface formed with a spherical surface, and the first centering housing includes a first guide portion including an inner circumferential surface formed with a spherical surface corresponding to a front outer circumferential surface of the centering guide, and the second centering housing includes a second guide portion including an inner circumferential surface formed with a spherical surface corresponding to a rear outer circumferential surface of the centering guide. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view of a clothes dryer according to an embodiment of the disclosure; 
         FIG. 2  is a side cross-sectional view of the clothes dryer according to an embodiment of the disclosure; 
         FIG. 3  is an exploded perspective view illustrating a drum, a bearing assembly, and a rear plate of the clothes dryer according to an embodiment of the disclosure; 
         FIG. 4  is an exploded perspective view illustrating the coupling of the shaft and the bearing assembly in the clothes dryer according to an embodiment of the disclosure; 
         FIG. 5  is a cross-sectional view illustrating the coupling of the shaft and the bearing assembly in the clothes dryer according to an embodiment of the disclosure; 
         FIG. 6  is an exploded perspective view of the bearing assembly in the clothes dryer according to an embodiment of the disclosure; 
         FIG. 7  is a perspective view of a centering guide in the clothes dryer according to an embodiment of the disclosure; and 
         FIG. 8  is a schematic view illustrating a coupling process of a first centering guide and a second centering guide in the clothes dryer according to an embodiment of the disclosure; and 
         FIG. 9  is a schematic view illustrating the coupling process of the first centering guide and the second centering guide in the clothes dryer according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments described in the disclosure and configurations shown in the drawings are merely examples of the embodiments of the disclosure, and may be modified in various different ways at the time of filing of the present application to replace the embodiments and drawings of the disclosure. 
     In addition, the same reference numerals or signs shown in the drawings of the disclosure indicate elements or components performing substantially the same function. 
     Also, the terms used herein are used to describe the embodiments and are not intended to limit and/or restrict the disclosure. The singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. In this disclosure, the terms “including”, “having”, and the like are used to specify features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more of the features, elements, steps, operations, elements, components, or combinations thereof. 
     It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, but elements are not limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the disclosure, a first element may be termed as a second element, and a second element may be termed as a first element. The term of “and/or” includes a plurality of combinations of relevant items or any one item among a plurality of relevant items. 
     In the following detailed description, the terms of “front end”, “rear end”, “upper portion”, “lower portion”, “upper end”, “lower end” and the like may be defined by the drawings, but the shape and the location of the component is not limited by the term. 
     The disclosure will be described more fully hereinafter with reference to the accompanying drawings 
       FIG. 1  is a perspective view of a clothes dryer according to an embodiment of the disclosure and  FIG. 2  is a side cross-sectional view of the clothes dryer according to an embodiment of the disclosure. 
     As illustrated in  FIGS. 1 and 2 , a clothes dryer  1  includes a housing  10  forming an exterior, a door  20  configured to open and close an inlet  13   a  provided on the front surface of the housing  10 , and a drum  30  rotatably installed in the housing  10  and in which laundry to be dried is placed. 
     The housing  10  is formed in a substantially box shape. More particularly, the housing  10  includes a top plate  11 , a bottom plate  12 , a front plate  13 , a left side plate (not shown), a right side plate  14 , and a rear plate  15 . 
     The housing  10  includes the inlet  13   a  provided on the front plate  13  and configured to allow objects to be dried to be inserted into or taken out from the inside of the drum  30 , and a control panel  16  provided on an upper side of the front plate  13  and configured to display a variety of information on the clothes dryer  1  or configured to receive an operation command. 
     On the inner front side of the housing  10 , a front support frame  17  corresponding to an opening of a body  31  to be described later is arranged. As for the front support frame  17 , a front end thereof forms a laundry inlet  17   a  corresponding to the above-described inlet  13   a.    
