Resolver stator

Abstract

Provided is a resolver stator with which it is possible to improve the detection accuracy of a resolver. This resolver stator comprises: a stator core, which has a plurality of teeth and in which slots are formed; excitation windings that are provided to the plurality of teeth; and output windings that are provided to the plurality of teeth. The excitation windings are configured from a first excitation winding and a second excitation winding to which mutually different excitation signals are inputted. The output windings are configured from a first output winding and a second output winding from which mutually different output signals are outputted. When s represents the number of slots, n1 represents the number of excitation cycles relating to the number of turns of each of the first excitation winding and the second excitation winding, and n2 represents the number of output cycles relating to the number of turns of each of the first output winding and the second output winding, the number of slots s is a common multiple of the number of excitation cycles n1 and the number of output cycles n2.

Description

Resolver stator

[0001] The present invention relates to a resolver stator.

[0002] Conventionally, a resolver stator including a stator core, an excitation winding, and an output winding has been known. The stator core has an annular core back and a plurality of teeth extending radially from the core back and arranged circumferentially. The excitation winding is provided on the plurality of teeth, and the number of turns on each of the plurality of teeth changes periodically in accordance with changes in circumferential position. The output winding is provided on the plurality of teeth, and the number of turns on each of the plurality of teeth changes periodically in accordance with changes in circumferential position (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 8-178610

[0004] In each of the excitation winding and the output winding, the actual value of the number of turns on each of the multiple teeth is an integer. Meanwhile, in each of the excitation winding and the output winding, the ideal value of the number of turns on each of the multiple teeth may include a decimal point. This may result in a quantization error in the number of turns between the actual value and the ideal value of the number of turns. However, the resolver stator described in Patent Document 1 has a problem in that the quantization error in the number of turns affects the output signal output from the output winding, resulting in a decrease in the detection accuracy of the resolver.

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a resolver stator that can improve the detection accuracy of a resolver.

[0006] A resolver stator according to the present invention includes: a stator core having an annular core back and a plurality of teeth extending radially from the core back and arranged circumferentially, with slots formed between each of the plurality of circumferentially adjacent teeth; excitation windings provided on the plurality of teeth, the number of turns of each of the plurality of teeth varying periodically in accordance with changes in circumferential position; and output windings provided on the plurality of teeth, the number of turns of each of the plurality of teeth varying periodically in accordance with changes in circumferential position, wherein the excitation windings are made up of a first excitation winding and a second excitation winding to which mutually different excitation signals are input, and the output windings are made up of a first output winding and a second output winding to which mutually different output signals are output, and wherein the number of slots is s, the number of excitation cycles is the number of cycles related to the respective numbers of turns of the first excitation winding and the second excitation winding, and the number of output cycles is n2, the number of slots s is a common multiple of the number of excitation cycles n1 and the number of output cycles n2. In the resolver stator according to the present invention, for each of the plurality of teeth, the number of turns of the first excitation winding is multiplied by the number of turns of the first output winding, and the sum of the multiplied numbers is 0; for each of the plurality of teeth, the number of turns of the first excitation winding is multiplied by the number of turns of the second output winding, and the sum of the multiplied numbers is 0; for each of the plurality of teeth, the number of turns of the second excitation winding is multiplied by the number of turns of the first output winding, and the sum of the multiplied numbers is 0; for each of the plurality of teeth, the number of turns of the second excitation winding is multiplied by the number of turns of the second output winding, and the sum of the multiplied numbers is 0.

[0007] According to the resolver stator of the present invention, the detection accuracy of the resolver can be improved.

[0008] Fig. 4 is a configuration diagram showing a resolver including a resolver stator according to embodiment 1. Fig. 5 is a table showing the number of turns of each of the excitation winding and the output winding of the resolver stator of Fig. 1. Fig. 6 is an explanatory diagram showing a quantization error of the number of turns that occurs between an actual value and an ideal value in the number of turns of the winding wound around the teeth. Fig. 7 is a configuration diagram showing a resolver including a resolver stator according to embodiment 2. Fig. 8 is a table showing the number of turns of each of the excitation winding and the output winding of the resolver stator of Fig. 4.

[0009] Embodiment 1 Fig. 1 is a configuration diagram showing a resolver including a resolver stator according to embodiment 1. Fig. 2 is a table showing the number of turns of each of the excitation winding and the output winding of the resolver stator of Fig. 1. The resolver includes a resolver rotor 1 and a resolver stator 2.

