Resolver stator and resolver

Abstract

A resolver stator (2) provided in a resolver (1) that detects the rotation angle of a resolver rotor (3) has a sheet-like substrate (26). Input coils (11, 12) to which an input signal (S1) is input, an output coil (15) that outputs an output signal (S3), and cancel coils (21, 22) are arranged on the substrate (26). A signal (S2) having a phase that cancels out the input signal (S1) is input to the cancel coils (21, 22).

Description

[Technical field]

[0001] The present invention relates to a resolver stator and a resolver including the resolver stator. [Background technology]

[0002] Conventionally, various methods have been proposed for improving the signal-to-noise ratio (S / N ratio) of a sheet-type resolver having a resolver stator and a resolver rotor with a sheet-shaped coil (also called a "sheet coil"). For example, Patent Document 1 discloses a resolver attached to a motor, which includes a substrate made of a nonmagnetic conductor, a plurality of coil patterns (coils) formed on the substrate, and a magnetic core disposed between the substrate and the plurality of coils. According to Patent Document 1, it is said that the influence of the alternating magnetic field of the motor can be eliminated by shielding the plurality of coils with a substrate made of a nonmagnetic conductor. It is also said that the magnetic core can prevent the magnetic flux of the coil from being canceled by the action of the substrate made of a nonmagnetic conductor, thereby improving the S / N ratio. In the resolver of Patent Document 1, a detection coil or excitation coil and a transformer coil are formed on the same substrate as the plurality of coils. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-226907 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a resolver such as that disclosed in Patent Document 1, parasitic capacitance may occur between multiple coils formed on the same substrate. Here, parasitic capacitance refers to capacitance (capacitor component) that exists parasitically inside an electronic component or in an electronic circuit due to a physical structure, regardless of the design intent. In a resolver such as that disclosed in Patent Document 1, noise may propagate from the detection coil or excitation coil to the transformer coil, or vice versa, through such parasitic capacitance, resulting in a decrease in the S / N ratio.

[0005] The resolver stator and resolver of the present invention have been devised in view of the above problems, and one of the objects of the present invention is to improve the S / N ratio and improve the detection accuracy of the resolver. However, the present invention is not limited to this object. Another object of the present invention is to achieve an effect that cannot be obtained by the conventional technology, which is derived from each configuration shown in the below-mentioned embodiment of the invention. [Means for solving the problem]

[0006] The disclosed resolver stator and resolver can be realized as the aspects (application examples) disclosed below, and solve at least a part of the above problems.

[0007] The resolver stator disclosed herein is a resolver stator provided in a resolver that detects the rotation angle of a resolver rotor, and includes a sheet-shaped substrate on which an input coil to which an input signal is input, an output coil to which an output signal is output, and a cancel coil are arranged, and a signal having a phase that cancels the input signal is input to the cancel coil.

[0008] The disclosed resolver includes the resolver stator according to the above aspect, and a resolver rotor disposed axially opposite the resolver stator. Effect of the Invention

[0009] According to the disclosed resolver stator and resolver, the S / N ratio can be improved, and the detection accuracy of the resolver can be improved. [Brief description of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view of a resolver to which a resolver stator according to an embodiment of the present invention is applied, cut in an axial direction; [Diagram 2] FIG. 2 is a schematic diagram showing the structure of the resolver in FIG. [Diagram 3] 3 is an enlarged schematic view of a main part (part X in FIG. 2) of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A resolver stator and a resolver as embodiments will be described with reference to the drawings. The embodiments described below are merely examples, and are not intended to exclude various modifications and application of techniques not explicitly described in the following embodiments. Each configuration of the present embodiment can be modified in various ways without departing from the spirit of the embodiment.

[0012] The resolver of the embodiment is a detector (sensor) that detects the rotation angle of a resolver rotor (hereinafter also simply referred to as "rotor") that rotates about a rotation axis C relative to a resolver stator (hereinafter also simply referred to as "stator"). The resolver stator of the embodiment is a stator included in such a resolver.

[0013] The stator of the embodiment has a sheet-shaped substrate. An input coil to which an input signal is input, and an output coil to which an output signal is output are arranged on the substrate. A cancel coil to which a signal of a phase that cancels the input signal is input is further arranged on the substrate. The stator of the embodiment aims to reduce the influence of a part of the input signal (noise) that interferes with the output signal (suppression of a decrease in the S / N ratio) by unintentionally electrically coupling the input coil and the output coil provided on the same substrate, and is characterized in that the noise is cancelled out by the signal input to the cancel coil. This improves the S / N ratio and improves the detection accuracy of the resolver.

