JPH0357915A - Magnetic resolver - Google Patents

Abstract

PURPOSE:To reduce errors of the true roundness generated in a rotor and a stator by overlapping a salient pole wound with a sin phase coil and a salient pole wound with a cos phase coil with predetermined angles mechanically shifted from each other. CONSTITUTION:A stator 3 is provided inside a cylindrical rotor 1 having teeth 2 formed with a predetermined pitch (p) in an outer periphery of the rotor. The stator 3 is formed by overlapping two stator plates of the same shape with a non-magnetic member 33 held therebetween. Each stator plate has 4n (n being an integer), for example, 16 salient poles 3111-31116 or 3211-32116. Teeth 4 are formed with a pitch (p) opossite to the teeth 2 at ends of these salient poles. The phase of teeth formed in the salient poles is shifted every p/4 in the arranging order of the poles. When the salient pole wound with a sin phase coil is mechanically shifted 360 deg./(number or salient poles) from the salient pole wound with a cos phase coil, the error components generated in an inductance of the coils due to the error of the true roundness can be effectively removed.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention relates to an improvement in a magnetic resolver in which a stator is constructed by stacking two stator plates. BACKGROUND ART Such a magnetic resolver is described in the specification of Japanese Patent Application No. 1983-30988 filed by the present applicant. This magnetic resolver uses two stator plates each having a plurality of salient poles with teeth shaped at a constant pitch p at the tip. Stack them one on top of the other, shifting them by a certain amount to form the stator. With the stator configured in this way, one stator plate (2
) The 0° phase coil is excited by a voltage signal Ecosωt (E is the amplitude of the voltage, ω is the angular velocity, and t is the time).
(2) The 0° phase coil on the other stator plate is excited by a voltage signal E sin ωt (hereinafter, this coil is referred to as a COS phase coil), and the excitation causes each coil to Rotation is detected based on the voltage generated across the . In such a magnetic resolver, the mechanical error occurring in the phase difference p/4 between the teeth of the two stator plates is caused by the excitation signal F,si
This was removed by adjusting the electrical angles of nωt and Ecosωt. Problems to be Solved by the Invention In a magnetic resolver, if there is an error in the roundness of the stator or rotor, the gap between the rotor and stator will fluctuate as the rotor rotates. This causes high-order ripples in the detection signal of the magnetic resolver, resulting in poor detection accuracy. The magnetic resolver mentioned above cannot correct errors in roundness like this. The present invention has been made to solve these problems, and its purpose is to realize a magnetic resolver that can effectively reduce errors in roundness occurring in the rotor and stator. Means for Solving the Problems The present invention is a magnetic resolver configured as follows. (1) There are 4n salient poles with teeth formed at the pitch p at the tip (
(n is an integer), and the phase of the teeth of each salient pole is shifted by p / 4 according to the order of arrangement of the salient poles, and according to the order of arrangement, 0° salient pole, 90° ultimate, 180° ultimate, 270° salient pole. A stator comprising a stator plate forming a pole, two of these stator plates with a non-magnetic member in between, and the 0° ultimate of one stator plate and the 90° ultimate of the other stator plate, and Each (2) 0° phase coil and the coil wound around one stator plate have a voltage of E sin ωt (E is the amplitude of the voltage, ω is the angular velocity,
(t is time), and the other stator plate (2) is 0.
The 0° phase coil is a bare coil connected in series with a signal source excited by the voltage Ecosωt, adjacent 0° salient poles, and 90° (2) coils in which the 0° phase coils are connected in series. ．． 2... A 0゛ phase coil consisting of pairs of coils connected in series, separated by mechanical angles, and adjacent 180゜ salient poles, In this way, the coils connected in series are separated by a mechanical angle of l = 1 2... Bears are connected in series and the coils are separated by a mechanical angle of l = 1 2... A pair of 180° phase coils are connected in parallel, and the voltage difference between the 0° phase coil and 180° phase coil on one stator plate is calculated, and the difference between the 0° phase coil and 180° phase coil on the other stator plate is calculated. A magnetic resolver comprising: an arithmetic circuit that calculates the difference in voltage between both ends of the coil, adds these two differences, and detects a rotation detection signal of the rotor. (2) The 04-phase coil has adjacent 0° salient poles and 90” (
2) A coil f in which the 0° phase coils are connected in series.
=1. 2... Pairs of coils separated by a mechanical angle are connected in series, and pairs of coils separated by a mechanical angle are connected in series, and the 180° phase coils are adjacent to each other. 180° salient pole and 270
(2) The 0° phase coils are connected in series with l=1.
Claim (1) characterized in that the coil is formed by connecting in series pairs of coils located at positions separated by a mechanical angle of 2... in series. Magnetic resolver described in section.

<Operation> In the present invention, the salient pole around which the sine phase coil is wound and the salient pole around which the cos phase coil is wound are separated by 360°/(
By shifting the mechanical angle by the number of salient poles and overlapping them, it is possible to effectively eliminate the error margin caused in the inductance of the coil due to the error in roundness.

Embodiments> The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention, in which (a) is a plan view and (b) is a cross-sectional view taken along the line XX in FIG. 1 (a).