[0010] The resolver rotor 1 is rotatably provided relative to the resolver stator 2. The direction along the axis of the resolver rotor 1 is defined as the axial direction D1. The direction along the radius of a circle centered on the axis of the resolver rotor 1 in a plane perpendicular to the axis of the resolver rotor 1 is defined as the radial direction D2. The direction along the circumference of a circle centered on the axis of the resolver rotor 1 in a plane perpendicular to the axis of the resolver rotor 1 is defined as the circumferential direction D3.

[0011] The resolver rotor 1 is disposed inside the resolver stator 2 in the radial direction D2. The resolver rotor 1 has four salient poles. Therefore, the axial multiplication factor X of the resolver is four.

[0012] The resolver stator 2 includes a stator core 3, an excitation winding 4, and an output winding 5. The stator core 3 has an annular core back 301 and a plurality of teeth 302 extending in the radial direction D2 from the core back 301 and arranged in the circumferential direction D3. A slot 303 is formed between each of the plurality of teeth 302 adjacent to each other in the circumferential direction D3.

[0013] The excitation winding 4 is provided on the plurality of teeth 302. The number of turns of the excitation winding 4 on each of the plurality of teeth 302 changes periodically in accordance with the change in position in the circumferential direction D3.

[0014] Specifically, the excitation winding 4 is composed of a first excitation winding 401 and a second excitation winding 402 to which different excitation signals are input. The number of turns of the first excitation winding 401 on each of the plurality of teeth 302 changes periodically in accordance with changes in position in the circumferential direction D3. The number of turns of the second excitation winding 402 on each of the plurality of teeth 302 changes periodically in accordance with changes in position in the circumferential direction D3.

[0015] The output winding 5 is provided on the plurality of teeth 302. The number of turns of the output winding 5 on each of the plurality of teeth 302 changes periodically in accordance with the change in position in the circumferential direction D3.

[0016] Specifically, the output winding 5 is composed of a first output winding 501 and a second output winding 502, which output different output signals from each other. The number of turns of the first output winding 501 on each of the plurality of teeth 302 changes periodically in accordance with the change in position in the circumferential direction D3. The number of turns of the second output winding 502 on each of the plurality of teeth 302 changes periodically in accordance with the change in position in the circumferential direction D3.

[0017] The resolver detects the rotation angle of the resolver rotor 1 using two excitation signals input to the first excitation winding 401 and the second excitation winding 402, respectively, and two output signals output from the first output winding 501 and the second output winding 502, respectively. Therefore, the resolver including the resolver stator 2 according to the first embodiment is a two-phase excitation, two-phase output type resolver.

[0018] In FIG. 2, the winding directions of the excitation winding 4 and the output winding 5 are each represented by a positive number in one direction and a negative number in the other direction.

[0019] Let s be the number of slots, which is the number of slots 303. Let n1 be the number of excitation cycles, which is the number of cycles related to the number of turns of each of the first excitation winding 401 and the second excitation winding 402. Let n2 be the number of output cycles, which is the number of cycles related to the number of turns of each of the first output winding 501 and the second output winding 502.

[0020] In the resolver stator 2 according to the first embodiment, the number of slots s=12, the number of excitation cycles n1=2, and the number of output cycles n2=6.

[0021] Furthermore, in the resolver stator 2 according to the first embodiment, the number of excitation cycles n1+the number of output cycles n2=the shaft multiplier angle X, or the number of excitation cycles n1-the number of output cycles n2=the shaft multiplier angle X is satisfied.

[0022] In the resolver stator 2 according to the first embodiment, the number of slots s may be any number as long as it is a common multiple of the number of excitation cycles n1 and the number of output cycles n2.

[0023] 3 is an explanatory diagram showing the quantization error of the number of turns of the winding wound around the teeth 302, which occurs between the actual value and the ideal value. For each of the excitation winding 4 and the output winding 5, the ideal value T2 of the winding can be determined from the ideal curve of the winding. The ideal value T2 of the winding may include a decimal point. For each of the excitation winding 4 and the output winding 5, the actual value T1 of the winding is an integer determined from the ideal value T2 of the winding.

[0024] In each of the excitation winding 4 and the output winding 5, there is a possibility that a difference will occur between the actual number of turns T1 and the ideal number of turns T2 for each of the multiple teeth 302. The difference between the actual number of turns T1 and the ideal number of turns T2 is referred to as the quantization error of the number of turns. If the quantization error of the number of turns affects the output signal output from the output winding 5, the detection accuracy of the resolver will be reduced.

