EP1655404B1

EP1655404B1 - Washing machine comprising a balancing device

Info

Publication number: EP1655404B1
Application number: EP05380220A
Authority: EP
Inventors: Kepa Ezkurra Galdos; Mikel Campos Isunza; Agustin Ugarte Basurto
Original assignee: Fagor Electrodomesticos SCL
Current assignee: Fagor Electrodomesticos SCL
Priority date: 2004-11-08
Filing date: 2005-10-11
Publication date: 2010-12-22
Anticipated expiration: 2025-10-11
Also published as: ES2357636T3; DE602005025445D1; EP1655404A1; PL1655404T3; ES2277487A1; ATE492674T1; ES2277487B1

Abstract

Device for the balancing of a washing machine with a rotating drum (2) that comprises a number of chambers (3) distributed in an inner periphery (20) of said drum (2), and also comprises a ring (5) situated on one end (22) of the drum (2), concentric to said drum (2) and connected to said chambers (3). The device comprises an intake duct (6) to pour water into said ring (5), with said water being distributed in the interior of the ring (5) and from said ring (5) into the chambers (3). The invention also comprises a method for the balancing of the washing machine.

Description

TECHNICAL FIELD

The present invention relates to washing machines of the type that have a floating unit that comprises a balancing device, a rotating drum and a tub. By means of said balancing device the intention is to compensate the possible imbalance caused by the distribution of laundry load in the washing machine drum.

PRIOR ART

Devices and methods for the balancing of washing machines with a rotating drum are known. More specifically, devices in which said means comprise a number of chambers disposed in the interior of the drum, with water being distributed inside said chambers to compensate for the imbalance are known.
ES2151332A1 ( EP 0856604 A ) discloses a device for the balancing of a washing machine that comprises a number of chambers, with each chamber comprising a solenoid valve from which water is supplied to it to compensate for the imbalance. Said supply is selective, with water being supplied to one or another chamber by its corresponding solenoid valve according to the angular position of the laundry load in the interior of the drum, a position determined by a position sensor.
US 6510715 B1 discloses a balancing device with a ring and chambers for compensating for an imbalance.
US 6477867 B1 discloses a balancing system for a laundry appliance, including force and acceleration transducers to detect the imbalance. If an imbalance is detected, the correction of said imbalance is implemented using a set of balancing chambers.
EP 1391549 A1 discloses a washing machine comprising a balancing device, a floating unit that comprises a drum which rotates in relation to an axis, the device comprising a number of hollow chambers distributed equidistantly in an inner periphery of said drum. Said chambers extend along at least part of the axial length of said drum and an imbalance generated by a laundry load situated in the interior of said drum is able to be compensated for by distributing water in the interior of said chambers while the drum is rotating. Said device also comprises a hollow ring, concentric to the axis of the drum and connected to one end of said drum, an intake duct to pour water into said ring, and a mouth for each chamber disposed on a lateral wall of the ring. Said mouths are connected to their corresponding chambers by a through duct, so that when water is poured into the ring, said water is distributed in the interior of said ring, the water being able to move to at least one chamber through its corresponding mouth and through duct.

DISCLOSURE OF THE INVENTION

It is an object of the invention to provide a washing machine comprising a balancing device.
Such a washing machine is provided by independent claim 1.
If water is poured into the ring when the drum is rotating at a speed higher than the critical speed corresponding to the resonance frequency of the floating unit, due to the centrifugal force and to an inertial physical principle, the water tends to distribute itself in opposition to the laundry load generating the imbalance, forming a circular crown eccentric to the ring. Said distribution causes the water to enter the appropriate chambers and in sufficient quantities to compensate for the imbalance.
In the device of the invention, it is not necessary to use a sensor to determine the angular position of the laundry load, nor is it necessary to use a solenoid valve for each chamber, as it is the distribution of the water in the ring that causes the chambers that have to compensate for the imbalance.
These and other advantages and characteristics of the invention will be made evident in the light of the drawings and the detailed description thereof.

