Cleaner head

Abstract

A cleaner head including a motor and a gear assembly is provided. The motor produces a driving rotational motion which drives a cleaning element in a cleaning motion. The gear assembly includes a gear element eccentrically drivable by an input rotational motion having a first rotational speed, and the gear assembly is configured such that when the gear element is eccentrically driven by the input rotational motion, the gear assembly produces an eccentric output rotational motion at a second rotational speed, the second rotational speed different from the first rotational speed. The driving rotation of the motor is transmitted to the gear assembly and used to drive a liquid pump.

Description

[0001] CLEANER HEAD

[0002] BACKGROUND

[0003] Appliances for cleaning or treating surfaces may comprise a cleaner head that is in contact with the surface to be cleaned or treated in use. Some appliances utilise liquids, such as water, to clean or treat a surface. Such liquids may be utilised alongside a roller, mop, wipe, or other component for applying a wiping force to the surface.

[0004] SUMMARY

[0005] A first aspect of the invention provides a cleaner head. The cleaner head comprises a motor, and a gear assembly. The motor is configured to produce a driving rotational motion to drive a cleaning element. The gear assembly is configured to drive a liquid pump. The gear assembly comprises a gear element eccentrically drivable by an input rotational motion having a first rotational speed. The gear assembly is configured such that when the gear element is eccentrically driven by the input rotational motion, the gear assembly produces an eccentric output rotational motion at a second rotational speed, the second rotational speed being different from the first rotational speed. The cleaner head is configured such that, when the motor produces the driving rotational motion: the driving rotational motion of the motor is transmitted to the gear assembly and used as the input rotational motion, and the eccentric output rotational motion of the gear assembly is transmitted to the liquid pump.

[0006] As the driving rotational motion of the motor is transmitted to the gear assembly and used as the input rotational motion, and the eccentric output rotational motion of the gear assembly is transmitted to the liquid pump and used as the eccentric driving rotational motion, the cleaning element and the liquid pump are both driven by the motor, rather than requiring separate motors. This can allow the cleaner head to be more compact and / or more lightweight compared with a cleaner head in which a first motor drives the cleaning element and a second motor drives the liquid pump.

[0007] The gear assembly converts an input first rotational speed to an output second rotational speed which is different from the first rotational speed, or in other words brings about a speed conversion from the input rotational speed to the output rotational speed. The gear assembly means the motor can drive the cleaning element at a higher speed or lower speed than the liquid pump. This can allow for more effective performance of either or both of the cleaning element and the liquid pump. For example, the liquid pump can dispense a more appropriate volume of liquid which may not occur if driven at the different rotational speed used to drive the cleaning element. Similarly, the cleaning element can be driven in a more effective cleaning motion which may not occur if driven at the different rotational speed used to drive the liquid pump.

[0008] The gear assembly converts an input first rotational motion to an output second rotational motion which is eccentric. The liquid pump, which is driven by an eccentric driving rotational motion, can thereby be driven by the output of the gear assembly without necessarily requiring intermediate components, for example. This can be contrasted with gear assemblies which produce a second rotational motion which is not eccentric, for example a typical cycloidal gear assembly. In such cases, an intermediate component would be required to drive the eccentrically-driven liquid pump. By avoiding the need for intermediate components, the cleaner head can be more compact and / or lightweight, for example.

[0009] The gear assembly converts the input first rotational motion having a first rotational speed to the output second rotational motion having a second rotational speed, different from the first rotational speed, by eccentrically driving a gear element. In this way, eccentricity is introduced to the rotational motion concurrently with the conversion in speed from the first rotational speed to the second rotational speed. This can be contrasted with a system in which speed conversion occurs at a first stage or due to a first component, and eccentricity in the rotational motion is introduced at a second stage or due to a second, separate component. The cleaner head can therefore be more compact and / or more lightweight compared with such a system.

[0010] In examples, the first rotational speed is faster than the second rotational speed. That is, the gear assembly brings about a speed reduction. This can be useful when a more appropriate driving rotational speed for the liquid pump is lower than an appropriate driving rotational speed of the cleaning element. This can occur when a vigorous cleaning motion from the cleaning element is required, for example, and only relatively small volumes of liquid are to be dispensed from the liquid pump, for example.

[0011] In examples, the gear assembly comprises a housing and an input shaft; the gear element comprises a cycloidal gear disposed in the housing and movably mounted eccentrically to the input shaft, and the cycloidal gear comprises an output shaft. In such examples, the gear assembly is configured such that when the input shaft undergoes the input rotational motion at the first rotational speed, the output shaft undergoes the eccentric output rotational motion at the second rotational speed. In examples, the cycloidal gear is movably mounted to the input shaft by a bearing. In other examples, a low coefficient of friction exists between the cycloidal gear and the input shaft such that the cycloidal gear is movably mounted.

