Patent Application
20080256987
This application claims the priority benefit of Korean Patent Application No. 2007-0038518, filed Apr. 19, 2007, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field
Embodiments relate to a drum washing machine, and more particularly, to a drum washing machine having ball balancers for rapidly reducing the vibration of a drum.
2. Description of the Related Art
Generally, drum washing machines are apparatuses, which wash laundry by the difference in elevation caused by lifting the laundry and then dropping the laundry. Each of these drum washing machines includes a tub for containing water, and a drum rotatably installed in the tub.
In a drum washing machine, a drum horizontally disposed is rotated in a clockwise direction and a counterclockwise direction alternately. When the drum is rotated, laundry vertically moves along the inner circumferential surface of the drum together with washing water, thus being washed and dehydrated.
In the above conventional washing machine, when the drum is rotated so as to wash and dehydrate the laundry, an unbalanced weight is generated due to the eccentric structure of the drum itself and the partial disposition of the laundry in the drum.
When the unbalanced weight is generated during the rotation of the drum, the drum is inevitably vibrated. Thus, a balancer for rapidly reducing the vibration is installed at one side of the drum.
Here, the balancer includes a plurality of masses having a designated weight so as to exhibit a balancing function, and a housing forming an internal space so as to guide the movement of the plurality of masses. Further, the internal space of the housing is filled with a fluid for assisting the proper movement of the masses and preventing the collision of the masses so as to reduce the vibration generated by the movement of the masses.
That is, in the conventional drum washing machine, the drum is rotated under the condition that the dynamic balance of the drum is not maintained due to the unbalanced weight. At this time, the masses move to a position symmetrically opposite to the unbalanced weight, and thus balance the drum, thereby reducing the vibration of the drum generated due to the unbalanced weight.
The masses and the fluid perform a circular movement and a centrifugal movement along the housing of the balancer. When an interval between the masses and the housing is large, noise is generated due to the centrifugal movement of the masses and the amount of the fluid filling the housing is increased.
Further, when the interval between the masses and the housing is small, the movement of the masses is disturbed and it is difficult to achieve a rapid balancing effect.
Therefore, one aspect of embodiments is to provide a drum washing machine having ball balancers, which adjust a proper interval between masses and a housing so as to effectively reduce the vibration of a drum.
In accordance with one aspect of embodiments, there is provided a drum washing machine including a drum rotatably installed so as to wash or dehydrate laundry; and balancers, each including a housing provided with a race formed therein, and a plurality of masses provided in the race and being movable in a circumferential direction, so as to reduce vibration caused by the rotation of the drum, wherein the race has a rectangular section, corner portions of which are rounded; and a value obtained by dividing the radius (rs) of the corner portions by the radius of the masses (R) is between 0.4 and 0.9 so as to effectively reduce the vibration of the drum.
In accordance with another aspect of embodiments, the inside of the race is filled with a fluid for reducing noise caused by the circumferential movement of the masses.
In accordance with another aspect of embodiments, the race has a ring shape.
In accordance with another aspect of embodiments, a gap (d) between the masses and the housing is maintained to approximately 2 millimeters.
In accordance with another aspect of embodiments, balancers are respectively provided on the front and rear surfaces of the drum such that the balancers are concentric with the drum.
In accordance with another aspect of embodiments, there is provided a balancer for a drum washing machine, which serves to reduce vibration caused by the rotation of a drum, comprising a plurality of masses; and a housing provided with a race, in which the masses move in a circumferential direction, wherein the race has a rectangular section, corner portions of which are rounded.
In accordance with another aspect of embodiments, a value obtained by dividing the radius (rs) of the corner portions by the radius (R) of the masses is between 0.4 and 0.9.
In accordance with another aspect of embodiments, a gap between the masses and the housing is maintained to approximately 2 millimeters.
In accordance with another aspect of embodiments, the inside of the race is filled with a fluid for reducing noise caused by the circumferential movement of the masses.
In accordance with another aspect of embodiments, the race has a ring shape.
In accordance with another aspect of embodiments, there is provided a balancer for a drum washing machine including a plurality of spherical masses; and a housing provided with a race having rounded corner portions, wherein the masses move within the race of the housing, and wherein a value obtained by dividing the radius (rs) of the corner portions by the radius (R) of the masses is between 0.4 and 0.9.
These and/or other aspects, features, and advantages will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings in which:
Reference will now be made in detail to exemplary embodiments, an example of which is illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. Exemplary embodiments are described below by referring to the annexed drawings.
