JP2009153358A - Flat motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a flat motor in a simple constitution, which can surely start normally and reversely and is suitable for operation in a low voltage and high current. <P>SOLUTION: A motor coil is formed of one conductor, and the bending cycle of the motor coil is coincident with the cycle of the SN magnetic poles of a rotor magnet. The flat motor is equipped with two sets of coil, wherein one set of coil is arranged, matching with the cycle of the S-pole and N-pole of the corresponding rotor magnet, while the other one set of coil is arranged, deviating its cycle by half a cycle, thereby the flat motor is driven by the currents of two phases deviated by half a cycle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a flat motor suitable for use with a low voltage and large current having a simple configuration and capable of forward and reverse rotation.

Examples of conventional flat motors are those that are reduced in size and thickness (Patent Document 1), those that use a magnet as a method for ensuring starting (Patent Document 2), and those that use a magnetic wire (Patent Document 2). )and so on.
Patent No. 3174517 Flat motor JP, 10-336983, A Flat motor armature structure JP, 2005-192320, A Flat motor

A conventional flat motor will be described below. As shown in Fig. 2 of Document 1, in a conventional flat motor, a conductive wire (mainly copper wire) is wound a plurality of times in an isosceles triangle shape to form a set of coils, and a plurality of these coils are combined to form a ring shape. It is the structure which comprises a stator and comprises. As shown in FIG. 1 of Reference 1, this coil (stator) is arranged close to the magnet forming the rotor to constitute a motor. Each set of coils is connected in three phases, and a rotational force is generated by passing a current through each phase.
In such a flat motor, there are many proposals such as thinning and a reliable starting method regarding the configuration and arrangement of the rotor and the stator. Document 1 attempts to reduce the thickness by devising the coil and its holding structure. However, the conventional flat motor is composed of a large number (6 to 9 sets) of coils, and further increases in thickness depending on the number of turns, so there is a limit to simplification and thinning. Further, when the position of the rotor coil stops at the boundary between the S pole and the N pole of the stator magnet, the magnet magnetic flux and the coil current are not orthogonal to each other, so that electromagnetic force is not generated or is placed in a weak state, which makes it difficult to start. It was. In the case of three-phase driving, the position can be detected by a sensor such as a hall sensor, and the rotor can be driven initially so that the rotor is at an appropriate position.
Document 2 uses a magnet as shown in FIG. 3 to prevent the coil from stopping at the boundary between the S pole and the N pole of the stator magnet so that reliable starting is possible. Document 3 uses a magnetic wire instead of a magnet.

As described above, the conventional flat motor has problems such as a simple configuration and facilitating starting and forward / reverse rotation. In addition, in a conventional flat motor, the coil is composed of a plurality of windings (several tens to several hundreds), so that the resistance (impedance) is high, and a large current cannot be passed at a low voltage. The form was not suitable for use in
On the other hand, in recent years, semiconductor elements have been miniaturized and increased in capacity, and accordingly, the operating voltage is decreasing and the operating current is increasing. A personal computer (hereinafter referred to as a personal computer) using a recent microprocessor that can be said to be a lump of semiconductor elements tends to have a low voltage and large current (for example, a current of about 100 A at a power supply voltage of about 1 V) as its power source.
In addition, there is a field of low voltage and large current in superconducting motors that apply the superconducting phenomenon. A superconducting motor uses a superconducting wire as a winding, and the superconducting wire has a resistance value of 0 when placed at an extremely low temperature (for example, minus 200 degrees), and does not generate heat when applied to a motor winding. Efficiency can be improved. Since the electric resistance of the motor winding is zero, there is an essentially low voltage and large current requirement for the power source.
The present invention was devised against the background of the application field of such a low voltage and large current, and provides a motor suitable for use in a low voltage and large current while improving the above-described problems of the conventional flat motor.

  The coil is formed of a single conductor, has a straight portion perpendicular to the rotation direction of the corresponding rotor magnet, and is bent according to the period of the S and N poles to have a periodic shape. Two coils of this conductor are provided, and one of the coils is arranged in accordance with the period of the S pole and N pole of the corresponding rotor magnet, and the other is arranged with a half period shifted, and the two sets of coils are arranged in a half period. The driving is performed with the two-phase currents shifted.

  In order to operate the flat motor having the above-described configuration, a two-phase drive current is applied to the two sets of coils. For example, if a drive current with a duty of 50% is flowed through one coil and a drive current delayed by a half cycle with a duty of 50% is passed through the other coil, either or both of the rotor magnets are in any position. Electromagnetic force is generated between the coil drive current and starts to rotate. In this case, the direction of rotation can be reversed by changing the phase of the current of the two sets of coils. For example, if the current is rotated by applying a current delayed by a half cycle to the other coil, the rotation direction is reversed by setting the forward rotation as a current advanced by a half cycle. The rotation speed can be controlled by changing the period of the drive current.