[0014] In the following description, the direction in which the rotation axis C extends (rotation axis direction) is defined as the axial direction, and the direction perpendicular to the axial direction and away from the rotation axis C and toward the rotation axis C is defined as the radial direction. In addition, in the radial direction, the side of the rotation axis C is defined as the radially inner side, and the opposite side (the side away from the rotation axis C) is defined as the radially outer side. The direction perpendicular to the axial direction and going around the rotation axis C is defined as the circumferential direction.

[0015] [1. Configuration] FIG. 1 is an axially cut and exploded perspective view of a resolver 1 to which a stator 2 (resolver stator) of this embodiment is applied, and FIG. 2 is a schematic diagram showing the configuration of the resolver 1. The resolver 1 is applied to, for example, a servo motor (not shown). As shown in FIGS. 1 and 2, the resolver 1 includes a stator 2 and a rotor 3 (resolver rotor). The rotor 3 is disposed with a small gap in a first axial direction D1 relative to the stator 2. Hereinafter, the direction opposite to the first axial direction D1 in the axial direction is referred to as a second direction D2.

[0016] The stator 2 and the rotor 3 each have a sheet-shaped substrate 26, 36 as shown in Fig. 1. A plurality of coils 11-15, 21-25 (sheet coils) are formed (printed) on the substrates 26, 36, respectively, as shown in Fig. 2. In other words, the resolver 1 is a sheet-type resolver having a plurality of sheet coils 11-15, 21-25. By using the sheet coils in this manner, the coils 11-15, 21-25 can be made thinner, and as a result, the resolver 1 can be made thinner.

[0017] In this embodiment, the resolver 1 is a composite resolver (double speed resolver) that detects a rotation angle using a plurality of shaft multiplier angles, and includes a first coil group 10 including first excitation coils 11 and 12 with a shaft multiplier angle of aX (a is a natural number) and a second coil group 20 including second excitation coils 21 and 22 with a shaft multiplier angle of bX (b is a natural number, 1≦b≦a-1). For example, the shaft multiplier angle of the first excitation coils 11 and 12 may be nX (n is a natural number equal to or greater than 2), and the shaft multiplier angle of the second excitation coils 21 and 22 may be 1X. The larger the value of n, the more the angular resolution of the resolver 1 is improved. In the present invention, the shaft multiplier angle of the second coil group 20 does not have to be 1X. However, it is preferable that the shaft multiplier angle of the second coil group 20 is a shaft multiplier angle that is a natural number smaller than n.

[0018] The resolver 1 is a two-input, one-output resolver. The first coil group 10 includes five coils, namely, two first excitation coils 11 and 12, a first detection coil 13, a first transmission coil 14, and a first reception coil 15 (transformer coil). The two first excitation coils 11 and 12 include a first sine excitation coil 11 and a first cosine excitation coil 12. The second coil group 20 includes five coils, namely, two second excitation coils 21 and 22, a second detection coil 23, a second transmission coil 24, and a second reception coil 25. The two second excitation coils 21 and 22 include a second sine excitation coil 21 and a second cosine excitation coil 22.

[0019] The first excitation coils 11 and 12, the first receiving coil 15, the second excitation coils 21 and 22, and the second receiving coil 25 are provided on a first substrate 26 of the stator 2 and are electrically connected to a signal processing circuit 4 (external device). Hereinafter, these coils 11, 12, 15, 21, 22, and 25 are collectively referred to as "stator side coils". A first input signal S1 (input signal) generated by the signal processing circuit 4 is input to the first excitation coils 11 and 12, and a second input signal S2 generated by the signal processing circuit 4 is input to the second excitation coils 21 and 22. The first receiving coil 15 outputs a first output signal S3 (output signal) to the signal processing circuit 4, and the second receiving coil 25 outputs a second output signal S4 to the signal processing circuit 4.

[0020] The resolver 1 of this embodiment aims to reduce the influence of a part (noise) of the first input signal S1 that interferes with the first output signal S3 due to unintentional electrical coupling between the first excitation coils 11, 12 and the first receiving coil 15 provided on the same first substrate 26. In the resolver 1, the above-mentioned noise is cancelled (cancelled) by the second input signal S2 input to the second excitation coils 21, 22. In other words, the first excitation coils 11, 12 are the above-mentioned "input coils", the first receiving coil 15 is the above-mentioned "output coil", and the second excitation coils 21, 22 are the above-mentioned "cancellation coils".

[0021] The stator 2 is a component fixed to a casing (not shown) of an apparatus to which the resolver 1 is applied (for example, a servo motor or an apparatus to which a servo motor is attached), and has a sheet-like first substrate 26. In this embodiment, the stator 2 further includes a core 27 arranged so as to overlap with the first substrate 26 in the axial direction, and a metal plate 28 arranged so as to overlap with the core 27 in the axial direction, as shown in Figs.

