Series of magnetic modulation gears and magnetic modulation gear

Abstract

To suitably line up magnetic modulation gears having different reduction ratios.SOLUTION: The series of magnetic modulating gears 1 comprises a first magnetic modulating gear 1A and a second magnetic modulating gear 1B. The first magnetic modulation gear 1A and the second magnetic modulation gear 1B each include an inner magnetic pole body 41a, an intermediate magnetic pole body 54, and an outer magnetic pole body 12, and any two of the number of inner pole pairs Ni which is the number of pole pairs of the inner magnetic pole body 41a, the number of magnetic pole pieces Np which is the number of magnetic poles of the intermediate magnetic pole body 54, and the number of outer pole pairs No which is the number of pole pairs of the outer magnetic pole body 12 are different from each other. At least one of the inner magnetic pole body 41a, the intermediate magnetic pole body 54 and the outer magnetic pole body 12 includes a component common to the first magnetic modulating gear 1A and the second magnetic modulating gear 1B.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a series of magnetic modulation gears and magnetic modulation gears. [Background technology]

[0002] Conventionally, a magnetic modulation gear has been known in which multiple pole pieces are arranged between two magnets arranged on the inner and outer periphery, and the magnetic flux distribution between the inner and outer periphery is modulated. In the magnetic modulation gear, torque is transmitted between the inner periphery magnet and the pole pieces, and a reduced or increased speed rotation is transmitted (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-17984 Summary of the Invention [Problem to be solved by the invention]

[0004] When magnetic modulation gears with different reduction ratios are made into a series, it is desirable to have a suitable configuration that allows as many parts as possible to be shared. An object of the present invention is to provide a suitable lineup of magnetic modulation gears with different reduction ratios. [Means for solving the problem]

[0005] The present invention provides a series of magnetic modulation gears, including a first magnetic modulation gear and a second magnetic modulation gear, The first magnetic modulation gear and the second magnetic modulation gear are each including an inner pole piece, a middle pole piece, and an outer pole piece; Any two of the number of pole pairs of the inner magnetic pole body, the number of magnetic poles of the intermediate magnetic pole body, and the number of pole pairs of the outer magnetic pole body are different, At least one of the inner magnetic pole piece, the intermediate magnetic pole piece, and the outer magnetic pole piece includes a component that is common to the first magnetic modulation gear and the second magnetic modulation gear. [Effects of the Invention]

[0006] According to the present invention, it is possible to suitably line up magnetic modulation gears with different reduction ratios. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a cross-sectional view of a magnetic modulation gear according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 3] 10A to 10C are diagrams illustrating variations of inner magnetic pole bodies according to an embodiment. [Figure 4] 10A and 10B are diagrams illustrating an example of the number of pole pairs and the damping ratio when the number of magnetic pole pieces is constant. [Figure 5] FIG. 10 is a diagram illustrating an example of the number of pole pairs and the damping ratio when the number of outer pole pairs is constant. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0009] The magnetic modulation gear series according to this embodiment is a product group of magnetic modulation gears 1 including a first magnetic modulation gear 1A and a second magnetic modulation gear 1B. The first magnetic modulation gear 1A and the second magnetic modulation gear 1B are magnetic modulation gears that have the same basic structure but different reduction ratios.

[0010] [Overall structure of magnetic modulation gear] FIG. 1 is a cross-sectional view of a magnetic modulation gear 1 according to this embodiment, and FIG. 2 is a cross-sectional view taken along line III-III in FIG. In the following description, the direction along the central axis Ax of the magnetic modulation gear 1 is referred to as the "axial direction," the direction perpendicular to the central axis Ax as the "radial direction," and the direction of rotation about the central axis Ax as the "circumferential direction." In addition, in the axial direction, the side connected to an external driven member (left side in the drawing) is referred to as the "output side," and the opposite side (right side in the drawing) is referred to as the "input side." In addition, an inner magnet 41c, which will be described later, is not shown in FIG. 2.

[0011] As shown in Figures 1 and 2, the magnetic modulation gear 1 according to this embodiment comprises a casing (frame) 10, an input side cover 20 and an output side cover 30 which cover both axial sides of the casing 10, and an input shaft 40 and a magnetic modulation body 50 whose main part is housed inside these.

