JP2015028450A - Rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor in which generation of disturbance in a magnetic flux is suppressed.SOLUTION: A rotor includes a first region (10a) in which a plurality of isomagnetic pole parts (11, 12) with different magnetic poles are alternately arranged in a circumferential direction, and a second region (30a) in which a chipped magnetic pole part (30) is provided. The chipped magnetic pole part consists of two ends (31, 32) and a central part (33) arranged between the two ends. The central part includes a first magnetic pole part (34) consisting of the same magnetic pole as those of the ends, and a second magnetic pole part (35) consisting of a magnetic pole different from those of the ends. The area of the second magnetic pole part is smaller than the area of the first magnetic pole part. Different polarity parts (13, 14) with a magnetic pole different from those of the isomagnetic pole parts are provided in the plurality of isomagnetic pole parts, and the area in the circumferential direction of the different polarity part provided in the isomagnetic pole part gradually becomes smaller as apart from the central part toward the circumferential direction so that magnetic force of the plurality of isomagnetic pole parts gradually gets stronger as apart from the central part toward the circumferential direction.

Description

  The present invention relates to a rotating body that rotates in the circumferential direction of a rotating shaft.

  Conventionally, as shown in Patent Document 1, for example, a magnetic position detection device having a magnetic member in which N poles and S poles are alternately arranged has been proposed.

JP 2006-23179 A

  The above-described magnetic member is usually provided with a first region in which N poles and S poles having the same size are alternately arranged, and a second magnetic pole portion larger than the magnetic pole provided in the first region. There is an area. The magnetic flux formed in the first region is used to detect the rotation angle of the magnetic member, and the magnetic flux formed in the second region is used to detect the reference position of the rotation angle of the magnetic member.

  By the way, as described above, when a large magnetic pole portion is formed in the second region, the magnetic force of the magnetic pole portion is strong, and therefore, the magnetic pole portion in the second region and the adjacent N pole or S pole in the first region. The magnetic flux formed by is disturbed. When such disturbance of magnetic flux occurs, there is a possibility that the rotation angle of the magnetic member cannot be detected with high accuracy.

  In view of the above problems, an object of the present invention is to provide a rotating body in which disturbance of magnetic flux is suppressed.

  In order to achieve the above-described object, the present invention is an annular rotating body that rotates in the circumferential direction of a rotating shaft that passes through its center (RC) in the thickness direction, and has an equal magnetic pole with a constant lateral width in the circumferential direction. And a plurality of equal magnetic pole portions (11, 12) having different magnetic poles in the circumferential direction on the outer ring surface of the rotating body. The first regions (10a) and the second regions (30a) in which the missing magnetic pole portions are formed are alternately arranged, and the missing magnetic pole portions are formed from magnetic poles different from the equimagnetic pole portions adjacent in the circumferential direction. Comprising two end portions (31, 32) and a central portion (33) disposed between the two end portions in the circumferential direction, wherein the central portion includes a plurality of second magnetic poles having the same magnetic pole as the end portion. One magnetic pole part (34) and a plurality of second magnetic pole parts (35) composed of magnetic poles different from the end parts, The area along the circumferential direction of one magnetic pole part is larger than the area in the circumferential direction of the second magnetic pole part adjacent to itself in the circumferential direction, and the properties as the magnetic pole in the central part are the same as the end part and the first magnetic pole part, respectively. And at least two of the plurality of equal magnetic pole portions are provided with different polar portions (13, 14) having different magnetic poles from itself, and the magnetic force of the plurality of equal magnetic pole portions is increased in the circumferential direction from the central portion. The area in the circumferential direction of the different pole part provided in the equal magnetic pole part gradually decreases as the distance from the center part increases in the circumferential direction.

  Thus, according to the present invention, the chipped magnetic pole portion (30) includes two end portions (31, 32) and a central portion (33) disposed between the two end portions (31, 32). Consists of. The central portion (33) includes a plurality of first magnetic pole portions (34) composed of the same magnetic pole as the end portions (31, 32) and a plurality of second magnetic pole portions composed of magnetic poles different from the end portions (31, 2). (35). In order to make the magnetism of the central portion (33) the same as that of each of the end portions (31, 32) and the first magnetic pole portion (34), the area along the circumferential direction of the first magnetic pole portion is adjacent to itself in the circumferential direction. It is larger than the area in the circumferential direction of the matching second magnetic pole part.

  According to this, the magnetic force of the center part (33) is weakened, and the magnetic force of the chipped magnetic pole part (30) is also weakened. Thereby, the magnetic flux formed around the chipped magnetic pole part (30) is prevented from being disturbed due to the chipped magnetic pole part (30). As a result, for example, the detection unit (200) that converts a magnetic signal into an electrical signal can be prevented from detecting the rotation angle of the rotating body (100) with high accuracy.