DESCRIPTION OF THE DRAWINGS

Fig. 1 is a front view in section of a washing machine with a rotating drum.
Fig. 2 is a cross-section of a washing machine according to a first embodiment of the invention.
Fig. 3 is a perspective view of the ring of the embodiment in Fig. 2.
Fig. 4 shows the distribution of the water in the interior of the ring of the embodiment in Fig. 2 in a first possible situation.
Fig. 5 shows the distribution of the water in the interior of the ring of the embodiment in Fig. 2 in a second possible situation.
Fig. 6 shows the distribution of the water in the interior of the ring of the embodiment in Fig. 2 in a third possible situation.
Fig. 7 is a flow diagram that shows the stages of the method for the balancing for the embodiment in Fig. 2.
Fig. 8 is a cross-section of a washing machine according to a second embodiment of the invention.

DETAILED DISCLOSURE OF THE INVENTION

The device and method of the invention are applied in washing machines that comprise, as shown in Figure 1, a floating unit 1 formed by a tub 4 and a drum 2 that rotates in relation to an axis 21. Said axis 21 can be horizontal, as in Figure 1, or inclined.
The floating unit 1 is connected by suspension means 10 to the structure of the washing machine. If the laundry load 9 to be washed forms an imbalanced mass in the interior of the drum 2, an imbalance is caused, as a result of which the floating unit 1 starts to rotate with an eccentricity E generating vibrations. The device of the invention comprises hollow chambers 3 distributed equidistantly in an inner periphery 20 of said drum 2, said chambers 3 extending along at least part of the axial length of said drum 2. As shown in figure 1, in this case said device comprises three chambers with a separation between them of 120°.
Figure 2 shows a first embodiment of the invention in which a longitudinal section has been formed along the sectional line A-A in Figure 1. In said embodiment, the device of the invention comprises an open hollow ring 5 concentric to the axis 21 of the drum 2 and connected to an end 22 of said drum 2, and an intake duct 6 fixed to the tub 4 in order to pour water into said ring 5. The chambers 3 extend along the entire axial length of the drum 2.
The device of the invention also comprises for each chamber 3 a mouth 8 disposed on a lateral wall 50 of the ring 5 at a certain radial distance H from the outer perimeter 51 of said ring 5, with said mouths 8 connected to their corresponding chambers 3 by a through duct 7, so that when water is poured into the ring 5, said water is distributed in the interior of said ring 5, with the water moving to at least one chamber 3 through its corresponding mouth 8 and through duct 7. The through ducts 7 are situated on the end closest to the axis 21 of a lateral surface 30 of said chambers 3, as shown in Figure 2.
The choice of an appropriate radial distance H is critical in the device of the invention, as it is said radial distance H wich determines from which moment each chamber 3 begins to fill up. To determine said radial distance H, first of all the maximum imbalance that said device can compensate for is established, and a radial distance H is selected that is slightly greater than double the eccentricity E corresponding to said maximum compensatable imbalance.
Centrifuging is conducted with the drum 2 rotating at a centrifuging speed which can, for example, be 2,000 rpm. Before the drum 2 rotates at said centrifuging speed, the stages shown in the flow diagram of figure 7 are followed in order to check if there is an imbalance or not, and to compensate for said imbalance if there is one. The different stages of the method for balancing according to the first embodiment of the invention are described below.

* Checking process Pc for the imbalance of the first embodiment:

In the checking process Pc the aim is to determine whether the laundry load 9 of the interior of the drum 2 causes an imbalance or not, and for that purpose, with said drum 2 rotating at the checking speed Vc, which, for example, can be 90 rpm, a vibration sensor (not shown in the figures) measures the vibration M of the floating unit 1. If the measured vibration M exceeds a threshold value Uc predetermined for the checking speed Vc, the speed of rotation of the drum 2 is increased to a balancing speed Ve and a balancing process Pe begins. If not, the speed of rotation of the drum 2 is increased to a supervision speed Vs and a supervision process Ps begins.

