Rotating electric machine

Abstract

Rotating electric machine with a stator (130) having an annular stator core (200) and a multiphase coil (132) attached to the stator core (200) having a plurality of phase coils (132U, 132V, 132W) to which alternating currents of different phases are supplied, and a rotor (120) which is inserted into the stator (130) and has a plurality of magnetic poles, wherein the stator core (200) has a plurality of partial stator cores (250) arranged in a ring shape in a direction of rotation of the stator core (200), the partial stator cores (250) each have a partial yoke (251) extending in the direction of rotation of the stator core (200) and arranged on an outer circumferential side of the multiphase coil (132), and a stator tooth (210) extending radially inwards from a circumferential surface of the partial yoke (251) and inserted from an outer circumference to an inner circumference of the multiphase coil (132), wherein the stator core (200) has a plurality of slots (220) defined between the stator teeth (210), wherein the phase coils (132) are inserted into the slots (220), wherein the stator teeth (210) have an intermediate homogeneous phase tooth (210U-U, 210V-V, 210W-W) which is sandwiched laterally between two slots (220) in which the phase coils of the same phase are each inserted, and an intermediate heterogeneous phase tooth (210W-U, 210U-V, 210V-W) which is sandwiched laterally between two slots (220) in which the phase coils (132) of different phases are each inserted, the intermediate-heterogeneous-phase tooth (210W-U, 210U-V, 210V-W) has an intermediate-heterogeneous-phase tooth body (236) defined by a pair of sides arranged laterally in the direction of rotation of the stator core (200), and an intermediate-heterogeneous-phase tooth head (235) arranged radially inward from the stator core (200) with respect to the intermediate-heterogeneous-phase tooth body, and extends continuously from the intermediate-heterogeneous-phase tooth body (236), and the interheterogeneous phase tooth head (235) has a first recess section (232) extending continuously from one side (230) of the pair of sides of the interheterogeneous phase tooth body (236) and extending towards the radially inner side away from a first imaginary lateral axis line (L1) and approaching a second imaginary lateral axis line (L2), and / or has a second recess section (234) extending continuously from the other side (231) of the pair of sides of the interheterogeneous phase tooth body (236) and extending towards the radially inner side away from the second imaginary lateral axis line (L2) and approaching the first imaginary lateral axis line (L1), wherein the first imaginary lateral axis line (L1) is an imaginary axis line extending along one side (230) of the pair of sides of the intermediate-heterogeneous-phase tooth, and wherein the second imaginary lateral axis line (L2) is an imaginary axis line extending along the other side (231) of the pair of sides of the intermediate-heterogeneous-phase tooth, and a first end surface (233) located at a radially inner end of the inter-heterogeneous phase tooth (210W-U, 210U-V, 210V-W) and a second end surface (243) located at a radially inner end of the inter-homogeneous phase tooth (210U-U, 210V-V, 210W-W) are arranged along a circumferential surface of the rotor (120).

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present invention relates to a rotating electrical machine and in particular to a rotating electrical machine with a multiphase coil including a plurality of phase coils. Description of the state of the art

[0002] JP 2008 - 160 939 A discloses a rotating electrical machine with a concentrated winding.

[0003] DE 600 22 973 T2 discloses a stator in which a stator tooth with a projection formed on it and a stator tooth without a projection are arranged alternately.

[0004] JP 2007 - 166 710 A discloses a rotating electrical machine in which teeth between slots with coils of the same phase are shaped such that a gap between the upper tooth end section and a rotating surface of the rotor has a constant width which is smaller than a maximum value of a variable width of a gap between the upper tooth end section of teeth between slots with coils of different phases and the rotating surface of the rotor.

[0005] JP 2007 - 295 712 A discloses a rotating electrical machine with a stator core in which tooth sections on which a concentric coil is wound are covered with resin.

[0006] JP S61 - 221 559 A discloses a rotating electric machine in which the stator has thick stator teeth and thin stator teeth.

[0007] JP 2003 - 088 027 A discloses an armature for a rotating electrical machine in which pole tooth edges are chamfered or rounded to ensure insulation by means of a resin coating.

[0008] The GB 2 260 860 A reveals various tooth shapes for a rotor or a stator of a rotating electric machine.

[0009] US 5 844 346 A, GB 2 312 336 A, US 710 425 A and GB 2 289 575 B reveal further examples of rotating electrical machines.

[0010] Various designs of rotating electrical machines, stators, and the like, featuring, for example, reduced vibrations, have been proposed. Japanese patent publication no. JP 2001-161048A, for instance, discloses a rotating electrical machine with a plurality of slotted cores and coils wound around winding assembly sections formed on the slotted cores.

[0011] Stator teeth are formed on the slotted cores, and each stator tooth has a flange formed on its upper surface. Japanese patent publication no. JP 2007-135330A discloses a stator with a slotted core with a flange and a slotted core without a flange, arranged alternately.

[0012] Japanese patent publication no. JP 2006-174651A discloses a stator with a plurality of slotted cores. Each slotted core has a yoke element, a main section formed in the center of the yoke element, and wing sections formed on the right and left sides of the main section, respectively. The main section and the right and left wing sections form a magnetic pole surface.

[0013] Japanese patent publication no. JP 2006-149167A discloses a stator with a plurality of stator teeth and a rotating electrical machine. An auxiliary groove extending in the axial direction is formed on a circumferential central section of the surface of each stator tooth.

[0014] In the conventional rotating electrical machines described above, a multiphase coil is wound around each stator tooth. The multiphase coil comprises U-phase, V-phase, and W-phase coils, and alternating currents with different phases are supplied to the respective phase coils.

[0015] The stator teeth feature an intermediate-heterogeneous-phase tooth (a tooth between different or heterogeneous phases), namely a tooth arranged between adjacent slots in which respective phase coils of different phases are inserted, and an intermediate-homogeneous-phase tooth (a tooth between similar or homogeneous phases), namely a tooth arranged between adjacent slots in which respective phase coils of the same phase are inserted. In such a rotating electrical machine, a magnetic flux is generated by each phase coil when alternating current is supplied to the phase coil. The flux state of the magnetic flux formed by each phase coil in the intermediate-heterogeneous-phase tooth and the flux state of the magnetic flux in the intermediate-homogeneous-phase tooth differ significantly from each other.

