JPH05292722A - Brushless dc reluctance motor - Google Patents

Abstract

PURPOSE:To obtain a brushless DC reluctance motor which can be rotated by a rotor of a ferromagnetic material using no permanent magnet by so forming the rotor as to be continuously rotated by switching excitations of electromagnets. CONSTITUTION:A rotor 1 of soft iron which is not a permanent magnet but made of a rectangular ferromagnetic material is provided integrally with a rotary shaft 2 provided rotatably by a bearing. Windings 3, 4, 4A are respectively provided on electromagnets 5, 6, 6A, and energizations of the windings 3, 4, 4A are switched by a switching signal. When the winding 3 is energized, the rotor 1 is received by a torque up to an angle of a minimum magnetic potential of the electromagnet 5. When the energization of the winding 3 is cut OFF at the moment, the rotor 1 tends to be continuously rotated. Then, when the next winding 4 is energized, the rotor 1 is similarly received by a torque up to a position of minimum magnetic potential. Here, the next winding 4A is again energized, the same operation is repeated thereby to obtain continuous rotation of the rotor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless DC reluctance motor, and more particularly, to a novel improvement for obtaining rotation by a rotor of a ferromagnetic material without using a permanent magnet.

[0002]

2. Description of the Related Art As a brushless motor of this type which has been conventionally used, the structure shown in FIGS. 5 and 6 is generally adopted. That is, the reference numeral 1 in FIG. 5 is a rotor of a rotary shaft 2 which is rotatably supported by a bearing (not shown), and the rotor 1 is composed of a rare earth magnet or the like and has two poles. It is composed of a magnetized permanent magnet.

Windings 3, 4 are provided around the rotor 1.
A pair of stators 5 and 6 having
The Hall element 7 provided in the vicinity of the position detects the rotational position of the rotor 1 and controls the energization of the windings 3 and 4.

The electrical connection between the windings 3 and 4 and the hall element 7 is as shown in FIG.
Is connected to the first and second transistors Q ₁ and Q ₂ and the power supply 8, and the Hall element 7 is connected between the bases of the transistors Q ₁ and Q ₂ .

Therefore, when the Hall element 7 is actuated by the magnetic pole S of the rotor 1 and the first transistor Q ₁ is turned on in the above configuration, the stator 5 becomes the S pole, and the rotor 1
Starts to rotate. When the rotor 1 rotates 180 degrees and the N pole of the rotor 1 comes close to the Hall element 7, the second transistor Q ₂ is turned on, and the magnetic pole of the stator 6 becomes the S pole of the rotor 1. The rotation continues.

[0006]

DISCLOSURE OF THE INVENTION Conventional brushless DC
Since the reluctance motor is configured as described above, the following problems exist. That is, since it is essential that the rotor is circular and is composed of permanent magnets, it becomes a permanent magnet using an expensive material, and it is impossible to reduce the cost.

The present invention has been made to solve the above problems, and in particular, a brushless DC system in which rotation is obtained by a rotor of a ferromagnetic material without using a permanent magnet.
An object is to provide a reluctance motor.

[0008]

SUMMARY OF THE INVENTION A brushless DC reluctance motor according to the present invention includes a rotor which is rotatably provided via a rotary shaft and which is made of a ferromagnetic material and has a non-circular shape. A plurality of electromagnets that are installed and sequentially excited are provided, and the rotor is continuously rotated by switching the excitation of each of the electromagnets.

More specifically, the rotor has a rectangular shape.

More specifically, the rotor has a cross shape.

More specifically, the direction of the magnetic force lines generated by the electromagnet is a direction orthogonal to the axial direction of the rotating shaft.

More specifically, the direction of the magnetic force lines generated by the electromagnet is parallel to the axial direction of the rotating shaft.

[0013]

In the brushless DC reluctance motor according to the present invention, since the rotor is made of a ferromagnetic material instead of a permanent magnet, when the winding of any one of the stators is energized, the rotor is not As shown in FIG. 2, the torque is received up to the minimum magnetic potential, and when the winding is de-energized at this moment, the rotor tries to continue to rotate in the same rotation direction due to inertia. Therefore, by energizing the windings of the next stator, torque is received up to the position of the minimum magnetic potential as described above, and this operation is successively performed on the windings of each stator, so that the rotor continues. Can rotate. The direction of the magnetic lines of force of each stator is shown in FIG.
As shown in FIG. 4, the direction may be orthogonal to the longitudinal direction of the rotating shaft, but in the case of being configured to be parallel to the longitudinal direction of the rotating shaft as shown in FIGS. The torque can be improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A brushless D according to the present invention will be described below with reference to the drawings.
A preferred embodiment of the C reluctance motor will be described in detail. It should be noted that the same or equivalent portions as those of the conventional example will be described by attaching the same reference numerals. 1 to 4 show a brushless DC reluctance motor according to the present invention.

