DESCRIPTION

The present invention relates to a laundry drier, in

particular to a tumble drier.

Known laundry driers comprise a cabinet, typically

parallelepiped-shaped, containing rotatable drum for housing the laundry to be dried. A flow of hot air is circulated through the drum, so as to dry the laundry contained therein.

A heating system is provided for heating the air; the heating system can comprise a heat pump system or one or more

electrical heaters, both housed within the cabinet, externally to the drum.

In known laundry driers, there is the problem that, since the drum is rotatable, it is difficult transmitting electrical energy from the "not rotatable" parts of the laundry drier (e.g. the cabinet, or components fixed thereof) to the internal of the drum; this layout, therefore, limits the possibility to mount in the drum electrical devices for treating the laundry and/or for detecting related physical parameters, which reguire to be electrically powered.

It is an object of the present invention to provide a laundry drier which does not present above mentioned problems, and which allows to treat the laundry in a more dedicated, localized, and effective way.

Above object is solved by a laundry drier comprising:

- a cabinet,

- a drum rotatably mounted inside the cabinet,

- at least one electric element mounted in the drum, - a wireless power transmitter unit fixed to said cabinet or to a component of said laundry drier unmovable with respect to said cabinet,

- a wireless power receiver unit mounted in/on said drum, wherein said wireless power transmitter unit is

electromagnetically coupled with said wireless power receiver unit, for transmitting electric power to the latter, and wherein said wireless power receiver unit is electrically coupled with said at least one electric element, for supplying electric power to the latter.

It is underlined that "component unmovable with respect to the cabinet" means that this component, or element, is fixed to the cabinet, or in other words that this component can't move (e.g. can't rotate, translate, oscillate, etc.) with respect to the cabinet .

Preferably, the at least one electric element comprises at least one heating element .

In a further advantageous embodiment, the at least one electric element comprises at least one interface unit designed to wirelessly transmit data.

In a further advantageous embodiment, said electric element comprises at least one sensor element.

Preferably, said at least one sensor element comprises at least one temperature sensing element.

Advantageously, said wireless power transmitter unit is electrically connected to an electric system of said laundry drier .

Preferably, the wireless power transmitter unit is wired electrically connected to said electric system of said laundry drier .

Preferably, the laundry drier comprises an electronic control unit which controls electric and electronic components of said laundry drier. Preferably, the cabinet comprises a basement provided with a duct containing one or more electromechanical components of said laundry drier.

Preferably, the laundry drier comprises an electrical motor assembly, for rotating, on command, said drum along a rotation axis .

Advantageously, the laundry drier comprises a control panel. Preferably, the control panel is positioned in a top portion of the laundry drier .

Advantageously, the drum has a first end facing a

loading/unloading opening obtained in a front wall of said cabinet, and a second end facing a rear wall of said cabinet. Advantageously, the laundry drier comprises one or more support elements for the rotation of the drum.

Preferably, the one or more support elements include one or more rollers .

Preferably, said one or more rollers are rotatably associated to said basement.

More preferably, the one or more rollers are positioned at the front and/or at the back of said drum.

Even more preferably, two rollers are positioned at the front and two rollers are positioned at the back of said drum.

Advantageously, the laundry drier comprises a fan or blower for circulating process air through a process air circuit of said laundry drier.

Advantageously, the laundry drier comprises a heating system producing heat for drying the laundry.

Advantageously, the heating system comprises a heat pump system arranged for removing humidity from the process air exhausted from the drum, and for heating such air before it re-enters the drum, in a condition suitable to further remove humidity from laundry. Advantageously, the heat pump system comprises a first heat exchanger, or condenser and a second heat exchanger, or evaporator, a refrigerant closed circuit, a compressor.

Advantageously, the heat pump system comprises, in

correspondence of evaporator, a condensed-water canister which collects the condensed water produced in said evaporator.

Preferably, the canister is located at the bottom of said evaporator .

Preferably, the laundry drier comprises a connecting pipe and a pump for taking condensed water contained in said canister in a reservoir. More preferably, the reservoir is located in a top portion of the laundry dryer .

Advantageously, the condenser and the evaporator of the heat pump system are housed within the duct formed in the basement. Advantageously the laundry drier comprises a frontal wall or flange, facing the first end of the drum.

