Rotary electric machine

Abstract

To provide a rotary electric machine to which a three-phase current is supplied from an inverter, capable of reducing electric sixth and twelfth torque ripples, and enhancing a redundancy.SOLUTION: Both of a three-phase current supplied from a first inverter and a third inverter and a three-phase current supplied from a second inverter and a fourth inverter have a predetermined current phase difference, respectively. A first coil body (Ua, Va, and Wa) of each phase is formed so that a first stator winding or a third stator winding is wound to first teeth. A second coil body (Ub, Vb, and Wb) of each phase is formed by a second stator winding or a fourth stator winding to second teeth. A third coil body (Uc, Vc, and Wc) of each phase is formed by winding any one phase of the three phases of the first stator winding and the third stator winding, and one phase of the three phases of the second stator winding or the fourth stator winding to the third teeth.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine.

Background Art

[0002] Conventionally, in a rotating electrical machine having two sets of stator windings supplied with three-phase currents from two inverters respectively, a technique for reducing electrical sixth and twelfth torque ripples by phase difference energization of the two inverters is known.

[0003] For example, the rotating electrical machine disclosed in Patent Document 1 includes coil bodies Ua, Va, Wa formed by winding the first stator windings of each phase around the first teeth, coil bodies Ub, Vb, Wb formed by winding the second stator windings of each phase around the second teeth, and coil bodies Uc, Vc, Wc formed by winding the first stator winding of any one phase and the second stator winding of any one phase around the third teeth. Phase difference energization with an electrical angle of 20° or 40° is performed on the first stator winding and the second stator winding by two inverters, and by generating a magnetomotive force obtained by adding magnetomotive forces with a combined phase difference of 80° or 40° in the coil bodies Uc, Vc, Wc, electrical sixth and twelfth harmonic components are canceled.

[0004] Patent Document 2 discloses a motor drive system that drives a rotating electrical machine (motor) having the configuration of Patent Document 1 with two inverters.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In this specification, a series of units including an inverter and a stator winding to which three-phase current is supplied from the inverter is referred to as a "system". Patent Documents 1 and 2 disclose a rotating electric machine and a motor drive system of a "two-system" in which three-phase current is supplied from two inverters to two corresponding sets of stator windings respectively. In a two-system redundant system, even if an inverter or a stator winding of one system fails, the rotation of the rotating electric machine (motor) can be continued using the other system. Therefore, it is applied to systems that require reliability, such as an electric power steering device of a vehicle.

[0007] However, in the future, in order to further improve safety and reliability, it is required to enhance the redundancy of the system. For example, when realizing a "four-system" system, although it is easy to increase the number of inverters from two to four, regarding the configuration of the stator windings of the rotating electric machine, the prior art disclosed in Patent Document 1 cannot be used as it is.

[0008] The present invention has been created in view of such points, and an object thereof is to provide a rotating electric machine that reduces electrical sixth and twelfth torque ripples and enhances redundancy in a rotating electric machine to which three-phase current is supplied from an inverter.

Means for Solving the Problems

[0009] The rotating electric machine according to the present invention includes a rotor (40) having a plurality of magnetic poles (42) with alternating polarities in the circumferential direction, a three-phase stator winding (32), and a stator (30) having a stator core (31) provided with a plurality of teeth (T1 to T18) at predetermined intervals in the circumferential direction around which the stator winding is wound, and the rotor rotates integrally with the rotation axis (11).

[0010] The stationary winding includes a first stationary winding (321) to which three-phase current is supplied from a first inverter (51), a second stationary winding (322) to which three-phase current is supplied from a second inverter (52), a third stationary winding (323) to which three-phase current is supplied from a third inverter (53), and a fourth stationary winding (324) to which three-phase current is supplied from a fourth inverter (54).

[0011] The three-phase current supplied from the first inverter and the three-phase current supplied from the third inverter are energized with the same current amplitude and phase. The three-phase current supplied from the second inverter and the three-phase current supplied from the fourth inverter are energized with the same current amplitude and phase. The three-phase current supplied from the first inverter and the third inverter and the three-phase current supplied from the second inverter and the fourth inverter have a predetermined current phase difference respectively. The predetermined current phase difference is set, for example, within a range of 15 to 25 degrees or within a range of 35 to 45 degrees.

[0012] The rotating electrical machine includes a first coil body (Ua) of the U phase, a first coil body (Va) of the V phase, a first coil body (Wa) of the W phase, a second coil body (Ub) of the U phase, a second coil body (Vb) of the V phase, a second coil body (Wb) of the W phase, a third coil body (Uc) of the U phase, a third coil body (Vc) of the V phase, and a third coil body (Wc) of the W phase.

[0013] The first coil body of the U phase is formed by winding the first stationary winding or the third stationary winding of the U phase among the three phases around the first tooth. The first coil body of the V phase is formed by winding the first stationary winding or the third stationary winding of the V phase among the three phases around the first tooth. The first coil body of the W phase is formed by winding the first stationary winding or the third stationary winding of the W phase among the three phases around the first tooth.

[0014] The second coil body of the U phase is formed by winding the second stator winding or the fourth stator winding of the U phase among the three phases around the second tooth. The second coil body of the V phase is formed by winding the second stator winding or the fourth stator winding of the V phase among the three phases around the second tooth. The second coil body of the W phase is formed by winding the second stator winding or the fourth stator winding of the W phase among the three phases around the second tooth.

[0015] The third coil body of the U phase is formed by winding the first stator winding or the third stator winding of any one phase among the three phases, and the second stator winding or the fourth stator winding of any one phase among the three phases around the third tooth. The third coil body of the V phase is formed by winding the first stator winding or the third stator winding of any one phase among the three phases, and the second stator winding or the fourth stator winding of any one phase among the three phases around the third tooth. The third coil body of the W phase is formed by winding the first stator winding or the third stator winding of any one phase among the three phases, and the second stator winding or the fourth stator winding of any one phase among the three phases around the third tooth.

[0016] The rotating electrical machine is set with the total phase difference of [pd1] below, or the total phase difference of [pd2] below, so as to achieve the following [G1] or [G2]. In the following "predetermined phase range including 20 degrees in electrical angle", for example, 20 degrees and 40 degrees in electrical angle are included.

[0017] [G1] Each phase difference between the magnetomotive force of the third coil body (Uc, Vc, Wc) of each phase and the magnetomotive force of the first coil body (Ua, Va, Wa) of each phase, and each phase difference between the magnetomotive force of the second coil body (Ub, Vb, Wb) of each phase and the magnetomotive force of the third coil body (Uc, Vc, Wc) of each phase are within a predetermined phase range including 20 degrees in electrical angle.

[0018] [G2]The phase differences between the magnetomotive forces of the second coil bodies (Ub, Vb, Wb) of each phase with respect to the magnetomotive forces of the first coil bodies (Ua, Va, Wa) of each phase, and the phase differences between the magnetomotive forces of the third coil bodies (Uc, Vc, Wc) of each phase with respect to the magnetomotive forces of the second coil bodies (Ub, Vb, Wb) of each phase are within a predetermined phase range including 20 degrees in electrical angle.

[0019] [pd1]The combined phase difference between the magnetomotive force generated by the first stator winding wound around the third tooth or a partial winding of the third stator winding and the magnetomotive force generated by the second stator winding wound around the third tooth or a partial winding of the fourth stator winding.

[0020] [pd2]The combined phase difference between the current flowing through the first stator winding wound around the third tooth or a partial winding of the third stator winding and the current flowing through the second stator winding wound around the third tooth or a partial winding of the fourth stator winding.

[0021] In the present invention, a four-system rotating electrical machine is provided in which three-phase currents are respectively supplied from four inverters to corresponding four sets of stator windings. For this rotating electrical machine, phase difference energization with a predetermined current phase difference is performed between the first and third system groups and the second and fourth system groups. In the third coil body, by setting the combined phase difference of [pd1] or [pd2] above for the magnetomotive force or current, the electrical sixth and twelfth harmonic components are canceled. Therefore, torque ripple can be reduced and redundancy can be increased.