[0022] The first substrate 26 is a thin sheet made of a non-conductive resin (e.g., polyimide). As shown in Fig. 1, the first substrate 26 has, for example, an annular substrate portion 26A that is developed around a rotation axis C, and a rectangular connector portion 26B that is provided so as to protrude radially outward from a part of the outer periphery of the substrate portion 26A.

[0023] The stator side coils shown in Fig. 2 are formed on the substrate portion 26A. As shown in Fig. 2, the substrate portion 26A has a thickness in the axial direction that is greater than that of the stator side coils. The stator side coils are formed on the substrate portion 26A without being exposed in the axial direction (i.e., so as to be built into the substrate portion 26A). In other words, both sides of the stator side coils in the axial direction are covered with a polyimide sheet that forms part of the substrate portion 26A. Each of the stator side coils is made of, for example, copper foil.

[0024] 1, its radially outer end is connected to the connector portion 4A of the signal processing circuit 4. This electrically connects each of the stator side coils to the signal processing circuit 4. Note that the signal lines of the stator side coils are made of, for example, copper foil.

[0025] The shape and radial and circumferential arrangement of the stator side coils in the substrate portion 26A are not particularly limited. In the present embodiment, as an example, as shown in Fig. 2, the first excitation coils 11 and 12, the first receiving coil 15, the second excitation coils 21 and 22, and the second receiving coil 25 are arranged in this order from the outside to the inside in the radial direction with a gap therebetween.

[0026] 1, the substrate portion 26A is provided with four regions R1, R2, R3, and R4 that are radially spaced apart from one another and form an annular shape centered on the rotation axis C. The stator side coils are disposed in the four regions R1, R2, R3, and R4, respectively. Hereinafter, the four regions R1, R2, R3, and R4 are referred to as a first region R1, a second region R2, a third region R3, and a fourth region R4, in that order from the region located radially outward toward the inside.

[0027] The first excitation coils 11, 12 are formed in a first region R1 provided at the outermost radial side, and n magnetic pole pairs are formed in the first region R1. In the first region R1, the two first excitation coils 11, 12 may be arranged so as to overlap in the axial direction as shown in Fig. 2, or may be arranged side by side in the radial direction. Alternatively, the two first excitation coils 11, 12 may be arranged so as to be staggered in the circumferential direction at the same position in the axial direction.

[0028] The first receiving coil 15 is formed in a second region R2 disposed adjacent to the first region R1 on the radially inner side. That is, the first receiving coil 15 is disposed adjacent to the first excitation coils 11, 12 when viewed from the axial direction. The first receiving coil 15 is a transformer coil that receives a signal from the first transmitting coil 14, and is formed by arranging a winding in a spiral shape around the rotation axis C in the second region R2.

[0029] The second excitation coils 21, 22 are formed in a third region R3 adjacent to the second region R2 on the radially inner side, and form one magnetic pole pair in the third region R3. That is, the second excitation coils 21, 22 are adjacent to the first receiving coil 15 when viewed from the axial direction. In other words, the first receiving coil 15 is disposed between the first excitation coils 11, 12 and the second excitation coils 21, 22, and the second receiving coil 25 is not disposed between the first receiving coil 15 and each of the first excitation coils 11, 12 and the second excitation coils 21, 22. The two second excitation coils 21, 22 may or may not be disposed so as to overlap in the axial direction in the third region R3, as shown in FIG. 2, similar to the two first excitation coils 11, 12.

[0030] The second receiving coil 25 is formed in a fourth region R4 that is provided at the innermost radial position. The second receiving coil 25 is a transformer coil that receives a signal from the second transmitting coil 24, and is formed by arranging a winding in a spiral shape around the rotation axis C in the fourth region R4.

[0031] The core 27 is a magnetic member that is laminated on the first substrate 26 on the second direction D2 side (the side away from the rotor 3) and is arranged to face each of the stator side coils in the axial direction. Examples of the magnetic material used for the core 27 include an electromagnetic steel sheet, an amorphous material, and a magnetic sheet containing ferrite powder. The core 27 may be composed of a plurality of members that form an annular shape with approximately the same diameter as each of the four regions R1, R2, R3, and R4, as shown in FIG. 1.

[0032] The metal plate 28 is a metal member laminated on the second direction D2 side of the core 27, and has, for example, a plate (sheet) shape that has approximately the same outer shape as the substrate portion 26A of the first substrate 26 when viewed in the axial direction and covers the substrate portion 26A from the second direction D2 side. The metal plate 28 may be directly fixed to the core 27 by metal screws or the like (not shown), or may be disposed via an adhesive sheet (insulating material) (not shown).

