Dirt separator for vacuum cleaner

Abstract

A dirt separator for a vacuum cleaner includes a chamber having an inlet through which dirt-laden fluid enters the chamber and an outlet through which cleaned fluid exits the chamber. A coil at the outlet rotates about the axis of rotation and includes an aperture through which the cleaned fluid passes. The dirt-laden fluid enters the chamber along a flow axis intersecting the disc.

Description

[0001] This application is a divisional application of the application for patent with application number 201880052107.7, application date 27 July 2018, and title "Dirt separator for a vacuum cleaner". TECHNICAL FIELD

[0002] The present invention relates to a dirt separator for a vacuum cleaner. BACKGROUND

[0003] Dirt separators for vacuum cleaners can include a perforated bag or a cyclonic separator. However, both types of separator have their disadvantages. For example, the holes of a bag quickly become clogged with dirt during use, while cyclonic separators can consume a high pressure. SUMMARY

[0004] The present invention provides a dirt separator for a vacuum cleaner, the dirt separator comprising: a chamber having an inlet through which dirt-laden fluid enters the chamber and an outlet through which cleaned fluid exits the chamber; and a disc located at the outlet, the disc being arranged to rotate about an axis of rotation and comprising apertures through which cleaned fluid passes, wherein the dirt-laden fluid enters the chamber along an axis of flow that intersects the disc.

[0005] Accordingly, the dirt-laden fluid entering the chamber is directed to the rotating disc. Upon contacting the disc, the disc applies a tangential force to the dirt-laden fluid, causing the dirt-laden fluid to swirl. As the dirt-laden fluid moves radially outwards, the tangential force applied by the disc increases. The fluid then draws through the apertures in the disc, while the dirt, due to its greater inertia, continues to move outwards and collects at the bottom of the chamber.

[0006] The dirt separator of the present application has advantages over conventional separators such as a porous bag or a cyclonic separator. For example, during use, the pores of a bag can quickly become clogged with dust. This then reduces the suction available at the cleaner head. With the dirt separator of the present application, rotation of the disk helps to ensure that the pores in the disk generally remain clean. As a result, a significant reduction in suction can not be observed during use. Cyclonic separators of vacuum cleaners typically include two or more stages of separation. The first stage typically includes a single, larger cyclone chamber for removing coarse dirt, while the second stage includes a plurality of smaller cyclone chambers for removing fine dirt. As a result, the overall size of the cyclonic separator can be large. Another difficulty with cyclonic separators is that they typically require high fluid velocities to achieve high separation efficiencies. In addition, fluid moving through a cyclonic separator generally follows a relatively long path from the inlet to the outlet. As a result, the pressure drop associated with a cyclonic separator can be high. With the dirt separator of the present application, relatively high separation efficiencies can be achieved in a more compact manner. In particular, the dirt separator can include a single stage having a single chamber. Furthermore, separation occurs primarily due to the angular momentum imparted to the dirt by the rotating disk. As a result, relatively high separation efficiencies can be achieved at relatively low fluid velocities. In addition, the path taken by fluid moving from the inlet to the outlet of the chamber is relatively short. As a result, the pressure drop across the dirt separator can be less than the pressure drop across a cyclonic separator having the same separation efficiency.

[0007] It is known to provide a rotating disk within a dirt separator of a vacuum cleaner. However, there has been a bias that a dirt separator must include a cyclone chamber to separate dirt from fluid. The disk then merely acts as an auxiliary filter to clean residual dirt from the fluid as it exits the cyclone chamber. There has also been a bias that the rotating disk must be protected from large amounts of dirt entering the cyclone chamber. As a result, dirt-laden fluid is introduced into the cyclone chamber in a manner that avoids direct impingement on the disk. The present application is based, in part, on the recognition that dirt separation can be achieved with a rotating disk without the need for a cyclone chamber. The present application is further based on the recognition that effective dirt separation can be achieved by introducing dirt-laden fluid into the chamber in a direction that is directly towards the disk. By directing dirt-laden fluid onto the disk, the dirt experiences a relatively high tangential force as it contacts the rotating disk. The dirt within the fluid is then thrown radially outward, while the fluid passes axially through the pores in the disk. As a result, effective dirt separation can be achieved without the need for cyclonic flow.

[0008] The flow axis can intersect the center of the disc. As a result, the dirt-laden fluid entering the chamber is directed to the center of the disc. An advantage of this is that the flow of the dirt-laden fluid over the disc surface can be more evenly distributed. In contrast, if the dirt-laden fluid is directed eccentrically at the disc, it is likely that the fluid will be distributed unevenly. The axial velocity of the fluid moving through the hole is then increased at those areas of the disc where the load is heaviest, resulting in a reduction in separation efficiency. Additionally, the dirt separated from the fluid can accumulate unevenly within the chamber, thereby compromising the capacity of the dirt separator. Re-entrainment of dirt can also increase, resulting in further reduction in separation efficiency. Another disadvantage of directing the dirt-laden fluid eccentrically is that the disc can be subjected to uneven structural loading. The resulting imbalance can cause increased vibration and noise, and / or can reduce the useful life of any bearings used to support the rotating disc.

[0009] The flow axis can be parallel to the axis of rotation. As a result, the angle of rotation required for the dirt-laden fluid to move radially over the surface of the disc is the same in all radial directions. Therefore, the flow of the dirt-laden fluid over the surface of the disc can be more evenly distributed.

[0010] The dirt separated from the dirt-laden fluid can accumulate at the bottom of the chamber and progressively fill in a direction towards the top of the chamber. The outlet can then be located at or near the top of the chamber, and the bottom of the chamber can be axially spaced from the top of the chamber. By locating the outlet at or near the top of the chamber, the disc can be kept free of the separated dirt accumulating within the chamber. As a result, efficient separation can be maintained as the chamber fills with dirt. The bottom of the chamber is axially spaced from the top of the chamber (i.e. in a direction parallel to the axis of rotation). An advantage of this is that dirt and fluid thrown radially outward by the disc are less likely to interfere with the dirt accumulating at the bottom of the chamber. Additionally, any vortices within the chamber are likely to move around the chamber rather than up and down the chamber. As a result, re-entrainment of the dirt accumulating in the chamber can be reduced, thereby improving separation efficiency.

[0011] The inlet is defined by the end of the inlet duct extending upwardly from the bottom of the chamber. When the dirt separator is used in a stick or upright vacuum cleaner, the cleaner head is typically located below the dirt separator. By extending the inlet duct upwardly from the bottom of the dirt separator, the duct between the cleaner head and the dirt separator can take a less convoluted path, thereby reducing pressure loss. For a canister vacuum cleaner, the dirt separator can be mounted on the base such that the bottom of the dirt separator is pointing towards the front of the base. The duct responsible for carrying fluid from the cleaner head to the dirt separator can then be used to steer the vacuum cleaner. In particular, the duct can be used to lift the front of the base, thereby making it easier to pull the base forwards or to steer the base to the left or right.