     The drum  30  is rotatably coupled to the front support frame  17 . The drum  30  includes the body  31  formed in a hollow cylindrical shape with the front and the rear open, and a rear wall  32  configured to cover the rear of the body  31  that is open. 
     In addition, as illustrated in  FIGS. 3 and 4 , the drum  30  includes a shaft  33  and a shaft flange  34 . In order to allow the drum  30  to be rotatably installed on the rear plate  15 , the shaft  33  is installed on the center of the rear wall  32  to form a rotation center of the drum  30 . The shaft flange  34  is configured to allow the shaft  33  to be stably fixed to the rear wall  32 . 
     Because the shaft  33  is fixed to the drum  30  through the shaft flange  34  fixed to the rear wall of the drum  30 , the shaft  33  rotates together with the drum  30 . The shaft flange  34  is fixed to the rear wall  32  of the drum  30  through a plurality fastening members. 
     Referring again to  FIG. 2 , the drum  30  includes lifters  37  arranged on an inner circumferential surface of the body  31  to raise the object to be dried upward. A plurality of lifters are spaced apart from each other in the circumferential direction. Therefore, as the drum  30  rotates, the object to be dried may be repeatedly moved upward by the lifters  37  and then dropped. Therefore, as the drum  30  rotates, an unbalanced load is inevitably generated in the drum  30 . 
     As described above, in the process of raising or falling the object to be dried in the drum  30 , the unbalanced load is inevitably generated in the drum  30 , and the drum  30  is moved due to the unbalanced load. 
     Therefore, a roller  18  configured to support a lower portion of the front side of the drum  30  is arranged in the housing  10 . The roller  18  is arranged in a lower portion of the front side of the housing  10  to allow the drum  30  to rotate smoothly. The arrangement and number of the rollers  18  may vary according to the design specifications. 
     The clothes dryer  1  further includes a driver  40  for rotating the drum  30 . 
     The driver  40  includes a drive motor  41  installed in the inner lower portion of the housing  10 , and a pulley  42  and a belt  43  configured to transmit the power of the drive motor  41  to the drum  30 . 
     The pulley  42  is connected to a motor shaft  44  of the drive motor  41 , and thus the pulley  42  is rotated in accordance with the rotation of the drive motor  41 . 
     The belt  43  is installed to be wound on an outer surface of the pulley  42  and an outer surface of the drum  30 , and thus the drum  30  is rotated together with the belt  43  as the pulley rotates. 
     The clothes dryer  1  includes a hot air supplier  50  configured to supply hot air into the drum  30 , and a hot air discharger  60  configured to discharge air that has been used for drying the object to be dried in the drum  30 . 
     Therefore, hot air is supplied into the drum  30  by the hot air supplier  50 , and the object to be dried in the drum  30  is dried by the supplied hot air. After absorbing the moisture from the object to be dried, the air has a high temperature and a high humidity state, and then the air is discharged to outside through the hot air discharger  60 . 
     The hot air supplier  50  includes a heater  51  configured to heat the suctioned air, and intake ducts  52  and  53  configured to guide the air heated by the heater  51  to flow into the drum  30 . 
     The intake ducts  52  and  53  include the lower intake duct  52  installed under the drum  30 , and the rear intake duct  53  installed at the rear of the drum  30  to connect an intake port  36  to the lower intake duct  52 . The heater  51  is arranged in the lower intake duct  52  to heat the air suctioned into the lower intake duct  52 . 
     The hot air discharger  60  includes a fan  61  configured to suction high temperature and high humidity air in the drum  30 , and an exhaust duct  62  configured to guide the air suctioned by the fan  61  to be discharged from the drum. The fan  61  is placed in a blower case  63 . Therefore, the air which absorbed moisture from the object to be dried is discharged to the outside through the exhaust duct  62 . 