[0033] The metal plate 28 is, for example, a sheet of non-magnetic aluminum material. However, the metal plate 28 does not have to be a non-magnetic material, and may be, for example, a magnetic material such as an iron plate. The provision of the metal plate 28 increases the rigidity of the stator 2 and suppresses distortion of the shape, compared with a case in which the stator 2 is composed only of the first substrate 26 and the core 27, which are thin sheets. Furthermore, when the stator 2 is fixed to another structure such as a case, operations such as screwing, crimping, and welding are facilitated. When the metal plate 28 is a non-magnetic material, it is less susceptible to the influence of leakage magnetic flux from a magnetic device such as a motor (noise due to external magnetic flux). The shielding effect of the metal plate 28 as a shield against external noise (electromagnetic waves) is enhanced by a metal material with low electrical resistance. For example, copper may be used.

[0034] The rotor 3 is a component that is rotatably supported (around the center of rotation) integrally with the rotation axis C with respect to the stator 2. The rotor 3 includes, for example, a second substrate 36, a core 37, and a metal plate 38, as shown in Figs.

[0035] The second substrate 36 is a thin sheet made of non-conductive resin (e.g., polyimide) similarly to the first substrate 26. The first detection coil 13, the first transmission coil 14, the second detection coil 23, and the second transmission coil 24 shown in FIG. 2 are formed on the second substrate 36. In the second substrate 36, these coils 13, 14, 23, and 24 may be covered on both axial sides with a polyimide sheet that forms a part of the second substrate 36, similarly to the stator side coil formed on the first substrate 26. Note that these coils 13, 14, 23, and 24 are made of, for example, copper foil. The second substrate 36 is, for example, as shown in FIG. 1, in the axial direction, in the shape of a ring having a diameter equal to that of the substrate portion 26A of the first substrate 26.

[0036] In the second substrate 36, the first detection coil 13, the first transmission coil 14, the second detection coil 23, and the second transmission coil 24 are disposed so as to face the first excitation coils 11 and 12, the first reception coil 15, the second excitation coils 21 and 22, and the second reception coil 25 in the axial direction, respectively. For example, the first detection coil 13 is provided in a fifth annular region R5 (see FIG. 1) having the same diameter as the first region R1, and the first transmission coil 14 is provided in a sixth annular region R6 (see FIG. 1) having the same diameter as the second region R2. The second detection coil 23 is provided in a seventh annular region R7 (see FIG. 1) having the same diameter as the third region R3, and the second transmission coil 24 is provided in an eighth annular region R8 (see FIG. 1) having the same diameter as the fourth region R4.

[0037] As shown in FIG. 2, the first detection coil 13 and the first transmission coil 14 are electrically connected (series connected) to each other. The second detection coil 23 and the second transmission coil 24 are electrically connected (series connected) to each other. The first detection coil 13, like the first excitation coils 11 and 12, has an axial multiplier angle of nX and forms n magnetic pole pairs in the fifth region R5. The second detection coil 23, like the second excitation coils 21 and 22, has an axial multiplier angle of 1X and forms one magnetic pole pair in the seventh region R7. Each of the first transmission coil 14 and the second transmission coil 24 is a transformer coil that transmits a signal to each of the first reception coil 15 and the second reception coil 25, and is formed by arranging a winding in a spiral shape around the rotation axis C in each of the sixth region R6 and the eighth region R8.

[0038] The core 37 is a magnetic member that is stacked on the second substrate 36 on the first direction D1 side (the side away from the stator 2) and is arranged to face each of the first detection coil 13, the first transmission coil 14, the second detection coil 23, and the second transmission coil 24 in the axial direction. The core 37 may be made of the same magnetic material as the core 27 of the stator 2. The core 37 may be made of a plurality of members each forming an annular shape with approximately the same diameter as each of the four regions R5, R6, R7, and R8, as shown in FIG. 1, for example.

[0039] The metal plate 38 is a member that is disposed on the first direction D1 side with respect to the core 37, and has, for example, a plate (sheet) shape that has substantially the same outer shape as the second substrate 36 when viewed in the axial direction and covers the second substrate 36 from the first direction D1 side. The metal plate 38 may be, for example, a sheet of non-magnetic aluminum material, similar to the metal plate 28 of the stator 2. Furthermore, the metal plate 38 may be disposed on the core 37 via an adhesive sheet (insulating material) (not shown), similar to the metal plate 28 of the stator 2.