[0012] The inlet can be defined by an end of an inlet duct, and the chamber can surround the inlet duct. That is, the chamber can surround the inlet duct along the entire length of the inlet duct extending within the chamber. As a result, dirt is less likely to become trapped between the inlet duct and the surrounding wall of the chamber.

[0013] The inlet can be defined by an end of an inlet duct, the inlet duct extending through a wall of the chamber, and the opposite end of the inlet duct can be attached to a different accessory of the vacuum cleaner. In particular, the inlet duct can be attached to a different accessory tool of the vacuum cleaner. By providing an inlet duct that can be directly attached to a different accessory, a relatively short path can be provided between the different accessory and the dirt separator. As a result, pressure losses can be reduced.

[0014] The inlet can be defined by an end of an inlet duct extending linearly within the chamber. This has the advantage that the dirt-laden fluid moves through the inlet duct along a straight path, and therefore pressure losses can be reduced.

[0015] The separation distance between the inlet and the disc can play an important role in achieving efficient separation. As the separation distance increases, the radial velocity of the dirt-laden fluid at the apertures can decrease, and therefore more dirt can be carried through the apertures by the fluid. Therefore, advantageously, the separation distance between the centre of the inlet and the centre of the disc is no greater than the diameter of the inlet. This helps to promote efficient separation, whilst providing sufficient space for dirt to pass between the inlet and the disc.

[0016] The diameter of the disc can be greater than the diameter of the inlet. This then has at least two benefits. Firstly, a relatively large total open area can be obtained for the disc. Indeed, the total open area of the disc can be greater than the total open area of the inlet. By increasing the total open area of the disc, the axial velocity of the fluid moving through the apertures can decrease. As a result, less dirt is carried through the apertures by the fluid, and therefore an increase in separation efficiency can be observed. Additionally, by increasing the total open area of the disc, a reduction in the pressure drop across the dirt separator can be achieved. Secondly, by having a relatively large disc, a relatively high tangential velocity can be achieved by the disc. As the tangential velocity of the disc increases, the tangential force exerted by the disc on the dirt-laden fluid increases. As a result, more dirt is separated from the fluid by the disc, and therefore an increase in separation efficiency can be observed.

[0017] The disc can comprise a perforated region and a non-perforated region. Holes are then formed in the perforated region and the flow axis intersects the non-perforated region. As a result, dirt-laden fluid entering the chamber is directed to the non-perforated region of the disc. This has at least two benefits. Firstly, the fluid is forced to turn before passing through the perforated region of the disc. As a result, the radial velocity of the fluid moving over the holes is higher and therefore less dirt carried by the fluid is able to match the rotation and pass axially through the holes. Secondly, relatively hard objects carried by the fluid can impact the disc and puncture or damage the blocks between the holes. By ensuring that the dirt-laden fluid is directed to the non-perforated region, damage to the disc by objects carried by the fluid can be reduced.

[0018] The width of the non-perforated region can be no less than the diameter of the inlet. In the case where the non-perforated region is circular, the width corresponds to the diameter of the non-perforated region. Alternatively, in the case where the non-perforated region is annular, the width corresponds to the difference between the outer diameter and the inner diameter of the non-perforated region. By ensuring that the width of the non-perforated region is at least the same size as the inlet, the dirt-laden fluid entering the chamber can be better encouraged to turn radially before passing through the non-perforated region. The benefit of this is that the radial velocity of the fluid moving over the holes is higher and therefore less dirt passes axially through the holes. In addition, by making the non-perforated region at least the same size as the inlet, the risk of damage to the disc is reduced.

[0019] The disc can be formed from metal. This has at least two benefits compared to a disc made from, for example, plastic. Firstly, a relatively thin disc with a relatively high stiffness can be achieved. Secondly, the disc is less susceptible to damage by hard or sharp objects carried by the fluid. This is particularly important as the dirt-laden fluid entering the chamber is directed onto the disc.

[0020] The dirt separator comprises an electric motor for driving the disc. As a result, the speed of the disc and therefore the tangential force applied to the dirt is relatively insensitive to flow rate and fluid velocity. Therefore, relatively high separation efficiency can be achieved at relatively low flow rates compared to a turbine.

[0021] The present invention also provides a hand-held vacuum cleaner comprising a dirt separator as described in any of the preceding paragraphs.

[0022] Although it is known to provide a rotating disc in a dirt separator of a vacuum cleaner, there is a prejudice that a dirt separator must comprise a cyclone chamber to separate dirt from fluid. As a result, the overall size of the dirt separator is relatively large and not suitable for use in a hand-held unit. With the dirt separator of the present invention, separation efficiency can be achieved in a relatively compact manner. Therefore, the dirt separator is particularly suitable for use in a hand-held unit.

[0023] The present invention also provides a stick vacuum cleaner comprising a handheld unit attached to a cleaner head by an elongate tube, wherein the handheld unit comprises a dirt separator as described in any of the preceding paragraphs, and the elongate tube extends along an axis parallel to the axis of rotation.

[0024] By having an elongate tube extending parallel to the axis of rotation, the pressure loss can be reduced as the dirt-laden fluid can be transported along a relatively straight path from the cleaner head to the dirt separator and the rotating disc. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order that the present invention can be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:

[0026] Figure 1 is a perspective view of a vacuum cleaner;

[0027] Figure 2 is a cross-section through a portion of a vacuum cleaner;

[0028] Figure 3 is a cross-section through a dirt separator of a vacuum cleaner;

[0029] Figure 4 is a plan view of a disc of a dirt separator;

[0030] Figure 5 shows the flow of dirt-laden fluid through a dirt separator;

[0031] Figure 6 shows the emptying of a dirt separator;

[0032] Figure 7 is a cross-section through a portion of a vacuum cleaner when the vacuum cleaner is used for above floor cleaning.

[0033] Figure 8 shows the tangential force exerted by the disc on the dirt-laden fluid on the circumference of the inlet conduit, which (a) points towards the centre of the disc and (b) is directed eccentrically;

[0034] Figure 9 is a cross-section through a first alternative dirt separator;

[0035] Figure 10 is a cross-section through a portion of a vacuum cleaner having a second alternative dirt separator;

[0036] Figure 11 is a cross-section through a third alternative dirt separator;

[0037] Figure 12 is a cross-section through a portion of a vacuum cleaner having a third alternative dirt separator;

[0038] Figure 13 Emptying of a third alternative dirt separator is shown;

[0039] Figure 14 is a cross-section through a fourth alternative dirt separator; and

[0040] Figure 15 An alternative disc assembly is shown which can form part of any one of the dirt separators. DETAILED DESCRIPTION

[0041] Figure 1 The vacuum cleaner 1 comprises a hand unit 2 attached to a cleaner head 4 by an elongate tube 3. The elongate tube 3 is detachable from the hand unit 2 so that the hand unit 2 can be used as a stand-alone vacuum cleaner.