[0012] In typical cycloidal drives which use cycloidal gears for speed conversion, and in examples speed reduction, an output shaft provided separately to the cycloidal gear engages with the cycloidal gear to remove eccentric motion and revert motion to a rotational motion without eccentricity. In the gear assembly described herein, the output shaft can be directly attached to the cycloidal gear, or is integrated as part of the cycloidal gear, and intermediate components for removing the eccentric motion are not required. Therefore, in examples where the gear assembly comprises a housing and an input shaft, the gear element comprising a cycloidal gear disposed in the housing and movably mounted eccentrically to the input shaft, and the cycloidal gear comprising an output shaft, the gear assembly can be made more lightweight and / or compact, and a risk of failure of the gear assembly and therefore cleaner head can be reduced by reducing the number of moving parts. This can improve an operational lifespan of the cleaner head, for example, which can be a length of time the cleaner head is used for before repair or part replacement is needed, for example. Additionally, the reduction in moving parts can make the gear assembly cheaper to manufacture, and the reduction in degrees of freedom for alignment of moving parts can allow the gear assembly to be more robust to fabrication intolerances, for example. In such examples, a speed conversion ratio of the rotational speed of the input rotational motion to the rotational speed of the output rotational motion can be determined by a design of the housing and a geometry of the cycloidal gear. For example, the housing may comprise a number of pins disposed on an inner circumference of the housing and the cycloidal gear may comprise a corresponding number of teeth, the reduction ratio being determined by their respective values. For example, the gear assembly may be configured such that the first rotational speed is at least nine times greater than the second rotational speed, and the reduction ratio is accordingly 9:1. In examples where the gear assembly comprises a cycloidal gear and housing, the cycloidal gear may comprise 9 teeth and the housing may comprise 10 pins in order to bring about the 9: 1 reduction ratio. This can allow a motor to both drive a relatively high frequency cleaning motion of a cleaning element compared with a relatively low liquid pump frequency.

[0013] In examples, the cleaner head comprises a cleaning element. The cleaning element is configured to be driven in a cleaning motion when coupled to the driving rotational motion produced by the motor. In examples, the cleaner head comprises a liquid storage tank configured to store a liquid. In examples, the cleaner head comprises a liquid pump configured to be driven by the eccentric driving rotational motion of the gear assembly, and configured to dispense the liquid from the liquid storage tank. A cleaner head comprising a cleaning element, liquid storage tank, and liquid pump can provide a compact cleaning appliance which is operable to dispense a liquid on a surface to be cleaned and engage the surface to be cleaned with a cleaning motion.

[0014] In examples, the liquid pump is directly driven by an output member of the gear assembly. In examples where the gear assembly comprises an output shaft, the output member may be the output shaft. Directly driving the liquid pump by the output member can mean there are no other intermediate components for transmitting rotational motion between the gear assembly and the liquid pump, which can improve the compactness of the cleaner head and / or reduce weight, for example. The size and / or weight of the cleaner head can be reduced compared with cleaner heads in which intermediate components are provided between the output member of the gear assembly and the liquid pump, for example. In examples, the liquid pump assembly comprises a diaphragm pump. A diaphragm pump can effectively make use of the eccentric driving rotation by using the eccentric driving rotation to oscillate a membrane of the diaphragm pump and thereby dispense a liquid. In some of these examples, the diaphragm pump comprises a plurality of pumping chambers and the diaphragm pump is configured such that, when the eccentric driving rotational motion drives the liquid pump assembly, the plurality of pumping chambers are sequentially compressed by the eccentric driving rotational motion and sequentially decompress to thereby dispense the liquid. A diaphragm pump comprising a plurality of pumping chambers which are sequentially compressed can thereby dispense liquid in a more continuous fashion compared with a single pumping chamber, for example, which typically has a pulsed fashion to the dispensing of liquid, because each pumping chamber can pump a smaller volume and the overall rate of pumping is higher. Having a more continuous flow of liquid can improve effectiveness of the cleaner head, for example.

[0015] In examples, the cleaning element comprises a roller which, when driven in a cleaning motion by the driving rotational motion of the motor, rotates about a longitudinal axis. The driving rotational motion of the motor can thereby be straightforwardly used to bring about a cleaning motion, which can reduce the requirement for intermediate components, for example, which can reduce the size and / or weight of the cleaner head. In some examples, the roller is configured to rotate at between 500 and 1200 revolutions per minute, and in some examples between 900 and 1000 revolutions per minute. Rotating the roller between 500 and 1200 revolutions per minute, for example between 900 to 1000 revolutions per minute, may help provide particularly good cleaning performance. Furthermore, in cleaner heads comprising a mangle configured to contact the roller and remove liquid from the roller, the aforementioned speeds have been found to provide particularly controlled, reliable and / or precise liquid removal from the roller, improving the performance of the cleaner head. The rate of rotation of the roller may be a steady state operational rotation speed of the roller, that is an average speed maintained through operation of the cleaner head.

[0016] In examples, the motor comprises a motor shaft, a first end of the motor shaft configured to transmit the driving rotational motion to the cleaning element and a second end of the motor shaft configured to transmit the driving rotational motion to the gear assembly. The motor shaft may extend from a first side of the motor and a second side of the motor. In such examples, the motor may be disposed between the cleaning element and the pump. In some such examples wherein the cleaning element comprises a roller, the roller is mounted to the first end of the motor shaft. In comprising a motor shaft which transmits the driving rotational motion to the cleaning element and to the gear assembly, the need for intermediate components is reduced or removed. This can further improve compactness and / or weight of the cleaner head.

