EP3693505A1

EP3693505A1 - Washing machine

Info

Publication number: EP3693505A1
Application number: EP20156139.6A
Authority: EP
Inventors: Fabio Roncati; Massimo DUGO
Original assignee: Candy SpA
Current assignee: Candy SpA
Priority date: 2019-02-08
Filing date: 2020-02-07
Publication date: 2020-08-12
Anticipated expiration: 2040-02-07
Also published as: EP3693505B1; RU2020105832A; IT201900001815A1; ES2939541T3; CN111549481A

Abstract

A washing machine (1) comprises a housing (2), a stationary wash tub (3) arranged inside the housing (2) and having an opening closable by means of a door (4) of the housing (2), a laundry basket (5) rotatably supported inside the wash tub (3) and operable in rotation about a basket rotation axis (34) by means of an electric motor (14), a water loading system (6) connectable to mains water system and in communication with the wash tub (3) to load water into the wash tub (3), as well as an electric induction generator (21) connected between the wash tub (3) and the laundry basket (5), and which generates electric current according to the rotation of the laundry basket (5) with respect to the tub (3).

Description

The present invention relates to a device and method for washing laundry, in particular to a domestic washing machine.
Domestic washing machines comprise a supporting and housing structure, inside which a wash tub is housed provided with a front opening closable by a porthole door frontally hinged to the housing. A basket for accommodating the laundry to be washed is arranged inside the wash tub in rotatable manner about a horizontal or inclined axis. The basket also defines a front opening positioned at the opening of the wash tub in order to allow loading and unloading the laundry.
The wash tub is adapted to contain the washing liquid during the steps of laundry washing.
A water loading system connectable to the water mains is provided in order to allow loading water from the mains, detergents and additive agents into the tub. On the bottom of the wash tub, there is a draining duct with an associated draining pump which removes the washing liquid from the tub and which controls, together with the loading system, the liquid level inside the wash tub.
In order to add detergent or treatment additive to the washing liquid, it is known to arrange a detergent tray in flow communication with the water loading system.
The detergent tray may be configured as a drawer which can be extracted from and inserted into the housing structure and which can be filled manually for each wash with an amount of detergent and/or treatment additive sufficient for a single washing cycle.
Washing machines with so-called "multiple dispensing" washing substance dispensing and dosing systems are also known, configured to contain an amount of treatment agent sufficient for a plurality of washing cycles and to automatically dispense a controlled dose of treatment agent for each washing cycle.
It is also known to position the multiple dispensing system in the front door and, more precisely, in the porthole of the front door of the washing machine.
An electric resistor is arranged inside the wash tub in the gap between the wall of the laundry basket to heat the washing liquid contained in the wash tub.
In order to reduce the consumption of water and detergent, it is known to equip washing machines with recirculation systems which remove the washing liquid from the bottom of the wash tub (where it accumulates even before touching the laundry in the basket) and reintroduce the washing liquid into the laundry basket, so that a reduced volume of liquid is repeatedly poured on the laundry to be washed.
Recirculation systems usually comprise a recirculation duct which extends outside the wash tub from a lower opening of the wash tub (for drawing the liquid to be recirculated) to an upper opening of the wash tub (for reintroducing the recirculated liquid), as well as an electric recirculation pump or ejector.
The features described hereto in relation to washing machines of the prior art known by the applicant may be entirely or partially also implemented in at least some embodiments of an improved laundry washing machine according to the invention.
Although the known washing machines are satisfactory from many points of view, they do not allow the use of electrical auxiliary functions at the laundry basket and/or the tub without needing to wire the wash tub and/or the basket and then connecting them electrically to the power supply of the washing machine. On the other hand, a wired electrical connection of the basket and/or wash tub to the mains power supply of the washing machine is generally undesirable and complicated due to the moist/wet environment, the direct contact between the user's hand and the metal wall of the basket, the relative movement between the basket and the wash tub and the cost and size of the wiring itself.
On the other hand, in order to further improve the operation of the washing machine and the user's perception of ergonomics, the need is felt to perform auxiliary electrical functions precisely at the tub and/or laundry basket. Examples of electrical functions may include lighting inside the laundry basket, detection of parameters and operating parameters of the washing machine (number of revolutions, position, speed, angular acceleration of the basket, electrical conductivity of laundry soaked in washing liquid and/or detection of features of the laundry (weight, color, stains, degree of filling of the basket, bulkiness of the laundry, liquid saturation of the laundry, temperature of the laundry).
These problems and requirements of washing machines also apply by analogy to dryer machines.
It is the object of the present invention to provide an improved washing machine having such features as to overcome the problems described with reference to the prior art and to provide one or more auxiliary electrical functions at the wash tub and/or at the laundry basket without a wiring of the wash tub-basket assembly drawing electricity directly from the (mains) power supply wiring of the washing machine.
It is a further object of the present invention to provide an improved laundry dryer machine having such features as to overcome the problems described with reference to the prior art and to provide one or more auxiliary electrical functions at the laundry basket without a wiring of the laundry basket drawing electricity directly from the (mains) power supply wiring of the dryer machines.
These and other objects are achieved by means of a washing machine according to the independent claim. The dependent claims relate to advantageous and preferred embodiments of the invention.
A washing machine comprises:

