Radial gap type rotary electric machine

Abstract

To provide a radial gap type rotary electric machine capable of suppressing iron loss and achieving high efficiency even at a high rotational speed, and further suppressing an increase in production cost.SOLUTION: The radial gap type rotary electric machine 30 includes a stator 31 and a rotatably assembled rotor 32. In a stator, a pair of claw pole members 1, 2 having p-pieces of claw poles are mutually inverted in the axial direction and combined to constitute an engagement part. A unit stator 31 in which an annular coil 8 is arranged at an engagement part is provided. A magnetic body is provided which covers both ends of the annular coil and a surface opposite to a surface of the annular coil facing the rotor. The claw pole is formed of a dust core and is formed such that a tooth width of a surface facing the rotor is wide and the tooth width gradually narrows toward an opposite surface in a cross section orthogonal to an axis. In the rotator, permanent magnets 3 in which N poles and S poles are alternately magnetized to 2p poles along the circumferential direction are arranged on a surface facing the stators.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a radial gap type rotating electric machine used as an electric motor or a generator. [Background technology]

[0002] There is a strong market demand for rotating electrical machines to be lighter, thinner, shorter, and smaller, and recently, there has been an increasing demand for energy saving and high efficiency as a measure against global warming. There is also a strong demand for low vibration, low noise, and low cost.

[0003] There are various types of rotating electric machines known, but among them, the toroidal coil type has been attracting attention in recent years because three-phase types are more efficient and have vibration advantages than two-phase types, the number of coils can be reduced with toroidal coil types compared to concentrated winding or distributed winding, the structure is simple and inexpensive because there is no need for iron core slots, and there are no coil ends and the winding factor is high, which is advantageous for making the rotating electric machine smaller.

[0004] Conventional brushless DC motors (hereafter referred to as "BLDCMs" in this specification) use permanent magnets in the rotor and laminated silicon steel stator cores, with three-phase configurations being the norm for efficiency and low vibration. Conventional BLDCMs use distributed winding coils for applications where low vibration is important, and concentrated winding coils for applications where low cost and efficiency are important. This is because distributed winding coils have sinusoidal magnetic flux distribution, resulting in low vibration, but the large coil ends increase copper loss and reduce efficiency. Both distributed and concentrated winding coils have the common problem of complex structure, as they require the coils to be wound into slots in the stator core.

[0005] On the other hand, if a toroidal coil type is adopted, the problems associated with distributed winding and concentrated winding coils can be solved. As an example, the rotating electric machines described in Patent Document 1 and Non-Patent Document 1 are known, and are mass-produced for practical use in stepping motors (hereinafter referred to as "STM" in this specification). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 07-227075 [Non-Patent Document 1] Improvement of PM Stepping Motor Characteristics, 1993, Japan Management Association, Motor Technology Symposium, 2-2-1 Summary of the Invention [Problem to be solved by the invention]

[0007] However, while this toroidal coil type three-phase rotating electric machine is not a problem when used as an STM with a rotation speed of several hundred RPM, which is primarily intended for positioning purposes, when used as a BLDCM, which is primarily used to obtain power, the rotation speed reaches several thousand RPM, which increases iron loss, mainly due to eddy current loss, and causes problems with reduced efficiency.

[0008] More specifically, as shown in Fig. 8, a conventional three-phase toroid coil STM includes a stator having a U-phase claw pole 40. The stator includes a stator 41 including a U-phase toroid coil, a stator 42 including a V-phase toroid coil, and a stator 43 including a W-phase toroid coil. The stator also includes a rotor 44 that is rotatably disposed with an air gap in the radial direction relative to the stator. Rotor 44 has multiple permanent magnets arranged on its outer periphery, and the multiple permanent magnets are alternately arranged so that the polarities on the surface of adjacent permanent magnets are north, south, and north. Note that Fig. 8 shows stators 41-43 in an exploded view to explain the positional relationship between rotor 44 and claw poles 40.