[0017] In examples, the cleaning element is configured to receive liquid from the liquid pump. This can enhance the cleaning effected by the cleaning motion of the cleaning element, for example. The cleaning element may comprise an absorbent or partially absorbent material in order to receive liquid from the liquid pump, such that liquid is retained, for example. The absorbent material may be at least partially textured in order to enhance the cleaning effect produced by the cleaning motion. In examples, the liquid pump dispenses water, such as soapy water.

[0018] In examples, the liquid pump is configured to dispense liquid onto the cleaning element. This can reduce waste of liquid which is dispensed but otherwise not utilised by the cleaning element, for example. The liquid pump can be configured to dispense the liquid evenly across the cleaning element to uniformly coat the cleaning element, for example, to thereby improve the uniformity of a cleaning effect by the cleaner head. In other examples, the liquid pump may be configured to dispense liquid near to, but not directly onto, the cleaning element, for example by dispensing liquid onto a surface to be cleaned. This can allow a liquid to, for example, spend a predetermined time on the surface to be cleaned before a cleaning motion on the surface to be cleaned is performed by the cleaning element, which can allow time for chemical reactions to take place to allow for a more effective clean, for example.

[0019] In examples, the liquid pump is configured to dispense liquid at a rate of between 25 and 35 millilitres per minute. This has been found to be a particularly effective rate to deliver liquid such that liquid is used efficiently, for example in handheld devices where only a limited supply of water is appropriate.

[0020] In examples, the gear assembly and liquid pump are configured such that the liquid pump can dispense liquid at a rate of between 25 and 35 millilitres per minute and the cleaning element is configured to be driven at between 500 and 1200 revolutions per minute, and in some such examples between 900 and 1000 revolutions per minute. The cleaner head, in comprising such a gear assembly, liquid pump and cleaning element, is therefore operable to drive the liquid pump and the cleaning element using a single motor and at effective respective driving speeds or driving rates. Driving the liquid pump and the cleaning element at respective appropriate speeds can allow the pump to dispense liquid and the cleaning element to produce a cleaning motion which most effectively coats the cleaning element in liquid, for example, and / or brings about a more effective cleaning effect per volume of liquid, for example.

[0021] According to a second aspect of the invention, there is provided a gear assembly for converting an input rotational motion to an output rotational motion. The input rotational motion has a different rotational speed to the output rotational motion. The gear assembly comprises an input member configured to receive an input rotational motion at a first rotational speed, a gear element configured to be eccentrically driven by the input rotational motion and thereby produce an eccentric output rotational motion at a second rotational speed, the second rotational speed different from the first rotational speed, and an output member configured to output the eccentric output rotational motion at the second rotational speed.

[0022] As illustrated above in view of the first aspect of the invention, this gear assembly can be useful where there is a requirement for both speed conversion and eccentricity of movement, such as that an input rotational motion is converted to a slower eccentric rotational output. In some examples, the gear assembly can drive an eccentrically-driven liquid pump. In other examples, the gear assembly can drive an eccentrically-driven cleaning element. For example, the cleaning element may produce a cleaning motion when oscillated by an eccentric rotational motion. A motor could thereby drive a first cleaning element at a first rotational speed produced by the motor, and use the gear assembly to eccentrically drive a second cleaning element using the eccentric second rotational motion at a slower or faster second rotational speed, to thereby produce a first and a second cleaning motion which have different respective driving speeds to each other.

[0023] In examples, the input member is an input shaft, and the output member is an output shaft, and the gear assembly comprises a housing and a cycloidal gear. The cycloidal gear comprises the output shaft, and is eccentrically and movably mounted to the input shaft and disposed in the housing. The cycloidal gear and the housing are configured such that when the input shaft undergoes the input rotational motion at the first rotational speed, the output shaft undergoes the eccentric output rotational motion at the second rotational speed. In examples, the cycloidal gear is movably mounted to the input shaft by a bearing.

[0024] In examples, the input rotational motion is faster than the output rotational motion.

[0025] According to a third aspect of the invention, there is provided a cleaning appliance comprising the cleaner head according to the first aspect of the invention. The cleaning appliance, in comprising a more compact and / or lightweight cleaner head, can be more effectively operated by a user. For example, the cleaning appliance may be used more precisely due to an improved handling arising from the reduced weight, or may be usable for longer periods of time due to the reduced weight.

[0026] Optional features of aspects of the present invention may be equally applied to other aspects of the present invention, where appropriate.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure l is a schematic view of a cleaner head according to the present invention;

[0029] Figure 2 is a schematic cross-sectional view of a gear assembly according to the present invention; Figure 3 is a schematic perspective view of a cycloidal gear element of the gear assembly of Figure 2;

[0030] Figure 4 is a schematic perspective view of the gear assembly of Figure 2;

[0031] Figure 5a, 5b are schematic plan view and cross-sectional view, respectively, of a liquid pump of the cleaner head of Figure 1; and

[0032] Figure 6 is a schematic illustration of a cleaning appliance comprising the cleaner head of Figure 1.