[0016] Furthermore, the reluctance of a magnetic circuit, when a magnetic flux from a magnet or the like provided in a rotor, proceeds from the surface of the rotor and enters the inter-heterogeneous phase tooth, is smaller than the reluctance of the magnetic circuit when the magnetic flux proceeds from the surface of the rotor and enters the inter-homogeneous phase tooth.

[0017] Therefore, when the rotor rotates and the magnetic flux from the magnet enters the interheterogeneous phase tooth, the torque applied to the rotor suddenly increases, likely causing vibrations and noise in the rotating electric machine. SUMMARY OF THE INVENTION

[0018] The present invention was made with regard to the problems described above, and one object of the invention is to provide a rotating electric machine with reduced vibrations and noise.

[0019] This problem is solved by a rotating electric machine as specified in claim 1.

[0020] Advantageous embodiments are specified in the dependent patent claims.

[0021] The rotating electric machine according to the invention can reduce vibrations and noise.

[0022] The foregoing and further tasks, features, embodiments and advantages of the present invention will become clearer with reference to the following detailed description of the present invention and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a side cross-sectional view of a rotating electric machine according to the present invention. Fig. Figure 2 shows a top view of a rotor. Fig. Figure 3 shows a top view of a stator. Fig. Figure 4 shows a development of a stator core according to Fig. 3. Fig. Figure 5 shows a top view to illustrate the result of a simulation showing magnetic flux strands from each pair of magnets. Fig. Figure 6 shows a top view, in which the rotating electric machine is in the state according to Fig. 5 is partially enlarged. Fig. Figure 7 shows a top view in which the rotor is in the state according to the rotor in relation to the rotor Fig. 6 is set back a bit. Fig. Figure 8 shows a top view illustrating the structure of a head section of an intermediate-heterogeneous-phase tooth. Fig. Figure 9 shows a top view illustrating the structure of a head section of an intermediate V-phase tooth. Fig. Figure 10 shows a graph illustrating vibrations generated when a rotating electric machine is driven according to a comparative example. Fig. 11 and Fig. Figures 12 each show a top view of an intermediate heterogeneous phase tooth, each representing a modification of a chamfer. Fig. Figure 13 shows a development of a stator where the number of slots (s) over which a coil is distributed is three. Fig. Figure 14 shows a schematic representation illustrating a method for manufacturing a rotating electrical machine according to an embodiment of the present invention. Fig. Figure 15 shows a development of a stator of a rotating electrical machine according to a second embodiment of the present invention. Fig. Figure 16 shows a top view of an intermediate heterogeneous phase tooth. Fig. Figure 17 shows a top view of an intermediate V-phase tooth. Fig. Figure 18 shows a development of a stator where the number of slots (s) over which a coil is distributed is three. DESCRIPTION OF PREFERRED EXECUTION EXAMPLES

[0023] A rotating electric machine according to embodiments of the present invention is described below with reference to Fig. 1 to 18 described.

[0024] It should be noted that where reference is made in the embodiments described below to any number, quantity, or the like, the scope of the present invention is not necessarily limited to that number, quantity, or the like, unless otherwise specified. Furthermore, not every element according to the following embodiments is necessarily required for the present invention, unless otherwise specified. Moreover, where a plurality of embodiments are given below, it is originally intended that the respective features according to the embodiments may be combined as appropriate. First embodiment

[0025] Fig. Figure 1 shows a side cross-sectional view of a rotating electric machine according to the present invention. As shown in Fig. As shown in Figure 1, the rotating electric machine 100 has a ring-shaped stator 130, a rotating shaft 110 which is inserted in the stator 130 and is rotatable about a center line of rotation O, and a rotor 120 which is attached to the rotating shaft 110 and is rotatable about the center line of rotation O.

[0026] The rotor 120 has a rotor core 121 formed by stacking a plurality of electromagnetic steel plates (steel sheets) and a plurality of permanent magnets 122 attached to the rotor core 121.

[0027] Near the outer circumferential edge of the rotor core 121, several magnet insertion openings 126, extending in the direction of the rotational centerline O, are spaced apart around the circumference. Permanent magnets 122 are inserted into the magnet insertion openings 126 and secured by resin 124 placed in the magnet insertion opening 126.

[0028] Fig. Figure 2 shows a top view of rotor 120. As it is in Fig. As shown in Figure 2, the rotor 120 has eight pairs of magnets 123A to 123H, spaced apart around the circumference.

[0029] The magnet pairs 123A to 123H each have two permanent magnets 122A and 122B, which are slightly spaced apart from each other in the direction of rotation.

[0030] The magnet pairs 123A to 123H are arranged such that the respective magnetic poles on the outer circumferential side of the rotor 120 differ between adjacent magnet pairs. In particular, with respect to magnet pairs 123A, 123C, 123E, and 123G, the permanent magnets 122A and 122B, which each form a magnet pair, are arranged such that the N pole is located on the outer circumferential side of the rotor 120. With respect to magnet pairs 123B, 123D, 123F, and 123H, the permanent magnets 122A and 122B, which form each magnet pair, are arranged such that the S pole is located on the outer circumferential side of the rotor 120. Thus, the number of magnetic poles of the rotating electric machine 100 according to the first embodiment is eight.

[0031] Fig. Figure 3 shows a top view of stator 130. As it is in Fig. As shown in Figure 3, the stator 130 has an annular stator core 200 centered on the rotational centerline O, and a multiphase coil 132 attached to the stator core 200. Fig. 3 represents P the direction in which the rotor is rotated.

[0032] The stator core 200 has a yoke 211 extending in a ring-shaped manner in the direction of rotation of the stator core 200, and a plurality (48) of stator teeth extending radially inwards from the inner circumferential surface of the yoke 211. Several (48) slots are formed between the stator teeth 210.

