Abstract:
A drum brush having a drum rotation body, a pair of bearing holders, a pair of bearings, a shaft, a pair of end-caps and pressing rings, includes bristle tufts, and the pair of bearing holders are provided to be connected to or integrally formed with both ends of the drum rotation body. A pair of bearings, each having an inner race and an outer race, are connected to each of the bearing holders. The shaft penetrates each of the inner races of the bearings and is connected to the end-cap at either end. The pressing ring is interposed between each bearing holder and each bearing to prevent rotation of the outer race. Accordingly, when the drum rotation body rotates, the bearing holder is not damaged by frictional contact with the bearing.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates generally to a vacuum cleaner and more particularly,.relates to a drum-brush having an improved structure, and a vacuum cleaner using the same.  
         [0003]     2. Description of the Background Art  
         [0004]     Conventional vacuum cleaners draw in dust and foreign substances from a surface being cleaned using a high vacuum pressure generated by an internal motor. Vacuum cleaners can largely be classed into upright-type, canister-type, and stick-type vacuum cleaners, according to their structure and general appearance.  
         [0005]      FIG. 1  shows an upright vacuum cleaner as an example of a conventional vacuum cleaner. As shown in  FIG. 1 , the conventional upright vacuum cleaner comprises a cleaner body  10  having a dust collection chamber  10   a  and a motor driving chamber (not shown), and a suction port body  20  connected to a lower part of the cleaner body  10 . The dust collection chamber  10   a  is in fluid communication with the motor driving chamber and a suction port  20 , and has therein a dust bag that filters out the dust from the air that is drawn into the suction port  20   a.  In the motor driving chamber, a suction motor  40  is mounted to generate a vacuum. When the suction motor  40  (shown in phantom) is driven, a vacuum is generated in the dust collection chamber  10   a,  and air and entrained dust are drawn into the dust bag in the dust collection chamber  10   a  through the suction port  20   a.  Then, the air flows out of the dust bag, while the dust is collected therein. The cleaned air is discharged to a discharge unit  11 , after passing through the motor driving chamber.  
         [0006]     A housing  21  of the suction port body  20  houses a drum brush  100  above the suction port  20   a.  The drum brush  100  agitates the surface being cleaned and loosens dirt and dust embedded in the surface being cleaned. The drum brush is normally rotated by a driving source, such as a motor or a turbine apparatus mounted in the suction port body  20 .  
         [0007]     Referring to  FIG. 2 , the drum brush  100  comprises a drum rotation body  110 , a shaft  140  and a bearing holder  120 , a bearing  130 , and an end-cap  150  at each end of the drum rotation body  110 . A spiral brush member  111  is attached to an outer circumference of the drum rotation body  110 , and a driving belt  30  ( FIG. 1 ) is connected adjacent one side of the outer circumference of the drum rotation body  110 . A bearing holder  120  is securely inserted, one in each end of the drum rotation body  110 , and a washer  160  is inserted in each bearing holder  120 . Each bearing  130  comprises an outer race  131  and an inner race  132 . The shaft  140  penetrates through the center of the drum rotation body  110  so that an end is inserted in the inner race  132  of the bearings  130 . End-caps  150  are connected, one each to both of the ends of the drum rotation body  110 . In the center of each end cap  150 , a shaft-receiving hole  150   a  is disposed to be engaged with an opposed end of the shaft  140 .  
         [0008]     As shown in  FIG. 3 , the end-cap  150  is connected to the housing  21 , and the shaft  140  extends through the inner race  132 , and is connected to an end of the end-cap  150 . As a result, the end-cap  150 , the shaft  140  and the inner race  132 , in combination, form a stationary assembly by being fixed relative to the housing  21 , and the outer race  131 , the bearing holder  120  and the drum rotation body  110 , in combination, form a rotating assembly. The washer  160 , which is inserted between the bearing holder  120  and axial surface of the bearing  130 , secures the outer race  131  of the bearing  130  to the bearing holder  120 . Therefore, when the driving belt  30  ( FIG. 1 ) operates to rotate the drum rotation body  110 , the combination of the drum rotation body  110 , the bearing holder  120  and the outer race  131  all rotate with respect to the shaft  140 .  