Brief Description of the Drawings

[0022]

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Embodiments for Carrying Out the Invention

[0023] A plurality of embodiments of the rotating electrical machine will be described with reference to the drawings. The "present embodiment" includes the following first to ninth embodiments. The same components in the plurality of embodiments are denoted by the same reference numerals and the description thereof is omitted. The rotating electrical machine of the present embodiment is applied to, for example, an electric power steering device of a vehicle, and is a motor that outputs a steering assist torque, and is configured by, for example, a permanent magnet type three-phase brushless motor. In the following description of the embodiments, "motor 10" corresponds to the rotating electrical machine. Also, the unit of electrical angle or phase, "degree", is represented as "°".

[0024] [Motor Drive System] First, referring to FIG. 1, the overall configuration of the four-system motor drive system that drives the motor 10 of the present embodiment will be described. In this specification, a series of units including an inverter and a stator winding to which a three-phase current is supplied from the inverter is referred to as a "system". A four-system system is a system in which four units are provided redundantly. The four-system motor drive system includes a control device 50 having four inverters 51 to 54 and a motor 10 having four sets of stator windings 321 to 324. The following "first inverter 51" and "second stator winding 322" respectively mean "inverter 51 of the first system" and "stator winding 322 of the second system".

[0025] The inverters 51 to 54 are configured by switching elements (for example, MOSFETs) of the upper and lower arms of a three-phase (that is, U-phase, V-phase, and W-phase) bridge connection. The inverters 51 to 54 perform a switching operation according to a drive signal commanded from the driver of the control device 50, convert the DC power of the batteries BT1 and BT2 into three-phase AC power, and supply a three-phase current to the stator windings 321 to 324.

[0026] In the configuration example of FIG. 1, the first inverter 51 and the second inverter 52 are connected in parallel to a common battery BT1, and the third inverter 53 and the fourth inverter 54 are connected in parallel to a common battery BT2. This is not the only case. The four inverters 51 to 54 may be connected to four batteries respectively. Also, if the possibility of battery failure or depletion is low, the four inverters 51 to 54 may be connected in parallel to one battery.

[0027] The first stator winding 321 is supplied with three-phase currents U1, V1, and W1 from the first inverter 51. The second stator winding 322 is supplied with three-phase currents U2, V2, and W2 from the second inverter 52. The third stator winding 323 is supplied with three-phase currents U3, V3, and W3 from the third inverter 53. The fourth stator winding 324 is supplied with three-phase currents U4, V4, and W4 from the fourth inverter 54. In each of the stator windings 321 to 324, the three-phase windings are connected at neutral points Q1 to Q4. Note that the three-phase stator windings are not limited to Y-connection (star connection) and may be configured in delta connection.

[0028] The conductor connecting each phase of the stator winding and the corresponding inverter is called a "lead wire". The symbols of the lead wires for the U-phase, V-phase, and W-phase are denoted as A, B, and C respectively. For example, the lead wire of the first stator winding 321 of the U-phase is represented by the symbol "A1", the lead wire of the second stator winding 322 of the V-phase is represented by the symbol "B2", and the lead wire of the third stator winding 323 of the W-phase is represented by the symbol "C3".

[0029] The current flowing in each phase of each system is detected by a current sensor (not shown). Also, the rotation angle of the motor 10 is detected by an angle sensor 56 (see FIG. 2). The control device 50 controls the operations of the inverters 51 to 54 by feedback control based on each phase current and rotation angle information.

[0030] Here, the three-phase currents U1, V1, W1 supplied from the first inverter 51 and the three-phase currents U3, V3, W3 supplied from the third inverter 53 are energized with the same current amplitude and phase. The three-phase currents U2, V2, W2 supplied from the second inverter 52 and the three-phase currents U4, V4, W4 supplied from the fourth inverter 54 are energized with the same current amplitude and phase.

[0031] The three-phase currents U1, V1, W1, U3, V3, W3 supplied from the first inverter 51 and the third inverter 53 and the three-phase currents U2, V2, W2, U4, V4, W4 supplied from the second inverter 52 and the fourth inverter 54 have a predetermined current phase difference respectively. Preferably, the "predetermined current phase difference" is 20° or 40°. As described in Patent Document 1, the 20° current phase difference may be set within the range of "15 to 25°", and the 40° current phase difference may be set within the range of "35 to 45°".

[0032] As will be described later, for each tooth around which the stator windings 321 to 324 are wound, a magnetomotive force proportional to the product of the current and the number of turns is generated. The phase of the magnetomotive force is equal to the current phase. The motor 10 outputs the sum of the torques generated coaxially by the magnetomotive forces generated by the four sets of stator windings 321 to 324 wound around each tooth.

[0033] [Configuration of the motor] Next, with reference to FIGS. 2 to 5, the configuration of the motor 10 will be described. The basic configuration of the motor 10 is the same as that described in FIG. 1 of Patent Document 1. FIG. 2 schematically shows only the stator 30, the rotor 40, and the substrate 55 to which the lead wires A1 to A4, B1 to B4, C1 to C4 are connected. In addition, the illustration and description of general motor components such as the housing and bearings are omitted.

[0034] In an electromechanical integrated motor in which the control device 50 is integrally formed, the control device 50 is mounted on the substrate 55 as shown by the dashed line. However, the motor 10 of the present embodiment is not limited to an electromechanical integrated type, and may be an electromechanical separate type motor connected to a separately provided control device 50 by a cable.

[0035] The stator 30 and the rotor 40 are provided coaxially with respect to the center line O of the rotating shaft 11. In the following description, the axial direction, the radial direction, and the circumferential direction respectively mean the axial direction, the radial direction, and the circumferential direction of the rotating shaft 11. The stator 30 has an annular stator core 31 and a three-phase stator winding 32. The stator winding 32 includes four systems of stator windings 321 to 324. The stator core 31 is formed by laminating, for example, thin plate-shaped magnetic steel sheets. The first to fourth stator windings 321 to 324 are respectively supplied with three-phase currents from the first to fourth inverters 51 to 54 to generate magnetomotive forces. Thereby, a rotating magnetic field is formed in the stator 30.

[0036] The rotor 40 is rotatably provided inside the stator 30 in the radial direction. The rotor 40 has a rotor core 41 made of a magnetic material and a plurality of magnetic poles 42 fixed to the rotor core 41 and having alternating polarities in the circumferential direction. The magnetic poles 42 are composed of permanent magnets. The rotating shaft 11 is fixed to the center of the rotor core 41. The rotor 40 rotates integrally with the rotating shaft 11 by the rotating magnetic field generated by the stator 30. The circumferential configuration of the stator 30 and the rotor 40 will be described later with reference to FIG. 5.

[0037] A sensor magnet 12 is fixed to the end of the rotating shaft 11 on the substrate 55 side. An angle sensor 56 such as a Hall element or an MR element is provided at a portion of the substrate 55 facing the sensor magnet 12 on the surface on the stator 30 and rotor 40 side (the lower surface in FIG. 2). The angle sensor 56 detects the rotation angle of the rotor 40 based on the change in the magnetic field of the sensor magnet 12. In order to improve the detection accuracy of the angle sensor 56, it is required to suppress the influence of external magnetic flux.

[0038] FIG. 3 shows an example of the arrangement of the lead wires A1 to A4, B1 to B4, and C1 to C4 of the stator windings 321 to 324 as viewed from the substrate 55 side. The lead wires A1, B1, C1 of the first stator winding 321 connected to the first inverter 51 and the lead wires A3, B3, C3 of the third stator winding 323 connected to the third inverter 53 are arranged such that each phase is symmetric about the rotation axis 11. The lead wires A2, B2, C2 of the second stator winding 322 connected to the second inverter 52 and the lead wires A4, B4, C4 of the fourth stator winding connected to the fourth inverter 54 are arranged such that each phase is symmetric about the rotation axis 11.

