US20110048081A1

US20110048081A1 - Balance ring system on two planes for a spin rotary machine

Info

Publication number: US20110048081A1
Application number: US12/712,331
Authority: US
Inventors: Leonardo Urbiola Soto; Alfonso Thompson Salinas; Martin Ortega Berta; Claudio Cesar Zenteno Sanchez
Original assignee: Individual
Current assignee: Mabe SA de CV
Priority date: 2009-02-27
Filing date: 2010-02-25
Publication date: 2011-03-03
Also published as: MX2009002329A; BRPI1002211A2; CA2693639A1

Abstract

A textile washing machine has a rotary basket balanced in at least one of its two planes, where optionally a first balance ring is structurally formed at the lower part of the basket or bottom of basket in order to balance the lower plane of the rotary basket and/or optionally, a second balance ring structured at the upper part of the basket. The first balance ring comprises: a channel or track that forms an integral part with the bottom of basket, a viscous drag fluid lodged in the track, a plurality of spheres lodged in the channel or track, immerse in the viscous drag fluid, and a lid that seals hermetically against the track. The lid comprises at least one radial rib in order to provide the bottom of basket with a structural reinforcement so that the bottom of basket does not weaken due to the presence of the track or channel. The second balance ring includes: a base with a first wall and a second wall, a cover that closes the base and with the same walls of the base, a working fluid lodged in the base, at least a curved blade lodged in the base where the blade covers from the first wall of the base and leaves a clearing between the blade and second wall, allowing the working fluid to have a vertical component; and at least a straight blade lodged in the base and alternated with the at least one aforementioned curved blade.

Description

RELATED APPLICATIONS

This application claims priority from Mexican application Serial No. MX/a/2009/002329 filed Feb. 27, 2009, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to washing machines, and more specifically, to washing machines that balance the load in a rotating centrifuge basket, where the balance system comprises balance rings in two planes.

