JPS62281746A - Flat-type motor - Google Patents

Abstract

PURPOSE:To lessen magnetic reluctance and improve motor efficiency by composing a main magnetic path with a core, a permanent magnet, a dished rotator and a yoke. CONSTITUTION:An annular permanent magnet 1 is secured to a dished rotator 2 made of a ferromagnetic material. A rotating shaft 3 is attached to the center of this dished rotator 2 to form a rotor. Said rotating shaft 3 is borne by a bearing 5 fitted to an anchor block 4. A ferromagnetic material plate yoke 6 is fitted so as to have a suitable gap from the bottom of the anchor block 4. A coil 7 has a ferromagnetic core 8 which is secured to the yoke 6 by means of a screw 9. A main magnetic path of this flat-type motor is composed of the core 8, permanent magnet 1, dished rotator 2 and yoke 6.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention The present invention relates to a flat type motor having a permanent magnet rotor that rotates by a rotating magnetic field formed by three-phase alternating current generated by an electronic circuit.

This type of flat type motor according to the prior art uses an air-core coil mainly for the purpose of reducing size and weight, reducing iron loss, and reducing cogging torque. Such air-core coils are suitable for the purpose of reducing size and weight, reducing iron loss, and reducing cogging torque, but the magnetic resistance in the main magnetic path is large (and the fact that efficiency decreases in this respect) is Therefore, in order to generate the same torque, it was necessary to increase the number of coil turns and reduce the gap between the rotor and stator, but there were manufacturing limitations and manufacturing costs This is not a sufficient solution as it goes against the request for reduction in energy consumption.Furthermore, when attaching the air-core coil to the magnetic path forming yoke, work such as using an appropriate adhesive to bond it is essential, and it may cause failure. This has the drawback that it tends to cause problems and the overall configuration becomes complicated.

An object of the present invention is to provide a flat type motor that can generate sufficiently strong and smooth torque with a simple configuration.

This object is achieved by a flat motor having the configuration described in the claims, that is, a three-phase stator coil consisting of a cored coil, and a flange on the side of the core of the stator coil near the rotor magnet. The flange is achieved by a flat motor shaped in such a way that the change in reluctance between adjacent coils is continuous and smooth.

According to the flat type motor according to the present invention, the magnetic resistance of the main magnetic flux path between the rotor magnet and the stator coil is significantly reduced, and the torque is significantly increased compared to a similar motor using a conventional air-core coil. The advantage is that the amount increases. Moreover, it is possible to reduce the unevenness of the generated torque, that is, the cogging in which the torque is uneven between adjacent coils, and the OA
Characteristics suitable as a drive source for appropriate applications such as equipment or FA equipment can be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A flat type motor according to the present invention will be described below with reference to the accompanying drawings showing embodiments.

FIG. 1 is a sectional view showing the overall configuration of a flat type motor according to the present invention. Here, an annular permanent magnet 1 is fixed to a disk-shaped rotating body 2 made of ferromagnetic material. A rotating shaft 3 is attached to the center of this dish-shaped rotating body 2, forming a rotor. This rotating shaft 3 is supported by a hair ring 5 attached to a fixed base 4. A yoke 6 made of a ferromagnetic plate is attached to the bottom of the fixed base 4 with an appropriate gap. This yoke 6 has an annular shape, and the coils 7 are evenly distributed on the annular ring so as to form a three-phase winding. This coil 7 has a core 8 of ferromagnetic material, and this core 8 is fixed to the yoke 6 with screws 9. The core 8 has a ferromagnetic collar 8a on the air gap side, which will be described later. Note that a circuit board 10 including an electronic circuit for generating a driving current as described later is disposed close to the fixed base 4.

FIG. 2 is a plan view showing the coil arrangement of the stator with the rotor shown in FIG. 1 removed. In this embodiment, six coils 7 are arranged on the annular yoke 6. Each coil 7
each has a core 8 which is fixed to the yoke 6 by a screw 9. Therefore, each coil 7 is securely and easily fixed to the yoke 6, and the trouble of adhesion etc. is saved. Note that the coils 7 are connected in series so that the coils face each other around the axis 3, and are separated from each other by 120 electrical degrees.