* Balancing process Pe for the first embodiment:

During the balancing process Pe water is poured into the ring 5 through the intake duct 6, with said water originating from a main water intake or from waste water from a previous washing thanks to a water pump not shown in the figures. Said balancing process Pe is conducted with the drum 2 rotating at the balancing speed Ve, which can be, for example, 300 rpm. As the maximum value of the vibration M of the floating unit 1 and, therefore, the greater eccentricity E, is produced with the drum 2 rotating at a higher speed but close to the critical speed corresponding to resonance frequency of the floating unit 1, the balancing speed Ve is higher than said critical speed, but close to it.
As the balancing speed Ve is higher than the critical speed, the water in the interior of the ring 5 tends to concentrate itself in opposition to the laundry load 9 that causes said imbalance, forming a water crown or circle of axis 11 in the interior of said ring 5, eccentric to the ring 5 itself. The value of the eccentricity E is half the peak-to-peak amplitude of the vibration M resulting from the imbalance.
When the water circle of axis 11 reaches, at some point, one of the mouths 8, the water moves to the chamber 3 corresponding to said mouth 8 through the mouth 8 itself and its corresponding through duct 7. The cross-section of the through ducts 7 is larger than the_cross-section of the corresponding mouths 8, as a result of which, as the water is introduced into the chambers 3, the air is expelled from the interior of said chambers 3.
If turbulences are formed in the water in the interior of the ring 5, said water may enter the chambers 3 not corresponding to it. To prevent said turbulences from forming, the ring 5 comprises a plurality of obstacles 52 in its interior. Said obstacles 52, shown in figure 3, are flat walls that are fixed alternately to the lateral wall 50 of the ring 5 and the lateral wall 53 facing said wall 50, encompass the entire width of the lateral walls 50 and 53 and extend perpendicularly from said lateral walls 50 and 53. Said obstacles have an approximate height of 75% of the separation between the lateral walls 50 and 53.
As regards the distribution of the water in the interior of the ring 5, three different situations may occur:

In a first situation, shown in figure 4, the laundry load 9 that generates the imbalance is situated at 180° from one of the chambers 3. The water enters said chamber 3 through its corresponding mouth 8 and through duct 7. At the same time as the imbalance is being compensated for, the circle of water that is formed in the interior of the ring 5 reduces its eccentricity until said circle of water is concentric to the ring 5.
In a second situation, shown in figure 5 , the laundry load 9 that generates the imbalance is situated above one of the chambers 3. To compensate for this imbalance, the water of the ring 5 moves into the other two chambers 3 through their corresponding mouths 8 and through ducts 7. At the same time as the imbalance is being compensated for, the circle of water that is formed in the interior of the ring 5 reduces its eccentricity until said circle of water is concentric to the ring 5.
In a third situation, shown in figure 6 , the laundry load 9 is not in any of the two previous situations. To compensate for the imbalance, the water of the ring 5 moves to the opposing chamber 3 closest to the radial direction of said laundry load 9, through its corresponding mouth 8 and through duct 7. As said chamber 3 fills up, the laundry load 9 causing the imbalance is modified at the same time as it changes its position, until two chambers 3 begin to fill up. It is at this moment that the second situation begins.

In the three situations, the vibration sensor continues measuring the vibration M of the floating unit 1 while water continues to be poured into the ring 5. When it is detected that the measured vibration M is no longer greater than a threshold value Ue predetermined for the balancing speed Ve, said balancing process Pe is understood to have been completed, water is no longer poured into the ring 5 and the speed of rotation of the drum 2 is increased to a supervision speed Vs, and the supervision process Ps begins.

