Patent Publication Number: US-2013227994-A1

Title: Appliance balance ring with fluid channels

Description:
FIELD OF THE INVENTION 
     The subject matter of the present disclosure relates generally to a balance ring for an appliance. 
     BACKGROUND OF THE INVENTION 
     During the operation of a washing machine, particularly during spin cycles, the machine can sometimes experience an extreme vibration. These vibrations can even cause displacement of the washing machine as it “walks” across a surface such as a floor. Typically, this event is due to the different shapes and densities of the clothing or objects that are being washed which, after the washing cycle and the draining of the wash basket, can stick together and cause differences in the center of mass inside the wash basket. The vibration problem can also be caused by the introduction of relatively heavier objects into the washing basket such as e.g., shoes. 
     By way of example, after the wash cycle and the draining of the wash fluid from the basket, the shoes may be located on one side of the wash basket or positioned in a manner that causes the center of mass of the combined wash basket and articles (such as the shoes, clothes, and other items being washed) to be off center. As the wash basket is rotated, particularly at high speeds during e.g., a spin cycle, the off centering and centrifugal forces create an imbalance that can generate undesired strain in the washing machine components, an undesirable level of noise, and/or “walking” of the appliance. In an extreme or prolonged situation, the imbalance created by the excessive vibration can also wear-out and damage the washing machine components. 
     As a result, in order to prevent this imbalance, various devices have been proposed. For example, washing machines have been equipped with balance rings, which are typically hollow rings that rotate with the wash basket. Inside the ring (or toroid) a weight such a liquid or solid balls have been inserted. During operation, the ring will act as a counterweight to the load of clothes because the liquid or solid balls will move to a position within the ring that counters the centrifugal forces created by the articles in the wash and thereby balance the basket during rotation. Balance rings of various configurations including chambers, partitions, and other elements to improve the balancing effect have also been proposed. 
     For washing machines, the above mentioned balance rings are typically attached or connected in some manner with the wash basket. For example, for a vertical axis washing machine, the balance ring can be attached to the top and/or bottom of the wash basket chamber. For a horizontal axis washing machine, it can be attached to the front, back, or both ends of the washing chamber. 
     With balance rings that incorporate counterweights within the balance ring, it is important that such weights move freely within the annular spaces of balance ring so as to readily provide a counter balance during spinning of the wash basket. If the counterweights become stuck at a certain position in the balance ring or cannot move freely, then the balance ring will not be able to counter an imbalance in the wash basket. 
     Balance rings can also be provided with a fluid within the annular space of the ring. The fluid can enhance the ability of the balance ring to stabilize a spinning wash basket. However, if counter weights are also provided within the balance ring, the fluid may impede the movement of the counter weights within the balance ring and, as a result, their effectiveness. 
     Accordingly, a balance ring for balancing the load of a rotating element within an appliance, such as e.g., the wash basket of a washing machine, would be beneficial. Such a balance ring that can also utilize a fluid as well as movable counterweights with the balance ring would be useful. A balance ring that allows the fluid and counterweights to move relative to each other would also be useful. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In one exemplary embodiment, the present invention provides a washing machine that includes a wash tub and a wash basket mounted in the wash tub and rotatable about an axis of rotation. The wash basket has a wash basket opening for receiving wash fluid and a wash load therein. The wash basket includes an external surface extending circumferentially about an axis of rotation of the wash basket. A motor is in mechanical communication with the wash basket and is configured for causing the wash basket to rotate. A balance ring is mounted onto the external surface of the wash basket. The balance ring is configured to offset imbalances created by articles in the wash tub when the wash basket is rotated by the motor. The balance ring has a top wall and a bottom wall. The balance ring also defines an annular chamber extending circumferentially about the axis of rotation of the wash basket, and a plurality of ribs projecting into the chamber from the top wall, the bottom wall, or both, of the balance ring. The ribs extend circumferentially around the axis of rotation of the wash basket. At least one cylindrically-shaped counter weight is positioned in the annular chamber. The counterweight has a pair of opposing, planar surfaces. 
     In another exemplary embodiment, the present invention provides a balance ring for stabilizing a rotating element of an appliance. The balance ring defines circumferential and radial directions. The balance ring has an annular space and includes a radially inner wall and a radially outer wall spaced apart along the radial direction from the radially inner wall. The annular space is positioned at least partially between the radially inner wall and the radially outer wall. A top extends between the radially inner and outer walls. A bottom extends between the radially inner and outer walls. At least one movable counterweight is positioned within the annular space. A plurality of projections are positioned within the annular space and are located upon the top, bottom, or both. The projections define one or more channels for the passage of a fluid between the counterweight and the top or bottom. 
