JP3548143B2 - Drum type washing machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drum-type washing machine that stores laundry in a drum and performs washing or washing and drying (here, a washing machine having both drying functions is also referred to as a “washing machine”).
[0002]
[Prior art]
The drum-type washing machine accommodates laundry in a drum rotated about a horizontal axis, and can perform washing to drying consistently. As a method of rotating and driving the main shaft of the drum, a so-called belt drive in which a motor is attached to the lower side of the outer tank and a pulley fixed to the motor shaft and a pulley attached to the main shaft of the drum are connected using a V-belt or the like. Generally,
[0003]
On the other hand, the present applicant proposed in Japanese Patent Application No. 9-24270 a so-called direct drive type drum type washing machine in which the motor shaft of the motor attached to the back of the outer tub and the main shaft of the drum are directly connected. ing. In this washing machine, since the outer tub has a substantially uniform weight distribution around the rotation axis, the center of gravity of the outer tub can be brought closer to the rotation center of the drum without using a balance weight, As a result, there is an advantage that vibration of the outer tank during rotation of the drum can be suppressed and the weight can be reduced.
[0004]
[Problems to be solved by the invention]
The present invention is directed to a drum type washing machine using an outer rotor type motor as a drive source for directly driving a drum, wherein a predetermined distance between an outermost peripheral surface of a core of a stator and a permanent magnet of the rotor facing the same even when the rotor rotates. It is an object of the present invention to provide a drum type washing machine in which a gap is ensured. Another object of the present invention is to provide a drum type washing machine capable of effectively cooling the windings of a motor.
[0005]
[Means for Solving the Problems]
Engaging Ru drum type washing machine of the present invention includes: a front outer tub which is open, is disposed in the outer tub, a drum front is opened, a main shaft fixed to the rear surface of the drum, the outer tub A cylindrical portion having a substantially cylindrical shape is formed in the center portion, and a bearing for rotatably supporting the main shaft via a bearing provided in the cylindrical portion, a rotor and a stator are provided. An outer rotor type motor in which a rotor is fixed to the main shaft and the stator is fixed to the bearing, wherein the rotor is mounted on a rotor housing in which a magnet mounting portion is formed on an outer peripheral concentric circle, and mounted on the magnet mounting portion. And a plurality of wings radially extending radially outward from the magnet mounting portion are formed at predetermined angular intervals in the rotor housing, and an inner circumferential portion of the rotor housing is provided behind the magnet mounting portion. Vent hole communicating penetrates, it is characterized in that an outer peripheral side.
[0008]
Embodiments of the Invention and Effects of the Invention
The engagement Ru drum type washing machine of the present invention, the stator is fixed to the bearing, a predetermined gap between the outermost peripheral surface and the rotor of the permanent magnet facing that of the stator core even when the rotor is rotated It is guaranteed that you can.
[0009]
Further, even when the rotor with a relatively low rotational speed rotates, it is possible to prevent the temperature of the coil and the bearing of the stator becomes too high.
[0010]
【Example】
Hereinafter, an embodiment of a drum type washing machine according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic side sectional view showing an entire configuration of a drum type washing machine according to the present embodiment. FIG. 2 is a side sectional view showing a detailed structure of a motor (A portion in FIG. 1) of the drum type washing machine. FIG. 3 is a sectional view taken along the line BB ′ in FIG. 2 showing a structure of a rotor of the motor.
[0011]
As shown in FIG. 1, in this drum type washing machine, a substantially cylindrical outer tub 2 having an open front surface is suspended and supported by an anti-vibration spring 3 and a damper 4 inside an outer box 1. Is provided with a door 5 for opening and closing the front opening of the outer tub 2. Similarly, a drum 6 having a front opening is disposed in the outer tub 2, and a main shaft 7 having a large diameter is attached to an end surface on the rear side of the drum 6 so as to rotate integrally. On the other hand, a bearing 8 having a substantially cylindrical shape at the center and a plurality of arms extending radially from the cylindrical portion toward the outer peripheral side is fixed to the rear end surface of the outer tub 2. The main shaft 7 is rotatably supported via a bearing 9 provided on the main shaft 7. The rotor 11 of the motor 10 is fixed to the tip of the main shaft 7, while the stator 21 of the motor 10 is fixed to the bearing 8. The motor 10 is an outer rotor type DC brushless motor having a flat shape in the depth direction of the washing machine, and details of its structure are as follows.