     The hot air discharger  60  further includes a filter duct  64  installed in the lower side of the front support frame  17  in such a way that one side of the filter duct  64  communicates with the inside of the drum  30  and the other side thereof communicates with the blower case  63 , and a filter  65  installed in the filter duct to filter out foreign substances contained in the air passing through the filter duct  64 . The filter  65  is attachable to or detachable from the filter duct  64  so that the filter  65  is removably installed in the filter duct  64 . 
     Air that has dried the object to be dried in the drum  30  may be discharged to the filter duct  64 . Foreign substances in the air flowing into the filter duct  64  may be filtered out by the filter  65 . A filter grill  66  in the form of a mesh may be installed in an inlet of the filter duct  64 . 
     The drum  30  is rotatably installed on the rear plate  15 . More particularly, the shaft  33  of the drum  30  is rotatably installed through a bearing assembly  70  installed on the rear plate  15 . Therefore, the drum  30  is rotatably installed on the rear plate  15  through the shaft. The shaft  33  is coupled to the bearing assembly  70  via a nut  35  which is fastened to the rear end thereof. 
     Referring to  FIGS. 5 and 6 , the shaft  33  is rotatably installed on the rear plate  15  through the bearing assembly  70 . 
     The bearing assembly  70  includes a bearing  71  through which the shaft  33  is installed to pass, a centering guide  72  formed in an annular shape and in which the bearing  71  is installed, a first centering housing  73  and a second centering housing  74  which are coupled to each other in a front-rear direction to accommodate the centering guide  72  to be moved therein, and an elastic member  75  configured to elastically support the centering guide  72 . 
     The bearing  71  is formed in an annular shape, and in which the shaft  33  is installed to penetrate. The bearing  71  rotatably supports the shaft  33 . The bearing  71  includes a bearing housing  71   a  formed in a hollow ring shape, and a plurality of balls  71   b  rotatably installed in the bearing housing  71   a.    
     Two bearings  71  are provided on opposite inner sides of the centering guide  72 . However, the number of bearing is not limited thereto, and a single bearing may be installed in the centering guide  72 . 
     Further, the bearing  71  is formed with a ball bearing but this is merely an example and is not limited thereto. That is, in addition to the ball bearings, various kinds of bearings such as roller bearings may be used for supporting the shaft  33 . 
     The centering guide  72  is installed to be rotatable in the front, rear, left, and right directions in a space between the first centering housing  73  and the second centering housing  74 . The centering guide  72  prevents a heavy load from acting on the shaft  33  by allowing the inclination of the shaft  33  to be varied in the front, rear, left, and right directions within a setting range. 
     The centering guide  72  includes an outer circumferential surface formed with a spherical surface. The centering guide  72  includes a fixing member  721  formed in an annular shape and in which the bearing  71  is fixed, and a guide member  722  formed in an annular shape and in which the fixing member  721  is fixed. The guide member  722  is integrally formed on the outside of the fixing member  721  through the insert injection molding method, and the outer circumferential surface of the guide member  722  is formed with a spherical surface. 
     The fixing member  721  is formed of a metal material so as to stably support the bearing  71 . The fixing member  721  includes a partition protrusion  721   a  protruding from the center of the inner circumferential surface of the fixing member  721  and extending in the circumferential direction to partition a space in which the bearings  71  are installed. The two bearings  71  are installed at opposite inner sides of the fixing member  721  about the partition protrusion  721   a.    
     As illustrated in  FIG. 7 , the fixing member  721  includes a chamfered portion  721   b  formed by processing a portion of the outer circumferential surface of the fixing member  721  to be a plane. Therefore, by the chamfered portion  721   b , it is possible to prevent separation of the fixing member  721  and the guide member  722  in the circumferential direction. 
     The fixing member  721  includes a pair of stepped portions  721   c  formed in a concave shape at axial opposite ends of the outer circumferential surface of the fixing member  721 . The guide member  722  includes a pair of catching portions  722   b  formed in a convex shape at axial opposite ends in an inner circumferential surface of the guided member  722  to be caught by the pair of stepped portions  721   c . Thus, it is possible to prevent separation of the fixing member  721  and the guide member  722  in the axial direction by the pair of stepped portions  721   c  and the pair of catching portions  722   b.    