DESCRIPTION OF THE RELATED ART

Any person who uses or has used a washing machine has had the opportunity to experience at times that the machine, when in spinning-dry (centrifuge) or in clothes dehydration process, produces extreme vibration, sometimes even making the machine move from its original place. This is known colloquially as “walking”. This occurs mainly because somehow the clothes and objects to be washed are not uniform, they have different shapes and their materials have different densities, and once the process of washing has finished and having drained the washing basket, most of the clothes are deposited and remain at one point of the mentioned basket. This makes and keeps the basket unbalanced.
This problem also occurs when big and heavy objects are introduced into the washing basket, like for example shoes. So when the washing process has finished and having drained the wash liquor from the basket, the shoes are deposited at the bottom of the basket producing great imbalance in the basket and hence generating undesired strain in the washing machine components such as, for example, excessive noise, severe vibration and frequent walking of the washing machine. On the other hand, the dynamic loads originated by the excessive vibration generate wear and damage of the washing machine components.
Due to the reasons just mentioned and others that a technician in the matter could discern, the centrifuge forces resulting from the objects in the washing basket need to be balanced.
Several efforts have been made concerning the solution of this problem. The prior art indicates that the use of the balance rings, which are hollow rings that are placed at the top of the washing basket; can be used as counterweight for the load of clothes because the interior part of the ring or toroid contains some liquid, solid balls or elements that contribute with mass. These elements can be made of steel slag or ceramics, and they adopt a position contrary to the centrifuge forces created by the position adopted by the objects to be washed, and so balancing the washtub.
For example, the document Hayashi's U.S. Pat. No. 4,044,026 et al, describes a balance ring placed at the top of a washing basket, which contains liquid solution in its interior, as well as a series of partitions that keep the liquid in chambers once the process of dehydration of objects to be washed by centrifugal action has initialized. The fact of having rotating blades in the partitions, where the liquid is kept separately while the washing basket is spinning in centrifugal mode, has the disadvantage of an undesired vibration during the system's transitional stage. Plus it does not allow the use of high velocity centrifuge, which is important when it comes to dehydrating more and consuming less time.
We can find another example of balance rings in document Do Weon Kim U.S. Pat. No. 5,782,110, which describes a balance ring that is prostrated on the washing basket, which in its interior has 3 tracks at different radius and with different widths of track, in which steel balls coated with oil are lodged. The diameter of the steel balls is in accordance with the width of the track in which they are placed, and so there are 3 different diameters of steel balls, which tend to be larger towards the outside. Once in the centrifugal stage, these steel balls counteract the loads that are imbalanced, giving balance to the washing basket when spinning. Even though the inventor of the document being discussed claims that his invention allows the spinning of the washing basket at high velocities, the construction of the mentioned balance ring is quite complicated, with too many parts involved, needs special fluid, is difficult to assemble and hence is expensive.
This is why the majority of solutions to this imbalance problem in a washing basket fall upon putting a crown on the wash basket with a balance toroidal ring, which solves the problem to a large extent. However, it is somehow obvious that an upper balance ring together with a lower one works better; that is to say, that by preferably placing a balance ring at the upper part of the basket, adding another balance ring at the lower part, helps to achieve a transitional state of vibration that is gentler and better controlled, together with the possibility of obtaining high velocity centrifuge, helping in what concerns efficiency of both the washing machine and the subsequent process of drying.
To wit that, when having high velocity centrifuge, this makes it possible to lessen the time the operation consumes when exerting stronger centrifugal force on the items placed in the washing basket, which results in the wash liquor mass being expelled faster towards the vertical wall in the washing basket, consequently, obtaining a dehydration of the items in the washing basket in less time, which results in an obvious saving of energy when using the washing machine. The following process, which is drying the clothes, also benefits with a higher velocity centrifuge because the clothes are already more dehydrated before beginning the drying process.
Several efforts have been directed in order to achieve these results that are highlighted in patent Jin Soo Kim U.S. Pat. No. 5,802,885, where a couple of disks are adapted, one for each extreme of the washing cylinder. These disks together with trays help contain the plurality of tracks on which several spheres will be running, which makes this design quite complicated because it contains many parts that need to be assembled, which makes it difficult to manufacture. Besides, the tracks' seal need maintenance, to with that the spheres have to be submerged in some kind of liquid, or if not, at least the tracks need to have a high friction coefficient.
Another example of this technique in patent Do Weon Kim et al. U.S. Pat. No. 5,761,933, describes a washing basket that is crowned on both upper and lower extremes, with a balance ring with liquid saline solution in its interior. The lower balance ring can be completely coupled with the lower part of the basket, having several chambers with an axis of symmetry that describes a concentric circumference to the basket where each chamber has a specific width in order to lodge different sizes of spheres. This assembly which is done at the lower part of the mentioned basket makes it extremely complicated and difficult to manufacture. Namely that, the sealing of each chamber has to be very well done and taken care of, because having several chambers, the probabilities of liquid leaks are higher, hence strict controls are required, as well as very strict manufacturing tolerances, which entails a manufacturing cost.
This is why one of the objectives of the present invention is to provide a system of balance rings in two planes, that do not require the use of an expensive fluid, that are easy to construct, that allow the reduction of the vibration generated in the transitional stage, a system that operates at high speeds, being it possible to adapt it to different types of wash baskets in washing machines with a vertical axis preferably, without having to exclude those with a horizontal axis, with a reduced number of parts, easy to assemble and manufacture, at low maintenance costs and reliable, among other characteristics.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to the field of washing machines, preferably automatic washing machines with a vertical or horizontal axis and machines that have in common that they have a basket with drilled holes, that spins around a rotation axis, propelled usually by an electric motor that can be coupled directly or using some mechanism for energy transmission, the most common being bands and pulleys, gear boxes, etc.
The mentioned washing machines, whether with horizontal or vertical axis undergo imbalance, caused to a large extent by the arrangement of the deposited objects within the washing basket or drum, objects which at their dehydrating stage have to spin at high velocities in order to force the water or washing liquor contained in the objects that are in the basket, to go towards the walls of the basket that have drilled holes, by action of the centrifugal force to which the mentioned objects are submitted, and so the washing liquor is then collected in the exterior tub so that it can be extracted with a pump towards the drainage.
Usually, the baskets are crowned with balance rings at only one of the extremes, which functioned correctly in the past, when the energy consumption requirements were not so strict, and when it was not necessary for the objects in the washing basket to spin at high velocities when at the stage of dehydration. This, without mentioning that the washing machines are manufactured at present with materials that are lighter, together with the technological advances in engineering, which leads to no longer requiring security factors as broad in order to make the pieces sturdy, hence heavy. And so, being the washing machines lighter, the vibration caused by imbalance becomes a major issue to deal with when considering the performance of the machine. To wit that, if the imbalance force is such, the washing machine will tend to “walk” or “dance”, which are undesirable conditions for the machine's adequate performance.
In this manner, the present invention suggests crowning both extremes of the basket with balance rings, placing at the opened extreme of the basket a balance ring with blades or chambers that works mainly with a fluid that can be calcium chloride or sodium chloride among others, same case as described in the application MX/a/2007/016516 for a hydrodynamic balance ring for a centrifugal rotation machine, from Ortega Breña et al.
Besides placing the ring at the other extreme of the washing basket, another ring is placed integrally at the exterior face of the disk or bottom of the basket, a balance ring with spheres made preferably of steel, of which weight, size and amount have been carefully selected, helping to simplify their manufacture, reducing the number of parts required and hence making it less costly and more reliable. The spheres run submerged in a fluid that has a specific viscosity; the fluid's specific function is to slither the spheres in transitional state so that they don't slip within the track and they reach the position contrary to the imbalanced load in a quicker manner. This also helps to mitigate the noise generated by the spheres by not allowing them to get to a standstill or “stop dead”; besides which the mentioned fluid absorbs the energy generated by the pile-up collision, plus the same fluid also has a weight that contributes to balance the magnitude of the vector resulting from forces.
Having two balance rings allows balancing the washing basket in two different planes, giving vectors that result in both planes, and these counteract the resulting magnitude of the imbalance vector, which is always variable in these planes. This helps the basket to balance itself in a short period of time, considerably reducing the force transmitted into the suspension system and from it into the cabinet, making it less probable that the washing machine “dances” or “walks”, in view of the fact that washing machines weigh less at present.
Balancing correctly and opportunely the objects distributed in a non uniform manner in the basket, which causes a considerable magnitude vector of imbalance, is desirable. To wit that, otherwise, some kind of mass or burden would have to be placed in the washing machine or the existing ones would have to be heavier, in order to avoid the “walking” or “dancing” phenomenon of the washing machine.
The balance ring containing balls placed at the exterior part of the disk or bottom of the basket has been thought to be completely adaptable to it, to wit that the track through which the spheres will be running is part belonging to the basket itself. This means, depending on the design of the basket, its bottom or disk, which preferably should result from a polymer injection process, contains within its intrinsic structure the mentioned track, being this part removed from the mold with the geometry of the track included, giving the washing basket a simplified yet sturdy bottom or disk. Namely that, the design has been such that the placing of the track at the exterior face of the bottom or disk of the washing baskets has a very good rigidity, giving flexibility in the assembly line, this is, the same basket, bottom or disk of basket can be used in washing machine designs for which due to factors concerning the company's decisions, costs or other marketing issues, they choose not to place a balance ring with spheres at the bottom or disk of the washing basket.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The particular characteristics and advantages of this invention, as well as other objects of the invention, will become apparent in the following description, given with the attached figures, which are:

FIG. 1 is a front cross-section of a washing machine.

FIG. 2 is a representative sketch of the imbalance phenomenon of the basket.

FIG. 3 is a second representative sketch of the imbalance phenomenon of the basket.

FIG. 4 is a third representative sketch of the imbalance phenomenon of the basket.

