JP7779072B2 - Rotating electric machines - Google Patents

Description

The present invention relates to a rotating electric machine.

Conventionally, rotating electric machines have been known that include a first armature winding to which three-phase current is supplied from a first inverter, and a second armature winding to which three-phase current is supplied from a second inverter. In such rotating electric machines, if a current phase difference occurs between the first inverter and the second inverter, the electromagnetic field generated in the air gap between the rotor and stator by the armature winding can become spatially unbalanced, potentially resulting in torque ripple.

For this reason, the rotating electric machine of Patent Document 1 includes a coil body formed by winding a first armature winding and a second armature winding around the teeth, a coil body formed by winding the first armature winding around the teeth, and a coil body formed by winding the second armature winding around the teeth, and each coil body is arranged with 2n-fold rotational symmetry around the axis.

This allows the electromagnetic field generated in the gap between the rotor and stator to be spatially balanced, even when a current phase difference occurs, suppressing torque ripple. This in turn helps to reduce vibration and noise.

Patent No. 5905176

Such rotating electrical machines require further suppression of vibration and noise, and it is believed that there is still room for technical improvement to meet these requirements. At the same time, it is believed that there is also room for further improvement in ease of manufacturing.

The present invention was made in consideration of the above circumstances, and aims to provide a rotating electric machine that is easy to manufacture while suppressing vibration and noise.

A rotating electric machine that solves the above problem is a rotating electric machine that includes a rotor having multiple magnetic poles with alternating polarities in the circumferential direction, a multi-phase stator winding, and a stator core having multiple teeth arranged at predetermined intervals in the circumferential direction and around which the stator winding is wound. The stator windings include a first stator winding to which a three-phase current is supplied from a first inverter, and a second stator winding to which a three-phase current is supplied from a second inverter. The three-phase currents supplied from the first inverter and the three-phase currents supplied from the second inverter have a predetermined current phase difference, and a U-phase coil body Ua formed by winding the first stator winding of the U-phase of the three phases around the first teeth, and a V-phase coil body Ub formed by winding the first stator winding of the V-phase of the three phases around the first teeth. a W-phase coil body Wa formed by winding the first stator winding of the W-phase of the three phases around a first tooth; a U-phase coil body Ub formed by winding the second stator winding of the U-phase around a second tooth; a V-phase coil body Vb formed by winding the second stator winding of the V-phase around a second tooth; a W-phase coil body Wb formed by winding the second stator winding of the W-phase around a second tooth; a U-phase coil body Uc formed by winding the first stator winding of any one of the three phases and the second stator winding of any one of the three phases around a third tooth; and a W-phase coil body Wc formed by winding the first stator winding of any one of the three phases and the second stator winding of any one of the three phases around a third tooth, wherein the phase differences of the magnetomotive forces of the coil bodies Uc, Vc, Wc of each phase relative to the magnetomotive forces of the coil bodies Ua, Va, Wa of each phase and the phase differences of the magnetomotive forces of the coil bodies Uc, Vc, Wc of each phase relative to the magnetomotive forces of the coil bodies Uc, Vc, Wc of each phase are The phase differences of the magnetomotive forces of the coil bodies Ub, Vb, Wb of each phase relative to the magnetomotive forces of the coil bodies Ua, Va, Wa of each phase, and the phase differences of the magnetomotive forces of the coil bodies Uc, Vc, Wc of each phase relative to the magnetomotive forces of the coil bodies Ub, Vb, Wb of each phase, are within a predetermined phase range including an electrical angle of 20 degrees. A combined phase difference is set between the magnetomotive force generated by the partial winding of the first stator winding wound on the third tooth and the magnetomotive force generated by the partial winding of the second stator winding wound on the third tooth, or a combined phase difference is set between the current flowing through the partial winding of the first stator winding wound on the third tooth and the current flowing through the partial winding of the second stator winding wound on the third tooth. The stator winding is connected to the inverter on one axial side, and on the other axial side, the partial winding of the first stator winding wound on the first tooth is connected to the partial winding of the first stator winding wound on the third tooth, and the partial winding of the second stator winding wound on the first tooth is connected to the partial winding of the second stator winding wound on the third tooth.

By ensuring that the phase differences between the magnetomotive force of the coil bodies Ua, Va, Wa and the magnetomotive force of the coil bodies Uc, Vc, Wc, and the phase differences between the magnetomotive force of the coil bodies Ub, Vb, Wb of each phase and the magnetomotive force of the coil bodies Uc, Vc, Wc of each phase are within a specified phase range, or by ensuring that the phase differences between the magnetomotive force of the coil bodies Ua, Va, Wa and the magnetomotive force of the coil bodies Ub, Vb, Wb of each phase and the magnetomotive force of the coil bodies Ub, Vb, Wb of each phase are within a specified phase range, it is possible to cancel out the sixth or twelfth electrical harmonic components and suppress torque ripple.

In addition, on one axial side, the stator winding is connected to the inverter, and on the other side, the partial winding of the first stator winding wound around the first tooth is connected to the partial winding of the first stator winding wound around the third tooth, and the partial winding of the second stator winding wound around the first tooth is connected to the partial winding of the second stator winding wound around the third tooth. This simplifies the connections and facilitates manufacturing.

FIG. FIG. FIG. 2 is a diagram showing the electrical configuration of a control device. FIG. 10 is a diagram showing the arrangement of partial windings. FIG. FIG. FIG. 4 is a diagram showing harmonic components of torque. Vector diagram showing the sum of magnetomotive forces. FIG. FIG. 1 is a diagram showing the arrangement of crossover wires, lead wires, and neutral points. FIG. 10 is a development view showing a connection state of partial windings in a comparative example. Graph showing the fluctuation of electromagnetic force. FIG. 10 is a diagram showing a stator winding according to a second embodiment. FIG. 10 is a development view showing a connection state of partial windings in the second embodiment. FIG. 4 is a diagram showing the winding direction of partial windings. FIG. 10 is a diagram showing a stator winding according to a third embodiment. FIG. 11 is a development view showing a connection state of partial windings in the third embodiment. FIG. 10 is a diagram showing the arrangement of partial windings in the fourth embodiment. FIG. 10 is a cross-sectional view showing a motor according to a fourth embodiment. FIG. 10 is a vector diagram showing the sum of magnetomotive forces in the fourth embodiment. FIG. 13 is a diagram showing the arrangement of partial windings in the fifth embodiment. FIG. 13 is a diagram showing the arrangement of partial windings in the sixth embodiment. FIG. 10 is a diagram showing the arrangement of partial windings in another example. FIG. 10 is a diagram showing the arrangement of partial windings in another example. FIG. 10 is a diagram showing the arrangement of partial windings in another example.

Each embodiment will be described below with reference to the drawings. Note that in the following embodiments, identical or equivalent parts are designated by the same reference numerals in the drawings, and the same explanations will be used for the parts with the same reference numerals. In the first embodiment, a motor 10 will be used as an example of a rotating electric machine.

(First embodiment)
The motor 10 shown in FIG. 1 is a permanent magnet field type motor, specifically a permanent magnet field type synchronous machine with three-phase windings. In other words, the motor 10 is a brushless motor. The three-phase windings are provided in two systems. The motor 10 includes a housing 20, a stator 30 fixed to the housing 20, a rotor 40 that rotates relative to the stator 30, and a rotating shaft 11 to which the rotor 40 is fixed. Hereinafter, in this embodiment, the axial direction refers to the axial direction of the rotating shaft 11 (indicated by arrow Y1 in the figure). The radial direction refers to the radial direction of the rotating shaft 11 (indicated by arrow Y2 in the figure). The circumferential direction refers to the circumferential direction of the rotating shaft 11 (indicated by arrow Y3 in the figure).

The housing 20 is cylindrical and contains the stator 30, rotor 40, and other components. The housing 20 is provided with bearings 23 and 24, which rotatably support the rotating shaft 11. The axis of the inner circumferential surface of the housing 20 is coaxial with the rotating shaft 11. An angle sensor 12 is provided at the tip of the rotating shaft 11. The angle sensor 12 may be a magnetic sensor or a resolver.

