JPH09233791A - Spindle motor and method for assembling it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make remachining unnecessary after assembling and to ensure simple assembling and high-precision revolution. SOLUTION: A motor is provided with a rotor hub 2 where a recording disk 14 is installed, a housing 1 mounted onto a stationary member 12 and bearings 5, 6 provided between the rotor hub 2 and the housing 1. The rotor hub 2 has an opening at one side of the direction of the axis of rotation. On the part of its circumference, a flange part 3 is provided to receive the recording disk 14. The height D1 from mounting reference surface A of the housing 1 for the stationary member 12 to disk installing surface B of the flange part 3 is determined by the height D2 from the mounting reference surface A to the disk installing back surface 15 of the flange part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor used for rotationally driving a recording disk such as an optical / magnetic disk.

[0002]

2. Description of the Related Art Generally, in a recording disk drive,
The positional relationship between the recording disc and the recording head for reading / writing the recording disc is maintained with extremely high precision and a minute gap. In recent years, such drive devices have been made smaller and lighter, and higher capacity and higher density have been advanced, but in the spindle motor in which such a recording disk is mounted, the recording disk crashes into the recording head. In order to prevent this, the rotation of the rotor hub in the direction of the rotation axis is slight and highly accurate rotation is being demanded. For this reason, in order to improve the dimensional accuracy of the individual parts that make up the motor, and to reduce variations in processing and assembly accuracy,
For example, as described in Japanese Patent Publication No. 63-57876, after the final assembly of the spindle motor,
The surface of the rotor hub is further machined so as to obtain a predetermined dimensional accuracy.

[0003]

However, in the above-mentioned method, since the spindle motor is processed again after the assembly is completed, it takes time to change the process on the production line and dust such as cutting chips generated by the processing is required. Adhere to the motor. Since the spindle motor is mounted in a drive environment in a clean environment, contamination such as dust must be strictly removed, and the removal work for that purpose is troublesome, resulting in an increase in manufacturing cost.

In response to the above problems, the spindle motor of the present invention does not require reworking after completion of assembly, is easy to assemble, requires no labor, and has high rotational accuracy. A motor and an assembling method thereof.

[0005]

In order to solve the above problems, a spindle motor according to the present invention includes a rotor hub on which a recording disk is mounted, a housing mounted on a stationary member, and the rotor hub and the housing. The rotor hub is formed so as to open at one side in the rotation axis direction, and a flange portion for receiving the recording disk in the rotation axis direction is provided at the outer peripheral portion on the opening side of the rotor hub. Further, in the spindle motor; the height dimension from the mounting reference surface of the housing to the stationary member to the disk mounting surface of the flange portion is defined by the height dimension from the mounting reference surface to the disk mounting back surface of the collar portion. It will be done.

According to another spindle motor of the present invention, in the motor configuration as described above, the height dimension from the mounting reference surface of the housing to the stationary member to the disk mounting surface of the collar portion is the mounting surface. It is defined by the height dimension from the reference plane to the predetermined inner wall portion of the rotor hub that reaches in the rotation axis direction.

Further, when assembling the spindle motor as described above, a spacer member having two defining surfaces for defining the height dimension from the mounting reference surface of the housing to the stationary member to the disk mounting surface of the collar portion. When one of the defining surfaces of the spacer member is brought into contact with the mounting reference surface of the housing in advance, and then the rotor hub is mounted on the housing through the bearing means, With the opening side facing the housing, the rotor hub is pressed in the rotation axis direction until the disc mounting back surface of the front collar portion comes into contact with the other prescribed surface of the spacer member. A method is provided in which a height between a disk mounting surface of the rotor hub and a mounting reference surface of the housing is predetermined.