[0040] The signal processing circuit 4 is an electric circuit that generates a first input signal S1 and a second input signal S2, and outputs a rotation angle (angle information 7) of the rotor 3 relative to the stator 2 based on the received first output signal S3 and second output signal S4. The signal processing circuit 4 may be provided, for example, outside the resolver 1, and may be formed on an annular substrate developed around the rotation axis C at a position different from the stator 2 and the rotor 3 in the axial direction, as shown in FIG.

[0041] 2, the signal processing circuit 4 includes a signal generating circuit 5 and a signal processing circuit 6. The signal generating circuit 5 generates a first input signal S1 and a second input signal S2, and inputs them to the first excitation coils 11, 12 and the second excitation coils 21, 22. The signal processing circuit 6 outputs angle information 7 corresponding to the rotation angle based on the first output signal S3 and the second output signal S4 output from the first receiving coil 15 and the second receiving coil 25.

[0042] In this embodiment, the resolver 1 is a modulated wave type resolver that receives an amplitude-modulated high-frequency (e.g., 100 kHz or higher) AC signal (a signal whose signal waveform includes a carrier wave and a modulating wave) and detects a rotation angle from a phase-modulated signal generated in the first detection coil 13 and the second detection coil 23 using the input signal. The signal generation circuit 5 inputs an amplitude-modulated AC signal (excitation signal) as a first input signal S1 to the first excitation coils 11 and 12. The signal generation circuit 5 inputs AC signals whose modulated wave phases differ from each other by 90 degrees to the first sine excitation coil 11 and the first cosine excitation coil 12, respectively.

[0043] The signal generating circuit 5 also inputs, as the second input signal S2, an amplitude-modulated AC signal (excitation signal) having a phase that cancels out the first input signal S1 to the second excitation coils 21 and 22 serving as cancel coils. The signal generating circuit 5 inputs, to each of the second sine excitation coil 21 and the second cosine excitation coil 22, AC signals whose modulated waves differ in phase from each other by 90 degrees.

[0044] The signal generating circuit 5 inputs, as the above-mentioned "signal of a phase canceling out the first input signal S1", a signal of a carrier phase whose electrical angle phase differs from the phase of the carrier wave of the first input signal S1 by a range of 90 degrees or more and 270 degrees or less, to the second excitation coils 21, 22. The signal generating circuit 5 of this embodiment inputs, to the second excitation coils 21, 22, a signal of an opposite phase (a signal whose phase differs by 180 degrees) from the phase of the carrier wave of the first input signal S1.

[0045] Specifically, the signal generating circuit 5 inputs sin(ω) to the first sine excitation coil 11 of the first excitation coils 11 and 12 having an axial multiplication factor of nX. c t) cos(ω m A first sine excitation signal S11 having a cosine waveform of ωt is input as a first input signal S1. A modulated wave [cos(ω m t)】, which is 90 degrees out of phase with sin(ω c t) sin(ω m t) A first cosine excitation signal S12 having a sine waveform is input as a first input signal S1.

[0046] The signal generating circuit 5 outputs a carrier wave [sin(ω c t)), which is the opposite phase to the phase of -sin(ω c t) cos(ω m A second sine excitation signal S21 having a cosine waveform of ωt is input as a second input signal S2. Also, a carrier wave [sin(ω c t)] and the modulation wave [cos(ω m t) ), which is 90 degrees out of phase with -sin(ω c t) sin(ω m t) A second cosine excitation signal S22 having a sine waveform is input as the second input signal S2.

[0047] In the first coil group 10, when the first input signal S1 is input to the first excitation coils 11 and 12, the first excitation coils 11 and 12 are excited to generate magnetic flux (see the hollow arrows in FIG. 2). This magnetic flux is linked to the first detection coil 13 on the rotor 3 side to generate an induced voltage. As a result, a phase-modulated signal (a composite waveform including phase information) is generated in the first detection coil 13, and the first transmission coil 14 is excited to generate magnetic flux (see the solid arrows in FIG. 2). This magnetic flux is linked to the first reception coil 15 on the stator 2 side to generate an induced voltage. The waveform of this induced voltage (a composite waveform including phase information) is output to the signal processing circuit 6 as the first output signal S3, and is converted by the signal processing circuit 6 into angle information 7 corresponding to the rotation angle and output.