The stator 30 is cylindrically disposed along the inner periphery of the housing 20, approximately at the center of the housing 20 in the axial direction. The stator 30 is fixed to the inner periphery of the housing 20, with the axis O of the rotating shaft 11 as its center. The stator 30 forms part of the magnetic circuit and has a ring-shaped stator core 31 (armature core) arranged radially opposite the outer periphery of the rotor 40, and a stator winding 32 (armature coil) wound around the stator core 31.

As shown in FIG. 2, the stator core 31 has an annular back yoke 33 and multiple teeth T1 to T18 that protrude radially from the back yoke 33 toward the rotating shaft 11 and are arranged circumferentially at a predetermined distance, with slots 35 (stator slots) formed between adjacent teeth T1 to T18. The slots 35 are arranged at equal intervals circumferentially in the stator core 31, and the stator winding 32 is wound around the slots 35. In this embodiment, the number of teeth T1 to T18 is 18, and the number of slots 35 is 18. For convenience of explanation, the teeth T1 to T18 are numbered counterclockwise and designated by the symbols T1 to T18. The stator winding 32 is housed and held in the slots 35. When power (AC power) is supplied to the stator winding 32, it generates magnetic flux.

The stator core 31 is an integrated unit formed by stacking multiple thin, annular magnetic steel plates (core sheets) in the axial direction of the stator core 31. The steel plates are formed by press-punching strips of electromagnetic steel material.

The rotor 40 constitutes part of the magnetic circuit, has one or more pairs of magnetic poles in the circumferential direction, and is arranged so as to face the stator 30 in the radial direction. In this embodiment, the rotor 40 has 14 magnetic poles (i.e., seven pairs of magnetic poles). The rotor 40 includes a rotor core 41 made of a magnetic material and permanent magnets 42 fixed to the rotor core 41. Specifically, as shown in FIG. 2, the rotor 40 includes 14 permanent magnets 42 as magnetic portions with alternating polarities in the circumferential direction, and the permanent magnets 42 are embedded in housing holes provided in the rotor core 41 along the axial direction.

The rotor 40 may have a known configuration, for example, an IPM (Interior Permanent Magnet) rotor or an SPM (Surface Permanent Magnet) rotor. A rotor with a field winding may also be used as the rotor 40. In this embodiment, an IPM rotor is used. The rotating shaft 11 is inserted into the rotor 40, and the rotor 40 is fixed to the rotating shaft 11 so as to rotate integrally with the rotating shaft 11 around the rotating shaft 11.

A control device 50 is connected to the motor 10. The control device 50 is primarily composed of a microcomputer equipped with a CPU, ROM, RAM, I/O, etc., and realizes various functions by the CPU executing programs stored in the ROM. Note that the various functions may be realized by electronic circuits, which are hardware, or at least a portion of them may be realized by software, i.e., by processing executed on a computer.

The control device 50 has functions such as converting power from an external source (e.g., a battery) and supplying it to the motor 10 to generate driving force. Furthermore, the control device 50 also has a function for controlling the motor 10 (such as current control) using information related to the rotation angle input from the angle sensor 12.

The control device 50 also includes a first inverter circuit 51 and a second inverter circuit 52, as shown in FIG. 3. The first inverter circuit 51 is configured as a full-bridge circuit having the same number of upper and lower arms as the number of three phases. The control device 50 controls the current in each phase by turning on and off the switching elements provided in each arm.

More specifically, as shown in FIG. 3, the first inverter circuit 51 includes a series connection of upper arm switches Sp and lower arm switches Sn as switching elements for each of the three phases consisting of U, V, and W phases. In this embodiment, voltage-controlled semiconductor switching elements, specifically IGBTs, are used as the upper arm switches Sp and lower arm switches Sn for each phase. MOSFETs may also be used. Freewheeling diodes (freewheeling diodes) Dp and Dn are connected in anti-parallel to the upper arm switches Sp and lower arm switches Sn for each phase, respectively.

The high-potential terminal (collector) of the upper arm switch Sp of each phase is connected to the positive terminal of the battery. The low-potential terminal (emitter) of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of the battery. The intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase are each connected to one end (lead lines A1, B1, C1) of the stator winding 32. The second inverter circuit 52 is similar to the first inverter circuit 51, so a detailed description will be omitted.

However, noise and vibration caused by torque ripple are a problem in rotating electrical machines. Torque ripple is primarily caused by the sixth-order harmonic component or the twelfth-order harmonic component, so it is desirable to suppress these. Therefore, the following configuration was adopted.

The stator windings 32 are classified into U-phase, V-phase, and W-phase stator windings 32, each representing one of the three phases. As shown in Figures 4 and 5, the U-phase stator winding 32 is composed of eight partial windings: +U11, +U12, -U13, -U14, -U21, +U22, +U23, and -U24. The V-phase stator winding 32 is composed of eight partial windings: -V11, +V12, +V13, -V14, +V21, -V22, -V23, and +V24. The U-phase stator winding 32 is composed of eight partial windings: -W11, -W12, +W13, +W14, +W21, +W22, -W23, and -W24.

As shown in Figures 2 and 4, the 24 partial windings are arranged in the following order corresponding to each of the teeth T1 to T18: +U11, +V21, -V11/+W21, -W11, -U21, +U12/-V22, +V12, +W22, -W12/+U22, -U13, -V23, +V13/-W23, +W13, +U23, -U14/+V24, -V14, -W24, +W14/-U24.

Note that the "+" and "-" signs indicate the direction of current, i.e., the polarity of the field generated by the partial winding. For example, in Figure 2 of this embodiment, if the current flow from the front side of the page to the back side is "+," the current flow from the back side to the front side is "-." In other words, when current flows through the stator winding 32, the "+" partial winding and the "-" partial winding generate magnetomotive forces that are opposite in the radial direction. The "+" partial winding and the "-" partial winding can be said to have a phase difference in magnetomotive forces of 180 electrical degrees. The "+" partial winding and the "-" partial winding can be achieved by winding the conductor in opposite directions. The same applies to the coil body described below.

Furthermore, "/" indicates that two partial windings are arranged at different radial positions for the same tooth T1 to T18. In other words, two partial windings are arranged for teeth T3, T6, T9, T12, T15, and T18. And one partial winding is arranged for the other teeth T1, T2, T4, T5, T7, T8, T10, T11, T13, T14, T16, and T17. Note that the radial positions of the partial windings may be swapped for teeth T3, T6, T9, T12, T15, and T18.

Next, the wiring of the stator winding 32 will be described with reference to Figure 5. In this embodiment, a Y connection (star connection) is used, but a delta connection is also possible.

As shown in FIG. 5, the stator winding 32 is composed of a first stator winding 32a and a second stator winding 32b. In the first stator winding 32a, a series connection consisting of U-phase partial windings +U11 and +U12 is connected in parallel to a series connection consisting of U-phase partial windings +U11 and +U12 to form a U-phase winding. Furthermore, in the first stator winding 32a, a series connection consisting of V-phase partial windings +V12 and +V13 is connected in parallel to a series connection consisting of V-phase partial windings -V14 and -V11 to form a V-phase winding. Furthermore, in the first stator winding 32a, a series connection consisting of W-phase partial windings -W11 and -W12 is connected in parallel to a series connection consisting of W-phase partial windings +W13 and +W14 to form a W-phase winding. One end of each of these phase windings is connected to the neutral point Q1, and the other end is connected to lead wires A1, B1, and C1, which are connected to the first inverter circuit 51. The U-phase winding is connected to lead wire A1, the V-phase winding is connected to lead wire B1, and the W-phase winding is connected to lead wire C1.