[0025] The output signal output from the output winding 5 is affected by the value obtained by multiplying the number of turns of the excitation winding 4 in each of the multiple teeth 302 by the number of turns of the output winding 5. Specifically, the output signal output from the first output winding 501 is affected by the value obtained by multiplying the number of turns of the first excitation winding 401 by the number of turns of the first output winding 501 and by the value obtained by multiplying the number of turns of the second excitation winding 402 by the number of turns of the first output winding 501. The output signal output from the second output winding 502 is affected by the value obtained by multiplying the number of turns of the first excitation winding 401 by the number of turns of the second output winding 502 and by the value obtained by multiplying the number of turns of the second excitation winding 402 by the number of turns of the second output winding 502.

[0026] In the resolver stator 2 according to the first embodiment, for each of the plurality of teeth 302, the number of turns of the first excitation winding 401 is multiplied by the number of turns of the first output winding 501, and the sum of the multiplied numbers is 0. Furthermore, for each of the plurality of teeth 302, the number of turns of the second excitation winding 402 is multiplied by the number of turns of the first output winding 501, and the sum of the multiplied numbers is 0. As a result, the influence of quantization errors in the number of turns in each of the first excitation winding 401, the second excitation winding 402, and the first output winding 501 is canceled out in the output signal output from the first output winding 501.

[0027] Furthermore, in the resolver stator 2 according to the first embodiment, for each of the plurality of teeth 302, the number of turns of the first excitation winding 401 is multiplied by the number of turns of the second output winding 502, and the sum of the multiplied numbers is 0. For each of the plurality of teeth 302, the number of turns of the second excitation winding 402 is multiplied by the number of turns of the second output winding 502, and the sum of the multiplied numbers is 0. As a result, the influence of quantization errors in the number of turns in each of the first excitation winding 401, the second excitation winding 402, and the second output winding 502 is cancelled out in the output signal output from the second output winding 502.

[0028] Therefore, due to such a relationship between the number of turns of the excitation winding 4 and the number of turns of the output winding 5, the influence of the quantization error of the number of turns in the output signal output from the first output winding 501 is canceled out, and the influence of the quantization error of the number of turns in the output signal output from the second output winding 502 is canceled out.

[0029] Such a relationship between the number of turns of the excitation winding 4 and the number of turns of the output winding 5 can be obtained by making the number of slots s a common multiple of the number of excitation cycles n1 and the number of output cycles n2. Therefore, by making the number of slots s a common multiple of the number of excitation cycles n1 and the number of output cycles n2, the influence of the quantization error of the number of turns in the output signal output from the first output winding 501 is canceled out, and the influence of the quantization error of the number of turns in the output signal output from the second output winding 502 is canceled out.

[0030] As described above, the resolver stator 2 according to the first embodiment includes the stator core 3, the excitation winding 4, and the output winding 5. The stator core 3 has an annular core back 301 and a plurality of teeth 302 extending from the core back 301 in the radial direction D2 and arranged in the circumferential direction D3, with slots 303 formed between each of the plurality of teeth 302 adjacent to each other in the circumferential direction D3. The excitation winding 4 is provided on the plurality of teeth 302, and the number of turns on each of the plurality of teeth 302 changes periodically in accordance with changes in position in the circumferential direction D3. The output winding 5 is provided on the plurality of teeth 302, and the number of turns on each of the plurality of teeth 302 changes periodically in accordance with changes in position in the circumferential direction D3. The excitation winding 4 is composed of a first excitation winding 401 and a second excitation winding 402 to which different excitation signals are input. The output winding 5 is composed of a first output winding 501 and a second output winding 502, from which different output signals are output. The number of slots, which is the number of slots 303, is denoted by s. The number of excitation cycles, which is the number of cycles related to the number of turns of each of the first excitation winding 401 and the second excitation winding 402, is denoted by n1. The number of output cycles, which is the number of cycles related to the number of turns of each of the first output winding 501 and the second output winding 502, is denoted by n2. In this case, the number of slots s is a common multiple of the number of excitation cycles n1 and the number of output cycles n2. With this configuration, the influence of quantization error in the number of turns in the output signal output from the first output winding 501 is canceled out, and the influence of quantization error in the number of turns in the output signal output from the second output winding 502 is canceled out. This can improve the detection accuracy of the resolver.

