JP2006275572A - Resolver device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor-stator structure of a resolver device for stably detecting highly accurate absolute accuracy and aimed at a thin type of a detector. <P>SOLUTION: This resolver device 20 is equipped with an annular rotor 21 formed out of a plurality of axially layered thin sheets and an annular stator 22 formed out of a plurality of axially layered thin sheets and disposed so as to confront the rotor. The ratio of the layer thickness of the rotor to that of the stator is caused to be 2 or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resolver device, and more particularly, to an improvement in a rotor / stator structure for stably detecting an angular position with high precision absolute accuracy (circumferential accuracy).

  The resolver device is used in various machines as an angle detector because of its advantages of a wide operating temperature range and excellent vibration resistance and durability.

  However, when such a resolver device is used, for example, as an angle detector of a direct drive motor mounted on a turning positioning device or the like, it is possible to stably detect an angular position with higher accuracy and absolute accuracy. There was a problem of being insufficient.

  In order to solve such a problem, a resolver structure aiming at increasing a tolerance for a relative thrust blur between the stator and the rotor is disclosed in, for example, Patent Document 1.

  5 and 6 are cross-sectional views of the main part showing the resolver structure disclosed in Patent Document 1. In FIG. 5, the resolver device 100 includes a ring-shaped stator iron core 103 in which a stator winding (coil) 102 is wound around each magnetic pole 101, and a laminated type that is rotatably disposed inside the ring-shaped stator iron core 103. Alternatively, it is composed of a sintered ring-shaped rotor 104.

In conventional general resolver apparatus, the thickness X ₂ with a thickness of X ₁ and the rotor 103 of the annular stator iron core 103 have been set in relation X 1 ₌ X _2, shown in Figure 5 in the resolver 100 are thickness _{X 1} of the annular stator iron core 103 is thinner than the thickness _{X 2} of the rotor 104, the thickness _{X 2} with a thickness of _{X 1} and the rotor 104 of the annular stator iron core 103 Is set to a relationship of X ₁ + 2α = X ₂ .

Further, in the resolver device 100 ′ shown in FIG. 6, the thickness X ₂ of the rotor 104 is thinner than the thickness X _{1 of} the annular stator iron core 103, and the thickness X ₁ of the annular stator iron core 103. And the thickness X _{2 of the} rotor 104 are set to have a relationship of X ₁ + 2α = X ₂ .

JP 2004-37306 A

  However, when the laminated thickness of the rotor 104 is smaller than the laminated thickness of the stator 103 as in the resolver device 100 ′, the magnetic flux generated from the stator 103 leaks to a portion other than the tooth surface of the rotor 104. Therefore, a stable detection signal could not be obtained.

  Also, the structure of the resolver device 100 is insufficient to obtain a stable detection signal. In particular, when the lamination thickness of the stator 103 is thin (3 mm or less), the magnetic flux generated from the stator 103 is transferred to the rotor 104. It was difficult to reach the tooth surface sufficiently. Therefore, in the resolver devices 100 and 100 ′, it is difficult to reduce the diameter and size of the stator 103 and the rotor 104 as well as highly accurate position detection.

  Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to be able to stably detect the angular position with high accuracy and to reduce the size of the detector. It is an object of the present invention to provide a rotor / stator structure of a resolver device.

  The above object of the present invention is to form an annular rotor formed from a plurality of thin plates laminated in the axial direction and an annular rotor formed from a plurality of thin plates laminated in the axial direction so as to face the rotor. In the resolver device provided with the stator, the lamination thickness ratio of the rotor to the stator is set to 2 or more.

  Also, the above object is effectively achieved by setting the lamination thickness ratio to 2 or 3.

  According to the resolver device of the present invention, the thickness of the rotor stack in the axial direction of the rotating shaft is more than twice the thickness of the stator stack in the axial direction of the rotating shaft. Since the magnetic flux generated from the coil reaches the tooth surface of the rotor stack without leaking, the angular position of the detected object can be stably detected with high accuracy and absolute accuracy. Thereby, even if the height of the rotor and the stator in the radial direction is made smaller than that of the conventional one, high detection accuracy can be maintained, so that the resolver device can be reduced in diameter and size. As a result, the resolver device according to the present invention can be applied as an angle detector of a small machine, and can improve the mountability.

  Furthermore, since the degree of freedom in layout in the thrust direction of the rotor and the stator can be increased, the tolerance management at the time of design can be simplified, and assembly and assembly can be easily performed.

  In addition, according to the resolver device of the present invention, the material cost can be reduced without reducing the detection accuracy by setting the rotor lamination thickness to be 2 to 3 times the stator lamination thickness.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing a main part of an electric motor including a resolver device according to an embodiment of the present invention. In the figure, a hollow shaft 12 is rotatably supported in a substantially cylindrical housing 11 of the motor 10, and the rotational torque of the motor is applied to the base end side (left side in FIG. 1) of the hollow shaft 12. The generated magnet 13 is integrally attached.

  Further, a stator 15 of a motor around which a coil 15 a is wound is disposed on the inner peripheral surface of the housing 11, and the motor 10 is configured by the rotor 14 including the hollow shaft 12 and the magnet 13 and the stator 15. It is configured.