[0009] A plurality of claw poles 40 are arranged on the surfaces of stator 41 including a U-phase toroid coil, stator 42 including a V-phase toroid coil, and stator 43 including a W-phase toroid coil, facing rotor 44. Adjacent claw poles 40 are arranged with a misalignment angle θ, which is an electrical angle of 60° or 120°. Each claw pole 40 is formed by stamping or bending electromagnetic steel sheet. Therefore, conventional claw poles 40 have a large iron loss and a low rotational speed, making them difficult to use in practical BLDCMs with high rotational speeds.

[0010] 9 is an orthogonal cross-sectional view of one phase of the claw poles in FIG. 8. Two adjacent claw poles 40 face the adjacent north and south poles of the rotor, but the mutual distance g must be large to suppress leakage flux between adjacent claw poles 40. In conventional claw-pole rotating electric machines, the claw poles are manufactured by punching magnetic steel plates using a press, so the area S of the opposing cross section between adjacent claw poles 40 is (plate thickness x axial length), and since the plate thickness is several mm, the area S is quite large. Meanwhile, the leakage flux permeance P across the gap g is calculated as P = μ0S / g, where μ0 is the magnetic permeability of air, which is 4π x 10 -7 The leakage flux permeance P is a small value, at only [H / m]. To keep the leakage flux small, the leakage flux permeance P must be small. Therefore, in the case of the claw poles 40 used in conventional claw-pole rotating electric machines, the area S is large for the reasons mentioned above, and the gap g is also large to keep the leakage flux permeance P small. As a result, the need to ensure the circumferential gap g requires a small claw pole tooth width, shown as b in FIG. 9 , which poses a problem: the opposing area S' of the claw poles 40 with the rotor 44 (the circumferential width b of the claw poles 40 × the axial length) cannot be increased. Because the flux linkage is proportional to this opposing area S', the flux linkage does not increase, posing a problem for achieving high torque.

[0011] As described above, the claw poles of conventional claw-pole rotating electric machines were manufactured by stamping or bending electromagnetic steel sheets, making it impossible to create complex shapes other than rectangular. As a result, the effective tooth width ratio k of conventional claw poles 40 was k = b / a, and the effective area of ​​the claw poles facing the rotor was approximately 70% of the rotor magnetic pole area, which posed a problem in that the magnetic flux linkage could not be increased accordingly.

[0012] Therefore, the present invention has been made to solve the above problems, and aims to provide a radial gap type rotating electric machine that can suppress iron loss and achieve high efficiency even at high rotational speeds, and further suppress high production costs, compared to conventional radial gap type rotating electric machines. [Means for solving the problem]

[0013] The radial gap type rotating electric machine according to the present invention, which solves the above-mentioned problems, is a radial gap type rotating electric machine having a stator and a rotor rotatably assembled to the stator with an air gap in the radial direction, wherein the stator has a pair of claw pole members each having a base and p claw poles projecting axially from the base and arranged concentrically with gaps in the circumferential direction, the claw poles of one claw pole member being inserted into the gaps of the other claw pole member and combined to form a meshing portion, and The rotor comprises a unit stator in which a torroid coil is arranged at a meshing portion, and the torroid coil has a magnetic body covering both ends of the torroid coil in the axial direction and the surface of the torroid coil opposite to the surface facing the rotor so that magnetic flux from the meshing portion interlinks with the torroid coil; the claw poles are formed from pressed iron cores and are formed so that the tooth width of the surface facing the rotor is wide in a cross section perpendicular to the axis and the tooth width gradually narrows toward the opposite surface; and the rotor has permanent magnets magnetized into 2p poles, with N and S poles alternately arranged along the circumferential direction on the surface facing the stator.

[0014] In the radial gap type rotating electric machine according to the present invention, it is preferable that a bobbin for the toroidal coil is disposed between the meshing portion and the toroidal coil.

[0015] In the radial gap type rotating electric machine according to the present invention, it is preferable that the claw pole member and the bobbin for the toroidal coil are integrally formed.

[0016] In addition, in the radial gap type rotating electric machine according to the present invention, it is preferable that the claw pole member and the bobbin for the toroidal coil are configured as separate bodies, and the bobbin for the toroidal coil has a claw pole receiving portion that positions the claw pole member.

