JP2007080405A - Disk rotating device - Google Patents

Abstract

In a conventional disk rotating device using a spindle motor, an engaging portion and a locking portion are provided inside a rotor to prevent the rotor from coming off, so that the structure is thick in the axial direction. It was difficult to reduce the thickness of the rotating device, and the material cost was high.
An engagement portion 107 is provided on the outer periphery of a disk-shaped flat portion 105 of a rotor yoke 104, and a retaining portion 109 is provided on the inner periphery of an opening hole 108 of a mount 103 to which a spindle motor is attached. When an excessive force such as a drop impact acts in the removal direction of the rotor 102, the engagement portion 107 and the retaining portion 109 face each other with a certain width, thereby preventing the rotor 102 from coming off. By adopting the above configuration, the disk rotating device can be thinned.
[Selection] Figure 1

Description

  The present invention relates to a disc rotation device that is optimal for use in an optical disc device such as a DVD player or a compact disc player.

  An optical disk device has been put to practical use as a device that performs recording and reproduction on a DVD or a compact disk. These DVDs and compact discs continuously record signals from the inner periphery to the outer periphery, and in order to continuously record and play back signals from rotating DVDs and compact discs, the optical pickup is placed on the base. In addition to being configured to be able to reciprocate in the radial direction of a DVD or compact disk, the turntable on which the disk is mounted must be configured to be rotationally driven by a spindle motor attached to the gantry.

Conventionally, as a disk rotating device using this type of spindle motor, for example, there is a device described in Patent Document 1.
FIG. 2 is a cross-sectional side view of an essential part of a conventional disk rotating device described in the patent document. In FIG. 2, the disk rotating device includes a spindle motor 200 and a mount 219, and the spindle motor 200 includes a stator 201 and a rotor 202.

  The stator 201 includes a plate-shaped chassis base 203, a cylindrical bearing housing 205 in which a bearing 204 is mounted, an iron core 206 fixed to the bearing housing 205, and a coil 207 attached to the iron core 206. Yes.

  On the other hand, the rotor 202 is a so-called outer rotor, and a rotor yoke 209 that is a magnetic body is fixed to the rotating shaft 208. The rotor yoke 209 is formed in a cap shape having a hollow cylindrical body portion 211 around the disc-shaped flat surface portion 210, and a magnet 212 is attached to the entire periphery of the body portion 211.

  The turntable 215 includes a disk mounting surface 213 and a disk positioning unit 214 that positions the disk with respect to the spindle motor 200, and is provided integrally with the rotor yoke 209.

Further, an engaging claw 217 extending from the insertion hole 216 provided in the rotor yoke 209 to the stator 201 side is provided integrally with the turntable 215 or separately, and a retaining portion 218 is provided at the tip of the bearing housing 205. The engaging claw 217 and the retaining portion 218 are formed in a non-contact manner so that the rotating shaft 208 of the rotor 202 is prevented from being detached from the bearing housing 205 of the stator 201.
JP 2004-248332 A

  However, in the conventional configuration, a space is required between the iron core 206 and the disk-shaped flat portion 210 of the rotor yoke 209 in order to dispose the engaging claw 217 and the retaining portion 218. As a result, the spindle motor 200 The structure is thick in the direction of the rotation axis 208. Further, the turntable 215 provided with the engaging claw 217 and the bearing housing 205 provided with the retaining portion 218 have complicated shapes, and are high-cost parts. Furthermore, the engaging claws 217 are often made by resin molding, and the cost of receiving inspection and the like is necessary from the viewpoint of maintaining quality such as dimensions and strength.

  In view of the above problems, the present invention provides a disk rotating device capable of preventing the rotor from being detached and making the spindle motor thin by devising the structure of the base for attaching the disk-shaped flat portion of the rotor yoke and the spindle motor. It is to provide.