[0012]
As shown in FIG. 2, the rotor 11 includes a rotor housing 12 made of a resin material or a metal material having a magnet attachment portion 13 formed on an outer peripheral concentric circle, and a plurality of permanent magnets attached to the magnet attachment portion 13. 19. The magnet mounting portion 13 is configured to divide the entire circumference into a predetermined number by ribs projecting inward at predetermined angles in the circumferential direction of the rotor housing 12, and permanent magnets 19 having N poles and S poles are alternately arranged in the section. Are arranged in a plurality. The permanent magnet 19 can be fixed to the rotor housing 12 by insert molding or other various methods.
[0013]
As shown in detail in FIG. 3, the rotor housing 12 is formed with a plurality of wings 14 radially extending radially outward from the magnet mounting portion 13 at predetermined angle intervals (30 degrees in FIG. 3). Further, a front wall portion 15 for closing the front of the adjacent wing body 14 and a rear wall portion 16 for closing the rear side are formed continuously with the wing body 14. Therefore, the wing 14, the front wall 15, the rear wall 16, and the magnet mounting portion 13 form a space that is open only on the outer peripheral side. Further, a ventilation hole 17 that communicates between the inner peripheral side and the outer peripheral side of the rotor housing 12 penetrates behind the magnet attachment portion 13. Further, on the inner periphery of the rotor housing 12, a rib-shaped auxiliary wing body 18 is formed in the same plane as the wing body. The rotor housing 12 having such a structure is screwed to a tip end surface of the main shaft 7 with a screw 20, and both are rotated integrally.
[0014]
On the other hand, the stator 21 is an annular member made of a resin material or the like, and has a stator housing 22 in which a plurality of hollow coil support portions are formed so as to protrude radially outward and have a core inserted in the coil support portion. (Iron core) 23 and a coil 24 wound around the outside of the coil supporting portion. The stator housing 22 is fixed to the arm of the bearing 8 by a screw 25, and a predetermined gap is formed between the outermost peripheral surface of the core 23 and the permanent magnet 19 facing the same even when the rotor 11 rotates as described later. Is guaranteed.
[0015]
In the above configuration, when a drive current is supplied from a control circuit (not shown) to the coil 24 of the stator 21, a magnetic path is formed in the permanent magnet 19 facing the coil 24 with a gap therebetween. As a result, the rotor 11 rotates, and the drum 6 is rotationally driven via the main shaft 7 at the same rotational speed as the rotor 11.
[0016]
The wing body 14 rotates integrally with the rotor housing 12, and as described above, the air existing in the space substantially defined by the adjacent wing body 14 is strongly pushed in the outer peripheral direction. As a result, the air pressure in the space drops instantaneously, so that air flows out from the inner peripheral side of the rotor housing 12 through the ventilation holes 17. Further, the air pressure in the space surrounded by the rotor housing 12 and the stator 21 is thereby temporarily reduced, and air flows in from the outside through the gap between the arms adjacent to the bearing 8 in front of the stator 21. In this way, an airflow as shown by an arrow in FIG. 2 is generated. Further, the auxiliary wing body 18 mainly has a function of a current plate, and makes the flow of air from the inner peripheral side to the outer peripheral side of the rotor housing 12 through the ventilation hole 17 more smooth.
[0017]
The air flow passes near the coil 24 of the stator 21. Although the coil 24 generates heat due to the heat loss of the driving current, the heat is carried away by such an air flow, so that it is possible to prevent the temperature of the coil 24 and its surroundings from becoming abnormally high. Further, a part of the air flow comes into contact with the cylindrical portion of the bearing 8 surrounding the bearing 9. When the main shaft 7 rotates, the bearing 9 generates heat due to friction. In particular, when the amount of load (the amount of laundry) on the drum 6 is large, that is, when the imbalance of the weight around the rotation axis of the drum 6 is large, the friction increases and the heat generation increases. Since the heat generated by such friction is taken away by the airflow in contact with the cylindrical portion of the bearing 8, it is possible to prevent the temperature of the bearing 9 and its surroundings from becoming abnormally high.