[0017] In the radial gap rotating electric machine according to the present invention, it is preferable that the surfaces of the claw poles facing the annular coil are formed to be thin in the axial direction from the bases to the tips.

[0018] In the radial gap type rotating electric machine according to the present invention, it is preferable that a plurality of the stator units are stacked and arranged in the axial direction.

[0019] In addition, in the radial gap type rotating electric machine according to the present invention, it is preferable that each of the unit stators arranged in a stacked phase configuration or either one of the rotors facing the unit stators be arranged with a predetermined electrical angle shifted in the circumferential direction.

[0020] In addition, in the radial gap type rotating electric machine according to the present invention, it is preferable that the air gap length of the surfaces of the claw poles facing the rotor is small at the center of the circumferential tooth width, and the air gap increases from the center toward the tooth width ends.

[0021] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions. [Effects of the Invention]

[0022] In a radial gap rotating electric machine according to the present invention, the claw poles are formed using a powder iron core. The claw poles have a wide tooth width on the surface facing the rotor in a cross section perpendicular to the axis, gradually narrowing toward the opposite surface. The rotor has permanent magnets magnetized with alternating north and south poles along the circumferential direction, forming 2p poles. This allows the claw pole tooth width to be increased to a value close to the rotor magnetic pole width (180°), minimizing leakage flux and increasing flux linkage, resulting in high torque. Furthermore, the powder iron core stator reduces iron loss. Furthermore, the toroidal coil structure ensures that the number of claw poles facing the rotor across the air gap (2p) is the same as the number of rotor poles (2p), increasing the winding factor and resulting in high efficiency. The winding factor is proportional to the sine of β = 2p / (number of stator teeth). In conventional BLDCMs with distributed or concentrated winding, β is always less than 1. Furthermore, because the toroidal coil system is used, it is possible to provide a radial gap type rotating electric machine that is less expensive than the conventional laminated system. Furthermore, the radial gap type rotating electric machine according to the present invention is robust, allows for improved assembly precision, and allows for the optimum amount of powdered iron core used and weight reduction. Furthermore, because the powdered iron core is made by coating and binding iron powder with resin, its electrical resistance is much higher than that of silicon steel plate, and eddy currents can be reduced to negligible levels, thereby reducing iron loss. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a partial cross-sectional view showing a radial gap rotating electric machine according to an embodiment of the present invention; [Figure 2] 1 is an axis-orthogonal cross-sectional view of a radial gap rotating electric machine according to an embodiment of the present invention; [Figure 3] FIG. 2 is a perspective view showing a claw pole member used in the rotating electric machine according to the embodiment of the present invention. [Figure 4] FIG. 2 is a plan view of a claw pole member used in the rotating electric machine according to the embodiment of the present invention. [Figure 5] An expanded cross-sectional view of a claw pole. [Figure 6]10A and 10B are diagrams showing modified examples of the claw pole member used in the rotating electric machine according to the embodiment of the present invention. [Figure 7] 10A and 10B are diagrams showing other modified examples of the claw pole member used in the rotating electric machine according to the embodiment of the present invention. [Figure 8] FIG. 10 is a partial cross-sectional view showing a conventional radial gap type rotating electric machine. [Figure 9] FIG. 10 is a diagram illustrating a conventional claw pole. DETAILED DESCRIPTION OF THE INVENTION

[0024] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0025] FIG. 1 is a partial cross-sectional view showing a radial gap type rotating electric machine according to an embodiment of the present invention, FIG. 2 is an axial cross-sectional view of the radial gap type rotating electric machine according to an embodiment of the present invention, FIG. 3 is a perspective view showing a claw pole member used in the rotating electric machine according to an embodiment of the present invention, FIG. 4 is a plan view of the claw pole member used in the rotating electric machine according to an embodiment of the present invention, FIG. 5 is an expanded cross-sectional view of the claw pole, FIG. 6 is a view showing a modified example of the claw pole member used in the rotating electric machine according to this embodiment of the present invention, and FIG. 7 is a view showing another modified example of the claw pole member used in the rotating electric machine according to an embodiment of the present invention.

