SUCTION NOZZLE
A suction nozzle includes a casing which defines a suction chamber, and an agitator rotatably mounted within the suction chamber. The agitator is supported in the suction chamber by a support member. A drive assembly arranged to rotate the agitator about an axis is mounted to the casing via the support member, and is mounted to the support member via a first soft mounting member. The support member is mounted to the casing via a second soft mounting member.
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This application is a national stage application under 35 USC 371 of International Application No. PCT/GB2018/052476, filed Aug. 31, 2018, which claims the priority of United Kingdom Application No. 1805265.4, filed Mar. 29, 2018, the entire contents of each of which are incorporated herein by reference.
FIELD OF THE DISCLOSUREThe present invention related to a suction nozzle of the type that can be used on a vacuum cleaner. The present invention also relates to a vacuum cleaner including such a suction nozzle. The invention is not limited to any particular type of vacuum cleaner, or suction nozzles for any particular type of vacuum cleaner. For example, the suction nozzle may be a cleaner head on an upright vacuum cleaner, or a floor tool on a cylinder vacuum cleaner or handheld vacuum cleaner.
BACKGROUND OF THE DISCLOSURESome known vacuum cleaner suction nozzles comprise a rotating agitator such as a brush bar, which is driven to rotate (for instance by an electric motor) so as to agitate carpet fibres to loosen dirt therefrom. A problem with such suction nozzles is that rotation of the agitator and/or a component involved in the driving of the agitator can introduce vibration. This vibration can cause the agitator to agitate the floor surface being cleaned unevenly, and/or can propagate to other areas of the suction nozzle. Such vibrations can pass to the handle of the vacuum cleaner and cause discomfort for the user, and/or can pass to other components of the vacuum cleaner (for instance a casing of the suction nozzle) which may amplify them and increase the noise produced by the suction nozzle.
Furthermore, manufacturing tolerances can lead to rotating components being slightly mis-aligned. This can lead to increased wear of moving parts, and if bad enough can even prevent the suction nozzle from being assembled.
It is possible to ‘soft mount’ components (i.e. mount them in such a way as to allow some degree of movement) with a view to limiting the propagation of vibrations. However, in some circumstances a vibrating component being allowed to move to some extent by the soft mounting can allow that component to disturb other components. For instance, a soft mounted motor being allowed to move can allow the motor to throw out of alignment an agitator attached thereto, actively causing the agitator to vibrate. Furthermore, the soft mounting of components can require large manufacturing tolerances so as to provide room for that component to move.
It is an object of the invention to mitigate or obviate the above disadvantages, and or to provide an improved or alternative suction nozzle or vacuum cleaner.
SUMMARY OF THE DISCLOSUREAccording to a first aspect of the present invention there is provided a suction nozzle comprising a casing which defines a suction chamber, and an agitator rotatably mounted within the suction chamber, wherein the agitator is supported in the suction chamber by a support member; a drive assembly arranged to rotate the agitator about an axis is mounted to the casing via the support member, and is mounted to the support member via a first soft mounting member; and the support member is mounted to the casing via a second soft mounting member.
This may be advantageous in that the first soft mounting member can limit the propagation of vibration from the drive assembly to the support member, and thus to the agitator supported thereby. Similarly, it can accommodate slight misalignment between the drive assembly and the support member (and thus the agitator supported thereby). Accordingly, the risk of the drive assembly throwing the agitator out of alignment and/or causing the agitator to vibrate is reduced. At the same time, the second soft mounting member can limit propagation of vibration from the support assembly (which may be vibrated by the agitator, and/or by the drive assembly if the first soft mounting member does not eliminate such vibration) to the casing, or accommodate slight misalignment therebetween. Accordingly, the present invention can advantageously reduce the noise generated by the suction nozzle without requiring loose tolerances or excessive freedom of movement of the components therein.
A soft mounting member is a component or assembly which attaches two components to one another, but permits a limited amount of relative movement therebetween.
The first or second soft mounting member may comprise an elastomeric component.
This may allow said soft mounting member to be of advantageously simple design. In addition, the hysteresis losses innate in elastomeric components may provide a vibration damping effect which actively reduces vibrations rather than just limiting their propagation. In contrast, if said soft mounting member comprised a coil spring in place of an elastomeric component, the soft mounting member may limit the propagation of vibrations but may have little or no damping effect on the vibrating component.
Preferably, both the first and second soft mounting members comprise an elastomeric component.
Said soft mounting component(s) may consist essentially of said elastomeric component, in which case the limited deformability of the elastomeric component may prevent excessive relative movement. Alternatively, the soft mounting component may comprise other components, such as a separate ‘over-travel-stop’ mechanism to prevent excessive relative movement.
Said elastomeric component may be positioned to act as an air seal.
This may avoid the need for a separate sealing member to be provided at or near said soft mounting member, thereby reducing the number of parts of the suction nozzle (and thus reducing its total cost and/or assembly time).
The drive assembly may be at least partially received inside the agitator.
This may reduce the overall size of the suction nozzle, thereby allowing it to be more maneuverable and/or allowing it to reach into smaller spaces during vacuuming.
The drive assembly is preferably substantially entirely received inside the agitator.
Alternatively, drive assembly may be positioned externally of the agitator, for driving the agitator to rotate using a drive belt.
The drive assembly may comprise an electric motor.