[0039] Here, "symmetric about the rotation axis 11" strictly means "symmetric about the center line O of the rotation axis 11". By arranging the lead wires through which currents of the same amplitude and phase flow at positions equidistant from the rotation axis 11, the disturbance magnetic flux is canceled on the rotation axis 11. Thereby, in the angle sensor 56 that detects the rotation angle of the rotor 40 based on the change in the magnetic field of the sensor magnet 12, the error due to the disturbance magnetic flux can be minimized.

[0040] The lead wires A1, B1, C1 of the first stator winding 321 and the lead wires A3, B3, C3 of the third stator winding 323 are combined into a "first lead wire group ABC13". Also, the lead wires A2, B2, C2 of the second stator winding 322 and the lead wires A4, B4, C4 of the fourth stator winding are combined into a "second lead wire group ABC24". In the arrangement example of FIG. 3, the center line M13 of the first lead wire group ABC13 and the center line M24 of the second lead wire group ABC24 are orthogonal.

[0041] Also, in the first lead wire group ABC13 and the second lead wire group ABC24, the distances between the in-phase lead wires arranged symmetrically are represented as opposing distances d13 and d24. In the arrangement example of FIG. 3, the opposing distances d13 and d24 of both lead wire groups ABC13 and ABC24 are further equal. That is, the four sets of lead wires A1 to A4, B1 to B4, and C1 to C4 are arranged with 90° rotational symmetry about the rotation axis 11. Therefore, an arrangement with excellent symmetry is realized.

[0042] However, it is not an essential requirement that the center lines M13 and M24 of the two lead wire groups ABC13 and ABC24 are perpendicular to each other, or that the opposing distances d13 and d24 of the two lead wire groups ABC13 and ABC24 are equal. For the arrangement examples of the lead wires A1 to A4, B1 to B4, and C1 to C4, which are different from the arrangement example in FIG. 3, refer to FIGS. 22 to 24, and other embodiments will be described later.

[0043] Next, referring to FIG. 4, the wiring of each stator winding 321 to 324 will be described. The “+” and “-” at the end of the symbol indicate the direction of the magnetomotive force generated according to the winding direction of the partial winding with respect to the same current direction. The winding pattern of the partial winding in which the magnetomotive force is generated in the positive direction is called “forward winding”, and the winding pattern of the partial winding in which the magnetomotive force is generated in the reverse direction is called “reverse winding”. The current flowing through the forward winding (+) partial winding and the current flowing through the reverse winding (-) partial winding have a phase difference of 180° in electrical angle. In this embodiment, by arranging a combination of a forward winding partial winding and a reverse winding partial winding on each tooth, a desired magnetomotive force phase difference can be set.

[0044] The first stator winding 321 has partial windings U1 + and U1 - of the U phase connected in series, partial windings V1 + and V1 - of the V phase connected in series, and partial windings W1 + and W1 - of the W phase connected in series. One end of the series connection body is connected to the neutral point Q1. At the other end of the series connection body, the partial windings of the U phase, V phase, and W phase are connected to the lead wires A1, B1, and C1, respectively. The lead wires A1, B1, and C1 are connected to the first inverter 51.

[0045] Similarly, the second stator winding 322 has partial windings U2 + and U2 - of the U phase connected in series, partial windings V2 + and V2 - of the V phase connected in series, and partial windings W2 + and W2 - of the W phase connected in series. One end of the series connection body is connected to the neutral point Q2. At the other end of the series connection body, the partial windings of the U phase, V phase, and W phase are connected to the lead wires A2, B2, and C2, respectively. The lead wires A2, B2, and C2 are connected to the second inverter 52.

[0046] Similarly, in the third stator winding 323, the partial windings U3+ and U3- of the U phase are connected in series, the partial windings V3+ and V3- of the V phase are connected in series, and the partial windings W3+ and W3- of the W phase are connected in series. One end of the series connection body is connected to the neutral point Q3. At the other end of the series connection body, the partial windings of the U phase, V phase, and W phase are connected to the lead wires A3, B3, and C3, respectively. The lead wires A3, B3, and C3 are connected to the third inverter 53.

[0047] Similarly, in the fourth stator winding 324, the partial windings U4+ and U4- of the U phase are connected in series, the partial windings V4+ and V4- of the V phase are connected in series, and the partial windings W4+ and W4- of the W phase are connected in series. One end of the series connection body is connected to the neutral point Q4. At the other end of the series connection body, the partial windings of the U phase, V phase, and W phase are connected to the lead wires A4, B4, and C4, respectively. The lead wires A4, B4, and C4 are connected to the fourth inverter 54.

[0048] Referring to FIG. 5, taking a 14-pole 18-slot IPM motor as an example, the circumferential configurations of the stator 30 and the rotor 40 will be described. Hereinafter, regarding the number of poles of the rotor 40 and the number of slots between the teeth of the stator 30, the number of poles is denoted as "P" and the number of slots is denoted as "S", and for example, 14 poles and 18 slots are expressed as "14P18S". 14P18S is a representative configuration of this embodiment and corresponds to the first to fourth embodiments. Note that FIG. 5 is a radial cross-sectional view of the stator 30 and the rotor 40, but the cross-sectional hatching is omitted for clarity. Also, although the cross-section of the stator winding 32 originally appears as a number of circles, it is schematically shown as a rectangular area without hatching. Note that the size of the rectangular area has no correlation with the actual cross-sectional area of the coil body.

[0049] First, the rotor 40 will be described. In the 14P18S motor, 14 magnetic poles 42 are fixed to the rotor core 41 such that the polarities alternate in the circumferential direction. The 14 magnetic poles 42 form 7 pairs of magnetic pole pairs. In the IPM motor, the magnetic poles 42 are embedded in the rotor core 41. However, not limited to the IPM motor, an SPM motor in which the magnetic poles 42 are provided on the surface of the rotor core 41 may be used.

[0050] Next, regarding the stator 30, the stator core 31 has an annular back yoke 33 and a plurality of teeth T1 to T18 protruding radially inward from the back yoke 33. A plurality of teeth T1 to T18 are provided at predetermined intervals in the circumferential direction, and slots 35 are formed between adjacent teeth. The number of teeth is equal to the number of slots 35, which is 18 in 14P18S. In the following radial cross-sectional view, tooth T1 is shown on the right side of the paper of the stator 30, and the remaining 17 teeth T2 to T18 are shown at equal intervals in the circumferential direction counterclockwise from tooth T1.

[0051] The 18 teeth T1 to T18 are arranged in the circumferential direction at intervals of a mechanical angle of 20°. The interval of the mechanical angle of 20° is converted into an electrical angle based on the number of magnetic poles P, that is, the number of magnetic pole pairs (P / 2). Since the mechanical angle {360 / (P / 2)}° corresponds to the electrical angle of 360°, the mechanical angle of 20° is converted into the electrical angle of (P × 10)°. In 14P18S, the interval between adjacent teeth in the circumferential direction is an electrical angle of 140°.

[0052] The stator winding 32 is housed in the slot 35 and wound around the teeth T1 to T18. By winding the stator winding 32 around each of the teeth T1 to T18, a "coil body" is formed. The motor 10 includes three types of coil bodies, namely, a first coil body, a second coil body, and a third coil body for each phase. That is, the motor 10 includes a first coil body Ua of the U phase, a first coil body Va of the V phase, a first coil body Wa of the W phase, a second coil body Ub of the U phase, a second coil body Vb of the V phase, a second coil body Wb of the W phase, a third coil body Uc of the U phase, a third coil body Vc of the V phase, and a third coil body Wc of the W phase.

