ROBOTIC CLEANER

A robotic cleaner may include a suction motor, a dust cup, and a suction motor air duct fluidly coupled to the suction motor and the dust cup. The suction motor air duct may include a debris barrier having a restricting region and a guard region.

TECHNICAL FIELD

The present disclosure is generally directed to automated cleaning apparatuses and more specifically to robotic cleaners having at least one dust cup.

BACKGROUND INFORMATION

Autonomous cleaning devices are configured to autonomously navigate a surface while at least partially cleaning the surface. One example of an autonomous cleaning device is a robotic vacuum cleaner. A robotic vacuum cleaner may include a controller, a plurality of driven wheels, a suction motor, a brush roll, and a dust cup. A suction motor air duct fluidly couples the suction motor to the dust cup. In operation, the suction motor is configured to generate a suction force at a dirty air inlet to the dust cup, causing air to flow into the dust cup through the suction motor air duct and into the suction motor. As such, while traversing the surface to be cleaned, debris is urged into the dust cup as a result of the suction generated by the suction motor. Debris collected within the dust cup may be emptied by removing the dust cup from the robotic vacuum cleaner, exposing a duct inlet of the suction motor duct. An exposed duct inlet may allow debris to inadvertently enter the suction motor air duct. Large debris that enters the suction motor air duct may become lodged in the suction motor, which may damage the suction motor (e.g., by impeding the rotation of an impeller of the suction motor).

DETAILED DESCRIPTION

The present disclosure is generally directed to a robotic cleaner. The robotic cleaner may include a body, a dust cup removably coupled to the body and having a dirty air inlet and a clean air outlet, a suction motor configured to generate a suction force at the dirty air inlet of the dust cup, and a suction motor air duct fluidly coupling the dust cup to the suction motor. The suction motor air duct includes a duct inlet proximate to the clean air outlet of the dust cup. When the dust cup is removed from the body of the robotic cleaner, the duct inlet is exposed. The suction motor air duct includes a debris barrier assembly (e.g., proximate to the duct inlet) configured to prevent large debris (e.g., debris having a maximum dimension of at least 2.5 millimeters, at least 3 millimeters, at least 3.5 millimeters, or at least 4 millimeters) from inadvertently entering the suction motor air duct via the duct inlet when the dust cup is removed from the body of the robotic cleaner. The debris barrier assembly includes a guard region and a restricting region. The guard region is configured to allow air to pass therethrough and the restricting region is configured to restrict (e.g., prevent or reduce) air passing therethrough.

In some instances, the dust cup may include one or more filter mediums disposed within the airflow path between the dirty air inlet and the clean air outlet. For example, the dust cup may be configured to receive a filter medium and a plenum may extend over the filter medium. The filter medium may be coupled to a filter frame, the filter frame may be configured to removably couple to the dust cup. The filter frame may be configured to improve airflow within the plenum.

FIG.1shows a schematic example of a robotic cleaner100. As shown, the robotic cleaner100includes a body102, one or more driven wheels103configured to urge the body102across a surface to be cleaned (e.g., a floor), a suction motor104(shown in hidden lines), a suction motor air duct106(shown in hidden lines), and a dust cup108removably coupled to the body102. The suction motor air duct106fluidly couples (e.g., directly fluidly couples) the suction motor104to the dust cup108.

In operation, the suction motor104is configured to cause air to flow into a dirty air inlet110(generally shown with a hidden line) of the dust cup108. The air flowing into the dirty air inlet110may have debris entrained therein. At least a portion of the entrained debris may be deposited in the dust cup108. The dust cup108can be removed from the body102of the robotic cleaner100to empty debris collected within the dust cup108.

FIG.2shows an end view of the robotic cleaner100ofFIG.1having the dust cup108removed therefrom (e.g., for emptying of debris). As shown, when the dust cup108is removed, a duct inlet200is exposed. To prevent large debris from entering the suction motor air duct106and becoming lodged within the suction motor104, the suction motor air duct106may include a debris barrier202. The debris barrier202may include a restricting region204and a guard region206. The restricting region204and/or guard region206may extend across an entire inlet width201of the duct inlet200.