* Supervision process Ps for the first embodiment:

In the supervision process Ps the drum 2 rotates at the supervision speed Vs, which can, for example, be 800 rpm. In said supervision process Ps, the vibration sensor measures the vibration M of the floating unit 1 and said measured vibration M is compared with a threshold value Us predetermined for said supervision speed Vs. If it is detected that the vibration M is greater than said threshold value Us, the speed of rotation of the drum 2 is reduced to the balancing speed Ve and a new balancing process Pe begins. If not, said speed of rotation of the drum 2 is increased to a centrifuging speed that, for example, can be 2,000 rpm, in order to conduct the centrifuging. This increase in speed can be direct or gradual, and the supervision process Ps can be repeated at each gradual increase of the speed of rotation of the drum 2.
Once the centrifuging has been completed, the process to evacuate the water begins. In said process to evacuate the water, the speed of rotation of the drum 2 is reduced to an evacuation speed, which, for example, can be 45 rpm. Said evacuation speed is selected so that the force of gravity is smaller than the centrifugal force and the water in the interior of the chambers 3 falls into the tub 4. Due to the fact that the diameter of the through ducts 7 is greater than that of the corresponding mouths 8, most of the water in the interior of the chambers 3 falls into the tub 4, while a small residual part falls into the ring 5.
In a second embodiment of the invention, shown in figure 8 , the device comprises, in addition to the three chambers 3 described in the first embodiment, three additional chambers 3' situated at 120° to each other in an inner periphery 20 of said drum 2. Said additional chambers 3' face the three chambers 3. In said second embodiment, the additional chambers 3' extend along a first half of the axial length of the drum 2, while the chambers 3 extend along a second half of the axial length of said drum 2.
The device of this embodiment comprises, in addition to the ring 5 of the first embodiment, an additional hollow ring 5' concentric to the axis 21, situated at the end of the drum 2 and fixed to a second end 23 of said drum 2, similar to the ring 5 shown in figure 3 . By means of a second intake duct 6' water can be poured into said additional ring 5'.
As with the ring 5, to prevent turbulences from occuring in the water in the interior of the additional ring 5' and said water from entering the chambers 3 not corresponding to it, the additional ring 5' has a number of obstacles 52' in its interior, similar to those of the ring 5.
On a lateral wall 50' of the additional ring 5' and at a radial distance H' taking as a reference the outer perimeter 51' of said additional ring 5', are disposed some mouths 8'. For each additional chamber 3' exists a mouth 8', and each one of said mouths 8' is connected to its corresponding additional chamber 3' by a through duct 7' aligned with said mouth 8'.
The balancing method for the second embodiment of the invention comprises the same stages as the method of the first embodiment.

* Checking process Pc' for the imbalance of the second embodiment:

In the checking process Pc', with the drum rotating at the checking speed Vc of the first embodiment, a vibration sensor not shown in the figures measures the vibration Ma' of a first half of the floating unit 1 adjacent to the additional chambers 3'. A second vibration sensor not shown in the figures measures the vibration Ma of a second half of the floating unit 1 adjacent to the chambers 3. If the vibrations Ma, Ma' or one of said measured vibrations Ma, Ma' are greater than the threshold value Uc determined for the checking speed Vc, the speed of rotation of the drum 2 is increased to the balancing speed Ve of the first embodiment and a balancing process Pe' begins. If not, the speed of rotation of the drum 2 is raised to the supervision speed Vs of the first embodiment and a supervision process Ps begins.

* Balancing process Pe' for the second embodiment:

With the drum 2 rotating at the balancing speed Ve, water is poured into at least one of the rings 5, 5', depending on the vibrations Ma, Ma' of the floating unit 1. Three different cases can occur:

If the laundry load 9 is situated in the first half of the axial length of the drum 2 corresponding to the zone closest to the front of the washing machine, the value Ma' is greater than the threshold value Ue and water is poured into the ring 5'. The value Ma, on the other hand, is smaller than the threshold value Ue and water is not poured into the ring 5.
If said laundry load 9 is in the second half of the axial length of the drum 2, the value Ma is greater than the threshold value Ue and water is poured into the ring 5. The value Ma', on the other hand, is smaller than the threshold value Ue and water is not poured into the ring 5'.
If the laundry load 9 is approximately in the centre of the axial length of the drum 2, the vibrations Ma, Ma' are greater than the threshold value Ue and water is poured into both the ring 5 and the additional ring 5'.

The rest of the balancing process Pe' is similar to the balancing process Pe of the first embodiment.