[0053] The first coil bodies Ua, Va, and Wa are each formed by winding the first stator winding 321 or the third stator winding 323 of the U phase, V phase, and W phase among the three phases around the first tooth. In the example of FIG. 5, teeth T1, T4, T7, T10, T13, and T16 correspond to the first tooth. The first coil bodies Ua, Va, and Wa are shown in a pair of rectangular areas on both sides of the first tooth.

[0054] The second coil bodies Ub, Vb, and Wb are each formed by winding the second stator windings 322 or the fourth stator windings 324 of the U-phase, V-phase, and W-phase among the three phases around the second teeth. In the example of FIG. 5, the teeth T2, T5, T8, T11, T14, and T17 correspond to the second teeth. The second coil bodies Ub, Vb, and Wb are illustrated in a pair of rectangular areas on both sides of the second teeth.

[0055] The third coil bodies Uc, Vc, and Wc are each formed by winding either the first stator winding 321 or the third stator winding 323 of any one of the three phases and either the second stator winding 322 or the fourth stator winding 324 of any one of the three phases around the third teeth. In the example of FIG. 5, the teeth T3, T6, T9, T12, T15, and T18 correspond to the third teeth. The third coil bodies Uc, Vc, and Wc are illustrated in two pairs of rectangular areas on both sides of the third teeth, that is, the radially inner area and the radially outer area.

[0056] FIG. 5 does not show the phase and system arrangements of the specific stator windings 321 to 324 wound around each of the teeth T1 to T18. FIGS. 9 to 21 below show examples of the phase and system arrangements of the stator windings 32 wound around each tooth according to the current phase difference between the first and third inverters 51 and 53 and the second and fourth inverters 52 and 54, and the resultant magnetomotive force phase difference.

[0057] [Phase difference energization and resultant magnetomotive force] Next, referring to FIGS. 6 to 8, the phase difference energization by the four-system inverters 51 to 54 and the resultant magnetomotive force in the third coil bodies Uc, Vc, and Wc will be described. The energization method in which the current amplitudes supplied by the first and third inverters 51 and 53 and the second and fourth inverters 52 and 54 are equal and the current phase difference is set to 20° is referred to as "20° phase difference energization", and the energization method in which the current phase difference is set to 40° is referred to as "40° phase difference energization".

[0058] Fig. 6 shows the current phases of each phase energized to the first coil bodies Ua, Va, Wa and the second coil bodies Ub, Vb, Wb in the 20° phase difference power supply and the 40° phase difference power supply. The phases of each phase of the three-phase current supplied from the first inverter 51 and the third inverter 53 to the first coil bodies Ua, Va, Wa are used as the reference phases. For example, for the U phase, the current phase 0° of the positive-wound partial windings U1+, U3+ of the first and third stator windings 321, 323 is the reference phase. The phases of each phase of the three-phase current supplied from the second inverter 52 and the fourth inverter 54 to the second coil bodies Ub, Vb, Wb are set such that the current phase difference from the reference phase is 20° or 40°.

[0059] The three-phase currents supplied from the first inverter 51 and the third inverter 53 to the first coil bodies Ua, Va, Wa are represented by formulas (1.1) to (1.6). The current amplitude I common to the four systems is referred to as the basic current amplitude I.

[0060] U1+ = U3+ = Isin(θ) ···(1.1) W1- = W3- = Isin(θ - 60) ···(1.2) V1+ = V3+ = Isin(θ - 120) ···(1.3) U1- = U3- = Isin(θ - 180) ···(1.4) W1+ = W3+ = Isin(θ - 240) ···(1.5) V1- = V3- = Isin(θ - 300) ···(1.6)

[0061] The three-phase currents supplied from the second inverter 52 and the fourth inverter 54 to the second coil bodies Ub, Vb, Wb by the 20° phase difference power supply are represented by formulas (2.1) to (2.6).

[0062] U2+ = U4+ = Isin(θ - 20) ···(2.1) W2- = W4- = Isin(θ - 80) ···(2.2) V2+ = V4+ = Isin(θ - 140) ···(2.3) U2- = U4- = Isin(θ - 200) ···(2.4) W2 += W4 += Isin(θ - 260) ···(2.5) V2 -= V4 -= Isin(θ - 320) ···(2.6)

[0063] The three-phase currents energized from the second inverter 52 and the fourth inverter 54 to the second coil bodies Ub, Vb, and Wb by the 40° phase difference energization are represented by equations (3.1) to (3.6).

[0064] U2 += U4 += Isin(θ - 40) ···(3.1) W2 -= W4 -= Isin(θ - 100) ···(3.2) V2 += V4 += Isin(θ - 160) ···(3.3) U2 -= U4 -= Isin(θ - 220) ···(3.4) W2 += W4 += Isin(θ - 280) ···(3.5) V2 -= V4 -= Isin(θ - 340) ···(3.6)

[0065] As will be described below regarding the summation of the currents and magnetomotive forces in the third coil bodies Uc, Vc, and Wc, the phase of the three-phase current generated by summation with a 20° phase difference energization coincides with the current phase of the 40° phase difference energization, and the phase of the three-phase current generated by summation with a 40° phase difference energization coincides with the current phase of the 20° phase difference energization. In any phase difference energization, the phase difference between the currents flowing through the second coil bodies Ub, Vb, Wb and the third coil bodies Uc, Vc, Wc with respect to the current flowing through the first coil bodies Ua, Va, Wa is 20° for one and 40° for the other.

[0066] As a result, as described in FIG. 7 and equations (15), (16) of Patent Document 1, FIG. 3 and equations (3.1), (3.2), etc. of Patent Document 2, the electrical sixth and twelfth harmonic components are canceled, and the electrical sixth and twelfth torque ripples can be reduced.

[0067] Referring to FIGS. 7 and 8, the phase difference and amplitude of the current and magnetomotive force combined by the third coil bodies Uc, Vc, and Wc during 20° phase difference energization and 40° phase difference energization will be described. The combination of partial windings of the stator winding 32 shown in FIG. 7 corresponds to the teeth T9 which are the third teeth of the first and second embodiments. The combination of partial windings of the stator winding 32 shown in FIG. 8 corresponds to the teeth T14 which are the third teeth of the third and fourth embodiments. Here, a general description will be given, and the details will be described later in each embodiment.

[0068] The current flowing through the partial winding of the first stator winding 321 or the third stator winding 323 wound around the third teeth, and the current flowing through the partial winding of the second stator winding 322 or the fourth stator winding 324 wound around the third teeth are respectively referred to as "first current vector a" and "second current vector b". Also, the current obtained by combining the current vector a and the current vector b and flowing through the third coil bodies Uc, Vc, and Wc is referred to as "combined current vector s". In FIGS. 7 and 8, the current vector a, the current vector b, and the combined current vector s are represented by vector symbols.

[0069] The amplitudes of the first current vector a and the second current vector b are equal to the basic current amplitude I. Also, the current phase difference between the first current vector a and the second current vector b is defined as the "combined phase difference". Since the phase of the magnetomotive force coincides with the current phase, the "combined phase difference" is also the phase difference between the phase of the magnetomotive force by the first current vector a and the phase of the magnetomotive force by the second current vector b. That is, the "combined phase difference" is defined in the following two meanings of [pd1] and [pd2].

[0070] [pd1] The combined phase difference between the magnetomotive force generated by the partial winding of the first stator winding 321 or the third stator winding 323 wound around the third teeth and the magnetomotive force generated by the partial winding of the second stator winding 322 or the fourth stator winding 324 wound around the third teeth.

[0071] The combined phase difference between the current flowing through the partial winding of the first stator winding 321 or the third stator winding 323 wound around the third tooth and the current flowing through the partial winding of the second stator winding 322 or the fourth stator winding 324 wound around the third tooth.

[0072] These combined phase differences [pd1], [pd2] are set so as to achieve the following objectives [G1] or [G2]. The "predetermined phase range including 20° in electrical angle" below includes electrical angles 20° and 40°.