  As described above, when the magnetic force of the chipped magnetic pole portion (30) is weakened, the magnetic force of the equimagnetic pole portion (11) adjacent to the chipped magnetic pole portion (30) in the circumferential direction or the magnetic pole portion (12) adjacent thereto. Becomes stronger with respect to the chipped magnetic pole part (30). Therefore, there is a possibility that the magnetic flux formed between the two may be disturbed.

  Therefore, in the present invention, the equal magnetic pole part (10) is provided with different polar parts (13, 14) having different magnetic poles from the self magnetic pole part (10), and the circumferential area of the different polar parts (13, 14) is the central part ( As the magnetic force of the plurality of equal magnetic pole portions (10) gradually increases as the distance from the central portion (33) increases in the circumferential direction, the magnetic field gradually decreases from the central portion (33) in the circumferential direction. As a result, the magnetic force of the equal magnetic pole portion (10) gradually increases as the distance from the central portion (33) increases, and the magnetic force difference between the equal magnetic pole portion (10) and the missing magnetic pole portion (30) gradually increases. As a result, turbulence in the magnetic flux formed between the equal magnetic pole part (10) and the chipped magnetic pole part (30) is suppressed.

  A configuration in which the first magnetic pole part, the second magnetic pole part, the end part, and the different pole part are symmetrically arranged in the circumferential direction via a reference line (BL) penetrating the center of the central part in the thickness direction is preferable. is there. According to this, the first magnetic pole portion (34), the second magnetic pole portion (35), the end portions (31, 32), and the different pole portions (13, 14) are respectively connected via the reference line (BL). Unlike the configuration arranged asymmetrically in the circumferential direction, the circumferential magnetic field via the reference line (BL) forms a symmetrical shape. Accordingly, the magnetic flux formed between the equal magnetic pole part (10) and the chipped magnetic pole part (30) is prevented from being disturbed, and the rotation angle of the rotating body (100) is increased by the detection part (200). It is suppressed that it becomes impossible to detect accurately.

  The second magnetic pole portion adjacent to the end portion in the circumferential direction has a larger area in the circumferential direction and a smaller area difference from the end portion than the second magnetic pole portion located on the reference line side. According to this, the magnetic force difference between the end portions (31, 32) and the second magnetic pole portion (35) adjacent to the end portions (31, 32) is reduced, and the end portions (31, 32) and the equal magnetic pole portion (adjacent to the end portions (31, 32) 11) is prevented from being disturbed in the magnetic flux formed between the two.

  The central portion is formed by alternately arranging the first magnetic pole portion and the second magnetic pole portion in the circumferential direction, and the area of the second magnetic pole portion included per unit area gradually increases as the distance from the reference line in the circumferential direction increases. It decreases, and the area of the first magnetic pole part gradually increases. According to this, the magnetic force of the central portion (33) gradually increases as it goes from the reference line BL toward the end portions (31, 32) along the circumferential direction. Therefore, unlike the configuration in which the magnetic force of the central portion (33) gradually decreases from the reference line (BL) toward the end portions (31, 32) along the circumferential direction, the chipped magnetic pole portion (30), The boundary as a magnetic pole with the equal magnetic pole part (11) adjacent in the circumferential direction becomes clear, and the occurrence of disturbance in the magnetic flux formed between them is suppressed.

  In order to make the properties of the central part as a magnetic pole the same as those of the end part and the first magnetic pole part, the area in the circumferential direction of all of the second magnetic pole parts is more circumferential than any of all of the first magnetic pole parts. The area of is small. According to this, unlike the configuration in which at least one area of the second magnetic pole part (35) is larger than any one of the first magnetic pole parts (34), the area is locally at the central part (33). In addition, the magnetism of the second magnetic pole portion (35) is suppressed from increasing.

  In addition, although the elements described in the claims and the means for solving the problems are attached with parentheses, the parentheses are attached to each component described in the embodiment. This is to simply show the correspondence with the elements, and does not necessarily indicate the elements themselves described in the embodiments. The description of the reference numerals with parentheses does not unnecessarily narrow the scope of the claims.