FIG. 5 is a front cross-section of a sub-washing machine in a representative sketch of imbalance forces of the basket.

FIG. 6 is an upper view of a balance ring containing liquid.

FIG. 7 is an upper view of a balance ring containing spheres.

FIG. 8 is a conventional exploded perspective view of a balance ring in the present invention.

FIG. 9 is a cross-section of a balance ring in the prior art.

FIG. 10 is a phantom conventional perspective of the internal geometry of a positive curved blade.

FIG. 11 is a cross-section of a balance ring in the present invention.

FIG. 12 is a cross-section of the parts of the balance ring in the present invention.

FIG. 13 is a cross-section phantom view of the balance ring in this invention.

FIG. 14 is a cross-section phantom view of the balance ring in this invention.

FIG. 15 is a cross-section conventional perspective in phantom view of the parts of the balance ring in the present invention.

FIG. 16 is a cross-section conventional perspective in phantom view of part of the balance ring in the present invention.

FIG. 17 is a cross-section of the front phantom view of part of the balance ring in the present invention.

FIG. 18 is a cross-section of the upper view of part of the balance ring in the present invention.

FIG. 19 is a cross-section of the upper view of part of the balance ring in the present invention.

FIG. 20 is a Bode plot comparing the basket's angular velocity in RPM versus the peak-to-peak vibration in the washing machine's cabinet.

FIG. 21 is a second Bode plot comparing the basket's angular velocity in RPM versus the peak-to-peak vibration in the washing machine's cabinet.

FIG. 22 is a front view of the basket in the present invention with the balance rings placed in the different planes.

FIG. 23 is an exploded conventional perspective view of the bottom of the basket.

FIG. 24 is an upper view of the spheres.

FIG. 25 is a conventional perspective of an upper view of the bottom of the basket.

FIG. 26 is a bottom conventional perspective view of the bottom of the basket.

FIG. 27 is a conventional perspective view of the lid of the inferior balance ring.

FIG. 28 is an upper view of the lid of the inferior balance ring.

FIG. 29 is a conventional perspective view of the bottom of the basket.

FIG. 30 is a comparative diagram between the balance forces, taking the number of existing balls into account.

FIG. 31 is a diagram of the imbalance forces in view of the number of balls.

FIG. 32 is a third Bode plot comparing the angular velocity of the basket in RPM versus the peak-to-peak vibration in the washing machine's basket.