[0073] [G1] Each phase difference between the magnetomotive force of the third coil bodies Uc, Vc, Wc of each phase with respect to the magnetomotive force of the first coil bodies Ua, Va, Wa of each phase and each phase difference between the magnetomotive force of the second coil bodies Ub, Vb, Wb of each phase with respect to the magnetomotive force of the third coil bodies Uc, Vc, Wc of each phase are within a predetermined phase range including 20° in electrical angle.

[0074] [G2] Each phase difference between the magnetomotive force of the second coil bodies Ub, Vb, Wb of each phase with respect to the magnetomotive force of the first coil bodies Ua, Va, Wa of each phase and each phase difference between the magnetomotive force of the third coil bodies Uc, Vc, Wc of each phase with respect to the magnetomotive force of the second coil bodies Ub, Vb, Wb of each phase are within a predetermined phase range including 20° in electrical angle.

[0075] Hereinafter, the combined phase difference of [pd1] is referred to as the "magnetomotive force phase difference". In the description of the embodiment, the magnetomotive force phase difference is mainly described as the combined phase difference. The magnetomotive force phase difference is set to an electrical angle of 80° or an electrical angle of 40°. As described in Patent Document 1, the magnetomotive force phase difference of 80° in electrical angle may be set in the range of "72 to 88° in electrical angle", and the magnetomotive force phase difference of 40° in electrical angle may be set in the range of "32 to 48° in electrical angle".

[0076] The amplitude of the magnetomotive force is proportional to the product of the current amplitude and the number of turns. Therefore, in order to match the amplitude of the magnetomotive force generated in the third coil bodies Uc, Vc, Wc by summation to the amplitude of the magnetomotive force generated in the first coil bodies Ua, Va, Wa and the second coil bodies Ub, Vb, Wb, it is necessary to set the ratio of the number of turns to be the reciprocal of the current amplitude ratio.

[0077] Here, the number of turns of the first stator winding 321 or the third stator winding 323 wound around the first teeth, and the number of turns of the second stator winding 322 or the fourth stator winding 324 wound around the second teeth are each designated as "Nab". Also, the number of turns of the first stator winding 321 or the third stator winding 323 wound around the third teeth, and the number of turns of the second stator winding 322 or the fourth stator winding 324 wound around the third teeth are each designated as "Nc". Based on the ratio of the current amplitude of the combined current vector s to the basic current amplitude I, by determining the ratio of the number of turns (Nab / Nc), magnetomotive forces with the same amplitude as the first coil bodies Ua, Va, Wa and the second coil bodies Ub, Vb, Wb are generated in the third coil body Uc, Vc, Wc. Thereby, the motor 10 can output a uniform torque.

[0078] The upper part of each of FIGS. 7 and 8 shows the combination of the current vector a and the current vector b when the magnetomotive force phase difference is 80°. In this case, the current amplitude of the combined U-phase current Us+ is 1.53 times the basic current amplitude I. Therefore, the number of turns of the first teeth, the second teeth, and the third teeth are set so as to satisfy the relationship of "1.4 ≦ Nab / Nc ≦ 1.6" within the range including "Nab / Nc = 1.53".

[0079] The lower part of each of FIGS. 7 and 8 shows the combination of the current vector a and the current vector b when the magnetomotive force phase difference is 40°. In this case, the current amplitude of the combined U-phase current Us+ is 1.88 times the basic current amplitude I. Therefore, the number of turns of the first teeth, the second teeth, and the third teeth are set so as to satisfy the relationship of "1.9 ≦ Nab / Nc ≦ 2.0" within the range including "Nab / Nc = 1.88".

[0080] FIG. 7 of Patent Document 2 discloses that when a two-phase motor with an exciting magnetic force phase difference set to 80° or 40° is energized with a 20° phase difference, the torque ripples of the 6th and 12th harmonics are reduced compared to the same-phase energization. In the present embodiment, by energizing a four-phase motor with enhanced redundancy with respect to the two-phase motors of Patent Documents 1 and 2 with a 20° or 40° phase difference, the torque ripples of the 6th and 12th harmonics can be reduced.

[0081] [Embodiment of Motor] Next, referring to FIGS. 9 to 21, specific arrangement examples of partial windings of the four-phase stator windings 321 to 324 determined according to combinations of current phase differences and exciting magnetic force phase differences for each configuration of the number of poles and slots will be described as the first to ninth embodiments.

[0082] In the first to eighth embodiments, the number of slots is 18. The first to fourth embodiments are 14P18S, corresponding to the first to fourth embodiments of Patent Document 1. The fifth embodiment is 22P18S, the sixth and seventh embodiments are 16P18S, and the eighth embodiment is 20P18S. The fifth to eighth embodiments correspond to the "other embodiments" of Patent Document 1. 14P18S and 22P18S are configurations corresponding to "m = 1" in the general form of "the number of poles is (18 ± 4) × m (m is an integer of 1 or more) and the number of slots is 18 × m". 16P18S and 20P18S are configurations corresponding to "n = 1" in the general form of "the number of poles is (18 ± 2) × n (n is an integer of 1 or more) and the number of slots is 18 × n".

[0083] As described in FIG. 9 and the like of Patent Document 1, compared to 16P18S and 20P18S, in 14P18S and 22P18S, the electromagnetic forces are distributed at four locations in the circumferential direction at 90° intervals, so the balance is good, which is advantageous for suppressing noise and vibration.

[0084] (First Embodiment) Fig. 9 shows a table of the arrangement examples of the partial windings of the four-phase stator windings 321 to 324 in the 14P18S motor. Fig. 9 shows the partial windings of the four-phase stator windings 321 to 324 determined according to the combination of the electrical angle corresponding to each tooth T1 to T18, the current phase difference between the phases, and the magnetomotive force, and the type of coil body. One type of partial winding is arranged on the first tooth and the second tooth. On the third tooth, two types of partial windings shown before and after " / " are arranged with different radial positions. Note that the radial positions of the two types of partial windings wound around the third tooth may be interchanged.

[0085] The first embodiment is the case where the magnetomotive force phase difference is 80° with 20° phase difference energization. The second embodiment is the case where the magnetomotive force phase difference is 40° with 20° phase difference energization. The third embodiment is the case where the magnetomotive force phase difference is 80° with 40° phase difference energization. The fourth embodiment is the case where the magnetomotive force phase difference is 40° with 40° phase difference energization.

[0086] In the first embodiment, by winding the partial winding U3+ (electrical angle 0°) of the U phase of the third stator winding 323 around the tooth T1 which is the first tooth, the first coil body Ua of the U phase is formed. By winding the partial winding V2+ (electrical angle 140° due to 20° phase difference energization) of the V phase of the second stator winding 322 around the tooth T2 which is the second tooth, the second coil body Vb of the V phase is formed.

[0087] Around the tooth T3 which is the third tooth, the partial winding W1+ (electrical angle 240°) of the W phase of the first stator winding 321 and the partial winding V2- (electrical angle 320° due to 20° phase difference energization) of the V phase of the second stator winding 322 are wound, whereby the third coil body Wc of the W phase is formed. The average of the electrical angles of the two types of partial windings W1+ / V2- is the electrical angle 280° of the third coil body Wc. The remaining teeth T4 to T18 are also described in the same way. Thus, a total of 24 types of partial windings of the four-phase stator windings 321 to 324 are arranged on 6 first teeth, 6 second teeth, and 6 third teeth.

[0088] As the first embodiment, FIG. 10 shows a diagram of the case where the magnetomotive force phase difference is 80° with a 20° phase difference energization. As an example of "magnetomotive force phase difference of 40°" in FIG. 7, the sum of the magnetomotive forces of the partial winding U1+ of the U-phase of the first stator winding 321 and the partial winding W4- of the W-phase of the fourth stator winding 324 in the third coil body Uc formed by winding around the teeth T9 of the first embodiment is shown.

