Patent Publication Number: US-11661695-B2

Title: Laundry apparatuses having dynamic balancing assemblies

Description:
FIELD 
     The present application relates to laundry apparatuses and in particular, laundry apparatuses that include dynamic balancing assemblies. 
     BACKGROUND 
     A laundry machine is an apparatus used to wash and/or dry a user&#39;s laundry (e.g., clothes, bedding, etc.). Generally, laundry machines having functionality to wash the user&#39;s laundry include a tub that receives and contains washing fluids (e.g., water, detergent, etc.), a drum rotatably installed in the tub, and a motor to rotate the drum. Through rotation of the drum, a series of washing stages including washing, rinsing, and spin cycle may be performed to substantially remove washing fluids from the laundry. 
     During the spin cycle, the drum typically spins laundry positioned therein at a rotational velocity sufficient for the centripetal acceleration to exceed gravitational acceleration causing the wet laundry to be pinned against the inside surface of the drum. Often the mass of the wet laundry is not uniformly distributed around the inside periphery of the drum and the composite center of mass of the rotating laundry is offset from the drum&#39;s axis of rotation. The offset of the center of mass of the rotating laundry from the primary rotation axis of the drum can generate strong vibrations, which can generate unwanted noise and/or damage components of the washing machine, such as the displaceable suspension, drum, drum bearings, tub, exterior housing, etc. Additionally, these vibrations may cause the entire laundry machine to vibrate which may be transmitted to the surrounding building in which the laundry machine is operated and/or cause the laundry machine to translate across the floor. 
     For this reason, laundry machines may include a balancing assembly to reduce vibration and stabilize the laundry machine by counteracting the load imbalance within the rotating drum. However, conventional balancing assemblies tend to be mounted to the drum in such a way that reduces capacity of the drum and therefore the reduces the amount of laundry the laundry machine is able to accommodate. Additionally, making a laundry machine larger to allow for greater load capacity may prevent use in smaller homes and/or apartments which may lack the appropriate space for larger laundry machines 
     Accordingly, a need exists for laundry apparatuses that include dynamic load balancing assemblies while maximizing load capacity. 
     SUMMARY 
     In an embodiment, a laundry apparatus includes a tub defining a fluid containment envelope, a drum positioned within the fluid containment envelope of the tub and rotatable relative to the tub about a primary rotation axis, a control unit, a motor coupled to the tub, one or more load imbalance sensors communicatively coupled to the control unit and configured to output a load imbalance signal to the control unit, and a dynamic balancing assembly communicatively coupled to the control unit. The drum includes a laundry-receiving portion for receiving one or more articles of laundry. The motor is communicatively coupled to the control unit and operatively coupled to the drum to cause rotation of the drum, wherein the motor is isolated from fluid within the fluid containment envelope. The load imbalance signal is indicative of a load imbalance within the drum. The dynamic balancing assembly includes an orbital balancing passage arranged concentrically around the motor, a first counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the first counterweight device along the orbital balancing passage to adjust an angular position of the first counterweight device around the primary rotation axis to counteract a detected load imbalance in the drum; and a second counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the second counterweight device along the orbital balancing passage to adjust an angular position of the second counterweight device around the primary rotation axis to counteract the detected load imbalance in the drum. A cross-sectional plane passing through the laundry apparatus at a position orthogonal to the primary rotation axis passes through the dynamic balancing assembly, the motor, and the fluid containment envelope of the tub. 
     In another embodiment, a laundry apparatus includes a tub, a drum, a control unit, a motor, one or more load imbalance sensors, and a dynamic balancing assembly. The tub includes a fluid containment envelope and a motor receiving envelope that extends into a volume of the fluid containment envelope and is isolated from fluid received in the fluid containment envelope. The drum is positioned within the fluid containment envelope of the tub and rotatable relative to the tub about a primary rotation axis centrally positioned in the tub, the drum comprising a laundry-receiving portion for receiving one or more articles of laundry. The motor is positioned within the motor receiving envelope such that the motor is positioned within the volume of the fluid containment envelope and isolated from the fluid received in the fluid containment envelope, wherein the motor is communicatively coupled to the control unit and operatively coupled to the drum to cause rotation of the drum. The one or more load imbalance sensors are communicatively coupled to the control unit and configured to output a load imbalance signal to the control unit, the load imbalance signal being indicative of a load imbalance within the drum. The dynamic balancing assembly is communicatively coupled to the control unit and attached to the drum within the fluid containment envelope. The dynamic balancing assembly includes an orbital balancing passage arranged concentrically around the motor, a first counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the first counterweight device along the orbital balancing passage to adjust an angular position of the first counterweight device around the primary rotation axis to counteract a detected load imbalance in the drum, and a second counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the second counterweight device along the orbital balancing passage to adjust an angular position of the second counterweight device around the primary rotation axis to counteract the detected load imbalance in the drum. A cross-sectional plane passing through the laundry apparatus at a position orthogonal to the primary rotation axis passes through the dynamic balancing assembly, the motor receiving envelope of the tub, and the fluid containment envelope of the tub. 
     In another embodiment, a method for balancing a laundry apparatus includes rotating a drum positioned within a fluid containment envelope of a tub with a motor about a primary rotation axis, the motor being positioned within a motor receiving envelope that isolates the motor from a fluid within the fluid containment envelope, detecting, with a control unit, a load imbalance signal output by one or more load imbalance sensors, wherein the load imbalance signal is indicative of a load imbalance within the drum, and controlling a dynamic balancing assembly coupled to the drum and positioned within the fluid containment enveloped. The dynamic balancing assembly includes an orbital balancing passage arranged concentrically around the motor, a first counterweight device positioned within the orbital balancing passage, and a second counterweight device positioned within the orbital balancing passage. The dynamic balancing assembly is controlled to controllably move the first counterweight device positioned within the orbital balancing passage to adjust an angular position of the first counterweight device around the primary rotation axis to counteract a detected load imbalance in the drum, and controllably move the second counterweight device positioned within the orbital balancing passage with the control unit to adjust an angular position of the second counterweight device around the primary rotation axis to counteract the detected load imbalance in the drum. A cross-sectional plane passing through the laundry apparatus at a position orthogonal to the primary rotation axis passes through the dynamic balancing assembly, the motor, and the fluid containment envelope of the tub. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the same will be better understood from the following description taken in conjunction with the accompanying drawing in which: 
         FIG.  1 A  schematically illustrates a perspective view of a laundry apparatus, according to one or more embodiments shown and described herein; 
         FIG.  1 B  schematically illustrates a front cross-sectional view of the laundry apparatus of  FIG.  1 A  with an imbalanced load, according to one or more embodiments shown and described herein; 
         FIG.  1 C  schematically illustrates a front cross-sectional view of the laundry apparatus of  FIG.  1 A  with a balanced load, according to one or more embodiments shown and described herein; 
         FIG.  1 D  schematically illustrates a perspective view of an enclosed laundry apparatus, according to one or more embodiments shown and described herein; 
         FIG.  2 A  schematically depicts a front perspective view of a tub and drum assembly of the laundry apparatus of  FIG.  1   , according to one or more embodiments shown and described herein; 
         FIG.  2 B  schematically depicts a rear perspective view of a tub and drum assembly of the laundry apparatus of  FIG.  1   , according to one or more embodiments shown and described herein; 
         FIG.  2 C  schematically depicts a side cross-sectional view of the tub and drum assembly of  FIGS.  2 A and  2 B , according to one or more embodiments shown and described herein; 
         FIG.  3    schematically depicts a side cross-sectional view of a tub of the tub and drum assembly of  FIGS.  2 A and  2 B  in isolation; and 
         FIG.  4    schematically illustrates a dynamic balancing assembly in isolation from the tub and drum assembly of  FIGS.  2 A and  2 B , according to one or more embodiments shown and described herein; 
         FIG.  5 A  schematically depicts a counterweight device of the dynamic balancing assembly of  FIG.  4   , according to one or more embodiments shown and described herein; 
         FIG.  5 B  schematically depicts an interior perspective view of a worm gear drive within the counterweight device illustrated in  FIG.  5 A ; 
         FIG.  6    depicts a flowchart illustrating a method of balancing a laundry apparatus, according to one or more embodiments shown and described herein; 
         FIG.  7 A  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  7 B  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  7 C  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  7 D  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  7 E  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  7 F  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  7 G  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  7 H  schematically illustrates a side cross-sectional view of a laundry apparatus, according to one or more embodiments, shown and described herein; 
         FIG.  8 A  illustrates a front cross-sectional view of a laundry apparatus with a tub and drum assembly mounted to an exterior housing through a displaceable suspension assembly, according to one or more embodiments shown and described herein; 
         FIG.  8 B  illustrates a side cross-sectional view of the laundry apparatus of  FIG.  8 A , according to one or more embodiments shown and described herein; 
         FIG.  9 A  illustrates a front cross-sectional view of a laundry apparatus with a tub and drum assembly mounted to an exterior housing through one or more tub mounts, according to one or more embodiments shown and described herein; 
         FIG.  9 B  illustrates a side cross-sectional view of the laundry apparatus of  FIG.  9 A , according to one or more embodiments shown and described herein; 
         FIG.  10 A  Illustrates a front cross-sectional view of a laundry apparatus with a tub and drum assembly mounted to an exterior housing through one or more tub mounts with additional laundry apparatus components positioned within free space between the exterior housing and the tub and drum assembly, according to one or more embodiments shown and described herein; and 