This may improve the reliability or controllability of the drive assembly, and/or allow the agitator to be rotated with advantageous speed and/or torque.
As an alternative, the drive assembly may comprise a turbine positioned in an air path through the suction nozzle (for instance a bleed path leading to the suction chamber from an inlet for ambient air).
The support member may accommodate wiring through which electrical power can be delivered to the motor.
This may allow the suction nozzle to be relatively small and/or of advantageously simple design (thus making the suction nozzle relatively cheap or quick to produce), in contrast to an arrangement where the wiring must be accommodated entirely outside of the support member.
The electric motor may be at least partially received inside the agitator.
This may further increase the compactness of the suction nozzle, improving its maneuverability and/or ability to reach into small spaces.
The electric motor may be positioned generally centrally between the two lateral sides of the agitator. As a relatively heavy component, the electric motor being positioned generally centrally may improve the balance of the suction nozzle.
The drive assembly may comprise a gearbox.
This may allow the drive assembly to rotate the agitator with advantageously high speed or torque, thereby improving its agitating action.
As an alternative, the prime mover of the drive assembly (for example an electric motor or turbine) may be connected directly to the agitator such that the two co-rotate.
Preferably, the gearbox is at least partially received within the agitator. This, again, can improve the compactness of the suction nozzle.
The gearbox may be an epicyclic gearbox.
This may provide the gearbox with an advantageously high gear ratio without occupying excessive space.
The sun gear, and the carrier of the planet gear or gears, may supportably engage one another.
The engagement between the sun gear and the planet carrier can limit misalignment therebetween. This can limit the uneven loading between planer gears (or between different regions of a single planet gear) which may occur due to misalignment, such uneven loading being a particularly common cause of noise and/or vibration within epicyclic gearboxes.
The sun gear may comprise a projection which is rotatably received within the planet carrier. A bearing such as a plain bearing or a roller bearing may be positioned between the projection and the planet carrier so as to reduce the friction therebetween.
The planet carrier may be supported by a further soft mounting member.
The further soft mounting member may limit the propagation of vibrations from the planet carrier to other components, and/or accommodate slight misalignment between the planet carrier and another component (such as the agitator or a support structure).
The idea of a soft mounted planet carrier is synergistic with the idea of the planet carrier and sun gear supportably engaging one another. If the planet carrier was only connected to the sun gear by the planet gear(s), the further soft mounting member allow the planet carrier to move slightly may introduce the uneven loading on the planet gear(s). The planet carrier and sun gear supportably engaging one another prevents this, however, as discussed above.
The gearbox may be mounted to the support member via the motor, and be mounted to the motor via a third soft mounting member.
The third soft mounting member may advantageously reduce the propagation of vibration from the gearbox to the motor (and thus to the agitator and/or casing), and/or may accommodate slight misalignment between the gearbox and the motor.
The agitator may be removable from the suction nozzle.
This can allow the agitator to be repaired or unclogged (for instance removing hair that has tangled around the agitator) with advantageous ease. In contrast, if the agitator was permanently mounted within the suction chamber then the user would have to reach their fingers into the suction nozzle, which can be relatively fiddly. The agitator being removable also allows the agitator to be replaced if necessary, rather than the entire suction nozzle having to be replaced as a single unit.
The agitator may be removable along the axis, out of an opening in a side of the casing.
This may provide a mechanism for agitator removal which can easily understood by the user. Instead or as well, it may place relatively few design constraints on the remainder of the suction nozzle.
The drive assembly may project in cantilevered fashion from a portion of the casing to which the support member is mounted.
This may allow the soft mounting members to provide the greatest possible reduction of vibration propagation. In contrast, if the drive assembly were supported at both ends then however effectively the soft mounting members reduced vibration propagation, vibration may be able to travel to the agitator and/or the casing through the component(s) supporting the drive assembly at the opposite end thereof to the support member.
The drive assembly preferably projects from a sidewall at one lateral end of the suction nozzle, and drivingly engages the agitator at the opposite lateral end of the suction nozzle.
The support member may engage the agitator such that substantially no relative translation therebetween can occur.
In other words, the support member may support the agitator such that the agitator can rotate about the axis, but cannot move radially with respect to that axis, or move such that said axis moves, to any significant extent.
This may be beneficial in that excessive movement of the agitator relative to the support member can be avoided (with the second soft mounting member nonetheless avoiding propagation of vibration from the agitator). In contrast, if the agitator was soft-mounted to the support member then the combined action of that soft mounting and the soft mounting provided by the second soft mounting member may allow the agitator to move sufficiently to affect the evenness of the agitating action provided on a floor surface, and may even allow the rotation of the agitator to become unstable.
The support member preferably defines at least part of a coolant path through which an air flow is passed through or over at least part of the drive assembly so as to cool it.
This may allow the suction nozzle to be relatively small and/or of advantageously simple design (thus making the suction nozzle relatively cheap or quick to produce), in contrast to an arrangement where the coolant path must be provided entirely separately to the support member.
According to a second aspect of the present invention there is provided a vacuum cleaner comprising a suction nozzle according to the first aspect of the invention, a dirt separator, and a vacuum motor configured to draw air into the suction chamber of the suction nozzle and then into the dirt separator.
This may provide a vacuum cleaner which provides one or more of the advantages discussed above.