[0012] The casing 10 is formed in a substantially cylindrical shape centered on a central axis Ax, and has a stator yoke 11 and an outer magnetic pole body 12 on its inner periphery. The stator yoke 11 is formed in a cylindrical shape and is fitted inside the casing 10 . The outer magnetic pole body 12 is composed of a plurality of outer magnets 12a. The plurality of outer magnets 12a are permanent magnets such as neodymium magnets, and have a greater number of pole pairs than the inner magnetic poles 41b of the input shaft 40 (described later). They are attached to the inner peripheral surface of the stator yoke 11 so that magnets with different polarities are arranged alternately in the circumferential direction. However, the outer magnetic pole body 12 may be an integral ring-shaped body, or may be composed of divided outer magnets 12a arranged in the circumferential direction. Furthermore, on the inner periphery of the casing 10, closer to the input side than the stator yoke 11, a bearing 61 (for example, a ball bearing) that rotatably supports the magnetic modulation body 50 is arranged.

[0013] The input side cover 20 is disposed on the input side of the casing 10 and covers the inner opening of the casing 10 from the input side. The outer periphery of the input side cover 20 is fitted with the casing 10 by a spigot joint. In addition, a bearing 62 (e.g., a ball bearing) that rotatably supports the input shaft 40 is disposed on the inner periphery of the input side cover 20.

[0014] The output side cover 30 is disposed on the output side of the casing 10, and covers the inner opening of the casing 10 from the output side. The outer periphery of the output side cover 30 is fitted with the casing 10 by a spigot. In addition, a bearing 63 (e.g., a ball bearing) that rotatably supports the magnetic modulation body 50 is disposed on the inner periphery of the output side cover 30.

[0015] The input shaft 40 is a shaft that rotates around the central axis Ax, and includes a disk portion 41 and a motor coupling portion 42. The input shaft 40 is rotatably supported by a bearing 62 arranged between the input side cover 20 and the input shaft 40, and a bearing 64 arranged between the input side cover 20 and the magnetic modulator 50. The motor connecting portion 42 extends axially toward the input side from the disk portion 41. The tip side of the motor connecting portion 42 protrudes to the outside from the input side cover 20, and this protrusion is connected to a motor (not shown).

[0016] The disk portion 41 has an inner magnetic pole body 41a on its outer periphery, which is arranged on the inner diameter side of the outer magnetic pole body 12. The inner magnetic pole body 41a is composed of multiple inner magnetic poles 41b. The multiple inner magnetic poles 41b are attached to the outer periphery of the disk portion 41 so that inner magnetic poles 41b with different polarities are arranged alternately in the circumferential direction. However, the inner magnetic pole body 41a may be an integral ring-shaped body, or may be composed of divided inner magnetic poles 41b arranged in the circumferential direction. As will be described later, the inner magnetic pole 41b is composed of at least one inner magnet 41c (see FIG. 3).

[0017] The magnetic modulation body 50 has an output shaft portion 51 and a cylindrical portion 52 . The output shaft 51 is a metal shaft that rotates around the central axis Ax. Approximately half of the output side of the output shaft 51 protrudes from the output-side cover 30 to the outside, and this protruding portion is connected to a driven member (not shown). An approximately central portion of the output shaft portion 51 in the axial direction is rotatably supported by a bearing 63 arranged between the output side cover 30. A bearing 64 (e.g., a ball bearing) that rotatably supports the input shaft 40 is arranged at the input side end of the output shaft portion 51. The output side end of the cylindrical portion 52 is connected to the outer periphery of the output shaft portion 51 at a position in the axial direction between the bearing 63 and the bearing 64.

[0018] The cylindrical portion 52 is formed in a substantially cylindrical shape centered on the central axis Ax, and has an intermediate magnetic pole body 54 arranged at an axial position corresponding to the outer magnetic pole body 12 and the inner magnetic pole body 41 a. The intermediate magnetic pole body 54 has a plurality of magnetic pole pieces 54 a. The multiple pole pieces 54a are arranged at predetermined intervals in the circumferential direction and are formed into a circular ring shape as a whole. The multiple pole pieces 54a (intermediate pole bodies 54) are arranged concentrically on the inner diameter side of the outer pole body 12 and on the outer diameter side of the inner pole body 41a, with a predetermined gap between them. Each pole piece 54a is made by laminating thin electromagnetic steel plates (laminated steel plates) in the axial direction.

[0019] Circumferentially adjacent pole pieces 54a are connected to each other by connecting portions 54b therebetween. The connecting portion 54b is made of resin and constitutes a part of the resin portion 56 described later. The outer peripheral surface of the connecting portion 54b is recessed radially inward relative to the outer peripheral surface of the pole piece 54a. However, the inner and outer circumferential surfaces of the connecting portion 54b may be flush with the corresponding surfaces of the pole piece 54a, or the inner circumferential surface may be recessed toward the outer diameter side. Furthermore, the connecting portion 54b may be made of an electromagnetic steel plate integrally with the pole piece 54a. In this case, the radial position and width of the connecting portion 54b are not particularly limited, but may be configured as described in, for example, WO 2023 / 026804.