         FIG.  10 B  illustrates a side cross-sectional view of the laundry apparatus of  FIG.  10 A , according to one or more embodiments shown and described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments described herein may be understood more readily by reference to the following detailed description. It is to be understood that the scope of the claims is not limited to the specific compositions, methods, conditions, devices, or parameters described herein, and that the terminology used herein is not intended to be limiting. In addition, as used in the specification, including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. When a range of values is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent basis “about,” it will be understood that the particular values form another embodiment. All ranges are inclusive and combinable. 
     Embodiments described herein are generally directed to a laundry apparatuses that include dynamic balancing assemblies while maximizing volumetric space for receiving laundry. For example, and as illustrated in the figures, a laundry apparatus according to the present disclosure generally includes a tub, a drum, and a dynamic balancing assembly. The drum is positioned within a fluid containment envelope of the tub and is rotatable relative to the tub about a primary rotation axis, the drum defines a laundry-receiving portion for receiving one or more articles of laundry. The dynamic balancing assembly includes an orbital balancing passage, arranged concentrically around a motor of the laundry apparatus, and first and second counterweight devices are positioned within the orbital balancing passage. The dynamic balancing assembly is positioned relative to the tub and/or drum so that a common cross-sectional plane passes through the dynamic balancing assembly, the motor, and the fluid containment envelope of the tub. As shown in the illustrated embodiments, such configuration allows for maximization of volume within the tub while still providing desired load balancing. These and additional features will be discussed in greater detail below. 
     As used herein, the term laundry apparatus may include a washing machine or combination washer/dryer machine. For example, the term laundry apparatus can describe any machine that relies on the centripetal acceleration from spinning to extract fluid from a wetted textile material including a dry cleaning machine, a washing machine, a washing machine employing working fluid other than water, centrifugal spinner, laundry dryer, etc. Additionally, laundry apparatuses may include any sized laundry apparatus including, but not limited to, industrial or residential sized units (including miniaturized and/or apartment units). 
     Referring to  FIG.  1 A , a laundry apparatus  10  is generally depicted. The laundry apparatus  10  may include an enclosed exterior housing  20 . Positioned within and supported by the exterior housing  20  is a tub and drum assembly  100 . The tub and drum assembly  100  may be accessible through an exterior housing port  11  formed within the exterior housing  20  that is selectively accessible by opening/closing of a hinged door  22 , for example. The laundry apparatus  10  may be a front-load laundry apparatus (e.g., a front-load washing machine) or, in other embodiments, may be a top load laundry apparatus (e.g., a top-load washing machine). In other embodiments the exterior housing port  11  might be positioned anywhere around the exterior housing  20  such as the side, back, bottom, or at some oblique angle. 
     Still referring to  FIG.  1 A , the laundry apparatus  10  may further include a control unit  24 . The control unit  24  may include processing circuitry and a non-transitory memory that includes logic in the form of machine-readable instructions that is used to control one or more operations of the laundry apparatus  10  as will be described in greater detail herein. For example, the control unit  24  may execute logic to operate valves and pumps during the washing and/or drying cycles, thereby controlling the various washing, rinsing, and spin cycles. The control unit  24  may further control a balancing operation by a dynamic balancing assembly  150 , which will be described in greater detail below. 
     Referring now to  FIG.  1 B  the laundry apparatus  10  is depicted more schematically to further illustrate the tub and drum assembly  100  within the exterior housing  20 , the tub and drum assembly  100  includes a tub  110  and a drum  130 . The drum  130  is configured to rotate about a primary rotation axis  102  within the tub  110 . The primary rotation axis  102  can be horizontal (e.g., parallel to the X/Y plane of the depicted coordinate axes), vertical (e.g., parallel to Z axis of the depicted coordinate axes), or at any angle, relative to the depicted coordinate axes. 
     Laundry  60  may be placed inside the drum  130  for laundering purposes. Laundry  60  may include, for example, soiled clothing, linens, and other fabric or textile articles. The laundry  60  may be washed and rinsed inside the drum  130 . During washing and rinsing with water, the laundry  60  may absorb water increasing the weight of the laundry  60 . The mass of water absorbed may be, for example, about 200% to about 400% the dry weight of the laundry  60 . Much of the absorbed water can be extracted mechanically by applying sustained high centripetal acceleration to the laundry  60  by spinning of the drum  130 . Spinning speeds may be about 700 rpm to about 1400 rpm. Centrifugal water extraction is commonly referred to as the spin cycle and depending on spin speed and geometry can generate centripetal acceleration of about 100 to about 600 times the acceleration of gravity. During the spin cycle, the drum  130  spins the laundry  60  at a rotational velocity sufficient for the centripetal acceleration to exceed gravitational acceleration such that the wet laundry  60  is pinned against the inside surface of the drum  130 . The rotational velocity sufficient for the centripetal acceleration to exceed gravitation acceleration is known as the satellite speed. 
     As noted above, during the spin cycle, the mass of the wet laundry  60  may not be uniformly distributed around the inside periphery of the drum  130 . Referring now to  FIG.  1 C , a schematic cross-sectional view of the tub and drum assembly  100  is depicted. As illustrated, the center of mass  61  of the rotating laundry  60  may be offset from the primary rotation axis  102  of the drum  130 , resulting in an imbalanced load within the drum  130 . This imbalanced load can generate vibrations within the laundry apparatus  10 . Such vibrations can generate unwanted noise, cause damage to the laundry apparatus  10 , cause the laundry apparatus  10  to travel across the floor, and or transmit vibrations to the surrounding building in which the laundry apparatus  10  is used, and/or cause unwanted vibration of the entire laundry apparatus  10  which can, as noted above, transmit into surrounding structure and shake the building in which the laundry apparatus  10  is used. As will be described in greater detail herein, load imbalance sensors  146  may be provided to detect the magnitude and rotational position of the imbalance and a dynamic balancing assembly  150  responsive to the detected load imbalance may be actuated to balance the laundry  60  within the drum  130 . 
     For example, and as will be described in greater detail herein, the dynamic balancing assembly  150  can be employed to reduce or eliminate the vibration caused by imbalanced laundry  60 . The dynamic balancing assembly  150  may include one or more counterweight devices and can include in some embodiments, at least two counterweight devices. For example, the dynamic balancing assembly may include a first counterweight device  170   a  and a second counterweight device  170   b  that are restrained to the rotating drum  130 . In the illustrated embodiments, the counterweight devices  170   a ,  170   b  follow an orbital path at a fixed radius from the primary rotation axis  102 . The relative angular position  53   a ,  53   b  for each counterweight device  170   a ,  170   b  can be adjusted relative to the reference angular position  52  on drum  130 . As an example load balancing operation, before the spin cycle, the angular positions  53   a  and  53   b  may be adjusted such that counterweight devices  170   a  and  170   b  are across from each other to provide balance between the first counterweight device  170   a  and the second counterweight device  170   b . The center of mass  55   a  for first counterweight device  170   a  and center of mass  55   b  for second counterweight device  170   b  have a combined center of mass at the primary rotation axis  102 . At speeds of about 100 rpm to about 200 rpm, the laundry  60  may be pinned by centripetal acceleration against the inside surface of rotating drum  130 . While pinned to the surface of the rotating drum, the center of mass  61  of the laundry  60  may be fixed at an angular position  62  from the reference angular position  52 . As illustrated, without balancing, the combined center of mass  63  (e.g., of the laundry  60 , the first counterweight device  170   a , and the second counterweight device  170   b ) is offset from the primary rotation axis  102  and will generate an imbalance and create vibration. As will be described in greater detail herein, load imbalance sensors  146  can detect the magnitude and rotational position of the combined center of mass  63 . Based on the detected magnitude and angular position  62  of the combined center of mass  63 , the angular positions  53   a  and  53   b  of the counterweight devices  170   a ,  170   b  can be adjusted (e.g., in a direction  57   a ,  57   b  of orbital travel) to shift the combined center of mass  63  closer to the primary rotation axis  102 , as illustrated in  FIG.  1 D . When balanced, the combined center of mass  63  may be coincident to the primary rotation axis  102 . A balanced laundry apparatus  10  will run smoothly without substantial vibration. 
       FIGS.  2 A and  2 B  illustrate the tub and drum assembly  100  in isolation from the exterior housing  20  of the laundry apparatus  10 .  FIG.  2 C  illustrates a cross-sectional view of the tub and drum assembly  100  of  FIGS.  2 A and  2 B . Referring collectively to  FIGS.  2 A- 2 C , the tub and drum assembly  100  generally include a tub  110 , a drum  130 , a motor  140 , one or more load balance sensors  146 , and the dynamic balancing assembly  150 , 
     The tub  110  is configured to support rotation of various components of the laundry apparatus  10  mounted thereto, while also containing washing fluids (e.g., water, detergent, bleach, softener, etc.) therein. A cross-section of the tub  110  in isolation from the tub and drum assembly  100  is illustrated in  FIG.  3   . The tub  110  comprises a tub body  112  that is shaped to provide a fluid containment envelope  113 . The tub body  112  may also be shaped to provide a motor receiving envelope  111  that extends into a volume of the fluid containment envelope  113 . 
     The tub body  112  may include a front wall  114  that is sized and shaped to surround exterior housing port  11  (illustrated in  FIG.  1 A ) and defines a tub laundry port  115 . A sidewall  116  of the tub body  112  may extend from the front wall  114  to a rear wall  117 , which defines a maximum depth of the tub  110 , to provide the fluid containment envelope  113 . Ports, not shown, for the ingress and egress of fluid into the fluid containment envelope  113  may be provided within the tub body  112 . 
     Formed within the rear wall  117  of the tub body  112  is the motor receiving envelope  111  sized and shaped to receive and support the motor  140  therein. For example, the rear wall  117  may define a rear-facing surface  118 . The motor receiving envelope  111  may extend from the rear-facing surface  118  into a volume of the fluid containment envelope  113 . In particular, a depth of the motor receiving envelope  111  may correspond to an axial depth of the motor  140  such that the motor  140  is substantially flush with or inset from with a rear-facing surface  118  of the rear wall  117 . The tub body  112  may further define a drive shaft opening  121  to support a drive shaft  144  extending from the motor  140  to be coupled to the drum  130 . The drive shaft  144  may be supported by a main bearing assembly  159  that is fixedly attached to the tub  110  (e.g., to a surface of the drive shaft opening  121 ) and operatively connected to the drum  130  thereby providing radial and axial support to the drum  130 . 