[0026] 1, a radial gap type rotating electric machine 30 according to this embodiment includes a hollow cylindrical stator 31 and a rotor 32 rotatably assembled to the inner circumferential side of the stator 31 with an air gap in the radial direction. The radial gap type rotating electric machine 30 according to this embodiment has a three-phase claw pole structure.

[0027] The stator 31 has unit stators 31a to 31c arranged in a stacked manner in the axial direction, and each of the stacked unit stators 31a to 31c is arranged with a circumferential offset of a predetermined electrical angle (120° electrical angle in the three-phase radial gap type rotating electric machine 30 according to this embodiment), similar to the conventional structure shown in FIG. 8 described above. The stator of each phase and the rotor facing it may be arranged in the same axial position without a circumferential offset of their magnetic pole positions, similar to the conventional structure shown in FIG. 8. Alternatively, as shown in FIG. 1, the unit stators 31a to 31c may be arranged in a stacked manner without a circumferential offset, and the phase positions of the rotor may be offset by 120° electrical angle. In FIG. 1, the latter arrangement is used for simplicity and clarity. Although the illustration of the rotor's magnetic poles is omitted, if FIG. 2 is taken as an orthogonal cross-sectional view at the axial center of the toroidal coil 8 in FIG. 1, the orthogonal cross-sectional view at the axial center of unit stator 31b is a view in which the rotor has been shifted, for example, in the clockwise direction by 40° mechanical angle (120° electrical angle) from the rotor position in FIG. 2, and the orthogonal cross-sectional view at the axial center of unit stator 31c is a view in which the rotor has been shifted in the clockwise direction by a further 40° mechanical angle (120° electrical angle) from the rotor position in the figure. The outer periphery of stator 31 is covered by a cylindrical body 6 made of a magnetic material, and brackets (not shown) are attached to both axial end faces. A bearing (not shown) is attached to the bracket to rotatably support the back yoke 4 of rotor 32 (described later).

[0028] As shown in FIG. 2, the rotor 32 has a hollow cylindrical back yoke 4 and a permanent magnet 3 arranged on the outer surface of the back yoke 4, the surface of which faces the claw pole members 1 and 2 of the stator 31 and is magnetized into six poles with alternating north and south poles along the circumferential direction.

[0029] The rotor 32 is arranged to be rotatable around the axis of the back yoke 4 relative to the stator 31 by a magnetic force generated by passing a current through the annular coil 8 .

[0030] It should be noted that the back yoke 4, which serves as the rotating shaft, does not need to be hollow cylindrical. However, in a configuration using an annular coil 8 and a rotor 32, such as the radial gap type rotating electric machine 30 according to this embodiment, the center of the radial gap type rotating electric machine 30 is often not used to generate torque. If the center is a hollow shaft, the radial gap type rotating electric machine 30 according to this embodiment can be used as a single-shaft motor when driving a load, and the lead wires of a two-shaft motor can be passed through it.

[0031] Next, the unit stators 31a to 31c will be described. Since the unit stators 31a to 31c have the same shape, the unit stator 31a will be described, and descriptions of the unit stators 32b and 31c will be omitted.

[0032] The stator unit 31a includes a pair of claw pole members 1 and 2, an annular coil 8 wound around the outer periphery of the claw pole members 1 and 2, and laminates 5 and 5 made of magnetic material disposed on both axial ends of the annular coil 8. The laminates 5 are preferably made of silicon steel plate.

[0033] As shown in FIG. 3, the claw pole members 1 and 2 have a base 11 curved in an arc shape to correspond to the outer surface of the rotor 32, and claw-shaped claw poles 12 protruding axially from the base. The multiple claw pole members 1 and 2 are arranged concentrically with gaps in the circumferential direction, forming an annular ring with three claw poles 12.

