JP2013059526A - Brushless motor for washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of electric corrosion of a bearing in an electric motor driven by an inverter in a PWM system.SOLUTION: The electric motor is provided with: a stator which includes a stator core wound with windings, a rotor which includes a rotator holding permanent magnets facing the stator in the circumferential direction and a shaft fastening the rotator so as to penetrate the center of the rotator; a bearing which supports the shaft; and two brackets which fix the bearing. The shaft voltage appearing between a bearing inner ring and a bearing outer ring of the bearing is suppressed than the withstand voltage of single bearing.

Description

  The present invention relates to a brushless motor for a drum type washing machine.

  Conventionally, it has been applied as a motor in a drum type washing machine having a rotating drum having an axis of rotation in a horizontal direction or an inclined direction and transmitting the power of the motor to the rotating drum via a belt and a pulley. In motors with brushes (for example, see Patent Document 1) and induction motors (for example, see Patent Document 2), steel plate motors having a frame such as aluminum have been used.

  FIG. 9 is a schematic sectional view of the conventional drum-type washing machine. As shown in FIG. 9, the conventional drum-type washing machine 50 rotates on the rotating drum 51 on the back surface of a water tank 52 that rotatably supports a rotating drum 51 having an axis of rotation in a horizontal direction or an inclined direction. A pulley 54 that transmits power via a shaft 53 and a motor 60 that transmits power to the pulley 54 via a belt 55 are provided. Further, as shown in FIG. 9, the motor 60 is generally fixed below the water tank 52.

  The conventional motor 60 includes a stator 61, a rotor (not shown) rotatably supported with a shaft 63 inside the stator, an output side bracket 63, an anti-output side bracket 64, and the like. The part is bare. Also, the brackets 63 and 64 are generally provided with openings, and are therefore advantageous in increasing the temperature. However, the outer periphery of the stator 61 and the interior of the motor 60 (winding, rotor) In such a structure, water does not enter the bearings. Therefore, in order to prevent water from entering the motor 60, measures are taken such as making the motor 60 difficult to get water by devising the shape of the rear surface of the water tank.

JP 2009-78056 A JP 2009-297123 A

  However, in the conventional drum-type washing machine, since the motor 60 is fixed below the water tank 52, it is difficult to completely prevent the motor 60 from being splashed with water by the above-described conventional technology, and rust. There is a problem that it is not possible to suppress the occurrence of. In addition, since it is not possible to completely prevent the winding from being splashed with water, it is necessary to take measures against problems caused by water wetting.

  The present invention has been made to solve such a problem. Even when the motor 60 is fixed below the water tank, the stator core, the windings, and the like are sealed by molding with a resin material. By stopping, it is possible to provide a brushless motor for a washing machine that can suppress the occurrence of rust and the occurrence of problems due to water wetting.

  However, when there is no wind flow around the motor, the molded motor is likely to accumulate heat, so a resin or metal inner fan is provided inside the motor, and the stator sucks outside air into the motor when the rotor rotates, or An object of the present invention is to provide a brushless motor for a washing machine capable of suppressing the occurrence of rust and problems caused by water wetting by reducing the temperature by providing a plurality of air holes for discharging. .

  The present invention relates to a brushless motor for a washing machine that is applied to a drum-type washing machine that includes a rotating drum having an axis of rotation in a horizontal direction or an inclined direction, and that transmits power to the rotating drum via a pulley. In the meantime, among the members constituting the stator, at least the stator core, the winding, and the winding insulator are sealed by molding with a resin material. However, since it is necessary to rotate the rotor, the gap surface formed between the stator and the rotor need not be sealed with a resin material.

  With such a configuration, water is not applied to the winding through which a current is passed, so that problems due to water wetting do not occur. Further, rust of the stator core made of iron material does not occur, there is no fear of characteristic deterioration due to rust, and a highly reliable brushless motor for a washing machine is provided.

  It is also possible to seal the rotor core and the magnet constituting the rotor by molding with a resin material.

  With such a configuration, like the stator, the rust of the rotor core does not occur, and there is no fear of characteristic deterioration. Furthermore, when a rare earth magnet is used as a magnet, deterioration of the characteristics due to rust of the magnet is a problem, but by sealing the entire magnet with a resin material, there is no concern about deterioration of the magnet characteristics, and reliability A brushless motor for a washing machine with high performance can be provided.