[0033] The stator core 200 is composed of a plurality of slotted stator cores 250 arranged in a ring in the direction of rotation of the stator core 200. Each slotted core 250 has a slotted yoke 251 extending in the direction of rotation of the stator core 200 and a stator tooth 210 extending radially inward from the surface of the slotted yoke 251. In the rotating electric machine 100 according to the first embodiment, each slotted stator core 250 has two stator teeth 210 spaced apart around their circumference.

[0034] The multiphase coil 132 has a U-phase coil 132U, a V-phase coil 132V and a W-phase coil 132W, thus making the multiphase coil 132 a three-phase coil.

[0035] The U-phase coil 132U is located on the outermost radial side, and the V-phase coil 132V is located on the inner radial side with respect to the U-phase coil 132U. The W-phase coil 132W is located on the inner radial side with respect to the V-phase coil 132V.

[0036] The U-phase coil 132U comprises unit U-phase coils 132U1 to 132U8, the V-phase coil 132V comprises V-phase coils 132V1 to 132V8, and the W-phase coil 132W comprises unit W-phase coils 132W1 to 132W8. Unit phase coils of the same phase are directly connected to each other.

[0037] Each unit phase coil is wound around a plurality of corresponding stator teeth 210, and a stator tooth 210 is arranged between unit phase coils of the same phase. Each unit phase coil is wound in the opposite direction to that in which an adjacent unit phase coil of the same phase is wound.

[0038] In particular, the winding directions of unit U-phase coils 132U1, 132U3, 132U5, and 132U7 are opposite to those of unit U-phase coils 132U2, 132U4, 132U6, and 132U8. The number of unit U-phase coils is equal to the number of magnetic poles. In the rotating electric machine 100, one type of unit U-phase coil (winding) is wound in a single slot, thus forming a single-layer winding. Another type of unit U-phase coil is distributed over two adjacent slots, thus forming a double-slot distribution coil (coil distributed over two slots). The number of slots over which the coil is distributed is therefore two.

[0039] The number of slots 220 (r: 48) is determined by the number of slots over which one type of unit phase coil is distributed (natural number s: 2), the number of magnetic poles (natural number m: 8) and the number of phases (natural number n: 3), where these numbers have a relationship as defined by the following equation (1): Number of slots (r) = Number of slots in which the coil is distributed (s) × Number of magnetic poles (m) × Number of phases (n)

[0040] Fig. Figure 4 shows a development of the stator core 200 according to Fig. 3. As it is in Fig. As shown in Figure 4, the slots 220 have a U-phase slot 220U, into which a unit U-phase coil is inserted, a V-phase slot 220V, into which a unit V-phase coil is inserted, and a W-phase slot 220W, into which a unit W-phase coil is inserted.

[0041] The stator teeth 210 have inter-homogeneous phase teeth (teeth between similar or homogeneous phases) (210U-U, 210V-V, 210W-W) and inter-heterogeneous phase teeth (teeth between different or heterogeneous phases) 210W-U, 210U-V, 210V-W.

[0042] In two slots 220, arranged on laterally opposite sides with respect to an inter-homogeneous-phase tooth, unit-phase coils of the same phases are inserted. This means that an inter-homogeneous-phase tooth is sandwiched between unit-phase coils of the same phase. The inter-homogeneous-phase teeth have inter-U phase teeth 210U-U, inter-V phase teeth 210V-V, and inter-W phase teeth 210W-W.

[0043] The intermediate U-phase tooth 210U-U is arranged between U-phase slots 220U, the intermediate V-phase tooth 210V-V is arranged between V-phase slots 220V, and the intermediate W-phase tooth 210W-W is arranged between W-phase slots 220W.

[0044] In each of the slots 220, which are arranged on laterally opposite sides with respect to the intermediate-heterogeneous-phase teeth 210W-U, 210U-V, 210V-W, unit-phase coils of different phases are inserted. This means that the intermediate-heterogeneous-phase teeth 210W-U, 210U-V and 210V-W are each arranged in a sandwich-like manner between unit-phase coils of different phases.

[0045] The intermediate heterophase tooth 210W-U is located between the W-phase slot 210W and the U-phase slot 220U. The intermediate heterophase tooth 210U-V is located between the U-phase slot 220U and the V-phase slot 220V. The intermediate heterophase tooth 210V-W is located between the V-phase slot 220V and the W-phase slot 220W.

[0046] Two U-phase slots 220U, two W-phase slots 220W, and two V-phase slots 220V are arranged in this order in the direction of rotation P of the rotor 120. Accordingly, the intermediate U-phase tooth 210U-U, the intermediate heterogeneous phase tooth 210W-U, the intermediate W-phase tooth 210W-W, the intermediate heterogeneous phase tooth 210V-W, the intermediate V-phase tooth 210V-V, and the intermediate heterogeneous phase tooth 210U-V are arranged in this order in the direction of rotation P. In this way, the intermediate homogeneous phase teeth and the intermediate heterogeneous phase teeth are arranged alternately in the direction of rotation P.

[0047] Fig. Figure 5 shows a top view illustrating the result of a simulation depicting the magnetic flux paths of each magnet pair. Electromagnetic field analysis software such as JMAG® (manufactured by JSOL Corporation) was used for the simulation.

[0048] As it is in Fig. As shown in Figure 5, magnetic fluxes are emitted by the permanent magnets 122A and 122B of the magnet pairs 123A to 123H provided in the rotor 120. These magnetic fluxes travel in their respective magnetic circuits, passing into the rotor 120 and then into the stator 130, before returning from the stator 130 to the rotor 120, and then back to the permanent magnets 122A and 122B, respectively. Here, the magnetic fluxes MF1 to MF5 of the permanent magnet 122B of the magnet pair 123A are examined in particular.

[0049] Among the magnetic fluxes MF1 to MF5, the magnetic flux MF1 passes through the outermost magnetic circuit, whereas the magnetic fluxes MF2 to MF5 pass through respective magnetic circuits that are arranged sequentially on the inner side with respect to the magnetic circuit of magnetic flux MF1. Therefore, of the magnetic fluxes MF1 to MF5 emitted from the permanent magnet 122B, the magnetic flux MF1 passes through the foremost position in the direction of rotation P.