According to an arrangement useful for understanding the invention there is provided a suction nozzle for a vacuum cleaner, the suction nozzle comprising an agitator defining a longitudinal axis and being rotatable about said longitudinal axis; a motor configured to rotate the agitator; and a coolant path extending from an inlet to an outlet, wherein the coolant path is configured to direct an air flow from the inlet, past the motor and subsequently over or through the motor, to the outlet.
This can allow the air flow to cool another component of the suction nozzle, while nonetheless cooling the motor adequately. As an example, the coolant path may position the air flow adjacent to the agitator before, during and/or after it runs past the motor. The air flow can therefore cool the agitator, and then subsequently run over or through the motor and thereby cool the motor as well. In contrast, if the air flow ran over or through the motor and then ran adjacent to the agitator, the air flow would cool the agitator to a lesser extent (or may even heat the agitator) due to the air flow having been heated significantly by the motor. If the air flow ran past the motor and adjacent to the agitator but did not then flow over or through the motor, the motor may not be cooled sufficiently and may therefore overheat.
Instead or as well, the air flow running both past the motor and then over or through the motor may increase the time during which the air flow is exposed to heat from the motor, thereby increasing the cooling effect provided to the motor by the air flow. For instance, in the above example the air flow may absorb a first quantity of heat from the motor when running past it, and absorb a second quantity of heat from the motor when subsequently flowing over or through it. If instead the air flow only ran over or through the motor, the first quantity of heat would remain in the motor and potentially contribute to overheating.
The air flow is preferably directed through the motor, rather than over it, after being directed past the motor. This can increase the total amount of heat which can be absorbed by the airflow, and/or can allow components of the motor which get particularly hot (such as commutator brushes) or are particularly vulnerable to overheating (such as the insulation between coils) to be cooled more effectively. Nonetheless, in some embodiments sufficient heat may be removed from the motor by the air flow running over it.
Reference to the air flow being directed ‘past’ the motor is intended to mean that the air flow is directed to traverse the outside of the motor, whether or not the air comes into contact with the motor. Reference to the air flow being directed ‘over’ the motor is intended to mean that the air flow is directed to traverse the outside of the motor while in contact therewith. Reference to the air flow being directed through the motor is intended to mean that the air flow is directed to traverse the inside of the motor.
The coolant path may be configured such that the air flow can absorb heat from the motor while being directed past the motor. Alternatively, the coolant path may space the air flow apart from the motor (while directing the air flow past the motor) so that the air flow absorbs negligible heat from the motor while being directed past it.
The coolant path may be configured to prevent said flow of air from contacting the agitator.
This can avoid the need for a dynamic seal (which can be relatively complex and expensive to produce) to be provided so as to prevent the air flow from leaking out of the coolant path.
The coolant path may be configured to prevent the air flow from contacting the motor as the air flow is directed past the motor.
The air flow not contacting the motor as it is directed past the motor can reduce the amount of heat the air flow collects from the motor as it passes the motor. The air flow may therefore be cooler during and after passing the motor, enabling the air flow to provide enhanced cooling to another component of the suction nozzle.
The motor may be received at least partially inside the agitator.
For example, at least 50% or at least 75% of the total axial length of the motor may be positioned inside the agitator. Preferably, the motor is received entirely inside the brush bar.
The motor being received at least partially inside the brush bar may provide an advantageously compact arrangement, in comparison to an arrangement where the agitator and motor are housed separately. In an arrangement with the motor at least partially received within the agitator, less space may be provided around the motor. The problem of the motor overheating can therefore be more acute, and therefore applying the above described solution to such an arrangement may be particularly beneficial.
The coolant path may be configured to direct said air flow past the motor between the motor and the agitator.
This may allow the air flow to cool the agitator as it passes the motor. Conventionally, the agitator is not particularly vulnerable to heat, however the agitator is often positioned in a manner that allows it to be touched by a user. It may therefore be advantageous in terms of safety for the agitator to be cooled in this manner.
Optionally, the suction nozzle further comprises two generally concentric sleeves; said sleeves are at least partially received inside the agitator; the motor is at least partially received inside said sleeves; and the coolant path is configured such that to said air flow runs in between said two sleeves past the motor, and runs inside said two sleeves over or through the motor.
The concentric sleeves may be an advantageously simple way of preventing the air flow from contacting the agitator and from contacting the motor while running past it, while allowing the air flow to run over or through the motor.
The suction nozzle may further comprise a gear assembly via which the motor can rotate the agitator, and the coolant path may further be configured to direct said air flow over or through said gear assembly.
The gear assembly may undergo significant heating due to friction between the meshing gears therein. It may therefore be particularly beneficial for the air flow to be directed over or through the gear assembly so that the gear assembly can be cooled.
Where the air flow is directed through the gear assembly rather than over it, this may provide particularly intensive cooling of the gear assembly. However, where the air flow is directed over the gear assembly rather than through it, this may beneficially reduce the chances of the air flow picking up wear particles from the gear assembly and depositing them on the motor (which may damage the motor).
Optionally, the gear assembly is an epicyclic gear train comprising a sun gear, one or more planet gears mounted on a carrier, and a ring gear; and the coolant path is configured to direct said air flow over the ring gear of the gear assembly.
The air flow being directed over the ring gear may offer the best compromise between maximising the cooling of the gear assembly and minimising the risk of the air flow picking up wear particles—the air flow contacts one of the gears of the gear assembly and may therefore provide good cooling, but does not flow inside the ring gear (where wear particles may accumulate).
