Separation system for vacuum cleaner

Abstract

A separation system for a vacuum cleaning appliance includes a vacuum generator; an outlet chamber extending in a first direction and defining an air outlet, where, in use, air is drawn by the vacuum generator in the first direction through the outlet chamber towards the air outlet. The system also includes an air permeable filter device separating the outlet chamber from the dirt collection chamber. An air inlet tube extending through at least a portion of the outlet chamber and including a throat portion defining a discharge opening into the dirt collection chamber; wherein the throat portion extends in a second direction transverse to the first direction. The throat portion of the air inlet tube is shaped to define a streamlined outer profile with respect to a first direction of air flow through the outlet chamber to the outlet opening. It is beneficial that the streamlined outer contour / surface of the inlet tube has the effect of improving the stationarity of the air flow through the outlet chamber to the outlet opening by reducing the flow separation of air as it flows around the inlet tube. The streamlined shape facilitates recovery of some flow energy that would typically be wasted when producing the separation flow, which has the effect of reducing the pressure drop of the separation system.

Description

Technical Field

[0001] The present invention relates to a separation system for separating dirt from an air flow, in particular in a vacuum cleaner. Background Art

[0002] Handheld vacuum cleaners and "stick vacs" are popular household machines because they are lightweight and easy to maneuver compared to larger mains-connected cylinder and upright vacuum cleaners. Practical portability is often at least partly achieved by battery-powered power, and many such machines are now bagless for convenience, allowing the collected dirt to be stored in an integrated dirt tank. Typically, handheld machines are used for frequent spot cleaning tasks, but as battery technology improves, the trend is towards longer cleaning operations. The fact that handheld vacuum cleaners have become the cleaner of choice in many households means that some users may prefer a larger dirt tank so that the cleaner can hold more dirt and debris between emptying the dirt tank. While there is pressure on the market to make handheld vacuum cleaners larger and more robust so that they can better perform the routine tasks of large, mains-connected machines, there is also an increasing demand for smaller machines that are lighter, more flexible, and especially can be lifted to high places. One example is the Dyson Micro 1.5km TM Another example of a vacuum cleaner is the Shark WandVac system.

[0003] One challenge in reducing the size of such handheld machines is to maintain the effectiveness of the separation system despite packaging constraints. Typically, there are difficulties in designing a cyclonic separation system into such a small package. It is against this background that the present invention was born. Summary of the invention

[0004] In a first aspect, the present invention provides a separation system for a vacuum cleaning appliance, comprising a vacuum generator; an outlet chamber extending in a first direction and defining an air outlet, wherein in use, air is drawn through the outlet chamber by the vacuum generator in the first direction toward the air outlet. The system also includes an air permeable filter device, separating the outlet chamber from the dirt collection chamber. An air inlet pipe extends through at least a portion of the outlet chamber and includes a throat portion defining a discharge opening into the dirt collection chamber; wherein the throat portion extends in a second direction transverse to the first direction. The throat portion of the air inlet pipe is shaped to define a streamlined outer profile with respect to the first direction of air flow through the outlet chamber to the outlet opening.

[0005] Beneficially, the streamlined outer contour / surface of the inlet tube has the effect of improving the smoothness of the airflow through the outlet chamber towards the outlet opening by reducing flow separation as the air flows around the inlet tube. The streamlined shape helps to recover some of the flow energy that would normally be wasted in producing the separated flow, thereby helping to reduce the pressure drop of the separation system.

[0006] In one example, the streamlined outer profile can be generally teardrop-shaped to define a blunt leading portion directed toward the oncoming airflow and a streamlined trailing portion directed toward the retreating airflow. The profile can also be generally elliptical. Thus, the outer profile at the throat portion location can be considered to have a first dimension aligned with a first direction and a second dimension aligned with a third direction perpendicular to the second direction, wherein the first dimension is greater than the second dimension.

[0007] The inner shape of the throat portion of the inlet pipe does not have to be the same as the outer contour. For example, the inner contour of the throat portion may be circular or elliptical, or any shape that best suits the flow inside the duct. When the inner contour is elliptical, the shape may be configured with its major axis transverse to the first direction. This provides a slightly flatter overall shape that extends across the direction of airflow and this may be beneficial to airflow.

[0008] The separation system may be constructed in a compact manner such that the dirt collection chamber also extends in the first direction. The dirt collection chamber and the outlet chamber may be parallel to each other. The two chambers may have substantially the same length, or one chamber may be longer than the other chamber.

[0009] The outer contours of the two chambers may define a generally cylindrical shape. The aspect ratio of the separation may be "tall and thin" such that the diameter of the cylindrical contour is less than 50% of the length of the output chamber along the first direction, alternatively less than 20% or even 10% of the length of the output chamber along the first direction. Furthermore, optionally, the dirt collection chamber is parallel to the outlet chamber and the throat portion of the inlet pipe may be adjacent to the outlet opening. These features allow for a slimmer and more compact packaging of the separation system, making the separation system particularly suitable for use in a lightweight handheld vacuum cleaner.