     In some embodiments, the main bearing assembly  159  includes a pair of rolling bearings such as deep groove ball bearings, angular contact bearings, cylindrical roller bearings, tapered roller bearings, spherical roller bearings, etc. The main roller bearing assembly may also include polymer or metallic bushings, air bearings, or magnetic bearings. The main bearing assembly  159  is configured to provide radial and axial support for the drum  130  as well as transmit any moments generated by imbalances in the drum  130  to the tub  110 . 
     Referring to  FIG.  2 C , the drum  130  is illustrated in a cantilevered configuration where the drum is supported from the rear by the main baring assembly  159  which is opposite of the drum opening  134  on the front side of the drum  130 . To better support moments from the drum  130 , it may be beneficial to maximize axial separation between bearing elements in the main bearing assembly  159 . As illustrated in  FIG.  2 C , the main bearing assembly  159  and drive shaft opening  121  can be axially extended back to fit inside the motor  140  and forward inside the protruding portion  138  of the drum body  132 . However, in other embodiments the drum  130  may be supported by a bearing assembly  159  on each end of the drum  130 . In such embodiment, the drum opening  134  might be on the front end of the drum  130  or might be on the side of the drum  130 . 
     As noted above, the motor  140  may be operatively coupled to the drum  130  for rotating the drum  130  within the fluid containment envelope  113  of the tub  110 . For example, the motor  140  may be rotatively coupled to the drum  130  via the drive shaft  144  that extends through the drive shaft opening  121 . In some embodiments, the drive shaft  144  might be directly attached to the drum  130 . In other embodiments, the drive shaft  144  might be attached to a support plate  156  and support plate  156  attached to the drum  130 . In other embodiments, the drive shaft  144  may be integrally formed with the drum  130 . In some embodiments, the drum  130  may be magnetically driven, such that no drive shaft  144  is needed. In some embodiments, the motor rotor  142  may be directly attached to the drum  130  and, such that no drive shaft  144  is needed. 
     The motor receiving envelope  111  of the tub  110  substantially isolates the motor  140  from washing fluid within the tub  110  and drum  130 . For example, the motor receiving envelope  111  may have a first inset wall  119  that extends into the volume of the fluid containment envelope  113  between the motor  140  and the orbital balancing passage  152 , as will be described in greater detail below. In some embodiments, the motor  140  may include a motor rotor  142  and a motor stator  143 . In the illustrated embodiment, at least a surface of the tub  110  and a surface of the motor  140  are substantially flush with one another. For example, and as illustrated an outer surface  147  of the motor rotor  142  is substantially flush with the rear-facing surface  118  of the tub  110 . Such may allow the tub  110  in close proximity with a back wall of the exterior housing  20  of the laundry apparatus  10 , thus maximizing the volume within the exterior housing  20  which may be used for laundry washing and/or drying purposes. In some embodiments, the surface of the tub  110  and the surface of the motor  140  may be offset from one another. 
     Referring again to  FIGS.  2 A- 2 C , the drum  130  is positioned within the fluid containment envelope  113  of the tub  110  and is rotatable relative to the tub  110  about a primary rotation axis  102  (illustrated in  FIG.  2 C ). The drum  130  includes a drum body  132  that is shaped to provide a laundry-receiving portion  133  for receiving one or more articles of laundry therein. For example, the laundry-receiving portion  133  may include a drum opening  134  for receiving/removal of laundry into the drum body  132 . The drum opening  134  may be arranged within the fluid containment envelope  113  of the tub  110  so as to be aligned with the tub laundry port  115  for access into the drum body  132 . The drum body  132  may include a plurality of apertures (not shown) to allow fluid to flow into and out of the drum body  132 . 
     The drum body  132  may extend from the drum opening  134  to a base wall section  136 . The base wall section  136  may define a recessed portion  137  and a protruding portion  138 . The protruding portion  138  may be centrally arranged on the primary rotation axis of the drum  130 . The recessed portion  137  may be concentrically arranged around the protruding portion  138  with a sloping wall  139  joining the recessed portion  137  and the protruding portion  138 . Stated another way, a depth of the laundry-receiving portion  133  of the drum  130  may be greatest when measured at the recessed portion  137 , and shortest when measured at the protruding portion  138 . The protruding portion  138  may be coupled to a drive shaft  144  of the tub and drum assembly  100 . 
     The drum  130  may further include one or more agitators  135  coupled to or integral with the drum body  132 . The one or more agitators  135  may be arranged to provide agitation to washing fluids and laundry within the laundry-receiving portion  133  of the drum  130 . The one or more agitators  135  may aid in removing debris from laundry through contact of the laundry with the one or more agitators  135 . The one or more agitators  135  may extend along a sidewall section  158  of the drum  130  and along the base wall section  136  to the protruding portion  138 . The one or more agitators  135  may be evenly spaced around the circumference of the drum  130 . 
     Coupled to the base wall section  136  may be the dynamic balancing assembly  150 . The dynamic balancing is configured to counter imbalances within the drum and tub assembly  100  created by spinning laundry, which may result in a smooth operation of the laundry apparatus  10  and eliminate a need to suspend the tub  110  from the exterior housing  20  by a traditional displaceable suspension system (e.g., springs, dampers, masses, etc.). 
     The dynamic balancing assembly  150  is adjustably arranged by the control unit  24  to balance a load imbalance within the tub and drum assembly  100 . The load imbalance can be detected by the control unit  24  based on an output of one or more load imbalance sensors  146 . However, it is contemplated that, in some embodiments, the dynamic balancing assembly  150  can be passive in operation with no automatic adjustment by the control unit  24 . Some examples of passive dynamic balancing assembly may include rings filled with fluids or weighted balls. 
     Still referring to  FIG.  2 C , in order to facilitate dynamic balancing, the dynamic balancing assembly  150  may include an orbital balancing passage  152 , a first counterweight device  170   a , and a second counterweight device  170   b  positioned within the orbital balancing passage  152 . As noted above with reference to  FIGS.  1 C and  1 D , the angular position for the first and second counterweight device  170   a ,  170   b  are adjustable relative to the reference angular position  52  of the drum to move the combined center of mass  63  of the laundry  60  and the first counterweight device  170   a , and the second counterweight device  170   b . The angular position  53   a  of the first counterweight device  170   a  and the angular position  53   b  of the second counterweight device  170   b  may be adjusted by any amount to move the combined center of mass  63  to be substantially coincident with the primary rotation axis  102 . During some balancing operations, the first and second counterweight devices  170   a ,  170   b  may be adjusted by a total angular displacement of 360 degrees or more during the spin cycle. 
     The orbital balancing passage  152  may provide a passage through which the first and second counterweight devices  170   a ,  170   b  may travel to balance a load imbalance within the tub and drum assembly  100 . For example, the orbital balancing passage  152  may be arranged concentrically around and provide an arcuate passage around the motor  140  and the primary rotation axis  102 . The orbital balancing passage  152  may be the coupled to the base wall section  136  of the drum  130 . In some embodiments, and as depicted, the orbital balancing passage  152  may be coupled to the base wall section  136  by a support plate  156 . The orbital balancing passage  152  may be coupled to the support plate  156  through any coupling techniques (e.g., welding, brazing, fastening, etc.) or may be integrally formed therewith. In some embodiments, the orbital balancing passage  152  may instead be directly coupled or integrally formed with the base wall section  136  of the drum  130 . 
     The orbital balancing passage  152  may include a passage body  154 , which constrains motion of the first and second counterweigh devices  170   a ,  170   b  to an orbiting motion about the primary rotation axis  102 . For example, the orbital balancing passage  152  may define a first orbital chamber  160  in which at least one of the first and second counterweight devices  170   a ,  170   b  sit. It is noted that while the first and second counterweight devices  170   a ,  170   b  are illustrated as being positioned within the same orbital chamber. In some embodiments, the first and second counterweight devices  170   a ,  170   b  may sit in parallel but separate orbital chambers. Such parallel orbital loads chambers may allow for concentration of the center of masses  55   a ,  55   b  of the first and second counterweight device  170   a ,  170   b  at the same angular position to provide greater load balance capabilities. In alternative embodiments the orbital balancing passage  152  does not include a passage body  154  that constrains radial motion of the first and second counterweight devices. Instead, the orbital chamber  160  may include a ring-shaped region of volume around the motor  140  and tub first inset wall  119 . For example, the first and second counterweight devices  170   a ,  170   b  can be rigidly coupled to disks coupled to a rotational shaft rotating around primary rotation axis  102 . 
     In embodiments, to maintain the first and second counterweight devices  170   a ,  170   b  within the first orbital chamber  160 , the dynamic balancing assembly  150  may include an orbital positioning device  164  arranged to enclose the first and second counterweight devices  170   a ,  170   b  within the orbital balancing passage  152 . The orbital positioning device  164  may further be arranged to restrain a first angular position of the first counterweight device  170   a  and a second angular position of the second counterweight device  170   b  within the orbital balancing passage  152 . For example, the orbital positioning device  164  may be a restraining wall  166 , which constrains the first and second counterweight devices  170   a ,  170   b  into contact with the orbital balancing passage  152 , such that the first and second counterweight devices  170   a ,  170   b  are only able to move in an arcuate path at a constant radius around the primary rotation axis  102  of the tub and drum assembly  100 . 
     In some embodiments, the orbital positioning device  164  may include a ring gear  167  that interacts with the first and second counterweight devices  170   a ,  170   b  to allow the first and second counterweight devices  170   a ,  170   b  to engage and traverse the ring gear  167  to move in an arcuate path about the primary rotation axis  102  of the tub and drum assembly  100  while remaining positioned within the first orbital chamber  160 . 
     In some embodiments, the orbital positioning device  164  may include both a ring gear  167  and a restraining wall  166 , which are positioned directly parallel to one another and are separated from one another by a gap  169 . As will be explained in greater detail herein, the gap  169  may allow for passage of one or more wires for communicatively coupling the first and second counterweigh devices  170   a ,  170   b  with the control unit  24 . 