DETAILED DESCRIPTION OF THE INVENTION

Theoretical Approach

The imbalance in a rotor can occur due to various causes, one of them can be due to the rotor's manufacturing method, having set more material in a specific point of the rotor, or on the contrary, due to a lack of uniformity in the density of the material. Sometimes, it may occur that other phenomena can cause the undesired vibrating effects in the washing machines, such as a deficient alignment of its shafts, defective bearings, inadequate lubrication of the bearings or supporting points that cause friction, mechanical looseness, and a deficient alignment of the bands with the pulleys, etc. The most interesting cause for purposes of the present invention is the imbalance due to the internal loads in the rotor. As can be deducted from FIG. 1, a washing basket 12 of a sub-washing machine 17 is set up within a tub 13. This basket 12 is moved or driven by a shaft 14 which is rigidly coupled with the bottom part of the basket 12, usually by means of a central part or link called hub 16. The shaft 14 can be coupled directly with a motor or induced pulley; in the case shown in FIG. 1 aforementioned, the shaft 14 is coupled with a planetary reduction gearbox 53, which at the same time obtains energy coming from an induced pulley 50 that obtains energy through a tread (not shown) that is energized by an electric motor 54. The basket 12 is composed in its lower part of a bottom of basket 58 which has a similar geometry to that of a disk, and which contains the hub 16, in order to spin in unison with it; the basket 12 also has a cylindrical wall that is crowned with the upper balance ring 10. The tub 13, in its lower part, has some supports that support the shock absorbers 18, from which rods 19 emanate.
The bottom of the basket 58, in its exterior face has a channel or track 57, which contains some spheres 59, as well as a drag fluid 60. In order to keep the spheres 59 and the drag fluid 60 inside, it is necessary to use a lid 64, that somewhere in its surface has a small hole 70 where the drag fluid 60 is introduced, and such hole 70 is sealed with a stopper 65. This lid 64 is specially designed to provide structural reinforcement to the bottom of the basket 58, because it is evident that when integrating the track 57 into the bottom of the basket 58, the result is a structural weakening of the component due to the interruption of the radial reinforcements 72, so consequently the design of the lid 64 requires special attention in order to avoid a reduced capacity of the bottom of the basket 58 to support the load of clothes and the efforts induced by the rotation. And so, the lid 64 is designed with such a geometry that its construction comprises a series of radial ribs 71 that give continuity to the radial reinforcements 72 of the bottom of the basket 58, hence achieving that with the assembly of lid 64 with the bottom of basket 58 a mechanical resistance equal or superior to the one present at the bottom of the basket 58 without the track 57 and with the continuous radial reinforcements 72 is obtained.
FIGS. 2, 3 and 4 help us understand the imbalance phenomenon in rotors, considering the basket 12 as a hollow rotor, in which in its interior all kinds of objects are deposited that adopt a random position in the interior of the mentioned hollow rotor. Having explained things, FIG. 2 illustrates a rotor or basket 12 which is supported on both extremes by the shaft 14. In this instance the rotor or basket 12 is not spinning, this is useful to exemplify what happens when the rotor or basket 12 undergoes a static imbalance, when putting identical imbalance loads 15, in the same angular position but in a different plane. It is evident that the center of gravity CG of the rotor or basket 12 as well as the principal axis of compliance or inertia 62 move a bit from the axis of symmetry 61 of the shaft 14 arrangement in the rotor or basket 12.
FIG. 3 is useful to describe another phenomenon of imbalance, in this case, the loads 15 are placed at the extremes of the rotor or basket 12 but at 180° one from the other and in a different plane, making the center of gravity CG stay in its place, but modifying the principal axis of inertia 62 taking a certain angle with respect to the axis of symmetry 61 of the shaft 14 arrangement in the rotor or basket 12. This angle will depend on the weight of the imbalance load 15, supposing that they are the same as well as their position within the rotor or basket 12. This phenomenon is commonly known as couple imbalance.
On its part, FIG. 4 shows another kind of imbalance, which is a combination of the cases presented in FIGS. 2 and 3, where the loads 15 are not placed symmetrically, and in fact, in this case they are not even equal; the loads 15 are placed randomly in any place within the cylindrical surface of the rotor or basket 12. This causes the center of gravity CG to move towards a position out of the axis of symmetry 61, where such position will depend on the position of the imbalance loads 15, as well as on their weight. In this last instance the rotor or basket 12, will tend to spin on the principal axis of inertia 62, and not on the axis of symmetry 61, axis on to which the bearings have been coupled, bearings that restrict four of the six degrees of liberty that the rotor or basket 12 could have, then producing an undesired vibration that could be so extensive that it would provoke the breakdown of a part, link or component.
In the case of the washing machines, these have the peculiarity that only one of the extremes of the basket 12 is held on to the shaft 14, leaving the other extreme free from the basket 12, this free extreme tends to describe a quasi elliptical transfer orbit on the axis of symmetry 61, what is commonly known as “pitch of the rotor”. When this happens, the basket 12 scrapes or patters the interior wall of the tub 13, wearing both pieces out and the case could be that one of them eventually breaks. On the other hand, the stated “pitch” manifests itself as transmitted forces into the washing machine's cabinet making it “jump”, “dance” or even “walk”. The magnitude of these vibrations has an impact on the centrifugal velocity, that is to say that if there is not a system that correctly balances the basket 12, the centrifugal velocity will have to be low, and obviously, when increasing the speed, the magnitude of the oscillations in the free extreme of the basket 12 will tend to be higher.
FIG. 5 shows a diagram of a sub-washing machine 17 which has a basket 12 where its bottom 58 is coupled with a shaft 14. The basket 12 is disposed in the interior of a tub 13, which hangs from the supports 52 to the cabinet by means of rods 19 with shock absorbers 18. It is noticeable that the basket 12 is crowned by an upper balance ring 10, and a lower balance ring 63 has also been placed; with this we are trying to obtain a balance in two planes. To wit that the rotors with a length a bit greater than their diameter are considered large rotors; it is commonly known that these large rotors should preferably be balanced at least in two planes. And so, returning to FIG. 5, it is preferable that the basket 12 is crowned with a balance ring containing liquid in is interior; we can find an example of these rings in document MX/a/2007/016516; these balance rings are of very low cost. On the other hand, the lower balance ring 63 here proposed is a ring based on spheres, made of dense material such as steel, heat stable (thermo-fixed) plastic, thermoplastic rubbers with ceramic components, etc. This combination is advantageous because of low costs and because it is easy to manufacture, and it gives balance to the basket 12 in two planes, crowning it in its free part, precisely where there is greater space, with a balance ring with liquid, and integrally, at the exterior face of the bottom of the basket 58 a channel of circular trajectory is procured, where the spheres 59 will be running immerse in a drag fluid 60, this channel is covered with a lid 64.
These balance rings work together, that is that the imbalance force IF caused by the imbalance mass or load 15 provokes a moment MCG in the center of gravity CG; this moment MCG, as well as the mentioned imbalance load 15 is counteracted by the resulting force FLD from the upper balance ring 10, which also causes a moment in the center of gravity CG. On its part, the lower balance ring 63 also exerts a resulting force FB that also acts on the center of gravity CG. In an ideal situation, the addition of moments in the center of gravity CG are zero, herewith the equation of moments (1) that is obtained at the point CG and resulting forces (2) is the following:
MGC=(FLD*d1)+(FD*d2)−(FB*(D2+D3)) (1)
Fnet=FLD−FD+FB (2)
where:
MGC=Moment in the center of gravity
Fnet=Net force resulting in the rotor or basket 12
FLD=Force resulting from the upper balance ring 10
d1=Distance from the center of gravity CG to the midpoint of the upper balance ring 10
FD=Imbalance force caused by the imbalance mass or load 15
d2=Distance from the center of gravity CG to the midpoint of the imbalance mass or load 15
FB=Force resulting from the lower balance ring 63
d3=Distance between the midpoint of the imbalance mass or load 15 to the midpoint of the lower balance ring 63.
It fits to point out that from analyzing the equation of moments in the CG point, it is inferable that without the lower balance ring, the resulting moment would be positive, causing a conical vibration mode 68, therefore the lower balance ring 63 reduces the magnitude of the resulting moment and directs to a softer movement of transfer of vibration 69 and consequently, to the alternation of forces transmitted to the suspension 19, hence the vibration is reduced, just as analyzed in FIG. 5.
FIG. 6 illustrates a typical balance ring with liquid, which comprises a series of blades 66 in its interior, in order to keep the liquid in small chambers and so to burst its flow within the toroidal chamber of the upper balance ring 10, causing a great volume of working fluid in the upper balance ring 10 to agglutinate at 180° opposite from the imbalance load 15. To wit that this kind of balance rings, due to the surface tension, as well as the high cohesion that molecules have in a liquid, a working fluid mass 67 is always in contact with the rest of the internal face of the external wall in the toroidal chamber of the upper balance ring 10. This mass of working fluid 67, which is straggled, generates a resulting force in the same direction of the imbalance force IF, increasing the imbalance force, decreasing the efficiency of the upper balance ring 10, because it has a component that pushes power in favor of the imbalance load or mass 15. As we have referred above, the washing basket 12 can be perceived as a large rotor, which is seized only by one of its extremes to the shaft 14, being this condition a favorable one in order to place at the lower part or bottom of the basket 58 a second balance ring 63, as shown in FIG. 7; and it is pointed out that there are some design restrictions, these are: the space between the tub 13 and the basket 12 is minimal, because if it is too wide more water than necessary will have to be used when washing or rinsing, and consequently there will be an inefficient use of this vital liquid; another aspect is that if the distance or gap between the tub 13 and the basket 12 is wider, the washing machine will have to be taller, and on this assumption, a user (person) of short height would have many problems when taking the articles in the machine out, because they end up placed in the interior face at the bottom of the basket 58. These and other reasons are why the space between the tub 13 and the basket 12 is considered, and why the designer has to consider it so that the distance does not increase, but rather decrease.
Having expressed the above mentioned, the solution proposed by the present invention is placing a lower balance ring 63 through which a series of spheres 59 will run, made of a material with high density and very resistant to impact. These spheres 59 are immersed preferably in a liquid fluid known as drag fluid 60, this way, when the basket 12 spins in a “ω” direction, both the drag fluid 60 and the spheres 59 adopt an opposite position from the imbalance load or mass 15, reducing at a minimum the “e” distance and consequently the principal axis of inertia 62 will be closer to the axis of symmetry 61, therefore the origin points “O” and “O′” will be very close. Making an analysis of a body not having a lower balance ring 63 we notice that these kinds of balance rings are efficient, to wit that the spheres 59 in unison with the drag fluid 60 contribute producing the resulting force FB, being a factor to be considered in the design that the mass of the spheres 60 as a whole to be greater or equal to the imbalance mass 15, having the spheres 59 made of a material with high density. The space required to lodge these is minimized, which means that the diameter at the bottom of the basket 58 can be used, and so the diameter of the spheres 59 can be reduced, using a larger amount, or vice versa.