Preferably, the first end of the drum abuts against a first cylindric gasket attached to said wall or flange.

Advantageously, the frontal wall or flange comprises a conduit fluidly connected to the duct of the basement.

Advantageously, the laundry drier comprises a removable lint filter provided for intercepting an air flow exiting said drum and for collecting lint particles contained therein.

Preferably, the laundry drier comprises a rear pipe, fluidly connecting the second end of the drum to the duct of the basement .

Preferably, the second end of the drum abuts against a second cylindric gasket attached to the rear pipe.

Advantageously, the wireless power transmitter unit is fixed to said wall or flange.

Preferably, the laundry drier comprises a removable lint filter provided for intercepting an air flow exiting said drum and for collecting lint particles contained therein. Advantageously, the laundry drier comprises a rear pipe fluidly connecting the second end of the drum to the duct of the basement.

Preferably, the second end of the drum abuts against a second cylindric gasket attached to the rear pipe.

In an advantageous embodiment, the at least one sensor element is fixed to the drum and designed to generate measurement data, said at least one interface unit being designed to wirelessly transmit said measurement data to said control unit .

In an advantageous embodiment, the wireless power transmitter unit and the wireless power receiver unit are positioned, one opposite to the other, fixed respectively to said cabinet or to a component of said laundry drier unmovable with respect to said cabinet (20), and to the drum, parallel in radial direction .

In an advantageous embodiment, the power transmitter unit comprises a transmission coil generating a magnetic field, and the power receiver unit comprises a reception coil generating power from the magnetic field generated by the transmission coil, and supplying the generated power to the at least one electric element.

In an advantageous embodiment, the transmission coil and the reception coil are aligned, centered and parallel in radial direction .

In an advantageous embodiment, the transmission coil and the reception coil have a common radius dimension approximately egual to the drum external radius, and are distanced in axial direction by a distance lower than their radius.

Preferably, the transmission coil and the reception coil are distanced in axial direction by a distance lower than 10 cm. More preferably, the transmission coil and the reception coil are distanced in axial direction by a distance lower than 5 cm . In an advantageous embodiment, the wireless power receiver unit comprises a receiver magnetic shielding member, and the wireless power transmitter unit comprises a transmission magnetic shielding member .

Preferably, the receiver magnetic shielding member is

positioned between the reception coil and the drum side, and the transmission magnetic shielding member is positioned between the transmission coil and the cabinet or component of said laundry drier unmovable with respect to said cabinet to which said wireless power transmitter unit is fixed.

Preferably, the wireless power receiver unit comprises a receiver shielding member positioned on the opposite side of the reception coil with respect to the wireless power

transmitter unit .

Advantageously, the wireless power transmitter unit comprises a transmission shielding member positioned on the opposite side of the transmission coil with respect to the wireless power receiver unit.

Advantageously, the wireless power receiver unit comprises at least two reception coils and the at least one electric element comprises at least two electric elements, the at least two reception coils supplying, respectively, the at least two electric elements.

Advantageously, the drum comprises at least one drum lifter and in the at least one electric element is contained or integrated in the at least one drum lifter.

Advantageously, the at least one interface unit is designed to wirelessly transmit said temperature measurement data to said control unit .

In an advantageous embodiment, the interface unit is

configured to wirelessly transmit to the control unit

measurement data received from at least another sensor element . In an advantageous embodiment, the wireless power receiver unit comprises a further coil arranged for wireless

transferring to said control unit measurement data from said at least one sensor element.

Other advantages and features of a laundry drier according to the present invention will be clear from the following detailed description, provided only as a non limitative example, in which:

Fig 1 is a sectional view of a possible embodiment of a laundry drier according to this invention.

Fig. 2 is a sectional view of the drum with lifters and heating elements, taken along the surface II-II of Fig. 1.

Fig. 3 is a sectional view of a detail of a possible

embodiment of a wireless transmitter power unit and a wireless receiver power unit according to the invention.

Fig. 4 is a sectional view showing more in detail an

advantageous embodiment of the fixation of the wireless power transmitter unit to a fixed or static region of the cabinet and the wireless power receiver unit to the drum.