The restricting region204may include one or more plates208(e.g., a plurality of spaced apart plates208) that are substantially impermeable to air. When the restricting region204includes a plurality of spaced apart plates208, a combined surface area of a dust cup facing surface of the plates208may be greater than the combined area of the regions separating the plates208. The restricting region204can be configured to augment the airflow passing through the suction motor air duct106. For example, the plate208can be shaped to encourage a smooth transition of air flowing into the suction motor air duct106. As shown, the guard region206includes a plurality of spaced apart protrusions210, wherein air is configured to flow between the protrusions210. A combined surface area of a dust cup facing surface of the protrusions210may be less than a combined area of the regions separating the protrusions210.

In some instances, at least a portion of the debris barrier202may be integrally formed from and/or coupled to the suction motor air duct106. For example, the protrusions210may be integrally formed from the suction motor air duct106and/or the plate208may be integrally formed from the suction motor air duct106. By way of further example, the protrusions210may be coupled to (e.g., using one or more adhesives, one or more mechanical fasteners, and/or any other form of coupling) the suction motor air duct106and/or the plate208may be coupled to the suction motor air duct106. Use of couplings to couple at least a portion of the debris barrier202to the suction motor air duct106may have an adverse impact on air flow compared to when the debris barrier202is integrally formed from the suction motor air duct106.

FIG.3shows a perspective view of an example of a suction motor air duct300(which may be an example of the suction motor air duct106) fluidly coupled to a suction motor302(which may be an example of the suction motor104) and a dust cup304(which may be an example of the dust cup108). The suction motor302is configured to draw air into the dust cup304and the through the suction motor air duct300.

FIG.4shows a cross-sectional view of the suction motor air duct300, the suction motor302, and the dust cup304taken along the line IV-IV ofFIG.3. As shown, the dust cup304includes a dirty air inlet400, a debris fin402extending into a debris cavity403of the dust cup304, a first filter medium404, a second filter medium406, a plenum408, and a clean air outlet410.

The suction motor air duct300includes a duct inlet412, a duct outlet414, and a debris barrier416. As shown, the suction motor air duct300may be made of two or more separate parts (e.g., a duct bottom portion421and a duct top portion423) that are coupled together. The duct inlet412is fluidly coupled to the clean air outlet410of the dust cup304and the duct outlet414is fluidly coupled to the suction motor302. The debris barrier416is positioned within the suction motor air duct300at location between the duct inlet412and the duct outlet414. For example, the debris barrier416may be positioned proximate to the duct inlet412(e.g., at distance from the duct inlet412measuring less than 35%, 30%, 25%, 20%, 10%, 5%, or 1% of the largest dimension of the suction motor air duct300).

The debris barrier415includes a restricting region418and a guard region420. As shown, the restricting region418includes one or more blocking plates422having a blocking side424and an airflow side426, wherein the airflow side426defines at least a portion of an inner surface of the suction motor air duct300and the blocking side424faces the dust cup304. The blocking plate422may be coupled to or integrally formed from the suction motor air duct300(e.g., the duct bottom portion421).

As also shown, the guard region420includes a plurality of spaced apart protrusions428between which air flows. The plurality of spaced apart protrusions428extend from the duct top portion423in a direction of the blocking plate422. The plurality of spaced apart protrusions428may be coupled to or integrally formed from the suction motor air duct300(e.g., the duct top portion423). Integrally forming the protrusions428and/or the blocking plate422with the duct top portion423and/or the duct bottom portion421may simplify the assembly process, reduce the number of fasteners, and/or increase the area available for airflow.

In operation, the suction motor302is configured to cause air to flow along a flow path430. As shown, the flow path430extends from the dirty air inlet400along a surface of the debris fin402and into the debris cavity403. From the debris cavity403, the flow path430extends through the first filter medium404and the second filter medium406and into the plenum408. The first filter medium404may be configured to collect larger debris than the second filter medium406. For example, the first filter medium404may be a mesh screen and the second filter medium406may be a pleated filter. In some instances, the second filter medium406may be a high efficiency particulate air (HEPA) filter.

Within the plenum408, the flow path430is caused to change direction (e.g., the flow path430may have an at least 80° change in direction, an at least 85° change in direction, or an at least 90° change in direction). The distance over which the change in direction occurs may have an impact on performance.