  Further, the rotor is provided with an inner fan inserted into a shaft and made of metal or resin and having at least two blades and having an outer shape larger than the inner diameter of the stator. It is provided with a plurality of air holes for sucking or discharging.

  With such a configuration, it is possible to provide a brushless motor for a washing machine that can suppress a temperature rise that is a problem with the motor configured by the mold.

  As described above, according to the present invention, the present invention is applied to a drum-type washing machine that includes a rotating drum having an axis of rotation in a horizontal direction or an inclined direction, and that transmits power to the rotating drum via a pulley and a belt. An object of the present invention is to provide a highly reliable brushless motor for a washing machine by sealing a stator or a rotor by molding with a resin material and providing an inner fan and an air hole. .

Sectional drawing of the drum type washing machine carrying the permanent magnet brushless motor which concerns on Example 1 of this invention. Sectional drawing of the permanent magnet brushless motor which concerns on Example 1 of this invention. The perspective view of the motor winding assembly in the permanent magnet brushless motor which concerns on Example 1 of this invention. The block diagram of the rotor in the permanent magnet brushless motor which concerns on Example 1 of this invention Sectional drawing of the permanent magnet brushless motor which concerns on Example 2 of this invention. The block diagram of the rotor in the permanent magnet brushless motor based on Example 2 of this invention Sectional drawing of the rotor core part in the permanent magnet brushless motor which concerns on Example 2 of this invention Sectional drawing of the permanent magnet brushless motor which concerns on Example 3 of this invention. The block diagram of the rotor in the permanent magnet brushless motor which concerns on Example 3 of this invention Sectional view of a drum-type washing machine equipped with a conventional motor

    Hereinafter, the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments and examples.

  FIG. 1 is a schematic cross-sectional view of a drum type washing machine equipped with a permanent magnet brushless motor according to Embodiment 1 of the present invention. As shown in FIG. 1, the drum-type washing machine 10 has a drum rotating shaft 13 on the rotating drum 11 on the back surface of a water tank 12 that rotatably supports a rotating drum 11 having an axis of rotation in a horizontal direction or an inclined direction. A pulley 14 that transmits power via the motor 15 and a motor 20 that transmits power to the pulley 14 via a belt 15 are provided. Further, as shown in FIG. 1, the motor 20 is usually fixed below the water tank 12.

  FIG. 2 is a schematic cross-sectional view of the permanent magnet brushless motor according to the first embodiment of the present invention. The motor 20 includes a stator 30 that is fixed to the water tub 12 of the drum type washing machine 10 and a rotor 40 that is rotatably held with respect to the stator 30.

  The stator 30 is typically a stator core 31 formed by laminating thin iron plates, a winding 33 wound around the stator core 31 via a winding insulating material 32, a stator core 31, a winding insulating material 32, and a winding. 33 includes a stator resin mold 34 including a housing 33 and a housing 36 for holding a bearing 35.

  The rotor 40 includes a rotor core 41 that is usually formed by laminating thin iron plates, a magnet 42 that is disposed inside or on the outer periphery of the rotor core 41, and end plates 43 that are disposed at both axial ends of the rotor core 41. And a motor shaft 23 and a motor pulley 25 for transmitting the power generated by the rotor 40 to the rotary drum 11.

  FIG. 3 is a perspective view of the motor winding assembly in a state where the stator core 31, the winding insulating material 32, and the winding 33 shown in FIG. 2 are assembled. As shown in FIG. 3, the winding 33 is wound in a state where electrical insulation from the stator core 31 is ensured via the winding insulating material 32.

  The winding 33 is generally composed of three phases U, V, and W, and generates a rotating magnetic field on the inner peripheral side of the stator core 31 by energizing a three-phase alternating current. In the state shown in FIG. 2, at least a portion excluding the inner peripheral side (gap surface 37) of the stator core 31, the winding insulating material 32, and the winding 33 are included in the stator resin mold 34, and an external space, that is, an air portion. It has become the structure which lost contact with.

  FIG. 4 shows the rotor 40 shown in FIG. 2 and the bearing 35 disposed on the rotor 40. In FIG. 4, an IPM rotor type configuration in which a magnet (not shown in FIG. 4) is included in the rotor core 41 is shown, and end plates 43 are respectively disposed at both axial ends of the rotor core 41. The magnet is prevented from jumping out in the axial direction.

  Further, the rotor core 41 is inserted with a motor shaft 23 held rotatably by a bearing 35, and power is supplied to the rotary drum 11 shown in FIG. 1 through a motor pulley 25 provided at the tip of the motor shaft 23. introduce.