[0048] The same is true for the second coil group 20. When a second input signal S2 is input to the second excitation coils 21, 22, the second excitation coils 21, 22 are excited to generate magnetic flux (see the hollow arrows in FIG. 2). This magnetic flux interlinks with the second detection coil 23 on the rotor 3 side to generate an induced voltage. As a result, a phase-modulated signal (a composite waveform including phase information) is generated in the second detection coil 23, and the second transmission coil 24 is excited to generate magnetic flux (see the solid arrows in FIG. 2). This magnetic flux interlinks with the second reception coil 25 on the stator 2 side to generate an induced voltage. The waveform of this induced voltage (a composite waveform including phase information) is output to the signal processing circuit 6 as the second output signal S4, and is converted by the signal processing circuit 6 into angle information 7 corresponding to the rotation angle and output.

[0049] Here, in the stator 2 of the resolver 1 as described above, the gap (radial gap) between the first excitation coils 11, 12 and the first receiving coil 15 formed on the same first substrate 26 can become a parasitic capacitance. Note that the parasitic capacitance here means a capacitance (capacitor component) that exists parasitically inside an electronic component or in an electronic circuit due to a physical structure, regardless of the design intent.

[0050] In the stator 2, a part of the first input signal S1 input to the first excitation coils 11 and 12 may leak through the parasitic capacitance and be propagated to the first receiving coil 15 as noise. In detail, as shown by a dashed line in Fig. 3, in the stator 2, the gap between the first sine excitation coil 11 and the first receiving coil 15 becomes a parasitic capacitance. The first sine excitation coil 11 and the first receiving coil 15 are unintentionally electrically coupled due to the parasitic capacitance, and a part of the first sine excitation signal S11 is propagated to the first receiving coil 15 as sine noise S11'. Similarly, the gap between the first cosine excitation coil 12 and the first receiving coil 15 becomes a parasitic capacitance, and a part of the first cosine excitation signal S12 is propagated to the first receiving coil 15 as cosine noise S12' due to the parasitic capacitance.

[0051] As a result, in the first receiving coil 15, a part of the first input signal S1 propagated through the parasitic capacitance interferes as noise (sine noise S11' and cosine noise S12') with the signal S15 received from the first transmitting coil 14 (hereinafter referred to as the "received signal S15"), and a waveform including noise may be output as the first output signal S3 to the signal processing circuit 6. This may decrease the S / N ratio and the detection accuracy of the resolver 1.

[0052] Therefore, in the stator 2 of this embodiment, as a configuration for reducing the influence of such noise on the first output signal S3, the second excitation coils 21, 22 are provided as canceling coils, and a signal with a phase that cancels the first input signal S1 is input to the second excitation coils 21, 22. In the stator 2, the gap between the second excitation coils 21, 22 and the first receiving coil 15 becomes a parasitic capacitance, and a part of the second input signal S2 is propagated to the first receiving coil 15 through the parasitic capacitance. As a result, a part of the first input signal S1 propagated to the first receiving coil 15 is cancelled by a part of the second input signal S2, thereby improving the S / N ratio.

[0053] 3, the gap between the second sine excitation coil 21 and the first receiving coil 15 becomes a parasitic capacitance. The second sine excitation coil 21 and the first receiving coil 15 are coupled by the parasitic capacitance, and a part of the second sine excitation signal S21 is propagated to the first receiving coil 15 as a sine canceling signal S21'. Similarly, the gap between the second cosine excitation coil 22 and the first receiving coil 15 becomes a parasitic capacitance, and a part of the second cosine excitation signal S22 is propagated to the first receiving coil 15 as a cosine canceling signal S22' by the parasitic capacitance.

[0054] As a result, in the first receiving coil 15, the sine noise S11' and the sine canceling signal S21' cancel each other out (symbol CXL in FIG. 3), and the cosine noise S12' and the cosine canceling signal S22' cancel each other out (symbol CXL in FIG. 3). In this way, the noises S11' and S12' propagated to the first receiving coil 15 are cancelled out by the canceling signals S21' and S22', and the first receiving coil 15 outputs the received signal S15 to the signal processing circuit 4 as the first output signal S3.

[0055] [2. Actions and Effects] (1) In the above-described stator 2 and resolver 1, first excitation coils 11, 12 (input coils) to which a first input signal S1 is input, and a first receiving coil 15 (output coil) that outputs a first output signal S3 are arranged on a first substrate 26. Second excitation coils 21, 22 serving as canceling coils are further arranged on the first substrate 26. A second input signal S2 having a phase that cancels out the first input signal S1 is input to the second excitation coils 21, 22.

[0056] In the first receiving coil 15, a parasitic capacitance occurs between the first excitation coils 11, 12 arranged on the same first board 26, and a part of the first input signal S1 is propagated to the first receiving coil 15 as noise (noises S11', S12') and interferes with the first output signal S3. However, in the first receiving coil 15, the above noise can be cancelled out by a part of the second input signal S2 (cancellation signals S21', S22') propagated through the parasitic capacitance generated between the first receiving coil 15 and the second excitation coils 21, 22 arranged on the same first board 26.

