JP3013605B2 - Skew method of magnetic resolver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skewing method for a magnetic resolver as a high-resolution sensor used for, for example, rotation control of a direct motor or the like, and more particularly to a skew method.
The present invention relates to a skewing method that is highly effective and easy to assemble.

[0002]

2. Description of the Related Art Conventionally, when a magnetic resolver is rotating, a stay is stopped.
A magnetic flux density change (permeance change) usually occurs between the gap between the rotor core and the rotor core.
The output sine wave is distorted, which makes it impossible to perform, for example, rotation control accurately. Therefore, a so-called skew method is generally used to approximate a sine wave without distortion. That is, various skew methods have been conventionally used to prevent sine wave distortion due to generation of harmonics based on magnetic flux density change. 4 to 6 show an example of a conventional skew method. FIG. 4 shows the magnetic pole pitch P of the rotor core 1 as the magnetic pole pitch P _S of the stator core 2.
This is an equivalent pitch skew method in which a skew is equivalently performed by setting a value larger (or smaller). FIG. 5 shows that the rotor core 1 and the stator core 2 have the same magnetic pole pitch P, but the stator core 2 is obliquely inclined with respect to the rotor core 1 as shown in FIG. Oblique skew method.

[0003]

In the equivalent pitch skew method shown in FIG. 4, since the magnetic pole pitch differs between the stator core and the rotor core, when the number of magnetic poles (the number of teeth) is small, the skew is increased. -There was a disadvantage that the effect was insufficient. In the oblique skew method as shown in FIGS. 5 and 6, it is difficult to machine the key groove obliquely, and it is necessary to use a jig. There were inconveniences such as unbalance.

[0004]

SUMMARY OF THE INVENTION In the present invention, when the stator core and the rotor core of a magnetic resolver are constituted by a laminate of a plurality of thin magnetic plates, each of the magnetic plates constituting the laminate is provided. A plurality of key grooves are provided on each sheet at a predetermined interval θ, and each time the magnetic plates are stacked one by one, the key grooves are shifted while being stacked.

[0005]

According to the present invention, when the iron core is laminated, the key is
A predetermined skew angle S can be obtained simply by shifting the groove and stacking.
Can be obtained, and a stator core or a rotor core having such a skew groove can be easily manufactured.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 shows a first embodiment of the present invention. In the magnetic resolver of the embodiment, a rotor core 3 is used.
A stator core 4 is disposed inside the stator core 4. The stator core 4 has, for example, 16 magnetic poles 4A, 4B, 4C,.
・ 4O and 4P are provided. Each magnetic pole is provided with a magnetic pole coil (not shown). In this case, each magnetic pole has an equally spaced pole array of A, B, -A, -B, A, B, -A,... Similarly to the structure of the linear pulse motor. Each of the magnetic poles has one key groove 5A, 5B, 5C,.
A total of 16 Ps are provided.

The interval between 16 key grooves arranged at equal intervals on the circumference of the stator core 4, that is, the key groove angle θ is expressed by the general formula (1). θ = (360 ° / K) ± (S / K) (1) where K is the number of key grooves and S is the skew angle (S = P /
N) and P are magnetic pole pitches, P = 360 ° / K, and N is an integer set corresponding to the harmonic order causing distortion. In this first embodiment, K = 1
6, P = 360 ° / 16 = 22.5 and N = 3, the key groove angle θ is given by the following equation (2). θ = 22.5 ± 0.47 (2) Here, the number of key grooves K is the same as the number of magnetic poles. The integer N is usually desirably about 3.

FIG. 2 is a view for explaining a method of stacking a plurality of magnetic plates constituting the stator core 4 in the first embodiment. Each magnetic plate having the same shape and having the same key groove is formed. (16 sheets in total) with key grooves (5A, 5B, 5C ...
When the sheets are stacked one by one while being shifted by the width of 5P), the stays stacked obliquely as a whole as shown in FIG.
Tacos 4 can be formed. At this time, the degree of the inclination is represented by the skew angle S. In this embodiment, since N = 3, the skew angle S is １ ／ of the magnetic pole pitch P.

Second Embodiment FIG. 3 shows a second embodiment of the present invention. The difference from the first embodiment is that a key groove is provided on the rotor core 3 side. And the key groove angle θ is shifted for each key groove.
In the case of this embodiment, it is not necessary to arrange the key grooves corresponding to the magnetic poles, and therefore, it is characterized in that more key grooves can be provided than the number of magnetic poles. For this reason, the degree of cancellation of harmonics is smooth, and the skew effect is further enhanced.

[0010]

According to the present invention, since a large number of key grooves can be provided on the rotor core side or the stator core side of the magnetic resolver in accordance with the number of magnetic poles as described above, an extremely high skew effect can be obtained. Not only can be obtained, but also the stator core or rotor core having such a skew groove can be easily assembled. In particular, when a key groove is provided on the rotor core side, it is excellent in that the degree of cancellation of harmonics is further smoothed.

[Brief description of the drawings]

FIG. 1 is a plan view showing an arrangement of key grooves provided on a stator core side according to a first embodiment of the present invention.

FIG. 2 is a main part side view for explaining a method of stacking the stator core shown in FIG. 1;

FIG. 3 is a plan view of a rotor core and a stator core showing a second embodiment of the present invention.

FIG. 4 is a view for explaining a first example of a conventional magnetic resolver skew method.

FIG. 5 is a view for explaining a second example of the conventional magnetic resolver skew method.

FIG. 6 is a diagram for supplementarily explaining a second example of a conventional magnetic resolver skew method.

[Explanation of symbols]

 3: rotor core 4: stator core 4A to 4P: magnetic pole 5A to 5P: key groove

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G01D 5/00-5/252 G01D 5/39 G01B 7/00-7/34

Claims (3)

(57) [Claims] A stator and a rotor of a magnetic resolver.
In a skewing method of a magnetic resolver in which a core is composed of a laminate of a plurality of thin magnetic plates, a plurality of key grooves in a rotor core of the magnetic resolver or a magnetic plate of a stator core are represented by the formula θ = ( 360 ° / K) ± (S / K) degrees are provided at intervals of a key groove angle θ, and when the magnetic plates are stacked, they are stacked while shifting the key grooves. A skewing method for a magnetic resolver, wherein a skew angle S is obtained.
Here, S = P / N, P is the magnetic pole pitch, N is an integer, K is the number of key grooves, and S is the skew angle. 2. A skew method for a magnetic resolver according to claim 1, wherein said key groove is provided on said stator core. 3. The skewing method according to claim 1, wherein said key groove is provided on said rotor core side.