In the figure, 1 is a cylindrical rotor with teeth 2 formed at a constant pitch p on the inner circumference. 3 is a stator disposed inwardly of the rotor 1, and two stator plates 31 and 32 of the same shape are connected to a non-magnetic member 33.
It is constructed by overlapping the . Each stator plate 31 and 32 has 4n salient poles (n is an integer), for example, 16 salient poles 31l1 to 311+e and 321 to 32.
1+s is provided. There are two teeth at the tips of these salient poles.
Teeth 4 are formed with a pitch p facing the . In the diagram,
Although only the salient poles 311 to 311+s are shown,
The salient poles 3211 to 32l+s are arranged under the stator plate 31 in an overlapping manner. The phases of the teeth formed on the salient poles are shifted by p/4 according to the order in which the salient poles are arranged. for example,
With respect to the teeth of the salient pole 31l, the salient pole 3112.3113.
The phase of the 3114 teeth is p/4.2p/4.3, respectively.
Salient pole 311+, shifted by p/4. 3112, 311:+. 3114
are respectively 0° salient pole, 90° salient pole, 180' salient pole, and 27
The salient pole of the stator plate 32 is assumed to be 0° salient pole, and the salient poles of the stator plate 32 are repeated as follows: 0° salient pole, 90° ultimate, 180° salient pole, and 2700 salient pole.
It is the same as.

Coils 3121 to 312+e and 3221 to 3 are attached to the salient poles 311 to 311+a and 3211 to 32I, θ, respectively.
22+s is wound. 41 is a signal source that excites the coils 3121 to 312+s with a voltage signal Ecosωt (E is the voltage amplitude, ω is the angular velocity, and t is time); 42 is the coil 322;
This is a signal source that excites +~322+e with a voltage signal Es i nωt. For this reason, the coils 312+ to 312
1e is a sin phase coil, coil 322. ~322,g
becomes a cos phase coil. 5 is an arithmetic circuit that calculates the rotation of the rotor 1 based on both voltages of the coils. Here, we will explain how to connect the coil. Figure 2 is an explanatory diagram showing the coils wound around two stator plates. In the stator plate 31, as shown in FIG.
) The 0° phase coils are connected in series to form coils L1 to L8.
is formed.

Furthermore, on days 1 to L, the O° phase coil Lso is formed by connecting as shown in Fig. 3, and the 180° phase coil Ls is formed by connecting as shown in Fig. 4.
Form +. On the other hand, on the stator plate 32, adjacent coils are connected in series to form coils 1 and 8, as shown in FIG. Furthermore, ~L8 is connected as shown in Fig. 3 to transverse the 0° phase coil Lco, and connected as shown in Fig. 4 to the 180° phase coil LC.
Configure I. In addition, in Figures 3 and 4, the coils are connected only to coils located at positions separated by a mechanical angle of 180°, such as L5+L2, 1, and 6, but the mechanical angle of Coil bears located at separate locations are connected in series.

Also, pairs that are separated by a mechanical angle are connected in parallel to form a 0° phase coil and a 180° phase coil, but pairs connected in series are connected in series to form an O° phase coil. A 180° phase coil may also be constructed. For example, an O° phase coil may be constructed by connecting coils L and L5 in series and coils L3 and L7 connected in series. The stator plates 31 and 32 are overlapped with centers 01 and 02 and lines X, X, and X2 passing through the centers. As a result, between the stator plates 31 and 32, 2
Corresponding coils are superimposed with a mechanical angle offset of 2.5°.

FIG. 5 shows an example of the configuration of the arithmetic circuit 5 that calculates the rotation detection signal based on the voltage across the coils connected in this manner. In a magnetic resolver configured in this way, errors in roundness that occur in the rotor and stator are removed as follows. If there is an error in the roundness of the stator or rotor, when the rotor 1 rotates by θ, the inductance of each (2) 0° phase coil changes as follows. L=LO(1+Δ,sin(θ1F+)+Δ2sin
(2θ+9!)2)-...+ms i n (Nθ
)} ■L0: Inductance, F
ilψ2: phase difference, m: constant, Δ1. Δ2: amplitude of variation, N: number of teeth of the rotor, where θ is the rotation angle where one pitch of the teeth of the rotor is 360°.

In the equation (2), it is assumed that the inductance value has a linear relationship with the gap between the rotor and stator. In this formula,
Δ1 sin (θ1P+) + Δ2 sin (2θ+ψ2)・
... is an error caused by the gap between the rotor and stator changing as the rotor rotates due to an error in roundness.