As still another method of assembling the spindle motor, a spacer having two defining surfaces for defining the height dimension from the mounting reference surface of the housing to the stationary member to the disk mounting surface of the collar portion. A member is used, and one predetermined surface of the spacer member is brought into contact with the mounting reference surface of the housing in advance, and the other predetermined surface of the spacer member is positioned inside the motor of the housing. When a part of the rotor hub is inserted into the housing and then the rotor hub is attached to the housing through the bearing means, the rotor hub is pressed in the rotation axis direction with the opening side of the rotor hub facing the housing. The rotor hub is connected to the housing by a predetermined inner wall portion of the rotor hub. Performed until it abuts the other defining surface of the support member, such a contact, the height of the mounting reference surface of the disk mounting surface of the rotor hub housing is defined in a predetermined, the method is provided.

According to the above spindle motor and its method, the height dimension between the mounting reference surface of the housing and the disk mounting surface of the rotor hub is defined as the height between the mounting reference surface of the housing and the back surface of the disk mounting surface of the rotor hub. doing. Therefore, the respective surfaces defined by both face each other in the rotation axis direction, and the spacer member defining the predetermined dimension can be interposed between the both surfaces so as to be sandwiched therebetween. Thus, when assembling the motor, the height dimension from the mounting reference surface to the disk mounting surface can be easily defined only by interposing the spacer member between the housing and the rotor hub.

According to the other spindle motor and the method thereof, similarly, the height dimension between the mounting reference surface of the housing and the disk mounting surface of the rotor hub reaches the rotation axis direction from the mounting reference surface. It was defined by the height dimension to the predetermined inner wall of the rotor hub. Again,
The reference planes defined on both sides face in the direction of the rotation axis, and a spacer member that defines the space between both planes can be interposed, which makes it possible to easily and accurately measure the height. Spindle motor and assembly can be done.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a spindle motor according to the present invention will be described in detail with reference to the accompanying drawings. As an example, FIG. 1 is an overall sectional view of a spindle motor that rotationally drives a magnetic disk. A housing 1 that constitutes a motor is attached to a base member 12 of the disk drive device. A cylindrical portion 13 is integrally formed in the center of the housing 1, and the shaft 4 is inserted and fixed. A pair of ball bearings 5 and 6 are mounted on the upper side of the shaft 4 in the figure, and the rotor hub 2 is rotatably supported via these ball bearings 5 and 6. Although not shown, a plurality of magnetic disks 40 are mounted on the outer peripheral portion of the rotor hub 2.
The lowermost magnetic disk 40 mounted is received and held by the collar portion 3 formed by integrally expanding the diameter.

The disk mounting side of the rotor hub 2 is in an air chamber in the disk drive device and is maintained in a clean space. Therefore, it is necessary to prevent unclean air and contamination inside the motor from leaking into the clean space. Therefore, in the spindle motor, the inside and outside of the motor are substantially sealed.
A magnetic fluid seal device 10 and a labyrinth seal bush 11 are provided adjacent to the outer side of each motor of the ball bearings 5 and 6. A rotor magnet 8 is annularly provided on a lower inner peripheral wall of the rotor hub 2 via a magnetic yoke 9. In the cylindrical portion 13 of the housing 1, stator windings 7 are radially provided so as to face the rotor magnet 8 in the radial direction. By inputting a required commutation signal to the stator winding 7,
The rotor hub 2 is rotationally driven by electromagnetic interaction with the rotor magnet 8.

Housing 1 fixed to base member 12
Is the reference surface, and the surface 14 of the flange 3 (of the rotor hub 2) on which the magnetic disk 14 is mounted is the reference surface B. The height dimension D1 between these points A and B is a predetermined dimension and is accurate. Must be maintained. According to the spindle motor of the present invention, the height dimension D1 is set to a predetermined dimension by using the spacer member 16 shown in FIG. For this reason, the distance D2 between the reference surface A and the back surface 15 of the collar portion 3, that is, the opposite side of the disk mounting surface and the reference surface B is set to substantially define the predetermined dimension of D1. As a result, in the conventional D1, the surface defining the dimension was the motor upper side surface (upward in the figure), but by defining it as D2, the two surfaces face each other in the rotation axis direction, as shown in FIG. It is possible to define the dimensions by interposing the different spacer members 16 so as to sandwich them.

