JP2011109861A - Molded motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a conventional lead type power IC has a disadvantage in reducing the thickness of a motor since an element is large, and further, an electronic component is dislocated under a resin pressure or a lead terminal is broken when the electronic component is covered with mold resin if the element is large. <P>SOLUTION: In a molded motor 1, a circuit board 5 with electronic components arranged thereon is covered with resin. Here, a power IC 11a of surface mounting type is employed to reduce the thickness of a motor frame in axial direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a molded motor in which a stator and a circuit board are covered with a mold resin to form a motor frame.

  It has been conventionally known that a brushless motor stator and a circuit board are covered with a mold resin and formed integrally with a motor frame. It is known that a power IC is used as an electronic component for driving the motor, and this power IC is covered with a mold resin (see Patent Document 1).

  Moreover, it has been conventional to cover a fuse with a mold resin to protect the motor by detecting overcurrent when the rotation of the brushless motor is locked, or to protect the motor by detecting the heating temperature of the winding. (See Patent Document 2).

  In motors that cover motor parts with a metal frame, water droplets can get into the motor frame and affect the electronic parts due to water droplets entering through the gaps in the motor frame, or increase the insulation distance in consideration of electrical insulation. Although it is necessary, the above-described molded motor provides a motor having excellent waterproofness because the electronic parts are integrally covered with resin, and also having excellent insulation properties because it is covered with an insulating resin. be able to.

Japanese Patent No. 36552455 Japanese Patent No. 3697589

  Since the conventional power IC is integrally provided with various control circuits such as a switching element, a driving IC, and a timing control IC, the element size is large. However, since the thickness of the frame of the molded motor described in the above-mentioned patent document is much thicker than the size of the electronic component, it is not necessary to consider the size of the electronic component so much.

  However, in order to meet the demand for miniaturization of the motor and reduction of the material usage fee of the mold resin, motors having a smaller size, particularly a smaller axial length than the structure of the above-mentioned patent document, have been developed by various devices. However, by reducing the size of the motor, the size of the electronic component such as the power IC cannot be ignored. When the motor frame is formed by covering with the mold resin, the motor is increased by the size of the element. The thickness of the frame will increase. Under such circumstances, a thinner motor is desired, and the size of the element has been a problem.

  As in the configuration of Patent Document 1, the thickness from the circuit board to the surface of the motor frame can be reduced by arranging the power IC on the surface of the circuit board on the stator side. It was necessary to secure an insulation distance from the child winding and to secure a distance for heat generation from the stator winding, and the thickness of the entire motor was not effectively reduced.

  Furthermore, if the electronic component is arranged on the surface of the circuit board on the motor frame surface side to reduce the thickness between the motor frame surface side and the circuit board, it is necessary to consider the impact from the outside. Therefore, as in Patent Document 1, the electronic components other than the power IC have been arranged on the surface of the circuit board on the stator side. Since a process of placing and soldering electronic components is necessary, a process of soldering all electronic components on one side is more desirable.

  Further, when resin molding is performed, if the flow rate of the resin is high, a large element has a problem that if the fixing is weak, the element flows and the position shifts. Further, in the conventional electronic component, since the lead terminal is provided in a floating shape, the lead terminal may be bent or broken by the resin pressure.

  In view of the above problems, the present invention provides a thinner mold motor.

  The invention of claim 1 includes a stator formed by winding a coil by applying an insulating member to a slot provided in an iron core, and an electronic component for controlling a motor, and the fixing provided on the insulating member A circuit board fixed at a portion, the electronic component mounted on the circuit board is a surface-mount type electronic component, the stator and the circuit board are covered with a mold resin, and the motor frame is A molded motor characterized by being formed.

  A second aspect of the present invention is the molded motor according to the first aspect, wherein the surface-mounted component is disposed on a surface of the circuit board on the stator side.

  A third aspect of the present invention is the molded motor according to the first aspect, wherein the surface-mounted component is disposed on a surface of the circuit board opposite to the stator.

  A fourth aspect of the present invention is the molded motor according to any one of the first to third aspects, wherein the surface-mounted component is a power IC that controls a driving current of the motor.

  A fifth aspect of the present invention is the molded motor according to the first to third aspects, wherein the surface-mounted component is a fuse for overcurrent protection.

  The invention according to claim 6 is the molded motor according to any one of claims 1 to 3, wherein the surface-mounted power IC and the surface-mounted fuse are mounted simultaneously.

  In the case of the molded motor according to the present invention, since the size of the electronic component is reduced by using the surface mount type electronic component, a thinner motor can be provided. In addition, even in a configuration in which electronic components are arranged on the surface of the circuit board on the stator side, it is possible to provide a motor that is thinner than conventional ones. Furthermore, since the amount of mold resin used can be reduced, an inexpensive motor can be provided.

It is sectional drawing of the mold motor of the 1st Example of this invention. (A) It is the schematic of power IC for surface mounting. (B) It is the schematic of the conventional power IC. It is sectional drawing of the mold motor of the 2nd Example of this invention. (A) It is the schematic of the fuse for surface mounting. (B) It is the schematic of the conventional fuse. It is sectional drawing of the conventional mold motor.