Fig. 5 is a block diagram of a first embodiment of a power supply circuit of the heating elements.

Fig. 6 is block diagram of another embodiment of a power supply circuit of the heating elements.

Fig. 7 is block diagram of another embodiment of a power supply circuit of the heating elements and of interface unit. In the figures same parts are indicated with the same

reference numbers .

In Fig. 1, an advantageous example of a laundry dryer 10 is illustrated, comprising a cabinet 20, preferably but not necessarily parallelepiped-shaped, and a drying chamber, such as a drum 50, for example having the shape of a hollow cylinder, for housing the laundry, not illustrated, to be dried .

The drum 50 is rotatably supported within the cabinet 20, so that it can rotate around a, preferably horizontal, rotation axis R (in alternative embodiments, rotation axis may be tilted) .

Access to the drum 50 is achieved for example via a door 4, preferably hinged to cabinet, which can open and close a loading/unloading opening 4a realized on the cabinet 20 itself .

Cabinet 20 generally includes a front wall 20a, a rear wall 20b, two sidewalls, not illustrated, all preferably mounted on a basement 24.

Cabinet 20 may include also a top wall 55. Preferably, the basement 24 is realized in plastic material, and more

preferably it is molded via an injection molding process.

Advantageously, basement 24 is hollow, and it preferably contains one or more electromechanical components of the laundry drier 10, as will be better explained in the

following .

Laundry dryer 10 also preferably comprises an electrical motor assembly, not illustrated, for rotating, on command, the drum 50 along its axis R.

Laundry dryer 10 may include an electronic control unit (for example the of the type numbered 60 in Figs. 3 to 6) which controls both the electrical motor assembly and other

components of the dryer 10, to perform, on command, one of the drying cycles preferably stored in the same central control unit. The programs as well other parameters of the laundry dryer 10, or alarm and warning functions can be set and/or visualized in a control panel 11, preferably positioned in a top portion of the dryer 10, such as above door 4.

The drum 50 includes a mantle 50c, having preferably a substantially cylindrical/tubular shape, which is preferably made of metal, and is arranged inside the cabinet 20 and adapted to rotate around the rotational axis R. The drum 50 has a first end 50a facing the loading/unloading opening 4a, and a second end 50b facing the rear wall 20b.

Drum 50 may be an open drum, i.e. both ends 50a and 50b can be opened (as in Fig. 1), or it may include a back wall (not shown in the attached Figures) fixedly connected to the mantle and rotating with the latter.

In order to rotate, one or more support elements for the rotation of the drum 50 are advantageously provided; these support elements preferably include one or more roller 31 (preferably two or more), more preferably rotatably associated to the basement 24. Preferably the roller (s) 31 are positioned at the front and/or at the back of the drum 50; more

preferably, two rollers 31 are positioned at the front and two rollers 31 are positioned at the back of the drum 50.

In another advantageous embodiment, not illustrated, a drum shaft, connected to a rear end of the drum 50, can support the latter .

Laundry dryer 10 advantageously comprises a process air circuit 18, indicated in Fig. 1 by a plurality of black arrows 18, showing the path flow of a process air stream through the dryer 10.

The process air circuit 18 advantageously comprises the drum 50 and a duct 24a in the basement 24. The laundry drier 10 also advantageously comprises a fan or blower 12 for circulating process air through the process air circuit 18, and in particular through the drum 50.

The laundry drier 10 advantageously comprise a heating system producing heat for drying the laundry.

In the advantageous embodiment of Fig. 1, the heating system comprises a heat pump system arranged for removing humidity from the process air exhausted from the drum 50, and for heating such air before it re-enters the drum 50, in a condition suitable to further remove humidity from laundry.

The heat pump system advantageously comprises a first heat exchanger (called also condenser) 191 and a second heat exchanger (called also evaporator) 192. Heat pump system 19 advantageously comprises a refrigerant closed circuit, not illustrated, in which a refrigerant fluid flows.

Heat pump system also advantageously comprises a compressor 193, receiving refrigerant in a gaseous state from the evaporator 192, and supplying it in a liguid stated to the condenser 191, thereby closing the refrigerant cycle.