PREFERRED EMBODIMENT OF THE INVENTION

As a first step, and to keep an order in the description, we will first deal with the construction of the upper balance ring 10. And so, FIG. 8 shows an exploded isometric drawing of the balance ring 10 where its basic elements are shown, a base 37 that contains blades 21, 22 or 23 in whichever of its configurations or combinations. This base is preferably molded by injection of some thermo-fixed polymer and its transversal section is similar to a “U” shape, with its walls configured as follows: an internal wall with a smaller diameter 30, an internal wall with a greater diameter 31 and an inferior wall 33. Concerning the internal upper wall 32, it is formed by the cover 26, which is similar to a ring with uniform thickness and should preferably be made by plastic injection molding. The cover 26 is jointed with the base preferably by process of ultrasound, “spin weld”, heat sealed or similar, or using some kind of sealer or agglutinant substance, to wit that the sealing has to be done very carefully, because the internal cavity of the balance ring 10 will be filled with some kind of working liquid, preferably calcium chloride or sodium chloride, which should not leak from its confinement. The stopper 25 is inserted into the hole provided for the filling of the working fluid in the balance ring 10, once full, the hole is sealed with the stopper 25.
FIG. 9 illustrates a transversal section of a typical balance ring 10 already existing in the prior art, where we can appreciate the form of a blade 66 in the interior of the chamber in the balance ring 10, in which we can see the different radius to be considered when calculating the volume of working liquid, which will vary depending on the loads to balance 15, the geometry of the basket 12, the capacity of the basket 12, the kind of suspension 11, among others, all these being the designer's responsibility and skill at all times. And so, the internal radius “r_i” has to be considered, in the majority of cases it coincides with the radius of the internal wall with a smaller diameter 30, due to the design requirements, it is somewhat difficult to obtain a chamber with transversal section completely rectangular in the balance ring 10; therefore, it is necessary to calculate the imaginary internal radius, called “r_iequivalent” or r_ie; the external radius “r_o” implies no major complications. To wit that because the balance ring 10 is held on by its external wall to the internal upper wall of the basket 12, the internal wall with a bigger diameter 31 makes it impossible to give a complex geometry to this external wall of the balance ring 10, what results in few design options. It is therefore recommended that only the internal wall with bigger diameter 31 is given thickness, in order to form the external wall of the balance ring 10. Another element to be considered when making calculations for the working liquid volume is the internal free height of the chamber at the interior of the balance ring 10, which in the mentioned figure is represented with an “h”. With this information, together with the form of the blades to be used, we then proceed to calculate and when necessary to design the experiments that will allow us to determine the amount of working liquid to be used, which fluctuates between fifty to eighty percent of the total volume in the internal chamber of the balance ring 10.
FIG. 10 on its part shows an isometric ghost view of the internal geometry of a positive curved blade 22. This denomination is taken from the direction of spinning ω of the basket 12. As an example for the description of the preferred modality of the present invention but not limited to this particularity, the positive blades 22 origin from the internal wall with smaller diameter 30 extending and following the curve L_θtowards the internal wall with bigger diameter 31, leaving a vertical space 39 between the positive curved blade 22 and the internal wall with bigger diameter 31. In the preferred modality of the present invention, all the blades 21, 22 or 23 have the same height as the base 57 of the balance ring 10, what makes their manufacture easier. Equally, in all the blades 21, 22 or 23, their lower part coincides with the internal lower wall 33, delimitating then the flow of working liquid through either the sides or the vertical spaces 34 and 39 between these blades 21, 22 or 23 and this internal wall with bigger diameter 31, or through the upper part 36, when the case is that there are bottom (lower) blades 28.
FIGS. 11 and 12 show a cross section drawing of the balance ring 10, where it is possible to appreciate how the top (upper) blade 27 is conformed, these blades obstruct the flow of liquid between the lower internal wall 33 towards the upper internal wall 32, originating from the internal wall with less diameter 31, following the curve L_θ, which in its parametric form is given by:
L _θ(x)=a(cos(θ+φ)+θ sin(θ+φ)) (3)
L _θ(y)=a(sin(θ+φ)+θ cos(θ+φ)) (4)