[0033] DETAILED DESCRIPTION

[0034] A cleaner head 10 according to the present invention is shown schematically in Figure 1.

[0035] The cleaner head 10 comprises a housing 15 and comprises, disposed within the housing 15, a motor 20, a cleaning element 30, a liquid pump 40, a liquid storage tank 42, and a gear assembly 100.

[0036] The gear assembly 100 is shown schematically in isolation in Figures 2, 3 and 4. The liquid pump is shown schematically in isolation in Figures 5a, 5b.

[0037] The motor 20 comprises a shaft 22. The motor 20 comprises a stator assembly (not shown) which comprises one or more coils, or windings, which can generate a magnetic field when energised, and a permanent magnet (not shown) is mounted to the shaft 22. The permanent magnet interacts with the magnetic field and results in a rotational motion of the shaft 22 along a longitudinal rotational axis A. In general, the motor 20 is configured to generate a rotational motion of the shaft 22, with such rotational motion being considered an output of the motor 20. It will be appreciated that the precise configuration of the motor 20 is immaterial to the present disclosure, and that the rotational motion of the shaft 22 can be brought about in a variety of manners. The cleaning element 30 comprises a roller 32 which is rotatably connected to the housing 15 such that the roller 32 is rotatable about a longitudinal axis B, which is parallel with the longitudinal rotational axis A. The roller 32 comprises an external surface formed from a material which is absorbent and comprises a textured external surface. The roller 32, when rotated, thereby undergoes a cleaning motion as the textured external surface, for example, can wipe or scrub a surface to be cleaned. In general, the cleaning element 30 is configured to be driven in a cleaning motion when coupled to a driving force, such as a driving rotation. In other examples the cleaning element 30 may not be a roller but may be a brush which undergoes a back-and-forth cleaning motion, for example.

[0038] The gear assembly 100 comprises a cycloidal gear 110 disposed within a housing 120, as can be seen in cross-sectional view in Figure 2.

[0039] The housing 120 is generally cylindrical, having a length in the direction of axis L (the axis L being into the page in Figure 2, and visible in the perspective view of Figures 3 and 4) and diameter indicated by axis W in Figure 2. The housing 120 comprises a cavity 121 which comprises a generally circular cross section in a plane perpendicular to the length L of the housing 120, and having a circumference which defines an inner circumference of the housing 120. The housing 120 comprises ten pins 126 disposed regularly around the circumference of the cavity 121. That is, there is a regular spacing between nearest- neighbour pins.

[0040] The cycloidal gear 110 is generally cylindrical, having a height in the direction of axis L and a diameter indicated by axis R. The cycloidal gear 110 comprises an aperture 113 positioned centrally relative to the diameter R. On a circumferential external surface the cycloidal gear 110 comprises nine teeth 112. The teeth have a generally curved external surface which has a profile based on epicycloid and hypocycloid curves, the profile being in the cross-sectional plane parallel with the diameter R. The skilled person will be familiar with the gear tooth profile of a cycloidal gear. The regular spacing between neighbouring pins 126 is configured to receive the plurality of teeth 112 of the cycloidal gear 110. When received, at least some of the plurality of teeth 112 of the cycloidal gear 110 engage with at least some of the pins 126. A through-hole (not directly visible in Figure 2) located centrally, relative to diameter of the cavity, in the base of the cavity 121 receives an input shaft 122. The cycloidal gear 110 is disposed within the cavity 121 such that the diameter R of the cycloidal gear is in the same plane as the diameter W of the housing 120. The cycloidal gear 110 is mounted to the input shaft 122 at the aperture 113 by a cam 114 with a rolling-element bearing 124 disposed between the cam 114 and the cycloidal gear 110, the rolling element bearing 124 circumferentially housing the cam 114 (the rolling element bearing not directly visible in Figure 3). The input shaft 122 does not pass through a geometrical centre of the cycloidal gear 110, but instead forms an off-centre axis of rotation. The presence of the cam 114 allows the input shaft 122 to be off-centre relative to the geometrical centre of the cycloidal gear 110. The geometrical centre of the cycloidal gear 110 is therefore off-axis relative to the through-hole, which can be considered a geometric centre of the gear assembly housing 120 and cavity 121. Accordingly, the cycloidal gear 110 sits off-centre within the cavity 121. The geometrical centre of the cycloidal gear 110 being off-axis relative to the input shaft 122 means the cycloidal gear 110 can be considered to be mounted eccentrically.

[0041] In other examples, the rolling-element bearing 124 may not be present, the cam 114 instead directly interfacing with the aperture 113 of the cycloidal gear 110 and the interface between the aperture 113 and the cam 114 permitting movement of the cycloidal gear 110 relative to the cam 114 and input shaft 122. For example, said interface may be lubricated, or the constituent materials the cam and / or aperture 113 are made from having sufficiently low friction to enable relative movement of each component, and in such examples the interface of the aperture 113 with the input shaft 122 could be considered to comprise a plain, or sliding contact, bearing. That is, more generally the cycloidal gear 110 is movably and eccentrically mounted to the input shaft 122, which, as explained, can be achieved in some examples by a lubricated cam, or a cam and a rolling bearing element.