Similarly, the second stator winding 32b has a U-phase winding formed by a series connection of U-phase partial windings -U21 and +U22 and a series connection of U-phase partial windings +U23 and -U24 connected in parallel. The second stator winding 32b also has a V-phase winding formed by a series connection of V-phase partial windings +V21 and -V22 and a series connection of V-phase partial windings -V23 and +V24 connected in parallel. The second stator winding 32b also has a W-phase winding formed by a series connection of W-phase partial windings -W23 and +W22 and a series connection of W-phase partial windings +W21 and -W24 connected in parallel. One end of each of these phase windings is connected to a neutral point Q2, and the other end is connected to leads A2, B2, and C2, which are connected to the second inverter circuit 52. The lead wire A2 is connected to the U-phase winding, the lead wire B2 is connected to the V-phase winding, and the lead wire C2 is connected to the W-phase winding.

As shown in Figure 6, the lead lines A1, B1, C1, A2, B2, and C2 are arranged so as to be point-symmetrical about the axis O of the rotation shaft 11. That is, the lead lines A1 and A2 are arranged at 180-degree intervals, the lead lines B1 and B2 are arranged at 180-degree intervals, and the lead lines C1 and C2 are arranged at 180-degree intervals. The lead lines A1, B1, C1, A2, B2, and C2 are arranged linearly along the axial direction.

Here, only the first stator winding 32a is wound (wound) around teeth T1, T4, T7, T10, T13, and T16, resulting in two coil bodies for each phase. The U-phase coil body is referred to as coil body Ua, the V-phase coil body as coil body Va, and the W-phase coil body as coil body Wa. Below, teeth around which only the first stator winding 32a is wound may be referred to as first teeth. In the first embodiment, teeth T1, T4, T7, T10, T13, and T16 correspond to the first teeth.

Furthermore, only the second stator winding 32b is wound around the teeth T2, T5, T8, T11, T14, and T17, thereby providing two coil bodies for each phase. The U-phase coil body is referred to as coil body Ub, the V-phase coil body as coil body Vb, and the W-phase coil body as coil body Wb. Below, teeth around which only the second stator winding 32b is wound may be referred to as second teeth. In the first embodiment, teeth T2, T5, T8, T11, T14, and T17 correspond to the second teeth.

The first stator winding 32a and the second stator winding 32b are wound around the teeth T3, T6, T9, T12, T15, and T18, providing two coil bodies for each phase. The U-phase coil body is referred to as coil body Uc, the V-phase coil body is referred to as coil body Vc, and the W-phase coil body is referred to as coil body Wc. Hereinafter, the teeth around which the first stator winding 32a and the second stator winding 32b are wound may be referred to as third teeth. In the first embodiment, the teeth T3, T6, T9, T12, T15, and T18 correspond to the third teeth.

As shown in Figure 2, the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc of each phase are arranged with two-fold rotational symmetry around the axis of the rotating shaft 11. In other words, even when rotated 180 mechanical degrees around the axis, the arrangement order of the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc remains the same.

Here, the magnetomotive force Fu1a of the partial windings +U11 and +U12, the magnetomotive force Fu1b of the partial windings −U13 and −U14, the magnetomotive force Fu2a of the partial windings +U22 and +U23, and the magnetomotive force Fu2b of the partial windings −U21 and −U24 can be expressed by equations (1) to (4). Note that “θ” is the phase of the current flowing through the stator winding 32 (based on the phase of the U-phase current supplied from the first inverter circuit 51). “β” is the phase difference between the current supplied from the first inverter circuit 51 and the current supplied from the second inverter circuit 52 (hereinafter, sometimes referred to as the current phase difference). Furthermore, “N” is the number of turns of each partial winding, and “I” is the magnitude of the current.

Similarly, the magnetomotive force Fv1a of the partial windings +V12 and +V13, the magnetomotive force Fv1b of the partial windings −V11 and −V14, the magnetomotive force Fv2a of the partial windings +V21 and +V24, and the magnetomotive force Fv2b of the partial windings −V22 and −V23 can be expressed by equations (5) to (8).

Similarly, the magnetomotive force Fw1a of the partial windings +W13 and +W14, the magnetomotive force Fw1b of the partial windings −W11 and −W12, the magnetomotive force Fw2a of the partial windings +W21 and +W22, and the magnetomotive force Fw2b of the partial windings −W23 and −W24 can be expressed by equations (9) to (12).

The sixth harmonic component "Tr6" of the torque in each phase can be expressed by Equation (13). The twelfth harmonic component "Tr12" of the torque in each phase can be expressed by Equation (14).

In equations (13) and (14), α is a constant that depends on noise, etc. In the first embodiment, the first term in equations (13) and (14) corresponds to the component based on the coil bodies Ua, Va, and Wa, the second term corresponds to the component based on the coil bodies Ub, Vb, and Wb, and the third term corresponds to the component based on the coil bodies Uc, Vc, and Wc.

Furthermore, "λ1" indicates the phase difference between the magnetomotive force of coil body Ub and the magnetomotive force of coil body Ua in the U phase. In other words, it indicates the phase lag of the magnetomotive force of coil body Ub with the magnetomotive force of coil body Ua as the reference. Similarly, "λ1" indicates the phase difference between the magnetomotive force of coil body Vb and the magnetomotive force of coil body Va in the V phase, and the phase difference between the magnetomotive force of coil body Wb and the magnetomotive force of coil body Wa in the W phase. Similarly, "λ2" indicates the phase difference between the magnetomotive force of coil body Uc and the magnetomotive force of coil body Ua in the U phase, and the phase difference between the magnetomotive force of coil body Vc and the magnetomotive force of coil body Va in the V phase, and the phase difference between the magnetomotive force of coil body Wc and the magnetomotive force of coil body Wa in the W phase. Furthermore, in equations (13) and (14), "Ta" is a constant proportional to the number of turns of the coil bodies Ua, Va, and Wa and the amplitude of the current. Furthermore, "Tb" is a constant proportional to the number of turns of the coil bodies Ub, Vb, and Wb and the amplitude of the current. Furthermore, "Tc" is a constant proportional to the number of turns of the coil bodies Uc, Vc, and Wc and the amplitude of the current.

Here, when "λ1" and "λ2" are "20 degrees" and "40 degrees" in electrical angle, respectively, and when "Ta", "Tb", and "Tc" are the same, it can be seen that the harmonic components of the torque are canceled out, as shown in Equations (15) and (16) and FIG. 7.

In this embodiment, the current phase difference "β" between the first inverter circuit 51 and the second inverter circuit 52 is set to an electrical angle of 20 degrees. In other words, the phase difference between the magnetomotive force of the coil bodies Ub, Vb, and Wb relative to the magnetomotive force of the coil bodies Ua, Va, and Wa is 20 degrees, and "λ1" is 20 degrees. Therefore, it can be said that torque ripple can be suppressed by ensuring that the phase difference between the magnetomotive force of the coil bodies Uc, Vc, and Wc relative to the magnetomotive force of the coil bodies Ua, Va, and Wa is 40 degrees.

In other words, the phase difference between the magnetomotive force of coil bodies Ub, Vb, and Wb relative to the magnetomotive force of coil bodies Ua, Va, and Wa, and the phase difference between the magnetomotive force of coil bodies Uc, Vc, and Wc relative to the magnetomotive force of coil bodies Ub, Vb, and Wb, should each be 20 degrees. While a phase difference of 20 degrees is desirable, it may also be within a predetermined phase range that includes 20 degrees (for example, a range of 15 to 25 degrees), and in this case, the torque ripple suppression effect can still be achieved.

In this embodiment, the phase difference between the magnetomotive force generated by the partial winding of the first stator winding 32a wound around each third tooth and the magnetomotive force generated by the partial winding of the second stator winding 32b is set to 40 degrees electrical angle so that the phase difference between the magnetomotive force of the coil bodies Uc, Vc, and Wc relative to the magnetomotive force of the coil bodies Ua, Va, and Wa is 40 degrees (so that the phase difference between the magnetomotive force of the coil bodies Uc, Vc, and Wc relative to the magnetomotive force of the coil bodies Ub, Vb, and Wb is 20 degrees). While 40 degrees is preferable, this may be changed within a range of 32 to 48 degrees. In the following, the phase difference between the magnetomotive force of the partial winding of the second stator winding 32b relative to the partial winding of the first stator winding 32a wound around each third tooth may be referred to as the total phase difference.

