JPS5816027B2 - small motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small motor used in watches and the like.

There have been various small motors in the past, but the stable operating conditions of the rotor are complex, such as the relationship between the static magnetic coupling force and the input pulse size between the rotor and stator magnetic poles, or the gap accuracy between the rotor and stake magnetic poles. There were drawbacks such as strict regulations and a cumbersome clock.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small motor that eliminates the drawbacks of the conventional motor, is easy to design and manufacture, and can be stably driven by unipolar input pulses.

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a pair of stator magnetic poles 1 and 2 arranged opposite to each other have an arc-shaped magnetic flux generating section 3 concentrically at a point 01, 4, and the two stator poles 1.2 are connected together via narrow portions 5, 6 in this embodiment.

When the coil 7 is energized, the magnetic flux generated from the magnetic flux generators 3 and 4 is substantially in the direction of the straight line L1, and the rotor 8 is rotated by an angle θ with respect to the straight line L1 to point 01 on the straight line sL2.
It is supported so that the center of rotation is a point 02 eccentric from the center by a distance e.

The rotor 8 is a permanent magnet magnetized into two poles, and a notch 9 is formed in one of the magnetized parts (in this embodiment, the S pole side).

Therefore, the lorry 8 is most stable in a positional relationship in which the N pole without the notch 9 in the non-conducting electrode faces the point P1, and the S pole with the notch 9 faces the point P2.

Therefore, the unipolar input pulse shown in Fig. 2 is applied to the drive coil 7.
When the stake magnetic pole 1 is excited to the S pole and the stator magnetic pole 2 is excited to the N pole, the rotor 8 rotates counterclockwise.
The N pole of rotor 8 is the center of stator magnetic pole 1 (on straight line L1)
Although the input pulse is cut off before the rotational displacement opposite to the rotor 8, the rotor 8 still rotates counterclockwise due to inertia.

The rotor 8 then rotates 180 degrees until its north pole faces point P2 and its south pole faces point P1. In this state, the static magnetic coupling force between the rotor 8 and stator magnetic poles 1 and 2 is the weakest. The inertial force of the rotor 8 overcomes this static magnetic coupling force, and the rotor 8 further rotates due to its inertia.

When the rotation angle of the rotor 1 exceeds 180°, the rotor 8 begins to receive a counterclockwise rotational force due to the static magnetic coupling force with the stator magnetic poles 1°2, and finally the NS pole of the rotor 8 changes again. It comes to a stable standstill facing points P, , P2.

That is, the rotor 8 rotates 360 degrees with one pulse.

Each time a unipolar pulse is input to the drive coil T, the rotor 8 rotates by 360° in the same manner as described above.

According to the small motor of the invention described above, it can be driven by unipolar input pulses, which simplifies the drive circuit.

In particular, the output amplifier section of the motor drive integrated circuit occupies most of the area, so the area of the output amplifier section of the motor drive integrated circuit can be halved, and the area for the motor drive can be reduced by half. Designing and manufacturing integrated circuits becomes easier, yields are improved, and costs are reduced.

Furthermore, since the stator magnetic poles can be formed into an extremely simple shape, they are easy to manufacture, have dimensional accuracy, and can be manufactured at low cost.

[Brief explanation of drawings]

The drawings relate to an embodiment of a small motor according to the present invention.
The figure is a plan view thereof, and FIG. 2 is a waveform diagram of a unipolar human power pulse. 1.2... Stator magnetic pole, 3, 4... Magnetic flux generation part,
5.6...Narrow width part, 7...Drive coil, 8...Rotor, 9...Notch part, 0...Center of magnetic flux generating part, 0
2... Center of rotation of the rotor.

Claims (1)

[Claims] 1. A pair of stator magnetic poles each having a substantially concentric semicircular arc-shaped magnetic flux generating portion are arranged opposite to each other, and the magnetic flux direction of the stake magnetic pole when energized is from the center of the magnetic flux generating portion. A permanent magnet rotor whose rotation center is eccentrically located in different directions is provided, and the rotor is magnetized into two NS poles, and a notch is formed in the magnetized portion of one of the rotors, so that one of the two stator magnetic poles is always connected when energized. A small motor configured by providing a drive coil to which a unipolar input pulse is applied so that the north pole is always excited with the other as the south pole. 2. The small motor according to claim 1, wherein both of the stake magnetic poles are integrally connected via a narrow portion.