Inner rotor motor and magnetic disc using same

Abstract

The inner-rotor motor of the invention includes a rotor having plural magnetic poles disposed circumferentially, and a stator having a stator core with plural magnetic pole teeth facing to the rotor, located outside a circumference of the rotor, which have coils each wound around thereof. In this construction, the stator is placed within a central angel 180 DEG with regard to a rotational center of the rotor, and the coils are set such that the numbers of turns of adjacent coils are unequal, and respective sums of the numbers of turns of the coils in respective phases are equal.The present invention can reduce manufacturing cost, making device small-sized and light-weighted, maintain stability of rotation of motor, and enhance operational stability of disk device.

Description

technical field [0001] The present invention relates to a thin inner rotor motor suitable for rotationally driving a medium used in, for example, a floppy disk drive, and a magnetic disk drive using the inner rotor motor. Background technique [0002] Beginning with personal computers, magnetic disk devices such as floppy disk devices have been widely used in office computers, word processors, etc., and their popularity is astonishing. Such a magnetic disk device employs, for example, the structure shown in FIG. 10 . [0003] Hereinafter, it will be briefly described with reference to the same drawing. In the figure, what is represented by symbol 101 is a case having a spindle center 102 as a rotation center of a magnetic disk, for example, it is stored in a case of a personal computer or the like (in the figure Not shown), which is opened at the front and above as a whole, and is composed of a bottomed box with a storage space where the magnetic disk cartridge 103 faces. ...

AI Technical Summary

Problems solved by technology

[0010] However, when the frame 161 and the core 163 are reduced according to the above-mentioned requirements, there is a problem as follows: that is, the magnetic interaction with the rotor 166 will be uneven in the circumferential direction, and it may not be possible to Keep the operation stability of the disk

[0011] Moreover, in order to reduce the area of ​​the core 163, it is considered to divide the structure of the core to have three frames, but in this case, since the frames are often arranged parallel to each other, the distance between the front end parts of the frames become too narrow, creating the problem that coil winding is not possible

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