[0057] In this manner, in the above-described stator 2 and resolver 1, by utilizing the parasitic capacitance that is parasitically generated between the first receiving coil 15 and the second exciting coils 21, 22 separate from the first exciting coils 11, 12, it is possible to cancel out and remove signals that become noise components within the first receiving coil 15. This improves the S / N ratio and improves the detection accuracy of the resolver 1.

[0058] In particular, in the sheet-type resolver 1 having the coils 11-15, 21-25 formed on the sheet-shaped substrates 26, 36, it is difficult to ensure a sufficient number of turns for each of the coils 11-15, 21-25. For this reason, the magnetic flux of the first excitation coils 11, 12 and the first transmission coil 14 is likely to be weak, and the strength of the reception signal S15 is likely to be weak. In such a resolver 1, if the second excitation coils 21, 22 to which the second input signal S2 having a phase that cancels out the first input signal S1 is provided and the signals that become noise components in the first reception coil 15 are cancelled out, the S / N ratio can be improved even if the strength of the reception signal S15 is weak, and the detection accuracy of the resolver 1 can be improved.

[0059] (2) In the above-described stator 2 and resolver 1, a signal having a carrier phase that differs from the carrier phase of the first input signal S1 by 90 degrees or more and 270 degrees or less is input as the second input signal S2 having a phase that cancels out the first input signal S1. Due to such a phase difference between the carrier waves of the first input signal S1 and the second input signal S2, the noises S11', S12' can be appropriately cancelled out by the cancellation signals S21', S22', thereby improving the detection accuracy of the resolver 1.

[0060] (3) In the above-described stator 2 and resolver 1, the first receiving coil 15 is disposed between the first exciting coils 11, 12 and the second exciting coils 21, 22. With such an arrangement, the signal strengths of the noises S11', S12' and the cancellation signals S21', S22' propagated to the first receiving coil 15 can be made equal. Therefore, signals that become noise components can be more appropriately cancelled out in the first receiving coil 15, thereby improving the detection accuracy of the resolver 1.

[0061] (4) The resolver 1 described above is a composite resolver including a first coil group 10 including the first excitation coils 11, 12 as input coils and a first receiving coil 15 as an output coil, and a second coil group 20 including second excitation coils 21, 22 having a different axial multiplier angle from the first excitation coils 11, 12. In this way, by utilizing the second excitation coils 21, 22 of the second coil group 20 as cancellation coils, it is possible to cancel signals (noises S11', S12') leaking from the first excitation coils 11, 12 without having to provide a coil dedicated to noise cancellation.

[0062] (5) In particular, as in the above-described stator 2, when the axial multiplier angle of the first excitation coils 11, 12 is larger than the axial multiplier angle of the second excitation coils 21, 22, the size of one magnetic pole of the first excitation coils 11, 12 formed in the first region R1 may be smaller than the size of one magnetic pole of the second excitation coils 21, 22 formed in the second region R2. For this reason, the magnetic flux of each magnetic pole of the first excitation coils 11, 12 is likely to be weak, and the strength of the reception signal S15 is likely to be weak. In such a resolver 1, if the second excitation coils 21, 22 of the second coil group 20 are utilized to cancel out signals that become noise components in the first reception coil 15, the S / N ratio can be improved even if the strength of the reception signal S15 is weak. Therefore, the detection accuracy of the resolver 1 can be improved. In other words, by using the excitation coil with the smaller axial multiplier angle (second excitation coil 21, 22) as a cancellation coil, the S / N ratio of the received signal of the coil group including the excitation coil with the larger axial multiplier angle (first excitation coil 11, 12) can be appropriately improved without adding any components.

[0063] [3.Other] The above-mentioned configurations of the stator 2 and resolver 1 are merely examples, and are not limited to the above-mentioned configurations. The stator 2 may have at least an input coil to which an input signal is input, an output coil to which an output signal is output, a cancel coil to which a signal of a phase that cancels the input signal is input, and a substrate on which these coils are arranged. For example, the axial multiplier angles of the first excitation coils 11, 12 and the second excitation coils 21, 22 are not limited to those described above, and for example, the axial multiplier angle of the first excitation coils 11, 12 may be 1X, and the axial multiplier angle of the second excitation coils 21, 22 may be nX.

[0064] The stator 2 does not have to be the stator 2 of the composite resolver 1 that detects the rotation angle using a plurality of shaft multiplier angles, and may be the stator of a resolver that detects the rotation angle using one shaft multiplier angle. In this case, the coils 21 to 25 of the second coil group 20 may be omitted, and instead of the second excitation coils 21 and 22, a coil dedicated to a cancel coil to which a signal with a phase that cancels the first input signal S1 (input signal) is input may be provided in the stator.