From the plenum408the flow path430extends through the clean air outlet410and duct inlet412and into the suction motor air duct300. When passing through the suction motor air duct300, the flow path430extends between the spaced apart protrusions428of the debris barrier415and along the airflow side426of the blocking plate422of the debris barrier415. The airflow side426of the blocking plate422can be configured to encourage a smooth airflow transition of air passing into the suction motor air duct300. For example, the airflow side426of the blocking plate422and the suction motor air duct300may include one or more planar surfaces (e.g., angled planar surfaces) and/or arcuate surfaces to encourage smooth airflow. From the suction motor air duct300, the flow path430extends through the duct outlet414and into the suction motor302.FIG.12shows a computational fluid dynamics (CFD) analysis corresponding to a suction motor air duct300having the debris barrier415andFIG.13shows a CFD analysis corresponding to the suction motor air duct300having a grid structure1400to block debris (see,FIG.14) coupled thereto. As shown, the debris barrier415provides improved performance relative to the grid structure1400(e.g., the debris barrier415may provide a performance increase of approximately 2.8 air watts).FIG.15shows a performance plot comparing the suction motor air duct300having the debris barrier415, the suction motor air duct300having the grid structure1400, the suction motor air duct300alone (e.g., without the debris barrier415or grid structure1400), and the impact of an orientation of the suction motor302(e.g., vertical impeller rotation axis and tilted/non-vertical impeller rotation axis).

FIG.5shows a perspective view of the suction motor air duct300and the suction motor302, wherein the dust cup304has been removed therefrom (e.g., for emptying debris accumulated within the dust cup304). As shown, when the dust cup304is removed, the duct inlet412is exposed to the surrounding environment. The debris barrier415prevents large debris (e.g., debris capable of causing damage to the suction motor302if it becomes lodged therein) from entering the suction motor air duct300when the dust cup304is removed.

As shown, the plurality of protrusions428are spaced apart by a protrusion separation distance500and have a protrusion length502and a protrusion width504. As shown, the protrusion separation distance500extends between immediately adjacent protrusions428. A protrusion passthrough region506is defined between immediately adjacent protrusions428. In other words, immediately adjacent protrusions428may be separated by a respective protrusion passthrough region506. Each protrusion passthrough region506defines an open area. The open area defined by a respective protrusion passthrough region506may be greater than the combined leading surface area of the protrusions428(e.g., the leading surface of the protrusion428being the surface facing the airflow) defining the protrusion passthrough region506. The leading surface area for a respective protrusion428may be the protrusion length502multiplied by the protrusion width504. In some instances, a combined open area (i.e., the summation of each open area within the guard region420) may be, for example, in a range of 500 square millimeters (mm2) to 700 mm2. By way of further example, the combined open area may be in a range of 550 mm2to 600 mm2. By way of still further example, the combined open area may be in a range of 650 mm2to 700 mm2. In some instances (see, e.g., the discussion accompanyingFIGS.6-10), the size and/or shape of the plenum408may be optimized to, for example, maximize the combined open area (e.g., without increasing a size of the dust cup304). Increasing the open area may improve performance (e.g., by increasing the air watts of the system).

The protrusion separation distance500may be, for example, in a range of 2 millimeters (mm) to 4 mm. By way of further example, the protrusion separation distance500may be 3 mm. By way of still further example, the protrusion separation distance500may be 3.5 mm. The protrusion separation distance500may be constant within the guard region420. Alternatively, the protrusion separation distance500may not be constant within the guard region420. For example, the protrusion separation distance500may increase with increasing distance from a center of the duct inlet412. In this example, the open area defined by the protrusion passthrough regions506may increase with increasing distance from the center of the duct inlet412.

The protrusion length502may be, for example, in a range of 2 mm to 4 mm. By way of further example, the protrusion length502may be 3 mm. By way of still further example, protrusion length502may be 3.5 mm. The protrusion length502may not be constant within the guard region420. For example, the protrusion length502for one or more of the protrusions428may be less than the protrusion length502for at least one other protrusion428(e.g., to facilitate the fluid coupling of the dust cup304to the suction motor air duct300). Alternatively, the protrusion length502may be the same for each protrusion.

The protrusion width504may be the same for each protrusion428. Alternatively, the protrusion width504for one or more protrusions428may be less than the protrusion width504of at least one other protrusion428. For example, the protrusion width504, for each protrusion428, may increase with increasing distance from a center of the duct inlet412.