Preferably, in correspondence of evaporator 192, the laundry dryer 10 may include a condensed-water canister (not

illustrated) which collects the condensed water produced, when the laundry dryer 10 is in operation, in the evaporator 192 by condensation of the surplus moisture in the process air stream arriving from the drum 50. Preferably, the canister is located at the bottom of the evaporator 192. Preferably, through a connecting pipe and a pump (not shown in the drawings), the collected water is sent in a reservoir located preferably in correspondence of the highest portion of the dryer 10 so as to facilitate a comfortable manual discharge of the water by the user of the dryer 10.

The condenser 191 and the evaporator 192 of the heat pump system are preferably housed within the duct 24a formed in the basement 24. In case of a condense-type dryer - as depicted in Fig. 1 - where the process air circuit 18 is a closed loop circuit, the condenser 191 is preferably located downstream (with reference to the air flow direction) of the evaporator 192.

Advantageously, the air exiting the drum 50 reaches the evaporator 192, which cools down and dehumidifies the process air, and then it enters the condenser 191, where it is warmed up by the heat pump system before re-entering the drum 50. Advantageously the laundry drier 10 comprises a frontal wall or flange 22, facing the first end 50a of the drum 50, and preferably comprising the loading/unloading opening 4a.

Advantageously, the first end 50a of the drum 50 abuts against a first cylindric gasket 22a, preferably made of felt, attached to the wall or flange 22.

Advantageously the frontal wall or flange 22 comprises a conduit 23, fluidly connected to the duct 24a of the basement 24, and comprised in the process air circuit 18.

Preferably a removable lint filter 26 is provided in the process air circuit 18 (preferably, but not necessarily, in the conduit 23 of the frontal wall or flange 22); the lint filter 26 is arranged for intercepting the air flow exiting the drum 50 and for collecting lint particles contained therein .

Advantageously the laundry drier 10 comprises a rear pipe 25, fluidly connecting the second end 50b of the drum 50 to the duct 24a of the basement 24. Preferably, the second end 50b of the drum 50 abuts against a second cylindric gasket 25a, preferably made of felt, attached to the rear pipe 25.

The laundry drier 10 comprises a wireless power supply transmitter unit 62, fixed to the cabinet 20 or to a component of the laundry drier unmovable with respect to the cabinet 20; in the example of Fig. 1, the wireless power supply

transmitter unit 62 is advantageously fixed to the frontal wall or flange 22. It is underlined that "component unmovable with respect to the cabinet 20" means that this component, or element, is fixed to the cabinet, or in other words that this component can't move (e.g. can't rotate, translate, oscillate, etc.) with respect to the cabinet 20.

The wireless power transmitter unit 62 is advantageously electrically connected, preferably wired, to the electric system, not illustrated, of the laundry drier 10; the electric system is connectable, for example, to the electric mains, not illustrated, of the building where the laundry drier 10 is installed, so as to be power supplied by such electric mains . Advantageously the laundry drier 10 comprises a wireless receiver power unit 63, mounted in/on the drum 50.

The wireless power transmitter unit 62 is electromagnetically coupled with the wireless power receiver unit 63, for

transmitting electric power to the latter.

In the advantageous example of Fig. 1, the wireless power receiver unit 63 is mounted on the first end 50a of the drum 50a, facing the frontal wall or flange 22.

In the advantageous example of Fig. 1, the wireless power supply transmitter unit 62 is mounted on the frontal wall or flange 22, so as to face the wireless power receiver unit 63. Preferably, the wireless receiver power unit 63 and the wireless power supply transmitter unit 62 are annular shaped, centred with the drum centre and mounted radially parallel respectively on the cabinet 20 or component 22 of the laundry drier 10 unmovable with respect to the cabinet 2) to which the wireless power transmitter unit 62 is fixed, and on the drum 50.

Advantageously, the drum 50 is provided with one or more lifters 500 (four in the example of Figs. 1 and 2), to lift the laundry in the drying cycle .

In a preferred embodiment, each lifter 500 comprises or encloses a heating element 200. The wireless power receiver unit 63, preferably through electric wires 63a electrically supplies the heating elements 200.

Fig. 2 schematically shows a sectional view of an advantageous example of a lifter 500. The heating element 200 is

advantageously integrated/contained in the lifter 500; in an advantageous embodiment, the heating element can be

cylindrical shaped, and have the same length of the lifter 500 in axial direction.