First, with reference to
A door 15 for opening and closing openings of the tub 20 and the drum 30 so as to put laundry into the drum 30 is installed on the front or upper surface of the main body 10. Here, ‘L’ represents laundry.
A water supply pipe 17 for supplying washing water to the tub 20 and a detergent supply device 19 for supplying a detergent to the tub 20 are installed in the upper portion of the main body 10. Here, the detergent supply device 19 forms an internal space containing the detergent, and is installed in the front surface of the main body 10 so as to allow a user to easily put the detergent thereinto.
A drain pump 27 and a drain pipe 29 for discharging the washing water contained in the tub 20 to the outside of the main body 10 are installed in the lower portion of the main body 10.
A driving unit 40 for transmitting power to the drum 30 so as to rotate the drum 30 is provided on the rear surface of the drum 30. Lifters 35 for lifting laundry to the upper portion of the drum 30 and then dropping the laundry so as to wash the laundry when the drum 30 is rotated by the driving unit 40 are provided at regular intervals on the inner circumferential surface of the drum 30.
Balancers 50, each of which has a ring shape and is concentric with the center of rotation of the drum 30, are respectively installed on the front and rear surfaces of the drum 30. The balancers 50 serve to rapidly reduce the vibration of the drum 30 generated by the unbalanced weight due to the eccentric structure of the drum 30 and the partial disposition of the laundry in the drum 30 when the drum 30 is rotated.
As shown in
In an exemplary embodiment, the masses 51 have a spherical shape, and are provided in the housing 53, as described above.
A race 54, in which the masses 51 are movable in the circumferential direction, is prepared in the housing 53. The race 54 has a rectangular section. Corner portions 54a of the race 54 having the rectangular section are rounded. The housing 53 is made of a material obtained by injection, a material obtained by die casting, or a metal panel.
The inside of the race 54 is filled with a fluid having viscosity so as to reduce noise generated when the masses 51 move in the race 54. The fluid flows along spaces between the race 54 and the masses 51. Particularly, in an exemplary embodiment, most of the fluid flows through the corner portions 54a of the race 54. The momentums of the masses 51 are determined by the viscosity of the fluid.
Accordingly, in an exemplary embodiment, as a result of the repetition of a test in which the viscosity of the fluid filling the race 54 of the ball balancer 50 is adjusted, the momentums of the masses 51 were obtained as shown in a graph of
A horizontal axis of the graph in
The shorter the time to drop the masses 51 in the race 54 is, the larger the momentums of the masses 51 are. The graph of
However, when the race 54 is machined, tolerance occurs. Further, in the case that the interval (d) between the masses 51 and the inner wall of the race 54 is increased more than a designated value, noise is generated when the masses 51 move. Accordingly, it is determined that the momentums of the masses 51 are optimized when the interval (d) between the masses 51 and the inner wall of the race 54 is approximately (about) 2 millimeters.
When the interval (d) between the masses 51 and the inner wall of the race 54 is approximately 2 millimeters, as described above, the ratio of a space between the masses 51 and the corner portions 54a of the race 54, that is, a value obtained by dividing the radius (rs) of the corner portions 54a by the radius (R) of the masses 51, is between 0.4 and 0.9 (0.4<rs/R<0.9).
Accordingly, in accordance with an exemplary embodiment, the balancer 50 has a value, obtained by the radius (rs) of the corner portions 54a by dividing the radius (R) of the masses 51, which is between 0.4 and 0.9. Thus, the balancer 50 of an exemplary embodiment minimizes the collision between the masses 51 and the race 54, while minimizing the interval between the masses 51 and the inner wall of the race 54 so as to use a small amount of the fluid, thereby effectively reducing vibration generated from the drum 30.
Further, the balancer 50 maintains the movement of the masses 51, while minimizing the interval between the masses 51 and the inner wall of the race 54 so as to use a small amount of the fluid, thereby reducing noise generated due to collision of the masses 51.
As apparent from the above description, an exemplary embodiment provides a drum washing machine with ball balancers having a value, obtained by dividing the radius of corner portions of a race by the radius of masses, which is between 0.4 and 0.9, thus effectively reducing vibration generated from a drum while using a small amount of a fluid.
Although a few exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these exemplary embodiments, the scope of which is defined in the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2007-0038518 | Apr 2007 | KR | national |
