JPH0139103Y2 - - Google Patents

Description

[Detailed Description of the Invention] a. Industrial Application Field The present invention relates to a hybrid stepping motor.

b. Prior Art As shown in FIG. 1, this type of stepping motor has a cup-shaped core body 2 ₁ , 2 formed by stacking steel plates on both ends of a cylindrical permanent magnet 1 magnetized in the longitudinal direction. The rotor 3 has a structure in which the rotor ₂ is fitted. The core bodies 2 ₁ and 2 ₂ are assembled by stacking steel plates having a large number of equally pitched protrusions on the outer periphery in such a manner that the protrusions of the individual steel plates coincide, and the protrusions of the individual steel plates provide the rotor teeth. 4 is formed.

In a conventional motor, rotor teeth 4 ( _hereinafter referred to as
The rotor teeth 4 of the core body ₂₂ located on the S pole side (hereinafter referred to as the rotor teeth on the S pole side) are 1/1/2 of each other as shown in the figure.
It is shifted by 2 pitches. This operation of shifting the rotor teeth 4 is performed using a special jig when assembling the rotor. As the number of teeth on the rotor increases, a high-precision jig is required and assembly is time-consuming. Conventionally, the number of rotor teeth 4 has been reduced to 50 or less, as shown in Figure 2. many.

When the number of rotor teeth 4 is set to 50, the basic step angle of the motor is 1.8° (200 steps per rotation), but a smaller step angle (for example, 0.9°) is often required. Conventionally, instead of increasing the number of rotor teeth, a method has been adopted in which the excitation sequence is devised to electrically reduce the step angle.

c. Problems to be Solved by the Invention The electrical method described above often has the following problems compared to the method of increasing the number of rotor teeth to reduce the step angle.

The drive circuit becomes complicated and expensive.

Efficiency is low.

Torque is small.

Stopping accuracy is not good.

The crash at the stop position is large.

Damping time is long.

Torque fluctuation is large.

Therefore, there was a strong demand for a stepping motor with 50 or more rotor teeth.

The purpose of this invention is to be able to easily and accurately manufacture a rotor, even when the number of rotor teeth is larger than that of conventional motors, thereby obtaining smaller step angles without using electrical methods. The object of the present invention is to provide a hybrid stepping motor that can perform the following steps.

d Means for solving the problem A rotor that has a permanent magnet magnetized in the motor axis direction in the center and has N-pole side rotor teeth and S-pole side rotor teeth on the N-pole side and S-pole side of the permanent magnet, respectively. In a hybrid stepping motor having a stator including a first half stator core and a second half stator core having stator teeth corresponding to the N pole side rotor teeth and the S pole side rotor teeth, respectively, the N pole side rotor teeth and the number of rotor teeth on the S pole side Z _R
are equal and are multiples of 4, and the rotor teeth on the N-pole side and the rotor teeth on the S-pole side are arranged at equal pitches T _R on the outer periphery of the rotor core parallel to the rotor axis, with the axes of each tooth aligned, The first half stator core and the second half stator core each consist of first to eighth salient stator poles 50 ₁ , 50 ₂ . . . 50 ₈ arranged at equal pitches, and each salient stator pole 50 ₁ , 50 ₂ . ...50 ₈ has small stator teeth arranged at equal pitch T _S for each stator salient pole on the surface facing the rotor core, and the first to eighth stator salient poles 50 ₁ of the first half stator core, 50 ₂ ... 50 ₈ The stator teeth closest to the center of each stator salient pole are 0, 1/4T _R and 1/4T R respectively with respect to the rotor teeth.
2T _R , -1/4T _R , 0, 1/4T _R , 1/2T _R , -1/4T _R , and the first to eighth stator salient poles 50 of the rear stator core ₁ , 50 ₂ ... 50 ₈ The upper stator small teeth are the first to eighth front half stator salient poles 50 ₁ , 50 ₂ ... 50 when viewed from the motor axis direction.
The above _- mentioned problem has been solved by a hybrid stepping motor characterized in that the stepping motor is arranged so as to be offset by 90 degrees with respect to the small stator teeth on the upper part of the stator.

e. Effect of the invention The stator of the motor of the invention is formed by joining a front half stator and a rear half stator in such a manner that one of them is rotated by 90 degrees with respect to the other.