The coolant path may be configured to direct the air flow over or through the gear assembly before directing the flow of air over or through the motor.
The air flow passing over or through the gear assembly before passing over or through the motor may allow both components to be cooled satisfactorily. In contrast, if the air flow passed over or through the motor before passing over or through the gear assembly, the gear assembly may be inadequately cooled (or even heated) due to the air flow being too hot from the motor.
The coolant path may be configured to direct said air flow into the agitator at an axial end of the agitator, and out of the agitator at the same axial end.
The air flow entering and exiting the agitator at the same axial end can reduce the number of design constraints placed on the other axial end of the agitator. For instance, the opposite axial end of the agitator can be engaged by the motor (or a component drivably connected thereto) and/or rotatably supported by a housing of the suction nozzle, without any complications being caused by the need to also accommodate a part of the coolant path.
The coolant path may be configured to direct said air flow to run along at least 50% of the axial length of the agitator. For instance, the coolant path may be configured to direct said air flow to run along at least 60% or at least 70% of the axial length of the agitator.
This can increase the proportion of the agitator which can be cooled by the air flow, and/or increase the amount of time the air flow spends in proximity to the agitator and able to receive heat therefrom.
The inlet may be configured such that air entering the inlet to form said air flow is taken from outside the suction nozzle.
This may mean that the air flow is cleaner, in comparison to an arrangement where the air enters the inlet from inside the suction nozzle, where dirt may be entrained therein. That dirt may then clog the coolant path and/or build up on a component such as the motor and affect its performance.
The inlet is preferably positioned in an upper region of the suction nozzle. This may reduce the possibility that dirt resting on a surface being treated becomes entrained in the air entering the inlet, in comparison to an arrangement where the inlet is positioned at a lower region.
The agitator may be a brush bar configured for agitating the fibres of a carpeted surface so as to release dirt therefrom. As one alternative, the agitator may be a polishing buffer. As another alternative, the agitator may be a rotating mop.
The coolant path may comprise a passage of annular cross section relative to the direction of movement of the air flow therethrough.
This may allow the cooling effect of the air flow through the coolant path to be more evenly distributed.
The annular section may be positioned circumferentially around the longitudinal axis of the agitator, and/or circumferentially around part of the motor (and/or part of the gear assembly, where present).
The passage of annular cross section may be a single annular passage, or an annular array of discrete flow passages.
Where the suction nozzle comprises generally concentric sleeves as discussed above, the passage of annular cross section may be provided between the two sleeves.
The motor may be mounted to one end of the suction nozzle, and engage the agitator at an opposite end of the suction nozzle.
For the avoidance of doubt, features described above in relation to arrangements useful for understanding the invention may be applied to aspects of the invention, as appropriate.
An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
Throughout the description and drawings, corresponding reference numerals denote corresponding features.
The suction nozzle 6 is shown in isolation in
The suction nozzle has a pair of large debris slots 28 in the sole plate 20, and a pair of bleeds 30 which run through the front casing. The large debris slots 28 and bleeds 30 can be opened and closed by a slidable switch 32 provided on the front casing 16c, but the function and structure of these components is not material to the present invention and therefore will not be described in detail.
In use, a user passes the suction nozzle 6 across a surface to be cleaned. The sole plate 20 engages the surface and air is sucked into the suction chamber 18 through the suction opening 22. The air is then drawn out of the suction chamber 18 and into the rolling assembly 4 through the outlet duct 12. When the suction nozzle 6 is resting on a hard surface such as a laminate floor, the suction nozzle 6 is supported by the wheels 21. However, when the suction nozzle 6 is resting on a carpeted surface, the wheels 21 sink into the pile of the carpet and the suction opening 22 is therefore positioned further down. This allows carpet fibres to protrude through the suction opening 22, whereupon they are disturbed by the rotating agitator 24 so as to loosen dirt and dust therefrom. The mechanism by which the agitator 24 is driven will now be described, with reference to
The agitator 24 has a substantially tubular part 24a in which the grooves 27 are provided, and a closed end part 24b. A drive assembly 33 arranged to rotate the agitator about the axis 26 is received entirely within the agitator 24. The drive assembly 33 comprises an electric motor 34 which is positioned approximately centrally between the two lateral sides (i.e. sidewalls 16e, 16f) of the suction nozzle, fully within the tubular part 24a or the agitator 24. The motor 34 is of conventional design and therefore will not be described in detail. The drive assembly further comprises a gearbox 36 through which the motor 34 drives the agitator. The gearbox 36 takes the form of an epicyclic gear train which comprises a sun gear 38, three planet gears 40 mounted on a carrier 42, and a ring gear 44. The gearbox 36 is mounted to the support member 72 via the motor 34. The gearbox 36 is mounted to the motor by virtue of the ring gear 44 being mounted to a casing 46 of the motor 34 by a gear adaptor 48. The ring gear 40 is mounted to the gear adaptor 48 via a cover 68, and the gear adaptor 48 is mounted to the casing 46 of the motor.
