JPH0851746A - Molded motor - Google Patents

Abstract

PURPOSE:To obtain a molded motor excellent in durability and reliability in which a magnet is prevented from being damaged due to difference of temperature characteristics between an end ring and the magnet by improving the material for the ring magnet fixed to the end ring of a rotor for the purpose of positional detection. CONSTITUTION:The molded motor comprises a stator A formed by winding a plurality of coils 3 around a stator core 1 through an insulator 2 and integrating molding of an electrically insulating synthetic resin, and a rotor B having an end ring fixed with a ring magnet 8 for detecting a position. The magnet 8 is a plastic magnet made of a mixture of ferrite and a thermoplastic synthetic resin having temperature characteristics similar to those of the end ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded motor used for driving a blower fan of a home air conditioner.

[Prior art]

Conventionally, as a motor used for a blower fan of a home air conditioner or the like, a DC motor whose speed can be easily adjusted is often adopted because it is necessary to control the amount of blown air in multiple stages.

The DC motor has the advantage that the winding structure can be simpler than that of the induction motor, but on the other hand, the current flowing through the coil (winding) becomes discontinuous, so that electromagnetic vibration is generated. Therefore, in order to reduce the electromagnetic vibration, a stator core and a coil integrally solidified with a thermosetting resin (hereinafter referred to as a mold motor) are often used.

This type of molded motor is disclosed in Japanese Patent Laid-Open No. 5-30.
It is configured as disclosed in Japanese Patent No. 8738 (H02K3 / 46) and the like. FIG. 9 shows a vertical sectional view of a conventional mold motor of this type.

That is, the stator core 101 has an insulator 102
The coil 103 is toroidally wound around the yoke of the iron core. On the other hand, the holding pin 102 of the insulator 102
A substantially donut-shaped printed circuit board 112 on which drive circuit components are mounted is mounted on A.
The mounting position of No. 2 is a position where the stator core 101 around which the coil 103 is wound does not come into contact with the coil 103.

Stator core 101 with coil 103 mounted
Is formed as a stator by being housed in a casing 104 integrally molded and solidified with an electrically insulating synthetic resin.

A plurality of lead wires 115 for power supply or speed detection are attached to the printed circuit board 112. The lead wires 115 are fixed to the bushes 116 made of synthetic resin at the time of resin molding. It is protected from the heat and pressure generated, or the adhesion with the resin is enhanced.

The bush 116 is usually composed of a pair of bush pieces 118 and 119 which are superposed on each other, and the plurality of lead wires 11 are formed on the respective superposed surfaces of the bush pieces.
Corresponding to No. 5, a plurality of grooves 118b and 119b having the same depth and a semicircular cross section are formed. And
The lead wire 11 is formed by the plurality of grooves 118b and 119b.
Holds 5 Reference numeral 105 is a rotor, 106 is a rotating shaft, and 107 and 111 are bearings that support the rotating shaft 106.

Further, a ring-shaped magnet 109 is attached to the end ring of the aluminum die casting of the rotor 105 so as to face the Hall element 108 of the printed board 112 by an adhesive material.

[0010]

However, according to the above construction, the ring-shaped magnet 109 attached to the end ring of the rotor 105 is usually formed of ferrite, and the physical properties of ferrite are that aluminum and the temperature characteristics thereof are different from each other. Since the (thermal expansion coefficient) is different, there is a problem that the end ring and the magnet 109 expand due to heat during operation, and the magnet 109 breaks when contracting.

The present invention has been made in view of the above points,
By improving the material of the ring-shaped magnet attached to the end ring of the rotor for position detection (or rotation detection), damage to the magnet due to the difference in temperature characteristics (coefficient of thermal expansion) between the end ring and magnet It is an object of the present invention to provide a molded motor that is prevented in advance and has excellent durability and reliability.

