Stator and motor

Abstract

To provide a stator capable of improving electrical characteristics by making the configuration of a coil of each phase proper, and a motor.SOLUTION: An inlet-side end ta of an inlet-side coil 12 (e.g., an inlet-side coil U1 of a U phase) of a first phase and an outlet-side coil 12 (e.g., an outlet-side coil V2 of a V phase) of a second phase, the coils being adjacent, are set to be disposed at positions being in an outermost layer and eccentric to a tip end side as winding positions with respect to teeth 11a.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a stator having a coil and a motor.

Background Art

[0002] In the stator of a motor, a plurality of turns of a conducting wire are wound around the teeth portion of a stator core to form a coil. For example, in the case of an outer stator type, the stator core includes a plurality of teeth portions whose tip portions face radially inward, and an annular portion that annularly connects the base end portions of the respective teeth portions located radially outward. The conducting wire wound around each teeth portion is arranged so as to be aligned along the extending direction of each teeth portion for each turn, and is arranged in a plurality of layers stacked on top of the previously wound conducting wire (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, since the stator core is generally at ground potential, a capacitance to ground parasitically exists in the conducting wire attached to the stator core. In this case, the capacitance to ground of the conducting wire wound a plurality of times varies depending on the arrangement position for each turn. Specifically, the capacitance to ground of the conducting wire is the largest at positions close to both the teeth portion and the annular portion, and is the second largest at positions close to either one of the teeth portion and the annular portion. The capacitance to ground becomes smaller as the conducting wire moves away from either or both of the teeth portion and the annular portion.

[0005] Furthermore, in the coils of each phase in a three-phase connection, the magnitude of the inter-phase potential difference is a concern. Depending on the position of the inlet end of each phase coil, i.e., the end connected to the control device side, relative to the teeth and annular portion of the stator core, the inter-phase potential difference between each phase can become large. In such cases, it becomes necessary to take measures such as setting a larger insulation distance between the coils of each phase or interposing additional insulating material between the coils of each phase. There was a concern that this would hinder the miniaturization and weight reduction of the stator, and consequently the entire motor.

[0006] The purpose of this disclosure is to provide a stator and motor that can improve electrical characteristics by optimizing the configuration of the coils in each phase. [Means for solving the problem]

[0007] A stator that solves the above problem comprises a stator core (11) having a plurality of teeth (11a) and an annular portion (11b) that connects the base ends of the plurality of teeth to each other, and a plurality of coils (12, U1~U4, V1~V4, W1~W4) which are wound around each of the plurality of teeth in a concentrated winding manner so as to be stacked in multiple layers, and the plurality of coils 3 A phase connection configuration is used. 3 Obtained from the phase motor input terminals (tu, tv, tw) 3 A stator (10A~10D) is configured to generate a rotating magnetic field through a plurality of coils based on phase drive power, wherein the ends of the coils and their conductors on the side electrically closer to the motor input terminal of the same phase are designated as the inlet coils (U1, V1, W1) and inlet end (ta), respectively, and the ends of the coils and their conductors on the side electrically farther from the motor input terminal of the same phase are designated as the outlet coils (U2~U4, V2~V4, W2~W4) and outlet end (tb), respectively, and in the circumferentially adjacent coils of different phases, the inlet end of the inlet coil of the first phase and the outlet end of the outlet coil of the second phase are both positioned on the outermost layer and offset toward the tip of the teeth portion.

[0008] A motor that solves the above problems is configured to include a stator (10A to 10D) and a rotor (20A to 20D) that is driven to rotate based on the rotating magnetic field generated by the stator.

[0009] With the above-described stator and motor configuration, the inlet end of the coil on the inlet side of the adjacent first phase and the outlet end of the coil on the outlet side of the second phase are positioned at the outermost layer and offset towards the tip side in terms of winding position relative to the teeth. In other words, since both are positioned at locations where the capacitance to ground is sufficiently small, it becomes possible to substantially reduce the capacitance to ground of the inlet end and outlet end of each phase coil as a whole, and it is expected that the inter-phase potential difference between adjacent different phases will be sufficiently suppressed. By optimizing the configuration of each phase coil in this way, improvements in the electrical characteristics of the stator and motor can be expected. [Brief explanation of the drawing]