[0010] The separation system may comprise a filter sheet separating the outlet chamber from the dirt collection chamber.Preferably, the filter sheet extends along at least half the length of the chamber, and preferably greater than 60%, or 70% or 80% of the length of the chamber.

[0011] The filter sheet may comprise two parts, each part being angled relative to each other to define a ridge therebetween.The angle between the two filter sheets may be varied to vary the relative volumes of the outlet chamber and the dirt collection chamber.

[0012] The filter sheet may be configured so that it is generally V-shaped along its length, defined by two adjacent filter portions. The relative angle of the two filter portions may be varied to vary the relative volumes of the dirt collection chamber and the outlet chamber. Preferably, the air outlet is adjacent the discharge opening.

[0013] The invention also comprises a vacuum cleaning appliance comprising a handle, a user interface, a power source and a separation system as defined above.

[0014] Features described above in conjunction with the first aspect of the invention are equally applicable to the second and third aspects of the invention, and vice versa.

[0015] In another aspect, the present invention provides a separation system for a vacuum cleaning appliance, comprising a vacuum generator and an outlet chamber extending in a first direction and defining an air outlet, wherein, in use, the vacuum generator draws air through the outlet chamber into the air outlet in the first direction. The system also includes an air permeable filter arrangement that separates the outlet chamber from a dirt collection chamber. An air inlet duct extends through at least a portion of the outlet chamber and defines a discharge opening into the dirt collection chamber, wherein the inlet duct has an increasing flow area along at least a portion of its length, such that the air inlet duct defines a first flow area at an upstream position relative to the discharge opening, wherein the discharge opening defines a second flow area, wherein the second flow area is greater than the first flow area.

[0016] Advantageously, increasing the flow geometry between the first flow area and the second flow area means that the air flow rate through the inlet duct is reduced before passing through the discharge opening. In turn, this results in a reduced pressure drop across the system, as the airflow through the dirt collection chamber has reduced flow separation. Such a configuration enables a compact separation system to be provided while mitigating the reduction in separation efficiency that would otherwise be associated with a more compact separation system.

[0017] In one example, the flow area of ​​the inlet duct increases continuously from a first flow area to a second flow area. The continuous, gradual increase in flow area can avoid step changes in the internal geometry of the duct, which may otherwise increase turbulence and noise. The first flow area can be defined by a first portion of the air inlet duct extending through the outlet chamber in a first direction. The first portion can have a substantially constant flow area along its length and then increase in size to the second flow area.

[0018] The discharge opening may be defined by a second portion of the air inlet duct extending in a second direction generally transverse to the first direction. A transversely extending section of the duct is useful in a compact separation system, but it may impede air flow through the outlet chamber. The second portion may have appropriate streamline features to improve airflow through it.

[0019] A transition portion may extend between the first and second portions of the inlet duct, the transition portion may follow a curved path between a first direction of the first portion and a transverse direction of the second portion. The radius of the curved path may be configured to limit the effect on the airflow through the duct, thereby avoiding an increased pressure drop.

[0020] The second flow area may be no greater than 150%, and optionally no greater than 120%, and optionally between 100% and 120%, of the first flow area.

[0021] The separation system may be constructed in a compact manner such that the dirt collection chamber also extends in the first direction. The dirt collection chamber and the outlet chamber may be parallel to each other. The two chambers may have substantially the same length, or one chamber may be longer than the other chamber.

[0022] The outer contours of the two chambers may define a generally cylindrical shape. The aspect ratio of the split may be "tall and thin" such that the diameter of the cylindrical contour is less than 50% of the length of the output chamber in the first direction, alternatively less than 20% or even 10% of the length of the output chamber in the first direction. This makes the split system particularly suitable for use in lightweight handheld vacuum cleaners.

[0023] The filter sheet may be configured so that it is generally V-shaped along its length, defined by two adjacent filter portions. The relative angle of the two filter portions may be varied to vary the relative volumes of the dirt collection chamber and the outlet chamber. Preferably, the air outlet is adjacent the discharge opening.

[0024] The invention also comprises a vacuum cleaning appliance comprising a handle, a user interface, a power source and a separation system as defined above. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a perspective view of a handheld vacuum cleaner that may include an exemplary separation system of the present invention;

[0026] Figure 2 yes Figure 1 A schematic diagram of a vacuum cleaner in FIG. 1 showing some hidden details;

[0027] Figure 3a and 3b are a pair of views showing a separation system from different perspectives so that its features may be best understood, wherein it should be noted that the separation system shown in these views does not embody an example of the present invention;

[0028] Figure 4 yes Figure 3a and 3b A schematic diagram of the separation system shown in , showing the gas flow through the separation system;

[0029] Figure 5a and 5b It is shown that Figure 3a and 3b A pair of views similar to the separation system shown in , but illustrating the first aspect of the invention;

[0030] Figure 6a and 6b It is shown that Figure 3a and 3b A pair of views similar to the separation system shown in , but illustrating a second aspect of the invention;

[0031] Figure 7a and 7b Schematic diagram of two different separation systems for comparison, where Figure 7b Depicted from Figure 6a and 6b The separation system Figure 7a Depicted from Figure 3a and 3b separation system. DETAILED DESCRIPTION

