JPH03212147A - Spindle motor - Google Patents

Abstract

PURPOSE:To effectively support a hub member by supporting the outer race of one bearing member to the hub member and the inner race to a shaft member, and supporting the outer race of the other bearing member to a mounting bracket and the inner race to the hub member. CONSTITUTION:A bearing member 42 is interposed at one end of a bearing member 14 between a large-diameter end and the end wall of a hub body 30, its inner race 14 is supported on the bearing member 14, and the outer race 46 is supported on a hub member 4. The other bearing member 48 is interposed at the other end side of the member 14 between the annular protrusion 10 of a mounting bracket 2 and the protrusion 34 to be supported on the member 4, its inner race 50 is supported on the outer periphery of a protrusion 34 to be supported, and its outer race 52 is supported on the inner periphery of the protrusion 10. Further, biasing means is interposed between the race 46 and the protrusion 34 to apply prepressure on the pair of the members 42, 48. Thus, the interval between a pair of the bearing members can be sufficiently obtained.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a spindle motor with a fixed shaft member.

[Prior art and its drawbacks]

A conventional spindle motor with a fixed shaft member includes a mounting bracket, a shaft member attached to the mounting bracket, and a hub member rotatably attached to the shaft member via a pair of bearing members. A stator is disposed at a portion of the shaft member between the pair of bearing members, and a rotor magnet is disposed on the inner circumferential surface of the hub member so as to face the stator.

However, this type of spindle motor has the following problems to be solved. At one end of the shaft member,
A bearing member is interposed between the shaft member and the hub member, and on the other end side of the shaft member, the shaft member is interposed between the shaft member and a bushing member fixed to the hub member. and,
In connection with this, a hole is formed in the shaft member and extends in the axial direction of the shaft member, and a lead wire extending from the armature coil of the stator is guided to the outside through the hole.

Therefore, the configuration of the motor itself is complicated, and the assembly work of the motor (particularly the work of leading out the lead wires to the outside) is not easy, resulting in high manufacturing costs.

Therefore, in order to eliminate the above-mentioned inconvenience,
An improved spindle motor as disclosed in Japanese Patent No. 277453 has been proposed and put into practical use. In the spindle motor, a pair of bearing members are not arranged at both ends of the shaft member, but are arranged at one end of the shaft member, and the hub member is supported cantilevered through the pair of bearing members. It becomes. However, even with this improved version,
Since the hub member has a cantilever support structure, there is an inconvenience in that the hub member tends to swing out.

[Purpose of the invention]

The present invention has been made in view of the above facts, and its main purpose is to provide a layer-improved structure that can reliably support a hub member while maintaining the advantage that lead wires can be led out from a mounting bracket. It is an object of the present invention to provide a spindle motor that has the following characteristics.

[Summary of the invention]

According to the present invention, there is provided a mounting bracket, a shaft member fixed to the mounting bracket, a hub member rotatably mounted relative to the shaft member, and a mechanism for rotatably supporting the hub member. A spindle motor including a pair of bearing members, one of the bearing members being interposed between the hub member and the shaft member, the outer ring being supported by the hub member,
The inner ring is supported by the shaft member, the other bearing member is interposed between the mounting bracket and the hub member, the outer ring is supported by the mounting bracket, and the inner ring is supported by the hub member. A spindle motor is provided.

[Specific examples of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a spindle motor according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, the illustrated spindle motor includes a mounting bracket 2 and a hub member 4 that is rotatable relative to the mounting bracket 2.
The hub member 4 can be formed from, for example, die-cast aluminum. The mounting bracket 2 includes a substantially circular bracket body 6, and the bracket body 6 is fixed to, for example, a frame (not shown) of a disk drive device. A cylindrical support protrusion 8 is integrally provided approximately at the center of the bracket body 6, and an annular protrusion 10 is integrally provided radially outward of the support protrusion 8. A through hole 12 extending in the axial direction is formed in the support protrusion 8.
A shaft member 14 is press-fitted into the through hole 12. One end (upper end) of the shaft member 14 has a larger diameter than the other end (lower end), and the other end with a smaller diameter is held until the shoulder 14a located in the axially intermediate portion comes into contact with the end surface of the support protrusion 8. By press-fitting into the through hole 12, the shaft member 14 is attached to the mounting bracket 2.
The large diameter end portion of the support protrusion 8 protrudes from the support protrusion 8 . Further, a stator 16 is attached to the outer circumferential surface of the annular protrusion lO. The stator 16 includes a stator core 18 formed by laminating plate-like members having a predetermined shape, and an armature coil 20 wound around the stator core 18. A circuit board 22 is disposed on the inner surface (upper surface in FIG. 1) of the bracket main body 6. The armature coil 20 from the stator I6 is connected to the circuit board 22
A hole 26 formed in the bracket main body 6 is electrically connected to a predetermined terminal portion on the top, and a lead wire 24 from the circuit board 22 is connected to the hole 26 formed in the bracket body 6.
The hole 26 is led out to the outside (lower side in FIG. 1) through the hole 26, and the hole 26 itself is closed with an adhesive 28. Note that the support protrusion 8 and/or the annular protrusion 10 may be formed separately from the bracket main body 6 and fixed thereto by means such as press fitting.

The hub member 4 has a substantially cup-shaped hub body 30, and an annular flange 32 that projects radially outward is integrally provided at the lower end of the hub body 30.

A recording member (not shown) such as a magnetic disk is placed on this annular flange 32, and is clamped as required between a clamp member (not shown) attached to the hub body 30. The hub body 30 also has a step-like extension extending radially inwardly toward the mounting bracket 2, ie, downwardly in FIG.

The second supported protrusion 34 may be formed separately and fixed to the hub body 30 by press fitting or the like. An annular rotor magnet 38 is disposed on the inner peripheral surface of the hub body 30 with a yoke member 36 interposed therebetween.

The rotor magnet 38 is located close to the outside of the stator 16, and the rotor magnet 38 is located on the circuit board 22.
A Hall element 40 is provided for detecting the angular position of 8.

The hub member 4 is rotatably supported as follows. That is, at one end of the shaft member 14, a bearing member 42 is interposed between its large diameter end and the end wall of the hub body 30, its inner ring 44 is supported by the shaft member 14, and its outer ring 46 is supported by the shaft member 14. It is supported by the hub member 4. In addition, the shaft member 14
At the other end side, the annular protrusion lO of the mounting bracket 2
The other bearing member 48 is interposed between the bearing member 48 and the supported protrusion 34 of the hub member 4, the inner ring 50 of which is supported by the outer circumferential surface of the supported protrusion 34, and the outer ring 52 of the annular protrusion 10. It is supported on the inner peripheral surface. In addition, biasing means (comprised in the specific example by a disc spring 54) for applying a preload to the pair of bearing members 42 and 48 is provided on the outer ring 4 of the bearing member 42.
6 and the supported protrusion 34 of the hub member 4. Therefore, as shown in FIG. 1, due to the action of the disc spring 54, the outer ring of the bearing member 42 is biased upward in FIG. 1, and the inner ring 50 of the bearing member 48 is biased downward in FIG. , and a preload is applied to the pair of bearing members 42 and 48 as required. In addition, the bearing member 4
A cap member 56 is attached to the outside of 2.

In such a spindle motor, the hub member 4 (along with the yoke member 36 and the rotor magnet 38) is rotationally driven as required with respect to the mounting bracket 2 and the shaft member 14 by the action of the stator 16 and the rotor magnet 38. The rotation of the hub member 4 is controlled by a signal from the Hall element 40.

〔Effect of the invention〕

In the spindle motor of the present invention, as can be easily understood from FIG. Hole 26 of mounting bracket 2
It is possible to secure a sufficient distance between the pair of bearing members 42 and 48 while maintaining the feature that the bearing members 42 and 48 are led out through the bearing member,
Therefore, the hub member 4 can be supported with sufficient reliability.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of an integrated spindle motor according to the present invention. 2... Mounting bracket 4... Hub member 8... Support protrusion 10... Annular protrusion 14... Shaft member 16... Stator 34... Supported protrusion 38... Rotor Magnets 42 and 48...Bearing members 44 and 50...Inner rings 46 and 52...Outer ring

Claims (1)

[Claims] 1. A mounting bracket, a shaft member fixed to the mounting bracket, a hub member rotatably mounted relative to the shaft member, and a hub member rotatably supported. In a spindle motor equipped with a pair of bearing members for the purpose of The other bearing member is interposed between the mounting bracket and the hub member, the outer ring is supported by the mounting bracket, and the inner ring is supported by the hub member. .