Preferably the lifters 500 have a perforated structure (i.e. their walls can have openings), so as to allow air to pass through and be heated by the heater 200.

In a preferred embodiment, the heaters 200 can be used as the heating system of the laundry drier 10, i.e. for heating the laundry contained in the drum 50.

In another advantageous embodiment, in which another heating system, for example a heat pump system, is provided in the laundry drier 10, the heater 200 can work together with the other heating system, for example for speeding up the heating process (and thus reducing the drying cycle time) .

Preferably, the wireless power receiver unit 63 is fixed parallel in radial direction opposite the wireless power transmitter unit 62.

In Fig. 3 it is shown a sectional view of an advantageous example of the power transmitter unit 62 and receiver unit 63. Advantageously, the power transmitter unit 62 has a

transmission coil 620 which is electromagnetically coupled to a reception coil 630 of the power receiver unit 63. They can be advantageously integrated into the enclosing material 622, 632, and they can advantageously have respectively magnetic sheets 621 and 631 that provide the side magnetic shield to the sides external to the coupling area and improve the magnetic coupling between the two coils 622 and 632. Preferably, the wireless power receiver unit 63 and the wireless power transmitter unit 62 are parallel, centred with respect to the drum 50 centre in order to maximize the electromagnetic coupling, as shown in Fig. 4.

The wireless power receiver unit 63 could be fixed in a U shaped opening formed in the drum 50 external periphery, while the power transmitter unit could have its side 622 fixed with screw or glued to the wall of the cabinet 200, or, as in Figure 4, to the frontal wall of flange 22.

Advantageously the laundry drier 10 comprises a control unit 60.

As shown in Fig. 5, advantageously the control unit 60 may generate an oscillating voltage by switching elements 602 that supply the transmission coil 620 of the power transmitter unit 62 coupled to the reception coil 630 of the power receiver unit 63. The voltage induced in the coil 630 is preferably rectified and conditioned in the coil interface block 611, and preferably brought, preferably with wires, to the heating elements 200, preferably connected in series. The components of the interface block 611 could be preferably integrated in the power receiver unit 63.

Advantageously, the appliance control unit 60 manages the complete drying operations, controlling the drum motor rotation speed as well as the other electric/electronic components of the laundry drier 10. Preferably, the appliance control units 60 can measure the temperature in the drum 50, and generate the proper voltage supplying the heating

elements, for example through a switching element 602.

Another advantageous embodiment is shown in Fig. 6 where the power receiver unit 63 has multiple coils 630, each coil 630 supplying through its own interface block 611 a heating element 200.

One further advantageous embodiment is shown in Fig. 7. In this embodiment on the drum 50 there is fixed an interface unit 61, together with the power receiver unit 63 and the heating element 200. The interface unit 61 can be supplied by a dedicated reception coil 640 of the receiver unit 63, as shown in Fig. 7, or it could be connected in parallel to the reception coil 630 supplying the heating elements 200.

The interface unit 61 has advantageously a wireless connection 601 to transfer measurement data to the appliance control unit 60.

In particular, the interface unit 61 could transfer to the appliance control unit 60 measured temperatures 615 from temperature measurement elements positioned in the lifters 500.

It would allow to design drying cycles based on the real temperature measured in the drum 50.

The interface unit 61 could be advantageously positioned integrated in the isolating support material 632 of the power receiver unit 63. Advantageously the interface unit 61 could sense and send additional measurement parameters, not only temperatures 615, but also e.g. unbalance, providing all needed sensing information 616 to the appliance control unit 60.

Advantageously, the wireless power receiver unit can supply power to any type of electric element mounted in/on the drum or fixed to the drum, including heating elements, signal transmission and/or reception elements (like wireless data transmission and/or reception devices) and sensor elements (like temperature sensors, humidity sensors, movement sensors such as speed or acceleration sensors) .

It is seen therefore how the invention achieves the proposed aim and objects, there being provided a laundry drier which, thanks to the wireless power transmission, allows electrically powering at least one electric element mounted in/on the rotatable drum, which opens new possibilities of treating the laundry, in a more dedicated, localized and effective way.