[0010] [Figure 1] This is a configuration diagram showing a motor including a stator in the first embodiment. [Figure 2] This is a configuration diagram showing a part of the stator in the first embodiment. [Figure 3] This is a circuit diagram showing the coil wiring configuration in the first embodiment. [Figure 4] This is a configuration diagram showing a motor including a stator in the second embodiment. [Figure 5] This is a configuration diagram showing a part of the stator in the second embodiment. [Figure 6] This is a circuit diagram showing the coil wiring configuration in the second embodiment. [Figure 7] This is a configuration diagram showing a motor including a stator in the third embodiment. [Figure 8] This is a configuration diagram showing a part of the stator in the third embodiment. [Figure 9] This is a circuit diagram showing the coil wiring configuration in the third embodiment. [Figure 10]It is a configuration diagram showing a motor including a stator in the fourth embodiment. [Figure 11] It is a configuration diagram showing a part of the stator in the fourth embodiment. [Figure 12] It is a circuit diagram showing a connection mode of coils in the fourth embodiment. [Figure 13] It is a waveform diagram for explaining the effects of each embodiment. [Figure 14] (a) to (e) are waveform diagrams for explaining the effects of each embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0011] (First Embodiment) Hereinafter, a first embodiment of a stator and a motor will be described. (Configuration of Motor M1 and Rotor 20A) As shown in FIG. 1, the motor M1 of the present embodiment includes a stator 10A configured in a substantially annular shape and a rotor 20A rotatably disposed inside the stator 10A. When a rotating magnetic field is generated in the stator 10A based on energization, the rotor 20A is rotationally driven based on the generated rotating magnetic field. Note that the configuration of the rotor 20A will be described first, and then the configuration of the stator 10A will be described.

[0012] The rotor 20A of the present embodiment includes a rotor core 22 having a rotation axis 21 and a permanent magnet 23 fixed to the outer peripheral surface of the rotor core 22. The rotor 20A of the present embodiment includes, for example, a 14-pole magnet pole portion by the permanent magnet 23.

[0013] (Configuration of Stator 10A) As shown in FIGS. 1 and 2, the stator 10A of the present embodiment includes a stator core 11 made of a magnetic metal material in a substantially annular shape and a plurality of coils 12 mounted on the stator core 11.

[0014] The stator core 11 includes a plurality of teeth portions 11a with the tip ends facing radially inward, and an annular portion 11b that connects the base ends of the respective teeth portions 11a located on the radially outer side to each other. In this embodiment, 12 teeth portions 11a are provided. Each tooth portion 11a extends in a substantially rectangular shape with the same width from the base end to the tip end in this embodiment. The annular portion 11b is formed by annularly connecting the divided portions for each tooth portion 11a in this embodiment. Note that an integral structure in which the annular portion 11b is not divided may also be used.

[0015] Each coil 12 is mounted on each tooth portion 11a. Each coil 12 is configured by winding a conductor 12a around each tooth portion 11a by concentrated winding. There are 12 coils 12 mounted for each tooth portion 11a, and the stator 10A of this embodiment includes a 12-pole coil magnetic pole portion. The conductor 12a is wound by aligned winding in this embodiment. The conductor 12a is arranged so as to be aligned along the extending direction of each tooth portion 11a for each turn, and is arranged in a plurality of layers, 3 layers in this embodiment, stacked on top of the previously wound conductor 12a.

[0016] As shown in FIG. 3 here, in this embodiment, the 12 coils 12 are configured in a three-phase Y-type connection mode. The 12 coils 12 having a Y-type connection mode are in a connection mode of two series and two parallel for 4 coils each in the U-phase, V-phase, and W-phase in this embodiment. The coils 12 of each phase will be described using the notations of a pair of coils U1, U2 forming two series and two parallel in the U-phase, a pair of coils V1, V2 forming two series and two parallel in the V-phase, and a pair of coils W1, W2 forming two series and two parallel in the W-phase. That is, in the U-phase, the coil U1 and the coil U2 are connected in series as a pair, and the coils U1 and U2 connected in series as a pair are connected in parallel. Also, in the V-phase, the coil V1 and the coil V2 are connected in series as a pair, and the coils V1 and V2 connected in series as a pair are connected in parallel. Also, in the W-phase, the coil W1 and the coil W2 are connected in series as a pair, and the coils W1 and W2 connected in series as a pair are connected in parallel.

