JP2002119007A - Mold motor with built-in circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor of which outside has no sparks, even if electronic components were to catch fires. SOLUTION: This motor includes a stator 6 with a wiring wound around a stator core, a rotor 2 consisting of a shaft and a magnet fixed on the shaft, a bearing bracket rotatably retaining the rotor 2 through a bearing, and a control substrate 3 controlling the rotational speed of the motor. An electronic component 8 which catches fire is disposed on the stator coil side of the control substrate 3. One or a plurality of holes 7 are formed in a mold covering the control substrate. These holes are formed inside the motor which houses the rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the safety of a molded motor having a built-in circuit.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view of a conventional molded motor, and FIG. 4 is a front view. Hereinafter, FIGS. 3 and 4
The configuration of the molded motor will be described with reference to FIG.

[0003] Reference numeral 32 denotes a rotor composed of a shaft 41 and a magnet 42 held on the shaft 41. Reference numeral 33 denotes a control board on which the electronic component 38 is mounted and controls the number of revolutions of the mold motor 30 and the like.

[0004] Reference numeral 35 denotes a wound stator;
This is a stator mold in which a control board 33 in which a drive circuit, a position detection circuit, and the like are built is integrally molded with resin.

A bearing bracket 39 rotatably holds the rotor 32 via a bearing 44. The bearing bracket 39 is fixed with resin at the time of molding. This bracket may not be used in some cases. Reference numeral 40 denotes a bearing bracket that rotatably holds the rotor via a bearing. The bearing bracket 40 is fitted into the stator mold 35 after the rotor 32 is inserted.

In such a configuration, there is a possibility that an abnormal load such as an excessive load may be applied to the molded-in-circuit type molded motor 30 to cause a lock, and that the motor may be ignited to generate heat. To cope with this, a flame-retardant resin has been used as a filling material.

[0007]

In the case of a conventional molded motor, even if a flame-retardant resin is used as a molding material, when a circuit in a substrate is broken due to some abnormality and an electronic component is ignited, the power is reduced. If it is large, sparks that hit the substrate surface in the mold may jump out of the mold.

When the position of the electronic component covered by the mold motor is close to the outer periphery of the mold, the tendency is strong, and the spark may ignite a nearby combustion material.

[0009]

SUMMARY OF THE INVENTION In a molded motor of an inner rotor type in which a control board for controlling a motor is housed in the motor, a motor wound around a stator core, a shaft and a magnet fixed to the shaft are used. A rotor, a bearing bracket for rotatably holding the rotor via a bearing, and a control board on which electronic components are mounted and which controls the number of rotations of a motor. By arranging one or more holes in the mold covering the control board and arranging them in the mold covering the control board, and opening these holes to the inside of the motor housing the rotor, Even if it is ignited, a spark is emitted on the rotor side and then becomes oxygen deficient and disappears, so there is no danger of ignition outside the motor.

[0010]

According to the present invention, since one or more holes are provided to the rotor side from the ignitable electronic parts in the control board covered with the mold resin, the mold motor may be damaged due to some abnormality. Even when heat is generated and the electronic component ignites, the ignited spark is emitted to the rotor side through this hole. Therefore, it is possible to prevent sparks from being emitted to the outside of the motor.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a molded motor with a built-in circuit according to the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view of a molded motor with a built-in circuit according to one embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1 and 2, a rotor 2, a control board 3, a bearing bracket 9,
10, the stator 6 and the control board 3 are covered with resin as in the case of the conventional built-in circuit type molded motor 30.

According to the present invention, the electronic component 8 mounted on the control board 3 and having a risk of firing is replaced with the rotor 2 of the control board 3.
In this configuration, one or more holes 7 are opened toward the rotor 2 from the vicinity of the electronic component 8 which may be ignited.

With such a configuration, even if the electronic component 8 is ignited, the spark moves to the rotor 2 side through the hole. After a while, the inside of the motor becomes oxygen-deficient and disappears naturally.

In this manner, by opening one or more holes 7 from the control board 3 where there is a risk of ignition toward the rotor 2, the ignited spark is directed toward the inside of the motor, and thereafter the acid is emitted. Since it becomes a missing state and is naturally digested, there is no danger of ignition outside the motor. Accordingly, the molded motor 1 has high safety, and it is possible to use a material that is less expensive than the conventional one.

[0016]

According to the structure of the present invention, even if an electronic component arranged on the control board is abnormally ignited and ignited, the hole provided on this board is opened to the rotor side. As a result, ignition to the outside of the motor can be prevented. Further, since a resin material which is cheaper than the conventional one can be used, the material cost is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a molded motor with a built-in circuit according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a sectional view of a conventional molded motor with a built-in circuit.

FIG. 4 is a front view of a conventional molded motor with a built-in circuit.

[Explanation of symbols]

 1, 30 Molded motor with built-in circuit 2 Rotor 3, 33 Control board 5, 35 Stator mold 6, 36 Stator 7 Hole 8, 38 Electronic component 9, 10, 39, 40 Ball bearing

Claims (1)

[Claims] An inner rotor type molded motor in which a control board for controlling a motor is housed inside the motor, wherein a stator wound on a stator core, a rotor comprising a shaft and a magnet fixed to the shaft are provided. A bearing bracket that rotatably holds the rotor via a bearing; and a control board on which electronic components are mounted and controls the number of rotations of a motor. A mold motor with a built-in circuit, wherein one or more holes are opened in a motor that accommodates a rotor in a mold that is disposed on a stator coil side and covers the control board.