The sum of magnetomotive forces will be described in detail below, taking the coil body Uc provided on the third tooth, tooth T9, as an example. As shown in Figures 2 and 4, the coil body Uc provided on tooth T9 is composed of partial windings -W12/+U22. The magnetomotive force Fw1b of the partial winding -W12 and the magnetomotive force Fu2a of the partial winding +U22 are as shown in equations (10) and (3). These are represented by a vector diagram as shown in Figure 8. The sum of the magnetomotive force Fw1b of the partial winding -W12 and the magnetomotive force Fu2a of the partial winding +U22 is then obtained as shown in equation (17).

In equation (17), the number of turns of the partial winding -W12 and the number of turns of the partial winding +U22 are both N. As shown in equation (17), by winding the partial winding -W12 and the partial winding +U22 around tooth T9, it is possible to achieve magnetomotive forces of coil bodies Uc, Vc, and Wc with a phase difference (combined phase difference) of 40 degrees relative to the magnetomotive forces of coil bodies Ua, Va, and Wa.

As shown in equation (17), the magnetomotive force is proportional to the number of turns of the partial winding. Therefore, if the number of turns of each partial winding is not set appropriately, the amplitude of the magnetomotive force will not be uniform among the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc. This means that variations will occur in the constants "Ta," "Tb," and "Tc" in equations (13) and (14). If the amplitudes of the magnetomotive forces are not uniform, the torque ripple cancellation effect will be reduced. Therefore, it is desirable to set the number of turns of each coil body Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc so that the amplitude of the magnetomotive force is within a specified amplitude range.

In this embodiment, therefore, to align the magnetomotive forces of the coil bodies Ua, Va, and Wa with those of the coil bodies Ub, Vb, and Wb, the number of turns of the coil bodies Ua, Va, and Wa and the coil bodies Ub, Vb, and Wb is set to the same number of turns, "Na."

In addition, the number of turns of the first stator winding 32a and the second stator winding 32b wound around each third tooth is set so that the magnetomotive forces of the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc of each phase are approximately the same.

Specifically, if the number of turns of the first stator winding 32a wound around the third tooth and the number of turns of the second stator winding 32b are "Nb," the numbers of turns "Na" and "Nb" are set to satisfy the relationship 1.8≦Na/Nb≦2.0. It is preferable for Na/Nb to be close to 1.88, and in this embodiment, the numbers of turns are set so that the ratio Na:Nb is 19:10 (Na/Nb is 1.9).

However, as mentioned above, when winding wire around each tooth T1 to T18 to form each partial winding, the following problem may arise. Namely, wires such as the crossover wires connecting the partial windings, the lead wires connected to the inverter circuits 51 and 52, and the connection wire connected to the neutral point may pile up at the end of the stator 30 in the axial direction, making wiring and connection of these wires difficult.

In this embodiment, as shown in Figure 9, the stator windings 32a, 32b are connected to the inverter circuits 51, 52 via lead wires A1, A2, B1, B2, C1, and C2 on one axial side of the teeth T1 to T18 (the upper side of Figure 9). Additionally, neutral points Q1, Q2 are provided on one side, and the partial windings +U12, -U14, -V11, +V13, -W12, +W14, +U22, -U24, -V22, +V24, +W21, and -W23 are connected to them. Note that Figure 9 is an exploded view in which the circumferential direction of the stator winding 32 is expanded left and right in Figure 9.

Furthermore, on the other axial side of teeth T1 to T18 (the lower side in Figure 9), the first stator winding 32a wound around the first tooth is connected to the first stator winding 32a wound around the third tooth, and the second stator winding 32b wound around the second tooth is connected to the second stator winding 32b wound around the third tooth.

For example, as shown in Figure 9, the partial winding +U11 wound around tooth T1, which serves as the first tooth, and the partial winding +U12 wound around tooth T6, which serves as the third tooth, are connected on the other side via a crossover wire 100 (shown by a dashed line).

Similarly, the partial winding +V21 wound around tooth T2, which serves as the second tooth, and the partial winding -V22 wound around tooth T6, which serves as the third tooth, are connected on the other side via a crossover wire 100 (shown by a dashed line).

As described above, the configuration of the first embodiment has the following advantages:

As shown in Figures 9 and 10, the stator windings 32a, 32b are connected to the inverter circuits 51, 52 on one axial side of the teeth T1 to T18, and neutral points Q1, Q2 are also provided. Furthermore, on the other side, the first stator winding 32a wound around the first tooth is connected to the first stator winding 32a wound around the third tooth, and the second stator winding 32b wound around the second tooth is connected to the second stator winding 32b wound around the third tooth. This allows for more distributed wiring and simplifies connections and wiring compared to when all connections are made on one side (the upper side of Figure 11), as shown in the comparative example in Figure 11.

The phase differences between the magnetomotive forces of the coil bodies Ub, Vb, and Wb relative to the magnetomotive forces of the coil bodies Ua, Va, and Wa, and the phase differences between the magnetomotive forces of the coil bodies Uc, Vc, and Wc relative to the magnetomotive forces of the coil bodies Ub, Vb, and Wb, are set within a predetermined phase range that includes 20 degrees. Specifically, the combined phase difference between the magnetomotive force generated by the partial winding of the second stator winding 32b wound around the third tooth and the magnetomotive force generated by the partial winding of the first stator winding 32a wound around the third tooth is set to be within a range of 32 to 48 degrees. In this embodiment, the combined phase difference is set to 40 degrees. In other words, the combined phase difference is set to 40 degrees. This cancels out the sixth- and twelfth-order harmonic components of the torque, suppressing torque ripple, as shown in equations (15) to (17).

The number of turns of each partial winding was set so that the magnetomotive forces of the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc are within a predetermined amplitude range (approximately the same in this embodiment). Specifically, if the number of turns of the first stator winding 32a wound around the first teeth is designated "Na," the number of turns of the second stator winding 32b wound around the second teeth is also designated "Na." Furthermore, if the number of turns of the first stator winding 32a wound around the third teeth and the number of turns of the second stator winding 32b are designated "Nb," the number of turns of each partial winding was set to satisfy the relationship 1.8≦Na/Nb≦2.0. In this embodiment, the number of turns was set so that the ratio Na:Nb was 19:10 (Na/Nb was 1.9). This allows the amplitudes of the magnetomotive forces of the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc to be approximately the same, thereby suppressing torque ripple.

The motor 10 has 14 magnetic poles and 18 slots 35. That is, the number of magnetic poles is (18±4) x m (m is an integer greater than or equal to 1), and the number of slots is 18 x m. This allows the electromagnetic force to be balanced around the axis.

This will be explained in detail based on Figure 12. Figure 12(a) shows the relationship between the electromagnetic force generated by each tooth T1 to T18 and the mechanical angle of the motor 10. Figure 12(b) shows the fluctuations in the electromagnetic force shown in Figure 12(a) along the circumferential direction when the rotating shaft 11 is the center.

As shown in Figure 4, the U-phase coil bodies Ua, Ub, and Uc are arranged at approximately 90-degree intervals. The same is true for the V-phase coil bodies Va, Vb, and Vc and the W-phase coil bodies Wa, Wb, and Wc. This results in a good balance of electromagnetic force, as shown in Figure 12. This prevents the electromagnetic force from being biased in any particular area, suppressing torque fluctuations and reducing vibration and noise.

As shown in Figure 6, lead wires A1, B1, C1, A2, B2, and C2 are arranged so that each phase is symmetrical around the axis of the rotating shaft 11. This allows the leakage magnetic flux generated from lead wires A1, B1, C1, A2, B2, and C2 to be balanced and canceled out, thereby suppressing detection errors in the angle sensor 12.

The first stator winding 32a wound around the first tooth and the first stator winding 32a wound around the third tooth are formed from continuous conductor wire. Similarly, the second stator winding 32b wound around the first tooth and the second stator winding 32b wound around the third tooth are formed from continuous conductor wire. This makes it possible to reduce the number of parts compared to when bus bars or other components are used. It also eliminates the need for connecting the partial windings to the bus bars, reducing the number of manufacturing processes.