[0017] As shown in Figure 1, the coils 12 of each phase are arranged in the order of coil U1, coil U2, coil W1, coil W2, coil V1, and coil V2 for half of the circumference of the stator 10A, and this arrangement is repeated for the remaining half of the circumference. There are two adjacent coils 12 of the same phase, and these are coils U1 and U2, coil V1 and V2, and coil W1 and W2, which are connected in series with each other within the same phase. Furthermore, adjacent coils 12 of the same phase that are connected in series have winding patterns in opposite directions. In other words, the polarity that appears when current is applied is opposite for each adjacent coil of the same phase. On the other hand, adjacent coils 12 of different phases have winding patterns in the same direction.

[0018] As shown in Figure 2, each phase coil 12 has a pair of ends of the conductor 12a, namely an inlet end ta and an outlet end tb. The leads of these inlet end ta and outlet end tb are uniformly located on one axial side of the stator core 11. Here, as shown in Figure 3, the inlet end ta is the end that is electrically closer to the control device (not shown), in other words, the end that is electrically closer to the motor input terminals tu, tv, tw of the motor M1's phase. The outlet end tb is the end that is electrically farther from the control device, in other words, the end that is electrically farther from the motor input terminals tu, tv, tw of the motor M1's phase. Similarly, for coils U1, V1, W1 and coils U2, V2, W2, the side that is electrically closer to the motor input terminals tu, tv, tw of their phase is the inlet side, and the side that is electrically farther from the motor input terminals tu, tv, tw of their phase is the outlet side. In the case of a Y connection as in this embodiment, coils U1, V1, and W1, which are close to the motor input terminals tu, tv, and tw of their respective phases, are on the input side, and coils U2, V2, and W2, which are farther from the motor input terminals tu, tv, and tw of their respective phases and on the neutral point tn side, are on the output side.

[0019] The inlet end ta of coil U1 is connected directly to the U-phase motor input terminal tu of motor M1, or via a busbar or the like. The outlet end tb of coil U1 is the end that is continuous with the inlet end ta of coil U2. When coils U1 and U2 are wound continuously with a single conductor 12a, the outlet end tb of coil U1 and the inlet end ta of coil U2 are both located radially outside the teeth portion 11a (see Figure 2), thus reducing the need for connecting wires 12x that span both the radially inside and outside. The outlet end tb of coil U2 is the end that connects to the neutral point tn, which is electrically farther away from the U-phase motor input terminal tu. The pair of coils U1 and U2 connected in series are positioned 180° opposite each other on the stator 10A and are connected to each other by a conductor 12a, or in parallel between the U-phase motor input terminal tu and the neutral point tn using a busbar or the like. Although not described in detail here, the same applies to the relationship between the V-phase coils V1 and V2 between the V-phase motor input terminal tv and the neutral point tn, and to the relationship between their respective inlet end ta and outlet end tb. Similarly, the same applies to the relationship between the W-phase coils W1 and W2 between the W-phase motor input terminal tw and the neutral point tn, and to the relationship between their respective inlet end ta and outlet end tb.

[0020] (Detailed configuration of coil 12) As shown in Figure 2, in this embodiment, in coils 12 of different phases, for example, U-phase and V-phase, the inlet coil U1 and the outlet coil V2 are arranged adjacent to each other. As described above, the coil 12 in this embodiment is made up of three layers of wire 12a wound in an aligned winding manner around the teeth portion 11a. The inlet end ta of coil U1 is at the radially innermost position of the outermost layer, that is, the position furthest from both the teeth portion 11a and the annular portion 11b. The outlet end tb of coil U1 is at the radially outermost position of the innermost layer, that is, the position closest to both the teeth portion 11a and the annular portion 11b, due to the winding of the wire 12a. On the other hand, the inlet end ta of coil V2 is at the radially outermost position of the innermost layer, that is, the position closest to both the teeth portion 11a and the annular portion 11b. The outlet end tb of coil V2 is located at the innermost radial point of the outermost layer, that is, the position furthest from both the teeth portion 11a and the annular portion 11b, due to the winding of the conductor 12a.

