JPS5869457A - Brushless motor - Google Patents

Abstract

PURPOSE:To obtain the smooth rotation of a rotor by composing pole pair of two teeth of different outer peripheral areas and displacing the electric center of the stator pole produced when the coil is energized from the mechanical center. CONSTITUTION:The inner surface of an annular rotor 1 made of a magnetic material is divided peripherally into two segments, N-pole and S-pole magnetizing units 1n, 1s so that the magnetically periodic angle of the stator 2 engaged with the inner surface of the rotor becomes approx. 180 deg.. The pole pair 2n, 2s of the stator 2 are respectively composed adjacent in peripheral direction to two teeth 3a, 3b of different outer peripheral areas, coils are wound on the teeth 3a, 3b in the same direction, thereby displacing at an angle theta from the electric center C1 of the stator pole produced when the coil A is energized to the mechanical center C2 of the pole pair attracting the rotor irrespective of the coil energization in the rotating direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brushless motor that is configured so that there is virtually no position where the torque becomes zero, so that smooth rotation of the rotor can be obtained. To explain the illustrated drawings, (1) #
The rotor has an annular shape made of a magnetic material, and its inner surface is divided into two in the circumferential direction into an N-pole magnetized part (111) and an 8-pole magnetized part (111).
111) From the magnetic field and K, the rotor (1)
The magnetic pole pairs (2!
l) and (2-) are respectively constructed by arranging two mirrors (38) and (5b) with different outer circumferential areas in adjacent brass tubes in the circumferential direction, and each of these two adjacent mirrors Φm (5M ),
(5b) by moving the coil towards the same friend *iiO,
The electrical center position of the black stator magnetic pole (however), which does not occur when the coil (4) is excited, and the approximate center position (0) of the six magnetic pole pairs that attract the rotor (1) regardless of coil excitation
2) are configured to be shifted by an angle θ in the rotation direction. v#) is a position detector fixed between the rotor (1) and the stator
detects the rotational position of the stator (
The rotor (1) is driven by intermittent current flowing through the rotor (1).

The method for configuring the stator (■) in the motor of the present invention is as follows:
As shown in Fig. 4 (4), the stator main material (2 &) with 4 slots of equal shape and size of each sickle, for example, the stator auxiliary material (2b) with 2 slots as shown in Fig. 4 (a). Alternatively, as shown in Fig. 4, the stator sub-materials (2G) having 4 slots but with different shapes and sizes of adjacent cods may be superimposed (8), etc., so as to be polished as shown in Fig. 5. -The outer circumferential area of (5a) is made to be larger red than the outer circumferential area of calligraphy (6b).Others mentioned above'yP4
#
1<54), the stator may be constructed so that the product is larger than the outer circumferential area of the shaft (3b). And Figure 4 0
) When the stator main material J material (2b) of FIG. Since the area of the teeth (3a) facing the magnetized portion of the rotor (1) is about 9, the interaction between the magnetic field from the coil (A) and the rotor (1) is also about . Therefore, the turns ratio of the coils of teeth (6) and (5b) should be set to about 1:2, so that when the coils are excited, the magnetic flux coming out of teeth (38) and (!lb) will be almost equal. In addition, after winding the coil around the stator Q), connect the teeth (3m) and (3b) with the fill wound in the same direction with a magnetic material (30) (3aL), ( 3b) If the gap is electrically integrated, the performance will be much better.

In general, in a two-phase PC brushless motor, there is a position where the torque becomes zero.In a conventional brushless motor, as shown in Figure 3, The magnetic period of the stator f2Y, which is divided into two parts and magnetized into the M-pole magnetized part (1t) and the 6-pole magnetized part (1'l), and is fitted on the inner surface of the rotor (1)' corner is 180'
At the same time, the stator magnetic pole pair (2'jl) facing the inner magnetized part of the rotor (1y) and the stator magnetic pole pair (2'jl), which are opposite to the inner magnetized part of the rotor (1y), have a single tooth with an even outer mm product on the rotor (1y). It has a configuration in which it protrudes at a symmetrical position corresponding to a rotation angle of 180@, and the mechanical center position of the magnetic pole pair coincides with the electrical center position of the stator magnetic pole, which becomes spontaneous when the coil hy is excited. Therefore, if there is one position detector (4)' for the rotor (1y), as shown by the dotted line in Fig. 6 showing the correlation between torque and rotation angle, 180° and 360° co)
The torque becomes zero depending on the angular position of rotor (1)'
This is the main cause of preventing smooth rotation. In order to ensure smooth rotation with the rotor (1), it is necessary to place a plurality of position detectors at key locations, which causes high costs.