[0050] Thus, when the rotor 120 rotates in the direction of rotation P, the magnetic flux MF1 also moves forward in the direction of rotation P, and moves successively from the intermediate-heterogeneous phase tooth 210V-W to the intermediate-V phase tooth 210V-V and further from the intermediate-V phase tooth 210V-V to the intermediate-heterogeneous phase tooth 210U-V, as shown in Fig. 5 is shown.

[0051] Fig. Figure 6 shows a top view, in which the condition is as follows Fig. 5 is partially enlarged, and Fig. Figure 7 shows a top view showing the state in which the rotor 120 is positioned relative to the one in Fig. The state shown in 6 is slightly offset in the direction of rotation P.

[0052] According to Fig. 6. The magnetic flux MF1 emitted from the permanent magnet 122B reaches the outer surface of the rotor 120. The magnetic flux MF1 then passes through an air gap, reaching the intermediate-heterogeneous-phase tooth 210U-V. The magnetic flux MF1 travels within the intermediate-heterogeneous-phase tooth 210U-V, reaches the yoke 211, and travels backward within the yoke 211 in the direction of rotation P.

[0053] In particular, it shows Fig. 7 the condition which, in relation to the condition according to Fig. 6 is arranged backwards at an electrical angle of 30°. The rotor 120 in the state according to Fig. 7 is rotated in the direction of rotation P to achieve the state according to Fig. to reach 6.

[0054] In this case, according to Fig. 7 the magnetic flux MF1 into the intermediate-V phase tooth 210V-V which is arranged backwards in the direction of rotation P with respect to the intermediate-heterogeneous phase tooth 219U-V.

[0055] Fig. Figure 8 shows a top view illustrating the structure of a head section of the intermediate-heterogeneous-phase tooth 210U-V, and Fig. Figure 9 shows a top view illustrating the construction of a head section of the inter-V phase tooth 210V-V.

[0056] The intermediate-heterogeneous phase tooth 210U-V has a body 236 defined by a pair of a side 230 and a side 231 arranged laterally in the direction of rotation P, and a head 235 extending continuously from the body 236 and arranged radially inwards with respect to the body 236.

[0057] The head 235 has a chamfer 232 extending continuously from side 230 and forward in the direction of rotation P with respect to side 230, a chamfer 234 extending continuously from side 231 and backward in the direction of rotation P with respect to side 231, and an inner end surface 233 extending continuously from chamfer 234 and chamfer 232 and arranged radially inside chamfer 234 and chamfer 232.

[0058] In the rotating electric machine 100 according to the present embodiment, side 230 and side 231 are inclined to approach each other towards the radially inner side.

[0059] Let it be assumed here that an imaginary axis extending along side 230, and in particular intersecting the center line of rotation O, is an imaginary side axis 1, and that an imaginary axis extending along side 231, and in particular intersecting the center line of rotation O, is an imaginary side axis L2. It is further assumed that a radially extending imaginary axis intersecting the midpoint in the latitude direction (direction of rotation P) of the inner end surface 233 and intersecting the center line of rotation O is an imaginary radial axis L3, and that an imaginary line extending from the inner end surface (inner circumferential surface) is an imaginary line L4.

[0060] It is also assumed that an imaginary intersection point of the imaginary side axis line L1 and the imaginary line L4 is an imaginary intersection point Q1, and that an imaginary intersection point of the imaginary side axis line L2 and the imaginary line L4 is an imaginary intersection point Q2.

[0061] The chamfer 232 is arranged on the side of the imaginary side axis line L2 with respect to the imaginary intersection point Q1, and extends away from the imaginary side axis line L1 and approaches the imaginary side axis line L2 and the imaginary radial axis line L3 from the boundary between the chamfer 232 and the side 230 to the radially inner side.

[0062] Furthermore, the chamfer 234 is arranged on the side of the imaginary side axis line L1 with respect to the imaginary intersection point Q2, and extends away from the imaginary side axis line L2 and approaches the imaginary side axis line L1 and the imaginary radial axis line L3 from the boundary between the chamfer 234 and the side 231 towards the radially inner side.

[0063] The head 235 thus decreases in circumference such that the head 235 extends away from the body 236 towards the radial inner side, i.e., it tapers. In contrast, the intermediate V-phase tooth 210V-V according to Fig. 9 does not have a tapered head 235 like that of the inter-heterogeneous phase tooth 210U-V described above. Instead, the sides 240 and 241 are arranged laterally in the circumferential direction such that they gradually approach each other towards the radially inner side, with an inner end surface 243 extending continuously from the sides 240 and 241. Preferably, the inner end surface 243 and the inner end surface 233 are each an arc whose center is located on the center line of rotation O.

[0064] Then, in that state, they overlap according to Fig. 9, in which the intermediate V-phase tooth 210V-V and the intermediate heterogene phase tooth 210U-V are assumed to be adjacent to each other, the sides 230 and 231 of the intermediate heterogene phase tooth 210U-V and the sides 240 and 241 of the intermediate V-phase tooth 210V-V overlap each other, and the inner end surface 233 of the intermediate heterogene phase tooth 210U-V and the inner end surface 243 of the intermediate V-phase tooth 210V-V overlap each other.

[0065] As regards the chamfer 232 and the chamfer 234, these are arranged in the intermediate V-phase tooth 210V-V.

[0066] Thus, as it is in Fig. Figure 9 shows that the chamfer 232, which is arranged between the side 230 and the inner end face 233 of the inter-heterogeneous phase tooth 210U-V, is shaped such that, with respect to the corner arranged between the side 240 and the inner end face 243 of the inter-V phase tooth 210V-V, it is arranged further away from the surface of the rotor 120 towards the radially outer side of the stator core 200.

[0067] Likewise, the chamfer 234, which is arranged between the side 231 and the inner end face 233 of the intermediate-heterogeneous phase tooth 210U-V, is arranged further away from the surface of the rotor 120 towards the radially outer side of the stator core 200 in relation to the corner arranged between the side 241 and the inner end face 243 of the intermediate-V phase tooth 210V-V.