[0089] The phase of the combined U-phase current Us+ is 40°, and the current amplitude is 1.53 times the basic current amplitude I flowing through the partial windings U1+ / W4- of the first and fourth stator windings 321 and 324. The phase difference between the magnetomotive force of the third coil body Uc and the magnetomotive force of the first coil body Ua formed by the partial winding U1+ is 40°. The phase difference between the magnetomotive force of the third coil body Uc and the magnetomotive force of the second coil body Wb formed by the partial winding W4- is also 40°. With this configuration, the operating effect of canceling the 6th and 12th harmonic components of electricity can be obtained.

[0090] By the way, in the two-system prior arts disclosed in Patent Documents 1 and 2, simply distributing the "partial winding of the first stator winding" to the partial windings of the first stator winding 321 and the third stator winding 323, and simply distributing the "partial winding of the second stator winding" to the partial windings of the second stator winding 322 and the fourth stator winding 324 may seem to be an extension of the prior art. However, the point of this embodiment lies in how to distribute the two-system "partial winding of the first stator winding" to the partial windings of the first and third stator windings 321 and 323, and how to distribute the two-system "partial winding of the second stator winding" to the partial windings of the second and fourth stator windings 322 and 324. Subsequently, this point will be described in detail.

[0091] As shown by the two-dot chain line ellipse in Fig. 9, for example, the partial winding V2+ of the U-phase of the second stator winding 322 is wound around the tooth T2, and similarly, the partial winding V2- of the U-phase of the second stator winding is wound around the tooth T3 adjacent in the circumferential direction. Thus, in the first embodiment, the first tooth and the third tooth around which the first stator winding 321 of the same phase is wound are adjacent, the second tooth and the third tooth around which the second stator winding 322 of the same phase is wound are adjacent, the first tooth and the third tooth around which the third stator winding 323 of the same phase is wound are adjacent, and the second tooth and the third tooth around which the fourth stator winding 324 of the same phase is wound are adjacent. This makes it easier to connect the wirings between the teeth.

[0092] In the configurations of 14P18S and 22P18S, when the magnetomotive force phase difference is 80°, the first tooth and the third tooth, and the second tooth and the third tooth around which the stator windings of the same phase in the same system are wound are adjacent in the circumferential direction. On the other hand, in the configurations of 16P18S and 20P18S, when the magnetomotive force phase difference is 40°, the first tooth and the third tooth, and the second tooth and the third tooth around which the stator windings of the same phase in the same system are wound are adjacent in the circumferential direction. Therefore, common operational effects can be obtained in addition to the first embodiment, in the third, fifth, seventh, and ninth embodiments.

[0093] Also, in the projection view in the direction of the rotation axis 11 shown in Fig. 10, both the first boundary line L1 and the second boundary line L2 are straight lines passing through the rotation axis 11. Here, "passing through the rotation axis 11" strictly means "passing through the center line O of the rotation axis 11". The first boundary line L1 and the second boundary line L2 have different inclinations from each other and intersect at the center line O of the rotation axis 11.

[0094] All the first teeth and third teeth around which the first stator windings 321 of each phase are wound, and all the first teeth and third teeth around which the third stator windings 323 of each phase are wound, are arranged in regions on opposite sides of each other with the first boundary line L1 as the boundary. All the second teeth and third teeth around which the second stator windings 322 are wound, and all the second teeth and third teeth around which the fourth stator windings 324 are wound, are arranged in regions on opposite sides of each other with the second boundary line L2 as the boundary.

[0095] In the figure, the "first" to "fourth" marked at the tips of the two-direction arrows orthogonal to the boundary lines L1 and L2 mean the regions where the first to fourth stator windings 321 to 324 are arranged. Thereby, the wiring regions of the stator windings 321 to 324 can be divided for each system. Therefore, the length of the jumper wire within each system can be shortened.

[0096] This configuration is also common to the second to ninth embodiments. When expressed using the up, down, left, and right directions in the direction of view on the paper surface in the figure where the tooth T1 is arranged on the right side, except for the eighth embodiment, the first boundary line L1 extends substantially in the left-right direction and divides the plurality of teeth T1 to T18 vertically. The upper side of the first boundary line L1 is the arrangement region of the first stator winding 321, and the lower side of the first boundary line L1 is the arrangement region of the third stator winding 323.

[0097] The second boundary line L1 extends substantially in the up-down direction and divides the plurality of teeth T1 to T18 horizontally. Except for the first and third embodiments, the left side of the second boundary line L2 is the arrangement region of the second stator winding 322, and the right side of the second boundary line L2 is the arrangement region of the fourth stator winding 324. On the other hand, in the first and third embodiments, conversely, the right side of the second boundary line L2 is the arrangement region of the second stator winding 322, and the left side of the second boundary line L2 is the arrangement region of the fourth stator winding 324.

[0098] Furthermore, by overlapping the arrangement regions of the stator windings 321 to 324 defined by the first and second boundary lines L1 and L2 with the arrangements of the lead wires A1 to A4, B1 to B4, C1 to C4 of each system shown in FIG. 3, the lengths of the lead wires A1 to A4, B1 to B4, C1 to C4 can be shortened. Therefore, the total winding resistance of the motor 10 can be reduced, and the power efficiency can be improved. Here, it is assumed that the viewing directions of FIG. 3 and FIG. 10 are the same. Regarding the left and right arrangements of the lead wires A2, B2, C2 of the second system and the lead wires A4, B4, C4 of the fourth system shown in FIG. 3, the arrangement of "left 2 - right 4" shown outside the parentheses is preferable except for the first and third embodiments, and the arrangement of "left 4 - right 2" shown inside the parentheses is preferable in the first and third embodiments.

[0099] (Second Embodiment) As the second embodiment, FIG. 11 shows a diagram in the case where the back electromotive force phase difference is 40° with 20° phase difference energization. As an example of "back electromotive force phase difference 40°" in FIG. 7, the sum of the back electromotive forces of the partial winding W1- of the W phase of the first stator winding 321 and the partial winding U2+ of the U phase of the second stator winding 322 in the third coil body Uc formed by winding around the tooth T9 of the second embodiment is shown.

[0100] The phase of the combined U-phase current Us+ is 40°, and the current amplitude is 1.88 times the basic current amplitude I flowing through the partial windings W1- / U2+ of the first and second stator windings 321 and 322. The phase difference between the back electromotive force of the third coil body Uc and the back electromotive force of the first coil body Wa formed by the partial winding W1- is 20°. The phase difference between the back electromotive force of the third coil body Uc and the back electromotive force of the second coil body Ub formed by the partial winding U2+ is also 20°.

[0101] (Third Embodiment) As the third embodiment, FIG. 12 shows a diagram in the case where the back electromotive force phase difference is 80° with 40° phase difference energization. As an example of "back electromotive force phase difference 80°" in FIG. 8, the sum of the back electromotive forces of the partial winding W3- of the W phase of the third stator winding 323 and the partial winding V2- of the V phase of the second stator winding 322 in the third coil body Uc formed by winding around the tooth T14 of the third embodiment is shown.

[0102] The phase of the combined U-phase current Us+ is 20°, and the current amplitude is 1.53 times the fundamental current amplitude I flowing through the partial windings W3- / V2- of the third and second stator windings 323, 322. The phase difference between the magnetomotive force of the third coil body Uc and the magnetomotive force of the first coil body Wa formed by the partial winding W3- is 40°. The phase difference between the magnetomotive force of the third coil body Uc and the magnetomotive force of the second coil body Vb formed by the partial winding V2- is also 40°.