  On the other hand, a resolver device 20 for detecting the angular position of the rotor 14 of the motor 10 is provided on the distal end side (right side in FIG. 2) of the hollow shaft 12. The resolver device 20 includes an annular rotor 21 that is integrally attached to the hollow shaft 12, and an annular stator 22 that is disposed so as to face the rotor 21. The rotor 21 and the stator 22 are composed of a plurality of thin plates stacked in the axial direction of the hollow shaft 12.

  FIG. 2 is a schematic cross-sectional view showing the main part of the resolver device 20. In the figure, a stator 22 has a stator pole 23 protruding from an annular base portion in an inner diameter direction (downward in FIG. 2), and a coil 24 is wound around the stator pole 23. A plurality of teeth 25 are formed on the outer peripheral surface of the rotor 21 along the circumferential direction so as to face the stator pole 23.

In the resolver device 20 according to the present embodiment, as shown in FIG. 2, the laminated thickness T ₁ of the rotor 21 in the axial direction is more than twice the laminated thickness T ₂ of the stator 22 in the axial direction (T ₁ ≧ 2T ₂ ).

  As a result, the magnetic flux generated from the coil 23 of the stator 22 can reach the tooth surface 25a of the rotor 21 without leaking, so that the angular position of the rotor 14 of the motor 10 can be stably detected with high precision absolute accuracy. can do. As a result, even if the heights of the rotor 21 and the stator 22 in the radial direction are kept thin, the angular position of the rotor 14 of the motor 10 can be maintained with high accuracy, so the diameter and size of the resolver device 20 can be reduced. Can be achieved.

  In addition, although the resolver apparatus 20 of this embodiment is an inner rotor type structure, even if an outer rotor type structure is employ | adopted, the same effect | action and effect can be acquired.

  Hereinafter, examples for verifying the effects of the above-described embodiment will be described with reference to the drawings.

  FIG. 3 is a cross-sectional view of a main part of the resolver device 20A according to the present embodiment. In the figure, the resolver device 20A includes a rotor 21A made of a hollow annular laminated core and a stator 22A made of an annular laminated iron core. The resolver device 20 of the above-described embodiment has an inner rotor type configuration, but the resolver device 20A of the present example has an outer rotor type configuration.

  On the inner peripheral surface of the rotor 21A, a plurality of salient pole-like teeth 25A are formed uniformly along the circumferential direction. Further, the annular base portion 26A of the stator 22A is provided with a plurality of salient pole-shaped stator poles 23A around which the coils 24A are wound evenly along the circumferential direction.

In this embodiment, the number of teeth 25A is 80 teeth, the number of stator poles 23A is 24 poles, the outer diameter is 100 mm, and the lamination thickness T ₂ (see FIG. 2) of the stator 22A in the axial direction is 2.4 mm. in the outer rotor type resolver apparatus 20A is (a laminate of a 0.2mm thickness of the iron plate), an experiment to measure the absolute accuracy [sec] of the angle detection when changing the stacked thickness T ₁ of the rotor 21 in the axial direction went. FIG. 4 is a graph showing the characteristics of the rotor / stator lamination thickness ratio and the absolute accuracy as a result of this experiment.

As is clear from the graph of FIG. 6, as the stacking thickness ratio (T ₁ / T ₂ ) increases, high-precision absolute accuracy is obtained. In particular, the range in which high-precision absolute accuracy is obtained is from a stacking thickness ratio (T ₁ / T ₂ ) of 2.0 or more.

Thus, according to the resolver apparatus according to the present invention, lamination thickness when the laminated thickness _{T 2} of the stator 22A is thin even _(T 2 = 2.4 mm), the laminate thickness _{T 1} of the rotor 21A stator 22A as described above experiment T _By setting it to 2 times or more of 2 (T ₁ ≧ 4.8 mm), it is possible to obtain the angular position with high accuracy and absolute accuracy.

Further, from the point where the lamination thickness ratio (T ₁ / T ₂ ) exceeds 2.0, the degree of improvement in absolute accuracy has become dull, and in particular, the lamination thickness ratio (T ₁ / T ₂ ) is 2.3. From this point on, the absolute accuracy is hardly improved. Therefore, in the resolver device according to the present invention, the lamination thickness ratio (T ₁ / T ₂ ) is preferably 2 to 3, particularly 2.0 to 2.3, from the viewpoint of thinning the resolver device. Is more preferable. Thereby, material cost can be reduced, maintaining a high precision absolute precision.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to this, In the range which does not deviate from the meaning, it can change suitably.

It is a schematic sectional drawing which shows the principal part of the electric motor provided with the resolver apparatus which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the said resolver apparatus. It is a schematic sectional drawing which shows the principal part of the resolver apparatus used for experiment. It is a graph of the experimental result which showed the characteristic of the lamination | stacking thickness ratio and absolute accuracy of a rotor / stator. It is a schematic sectional drawing which shows the principal part of the conventional resolver structure. It is a schematic sectional drawing which shows the principal part of the other conventional resolver structure.

Explanation of symbols

20, 20A resolver device 21, 21A rotor (rotor lamination)
22,22A Stator (stator lamination)
24, 24A Coil T ₁ Thickness of rotor stacking T ₂ Thickness of stator stacking

Claims (2)

An annular rotor formed from a plurality of thin plates laminated in the axial direction;
A resolver device comprising an annular stator formed of a plurality of thin plates stacked in an axial direction and arranged to face the rotor,
A resolver device characterized in that a lamination thickness ratio of the rotor to the stator is 2 or more. The resolver device according to claim 1, wherein the lamination thickness ratio is 2 to 3.

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