a housing,
a stationary wash tub located inside the housing and having a front opening closable by means of a porthole door hinged to the front of the housing, or a top opening closable and accessible by means of an upper door of the housing,
a basket arranged inside the wash tub and rotatable about a horizontal or inclined axis, wherein the basket delimits a peripheral or front loading opening for loading and unloading the laundry to be washed,
a water loading system connectable to the water mains and in communication with the wash tub to load water in the wash tub,
a draining duct connected to the wash tub and to a draining pump to remove the washing liquid from the wash tub and to adjust a liquid level inside the wash tub together with the water loading system,
a dispensing system for the supply of laundry treatment substances.

According to an aspect of the invention, the washing machine comprises an electric generator connected between the wash tub and the laundry basket and which generates electricity in dependency of the rotation of the laundry basket with respect to the wash tub.
The electricity generated in this manner is available directly at the wash tub and/or basket without any need for connection wiring to the main power supply of the household appliance.
Such electric current is the result of energy conversion of mains electricity into a rotary motion of the electric motor which drives the movement of the basket and the rotary motion of the basket into electric current. The advantage of the availability of electricity at the wash tub and/or basket without the wiring problems prevails over the disadvantage of energy losses which occur during the two conversion phases.
Further advantageous aspects of the invention will be apparent from the following description of some embodiments provided by way of non-limiting example with reference to the accompanying figures, in which:

figure 1 is a diagrammatic front view of a washing machine according to an embodiment of the invention;
figures from 2 to 5 are section views of a supporting region of the wash tub according to embodiments.