     As noted above, motion of the first and second counterweight devices  170   a ,  170   b  may be responsive to communications from the control unit  24 . The control unit  24  may communicate with the first and second counterweight devices  170   a ,  170   b  through wireless or wired communications. Orbital movement of the first and second counterweight devices  170   a ,  170   b  may make maintaining wired communication difficult due to twisting and tangling of the wires. An alternative approach is brushed commutation with slip rings or brushes and commutators. Brushed approaches face challenges with corrosion and wear especially in a wet environment. Wired connections can be made fully hermetic and impervious to moisture if the cable management challenges can be overcome. One approach may be to use one or more clock springs. For example, the one or more clocksprings may include first and second clocksprings  180   a ,  180   b  that communicatively couple the first and second counterweight devices  170   a ,  170   b  to the control unit  24  (illustrated in  FIG.  1   ). The first and second clocksprings  180   a ,  180   b  may be positioned concentrically with the orbital balancing passage  152 .  FIG.  4    illustrates the first and second clocksprings  180   a ,  180   b , the first and second counterweight devices  170   a ,  170   b , and the ring gear  167  in isolation from the rest of the dynamic balancing assembly  150 . The first and second clocksprings  180   a ,  180   b  may be axially displaced along the primary axis  102  to allow independent orbital motion of the first and second clocksprings  180   a ,  180   b.    
     In the illustrated embodiment, the first clockspring  180   a  is coupled to the first counterweight device  170   a  and the second clockspring  180   b  is coupled to the second counterweight device  170   b . Clocksprings may be characterized in that they generally include a flat cable wound in a coiled (spiral) shape. Each of the first and second clocksprings  180   a ,  180   b  may include, for example, an electrical cable with one more electrical conductors to communicate electrical signals and voltage. For example, a ribbon cable may be suitable for clockspring construction. Each clockspring  180   a ,  180   b  may communicate power and motor signals to driving motors  174   a ,  174   b  to move the first and/or second counterweight devices  170   a ,  170   b  along the orbital balancing passage  152  to adjust an angular position of the first and/or second counterweight devices  170   a ,  170   b  around the primary rotation axis  102 . In embodiments, the clocksprings  180   a ,  180   b  may also communicate position feedback and/or other sensor signals from the orbiting counterweight devices  170   a ,  170   b  back to the control unit  24 . Sensors included in or on the orbiting counterweights devices  170   a ,  170   b  may include, but are not limited to, force sensors, vibration sensors, temperature sensors, position feedback sensors, accelerometer sensors, etc. 
     As the first and second counterweight devices  170   a ,  170   b  orbit about the ring gear  167 , the coil winds tighter or loosens depending on the direction of travel while maintaining the electrical connection. A clockspring has limited range of angular travel. At the end of travel the coil cannot accommodate additional relative angular motion between the inside and outside of the coil. Clocksprings according to the present disclosure may accommodate one or more revolutions of angular travel (e.g., two or more revolution, 3 or more revolutions, four or more revolutions, four of fewer revolutions, etc.). The control unit  24  may execute logic to ensure that the first and second counterweight devices  170   a ,  170   b  are only able to make a certain number of revolutions or move a certain degree around the orbital balancing passage  152  to not exceed the angular travel possible for the clocksprings  180   a ,  180   b . This may avoid stretching or damaging the cable and maintains electrical connection between the counterweight devices  170   a ,  170   b  and control unit  24 . After the spin cycle and balancing is complete, the position of both first and second counterweight devices  170   a  and  170   b  can be returned to a home position that is, for example, in the middle of angular travel range for the first and second clocksprings  180   a  and  180   b.    
     Referring again to  FIG.  2 C , the orbital balancing passage  152  may further define a clockspring chamber  168  positioned radially inward from the first orbital chamber  160 . Each of the first and second clocksprings  180   a ,  180   b  may be positioned within the clockspring chamber  168 . To connect to the first and second counterweight devices  170   a ,  170   b , lead wires from the first and second clocksprings  180   a ,  180   b  may extend through the gap  169  to be coupled to the respective first and second counterweight devices  170   a ,  170   b.    
     As noted above, the orbital balancing passage  152  (including the first orbital chamber  160  and the clockspring chamber  168 ) may be directly coupled to the base wall section  136  or may be coupled to the base wall section  136  by support plate  156 . The support plate  156  may extend along the base wall section  136  and be shaped to conform to a shape of the protruding portion  138  and the recessed portion  137 . That is, the support plate  156  may be coextensive along the at least a portion of the base wall section  136 . The support plate  156  may be coupled to the base wall section  136  through any coupling techniques (e.g., welding, brazing, fastening, etc.) or may be integrally formed therewith. 
     An extending portion  155  of the support plate  156  may separate from the base wall section  136  at a transition point  153  where the base wall section  136  transitions to a sidewall section  158  via a curved wall section  157 . The extending portion  155  may be perpendicular to the sidewall section  158  of the drum  130 . The extending portion  155  may extend to a diameter that is larger than a maximum diameter of the sidewall section  158  of the drum  130 . However, in some embodiments, the extending portion  155  may be equal to or less than a maximum diameter of the sidewall section  158  of the drum  130 . In the illustrated embodiment, the orbital balancing passage  152  may be arranged at the distal end of the extending portion  155  to maximize the applied moment provided by the first and second counterweight devices  170   a ,  170   b . The orbital balancing passage  152  may enclose both the first and second counterweight devices  170   a ,  170   b , and the first and second clocksprings  180   a ,  180   b  between the orbital balancing passage  152  and the support plate  156 . 
     As noted above, the drum  130  may be operatively coupled to the motor  140  via a drive shaft  144  defining the primary rotation axis  102 . In embodiments, the drive shaft  144  may be integrally formed within the support plate  156  of the drum  130 . In other embodiments, the drive shaft  144  may be fixedly coupled to the support plate  156  or directly fixedly coupled to the drum body  132  via any coupling technique (e.g., welding, brazing, fastening, etc.). It is noted that lead wires from the first and second clocksprings  180   a ,  180   b  may be routed through openings in the support plate  156  and through a center opening  145  of the drive shaft  144  with communication to the control unit  24  (illustrated in  FIGS.  1 A and  4   ). The lead wires  181   a ,  181   b  from an inner coil of the first and second clocksprings  180   a ,  180   b  may be connected to a rotational commutation device  182 . One side or the rotating end  183  of the rotational commutation device  182  may rotate with the drum  130  and may be installed at a back end of the drive shaft  144 . The other side or the non-rotating end  185  of the rotational commutation device  182  does not rotate with the drum  130  and may be connected to the tub  110  or exterior housing  20 . The rotational commutation device  182  communicates multiple paths of electrical current from multiple conductors of lead wires to communicate power and sensor signals between the rotating and non-rotating components of the laundry apparatus  10 . The rotational commutation device  182  may be a slip ring, brushed commutator, inductive commutator, etc. Lead wires  26  from the non-rotating end of the rotational commutation device  182  can connect to the control unit  24 . The control unit  24  may include a drive amplifier (not shown) or other electronic circuits to provide power to the driving motors  174   a ,  174   b  through the first and second clocksprings  180   a ,  180   b  to adjust angular position of the first and second counterweight devices  170   a ,  170   b . The rotational commutation device  182  can also communicate sensor signals from devices in the rotating drum  130  such as counterweight device position sensors, homing sensors, temperature sensors, force sensors, vibration sensors, load imbalance sensors  146 , and accelerometers to the control unit  24  for processing. The rotational commutation device  182  can alternatively communicate power and control signals to an intermediate drive amplifier that may rotate with the drum  130  and is connected to the first and second counterweight devices  170   a ,  170   b  by the first and second clocksprings  180   a ,  180   b.    
     Referring now to the first and second counterweight devices  170   a ,  170   b , the first and second counterweight devices  170   a ,  170   b  are configured to be controllably moved about the orbital balancing passage  152  to balance an imbalanced laundry load within the laundry apparatus  10 . For example, the first and second counterweight devices  170   a ,  170   b  may have a combined mass that is sufficiently large to balance a moment of a combined full design capacity laundry load saturated with a washing fluid. The first and second counterweight devices  170   a ,  170   b  can be constructed of a high density material such as steel, cast iron, tungsten, bronze, brass, lead, nickel, copper, aluminum, concrete, ceramic, glass, etc to minimize the volume occupied by the first and second counterweight devices  170   a ,  170   b  and the orbital balancing passage  152 . As will be described in greater detail below, the first counterweight device  170   a  and the second counterweight device  170   b  may be cooperatively controlled by the control unit  24  in response to detecting the load imbalance in the drum  130  based on the load imbalance signal output by the one or more load imbalance sensors  146 . 
       FIGS.  5 A and  5 B  illustrates a counterweight device  170  in isolation from the tub and drum assembly  100 . Each of the first and second counterweight devices  170   a ,  170   b  may be substantially identical to the counterweight device  170  illustrated in  FIGS.  5 A and  5 B . Referring particularly to  FIG.  5 A , the counterweight device  170  may include a curved body  172  shaped to travel through the orbital balancing passage  152 . The curved body  172  may house one or more weights (not shown). Coupled to the curved body  172  may be a driving motor  174 , which is communicatively coupled to the control unit  24  (shown in  FIGS.  1 A and  4   ) through the clock spring  180 . 
     Referring to  FIG.  5 B  which illustrates a driving assembly  173  of the counterweight device  170 , the driving motor  174  may drive a worm gear  176 . The driving motor  174  more be a reversible motor so as to be able to drive the counterweight device  170  in both a clockwise direction and a counterclockwise direction about the orbital balancing passage  152 . The worm gear  176  may be meshed with a worm wheel  177  that is mounted to a rotational axis  178 . Also mounted to the rotational axis  178  is a pinion gear  171 . That is, the pinion gear  171  may share a common rotational axis  178  with the worm wheel  177  such that rotation of the worm wheel  177  rotates the pinion gear  171 . Referring again to  FIG.  5 A , the pinion gear  171  is positioned at an edge  175  of the curved body  172  so as to be able to mesh with the ring gear  167  (illustrated in  FIG.  4   ). Accordingly, rotation of the worm gear  176  by the driving motor  174  causes the pinion gear  171  to rotate, which causes the counterweight device  170  to traverse the ring gear  167  and the orbital balancing passage  152 . 
     The counterweight device  170  may further include one or more wheels  179  positioned along the counterweight body the counterweight wheel may be arranged to contact the orbital balancing passage  152  and/or the retention device when positioned within the orbital balancing passage  152 . The one or more wheels  179  may be freely rotatably. In other embodiments, the one or more wheels  179  may be driven wheels (e.g., via a driving motor  174 ). Alternatively the wheels  179  can be replaced with bushings or bearings that allow relative motion at reduced friction between the counterweight device  170  and the orbital balancing passage  152 . 