[0012]

A molded motor of the present invention is a stator obtained by winding a plurality of coils around a stator core through an insulator and then integrally molding the synthetic iron resin with an electrically insulating property. And a rotor in which a ring-shaped magnet for position detection is attached to the end ring.The magnet is made of a plastic magnet that has the same temperature characteristics as the end ring by mixing ferrite and thermoplastic synthetic resin. It is what

[0013]

In the molded motor of the present invention having the above-mentioned structure, the material of the ring-shaped magnet attached to the end ring of the rotor for position detection (or rotation detection) is a plastic magnet, and this plastic is the end ring. Since it is close to the coefficient of thermal expansion of aluminum or zinc that composes, it expands and contracts in the same way as the end ring and does not generate thermal strain in the magnet, preventing damage to the magnet and preserving the rotor's durability. It is possible to provide a molded motor having excellent properties and reliability.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 1, the mold motor of the present invention has a stator A, a rotor B, and a rotary shaft C, and a stator core 1 has a tooth portion 1 of the core 1 via an insulator (insulator) 2.
A coil 3 is wound in a toroidal shape on a yoke extending between b and 2b, and a frame 4 is formed by molding from the outside with a premix made of an insulating synthetic resin such as unsaturated polyester resin. Here, as shown in FIG. 4, the stator core 1 is formed by laminating a plurality of half-doughnut-shaped electromagnetic steel plates and connecting the protrusions 5 to each other. It is obtained by forming a donut shape by providing a coil and a semi-doughnut shape) and then abutting each other in that state and then mold-bonding with the synthetic resin.

Further, in FIG. 1, the frame 4 is provided with a bearing housing 6 formed integrally with the frame 4 on one side in the axial direction. A bracket 9 formed by drawing a steel plate is provided on the other side of the frame 4 in the axial direction.
The rotor B is supported by a bearing 11 and a bearing 7 which are fixed to the inside and are fitted inside.

A ring-shaped plastic magnet 8 for position detection (or rotation detection) is attached to the rotor B at a position facing a Hall element H of a printed circuit board 12 described later.

As shown in FIGS. 2 and 3, a plurality of holding pins P1 ..., P2 ... Are erected on the insulator 2 of the stator A composed of the stator core 1, the insulator 2 and the coil 3. The holding pin P near the abutting portion of the iron cores 1a, 2a
1 ... is thick, and the holding pins P2 ... Separated from the butted portion are thin. The holding pin P2 is formed farther from the rotation axis C of the rotor B than the holding pin P1. Then, the holding pins P1 ..., P2 ...
A substantially donut-shaped printed circuit board 12 on which components for driving circuits such as a Hall element H (located on the back side of the circuit board 12) for detecting the position of the rotor B are mounted is mounted on the printed circuit board 1.
The mounting position of 2 is a position where it does not contact the coil 3. The stator core 1 having the coil 3 mounted thereon is integrally molded and solidified with the above-mentioned synthetic resin having electric insulation properties to form the stator A. At this time, the printed circuit board 12 is also embedded in the resin.

The printed circuit board 12 has a terminal 13 to which a power source is connected and a plurality of terminals 14 to which the coil 3 is connected.
A plurality of wiring patterns are formed between and. For example, in case of four poles, as shown in FIG. 2, D, E, F, G,
N wiring patterns are formed, and in the case of two poles, I, J, K, L, and M wiring patterns are formed as shown in FIG. A lead wire 15 for supplying power connected to the terminal 13 is attached to the printed board 12.
The lead wire 15 is protected by a bush 16 made of synthetic resin such as polybutylene terephthalate fixed to the lead wire from heat and pressure generated at the time of resin molding which will be described later, or the adhesion with the resin is improved. ing.

The bush 16 is composed of a pair of bush pieces 18, 19 which are superposed on each other via a thin connecting piece 17, as shown in FIGS.
A plurality of grooves 18b, 19b having different depths corresponding to the plurality of lead wires 15 are formed on the respective overlapping surfaces 18a, 19a
Are formed. That is, the groove 18b of the bush piece 18 on the upper side of the bush 16 has a semicircular cross section (180
On the other hand, the groove 19b of the bush piece 19 on the lower side of the bush 16 is formed to have a cross-sectional shape larger than a semi-round shape (180 degrees).

Further, four through holes 20 are formed on the overlapping surface 19a of the bush piece 19, and the overlapping surface 18a of the other bush piece 18 is formed to be shorter than the depth X of the through hole 20. Four protrusions 2 of height Y to fit 20
1 is formed. While the bush 16 holds the lead wire 15 by the plurality of grooves 18b and 19b, at the same time as the resin molding and solidification of the stator core 1 around which the coil 3 is wound, about half of the bush 16 main body is integrally embedded in the resin. It is fixed to the stator A.