With reference to the figures, a washing machine 1 or washer-dryer comprises a supporting and housing structure 2, inside which a washing tub 3 is housed provided with an opening (either frontal or peripheral) closable by a door 4 (e.g. a porthole door) hinged either frontally or above the housing 2. A basket 5 to accommodate the laundry to be washed is housed inside the wash tub 3 in rotatable manner about a horizontal or inclined axis. The basket 5 may also delimit a front opening positioned at the opening of the wash tub 3 or a peripheral closable opening, in order to be able to load and unload of the laundry.
The wash tub 3 is adapted to contain the washing liquid during the steps of the laundry washing.
A water loading system 6 connectable to the water mains is provided in order to allow the loading of the tub 3 with water from the mains. The loading system 6 may comprise a plurality of ducts which extend, e.g. from one or more, e.g. two supply solenoid valves 7, 8, either directly or through detergent compartments of a detergent basin 9, to the wash tub 3.
A draining duct 11 with associated draining pump 12 is connected to the bottom 10 of the wash tub 3 and removes the washing liquid from the tub 3 and controls the liquid level inside the tub 3, together with the supply solenoid valves 7, 8.
For heating the washing liquid contained in the tub 3, an electric resistor 13 may be provided and arranged inside the tub 3, in particular on the tub bottom 10, in the gap between the wall of the tub 3 and the laundry basket 5.
For agitating and remixing the laundry with the washing liquid, the laundry basket 5 can be actuated in rotation by an electric motor 14 and a transmission 15, e.g. a belt.
The operation of the washing machine 1 is controlled by an electronic control unit 16, operatively connected to a user control interface 17 positioned at an outer wall or the door 4 of the housing 2 and which allows the selection of washing and/or drying cycles (more generally, of treatment cycles) and their features. In response to the selections made by the user by means of the user interface 17, the control unit 16 governs the various components of the washing machine 1 for automatically washing the laundry.
The washing machine 1 may further comprise a dispensing system 18 of the "multiple dosing" type for dispensing laundry treatment agents.
Either in addition or alternatively to the detergent tray 9, the dispensing system 18 comprises a plurality of tanks 19 to contain the treatment agents, e.g. detergent for resistant white items, detergent for delicate colored items, detergent for wool, perfuming substances, enzymes, fixing agents and/or fabric softener. The plurality of tanks 19 may be positioned in the porthole door 4 and the individual tanks 19 are dimensioned to contain each a volume of the treatment agent sufficient for a plurality of washing cycles.
The washing machine 1 may further comprise a system 20 for recirculating the washing liquid from the bottom of the wash tub 10 to the laundry basket 5, similarly to the recirculation systems described with reference to the prior art.
According to an aspect of the invention, the washing machine 1 comprises an electric induction generator 21 connected between the wash tub 3 and the laundry basket 5 and which generates electricity according to the rotation of the laundry basket 5 with respect to the wash tub 3.
The electrical current thus generated is available directly at the wash tub 3 and/or the basket 5 with no need for connection wiring to the main power supply of the household appliance 1.
Such electric current is the result of an energy conversion of mains electricity into a rotary motion of the electric motor 14 which drives the movement of the basket 5 and the rotary motion of the basket 5 into electric current. The advantage of the availability of electricity at the wash tub 3 and/or basket 5 without the wiring problems prevails over the disadvantage of energy losses which occur during the two conversion phases.
According to an embodiment, the basket 5 is rotatably supported by wash tub 3 by means of a shaft or hub 22 which is integral with a side wall 23 (e.g. rear wall opposite to the front opening) of the basket 5 and is rotatably supported in a wall 24 (side wall, e.g. rear opposite to the front opening) of wash tub 3, by means of at least one radial bearing, preferably by two radial rolling bearings 25, 26 spaced from one another along the rotation axis of basket 34 in order to better withstand bending moments of the shaft 22.
Advantageously, the electric generator 21 is positioned in an axially confined space between the two roller bearings 25, 26 and radially between the shaft 22 of the basket 5 and the side wall 24 of the wash tub 3. This position protects the electric generator 21 and allows a local wiring protected by means of a groove or hole 25 made in the shaft 22 and/or through a groove or hole 26 made in the side wall 24 of the wash tub 3.
According to an alternative embodiment, the electric generator 21 is positioned on an outer side 37 (of the side wall 24) of the wash tub 3, facing away from wash tub 5, and freely accessible from the outside of wash tub 3. This facilitates the assembly and maintenance of the electric generator 21 and in all cases allows protection of the local wiring by means of a groove or hole 25 made in the shaft 22 and/or through a groove or hole 26 made in the side wall 24 of the wash tub 3.
According to an embodiment, the electric generator 21 comprises a magnetic part 27, e.g. having a plurality of permanent magnets, and a winding part 28 comprising a plurality of conductor coils, wherein the winding part 28 is arranged in a pivoting manner with respect to the magnetic part 27. In such a manner, due to the relative rotation between the magnetic part 27 and winding part 28, the resulting movement of the conductor coils through the magnetic field generates electrical current (induction effect) in the conductor coils in a known way.
According to an embodiment, the magnetic part 27 is fixed to the shaft 22 of the basket 5 or to the basket 5 and the winding part 28 is fixed to the tub 3, so that the current is generated in the winding part 28 at the tub 3.
Alternatively or additionally, the magnetic part 27 of an electric generator 21' is fixed to the wash tub 3 and its winding part 28 is fixed to the basket 5 or to the shaft 22 so that the current is generated in the winding part 28 at the basket 5.
According to a further embodiment, the washing machine 1 may comprise two electric generators 21, 21' configured and/or positioned as described above, wherein:

the winding part 28 of a first electric generator 21 is fixed to the shaft 22 of the basket 5 or to the basket 5 so that the current is generated in the winding part 28 at the basket 5, and
the winding part 28 of the second electric generator 21' is fixed to the wash tub 3 so that the current is generated in the winding part 28 at the wash tub 3,