In order to solve the above-described problems, the disk rotating device of the present invention includes:
A plate-like chassis base with a bearing housing attached to the center;
A rotating shaft rotatably supported by a bearing mounted on the bearing housing;
A rotor-shaped yoke having a disk-shaped plane part with the rotating shaft attached to the center part and a hollow cylindrical body part formed around the disk-shaped plane part, and a magnet attached to the inside of the body part;
A tar table that is attached to the rotating shaft and has a flat surface portion on which a disk is placed and a positioning portion that positions the disk;
An iron core and a coil disposed between the bearing housing and the body portion of the rotor yoke;
A plate-shaped gantry having a cylindrical opening hole for accommodating the rotor yoke and having the chassis base attached on one surface;
A retaining portion having an inner diameter smaller than the outer diameter of the rotor yoke is provided on the edge of the opening hole in contact with the surface opposite to the surface on which the chassis base is attached, of the inner periphery of the pedestal that contacts the opening hole In addition, an engaging portion is provided on the outer peripheral side of the disc-shaped flat portion of the rotor yoke so as to face the retaining portion and prevent the rotation shaft from coming off from the bearing housing.

  In the disk rotating device of the present invention, as the method of creating the engagement portion, the disk-shaped plane portion is formed when the peripheral portion of the disk-shaped metal plate is pressed to form the hollow cylindrical body portion of the rotor yoke. It is preferable that a U-shaped hole is formed in a curved surface portion formed at a boundary between the body portion and the body portion, and a metal piece protruding in the radial direction is used as the engaging portion.

  Further, in the disk rotating device of the present invention, it is preferable that the end portion dimension of the metal piece is equal to the outer diameter dimension of the rotor yoke. Similarly, it is preferable that the engaging portions are provided at three locations approximately every 120 degrees around the rotation axis on the outer peripheral side of the disk-shaped flat portion of the rotor yoke.

  According to the disk rotating device of the present invention, the thickness of the spindle motor can be reduced. Further, the shapes of the rotor and the stator can be simplified, and the reliability can be improved while reducing the cost.

Hereinafter, a disk rotating device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional side view of an essential part of a disk rotating device according to an embodiment of the present invention. In the figure, components having the same functions as those in FIG.
In FIG. 1, the disk rotating device is composed of a spindle motor 100 and a plate-like mount 103 having a certain thickness, and the spindle motor 100 is composed of a stator 101 and a rotor 102.

  The stator 101 includes a plate-like chassis base 203, a cylindrical bearing housing 205 in which a bearing 204 is mounted, an iron core 206 fixed to the bearing housing 205, and a coil 207 attached to the iron core 206. These structures are the same as those of the conventional disk rotating apparatus shown in FIG.

  On the other hand, the rotor 102 is composed of a rotor yoke 104 made of a magnetic material fixed to a rotating shaft 208. The rotor yoke 104 is formed in a cap shape in which a hollow cylindrical body portion 106 is provided around a disc-shaped flat portion 105. An engaging portion 107 is provided on the outer peripheral side of the disk-shaped flat portion 105 of the rotor yoke 104, while the chassis base 203 is attached to the inner periphery of the opening 108 for accommodating the rotor yoke 104 provided in the mount 103. A rib-shaped retaining portion 109 is provided over the entire circumference at the edge of the opening hole that contacts the surface opposite to the surface.

  Usually, the engaging portion 107 and the retaining portion 109 overlap each other by the dimension A in the radial direction of the rotor 102. Further, a gap is provided between the rotor yoke 104 and the gantry 103 so that the rotor yoke 104 can rotate. Further, since the rotor 102 is attracted to the stator 101 side by the attraction force generated by the magnet 212 and the iron core 206, the rotor 102 can rotate without contacting the gantry 103.

  On the other hand, when an excessive force such as a drop impact acts in the removal direction of the rotor 102, the engaging portion 107 and the retaining portion 109 face each other by the dimension A, and the rotating shaft 208 of the rotor 102 is the bearing housing 205 of the stator 101. To prevent it from exiting.

  In the present embodiment, a method for forming the engaging portion 107 in the rotor yoke 104 will be described. Normally, the rotor yoke 104 is formed by bending the peripheral portion of a magnetic disc-shaped metal plate by press working. At this time, the core shown in the figure is shown at the boundary between the disc-shaped flat portion 105 and the hollow cylindrical body portion 106. The rotor yoke 104 having the engagement portion 107 is formed by opening a letter-shaped hole 110 and bending the peripheral portion of the metal plate so as to form a curved surface at the boundary while leaving a radially protruding metal piece to be the engagement portion 107. Can be created easily.