[0042] Reference is now made to Figures 2 to 7 The hand unit 2 comprises a dirt separator 10, a pre-motor filter 11, a vacuum motor 12 and a post-motor filter 13. The pre-motor filter 11 is located downstream of the dirt separator 10 but upstream of the vacuum motor 12, and the post-motor filter 13 is located downstream of the vacuum motor 12. In use, the vacuum motor 12 draws dirt-laden fluid through a suction inlet on the underside of the cleaner head 4. From the cleaner head 4, the dirt-laden fluid is drawn along the elongate tube 3 and into the dirt separator 10. The dirt is then separated from the fluid and retained within the dirt separator 10. The cleaned fluid exits the dirt separator 10 and is drawn through the pre-motor filter 11 which removes any remaining dirt from the fluid before it passes through the vacuum motor 12. Finally, the fluid expelled by the vacuum motor 12 passes through the post-motor filter 13 and is exhausted from the vacuum cleaner 1 through a vent 14 in the hand unit 2.

[0043] The dirt separator comprises a container 20, an inlet duct 21 and a disc assembly 22.

[0044] The container 20 comprises a top wall 30, a side wall 31 and a bottom wall 32 which together define a chamber 36. An opening in the centre of the top wall defines an outlet 38 of the chamber 36. The bottom wall 32 is attached to the side wall 31 by a hinge 33. A catch 34 attached to the bottom wall 32 engages with a recess in the side wall 31 to hold the bottom wall 32 in a closed position. Release of the catch 34 then causes the bottom wall 32 to swing to an open position as shown in Figure 6

[0045] The inlet duct 21 extends upwardly through the bottom wall 32 of the container 20. The inlet duct 21 extends centrally within the chamber 36 and terminates a short distance from the disc assembly 22. One end of the inlet duct 21 defines an inlet 37 of the chamber 36. The opposite end of the inlet duct 21 is attachable to the elongate tube 3 or an accessory tool when the hand unit 2 is used as a stand-alone vacuum cleaner.​

[0046] The disc assembly 22 comprises a disc 40 coupled to an electric motor 41. The electric motor 41 is located outside the chamber 36 and the disc 40 is located at and covers the outlet 38 of the chamber 36. When energized, the electric motor 41 rotates the disc 40 about an axis of rotation 48. The disc 40 is formed of metal and comprises a central non-perforated area 45 surrounded by a perforated area 46. The periphery of the disc 40 covers the top wall 30 of the container 20. When the disc 40 is rotating, the periphery of the disc 40 contacts and forms a seal with the top wall 30. To reduce friction between the disc 40 and the top wall 30, a ring of low friction material (e.g. PTFE) can be provided around the top wall 30.

[0047] In use, the vacuum motor 12 draws the dirt-laden fluid into the chamber 36 through the inlet 37. The inlet duct 21 extends centrally within the chamber 36 along an axis that coincides with the axis of rotation 48 of the disc 40. As a result, the dirt-laden fluid enters the chamber 36 in an axial direction (i.e. in a direction parallel to the axis of rotation 48). Furthermore, the dirt-laden fluid is directed at the center of the disc 40. The central non-perforated area of the disc 40 diverts and moves the dirt-laden fluid radially outward (i.e. in a direction perpendicular to the axis of rotation). The rotating disc 40 imparts a tangential force to the dirt-laden fluid, causing the fluid to swirl. As the dirt-laden fluid moves radially outward, the tangential force imparted by the disc 40 increases. Upon reaching the perforated area 46 of the disc 40, the fluid is axially drawn through the holes 47 in the disc 40. This requires a further turn in the direction of the fluid. The inertia of larger and heavier dirt is too great for the dirt to follow the fluid flow. As a result, the dirt is not drawn through the holes 47 but continues to move radially outward and eventually collects at the bottom of the chamber 36. Smaller and lighter dirt can follow the fluid through the disc 40. Most of the dirt is then removed by the pre- and post-motor filters 11, 13. To empty the dirt separator 10, the catch 34 is released and the bottom wall 32 of the container 20 swings open. As shown, the container 20 and the inlet duct 21 are configured such that the inlet duct 21 does not prevent or hinder the movement of the bottom wall 32. Figure 6

[0048] In addition to cleaning floor surfaces, the vacuum cleaner 1 can also be used to clean surfaces above the floor, such as shelves, curtains or a ceiling. When cleaning these surfaces, the handheld unit 2 can be inverted, as shown in Fig. 6. The disc 40 is then rotated in the opposite direction to that shown in Fig. 1. The dirt-laden fluid is drawn into the chamber 36 through the inlet 37. The inlet duct 21 extends centrally within the chamber 36 along an axis that coincides with the axis of rotation 48 of the disc 40. As a result, the dirt-laden fluid enters the chamber 36 in an axial direction (i.e. in a direction parallel to the axis of rotation 48). Furthermore, the dirt-laden fluid is directed at the center of the disc 40. The central non-perforated area of the disc 40 diverts and moves the dirt-laden fluid radially outward (i.e. in a direction perpendicular to the axis of rotation). The rotating disc 40 imparts a tangential force to the dirt-laden fluid, causing the fluid to swirl. As the dirt-laden fluid moves radially outward, the tangential force imparted by the disc 40 increases. Upon reaching the perforated area 46 of the disc 40, the fluid is axially drawn through the holes 47 in the disc 40. This requires a further turn in the direction of the fluid. The inertia of larger and heavier dirt is too great for the dirt to follow the fluid flow. As a result, the dirt is not drawn through the holes 47 but continues to move radially outward and eventually collects at the bottom of the chamber 36. Smaller and lighter dirt can follow the fluid through the disc 40. Most of the dirt is then removed by the pre- and post-motor filters 11, 13. To empty the dirt separator 10, the catch 34 is released and the bottom wall 32 of the container 20 swings open. As shown, the container 20 and the inlet duct 21 are configured such that the inlet duct 21 does not prevent or hinder the movement of the bottom wall 32. Figure 7 ​The dirt 50 collected in the chamber 36 can then fall toward the disk 40. Any dirt that lands on the disk 40 is likely to be sucked through or clog some of the holes 47 in the perforated area 46. As a result, the available open area of the disk 40 will decrease and the velocity of the fluid moving axially through the disk 40 will increase. The fluid can then carry more dirt through the disk 40 and the separation efficiency of the dirt separator 10 can decrease. The top wall 30 of the container 20 is not flat but stepped. As a result, the chamber 36 includes a channel between the step in the side wall 31 and the top wall 30. This channel surrounds the disk 40 and is used to collect dirt 50 that falls out of the chamber 36. As a result, less dirt can fall onto the disk 40 when the hand-held unit 2 is inverted.