[0065] The stator 2 does not have to be the stator 2 of the two-input, one-output resolver 1, but may be the stator of a one-input, two-output resolver. In this case, the stator may be provided with one input coil, two output coils, and one cancel coil. In other words, the resolver 1 does not have to be a two-input, one-output detector, but may be a one-input, two-output detector.

[0066] The resolver 1 does not have to be one in which the excitation coils 11, 12, 21, and 22 are provided on the stator 2 and the detection coils 13 and 23 are provided on the rotor 3. The resolver may be one in which, for example, the excitation coil is provided on the rotor and the detection coil is provided on the stator. Alternatively, the resolver may be one in which the excitation coil and the detection coil are provided on the stator and the rotor has a conductor that generates a demagnetizing field in a direction that cancels the magnetic field of the excitation coil with a magnitude according to the rotation angle. In other words, the rotor of the resolver does not have to be provided with a coil.

[0067] The stator may have at least the input coil, the output coil, and the cancel coil on the same substrate, and the arrangement of these is not limited to the above. For example, in the above-mentioned stator 2, the first receiving coil 15 is arranged between the first excitation coils 11, 12 and the second excitation coils 21, 22, but both the first excitation coils 11, 12 and the second excitation coils 21, 22 may be arranged radially inside or outside the first receiving coil 15. Not only the first receiving coil 15 but also the second receiving coil 25 may be arranged between the first excitation coils 11, 12 and the second excitation coils 21, 22. In other words, the above-mentioned arrangement of the stator side coils is an example, and is not limited to the above-mentioned arrangement.

[0068] The signal input to the canceling coil needs to be at least a signal with a phase that cancels the input signal, and does not need to be a signal with an opposite phase to the phase of the carrier wave of the input signal. A part of the input signal (the noises S11', S12' described above) propagated to the output coil via the parasitic capacitance may be out of phase with the input signal due to the relationship between the parasitic capacitance and inductance. Similarly, a part of the signal of the canceling coil propagated to the output coil (the canceling signals S21', S22' described above) may be out of phase with the signal input to the canceling coil. Therefore, it is preferable that the phase of the carrier wave of the signal input to the canceling coil is appropriately set in consideration of such a shift, within a range that differs from the phase of the carrier wave of the input signal by 90 degrees or more and 270 degrees or less. [Explanation of symbols]

[0069] 1 Resolver 2 Stator (resolver stator) 3 Rotor (resolver rotor) 4. Signal processing circuit (external device) 10 First coil group 11 First sine excitation coil (first excitation coil, input coil) 12 First cosine excitation coil (first excitation coil, input coil) 15 First receiving coil (transformer coil, output coil) 20 Second coil group 21 Second sine excitation coil (second excitation coil, cancellation coil) 22 Second cosine excitation coil (second excitation coil, cancellation coil) 26 First board (board) S1 First input signal (input signal) S2 Second input signal (signal with phase that cancels the input signal) S3 First output signal (output signal) S11 First sine excitation signal (input signal) S12 First cosine excitation signal (input signal) S21 Second sine excitation signal (signal with phase that cancels the input signal) S22 Second cosine excitation signal (signal with phase that cancels the input signal)

Claims

1. A resolver stator provided in a resolver that detects a rotation angle of a resolver rotor, A sheet-shaped substrate is provided. An input coil for receiving an input signal, an output coil for outputting an output signal, and a cancellation coil are arranged on the substrate, A signal having a phase that cancels the input signal is input to the cancel coil. A resolver stator comprising:

2. The signal having a phase that cancels out the input signal is a signal having a carrier phase that differs from the carrier phase of the input signal by a range of 90 degrees or more and 270 degrees or less.

2. The resolver stator according to claim 1,

3. The output coil is disposed between the input coil and the cancel coil when viewed in the axial direction.

2. The resolver stator according to claim 1,

4. the resolver is a composite resolver including a first coil group including a first excitation coil as the input coil and a transformer coil as the output coil, and a second coil group including a second excitation coil having a different axial multiplication angle from that of the first excitation coil, The second excitation coil is disposed on the substrate as the cancel coil.

2. The resolver stator according to claim 1,

5. The axial multiplication angle of the first excitation coil is aX, The second excitation coil has an axial multiplication angle of bX (a and b are natural numbers, 1≦b≦a-1). The resolver stator according to claim 4 .

6. A resolver stator according to any one of claims 1 to 5; a resolver rotor disposed axially opposite the resolver stator; A resolver comprising:

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