  In the permanent magnet brushless motor according to the first embodiment of the present invention described above, as can be seen from FIGS. 2 and 3, the winding 33 to which a current is applied is included in the stator resin mold 34 and water is applied. Since there is no structure, problems due to water wetting will not occur.

  Further, since the stator core 31 is also encapsulated in the stator resin mold 34 like the winding 33, there is no fear of deterioration of characteristics due to rust of the stator core 31 except for the gap surface 37 in which the rotor core 41 always rotates oppositely. Therefore, it can be said that it is suitable for improving the reliability of the brushless motor for washing machines.

  In the first embodiment, the IPM rotor type is described, but it is obvious that the same effect can be obtained in other configurations such as an SPM rotor type in which magnets are arranged on the surface of the rotor core 41. It is.

  FIG. 5 is a schematic cross-sectional view of a permanent magnet brushless motor according to Embodiment 2 of the present invention. The permanent magnet brushless motor shown in FIG. 5 is also fixed to the drum type washing machine as shown in FIG.

  As shown in FIG. 5, the motor 20 includes a stator 30 that is fixed to the water tub 12 of the drum type washing machine 10 and a rotor 40 that is rotatably held with respect to the stator 30. The stator 30 normally holds a stator core 31 formed by laminating thin iron plates, a winding 33 wound around the stator core 31 via a winding insulating material 32, a stator core 31, and a bearing 35. And a stator frame 38 fixed to the frame.

  5 shows a configuration having a housing 38a for holding a bearing integrated with the stator frame 38, the stator frame 38 and the housing 38a may be separated. Further, the rotor 40 includes a rotor core 41 that is usually formed by laminating thin iron plates, a magnet 42 that is disposed inside or on the outer periphery of the rotor core 41, a rotor resin mold 45 that includes the rotor core 41 and the magnet 42, It comprises a motor shaft 23 and a motor pulley 25 for transmitting the power generated by the rotor 40 to the rotary drum 11. The configuration of the stator core 31, the winding insulating material 32, and the winding 33 is the same as that shown in FIG.

  FIG. 6 shows the rotor 40 shown in FIG. 5 and the bearing 35 disposed on the rotor 40. A motor shaft 23 rotatably held by a bearing 35 is inserted into the rotor core 41, and power is transmitted to the rotary drum 11 shown in FIG. 1 via a motor pulley 25 disposed at the tip of the motor shaft 23. .

  The rotor core 41 is sealed inside and at least both ends by a rotor resin mold 45.

  In the second embodiment of the present invention, the configuration of the IPM rotor type shown in FIG. 7 in which the magnet 42 is included in the rotor core 41 is shown, and the magnet 42 is completely covered by the rotor resin mold 45. As a result, it is possible to prevent the magnet 42 from jumping out of the rotor core 41 in the axial direction and to prevent the magnet 42 from being splashed with water.

  In particular, a drum type washing machine motor needs to be downsized while securing a high torque, and a neodymium rare earth magnet is often used as the magnet 42. This neodymium-based rare earth magnet has a high residual magnetic flux density and can improve motor torque, but has a drawback of being deteriorated by rust.

  Therefore, as shown in FIG. 6, by sealing the magnet 42 with the rotor resin mold 45, there is no fear of characteristic deterioration due to rust of the magnet 42, and a highly reliable motor with little deterioration over time of the characteristic is provided. It becomes possible.

  In the second embodiment, the configuration of the rotor of the IPM method (magnet embedded type) is described. However, the configuration of the rotor of the SPM method (surface magnet type) in which the magnet is disposed on the surface of the rotor core 41. It is obvious that the same effect can be obtained in other configurations. Moreover, it is suitable not only for neodymium rare earth magnets but also for other magnets such as ferrite magnets.

  FIG. 8 is a schematic cross-sectional view of a permanent magnet brushless motor according to Embodiment 3 of the present invention. The permanent magnet brushless motor shown in FIG. 8 is also fixed to the drum type washing machine as shown in FIG. 1 as in the first embodiment.

  As shown in FIG. 8, the motor 20 includes a stator 30 that is fixed to the water tub 12 of the drum type washing machine 10 and a rotor 40 that is rotatably held with respect to the stator 30.