[0042] The cycloidal gear 110 further comprises an output shaft 118 which protrudes generally perpendicular to the diameter R of the cycloidal gear 110 and is positioned centrally relative to the diameter R of the cycloidal gear 110. An outlet aperture 128 of the housing 120 is positioned on a surface opposite the base of the cavity 121 and input shaft 122, and receives the output shaft 118 of the cycloidal gear 110. The output shaft 118 protrudes from the housing 120 of the gear assembly 100 such that it can be engaged with by components external to the gear assembly 100.

[0043] Rotation of the input shaft 122 induces rotation of the cycloidal gear 110. Because the cycloidal gear 110 is mounted eccentrically to the input shaft 122 by the cam 114 and rolling-element bearing 124, and the housing 120 comprises pins 126 configured to engage with the cycloidal gear 110, the cycloidal gear 110 undergoes an eccentric rotation motion, indicated by arrow P in Figure 4, which is slower than the rotation of the input shaft 122. That is, the input shaft 122 is rotated in a first rotational motion at a first rotational speed, and the cycloidal gear 110 and constituent output shaft 118 are accordingly rotated in an eccentric rotational motion at a second rotational speed which is slower than the first rotational speed. An eccentric rotational motion is a rotation about a rotational axis which is off-centre from the rotating component. Accordingly, the cycloidal gear 110, in rotating eccentrically, does not rotate its geometrical centre, but instead precesses around the cavity

[0044] 121 and the rotational axis of the input shaft 122, and so the output shaft 118 also precesses around the outlet aperture 128.

[0045] In this example, the output shaft 118 is positioned centrally relative to the diameter R of the cycloidal gear 110 such that the output shaft 118 tracks a circular path, but it will be appreciated that selecting the position of the output shaft 118 can determine the precise path of the output shaft 118. The outlet aperture 128 should be sufficiently large so as not to restrict movement of the output shaft 118.

[0046] In such a manner, the gear assembly 100 can receive an input rotational motion and convert this input rotational motion to an eccentric output rotational motion. The input rotational motion is faster than the eccentric output rotational motion. The ratio of the speeds of the input rotational motion to the output rotational motion is determined by the configuration of the gear assembly. For example, in this example, the housing having ten pins and the cycloidal gear 110 having nine teeth means the speed reduction ratio is 9: 1, such that the output rotational motion has a speed nine times slower than the input rotational motion. The skilled person will appreciate that, in other examples, other speed reduction ratios can be obtained by suitable configuration of the housing and the cycloidal gear. More generally, speed conversion ratios between the input and output rotational speeds can be determined by the configuration of the gear assembly 100.

[0047] The gear assembly input shaft 122 and output shaft 118 can be understood more generally to be input and output members. That is, in other examples, other configurations of coupling motion into and out from the gear assembly 100 can be used which do not include shaft structures, or include additional components. For example, the output shaft 118 may comprise a hole for receiving a further, external shaft, and motion of the output shaft 118 is transmitted to such a received external shaft.

[0048] The liquid storage tank 42 comprises a hollow internal volume for storing a volume of liquid. The liquid may be, for example, tap water, distilled water, soapy water, detergent, polish, or any other liquid suitable for cleaning. The liquid storage tank comprises an inlet (not shown) such that a user can refill the liquid storage tank 42, and an outlet (not shown) which provides a feedline such that liquid can be dispensed from the liquid storage tank 42. In cleaner head 10, the outlet of the liquid storage tank 42 is connected to the liquid pump 40. The particular position of the liquid storage tank 42 relative to the liquid pump 40 and other components of the cleaner head 10 can vary between examples, as the outlet allows liquid to be straightforwardly to the liquid pump 40.

[0049] The liquid pump 40, in this example, is a diaphragm pump. The liquid pump 40 of Figure 1 is illustrated in isolation in Figures 5a, 5b and comprises a pump housing 41 comprising three chambers 44a-c, an inlet 43a, an outlet 43b, and also comprises a diaphragm 46, driving shaft 48 and plate 49.

[0050] In this example, the chambers 44a-c are generally cylindrical in shape and can be considered to have a volume bounded by a circular top surface 45a-c, a circular bottom surface 45d-f, and curved side walls connecting the top surface to the bottom surface. The three chambers 44a-c are, in this example, identical in volume and are arranged alongside one another such that they can be considered to be positioned in an equilateral triangle configuration, as can be seen in Figure 5a.

[0051] Each chamber 44a-c is fluidically connected to the inlet 43a and the outlet 43b at their respective bottom surfaces 45d-f. The inlet 43a of the liquid pump 40 is connected to the liquid storage tank 42 such that liquid can be transported from the liquid storage tank 42 to the liquid pump 40. The outlet 43b transports pumped liquid from the liquid pump 40 to a downstream destination (not pictured), and described later.