[0032] Examples of the present invention relate to separation systems for vacuum cleaners, particularly handheld vacuum cleaners, wherein the compact construction of the separation system is particularly useful and makes the machine more efficient and ergonomic. In such a separation system, an inlet pipe entering a dirt collection chamber extends through and through at least a portion of an outlet chamber to be discharged into the dirt collection chamber. Clean air flows through the outlet chamber at high speed, through the inlet pipe, and flows to the outlet of the separation system. In addition, dirty air flows into the dirt collection chamber at high speed and is filtered by a filter device therein. The arrangement of the inlet pipe extending through the outlet chamber and the configuration of the discharge opening entering the dirt collection chamber are sources of system pressure drop, which can reduce efficiency. An embodiment of the present invention provides a separation system of this type, i.e., it constructs the inlet pipe to reduce the pressure drop of the airflow through the outlet chamber. A further example of the present invention is to construct the discharge opening of the inlet pipe into the dirt collection chamber to further improve the airflow characteristics of the system and reduce the pressure drop. The examples of the present invention described herein may be combined or may be implemented separately.

[0033] refer to Figure 1 , the vacuum cleaner 2 comprises an elongated main body 4, which is attached to a cleaning tool 5 by a detachable tube or "wand" 6. The wand 6 can be separated from the main body 4. Likewise, the cleaning tool 5 can be separated from the wand 6.

[0034] The cleaning tool 5 shown here is a motorized floor tool comprising a generally cylindrical housing 7 housing a motor-driven brush bar (not shown). The cleaning tool 5 also comprises an articulated joint 8 having a wheel arrangement 9 allowing the user to guide the cleaning tool 5 over the surface to be cleaned by controlling the twisting movement of the body 4 of the vacuum cleaner 2. Figure 1 The surface to be cleaned is not shown, but its presence is implied.

[0035] It should be noted that the type of cleaning tool 5 shown here is known and is not the focus of the present invention. Other cleaning tools may be used. For example, the vacuum cleaner 2 may be attached with a passive tool such as a crevice tool or a mattress tool instead of a conventional tool such as a mattress tool. Figure 1 The motor driven floor tool shown.

[0036] Figure 1 An overview of the general external construction of the vacuum cleaner 2 is shown, and Figure 2 The vacuum cleaner 2 is shown schematically so that its internal components can be more fully understood.

[0037] In general, the vacuum cleaner includes a control system 10, a power system 12 and a separation system 14, wherein the separation system 14 includes an airflow generator 16 and a dirt separator 18. The power system 12 in this example includes a battery pack 20. Although the power system can also be implemented by a power cable, for portability considerations, batteries are preferred in this example. The control system 10 is connected to the power system 12 and controls the application of power to the airflow generator 16 under the command of a user interface 22. The user interface 22 can be a simple on-off touch switch, or it can be a more complex interface, such as including a touch screen. The user interface provides the user with a means to turn the vacuum cleaner on and off, and can also provide options for other functions, such as displaying battery life, filter life, operating time, etc.

[0038] The airflow generator 16 includes an electric motor 24, which is powered by a battery pack 20 under the control of the control system 10. A fan 26 connected to the electric motor 24 generates an airflow through the machine, which flows from the cleaning tool 6, through the dirt separator 18, through the airflow generator 16, and out of the air outlet 28. A filter (not shown) may be provided at the air outlet to filter fine dirt particles in the airflow flowing out of the machine. The filter may be a HEPA filter. The filter may be removable.

[0039] The air flow is conveyed from the cleaning tool 5 to the dirt separator 18 through an inlet duct 30. The inlet duct 30 may define an external surface of the vacuum cleaner 2, or it may be an internal duct enclosed by a housing, as shown here.

[0040] The air flow is conveyed from the dirt separator 18 to the air flow generator 16 via an outlet duct 32. Again, the outlet duct 32 may define an external surface of the vacuum cleaner 2, or it may be located inside an external machine housing, as shown here.

[0041] like Figure 1 and Figure 2 As shown, the vacuum cleaner 2 has a substantially linear construction and extends along a machine axis X. The outer contour of the vacuum cleaner is substantially cylindrical around the machine axis X and has a substantially constant lateral dimension between 35 mm and 50 mm. Preferably, the maximum lateral dimension along the length of the vacuum cleaner is 38 mm. This gives the vacuum cleaner 2 a very compact overall construction and a low mass, thereby improving the ergonomics of the machine.

[0042] exist Figure 2 In FIG. 1 , the dirt separator 18 is shown in schematic form. However, Figure 3a , 3b and Figure 4 An example of a dirt separator 18 that may be used is shown. This example of a dirt separator is not central to the present invention but is described here to provide context for examples of the present invention that will be described later. The dirt separator in this figure will be referenced '40'.

[0043] The dirt separator 40 has a generally cylindrical shape and defines two main chambers arranged adjacent to each other. These chambers are elongated but relatively narrow, which provides an elongated shape that helps maintain a narrow outer diameter of the vacuum cleaner 2. The first chamber is a dirt collection chamber 42, into which air laden with dirt and debris flows for cleaning. The second chamber is an outlet chamber 44. From the dirt collection chamber 42, air flows through a filter device 46 into the outlet chamber 44. The filter device 46 in this example separates the dirt collection chamber 42 from the outlet chamber 44. The air flows out of the outlet chamber 44 through the outlet duct 32.