[0020] A bearing support ring 55 made of metal (for example, stainless steel) is disposed at the input side end of the cylindrical portion 52. The bearing support ring 55 is fixed to the outer periphery of the cylindrical portion 52, and an inner ring of a bearing 61 disposed between the cylindrical portion 52 and the casing 10 is fitted onto the outer periphery of the bearing support ring 55. The cylindrical portion 52, excluding the pole pieces 54a and the bearing support ring 55, is a resin portion 56 made of resin (e.g., super engineering plastic). Resin is also filled between the multiple pole pieces 54a, and this portion constitutes the above-mentioned connecting portion 54b. The output side end of the resin portion 56 projects radially inward and is connected to the output shaft portion 51. A plurality of protrusions 57 projecting radially inward are arranged circumferentially on the inner periphery of this end. The plurality of protrusions 57 are molded to correspond to the plurality of recesses 51a on the outer periphery of the output shaft portion 51, and engagement between the protrusions 57 and the recesses 51a firmly fixes the output shaft portion 51 and the cylindrical portion 52 (resin portion 56) together, suppressing mutual movement in the radial and axial directions.

[0021] [Configuration of inner pole body] As shown in Figures 3(a) and 3(b), in the inner magnetic pole body 41a, each inner magnetic pole 41b is composed of at least one inner magnet 41c. Each inner magnet 41c is a permanent magnet, such as a neodymium magnet, and includes magnets of different polarities, all of which are substantially the same shape and size. Specifically, each inner magnetic pole 41b is composed of at least one inner magnet 41c of the same polarity that is adjacent to each other in the circumferential direction. Each inner magnet 41c is formed to a size that divides the inner magnetic pole body 41a evenly around the circumference, regardless of polarity. In the inner magnetic pole body 41a configured in this manner, the number of pole pairs (the number of inner pole pairs Ni) of the inner magnetic pole 41b can be changed by changing the arrangement of the inner magnets 41c. In the example of Figure 3, each inner magnet 41c has a size that divides the circumference into 12 equal parts, and the number of inner pole pairs Ni is (a) 6, (b) 3, (c) 2, and (d) 1.

[0022] [Relationship between the number of magnetic poles (pole pairs) and reduction ratio] In the magnetic modulation gear 1, when the input shaft 40 rotates around the central axis Ax, the spatial magnetic flux waveform formed by the inner magnetic pole body 41a (inner magnetic pole 41b) is modulated by the intermediate magnetic pole body 54 (pole piece 54a) to the same frequency as that of the outer magnetic pole body 12 (outer magnet 12a). Then, rotational torque is transmitted to the magnetic modulation body 50 using the magnetic force between the intermediate magnetic pole body 54 and the outer magnetic pole body 12. In this way, the rotational motion input to the input shaft 40 is decelerated and output to a driven member (not shown) connected to the output shaft portion 51 of the magnetic modulation body 50. Alternatively, the intermediate magnetic pole body 54 may be fixed, and the outer magnetic pole body 12 may be provided on a rotatable low-speed rotor, and output may be taken from the low-speed rotor.

[0023] Here, the reduction ratio R of the magnetic modulation gear 1 is expressed by the following formula (1) when the output shaft is the intermediate magnetic pole body 54, and by the following formula (2) when the output shaft is the outer magnetic pole body 12. R=Np / Ni (1) R=No / Ni (2) Here, Np is the number of magnetic poles of the intermediate magnetic pole body 54 (number of magnetic pole pieces 54a: number of magnetic pole pieces), No is the number of pole pairs of the outer magnet 12a (number of outer pole pairs), and Ni is the number of pole pairs of the inner magnetic pole body 41a (number of inner pole pairs).

