JPH06121512A - Motor frame - Google Patents

Abstract

PURPOSE:To obtain a motor frame in which cutting can be made at required points on the inner and outer peripheries of a motor frame by single chucking and thereby concentricity and perpendicularity are enhanced at each part. CONSTITUTION:In a motor having a frame 1 for securing a stator, a level difference is provided on the outer peripheral face of the flame 1 in order to form a small diameter part 1e. Cutting is made on the inner and outer peripheral faces of the frame 1 with reference to the small diameter part 1e.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor frame used in, for example, a magnetic disk drive device.

[0002]

2. Description of the Related Art For example, there is a motor shown in FIG. 3 as a motor for rotationally driving a magnetic disk or the like. In FIG. 3, the frame 41 has a dish-shaped portion and a boss portion 41f at the center thereof, and an iron shaft 47 is fitted and fixed to the boss portion 41f. Inner rings 43b, 43b of the upper and lower ball bearings 43, 43 are fitted on the outer periphery of the upper portion of the shaft 47, and outer rings 43a, 43a of the ball bearings 43, 43 are fitted.
Is fitted into the inner diameter portion of the hub 48, so that the hub 48 is rotatably supported. The hub 48 is for holding a magnetic disk (not shown) integrally and rotationally driving it, and has a flange 53 for holding the magnetic disk on the outer diameter portion and a screw hole 54 for fixing the disk at the upper end portion. ing. One or a plurality of magnetic disks are stacked on the flange 53 with an appropriate spacer interposed, and a clamper is further stacked on the magnetic disk, and a set screw inserted in the clamper has a screw hole for fixing the disk. By being screwed into 54, the magnetic disk is integrally fixed to the hub 48.

A ring-shaped drive magnet 46 is fixed to the lower surface side of the flange 53 of the hub 48 via a ring-shaped yoke 49. Boss portion 41f of frame 41
A stator core 51 is fitted and fixed to the outer periphery of the. The stator core 51 has a plurality of salient poles, each salient pole faces the inner peripheral surface of the drive magnet 46, and a coil 52 is wound around each salient pole. The drive magnet 46 and a member integrated with the drive magnet 46 form the rotor of the disk drive motor, and the stator core 51 and the coil 52 form the stator of the motor.

As shown in FIG. 4, the frame 41 used in the motor having the above-described structure has a fitting surface 4 for the shaft 47.
1c and the outer peripheral surface 41a coaxiality, and the shaft fitting surface 41c
In order to obtain the dimensional accuracy of the motor mounting surface 41d that extends outward in the form of a flange, the respective surfaces are cut. The procedure of the cutting process performed on the frame 41 is as follows. 1. The outer peripheral surface 41a of the motor frame 41 is chucked by a jig, and the stator core mounting portion 41b and the shaft fitting surface 41c on the inner peripheral side are cut. 2. If the outer peripheral surface 41a is chucked, the outer peripheral surface 41a and the motor mounting surface 41d cannot be cut. Therefore, the outer peripheral surface 41a is unchucked, and the stator core mounting surface 41b is newly chucked with a jig. Then, the outer peripheral surface 41a of the motor frame and the motor mounting surface 4
Cut 1d.

[0005]

If the frame 41 is re-chucked to the jig when the frame 41 is cut as in the conventional case, the coaxiality between the shaft fitting surface 41c and the outer peripheral surface 41a, The perpendicularity between the shaft fitting surface 41c and the motor mounting surface 41d deteriorates. Further, since there is no standard for chucking the frame 41, the machining accuracy varies, and the quality of the frame 41 cannot be stabilized.

The present invention has been made in order to solve the above-mentioned problems, and makes it possible to perform a cutting process on a necessary portion of the inner circumference and the outer circumference of a motor frame by one chucking, and each portion. It is an object of the present invention to provide a motor frame capable of improving the coaxiality and squareness of the motor.

[0007]

In order to achieve the above object, the present invention provides a motor provided with a frame for fixing a stator, in which a step is provided on the outer peripheral surface of the frame to form a small diameter portion. It is characterized in that the inner peripheral surface and the outer peripheral surface of the frame are machined with reference to the small diameter portion.

[0008]

[Function] By chucking the small-diameter portion formed on the outer peripheral surface of the frame with a jig, the outer peripheral surface of the frame, the shaft fitting surface, the stator core mounting surface, and the motor mounting surface are machined in one chucking. be able to.