[0049] The dirt separator 10 has several advantages over conventional separators that employ a perforated bag. During use, the holes of the bag quickly become clogged with dirt. This then reduces the suction obtained at the cleaner head. In addition, the bag must usually be replaced when it is full and it is not always easy to determine when the bag is full. With the dirt separator described herein, the rotation of the disk 40 ensures that the holes 47 in the perforated area 46 remain generally clean. As a result, no significant reduction in suction is observed during use. In addition, the dirt separator 10 can be emptied by opening the bottom wall 32 of the container 20, thereby avoiding the need to replace the bag. Furthermore, by using a transparent material for the side wall 31 of the container 20, the user can relatively easily determine when the dirt separator 10 is full and needs to be emptied. The above disadvantages of perforated bags are well known and can also be well addressed by separators that employ cyclonic separation. However, the dirt separator 10 described herein also has advantages over cyclonic separators.

[0050] To achieve a relatively high separation efficiency, cyclonic separators of vacuum cleaners typically include two or more stages of separation. The first stage typically includes a single, relatively large cyclone chamber for removing coarse dirt, while the second stage includes multiple, relatively small cyclone chambers for removing fine dirt. As a result, the overall size of the cyclonic separator can be relatively large. Another difficulty with cyclonic separators is that they require high fluid velocities to achieve high separation efficiencies. In addition, the fluid moving through the cyclonic separator typically follows a relatively long path from the inlet to the outlet. The long path and high velocities result in high aerodynamic losses. As a result, the pressure drop associated with the cyclonic separator can be high. With the dirt separator described herein, relatively high separation efficiencies can be achieved in a more compact manner. In particular, the dirt separator includes a single stage having a single chamber. In addition, the separation occurs primarily due to the angular momentum imparted to the dirt-laden fluid by the rotating disk 40. As a result, relatively high separation efficiencies can be achieved at relatively low fluid velocities. In addition, the path taken by the fluid moving from the inlet 37 to the outlet 38 of the dirt separator 10 is relatively short. Due to the lower fluid velocities and shorter path, the aerodynamic losses are less. As a result, for the same separation efficiency, the pressure drop across the dirt separator 10 is less than the pressure drop across a cyclonic separator. Thus, the vacuum cleaner 1 is able to achieve the same cleaning performance as a cyclonic vacuum cleaner using a less powerful vacuum motor. This is particularly important if the vacuum cleaner 1 is powered by a battery, as any reduction in the power consumption of the vacuum motor 11 can be used to increase the run time of the vacuum cleaner 1.

[0051] It is known to provide a rotating disk within a dirt separator of a vacuum cleaner. For example, DE 196 37 431 and US 4 382 804 each describe a dirt separator having a rotating disk. However, there is a bias that a dirt separator must include a cyclone chamber to separate dirt from the fluid. The disk then acts as a secondary filter to clean residual dirt from the fluid as it exits the cyclone chamber. There is also a bias that the rotating disk must be protected from the bulk of the dirt entering the cyclone chamber. Thus, the dirt-laden fluid is introduced into the cyclone chamber in a manner that avoids direct impact with the disk.

[0052] The dirt separator described herein takes advantage of the discovery that dirt separation can be achieved with a rotating disk without the need for a cyclone chamber. The dirt separator further takes advantage of the discovery that effective dirt separation can be achieved by introducing the dirt-laden fluid into the chamber in a direction that is directly towards the disk. By directing the dirt-laden fluid onto the disk, the dirt is subjected to a relatively high force as it contacts the rotating disk. The dirt within the fluid is then thrown radially outward, while the fluid passes axially through the holes in the disk. As a result, effective dirt separation can be achieved without the need for cyclonic flow.

[0053] The separation efficiency of the dirt separator 10 and the pressure drop across the dirt separator 10 are sensitive to the size of the holes 47 in the disk 40. For a given total open area, the separation efficiency of the dirt separator 10 increases as the hole size decreases. However, as the hole size decreases, the pressure drop across the dirt separator 10 also increases. The separation efficiency and the pressure drop are also sensitive to the total open area of the disk 40. In particular, as the total open area increases, the axial velocity of the fluid moving through the disk 40 decreases. As a result, the separation efficiency improves and the pressure drop decreases. Thus, it is advantageous to have a large total open area. However, increasing the total open area of the disk 40 is not without difficulty. For example, as already noted, increasing the size of the holes to increase the total open area can actually decrease the separation efficiency. Instead, the total open area can be increased by increasing the size of the perforated region 46. This can be accomplished by increasing the size of the disk 40 or by decreasing the size of the non-perforated region 45. However, each option has its drawbacks. For example, since a contact seal is formed between the perimeter of the disk 40 and the top wall 30, more power will be required to drive a disk 40 having a larger diameter. Additionally, a rotating disk 40 of a larger diameter can create more agitation within the chamber 36. As a result, the re-entrainment of dirt that has already collected in the chamber 36 can increase, thus the separation efficiency can actually decrease net. On the other hand, if the diameter of the non-perforated region 45 is decreased, the axial velocity of the fluid moving through the disk 40 can actually increase for reasons that will be detailed below. Another way to increase the total open area of the disk 40 is to decrease the land between the holes 47. However, reducing the land has its own difficulties. For example, the stiffness of the disk 40 can decrease and the perforated region 46 can become more fragile, thus more susceptible to damage. Additionally, reducing the land between the holes can introduce manufacturing difficulties. Thus, many factors are considered in the design of the disk 40.

[0054] The disk 40 includes a central non-perforated region 45 surrounded by a perforated region 46. Providing a central non-perforated region 45 has several advantages, which will now be described.

[0055] The stiffness of the disk 40 can be important to achieve an effective contact seal between the disk 40 and the top wall 30 of the container 20. Having a non-perforated central region 45 increases the stiffness of the disk 40. As a result, a thinner disk can be used. Such a benefit is that the disk 40 can be manufactured in a more timely and cost effective manner. Furthermore, for certain manufacturing methods (e.g., chemical etching), the thickness of the disk 40 can define the smallest possible size of the holes 47 and the land. Thus, a thinner disk has the advantage that such a method can be used to manufacture a disk having relatively small hole and / or land sizes. Furthermore, the cost and / or weight of the disk 40 and the mechanical power required to drive the disk 40 can be reduced. Thus, a less powerful and possibly smaller and less expensive motor 41 can be used to drive the disk 40.