[0052] The diaphragm 46 comprises three portions 46a-c, each portion 46a-c forming the respective top surface 45a-c of the chambers 44a-c. The diaphragm 46 is formed from a flexible material, such as rubber, such that the top surface 45a-c of the chambers 44a-c is movable. The driving shaft 48 is coupled to each respective portion of the diaphragm 46 by the plate 49 such that the driving shaft can move the diaphragm 46.

[0053] Considering just a single chamber 44a: the driving shaft 48 and plate 49 are configured such that the portion 46a of the diaphragm 46 which forms the top surface 45a of the chamber 44a can be pulled away from the bottom surface 45d of the chamber 44a. That is, when the driving shaft 48 is tilted in a direction away from the chamber 44a, the plate 49 is similarly tilted upwards and thereby pulls the portion 46a of the diaphragm 46 away from the bottom surface 45d. This results in an expansion of the chamber 44a, and the volume of the chamber 44a increases. The driving shaft 48 and plate 49 are also configured such that the diaphragm portion 46a can be pushed towards the bottom surface 45d of the chamber 44a. That is, when the driving shaft 48 is tilted towards the chamber 44a, the plate 49 is tilted downwards and pushes the portion 46a of the diaphragm 46 towards the bottom surface 45d. This results in compression of the chamber 44a, and the volume of the chamber 44a decreases. Each chamber 44a-c can therefore undergo compression or expansion of its volume as the driving shaft 48 is eccentrical rotated, as indicated in Figure 5b. It will be appreciated that the driving shaft 48 and plate 49 need not necessarily be tilted, but can alternatively or additionally be translated in a plane generally parallel to the diaphragm 46 towards and away from the portion 46a of the diaphragm 46 to achieve the aforementioned compression and expansion effects. Due to the side-by-side arrangement of the chambers 44a-c and the position of the driving shaft 48 and plate 49, when the driving shaft 48 and plate 49 are eccentrically rotated, each chamber 44a-c is compressed at a different time. This means the aforementioned compression and expansion of the chambers 44a-c occurs sequentially. That is, for example, whilst the first chamber 44a is maximally compressed, the second chamber 44b may be undergoing expansion and the third chamber 44c may be undergoing compression.

[0054] As described above, the outlet 43b of the liquid pump 40 provides liquid to a downstream destination. A path of pipework for transporting the liquid may be provided between the outlet 43b of the liquid pump 40 and the downstream destination. In some examples, the downstream destination is a reservoir comprising a plurality of reservoir outlets, the reservoir and associated reservoir outlets positioned proximate to the cleaning element 30 and configured, in examples along with a distribution element, to coat the cleaning element 30 with the liquid. In other examples, the outlet 43b is connected to a directional dispensing element, such as a nozzle, and without such a reservoir, and is configured to dispense liquid onto a specific portion of the cleaning element. In yet further examples, the outlet 43b may be configured to dispense liquid into the vicinity of the cleaning element, but not directly onto or only partially onto the cleaning element, for example, in order to coat a surface to be cleaned, for example.

[0055] In use, a liquid is provided to the liquid pump 40 from the liquid storage tank 42 via the inlet 43a. When the driving shaft 48 is eccentrically rotated, at least a first chamber 44a-c undergoes expansion. This sucks the liquid through an inlet valve (not pictured) of the inlet 43 a and into the chamber. As the eccentric rotation of the driving shaft 48 continues, at least a first chamber 44a-c containing water undergoes compression. This ejects liquid from the chamber through an outlet valve (not pictured) of the outlet 43b of the liquid pump 40. The sequential compression and expansion of the chambers 44a-c means the flow of liquid dispensed from the outlet 43b of the liquid pump 40 is maintained at a relatively uniform rate compared with, for example, a single-chamber device. The liquid pump can be arranged to provide a liquid flow rate of around 30 ml / min, or more generally between 25 and 35 ml / min, alongside a pressure of around 13.5kPa to 14.5kPa. Generally, the liquid pump 40 is operable to pump a liquid when driven by an eccentric driving motion. As the skilled person will appreciate, other variants of a diaphragm pump, for example, can similarly receive an eccentric driving motion in order to dispense a liquid. The liquid pump may comprise a diaphragm configuration with just a single chamber, for example. It will accordingly be understood that the precise configuration of the liquid pump 40 is immaterial to the present disclosure beyond receiving an eccentric driving rotational motion to provide power for dispensing of the liquid.

[0056] Having considered the motor 20, gear assembly 100, cleaning element 30, and liquid pump 40 individually, their arrangement as connected components within the cleaner head 10 will now be described. It will be appreciated that Figure 1 does not imply any particular geometrical relationship between the components, or any particular geometrical qualities of the components themselves, but instead illustrates their functional relationship, such as the transmission of rotational motion between respective components or of liquid between the liquid storage and the liquid pump, for example.