Since the magnetic pole pairs (2m) and (2I) in the motor of the present invention are each composed of two teeth (3→, C3b) with different outer peripheral areas, the stator generated when the coil (4) is excited A feature is that the electrical center position (C1) of the magnetic poles does not overlap with the mechanical center position (C1) of the magnetic pole pair. The basic principle will be explained in detail with reference to FIG. 4 as follows. First, when a stator main material (2a) with four slots with uniform tooth shape and size as seen in JIF4 diagram (■) is combined with a bipolar magnetized four-slot rotor, the rotor is rotated. , the rotor magnetic pole center will stop at the position indicated by the arrow, that is, the mechanical center position of the magnetic pole pair 0
Next, as shown in Fig. 4), the stator main material (2
When the coil (2) is wound in the same direction around the two adjacent teeth (a) and energized, the center of the rotor magnetic pole will stop at the position indicated by the arrow, that is, the electrical center position of the pair of magnetic poles. Since this stop position coincides with the mechanical center position shown in Fig. 4 (1), there is no difference from a conventional brushless motor. When using stator auxiliary material (2b) of 0
．． The assembly stops at the position indicated by the arrow at the center of the rotor magnetic pole 1. This stop position does not coincide with the electrical stop position of the port in FIG. Therefore, the stator auxiliary material (2b) on the side of FIG.
If this is combined with the stator main material (2a) in FIG. 4 (4) above, the electrical center position (01) of the stator magnetic poles generated by coil excitation and the rotor (1) can be adjusted independently of coil excitation. Mechanical center position of attracting magnetic pole pair (02)
is shifted by 8 angles in the direction of rotation. In this way, the mechanical center position (02) of the &C magnetic pole pair deviates from the electrical center position t(01) of the stator magnetic pole.
This is due to the large area.

In the motor of the present invention, when the rotor (1) is in the position shown in Fig. 2 (4), the stator magnetic pole pairs (2n) and (2S
) When the coil (4) wound around the rotor (1) is excited, the detection range is the electrical angle range shown by the dotted line in both figures of FIG. (1n
) is the electrical angle range shown by the thick solid line in Figure 2 (6)), and the operating range where the stator magnetic pole pair and the rotor magnetized part attract each other is the electrical angle range shown by the chain line. Become. When the rotor (1) is in the position shown in Fig. 2 (B), its own stator magnetic pole pair (2!l) is on the right and (2m
) When the K-wound coil is excited, the detection list range falls into the electrical angle range I8''I shown by the dotted line in Figure 2 @ due to the configuration described above.
-In contrast, the N-pole magnetized part (1・) of the rotor (1)
.

The operating range of the torque exerted by k is the electrical angle indicated by the thick solid line in the example in FIG. 2, and the operating range in which the stator magnetic pole pair and the rotor magnetized portion attract each other is the electrical angle range indicated by the chain line.

Position detector (2) of the rotor (1) in the motor of the present invention
In Figure 19, which shows the correlation between torque and rotation angle, when the coil is energized, IC, ! is shown as a solid line. It-2 diagram (&), (1 in Bl
The torque becomes zero at angles of 80°* and 360°d, but the magnetic pole pair of the stator Since the electrical center position (01) of the magnetic pole pair of the stator C21 when excited is shifted by 8 degrees, regardless of whether the coil is excited or not, it will be delayed for 1 second in Fig. 2 (4).
The stator at an angle of o'*yohis 6o'o')■
This means that the magnetic pole pair has a torque that attracts the rotor (1).