[0068] When the rotating electric machine 100 is to be driven, alternating currents with differing phases are supplied to the U-phase coil 132U, the V-phase coil 132V, and the W-phase coil 132W to rotate the rotor 120. As the rotor 120 rotates, the magnetic flux MF1 penetrates the inter-V-phase tooth 210V-V, as shown in Fig. Figure 9 is shown. When the rotor 120 rotates, the magnetic flux MF1 is shifted forward in the direction of rotation P, and accordingly reaches the inside of the inter-V phase tooth 210V-V.

[0069] In particular, according to Fig. 9 The magnetic flux MF1 is emitted from the emission position S1 on the surface of the rotor 20 to the inter-V phase tooth 210V-V. The emitted magnetic flux MF1 propagates forward in the direction of rotation P, while radially outward, and reaches the inter-V phase tooth 210V-V. Therefore, as the magnetic flux MF1 begins to penetrate the inter-V phase tooth 210V-V while the rotor 120 successively rotates, the magnetic flux MF1 enters the inter-V phase tooth 120V-V from the corner defined by the side 240 and the inner end face 243 and its proximity.

[0070] Then, as the rotor 120 continues to rotate, the magnetic flux MF1 reaches the inside of the interheterogeneous phase tooth 210U-V, as shown in Fig. Figure 8 shows that the magnetic flux MF1 enters the interheterogeneous phase tooth 210U-V from the chamfer 232 as described above.

[0071] The magnetic flux MF1 is emitted from emission position S1 on the surface of rotor 120. The magnetic flux MF1 enters the intermediate-heterogeneous-phase tooth 210U-V from entry position S4 of the intermediate-heterogeneous-phase tooth 210U-V. In the example according to Fig. 8 is the entry position S4 located at the chamfer 232.

[0072] The chamfer 232 of the intermediate-heterogeneous-phase tooth 210U-V is arranged radially outwards with respect to the corner of the intermediate-V-phase tooth 210V-V defined by the side 240 and the inner end face 243. Therefore, the path length W2 between the emission position S1 and the entry position S4 is as follows: Fig. 8 longer than the path length W1 between the emission position S1 and the entry position S2 according to Fig. 9.

[0073] Thus, the distance between the rotor 120 and the intermediate-heterogeneous-phase tooth 210U-V, over which the magnetic flux MF1 emitted from the rotor 120 travels to begin penetrating the intermediate-heterogeneous-phase tooth 210U-V, is longer than the distance between the rotor 120 and the intermediate-V-phase tooth 210V-V, over which the magnetic flux MF1 emitted from the rotor 120 travels to begin penetrating the intermediate-V-phase tooth 210V-V.

[0074] While the respective forms of the intermediate V-phase tooth 210V-V and intermediate heterogene phase tooth 210U-V are described above with reference to Fig. 8 and Fig. As described in section 9, other intermediate homogeneous phase teeth are shaped similarly to the intermediate V-phase tooth 210V-V, and other intermediate heterogeneous phase teeth are also shaped similarly to the intermediate heterogeneous phase tooth 210U-V. While the rotating electric machine 100 is driven, magnetic fluxes are generated by the U-phase coil 132U, the V-phase coil 132V, and the W-phase coil 132W, respectively, and the magnetic fluxes from the respective coils flow into the stator teeth 210.

[0075] The state of the magnetic flux in the interhomogeneous phase teeth (inter-U phase teeth 210U-U, inter-V phase teeth 210V-V and inter-W phase teeth 210W-W) and the state of the magnetic flux in the interheterogeneous phase teeth 210W-U, 210U-V and 210V-W are different from each other.

[0076] If the respective shapes of all stator teeth 210 are identical and the respective dimensions of the air gaps between the stator teeth 210 and the rotor 120 are identical, the resistance to a magnetic flux from a permanent magnet provided in the rotor 120, which runs in the inter-heterogeneous phase teeth 210W-U, 210U-V and 210V-W, is smaller than the resistance to the magnetic flux in the inter-homogeneous phase teeth (inter-U phase teeth 210U-U, inter-V phase teeth 210V-V, inter-W phase teeth 210W-W).

[0077] In contrast, according to the embodiment described above, the path length of the magnetic flux MF1 between the rotor 120 and an intermediate heterogeneous phase tooth, over which the magnetic flux passes and begins to enter the intermediate heterogeneous phase tooth, is longer than the path length of the magnetic flux MF1 between the rotor 120 and an intermediate homogeneous phase tooth, over which the magnetic flux passes and begins to enter the intermediate homogeneous phase tooth when each multiphase coil is supplied with alternating current.

[0078] Accordingly, the reluctance of the magnetic circuit of the magnetic flux from the permanent magnet 122 when the magnetic flux begins to enter an inter-heterogeneous phase tooth, and the reluctance of the magnetic circuit of the magnetic flux when the magnetic flux begins to enter an inter-homogeneous phase tooth, are identical to each other or very close to each other.

[0079] Therefore, even if the magnetic flux from the permanent magnet 122 travels from an intermediate homogeneous-phase tooth to an intermediate heterogeneous-phase tooth, a strong variation or fluctuation in the reluctance of the magnetic circuit through which the magnetic flux passes can be suppressed. Thus, a sudden decrease in reluctance can be suppressed when the magnetic flux from the permanent magnet 122 travels from an intermediate homogeneous-phase tooth to an intermediate heterogeneous-phase tooth. Accordingly, a torque ripple (24th-order component of the rotation: sixth-order component of the electric angle) that occurs in the rotating electric machine 100 can be reduced, thereby suppressing the generation of vibrations.

[0080] The chamfer 232 extends towards the radially inner side of the stator core 120, while extending forward in the direction of rotation P.

[0081] Thus, the reluctance between the rotor 120 and the inter-heterogeneous phase teeth 210W-U, 210U-V and 210V-W decreases when the rotor 120 rotates.

[0082] Furthermore, the magnitude of the magnetic fluxes from the permanent magnet 122 increases, and a large torque can be applied to the rotor 120.

[0083] Then, when the magnetic flux from the permanent magnet 122 reaches the inner end surface 233, the magnetic resistance of the magnetic flux circuit becomes minimal, while the magnetic flux magnitude increases. Accordingly, the torque applied to the rotor 120 can be increased.