The spacer member 16 is, as shown in FIG.
The bottom portion 19 of the motor housing 1 is in contact with the inner bottom wall 18 formed in an annular shape. And the spacer member 16
The back (lower) surface 15 of the collar portion 3 of the motor is brought into contact with the upper end surface 17 of the. Therefore, the dimension T that defines the distance between the spacer members 16 is predetermined and accurately finished in advance, and defines the height dimension D2 on the motor side and thus D1. The thickness dimension of the collar portion 3 of the rotor hub on the spindle motor side is machined in advance. In this case, it is machined as a single body and easily maintained to a predetermined dimensional accuracy.

Next, a method of assembling a spindle motor capable of obtaining the above height dimension with accuracy will be described by using the spacer member 16 as an example of the spindle motor shown in FIG. As shown in FIG. 3, the rotor magnet 8 is mounted on the rotor hub 2 via the magnetic yoke 9 in advance, and the outer rings of the ball bearings 5 and 6 are fixed by adhesion or the like. After that, the shaft 4 is inserted into each inner ring of the ball bearings 5 and 6, and
The shaft 4 is fixed at a predetermined position, as shown in, and a predetermined preload is applied to each ball bearing 5, 6. As a result, the rotor hub 2 is rotatably supported on the shaft 4.

Further, as shown in FIG. 5, the rotor hub 2 has a magnetic fluid sealing device 10 and a labyrinth bush 1.
1 is attached to complete the rotating member side. The outer peripheral wall of the rotor hub 2 and the flange portion 3 are preliminarily machined to a predetermined thickness, and do not include a machining margin for additional machining after completion. On the other hand, on the housing 1 side, the stator winding 7 is fitted and fixed to the outer peripheral portion of the cylindrical portion 13.

As shown in FIG. 6, the housing 1 is mounted on the spacer member 16, and at this time, the bottom portion 19 of the housing 1 is mounted.
Are set so as to be bonded to the bottom surface 18 of the spacer member 16. The inner diameter of the hole 21 of the spacer member 16 is formed so as to correspond to the outer diameter of the lower protruding portion 22 of the housing 1, thereby positioning the motor at a predetermined position. Next, the lower end of the shaft 4 is inserted into the opening 20 of the cylindrical portion 13.

The shaft 4 is continuously inserted toward the lower end of the opening of the cylindrical portion 13, and is pressed until the back surface 15 of the collar portion 3 contacts the upper end surface 17 of the spacer member 16. As a result, the disk mounting receiving surface of the motor (the surface of the collar portion 3)
The height dimension D1 of B (that is, 14) and the mounting reference surface A of the housing 1 is defined by the T dimension of the spacer member 16.
Since the thickness dimension of the collar portion 3 is preliminarily machined with a predetermined precision, the above T dimension is the dimension D2. By simply pressing against 1, the height dimension D1 can be obtained easily and accurately due to the depth of contact. In the above description, the shaft 4 is fixed to the rotor hub 2 and then inserted and fixed to the housing 1. However, in addition to this, the shaft 4 is fixed to the housing 1 in advance, and the ball bearing 5 in such a state. ,
The rotor hub 2 provided with 6 may be mounted on the shaft 4. The effect of height dimension on the rotor hub in this case is unchanged.

In the illustrated example, the housing 1 of the spindle motor is formed such that the maximum outer diameter dimension thereof is smaller than the maximum outer diameter dimension of the rotor hub 2. Therefore, the spacer member 16 has a substantially dish shape that covers the housing 1. By the way, when the housing constituting the spindle motor is, on the contrary, larger than the outer diameter of the rotor hub, that is, in the spindle motor having the structure shown in FIG. Is shown) can be used.

As shown in FIG. 8, the spacer member 23 of FIG. 9 has a corresponding surface 31 corresponding to the mounting reference surface 32 of the motor housing 27 and joined to the mounting reference surface 32, and a pin protruding toward the motor side. A protrusion 25 such as a member is fixed or integrally formed, and the tip end of the protrusion 25 serves as the other corresponding surface 26. As a result, in the spindle motor configured as shown in FIG.
3 so that the projection 25 is inserted into the spacer member 2
The corresponding surface 31 of No. 3 can be set by joining to the mounting reference surface 32 of the housing 27.

Although not shown in the drawing, the portion where the protrusion 25 is inserted into the housing 27 can be formed by utilizing a gap between the radially extending slots of the stator winding 50 and the like, and the protrusion 25 can be easily inserted in this gap. Can be inserted through. It also abuts the protrusion 25 (of the rotor hub 28).
The position of the inner wall 29 can be arbitrarily selected, and a corresponding insertion portion of the protrusion 25 can be freely provided on the housing 27 side.

Thereafter, although not shown, the rotor hub 28
Is inserted into the housing 27 side from the upper side to the lower side in the drawing. Then, the rotor hub 2 is moved with a predetermined amount of movement by pressing.
The inner wall 29 of 8 is joined to the corresponding surface 26 of the protrusion 25 and comes into contact with it. As a result, the height dimension D1 of the disc mounting surface 35 of the rotor hub 28 and the mounting reference surface 32 of the housing 27 is defined by the spacer member 23, that is, the height dimension D2. As a result, the rotor hub 28 (the shaft 3
By simply pressing 6) onto (the cylindrical portion 37 of) the housing 27, a highly precise predetermined height dimension can be obtained.

The protruding portion 25 projecting from the spacer member 23 may be provided at one location, but when the rotor hub 28 is pressed, it abuts against the inner wall 29 of the rotor hub 28.
The spacer member 23 may be provided at three or more locations (defining a plane) at equal intervals in the circumferential direction. In addition, in the illustrated example, the mounting reference surface of the housing 27 is set to 32 portions, but in addition to this, the housing bottom surface 3
In the case of 0, the bottom portion 24 of FIG. 9 can be set as the corresponding surface of the spacer member 23.

In each of the above spindle motors, as long as one of the rotor hubs has one opening in the direction of the rotation axis, it can be freely applied regardless of whether the shaft is stationary or rotationally driven. Further, it is possible to deal with the above by using the spacer member according to the size of the housing constituting the motor. A spacer member and an assembling method can be adopted within the scope of the gist of the present invention.

[0025]

According to the spindle motor and the assembling method thereof of the present invention, the height dimension D1 between the mounting reference surface A of the housing 1 and the disk mounting surface B of the rotor hub 2 is set to the mounting reference surface A of the housing and the rotor hub. It is defined as the height D2 with the back surface 15 of the disk mounting surface. Therefore, the respective surfaces defined by both face each other in the rotation axis direction, and the spacer member 16 defining a predetermined dimension can be interposed between the both surfaces. Thus, when assembling the motor, the height dimension D2 and hence D1 can be easily and accurately defined by merely interposing the spacer member 16 between the housing 1 and the rotor hub 2.

Further, according to the spindle motor and the assembling method thereof when the housing outer diameter is larger than the rotor hub outer diameter, similarly, the height dimension D1 between the mounting reference surface 32 of the housing 27 and the disk mounting surface 35 of the rotor hub 28. To
It is defined by a height dimension D2 from the mounting reference surface 32 to a predetermined inner wall portion 29 of the rotor hub 28 that reaches in the rotation axis direction. Also in this case, the respective surfaces defined by both face the rotation axis direction, and the spacer member 23 defining the both surfaces is interposed so that the height dimension can be easily and accurately determined. Spindle motor and assembly can be done.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an entire spindle motor according to the present invention.

2 is a cross-sectional view of a spacer member used in the spindle motor of FIG.

FIG. 3 is a cross-sectional view showing the assembly sequence of the spindle motor of the present invention.

FIG. 4 is a cross-sectional view showing the assembly sequence of the spindle motor of the present invention.

FIG. 5 is a cross-sectional view showing the assembly sequence of the spindle motor of the present invention.