     Referring again to  FIG.  2 C , when assembled, a cross-sectional plane  190 , passing through the laundry apparatus  10  at a position orthogonal to the primary rotation axis  102 , passes through dynamic balancing assembly  150  (e.g., the first counterweight device  170   a , the second counterweight device  170   b , or a combination thereof), the motor  140 , the fluid containment envelope  113 , and the first inset wall  119  of tub  110 . Note that while the cross-sectional plane  190  can pass through both the motor  140  and dynamic balancing assembly  150 , the motor is isolated from washing fluid by the first inset wall  119  of tub  110 . The dynamic balancing assembly  150  is directly connected to the drum  130  which allows effective counterbalancing to an imbalance caused by the center of mass  61  of laundry  60  and the first and second counterweight devices  170   a ,  170   b . Because of the inset wall  119  of tub  110 , the back of the motor  140  may, in some embodiments, be substantially flush with or closely proximate to a plane defined by a rear surface of the dynamic balancing assembly  150  instead of the back of the motor  140  being substantially offset from the back of the dynamic balancing assembly  150  which may cause the rear wall of the exterior housing  20  to increase in depth or to reduce the depth of the drum  130  and reduce the volume of the laundry receiving portion  133 . In embodiments wherein the first and second counterweight devices  170   a ,  170   b  are positioned in parallel but separate planes, the cross-sectional plate may only pass through one of the first counterweight device  170   a  or the second counterweight device  170   b . The cross-sectional plane  190  may additionally pass through at least one or the first clockspring  180   a  and the second clock spring  180   b . Accordingly, the present design provides for a more efficient use of space within the tub  110  and the laundry apparatus  10  by aligning various components along a common plane  190 . Such alignment allows for a greater amount of space to be reserved for the laundry-receiving portion  133  of the drum  130 . 
     Referring again to  FIGS.  1  and  2 A- 2 C , to provide for dynamic balancing of the laundry apparatus  10 , the laundry apparatus  10  may further include one or more load imbalance sensors  146  communicatively coupled to the control unit  24  and configured to output a load imbalance signal to the control unit  24 . The load imbalance signal may be indicative of a load imbalance within the drum  130 . For example, the load imbalance signal may be indicative of an angular position and a magnitude of the load imbalance within the drum  130 . The one or more load imbalance sensors  146  may be mounted anywhere in the laundry apparatus  10  and attuned to detect balance conditions within the drum  130 . For example, the one or more dynamic balancing sensors may include accelerometers and/or motor rotational position sensors to determine a center of mass within the load of laundry to determine if a load imbalance is present. Another embodiment may use motor torque sensors and motor rotational position sensors to determine a center of mass within the load of laundry to determine if a load imbalance is present. In yet further embodiments, force sensors may be used along with motor rotation position sensors to determine a center of mass within the load of laundry to determine if a load imbalance is present. Other sensors may include vibrational sensors or the like to determine the presence of a load imbalance. The load imbalance sensors  146  can detect relative and/or absolute variations in displacement, velocity, and/or acceleration of components of the laundry appliance  10 . For instance, a displacement-based load imbalance sensor  146  can measure small changes of displacement between the tub  110  and exterior housing  20  caused by an imbalanced load. In another example, an acceleration-based load imbalance sensor may measure fluctuations of acceleration of an accelerometer mounted to the tub  110 . In some embodiments, load imbalance may also be sensed by measuring change in force, torque, or strain between components of the laundry appliance  10 . In further embodiments, load imbalance may also be measured by monitoring the current to motor  140 . In yet further embodiments, load imbalance can also be determined based on acoustic analysis of noise during operation. 
     The angular position of the combined center of mass  63  relative to the primary rotation axis  102 , as illustrated in  FIGS.  1 C and  1 D , can be determined by measuring the angular position of the center of mass  61  of the laundry  60 . This is measured relative to a reference angular position  52  of the drum  130 . The reference angular position  52  of the drum  130  may be measured by a drum rotation sensor such as a magnetic or optical proximity sensor, a hall effect sensor, an encoder, resolver, etc. The reference angular position  52  of the drum  130  may, in some embodiments, be measured by motor position sensors. The angular position for center of mass  61  of the laundry  60  may be measured by the load imbalance sensor  146  relative to the reference angular position  52  of the drum  130 . Signals from the load imbalance sensor  146  can be analyzed in the time domain or alternatively in the frequency domain. Additionally, a magnitude of the imbalance signal from the load imbalance sensor  146  may be used to estimate the equivalent lumped mass at the center of mass  61  for laundry  60 . For example, the total mass of laundry  60  may be measured directly by load cells or strain gauge sensors. In some embodiments, the total mass of the laundry  60  may be calculated based on inertia of the laundry measured by accelerating or decelerating the spinning of the drum  130 . Control unit  24  may periodically or continuously calculate an estimate for magnitude and angle of imbalance to be countered by adjusting angular positions of the first and second counterweight devices  170   a ,  170   b . The amount of adjustment of the first and second counterweight devices  170   a ,  170   b  may be calculated by the control unit  24  so as to move the combined center of mass  63  of the laundry  60 , the first counterweight device  170   a , and the second counterweight device  170   b , to cause the combined center of mass  63  to be substantially coincident with the primary rotation axis  102  and eliminate or substantially reduce the vibrations that would result from a load imbalance. In embodiments, the control unit may not calculate an amount of adjustment for the first and second counterweight devices  170   a ,  170   b . Instead, the control unit may adjust the first and second counterweight devices  170   a ,  170   b  using a differential “trial and error” solution where angular positions  53   a ,  53   b  are adjusted until imbalance is reduced and eliminated. Another control strategy can employ a combination of a mathematical control scheme with fine tuning adjustments to further reduce imbalance signal. 
       FIG.  6    illustrates a flowchart depicting a method  200  for balancing the laundry apparatus  10  as described herein. The method  200  may start at step  202  and may include loading laundry within the laundry apparatus  10  and starting the laundry apparatus  10 . At step  204 , the method  200  includes rotating the drum  130 . At step  206 , the method  200  may further include receiving with the control unit  24 , a load imbalance signal output by the one or more load imbalance sensors  146 . At step  208 , the method  200  includes detecting, with the control unit  24 , a load imbalance signal output by the one or more load imbalance sensors  146  and determining whether a load imbalance is present within the drum  130  based on the load imbalance signal. Where a load imbalance is not detected, the method  200  may include monitoring the load for the load imbalance signal. Where a load imbalance is detected, the method  200  further includes, at step  210 , controlling the dynamic balancing assembly  150  to controllably move the first counterweight device  170   a  positioned within the orbital balancing passage  152  to adjust an angular position of the first counterweight device  170   a  around the primary rotation axis to counteract a detected load imbalance in the drum  130  and controllably move the second counterweight device  170   b  positioned within the orbital balancing passage  152  with the control unit  24  to adjust an angular position of the second counterweight device  170   b  around the primary rotation axis to counteract the detected load imbalance in the drum  130 . The control unit  24  may continue to monitor the laundry apparatus  10  for further load imbalances. In embodiments, the control unit  24  may only detect load imbalances and initiate movement of the first and second counterweight devices  170   a ,  170   b  during certain laundry cycles (e.g., the spin cycle). For example, the method may include monitoring the drum  130  with the one or more load imbalance sensors  146  continuously during acceleration from a satellite speed (e.g., a base operating speed sufficient for the centripetal acceleration to exceed gravitation acceleration) to a maximum water extraction speed (e.g., 800 RPM or greater, 1,000 RPM or greater, etc.). 
     The dynamic balancing assembly  150  illustrated in  FIG.  2 C , is illustrative of a single plane balancer where in the counterweight devices  170   a ,  170   b  are located on a single plane (i.e., within the same plane) perpendicular to the primary rotation axis  102 . Single plane balancing may be effective in many instances. In particular, single plane balancing is effective when the depth of the drum  130  is relatively shallow such that the center of mass  61  for laundry  60  is in proximity with the plane of the counterweight devices  170   a ,  170   b . Single plane balancing may also be particularly effective when the geometry of the drum  130  causes the center of mass  61  for laundry  60  to remain in proximity with a plane in which the counterweight devices  170   a ,  170   b  are supported. Tilting the primary rotation axis  102  so that the back of the drum  130  with the dynamic balancing assembly  150  is lower than the front of the drum  130  could cause the laundry  60  to slide toward the back of the drum due to gravitational acceleration so as to be closely positioned to the dynamic balancing assembly  150 . 
     However, in other embodiments, counterweight devices can be located within two or more planes perpendicular to the primary rotation axis  102 . Two plane dynamic balance may be accomplished by configuring the tub and drum assembly  100  to include two or more dynamic balancing assemblies  150 . The two or more dynamic balancing assemblies  150  may be provided with some axial separation along the primary rotation axis  102 . Each of the two or more dynamic balancing assemblies  150  will be coincident with a plane oriented perpendicular to the primary rotation axis  102 . Two plane balancing may be additionally effective at eliminating imbalances created when the center of mass  61  of the laundry  60  is not in proximity with a single plane supporting the counterweight devices  170 . Two plane balancing can be useful when the depth of the drum  130  is deep (e.g., depth of the drum to diameter ratio is greater than 1) and the center of mass  61  of the laundry cannot be moved proximate to a single plane supporting the counterweight devices during operation. 
       FIGS.  7 A- 7 H  show some schematic illustrative embodiments of tub and drum assemblies  100  with various configurations including two or more dynamic balancing assemblies  150 .  FIG.  7 A  illustrates a tub and drum assembly  100  with a cantilevered drum  130  configured for single plane balancing with a single dynamic balancing assembly  150  mounted to the rear of the drum  130 , such as discussed in greater detail above. The cantilevered drum  130  employs a main bearing assembly  159 , such as illustrated in  FIG.  1 C  at the rear of the drum. A motor  140  is coupled to the rear of the drum and mounted concentrically inset relative to the dynamic balancing assembly  150 . 