The sun gear 38 is fixedly mounted on an output shaft 50 of the motor 34. The carrier 42 is fixedly mounted to a drive dog 54. The drive dog 54 has an external array 56 of teeth which mesh with an internal array of complementary teeth provided on the agitator 24. Accordingly, when the motor 34 is energised, the output shaft 50 and thus the sun gear 38 rotates and the ring gear 44 remains stationary. The planet gears 40 orbit the sun gear 38 and therefore the carrier 42, and thus the drive dog 54 and agitator 24, rotate as well. The gearbox 36 gears down the drive from the motor 34 so that the agitator 24 rotates at a lower speed, but under higher torque, than the output shaft 50 of the motor.
It is noteworthy that the sun gear 38 and carrier 42 supportably engage one another. More specifically, the output shaft 50 extends through the sun gear 38 and forms a projection 51 thereof which is received within the planet carrier 42. A plain bearing 52 engages the projection 51 and the planet carrier 42, reducing friction therebetween (as the projection rotates inside the planet carrier).
The gear adaptor 48 extends circumferentially around the motor 34 and ring gear 40, and has a circumferentially-spaced set of arms 60 with gaps 62 therebetween. The gaps 62 extend radially inwards through the gear adaptor and terminate at positions axially aligned with breather holes 64 in the front of the casing 46 of the motor 34. An o-ring 66 is positioned between the gear adaptor 48 and the casing 46 of the motor 34. The axial end of the ring gear 44 opposite to the motor 34 is positioned inside a cover 68. Like the gear adaptor 48, the cover 68 extends circumferentially around the ring gear 44. These features of the gear adaptor 48 and cover 68 are more clearly visible in
The drive assembly 33 is mounted to the casing 16 via a support member 72, and is mounted to the support member 72 by a first soft mounting member 76. More particularly, the motor 34 of the drive assembly 33 is mounted to a motor adaptor 74 which is mounted to the first soft mounting member 76, and the first soft mounting member 76 is mounted to the support member 72. The support member 72 is attached to the casing 16 via a second soft mounting member 82. More particularly, the support member 72 is mounted to a mounting member 78 via a sealing member 80, and the mounting member 78 is attached to the end wall 16e of the casing 16 via the second soft mounting member 82. In this embodiment, the first soft mounting member 76 and the second soft mounting member 82 each take the form of an elastomeric component.
The drive assembly 33 projects from end wall 16e (the portion of the casing to which the support member 72 is mounted) in cantilevered fashion. In other words, the drive assembly is not supported at the end of the drive assembly opposite to the end mounted on the end wall 16e by the mounting member 72. The drive assembly, more specifically the drive dog 54 of the drive assembly, engages the agitator 24 at the opposite lateral end of the suction nozzle 6 (i.e. the end on which end wall 16f is provided).
It is noteworthy that the cover 68 is made of elastomeric material, and forms a third soft mounting member. The cover 68 permits relative movement of the ring gear 40 and the motor 34, thereby acting to deaden the propagation of vibration therebetween and accommodating any slight misalignment between the ring gear 40 and the motor 34 (more particularly the output shaft 50 of the motor).
The motor adaptor 74 is generally cup-shaped, with its open end abutting the casing 46 of the motor 34 so that inside space 84 of the motor adaptor 74 is in communication with breather holes 86 in the rear of the casing 46 of the motor 34. The closed end of the motor adaptor 74 has an aperture 88 in communication with the inside space 84.
The support member 72 is generally cylindrical, and has a hollow interior which defines an inflow chamber 90, an outflow chamber 92 and a wiring chamber 94. Each of these chambers 90, 92, 94 is open at each axial end of the support member 72. The support member 72 also has a radial aperture 96 in fluid communication with the inflow chamber 90. As discussed below, the support member 72 also supports the agitator 24 in the suction chamber 18.
The mounting member 78 and second soft mounting member 82 co-operatively define a generally L-shaped channel 98 with a generally radially-extending arm 100 and a generally longitudinally-extending arm 102. Arm 100 has an axially-facing aperture 101 therein. Arm 102 is positioned within a duct 104 defined in the lower casing 16b. The duct 104 runs generally axially and terminates at the outlet 12. The mounting member 78 and second soft mounting member 82 also define an inlet chamber 106 which is separate to the L-shaped channel 98, and which is positioned in fluid communication with a vent 108 in end wall 16e. The mounting member 78 and second soft mounting member 82 also define an aperture 110 in fluid communication with the inlet chamber 106.
The wiring chamber 94 of the support member 72 is closed (in this case sealed) at one end by first soft mounting member 76, and at its other end by sealing member 80. The wiring chamber 94 is therefore air-tight. Wiring 112 for transmitting electrical power to the motor 34 runs through a wiring chamber 94 of the support member 72, and through a ferrite toroid 114 for suppressing electrical noise that is also positioned inside the wiring chamber.
The inflow chamber 90 of the support member 72 is sealed closed at one end by first soft mounting member 76, but at its other end is sealed against the aperture 110 in the mounting member 78 and second soft mounting member 82. The inflow chamber 90 is therefore in fluid communication with the inlet chamber 106.
One end of the outflow chamber 92 is sealed against the aperture 88 of the motor adaptor 74 by a duct 115 of the first soft mounting member 76. The outflow chamber 92 is therefore in fluid communication with the inside space 84 of the motor adaptor 74. The other end of the outflow chamber 92 is sealed against the aperture 101 in the radially-extending arm 100 of the L-shaped channel 98 by sealing member 80. The outflow chamber 92 is therefore also in fluid communication with the duct 104 in the lower casing 16b.