Where:

a=constant with a preferential value of r_ie
φ=phase angle in radians that defines the radial position at the beginning of the curve;
leaving a vertical space 39 between the upper blade 27 and the internal wall with bigger diameter 30. This vertical space 39 allows the vertical flow of the undulating vertical current of the working liquid towards the interior of the internal chamber of the balance ring 10. In the preferred modality of the invention, the upper blade 27 is conformed of a lower blade 28 that may have the form of the blades 21, 22 or 23, their height being limited for manufacturing reasons to that of the base 37 of the balance ring 10, complementing their height with a protuberance formed at the lower face of the cover 26. This protuberance is known as complement of blade 38, being it possible that its cross section takes the shape of blades 21, 22 or 23, so that the upper face of the blade 28 is coupled with the lower face of the complement of blade 38, and forming then a barrier with a floor surface in the internal lower wall 33 with a roof surface on the internal upper wall 32. In an alternative modality, the complement of blade 38 can be shorter, this with the purpose of allowing the flow of the working liquid through the upper part of the blade 28 in order to allow the flow of working liquid in its horizontal component. The same effect or a similar one could be achieved making blades 28 of at least two different sizes, or if not available, also making the complement of blade 38 of at least two different sizes, taking them off completely from the lower face of the cover 26, in order to leave space for the extended blades 28, or a combination of the options above mentioned, which will have to be herewith written as if literally they were inserted. To wit that in any preferred modality, the blades 27 block completely the horizontal component of the flow of the working liquid, understanding that in the alternative modality, the upper blades 27 do allow the flow of the working liquid to have a horizontal component because there is a clearing 36 between the upper blade 28 and the upper internal wall 32, or between the upper blade 28 and the complement of blade 38.