[0056] By having a central non-perforated region 45, the dirt-laden fluid entering the chamber 36 is forced to turn from an axial direction to a radial direction. The dirt-laden fluid then moves outward on the surface of the disc 40. This has at least two benefits. First, when the dirt-laden fluid moves over the perforated region 46, the fluid needs to turn a large angle (approximately 90 degrees) to pass through the holes 47 in the disc 40. As a result, less dirt carried by the fluid is able to match the turn and pass through the holes 47. Second, as the dirt-laden fluid moves outward on the surface of the disc 40, the dirt-laden fluid helps to scour the perforated region 46. Thus, any dirt that can have been trapped in the holes 47 is cleaned out by the fluid.

[0057] The tangential velocity of the disc 40 decreases from the periphery to the center of the disc 40. As a result, the tangential force exerted by the disc 40 on the dirt-laden fluid decreases from the periphery to the center. If the central region 45 of the disc 40 were perforated, more dirt can pass through the disc 40. By having a central non-perforated region 45, the holes 47 are disposed at a region of the disc 40 where the tangential velocity, and thus the tangential force exerted on the dirt, is relatively high.

[0058] As the dirt-laden fluid introduced into the chamber 36 changes from axial to radial, relatively heavy dirt can continue to travel in the axial direction and impact the disc 40. If the central region 45 of the disc 40 were perforated, the relatively hard objects impacting the disc 40 can puncture or damage the patches between the holes 47. By having a non-perforated central region 45, the risk of damaging the disc 40 is reduced.

[0059] The diameter of the non-perforated region 45 is greater than the diameter of the inlet 37. As a result, hard objects carried by the fluid are less likely to impact the perforated region 46 and damage the disc 40. In addition, the dirt-laden fluid is better encouraged to turn from the axial direction to the radial direction upon entering the chamber 36. The separation distance between the inlet 37 and the disc 40 plays an important role in achieving these two benefits. As the separation distance between the inlet 37 and the disc 40 increases, the radial component of the velocity of the dirt-laden fluid at the perforated region 46 of the disc 40 can decrease. As a result, more dirt can be carried through the holes 47 in the disc 40. As a result, as the separation distance increases, the hard objects carried by the fluid are more likely to impact the perforated region 46 and damage the disc 40. Thus, a relatively small separation distance is desired. However, if the separation distance is too small, dirt larger than the separation distance will not be able to pass between the inlet pipe 21 and the disc 40, and thus will be trapped. The size of the dirt carried by the fluid will be limited, among other things, by the diameter of the inlet pipe 21. In particular, the size of the dirt is unlikely to be larger than the diameter of the inlet pipe 21. Thus, by employing a separation distance no greater than the diameter of the inlet 37, the above benefits can be achieved while providing sufficient space for the dirt to pass between the inlet pipe 21 and the disc 40.

[0060] Regardless of the selected separation distance, the non-perforated region 45 of the disk 40 continues to provide advantages. In particular, the non-perforated region 45 ensures that the holes 47 on the disk 40 are disposed at regions where the tangential force exerted by the disk 40 on the dirt is relatively high. Additionally, although the dirt-laden fluid follows a more divergent path as the separation distance increases, relatively heavy objects can continue to follow a relatively straight path as they enter the chamber 36. Thus, the central non-perforated region 45 continues to protect the disk 40 from potential damage.

[0061] Despite the advantages, the diameter of the non-perforated region 45 need not be larger than the diameter of the inlet 37. By reducing the size of the non-perforated region 45, the size of the perforated region 46 can be increased, thereby increasing the total open area of the disk 46. As a result, the pressure drop across the dirt separator 10 can be reduced. Additionally, it can be observed that the axial velocity of the dirt-laden fluid moving through the perforated region 46 decreases. However, as the size of the non-perforated region 45 is reduced, a point will be reached at which the fluid entering the chamber 36 is no longer forced to turn from axial to radial before encountering the perforated region 46. Thus, a point will be reached at which the decrease in axial velocity due to the larger open area is offset by the increase in axial velocity due to the smaller turn angle.

[0062] It is conceivable that the central region 45 of the disk 40 could be perforated. Although many of the advantages described above would then be lost, a disk 40 having a full perforation can still have advantages. For example, the disk 40 can be simpler and / or less expensive to manufacture. In particular, the disk 40 can be cut from a continuous perforated sheet. Even if the central region 45 is perforated, the disk 40 will continue to exert a tangential force on the dirt-laden fluid entering the chamber 36, although the force will be less at the center of the disk 40. The disk 40 will thus continue to separate dirt from the fluid, although with less efficiency. Additionally, if the central region 45 of the disk 40 is perforated, the dirt can clog the hole at the exact center of the disk 40 due to the lower tangential force exerted by the disk 40. With the hole at the exact center clogged, the disk 40 will behave as if the center of the disk 40 were non-perforated. Alternatively, the central region 45 can be perforated, but have an open area that is less than the open area of the surrounding perforated region 46. Also, the open area of the central region 45 can increase as one moves radially outward from the center of the disk 40. This has the benefit that the open area of the central region 45 increases as the tangential velocity of the disk 40 increases.

[0063] The inlet duct 21 extends along an axis that coincides with the axis of rotation 48 of the disk 40. As a result, the dirt-laden fluid entering the chamber 36 is directed to the center of the disk 40. This has the advantage that the dirt-laden fluid is distributed evenly over the surface of the disk 40. In contrast, if the inlet duct 21 were directed eccentrically at the disk 40, the fluid would be distributed unevenly. To illustrate this point,Figure 8 The tangential forces exerted by the disc on the dirt-laden fluid at the circumference of the inlet duct 21 are shown to be directed (a) at the centre of the disc 40 and (b) eccentrically. It can be seen that when the inlet duct 21 is directed eccentrically, the dirt-laden fluid does not flow uniformly over the surface of the disc 40. In Figure 8 In the example shown in (b), little of the dirt-laden fluid can be seen in the lower half of the disc 40. This uneven distribution of fluid over the disc 40 can have one or more adverse effects. For example, the axial velocity of the fluid through the disc 40 can increase at those regions which are maximally exposed to the dirt-laden fluid. As a result, the separation efficiency of the dirt separator 10 can be reduced. In addition, the dirt separated by the disc 40 can be unevenly collected within the container 20. As a result, the capacity of the dirt separator 10 can be compromised. Re-entrainment of dirt 50 which has already been collected within the container 20 can also increase, leading to further reductions in separation efficiency. Another disadvantage of directing the dirt-laden fluid eccentrically is that the disc 40 is subjected to uneven structural loading. The resulting imbalance can cause poor sealing with the top wall 30 of the container 20 and can reduce the useful life of any bearings used to support the disc assembly 22 in the vacuum cleaner 1.