A hole is formed at an appropriate position in the yoke 6, into which a detection part of a rotor position detector 11, 12, 13 attached to the rotating board is inserted. These rotor position detectors can use, for example, Hall elements, and switch the current supplied to the coils according to the rotor magnetic poles to control the direction and intensity of the magnetic flux acting on the rotor. In this way, the circuit board 1
Connect only the tip of the rotor position detector attached to the yoke 6.
It is sufficient to protrude a little from the hole, which simplifies the overall configuration.

FIG. 3 is an example of an annular permanent magnet that can be applied to the rotor of this embodiment. The stator of this example is formed as a three-phase winding with six coils arranged as described above, but the permanent magnet is made by dividing an annular ferrite into eight equal parts and magnetizing them to have alternating polarity. It is something. Therefore, starting torque can always be generated from a stationary state.

Figure 4 shows the shape of the core 8 of the stator coil 7, which is made of a round iron bar processed to the required length.
has. The flange 8b needs to be configured in such a shape that the generated torque FK has the following relationship with the flange of an adjacent coil, regardless of the coil outer shape.

FK=R(sinθ+5in(θ+120)+
5 inches (θ+240)) Note that this core 8 can also be made of other materials, such as soft ferrite.
It is also possible to punch out silicon steel plates into disks of the same size and stack an appropriate number of disks. With this configuration, iron loss can be reduced and motor efficiency can be improved. In this case, the provision of the collar made of a suitable material is the same as described above.

These fixings of the core to the yoke 6 can be easily carried out with a screw inserted through the center 8a. In addition, Tsuba 8b
The shape may be an ellipse as shown in FIG. 4, a capsule shape, or an elongated polygon as appropriate.

FIG. 5 shows the connection state of six stator coils 7. In the coil arrangement shown in FIG. 2, one phase is a three-phase star-shaped connection in which opposing coils are connected in series. It is. In such a connection, between terminals A and B, between B and C,
By sequentially switching the three-phase alternating current to flow between C and A, a rotating magnetic field is generated, and the rotor magnets generate torque. The rotation direction can be easily switched by changing the phase sequence, and the rotation speed can be easily controlled by changing the voltage applied to the coil. Such control is achieved by well-known electronic circuits on circuit board 10 and rotor position detectors 11.12.
．． 13, but will not be described in detail.

The main magnetic path of the flat type motor according to the present invention includes the core 8, (
Since it is composed of a magnetic material collar + air gap), a permanent magnet 1, a dish-shaped rotating body 2, and a yoke 6, the magnetic resistance is low. Therefore, losses are reduced and motor efficiency is significantly improved. Further, the coil can be easily and firmly attached to the yoke 6 by mechanically attaching the core 7.

Therefore, the work becomes easier and manufacturing costs can be reduced. Furthermore, since the control and drive circuits are integrated, there is an advantage that there are fewer restrictions on use.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the overall configuration of a flat type motor according to the present invention, FIG. 2 is a plan view showing the structure of a stator,
FIG. 3 is a plan view showing the shape of the rotor permanent magnet, FIG. 4 is a perspective view showing the structure of the core, and FIG. 5 is a connection diagram showing the connection state of the stator coils. The correspondence of reference numerals in the figure is as follows. 1: Annular permanent magnet 2: Disc-shaped rotating body 3: Rotating shaft 4: Fixed base 5: Bearing 6: Yoke
7: Coil 8: Core 8a: Screw hole 8b: Tsuba 9: Screw 10: Circuit board

Claims (1)

[Scope of Claims] A flat type motor having a permanent magnet rotor, which has a three-phase stator coil consisting of a cored coil, and a flange is provided on the side of the core of the stator coil near the rotor magnet,
A flat type motor characterized in that the flange is formed in a shape such that changes in magnetic resistance between adjacent coils are continuous and smooth.