[0084] In the rotating machine 100 according to the present embodiment, the chamfer 234 is formed at the position opposite the chamfer 232 of the head 235 of the intermediate-heterogeneous-phase tooth.

[0085] This chamfer slopes towards the radially inner side of the stator core 200 in the direction opposite to the direction of rotation P. Therefore, if the rotor 120 of the rotating electric machine 100 is driven rotating in the direction opposite to the direction of rotation P, the torque ripple occurring in the rotating electric machine 100 can also be reduced.

[0086] Fig. Figure 10 shows a graph illustrating vibrations generated when a rotating electric machine of a comparative example is driven. Fig. Figure 10 represents the horizontal axis of rotation (electrical angle) of the rotor 120, and the vertical axis represents the torque acting on the rotor 120. In the rotating electric machine according to the comparative example, the respective shapes of all stator teeth 210 are identical to the shape of the inter-U-phase tooth 210U-U. Furthermore, the respective dimensions of the air gaps between the stator teeth 210 and the rotor 120 are also identical. Additionally, in the rotating electric machine according to the comparative example, the number of slots is 48, the number of magnetic poles is 8, and the number of phases is 3, which are the same as the respective numbers in the rotating electric machine 100 according to the present embodiment.

[0087] In the rotating electrical machine according to the comparative example, which is constructed in the manner described above, the respective flux states of a magnetic flux from the multiphase coil that enters or passes through an inter-homogeneous-phase tooth and that which enters an inter-heterogeneous-phase tooth are also different from each other. Therefore, the reluctance of the magnetic circuit that passes through the inter-heterogeneous-phase tooth and the rotor 120 is lower than the reluctance of the magnetic circuit that passes through the inter-homogeneous-phase tooth and the rotor 120.

[0088] Then, when the magnetic flux from the permanent magnet moves from the interhomogeneous-phase tooth to the interheterogeneous-phase tooth, the reluctance suddenly decreases, resulting in a large torque ripple. As described in Fig. As shown in Figure 10, in the rotating electric machine, according to the comparative example, the peak of the torque occurs every 60° in the electric angle.

[0089] Although the above described Fig. Figures 1 to 9 illustrate an example in which the chamfers 232 and 234 are tapered surfaces; the shape of the chamfers 232 and 234 is not limited to such a shape. Fig. 11 and Fig. Figures 12 each show a top view of an intermediate-heterogeneous-phase tooth 210U-V, illustrating a modification of the chamfers 232 and 234. As shown in Fig. 11 and Fig. As shown in Figure 12, the chamfers 232 and 234 can have the shape of a curve.

[0090] Furthermore, although the Fig. Figures 1 to 9 illustrate the rotating electrical machine in which the number of slots (s) over which the coil is distributed is two, for example, 3. Fig. Figure 13 shows a development of a stator 130 in which the number of slots over which the coil is distributed is three (triple-slot distribution coil or coil distributed over three slots). In the case of the coil distributed over three slots, a type of unit-phase coil is distributed over three adjacent slots.

[0091] According to Fig. 13 are three U-phase slots 220U, three V-phase slots 220V, and three W-phase slots 220W arranged in sequence. Therefore, two intermediate homogeneous phase teeth are arranged between two intermediate heterogeneous phase teeth. That is, between intermediate heterogeneous phase teeth there are (is) intermediate homogeneous phase teeth (tooth), the number of which corresponds to ((number of slots over which a coil is distributed)-1). The respective heads of the intermediate heterogeneous phase teeth have chamfers 232 and 234 as shaped.

[0092] Fig. Figure 14 shows a schematic view illustrating a method for manufacturing a rotating electric machine 100 according to the present embodiment. As shown in Fig. As shown in Figure 14, in the process for manufacturing the stator 130, a tubular multiphase coil 132 is prepared, which is pre-wound. Then, slotted stator cores 250 are successively inserted from the outer circumferential surface of this multiphase coil 132 to produce the stator 130.

[0093] Each stator tooth 210 of the stator core 200 is shaped such that the tooth tapers towards the radially inner side.

[0094] For example, as described above Fig. As shown in Figure 8, sides 230 and 231 of each intermediate-heterogeneous-phase tooth are shaped such that the sides approach each other towards the radially inner side of the stator core 200. Furthermore, as described above Fig. As shown in Figure 9, the sides 240 and 241 of each inter-homogeneous phase tooth are also shaped such that the sides approach each other towards the radially inner side of the stator core 200.

[0095] Since each stator tooth 210 tapers towards its radially inner side, the slotted stator core 250 can be easily inserted from the outer circumferential surface of the multiphase coil 132. Furthermore, this prevents the multiphase coil 132 from being damaged by each stator tooth 210.

[0096] The stator 130 is produced in this way, and then the stator 130 is mounted in a motor housing, and the rotor 120 is arranged in the stator 130. Accordingly, the rotating electric machine 100 is manufactured. Second embodiment

[0097] With reference to Fig. Sections 15 to 18 describe a rotating electric machine 100 according to a second embodiment of the present invention. In the Fig. The structures shown in sections 15 to 18 are components identical to those shown in [reference to relevant section]. Fig. Items 1 to 14, or equivalent to them, are designated by the same reference symbols, which is why their description may not be repeated depending on the case.

[0098] Fig. Figure 15 shows a development of a stator 130 according to the second embodiment of the present invention. As shown in Fig. As shown in Figure 15, in the rotating electric machine 100 according to the second embodiment, chamfers are formed not only on the intermediate heterogeneous phase teeth 210U-V, 210V-W and 210W-U, but also on the intermediate-U phase teeth 210U-U, the intermediate-V phase teeth 210V-V and the intermediate-W phase teeth 210W-W.

[0099] Fig. Figure 16 shows a top view of an intermediate heterogeneous phase tooth 210U-V, and Fig. Figure 17 shows a top view of an intermediate V-phase tooth 210V-V.

[0100] As it is in Fig. As shown in Figure 16, chamfers 232 and 234 are formed along the surface of the intermediate heterogeneous phase teeth 210U-V, extending continuously from an inner end surface 233 located on the radially inner side and sides 230 and 231 located laterally in the circumferential direction, between the inner end surface 233 and the sides 230 and 231.