[0031] Furthermore, in the resolver stator 2 according to the first embodiment, for each of the plurality of teeth 302, the number of turns of the first excitation winding 401 is multiplied by the number of turns of the first output winding 501, and the sum of the multiplied numbers is 0. For each of the plurality of teeth 302, the number of turns of the first excitation winding 401 is multiplied by the number of turns of the second output winding 502, and the sum of the multiplied numbers is 0. For each of the plurality of teeth 302, the number of turns of the second excitation winding 402 is multiplied by the number of turns of the first output winding 501, and the sum of the multiplied numbers is 0. For each of the plurality of teeth 302, the number of turns of the second excitation winding 402 is multiplied by the number of turns of the second output winding 502, and the sum of the multiplied numbers is 0. This configuration cancels out the influence of quantization error in the number of turns in the output signal output from the first output winding 501, and cancels out the influence of quantization error in the number of turns in the output signal output from the second output winding 502. This makes it possible to improve the detection accuracy of the resolver.

[0032] Embodiment 2 Fig. 4 is a configuration diagram showing a resolver including a resolver stator 2 according to embodiment 2. Fig. 5 is a table showing the number of turns of each of the excitation winding 4 and the output winding 5 of the resolver stator 2 of Fig. 4.

[0033] In the resolver stator 2 according to the second embodiment, the number of slots s=16, the number of excitation cycles n1=4, and the number of output cycles n2=8.

[0034] In addition, in the resolver stator 2 according to the second embodiment, the number of excitation cycles n1+the number of output cycles n2=the shaft multiplier angle X, or the number of excitation cycles n1-the number of output cycles n2=the shaft multiplier angle X is satisfied.

[0035] In the resolver stator 2 according to the second embodiment, the number of slots s may be any number that is a common multiple of the number of excitation cycles n1 and the number of output cycles n2.

[0036] Other configurations of the resolver stator 2 according to the second embodiment are similar to those of the resolver stator 2 according to the first embodiment.

[0037] As described above, in the resolver stator 2 according to embodiment 2, the number of slots s is a common multiple of the number of excitation cycles n1 and the number of output cycles n2, similarly to the resolver stator 2 according to embodiment 1. With this configuration, the influence of the quantization error of the number of turns in the output signal output from the first output winding 501 is canceled out, and the influence of the quantization error of the number of turns in the output signal output from the second output winding 502 is canceled out. This makes it possible to improve the detection accuracy of the resolver.

[0038] Although the resolver stators 2 according to the preferred embodiments have been described above, the resolver stators 2 according to the above-described embodiments are not limited to these. Various modifications and alterations can be made to the resolver stators 2 according to the above-described embodiments without departing from the scope of the claims.

[0039] 1 resolver rotor, 2 resolver stator, 3 stator core, 4 excitation winding, 5 output winding, 301 core back, 302 teeth, 303 slot, 401 first excitation winding, 402 second excitation winding, 501 first output winding, 502 second output winding.

Claims

1. A resolver stator having an annular core back (301) and a plurality of teeth (302) extending radially from the core back (301) and arranged circumferentially, with slots (303) formed between each of the plurality of circumferentially adjacent teeth (302); an exciting winding (4) provided on the plurality of teeth (302), the number of turns in each of the plurality of teeth (302) varying periodically according to the change in the circumferential position; an output winding (5) provided on the plurality of teeth (302), the number of turns in each of the plurality of teeth (302) varying periodically according to the change in the circumferential position; the exciting winding (4) being composed of a first exciting winding (401) and a second exciting winding (402) to which different exciting signals are input; the output winding (5) being composed of a first output winding (501) and a second output winding (502) from which different output signals are output; when the number of slots, which is the number of slots (303), is s, the number of exciting cycles, which is the number of cycles related to the number of turns of each of the first exciting winding (401) and the second exciting winding (402), is n1, and the number of output cycles, which is the number of cycles related to the number of turns of each of the first output winding (501) and the second output winding (502), is n2, the number of slots s is a common multiple of the number of exciting cycles n1 and the number of output cycles n2.

2. For each of the plurality of teeth (302), multiplying the number of turns of the first exciting winding (401) by the number of turns of the first output winding (501), the sum of the multiplied numbers is 0; for each of the plurality of teeth (302), multiplying the number of turns of the first exciting winding (401) by the number of turns of the second output winding (502), the sum of the multiplied numbers is 0; for each of the plurality of teeth (302), multiplying the number of turns of the second exciting winding (402) by the number of turns of the first output winding (501), the sum of the multiplied numbers is 0; for each of the plurality of teeth (302), multiplying the number of turns of the second exciting winding (402) by the number of turns of the second output winding (502), the sum of the multiplied numbers is 0. The resolver stator according to claim 1.

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