         [0009]     However, in the conventional drum brush  100  having the above construction, the outer race  131  of the bearing  130  may rotate within its seat in an inner circumference of the bearing holder  120 , or may rotate together with the bearing holder  120  within its seat, due to vibration caused by the rotation of the drum rotation body  110 . Therefore, frictional heat may be generated between bearing holder  120  and the outer race  131 . When used for an extended period of time, the bearing holder  120 , which may be made of a plastic or other similar materials, becomes worn out and may be damaged by the heat. Furthermore, the drum rotation body  110  may vibrate due to eccentric motion when rotating. Thus, what is needed is a mechanism that will retain the stationary parts stationary relative to each other.  
       SUMMARY OF THE INVENTION  
       [0010]     An aspect of the present invention is to solve at least the above problems and disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a drum brush, which does not cause damage to the bearing holder, by preventing the outer race of a bearing inserted in the bearing holder from rotating, for use in a vacuum cleaner.  
         [0011]     In order to achieve the above-described aspects of the present invention, there is provided a drum brush having a drum rotation body, a pair of bearing holders, a pair of bearings, a shaft, and a pair of end-caps and pressing rings. The drum rotation body includes a brush member, and a pair of bearing holders is provided in to be connected one to each end of the drum rotation body. The bearings each comprise an inner race and an outer race, which are connected to each of the bearing holders. The shaft penetrates each of the inner races of the bearings and is connected to the end-caps at either end. A pressing ring is interposed between each of the bearing holders and the bearings to prevent rotation of the outer races.  
         [0012]     In the drum brush of the above construction, the pressing rings may comprise a body plate, and at least one pressing protrusion formed on the body plate.  
         [0013]     The pressing protrusion preferably protrudes toward an inner circumference of the pressing ring.  
         [0014]     A fixing protrusion is preferably provided on an outer circumference of the pressing ring.  
         [0015]     The pressing ring is preferably made of stainless steel.  
         [0016]     A fixing rib is included in each bearing holder, which tightly contacts the outer race of the associated bearing.  
         [0017]     A locking groove is preferably formed inside the end of the drum rotation body, and a corresponding locking protrusion is formed on an outer circumference of the bearing holder for insertion into the locking groove.  
         [0018]     In a vacuum cleaner comprising a cleaner body in which a vacuum generating device for generating a suction force, and a dust collection chamber for collecting dust are provided, a suction port body having a suction port connected to the dust collection chamber, and a drum brush rotatably mounted to the suction port body, the drum brush comprises a drum rotation body, a pair of bearing holders, a pair of bearings, a shaft, and a pair of end-caps and pressing rings. The pressing rings are interposed between each of the bearing holders and the bearings in order to prevent rotation of the outer races of the bearings.  
         [0019]     The drum rotation body and the bearing holder may be integrated to save the number of component parts and manufacturing processes. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0020]     The above object and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawing figures, wherein;  
         [0021]      FIG. 1  is a perspective view of a conventional upright vacuum cleaner;  
         [0022]      FIG. 2  is a perspective, exploded view of a conventional drum brush;  
         [0023]      FIG. 3  is a sectional view of the drum brush shown in  FIG. 2  in an assembled state;  
         [0024]      FIG. 4  is a perspective, exploded view of a drum brush according to an embodiment of the present invention;  
         [0025]      FIG. 5  is a perspective view of a fixing ring of the drum brush according to an embodiment of the present invention;  
         [0026]      FIG. 6  is a sectional view of the drum brush according to an embodiment of the present invention in an assembled state;  
         [0027]      FIG. 7  is an exploded perspective view schematically showing a drum brush according to another embodiment of the present invention; and  
         [0028]      FIG. 8  is a sectional view of a drum brush as completely assembled, according to yet another embodiment of the present invention. 