       FIG.  7 B  illustrates a tub and drum assembly  100  with a cantilevered drum  130  configured for two plane balancing with a first dynamic balancing assembly  150   a  mounted to the rear of the drum  130  and a second dynamic balancing assembly  150   b  mounted to the front of the drum  130 . A Motor  140  is coupled to the rear of the drum  130  and mounted concentrically inset relative to the first dynamic balancing assembly  150   a.    
       FIG.  7 C  illustrates a tub and drum assembly  100  with a cantilevered drum  130  configured for two plane balancing with a first dynamic balancing assembly  150   a  mounted to the rear of the drum  130  and a second dynamic balancing assembly  150   b  mounted to the inside rear of the drum  130 . A Motor  140  is coupled to the rear of the drum  130  and mounted concentrically inset relative to the first dynamic balancing assembly  150   a.    
       FIG.  7 D  illustrates a tub and drum assembly  100  with a cantilevered drum  130  configured for two plane balancing with a first dynamic balancing assembly  150   a  mounted to the rear of the drum  130  and a second dynamic balancing assembly  150   b  mounted behind the first dynamic balancing assembly  150   a . A motor  140  is coupled to the rear of the drum  130  and mounted concentrically inset relative to the first and second dynamic balancing assemblies  150   a ,  150   b.    
       FIG.  7 E  illustrates a tub and drum assembly  100  with a simply supported drum  130  (e.g., supported at both the front end and the rear end of the drum) configured for single plane balancing with a single dynamic balancing assembly  150  mounted to the rear of the drum  130 . The simply supported drum  130  may employ main bearing assemblies (not shown) at the rear and front of the drum  130 . A motor  140  is coupled to the rear of the drum  130  and mounted concentrically inset relative to the dynamic balancing assembly  150 . 
       FIG.  7 F  illustrates a tub and drum assembly  100  with a simply supported drum  130  configured for two plane balancing with a first dynamic balancing assembly  150   a  mounted to the rear of the drum  130  and a second dynamic balancing assembly  150   b  mounted to the front of the drum  130 . Motors  140   a ,  140   b  are coupled to the rear and front of the drum  130  and mounted concentrically inset relative to respective the first and second dynamic balancing assemblies  150   a ,  150   b.    
       FIG.  7 G  illustrates a tub and drum assembly  100  with a simply supported drum  130  configured for two plane balancing with a first dynamic balancing assembly  150   a  mounted to the rear of the drum  130  and a second dynamic balancing assembly  150   b  mounted to the front of the drum  130 . A Motor  140  is coupled to the rear of the drum and mounted concentrically inset relative to the first dynamic balancing assembly  150   a.    
       FIG.  7 H  illustrates a tub and drum assembly  100  with a simply supported drum  130  configured for two plane balancing with a first dynamic balancing assembly  150   a  mounted to the rear of the drum  130  and a second dynamic balancing assembly  150   b  mounted behind the first dynamic balancing assembly  150   a . A Motor  140  is coupled to the rear of the drum and mounted concentrically inset relative to the first and second dynamic balancing assemblies  150   a ,  150   b.    
     Alternatively for the embodiments illustrated in  FIGS.  7 A- 7 H , a passive dynamic balancing assembly such as a simple fluid and weighted ball filled balancing ring could be used in place of an active dynamic balancing assembly controlled by a control unit. Alternatively for the embodiments illustrated in  FIGS.  7 A- 7 H , the dynamic balancing assembly  150  could use means for dynamically balancing other than adjusting angular position of counterweight devices  170 . Some alternative embodiments may include counterweights having an adjustable radial position from primary rotation axis  102 , variable mass bodies such as fluid or powder filled bladders or cylinders, orbital masses that can shift off-center from primary rotation axis  102 , rings filled with weighted balls with adjustable orbital position by magnetic attraction, etc. 
     Referring now to  FIGS.  8 A and  8 B , the tub and drum assembly  100  is located inside of the exterior housing  20  of a laundry apparatus  10 . The tub  110  may be attached to the exterior housing  20  via a displaceable suspension  30 . The displaceable suspension  30  may include any tuned passive elements used to reduce vibrations or the effects thereof, including, but not limited to, springs  31 , additional suspension mass(es)  32  attached to the tub, and dampers  33  designed to reduce transmittance of vibrations and absorb energy from spinning imbalanced laundry to the exterior housing  20 , or the like. The displaceable suspension  30  allows the tub  110  to displace relative to the exterior housing  20 . The displacement of the tub  110  may cause travel in any direction. For example the direction of travel can be in the radial direction or axial direction relative to the primary rotation axis  102 . Significant displacement of the tub may absorb vibrations and dampen the motion of a vibrating tub and drum assembly  100 . In some embodiments, the displaceable suspension  30  may include active members such as linear motors, torsional motors, dampers with magnetorheological fluid, voice coil actuators, pneumatic actuators, magnetic actuators, etc. to dampen vibrations. Passive and active suspension members may rely on relative motion between the tub and drum assembly  100  and the exterior housing  20  to absorb vibrations transmitted to exterior housing  20 . 
     A travel volume  35  surrounding the tub  110  may be delineated by a swept volume of the tub and drum assembly  100  following the maximum possible travel distance  34  in all directions. That is, the travel volume  35  may be space within the exterior housing left empty or free from obstructions between the tub  110  and exterior housing  20  to accommodate movement of the tub and drum assembly  100 . The provide enough space for the travel volume  35 , the interior of the exterior housing  20  may be significantly larger than the exterior dimensions of the tub  110 . This may create a practical limitation to the size of the tub and drum assembly  100  and internal laundry capacity for a given exterior housing size. If the diameter of the tub and drum assembly  100  approaches the inside width or height of the exterior housing  20 , the displaceable suspension  30  would have limited travel space available and would be unable to isolate vibration from the tub and drum assembly  100  to the exterior housing  20 . Likewise, if the axial depth of the tub and drum assembly  100  approaches the inside depth of the exterior housing  20 , the displaceable suspension  30  would have limited travel space available and would be unable to isolate vibration due to load imbalance from transmitting to the exterior housing  20 . 
     The addition of a dynamic balancing assembly  150  described above to a laundry apparatus  10  using a displaceable suspension  30  can greatly reduce or eliminate the vibrations generated by the laundry imbalance. If the masses of the first and second counterweight devices  170   a ,  170   b  are not sized to balance the potential imbalance of the largest possible laundry load, then some imbalance can still be generated even with the dynamic balancing assembly  150  and the displaceable suspension  30  may dampen the remaining vibration through displacement of the displaceable suspension. The addition of the dynamic balancing assembly  150  may reduce the maximum travel distance  34  and can reduce the travel volume  35  needed to allow for the maximum travel. For example, the maximum travel distance for the tub and drum assembly  100  may be less than about 6 mm. In such embodiments, the dimensions of the tub and drum assembly  100  may be enlarged such that the travel volume  35  extends to an interior surface of the exterior housing  20 . Stated another way, the tub and drum assembly  100  may be in much closer proximity to the exterior housing  20 , so as to fill up more of the space within the exterior housing  20 . 
     A dynamic balancing assembly  150  can greatly reduce or eliminate vibration transmitted to the laundry apparatus  10  from laundry imbalance. Elimination of imbalance and vibration can allow construction of a laundry apparatus  10  without a displaceable suspension  30 . Referring to  FIGS.  9 A and  9 B , the tub and drum assembly  100  may be located inside of the exterior housing  20  of a laundry apparatus  10  by attaching the tub  110  to the exterior housing  20  with one or more tub mounts  40  or a plurality of tub mounts. The tub mounts  40  include of a plurality of various mounting interfaces to attach the tub  110  to the exterior housing  20 . The tub mounts  40  may be components separate from the tub  110  and exterior housing  20  or may be integral to the tub  110  and/or the exterior housing  20 . The tub mounts  40  can include any rigid or stiff material that has minimal displacement during loading of laundry  60  into drum  130 . The tub mounts  40  may alternatively provide some compliance and may allow minimal displacement (e.g., for example a maximum displacement of 6 mm or less with 25 lb force applied). Compliant tub mounts  40  may be constructed using vibration isolators, elastomeric motor mounts, stiff springs (e.g., a spring having a maximum extension/contraction of 6 mm or less), fluid filled motor mounts, etc. The tub mounts  40  may be produced from any material including, but not limited to a polymer, elastomeric, metallic components, or any combination thereof. The tub mounts  40  can be attached by bolts, screws, rivets, adhesive, welding, etc. 
     A dynamically balanced tub and drum assembly  100  with dynamic balancing assembly  150  supported by tub mounts  40  may be substantially free from vibration during operation such that the tub  110  will not substantially move relative to the exterior housing  20 . A balanced tub and drum assembly  100  without a displaceable suspension  30  may not require any of the travel volume  35  or a greatly reduced travel volume and will allow the tub and drum assembly  100  to fully occupy the interior volume of the exterior housing  20 . Given the same dimensions of exterior housing  20 , the tub and drum assembly  100  without a displaceable suspension  30  may be significantly larger than the tub and drum assembly  100  with a displaceable suspension  30 . The larger tub and drum assembly may have more interior volume in the laundry receiving portion  133  and may accommodate more laundry  60 . Similarly, given the same dimensions for the tub and drum assembly  100  and the same laundry  60  capacity, the exterior housing  20  without a displaceable suspension  30  can be significantly smaller than the exterior housing  20  with a displaceable suspension  30 . Eliminating the displaceable suspension  30  by applying a dynamic balancing assembly  150  may allow for construction of a compact laundry apparatus with useful volume of laundry receiving portion  133  and laundry  60  capacity. Eliminating the displaceable suspension  30  by applying a dynamic balancing assembly  150  may also allow for construction of a standard size laundry apparatus with superior volume of laundry receiving portion  133  and laundry  60  capacity. 
     It may be impractical to construct a compact laundry apparatus with very small external housing dimensions if the tub and drum assembly  100  are supported by a displaceable suspension  30  that accommodates a maximum travel of 25.4 mm, as the resulting laundry capacity may be very small. It is especially impractical to construct a compact laundry apparatus with an external housing  20  of a very small depth (e.g., 32 cm or less) if the tub and drum assembly  100  are supported by a displaceable suspension  30  with a maximum travel of 25.4 mm as the resulting laundry capacity would still be very small. TABLE 1 compares drum internal volume and drum dimensions for four different laundry apparatus configurations having varying exterior housing dimensions compared with and without a displaceable suspension. The radial and axial travel for the examples are is about 2.5 cm. The laundry apparatus configurations with the dynamic balancing assembly  150  and no suspension has larger drum  130  volume by 37.4%-92.7%. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Dimension Comparison with and without Dynamic Balancing Assembly 
               