[0009]

Embodiments of the motor frame according to the present invention will be described below. In FIG. 1, the frame 1 has a cup shape as a whole, and has a boss portion 1f integrally formed at the center thereof. The outer periphery of the boss portion 1f of the frame 1 is the stator core mounting portion 1b, and the outer periphery of the boss portion 1f is the shaft mounting surface 1c. A flange-shaped portion is formed on the outer peripheral side of the frame 1, and the flange-shaped portion serves as a motor mounting surface 1d. A shaft 7 made of iron is fitted and fixed to the shaft fitting surface 1c of the boss portion 1f. Further, a small diameter portion 1e is formed by providing a step portion over the entire circumference at the lower end portion of the outer peripheral surface of the frame 1.

Inner rings 3b, 3b of the upper and lower ball bearings 3, 3 are fitted to the outer periphery of the upper portion of the shaft 7, and outer rings 3a, 3a of the ball bearings 3, 3 are fitted to the inner diameter portion of the hub 8. The hub 8 is rotatably supported. The hub 8 has a flange 13 for holding the magnetic disk (not shown) and holds the magnetic disk in rotation, and has a flange 13 for holding the magnetic disk on the outer diameter portion and a screw hole 14 for fixing the disk at the upper end portion. ing. One or a plurality of magnetic disks are stacked on the flange 13 with an appropriate spacer interposed, and a clamper is further stacked on the magnetic disk, and a set screw inserted into the clamper has a screw hole for fixing the disk. The magnetic disk is integrally fixed to the hub 8 by being screwed into the hub 14.

On the lower surface side of the flange 13 of the hub 8, a ring-shaped drive magnet 6 is provided via a ring-shaped yoke 9.
Is stuck. The yoke 9 and the drive magnet 6 are located inside the dish-shaped portion of the frame 1. The stator core 11 is fitted and fixed to the stator core mounting surface 1b on the outer periphery of the boss portion 1f of the frame 1. The stator core 11 has a plurality of salient poles, each salient pole faces the inner peripheral surface of the drive magnet 6, and a coil 12 is wound around each salient pole. The drive magnet 6 and a member integrated with the drive magnet 6 form a rotor of the disk drive motor, and the stator core 11 and the coil 12 form a stator of the motor.

The frame 11 applied to the motor as described above has the coaxiality between the shaft fitting surface 1c and the outer peripheral surface 1a as shown in FIG. 2 and the straightness between the shaft fitting surface 1c and the motor mounting surface 1d. It has been cut to create an angle. During cutting, the frame 1 is chucked by the jig at the small diameter portion 1e. By chucking the small-diameter portion 1e of the frame 1 with a jig, the outer peripheral surface 1a, the stator core mounting surface 1b, the shaft fitting surface 1c, and the motor mounting surface 1d of the frame 1 can be contacted with blades, so It becomes possible to complete the cutting of each of the above surfaces by chucking, the coaxiality between the shaft fitting surface 1c and the outer peripheral surface 1a, and the shaft fitting surface 1c.
Thus, the perpendicularity of the motor mounting surface 1d can be improved. Therefore, the coaxiality between the outer peripheral surface 1a and the shaft 7 and the perpendicularity between the shaft 7 and the motor mounting surface 1d can be improved. In addition, since the chucking of the frame 1 only needs to be performed once, the cost can be reduced.

Further, since the small-diameter portion 1e serves as a reference when chucking the frame 11, it is possible to form a frame of stable quality without causing variations among products.

Although the embodiment shown in the figure shows a shaft fixed type motor, the present invention is also applicable to a shaft rotating type motor.

[0015]

According to the present invention, in a motor having a frame for fixing a stator, a step is formed on the outer peripheral surface of the frame to form a small diameter portion, and the small diameter portion is chucked with a jig, and the small diameter portion is chucked. By using the part as a frame, the inner peripheral surface and the outer peripheral surface of the frame can be cut by one-time chucking, and the external coaxiality and squareness can be improved. The cutting process can be performed efficiently.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a motor to which a motor frame according to the present invention is applied.

FIG. 2 is a sectional view showing an embodiment of a motor frame according to the present invention.

FIG. 3 is a sectional view showing an example of a motor to which a conventional motor frame is applied.

FIG. 4 is a sectional view showing an example of a conventional motor frame.

[Explanation of symbols]

 1 frame 1e small diameter part 11 stator core

Claims (1)

[Claims] 1. In a motor having a frame for fixing a stator, a step is provided on an outer peripheral surface of the frame to form a small diameter portion, and the inner peripheral surface and the outer peripheral surface of the frame are cut with reference to the small diameter portion. A motor frame characterized by the above.