     
    
       [0029]     In the drawing figures, it will be understood that identical reference numerals refer to identical or like elements, features and structures between the different drawing figures.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]     Hereinbelow, an embodiment of the present invention will be described in detail with reference to the accompanying drawing figures. Further, in referring to the elements having the same structure and operation as that described relating to the prior art, the elements will be identified by the same reference numerals throughout the drawing figures.  
         [0031]     As shown in  FIG. 4 , the inventive drum brush  200  according to an embodiment of the present invention comprises a drum rotation body  210 , a bearing holder  220 , a bearing  230 , a shaft  240 , an end-cap  250  and a pressing ring  260 . The bearing holder  220 , the bearing  230 , the shaft  240 , the end-cap  250  and the pressing ring  260 , respectively, are shown at one end of the drum brush  200 . However, it is understood that the elements are provided in pairs for inserting at both ends of the drum rotation body  210 . It will be understood that a mirror image of the connection structure illustrated and described is disposed at the other end of the drum rotation body  210 . However, since the shape and function of such mirror image will be fully understood from the following description, it will not be further described or illustrated.  
         [0032]     The drum rotation body  210  comprises one or more spirally disposed rows of bristle tufts  211 , which are connected along an outer circumference of the body  210  to loosen and dislodge dust on a surface being cleaned. At least one locking groove  212  is provided on the inner surface of the end of the drum rotation body  210 . A plurality of locking grooves  212  can be provided, as shown in  FIG. 4 . When a plurality of the locking grooves  212  are provided, intervals between the respective locking grooves  212  are preferably uniform. An annularly shaped belt connection part  213  is formed at one side of the outer circumference of the drum rotation body  210 , preferably adjacent one of the ends, as shown. The belt connection part  213  is used for engagement with the driving belt  30  ( FIG. 1 ), which is connected to transmit a rotational driving force to the drum rotation body  210 .  
         [0033]     A bearing holder  220  is disposed at each end of the drum rotation body  210 . The bearing holder  220  has one or more spaced locking protrusions  221  for engagement with the locking grooves  212  of the drum rotation body  210 . The bearing  230  includes an outer race  231  and an inner race  232 , and is mounted in the bearing holder  220 , which is connected to an end of the drum rotation body  210 . Inside the bearing holder  220 , a fixing rib  222  ( FIG. 6 ) is provided to be in tight contact with the bearing  230  so as to prevent relative axial motion between the bearing holder and the outer race  231  of the bearing  230 . The fixing rib  222  tightly contacts the outer race  231  of the bearing  230 , thereby reinforcing engagement between the bearing holder  220  and the outer race  231 .  
         [0034]     The shaft  240  is mounted in the drum rotation body  210  so that an end thereof protrudes beyond the end of the drum rotation body  210 . A first knurled portion  241  is formed at the end of the shaft  240 . The shaft  240  is forcibly inserted in the inner race  232  of the bearing  230  to form an interference fit therebetween as shown in  FIG. 6 , and the end of the shaft  240  protrudes from the inner race  232  to be connected to the end-cap  250  by engagement therewith.  
         [0035]     The end-cap  250  covers an end of the drum rotation body  210 , and supports the inner race  232  -of the bearing  230  and the shaft  240 . A boss  251  ( FIG. 6 ) protrudes inwardly in the center of the end-cap  250 , and a connection hole  251   a  is formed in the boss  251 , to which the end of the shaft  240  is inserted. On an inner circumference of the boss  251 , a second knurled portion  252  is provided, corresponding to the first knurling portion  241  for engagement therewith. When the shaft  240  is inserted in the connection hole  251   a,  the second knurled portion  252  tightly contacts the first knurled portion  241  in an interference fit, and the shaft  240  is fixed to the end-cap  250 . The boss  251  also tightly contacts the inner race  232  of the bearing  230 , and retains its relative position as a result of frictional force.  