Second Embodiment
The configuration of the first embodiment may be partially modified as follows: In the second embodiment, the wiring method is modified. Specifically, the modification is made as shown in FIGS. 13 and 14.

In other words, the partial windings connected in series via the jumper wire 100 are constructed by winding a single continuous conductor in the same direction. Furthermore, as shown in Figure 15(a), the two partial windings connected in series are configured so that winding begins on the circumferential outside of one partial winding and ends on the circumferential outside of the other partial winding. Furthermore, the jumper wire 100 connecting the partial windings connected in series is pulled out from the circumferential outside of the partial winding where winding begins in the winding direction of that partial winding, and pulled in from the circumferential outside of the partial winding where winding ends in the winding direction of that partial winding. In other words, the direction in which the jumper wire 100 is pulled out from one partial winding is the same as the winding direction of the partial winding, and the direction in which the jumper wire 100 is pulled into the other partial winding is the same as the winding direction of the partial winding. Furthermore, the jumper wire 100 is wound so that a predetermined tension is applied.

This makes it easy to apply a predetermined tension to the crossover wire 100, as shown in Figure 15(a). For example, as shown in the comparative example in Figure 15(b), if winding starts from the circumferential inside of one partial winding and ends on the circumferential inside of the other partial winding, it becomes difficult to apply tension to the crossover wire 100. In other words, if the crossover wire 100 is pulled out from the circumferential inside of the partial winding where winding starts and pulled in from the circumferential inside of the partial winding where winding ends, the partial windings tend to unwind, making it difficult to apply tension to the crossover wire 100.

However, this does not occur with the winding method of the second embodiment, as shown in Figure 15(a). This makes it easier to wind the conductor and prevents the partial winding from unwinding after winding has finished.

(Third embodiment)
The configuration of the second embodiment may be partially modified as follows: In the third embodiment, the wiring method is further modified. Specifically, the modification is made as shown in FIGS. 16 and 17.

In other words, in the first stator winding 32a, of the partial windings +U11, +U12, +V12, +V13, +W13, and +W14 wound in the first direction, the partial windings +U12, +V13, and +W14 that form the start of the winding (connected to the first inverter circuit 51) are configured to be positioned on one side of the circumferential direction (e.g., clockwise) relative to the partial windings +U11, +V12, and +W13 that form the end of the winding. Furthermore, in the first stator winding 32a, of the partial windings -U13, -U14, -V11, -V14, -W11, and -W12 wound in the second direction, the partial windings -U13, -V14, and -W11 (connected to the second inverter circuit 52) that form the winding start are configured to be located on the other circumferential side (e.g., counterclockwise) of the partial windings -U14, -V11, and -W12 that form the winding end. The same is true for the second stator winding 32b.

As a result, in the first stator winding 32a, the partial windings +U11, +U12, +V12, +V13, +W13, and +W14 wound in the first direction are wired so that their crossover wires 100 do not overlap each other. In other words, the partial windings +U11, +U12, +V12, +V13, +W13, and +W14 that make up the first stator winding 32a and are wound in the first direction are not interposed between the partial windings +U11, +U12, +V12, +V13, +W13, and +W14 that are connected in series in the circumferential direction.

Furthermore, in the first stator winding 32a, the partial windings -U13, -U14, -V11, -V14, -W11, and -W13 wound in the second direction are wired so that their crossover wires 100 do not overlap one another. In other words, the partial windings -U13, -U14, -V11, -V14, -W11, and -W13 that make up the first stator winding 32a and are wound in the second direction are not interposed between the partial windings -U13, -U14, -V11, -V14, -W11, and -W13 that are connected in series in the circumferential direction. The same applies to the second stator winding 32b.

As a result, in the third embodiment, the overlap of the crossover wires 100 can be reduced compared to the second embodiment. This simplifies the connection process and reduces the axial dimension.

(Fourth embodiment)
In the fourth embodiment, the configurations of the first to third embodiments are partially modified. In the first to third embodiments, the total phase difference is 40 degrees, but in the fourth embodiment, the total phase difference is 80 degrees. That is, in the fourth embodiment, the total phase difference between the magnetomotive force generated by the partial winding of the second stator winding 32b and the magnetomotive force generated by the partial winding of the first stator winding 32a wound around each third tooth is set to 80 degrees so that the phase difference between the magnetomotive force of the coil bodies Uc, Vc, and Wc and the magnetomotive force of the coil bodies Ua, Va, and Wa is 80 degrees. While 80 degrees is preferable, the total phase difference may be within a range of 72 to 88 electrical degrees.

When doing this, the partial winding arrangement for each phase will be as shown in Figures 18 and 19. Here, we will use the coil body Uc provided on tooth T9 as an example to explain how the combined phase difference is 80 degrees.

As shown in Fig. 18, the coil body Uc provided on tooth T9 is composed of a partial winding +U12/-W22. The magnetomotive force Fu1a of the partial winding +U12 and the magnetomotive force Fw2b of the partial winding -W22 are as shown in equations (1) and (12). These magnetomotive forces can be expressed in a vector diagram as shown in Fig. 20. The magnetomotive force Fu1a of the partial winding +U12 and the magnetomotive force Fw2b of the partial winding -W22 are added together to obtain the result shown in equation (18).

In equation (18), the number of turns of the partial winding +U12 and the number of turns of the partial winding -W22 are both N. As shown in equation (18), by winding the partial winding +U12 and the partial winding -W22 around tooth T9, it is possible to achieve magnetomotive forces of coil bodies Uc, Vc, and Wc with a phase difference (combined phase difference) of 40 degrees relative to the magnetomotive forces of coil bodies Ua, Va, and Wa.

As shown in equation (18), the magnetomotive force is proportional to the number of turns of the partial winding. Therefore, if the number of turns of each partial winding is not set appropriately, the amplitude of the magnetomotive force will not be consistent between the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc.

In the fourth embodiment, the number of turns of the coil bodies Ua, Va, Wa and the coil bodies Ub, Vb, Wb are all the same, "Na," and the number of turns of the first stator winding 32a wound around the third teeth and the number of turns of the second stator winding 32b are "Nb." The numbers of turns "Na" and "Nb" are set to satisfy the relationship 1.4≦Na/Nb≦1.6. It is preferable for Na/Nb to be a value close to 1.53, and in this embodiment, the number of turns is set so that the ratio Na:Nb is 3:2 (Na/Nb is 1.5).

As described above, the configuration of the fourth embodiment has the following advantages:

The phase differences between the magnetomotive forces of the coil bodies Ub, Vb, and Wb relative to the magnetomotive forces of the coil bodies Ua, Va, and Wa, and the phase differences between the magnetomotive forces of the coil bodies Uc, Vc, and Wc relative to the magnetomotive forces of the coil bodies Ub, Vb, and Wb, are set within a predetermined phase range that includes 20 degrees. Specifically, the combined phase difference between the magnetomotive force generated by the partial winding of the second stator winding 32b wound around the third tooth relative to the magnetomotive force generated by the partial winding of the first stator winding 32a wound around the third tooth is set to be in the range of 72 to 88 electrical degrees. In this embodiment, the combined phase difference is set to 80 degrees. This cancels out the sixth- and twelfth-order harmonic components of the torque, suppressing torque ripple, as shown in equations (15), (16), and (18).

The number of turns is set to satisfy the relationship 1.4≦Na/Nb≦1.6. In this embodiment, the number of turns is set so that the Na:Nb ratio is 3:2 (Na/Nb is 1.5). This allows the amplitudes of the magnetomotive forces of the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc to be approximately the same, thereby suppressing torque ripple.

The motor 10 has 14 magnetic poles and 18 slots 35. That is, the number of magnetic poles is (18±4) x m (m is an integer greater than or equal to 1), and the number of slots is 18 x m. This allows the electromagnetic force to be balanced around the axis, as in the first to third embodiments.