[0044] It can be seen from the figure that, especially from Figure 4 As can be seen in Figure 4 , the dirt collection chamber 42 and the outlet chamber 44 extend along a separator axis Y. The axis Y may coexist with or may be displaced from the machine axis X. In this example, the dirt collection chamber 42 and the outlet chamber 44 are approximately the same length end to end, but this is not required.

[0045] When considered in a plane perpendicular to the axis Y, the dirt collection chamber 42 and the outlet chamber 44 have different respective cross-sectional areas. Figure 4 It will be appreciated that the dirt collection chamber 44 and the outlet chamber 44 are defined by a common outer wall 50. In this example, the outer wall 50 is cylindrical.

[0046] The filter arrangement 46 extends through the interior defined by the outer wall 50 and thereby divides the interior into a dirt collection chamber 42 and an outlet chamber 44 .

[0047] The filter device 46 is sheet-like or planar in form and extends between two regions on the outer wall 50. In one example, the filter device 46 can be a pleated sheet, which provides a larger surface area for effective filtering. Therefore, the filter device 46 here is a surface filter medium that is pleated to increase its surface area. However, it is contemplated that other forms of filter media may also be acceptable for use, such as depth-based filter media. The filter medium may also be a mesh, such as a plastic mesh or a metal mesh.

[0048] In this example, the filter device 46 has two sections 46a, 46b. The first filter section 46a extends between a first area on the outer wall 50 defined by a first filter support 52 and a second filter support 54 with a center. The second filter section 46b extends between a second area on the outer wall defined by a third filter support 56 and a center filter support 54. The first and third filter supports 52, 56 can be any suitable structure to support the linear edges of the filter device 46. For example, they take the form of a track, for example made of a polymer material, which extends along the outer wall 50 and defines a groove to accommodate the edge of the corresponding filter section.

[0049] The central support 54 may be defined by a suitable columnar structure extending from the bottom to or near the top of the dirt separator 18 and suitably configured to support the area where the first filter section 46a meets the second filter section 46b.

[0050] Thus, in planar cross-section, the filter device 46 defines a V-shape with an apex located at the center support 54. Thus, the apex and the center support act as the spine of the filter device 46. In some examples, the filter sections 46a, 46b may be separate filter members, or they may define a single sheet that is longitudinally bent at the apex. Although the center support 54 may be omitted, it is currently preferred to provide robustness and rigidity to the filter device 46. The filter device 46 may be configured to be detachable from the dirt separator 18.

[0051] Presently, it is contemplated that filter device 46 includes a filter support or frame 58 that supports filter sections 46a, 46b. Filter frame 58 may be embodied as a rigid panel, such as made of a plastic material, that holds relatively flexible filter material inside outer wall 50 in tension.

[0052] Although not shown in the figures, the dirt collection chamber 42 can be configured to be emptied. This can be achieved in a variety of ways. For example, a portion of the outer wall 50 can be removable (e.g., hinged) to allow access to the interior so that dirt can be removed from the chamber 42. Other methods are also possible.

[0053] The airflow enters the dirt collection chamber 42 through an inlet pipe 60 which is an extension of the inlet conduit 30 extending from the cleaning tool 5. The inlet pipe 60 extends through the outlet chamber 44 and in this example it extends in a direction parallel to the axis Y of the dirt separator 18.

[0054] The inlet pipe 60 in this example extends from the lower end of the outlet chamber 42 toward the upper end of the outlet chamber 42. It should be noted that the terms "lower" and "upper" are in the context of the orientation of the figure. Towards its upper end, the inlet pipe 60 turns about 90 degrees and extends toward the dirt collection chamber 42. The lower portion 61 of the inlet pipe 60 is substantially linear and extends in the longitudinal direction of the outlet chamber 42. The interior of the inlet pipe 60 opens into the dirt collection chamber 42, thereby forming a discharge opening 62.

[0055] pass Figure 4 The air flow through the dirt separator 18 can be understood. When the airflow generator 16 is activated, a relative vacuum is created at the outlet duct 32 of the dirt separator 18. As a result, relatively clean air is drawn from the outlet chamber 44. In response, dirt-laden air is drawn into the dirt collection chamber 42 through the inlet tube 60 and the discharge opening 62. The dirty air first flows through the lower portion 61 of the inlet tube 60, then turns 90 degrees and enters the dirt collection chamber 42 at the discharge opening 62. The air flow through the inlet tube 60 is shown as arrow A.

[0056] At this point it should be understood that the airflow must turn another 90 degrees before it can flow into the dirt collection chamber 42. To aid in redirection, a flow guide 64 is provided in this example. The flow guide 64 may be a separate component located within the dirt collection chamber 42. Alternatively, the flow guide 64 may be defined by the upper surface of the dirt collection chamber 42. The air flow through the dirt collection chamber 42 is shown as arrow B.