         [0036]     The pressing ring  260  is shown in greater detail in  FIG. 5 , and comprises an annular body plate  261  formed by curving an elongated metal band, and a plurality of pressing protrusions  262 , protruding toward an inner circumference of the body plate  261 . The pressing protrusions  262  may be formed by pressing of the body plate  261 . The shape of the pressing protrusions can vary, and it is not limited to a square or frustum, as shown in  FIG. 5 . On an outer circumference of the body plate  261 , one or more fixing protrusions  263  are formed, which also may be formed by pressing of the body plate  261 . The pressing ring  260  is preferably made of a stainless steel having high strength and resistance against corrosion that may otherwise result from possible oil leaking from the bearing  230 .  
         [0037]     The pressing ring  260  is interposed between an inner annular surface of the bearing holder  220  and the outer race  231  of the bearing  230 , as shown in  FIG. 6 , and the outer race  231  is fixed to the bearing holder  220 . Since the fixing protrusions  263  ( FIG. 5 ) of the pressing ring  260  tightly contact an inner circumference of the bearing holder  230 , the pressing holder  260  cannot easily be withdrawn from the bearing holder  220 .  
         [0038]     According to another embodiment of the present invention, as shown in  FIGS. 7 and 8 , the bearing holder  220  may be integrally formed with the drum rotation body  210 . Same drawing reference numerals are used for the same elements as in the previous embodiment of the present invention.  
         [0039]     As shown in  FIG. 7 , the drum brush  300  comprises a drum rotation body  310 , a bearing holder  320 , the bearing  230 , the shaft  240 , the end-cap  250  and the pressing ring  260 . The bearing holder  320  is integrally formed with both ends of the drum rotation body  310 , thereby supporting the outer race  231  of the bearing  230 . Inside the bearing holder  320 , a fixing rib  322  ( FIG. 8 ) is provided in tight contact with the bearing  230 . The fixing rib  222  tightly contacts the outer race  231  of the bearing  230 , thereby reinforcing engagement between the bearing holder  220  and the outer race  231 .  
         [0040]     After assembly, the drum brush  200  and  300  is mounted in a housing  21  of a suction port body  20  ( FIG. 1 ), with the end-cap  250  fixed to the housing  21 , with a brush member  211  protruding out of a suction port  20   a  ( FIG. 1 ) extending underneath the housing  21 , as shown in  FIG. 6 . Because the end-cap  250  is fixed so as to avoid rotation, the shaft  240  and the inner race  232  are also fixed in place. The outer race  231 , the bearing holder  220  and  320  and the drum rotation body  210  and  310  altogether constitute a rotating assembly, which rotates with respect to the shaft  240 .  
         [0041]     During operation, a suction motor  40  ( FIG. 1 ) in the cleaner body is driven, thereby generating a vacuum pressure in a dust-collection chamber. Additionally, the drum rotation body  210  and  310  ( FIG. 4 ) is rotated by a driving force applied through a driving belt  30  (as shown in  FIG. 1 ), extending from the motor or a turbine provided in the suction port body  20  of the vacuum cleaner. The dust lying on a surface being cleaned under the suction port  20   a  is loosened and dislodged by the brush member  211  of the drum rotation body  210  and  310 , and is then drawn into the suction port  20   a.    
         [0042]     When the drum rotation body  210  and  310  rotates, the pressing ring  260  between the bearing holder  220  and  320  and the outer race  231  inhibits the relative rotation of the bearing holder  220  and  320  with respect to the outer race  231 . Therefore, the drum rotation body  210  and  310  can rotate in a stable manner.  
         [0043]     As can be appreciated from the above description and by the illustrated embodiments of the present invention, the pressing ring  260  is provided to prevent the bearing holder  220  and  320  and the outer race  231  from rotating relative to each other. As a result, rotation of the drum rotation body  210  and  310  does not cause abrasion or damage to the bearing holder  220  and  320 .  
         [0044]     Furthermore, according to the present invention, the drum rotation body  210  and  310  is inhibited from eccentric vibration when rotating.  
         [0045]     According to another embodiment of the present invention, since the drum rotation body and the bearing holder are integrally formed with each other, the number of component parts and manufacturing processes can be reduced, thereby improving productivity of the drum brush.  
         [0046]     While the invention has been shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.