[0064] The inlet duct 21 is attached to the bottom wall 32 and can be integrally formed with the bottom wall 32. The inlet duct 21 is therefore supported within the chamber by the bottom wall 32. Alternatively, the inlet duct 21 can be supported by the side wall 31 of the container 20, for example using one or more brackets extending radially between the inlet duct 21 and the side wall 31. An advantage of this arrangement is that the bottom wall 32 can be freely opened and closed without moving the inlet duct 21. As a result, a taller container 20 with greater dirt capacity can be employed. However, a disadvantage of this arrangement is that when the bottom wall 32 is opened, the brackets used to support the inlet duct 21 can prevent dirt from falling from the chamber 36, making emptying of the container 20 more difficult.

[0065] The inlet duct 21 extends linearly within the chamber 36. This has the advantage that the dirt-laden fluid moves through the inlet duct 21 along a straight path. However, this arrangement is not without difficulties. The bottom wall 32 is arranged to open and close and is attached to the side wall 31 by a hinge 33 and a catch 34. Thus, when a user applies a force to the handpiece 2 to manoeuvre the cleaner head 4 (e.g. a pushing or pulling force to manoeuvre the cleaner head 4 forwards and backwards, a twisting force to manoeuvre the cleaner head left or right, or a lifting force to lift the cleaner head 4 off the ground), this force is transmitted to the cleaner head 4 through the hinge 33 and catch 34. Thus, the hinge 33 and catch 34 must be designed to withstand the required forces. As an alternative arrangement, the bottom wall 32 can be fixed to the side wall 31 and the side wall 31 can be removably attached to the top wall 30. The container 20 can then be emptied by removing the side and bottom walls 31, 32 from the top wall 30 and inverting. Although this arrangement has the advantage that the hinge and catch do not have to be designed to withstand the required forces, emptying of the dirt separator 10 is less convenient.

[0066] An alternative dirt separator 101 is shown in Figure 9 A portion of the inlet duct 21 extends along the side wall 31 of the container 20 and is attached to or formed integrally with the side wall 31 of the container 20. The bottom wall 32 is in turn attached to the side wall 31 by a hinge 33 and catch (not shown). However, the inlet duct 21 no longer extends through the bottom wall 32. Thus, the position of the inlet duct 21 does not change when the bottom wall 32 is moved between the closed and open positions. This has the advantage that the container 20 is convenient to empty without having to design the hinge and catch to withstand the required forces. However, from Figure 9 It will be apparent that the inlet duct 21 is no longer straight. As a result, the pressure drop associated with the dirt separator 10 can increase due to the losses that will be increased due to the bend in the inlet duct 21. Although Figure 9 The inlet duct 21 of the arrangement shown is no longer straight, the end of the inlet duct 21 continues to extend along an axis that coincides with the rotational axis 48 of the disc 40. As a result, the dirt-laden fluid continues to be directed in an axial direction at the centre of the disc 40 into the chamber 36.

[0067] Figure 10 Another dirt separator 102 is shown in which the inlet duct 21 extends linearly through the side wall 31 of the container 20. The bottom wall 32 is then attached to the side wall 31 by a hinge 33 and held closed by a catch 34. In Figure 3 and 9In the illustrated arrangement, the chamber 36 of the dirt separator 10, 101 is substantially cylindrical, with the longitudinal axis of the chamber 36 coinciding with the axis of rotation 48 of the disc. The disc 40 is then positioned towards the top of the chamber 36, and the inlet conduit 21 extends upwards from the bottom of the chamber 36. Reference to the top and bottom should be understood to mean that dirt separated from the fluid collects preferentially at the bottom of the chamber 36, and fills progressively in a direction towards the top of the chamber 36. By Figure 10 In the illustrated arrangement, the chamber 36 is of a shape that can be considered to be a combination of a cylindrical top and a cuboidal bottom. The disc 40 and the inlet conduit 21 are then both positioned towards the top of the chamber 36. Since the inlet conduit 21 extends through the side wall 31 of the container 20, this arrangement has the advantage that the container 20 can be conveniently emptied through the bottom wall 32, without the need for hinges and catches that can be able to withstand the forces required to operate the cleaner head 4. In addition, since the inlet conduit 21 is linear, pressure losses associated with the inlet conduit 21 are reduced. This arrangement has at least three other advantages. First, the dirt capacity of the dirt separator 102 is significantly increased. Second, when the hand unit 2 is inverted for floor cleaning, dirt within the container 20 is less likely to fall onto the disc 40. As a result, the chamber 36 does not need to include a protective channel around the disc 40, and therefore a larger disc 40 with a larger total open area can be used. Third, when placed on a horizontal surface, the bottom wall 32 of the container 20 can be used to support the hand unit 2. However, this arrangement is not without difficulties. For example, a larger container 20 can hinder access to narrow spaces, for example between furniture or appliances. In addition, the bottom of the chamber 36 is radially spaced apart from the top of the chamber 36. That is, the bottom of the chamber 36 is spaced apart from the top of the chamber 36 in a direction perpendicular to the axis of rotation 48 of the disc 40. As a result, dirt and fluid thrown radially outwards by the disc 40 can interfere with dirt collected in the bottom of the chamber 36. In addition, any vortices within the chamber 36 will tend to move up and down the chamber 36. As a result, re-entrainment of dirt can increase, leading to reduced separation efficiency. Conversely, in the arrangement of the dirt separator 10, 101, 102 described above, the bottom of the chamber 36 is axially spaced apart from the top of the chamber 36. Dirt and fluid thrown radially outwards by the disc 40 are therefore less likely to interfere with dirt collected in the bottom of the chamber 36. In addition, any vortices within the chamber 36 move around the chamber 36 rather than up and down the chamber 36. Figure 3 and 9 In the illustrated arrangement, the bottom of the chamber 36 is axially spaced apart from the top of the chamber 36. Dirt and fluid thrown radially outwards by the disc 40 are therefore less likely to interfere with dirt collected in the bottom of the chamber 36. In addition, any vortices within the chamber 36 move around the chamber 36 rather than up and down the chamber 36.