[0024] Furthermore, the relationship of the following formula (3) holds between the number of magnetic pole pieces Np, the number of outer pole pairs No, and the number of inner pole pairs Ni. Np = Ni + No (3)

[0025] [Magnetic Modulation Gear Series] Next, a series system of the magnetic modulation gear 1 according to this embodiment will be described. The series of magnetic modulation gears 1 according to this embodiment is organized according to the characteristics of the reducer (frame number and reduction ratio R). Here, the "frame number" of a reducer means "the size classification when focusing on one of the various concepts of transmission torque, such as the output torque, peak torque, or rated torque of a reducer, with the same reduction ratio R." In other words, if the reduction ratio R is the same, reducers with different frame numbers will have the same tendency for size relationships, regardless of the specific type of transmission torque being focused on, and this tendency also coincides with the size relationships of the reducers (there is no reversal of the size relationships). In this embodiment, the term "series of magnetic modulation gears" is understood to mean "a group of magnetic modulation gears that are in the same line-up, and that, except for the points described below, have a common configuration other than the magnetic modulation power transmission section (inner magnetic pole body 41a, intermediate magnetic pole body 54, outer magnetic pole body 12), and have different reduction ratios R." Here, "common configuration (same shape and dimensions)" means that the basic shapes and dimensions are designed to be the same, and slight differences due to manufacturing errors and the like do exist.

[0026] Here, when multiple reduction ratios R are available for magnetic modulation gears of the same frame number (size), different reduction ratios R can be achieved by changing any two of the number of inner pole pairs Ni, the number of outer pole pairs No, and the number of magnetic pole pieces Np according to the above formulas (1) to (3). For example, if the number of pole pieces Np is constant, the number of inner pole pairs Ni, the number of outer pole pairs No, and the reduction ratio R will be as shown in Figure 4. Also, if the number of outer pole pairs No is constant, the number of inner pole pairs Ni, the number of pole pieces Np, and the reduction ratio R will be as shown in Figure 5.

[0027] Furthermore, in the magnetic modulation gear 1 of this embodiment, as described above, the number of inner pole pairs Ni can be changed by adjusting the arrangement of the inner magnets 41c in the inner magnetic pole body 41a. Therefore, in the lineup of the series of magnetic modulation gears 1 of this embodiment (for example, the first magnetic modulation gear 1A and the second magnetic modulation gear 1B), the inner magnetic pole body 41a can be configured to be composed of a common plurality of inner magnets 41c, with the number of pole pairs (the number of inner pole pairs Ni) being different from each other. In other words, in the series of magnetic modulation gears 1 of this embodiment, different numbers of inner pole pairs Ni can be realized while using inner magnets 41c with a common configuration.

[0028] Therefore, in the series of magnetic modulation gears 1 of this embodiment, when the number of magnetic pole pieces Np is constant, different numbers of outer pole pairs No can be realized by preparing different magnets (outer magnets 12a) for only the outer magnetic pole bodies 12 (see FIG. 4). The outer magnets 12a may have a common configuration and the spacing between them may be changed. In other words, to realize a smaller number of pole pairs, the spacing between adjacent outer magnets 12a may be increased. Furthermore, when the number of outer pole pairs No is constant, that is, when the number of magnetic pole pieces Np is changed, magnetic pole pieces 54a of the same shape may be used, and the number and spacing thereof may be changed (see FIG. 5). Here, the inner magnetic pole body 41a is configured from an inner magnet 41c of a shape and size that is common to the same series. However, it is sufficient if at least one of the inner magnetic pole body 41a, the intermediate magnetic pole body 54, and the outer magnetic pole body 12 includes a component that is common to two magnetic modulation gears 1 of the same series. For example, the number of pole pairs of the outer magnet 12a may be configured to be variable, similar to the inner magnet 41c of this embodiment.

[0029] [Technical effect of this embodiment] As described above, according to this embodiment, two magnetic modulation gears 1 in the same series differ in any two of the number of pole pairs of the inner magnetic pole body 41a (number of inner pole pairs Ni), the number of magnetic poles of the intermediate magnetic pole body 54 (number of magnetic pole pieces Np), and the number of pole pairs of the outer magnetic pole body 12 (number of outer pole pairs No). In addition, at least one of the inner magnetic pole body 41a, the intermediate magnetic pole body 54, and the outer magnetic pole body 12 includes a component that is common to two magnetic modulation gears 1 in the same series. This allows magnetic modulation gears 1 with different reduction ratios R to be suitably lined up in a series of the same size (frame number).

