JPH06178470A - Brushless motor - Google Patents

Abstract

PURPOSE:To generate a maximum torque by a method wherein three commutating poles faced with the shaft center and three PSI-shaped magnetic poles provided with arm parts on both sides are erected and installed alternately on the inside-diameter side of a doughnut-shaped yoke part, and an action width between the adjacent arm parts is made nearly equal to an action width formed in a rotor. CONSTITUTION:Three commutating poles faced with the shaft center at equal intervals and PSI-shaped magnetic poles 11, 12, 13 provided with arm parts 17, 18 on both sides between them are formed on the inside-diameter side of a doughnut-shaped yoke part 4, and a stator iron core 14 is constituted. Coils 5, 6, 7 are wound on support parts of the magnetic poles 11, 12, 13, and coils 8, 9, 10 are wound between the adjacent arm parts 17, 18. Tip parts of the commutating poles and of the magnetic poles form nearly equal action widths X, Y at 90 deg., so as to correspond to a rotor 15 as a permanent magnet, and the magnetic flux of the rotor 15 acts. The rotor 15 is divided into four in the circumferential direction, and the divided rotors are magnetized sequentially at N-poles and G-poles and form the angle of 90 deg.. Thereby, a maximum torque is generated between the stator and the rotor 15, and the efficiency of the motor is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises three doughnut-shaped yoke portions on the inner diameter side, and three auxiliary poles extending in the axial direction. The present invention relates to a brushless motor including three Ψ-shaped magnetic poles each including an arm portion formed in

[0002]

2. Description of the Related Art A brushless motor is constructed so that the position of a rotor composed of a permanent magnet is detected by a Hall element or the like and the UVW phase windings of a stator core are sequentially energized. Has been done. Such a brushless motor has a great utility value as a small rotating electric machine capable of controlling the number of revolutions because the number of revolutions of the rotor can be arbitrarily controlled by adjusting the time for which the UVW phase winding is energized.

However, in the conventional brushless motor, as shown in FIG. 4, the yoke portion 1 has three magnetic poles 2a,
When 2b and 2c are formed and windings U, V and W are wound, U, V and W phases can be formed on the magnetic poles 2a, 2b and 2c. Then, the rotor 3 is magnetized and the poles 3N, 3S
Is formed. With such a configuration, by providing a magnetic sensor such as a Hall element for detecting the position of the rotor 3 in the rotation direction, it is possible to easily configure a brushless motor having a simple structure and easy control of the rotation speed. . However, on the other hand, the working width B of the poles 3N, 3S of the rotor 3 is larger than the working width of the magnetic poles 2a, 2b, 2c.
This difference is that the action width A of each magnet is 120 ° with respect to the action width of 180 ° of the rotor 3,
The magnetic flux of the poles 3N and 3S was not used 100% effectively, and the structure was inefficient.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an efficient brushless motor having a structure in which 100% of the magnetic flux of the rotor can be effectively utilized.

[0005]

According to the present invention, the width between the working portions of a pair of Ψ-shaped arms is made substantially the same as the working width of the poles formed on the rotor, and the width between the adjacent arm portions is reduced. The problem is solved by making the operating width of the above-mentioned approximately the same as the operating width of the pair of arm portions.

[0006]

Since the U, V, and W phases are formed by winding the winding between the support portion and the adjacent arm portions, the action portions between the pair of arm portions and between the adjacent arm portions are formed to have the same width. Since the poles formed on the rotor have the same width as this, the width of the working portion of the magnetic pole and the working width of the rotor are the same. Therefore, 100% of the magnetic flux generated in the rotor acts on the magnetic pole to obtain the maximum torque.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 is a plan view of a main portion showing a state in which a stator core is wound. FIG. 2 is a plan view of a main portion showing the action width of the magnetic flux generated in the stator core. Figure 3
FIG. 4 is a diagram showing torque generated between a magnetic pole of a stator core and a pole of a rotor.

In FIG. 1, a brushless motor is provided with windings 5, 6, 7, 8, 9, 10 in a yoke portion 4 to form U, V and W phases, respectively. , 6,
Magnetic poles 11, 12, 1 for supporting 7, 8, 9, 10
3 is formed and constitutes the stator core 14. Then, a rotation 15 composed of a permanent magnet is provided on the inner diameter side. Further, a brushless motor is configured by including a rule element and a control circuit for detecting the position of the rotor 15 in the rotation direction.