If the stator is configured in this way, it will be equivalent to the case where the N-pole side rotor teeth and the S-pole side rotor teeth are shifted by 1/2 pitch as in the conventional motor, so the motor of the present invention is different from the conventional motor described above. A similar stepping operation is performed.

f Embodiments The present invention will be described in detail below with reference to embodiments shown in the drawings.

In the embodiment of the stepping motor according to the invention shown in FIG.
The number Z _R is set to Z _R =100. Note that this number of teeth can be arbitrarily set as long as it satisfies the relationship Z _R =4N (N is an integer).

As shown in FIG. 5, the rotor 30 has a structure in which a north-pole side core body 20 ₁ and a south-pole side core body 20 ₂ are fitted into both ends of the magnet 10, respectively, as in the conventional motor. The rotor teeth 40 provided on these core bodies have their longitudinal axes aligned with each other. In this respect, the configuration differs from conventional motors in which both teeth are shifted by 1/2 pitch.

On the other hand, the stator 50 shown in FIG. 5 is divided into two parts in the stacking direction, and a first half stator 50a facing the north pole side core and a second half stator 50b facing the south pole side core are connected in cascade. It has a structure. As shown in FIG. 3, each of the stator cores 50a and 50b has eight salient poles 50 ₁ arranged at a pitch of 45°, similar to the stator of the conventional motor.
50 ₂ ...50 ₈ , and each of these salient poles has eight (nine for the salient poles 50 ₁ and 50 ₅ ) small stator teeth 60 protruding from the surface facing the rotor 30. be. Note that the pitch T _S of the stator small teeth 60 is the pitch T _R of the rotor teeth 40 (=
360°/number of rotor teeth Z _R = 360°/100=3.6°), it is set to be 0.9T _R T _S 1.1T _R.

The nine small teeth provided on the salient poles 50 ₁ and 50 ₅ are as follows:
By removing the small teeth located in the center, the number of small teeth can be the same as that of the other salient poles (eight).

Now the rotor teeth 40 and stator small teeth 60
Considering the correspondence relationship with reference _{to FIG .}
In the group of 0, the small tooth closest to the center line of the small tooth group (meaning the bisector of the center of the small teeth at both ends on each salient pole) is 0, 1/4T _R , 2/4T _R , −1/4T _R , 0,
They are provided so as to be shifted by 1/4T _R , 2/4T _R , and -1/4T _R . In addition, when the pitch T _R of the rotor teeth 40 and the pitch T _S of the stator small teeth 60 are T _S = T _R ,
Not only the small teeth near the center line but also the surrounding small teeth naturally follow the relationship between the rotor teeth and the stator teeth.

The correspondence between the rotor teeth and the stator small teeth is the number of teeth 4 on the rotor 3 in the case of a conventional motor.
Since the number N obtained by dividing T _R by 4 is not an integer, for example, in the case of the motor shown in Figure 2, T _R /4=
50/4=12.5. Therefore, as shown in the figure, the small teeth 6 of each stator salient pole 5 ₁ , 5 ₂ . . . 0 ₈
are provided in exactly the same manner, thereby obtaining the above relationship. The stator 5 shown in the figure has no directionality, and if the positions of the salient poles are aligned, the small teeth 6 of each salient pole will also match with each other.

Meanwhile, the rotor 30 of the motor according to the present invention
is the number of rotor teeth that satisfies the relationship Z _R /4 = integer
Since Z _R =100, the above relationship cannot be obtained if the stator small teeth 60 of each salient pole are arranged in the same manner. Therefore, as shown in Fig. 3, the arrangement position of the small teeth 60 of each salient pole (pitch T _S is the same)
The above relationship is obtained by changing . In that case, the salient poles 50 ₁ and 50 ₅ , 50 ₃ and 50 ₇ are each provided with small teeth 60 symmetrically with respect to the center line of the salient poles, and therefore the small teeth of the salient poles 50 ₁ and 50 ₅ and the protrusion pole 50 ₃ and 5
As a result, the small teeth of 0 ₇ are arranged in the same manner.

