JPS5889055A - Brushless motor - Google Patents

Abstract

PURPOSE:To eliminate the substantial presence of a position where torque becomes zero by suitably displacing the central position of a stator pole from the central position of the pole pair which attract a rotor in a rotating direction. CONSTITUTION:An annular rotor 1 formed of a magnetic material is divided on the inner surface into two in the circumferential direction, which are distinctly magnetized into N-pole magnetized part 1n and S-pole magnetized part 1s. The magnetic periodical angle of the stator 2 which is engaged with the inner surface of the rotor 1 becomes substantially 180 deg.. The pole pair 2n and 2s of the stator 2 have stator teeth 3a, 3b of the number made of integer times more than 2 of the number of poles, coils are wound on the stator teeth 3a, 3b in the same polarity in different number of turns in the same direction, and the central position C1 of the stator pole produced when the coil is energized, and the mechanical central position C2 of the pole pair which attract the rotor 1 irrespective of the coil energization are displaced from each other at an angle theta in the rotating direction.

Description

[Detailed description of the invention] The present invention relates to a brushless motor.

Generally, in a two-phase DO brushless motor, there is a position where the torque becomes zero.

In a conventional brushless motor, as shown in Fig. 2, the inner surface of the rotor (1)' is divided into two in the circumferential direction, and an M-pole magnetic part (γn
) and the S-pole magnetized part (7g), and the rotor (1
)' is fitted inward so that the magnetic periodic angle of the stator (2r) is 180°, and the stator magnetic pole pair (2In) and (2s) facing the inner magnetized part of the rotor (1γ) is , 4111 coils are installed protrudingly at the f position in the pair corresponding to the rotation angle of 180° of the rotor (1)', and a coil with the same number of turns is attached to each m (31'--... change). Therefore, the mechanical center position of the magnetic pole pair is
This is the same as the electrical center position of the stator magnetic poles that occurs when the stator is excited. Therefore, if there is one rotor (11' position If detection! +4)', the second 180° and 660° in the diagram
[At the corner position of fl, the torque becomes zero, and the rotor (
This is the main cause of hindering the smooth rotation of 1y. and rotor (
1. In order to ensure smooth rotation, it is necessary to install a plurality of 11 position detectors at important points in the toilet, and it is also necessary to increase the number of phases of the stator, which makes cost A) more robust. be.

In the motor of the present invention, the inner surface of the rotor in the form of a block is divided into one direction number ζ and divided into an N-pole magnetized part and an S-1# magnetized part. is an integer 6 that is greater than or equal to the number of poles, and the coils wound around the stator poles in the same pole are in the same direction and have different numbers, and the center position of the stator magnetic pole that is generated when the coil is started. The center position of the pair of magnetic poles that attract the rotor regardless of coil excitation is shifted by a large amount in the direction of rotation, so that there is virtually no position where the torque becomes zero. .

Below, we will explain about Figure (3) showing the actual side of the present invention. (1) is a single-column-shaped rotor made of magnetic material, whose cabinet is divided into two in the circumferential direction. Body pole IIIM! 1 part (1n) and s, 1 magnetized db (1m) KI1. m4W
Fli:g inwardly of the rotor (1) by tV
Stator (210) = The periodic angle should be approximately 180°. Magnetic pole pair of stator (2) (
2! l) and (2-) respectively have stator rods (58), <5b) with the number of teeth consisting of an integral multiple of 2 or more of the number of poles, and stators within the same pole <3 &), (3kl).
) are wound with coils with different numbers of turns in the same direction, and the electrical center position 01 of the stator magnetic pole that occurs when the coil is excited, and the magnetic pole that attracts the rotor (1) regardless of the coil excitation. It is assumed that the mechanical center position 0□ of the pair is shifted by 6 angles in the rotation direction. G
4) is the connection El! between the rotor (1) and the steering wheel C21! i
The position detector is a fixed position detector, which detects the rotational position of the -1 rotor, and uses the detection force to apply a current of 1IIr to the coil 5 of the stator (1) to drive the rotor (1).

Note that adjacent stator plates (351) and (3k) are not necessarily formed in the same shape. In addition, after winding the fill around the stator magnetic pole pair (2 m) and (2 m), the coil was wound in the same direction (3 hatake) and <5
k) by connecting it with a monomer (3M), (3b)
If the sound is integrated electrically, the performance will be much better.

The stator (2) in the motor of the present invention has the stator magnetic pole r≦random center position O1 that occurs when the coil (5) is excited.
is characterized in that it does not coincide with the mechanical center position of the magnetic pole pair. In this way, the crest that slips from the mechanical center position 02 of the m-pair or the electrical center position 01 of the stator magnetic pole is -1111c circle X? -Yugashi (3m), (
3b) kcJH! The number of turns of the coil is increasing, and the magnetic force generated on the outer 4 edges of the tooth (6) and the tooth (3b) are
This is because there is a difference in strength between the magnetic force generated at the outer peripheral end 41 & of the magnetic field.