     In still another exemplary embodiment, the present invention provides a washing machine that includes a wash tub and a wash basket mounted in the wash tub. The wash basket is rotatable about an axis of rotation and is configured for the receipt of laundry articles therein. The wash basket defines a wall extending circumferentially about the wash basket. A motor is in mechanical communication with the wash basket and is configured for causing the wash basket to rotate. A balance ring is mounted onto the wall of the wash basket. The balance ring includes a chamber extending circumferentially about the wash basket and a plurality of ribs extending circumferentially about the balance ring and projecting into the chamber. A plurality of counter weights are positioned within the chamber of the balance ring. The counter weights are movable within the chamber and are positioned in contact with one or more of the plurality of ribs. A fluid is located in the chamber of the balance ring. The ribs define one or more channels through which the fluid may pass between the counter weights and the balance ring. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  provides a perspective view of an exemplary embodiment of a washing machine appliance of the present invention. 
         FIG. 2  provides a cross-sectional view of the exemplary embodiment of  FIG. 1 . 
         FIG. 3  is a cross-sectional view of a portion of the wash basket and wash bin of the exemplary appliance of  FIG. 1 . 
         FIG. 4  is a perspective view of the lower portion of an exemplary embodiment of a balance ring of the present invention. 
         FIG. 5  is a close-up, perspective and cross-sectional view of the lower portion of the exemplary balance ring shown in  FIG. 4 . 
         FIG. 6  provides a partial perspective and cross-sectional view of the balance ring shown in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides a balance ring for an appliance such as e.g., a washing machine. The balance ring includes an annular space with one or more features that project into the annular space. The features can provide channels for movement of fluid relative to counter weight(s) positioned in the annular space so as to facilitate counter balancing of a rotating element in the appliance such as e.g., the wash basket of a washing machine. Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, 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 scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
       FIG. 1  is a perspective view of an exemplary vertical axis washing machine  50  including a cabinet  52  and a top cover  54 .  FIG. 2  is a side cross-sectional view of the exemplary embodiment of  FIG. 1 . While a vertical axis washing machine will be used to describe an exemplary embodiment of the present invention, it should be understood that the present invention is not limited to vertical axis washing machine and, instead, could be used with horizontal axis washing machines or even other appliances having a rotating element for which counterbalancing may be needed. 
     A backsplash  56  extends from cover  54 , and a control panel  58  including a plurality of input selectors  60  is coupled to backsplash  56 . Control panel  58  and input selectors  60  collectively form a user interface input for operator selection of machine cycles and features. For example, in one embodiment, a display  61  indicates selected features, a countdown timer, and/or other items of interest to machine users. A door or lid  62  is mounted to cover  54  and is rotatable about a hinge (not shown) between an open position (not shown) facilitating access to wash tub  64  located within cabinet  52 , and a closed position (shown in  FIG. 1 ) forming an enclosure over wash tub  64 . Wash tub  64  includes a bottom wall  66  and a sidewall  68 , and a basket  70  that is rotatably mounted within wash tub  64 . A pump assembly (not shown) is located beneath tub  64  and basket  70  for gravity assisted flow when draining tub  64 . 
     Referring now to  FIG. 2 , wash basket  70  is movably disposed and rotatably mounted in wash tub  64  in a spaced apart relationship from tub sidewall  68  and the tub bottom  66 . Basket  70  includes an opening  72  for receiving wash fluid and a washload therein. Basket  70  includes a plurality of perforations  74  therein to facilitate fluid communication between an interior of basket  70  and wash tub  64 . 
     An agitation element  76 , such as a vane agitator, impeller, auger, or oscillatory basket mechanism, or some combination thereof is disposed in basket  70  to impart an oscillatory motion to articles and liquid in basket  70 . In different embodiments, agitation element  76  includes a single action element (i.e., oscillatory only), double action (oscillatory movement at one end, single direction rotation at the other end) or triple action (oscillatory movement plus single direction rotation at one end, singe direction rotation at the other end). As illustrated in  FIG. 2 , agitation element  76  is oriented to rotate about a vertical axis A. Basket  70  and agitator  76  are driven by permanent magnet synchronous motor  78 , which operates to turn or rotate agitator  76  and/or basket  70  with tub  64  as will be more fully described below. 
     Operation of machine  50  is controlled by a controller or processing device (not shown) that is operatively coupled to the user interface input  58  located on washing machine backsplash  56  (shown in  FIG. 1 ) for user manipulation to select washing machine cycles and features. In response to user manipulation of the user interface input  58 , the controller operates the various components of machine  50  to execute selected machine cycles and features. 