FIG. 13 illustrates a cross section of the balance ring 10 in ghost view, and it is possible to appreciate the conformation of a blade 28, where it is obvious that the blade 28 has the same height as the base 37 of the balance ring 10. This figure illustrates a blade that originates from the internal wall with a smaller diameter 31 following the form L_θtowards the internal wall with a bigger diameter 30, without touching it, and where there is a space or side 34 between the vertical face of the blade 28 and the internal wall with smaller diameter 31. Having the blade 28 the same height as the base 37 of the balance ring 10, there is a clearing 36 between the upper face of the blade 28 and the internal upper wall 32. This way, the clearings 36 and the sides 34 and 39 allow the flow of working liquid to have horizontal components as well as vertical components, respectively.
FIGS. 14, 15, 16 and 17 make it possible to understand the assembly of a base 37 with a cover 26. In order to easily assemble the base 37 with the cover 26, a localizer 40 was conceived, and which, in a descriptive but not limitative way for purposes of describing the best way to carry out the invention, comprises a pair of walls in high relief 40 in the internal lower wall 32, which can be appreciated in FIGS. 14 and 15. These walls in high relief or localizer 40 have a bay with a duct forming a “Y”, which is inverted as shown in the figures just mentioned, in this occasion the bay is wide and it allows to localize as well as to guide the upper part of the blade 28, making it possible for the cover 26 to always rest in the right position accordingly with the base 37 when assembling, what is illustrated in FIGS. 16 and 17, and hence avoiding localization errors that could cause an undesirable malfunctioning of the balance ring 10.
FIGS. 18 and 19 are useful because they identify and show the different kinds of blades 21, 22, 23, to wit that the base 26 can lodge different types of blades. And so the prior art describes arrangements of straight radial blades, that as discussed in the chapter concerning background, as well as in the theoretical statement, these arrangements are not optimal. So there is FIG. 18 that presents the preferred modality of the invention, which comprises an arrangement of positive curved blades 22 with negative curved blades 23, with their respective clearings 34 and 39. FIG. 19 illustrates an alternative modality of the invention that provides an arrangement of positive curved blades 22 with straight blades 21. This is comprehensive because of the spinning direction of the basket 12, and it is obvious for a technician in the matter that if the basket 12 spins in opposite direction the use of negative curved blades 23 instead of the positive curved blades 22, could produce better results.
FIG. 20 represents a Bode plot in which the angular velocity of the basket 12 is represented graphically, in revolutions per minute (rpm) versus the peak-to-peak vibration measured at the front face of the washing machine's cabinet. For this graphic the walking threshold is of approximately 1 mm. This means that, given an angular velocity, if the peak-to-peak vibration exceeds a millimeter, the washing machine will tend to move randomly towards any direction. In this graphic we can also appreciate the vibrations resulting from the use of different arrangements of the balance ring 10. For this purpose, using the same sub-washing machine 17, with the same imbalance load 15, several balance rings 10 were placed with different internal arrangements, which for the curve “A0” a conventional balance ring 10 was used, and which uses straight radial blades 21. It is pointed out that bellow the 100 rpm the highest peak is of 2 mm, and then, above the 600 rpm the vibration separates from the other curves, indicating that the design of a conventional balance ring does not withstand high rpm in an optimal manner. As can be deduced from this graphic, above the 800 rpm, there is an existing difference of approximately 1 mm from the rest of the curves. It is also noticeable that when getting closer to the 900 rpm it has a peak higher than 3 mm, this way indicating the incapacity of this kind of balance rings 10 to balance loads 15 at more than 600 rpm. On the other hand, the curve “A2” has an arrangement of twelve positive curved blades 22 with twelve straight blades 21 alternated, noticeably diminishing the vibration compared to the base curve “A0”, and proving then that the molecules “P”, thanks to the curvature of the blades 22, reach faster from their stable state towards the internal wall with larger diameter 31, and so it is inferable that the transitional state is shorter (considering a constant acceleration), also producing vibrations of lesser magnitude (of 1 mm approximately) and functioning much better between 600 rpm and 850 rpm. The curve “A3” is also noticeable in the graphic of FIG. 20, describing a behavior similar to that of “A2” and corresponding to a second preferred configuration of the balance ring with twelve positive curved blades 22 and thirteen straight radial blades 21.
FIG. 21 shows another Bode plot, for the left lateral face of the washing machine, for this measurement the walking threshold presents itself at about 1.4 mm of peak-to-peak vibration, as can be observed in the diagram; the three curves “A0”, “A2” and “A3” behave similarly from zero to seven hundred rpm. Above this last angular velocity, the vibration caused by “A0” starts getting higher than “A2” and “A3”, rocketing higher than eight hundred rpm, having a peak higher than 3.5 mm close to the nine hundred rpm, which is about 2 mm higher than “A2” or “A3”. Also, from an analysis of the Bode plot afore commented, it can be inferred that the conventional balance rings 10 with straight radial blades 21 are not adequate for high rpm, because when the rpm are increased their capacity to balance is significantly decreased, situation that does not occur with the configurations here proposed.
FIG. 22, on its part, illustrates the arrangement of two balance rings 10 and 63 disposed in two different planes corresponding to the extremes of the basket 12. It is noticeable that the upper balance ring 10 is crowned onto the basket 12 in its upper part, set up on the cylindrical wall. In the lower part of this cylindrical wall is the bottom of the basket 58, which is manufactured preferably with some kind of injectable polymer. This one mechanically couples the hub 16 into its center part and is a part of the reinforcement mechanism, manufactured preferably with some metal or light metallic alloy, in order to make it more resistant to the stress transmitted from torque via the shaft 14 to the basket 12; the hub in its part transmits the energy towards the bottom of the basket 58, in order to have them all rotate in unison as a whole. The track or channel 57 is located on the exterior face of this bottom of basket 58; in this channel 57 the spheres 59 as well as the drag fluid 60 will be lodged. These together are covered with the lid 64 of the lower balance ring 63. With the purpose of following the order of the description, we will now give the details of the particular construction of the lower balance ring 63.
FIG. 23 shows an exploded drawing of the bottom of basket 58 with channels. It has a series of radial reinforcements 72 and circumferential or annular reinforcements 73, that is, that this piece withstands the weight of the wash liquor and the weight of the objects to be washed already introduced into the basket 12. It is also able to support the vibration, as well as the dynamic loads exerted on it during the washing and centrifuge stages, hence being it another function to lodge the track or channel 57 where the spheres 59 will be spinning. And so, this piece not only has contention functions, but also contributes to the balance of the lower plane of the basket 12. All the previous information can be observed in FIG. 25 as well. FIG. 26 shows the bottom of basket 58 from an upper view, which has the channel or track 57 at its lower part.
FIG. 24, on its part, shows a series of spheres 59, that are manufactured with a high density material, with good resistance to impact, with a high fluidity point, anticorrosive and hardness, among other properties. The material usually recommended is steel, and it can be low carbon steel with heat treatment by cementing or stainless steel, the choice inextricably depends on the drag fluid 60 that will be used, although other materials could be used, like a plastic or thermo-fixed polymer with a kind of specific combination of a ceramic material. The number of spheres 59 to be used, as mentioned a few lines above in the theoretical approach section, respond to: in the first place, the weight or force of the load to be balanced; in the second place, it is preferable not to use more spheres than necessary because it would increase the manufacturing costs; and in the third place, the particular diameter of the spheres 59, which is related to the radius of the track or channel 57. And so, experimenting with these variables we can obtain, first of all, the graphic of FIG. 30, in which we can observe in the vertical axis, the force in Newtons that is exerted by a specific number of spheres 59 all with the same specific diameter, in a track 57. Analyzing this graphic we can delimit the number of spheres 59 to between fifteen and thirty, to wit that the force required to counteract an imbalance load 15, in a basket 12 is higher than 700 N. The graphic in FIG. 31 is drawn from the equations (1) and (2), and for that, for the calculations a one kilogram imbalance load 15 was used, at a maximum speed of 850 rpm. In the left vertical axis the scale of the resulting force in Newtons is obtained. In the horizontal axis the number of spheres 59 is represented. In the second vertical axis located at the right of the graphic mentioned, the net momentum resulting in the rotor or basket 12 when adding the lower balance ring 63 in N*m is obtained. From here we can deduce that the number of spheres 59 fluctuates between fifteen and twenty five spheres 59. This range in the number of spheres 59 guarantees that the basket 12 will not scrape the tub 13, reason for which the quasi-elliptic trajectory or “pitching” of the basket does not have such magnitude as to cause these pieces to have contact between them, what according to experience is an acceptable parameter of imbalance in a washing machine. So, the only decision left to the designer is that when considering the number of spheres 59 to be used, the cost of the spheres 59 versus the capacity of balancing should also be considered.
FIGS. 27 and 28 show the lid 64 of the lower balance ring 63, this lid can be adhered to or coupled with the bottom of the basket 58 using mechanical methods like “spin weld” or ultrasound, heat sealed, or using some kind of glue or agglutinant substance, what should guarantee at all times that the chamber formed by the track or channel 57 and the lid 64 will be hermetically sealed. To wit that the drag fluid 60 to be introduced has a viscosity at 40° C. of between 200 and 300 cSt, with a inflammability temperature higher than 300° C. The acidity in the drag fluid 60 should also be taken care of, namely, that the acidity could age or damage the spheres 59, or it could ruin the manufacturing material of the bottom 58. The designer should have in mind that the selection of the drag fluid 60 is a factor that needs to be considered in the compliance of the applicable environment legislation (standards).
The design of the bottom of basket 58 is such that it provides flexibility for its manufacture. Namely, that the bottom of basket 58 is convertible: with or without track 57, what gives it adaptability according to the washing machine model, which, for reasons of business decisions, costs and marketing, among others, the choice could be not to provide it with a balance ring containing spheres 59 at the bottom of basket, as is shown in FIG. 29, in which case, the lid 64 is not placed and in the injection mold the insertion is changed so that the radial reinforcements 72 are formed in a continuous manner within the space of the track 57, hence at the bottom of basket 58 there is very good rigidity thanks to an adequate design of the radial and annular reinforcements 72 and 73. Besides, if we wish to include the balance ring with spheres 59 and form a channel 57 by changing the insertion, and interrupt the radial reinforcements 72, the radial ribs 71 in the lid 64 give enough rigidity and mechanical resistance to support the static washing load, as well as the efforts resulting from rotation and the vibration.
The graphic in FIG. 32, on its part, illustrates the important reduction of vibration or imbalance when implementing a lower balance ring 63 into a basket 12, using a balance ring 10 with liquid and blades with involute curve, avoiding the peak generated in the vicinity of seven hundred rpm, showing the angular velocity spectrum of the basket 12, at all times, a more uniform behavior.
It is important to point out that the modalities here described should not be interpreted restrictively, to with that they are illustrative of the best way to carry out the invention here commented, that is, that several modifications and variations can be foreseen by a technician with some knowledge of this particular technique; these modifications and variations should not be left out from the legal protection of the following claims.