[0068] In each of the dirt separators 10, 101, 102 described above, at least the end of the inlet conduit 21, i.e. the part with the inlet 37, extends along an axis that coincides with the axis of rotation 48 of the disc 40. As a result, dirt-laden fluid enters the chamber 36 in an axial direction directed at the centre of the disc 40. The advantages of this have been described above. However, in certain circumstances, it is desirable to have an alternative arrangement. For example, Figures 11-13The dirt separator 103 is shown, wherein the inlet duct 21 extends along an axis that is angled relative to the rotational axis 48 of the disc 40. That is, the inlet duct 21 extends along an axis that is not parallel to the rotational axis 48. As a result of this arrangement, dirt-laden fluid enters the chamber in a direction that is not parallel to the rotational axis 48. However, the dirt-laden fluid that enters the chamber 36 continues to be directed towards the disc 40. In fact, with the dirt separator 103 shown in Figures 11-13 , the dirt-laden fluid continues to be directed towards the centre of the disc 40. This particular arrangement can be advantageous for several reasons. First, when the vacuum cleaner 1 is used for floor cleaning, as shown in Figure 1 , the handheld unit 2 is typically pointed downwards at an angle of approximately 45 degrees. As a result, dirt can collect unevenly within the dirt separator. In particular, dirt can preferentially collect along one side of the chamber 36. With the dirt separator 10 shown in Figure 3 , this uneven dirt collection can mean that dirt fills along one side to the top of the chamber 36, triggering a chamber full condition, even though the opposite side of the chamber 36 can be relatively dirt-free. As shown in Figure 12 , the dirt separator 103 of Figures 11-13 can make better use of the available space. As a result, the capacity of the dirt separator 10 can be increased. It can also be said that the dirt separator 101 of Figure 9 has this advantage. However, the inlet duct 21 of the dirt separator 101 comprises two bends. In contrast, the inlet duct 21 of the dirt separator 103 of Figures 11-13 is generally linear, and therefore has less pressure loss. Figures 11-13 Another advantage of the arrangement shown in Figure 3 involves emptying. As with the arrangement shown in Figure 6 , the inlet duct 21 is attached to and moves with the bottom wall 32. As shown in Figure 3 , when the dirt separator 10 of Figure 13 is held vertically and the bottom wall 32 is in the open position, the inlet duct 21 extends horizontally. In contrast, as shown in Figures 11-13 , when the dirt separator 103 of is held vertically and the bottom wall 32 is open, the inlet duct 21 is inclined downwards. As a result, dirt is better encouraged to slide from the inlet duct 21.

[0069] In Figures 11-13In the arrangement shown in Fig. 1 1, the dirt-laden fluid entering the chamber 36 continues to be directed to the center of the disc 40. Although this arrangement has advantages, it is still possible to achieve efficient separation of dirt by directing the dirt-laden fluid off-center. Moreover, in some cases, it is desirable to direct the dirt-laden fluid off-center. For example, if the central region of the disc 40 is perforated, the dirt-laden fluid can be directed off-center, thereby avoiding the region of the disc 40 where the tangential velocity is slowest. As a result, a net increase in separation efficiency can be observed. By way of example, Figure 14 An arrangement is shown in which the dirt-laden fluid entering the chamber 36 is directed off-center at the disc 40. Similar to the arrangement shown in Fig. 1 1, Figure 9 The inlet duct 21 is formed integrally with the side wall 31 of the container 20, and the bottom wall 32 is attached to the side wall 31 by a hinge 33 and a snap (not shown) in the arrangement shown in Fig. 1 1. The position of the inlet duct 21 remains fixed as the bottom wall 32 moves between the closed and open positions. This has the advantage that the container 20 is easy to empty without having to design the hinge and snap to withstand the forces required to manipulate the cleaner head 4. Moreover, in contrast to the dirt separator 101 of Fig. 1 1, Figure 9 The inlet duct 21 is straight in contrast to the dirt separator 101 of Fig. 1 1, thus reducing the pressure loss due to the movement of the dirt-laden fluid through the inlet duct 21.

[0070] In a more general sense, the dirt-laden fluid can be said to enter the chamber 36 along a flow axis 49. The flow axis 49 then intersects the disc 40 such that the dirt-laden fluid is directed to the disc 40. This has the advantage that the dirt-laden fluid hits the disc 40 soon after entering the chamber 36. The disc 40 then imparts a tangential force on the dirt-laden fluid. The fluid is drawn out through the holes 47 in the disc 40, while the dirt, due to its greater inertia, moves radially outward and collects in the chamber 36. In Figure 3 , 9 , 10 and 1 1, the flow axis 49 intersects the center of the disc 40, while in Figure 14 the arrangement shown in Fig. 1 1, the flow axis 49 intersects the disc 40 off-center. Although it is advantageous to have a flow axis 49 that intersects the center of the disc 40, it is still possible to achieve efficient separation of dirt by having a flow axis 49 that intersects the disc 40 off-center.

[0071] In each of the above arrangements, the inlet duct 21 has a circular cross-section, and thus the inlet 37 has a circular shape. It is conceivable that the inlet duct 21 and the inlet 37 can have alternative shapes. Likewise, the shape of the disc 40 need not be circular. However, since the disc 40 rotates, it is unclear what advantages would be gained by having a non-circular disc. The perforated and non-perforated areas 45, 46 of the disc 40 can also have different shapes. In particular, the non-perforated area 45 need not be circular or located in the centre of the disc 40. For example, in the case where the inlet duct 21 is directed eccentrically at the disc 40, the non-perforated area 45 can take the form of a ring. In the above discussion, reference is sometimes made to the diameter of a particular element. When that element has a non-circular shape, the diameter corresponds to the maximum width of that element. For example, if the inlet 37 is rectangular or square, the diameter of the inlet 37 would correspond to the diagonal of the inlet 37. Or, if the inlet is elliptical, the diameter of the inlet 37 would correspond to the width of the inlet 37 along the major axis.

[0072] The disc 40 is formed from metal, for example stainless steel, which has at least two advantages over, for example, plastic. Firstly, a relatively thin disc 40 can be achieved which has a relatively high stiffness. Secondly, a relatively hard disc 40 can be obtained which is less susceptible to damage from hard or sharp objects falling onto the disc 40 when the hand-held unit 2 is inverted as shown. However, despite these advantages, it is conceivable that the disc 40 is formed from an alternative material, for example plastic. Indeed, the use of plastic can have advantages over metal. For example, by forming the disc 40 from a low-friction plastic, such as Delrin, the ring of low-friction material (e.g. PTFE) provided around the top wall 30 of the container 20 can be omitted. Figure 7