According to an embodiment, a multiplication or reduction transmission (reduction gear) 29 is arranged between the electric generator 21, 21' and at least one of basket 5 and wash tub 3 in order to reconcile the range of number of revolutions at which the electric generator 21 works with the range of number of revolutions at which the basket 5 is to be rotated.
According to an embodiment, the washing machine 1 comprises at least one chargeable electric accumulator 30, 30' fixed to the tub 3 or to the basket 5 and electrically connected to the electric generator 21, 21'. This allows compensating for variations in electrical power due to variations in the rotational speed of the basket 5 and to accumulate electrical energy which can be used when basket 5 is stationary.
The electric generator 21,21' can be either a dynamo with a switch to generate direct current or an alternator capable of generating alternating current.
According to an embodiment, the electric generator 21, 21' can be in signal connection (via signal wire or wireless) with the control unit 16 of the washing machine 1, e.g. so as to supply to the control unit 16 a signal indicating the angular position and/or the instantaneous angular speed (or number of revolutions) of the basket 5 with respect to the wash tub 3.
This is particularly advantageous for implementing of laundry anti-imbalance strategies in the basket 5 in order to reduce the dynamic stresses of the washing machine 1 in preparation for the steps of washing and/or of high-speed spinning in the basket 5. Anti-imbalance procedures are carried out by control unit 16 by means of the steps of:

identifying a state of imbalance of the laundry in the basket 5 by comparing detected rotational speed values (number of revolutions) of the basket 5 with reference values for a determined control program of the electric motor 14,
in the event of an identified state of imbalance, implementing a sequence of alternating rotatory movements of the electric motor 14, and thus of the basket 5, with the aim of re-balancing (or in other words, equalizing the spatial distribution of the) laundry in the basket 5.

Experimental tests have shown that an "indirect" detection of the basket 5 speed by reading the motor speed 14, e.g. by means of a tachogenerator positioned on the motor rotor, does not take into account the transmission ratio alteration due to belt slippage and is therefore inaccurate.
A "direct" detection on the basket 5 through the use of the electric generator 21, 21' as tachogenerator more precisely identifies the dynamics of basket 5 and allows a more targeted adjustment of the control of the electric motor 14 to balance the load of laundry in basket 5. As a result, the structure of the washing machine 1 is subject to reduced mechanical stress.
Furthermore, the "direct" detection of the RPM at the basket 5 by means of the use of the electric generator 21, 21' as tachogenerator allows a simplification of the software (or method) of anti-balancing of the control unit 16, compared to a reading of the number of revolutions at the motor 14 in which it is necessary to customize the software for a variety of different types of electric motors and different motor pulley diameters.
According to an embodiment, the electric generator 21, 21' comprises angular position detection means of the basket connected to the control unit and the control unit governs the motor to make a basket stop in a predefined angular position (e.g. with the laundry loading opening facing upwards in top-loading washing machines), according to an angular basket position signal provided by the electric generator 21, 21'.
According to embodiments, the washing machine 1 comprises one or more or all of the following:

a system for lighting 31 the inside of the laundry basket 5 and/or
one or more detectors 32 of operating parameters and/or quantities of the washing machine 1 (e.g. number of revolutions, position, speed, angular acceleration of basket 5), e.g. Hall effect sensors,
one or more detectors 33 of features of the laundry (e.g. electrical conductivity of the laundry in the basket 5, weight of the laundry in the basket 5, color of the laundry in the basket 5, stains on the laundry in basket 5, degree of filling of the basket 5, bulkiness of the laundry in the basket 5, liquid saturation of the laundry in the basket 5, temperature of the laundry in the basket 5), e.g. conductivity sensors, optical sensors, resistance sensors, weight sensors,
wherein said one or more systems 31 or detectors 32 or sensors 33 are electrically connected to and powered by the current generator 21, 21' and can optionally be in signal connection with the control unit 16.

As already mentioned in the introduction, the invention can also apply to drier machines with a laundry basket or drum 5 rotatably supported in a stationary support structure and which can be actuated in rotation by an electric motor 14, either similarly or identically to what has been described with reference to the washing machine 1, with the only difference that the electric generator 21, 21' is coupled between the basket 5 and the stationary support structure instead of the wash tub 3.
Finally, the present invention further relates to the operating method of the washing machine 1 or the dryer machine, the features of which are not repeated herein for the sake of brevity.
Obviously, a person skilled in the art may make further changes and variants to the washing machine 1, to the washer-dryer machine and to laundry treatment method according to the present invention all without departing from the scope of protection of the invention, as defined in the following claims.