It is a perspective view which shows roughly the relative position of a rotary body and a detection part. It is a graph which shows the fluctuation | variation with respect to the rotation angle of the magnetic flux converted into the electrical signal in the detection part. It is the expanded view which cut off a part of outer ring surface of a rotary body, and expand | deployed on the plane. FIG. 4 is an enlarged development view of a region A shown in FIG. 3. It is a graph which shows the air gap dependence of the angle error of the boundary in the structure which does not have a different pole part in a rotary body. It is a graph which shows the air gap dependence of the angle error of the boundary in the structure which has a different pole part in a rotary body. It is an expanded view which shows the modification of a rotary body. FIG. 8 is an enlarged development view of a region A shown in FIG. 7. It is an expanded view which shows the modification of a rotary body. It is an expanded view which shows the modification of a rotary body. It is an expanded view which shows the modification of a rotary body.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
Based on FIGS. 1-6, the rotary body which concerns on this embodiment is demonstrated. In FIGS. 1, 3, and 4, the N pole is hatched to clarify the magnetic poles. In FIG. 4, although not shown in the drawing, the equal magnetic pole portions 11 and 12 adjacent to the chipped magnetic pole portion 30 on the right side of the drawing are indicated by broken lines. The boundaries between the equal magnetic pole portions 11 and 12 having different magnetic poles and the boundary between the chipped magnetic pole portion 30 and the equal magnetic pole portion 10 are shown using #. For example, the fifth boundary is indicated as # 5. As shown in FIG. 3, in the present embodiment, there are a total of N boundaries as described above. N is a natural number of 4 or more, and is 58 in this embodiment.

  In the following, a plane at the same height position where each of the rotator 100 and the detection unit 200 is arranged is a specified plane, orthogonal to the specified plane, and penetrates the center of rotation RC (x mark shown in FIG. 1) of the rotator 100. The direction is indicated as the axial direction. Further, a direction around the axial direction is indicated as a circumferential direction (curved arrow shown in FIG. 1), and a direction orthogonal to the axial direction is indicated as a radial direction (for example, a one-dot chain line shown in FIG. 1). In addition, the axis | shaft of the rotary body 100 along the above-mentioned axial direction is equivalent to the rotating shaft as described in a claim, and an axial direction is equivalent to the thickness direction as described in a claim.

  The rotating body 100 has an annular shape as shown in part in FIG. The rotating body 100 includes an equal magnetic pole part 10 having a constant lateral width in the circumferential direction and a chipped magnetic pole part 30 having a wider lateral width than the equal magnetic pole part 10. As shown in FIG. 3, the outer ring surface of the rotator 100 includes a first region 10 a in which the equal magnetic pole portion 10 is formed and a second region 30 a in which the chipped magnetic pole portion 30 is formed. In the present embodiment, the horizontal width of the first region 10a is 342 ° in terms of the central angle of the rotating body 100, and the horizontal width of the second region 30a is 18 °. The thickness of each of the magnetic pole portions 10 and 30 constituting each of the above-described regions 10a and 30a, that is, the thickness of each of the magnetic pole portions 11 to 14 and 31 to 35 shown below has the same thickness as that of the rotating body 100. . Accordingly, the volume (magnetic force) of each of the magnetic pole portions 11, 12, 31 to 35 is determined by the width in the circumferential direction (hereinafter, referred to as a lateral width).

  The equal magnetic pole portion 10 includes a first equal magnetic pole portion 11 and a second equal magnetic pole portion 12 having a different polarity, and a plurality of first equal magnetic pole portions 11 and second equal magnetic pole portions 12 in the circumferential direction. Are arranged alternately. In the present embodiment, the first equal magnetic pole portion 11 has an N pole and the second equal magnetic pole portion 12 has an S pole, and the magnetic flux flows from the first equal magnetic pole portion 11 to the second equal magnetic pole portion 12. Magnetic flux between adjacent equal magnetic pole portions 11 and 12 flows so as to draw a semicircular locus, and the magnetic flux that draws this semicircular locus rotates together with the rotating body 100. Thereby, as shown in FIG. 2, the direction of the magnetic flux which permeate | transmits the detection part 200 changes periodically.

  The detection unit 200 detects the rotation angle of the rotating body 100 based on the magnetic flux formed in the first region 10a, and the reference position of the rotation angle of the rotating body 100 based on the magnetic flux formed in the second region 30a. Is detected. The detection unit 200 converts a periodic change in the direction of the magnetic flux into an electric signal, and compares the converted electric signal with a threshold value. Then, the converted electrical signal is converted into a pulse signal according to the comparison result. The rising edge or falling edge of the pulse of this pulse signal is at the boundary between adjacent equal magnetic pole portions 11 and 12, and the boundary between the missing magnetic pole portion 30 and the equal magnetic pole portion 10 (first equal magnetic pole portion 11). Equivalent to. In the present embodiment, the equal magnetic pole portions 11 and 12 are 57 in total, and the lateral width thereof is 6 ° in terms of the central angle of the rotating body 100.