Fifth Embodiment
In the first to fourth embodiments, the current phase difference "β" between the first inverter circuit 51 and the second inverter circuit 52 is set to an electrical angle of 20 degrees, but in the fifth embodiment, it is set to 40 degrees. In other words, the phase differences between the magnetomotive forces of the coil bodies Ub, Vb, and Wb and the magnetomotive forces of the coil bodies Ua, Va, and Wa are each 40 degrees.

For this reason, in the fifth embodiment, in equations (13) and (14), the first term corresponds to the component based on the coil bodies Ua, Va, and Wa, the second term corresponds to the component based on the coil bodies Uc, Vc, and Wc, and the third term corresponds to the component based on the coil bodies Ub, Vb, and Wb.

In the fifth embodiment, "λ1" indicates the phase difference between the magnetomotive force of coil body Uc and the magnetomotive force of coil body Ua in the U phase; the phase difference between the magnetomotive force of coil body Vc and the magnetomotive force of coil body Va in the V phase; and the phase difference between the magnetomotive force of coil body Wc and the magnetomotive force of coil body Wa in the W phase. Similarly, "λ2" indicates the phase difference between the magnetomotive force of coil body Ub and the magnetomotive force of coil body Ua in the U phase; the phase difference between the magnetomotive force of coil body Vb and the magnetomotive force of coil body Va in the V phase; and the phase difference between the magnetomotive force of coil body Wb and the magnetomotive force of coil body Wa in the W phase. Furthermore, in equations (13) and (14), "Ta" is a constant proportional to the number of turns of coil bodies Ua, Va, and Wa and the amplitude of the current. "Tb" is a constant proportional to the number of turns of the coil bodies Uc, Vc, and Wc and the amplitude of the current. "Tc" is a constant proportional to the number of turns of the coil bodies Ub, Vb, and Wb and the amplitude of the current.

Therefore, if the phase difference between the magnetomotive forces of the coil bodies Ua, Va, and Wa and the magnetomotive forces of the coil bodies Uc, Vc, and Wc is set to 20 degrees, it can be said that torque ripple can be suppressed according to equations (15) and (16).

In other words, the phase difference between the magnetomotive force of the coil bodies Ua, Va, Wa and the magnetomotive force of the coil bodies Uc, Vc, Wc, and the phase difference between the magnetomotive force of the coil bodies Ub, Vb, Wb and the magnetomotive force of the coil bodies Uc, Vc, Wc, should each be 20 degrees. While a phase difference of 20 degrees is desirable, it may also be within a predetermined phase range that includes 20 degrees (for example, a range of 15 to 25 degrees), and torque ripple suppression effects can still be achieved in this case.

Therefore, in the fifth embodiment, the phase difference between the magnetomotive force generated by the partial winding of the first stator winding 32a wound around each third tooth and the magnetomotive force generated by the partial winding of the second stator winding 32b is set to be in the range of 72 to 88 electrical degrees. In other words, the total phase difference is set to be in the range of 72 to 88 electrical degrees. As with the first embodiment, in the fifth embodiment, it is desirable to set the total phase difference to 80 degrees.

Specifically, as shown in Figure 21, partial windings are arranged on each of teeth T1 to T18. This configuration allows the phase difference between the magnetomotive force of coil bodies Uc, Vc, and Wc relative to the magnetomotive force of coil bodies Ua, Va, and Wa, and the phase difference between the magnetomotive force of coil bodies Ub, Vb, and Wb relative to the magnetomotive force of coil bodies Uc, Vc, and Wc to be 20 degrees. Furthermore, as with the first embodiment, to align the magnetomotive forces of coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc, the number of turns is set so that the Na:Nb ratio is 3:2 (Na/Nb is 1.5). The connection of each partial winding is the same as in any of the first to third embodiments.

By configuring as described above, the fifth embodiment can achieve the same effects as the first to fourth embodiments.

Sixth Embodiment
In the sixth embodiment, the current phase difference "β" between the inverter circuits 51 and 52 is set to 40 degrees, and the total phase difference is set to 40 degrees, unlike in the fifth embodiment. In other words, the phase difference between the magnetomotive force generated by the partial winding of the first stator winding 32a wound around each third tooth and the magnetomotive force generated by the partial winding of the second stator winding 32b is set to 40 degrees. Note that, although 40 degrees is preferable, it may be changed within a range of 32 to 48 degrees.

Specifically, as shown in FIG. 22, partial windings are arranged on each of teeth T1 to T18. This configuration allows the phase difference between the magnetomotive force of coil bodies Uc, Vc, and Wc relative to the magnetomotive force of coil bodies Ua, Va, and Wa, and the phase difference between the magnetomotive force of coil bodies Ub, Vb, and Wb relative to the magnetomotive force of coil bodies Uc, Vc, and Wc to be 20 degrees. Furthermore, for the same reasons as in the second embodiment, the number of turns is set so that the ratio Na:Nb is 19:10 (Na/Nb is 1.9) to align the magnetomotive forces of coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc. The connection of each partial winding is the same as in any of the first to third embodiments.

As a result, the sixth embodiment can achieve the same effects as the first to fifth embodiments.

(Other embodiments)
In the above embodiment, the number of magnetic poles may be 22, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 20 degrees, and the total phase difference may be 80 degrees. An example of the arrangement of partial windings in this case is shown in FIG. 23 .

In this case, as shown in Figure 23, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around one of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding -U12 of the first stator winding 32a wound around tooth T2, the third tooth, can be connected to the partial winding +U11 of the first stator winding 32a wound around tooth T1, the circumferentially adjacent first tooth.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the other of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding +W21 of the second stator winding 32b wound around tooth T2, the third tooth, can be connected to the partial winding -W22 of the second stator winding 32b wound around tooth T3, the circumferentially adjacent second tooth. This allows the jumper wires connecting the slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 22, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 20 degrees, and the combined phase difference may be 40 degrees. An example of the partial winding arrangement in this case is shown in Figure 23.

- In the above embodiment, the number of magnetic poles may be 22, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 40 degrees, and the combined phase difference may be 80 degrees. An example of the partial winding arrangement in this case is shown in Figure 23.

In this case, as shown in Figure 23, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around one of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding +V11 of the first stator winding 32a wound around tooth T3, the third tooth, can be connected to the partial winding -V12 of the first stator winding 32a wound around tooth T4, the circumferentially adjacent first tooth.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the other of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding +U22 of the second stator winding 32b wound around tooth T3, the third tooth, can be connected to the partial winding -U21 of the second stator winding 32b wound around tooth T2, the circumferentially adjacent second tooth. This allows the jumper wires connecting the slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 22, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 40 degrees, and the combined phase difference may be 40 degrees. An example of the partial winding arrangement in this case is shown in Figure 23.

- In the above embodiment, the number of magnetic poles may be 16, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 20 degrees, and the combined phase difference may be 80 degrees. An example of the partial winding arrangement in this case is shown in Figure 24.

In this case, as shown in Figure 24, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around the teeth T1 to T18, which are two teeth adjacent in the circumferential direction. For example, in this example, the partial winding +V11 of the first stator winding 32a wound around tooth T2, the third tooth, can be connected to the partial winding +V12 of the first stator winding 32a wound around tooth T4, the first tooth, which is two teeth adjacent in the circumferential direction.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the teeth T1 to T18, which are two teeth adjacent in the circumferential direction. For example, in this example, partial winding U21 of the second stator winding 32b wound around tooth T2, the third tooth, can be connected to partial winding U24 of the second stator winding 32b wound around tooth T18, the second tooth adjacent in the circumferential direction. This allows the jumper wires connecting between slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 16, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 20 degrees, and the combined phase difference may be 40 degrees. An example of the partial winding arrangement in this case is shown in Figure 24.

In this case, as shown in Figure 24, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around one of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding -U12 of the first stator winding 32a wound around tooth T2, the third tooth, can be connected to the partial winding +U11 of the first stator winding 32a wound around tooth T1, the circumferentially adjacent first tooth.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the other of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding +V21 of the second stator winding 32b wound around tooth T2, the third tooth, can be connected to the partial winding -V22 of the second stator winding 32b wound around tooth T3, the circumferentially adjacent second tooth. This allows the jumper wires connecting the slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 16, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 40 degrees, and the combined phase difference may be 80 degrees. An example of the partial winding arrangement in this case is shown in Figure 24.