[0021] Furthermore, the inlet end ta of coil U1 is located on the side of its teeth 11a that is on coil V2, and the outlet end tb of coil V2 is located on the side of its teeth 11a that is on coil U1. In other words, the inlet end ta of coil U1 and the outlet end tb of coil V2 are physically close together with only a small gap between them. Since these inlet end ta of coil U1 and outlet end tb of coil V2 are located furthest from both the teeth 11a and the annular portion 11b, the configuration minimizes the parasitic capacitance to ground for each. The same applies to the relationship with other coils of different phases 12, i.e., the relationship between the adjacent inlet coil V1 and outlet coil W2. The same also applies to the relationship between the adjacent inlet coil W1 and outlet coil U2.

[0022] (Operation of this embodiment) The operation of this embodiment will now be described. The control unit generates three-phase drive power through the operation of its built-in three-phase inverter. Three-phase drive is common among multi-phase drives, and using a general-purpose three-phase inverter offers advantages in terms of system cost. The three-phase drive power output from the control unit is supplied to the coils 12 of each phase for the rotational drive of the motor M1.

[0023] As shown in Figure 14(a), the input voltage Vm of the motor M1 is superimposed on the rectangularly changing output voltage Vc of the control device by a surge component that fluctuates rapidly transiently, for example, immediately after the rise time. The surge component superimposed on the input voltage Vm is mainly caused by the inductance component in the circuit, including the connecting cable (not shown) between the control device and the motor M1.

[0024] Furthermore, in each phase coil 12, the capacitance to ground differs depending on the position of the conductor 12a attached to each tooth portion 11a of the stator core 11 for each turn. For example, the conductor 12a placed in a position close to both the tooth portion 11a and the annular portion 11b of the stator core 11, that is, at position P1 shown in Figure 2, which is the outermost radial position of the innermost layer, has the largest capacitance to ground. Therefore, the surge component superimposed on the voltage is the largest, as shown in Figure 14(b). The conductor 12a placed in a position close to either the tooth portion 11a or the annular portion 11b, in this case at position P2 shown in Figure 2, which is the innermost radial position of the innermost layer, which is close to the tooth portion 11a, has the next largest capacitance to ground. Therefore, the surge component superimposed on the voltage is the next largest, as shown in Figure 14(c). For the conductor 12a located at position P3, the outermost radially outermost position of the outermost layer, which is close to the annular portion 11b, its capacitance to ground is the second largest. Therefore, the surge component superimposed on the voltage is the second largest, as shown in Figure 14(d). For the conductor 12a located at position P4, the innermost radially innermost position of the outermost layer, which is furthest from both the teeth portion 11a and the annular portion 11b, its capacitance to ground is the smallest. Therefore, the surge component superimposed on the voltage is the smallest, as shown in Figure 14(e).

[0025] In this embodiment, the inlet end ta of the adjacent inlet coil U1 and the outlet end tb of the adjacent outlet coil V2 are both located at position P4, as shown in Figure 2, which is the furthest point from both the teeth portion 11a and the annular portion 11b. Therefore, the capacitances to ground of the inlet end ta of the inlet coil U1 and the outlet end tb of the outlet coil V2 are the smallest possible. The same applies to the relationship between adjacent inlet coil V1 and outlet coil W2, and between adjacent inlet coil W1 and outlet coil U2. In other words, the capacitances to ground of the inlet end ta and the outlet end tb of the coil 12 for each phase as a whole are substantially small. As a result, the surge component superimposed on the input voltage Vm of each phase is minimized, and as shown in Figure 13, the inter-phase potential difference between adjacent phases can be sufficiently suppressed during the transient period when surges occur compared to the comparative example described later. Furthermore, sufficient suppression of the inter-phase potential difference between phases is also possible during the steady-state period when the surge subsides. Furthermore, it suppresses surge concentration not only between phases but also within the same phase.

[0026] In contrast, the comparative example is a typical configuration in which the radial positions of the inlet ends of adjacent U-phase coils on the inlet side and V-phase coils on the inlet side are aligned. The capacitance to ground at each inlet end of the different-phase coils on the inlet side is smallest, but the capacitance to ground at each outlet end of the different-phase coils on the outlet side is largest. The same applies to the V-phase and W-phase. With such combinations of end arrangements in the coils of each phase, as shown in Figure 13, the inter-phase potential difference between adjacent different-phase coils becomes large in both the transient period when surges occur and the steady-state period when surges subside. In this embodiment, the inter-phase potential difference between different phases is sufficiently suppressed compared to this comparative example.