  The chipped magnetic pole portion 30 is formed between two end portions 31 and 32 made of magnetic poles different from the equimagnetic pole portion (first equimagnetic pole portion 11) adjacent in the circumferential direction and between the two end portions 31 and 32 in the circumferential direction. And a central portion 33 arranged. The central portion 33 includes a first magnetic pole portion 34 made of the same magnetic pole as the end portions 31 and 32, and a second magnetic pole portion 35 made of a magnetic pole different from the end portions 31 and 32. As shown in FIGS. 3 and 4, the magnetic pole portions 34 and 35 each have a rectangular shape with a constant thickness, and are alternately arranged in the circumferential direction to form a stripe shape. In addition, since the area along the circumferential direction of the first magnetic pole portion 34 is larger than the area in the circumferential direction of the second magnetic pole portion 35 adjacent to itself in the circumferential direction, the property of the central portion 33 as the magnetic pole is This is the same as each of the end portions 31 and 32 and the first magnetic pole portion 34. In the present embodiment, the total area of all the second magnetic pole portions 35 is smaller than the total area of all the first magnetic pole portions 34, and the area of each of all the second magnetic pole portions 35 is all the first magnetic pole portions 35. The area is smaller than any of the portions 34.

  In the present embodiment, in order to make the magnetic flux formed at the central portion 33 uniform, the lateral widths L1 of all the first magnetic pole portions 34 are equal to each other, and the lateral widths L2 of all the second magnetic pole portions 35 are equal to each other. It has become. The horizontal width L1 of the first magnetic pole portion 34 is 1.25 ° in terms of the center angle of the rotating body 100, and the horizontal width L2 of the second magnetic pole portion 35 is 0.5 °. Since there are six first magnetic pole portions 34, the total area is proportional to 6 × 1.25 ° (7.50 °), and since there are seven second magnetic pole portions 35, the total area is 7 X Proportional to 0.50 ° (3.50 °). The lateral width L2 of the second magnetic pole portion 35 is 0.4 to 0.7 times the lateral width L1 of the first magnetic pole portion 34, and the sum of the lateral widths of all the second magnetic pole portions 35 is all the first magnetic pole portions. 34 and the end portions 31 and 32 have a relationship of 0.18 to 0.33 times the total lateral width. That is, the ratio of the S pole in the chipped magnetic pole part 30 is 67 to 82%, and the ratio of the N pole is 18 to 33%. The lateral width L5 of the central portion 33 is 11.00 °.

  Further, the lateral widths L3 and L4 of the end portions 31 and 32 are respectively set so that the magnetic flux portions 34 and 35 are stronger than the magnetic fluxes formed by the magnetic pole portions 34 and 35, respectively. Are wider than the horizontal widths L1 and L2. The lateral widths L3 and L4 of the end portions 31 and 32 are equal to each other. The lateral widths L3 and L4 of the end portions 31 and 32 are 3.40 ° in terms of the center angle of the rotating body 100, and the lateral widths L3 and L4 are 0.14 to 0.25 times the lateral width of the chipped magnetic pole portion 30. It is.

  Next, feature points of the rotating body 100 according to the present embodiment will be described. As shown in FIGS. 3 and 4, at least two of the plurality of equal magnetic pole portions 11 and 12 are provided with different pole portions 13 and 14 having different magnetic poles from the same. In the present embodiment, one first different pole portion 13 is formed in each of the two first equal magnetic pole portions 11 adjacent to the chipped magnetic pole portion 30 in the circumferential direction, and in the circumferential direction with the first equal magnetic pole portion 11. One second different pole portion 14 is formed in each of two adjacent second equal magnetic pole portions 12. As described above, the equal magnetic pole portions 11 and 12 have the same widths L1 and L2 and the same area, but the different pole portions 13 and 14 have the same widths L6 and L7, and the areas are also different. This is so that the magnetic force of the equal magnetic pole portions 11 and 12 gradually increases as the distance from the central portion 33 in the circumferential direction increases. The lateral width L6 is wider than the lateral width L7, and the first different pole portion 13 is the second The area is larger than that of the different pole portion 14. With such a configuration, the areas of the different pole portions 13 and 14 provided in the equal magnetic pole portions 11 and 12 are gradually reduced as they are separated from the central portion 33 in the circumferential direction. The lateral width L6 of the first different pole portion 13 is 0.5 °, and the lateral width L7 of the second different pole portion 14 is 0.4 °. The width of each of the different pole portions 13 and 14 formed in one of the equal magnetic pole portions 11 and 12 is 0.03 to 0.20 times the width of each of the equal magnetic pole portions 11 and 12. Further, in order to suppress the influence on the equal magnetic pole portions 11 and 12 that affect the chipped magnetic pole portion 30 and are separated from the chipped magnetic pole portion 30 in the circumferential direction, the different magnetic pole portions 13 and 14 have the same magnetic pole portions 11 and 12 respectively. Of the two end portions in the circumferential direction, it is formed between the end portion on the chipped magnetic pole portion 30 side and the center thereof. Specifically, each of the different pole portions 13 and 14 is 0.20 to 0.40 times the lateral width of the equal magnetic pole portions 11 and 12 from the end of the equal magnetic pole portions 11 and 12 on the chipped magnetic pole portion 30 side. It is formed at a distant position. In the present embodiment, as shown in FIGS. 3 and 4, the magnetic pole portions 34 and 35, the end portions 31 and 32, and the different polarities are provided via a reference line BL passing through the center of the central portion 33 in the axial direction. Each of the parts 13 and 14 is symmetrically arranged in the circumferential direction.