[0057] The cleaning element 30 is coupled to a first end 22a of the shaft 22 of the motor 20. In this example, the cleaning element 30 is directly mounted to the first end 22A of the shaft 22, but in other examples there may be intermediate components, such as drive belts and pulleys, or a compound gear train, for example, which couple the motion from the shaft 22 to the cleaning element 30. Such intermediate components can, in examples, modify the rotational speed provided to the cleaning element 30, whilst in other examples the rotational speed is maintained as that provided by the motor 20. In general, when the motor 20 produces a driving rotational motion at a first rotational speed, the cleaning element 30, which in this example comprises a roller 32, undergoes a cleaning motion, which in this example is rotation of the roller 32. In use of the cleaning head 10, therefore, the cleaning element 30 can engage with a surface to be cleaned and the motor 20 provides a driving rotational motion such that the cleaning element 30 undergoes the cleaning motion in order to clean the surface. A second end 22b of the shaft 22 of the motor 20 is received by the gear assembly 100 as the input shaft 122. In this example, the input shaft 122 of the gear assembly 100 and the shaft 22 of the motor are the same component, but in other examples intermediate components may couple the input shaft 122 of the gear assembly 100 to the shaft 22 of the motor, wherein the input shaft 122 is a distinct component from the shaft 22 of the motor. As described earlier, the motor gear assembly 100 converts a first rotational motion having a first rotational speed to a second, eccentric rotational motion having a second rotational speed. The gear assembly 100 thereby converts the driving rotational motion produced by the motor 20 to a slower rotational motion whilst also introducing eccentricity into the rotational motion, thereby producing the eccentric rotational motion described earlier.

[0058] The liquid pump 40 is coupled to the output shaft 118 of the gear assembly 100. When the motor produces the driving rotational motion, the output shaft 118 of the gear assembly 100 undergoes eccentric rotational motion and the liquid pump 40 is driven by the eccentric rotational motion to thereby dispense a liquid stored in the liquid storage tank 42.

[0059] In use of the cleaner head 10, therefore, the motor 20 is operable to drive both the cleaning element 30 and the liquid pump 40. The motor 20 is able to drive the cleaning element 30 at a higher speed than the liquid pump 40. This can be useful where the cleaning element 30 requires a higher driving speed to produce a sufficiently vigorous cleaning motion, for example, but where that same higher driving speed would be excessive for operation of the liquid pump 40, which may only need to dispense a relatively small volume of liquid. For example, in the example of Figure 1, the liquid pump is configured to dispense liquid at a rate of between 25 and 35 millilitres per minute, whilst the roller 32 is configured to rotate at between 500 and 1200 revolutions per minute, and more specifically at between 900 and 1000 revolutions per minute, as these respective rates have been found to be particularly effective at producing a cleaning effect. The gear assembly 100 can be configured such that both the liquid pump 40 and the cleaning element 30 are respectively operated at optimal (within tolerances) speeds by arranging the speed reduction accordingly.

[0060] The gear assembly 100, in converting relatively higher driving rotational motion of the motor 20 to a slower eccentric rotation, thereby negates the need for a second motor 20 such that the liquid pump 40 and cleaning element 30 have respective dedicated motors.

[0061] This reduces the overall size, weight and manufacturing cost of the cleaning head 10.

[0062] Figure 8 schematically illustrates a cleaning appliance 1000 comprising the cleaning head 10. The cleaning appliance 1000, in comprising the cleaning head 10 comprising the gear assembly 100, has a reduced size and / or weight relative to cleaning appliances which comprise multiple motors for driving a liquid pump and cleaning element, for example. This can allow a user of the cleaning appliance 1000 to more precisely or effectively operate the cleaning appliance, for example.

[0063] The above examples are to be understood as illustrative examples of the invention. Further embodiments are envisaged.

[0064] For examples, in the examples of Figures 1 to 5b, the gear assembly is configured to reduce the rotational speed of the input rotational motion and generate an eccentric output rotational motion with a lower rotational speed. In other examples, the gear assembly is configured to produce an eccentric output rotational motion having a higher rotational speed than the input rotational motion. The skilled person will appreciate this is useful where a higher driving speed of the liquid pump is required than that produced to drive the cleaning element, for example.

[0065] For example, in the examples of Figures 1 to 5b, the gear assembly comprises a cycloidal gear disposed in a housing. In other examples, other gear assemblies exhibiting eccentric motion can be used, such as a harmonic (or strain wave) gearing configuration.

[0066] In the examples of Figures 1 to 5b, the slower eccentric motion produced by the gear assembly 100 is used to drive a liquid pump. However, other uses for this slower eccentric motion can include driving a second cleaning element which undergoes a slower, eccentric cleaning motion, for example. In such examples, similar benefits can be achieved as only a single motor can be used to drive the two steering elements. In the above examples, the cleaning element is directly mounted to the shaft of the motor and the gear assembly directly receives the shaft of the motor as an input. This can provide a compact design with minimal, if any, intermediate components required to reduce size and weight of the cleaner head 10. In other examples, other layouts, or topologies, are possible, for example where having the cleaning element, motor and gear assembly colinear results in an unsuitable overall form factor. In such examples, the use of intermediate components such as additional shafts, drive belts, and the like may allow for the transmission of the driving rotational force produced by the motor. For example, in the example of Figure 1, a first end of the motor shaft drives the cleaning element and a second end of the motor shaft is received by the gear assembly. However, in other examples, only one side of the motor shaft may be used, wherein the cleaning element may be mounted midway along the motor shaft, and a far end of the motor shaft is received by the gear assembly.