     In an illustrative embodiment, laundry items are loaded into basket  70 , and washing operation is initiated through operator manipulation of control input selectors  60  (shown in  FIG. 1 ). Wash tub  64  is filled with water and mixed with detergent to form a wash fluid. The contents of the basket  70  are agitated with agitation element  76  for cleansing of laundry items in basket  70 . More specifically, agitation element  76  is moved back and forth in an oscillatory back and forth motion. In the illustrated embodiment, agitation element  76  is rotated clockwise a specified amount about the vertical axis of the machine, and then rotated counterclockwise by a specified amount. The clockwise/counterclockwise reciprocating motion is sometimes referred to as a stroke, and the agitation phase of the wash cycle constitutes a number of strokes in sequence. Acceleration and deceleration of agitation element  76  during the strokes imparts mechanical energy to articles in basket  70  for cleansing action. The strokes may be obtained in different embodiments with a reversing motor, a reversible clutch, or other known reciprocating mechanism. 
     After the agitation phase of the wash cycle is completed, tub  64  is drained with the pump assembly. Laundry items are then rinsed and portions of the cycle repeated, including the agitation phase, depending on the particulars of the wash cycle selected by a user. One or more spin cycles may also be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed through openings  74  in basket  70 . During a spin cycle, basket  70  is rotated at relatively high speeds. As previously indicated, imbalances in the wash basket  70  during the spin cycle can cause undesirable vibrations and even movement of washing machine  50 . 
     Accordingly, wash basket  70  is equipped with a balance ring  80  as shown in  FIGS. 2 and 3 . Balance ring  80  includes a plurality of counter weights  86  that are movable within an annular chamber  104  contained within the toroid shaped balance ring  80 . As previously described, counter weights  86  serve to counter balance an unbalanced load during spinning of basket  70  to remove water and other fluids through holes  74 . Balance ring  80  also includes a fluid within annular chamber  104 . Such fluid could be e.g., silicone, water, or other compositions as well. 
     Referring to  FIGS. 2 through 4 , balance ring  80  is attached to external surface  82  of wash basket  70 . External surface  82  extends circumferentially around the axis of rotation A of basket  70 . A plurality of fasteners  84  are used to fixedly attach balance ring  80  to basket  70  at positions that are circumferentially spaced about external surface  82 . Fasteners  84  may be e.g., bolts or screws that are extended through apertures  110  in fastener guides  90 , which are also circumferentially spaced about external surface  82  ( FIG. 4 ). Although shown in this exemplary embodiment as being mounted to the wash basket, it should be understood that the balance ring could be mounted to other rotating members of the appliance as well including e.g., the motor. Also, the balance ring could be mounted to the top, bottom, or both of the wash basket. As will be understood by one of skill in the art using the teachings disclosed herein, other configurations may be used as well. 
       FIG. 5  provides a close-up, perspective and cross-sectional view of the bottom or lower portion  88  of the exemplary balance ring  80  shown in  FIG. 4 .  FIG. 6  provides a partial perspective and cross-sectional view of balance ring  80  with the top or upper portion  102  connected with lower portion  88 . Portions  88  and  102  can be created by e.g., plastic injection molding. Upper portion  102  includes a pair of tongues  122  that are received into U-shaped channels  120  on lower portion  88 . Other constructions may be used as well. Together, portions  88  and  102  provide a top wall  116  and bottom wall  118  that are connected by radially inner wall  112  and radially outer wall  114  to form annular chamber  104 . 
     Counter weight  86  is cylindrically-shaped and includes a pair of opposing, planar surfaces  94  and  96  spaced in a manner that give an overall disk or puck appearance. As previously discussed, counter weight  86  (along with other counter weights that may be used) move within annular chamber  104  when wash basket  70  spins as to offset or counter balance loads in basket  70 . As such, relatively unrestricted movement of counter weight  86  within a fluid present in chamber  104  is desirable. 
     Accordingly, to facilitate such movement, a plurality of projections or ribs  98  and  100  project into annular chamber  104  and provide channels  106  and  108  through which fluid may pass and/or be displaced to facilitate the movement of counter weight  86  through chamber  104 . More particularly, ribs  96  project from the bottom wall  118  to create multiple channels  108  while ribs  100  project from the top wall  116  to create multiple channel  106 . Ribs  96  and  100  each extend circumferentially about the balance ring  80 . As counter weight  86  moves through chamber  104  due to e.g., centrifugal forces created by the rotation of basket  70 , channels  106  and  108  readily allow for the displacement or flow of fluid past counter weight  86 . For example, fluid can readily pass between planar surface  96  of counter weight  86  and the bottom surface  92  of bottom wall  118 . As such, channels  106  and  108  serve to help ensure that counter weight  86  is readily moveable within chamber  104 . 
     While the exemplary embodiment of a balance ring  80  shows only four ribs (two for each portion  88  and  102 ), a different number and configuration of ribs may be used as will be understood by one of skill in the art using the teachings disclosed herein. Additionally, the present invention is not limited to the particular shape for ribs  98  and  100  as shown in the figures, it being understood that other shapes be used as well. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.