Claims

1. A textile washing machine having a rotary basket balanced in both its planes with a first balance ring that crowns the basket in order to balance the upper plane of the rotary basket, and a second balance ring structured in the lower part of the basket, the machine comprising:

a. a channel or track that is an integral part of the bottom of the basket;

b. a viscous drag fluid lodged in the track;

c. a plurality of spheres lodged in the channel or track, immerse in the viscous drag fluid; and

d. a lid that seals hermetically against the track, the lid comprises at least one radial rib in order to provide structural reinforcement at the bottom of basket, in order to prevent the bottom of basket from weakening due to the presence of the track or channel.

2. The washing machine according to claim 1, additionally comprising a hole in the cover through which the injection of the drag fluid is carried out and a stopper that seals this hole in order to avoid the spilling of the drag fluid once it has been injected.

3. The washing machine according to claim 1, wherein the bottom of basket is manufactured from a polymer.

4. The washing machine according to claim 1, wherein the spheres are made of steel and the amount of spheres oscillates between fifteen and thirty.

5. The washing machine according to claim 1, wherein the first balance ring is disposed in the upper part of the basket in order to balance the upper plane of the mentioned basket and comprises:

a. a base with a first wall with a bigger diameter and a second wall with a smaller diameter;

b. a cover that closes the base and with the same walls as the base;

c. a working fluid lodged in the mentioned base;

d. at least one curved blade lodged in the base where the blade covers from the first wall of the base, leaving a clearing between the blade and the second wall, allowing the working fluid to have a vertical component; and

e. at least a straight blade lodged in the base and alternated with it at least one curved blade.

6. The washing machine according to claim 5, wherein the second balance ring comprises a plurality of curved blades, wherein this plurality of curved blades, a series of curved blades are upper blades and a series of curved blades are lower blades, where the lower blades and the upper blades are alternated.

7. The washing machine according to claim 5, wherein the curved blades follow the equations described by:

L _θ(x)=a(cos(θ+φ)+θ sin(θ+φ)

L _θ(y)=a(sin(θ+φ)+θ cos(θ+φ)

8. The washing machine according to claim 5, wherein the curved blades are positive with regard to the direction of spinning.

9. The washing machine according to claim 7, where the mentioned curved blades are negative with regard to the spinning direction, corresponding to an inversion of the curve L_θor the arithmetic multiplication by −1.

10. The washing machine according to claim 6, wherein the upper blades and/or the lower blades have a clearing that allows the flow of working liquid to have a horizontal component.

11. A textile washing machine having a rotary basket balanced in its two planes, where a first balance ring is structurally formed at the lower part of the basket or bottom of basket and a second balance ring is structured at the upper part of the basket in order to balance the upper plane of the mentioned rotary basket, the second balance ring comprises:

a. a base with a first wall and a second wall;

b. a cover that closes the base and with the same walls of the base;

c. a working fluid lodged in the base;

d. at least one curved blade lodged in the base where the blade covers from the first wall of the base and leaves a clearing between this blade and the second wall, allowing the working fluid to have a vertical component; and

e. at least one straight blade lodged in the base and alternated with it at least one curved blade.

12. The washing machine according to claim 11, wherein the second balance ring comprises a plurality of curved blades, wherein this plurality of curved blades, a series of curved blades are upper blades and a series of curved blades are lower blades, where the lower blades and the upper blades are alternated.

13. The washing machine according to claim 11, wherein the curved blades follow the equation described by:

L _θ(x)=a(cos(θ+φ)+θ sin(θ+φ))

L _θ(y)=a(sin(θ+φ)+θ cos(θ+φ))

14. The washing machine according to claim 11, wherein the curved blades are positive with regard to the direction of spinning ω.

15. The washing machine according to claim 13, wherein the curved blades are negative with regard to the direction of spinning, corresponding to an inversion of the curve L_θor an arithmetic multiplication by −1.

16. The washing machine according to claim 12, wherein the upper blades and/or the lower blades have a clearing that allows the flow of working liquid to have a horizontal component.

17. A system of balance rings in a textile washing machine having a rotary basket balanced in both its planes, where a first balance ring is structurally formed at the lower part of the basket or bottom of basket in order to balance the lower plane of the rotary basket and where a second balance ring is structurally formed at the upper part of the basket in order to balance the upper plane of the rotary basket, the first balance ring comprising:

a. a channel or track that is an integral part of the bottom of basket;

b. a viscous drag fluid lodged in the track;

d. a lid that seals hermetically against the track, the lid comprises at least one radial rib in order to provide the bottom of basket with a structural reinforcement, so that the bottom of basket does not weaken due to the presence of the track or channel; and

the second balance ring comprising:

a. a base with a first wall and a second wall;

b. a cover that closes the base and with the same walls as the base;

c. a working fluid lodged in the base;

d. at least one curved blade lodged in the base, where the blade covers from the first wall of the base and leaves a clearing between the blade and the second wall, allowing the working fluid to have a vertical component; and