In this case, as shown in Figure 24, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around the teeth T1 to T18 that are two teeth adjacent in the circumferential direction. For example, in this example, the partial winding +U12 of the first stator winding 32a wound around tooth T3, the third tooth, can be connected to the partial winding +U11 of the first stator winding 32a wound around tooth T1, the first tooth that is two teeth adjacent in the circumferential direction.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the teeth T1 to T18 that are two teeth adjacent in the circumferential direction. For example, in this example, the partial winding +W21 of the second stator winding 32b wound around tooth T3, the third tooth, can be connected to the partial winding +W22 of the second stator winding 32b wound around tooth T5, the second tooth adjacent in the circumferential direction. This allows the jumper wires connecting between slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 16, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 40 degrees, and the combined phase difference may be 40 degrees. An example of the partial winding arrangement in this case is shown in Figure 24.

In this case, as shown in Figure 24, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around one of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding -V11 of the first stator winding 32a wound around tooth T3, the third tooth, can be connected to the partial winding +V12 of the first stator winding 32a wound around tooth T4, the circumferentially adjacent first tooth.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the other of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding -V22 of the second stator winding 32b wound around tooth T3, the third tooth, can be connected to the partial winding +V21 of the second stator winding 32b wound around tooth T2, the circumferentially adjacent second tooth. This allows the jumper wires connecting the slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 20, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 20 degrees, and the combined phase difference may be 80 degrees. An example of the partial winding arrangement in this case is shown in Figure 25.

In this case, as shown in Figure 25, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around the teeth T1 to T18 that are two teeth adjacent in the circumferential direction. For example, in this example, the partial winding +U12 of the first stator winding 32a wound around tooth T3, the third tooth, can be connected to the partial winding +U11 of the first stator winding 32a wound around tooth T1, the first tooth that is two teeth adjacent in the circumferential direction.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the teeth T1 to T18 that are two teeth adjacent in the circumferential direction. For example, in this example, partial winding -W21 of the second stator winding 32b wound around tooth T3, the third tooth, can be connected to partial winding -W22 of the second stator winding 32b wound around tooth T5, the second tooth adjacent in the circumferential direction. This allows the jumper wires connecting between slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 20, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 20 degrees, and the combined phase difference may be 40 degrees. An example of the partial winding arrangement in this case is shown in Figure 25.

In this case, as shown in Figure 25, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around one of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding -W11 of the first stator winding 32a wound around tooth T3, the third tooth, can be connected to the partial winding +W12 of the first stator winding 32a wound around tooth T4, the circumferentially adjacent first tooth.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the other of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding +U22 of the second stator winding 32b wound around tooth T3, the third tooth, can be connected to the partial winding -U21 of the second stator winding 32b wound around tooth T2, the circumferentially adjacent second tooth. This allows the jumper wires connecting the slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 20, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 40 degrees, and the combined phase difference may be 80 degrees. An example of the partial winding arrangement in this case is shown in Figure 25.

In this case, as shown in Figure 25, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around the teeth T1 to T18, which are two teeth adjacent in the circumferential direction. For example, in this example, the partial winding +W11 of the first stator winding 32a wound around tooth T2, the third tooth, can be connected to the partial winding +W12 of the first stator winding 32a wound around tooth T4, the first tooth, which is two teeth adjacent in the circumferential direction.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the teeth T1 to T18, which are two teeth adjacent in the circumferential direction. For example, in this example, the partial winding +V21 of the second stator winding 32b wound around tooth T2, the third tooth, can be connected to the partial winding +V24 of the second stator winding 32b wound around tooth T18, the second tooth adjacent in the circumferential direction. This allows the jumper wires connecting the slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be 20, the number of slots may be 18, the current phase difference β between the first inverter circuit 51 and the second inverter circuit 52 may be 40 degrees, and the combined phase difference may be 40 degrees. An example of the partial winding arrangement in this case is shown in Figure 25.

In this case, as shown in Figure 25, the first stator winding 32a wound around the third tooth can be connected to the first stator winding 32a wound around one of the circumferentially adjacent teeth T1 to T18. For example, in this example, the partial winding -U12 of the first stator winding 32a wound around tooth T2, the third tooth, can be connected to the partial winding +U11 of the first stator winding 32a wound around tooth T1, the circumferentially adjacent first tooth.

Similarly, the second stator winding 32b wound around the third tooth can be connected to the second stator winding 32b wound around the other of the circumferentially adjacent teeth T1 to T18. For example, in this example, partial winding-U21 of the second stator winding 32b wound around tooth T2, the third tooth, can be connected to partial winding-U22 of the second stator winding 32b wound around tooth T3, the circumferentially adjacent second tooth. This allows the jumper wires connecting the slots 35 at the coil ends to be shorter, making connections easier and enabling miniaturization.

- In the above embodiment, the number of magnetic poles may be (18±4)×m (m is an integer greater than or equal to 1) and the number of slots may be 18×m. Alternatively, the number of magnetic poles may be (18±2)×n (n is an integer greater than or equal to 1) and the number of slots may be 18×n. If the number of magnetic poles is (18±4)×m (m is an integer greater than or equal to 1) and the number of slots is 18×m, as described above in Figure 12, the electromagnetic force increases at 90-degree intervals, achieving balance and suppressing noise and vibration.

- In the above embodiment, the current phase difference "β" between the first inverter circuit 51 and the second inverter circuit 52 is preferably "20 degrees" or "40 degrees," but may be changed within the ranges of 15 to 25 degrees and 35 to 45 degrees, respectively.

- In the above embodiment, the combined phase difference between the first stator winding 32a and the second stator winding 32b wound around the third teeth is preferably 40 degrees or 80 degrees, but may be changed within the ranges of 32 to 48 degrees and 72 to 88 degrees, respectively.

- In the above embodiment, the motor 10 is not limited to a radial gap motor and may be, for example, an axial gap motor. The motor 10 may also be a reluctance motor or an induction motor.

In the above embodiment and modified example, torque ripple is suppressed by setting the combined phase difference (magnetomotive force combined phase difference) between the magnetomotive force generated by the partial winding of the first stator winding 32a wound around the third tooth and the magnetomotive force generated by the partial winding of the second stator winding 32b wound around the third tooth to be within a predetermined range. Instead of this magnetomotive force combined phase difference, the combined phase difference (current combined phase difference) between the current flowing through the partial winding of the first stator winding 32a wound around the third tooth and the current flowing through the partial winding of the second stator winding 32b wound around the third tooth may be used.

It should be noted that the phase of the current flowing through the partial windings will be shifted by 180 degrees depending on the winding direction of the partial winding. In other words, even for the same U-phase partial winding, the current flowing through the "+" partial winding and the current flowing through the "-" partial winding will be shifted by 180 degrees in phase, and the phase difference of the combined currents must be considered.

For example, if the inverter current phase difference "β" is 20 degrees, and the phase of the current flowing through the U-phase partial winding and the "+" partial winding is the reference phase "θ," the phase of the current flowing through the V-phase partial winding and the "-" partial winding is "θ - 120 (phase shift due to V-phase) - 20 (shift based on current phase difference β) - 180 (phase shift due to winding direction)" = "θ - 320."

β...current phase difference, 10...motor, 30...stator, 32...stator winding, 32a...first stator winding, 32b...second stator winding, 40...rotor, 51...first inverter circuit, 52...second inverter circuit, T1 to T18...teeth.