  Hereinafter, the function and effect of the rotating body 100 will be described. As described above, the chipped magnetic pole portion 30 includes the two end portions 31 and 32 and the central portion 33 disposed between the two end portions 31 and 32. The central portion 33 has a plurality of first magnetic pole portions 34 made of the same magnetic poles as the end portions 31 and 32 and a plurality of second magnetic pole portions 35 made of magnetic poles different from the end portions 31 and 2. In order to make the magnetism of the central portion 33 the same as that of each of the end portions 31 and 32 and the first magnetic pole portion 34, the area along the circumferential direction of the first magnetic pole portion 34 is adjacent to itself in the circumferential direction. It is larger than the area of 35 in the circumferential direction.

  According to this, the magnetic force of the central portion 33 is weakened, and the magnetic force of the chipped magnetic pole portion 30 is also weakened. Thereby, the magnetic flux formed around the chipped magnetic pole part 30 due to the chipped magnetic pole part 30 is suppressed from being disturbed. As a result, for example, the detection unit 200 shown in the present embodiment can prevent the rotation angle of the rotating body 100 from being detected with high accuracy.

  As described above, when the magnetic force of the chipped magnetic pole part 30 is weakened, the magnetic force of the equimagnetic pole part 11 adjacent to the chipped magnetic pole part 30 in the circumferential direction and the magnetic pole part 12 adjacent to the chipped magnetic pole part 30 are Strengthen. Therefore, there is a possibility that the magnetic flux formed between the two may be disturbed.

  In FIG. 5, unlike the present embodiment, boundaries # N−2, # N−1, #N, # 1, # 2, and # 3 when the different pole portions 13 and 14 are not formed on the rotating body 100 are shown. The relationship between each angle error and the separation distance (air gap) between the rotating body 100 and the detection unit 200 is indicated by a solid line, a broken line, a one-dot chain line, a two-dot chain line, a thick line, and a thick broken line. The boundary between the chipped magnetic pole part 30 and the first equal magnetic pole part 11 adjacent thereto is #N and # 1. The boundaries between the first equal magnetic pole part 11 and the adjacent second equal magnetic pole part 12 are # N-1 and # 2. The boundary between the second equal magnetic pole part 12 and the adjacent first equal magnetic pole part 11 is # N-2 and # 3. Magnetic fluxes at the boundaries # N−2, # N−1, #N, # 1, # 2, and # 3 located in the vicinity of the chipped magnetic pole part 30 are mainly affected by the chipped magnetic pole part 30. Magnetic fluxes formed at the boundaries # 4 to # N-3 of the other equal magnetic pole portions 11 and 12 are not so affected by the missing magnetic pole portion 30 and have a small angle error with respect to the air gap. However, as shown in FIG. 5, each of the boundaries # N−2, # N−1, #N, # 1, # 2, and # 3 is affected by the chipped magnetic pole portion 30 to some extent. An angular error occurs. Since the different pole portions 13 and 14 are not formed on the rotating body 100, the balance of magnetic force is not adjusted, and an angle error occurs at each boundary.

  On the other hand, in the rotating body 100 described in the present embodiment, the uniform magnetic pole portion 10 is provided with the different polar portions 13 and 14 having different magnetic poles from the same magnetic pole portion 10. As the distance from the portion 33 in the circumferential direction is gradually decreased. As a result, the magnetic force of the equal magnetic pole portions 11 and 12 gradually increases as the distance from the central portion 33 increases, and the magnetic force difference between the equal magnetic pole portions 11 and 12 and the chipped magnetic pole portion 30 gradually increases. Therefore, as shown in FIG. 6, the magnetic force is balanced, and the angle error generated at the boundaries # N−2, # N−1, #N, # 1, # 2, and # 3 is reduced. As a result, turbulence in the magnetic flux formed between the equal magnetic pole portions 11 and 12 and the chipped magnetic pole portion 30 is suppressed.