As shown, the restricting region418includes a plurality of the blocking plates422spaced apart by a plate separation distance508and having a plate length510and a plate width512. A plate passthrough region514is defined between immediately adjacent blocking plates422. In other words, immediately adjacent blocking plates422are separated by a respective plate passthrough region514. Each plate passthrough region514defines an open area. The open area defined by a respective plate passthrough region514may be less than the surface area of the blocking sides424(e.g., the surface area defined by the plate length510and the plate width512) of the blocking plates422that define the respective plate passthrough region514. As shown, in some instances, the protrusions428immediately adjacent to opposing sides of the plate passthrough region514have an end profile515that generally corresponds to a shape of the corresponding blocking plate422such that at least a portion of the protrusion428extends along the airflow side426of the blocking plate422. As also shown, in some instances, the protrusion428extending from a location that is between immediately adjacent plates422may have an end profile517, wherein the protrusion length502changes from a first protrusion length to a second, greater, protrusion length. In some instances, the plate passthrough region514may include an obstruction plate516that reduces the open area of the plate passthrough region514. For example, the obstruction plate516may be configured to reduce the open area of the plate pass through region514by 5% to 50%. As also shown, protrusions428extending over a respective blocking plate422may be spaced a part from the blocking plate422by a plate-protrusion separation distance519. The plate-protrusion separation distance519may be less than, or equal to, the protrusion separation distance500. The plate-protrusion separation distance519may be the same or different for each protrusion428.

The plate separation distance508may be the same within the restricting region418. Alternatively, the plate separation distance508may be different within the restricting region418. The plate length510may be the same for each blocking plate422within the restricting region418. Alternatively, the plate length510for at least one blocking plate422may be different from the plate length510of at least one other blocking plate422. For example, the plate length510, for each blocking plate422, may decrease with increasing distance from a center of the suction motor air duct300. The plate width512may be the same for each blocking plate422within the restricting region418. Alternatively, the plate width512for at least one blocking plate422may be different from the plate width512for at least one other blocking plate422. For example, the plate width512, for each blocking plate422, may decrease with increasing distance from a center of the suction motor air duct300.

As shown, each blocking plate422extends from the duct bottom portion421of the suction motor air duct300at a plate angle θ. The plate angle θ extends between the blocking side424of a respective blocking plate422and the duct bottom portion421. The plate angle θ may be a non-perpendicular angle (e.g., an acute angle). For example, the plate angle θ may be at least 45°. By way of further example, the plate angle θ may be between 45° and 90°.

The plate angle θ may be the same for each blocking plate422within the restricting region418. Alternatively, the plate angle θ for at least one blocking plate422may be different from the plate angle θ of at least one other blocking plate422. For example, the plate angle θ corresponding to each blocking plate422may increase with increasing distance from a center of the suction motor air duct300. In some instances, the obstruction plate516may extend from the duct bottom portion421at the plate angle θ.

FIG.6shows a cross-sectional view of the suction motor air duct300and dust cup304with the suction motor302removed therefrom for clarity of illustration. As shown, each blocking plate422extends such that a top surface602of each blocking plate422is proximate to the plenum408. For example, the top surface602may be substantially co-planar with at least one surface forming a bottom portion604of the plenum408. When the top surface602is arcuate, the top surface602of the blocking plate422may be considered to be co-planar with at least a portion of the bottom portion604when the upper most portion of the blocking plate422is substantially tangent with at least one surface forming the bottom portion604of the plenum408.

The bottom portion604of the plenum408may be defined, at least in part, by one or more of the second filter medium406and/or a filter frame606within which the second filter medium406is disposed. In this instance, the top surface602of each blocking plate422may be substantially coplanar with a plane defined by the second filter medium406and/or the filter frame606.

In some instances, the size and/or shape of the plenum408may be optimized to improve airflow. For example, optimizing the size and/or shape of the plenum408may include increasing a plenum height608without increasing a size of the dust cup304. Adjusting a sizing and/or shape of the plenum408may include adjusting the filter frame606of the second filter medium406.

One example of a filter frame700disposed within the dust cup304is shown inFIG.7and another example of a filter frame800disposed within the dust cup304is shown inFIG.8.