            
           
           
               
               
               
            
               
                   
                   
                 With Dynamic 
               
               
                   
                 With Suspension 
                 Balancing Assembly 
               
               
                   
                 with 25.4 mm Travel 
                 and No Suspension 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Housing 
                 Housing 
                 Housing 
                 Drum 
                 Drum 
                   
                 Drum 
                 Drum 
                   
               
               
                 Outer 
                 Outer 
                 Outer 
                 Internal 
                 Internal 
                 Drum 
                 Internal 
                 Internal 
                 Drum 
               
               
                 Width 
                 Height 
                 Depth 
                 Depth 
                 Diameter 
                 Volume 
                 Depth 
                 Diameter 
                 Volume 
               
               
                 (mm) 
                 (mm) 
                 (mm) 
                 (mm) 
                 (mm) 
                 (liter) 
                 (mm) 
                 (mm) 
                 (liter) 
               
               
                   
               
               
                 610 
                 762 
                 305 
                 102 
                 483 
                 19 
                 152 
                 533 
                  34 
               
               
                 610 
                 762 
                 406 
                 203 
                 483 
                 37 
                 254 
                 533 
                  57 
               
               
                 610 
                 762 
                 610 
                 406 
                 483 
                 74 
                 457 
                 533 
                 102 
               
               
                 508 
                 610 
                 305 
                 102 
                 381 
                 12 
                 152 
                 432 
                  22 
               
               
                   
               
            
           
         
       
     