  Conventionally, a plurality of sets (6-9 sets) of coils can be replaced with two sets of coils, so that the structure can be simplified and the thickness can be reduced. In addition, since the drive circuit is clearer with a two-phase drive circuit than a conventional three-phase drive circuit, the circuit configuration is simplified. Since the two coils are shifted from each other by a half cycle, even if one coil stops between the S pole and the N pole of the rotor magnet, the other coil is located at the center of the S pole or N pole shifted by a half cycle. There is an effect that electromagnetic force is always generated and driving can be performed reliably, and a flat motor suitable for use at a low voltage and large current can be realized.

  Hereinafter, typical examples of the present invention will be described. FIG. 1 shows a rotor magnet having a donut shape magnet having NS magnetic poles in the front and back direction (thickness direction) divided into 8 parts in the circumferential direction and 8 poles alternately having S and N magnetic poles. . FIG. 2 shows a coil A having terminals A1-A2 and a coil B having terminals B1-B2, and the two coils are arranged so as to be shifted from each other by a half cycle as shown in the figure. The coils A and B are composed of a conductor plate (copper plate) and are affixed in an insulated state. The linear portion of the coil disposed on the surface of the rotor magnet is an effective portion that contributes to torque. Although the coil portions on the outer circumference and the inner circumference are straight lines in the drawing, it is actually preferable to have a circular arc shape along the outer circumference and the inner circumference of the rotor. The bending period (pitch) of the two coils corresponds to the pitch between the poles of the rotor magnet as shown in FIG. 3, that is, when one coil stops between the south pole and the north pole of the rotor magnet, Since the coil is shifted by a half period (half pitch), the coil is in the center of the S or N pole. FIG. 4 is a schematic view of a flat motor according to the present invention. A stator H comprising coils A and B is fixedly attached to a cover J, and a rotor E composed of a magnet C and a yoke D is attached to a rotating shaft F. It has been. The rotating shaft F is attached to the cover through the bearing G and is rotatable.

  Next, the operation of the above configuration will be described. Two-phase drive currents a and b shown in FIG. 6 are applied to the two sets of coils A and B. The direction of the current of the drive current a is reversed every 50% of the cycle, and the direction of the drive current b is reversed every 50%, but the waveform is delayed by a half cycle from the point of view of a. Here, the period coincides with the S-pole and N-pole periods of the rotor magnet. For example, even when the rotor magnet is at the position shown in FIG. 3 and the A coil is between the magnetic poles and no magnetic force is generated, the B coil is inward (axial) on the S pole and outward (on the n pole) ( (Anti-axial direction) current, and electromagnetic force in the right direction is generated from Faraday's law. At this time, the same electromagnetic force is generated on each of the other magnetic poles, but since the coil is fixed, the rotor magnet starts and rotates counterclockwise. When the magnet rotates and comes between the S and N poles under the B coil, the current is reversed. At this time, since there is no magnetic pole under the B coil, no electromagnetic force is generated. However, since the A coil is on the S pole and the current is inward, a right electromagnetic force is generated. Therefore, the rotor magnet further rotates to the left. Next, when the B coil is on the N pole, since the current is reversed, it is an outward current, and a right electromagnetic force is generated from Faraday's law. In other words, the current waveforms of the A and B coils are driven so that an inward current flows on the S pole and an outward current flows on the n pole.

Therefore, regardless of the position of the coils A and B, an electromagnetic force is generated between one or both of the coil drive currents and the rotor magnet to start and rotate. In this case, the direction of rotation can be reversed by changing the phase of the current of the two sets of coils. For example, if the current is rotated by applying a current delayed by a half cycle to the other coil, the rotation direction is reversed by setting the forward rotation as a current advanced by a half cycle. The rotation speed can be controlled by changing the cycle of the drive current, but for more accurate control, the current rotation speed is detected by the rotation sensor and calculated with the set value to obtain the optimal frequency, current value, etc. It is possible by supplying.
As described above, it is possible to start reliably and control the rotation direction with a simple configuration. In addition, since the number of coils is small and the number of windings is small, the resistance (impedance) is small, so that a flat motor suitable for low voltage and large current can be realized.

The coils may be formed on both sides of a thin insulating substrate as shown in FIG. 5, that is, the A1-A2 coil is formed on the A surface, and the B1-B2 coil is formed on the B surface with a half-cycle shift. Can also be configured.
Further, a superconducting motor can be obtained by using a superconductor for the coil portion or the entire coil portion in a cryogenic environment. In this case, since a larger current can flow through the coil, characteristics (torque etc.) can be improved.

  The present invention can be used as a power source for a small machine that operates at a low voltage, or a small low-voltage power generator.

Rotor magnet coil Rotor magnet and coil arrangement Structure diagram of flat motor of the present invention Coil configuration example Drive waveform diagram

Explanation of symbols

A Coil A
B Coil B
C Rotor magnet D Yoke E Rotor F Rotating shaft G Bearing H Stator J Cover

Claims (2)

  A flat motor suitable for use at a low voltage and a large current, in which a coil is formed of a single conductor, and its bending cycle is made to coincide with the cycle of the SN magnetic pole of the rotor magnet. A flat motor in which one is arranged in accordance with the period of the S pole and N pole of the corresponding rotor magnet and the other is arranged with a half-cycle shift.   2. A flat motor having a coil portion made of a superconductor according to claim 1.