The plastic magnet 8 is formed of a plastic magnet in which ferrite and a thermoplastic synthetic resin are mixed, and the thermoplastic synthetic resin has a coefficient of thermal expansion (temperature) equal to that of an aluminum end ring 22 described later. Characteristics).

On the other hand, the rotor B is formed by casting an iron core by aluminum die casting, and the ring magnet is attached to the step portion 23 of the end ring 22 with an adhesive.

In the molded motor thus constructed, the end ring 22 of the rotor B is used for position detection.
The material of the ring-shaped magnet 8 attached to is a plastic magnet, and this plastic is aluminum (or zinc) used for the end ring as described above.
Since it is close to the coefficient of thermal expansion (temperature characteristic) of
Even if it is heated by the heat during the operation, it expands and contracts similarly to the end ring 22, does not generate thermal strain in the magnet, prevents damage (cracking) of the magnet 8 in advance, and improves the durability of the rotor B. In addition, it is possible to provide a molded motor having excellent reliability.

Further, since the groove 19b of the bush piece 19 below the bush 16 is formed to have a sectional shape larger than a semicircular shape (180 degrees), the lead wire 15 should be firmly held by this groove 19b. Therefore, even if heat or pressure is applied during resin molding of the stator core 1, the lead wire 15 can be reliably positioned in the groove 19b. As a result, the assembling workability can be improved by the simple structure of increasing the depth of the groove 19b of the one bush piece 19. That is, the groove 19b formed deeply
Since the cross-sectional shape is an arc shape larger than a true semicircle, the lead wire 15 can be reliably held by the edge portions protruding at both ends of this arc. However, the groove 19b does not necessarily have to be formed larger than the true semicircle, and the same effect can be obtained by merely forming the groove deeper than the true semicircle.

Further, four through holes 20 are formed on the overlapping surface 19a of the bush piece 19, and the overlapping surface 18a of the other bush piece 18 is formed to be shorter than the depth X of the through hole 20. Four protrusions 2 of height Y to fit 20
Since 1 is formed, a part of the through hole 20 remains hollow when the bush pieces 18 and 19 are fitted together. Since resin intrudes into this cavity and is solidified during resin molding of the stator core 1, the binding force of the bush pieces 18 and 19 and the fixing of the bush 16 itself become stronger, and the bush 16 is firmly fixed to the stator core 1. Fixed.

Therefore, the lead wire 15 is hardly detached from the bush 16 even when the molded motor is used or the secular change, and the bush 16 does not drop from the stator A. It is possible to obtain a molded motor having excellent properties and reliability.

Although the present embodiment is premised on the DC motor, it goes without saying that the same operational effect can be obtained even when applied to an induction motor.

[0028]

As described above, according to the present invention, the material of the ring-shaped magnet attached to the end ring of the rotor for position detection is the plastic magnet, and this plastic is the material used for the end ring. Since it is close to the coefficient of thermal expansion (temperature characteristic), it expands and contracts in the same way as the end ring and does not generate thermal strain in the magnet, preventing damage to the magnet before it causes durability and reliability of the rotor. It is possible to provide a molded motor having excellent properties.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a mold motor showing an embodiment of the present invention.

FIG. 2 is a plan view of a printed circuit board and a stator core of a 4-pole mold motor.

FIG. 3 is a plan view of a printed circuit board and a stator core of a two-pole mold motor.

FIG. 4 is a plan view of a stator core.

FIG. 5 is a developed plan view of a bush.

FIG. 6 is a developed sectional view of a bush.

FIG. 7 is an exploded front view of the bush.

FIG. 8 is a front view of the rotor.

FIG. 9 is a vertical cross-sectional view showing a conventional mold motor.

[Explanation of symbols]

 A Stator B Rotor C Rotating shaft 1 Stator iron core 2 Insulator 3 Coil 4 Casing 8 Ring magnet 22 End ring 23 Stepped portion

Claims (1)

[Claims] 1. A stator formed by winding a plurality of coils around a stator core through an insulator, and integrally molding the synthetic iron resin with an electrically insulating property, and an end ring having a ring shape for position detection. In a molded motor including a rotor to which a magnet is attached, the magnet is formed of a plastic magnet having a temperature characteristic equivalent to that of the end ring, in which ferrite and thermoplastic synthetic resin are mixed. Molded motor.