[0073] In the above arrangements, the disc assembly 22 comprises the disc 40 which is attached directly to the shaft of the electric motor 41. It is conceivable that the disc 40 can be indirectly attached to the electric motor, for example by means of a gear box or drive dog. Furthermore, the disc assembly 22 can comprise a carrier to which the disc 40 is attached. By way of example, Figure 15 A disc assembly 23 is shown having a carrier 70. The carrier 70 can be used to increase the stiffness of the disc 40. As a result, a thinner disc 40 can be used or a disc 40 having a greater diameter and / or a greater total open area. The carrier 70 can also be used to form a seal between the disc assembly 23 and the container 20. In this regard, although a contact seal between the disc 40 and the top wall 30 has been described so far, an alternative type of seal, for example a labyrinth seal or a fluid seal, can equally be employed. The carrier 70 can also be used to block the central region of a disc which is entirely perforated. In Figure 15 In the example shown, the carrier 70 comprises a central hub 71 which is connected to a rim 72 by radial spokes 73. Fluid then passes through the carrier 70 through the holes 74 between adjacent spokes 73. ​

[0074] Each of the aforementioned disk assemblies 22, 23 includes an electric motor 41 for driving the disk 40. It is conceivable that disk assemblies 22, 23 may include alternative devices for driving the disk 40. For example, the disk 40 may be driven by a vacuum motor 12. This arrangement... Figure 1 The arrangement shown is particularly feasible, in which the vacuum motor 12 rotates about an axis coinciding with the axis of rotation 48 of the disc 40. Alternatively, the disc assemblies 22, 23 may include turbines powered by a flow of fluid moving through the disc assemblies 22, 23. Turbines are generally cheaper than electric motors, but the speed of the turbine, and therefore the speed of the disc 40, depends on the flow rate of fluid moving through the turbine. As a result, high separation efficiency may be difficult to achieve at low flow rates. Additionally, if dirt clogs any of the holes 47 in the disc 40, the opening area of ​​the disc 40 will decrease, thereby restricting the flow of fluid to the turbine. As a result, the speed of the disc 40 will decrease, and therefore the likelihood of clogging will increase. A racetrack effect then occurs, in which the disc 40 becomes increasingly slower as it becomes clogged, and the disc 40 becomes increasingly clogged as it slows down. Furthermore, if the suction port in the vacuum cleaner head 4 is temporarily blocked, the speed of the disc 40 will decrease significantly. Dirt may then accumulate in large quantities on the disc 40. When the obstruction is subsequently removed, the contaminant will limit the opening area of ​​disk 40 to a certain extent, preventing the turbine from driving disk 40 at a sufficient speed to remove the contaminant. While electric motors are generally more expensive, they have the advantage that the speed of disk 40 is relatively insensitive to flow rate or fluid velocity. As a result, high separation efficiency can be achieved at low flow rates and low fluid velocities. Additionally, disk 40 is less likely to become clogged with contaminant. Another advantage of using an electric motor is that it requires less electrical energy. That is, for a given flow rate and disk speed, the power drawn by electric motor 41 is less than the additional power drawn by vacuum motor 12 to drive the turbine.

[0075] To date, the dirt separator 10 has been described as forming part of a handheld unit 2, which can be used as a standalone vacuum cleaner or attached to a vacuum cleaner head 4 via an elongated tube 3 to function as a stick vacuum cleaner 1. Providing a disc assembly within a handheld unit is by no means intuitive. While it is known to incorporate a rotating disc in a dirt separator of a vacuum cleaner, there is a bias that the dirt separator must include a cyclone chamber to separate dirt from fluid. As a result, the overall size of the dirt separator is relatively large and unsuitable for use in a handheld unit. Using the dirt separator described herein, separation efficiency can be achieved in a relatively compact manner. Therefore, the dirt separator is particularly well-suited for use in handheld units.

[0076] The weight of the hand-held unit is obviously an important consideration in its design. Thus, the inclusion of an electric motor in addition to the vacuum motor is not an obvious design choice. Further, where the hand-held unit is battery powered, it can be reasonably assumed that the power consumed by the electric motor will reduce the run time of the vacuum cleaner. However, by using an electric motor to drive the disc, a relatively high separation efficiency can be achieved for a relatively modest pressure drop. Thus, the same cleaning performance can be achieved using a smaller vacuum motor which consumes less electrical power than a conventional hand-held vacuum cleaner. Thus, a smaller vacuum motor which consumes less electrical power can be used. As a result, a net reduction in weight and / or power consumption is possible.

[0077] Although the dirt separator described herein is particularly suitable for use in a hand-held vacuum cleaner, it will be appreciated that the dirt separator can equally be used in alternative types of vacuum cleaner, such as an upright, canister or robotic vacuum cleaner.

Claims

1. A handheld vacuum cleaner, comprising a dirt separator, wherein, The waste separator includes: A chamber having an inlet and an outlet, wherein fluid carrying contaminants enters the chamber through the inlet and cleaned fluid exits the chamber through the outlet; and A disc located at the outlet, the disc being arranged to rotate about a rotation axis, and including orifices for the passage of cleaned fluid. The fluid carrying contaminants enters the chamber along the flow axis intersecting the disc. The sludge separator includes an electric motor for driving a disc around a rotating axis. The handheld vacuum cleaner also includes a vacuum motor configured to draw air into the chamber via an inlet. The separation distance between the center of the inlet and the center of the disk is not greater than the diameter of the inlet.

2. The handheld vacuum cleaner according to claim 1, wherein, The flow axis intersects the center of the disk.

3. The handheld vacuum cleaner according to claim 1 or 2, wherein, The flow axis is parallel to the rotation axis.

4. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The contaminants separated from the contaminant-laden fluid accumulate at the bottom of the chamber and gradually fill in the direction toward the top of the chamber, the outlet being located at or near the top of the chamber, and the bottom of the chamber being axially spaced from the top of the chamber.

5. The handheld vacuum cleaner according to claim 4, wherein, The inlet is defined by the end of an inlet conduit extending upward from the bottom of the chamber.

6. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The inlet is defined by the end of an inlet pipe, and the chamber surrounds the inlet pipe.

7. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The inlet is defined by the end of an inlet pipe that extends through the wall of the chamber, and the opposite end of the inlet pipe can be attached to various accessories of the vacuum cleaner.

8. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The inlet is defined by the end of an inlet conduit that extends linearly within the cavity.

9. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The diameter of the disk is larger than the diameter of the inlet.

10. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The total opening area of ​​the disk is greater than the total opening area of ​​the inlet.

11. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The disk includes a perforated region and a non-perforated region, with holes formed in the perforated region and the flow axis intersecting the non-perforated region.

12. The handheld vacuum cleaner according to claim 10, wherein, The width of the non-perforated area is not less than the diameter of the inlet.

13. The handheld vacuum cleaner according to any one of the preceding claims, wherein, The disk is made of metal.

14. A stick vacuum cleaner comprising a handheld unit attached to a vacuum cleaner head via an elongated tube, wherein, The handheld unit includes a handheld vacuum cleaner according to any one of claims 1 to 13, and the elongated tube extends along an axis parallel to the axis of rotation.

Images