[0101] Chamfers 232 and 234 extend away from the outer circumferential surface of the rotor core 121 from the inner end face 233 to the sides 230 and 231.

[0102] As it is in Fig. As shown in Figure 17, the inter-V phase tooth 210V-V has a body 246 defined by sides 240 and 241 and a head 245 extending continuously from the body 246 and arranged radially inwards with respect to the body 246.

[0103] The head 245 has an inner end surface 243 arranged at the radially inner end, a chamfer 242 extending continuously from the inner end surface 243 and from the side 240, and a chamfer 244 extending continuously from the inner end surface 243 and from the side 241.

[0104] The chamfers 242 and 244 also extend away from the outer circumferential surface of the rotor core 221, from the inner end face 243 towards the sides 240 and 241.

[0105] It is here assumed that an imaginary axis line extending along side 240 is an imaginary side axis line L5, and that an imaginary line extending along side 241 is an imaginary side axis line L6, with the inter-V phase tooth 210V-V viewed from above in the direction of the rotational center line O.

[0106] The chamfer 242 is inclined such that it extends away from the imaginary side axis line L5 while approaching the imaginary side axis line L6 from side 240 towards the inner end surface 243. The chamfer 244 extends such that it extends away from the imaginary side axis line L6 while approaching the imaginary side axis line L5 from side 241 towards the inner end surface 243.

[0107] When the intermediate-heterogeneous phase tooth 210U-V and the intermediate-V phase tooth VV are superimposed, the sides 241 and 240 of the intermediate-V phase tooth 210V-V and the sides 231 and 230 of the intermediate-heterogeneous phase tooth 210U-V essentially coincide, and the inner end surface 243 of the intermediate-V phase tooth 210V-V and the inner end surface 233 of the intermediate-heterogeneous phase tooth 210U-V essentially coincide.

[0108] The chamfer 232 of the intermediate-heterogeneous-phase tooth 210U-V is located further away from the outer circumferential surface of the rotor core 221 compared to the chamfer 242 of the intermediate-V-phase tooth 210V-V. Similarly, the chamfer 234 of the intermediate-heterogeneous-phase tooth 210U-V is located further away from the outer circumferential surface of the rotor core 121 compared to the chamfer 244 of the intermediate-V-phase tooth 210V-V. Other intermediate U-phase teeth 210U-U and intermediate W-phase teeth 210W-W are shaped similarly to the intermediate V-phase tooth 210V-V, and other intermediate heterophase teeth WU and intermediate heterophase teeth 210V-W are shaped similarly to the intermediate heterophase tooth 210U-V.

[0109] Accordingly, the reluctance of a magnetic circuit through which a magnetic flux from the permanent magnet 122 passes when the magnetic flux from the permanent magnet 122 begins to flow into the inter-heterogeneous phase tooth, and the reluctance of the magnetic circuit through which the magnetic flux from the permanent magnet 122 passes when the magnetic flux from the permanent magnet 122 begins to flow into the inter-homogeneous phase tooth, are essentially identical to each other.

[0110] Thus, vibrations and noise are also suppressed in the rotating electric machine according to the second embodiment, as in the rotating electric machine according to the first embodiment.

[0111] In the rotating electric machine according to the second embodiment, chamfers are formed not only on the head of the interphase heterogeneous tooth, but also on the head of the interphase homogeneous tooth. Thus, if a plurality of slotted stator cores 250 are inserted from the outer circumferential surface of the multiphase coil 132, as is the case in Fig. As shown in Figure 14, this prevents the surface of the multiphase coil 132 from being damaged by each stator tooth. Furthermore, the slotted stator cores 250 can be easily inserted into the multiphase coil 132, and the assembly efficiency of the rotating electric machine can be improved.

[0112] In the Fig. In the example shown in Figure 17, a cutting angle θ2, which is a smaller of the cutting angles defined by the chamfer 244 and the inner end surface 243, is made essentially equal to the cutting angle θ1, which is a smaller of the cutting angles defined by the chamfer 234 and the inner end surface 233. However, the relative sizes of the angles are not limited to those described above.

[0113] Preferably, the cutting angle θ2 is larger than the cutting angle θ1. Furthermore, preferably, the boundary between the chamfer 244 and the side 241 is positioned closer to the inner end face 243 (the inner end face 233) with respect to the boundary between the chamfer 234 and the side 231. The chamfer 244 can thus be shaped such that it allows the chamfer 232 to be arranged further away from the outer circumferential surface of the rotor core 121 with respect to the chamfer 243. The chamfer 242 is shaped similarly to the chamfer 244, and the chamfer 232 is shaped similarly to the chamfer 234.

[0114] Although in the above with reference to the examples according to Fig. In the rotating electrical machine described in sections 15 to 17, where the number of slots (s) over which the coil is distributed is two, the number of slots (s) can, for example, be three. Fig. Figure 18 shows a development of a stator 130 in which the number of slots (s) over which a coil is distributed is three.

[0115] In the example according to Fig. In 18, three U-phase slots (220U), three V-phase slots (220V), and three W-phase slots (220W) are arranged in sequence. Therefore, two intermediate homogeneous phase teeth are arranged between the intermediate heterogeneous phase teeth. Specifically, the number of intermediate homogeneous phase teeth arranged between the intermediate heterogeneous phase teeth is ((number of slots (s) over which the coil is distributed)-1).

[0116] The inter-heterogeneous phase teeth each have chamfers 232 and 234 as shaped, and the other inter-homogeneous phase teeth also have chamfers 242 and 244.

[0117] Although the present invention has been described and illustrated in detail, it is clearly understood that this serves only for illustration and as an example, and is not to be understood as a limitation, the scope of the present invention being interpreted with regard to the attached claims.

[0118] In a rotating electric machine, a path length between a rotor and an intermediate-heterogeneous phase tooth (210U-V), where a magnetic flux (MF1) from a magnet pool runs from the rotor and begins to enter the intermediate-heterogeneous phase tooth (210U-V), is longer than a path length between the rotor and an intermediate-V phase tooth (210V-V), where the magnetic flux (MF1) runs from the rotor and begins to enter the intermediate-V phase tooth (210V-V).