[0030] Furthermore, according to this embodiment, the two magnetic modulation gears 1 in the same series have inner magnetic pole bodies 41a configured with inner magnets 41c of the same shape and size, but have different numbers of pole pairs (number of inner pole pairs Ni). This allows for a suitable lineup of magnetic modulation gears 1 with different reduction ratios R while reducing costs. In other words, if you try to simply make two of the number of inner pole pairs Ni, the number of magnetic pole pieces Np, and the number of outer pole pairs No different in a series with the same frame number, the number of drawings will increase, making it difficult to obtain economies of scale for parts (part unit price, management costs, etc.). In this regard, according to this embodiment, the number of inner pole pairs Ni can be changed while using the same inner magnet 41c. Therefore, the reduction ratio R can be changed simply by adjusting the configuration of either the intermediate magnetic pole body 54 or the outer magnetic pole body 12. This reduces the number of parts in the entire series, thereby reducing costs.

[0031] Furthermore, according to this embodiment, when two magnetic modulation gears 1 in the same series have different numbers of magnetic pole pieces Np and the same number of outer pole pairs No, it is preferable that the intermediate magnetic pole bodies 54 are composed of magnetic pole pieces 54a of a common shape and size. This allows the pole piece 54a to be shared between two magnetic modulation gears 1 of the same series, thereby reducing costs.

[0032] Furthermore, according to this embodiment, when two magnetic modulation gears 1 in the same series have the same number of magnetic pole pieces Np but different numbers of outer pole pairs No, it is preferable that the outer magnetic pole bodies 12 are composed of outer magnets 12a of a common shape and size, and the spacing between two adjacent outer magnets 12a is different. This allows two magnetic modulation gears 1 of the same series to share the outer magnet 12a, thereby reducing costs.

[0033] Furthermore, according to this embodiment, in each magnetic modulation gear 1, the inner magnetic pole body 41a has multiple inner magnets 41c formed to the same size and shape, and at least one inner magnet 41c of the same polarity adjacent to each other in the circumferential direction constitutes each of the multiple inner magnetic poles 41b. As a result, by adjusting the arrangement of the inner magnets 41c, it is possible to change the number of inner pole pairs Ni. Also, by dividing the inner magnets 41c, it is possible to suppress eddy currents.

[0034] [others] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the details shown in the above-described embodiments can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0035] 1, 1A, 1B magnetic modulation gear 12 Outer pole body 12a outer magnet 41a Inner pole body 41b Inner magnetic pole 41c Inner magnet 54 Intermediate magnetic pole body 54a pole piece Ni number of inner pole pairs No. of outer pole pairs Np Number of pole pieces R Reduction ratio

Claims

1. A series of magnetic modulation gears including a first magnetic modulation gear and a second magnetic modulation gear, The first magnetic modulation gear and the second magnetic modulation gear are each including an inner pole piece, a middle pole piece, and an outer pole piece; any two of the number of pole pairs of the inner magnetic pole body, the number of magnetic poles of the intermediate magnetic pole body, and the number of pole pairs of the outer magnetic pole body are different, At least one of the inner magnetic pole body, the intermediate magnetic pole body, and the outer magnetic pole body includes a component common to the first magnetic modulation gear and the second magnetic modulation gear. A series of magnetic modulation gears.

2. The first magnetic modulation gear and the second magnetic modulation gear are The inner magnetic pole bodies are composed of inner magnets of a common shape and size, and have different numbers of pole pairs.

2. The series of magnetic modulation gears according to claim 1.

3. The first magnetic modulation gear and the second magnetic modulation gear are the numbers of magnetic poles of the intermediate magnetic pole bodies are different from each other, the number of pole pairs of the outer magnetic pole bodies is equal to each other; 3. The series of magnetic modulation gears according to claim 2.

4. The first magnetic modulation gear and the second magnetic modulation gear are The intermediate pole body is composed of pole pieces of a common shape and size.

4. The series of magnetic modulation gears according to claim 3.

5. The first magnetic modulation gear and the second magnetic modulation gear are the numbers of magnetic poles of the intermediate magnetic pole bodies are equal to each other, The numbers of pole pairs of the outer magnetic pole bodies are different from each other.

3. The series of magnetic modulation gears according to claim 2.

6. The first magnetic modulation gear and the second magnetic modulation gear are The outer magnetic pole body is composed of outer magnets of a common shape and size, and the intervals between two adjacent outer magnets are different from each other.

6. The series of magnetic modulation gears according to claim 5.

7. an inner pole body including a plurality of inner magnets arranged in a circumferential direction; an intermediate magnetic pole body disposed radially outer than the inner magnetic pole body; an outer magnetic pole body disposed radially outer than the intermediate magnetic pole body; Equipped with The inner pole body is The inner magnets are formed to the same size and shape, At least one of the inner magnets having the same polarity and adjacent to each other in the circumferential direction constitutes each of a plurality of magnetic poles. Magnetic modulation gear.

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