[0057] The air flows downwardly through the dirt collection chamber 42 and through the filter means 46 into the outlet chamber 44. This airflow is indicated by arrows C. The air is then drawn upwardly through the outlet chamber 42 towards the outlet duct 32 in a direction parallel to the separator axis Y as indicated by arrows D.

[0058] At this point it should be understood that dirty air enters the dirt separator 18 via an inlet duct 60 which extends through a lower wall (in the orientation of the drawing) of the dirt collector 18 at the end of the dirt separator 18 opposite the outlet conduit 32 .

[0059] The advantage is that Figure 3a , 3b The construction of the dirt separator 18 shown in Figures 4 and 5 has a compact outer profile, which makes it particularly suitable for use in hand-held vacuum cleaning appliances, in which it is desirable to have a relatively narrow outer profile, which helps to reduce the mass of the machine. Specifically, in this example, the vertical 'height' (i.e. the length along the first direction) of the inner chamber 42, 44 of the dirt separator 18 is much greater than the lateral 'width' (i.e. its diameter) of the dirt separator 18. Preferably, the height is about five times its width / diameter or, in other words, the width / diameter is about 20% or less of the height of the dirt separator. This can be considered to provide an aspect ratio between the height of the chamber 42, 44 and the width of the dirt separator 18 of greater than 1:5, up to about 1:10.

[0060] However, while a compact arrangement is ideal, it is a challenge to keep the pressure drop across the separator as low as possible in order to maximize the suction power available to the floor tool. Figure 4 It can be seen that the airflow entering the dirt collection chamber 42 from the inlet pipe 60 must turn 180 degrees to pass through the filter device 46. This drastic change in airflow direction creates resistance to the airflow, which is a factor that causes the pressure drop across the dirt separator 18. In addition, the change in direction and the inherent geometry will cause turbulence, as shown in FIG. Figure 4 As shown in the air vortex in FIG. 7 , the area marked as 70 can be regarded as a “flow separation area”.

[0061] Another factor that increases flow turbulence is the configuration of the inlet tube 60 within the outlet chamber 44, and in particular the manner in which a portion of the inlet tube 60 extends perpendicular to the flow of air within the outlet chamber 44. Note that as shown, the inlet tube 60 is circular in cross-section, which is a blunt body to the airflow and tends to create excessive turbulence, thereby increasing the pressure drop through the entire system.

[0062] Figure 5a and 5b An example of a dirt separator is shown which solves some of the problems mentioned above. Figure 6a and 6b Another example of a dirt separator is shown which solves some of the above problems. In these figures, the overall construction of the dirt separator is the same as described above and in Figure 3a , 3b and Figure 4 There are many similarities between the dirt separator 40 shown in FIG. Therefore, the same reference numerals will be used to refer to the same or corresponding features.

[0063] First reference Figure 5a and 5bIt can be understood that the dirt separator 40 has Figure 3a , 3b 4. Therefore, for the sake of brevity, only the differences are described here. Note that the construction of the inlet pipe and discharge outlet is different from the equivalent features in the previous figures.

[0064] like Figure 5a and 5b As shown, the inlet pipe 60 extends through the outlet chamber 44 in a direction parallel to the separator axis Y, in the same manner as in the previous example. More specifically, the first portion 61 of the inlet pipe 60 extends in a first direction aligned with the separator axis Y. The first portion 61 then transitions to a second portion or "throat" portion 72, which extends transversely to the separator axis Y. More specifically, the throat portion 72 extends perpendicular to the separator axis Y, although strict perpendicularity is not required. The throat portion 72 defines a discharge opening 74 leading to the dirt collection chamber 42. The discharge opening 74 is located upstream of the filter medium of the filter device 46. It is noteworthy that in this example, the discharge opening 74 is defined in the surface or wall of the filter frame 58, which separates the dirt collection chamber 42 from the outlet chamber 44.

[0065] Through research especially Figure 5b It will be appreciated that the cross-sectional area of ​​the inlet pipe 60, when considered along the direction of gas flow, is different between the discharge opening 74 and the region of the inlet pipe 60 upstream of the discharge opening 74. This can be understood from the two descriptions of the pipe "flow area", which are shown as a first flow area 76 and a second flow area 78. The first flow area 76 is taken from the portion of the inlet pipe 60 near the inlet end of the outlet chamber 44. At this point, the inlet pipe 60 has a constant flow area along a portion of its length. Here, the constant flow area section extends about 40% of the length of the outlet chamber 44 along the separator axis Y. However, it is conceivable that the constant flow area portion may extend between 20% and 50% of the length of the outlet chamber 44. In this example, the first flow area is circular, as shown by the orthogonal dimensions marked D1 and D2. Therefore, at this point, the inlet pipe 60 has a circular profile.

[0066] This is similar to Figure 5b The second flow area 78 of the discharge opening 74 is shown for comparison, having dimensions D3 and D4. It can be seen that the second flow area 78 is larger than the first flow area 76. In some examples, the second flow area can be between 50% and 300% larger than the first flow area, and preferably less than 150% larger, although the exact value will depend on size packaging constraints. Preferably, the second flow area is approximately 100% to 120% larger than the first flow area.