In the motor of the present invention, when the dead rotor (II) is in the position shown in FIG. 1 (4), the stator magnetic pole pairs (2n) and (21)
When the E@ magnetized coil 5 is excited, the detection range is the electrical angle range shown by the dotted line in FIG. (1 serving)
The creation and transformation of the torque acting on the fly is in the range of electrical angles shown in 1-(4). -H at the corner
becomes.

When the rotor (1) is in the position shown in Figure 1 (to), when the coil B equipped with the stator magnetic pole pair (2n) and (2Ks) is excited, the detection range is the electrical angle range shown by the dotted line in Fig. 1 (to), whereas the operating range of the torque acting on the M-pole magnetized portion (In) K of the rotor (1) is the range shown by the dotted line in Fig. 1 (to). The electrical angle range is shown by the solid line, and the operating range in which the fourth stator magnetic pole pair and the rotor contact are mutually dependent is the electrical angle range shown by the chain line.

In the motor of the present invention, when the position detector 4) of the rotor (1) is set to 11, in FIG. 8 showing the correlation between torque and rotation angle, if coil 5 is excited, K111El( A1. (The torque becomes zero at angles of 180° and 360'[l'l in Bl, but the mechanical center position oJ1 where the magnetic pole pair of the stator (2) pulls the magnetized part of the rotor (1) And coil 5 is ni
l! rii, the electrical center position O1 of the magnetic pole pair of the red stator ■ is off by 6 degrees, so the coil 5 is
* I E (At 1L
K14+! 180'g Yohi 3600d) angle 1 and stator ■ i! Therefore, the pair of wheels has a torque that pulls the rotor (1) closer together.

This state appears as indicated by the dotted line in FIG.

If the above-mentioned torque generation 1m81 is expressed as a solid line in contrast to the dotted line that shows the torque generation mode of a brushless motor depending on the torque and rotation angle, it can be seen that when the rotation angle is KO ~ 180°, the above-mentioned figure 1 ( In the case shown in 4), the generated torque is a combination of the torque obtained by exciting the coil as shown in 3 and the torque obtained by the mutual attraction of the stator magnetic pole pair and the rotor. Furthermore, in the case of a rotation angle of 180 to 660 degrees, the above-mentioned 1B! 1J
(Even in the case indicated by Bl, the generated torque is a combination of the black torque obtained by exciting coil B as shown in the figure and the torque obtained by the mutual contact between the stator magnetic pole pair and the rotor. Therefore, by repeating the above-mentioned torque generation mode as the rotor rotates,
The motor of the present invention uses only one rotor position detector (4) to draw a torque curve as shown by the solid line in Figure 5, and since there is no position where the torque becomes zero, smooth rotation is maintained. It becomes.

In addition, Figure 16 shows a known circuit configuration in which the rotor position detector (4I, stator coil, and B are connected in parallel). In addition to showing the output voltage, FIG. 5 also shows five-point output.

As described above, according to the present invention, there is no position where the torque becomes zero, so the brushless rotor rotates smoothly.
In addition, the desired effect can be achieved with a single rotor position detector, instead of requiring multiple rotor position detectors as in the past, significantly reducing the cost of moxibustion of the motor. This has the advantage that it can be reduced to

[Brief explanation of drawings]

Figure 1), (The crow is an explanatory diagram showing the correspondence between the rotor and stator in an embodiment of the present invention, Figure 2 (4), however) shows the correspondence between the rotor and stator in a conventional brushless motor. FIG. 16 is an explanatory diagram showing the rotor configuration V in the motor of the present invention; FIG. 4 is an explanatory diagram showing an example of the stator configuration in the motor of the present invention, lp
Section 5 is a torque curve diagram showing the correlation between the rotation angle and torque of the motor of the present invention shown in FIG. 1 and the conventional motor shown in FIG. Figures 5 to 8 are curve diagrams showing the correlation between the rotation angle and torque of the motor of the present invention. In the drawings, (11 is the rotor, port 1) is N extremely hot @ part, (1-
) is the S pole magnetized part, Q) is the stator, (2n) and (2
(Hata) is the stator magnetic pole pair, (6a) and (6k) are the stator stitches constituting the magnetic pole pair, M and B are the coils that form the stator magnetic pole pair K11ii, 01 is the electrical center position of the stator magnetic pole, and 0 is the stator magnetic pole pair. This is the sensitive center position of the magnetic pole pair. F
To the fountain, ¥3121 ¥t! trouble

Claims (1)

[Claims] The inward direction of the annular rotor is divided in the circumferential direction into a N-pole magnetized portion Ia and an S-pole magnetized portion.
The number of teeth of the stator to be fitted with iK is an integer multiple of 2 or more of the number of poles, and the coils wound around the stator teeth in the same pole are in the same direction and JI4 number of turns. The center position of the stator magnetic pole that occurs when the coil is excited, and the coil IIl]
A brushless motor configured so that there is virtually no position where the torque becomes zero by appropriately shifting the center position of the magnetic pole pair that engages the rotor in the rotation direction regardless of m.