* Supervision process Ps' for the second embodiment:

In the checking process Ps', with the drum rotating at the supervision speed Vs, the vibrations Ma, Ma' of the floating unit 1 are measured. Said vibrations Ma, Ma' are compared with the threshold value Us, and if it is detected that at least one of the vibrations Ma, Ma' is greater than the threshold Us predetermined for said supervision speed Vs, the speed of rotation of the drum 2 is reduced to the balancing speed Ve and the balancing process Pe' begins. If not, said speed of rotation of the drum 2 is increased to a centrifuging speed that, for example, can be 2,000 rpm, in order to conduct the centrifuging. This increase in speed can be direct or gradual, and the supervision process Ps' can be repeated at each gradual increase of the speed of rotation of the drum 2.
Once the centrifuging has been conducted, the process to evacuate the water from the chambers 3, 3' is carried out, which is similar to the process of evacuating the water from the chambers 3 of the first embodiment.

Claims

A washing machine comprising a balancing device, a floating unit (1) that comprises a drum (2) that rotates in relation to an axis (21), and the device comprising a number of hollow chambers (3) distributed equidistantly in an inner periphery (20) of said drum (2), said chambers (3) extending along at least part of the axial length of said drum (2) and an imbalance generated by a laundry load (9) situated in the interior of said drum (2) being able to be compensated for by distributing water in the interior of said chambers (3) while the drum (2) is rotating, said device comprising a hollow ring (5), concentric to the axis (21) of the drum (2) and connected to one end (22) of said drum (2), and an intake duct (6) to pour water into said ring (5), said device also comprising for each chamber (3) a mouth (8) disposed on a lateral wall (50) of the ring (5) at a certain radial distance (H) from the outer perimeter (51) of said ring (5), with said mouths (8) connected to their corresponding chambers (3) by a through duct (7), so that when water is poured into the ring (5), said water is distributed in the interior of said ring (5), the water being able to move to at least one chamber (3) through its corresponding mouth (8) and through duct (7), characterised in that a maximum compensatable imbalance is established, the radial distance (H) being slightly greater than double the eccentricity (E) corresponding to said maximum compensatable imbalance.
The washing machine according to claim 1, wherein the chambers (3) are three.
The washing machine according to any of the preceding claims, wherein the mouth (8) and the through duct (7) of each chamber (3) are aligned, with the cross-section of said through duct (7) being greater than the cross-section of said mouth (8).
The washing machine according to any of the preceding claims, wherein the through duct (7) is situated on the end closest to the axis (21) of a lateral surface (30) of its corresponding chamber (3).
The washing machine according to any of the preceding claims, wherein the ring (5) has a number of obstacles (52) in its interior.
The washing machine according to any of the preceding claims, wherein the chambers (3) extend along the entire axial length of said drum (2).
The washing machine according to any of claims 1 to 5, wherein the device comprises a plurality of additional hollow chambers (3') distributed equidistantly in the inner periphery (20) of the drum (2), said additional chambers (3') extending along part of the axial length of said drum (2) and with the additional chambers (3') remaining facing the chambers (3), said chambers (3) extending along part of the axial length of said drum (2), an additional hollow ring (5'), concentric to the axis (21) of said drum (2) and connected to a second end (23) of the drum (2), and an intake duct (6') to pour water into said additional ring (5'), said device also comprising for each additional chamber (3') at least one mouth (8') disposed on a lateral wall (50') of the additional ring (5') at a certain radial distance (H') from the outer periphery (51') of said additional ring (5'), said mouths (8') being connected to their corresponding additional chambers (3') by a through duct (7'), so that when water is poured into the additional ring (5'), said water is distributed in the interior of said additional ring (5'), the water being able to move to at least one additional chamber (3') through its corresponding mouth (8') and through duct (7').
The washing machine according to the preceding claim, wherein the chambers (3) and the additional chambers (3') are prolonged up to the middle of the axial length of said drum (2).
The washing machine according to any of the preceding claims, wherein the device comprises a vibration sensor to measure a vibration (M) of the floating unit (1).