Claims (15)

A rotating electric machine (10) including a rotor (40) having a plurality of magnetic poles whose polarities alternate in the circumferential direction, and a stator (30) having a stator core having a polyphase stator winding (32) and a plurality of teeth (T1 to T18) provided at predetermined intervals in the circumferential direction and around which the stator winding is wound,
The stator windings include a first stator winding (32a) to which a three-phase current is supplied from a first inverter (51) and a second stator winding (32b) to which a three-phase current is supplied from a second inverter (52),
the three-phase current supplied from the first inverter and the three-phase current supplied from the second inverter have a predetermined current phase difference (β),
a U-phase coil body Ua formed by winding the first stator winding of the U-phase among the three phases around a first tooth;
a V-phase coil body Va formed by winding the first stator winding of the V-phase among the three phases around a first tooth;
a W-phase coil body Wa formed by winding the first stator winding of the W-phase among the three phases around a first tooth;
a U-phase coil body Ub formed by winding the U-phase second stator winding around a second tooth;
a V-phase coil body Vb formed by winding the V-phase second stator winding around a second tooth;
a W-phase coil body Wb formed by winding the second stator winding of the W-phase around a second tooth;
a U-phase coil body Uc formed by winding the first stator winding of any one of the three phases and the second stator winding of any one of the three phases around a third tooth;
a V-phase coil body Vc formed by winding the first stator winding of any one of the three phases and the second stator winding of any one of the three phases around a third tooth;
a W-phase coil body Wc formed by winding the first stator winding of any one of the three phases and the second stator winding of any one of the three phases around a third tooth,
The phase differences of the magnetomotive force of the coil bodies Uc, Vc, Wc of each phase relative to the magnetomotive force of the coil bodies Ua, Va, Wa of each phase, and the phase differences of the magnetomotive force of the coil bodies Ub, Vb, Wb of each phase relative to the magnetomotive force of the coil bodies Uc, Vc, Wc of each phase are set within a predetermined phase range including 20 degrees in electrical angle,
Alternatively, a total phase difference between the magnetomotive force generated by the partial winding of the first stator winding wound on the third tooth and the magnetomotive force generated by the partial winding of the second stator winding wound on the third tooth, or a total phase difference between the current flowing in the partial winding of the first stator winding wound on the third tooth and the current flowing in the partial winding of the second stator winding wound on the third tooth, is set so that each phase difference between the magnetomotive force of the coil bodies Ub, Vb, Wb of each phase and the magnetomotive force of the coil bodies Ua, Va, Wa of each phase and each phase difference between the magnetomotive force of the coil bodies Uc, Vc, Wc of each phase and the magnetomotive force of the coil bodies Ub, Vb, Wb of each phase are within a predetermined phase range including 20 electrical degrees,
On one side in the axial direction, the stator winding is connected to the inverter, and on the other side, a partial winding of the first stator winding wound on the first teeth is connected to a partial winding of the first stator winding wound on the third teeth, and a partial winding of the second stator winding wound on the first teeth is connected to a partial winding of the second stator winding wound on the third teeth,
a winding direction of the first stator winding wound around the third teeth is different from a winding direction of the second stator winding wound around the third teeth,
On the other side in the axial direction, a crossover wire (100) connected to the first stator winding and a crossover wire (100) connected to the second stator winding are drawn out from slots (35) on both sides in the circumferential direction centered on the third tooth,
the partial winding of the first stator winding wound around the first teeth and the partial winding of the first stator winding wound around the third teeth are formed of a continuous wire, and the partial winding of the second stator winding wound around the first teeth and the partial winding of the second stator winding wound around the third teeth are also formed of a continuous wire,
The partial windings connected in series are wound in the same direction,
the crossover wires connecting the series-connected partial windings are pulled out from the circumferential outside of the partial winding at the winding start in the winding direction of the partial winding, and pulled in from the circumferential outside of the partial winding at the winding end in the winding direction of the partial winding, and a predetermined tension is applied to the crossover wires;
In the first stator winding, among the partial windings wound in a first direction, the partial winding connected to the first inverter and serving as a winding start is disposed on one side in the circumferential direction relative to the partial winding serving as a winding end, and in the first stator winding, among the partial windings wound in a second direction, the partial winding connected to the second inverter and serving as a winding start is disposed on the other side in the circumferential direction relative to the partial winding serving as a winding end,
the first stator winding is arranged in such a way that, in the circumferential direction, partial windings of the first stator winding that are wound in the first direction and connected in series are not interposed between partial windings, and other partial windings that are part of the first stator winding and are wound in the first direction,
the first stator winding is arranged in such a way that other partial windings that are wound in the second direction and that are part of the first stator winding are not interposed between partial windings that are wound in the second direction and are connected in series in the circumferential direction,
In the second stator winding, among the partial windings wound in a first direction, the partial winding connected to the first inverter and forming the winding start is disposed on one side in the circumferential direction relative to the partial winding forming the winding end, and in the second stator winding, among the partial windings wound in a second direction, the partial winding connected to the second inverter and forming the winding start is disposed on the other side in the circumferential direction relative to the partial winding forming the winding end,
the second stator winding is arranged in such a way that, in the circumferential direction, partial windings of the second stator winding that are wound in the first direction and connected in series are not interposed between partial windings of the second stator winding that are wound in the first direction, and
A rotating electric machine in which partial windings of the second stator winding that are wound in the second direction and connected in series are arranged in the circumferential direction so that other partial windings that are wound in the second direction and that constitute the second stator winding are not interposed between the partial windings. 2. The rotating electric machine according to claim 1, wherein the number of turns of the first stator winding wound around the third teeth and the number of turns of the second stator winding wound around the third teeth are made different from the number of turns of the first stator winding wound around the first teeth or the number of turns of the second stator winding wound around the second teeth so that the magnetomotive force of the coil bodies Ua, Va, Wa, Ub, Vb, Wb, Uc, Vc, and Wc of each phase falls within a predetermined amplitude range. 3. The rotating electric machine according to claim 1, wherein the total phase difference is set in a range of 72 to 88 electrical degrees. 4. The rotating electric machine according to claim 3 , wherein the number of magnetic 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. 4. The rotating electric machine according to claim 3 , wherein the number of magnetic 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. 3. The rotating electric machine according to claim 1, wherein the number of magnetic poles of the rotor is "14" or "22", the number of slots between the teeth is "18", and the total phase difference is 80 degrees in electrical angle. 3. The rotating electric machine according to claim 1, wherein the number of magnetic poles of the rotor is "16" or "20", the number of slots between the teeth is "18", and the total phase difference is 80 degrees in electrical angle. A rotating electric machine according to any one of claims 3 to 7, wherein the number of turns of the first stator winding wound around the first teeth and the number of turns of the second stator winding wound around the second teeth are each defined as "Na", and the number of turns of the first stator winding wound around the third teeth and the number of turns of the second stator winding wound around the third teeth are each defined as "Nb", and the number of turns of each is set to satisfy the relationship 1.4≦Na/Nb≦1.6. 3. The rotating electric machine according to claim 1 , wherein the total phase difference is set in a range of 32 to 48 degrees in electrical angle. 10. The rotating electric machine according to claim 9 , wherein the number of magnetic 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. 10. The rotating electric machine according to claim 9 , wherein the number of magnetic 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. 3. The rotating electric machine according to claim 1, wherein the number of magnetic poles of the rotor is "16" or "20", the number of slots between the teeth is "18", and the total phase difference is 40 degrees in electrical angle. A rotating electric machine according to any one of claims 9 to 12, wherein the number of turns of the first stator winding wound around the first teeth and the number of turns of the second stator winding wound around the second teeth are each defined as "Na", and the number of turns of the first stator winding wound around the third teeth and the number of turns of the second stator winding wound around the third teeth are each defined as "Nb", and the number of turns of each is set to satisfy the relationship 1.8 ≦ Na/Nb≦2.0. The rotating electric machine according to any one of claims 1 to 13, wherein a current phase difference between the three-phase current supplied from the first inverter and the three-phase current supplied from the second inverter is set within a range of 15 to 25 degrees or a range of 35 to 45 degrees. An angle sensor (12) is provided on the rotating shaft (11) of the rotating electric machine,
A rotating electric machine according to any one of claims 1 to 14, wherein the lead wires (A1, B1, C1) of the first stator winding connected to the first inverter and the lead wires (A2, B2, C2) of the second stator winding connected to the second inverter are arranged so that each phase is symmetrical about the rotation axis.