With reference toFIG.7, the filter frame700includes one or more frame sidewalls702that define a filter cavity701. The filter cavity701includes a dirty side open end703and a clean side open end705opposite the dirty side open end703. A frame support704extends at least partially along at least one of the one or more frame sidewalls702and into the filter cavity701. As shown, the frame support704is disposed at a location closer to the dirty side open end703than the clean side open end705. The second filter medium406is disposed within the filter cavity701and contacts (e.g., is coupled to) the frame support704. As shown, the frame sidewall702extends beyond the second filter medium406and into the plenum408and below a dirty air side706of the second filter medium406and the frame support704extends along the dirty air side706of the second filter medium406.

With reference toFIG.8, the filter frame800includes one or more frame sidewalls802that define a filter cavity801. The filter cavity801includes a dirty side open end803and a clean side open end805that is opposite the dirty side open end803. A frame support804extends at least partially along at least one of the one or more frame sidewalls802and into the filter cavity801. As shown, the frame support804is disposed at a location that is closer to the clean side open end805than to the dirty side open end803. The second filter medium406is disposed within the filter cavity801and contacts (e.g., is coupled to) the frame support804. As shown, the frame support804extends from a distal end of the frame sidewall802and along a clean air side806of the second filter medium406.

The filter frame800ofFIG.8increases the plenum height608when compared to the filter frame700ofFIG.7. For example, the plenum height608inFIG.8may be approximately (e.g., within 1%, 5%, 10%, 15%, or 20% of) 1.7 mm greater than that inFIG.7. Increasing the plenum height608may result in a smoother directional transition (e.g., from a vertical direction to a horizontal direction) in airflow entering the plenum408, which may improve performance.FIG.9shows a computational fluid dynamics (CFD) analysis of a dust cup having the filter frame700andFIG.10shows a CFD analysis of a dust cup having the filter frame800ofFIG.8.FIG.11shows a performance plot of a first dust cup design having the filter frame700, the first dust cup design having the filter frame800, a second dust cup design having the filter frame700, and the second dust cup design having the filter frame800. As shown, the filter frame800can have a 3% to 4% increase in in air watts compared to filter frame700.

An example of a robotic cleaner, consistent with the present disclosure, may include a suction motor, a dust cup, and a suction motor air duct fluidly coupled to the suction motor and the dust cup, the suction motor air duct including a debris barrier having a restricting region and a guard region.

In some instances, the restricting region may include one or more blocking plates. In some instances the one or more blocking plates may extend from a bottom portion of the suction motor air duct at a plate angle. In some instances, the plate angle may be an acute angle. In some instances, the one or more blocking plates may be integrally formed from the bottom portion of the suction motor air duct. In some instances, the guard region may include a plurality of spaced apart protrusions separated by a respective protrusion passthrough region. In some instances, each protrusion passthrough region may define an open area and a combined open area of the guard region may be in a range of 500 square millimeters (mm2) to 700 mm2, the combined open area being a summation of each open area in the guard region. In some instances, the dust cup further may further include a filter medium disposed within a filter frame. In some instances, the filter frame may include one or more frame sidewalls and a frame support extending from the frame sidewall. In some instances, the frame support may extend from a distal end of at least one of the one or more frame sidewalls and along a clean air side of the filter medium. In some instances, the restricting region may include a plurality spaced apart blocking plates separated by a respective plate passthrough region. In some instances, the plate passthrough region may include an obstruction plate.

An example of a suction motor air duct, consistent with the present disclosure, may include a duct top portion, a duct bottom portion, and a debris barrier having a restricting region and a guard region, wherein the restricting region includes one or more blocking plates and the guard region includes a plurality of spaced apart protrusions separated by a respective protrusion passthrough region.

In some instances, the one or more blocking plates may extend from the duct bottom portion. In some instances, the protrusions may extend from the duct top portion in a direction of the one or more blocking plates. In some instances, the protrusions may be spaced apart from a respective one of the one or more blocking plates by a plate-protrusion separation distance. In some instances, the plate-protrusion separation distance may be less than, or equal to, a protrusion separation distance, the protrusion separation distance extending between immediately adjacent protrusions. In some instances, the one or more blocking plates may be integrally formed from the duct bottom portion. In some instances, the protrusions may be integrally formed from the duct top portion.