[0034] The claw pole members 1 and 2 are preferably fixed by molding with resin (not shown). Alternatively, as shown in Fig. 2, instead of using the resin molding, a bobbin 7 for the toroidal coil 8 may be used, and a triangular claw pole receiving portion 7a that fits into a tapered portion 14 of a claw pole 12 (described later) may be provided on the inner periphery of the toroidal coil bobbin 7, so that the claw pole members 1 and 2 are held by the toroidal coil bobbin 7. The toroidal coil bobbin 7 is disposed between the meshing portion 13 and the toroidal coil 8.

[0035] The claw pole members 1 and 2 are formed from powder iron cores. As shown in FIG. 2, the claw pole 12 has a wide tooth width on the side facing the rotor 32 in a cross section perpendicular to the axis. Tapered portions 14, 14 are formed on both sides along the longitudinal direction so that the tooth width on the opposite side, facing the toroidal coil 8, gradually narrows. This is to increase the claw pole tooth width close to the magnetic pole width of the rotor 32, while simultaneously reducing the leakage flux between adjacent meshing claw poles by minimizing the aforementioned leakage flux permeance P. While the effective tooth width ratio k in the conventional technology is approximately 0.7, the tapered portion 14 increases the effective tooth width ratio k to a value close to 1, as described below, enabling higher torque. Furthermore, as shown in FIGS. 2 and 3, the claw pole 12 is thin-walled from the base 11 to the tip along the axial direction. This is because the amount of interlinkage magnetic flux at the tip of the claw pole is small, so the gum is made thin, and the magnetic flux concentrates more as it approaches the base of the tooth, increasing the thickness of the tooth as this increases the magnetic flux density at the tooth. This avoids magnetic saturation while also aiming for lightweight and low cost by optimizing the amount of material used, and is the reason why pressed iron cores are used in claw pole members 1 and 2.

[0036] As shown in Figures 3 and 4, the claw pole members 1 and 2 are arranged at a predetermined interval in the circumferential direction as described above, and are combined by being inverted relative to each other in the axial direction, with the claw poles 12 of one claw pole member 1 inserted into the gaps between the claw poles 12 of the other claw pole member 2, to form meshing portions 13 on the outer surfaces of the claw poles 12, and as shown in Figure 1, the annular coil 8 is arranged in the meshing portions 13.

[0037] The toroidal coil 8 is constructed by winding a wire around the axis of the meshing portion 13, and is excellent in space saving because there are no coil ends as compared with concentrated winding or distributed winding.

[0038] 1, annular silicon steel laminates 5, 5 are disposed on both axial ends of the toroidal coil 8, and their outer peripheries are in contact with the inner periphery of a cylinder 6 made of a pressed iron core or the like, forming a magnetic path for the interlinkage magnetic flux of the permanent magnets 3 of the rotor 32. The laminations 5 are made of silicon steel to reduce iron loss, but if they are configured as an extension of the bases 11 of the claw pole members 1, 2, it is possible to omit the silicon steel plates and omit the laminations 5.

[0039] As shown in Figures 2 and 5, the claw poles 12 have tapered portions 14 formed on both sides, resulting in a roughly trapezoidal cross section. Because the claw poles 12 have a trapezoidal cross section, the area facing the rotor 32 is generally large, resulting in a wide tooth base width. The name "claw pole" comes from the resemblance of this trapezoidal tooth shape to a hawk's talon, but conventional rectangular shapes are also called claw poles. Generally, the magnetic flux from the rotor 32 concentrates at the tooth base of a claw pole, making the tooth base prone to magnetic saturation. For this reason, a trapezoidal shape like that of the radial gap rotating electric machine 30 according to this embodiment is preferable to a rectangular shape.

[0040] FIG. 5 illustrates the cross sections of adjacent claw poles 12 of a radial gap rotating electric machine 30 according to this embodiment, linearly developed in the circumferential direction of the air gap. The base of the trapezoidal cross section, i.e., the bottom side of the figure, is the air gap side facing the rotor 32. Because this is a linear development, the base of the trapezoid is a straight line. However, because the outer periphery of the rotor 32 is arc-shaped, it is desirable for the rotor-facing portions of the claw poles 12 to be arc-shaped, as this reduces the equivalent air gap. Furthermore, because they are formed using a powder iron core, they can be manufactured using a mold, making it easier to manufacture claw poles 12 with complex shapes. The cross-sectional shape of the claw poles 12 of the radial gap rotating electric machine 30 according to this embodiment is not limited to a trapezoidal shape; they may also be semicircular or crescent-shaped, as shown in FIG. 7.