FIG. 6 is a cross-sectional view showing the assembly sequence of the spindle motor of the present invention.

FIG. 7 is a sectional view showing an assembling sequence of the spindle motor of the present invention.

FIG. 8 is a sectional view showing an entire spindle motor according to another embodiment of the present invention.

9 is a cross-sectional view of a spacer member used in the spindle motor of FIG.

[Explanation of symbols]

 1 Housing 2 Rotor Hub 3 Collar 4 Shaft 5 and 6 Ball Bearing 7 Stator Winding 8 Rotor Magnet 9 Magnetic Yoke 16 and 23 Spacer Member

Claims (4)

[Claims] 1. A rotor hub on which a recording disk is mounted, a housing mounted on a stationary member, and a bearing means provided between the rotor hub and the housing, the rotor hub being arranged in a rotational axis direction. In a spindle motor, one side of which is formed to have an opening and an outer peripheral portion on an opening side of the rotor hub is provided with a flange portion that receives a recording disk in a rotation axis direction. A height dimension from a mounting reference surface to a disc mounting back surface of the collar portion is defined by a height dimension of the portion to the disc mounting front surface. 2. A rotor hub on which a recording disk is mounted, a housing mounted on a stationary member, and a bearing means provided between the rotor hub and the housing, the rotor hub being arranged in a rotational axis direction. In a spindle motor, one side of which is formed to have an opening and an outer peripheral portion on an opening side of the rotor hub is provided with a flange portion that receives a recording disk in a rotation axis direction. The spindle motor is characterized in that the height dimension of the portion to the disc mounting surface is defined by the height dimension from the mounting reference surface to a predetermined inner wall portion of the rotor hub that reaches in the rotation axis direction. 3. A rotor hub on which a recording disk is mounted, a housing mounted on a stationary member, and bearing means provided between the rotor hub and the housing, the rotor hub being arranged in a rotational axis direction. An assembling method for assembling a spindle motor, wherein one side is formed to have an opening and an outer peripheral portion on an opening side of the rotor hub is provided with a flange portion for receiving a recording disk in a rotation axis direction. A spacer member having two defining surfaces for defining the height dimension from the surface to the disk mounting surface of the flange portion is used, and one of the defining surfaces of the spacer member is previously attached to the mounting reference surface of the housing. When the rotor hub is attached to the housing through the bearing means, the rotor hub is placed in front of the rotor hub. With the opening side facing the housing, the rotor hub is pressed in the rotational axis direction to be gradually coupled to the housing, and the pressing is performed by the disk mounting back surface of the flange portion of the rotor hub being the other of the spacer members. A method of assembling a spindle motor, which is performed until it comes into contact with a prescribed surface, and the height of the disk mounting surface of the rotor hub and the mounting reference surface of the housing is prescribed by such contact. 4. A rotor hub on which a recording disk is mounted, a housing mounted on a stationary member, and a bearing means provided between the rotor hub and the housing, the rotor hub being arranged in a rotational axis direction. An assembling method for assembling a spindle motor, wherein one side is formed to have an opening and an outer peripheral portion on an opening side of the rotor hub is provided with a flange portion for receiving a recording disk in a rotation axis direction. A spacer member having two defining surfaces for defining the height dimension from the surface to the disk mounting surface of the flange portion is used, and one of the defining surfaces of the spacer member is previously attached to the mounting reference surface of the housing. Before contacting, the other defining surface of the spacer member is positioned inside the motor of the housing. When a part of the spacer is inserted into the housing and then the rotor hub is attached to the housing through the bearing means, the rotor hub is moved in the rotation axis direction with the opening side of the rotor hub facing the housing. By pressing and gradually coupling to the housing, the pressing is performed until a predetermined inner wall portion of the rotor hub comes into contact with the other prescribed surface of the spacer member, and by such abutment, the disk mounting surface of the rotor hub is A method of assembling a spindle motor, wherein a height of the housing with respect to a mounting reference surface is prescribed.