JP2650033B2 - motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor suitable for a spindle motor that rotationally drives a disk-shaped recording medium.

[Conventional technology]

FIG. 2 shows a conventional disk-shaped recording medium (hereinafter referred to as a medium).
FIG. 2 is an explanatory side view of one side of a cross section of a spindle motor that rotationally drives a spindle motor, wherein 1 engages the medium (not shown);
A shaft that rotates at a predetermined number of revolutions integrally with the medium, 1a positions the medium, and the upper end of the shaft 1 engaging with the shaft 1 is formed of a soft magnetic plate at the upper end 2a. A spindle having a chucking plate for positioning a center (not shown), which is an engaging portion for engaging the medium, in the height direction, and being press-fitted or bonded to the shaft 1 by press-fitting, a spindle 2a Spindle 2 which is a surface
An upper end portion (hereinafter referred to as a center receiving surface) 3 is adhesively fixed to the spindle 2 and a chucking magnet for suction for positioning the center chucking plate with respect to the center receiving surface 2a. (Not shown), housing for engaging circuit board 6 and stator 7, 4a
Is an engaging portion for engaging the chassis with the housing 4, 4b is an engaging portion for engaging the circuit board 6, 4c is an engaging portion for engaging the stator 7, and 5 is an inner diameter (inner ring) side of the shaft 1. Engage,
A ball bearing that engages the outer diameter (outer ring) side with the housing 4, 6 is a circuit board on which elements such as a driver IC for driving a motor or a printed pattern are mounted, and 7 is a slot portion around which a motor driving coil is wound. The stator 7a is integrally formed by caulking or the like and fixed to the housing 4 by press-fitting or bonding. The stator 8 is a multi-pole magnetized FG facing a FG (frequency generator) pattern printed on the circuit board 6. A main magnet having an integral magnet 8a, 8a is a circuit board 6
FG magnet on the upper surface of the main magnet which is multipolar magnetized facing the FG pattern printed on the rotor, 9 is a rotor yoke to which the main magnet 8 is fixed, 10 is a spacer, and 11 is a preload applied to the ball bearing 5. And an elastic member 12 for fixing the rotor yoke 9 to the shaft 1.

According to the configuration of the conventional example described above, the medium is positioned by the chucking plate on the center receiving surface 2a of the spindle 2 and the tip 1a of the shaft 1 and engaged with the shaft 1 to form a pattern or an IC element necessary for driving the motor. A circuit board 6 on which a housing 4 is mounted, a ball bearing 5 having a part of the outer diameter fixed to the housing 4, and a stator 7 integrally formed with a slot portion 7a around which a motor driving coil is wound. A motor is driven to rotate the medium at a predetermined rotation speed.

In this case, high rotational accuracy is required for the conventional spindle motor. That is, low torque ripple and high FG
Accuracy is required.

First, in order to reduce the torque ripple of the spindle motor, the magnetization direction of the main magnet 8 must be improved or the gap between the slot 7a and the main magnet 8 must be improved.
7b must be tightly managed.

In order to achieve the high FG accuracy, the FG magnet
It is necessary to accurately set the coaxial relationship between the FG magnet 8a and the FG pattern of the circuit board 6, and it is necessary to minimize the deflection of the FG magnet 8a in the thrust direction.

In order to realize these in the configuration of the conventional example, the processing accuracy of the housing 4 must be extremely enhanced.
This naturally has the disadvantage of increasing costs.

[Problems to be solved by the invention]

As described above, in the conventional example, as described above, the medium is fixed to the shaft 1, and the circuit board 6, the ball bearing 5,
When the spindle motor is driven by the stator 7 and the medium is rotated at a predetermined number of revolutions, it is necessary to improve the processing accuracy of the housing 4 as much as possible in order to reduce the torque ripple and increase the FG accuracy. There was a problem of going up.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the conventional example, and has as its object to easily realize a low ripple and a high FG accuracy.

[Means for solving the problem]

In order to achieve the above object, in the present invention, the motor is configured as in the following (1).

(1) A ball bearing that supports a rotating shaft at an inner diameter portion, a housing that holds the ball bearing at a portion of an outer diameter portion, and that is positioned at a portion of the outer diameter portion of the ball bearing other than that held by the housing. A substrate on which a frequency generator pattern is formed and fixed to the housing while being fixed to the outer diameter portion of the ball bearing, and arranged in parallel with the substrate in the direction of the rotation axis, and driven by a motor. A stator integrally formed with a coil winding portion wound with a coil for use, and a first magnet portion attached to the rotating shaft so as to face the frequency generator pattern; And a rotor yoke in which a magnet part is attached to face the coil winding part.