Claims

[1] Rotating electrical machine with a stator (130) having an annular stator core (200) and a multi-phase coil (132) attached to the stator core (200) and having a plurality of phase coils (132U, 132V, 132W) each supplied with alternating currents of different phases, and a rotor (120) inserted into the stator (130) and having a plurality of magnetic poles, wherein the stator core (200) has a plurality of partial stator cores (250) arranged in a ring shape in a circumferential direction of the stator core (200), the partial stator cores (250) each have a partial yoke (251) extending in the circumferential direction of the stator core (200) and arranged on an outer circumferential side of the multi-phase coil (132), and a stator tooth (210) extending radially inward from a circumferential surface of the partial yoke (251) and inserted from an outer circumference to an inner circumference of the multi-phase coil (132), wherein the stator core (200) has a plurality of slots (220) defined between the stator teeth (210), the phase coils (132) being inserted into the slots (220), wherein the stator teeth (210) comprise an intermediate homogeneous phase tooth (210U-U, 210V-V, 210W-W) laterally sandwiched between two slots (220) in which the phase coils of the same phase are respectively inserted, and an intermediate heterogeneous phase tooth (210W-U, 210U-V, 210V-W) laterally sandwiched between two slots (220) in which the phase coils (132) of different phases are respectively inserted, the inter-heterogeneous-phase tooth (210W-U, 210U-V, 210V-W) has an inter-heterogeneous-phase tooth body (236) defined by a pair of laterally arranged sides in the circumferential direction of the stator core (200), and an inter-heterogeneous-phase tooth tip (235) arranged radially inwardly of the stator core (200) with respect to the inter-heterogeneous-phase tooth body (236) and extending continuously from the inter-heterogeneous-phase tooth body (236), and the interheterogeneous-phase tooth tip (235) has a first recess portion (232) extending continuously from one side (230) of the pair of sides of the interheterogeneous-phase tooth body (236) and extending toward the radially inner side away from a first imaginary side axis line (L1) and approaching a second imaginary side axis line (L2), and / or a second recess portion (234) extending continuously from the other side (231) of the pair of sides of the interheterogeneous-phase tooth body (236) and extending toward the radially inner side away from the second imaginary side axis line (L2) and approaching the first imaginary side axis line (L1), wherein the first imaginary lateral axis line (L1) is an imaginary axis line extending along one side (230) of the pair of sides of the intermediate heterogeneous phase tooth, and wherein the second imaginary side axis line (L2) is an imaginary axis line extending along the other side (231) of the pair of sides of the intermediate heterogeneous phase tooth, and a first end surface (233) located at a radially inner end of the intermediate heterogeneous phase tooth (210W-U, 210U-V, 210V-W) and a second end surface (243) located at a radially inner end of the intermediate homogeneous phase tooth (210U-U, 210V-V, 210W-W) are arranged along a circumferential surface of the rotor (120). [2] A rotating electric machine according to claim 1, wherein the interheterogeneous phase tooth (210W-U, 210U-V, 210V-W) has the first recess portion and the second recess portion, the inter-homogeneous-phase tooth (210U-U, 210V-V, 210W-W) has an inter-homogeneous-phase tooth body (246) defined by a pair of sides (240, 241) extending laterally in the circumferential direction of the stator core (200), and an inter-homogeneous-phase tooth tip (245) disposed radially inwardly from the stator core (200) with respect to the inter-homogeneous-phase tooth body (246) and extending continuously from the inter-homogeneous-phase tooth body (246), the intermediate homogeneous phase tooth tip (245) has a third recess portion (242) extending continuously from one side (240) of the pair of sides of the intermediate homogeneous phase tooth body (246) and extending to the radially inner side away from a third imaginary side axis line (L5) and approaching a fourth imaginary side axis line (L6), and a fourth recess portion (244) extending continuously from the other side (241) of the pair of sides of the intermediate homogeneous phase tooth body (246) and extending to the radially inner side away from the fourth imaginary side axis line (L6) and approaching the third imaginary side axis line (L5), wherein the third imaginary lateral axis line (L5) is an imaginary lateral axis line extending along one side (240) of the pair of sides (240, 241) of the intermediate homogeneous phase tooth (210U-U, 210V-V, 210W-W), and wherein the fourth imaginary side axis line (L6) is an imaginary axis line extending along the other side (241) of the pair of sides (240, 241) of the intermediate homogeneous phase tooth (210U-U, 210V-V, 210W-W), and the first recess portion (232) is arranged radially outward with respect to the third recess portion (242), and the second recess portion (234) is arranged radially outward with respect to the fourth recess portion (244). [3] Rotating electric machine according to claim 2, wherein a smaller one of intersection angles defined by the first end surface (233) and the first recess portion (232) is smaller than a smaller one of intersection angles defined by the second end surface (243) and the third recess portion (242), and a smaller one (θ1) of intersection angles defined by the first end surface (233) and the second recess portion (234) is smaller than a smaller one (θ2) of intersection angles defined by the second end surface (243) and the fourth recess portion (244). [4] A rotating electric machine according to claim 1, wherein respective corners between the first end surface (233) and respective sides of the inter-heterogeneous-phase tooth (210U-U, 210V-V, 210W-W) arranged laterally in the circumferential direction of the stator core (200) are arranged farther away from the rotor (120) with respect to respective corners between a radially inwardly arranged end surface (243) of the inter-homogeneous-phase tooth (210U-U, 210V-V, 210W-W) and respective sides of the inter-homogeneous-phase tooth (210U-U, 210V-V, 210W-W) arranged laterally in the circumferential direction of the stator core (200). [5] A rotating electric machine according to claim 1, wherein the stator teeth (210) are tapered radially inwardly from a bottom surface on the partial yoke side to an end surface. [6] Rotating electric machine according to claim 1, wherein the multiphase coil (132) is a coil distributed over s slots, distributed over s (s is a positive number) slots, and the number of intermediate homogeneous phase teeth (210U-U, 210V-V, 210W-W) arranged between the intermediate heterogeneous phase teeth (210W-U, 210U-V, 210V-W) is (s-1).

Images