[0067] The second flow area 78 can be circular, but in this example it is shown as being generally elliptical or oval. The dimensions D3 and D4 of the second flow area 78 are greater than the dimensions D1 and D2 of the first flow area 76. In addition, the dimensions D3 and D4 are not equal. As shown, the lateral dimension D3 is greater than the longitudinal dimension D4.

[0068] In order to provide a smoother flow of air through the inlet duct 60 between the first flow area 76 and the second flow area 78, in this example, the inlet duct 60 has a transition portion 80 between the first portion 61 and the throat portion 72. It should be understood that the transition portion 80 has a gradually increasing flow area along its length. This continuously increasing flow area avoids excessive flow turbulence in the airflow by reducing the air velocity, thereby avoiding causing a pressure drop. Preferably, the gradual increase in flow area means that there is no sharp step or size change along the length of the inlet duct between the first portion 61 and the discharge opening 74.

[0069] The increased flow area along the inlet tube 60 acts to slow the velocity of the airflow before it exits the discharge opening 74 into the dirt collection chamber 74. This has the effect of reducing the circulation of the airflow as it enters the dirt collection chamber 42 (eg, Figure 4 70 to demonstrate this problem) and helps to minimize the size of the flow separation bubbles in region 70, thereby helping to reduce turbulence entering the dirt collection chamber 42.

[0070] Now go to Figure 6a and 6b The example dirt separator shown in FIG. 1 , it should be noted that it has many common features with the example dirt separator described above. Therefore, for the sake of brevity, only the differences are described here.

[0071] The dirt separator 40 in this example of the invention comprises a dirt collection chamber 42 and an outlet chamber 44, as in the previous examples. Furthermore, an inlet pipe 60 extends through the outlet chamber 44 in a first direction (ie in line with the separator axis Y).

[0072] The inlet tube 60 extends longitudinally through the outlet chamber 44. The inlet tube 60 has a circular outlet profile at the first portion 61 and then widens or tapers outwardly as it extends upwardly through the transition portion 80 toward the upper end of the inlet tube 60. It is worth noting that although the inlet tube 60 tapers outwardly in this example, it can also maintain a circular outer profile as the first portion 61 of the inlet tube 60.

[0073] At its upper end, the inlet tube 60 turns a 90 degree angle, at which point it extends through a throat portion 72 and defines a discharge opening 74 into the dirt collection chamber 42 . Figure 6aThe illustration in shows the internal shape of the discharge opening 74. It can be seen that the discharge opening 74 in this example has a slightly elliptical shape, which facilitates airflow through the throat portion 72, as discussed in the previous example. Here, the generally elliptical inner profile is shaped so that its major axis is transverse to the first direction. In this example, a circular inner profile is also acceptable. However, an inner profile as described in the previous example is also acceptable.

[0074] from Figure 6a As can be clearly seen from the illustration in FIG. 7 , the outer contour of the throat portion 72 near the discharge opening 74 is different from the inner contour of the throat portion 72. Conventionally, a tube has a wall thickness that is substantially constant over its entire length. Even if the internal shape of the tube changes along the length of the tube, the wall thickness will remain substantially constant.

[0075] However, in this example of the invention, it will be appreciated that the thickness of the wall of the inlet pipe 60, and in particular the thickness of the wall of the throat portion 72 of the inlet pipe 60, varies significantly along the length of the inlet pipe 60. Thus, at least in the region of the discharge opening 74, the outer profile or shape of the inlet pipe 60 is significantly different from the inner profile of the inlet pipe 60.

[0076] The purpose of changing the outer profile of the inlet tube 60 in this example is to provide the inlet tube 60 with a streamlined outer profile in the first direction of airflow through the outlet chamber 44. This improves the smoothness of airflow through the outlet chamber 44 to the outlet opening 32 by reducing flow separation as the air flows around the inlet tube 60. The streamlined shape helps to recover some of the flow energy that would normally be wasted when generating a separated flow, thereby having the effect of reducing the pressure drop of the separation system.

[0077] refer to Figure 7b To understand this more fully, Figure 7b Shows Figure 6a and 6b Schematic diagram of a dirt separator shown in . Note that for clarity and illustration purposes, Figure 7b The shape of the inlet pipe 60 shown in FIG. 1 has been exaggerated. For comparison, Figure 7a The air flow through the dirt separator 18 is shown, which is connected to the Figure 3a and 3b The dirt separator 18 shown in FIG.

[0078] Please note, Figure 7a and 7b Only approximately half of the dirt separator is shown so that the airflow through the outlet chamber 44 can be fully appreciated. Figure 7a The construction of the dirt separator 18 in does not form part of the present invention.

[0079] Will Figure 7b and Figure 7a By comparison, it can be seen that the throat portion 80 of the inlet duct 60 has a streamlined feature 90 that extends the outer profile of the inlet duct 60 in the direction of the downstream airflow. Thus, the throat portion 72 of the inlet duct 60 is provided with a streamlined tail section 92 in the direction of the airflow through the outlet chamber 44. The streamlined feature 90 is in the form of a ridge, protuberance or projection that shapes the downstream portion of the inlet duct 60 to reduce flow separation behind the duct. Due to the streamlined tail section 92 of the inlet duct 60, air flows upward through the outlet chamber 44 and then around the throat portion 72, which is more Figure 7a The situation with the configuration shown in is much more stable.