Also, msin(Nθ
) is the signal component. Here, θ is set to 0° at the position indicated by X1 and X2 at the top of Fig. 2. In the stator plate 31 on which sine-phase coils are wound, the average inductance of each coil and ~L8 when the rotor rotates by θ is as follows, where Δ is the rate of variation. In these equations, I-1 to L8 are also used as the inductances of the coils L and L8. Therefore, the inductance LSO of the 0° phase coil is as follows. On the other hand, the inductance LS of the 1800-phase coil is given by the following formula. 1■ θ′ = θ+45°■ In the formula, 'l<=t, 17 l・2, 1t L, -even=L, LO'i・mu(/1△"sin'2e). These formulas If k is an odd number, the variation is not included. If k = 2, 6, ..., that is, if k = (4 (1-1) + 21), then ! = 1.2 ), the variation appears as a quadratic term.Here, from l〉Δ》Δ2, the quadratic variation can be ignored as it is 1/1 minute smaller.In the case of k=4.8... In other words, when expressed as k=41, the variation becomes a first-order term.The present invention is characterized by reducing this term.That is, k=4/
Then, Lso''I, {1+Δsin(4fθ)}.Therefore, the 41st-order component appears as an error.Similarly, in equation (■), Ls+=Lo(1+Δsin(4lθ')}=Lo(1
−Δsin(41θ)}, and the 41st order component becomes the error. Considering the 41st order error component and a certain part of the signal, the coil LG
Both @voltages VsO, V5, of O + LS, are Vsj = HA (J-Δs'm (4 no ρ no-m sin
Nθ) vswtThe difference between these voltages taken at underground l in Figure 5 is as follows. 'Jso − Vs+ ・2A (△Sin(41e)
+ms1n NOJ Cosut For the coil wound around the stator plate 32, similarly to the coil wound around the stator plate 31, the difference between the voltages VCO and VCI across the coils LCO and LCI taken by the amplifier 52 is as follows.

In this equation, ψ is the mechanical deviation between the stn phase coil and the COS phase coil. Final magnetic resolver output vsz taken by adder 53
o is as follows. VSrq = Vso − Vs+ + Vto −
Vt+=2A. ．． , Sin (Nθ+wt)■
The first term on the right side of the equation becomes the signal component, and the second term on the right side becomes the error component. To reduce the error component, it is necessary to choose ゛ψ such that the maximum value of is minimized. Among 41=4.8.12... in this equation, if we focus on 4l=4, which has a large variation, when F=22.5°, the second term of the formula becomes 1, resulting in an error. becomes the minimum. This angle corresponds to 360°/16.

Generally, if ψ=360″/number of salient poles, the error component will be minimized.

Although the embodiment uses an outer rotor type magnetic resolver, it may also have an inner rotor type configuration. Effects> According to the present invention, it is possible to effectively remove the 41st-order error component, which has a large effect on the signal component, by the variation that occurs in the detection signal due to the error in the roundness of the rotor and stator. This reduces the influence of roundness errors and provides highly accurate detection signals.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the present invention, Figs. 2 to 4 are explanatory diagrams showing how to connect the coils, and Fig. 5 is a diagram showing a specific example of the structure of the arithmetic circuit. . 1... Rotor, 2.5... Teeth, 3... Stator,
31.32... Stator plate, 311, ~ 311+s,
321, ~321+ s... salient pole, 312, ~312
+s. 322, ~322+ e...Coil, 41.4
2...Signal source, 5...Arithmetic circuit.

Claims (2)

[Claims] (1) There are 4n salient poles with teeth formed at the pitch p at the tip (
n is an integer), and the phase of the teeth of each salient pole is shifted by p/4 according to the arrangement order of the salient poles, and according to the arrangement order, 0° salient pole, 90° salient pole, 180° salient pole, 270° salient pole. A stator consisting of a stator plate forming a salient pole, two stator plates with a non-magnetic material in between, and the 0° ultimate of one stator plate and the 90° salient pole of the other stator plate stacked together. The coils wound around each of the salient poles and the coil wound around one stator plate have a voltage of Esinωt (E is the amplitude of the voltage, ω is the angular velocity,
t is time), and the coil wound around the salient pole of the other stator plate is excited by a voltage Ecosωt, and the adjacent coils wound at 0° and 90° are connected in series. For this pair of coils connected in series, (360°/number of salient poles 18) x i where (360°/number of salient poles 18) x i < 360° i = 1
, 2... Pairs separated by a mechanical angle of Coils wound around salient poles are connected in series, and in a pair of series-connected coils, (360°/number of salient poles 18)×i where (360°/number of salient poles 18)×i<360°i =1
, 2... Pairs separated by mechanical angles are connected in series, and the series-connected coils are connected in parallel to form a 180° phase coil, and a 0° phase coil on one of the stator plates. The rotation of the rotor is detected by taking the difference in the voltage across the coil and the 180° phase coil, taking the difference in the voltage across the 0° phase coil and the 180° phase coil on the other stator plate, and adding these two differences. A magnetic resolver equipped with an arithmetic circuit that detects signals. (2) The above-mentioned 0° phase coil consists of coils wound around adjacent 0° salient poles and 90° salient poles, which are connected in series. )×i However, (360°/number of salient poles 18)×i<360°i=1
, 2... Pairs separated by a mechanical angle of salient pole and 270
゜ Coils wound around salient poles are connected in series, and with a pair of coils connected in series, (360゜/number of salient poles 18)
×i However, (360°/number of salient poles 18) ×i<360°i=1
, 2... Pairs separated by mechanical angles are connected in series, and the series-connected pairs are connected in series. magnetic resolver.