  The stator 30 is typically a stator core 31 formed by laminating thin iron plates, a winding 33 wound around the stator core 31 via a winding insulating material 32, a stator core 31, a winding insulating material 32, and a winding. 33 includes a stator resin mold 34 including a housing 33 and a housing 36 for holding a bearing 35.

  The rotor 40 includes a rotor core 41 that is usually formed by laminating thin iron plates, a magnet 42 that is disposed inside or on the outer periphery of the rotor core 41, and end plates 43 that are disposed at both axial ends of the rotor core 41. And a motor shaft 23 and a motor pulley 25 for transmitting the power generated by the rotor 40 to the rotary drum 11.

  The rotor 40 is provided with an inner fan 46 which is inserted into the motor shaft 23 and is formed of metal or resin and has at least two blades and has an outer shape larger than the inner diameter of the stator 30. A plurality of air holes for sucking or discharging outside air are provided inside.

  The configuration of the stator core 31, the winding insulating material 32, and the winding 33 is the same as that shown in FIG. 3, and the configuration of the rotor 40 is the same as that shown in FIG.

  In the third embodiment, as is clear from the first and second embodiments, the winding 33 to which a current is applied is included in the stator resin mold 34 and has a structure in which water is not applied. Problems due to water wetting do not occur, and there is no fear of characteristic deterioration due to rust of the stator core 31.

  Further, by completely covering the magnet 42 with the rotor resin mold 45, it is possible to prevent the magnet 42 from jumping out of the rotor core 41 in the axial direction and to prevent the magnet 42 from being splashed with water. Thus, since there is no concern about the deterioration of characteristics due to the rust of the magnet 42, it is possible to provide a highly reliable motor with little deterioration of characteristics over time.

  Further, by providing the inner fan and the air hole, it is possible to reduce the temperature rise and provide a highly reliable motor.

  In the third embodiment, the IPM rotor type is described as in the first and second embodiments. However, other configurations such as an SPM rotor type in which magnets are arranged on the surface of the rotor core 41 are used. It is obvious that the same effect can be obtained in. Moreover, it is suitable not only for neodymium rare earth magnets but also for other magnets such as ferrite magnets.

  The permanent magnet brushless motor for a drum type washing machine according to the present invention seals the stator core and the windings with a resin molding material, so that safety and reliability can be improved and the magnet is sealed with the resin molding material. Since it has stopped, it is possible to prevent deterioration of motor characteristics over time, and by providing an internal fan and air holes, heat dissipation in the molded motor is also improved, resulting in a highly reliable and high performance motor. Can be provided. In particular, it is suitable for applications that require high reliability and high performance, such as home appliances used around water, represented by drum-type washing machines.

DESCRIPTION OF SYMBOLS 10 Drum type washing machine 11 Rotating drum 12 Water tank 13 Drum rotating shaft 14 Pulley 15 Belt 20 Motor 23 Motor shaft 25 Motor pulley 30 Stator 31 Stator core 32 Winding insulating material 33 Winding 34 Stator resin mold 35 Bearing 40 Rotor 41 Rotor core 42 Magnet 45 Rotor resin mold 46 Inner fan 50 Drum-type washing machine 51 Rotating drum 52 Water tank 53 Drum rotating shaft 54 Pulley 55 Belt 60 Motor 61 Stator

Claims (3)

A rotating drum for storing laundry and having a rotation axis in a horizontal direction or an inclination direction, a water tank containing the rotating drum and elastically supported in a washing machine body, and attached to the rear surface of the water tank, the rotation In a pulley for transmitting power to a drum via a drum rotation shaft, and a brushless motor for a drum-type washing machine that transmits power to the pulley via a belt and drives the rotary drum attached below the water tank The motor is fixed to the water tank, and includes a stator including at least a stator core, a winding and a winding insulator, and a rotor connected to the belt and configured to be rotatably held including at least a rotor core and a magnet. Except for the gap surface formed between the stator and the rotor, in the stator, at least the stator core and the winding With a line insulator is molded of a resin material, in the above rotor, brushless motor for a washing machine comprising at least the rotor core and the magnet is molded by a resin material configuration. The brushless motor for a washing machine according to claim 1, wherein the rotor includes an inner fan inserted into a shaft and formed of metal or resin and having at least two blades, and the stator is rotated when the rotor rotates. A brushless motor for a washing machine having a plurality of air holes for sucking or discharging outside air into the motor. 2. The brushless motor for a washing machine according to claim 1, wherein the outer diameter of the inner fan provided in the rotor is larger than the inner diameter of the stator.

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