[0103] (Fourth Embodiment) As the fourth embodiment, FIG. 13 shows a diagram in the case where the magnetomotive force phase difference is 40° with a 40° phase difference energization. As an example of "magnetomotive force phase difference 40°" in FIG. 8, the summation of the magnetomotive forces of the U-phase partial winding U3+ of the third stator winding 323 and the U-phase partial winding U4+ of the fourth stator winding 324 in the third coil body Uc formed by winding around the teeth T14 of the fourth embodiment is shown.

[0104] The phase of the combined U-phase current Us+ is 20°, and the current amplitude is 1.88 times the fundamental current amplitude I flowing through the partial windings U3+ / U4+ of the third and fourth stator windings 323, 324. The phase difference between the magnetomotive force of the third coil body Uc and the magnetomotive force of the first coil body Ua formed by the partial winding U3+ is 20°. The phase difference between the magnetomotive force of the third coil body Uc and the magnetomotive force of the second coil body Ub formed by the partial winding U4+ is also 20°.

[0105] (Fifth Embodiment) FIG. 14 shows a table of an arrangement example of the partial windings of the four-system stator windings 321 to 324 in a 22P18S motor. As the fifth embodiment, FIG. 15 shows a diagram in the case where the magnetomotive force phase difference is 80° with a 20° phase difference energization.

[0106] (Sixth and Seventh Embodiments) FIG. 16 shows a table of an arrangement example of partial windings of four-system stator windings 321 to 324 in a 16P18S motor. FIG. 17 shows a diagram in the case where the electromotive force phase difference is 80° with 20° phase difference energization as the sixth embodiment. Further, FIG. 18 shows a diagram in the case where the electromotive force phase difference is 40° with 20° phase difference energization as the seventh embodiment. As described above, in the configurations of 16P18S and 20P18S, when the electromotive force phase difference is 40°, the first teeth and the third teeth around which the stator windings of the same phase of the same system are wound, and the second teeth and the third teeth are adjacent in the circumferential direction.

[0107] (Eighth Embodiment) FIG. 19 shows a table of an arrangement example of partial windings of four-system stator windings 321 to 324 in a 20P18S motor. FIG. 20 shows a diagram in the case where the electromotive force phase difference is 80° with 20° phase difference energization as the eighth embodiment.

[0108] (Ninth Embodiment) 28P36S of the ninth embodiment corresponds to "18 - 4" in the general form of "the number of magnetic poles is (18 ± 4) × m (m is an integer of 1 or more), and the number of slots is 18 × m" with "m = 2". FIG. 21 shows a diagram in the case where the electromotive force phase difference is 80° with 20° phase difference energization. In FIG. 21, the symbols of 36 teeth are omitted. In the ninth embodiment, the same effects as those of the above embodiments can be obtained, and it can also be applied to an 8-system.

[0109] Similarly, the configuration corresponding to "18 + 4" in the general form of "the number of magnetic poles is (18 ± 4) × m (m is an integer of 1 or more), and the number of slots is 18 × m" with "m = 2" is 44P36S. Also, the configurations corresponding to "n = 2" in the general form of "the number of magnetic poles is (18 ± 2) × n (n is an integer of 1 or more), and the number of slots is 18 × n" are 32P36S and 40P36S. Further, it can be expanded even when "m ≧ 3" or "n ≧ 3".

[0110] (Other Embodiments) (a) In motors with each "number of poles - number of slots", the arrangement of the partial windings of the stator winding 32 wound around each tooth is not limited to the above example. Based on the tooth T1 where the current phase is 0° electrical angle, it may be arranged in the reverse direction to the above example. The first stator winding 321 and the third stator winding 323 may be completely interchanged, and the second stator winding 322 and the fourth stator winding 324 may be completely interchanged.

[0111] (b) Regarding the arrangement of the lead wires A1 - A4, B1 - B4, C1 - C4 of the stator windings 321 - 324, alternative arrangement examples different from those in FIG. 3 are shown in FIGS. 22 - 24. In all cases, similar to the arrangement example in FIG. 3, in the first lead wire group ABC13, the lead wires A1, B1, C1 and the lead wires A3, B3, C3 are arranged such that each phase is symmetric about the rotation axis 11. In the second lead wire group ABC24, the lead wires A2, B2, C2 and the lead wires A4, B4, C4 are arranged such that each phase is symmetric about the rotation axis 11. Thereby, in the angle sensor 56 that detects the rotation angle of the rotor 40 based on the change in the magnetic field of the sensor magnet 12, the error due to external magnetic flux can be minimized.

[0112] In the arrangement example shown in FIG. 22, the center line M13 of the first lead wire group ABC13 and the center line M24 of the second lead wire group ABC24 are not orthogonal, but intersect at an angle less than 90° (about 75° in the example of the figure). The opposing distances d13, d24 of both lead wire groups ABC13, ABC24 are equal. In the arrangement example shown in FIG. 23, compared to FIG. 22, the opposing distances d13, d24 of both lead wire groups ABC13, ABC24 are different. That is, the first lead wire group ABC13 and the second lead wire group ABC24 are arranged on concentric circles with different diameters. In the arrangement example shown in FIG. 24, the intersection angle of the center lines M13, M24 of both lead wire groups ABC13, ABC24 is 0°. That is, the first lead wire group ABC13 and the second lead wire group ABC24 are arranged side by side within a region of a predetermined width.

[0113] As described above, the present invention is not limited to such embodiments, and can be implemented in various forms without departing from the gist thereof.

[0114] The disclosure of "The combined phase difference is set in the range of 72 to 88 degrees in electrical angle, the number of poles of the rotor is (18 ± 4) × m (m is an integer of 1 or more), and the number of slots between the teeth is 18 × m, or the number of poles of the rotor is (18 ± 2) × n (n is an integer of 1 or more), and the number of slots between the teeth is 18 × n rotary electric machine." and "The combined phase difference is set in the range of 32 to 48 degrees in electrical angle, the number of poles of the rotor is (18 ± 4) × m (m is an integer of 1 or more), and the number of slots between the teeth is 18 × m, or the number of poles of the rotor is (18 ± 2) × n (n is an integer of 1 or more), and the number of slots between the teeth is 18 × n rotary electric machine." may be combined with the disclosure of "The current phase difference between the three-phase current supplied from the first inverter and the third inverter and the three-phase current supplied from the second inverter and the fourth inverter is set within the range of 15 to 25 degrees or within the range of 35 to 45 degrees rotary electric machine." respectively.

[0115] The disclosure of "A rotary electric machine arranged such that the first tooth around which the first stator winding of the same phase is wound and the third tooth are adjacent in the circumferential direction, the second tooth around which the second stator winding of the same phase is wound and the third tooth are adjacent in the circumferential direction, the first tooth around which the third stator winding of the same phase is wound and the third tooth are adjacent in the circumferential direction, and the second tooth around which the fourth stator winding of the same phase is wound and the third tooth are adjacent in the circumferential direction." may be combined with the disclosure of any of the rotary electric machines described previously.

[0116] "Regarding the disclosure of "a rotating electrical machine in which, in a projection view in the direction of the rotating shaft, all of the first teeth and the third teeth around which the first stator windings of each phase are wound and all of the first teeth and the third teeth around which the third stator windings of each phase are wound are arranged in regions on opposite sides of a first boundary line (L1) that is a straight line passing through the rotating shaft, and all of the second teeth and the third teeth around which the second stator windings of each phase are wound and all of the second teeth and the third teeth around which the fourth stator windings of each phase are wound are arranged in regions on opposite sides of a second boundary line (L2) that is a straight line passing through the rotating shaft.", it may be combined with the disclosure of any rotating electrical machine described previously."

Explanation of Signs

[0117] 10 ··· Motor (Rotating Electrical Machine), 30 ··· Stator, 31 ··· Stator Core, 32 ··· Stator Winding, 321 ··· First Stator Winding, 322 ··· Second Stator Winding, 323 ··· Third Stator Winding, 324 ··· Fourth Stator Winding, 40 ··· Rotor, 42 ··· Magnetic Pole (Permanent Magnet), 51 ··· First Inverter, 52 ··· Second Inverter, 53 ··· Third Inverter, 54 ··· Fourth Inverter, Ua, Va, Wa ··· First Coil Body, Ub, Vb, Wb ··· Second Coil Body, Uc, Vc, Wc ··· Third Coil Body, T1~T18 ··· Teeth.