Claims

A washing machine (1) comprising:
- a housing (2),

- a stationary wash tub (3) arranged inside the housing (2) and having an opening closable by means of a door (4) of the housing (2),

- a laundry basket (5) rotatably supported inside the wash tub (3) and operable in rotation about a basket rotation axis (34) by means of an electric motor (14),

- a water loading system (6) connectable to a mains water system and in communication with the wash tub (3) for loading water into the wash tub (3),
characterized in that it comprises an electric induction generator (21) connected between the wash tub (3) and the laundry basket (5), and which generates electric current in dependency of the rotation of the laundry basket (5) with respect to the tub (3).
A washing machine (1) according to claim 1, wherein the basket (5) forms a shaft (22) protruding from a side wall (23) of the basket (5), and rotatably supported in a side wall (24) of the tub (3) by means of at least one radial bearing or by means of two radial bearings (25, 26) spaced apart from each other along the basket rotation axis, wherein the electric generator (21) is positioned adjacent to said one or more radial bearings (25, 26).
A washing machine (1) according to claim 2, wherein the electric generator (21) is positioned in an axially confined space between the two roller bearings (25, 26) and radially between the shaft (22) of the basket (5) and the side wall (24) of the tub (3).
A washing machine (1) according to claim 2, wherein the electric generator (21) is positioned on an outer side (37) of the tub (3), facing away from the basket (5).
A washing machine (1) according to one of the preceding claims, comprising a local basket electrical wiring (35) connected to the electric generator (21) and extended in a groove or hole (25) in the shaft 22.
A washing machine (1) according to one of the preceding claims, comprising a local tub electrical wiring (36) connected to the electric generator (21) and extended in a groove or hole (26) in the side wall (24) of the tub (3).
A washing machine (1) according to one of the preceding claims, wherein the electric generator (21) comprises:
- a magnetic part (27), having a plurality of magnets, and

- a winding part (28) comprising a plurality of conductor coils,
wherein the winding part (28) is arranged in a rotating manner with respect to the magnetic part (27),
wherein the magnetic part (27) is coupled to the shaft (22) or to the basket (5) and the winding part (28) is coupled to the tub (3), so that the current is generated in the winding part (28) at the tub (3).
A washing machine (1) according to one of the preceding claims, wherein the electric generator (21) or a further electric generator (21') comprises:
- a magnetic part (27), having a plurality of magnets, and

- a winding part (28) comprising a plurality of conductor coils,
wherein the winding part (28) is arranged in a rotating manner with respect to the magnetic part (27),
wherein the magnetic part (27) is coupled to the tub (3) and the winding part (28) is coupled to the basket (5) or to the shaft (22), so that the current is generated in the winding part (28) at the basket (5).
A washing machine (1) according to one of the preceding claims, comprising two said electric generators (21, 21'), wherein:
- the winding part (28) of a first electric generator (21) is coupled to the shaft (22) or to the basket (5), so that the current is generated in the winding part (28) at the basket (5), and

- the winding part (28) of the second electric generator (21') is coupled to the tub (3), so that the current is generated in the winding part (28) at the tub (3).
A washing machine (1) according to one of the preceding claims, wherein the electric generator (21, 21') is coupled to at least one of the basket (5) and the tub (3) by means of a reduction transmission (29).
A washing machine (1) according to one of the preceding claims, comprising at least one chargeable electric accumulator (30, 30') fixed to the tub (3) or to the basket (5) and electrically connected to the electric generator (21, 21').
A washing machine (1) according to one of the preceding claims, wherein the electric generator (21, 21') is in signal connection with a control unit (16) of the washing machine (1) and provides the control unit (16) with a signal indicative of the angular position, and/or number of revolutions, of the basket (5) with respect to the tub (3).
A washing machine (1) according to claim 12, wherein the control unit (16) performs an anti-imbalance procedure by means of the steps of:
- identifying a state of imbalance of the laundry in the basket (5) by means of comparing rotational speed values of the basket (5), which are recorded by means of the electric generator (21, 21') with reference values for a determined control program of the electric motor (14),

- in the event of having identified a state of imbalance, implementation of a sequence of alternating rotatory movements of the electric motor (14) with the aim of equalizing the laundry distribution in the basket (5).
A washing machine (1) according to one of the preceding claims, comprising one or more of:
- a system for lighting (31) the inside of the laundry basket (5) and/or

- one or more detectors (32) of operating parameters of the washing machine (1),

- one or more detectors (33) of characteristics of the laundry,
electrically connected to the current generator (21, 21').
A dryer machine, comprising:
- a housing (2),

- a stationary support structure (3) arranged inside the housing (2),

- a laundry basket (5) rotatably supported inside the stationary support structure (3) and operable in rotation about a basket rotation axis (34) by means of an electric motor (14), characterized by comprising an electric induction generator (21) connected between the stationary support structure (3) and the laundry basket (5), which generates electric current in dependency the rotation of the laundry basket (5) with respect to the stationary support structure (3).