     In some embodiments, instead of maximizing drum volume, the additional space provided by eliminating the displaceable suspension and/or the travel volume may be used for packing various internal laundry apparatus components  41  inside the volume of a laundry apparatus  10 . Traditionally, packaging internal laundry apparatus components has been challenging especially when the exterior housing  20  has compact dimensions or if the laundry apparatus is a combination washer/dryer. Referring to  FIGS.  10 A and  10 B , the tub and drum assembly  100  is located inside of the exterior housing  20  of a laundry apparatus  10  by attaching the tub  110  to the exterior housing  20  with a tub mounts  40 , as described above. As noted above, the tub and drum assembly  100  with dynamic balancing assembly  150  may be constructed without a displaceable suspension and will not require any travel volume or only a small travel volume (e.g., 6 mm or less radially in any direction and 6 mm axially). If the exterior dimensions of the tub and drum assembly  100  are smaller than the internal dimensions inside the exterior housing  20 , the volume between the tub and drum assembly  100  and the exterior housing  20  may be used for placement of laundry apparatus components  41 . Laundry apparatus components  41  can include, but are not limited to, pumps, water hoses, air ducts, water storage sumps, power supplies, control units, electronic circuitry, sensors, air heaters, water heaters, drying components, condensation equipment, refrigeration components, moisture storage components, vessels for storage of water. Storage of detergent and chemicals, detergent and chemical dispensers, fans, storage of hoses, hose reels, casters, etc. Substantial elimination of the travel volume  35  of the tub  110  allows design of a laundry apparatus  10  with a high volume capacity for the laundry-receiving portion  133  and volume to install internal laundry apparatus components  41 . For example, positions in which the tub and drum assembly  100  is closest to the various surfaces (e.g., front, back, top, bottom, or sidewall), may define pinch points PP. Without using the active balancing assembly  150 , a displaceable suspension as illustrated in  FIG.  8 A  may be necessary for damping vibrations. Accordingly, the travel volume  35  necessary to allow for movement of the displaceable suspension likely provides too little space for storage of laundry apparatus components  41  within the pinch points PP, whereas, and as illustrated in  FIG.  10 A , laundry apparatus components may be positioned in the pinch points PP, without encroaching on the space needed for the travel volume  35 . 
     Embodiments can be described with reference to the following numbered clauses, with preferred features laid out in the dependent clauses. 
     1. A laundry apparatus comprising: a tub defining a fluid containment envelope; a drum positioned within the fluid containment envelope of the tub and rotatable relative to the tub about a primary rotation axis, the drum comprising a receiving portion for receiving one or more articles of laundry; a control unit; a motor coupled to the tub, wherein the motor is communicatively coupled to the control unit and operatively coupled to the drum to cause rotation of the drum, wherein the motor is isolated from fluid within the fluid containment envelope; one or more load imbalance sensors communicatively coupled to the control unit and configured to output a load imbalance signal to the control unit, the load imbalance signal being indicative of a load imbalance within the drum; and a dynamic balancing assembly communicatively coupled to the control unit, the dynamic balancing assembly comprising: an orbital balancing passage arranged concentrically around the motor; a first counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the first counterweight device along the orbital balancing passage to adjust an angular position of the first counterweight device around the primary rotation axis to counteract a detected load imbalance in the drum; and a second counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the second counterweight device along the orbital balancing passage to adjust an angular position of the second counterweight device around the primary rotation axis to counteract the detected load imbalance in the drum; wherein a cross-sectional plane passing through the laundry apparatus at a position orthogonal to the primary rotation axis passes through the dynamic balancing assembly, the motor, and the fluid containment envelope of the tub. 
     2. The laundry apparatus of clause 1, further comprising a main bearing assembly fixedly attached to the tub and operatively connected to the drum providing radial and axial support to the drum. 
     3. The laundry apparatus of any preceding clause, wherein: the dynamic balancing assembly comprises an orbital positioning device positioned to restrain a first angular position of the first counterweight device and a second angular position of the second counterweight device within the orbital balancing passage; and the first counterweight device and the second counterweight device are constrained into contact with the orbital balancing passage. 
     4. The laundry apparatus of any preceding clause, wherein: the tub further comprises a motor receiving envelope that extends into a volume of the fluid containment envelope; the motor is positioned within the motor receiving envelope; and the motor receiving envelope is isolated from the fluid within the fluid containment envelope. 
     5. The laundry apparatus of clause 4, wherein the motor receiving envelope comprises a first inset wall extending into the volume of the fluid containment envelope between the motor and the orbital balancing passage. 
     6. The laundry apparatus of any preceding clause, wherein at least a surface of the tub and a surface of the motor are substantially flush with one another. 
     7. The laundry apparatus of any preceding clause, wherein the first counterweight device and the second counterweight device each comprise a driving motor that causes a respective counterweight device to travel along the orbital balancing passage. 
     8. The laundry apparatus of any preceding clause, wherein the first counterweight device and the second counterweight device are cooperatively controlled by the control unit in response to detecting the load imbalance in the drum based on the load imbalance signal output by the one or more load imbalance sensors. 
     9. The laundry apparatus of any preceding clause, wherein the first counterweight device and the second counterweight device orbit the primary rotation axis within the orbital balancing passage and at constant radius from the primary rotation axis. 
     10. The laundry apparatus of any preceding clause, wherein the laundry apparatus is a front-load washing machine. 
     11. A laundry apparatus comprising: a tub comprising a fluid containment envelope and a motor receiving envelope that extends into a volume of the fluid containment envelope and is isolated from fluid received in the fluid containment envelope; a drum positioned within the fluid containment envelope of the tub and rotatable relative to the tub about a primary rotation axis centrally positioned in the tub, the drum comprising a receiving portion for receiving one or more articles of laundry; a control unit; a motor positioned within the motor receiving envelope such that the motor is positioned within the volume of the fluid containment envelope and isolated from the fluid received in the fluid containment envelope, wherein the motor is communicatively coupled to the control unit and operatively coupled to the drum to cause rotation of the drum; one or more load imbalance sensors communicatively coupled to the control unit and configured to output a load imbalance signal to the control unit, the load imbalance signal being indicative of a load imbalance within the drum; and a dynamic balancing assembly communicatively coupled to the control unit and attached to the drum within the fluid containment envelope, the dynamic balancing assembly comprising: an orbital balancing passage arranged concentrically around the motor; a first counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the first counterweight device along the orbital balancing passage to adjust an angular position of the first counterweight device around the primary rotation axis to counteract a detected load imbalance in the drum; and a second counterweight device positioned within the orbital balancing passage and responsive to the control unit, wherein the control unit controllably moves the second counterweight device along the orbital balancing passage to adjust an angular position of the second counterweight device around the primary rotation axis to counteract the detected load imbalance in the drum; wherein a cross-sectional plane passing through the laundry apparatus at a position orthogonal to the primary rotation axis passes through the dynamic balancing assembly, the motor receiving envelope of the tub, and the fluid containment envelope of the tub. 
     12. The laundry apparatus of clause 11, further comprising a main bearing assembly fixedly attached to the tub and operatively connected to the drum providing radial and axial support to the drum. 
     13. The laundry apparatus of clause 11 or 12, wherein: the dynamic balancing assembly comprises an orbital positioning device positioned to restrain a first angular position of the first counterweight device and a second angular position of the second counterweight device within the orbital balancing passage; and the first counterweight device and the second counterweight device are constrained into contact with the orbital balancing passage. 
     14. The laundry apparatus of any of clauses 11-13, wherein at least a surface of the tub and a surface of the motor are substantially flush with one another. 
     15. The laundry apparatus of any of clauses 11-14, wherein the first counterweight device and the second counterweight device each comprise a driving motor that causes a respective counterweight device to travel along the orbital balancing passage. 
     16. A method of balancing a laundry apparatus comprising: rotating a drum positioned within a fluid containment envelope of a tub with a motor about a primary rotation axis, the motor being positioned within a motor receiving envelope that isolates the motor from a fluid within the fluid containment envelope; detecting, with a control unit, a load imbalance signal output by one or more load imbalance sensors, wherein the load imbalance signal is indicative of a load imbalance within the drum; and controlling a dynamic balancing assembly coupled to the drum and positioned within the fluid containment enveloped, the dynamic balancing assembly comprising an orbital balancing passage arranged concentrically around the motor, a first counterweight device positioned within the orbital balancing passage, and a second counterweight device positioned within the orbital balancing passage, to: controllably move the first counterweight device positioned within the orbital balancing passage to adjust an angular position of the first counterweight device around the primary rotation axis to counteract a detected load imbalance in the drum; and controllably move the second counterweight device positioned within the orbital balancing passage with the control unit to adjust an angular position of the second counterweight device around the primary rotation axis to counteract the detected load imbalance in the drum, wherein a cross-sectional plane passing through the laundry apparatus at a position orthogonal to the primary rotation axis passes through the dynamic balancing assembly, the motor, and the fluid containment envelope of the tub. 
     17. The method of clause 16, wherein the load imbalance signal is indicative of an angular position of a load within the drum and a magnitude of the load imbalance within the drum. 
     18. The method of clause 16 or 17, further comprising monitoring the drum with the one or more load imbalance sensors continuously during acceleration from a satellite speed to a maximum water extraction speed. 
     19. The method of any of clauses 16-18, wherein the first counterweight device and the second counterweight device each comprise a driving motor communicatively coupled to the control unit cause a respective counterweight device to travel along the orbital balancing passage. 
     20. The method of any of clauses 16-19, wherein the motor receiving envelope extends into a volume of the fluid containment envelope. 
     It should now be understood that embodiments described herein are generally directed to a laundry apparatuses that include dynamic balancing assemblies that maximize volumetric space for receiving laundry. For example, and as illustrated in the figures, a laundry apparatus according to the present disclosure generally includes a tub, a drum, and a dynamic balancing assembly. The drum is positioned within a fluid containment envelope of the tub and is rotatable relative to the tub about a primary rotation axis  102   102 , the drum defines a laundry-receiving portion for receiving one or more articles of laundry. The dynamic balancing assembly includes an orbital balancing passage, arranged concentrically around a motor of the laundry apparatus, and first and second counterweight devices are positioned within the orbital balancing passage. The dynamic balancing assembly is positioned relative to the tub and/or drum so that a common cross-sectional plane passes through the dynamic balancing assembly, the motor, and the fluid containment envelope of the tub. 
     The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”