  The magnetic pole portions 34 and 35, the end portions 31 and 32, and the different pole portions 13 and 14 are arranged symmetrically in the circumferential direction via the reference line BL. According to this, the magnetic field in the circumferential direction via the reference line BL is symmetric, unlike the configuration in which the magnetic pole part, the end part, and the different pole part are arranged asymmetrically in the circumferential direction via the reference line BL. Form the shape. Therefore, the magnetic flux formed between the equal magnetic pole part 10 and the chipped magnetic pole part 30 is prevented from being disturbed, and the detection part 200 cannot detect the rotation angle of the rotating body 100 with high accuracy. It is suppressed.

  The area of each of the second magnetic pole portions 35 is smaller than that of all of the first magnetic pole portions 34. According to this, unlike the configuration in which at least one area of the second magnetic pole part is larger than any one of the first magnetic pole parts, the magnetic property of the second magnetic pole part 35 locally at the central part 33. Is suppressed from strengthening.

  The magnetic pole portions 34 and 35 each have a rectangular shape with a constant thickness, and are alternately arranged in the circumferential direction. That is, each of the magnetic pole portions 34 and 35 has a stripe shape. According to this, the central portion 33 is formed at the central portion 33 only by adjusting the lateral width, unlike the case where the magnetic portion has a different magnetic pole and is formed of a magnetic pole portion such as a triangle or a trapezoid having a non-uniform thickness. Magnetic flux can be adjusted.

  The lateral widths L3 and L4 of the end portions 31 and 32 are wider than the lateral widths L1 and L2 of the magnetic pole portions 34 and 35, respectively. According to this, unlike the configuration in which the lateral width of the end portion is narrower than the lateral width of the magnetic pole portion, the magnetic flux formed by the end portions 31 and 32 and the first equal magnetic pole portion 11 adjacent thereto is adjacent in the circumferential direction. It is possible to approach the magnetic flux formed by the equal magnetic pole portions 11 and 12. Accordingly, it is possible to prevent the detection unit 200 from detecting the rotation angle of the rotating body 100 with high accuracy.

  In order to make the magnetic flux formed at the central portion 33 uniform, the lateral widths L1 of all the first magnetic pole portions 34 are equal to each other, and the lateral widths L2 of all the second magnetic pole portions 35 are equal to each other. According to this, unlike the configuration in which the widths of all the first magnetic pole portions are different from each other and the widths of all the second magnetic pole portions are different from each other, the magnetic flux formed in the central portion 33 is uniform. Thereby, it is suppressed that it becomes impossible to detect the rotation angle of the rotating body 100 with high accuracy due to local magnetic flux disturbance.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, there are 57 examples in which the equal magnetic pole portions 11 and 12 are combined, and there are 58 boundaries. However, the total number of the equal magnetic pole portions 11 and 12 is three or more, and the number of boundaries may be four or more.

  In the present embodiment, the horizontal width of the first region 10a is 342 ° in terms of the central angle of the rotating body 100, and the horizontal width of the second region 30a is 18 °. However, the first region 10a only needs to have a longer width than the second region 30a, and is not limited to the above example.

  In the present embodiment, an example in which the horizontal width of each of the equal magnetic pole portions 11 and 12 is 6 ° in terms of the central angle of the rotating body 100 has been described. However, the width of each of the equal magnetic pole portions 11 and 12 is not limited to the above example, and may be 5 °, for example. The second region 30 a has a longer width than the equimagnetic pole portion 10.

  In the present embodiment, an example is shown in which the magnetic pole portions 34 and 35 each have a rectangular shape with a constant thickness and are alternately arranged in the circumferential direction. However, the shape and arrangement of the magnetic pole portions 34 and 35 are not limited to the above example, and the properties of the central portion 33 as the magnetic pole may be the same as those of the end portions 31 and 32 and the first magnetic pole portion 34. .

  In this embodiment, the lateral width L1 of the first magnetic pole portion 34 is 1.25 °, and the lateral width L2 of the second magnetic pole portion 35 is 0.5 °. However, the width L1 is not limited to the above example as long as it is wider than the width L2. More preferably, the lateral width L2 of the second magnetic pole part 35 is in a relationship of 0.4 to 0.7 times the lateral width L1 of the first magnetic pole part 34.

  In the present embodiment, an example in which there are six first magnetic pole portions 34 and seven second magnetic pole portions 35 is shown. However, the total area of all the second magnetic pole portions 35 only needs to be smaller than the total area of all the first magnetic pole portions 34, and the number of magnetic pole portions 34 and 35 is not limited to the above example. More preferably, the total lateral width of all the second magnetic pole portions 35 is in a relationship of 0.18 to 0.33 times the total lateral width of all the first magnetic pole portions 34 and the end portions 31 and 32.