     The guide member  722  is formed of lubricating resin so that the centering guide  72  may easily move along the inner surface of the centering housings  73  and  74 . The guide member  722  is formed by mixing Teflon having lubricity with Polyoxymethylene (POM) resin having excellent abrasion resistance. Accordingly, the guide member  722  has excellent wear resistance and lubricity. 
     Therefore, the bearing  71  may be stably fixed through the fixing member  721  formed of a metal material, and the centering guide  72  may be easily rotated in the front, rear, left, and right directions through the guide member  722  formed of a resin material having lubricity. 
     The guide member  722  includes a locking groove  722   a  extending in the axial direction on an outer circumferential surface thereof that is the outer circumferential surface of the centering guide  72 , and configured to be locked by a locking portion  753  of the elastic member  75 . A plurality of locking grooves  722   a  is provided on the outer circumferential surface of the guide member  722  and spaced apart from each other in the circumferential direction. 
     Referring to  FIGS. 5 and 6 , the first centering housing  73  includes a first flange  731  formed in annular shape, and a first guide portion  732  extending to the front side from the inner end of the first flange  731  to accommodate a front end portion of the centering guide  72 . The second centering housing  74  includes a second flange  741  formed with an annular plate, and a second guide portion  742  extending to the rear side from the inner end of the second flange  741  to accommodate the rear end portion of the centering guide  72 . 
     The first flange  731  includes a first through hole  731   a  formed in a circular shape, and a fixing rib  731   b  formed in an annular shape and extending from the inner end of the first through hole  731   a  to the rear side. A plurality of first through holes  731   a  and fixing ribs  731   b  are provided and spaced apart from each other in the circumferential direction. 
     The second flange  741  includes a second through hole  741   a  formed in a circular shape. A plurality of second through holes  741   a  is provided to be spaced apart from each other in the circumferential direction and the plurality of second through holes  741   a  is formed at positions corresponding to the first through holes  731   a . The second through hole  741   a  is formed to have a larger diameter than the fixed rib  731   b  so that the fixing rib  731   b  may penetrate through the second through hole  741   a  and the rear end thereof may protrude to the rear side. 
     Therefore, as illustrated in  FIG. 8 , the fixing ribs  731   b  are installed to pass through the second through holes  741   a , and then the rear end of the fixing ribs  731   b  is deformed by a curling process, as illustrated in  FIG. 9 . The rear end of the fixing ribs  731   b  are supported by the rear surface of the second flange  741  adjacent to the second through hole, and thus the coupling between the first centering housing  73  and the second centering housing  74  is completed. Therefore, the first centering housing  73  and the second centering housing  74  may be coupled to each other without a separate fastening member. 
     As illustrated in  FIG. 5 , the outer circumferential surface of the first guide portion  732  and the outer circumferential surface of the second guide portion  742  are formed with a spherical shape so as to correspond to the outer circumferential surface of the centering guide  72 . The inner circumferential surface of the first guide portion  732  is formed with a spherical surface corresponding to the front outer circumferential surface of the centering guide  72 , and the inner circumferential surface of the second guide portion  742  is formed with a spherical surface corresponding to the rear outer circumferential surface of the centering guide  72 . Therefore, the centering guide  72  may be rotated in the front, rear, left, and right directions along the inner circumferential surfaces of the first centering housing  73  and the second centering housing  74 . 
     As illustrated in  FIGS. 5 and 6 , the elastic member  75  includes a base portion  751 , a plurality of elastic portion  752  extending from the inner end of the base portion  751 , and a plurality of locking portions  753  extending from the inner end of the base portion  751 . 
     The base portion  751  is fitted and fixed between the first flange  731  and the second flange  741  while the first centering housing  73  and the second centering housing  74  are coupled to each other. Therefore, it is possible to prevent the elastic member  75  from rotating in the circumferential direction. 