Therefore, when the stator shown in FIG. 3 and the stator rotated by 90 degrees are superposed, each of the stator salient poles 50 ₁
The ~ ₅₀₈ tooth groups are offset by 1/2 pitch from each other.

The stator 50 of the motor of the present invention has the first half stator 50a and the second half stator 50b configured as described above, one of which is rotated by 90 degrees, that is, the axis of one stator X-X
are connected to each other so as to overlap the axis Y-Y of the other stator.

If the stator 50 is configured in this way, it will be equivalent to the case where the rotor teeth on the N-pole side and the rotor teeth on the S-pole side are shifted by 1/2 pitch as in the conventional motor. (In this example, the step angle is
0.9°). In addition, in the above example,
Although the stator is wound in a two-phase four-pole structure, it is of course possible to wind it in a four-phase structure.

g. Effects of the invention The stepping motor according to the invention uses a rotor in which the longitudinal axes of the rotor teeth on the N-pole side and the rotor teeth on the S-pole side are aligned as described above, so when assembling the rotor, No need for a high-precision jig to shift the rotor teeth by 1/2.
Moreover, since the rotor teeth can be cut using a cutting machine after the rotor is assembled, the workability during assembly is excellent, and the rotor teeth with a small pitch (for example, the 100 rotor teeth shown in the example) can be cut with high precision. and can be easily formed. Therefore, according to the present invention, a stepping motor with a small step angle can be provided at low cost.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the structure of the rotor of a conventional hybrid stepping motor, Fig. 2 is a conceptual diagram showing the arrangement and structure of the rotor and stator of the conventional motor, and Fig. 3 is a perspective view showing the structure of the rotor of a conventional hybrid stepping motor. A conceptual diagram showing the arrangement and configuration of the rotor and stator according to an embodiment of the ping motor. Fig. 4 is a diagram showing the correspondence relationship between the rotor teeth and the small stator teeth in the front half. Diagram showing the correspondence with the rear stator small teeth,
FIG. 6 is a half-cut longitudinal sectional view of the stepping motor according to the present invention. 10... Magnet, 20 ₁ , 20 ₂ ... Core body, 30
... Rotor, 40 ... Rotor teeth, 50 ... Stator, 50a ... First half stator, 50b
...Second half stator, 50 ₁ to 50 ₈ ... Stator salient poles, 60 ... Stator small teeth.

Claims (1)

[Scope of Claim for Utility Model Registration] A rotor that has a permanent magnet magnetized in the direction of the motor axis in the center and has N-pole rotor teeth and S-pole rotor teeth on the N-pole side and S-pole side of the permanent magnet, respectively. In a hybrid stepping motor having a stator including a first half stator core and a second half stator core each having stator teeth corresponding to the N-pole rotor teeth and the S-pole rotor teeth, the N-pole rotor Teeth and number of rotor teeth on S pole side Z _R
are equal and are multiples of 4, and the rotor teeth on the N-pole side and the rotor teeth on the S-pole side are arranged at equal pitches T _R on the outer periphery of the rotor core parallel to the rotor axis, with the axes of each tooth aligned, The first half stator core and the second half stator core each consist of first to eighth salient stator poles 50 ₁ , 50 ₂ . . . 50 ₈ arranged at equal pitches, and each salient stator pole 50 ₁ , 50 ₂ . ...50 ₈ has small stator teeth arranged at equal pitch T _S for each stator salient pole on the surface facing the rotor core, and the first to eighth stator salient poles 50 ₁ of the first half stator core, 50 ₂ ... 50 ₈ The stator teeth closest to the center of each stator salient pole are 0, 1/4T _R and 1/4T R respectively with respect to the rotor teeth.
2T _R , −1/4T _R , 0, 1/4T _R , 1/2T _R , −1/4T _R , and are arranged so as to produce a deviation of 2T R , −1/4T R , 0, 1/4T R , 1/2T R , −1/4T R on the first to eighth stator salient poles of the rear stator core. The stator teeth are arranged so as to be offset by 90° with respect to the stator teeth on the first to eighth front half stator salient poles 50 ₁ , 50 ₂ . . . 50 ₈ when viewed from the motor axis direction. A hybrid stepping motor characterized by: