JPH02164257A - Disc driving motor - Google Patents

Abstract

PURPOSE:To facilitate correct assembly by interposing a laterally pressing spring between a bracket and a stator core secured to the bracket having a cylinder section axially extended to support bearings rotatably supporting a shaft. CONSTITUTION:Upper and lower bearings 9 and 10 are secured to a bracket 3b having a cylinder section 23, with which a shaft 1 is rotatably supported. A disc (not illustrated) held by a hub 2 secured to the shaft 1 is rotated. One and over notched sections 22 are provided to the bracket 3b are lateral pressure spring sections 21 for lateral pressure springs are arranged. The positioning and securing of the laterally pressing springs 17a is performed by clamping with the cylinder section 23 of the bracket 3b and the radial surface of the stator core 7. The motor is thereby made thin and miniaturized so that the assembly can be performed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a disk drive motor (hereinafter referred to as a motor) for rotationally driving a disk of a magnetic disk device.

BACKGROUND OF THE INVENTION In recent years, motors have been required to have high precision, high quality, and miniaturization.

The conventional motor described above will be described below with reference to the drawings.

FIG. 3 shows a sectional view of a conventional motor.

In FIG. 3, 1 is a motor shaft, 2 is a hub fixed to the shaft 1, 5 is a ring-shaped rotor magnet, and 6 is a rotor frame for fixing the rotor magnet 5, which is fixed to the shaft l.

7 is a stator core provided at a position facing the rotor magnet 5, and 11 is a winding wound around the stator core 7. 3 is a bracket, and the stator core 7 is fixed to this bracket 3. Further, a stator board 4 is attached to the bracket 3, and a winding i is attached to the stator board 4.
A position detection element 8 is arranged for controlling the excitation of ll.

A lower bearing ring 10 and an upper bearing 9 are configured on the bracket 3 at positions separated from each other in the axial direction, and a preload spring 15 applies a preload to the lower bearing 10 and the upper bearing 9. Further, the bracket 3 is machined with a groove for holding a lateral pressure O-ring 16 that applies lateral pressure to the lower bearing 101, and the lateral pressure O-ring 16 applies lateral pressure to the lower bearing.

The magnetic fluid seal 14 is composed of a seal magnet 12b and a magnetic fluid 13 injected into the gap between the shaft 1 and the seal yoke 12a, and prevents dust from entering through the upper bearing 9 and grease from scattering from the bearings 9 and 10. It is prevented.

Furthermore, FIG. 4 shows a sectional view of another conventional motor, and the same components as those in FIG. 3 are omitted, and only the different configurations will be explained. A lateral pressure spring 17 that applies lateral pressure to the lower bearing 9 is fixed to the bracket 3a with screws 18.

In recent years, disk devices have been moving toward higher density and faster access, and one of the problems with this is thermal off-track, in which the track position shifts when the temperature changes.

Since the usable track density is determined by this thermal off-track, it is necessary to improve this thermal off-track in order to increase the density. Thermal off-track is a phenomenon that occurs when the motor parts are made of different materials and the motor parts have different expansion coefficients, causing the hub to collapse due to temperature changes. Since the direction in which the hub falls is not determined, thermal off-track cannot be improved, which causes malfunctions as the density increases. As a countermeasure to this problem, a means is needed to improve thermal off-track by applying lateral pressure at 90 degrees with respect to the head direction, giving directionality to the fall of the hub.

Problems to be Solved by the Invention However, in conventional configurations, methods have been used to apply lateral pressure in the radial direction using an O-ring, or to determine the direction of heat sagging of the hub using a lateral pressure spring, but when using an O-ring, , The groove where the O-ring is inserted must be made eccentric (it is difficult to process, it takes time to insert the bearing, and there are large variations in lateral pressure. Also, the lateral pressure spring is fixed with a screw. This type of structure requires a lot of man-hours and also requires space for screws to attach lateral pressure springs, making it unsuitable for miniaturization and thinning.

Means for Solving the Problems In order to solve the above problems, the motor of the present invention includes a shaft rotatably supported by a bearing, a hub fixed to the shaft and having a portion for holding a disk, and a hub fixed to the shaft. A stator core includes a rotor having a rotor, a bracket having a cylindrical portion extending in the axial direction that supports the bearing, a stator core having the bracket, and a lateral pressure spring that biases the bearing in the radial direction. The stator core is sandwiched between the stator core and the stator core in the radial direction.

Function The present invention has the above-mentioned configuration, in which the lateral pressure spring is held by the bracket tube and the stator, and can be easily assembled, and can accurately apply lateral pressure to the bearing.The following is an embodiment of the present invention. The motor will be explained with reference to the drawings.

Note that the same parts as in the conventional configuration are given the same reference numerals as in the conventional example, and the explanation thereof will be omitted.

FIG. 1 shows a sectional view of the motor in the first embodiment,
FIG. 2 shows the lateral pressure spring of the same embodiment.

In the figure, 3b is a bracket, and the notch 22
is provided at one or more locations, and the lateral pressure spring portion 21 of the lateral pressure spring 17a is provided.

Further, the lateral pressure spring 17a is positioned and fixed by being held between the bracket cylindrical portion 23 and the radial surface of the stator core 7. In the above configuration, the lower ball bearing 10 is provided with a lateral pressure spring 17a that applies a constant lateral pressure. By doing this, it is possible to eliminate the screws for mounting the lateral pressure spring 17a, which is effective when downsizing and when there is little space in the radial direction.
can be obtained with high precision using a mold.

Effects of the Invention As described above, the present invention has a structure in which a notch is provided in the bracket, a lateral pressure spring is inserted, and the bracket is positioned and fixed on the radial plane of the bracket cylinder and the stator core.
It is possible to provide a motor that is easily assembled, smaller, and thinner.

In addition, the notches of the bracket and the lateral pressure springs can be manufactured with high precision (using molds), so variations in the spring pressure of the lateral pressure springs are reduced, which is advantageous both economically and in terms of precision.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a perspective view of a side pressure spring of the embodiment of the present invention, and FIGS. 3 and 4 are sectional views of a conventional example. 1...Shaft, 2...Hub, 3b.
... Bracket, 5 ... Rotor magnet, 6 ... Rotor frame, 7 ... Stator core, 9 ... Upper bearing, IO ...
... lower bearing, 15 ... preload spring,
17a... lateral pressure spring, 21... lateral pressure spring part, 22... notch part. Figure 21-11 Detective 1st Pressure Capacity

Claims (1)

[Claims] A shaft rotatably supported by a bearing, a hub fixed to the shaft and having a portion for holding a disk, a rotor fixed to the shaft, and a cylindrical portion extending in the axial direction supporting the bearing. a bracket; a stator core fixed to the bracket;
a lateral pressure spring that urges the bearing in the radial direction, a notch in which the lateral pressure spring is disposed is provided in the cylindrical portion, and a portion of the lateral pressure spring is provided in the radial direction of the cylindrical portion and the stator core. A clamped disc drive motor.