The suction nozzle 6 also has an inner sleeve 116 and an outer sleeve 118 positioned generally concentrically with respect to one another. The sleeves 116, 118 are received inside the agitator 24, and the drive assembly 33 is received almost entirely within the sleeves (with the exception of the drive dog 54). The sleeves 116, 118 extend circumferentially around the motor 34 and gearbox 36, and are concentrically positioned inside the tubular part 24a or the agitator 24. The inner sleeve 116 is supported on first soft mounting member 76, an o-ring 120 positioned around the motor adaptor 74, an o-ring 122 positioned around the gear adaptor 48, and the cover 68.
The outer sleeve 118 is supported on a sealing member 124 that is mounted on the support member 72, and an o-ring 126 positioned around the inner sleeve 116. The sleeves 116, define a generally annular gap 128 therebetween which forms part of a coolant flow path through which ambient air is drawn into the cleaner head through a vent 108 in the end wall 16f, over the gearbox 36, through the motor 34 and into the suction chamber 18. This will be described in more detail later. As is also discussed in more detail later, the gap 128 forms a passage of annular cross section (relative to the direction of movement of the air flow therethrough). This passage is positioned circumferentially around the agitator axis 26, and circumferentially around the motor 34 and the gearbox 36.
The inner sleeve 116 has an inlet aperture 130 at one end, a circumferential array of outlet apertures 132 at the other end, and a circumferential array of longitudinal ridges 134. The inner sleeve 116 also provides additional support for the carrier 42 via a bearing 135 and an elastomeric bearing cover 137. The bearing cover 137 forms a further soft mounting member which supports the planet carrier 42, limiting the propagation of vibration between the planet carrier 42 and the inner sleeve 116, and accommodating a small amount of misalignment therebetween (to the extent that this is permitted by the engagement between the projection 51 of the sun gear 38 and the carrier 42).
The ridges 134 project radially outwards towards the outer sleeve 118, but are nonetheless radially spaced therefrom. The inlet aperture 130 of the inner sleeve 116 is positioned in alignment with the aperture 96 in the inflow chamber 90 of the support member 72. Accordingly, the gap 128 between the sleeves 116, 118 is in fluid communication with the inflow chamber 90. Each outlet aperture 132 is positioned in alignment one of the gaps 62 in the gear adaptor 48, therefore the gap 128 is also in fluid communication with the breather holes 64 in the front of the casing 46 of the motor 34.
The suction nozzle 6 defines a coolant path configured to direct an air flow from an inlet, past the motor and subsequently over or through the motor, to an outlet. In this case, the vent 108 in the end wall 16e forms the inlet of the coolant path, the duct 104 in the lower casing 16b forms the outlet, and the coolant path directs the air flow past the motor and subsequently through the motor. The coolant path runs through the vent 108, into the inflow chamber 109 through the inlet chamber 106, and into the gap 128 between the sleeves 116, 118. The air flow is then directed past the motor, axially along the gap 128 between the sleeves. The air then flows out of the gap 128, over the gearbox 36 and through the motor 34 inside of the sleeves 116, 188. It then flows into the outflow chamber 92, through the L-shaped channel 98 and duct 104, and exits the suction nozzle 6 through the outlet 12. This will be described in more detail below.
When the vacuum cleaner 2 is in use, the vacuum motor reduces the pressure at the outlet 12. This, in turn, reduces the pressure inside the suction chamber 18 so as to draw air into it through the suction opening 22. Since the duct 104 is in fluid communication with the outlet 12, the pressure in the duct is also reduced. This acts to draw an air flow (in this case a separate air flow to the dirt-entraining air entering the suction chamber 18 through the suction opening 22) through the coolant path. The air flow enters the coolant path through the vent 108 and into the inlet chamber 106 that is defined by the mounting member 78 and sealing member 83. The vent 108 is positioned on an external surface of the suction nozzle 6, and therefore the air flow is taken from the relatively clean air outside the suction nozzle. In contrast, if the air flow was taken from the suction chamber 18 then dirt entrained therein would be passed through the coolant path, potentially clogging the coolant path and/or damaging the motor. The vent 108 is also positioned at an upper region of the suction nozzle 6 so as to space it apart from the surface being cleaned and thereby reduce the chances of the air flow entering the vent 108 entraining dirt resting on the surface.
From the inlet chamber 106, the air flow is drawn into the inflow chamber 90 through the aperture 110, and then into the gap 128 through the radial aperture 96 of the support member 72 and the inlet aperture 130 in the inner sleeve 116. The second soft mounting member 82 acts as an air seal in that it prevents leakage of air out of the inflow chamber around the outside of the mounting member 78. Further, the air flow is prevented from leaking out of the coolant path between the inner sleeve 116 and motor adaptor 74 by the first soft mounting member 76 engaging the inner sleeve. The first soft mounting member 76 is therefore also positioned to act as an air seal. In some situations some of the air flow may leak out between the inner sleeve 116 and the support member 72, however any such air would nonetheless be directed into the gap 128 by sealing member 124.