[0080] The other side 96 of the throat portion 72 of the inlet duct 60 (i.e., the leading section when considered in the direction of the airflow) presents a blunt body to the airflow compared to the streamlined tail section 92. When the blunt leading section 96 is considered together with the streamlined tail section 92, it can be appreciated that the combined effect is to define a teardrop-like shape in the airflow, which is a more efficient aerodynamic shape that provides less resistance to the airflow. Figure 6a The teardrop shape can be seen in the inset detail.

[0081] The streamlined tail section 92 may be a solid extension of the throat portion 80 of the inlet pipe 60, such as Figure 6a and Figure 7b As shown, it can also be achieved with a hollow shell. Either method can achieve airflow benefits. Although a solid streamlined tail section 92 can increase the overall mass of the vacuum cleaner, it is believed that it is simpler to manufacture. In contrast, a hollow tail section 92 can achieve some slight weight advantages, but it may be more complicated to manufacture.

[0082] It should be noted that an elliptical or teardrop shape is not required, although it is beneficial for airflow. Therefore, in principle, the outer profile of the throat portion 72 can have such a configuration that its size in the first direction (i.e., the direction of airflow through the outlet chamber 44) is greater than the size of the throat portion 72 in the third direction (i.e., the direction through the throat portion 72). In other words, the streamlined tail section 92 of the inlet pipe 60 has an aspect ratio such that its height is greater than its width in the direction of airflow. Preferably, the aspect ratio of the streamlined tail section 72 should be greater than 1:1.2 but less than 1:2.

[0083] The first, second and third directions are as follows Figure 7b . Note that for clarity, a third direction is shown here on the Z axis, but it should be understood to point into the page. It is understood that the third direction is perpendicular to the second direction.

[0084] refer to Figure 7aAs can be appreciated, the air flow through the outlet chamber 44 (as indicated by arrow D) passes along and around the inlet tube 60 as the air advances toward the outlet duct 32. The throat portion 72 of the inlet tube 60 has a circular outer contour, presenting a blunt body to the air flow, thereby acting as an obstruction. As a result, the air flow above the throat portion 72 tends to separate at the trailing side of the throat portion 80, which can result in Figure 7a The separation zone 98 is shown in FIG. This is a potentially significant source of pressure drop in the dirt separator 18.

[0085] However, by observing Figure 7b It can be seen that the streamlined tail section 92 of the throat portion 72 means that air flows more smoothly over and around the inlet pipe 60, which means that the airflow tends to remain attached to the bulbous streamlined tail section 92, which reduces pressure drops and improves the efficiency of the dirt separator 40.

[0086] It should be noted that the features of the first example of the present invention can be appropriately combined with the features of the second example of the present invention unless otherwise specified.

[0087] In one embodiment, the separation system of the vacuum cleaning appliance may be equipped with the following provisions:

[0088] 1. A separation system for a vacuum cleaning appliance, comprising:

[0089] Vacuum generator;

[0090] an outlet chamber extending in a first direction and defining an air outlet, wherein, in use, air is drawn by the vacuum generator through the outlet chamber in the first direction towards the air outlet,

[0091] an air permeable filter arrangement separating the outlet chamber from the dirt collection chamber;

[0092] an air inlet tube extending through at least a portion of the outlet chamber and defining a discharge opening into the dirt collection chamber, wherein the inlet tube has an increasing flow area along at least a portion of its length such that the air inlet tube defines a first flow area at an upstream position relative to the discharge opening, wherein the discharge opening defines a second flow area, wherein the second flow area is greater than the first flow area.

[0093] 2. A separation system according to clause 1, wherein the flow area of ​​the air inlet pipe increases continuously from a first flow area to a second flow area.

[0094] 3. A separation system according to clause 1 or 2, wherein the first flow area is defined by a first portion of the air inlet duct extending through the outlet chamber in a first direction.

[0095] 4. A separation system according to clause 3, wherein the first portion of the air inlet duct extends a length in the first direction and has a substantially constant flow area along its length.

[0096] 5. A separation system according to any of the preceding clauses, wherein the discharge opening is defined by a second portion of the air inlet duct, the second portion extending in a second direction substantially transverse to the first direction.

[0097] 6. A separation system according to clause 5, when referring to clause 4, wherein the air inlet duct includes a transition portion extending between the first portion and the second portion.

[0098] 7. The separation system of clause 6, wherein the transition portion defines a flow area that increases along its length.

[0099] 8. A separation system according to clause 7, wherein the flow area of ​​the transition section increases continuously along its length.

[0100] 9. A separation system according to any one of clauses 5 to 8, when referring to clause 4, wherein the transition portion has at least a portion that is curved between the first portion and the second portion.

[0101] 10. A separation system according to any of the preceding clauses, wherein the second flow area is not more than 150% of the first flow area, and preferably not more than 120% of the first flow area.