  In the present embodiment, the example in which the ratio of the S pole in the chipped magnetic pole part 30 is 67 to 82% and the ratio of the N pole is 18 to 33% is shown. However, conversely, the ratio of the N pole in the chipped magnetic pole part 30 may be 67 to 82%, and the ratio of the S pole may be 18 to 33%. In this case, as shown in FIGS. 7 and 8, each of the end portions 31 and 32 and the first magnetic pole portion 34 is an N pole, and the second magnetic pole portion 35 is an S pole. Further, the equimagnetic pole portion (first equimagnetic pole portion 11) adjacent to the chipped magnetic pole portion 30 in the circumferential direction becomes the S pole, and the equimagnetic pole portion (second equimagnetic pole portion 12) adjacent thereto becomes the N pole. Further, the first different pole portion 13 becomes the N pole, and the second different pole portion 14 becomes the S pole.

  In the present embodiment, an example in which the lateral widths L3 and L4 of the end portions 31 and 32 are equal to each other is shown. However, it is possible to adopt a configuration in which the lateral widths L3 and L4 of the end portions 31 and 32 are different from each other. However, the lateral widths L3 and L4 are preferably in a relationship of 0.14 to 0.25 times the lateral width of the chipped magnetic pole part 30.

  In the present embodiment, one first different pole portion 13 is formed in each of the two first equal magnetic pole portions 11 adjacent to the chipped magnetic pole portion 30 in the circumferential direction, and in the circumferential direction with the first equal magnetic pole portion 11. An example is shown in which one second different pole portion 14 is formed in each of two adjacent second equal magnetic pole portions 12. However, it is only necessary that the first different pole portion 13 is formed in each of the two first equal magnetic pole portions 11 adjacent to the chipped magnetic pole portion 30 in the circumferential direction. The second different pole portion 14 may not be formed in each of the two adjacent second equal magnetic pole portions 12. Further, as shown in FIGS. 9 and 10, the number of first different pole portions 13 formed in the first equal magnetic pole portion 11 and the number of second different pole portions 14 formed in the second equal magnetic pole portion 12. Each is not limited. As the magnetic force of the equal magnetic pole portions 11 and 12 gradually increases as the distance from the central portion 33 increases in the circumferential direction, the areas of the different polar portions 13 and 14 gradually decrease as the distance from the central portion 33 increases in the circumferential direction. Just do it. In FIG. 9, two first different magnetic pole portions 13 are formed in each of the two first equal magnetic pole portions 11 adjacent to the chipped magnetic pole portion 30 in the circumferential direction, and adjacent to the first equal magnetic pole portion 11 in the circumferential direction. One second different pole portion 14 is formed in each of the two second equal magnetic pole portions 12. Further, in FIG. 10, one first different pole portion 13 is formed in each of two first equal magnetic pole portions 11 adjacent to the chipped magnetic pole portion 30 in the circumferential direction. Two second different pole portions 14 are formed in each of two adjacent second equal magnetic pole portions 12. 9 and 10, the total area of the first different pole portion 13 is larger than the total area of the second different pole portion 14. Needless to say, the first different pole portion 13 is formed on the first equal magnetic pole portion 11 that forms the boundaries # N-3 and N-2 and the first equal magnetic pole portion 11 that forms the boundaries # 3 and # 4. A formed configuration or the like can also be employed.

  In the present embodiment, the lateral width L6 of the first different pole portion 13 is 0.5 °, and the lateral width L7 of the second different pole portion 14 is 0.4 °. However, the total lateral width of the different pole portions 13 and 14 formed in one equal magnetic pole portion 11 and 12 is not limited to the above example, and the width of each of the equal magnetic pole portions 11 and 12 is 0.03 to 0. It may be 20 times.

  In the present embodiment, the configuration in which the magnetic pole portions 34 and 35, the end portions 31 and 32, and the different polar portions 13 and 14 are symmetrically arranged in the circumferential direction via the reference line BL is shown. However, it is also possible to employ a configuration in which the magnetic pole portions 34 and 35, the end portions 31 and 32, and the different polar portions 13 and 14 are arranged asymmetrically in the circumferential direction via the reference line BL.

  In the present embodiment, in order to make the magnetic flux formed in the central portion 33 uniform, the lateral widths L1 of all the first magnetic pole portions 34 are equal to each other, and the lateral widths L2 of all the second magnetic pole portions 35 are equal to each other. An example is shown. However, it is also possible to adopt a configuration in which the lateral widths L1 of all the first magnetic pole portions 34 are different from each other and the lateral widths L2 of all the second magnetic pole portions 35 are different from each other. Alternatively, a configuration in which at least one set of lateral widths L1 in all the first magnetic pole portions 34 is different from each other, and at least one set of lateral widths L2 in all the second magnetic pole portions 35 may be equal to each other.