[0041] Furthermore, the claw poles 12 of the radial gap type rotating electric machine 30 according to this embodiment have thin tapered portions 14 on both sides. By forming the tapered portions 14 on the claw poles 12, the rotor magnetic flux can be collected sufficiently efficiently and turned into flux linkage. Moreover, even when the gap g between the tapered portions 14 of the adjacent claw pole members 1, 2 is close to zero and they are brought close to the point of contact, the facing area S of the tapered portion tips between the adjacent claw pole members 1, 2 is extremely small, so the leakage flux permeance P between the adjacent claw pole members 1, 2 is kept small, and therefore the leakage flux does not increase.

[0042] In the above description, the claw pole 12 is erected from the base 11, and the tooth widths of the base end and tip end of the claw pole 12 are approximately the same. However, as shown in FIG. 6, the tooth width of the tip end may be narrower than that of the base end.

[0043] 5 corresponds to the pole pitch of the rotor magnetic poles, and is the pitch of the claw poles 12. If b is the average tooth width of the claw poles 12 facing the toroidal coil 8 excluding the tapered portions 14, c is the average tooth width of the claw poles 12 facing the permanent magnet 3, and d is the circumferential length equal to the sum of the widths of the tapered portions 14 of the claw poles 12 at two locations, the effective tooth width ratio k can be calculated as k = (b + d) / a. The radial gap rotating electric machine 30 according to this embodiment can achieve an effective tooth width ratio k of up to a value close to 1. Considering that the effective tooth width ratio k of conventional rectangular claw poles is approximately 0.7, the flux linkage is proportional to the effective tooth width ratio k, making it possible to obtain high torque.

[0044] Furthermore, in the radial gap rotating electric machine 30 according to this embodiment, the tapered portions 14 on the claw poles 12 form an edge-like facing area S between adjacent claw poles 12, enabling this area to approach zero. In this case, even a small amount of leakage magnetic flux passes through the magnetic material, causing magnetic saturation. Even if the gap g becomes very close, the leakage magnetic flux does not increase. This is because, in the equation for calculating the leakage magnetic flux permeance P described above, S / g has both the facing area S and the gap g close to zero in both the numerator and denominator, canceling out to approximately 1. This results in the leakage magnetic flux permeance P becoming μ0, making it possible to reduce it to the same level as the air permeability. Strictly speaking, the area of ​​the tapered portions 14 is included in the facing area S by multiplying it by a small coefficient less than 1. However, due to the distance from the gap g, its effect can be ignored.

[0045] As shown in FIGS. 4 and 6, the claw poles 12 have an effective length h. If a tapered portion is provided at the tip of the claw pole 12 along the circumferential direction, the effective length h can be increased and the claw poles 12 can be disposed closer to the other base portion 11. As a result, the opposing area with the rotor 32 can be increased accordingly, resulting in higher torque.

[0046] As described above, in the rotating electric machine according to this embodiment, the claw pole members 1 and 2 are manufactured from pressed powder, allowing for a high degree of freedom in design. Furthermore, although not shown, the center of the stator winding pole teeth (claw pole portions) on the rotor-facing surfaces can be configured as a peak where the gap is smallest, with the gap increasing portions formed so that the gap gradually increases toward the circumferential ends. This effectively results in a radial gap rotating electric machine with lower vibration and noise than conventional radial gap rotating electric machines. This is because the magnetic flux distribution becomes sinusoidal and does not contain harmonics. See Figure 7 for an image of the cross section of the claw pole, where the curved surface faces the rotor across an air gap. This type of shape is easily manufactured using a powder iron core.

