JP2003250291A - Motor using permanent magnet for rotor and stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-speed and high-output brushless motor wherein permanent magnets are used for a rotor and a stator, stationary torque is high, power is saved, and revolution is easily controlled. <P>SOLUTION: Coils are wound around the permanent magnets of the stator. Current is passed through the coils for a short time in a position where repulsive force is maximized against the permanent magnets of the rotor arranged so that the north pole and the south pole alternate. Thus, reversed magnetic fields are applied to magnetize stator magnets so that the polarity thereof is reversed. As a result, revolution without interruption is implemented. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

[Industrial application] Brushless motor with large static torque, high speed and high output with little electric power and easy rotation control.

[0002]

2. Description of the Related Art In a motor using a permanent magnet, the rotor does not rotate unless a rotating magnetic field is generated by passing a current through either the rotor or the field coil.

[0003]

One of the magnets is magnetized in the opposite polarity with a small amount of electric power to generate a rotating torque.

[0004]

[Means for Solving the Problems] A rotation angle detector is attached to a rotary shaft, a current is made to flow through a coil wound around a stator magnet at an optimum position for a short time, and a reverse magnetic field is applied to reverse the polarity of the stator magnet. Magnetize.

[0005]

As shown in FIG. 1, the rotor magnets A and B are attached to the rotary disk, and the coiled stator magnets a and b are fixed.
When both a and b are attracted to A, A stands still between a and b. Here, when a magnetic field is applied so that b repels A, and A is magnetized in the opposite polarity, A approaches a and tries to pass past a and return. Then, when a magnetic field is applied to a at a position where it passes a and the polarity is reversed, the rotor is accelerated in the arrow direction. Then, B is in the attracted state with respect to b.a. Similarly, the polarity of b.a is reversed to obtain the continuous rotation. The rotation speed can be controlled by delaying the magnetization timing.

FIG. 2 shows a block diagram of the control unit, and FIG. 3 shows a magnetization time chart of the stator magnet. The signal of the rotation angle detector is made into a narrow pulse of a constant width by the one-shot multivibrator, and the first Pulse demagnetizes and the second pulse magnetizes the polarity in reverse. At this time, the impedance of the coil increases in the reverse magnetic field. It takes only a very short time to demagnetize or magnetize the permanent magnet,
Magnetized magnets retain their properties. A ferrite magnet, an alnico magnet, or a rare earth magnet is used for the rotor, and an alnico magnet with a small holding force is used for the stator.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a one-way rotation motor in which the rotor has a relatively large radius and the polarity of the stator magnet is reversed by one pulse will be described. As shown in Fig. 4, eight polygonal permanent magnets N and S are bonded alternately so that the different poles face each other on the inner side of two iron rotating discs with a diameter of 25 cm. A wedge-shaped iron piece for preventing magnetism is bonded to form an 8-pole rotor. Next, when a stator magnet in which a coil is wound around a rod-shaped permanent magnet is inserted between the magnets, a maximum static torque of about 5 kg-cm is generated.
When the rotor is rotated a little in the direction of the arrow, the stator magnet is magnetized in the opposite direction and starts to rotate, and the opposite magnetization is repeated at a position beyond the maximum attraction force, resulting in about 750 rpm. Here, the electric power required for one magnetization is about 900 VA · 400 μs, but 600
At VA · 100 μs, the speed is 350 rpm. Thus, even a motor having a large rotor radius can be rotated with a small amount of electric power. If a stronger rotor magnet is used, a motor with an efficiency of 100% or more is possible. Other.
Reverse rotation is still performed as it is, but for reversible operation, a V-shaped notch is inserted into a plate-shaped permanent magnet as shown in Fig. 6 and a plate-shaped iron piece is adhered to it, and demagnetization occurs at the center and the repulsive force is maximized. It is more effective to magnetize in the opposite direction.

[0008]

INDUSTRIAL APPLICABILITY The present invention can be used in various devices as a high-speed, high-output brushless motor having a large static torque and easy rotation control. And unlike a general motor, even if it stops due to overload, it will not burn out.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is a block diagram of a control unit.

FIG. 3 is a magnetization time chart of a stator magnet.

FIG. 4 is a perspective view of the embodiment.

FIG. 5 is a sectional view of a rotor magnet.

FIG. 6 is an example of another rotor magnet.

[Explanation of symbols]

1 rotating disk 2 Rotor magnet A 3 Rotor magnet B 4 Stator magnet a 5 Stator magnet b 6 Magnetizing coil 7 timer circuit 8 one-shot multi-vibrator 9 transistor switch 10 power supply 11 Stator magnet 12 iron disk 13 rotation axis 14 Rotor magnet N 15 Rotor magnet S 16 wedge-shaped iron piece 17 Plate-shaped iron piece 18 Stator magnet support frame 19 Rotation angle detection disk 20 Fort Interrupter R 21 Fort Interrupter S

Claims (3)

[Claims] 1. A motor for obtaining a continuous rotation by applying a magnetic field to one of the magnets after the attraction cycle of the rotor magnet and the stator magnet is finished and magnetizing the magnets in the opposite polarity. 2. The rotor magnet is controlled by changing the pulse width to control the magnetizing power, and by delaying the signal of the rotation angle detector or by moving the rotation angle detector back and forth in the rotation direction to control the rotation speed. The rotation direction is controlled by two stator magnets whose positions are offset from each other and a detector. 3. An iron piece is adhered to a rotor magnet to change the direction of magnetic force lines to improve efficiency and prevent demagnetization.