[Action]

According to the configuration (1), the position of the first magnet portion with respect to the frequency generator pattern and the gap between the second magnet portion with respect to the coil winding portion can be easily and accurately set.

〔Example〕

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

FIG. 1 is an explanatory side view of one side section of a spindle motor according to an embodiment of the present invention.

In the figure, reference numeral 13 denotes a lower ball bearing in which a part of the outer diameter (outer ring) is fixed to the housing 15 and a part of the outer diameter is fitted with the circuit board 6 and the stator 7; An upper ball bearing having a diameter fixed to the housing 15, and 15 is a housing.

In the figure, the same or corresponding components as those in the above-mentioned conventional example are denoted by the same reference numerals, and duplicate description will be omitted.

Next, the configuration of this embodiment will be described in more detail with reference to FIG.

The lower ball bearing 13 has a part 13a of the outer diameter fixed to the housing 15 by press-fitting or bonding, and the other outer diameter is exposed from the housing 15. The circuit board 6 is positioned at a part 13b of the exposed outer diameter and fixed by fitting or the like, and the stator 7 is positioned at another part 13c of the exposed outer diameter and fitted by fitting or the like. It is fixed. As described above, the circuit board 6 and the stator 7 are positioned by the outer diameter of the lower ball bearing 13, and the circuit board 6 and the stator 7 are joined together.
At 6a, it is fixed to the housing 15 with screws or the like (not shown).

According to the configuration of the above-described embodiment, the medium is positioned on the chucking plate on the center receiving surface 2a of the spindle 2 and the tip 1a of the shaft 1 and is engaged with the shaft 1. Next, the outer diameter of the lower ball bearing 13 is fixed by positioning to the circuit board 6 on which the motor driving pattern or element is mounted, the housing 15, the circuit board 6, and the stator 7. Fixed lower ball bearing 13
And the stator 7 fixed to the outer diameter of the lower ball bearing 13, fixed to the circuit board 6 and the housing 15, and integrally formed with the slot 7 a around which the motor driving coil is wound, thereby forming the spindle motor. Drive to rotate the medium at a predetermined number of revolutions.

As described above, in the spindle motor of this embodiment, since the circuit board 6 is positioned and fixed by the outer diameter of the lower ball bearing 13, the FG pattern formed on the circuit board 6 and the rotor yoke 9 The FG magnet 8a adhered to the FG magnet is precisely coaxial with the FG magnet 8a, and the FG can be easily made highly accurate. Further, since the stator 7 is also positioned and fixed by the outer diameter of the lower ball bearing 13, the variation in the gap 7b between the slot 7a and the main magnet 8 is reduced, and the torque ripple can be further reduced. Also, the cost of the housing 15 can be reduced by reducing the parts that require high-precision processing.

Although the embodiment described above is a spindle motor of a type using a ball bearing in a circumferentially facing type, the same operation and effect can be obtained by a spindle motor of a surface facing type.

In the above-described embodiment, the member in which the ball bearing engages is the housing. However, the same operation and effect as described above can be obtained even when the motor housing and the chassis of the apparatus main body are shared.

〔The invention's effect〕

As described above, according to the present invention, the position of the first magnet unit with respect to the frequency generator pattern,
Further, the gap between the second magnet portion and the coil winding portion can be easily and accurately set, so that the rotation accuracy can be improved and the torque ripple can be further reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view of one side of a spindle motor according to an embodiment of the present invention, and FIG. 2 is a side sectional side view of a conventional spindle motor. DESCRIPTION OF SYMBOLS 1 ... Shaft 2 ... Spindle 3 ... Chucking magnet 4, 15 ... Housing 5 ... Ball bearing 6 ... Circuit board 7 ... Stator 8 ... Main magnet 9 ... Rotor yoke 13 ... Lower ball bearing 14 …… Top ball bearing

Claims (1)

(57) [Claims] 1. A ball bearing that supports a rotating shaft at an inner diameter portion, a housing that holds the ball bearing at a portion of an outer diameter portion, and a ball bearing that has an outer diameter portion other than that held by the housing. Positioned and fixed to the housing, a substrate on which a frequency generator pattern is formed, and positioned at the outer diameter portion of the ball bearing and fixed to the housing, and juxtaposed to the substrate in the rotation axis direction, A stator integrally formed with a coil winding portion around which a motor driving coil is wound; a stator connected to the rotating shaft; a first magnet portion attached to face the frequency generator pattern; And a rotor yoke in which the second magnet part is attached to face the coil winding part.