[0047] Furthermore, in the above embodiment, the radial gap rotating electric machine 30 has been described as a three-phase type, but the radial gap rotating electric machine 30 according to this embodiment is not limited to a three-phase type and may be configured as a two-phase rotating electric machine. In this case, two of the above-mentioned unit stators may be arranged with a phase difference of 90° electrical angle in the axial direction.

[0048] Furthermore, the radial gap type rotating electric machine 30 according to the present embodiment has been described above in terms of a case where the rotor 32 is disposed on the inner peripheral side of the stator 31, but the rotor 32 may be disposed on the outer peripheral side of the stator 31. It is clear from the claims that such modified or improved embodiments are also included within the technical scope of the present invention. [Industrial Applicability]

[0049] The radial gap rotating electric machine of the present invention can be used as an electric motor or generator, and is extremely practical, being inexpensive, robust, lightweight, thin, short, and small, and suitable for high torque and high efficiency. For example, a one-phase rotating electric machine is ideal as a highly efficient single-phase AC generator. A two-phase rotating electric machine is suitable for high-torque STM. A three-phase rotating electric machine, made with a powdered iron core, is suitable for a high-power BLDCM. Therefore, it is expected to make a great contribution to industry. [Explanation of symbols]

[0050] 1, 2 claw pole member, 3 permanent magnet, 4 back yoke, 5 laminated body, 6 cylinder, 7 bobbin for toroidal coil, 7a claw pole receiving portion, 8 toroidal coil, 11 base, 12, 15 claw pole, 13 meshing portion, 14 tapered portion, 30 radial gap type rotating electric machine, 31 stator, 31a, 31b, 31c unit stator, 32 rotor.

Claims

1. A radial gap type rotating electric machine having a stator and a rotor rotatably assembled to the stator with an air gap in the radial direction, The stator comprises a pair of claw pole members each including a base and p claw poles projecting from the base in the axial direction and arranged concentrically with gaps in the circumferential direction, the pair of claw pole members being axially inverted with respect to each other so that the claw poles of one claw pole member are inserted into the gaps of the other claw pole member to form meshing sections, and a unit stator in which an annular coil is arranged in the meshing sections, the annular coil comprising a magnetic body covering both ends of the annular coil in the axial direction and a surface of the annular coil opposite to the surface facing the rotor so that magnetic flux from the meshing sections interlinks with each other, the claw poles are formed of powder iron cores, and are formed so that, in a cross section perpendicular to the axis, a tooth width is wide on a surface facing the rotor and the tooth width gradually narrows toward the opposite surface, The rotor is a radial gap type rotating electric machine, characterized in that permanent magnets magnetized into 2p poles, alternating north and south poles, are arranged along the circumferential direction on the surface facing the stator. Here, p is an integer of 2 or more.

2. 2. The radial gap type rotating electric machine according to claim 1, A radial gap type rotating electric machine, characterized in that a bobbin for the toroidal coil is disposed between the meshing portion and the toroidal coil.

3. 3. The radial gap type rotating electric machine according to claim 2, 10. A radial gap type rotating electric machine, wherein the claw pole member and the bobbin for the toroid coil are integrally formed.

4. 3. The radial gap type rotating electric machine according to claim 2, The claw pole member and the bobbin for the toroidal coil are configured separately, a bobbin for the toroidal coil including a claw pole receiving portion for positioning the claw pole member;

5. 2. The radial gap type rotating electric machine according to claim 1, a surface of each of the claw poles facing the annular coil that is formed to be thinner in the axial direction from the base to the tip;

6. 2. The radial gap type rotating electric machine according to claim 1, A radial gap type rotating electric machine, characterized in that a plurality of the stator units are stacked in the axial direction.

7. 7. The radial gap type rotating electric machine according to claim 6, a radial gap type rotating electric machine, characterized in that each of the unit stators arranged in a stacked phase arrangement or one of the rotors facing the unit stators is arranged with a circumferential shift of a predetermined electrical angle.

8. The radial gap type rotating electric machine according to any one of claims 1 to 7, a radial gap type rotating electric machine, characterized in that the air gap length of the claw poles on their surfaces facing the rotor is small at the center of the circumferential tooth width, and the air gap increases from the center to the tooth width ends.

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