[0027] Furthermore, in this embodiment, the inlet end ta of the adjacent inlet coil U1 and the outlet end tb of the outlet coil V2 are physically close together with only a small gap between them. As described above, since the surge component superimposed on the voltage is sufficiently small, it is possible to set a small insulation distance between, for example, the inlet end ta of coil U1 and the outlet end tb of coil V2. It is also possible to eliminate the need for insulating material between them. This contributes to the miniaturization and weight reduction of the stator 10A and, consequently, the entire motor M1.

[0028] (Effects of this embodiment) The effects of this embodiment will now be explained. (1-1) The inlet end ta of the inlet coil 12 of the adjacent first phase and the outlet end tb of the outlet coil 12 of the second phase are set to be positioned on the outermost layer and offset towards the tip side as winding positions relative to the teeth portion 11a. In other words, since both are positioned in a location where the capacitance to ground is sufficiently small, the capacitance to ground of the inlet end ta and the outlet end tb of the coil 12 of each phase as a whole can be substantially sufficiently reduced, and the interphase potential difference between adjacent different phases can be sufficiently suppressed. By optimizing the configuration of the coils 12 of each phase in this way, the electrical characteristics of the stator 10A and the motor M1 can be improved.

[0029] (1-2) The inlet end ta of the inlet coil 12 of the adjacent first phase and the outlet end tb of the outlet coil 12 of the second phase are located at the position most offset towards the tip of the teeth portion 11a, thus providing a configuration that can more reliably suppress the interphase potential difference between adjacent different phases.

[0030] (1-3) The inlet end ta of the inlet coil 12 of the adjacent first phase and the outlet end tb of the outlet coil 12 of the second phase are arranged to be physically close to each other and facing each other between the adjacent teeth 11a on which they are mounted. Since the capacitance to ground of each end ta and tb is small and the surge is small, the insulation distance between each end ta and tb can be set to be small, and there is no need to take measures such as interposing additional insulating material. This contributes to making the stator 10A, and by extension the entire motor M1, smaller and lighter.

[0031] (1-4) Since the inlet end ta and outlet end tb of each phase coil 12 are unified on one axial side of the stator core 11, connection work for each end ta, tb, wiring work for the conductors 12a, etc., can be made easier.

[0032] (Second Embodiment) The following describes a second embodiment of the stator and motor. The motor M2 of this embodiment will be described primarily for its differences from the motor M1 of the first embodiment.

[0033] (Configuration of motor M2 and rotor 20B) The motor M2 of this embodiment comprises a stator 10B and a rotor 20B. The rotor 20B of this embodiment is equipped with, for example, a 10-pole magnetic pole section made of permanent magnets 23.

[0034] (Configuration of Stator 10B) As shown in Figures 4 and 5, the stator 10B of this embodiment has 12 coils 12, each consisting of concentrated windings of conductors 12a around 12 teeth 11a, and is equipped with 12 coil magnetic poles. The winding of the conductors 12a in this embodiment is a random winding, not particularly aligned. Even though the conductors 12a are randomly wound, in each phase coil 12, multiple layers, approximately three layers in this embodiment, are stacked on top of the previously wound conductors 12a.

[0035] As shown in Figure 6, the 12 coils 12 in this embodiment are configured in a 3-phase Y-type connection. The 12 coils 12, which form a Y-type connection, are connected in a 4-series configuration, with 4 coils in each of the U-phase, V-phase, and W-phase. The coils 12 in each phase will be described using the notations U1, U2, U3, U4 for the 4-series coils in the U-phase, V1, V2, V3, V4 for the 4-series coils in the V-phase, and W1, W2, W3, W4 for the 4-series coils in the W-phase. That is, in the U-phase, coils U1 to U4 are connected in series, in the V-phase, coils V1 to V4 are connected in series, and in the W-phase, coils W1 to W4 are connected in series.

[0036] As shown in Figure 4, the coils 12 of each phase are arranged in the following order around the stator 10B: coil U1, coil U2, coil W3, coil W4, coil V1, coil V2, coil U3, coil U4, coil W1, coil W2, coil V3, and coil V4. There are two adjacent coils 12 of the same phase, and they are wound in opposite directions. In other words, the polarity that appears when current is applied to adjacent coils of the same phase is opposite. Also, adjacent coils 12 of different phases are wound in the same direction.