First, what is denoted by reference numeral 1 in FIGS. 1 and 2 is not a permanent magnet but a rotor made of soft iron which is a rectangular ferromagnetic material, and the rotor 1 is rotatable by a bearing (not shown). It is provided integrally with the provided rotary shaft 2. Around the rotor 1, a plurality of U-shaped electromagnets 5, 6 and 6A are arranged at respective vertices of an equilateral triangle having the rotation axis 2 as its center of gravity.

A winding 3 is provided on each of the electromagnets 5, 6 and 6A.
4, 4A are provided, and the switching of excitation to each of the windings 3, 4, 4A is configured by, for example, a well-known combination of a baffle plate, a light emitting diode and a transistor circuit, or an encoder, although not shown. The energization of each winding 3, 4, 4A is switched by the obtained switching signal.

Next, in the above-mentioned configuration, FIG. 1 and FIG.
When the motor shown by 1 is rotated, first, when the winding 3 is energized, the rotor 1 receives the torque up to the angle at which the magnetic potential of the electromagnet 5 is minimum, and the state shown in FIG. 2 is obtained. When the winding 3 is de-energized at this moment, the rotor 1 tries to continue rotating due to inertia. Then, when the next winding 4 is energized, the rotor 2 receives the torque up to the position where the magnetic potential is at a minimum, as described above.

Here, the next winding 4A is again energized and the same operation as described above is repeated to obtain continuous rotation of the rotor 1. Although the rotor 1 has a rectangular shape, the shape is not limited as long as the shape is non-circular. Further, the arrangement of the electromagnets 5, 6, 6A can be variously changed.

Next, as shown in FIG. 2, each electromagnet 5,
The direction of the magnetic force lines 20 obtained from 6, 6A is formed in a direction orthogonal to the longitudinal direction of the rotating shaft 2.

Further, in the construction of another embodiment shown in FIGS. 3 and 4, the orientation of each electromagnet 5, 6, 6A is changed by 90 degrees from that of the construction of FIG. 1 and FIG. The outer ends of the rotor 1 are arranged in the openings 30 of 6 and 6A so as to overlap with each other, and the direction of the magnetic force lines 20 generated from the electromagnets 5, 6 and 6A is parallel to the axial direction of the rotary shaft 2. Is configured.

Therefore, the rotor 1 is in a direction orthogonal to the direction of the magnetic force lines 20 of the configuration shown in FIG. 1 and FIG.
Are superposed on each opening 30, the electromagnets 5, 6, 6
Since the distance between the magnetic pole A and the rotor 1 can be shortened, it is not necessary to generate an unnecessary magnetic field in the space, and high torque can be achieved. In addition, the rotor 1 is designed to minimize the eddy current loss.
A laminated structure is adopted.

3 and 4, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof is omitted to avoid duplication. Further, the shape of the rotor 1 in the above-described embodiment is not limited to the rectangular shape, but may be a cross shape, a star shape, or a shape close to a circle, and the larger the number of the electromagnets 5, 6, 6A, the smoother the shape. You can get the rotation. The means for switching the windings 3, 4, and 4A is not limited to the above-mentioned configuration, and a known encoder or the like can be used.

[0023]

Since the brushless DC reluctance motor according to the present invention is configured as described above, it is possible to employ a ferromagnetic material instead of a permanent magnet for the rotor, and the cost of the entire motor is significantly higher than in the conventional case. Thus, an inexpensive high torque DC motor can be obtained with a simple structure.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a brushless DC reluctance motor according to the present invention.

FIG. 2 is an operation explanatory diagram of FIG.

FIG. 3 is a schematic configuration diagram showing another embodiment.

FIG. 4 is a plan view of FIG.

FIG. 5 is a schematic configuration diagram showing a conventional brushless DC motor.

FIG. 6 is a conventional circuit diagram.

[Explanation of symbols]

 1 Rotor 2 Rotation axis 5, 6, 6A Electromagnet 20 Magnetic field line

Claims (5)

[Claims] 1. A rotor (1) which is rotatably provided via a rotation shaft (2) and which is made of a ferromagnetic material and has a non-circular shape,
A plurality of electromagnets (5, 6, 6A) arranged with the rotating shaft (2) as a center of gravity and sequentially excited, and the rotor (1 by switching excitation of each of the electromagnets (5, 6, 6A). ) Is continuously rotated, a brushless DC reluctance motor. 2. The brushless DC reluctance motor according to claim 1, wherein the rotor (1) has a rectangular shape. 3. The brushless DC reluctance motor according to claim 1, wherein the rotor (1) has a cross shape. 4. A magnetic field line (2) generated by the electromagnet (5, 6, 6A).
The brushless DC reluctance motor according to any one of claims 1 to 3, wherein the direction (0) is orthogonal to the axial direction of the rotating shaft (2). 5. A magnetic field line (2) generated by the electromagnet (5, 6, 6A).
The brushless DC reluctance motor according to any one of claims 1 to 3, wherein the direction (0) is parallel to the axial direction of the rotating shaft (2).