In FIG. 2, in the brushless motor, magnetic poles 11, 12, and 13 formed in a Ψ shape are formed on the inner diameter side of the yoke portion 4, respectively, and the magnetic poles 11, 12, and 13 are formed.
Is a support portion 16 provided upright in the radial direction and the support portion 16
And a pair of arms 17 and 18 formed so as to be bent in a hook shape in the circumferential direction.

On the inner diameter side of the arm portions 17 and 18, there is formed an action portion which is formed in an arcuate shape and faces the rotor 15 installed therein with a slight gap. Further, the maximum width X of the acting portion, which is a portion of the arm portions 17 and 18 facing the rotor 15 and on which the magnetic flux acts, is formed to be approximately 90 °. Further, the maximum width Y of the action portion that acts on the rotor 15 of the adjacent arm portions 17 and 18 is also formed at 90 °. The rotor 15 is divided into four in the circumferential direction and is sequentially magnetized into N poles and S poles. The N poles and S poles forming the poles also form 90 °, and the magnetic poles 11 and 12 are formed. , 13 have the same angle as the working widths X and Y formed therein, and have substantially the same working width.

FIG. 3 shows a state in which the torque generated in the rotor 15 can draw an ideal torque curve 19 with respect to the time axis t.

In the brushless motor having such a structure, steel plates are punched and laminated by a press to form the windings 5, 6, 7,
The stator core 14 is constructed by winding 8, 9, and 10. The windings 5, 6, 7, 8, 9 and 10 rotate the nozzle in the axial direction and the circumferential direction from the inner diameter side of the stator core 14 to support the magnetic poles 11, 12 and 13 and the adjacent arms. Part 1
Wrap between 7 and 18. Then, the rotor 15 is incorporated to form a brushless motor.

Therefore, the windings 5 forming the U, V and W phases,
When 6, 7, 8, 9, 10 are energized, for example, winding 5
If a U-phase current flows through the coil and the winding 8, the working width X and the working width Y
The magnetic flux of the stator core 14 is generated in the and. Therefore, the north pole or the south pole of the rotor 15 is attracted to the acting portions X and Y to generate the rotation torque 19.

At this time, the working width formed between the arm portions of the magnetic poles 11, 12, and 13 and the working width formed on the rotor 15 become 90 °, respectively, so that the U, V, and W phases are sequentially arranged. Rotating torque is generated in the rotor 15 with a torque curve as shown in FIG. 3 during switching and energization, and maximum torque due to the magnetic flux of the stator core 14 and the rotor 15 can be generated.

The width of the magnetic flux generated on the side of the stator core 14 and the width of the magnetic flux formed on the rotor 15 are the same, and the magnetic flux generated between the stator core 14 and the rotor 15 is There is no waste and efficiency is improved.

The stator core 14 has windings 5, 6, 7, 8, 9, 10 of the supporting portion 16 and the arm portions 17, 18, respectively.
By greatly swelling the portion that accommodates the magnetic field in the radial direction, the windings 5, 6, 7, 8, 9, 10 are concentrated in the center of the magnetic flux, which reduces the resistance to the flow of the magnetic flux and improves efficiency. Can be improved.

[0017]

According to the present invention, the maximum torque can be generated between the stator core and the rotor, the efficiency is improved, and an ideal brushless motor can be constructed. , Which is extremely large compared to the conventional brushless motor.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part showing a state where a stator core is wound.

FIG. 2 is a plan view of a main portion showing an action width of a magnetic flux generated in a stator core.

FIG. 3 is a diagram showing a torque generated between a magnetic pole of a stator core and a pole of a rotor.

FIG. 4 is a plan view of an essential part showing a conventional brushless motor.

[Explanation of symbols]

 4 ... Yoke part 15 ... Rotor 16 ... Support part 17, 18 ... Arm part X, Y ... Working width

Claims (1)

[Claims] 1. A donut-shaped yoke portion is provided with three auxiliary poles extending in the axial direction on the inner diameter side, and between the auxiliary poles, a yoke-side support portion and an arm portion formed on the inner diameter side. In a brushless motor having three Ψ-shaped magnetic poles consisting of and, the width between the working portions of a pair of Ψ-shaped arms is made approximately the same as the working width of the poles formed on the rotor, A brushless motor characterized in that an operating width between adjacent arm portions is substantially the same as an operating width of the pair of arm portions.