[0067] In other examples, a further liquid tank may be provided in order to receive dirty water after use by the cleaner head, for example. The further liquid tank may collect such water from the cleaning element 30, for example through use of a mangle.

[0068] It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

CLAIMS1. A cleaner head comprising: a motor configured to produce a driving rotational motion to drive a cleaning element; and a gear assembly configured to drive a liquid pump, the gear assembly comprising a gear element eccentrically drivable by an input rotational motion having a first rotational speed, the gear assembly configured such that when the gear element is eccentrically driven by the input rotational motion, the gear assembly produces an eccentric output rotational motion at a second rotational speed, the second rotational speed being different from the first rotational speed, wherein the cleaner head assembly is configured such that, when the motor produces the driving rotational motion: the driving rotational motion of the motor is transmitted to the gear assembly and used as the input rotational motion, and the eccentric output rotational motion of the gear assembly is transmitted to the liquid pump.

2. The cleaner head of claim 1, wherein the first rotational speed is faster than the second rotational speed.

3. The cleaner head of claim 1 or 2, wherein the gear assembly comprises a housing and an input shaft, and wherein the gear element comprises a cycloidal gear disposed in the housing and movably mounted eccentrically to the input shaft, the cycloidal gear comprising an output shaft, the gear assembly configured such that when the input shaft undergoes the input rotational motion at the first rotational speed, the output shaft undergoes the eccentric output rotational motion at the second rotational speed.

4. The cleaner head of any previous claim, wherein the gear assembly is configured such that the first rotational speed is at least nine times greater than the second rotational speed.

5. The cleaner head of any previous claim further comprising a cleaning element, configured to be driven in a cleaning motion when coupled to the driving rotational motion produced by the motor; a liquid storage tank configured to store a liquid; and a liquid pump, configured to be driven by the eccentric driving rotational motion of the gear assembly and configured to dispense the liquid from the liquid storage tank.

6. The cleaner head of claim 5 wherein the liquid pump is directly driven by an output member of the gear assembly.

7. The cleaner head of claim 5 or 6, wherein the liquid pump comprises a diaphragm pump.

8. The cleaner head of claim 7, wherein the diaphragm pump comprises a plurality of pumping chambers, the diaphragm pump configured such that, when the eccentric driving rotational motion drives the liquid pump assembly, the plurality of pumping chambers are sequentially compressed by the eccentric driving rotational motion and sequentially decompress to thereby dispense the liquid.

9. The cleaner head of any one of claim 5 to 8, wherein the cleaning element comprises a roller which, when driven in a cleaning motion by the driving rotational motion of the motor, rotates about a longitudinal axis.

10. The cleaner head of claim 9, wherein the roller is configured to rotate at between 500 and 1200 revolutions per minute.

11. The cleaner head of claim 10, wherein the roller is configured to rotate at between 900 and 1000 revolutions per minute.

12. The cleaner head of any previous claim, wherein the motor comprises a motor shaft, a first end of the motor shaft configured to transmit the driving rotational motion to the cleaning element and a second end of the motor shaft configured to transmit the driving rotational motion to the gear assembly.

13. The cleaner head of claim 12 when dependent on claim 9, wherein the roller is mounted to the first end of the motor shaft.

14. The cleaner head of any one of claims 5 to 13, wherein the cleaning element is configured to receive liquid from the liquid pump.

15. The cleaner head of any one of claims 5 to 14, wherein the liquid pump is configured to dispense liquid onto the cleaning element.

16. The cleaner head of any one of claims 5 to 15, wherein the liquid pump is configured to dispense liquid at a rate of between 25 and 35 millilitres per minute.

17. A gear assembly for converting an input rotational motion to an output rotational motion having a different rotational speed to the input rotational motion, the gear assembly comprising an input member configured to undergo an input rotational motion at a first rotational speed, a gear element configured to be eccentrically driven by the input rotational motion and thereby produce an eccentric output rotational motion at a second rotational speed, the second rotational speed different from the first rotational speed, and an output member configured to output the eccentric output rotational motion at the second rotational speed.

18. The gear assembly of claim 17, whereinthe input member is an input shaft and the output member is an output shaft; and the gear assembly comprises a housing, and a cycloidal gear comprising the output shaft, and eccentrically and movably mounted to the input shaft and disposed in the housing, and the cycloidal gear and the housing configured such that when the input shaft undergoes the input rotational motion at the first rotational speed, the output shaft undergoes the eccentric output rotational motion at the second rotational speed.

19. The gear assembly of claim 17 or 18 wherein the first rotational speed is faster than the second rotational speed.

20. A cleaning appliance comprising the cleaner head of any one of claims 1 to 16 or the gear assembly of any one of claims 17 to 19.

Images