  1, the motor 1 of the present invention is a brushless motor, and includes a stator formed by applying an insulating member 3 to an iron core 2 formed by laminating steel plates and winding a winding 4, and a drive element. The circuit board 5 is integrated with a mold resin to form a cylindrical motor frame 6. A rotor 7 made of a magnet resin is disposed inside the cylindrical motor frame 6. A rotating shaft 8 is attached to the rotor 7, and bearings 9 are attached to both ends of the rotating shaft 8.

  The circuit board 5 is fixed by pins 13 provided on the insulating member 3, and the stator core 2 and the circuit board 5 are arranged at positions aligned in the axial direction. The winding end of the winding 4 is entangled with the pin 13 and fixed by soldering, and is electrically connected to the circuit board 5.

  The bearing 9 is housed in an annular bearing bracket 10, and the bearing bracket 10 is fixed to the motor frame 6. Of the bearing brackets 10 provided on both sides, one bearing bracket 10 a is embedded in the motor frame 6, and the other bearing bracket 10 b is fitted to the motor frame 6 at the end of the bearing bracket. By arranging the end of the bearing bracket 10a and the curved portion of the bearing bracket 10b so as to be accommodated in the constricted portion of the rotor 7, the bearing bracket 10 can be accommodated in the central portion of the motor as much as possible. The length can be shortened.

Example 1
The motor of the present invention uses a surface mount type power IC. As shown in FIG. 2, the conventional lead type power IC 11b has a thickness of about 4 mm, whereas the surface mount type power IC 11a has a thickness of about 1 mm. Therefore, as compared with the conventional molded motor of FIG. 5, in the molded motor of the present invention, the thickness of the motor frame 6 can be reduced by the thickness of the power IC. Furthermore, since the area that contacts the resin during resin molding is narrowed, the power IC is not caused to flow and misalignment does not occur. Furthermore, since the surface mount type power IC 11a has much smaller floating of the lead terminal 12a, the damage of the terminal due to the resin pressure is reduced.

  Further, by disposing the surface mount type power IC 11a on the surface of the circuit board 5 on the stator side, the distance between the surface of the circuit board 5 and the motor frame 6 can be reduced. Therefore, the distance between the stator winding 4 and the circuit board 5 can also be reduced, and the axial thickness can be effectively reduced. Furthermore, since all the electronic components including the power IC can be mounted on one surface of the circuit board 5, a process such as soldering is simplified.

(Example 2)
As an example, in the case of a sensorless circuit board, the distance between the circuit board 5 and the stator side becomes shorter from the circuit board 5 to the rotor 7 as shown in FIG. In this case, the power IC 11a may be arranged on the stator side as in the above configuration, but the thin object can be achieved even if it is arranged on the surface opposite to the stator side. With this configuration, it is possible to take a distance from the stator winding that is a heating element.

  In addition, the winding end of the stator is wound around the pin 13 for fixing the circuit board 5 and soldered. This winding end is provided at the tip of the pin on the side opposite to the stator of the circuit board 5. Therefore, it is desirable to arrange a circuit pattern or an electronic component on the side opposite to the stator of the circuit board 5 in terms of circuit arrangement. Even in this case, it is possible to obtain the effect of reducing the thickness of the motor frame 6 by mounting the surface mount type power IC 11a.

(Example 3)
When the rotor is locked due to an overload while the motor is being driven, an overcurrent flows through the motor and the winding is overheated or the electronic components are destroyed. Although a fuse is used for this overcurrent protection, the conventional lead type has the same problem as the power IC in order to reduce the thickness of the motor. In the present embodiment, the above effect can be obtained by using the lead type fuse 13b for the surface mount type fuse 13a.

  As shown in FIG. 4, the height of the lead type fuse 13b from the substrate is about 5 mm, but the surface mount type fuse 13a has a size significantly different from about 0.4 mm. The thickness is also thin.

(Other examples)
The present invention is not limited to the above-described configuration, and can be applied to various configurations as long as it is an electric motor that covers surface-mounted electronic components with a mold resin.

  The motor of the present invention is used for a motor for driving a device used in a home such as an air conditioner, an air cleaner, a dehumidifier, and a humidifier. By reducing the size of the motor, the size of the entire device is reduced. Can be. Furthermore, since there are few defects at the time of covering an electronic component with resin, a good quality molded motor can be provided.

DESCRIPTION OF SYMBOLS 1a, 1b Motor 2 Stator core 3 Insulating member 4 Stator winding 5 Circuit board 6 Motor frame 7 Rotor 8 Rotating shaft 9 Bearing 10a, 10b Bearing bracket 11a, 11b Power IC
12a, 12b Lead terminal 13 Pin 14a, 14b Fuse

Claims (6)

A stator formed by winding a coil by applying an insulating member to a slot provided in an iron core;
A circuit board provided with electronic parts for controlling the motor and fixed by a fixing portion provided in the insulating member;
In motors with
The electronic component mounted on the circuit board is a surface mount type electronic component,
A molded motor, wherein the stator and the circuit board are covered with a mold resin to form a motor frame.   The molded motor according to claim 1, wherein the surface mount component is disposed on a surface of a circuit board on a stator side.   The molded motor according to claim 1, wherein the surface mount component is disposed on a surface of the circuit board opposite to the stator.   4. The molded motor according to claim 1, wherein the surface mount component is a power IC that controls a drive current of the motor.   4. The molded motor according to claim 1, wherein the surface mount component is an overcurrent protection fuse.   4. The molded motor according to claim 1, wherein the surface mount power IC and the surface mount fuse are mounted simultaneously.