[0102] 11. A separation system according to any of the preceding clauses, wherein the dirt collection chamber extends in a first direction.

[0103] 12. A separation system according to clause 11, wherein the dirt collection chamber is parallel to the outlet chamber.

[0104] 13. A separation system according to any of the preceding clauses, wherein the dirt collection chamber and the outlet chamber together define a cylindrical profile.

[0105] 14. Separation system according to clause 13, wherein the diameter of the cylindrical profile is less than 50% of the length of the output chamber along the first direction.

[0106] 15. The separation system according to clause 13, wherein the diameter of the cylindrical profile is less than 20% of the length of the output chamber along the first direction.

[0107] 16. Separation system according to clause 14 or 15, wherein the diameter of the cylindrical profile is greater than 10% of the length of the output chamber in the first direction.

[0108] 17. A separation system according to any of the preceding clauses, wherein the filter means comprises filter sheets extending in a first direction.

[0109] 18. The separation system of clause 17, wherein the filter plate has a first portion and a second portion, wherein the first portion is angled with respect to the second portion such that a vertex is defined between the first portion and the second portion.

[0110] 19. The separation system of clause 18, wherein the apex is oriented to extend in a first direction.

[0111] 20. A separation system according to any of the preceding clauses, wherein the air outlet is adjacent to the discharge opening.

[0112] 21. A separation system according to any of the preceding clauses, wherein the air outlet extends in a first direction.

[0113] 22. A vacuum cleaning appliance comprising a handle, a user interface, a power source and a separation system as defined in clauses 1 to 21.

[0114] 23. A vacuum cleaning appliance according to clause 22, wherein the handle and power source are contained within an elongate housing.

[0115] 24. A vacuum cleaning appliance according to clause 22 or 23, wherein the elongate housing is oriented to extend along the first direction of the separation system.

[0116] Some variations of the specific examples of the present invention shown in the drawings and described above have been described. However, it will be appreciated by those skilled in the art that other variations and modifications may be made to these specific examples without departing from the scope of the present invention as defined by the claims.

Claims

1. A separation system for a vacuum cleaning appliance, comprising: Vacuum generator; an outlet chamber extending in a first direction and defining an air outlet, wherein, in use, air is drawn through the outlet chamber by the vacuum generator in the first direction towards the air outlet; an air permeable filter arrangement separating said outlet chamber from a dirt collection chamber; an air inlet conduit extending through at least a portion of the outlet chamber, and wherein the air inlet conduit includes a throat portion defining a discharge opening into the dirt collection chamber; wherein the throat portion extends in a second direction transverse to the first direction; and Wherein the throat portion of the air inlet duct is shaped to define a streamlined outer profile with respect to the first direction of air flow through the outlet chamber to the outlet opening.

2. The separation system of claim 1, wherein the outer profile of the throat portion comprises a blunt leading portion and a streamlined trailing portion with respect to the direction of air flow through the outlet chamber.

3. The separation system of claim 1 or 2, wherein the outer profile of the throat portion has a first dimension aligned with a first direction and a second dimension aligned with a third direction perpendicular to the second direction, wherein the first dimension is greater than the second dimension.

4. The separation system of claim 3, wherein the outer contour of the throat portion is generally elliptical.

5. The separation system of any one of the preceding claims, wherein the throat portion defines an inner contour that is different from the outer contour. The separation system of claim 5 , wherein the inner contour of the throat portion is circular.

7. The separation system of claim 5, wherein the inner contour of the throat portion is generally elliptical.

8. The separation system of claim 7, wherein the generally elliptical inner profile is shaped such that its major axis is transverse to the first direction.

9. A separation system according to any one of the preceding claims, wherein the dirt collection chamber extends in the first direction.

10. The separation system according to any one of the preceding claims, wherein the dirt collection chamber is parallel to the outlet chamber.

11. The separation system of any one of the preceding claims, wherein the throat portion of the inlet pipe is adjacent to the outlet opening.

12. A separation system according to any one of the preceding claims, wherein the dirt collection chamber and the outlet chamber together define a cylindrical profile.

13. The separation system of claim 12, wherein a diameter of the cylindrical profile is less than 50% of a length of the output chamber along the first direction.

14. The separation system of claim 12, wherein a diameter of the cylindrical profile is less than 20% of a length of the output chamber along the first direction.

15. The separation system of claim 13 or 14, wherein the diameter of the cylindrical profile is greater than 10% of the length of the output chamber in the first direction.

16. A separation system according to any one of the preceding claims, wherein the filter means comprises filter sheets extending in the first direction.

17. The separation system of claim 16, wherein the filter sheet has a first portion and a second portion, wherein the first portion is angled with respect to the second portion such that a ridge is defined between the first portion and the second portion.

18. The separation system of claim 17, wherein the ridges are oriented to extend along the first direction.

19. A vacuum cleaning appliance comprising a handle, a user interface, a power source and a separation system as defined in claims 1 to 18.

20. The vacuum cleaning appliance of claim 19, wherein the handle and the power source are contained within an elongate housing.

21. The vacuum cleaning appliance of claim 20, wherein the elongate housing is oriented to extend along the first direction of the separation system.

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