Upon entering the gap 128 through the inlet aperture 130 of the inner sleeve 116, the air can flow circumferentially around the gap, between the ridges 134 and the outer sleeve 118. The air flow then flows axially along the gap 128, between the motor 34 and the agitator 24, past the motor while circumferentially distributed around it. As the air flow passes the motor 34, it absorbs some heat therefrom and therefore has a cooling effect on the motor. The air flow also absorbs heat from the agitator 24 as the air flows along the gap 128 (and to a lesser extent as the air flows along the inflow chamber 90), ensuring that the agitator remains cool enough to be touched by the user.
When the air flow running axially along the gap 128 reaches the outlet apertures 132, it has run along around 70% of the total axial length of the agitator 24 (around 20% of the length of the agitator in the inflow chamber 90, and around 50% if the length of the agitator in the gap 128). This relatively large proportion means that the cooling influence of the air flow is experienced by a larger proportion of the agitator 24. This is particularly true for the proportion of the axial length of the agitator 24 along which the air passes whilst in the gap 128, since the air flow is positioned closer to the agitator while in the gap.
Once the air flow has reached the outlet apertures 132 of the inner sleeve 116, the air flow runs over the parts of the ring gear 44 that are left exposed by the cover 68 and the arms 60 of the gear adaptor 48, and into the gaps 62 of the gear adaptor. As the air flow passes over the ring gear 44, it absorbs heat therefrom and therefore cools the ring gear 44 (and thus the gearbox 36 as a whole). Air is prevented from leaking out of the coolant path past the outlet apertures 132 in between the sleeves 116, 118 by o-ring 126, and is prevented from leaking out between the inner sleeve 116 and the gear adaptor 48 by o-ring 122. Further, air is prevented from leaking out of the coolant path and into the gearbox 36 between the ring gear 44 and the motor casing 46 by o-ring 66, and is prevented from leaking out between the inner sleeve 116 and ring gear 44 by sealing engagement between the ring gear, elastomeric cover 68 and inner sleeve 116. The cover 68 (the third soft mounting member) is therefore also positioned to act as an air seal.
Since the air flow runs past the motor 34 between the sleeves 116, 118, as the air flow is directed past the motor it is prevented from contacting the motor. The inner sleeve 116 spaces the air flow apart from the motor 34, therefore the air flow does not absorb as much heat from the motor at this point as it would do if the inner sleeve was absent and the air flow could run over the motor. The air flow is therefore cooler when it reaches the gearbox 36, and is thus more able to cool it. That being said, the inner sleeve 116 conducts heat away from the motor 34 and a significant proportion of this heat is absorbed by the air flow, therefore the air flow nonetheless has a cooling effect on the motor 34 as it is directed past it.
The outer sleeve 118 (along with the inflow and outflow chambers 90, 92 of the support member 72) is positioned to as to prevent the air flow from contacting the agitator. In contrast, if the outer sleeve 118 was absent and tubular portion 24a of the agitator 24 formed a wall of the coolant flow path, it would be necessary to provide kinetic seals at each end of the tubular portion (e.g. one between the tubular portion 24a and the first soft mounting member 76, and another between the tubular portion and the end of the inner sleeve 116 which supports the carrier 42). Such kinetic seals are generally relatively expensive, require relatively tight tolerances and wear out relatively quickly.
From the gaps 62 in the gear adaptor 48, the air flow runs into the casing 46 of the motor 34 through the breather holes 64, through the motor, out of the motor through the holes 86 and into the inside space 84 of the motor adaptor 74. As the air flow passes through the motor 34, it absorbs further heat from the motor, thereby providing an additional cooling effect thereto.
From the inside space 84 of the motor adaptor 74, the air flow runs through the aperture 88 in the motor adaptor, through the duct 115 of the first soft mounting member 76 and into the outflow chamber 92 of the support member 72. Leakage of air out of the coolant path between the motor adaptor 74 and first soft mounting member 76 is prevented by engagement between the first soft mounting member 76 and the inner sleeve 116 and by the o-ring 120.
The air in the outflow chamber 92 is then drawn through the aperture 101 into radially-extending arm 100 of the L-shaped channel 98 defined by the mounting member 78 and second soft mounting member 82. The air then flows along the L-shaped channel 98, into the duct 104 which forms the outlet from the coolant path. The air flow then merges with dirt-entrained air flowing from the suction chamber 18, and exits the suction nozzle 6 through the outlet 12.
It is noteworthy that in this embodiment the air flow through the coolant path flows over the gearbox 36 and then through the motor 34. This ensures that the gearbox is cooled sufficiently. If instead the air flow passed through the motor 34 and then over the gearbox 36 (which may appear to be preferable at first glance, so as to avoid wear particles from the gearbox from being drawn into the motor), the air flow may be too hot by the time it reaches the gearbox for the gearbox to be cooled adequately.
It is also to be noted that in this embodiment the coolant path directs the air flow to enter the agitator 24 at one axial end (through the aperture 110 and the inflow chamber 90), and to exit the agitator at the same axial end (through the outflow chamber 92 and the aperture 101). This enables the opposite end of the agitator and the associated structure to be relatively simple in comparison to an arrangement where the coolant path was required to pass through this end of the agitator as well.