  For example, as shown in FIG. 10, the second magnetic pole portion 35 adjacent to the end portions 31 and 32 in the circumferential direction has a larger area in the circumferential direction than the three second magnetic pole portions 35 located on the reference line BL side. The area difference between the end portions 31 and 32 is small. According to this, the magnetic force difference between the end portions 31 and 32 and the second magnetic pole portion 35 adjacent thereto is reduced, and between the end portions 31 and 32 and the first equal magnetic pole portion 11 adjacent thereto. Disturbances in the formed magnetic flux are suppressed. In FIG. 10, seven second magnetic pole portions 35 are formed. However, each of the second equal magnetic pole portions 35 located on the above-described reference line BL side has the same area, and the remaining four second magnetic pole portions. The areas of 35 are equal. Specifically, the lateral width of the three second equal magnetic pole portions 35 is 0.5 °, and the lateral width of the remaining four second equal magnetic pole portions 35 is 0.6 °.

  For example, as shown in FIG. 11, the area of the second magnetic pole part 35 included per unit area gradually decreases as the distance from the reference line BL in the circumferential direction decreases, and the area of the first magnetic pole part 34 gradually increases. Increasing configurations can also be employed. According to this, the magnetic force of the center part 33 increases gradually as it goes to the edge parts 31 and 32 along the circumferential direction from the reference line BL. Therefore, unlike the configuration in which the magnetic force in the central portion gradually decreases from the reference line BL toward the end portion along the circumferential direction, the chipped magnetic pole portion 30 and the first equal magnetic pole portion 11 adjacent thereto in the circumferential direction. Boundaries #N and # 1 as magnetic poles become clear, and turbulence in the magnetic flux formed between them is suppressed.

10, 11, 12, etc. Magnetic pole part 10 a, first region 30, chipped magnetic pole part 30 a, second region 31, 32, end 33, central part 34,. 1st magnetic pole part 35 ... 2nd magnetic pole part 13, 14 ... different pole part 100 ... rotating body

Claims (5)

An annular rotating body that rotates in the circumferential direction of a rotating shaft that penetrates its center (RC) in the thickness direction,
An equal magnetic pole portion (10) having a constant lateral width in the circumferential direction;
A chipped magnetic pole part (30) having a wider width than the equal magnetic pole part,
The outer ring surface of the rotating body has a first region (10a) in which a plurality of the equal magnetic pole portions (11, 12) having different magnetic poles are alternately arranged in the circumferential direction, and a first portion where the chipped magnetic pole portions are formed. 2 regions (30a),
The chipped magnetic pole portion includes two end portions (31, 32) made of a magnetic pole different from the equimagnetic pole portion adjacent in the circumferential direction, and a central portion disposed between the two end portions in the circumferential direction. (33)
The central portion includes a plurality of first magnetic pole portions (34) made of the same magnetic pole as the end portion, and a plurality of second magnetic pole portions (35) made of a magnetic pole different from the end portion,
The area of the first magnetic pole part along the circumferential direction is larger than the area of the second magnetic pole part adjacent to itself in the circumferential direction in the circumferential direction, and the property of the central part as the magnetic pole is the end part. And the same as each of the first magnetic pole portions,
At least two of the plurality of equi-magnetic pole portions are provided with different pole portions (13, 14) having different magnetic poles from themselves,
The magnetic pole portions of the different magnetic pole portions provided in the equal magnetic pole portion as it moves away from the central portion in the circumferential direction so that the magnetic force of the plurality of equal magnetic pole portions gradually increases as the distance from the central portion in the circumferential direction increases. A rotating body characterized by a gradually decreasing area in the circumferential direction.   Each of the first magnetic pole part, the second magnetic pole part, the end part, and the different pole part is symmetrical in the circumferential direction via a reference line (BL) penetrating the center of the central part in the thickness direction. The rotating body according to claim 1, wherein the rotating body is arranged.   The second magnetic pole portion adjacent to the end portion in the circumferential direction has a larger area in the circumferential direction and a smaller area difference from the end portion than the second magnetic pole portion located on the reference line side. The rotating body according to claim 2, wherein the rotating body is provided. The central portion is formed by alternately arranging the first magnetic pole portion and the second magnetic pole portion in the circumferential direction,
The area of the second magnetic pole part included per unit area gradually decreases and the area of the first magnetic pole part gradually increases as the distance from the reference line in the circumferential direction increases. The rotating body according to 2.   In order to make the properties of the central portion as magnetic poles the same as the end portions and the first magnetic pole portions, the first magnetic pole portions and the second magnetic pole portions are alternately arranged in the circumferential direction, 5. The area in the circumferential direction of each of the second magnetic pole parts is smaller in area in the circumferential direction than any of all the first magnetic pole parts. Rotating body.

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