     The plurality of elastic portions  752  is spaced apart from each other in the circumferential direction and elastically supported on the outer circumferential surface of the centering guide  72  formed with a spherical shape. The elastic portions  752  are elastically supported on the front outer circumferential surface of the centering guide  72  to elastically support the centering guide  72  to the rear side. 
     The plurality of locking portions  753  is spaced apart from each other in the circumferential direction and inserted into the locking grooves  722   a  of the guide member  722 . Therefore, by the locking groove  722   a  and the locking portion  753 , it is possible to prevent the centering guide  72  from rotating in the circumferential direction. 
     Hereinafter a manufacturing method of a bearing assembly applied to the clothes dryer according to an embodiment of the disclosure will be described. 
     First, the fixing member  721  formed in an annular shape and formed of a metal material is manufactured. In the process of manufacturing the fixing member  721 , the chamfered portion  721   b  and the stepped portion  721   c  are formed on the outer circumferential surface of the fixing member  721 . 
     Next, the centering guide  72  is manufactured by forming the guide member formed of the resin material on the outer side of the fixing member  721  through the insert injection molding method. By the chamfered portion  721   b , the separation of the fixing member  721  and the guide member  722  in the circumferential direction is prevented. Further, the separation of the fixing member  721  and the guide member  722  in the axial direction is prevented by the stepped portion  721   c  and axial opposite end portions of the guide member  722  configure to cover the stepped portion  721   c.    
     After the manufacture of the centering guide  72  is completed, two bearings  71  are fixed to the inside of the centering guide  72  that is the opposite inner sides of the centering guide  72 . The bearings  71  are pressed and fixed to opposite inner sides of the fixing member  721 . 
     Because the bearings  71  are installed and used in the centering guide  72  as described above, various types of bearings  71  having excellent mechanical characteristics may be installed and used in the centering guide  72 . That is, the bearing assembly  70  having a centering function may be easily manufactured by using a bearing  71  which is generally used. 
     After arranging the centering guide  72 , in which the bearing  71  is installed, and the elastic member  75  between the first centering housing  73  and the second centering housing  74 , the first centering housing  73  and the second centering housing  74  are coupled to each other. 
     The fixing ribs  731   b  are installed to pass through the second through holes  741   a , and then the rear end of the fixing ribs  731   b  is deformed by the curling process and thus the rear end of the fixing rib  731   b  is supported by the rear surface of the  741  adjacent to the second through hole. Accordingly, the coupling of the first centering housing  73  and the second centering housing  74  is completed. 
     Because the base portion  751  of the elastic member is fitted and fixed between the first flange  731  and the second flange  741  in the process of coupling the first centering housing  73  and the second centering housing  74 , it is possible to prevent the rotation of the elastic member  751  in the circumferential direction. Further, the locking portion  753  of the elastic member  75  is locked to the locking groove  722   a  of the outer circumferential surface of the guide member  722 . Therefore, the centering guide  72  may move only in the front, rear, left, and right directions, without rotating in the circumferential direction. 
     The first centering housing  73  and the second centering housing  74  are coupled to each other as mentioned above, and then the manufacturing of the bearing assembly  70  is completed. 
     After the manufactured bearing assembly  70  is fixed to the rear plate  15  of the housing  10  through the fastening members, the shaft  33  is installed to penetrate the inside of the bearings  71 . Next, by fastening the nut  35  to the rear end of the shaft  33 , the drum  30  is rotatably installed in the housing  10  through the bearing assembly  70 . 
     As is apparent from the above description, the bearing assembly and the clothes dryer including the same may prevent an excessive load from being applied to the shaft although the unbalanced load is applied to the drum. 
     The bearing assembly and the clothes dryer including the same may simply manufacture the bearing assembly having a centering function using a bearing that is generally used. 
     Although a few embodiments of the disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.