Claims

1. A rotor (40) having a plurality of magnetic poles (42) with alternating polarities in the circumferential direction, a three-phase stator winding (32), and a stator core (31) having a plurality of teeth (T1 to T18) provided at predetermined intervals in the circumferential direction around which the stator winding is wound, in a rotating electrical machine (10) in which the rotor rotates integrally with a rotation axis (11), the stator winding includes a first stator winding (321) to which a three-phase current is supplied from a first inverter (51), a second stator winding (322) to which a three-phase current is supplied from a second inverter (52), a third stator winding (323) to which a three-phase current is supplied from a third inverter (53), and a fourth stator winding (324) to which a three-phase current is supplied from a fourth inverter (54), the three-phase current supplied from the first inverter and the three-phase current supplied from the third inverter are energized with the same current amplitude and phase, the three-phase current supplied from the second inverter and the three-phase current supplied from the fourth inverter are energized with the same current amplitude and phase, the three-phase current supplied from the first inverter and the third inverter and the three-phase current supplied from the second inverter and the fourth inverter have a predetermined current phase difference respectively, a first U-phase coil body (Ua) formed by winding the first stator winding or the third stator winding of the U-phase among the three phases around the first tooth, a first V-phase coil body (Va) formed by winding the first stator winding or the third stator winding of the V-phase among the three phases around the first tooth, a first W-phase coil body (Wa) formed by winding the first stator winding or the third stator winding of the W-phase among the three phases around the first tooth, a second U-phase coil body (Ub) formed by winding the second stator winding or the fourth stator winding of the U-phase among the three phases around the second tooth, a second V-phase coil body (Vb) formed by winding the second stator winding or the fourth stator winding of the V-phase among the three phases around the second tooth, a second W-phase coil body (Wb) formed by winding the second stator winding or the fourth stator winding of the W-phase among the three phases around the second tooth, The third coil body (Uc) of the U phase formed by winding the first stator winding or the third stator winding of any one of the three phases, and the second stator winding or the fourth stator winding of any one of the three phases around the third teeth, The third coil body (Vc) of the V phase formed by winding the first stator winding or the third stator winding of any one of the three phases, and the second stator winding or the fourth stator winding of any one of the three phases around the third teeth, The third coil body (Wc) of the W phase formed by winding the first stator winding or the third stator winding of any one of the three phases, and the second stator winding or the fourth stator winding of any one of the three phases around the third teeth, and The respective phase differences between the magnetomotive forces of the third coil bodies (Uc, Vc, Wc) of each phase with respect to the magnetomotive forces of the first coil bodies (Ua, Va, Wa) of each phase, and the respective phase differences between the magnetomotive forces of the second coil bodies (Ub, Vb, Wb) of each phase with respect to the magnetomotive forces of the third coil bodies (Uc, Vc, Wc) of each phase are within a predetermined phase range including 20 degrees in electrical angle, or The respective phase differences between the magnetomotive forces of the second coil bodies (Ub, Vb, Wb) of each phase with respect to the magnetomotive forces of the first coil bodies (Ua, Va, Wa) of each phase, and the respective phase differences between the magnetomotive forces of the third coil bodies (Uc, Vc, Wc) of each phase with respect to the magnetomotive forces of the second coil bodies (Ub, Vb, Wb) of each phase are within a predetermined phase range including 20 degrees in electrical angle, The combined phase difference between the magnetomotive force generated by the partial winding of the first stator winding or the third stator winding wound around the third teeth and the magnetomotive force generated by the partial winding of the second stator winding or the fourth stator winding wound around the third teeth, or A rotating electrical machine in which the combined phase difference between the current flowing through the partial winding of the first stator winding or the third stator winding wound around the third teeth and the current flowing through the partial winding of the second stator winding or the fourth stator winding wound around the third teeth is set.

2. The current phase difference between the three-phase current supplied from the first inverter and the third inverter and the three-phase current supplied from the second inverter and the fourth inverter is set within a range of 15 to 25 degrees or within a range of 35 to 45 degrees. The rotating electrical machine according to claim 1.

3. The combined phase difference is set within a range of 72 to 88 degrees in electrical angle, The number of poles of the rotor is (18 ± 4) × m (m is an integer of 1 or more), and the number of slots between the teeth is 18 × m, or The number of poles of the rotor is (18 ± 2) × n (n is an integer of 1 or more), and the number of slots between the teeth is 18 × n. The rotating electrical machine according to claim 1.

4. When the number of turns of the first stator winding or the third stator winding wound around the first tooth and the number of turns of the second stator winding or the fourth stator winding wound around the second tooth are each "Nab", and the number of turns of the first stator winding or the third stator winding wound around the third tooth and the number of turns of the second stator winding or the fourth stator winding wound around the third tooth are each "Nc", The number of turns of each winding is set so as to satisfy the relationship of 1.4 ≦ Nab / Nc ≦ 1.

6. The rotating electrical machine according to claim 3.

5. The combined phase difference is set within a range of 32 to 48 degrees in electrical angle, The number of poles of the rotor is (18 ± 4) × m (m is an integer of 1 or more), and the number of slots between the teeth is 18 × m, or The number of poles of the rotor is (18 ± 2) × n (n is an integer of 1 or more), and the number of slots between the teeth is 18 × n. The rotating electrical machine according to claim 1.

6. When the number of turns of the first stator winding or the third stator winding wound around the first tooth and the number of turns of the second stator winding or the fourth stator winding wound around the second tooth are each "Nab", and the number of turns of the first stator winding or the third stator winding wound around the third tooth and the number of turns of the second stator winding or the fourth stator winding wound around the third tooth are each "Nc", The number of turns of each winding is set so as to satisfy the relationship of 1.8 ≦ Nab / Nc ≦ 2.

0. The rotating electrical machine according to claim 5.

7. The first teeth around which the first stator winding of the same phase is wound and the third teeth are adjacent to each other in the circumferential direction, The second teeth around which the second stator winding of the same phase is wound and the third teeth are adjacent to each other in the circumferential direction, The first teeth around which the third stator winding of the same phase is wound and the third teeth are adjacent to each other in the circumferential direction, The rotating electrical machine according to claim 1, wherein the second teeth around which the fourth stator winding of the same phase is wound and the third teeth are arranged to be adjacent to each other in the circumferential direction.

8. In the projection view in the direction of the rotating shaft, All of the first teeth and the third teeth around which the first stator winding of each phase is wound and all of the first teeth and the third teeth around which the third stator winding of each phase is wound are arranged in regions on opposite sides with respect to a first boundary line (L1) which is a straight line passing through the rotating shaft, The rotating electrical machine according to claim 1, wherein all of the second teeth and the third teeth around which the second stator winding of each phase is wound and all of the second teeth and the third teeth around which the fourth stator winding of each phase is wound are arranged in regions on opposite sides with respect to a second boundary line (L2) which is a straight line passing through the rotating shaft.

9. An angle sensor (56) for detecting the rotation angle of the rotor based on a change in the magnetic field of a sensor magnet (12) fixed to an end of the rotating shaft is provided, The lead wires (A1, B1, C1) of the first stator winding connected to the first inverter and the lead wires (A3, B3, C3) of the third stator winding connected to the third inverter are arranged such that each phase is symmetric about the rotating shaft, The rotating electrical machine according to any one of claims 1 to 8, wherein the lead wires (A2, B2, C2) of the second stator winding connected to the second inverter and the lead wires (A4, B4, C4) of the fourth stator winding connected to the fourth inverter are arranged such that each phase is symmetric about the rotating shaft.

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