  Further, in the present embodiment, three engaging portions 107 are provided at equal intervals (approximately every 120 degrees) on the outer periphery of the disk-shaped flat portion 105 of the rotor yoke 104. There are no particular restrictions on the number and size of the engaging portions 107, but it is preferable to provide three practically in consideration of the ease of making a mold used in press working and the difficulty of removing the rotor 102.

  As described above, by adopting the structure of the present embodiment, a space as in the case where the engaging portion and the retaining portion are disposed inside the rotor yoke is not required, so that the thickness of the spindle motor 100 is reduced. In addition, the shape of the engaging portion and the retaining portion is simpler than that of the conventional device of FIG.

  In general, in an optical disk apparatus using a disk rotating device, a drive shaft that slidably guides an optical pickup is attached to the gantry 103, and the optical pickup reciprocates between the inner periphery and the outer periphery of the optical disk along the drive shaft. To do. At this time, the movement range of the optical pickup is restricted by the outer diameter of the rotor 102. On the other hand, since the efficiency of the motor can be increased as the rotor diameter increases, the spindle motor becomes more efficient as the rotor outer diameter increases.

  In the disk rotating device of the present invention, the structure in which the engaging portion that prevents the rotor from coming off is arranged outside the rotor yoke 104 is not adopted, and the tip end size of the engaging portion 107 is made the same as the outer diameter size of the rotor yoke 104. With this configuration, the outer diameter of the rotor can be maximized while there is a restriction on the moving range of the optical pickup, and as a result, an efficient motor can be created.

  The disk rotating device according to the present invention realizes a thin spindle motor by adopting a structure that prevents the rotor from coming off by an engaging portion provided on the rotor and a retaining portion provided on the mount. The present invention can be applied not only to an optical disk device but also to portable devices where thinner products are desired.

Cross-sectional side view of essential parts of a disk rotating device according to an embodiment of the present invention Cross-sectional side view of main part of conventional disk rotating device

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Spindle motor 101 Stator 102 Rotor 103 Base 104 Rotor yoke 105 Disc type plane part 106 Body part 107 Engagement part 108 Opening hole 109 Detachment part 110 Hole 203 Chassis base 204 Bearing 205 Bearing housing 206 Iron core 207 Coil 208 Rotating shaft 212 Magnet 213 Disc Placement part 214 Disc positioning part 215 Turntable

Claims (4)

A plate-like chassis base with a bearing housing attached to the center;
A rotating shaft rotatably supported by a bearing mounted on the bearing housing;
A rotor-shaped yoke having a disk-shaped plane part with the rotating shaft attached to the center part and a hollow cylindrical body part formed around the disk-shaped plane part, and a magnet attached to the inside of the body part;
A turntable attached to the rotating shaft and having a flat surface portion on which a disk is placed and a positioning portion for positioning the disk;
An iron core and a coil disposed between the bearing housing and the body portion of the rotor yoke;
A plate-shaped gantry having a cylindrical opening hole for accommodating the rotor yoke and having the chassis base attached on one surface;
A retaining portion having an inner diameter smaller than the outer diameter of the rotor yoke is provided on the edge of the opening hole in contact with the surface opposite to the surface on which the chassis base is attached, of the inner periphery of the pedestal that contacts the opening hole In addition, the disk rotating device is characterized in that an engaging portion is provided on the outer peripheral side of the disk-shaped flat portion of the rotor yoke so as to face the retaining portion and prevent the rotating shaft from coming off from the bearing housing.   In the rotor yoke in which a hollow cylindrical body portion is formed by pressing a peripheral portion of a disk-shaped metal plate, a U-shaped hole is formed in a curved portion formed at a boundary between the disk-shaped plane portion and the body portion. The disk rotating device according to claim 1, wherein a metal piece protruding in a radial direction is used as the engaging portion.   3. The disk rotating device according to claim 2, wherein a tip end dimension of the metal piece is equal to an outer diameter dimension of the rotor yoke. The disk rotation according to any one of claims 1 to 3, wherein the engagement portion is provided at three positions about 120 degrees around the rotation axis on the outer peripheral side of the disk-shaped flat portion of the rotor yoke. apparatus.

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