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

If the above-mentioned torque generation mode is represented by a solid line in contrast to the dotted line showing the torque generation mode of the conventional brushless motor in FIG. 6, which shows the correlation between torque and rotation angle, the rotation angle is 00 to 18o0. In the case of , that is, the case shown in Figure 2 (4) above, the generated torque is the torque obtained by exciting the coil ① shown in the figure, and the torque obtained by the mutual attraction of the stator magnetic pole pair and the rotor. The result is a combination of the torque and the torque that is applied. Furthermore, the rotation angle is 180
Even in the case of 36° to 36o0, that is, the case shown in Fig. 2 above, the generated torque is the torque obtained by exciting the coil (to) as shown in the figure, and the torque obtained when the stator magnetic pole pair and rotor are mutually When they attract each other, they are combined with the torque obtained by separating them. Therefore, due to the repetition of the above-mentioned torque generation mode as the rotor rotates, the motor of the present invention draws a torque curve as shown by the solid line in FIG. 6 using only one rotor position detector 4). Since there is no position where the torque becomes zero, smooth rotation is maintained.

The OFF diagram shows a known circuit configuration in which the rotor position detector (4) and the stator boiler (4) are connected in parallel, and the five points in the circuit configuration diagram in FIG. 8 (4), β) In addition to showing the output voltage at point B, FIG. 6 also shows the five-point output.

In the motor of the present invention, the number of poles of the stator does not necessarily have to be as shown in FIG.
Of course, it may be an integral multiple of the above value.

[Brief explanation of drawings]

Figure 1 is a vertical sectional side view of the motor of the present invention, Figure 2 is a side view of the motor,
is an explanatory diagram showing the correspondence relationship between the rotor and the stator in an embodiment of the present invention, FIG. 3 (4), @ is an explanatory diagram showing the correspondence relationship between the rotor and the stator in a conventional brushless motor, and FIG. 4), @, p, (D) is an explanatory diagram showing an example of the structure of the stator in the motor of the present invention, FIG. 5 is a perspective view showing an example of the structure of the stator in the motor of the present invention,
Fig. 6 is a torque curve diagram showing the correlation between the rotation angle and torque of the motor of the present invention shown in Fig. 2 and the conventional motor shown in Fig. 3; FIG. 9 is a circuit diagram of the inventive motor, an output voltage diagram at (9) @2 points in the circuit diagram, and a torque curve diagram showing the correlation between the rotation angle and torque of the inventive motor. In the drawing, (1) is the rotor, (1n) is the N-pole magnetized part, and (1) is the rotor.
(2) is the S-pole magnetized part, (2) is the stator, (221):
1 and (21) are stator pole pairs, C5&> and (6
b) is two teeth with different peripheral areas, (4) and )
is the coil, (0 slope is the electrical center position of the stator magnetic pole,
('') is the mechanical center position of the magnetic pole pair. Patent applicant Nidec Corporation Agent Takanobu Ito, Li 2° y〉ri b xz concave (Hens Kaya, 8IiJ (B) + m 10 rotation angle ILC machine $, angle angle

Claims (1)

[Claims] A pair of magnetic poles of a stator is fitted into the inner surface of the cough rotor by partitioning the inner surface of the ill-shaped rotor into the same sections in the circumferential direction and fitting the N-pole magnetized section, the 8-pole magnetized section, and the KEKIII magnetized section into the inner surface of the cough rotor. Each stator is constructed by arranging two teeth with different outer peripheral areas adjacent to each other in the circumferential direction, and becomes spontaneous when a coil wound around each of these two adjacent teeth is excited. Since the center position of the magnetic pole and the center position of the magnetic pole pair that attracts the magnet regardless of coil excitation are appropriately shifted in the rotation direction, there is virtually no position where the torque is zero. A brushless motor configured as follows. 2. The two coils that make up each pair of magnetic poles of the stator and the coils wound around the teeth have a difference in the number of turns that is inversely proportional to the outer circumferential area of these two teeth. Scope of Utility Model Registration Request @ No. 1
Brushless motor as described in section.