JP2006129633A - Brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, in a disk rotation motor used in an optical disk device such as a CD, DVD or the like, foreign matter may intrude through a cutout or an opening part formed on a base plate for the reduction of weight, thereby causing a motor in a locked state. <P>SOLUTION: A plurality of cutouts 32 and openings 33 formed on the base plate 29 are covered with a printed board 30 connected to the base plate, thereby preventing foreign matter from intruding thereinto without using a new member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to prevention of foreign matter intrusion of a brushless motor.

  In recent years, optical disk devices for mobile use have been required to be smaller and thinner, and weight reduction has been listed as an important requirement, and the disk rotation motor used for this has also been strongly demanded for weight reduction. However, the base plate is generally made of an iron, stainless steel, or brass material for the purposes of rigidity, accuracy, magnetism, etc., and occupies a large weight ratio in a disk rotation motor. ing.

  FIG. 4 shows a conventional example of the structure of a disk rotating motor used in an optical disk apparatus such as a CD or a DVD. The disk rotation motor is composed of a rotor portion 1 and a stator portion 2. Among them, the rotor part 1 includes an integrated rotor frame 5 in which the turntable part 3 and the yoke part 4 are integrated, a disk holding member 6 that presses and supports the disk together with the turntable part 3, a rotor magnet 7, a shaft 8, The stator portion 2 includes a bearing member 10, a metal housing 11 that holds the bearing 10, a core 12 that is disposed to face the rotor magnet 7, and is wound, and a metal base plate 13 and a bracket 15 made of a printed circuit board 14 such as an FPC.

  In the above configuration, in order to reduce the weight of the brushless motor, generally, measures such as changing the material or reducing the thickness of the material are taken, but for further weight reduction, the base plate 13 is notched. It is necessary to provide a part and an opening.

So far, it has been proposed to form an opening in the base plate 13 for the purpose of reducing the thickness of the motor rather than reducing it (see, for example, Patent Document 1 and Patent Document 2).
Japanese Patent Laid-Open No. 11-187637 (page 4, FIG. 1) Japanese Patent Application Laid-Open No. 2004-213807 (page 8, FIG. 3)

  In the above conventional configuration, in order to reduce the weight of the brushless motor, when the notch or opening is formed in the base plate and reaches the rotor part region, there is a risk that foreign matter will enter and the motor will be locked. Therefore, it is necessary to block the notch and the opening by some method.

  For example, Patent Document 2 proposes that a sheet-shaped protective material is provided on the side opposite to the rotor portion on the base plate. However, in this case, since a convex portion is formed on the base plate, it is not suitable for thinning the motor. Further, since a new member is required, it is not desirable from the viewpoint of cost.

  The present invention solves such a conventional problem, and an object thereof is to prevent adverse effects that may occur when a brushless motor is reduced in weight without using a new member.

In order to solve the above problems, the present invention provides a plurality of notches or openings on a base plate formed to reduce the weight of a brushless motor, an FPC joined to the base plate, or a glass epoxy substrate, Or, it is blocked with a paper phenol substrate to prevent foreign substances from entering.

  According to the first aspect of the present invention, there is obtained an advantageous effect that it is possible to prevent a harmful effect that occurs when the brushless motor is reduced in weight, such as a foreign matter entering from a plurality of notches or openings formed in the base plate. It is done. In addition, it is not necessary to use a new member to close the notch or opening formed in the base plate, which is beneficial in terms of cost, and the notch or opening on the side opposite to the rotor portion on the base plate. Since there is no member for closing the part, it is useful for thinning. Further, closing the notch and the opening can prevent leakage of noise such as wind noise generated by the rotation of the rotor, so that an effect of reducing motor noise can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
1 is a structural sectional view of a motor according to Embodiment 1 of the present invention. In FIG. 1, the brushless motor is attached to the rotor frame 18 and the integrated rotor frame 18 in which the turntable portion 16 and the yoke portion 17 on which the disc is mounted are integrated, and the disc holding member 19 that presses and supports the disc together with the turntable portion 16. A rotor portion 23 comprising a rotor magnet 20 and a shaft 21 fixed to the center of the rotor frame and a retaining member 22; a bearing 24 for supporting the shaft 21; a metal housing 25 for holding the bearing; and the rotor magnet 20 And a stator portion 28 having a core 26 which is disposed opposite to and wound with a winding, and a bracket 27 which holds the housing 25.

  The bracket 27 is constituted by a combination of a metal base plate 29 and an FPC printed circuit board 30, and the base plate 29 and the FPC printed circuit board 30 are bonded by a method such as adhesion or double-sided tape.

  FIG. 2 is a perspective view of the motor according to Embodiment 1 of the present invention, and is a view of the brushless motor as viewed from the side opposite to the rotor portion 23. The base plate 29 is formed with a plurality of cutouts 32 and fan-shaped openings 33 mainly for the purpose of reducing the weight of the motor. The cutouts 32 and the openings 33 are formed on the printed circuit board of the FPC. It is blocked by 30. As a result, not only foreign matter can be prevented from entering, but also noise leakage can be prevented. At this time, the printed circuit board 30 of the bracket 27 may use a glass epoxy board or a paper phenol board in addition to the FPC. Further, the weight reduction form of the base plate 29 can be applied to a structure in which a large number of small-diameter holes 35 are formed as shown in FIG.

  As a result, it is possible to prevent harmful effects such as foreign object intrusion when the motor is lightened.

  This is useful for brushless motors for mobile devices that require weight reduction, such as spindle motors for optical media.

Cross-sectional view of the structure of a motor according to an embodiment of the present invention 1 is a perspective view of a motor according to Embodiment 1 of the present invention. The perspective view of the motor of the other example which concerns on Embodiment 1 of this invention Cross-sectional view of the structure of a conventional brushless motor

Explanation of symbols

1, 23 Rotor part 2, 28 Stator part 3, 16 Turntable part 4, 17 Yoke part 5, 18 Rotor frame 6, 19 Disc holding member 7, 20 Rotor magnet 8, 21 Shaft 9, 22 Retaining member 10, 24 Bearing 11, 25 Metal housing 12, 26 Core 13, 29 Base plate 14, 30 Printed circuit board 15, 27 Bracket 32 Notch 33 Opening 35 Small diameter hole

Claims (1)

A rotor part having a turntable part for mounting a disk, a rotor frame, a disk holding member that presses and supports the disk together with the turntable part, a rotor magnet attached to the rotor frame, and a shaft fixed to the center of the rotor frame And a stator part comprising: a bearing that supports the shaft; a metal housing that holds the bearing; a core that is disposed opposite to the rotor magnet and that is wound; and a bracket that holds the housing. In the motor, the bracket is constituted by a combination of a metal base plate and a printed board, and the base plate is formed with a plurality of notches or openings, and the notches or openings are closed by the printed board. Brasley consisting of Motor.

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