This application is based on an application No. 2001-291715 filed in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a washing machine comprising a centrifugal spin-drying function, and particularly, to a drum washing machine having a drum that rotates around its approximately horizontal axis.
2. Description of Related Art
A drum washing machine comprises a cylindrical drum that rotates for washing and spin-drying with the washing put therein. The drum is provided with its end surfaces extending in a front-and-back direction inside a cylindrical outer tank. A rotating shaft extending in an approximately horizontal direction is connected to the rear end surface of the drum. The rotating shaft is received in the outer tank so as to be rotatable, to project toward the back of the outer tank. A motor is coupled to a rear end of the rotating shaft using a DD (Direct Drive) system, for example. The drum is rotated around the rotating shaft inside the outer tank by driving force of the motor.
One of problems of the drum washing machine is that when the drum is rotated at high speed with the washing unevenly distributed inside the drum at the time of spin-drying, an eccentric load is produced inside the drum, which causes vibration of the outer tank and noise caused by the vibration. For this problem, it is proposed that a balance in weight in the direction of rotation of the drum is attained by providing a plurality of water storage boxes, for example, capable of storing water by centrifugal force developed at the time of rotating the drum on the end surface of the drum, and making, when the eccentric load due to the uneven distribution of the washing is produced inside the drum, the amount of water in the water storage box at a position near to the position of the eccentric load smaller than the amount of water in the other water storage box to set off the eccentric load by the weight of the water.
In the drum washing machine according to the prior art, an opening for getting the washing in and out of the drum is formed in the front end surface of the drum. Accordingly, the water storage box cannot be provided on the front end surface of the drum, but is inevitably provided on the rear end surface of the drum. However, the eccentric load due to the uneven distribution of the washing is easily produced at a position, offset toward the opposite side (on this side) of the motor, in the drum. In this case, even if the amount of water in the water storage box provided on the rear end surface of the drum is adjusted, the eccentric load cannot, in some cases, be sufficiently compensated for.
Therefore, a primary object of the present invention is to solve the above-mentioned technical problems and to provide a drum washing machine capable of satisfactorily compensating for an eccentric load produced by the uneven distribution of the washing in a drum and restraining vibration and noise at the time of spin-drying.
Still another object of the present invention is to provide a drum washing machine that is convenient to use and produces a quiet operating sound.
In order to attain the above-mentioned object, the present invention is directed to a drum washing machine having a drum (4) for putting the washing, and rotating the drum around its approximately horizontal axis of rotation to spin-dry the washing put in the drum by centrifugal force, characterized by comprising rotating shafts (51L, 51R) respectively extending outward along the axis of rotation from both end surfaces (41L, 41R) of the drum; a drum rotating motor (6) coupled to one of the rotating shafts; and a water storage balancer (G) comprising a plurality of water storage tanks (8) attached to the end surface (41L), on the opposite side of the position where the drum rotating motor is provided, of the drum and formed on its circumference centered around the axis of rotation, the amount of water in each of the water storage tanks (8) being adjusted so as to set off an eccentric load produced in the drum by the uneven distribution of the washing.
An alphanumeric character put in parentheses denotes a corresponding constituent element or the like in an embodiment, described later. The same is true for the following summary items.
According to the present invention, the drum is supported so as to be rotatable by the rotating shafts respectively extending in an approximately horizontal direction outward from both the end surfaces. The drum rotating motor is coupled to one of the rotating shafts, and the water storage balancer for setting off the eccentric load produced in the drum by the uneven distribution of the washing is attached to the end surface, on the opposite side of the position where the drum rotating motor is provided, of the drum.
Consequently, the washing is unevenly distributed at a position, offset toward the opposite side of the position where the drum rotating motor is provided, in the drum, thereby making it possible to set off, even when the eccentric load is produced in the drum, the eccentric load by the function of the water storage balancer. Accordingly, it is possible to satisfactorily restrain the generation of vibration caused by the uneven distribution of the washing and noise caused by the vibration.
The drum washing machine according to the present invention may further comprise a motor-side water storage balancer (G) comprising a plurality of water storage tanks (8) attached to the end surface (41R), on the side of the position where the drum rotating motor is provided, of the drum and formed on its circumference centered around the axis of rotation, the amount of water in each of the water storage tanks being adjusted so as to set off an eccentric load produced in the drum by the uneven distribution of the washing.
When such construction is added, the washing is unevenly distributed at the position, offset toward the side of the position where the drum rotating motor is provided, in the drum, thereby making it possible to set off, even when the eccentric load is produced in the drum, the eccentric load by the function of the motor-side water storage balancer. Accordingly, it is possible to effectively restrain the generation of vibration caused by the uneven distribution of the washing and noise caused by the vibration.
The drum washing machine according to the present invention may further comprise a fluid balancer (9) attached to the end surface, on the opposite side of the position where the drum rotating motor is provided, of the drum, and setting off vibration caused by the uneven distribution of the washing due to the uneven distribution of a liquid inside the drum at the time of rotating the drum at high speed.
The present invention may further comprise a motor-side fluid balancer (9) attached to the end surface, on the side of the position where the drum rotating motor is provided, of the drum, and setting off vibration caused by the uneven distribution of the washing due to the uneven distribution of a liquid inside the drum at the time of rotating the drum at high speed.
When such construction is added, the fluid balancer is provided, thereby making it possible to restrain vibration which cannot be restrained depending on the function of the water storage balancer and vibration caused by an eccentric load which is so small that it need not be compensated for by making balance adjustment using the water storage balancer. Accordingly, it is possible to effectively restrain the vibration and noise caused by the vibration.
The washing machine according to the present invention may further comprise an outer tank (2) elastically supported by an elastic member (3F, 3B) and accommodating the drum so as to be rotatable. Further, the elastic member maybe a damper (3F, 3B) for supporting a portion, near the drum rotating motor, of the outer tank from below. In this case, the eccentric load due to the uneven distribution of the washing is almost produced on the opposite side of the drum rotating motor with respect to the position where the outer tank is supported by the damper. Accordingly, the present invention is particularly effective in restraining the vibration caused by the eccentric load and the noise caused by the vibration.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.