[0018]
The cooling effect of the stator 21 increases as the size of the wing 14 increases, but as the size increases, the wind noise generated by the wing 14 increases, and the load on the motor 10 increases due to an increase in air resistance. Therefore, it is desirable to appropriately determine the size of the wing body 14 within an acceptable range.
[0019]
Usually, in this type of washing machine, sufficient performance can be obtained with the motor 10 having an outer diameter considerably smaller than the outer diameter of the outer tub 2. The space is not used (so-called dead space). Therefore, the maximum outer diameter of the motor 10 can be smaller than the outer diameter of the outer tub 2 even if the wings 14 are provided so as to protrude outside the rotor housing 12 as in the above embodiment. In other words, according to the configuration of the motor described above, the dead space can be effectively used.
[0020]
By the way, in the configuration of the above embodiment, the drum 6 and the rotor 11 are respectively mounted on both ends of the main shaft 7 with the two bearings 9 supporting the main shaft 7 interposed therebetween. With such a structure, it is difficult to widen the interval between the two bearings 9 that contact the main shaft 7. If the distance between the two bearings 9 can be increased, the main shaft 7 is more stably held, so that the vibration of the drum 6 and the outer tub 2 can be suppressed.
[0021]
Therefore, the structure can be modified as shown in FIG. In this example, the bearing is divided into a front bearing 81 directly attached to the rear end face of the outer tub 2 and a rear bearing 82 attached to the front bearing 81 and supporting the main shaft 7 on the rear side of the motor 10. I have. The main shaft 7 is supported by a bearing 9 provided in a cylindrical portion inside the front bearing 81 and a bearing 9 provided in a cylindrical portion inside the rear bearing 82, and the rotor 11 is attached to the main shaft 7 therebetween. Of the rotor housing 12 is fixed. As a result, the distance between the bearings 9 can be increased, and the main shaft 7 is supported before and after the rotor 11 which is a rotary drive source. Failures and the like can be reduced.
[0022]
The above embodiment is merely an example, and it is apparent that changes and modifications can be made as appropriate within the scope of the present invention.
[Brief description of the drawings]
FIG. 1 is a schematic side sectional view showing the overall configuration of a drum type washing machine according to one embodiment of the present invention.
FIG. 2 is a side sectional view showing a detailed structure of a motor (A in FIG. 1) of the drum type washing machine.
FIG. 3 is a sectional view taken along line BB ′ in FIG. 2;
FIG. 4 is a schematic side sectional view of a drum type washing machine according to another embodiment of the present invention.
[Explanation of symbols]
2 ... Outer tank 6 ... Drum 7 ... Main shaft 8 ... Bearing 9 ... Bearing 10 ... Motor 11 ... Rotor 12 ... Rotor housing 14 ... Wing body 15 ... Front wall 16 ... Rear wall 17 ... Vent hole 18 ... Auxiliary wing 19 ... permanent magnet 21 ... stator 22 ... stator housing 23 ... core 24 ... coil

Claims (1)

An outer tank with an open front,
A drum arranged in the outer tank and having an open front surface;
A main shaft fixed to the back of the drum;
A bearing fixed to the back surface of the outer tub and having a substantially cylindrical portion formed at the center thereof, the bearing rotatably supporting the main shaft via a bearing provided in the cylindrical portion,
An outer rotor type motor comprising a rotor and a stator, wherein the rotor is fixed to the main shaft, and the stator is fixed to the bearing;
Equipped with a,
The rotor is composed of a rotor housing in which a magnet mounting portion is formed on an outer peripheral concentric circle, and a plurality of permanent magnets mounted on the magnet mounting portion,
In the rotor housing, a plurality of wings are formed at a predetermined angular interval, which radiate radially outward from the magnet mounting portion.
A drum type washing machine characterized in that a ventilation hole communicating between the inner peripheral side and the outer peripheral side of the rotor housing penetrates behind the magnet mounting portion .

Images