In this embodiment, the agitator 24 is removable from suction chamber 18 (and from the suction nozzle 6 in its entirety). More particularly, it is removable from around the drive assembly 33. This will be described in more detail below with reference to
The agitator is supported for its rotation on two bearings 142, 144. Bearing 142 is positioned in the hair ingress flange 140 of the end cap, and engages a stub 146 of the closed end part 24b of the agitator 24. Bearing 144 is positioned on the support member 72. The support member 72 therefore supports the agitator for rotation inside the suction chamber 18. Bearing 144 is positioned adjacent to another hair ingress flange 148, and engages the inside of the tubular part 24a of the agitator 24 via a support ring 150. The support ring 150 has a circumferential array of spaced-apart fins 152 which slidingly engage the tubular part 24a of the agitator. The fins 152 being spaced apart means that any pressure difference across the support ring 150 (for instance due to a temperature difference) can equalise. Otherwise, this pressure difference could pull dirt into the bearing 144 and clog it. The support ring 150 is substantially rigid, therefore the engagement between the support member 72 and the agitator 24 substantially prevents relative translation between the agitator and the support member (while the bearing 92 allows the agitator to rotate in a fixed position 24 relative to the support member 72).
The end cap 138 has circumferential array of recesses 154, each recess being bounded by an outwardly-projecting ridge 156. The aperture 136 has a complementary circumferential array of projections in the form of lugs 158. The end cap 138 can be attached to the casing suction nozzle 6 by rotating the end cap about the longitudinal axis 26 of the agitator 24 to a locked position, which positions each lug 158 within a corresponding recess 154. In other words, the ridges 156 are ‘hooked’ onto the lugs 158. The end cap 138 can be released from the suction nozzle 6 by rotating the end cap 138 to the unlocked position, which positions the lugs 158 outside of the recesses 154.
The end cap 138 has a pivotable latch member 160 which can secure the end cap in the locked position. This reduces the risk of the end cap 138 being rotated to the unlocked position (thereby potentially opening the aperture 136 and releasing the agitator 24) unintentionally, for instance due to a knock. The latch member 160 is pivotably mounted on the end cap 138, and has a latch tooth (not visible) and a push-button 162. The latch tooth (not visible) engages an abutment surface 164 provided on the lower casing 16b so as to prevent rotation of the end cap 138 to the unlocked position. Further, the latch tooth (not visible) can be lifted out of alignment with the abutment surface by pressing the button 162 and thereby pivoting the latch member 160.
The agitator 24 slidably engages the bearing 144 via the support ring 150 as noted above. However, the stub 146 of the agitator 24 and the bearing 142 exhibit an interference fit. Accordingly, when a user removes the end cap 138, the agitator is removed along with it. Nonetheless, the agitator 24 and end cap 138 are separable from one another by applying sufficient force to overcome the interference fit between the bearing 142 and the agitator 24.
It will be appreciated that numerous modifications to the above described embodiments may be made without departing from the scope of invention as defined in the appended claims. For instance, in a modification of the above embodiment the first and second soft mounting members may be two parts of a single elastomeric moulding. For instance they may be two ends of a moulding which covers substantially all of the outer surfaces of the support member and mounting member.
It is to be noted that although the mounting member has been described as an independent component, it may instead be considered to be part of a two-piece support element. Equally, it may be considered to be part of a two-piece second soft mounting member.
Claims
1. A suction nozzle comprising a casing which defines a suction chamber, and an agitator rotatably mounted within the suction chamber, wherein:
- the agitator is supported in the suction chamber by a support member;
- a drive assembly arranged to rotate the agitator about an axis is mounted to the casing via the support member, and is mounted to the support member via a first soft mounting member; and
- the support member is mounted to the casing via a second soft mounting member.
2. The suction nozzle of claim 1, wherein the first or second soft mounting member comprises an elastomeric component.
3. The suction nozzle of claim 2, wherein said elastomeric component is positioned to act as an air seal.
4. The suction nozzle of claim 1, wherein the drive assembly comprises an electric motor.
5. The suction nozzle of claim 3, wherein the drive assembly comprises an electric motor and the electric motor is at least partially received inside the agitator.
6. The suction nozzle of claim 1, wherein the drive assembly is at least partially received inside the agitator.
7. The suction nozzle of claim 1, wherein the drive assembly comprises a gearbox.
8. The suction nozzle of claim 7, wherein the gearbox is an epicyclic gearbox.
9. The suction nozzle of claim 8, wherein a sun gear and a carrier of at least one planet gear of the epicyclic gearbox supportably engage one another.
10. The suction nozzle of claim 7, wherein a carrier of the gearbox is supported by a further soft mounting member.
11. The suction nozzle of claim 7, wherein the gearbox is mounted to the support member via a motor, and is mounted to the motor via a third soft mounting member.
12. The suction nozzle of claim 1, wherein the agitator is removable from the suction nozzle.
13. The suction nozzle of claim 1, wherein the drive assembly projects in cantilevered fashion from a portion of the casing to which the support member is mounted.
14. The suction nozzle of claim 1, wherein the support member engages the agitator such that substantially no relative translation therebetween can occur.
15. A vacuum cleaner comprising the suction nozzle of claim 1, a dirt separator, and a vacuum motor configured to draw air into the suction chamber of the suction nozzle and then into the dirt separator.
Type: Application
Filed: Aug 31, 2018
Publication Date: Jan 21, 2021
Applicant: Dyson Technology Limited (Wiltshire)
Inventors: Daniel Martin TAYLOR (Bristol), Martin Deric CUTTING (Swindon), Oliver Rayleigh STRUTT (Gloucester), Samuel Fraser TWIST (Bristol)
Application Number: 17/042,587