[0037] As shown in Figure 5, each phase coil 12 has a pair of ends of the conductor 12a, namely an inlet end ta and an outlet end tb. As shown in Figure 6, the inlet end ta of coil U1 is connected directly to the U-phase motor input terminal tu of motor M1 or via a busbar or the like. The outlet end tb of coil U1 is the end that is continuous with the inlet end ta of coil U2. When coils U1 and U2 are wound continuously with a single conductor 12a, both the outlet end tb of coil U1 and the inlet end ta of coil U2 are located radially outward (see Figure 5), so the routing of the jumper wire 12x in this embodiment can be suppressed to avoid spanning radially inward and outward. Coils U3 and U4 are located 180° opposite to coils U1 and U2 in the stator 10B (see Figure 4). The inlet end ta of coil U3 is continuous with the outlet end tb of coil U2 by the conductor 12a or connected via a busbar or the like. The outlet end tb of coil U3 is the end that is continuous with the inlet end ta of coil U4 via a jumper wire 12x (not shown). The outlet end tb of coil U4 is the end that is connected to the neutral point tn, which is electrically farther away from the U-phase motor input terminal tu. The same applies to the relationship between the V-phase coils V1 to V4 between the V-phase motor input terminal tv and the neutral point tn, and to the relationship between their respective inlet ends ta and outlet ends tb. The same also applies to the relationship between the W-phase coils W1 to W4 between the W-phase motor input terminal tw and the neutral point tn, and to the relationship between their respective inlet ends ta and outlet ends tb.

[0038] (Detailed configuration of coil 12) As shown in Figure 5, in this embodiment, in coils 12 of different phases, for example, U-phase and V-phase, the inlet coil U1 and the outlet coil V4 are arranged adjacent to each other. As described above, the coil 12 in this embodiment is made up of approximately three layers of conductor wire 12a wound randomly around the teeth portion 11a. The inlet end ta of coil U1 is at the radially innermost position of the outermost layer, that is, the position furthest from both the teeth portion 11a and the annular portion 11b. The outlet end tb of coil U1 is at the radially outermost position of the innermost layer, that is, the position closest to both the teeth portion 11a and the annular portion 11b, due to the winding of the conductor wire 12a. On the other hand, the inlet end ta of coil V4 is at the radially outermost position of the innermost layer, that is, the position closest to both the teeth portion 11a and the annular portion 11b. The outlet end tb of coil V4 is located at the innermost radial point of the outermost layer, that is, the position furthest from both the teeth portion 11a and the annular portion 11b, due to the winding of the conductor 12a.

[0039] Furthermore, the inlet end ta of coil U1 is located on the side of its teeth 11a that is on coil V4, and the outlet end tb of coil V4 is located on the side of its teeth 11a that is on coil U1. In other words, the inlet end ta of coil U1 and the outlet end tb of coil V4 are physically close together with only a small gap between them. Since the inlet end ta of coil U1 and the outlet end tb of coil V4 are located furthest from both the teeth 11a and the annular portion 11b, the configuration minimizes the parasitic capacitance to ground for each of them. The same applies to the relationship with other coils of different phases 12, namely the relationship between the adjacent inlet coil V1 and outlet coil W4. The same also applies to the relationship between the adjacent inlet coil W1 and outlet coil U4.

[0040] (Operation of this embodiment) The operation of this embodiment will now be described. In this embodiment, although there are some differences in configuration from the first embodiment, including the number of poles and interphase connections, the relationship between the inlet end ta of the adjacent inlet coil U1 and the outlet end tb of the adjacent outlet coil V4 is similar, with both arranged to have the smallest capacitance to ground. The same applies to the relationship between the adjacent inlet coil V1 and the outlet coil W4, and between the adjacent inlet coil W1 and the outlet coil U4. In other words, in this embodiment as well as in the first embodiment, the capacitance to ground of the inlet end ta and the outlet end tb of the entire coil 12 of each phase is substantially small. As a result, it can be inferred that in this embodiment as well, the interphase potential difference between adjacent different phases is sufficiently suppressed, similar to the first embodiment (see Figure 13), both during the transient period when surges occur and during the steady-state period when surges subside. Similarly, it can be inferred that the concentration of surges not only between phases but also within the same phase is suppressed.

[0041] (Effects of this embodiment) The effects of this embodiment will now be explained. (2-1) Although this embodiment has some configuration differences from the first embodiment described above, it is possible to sufficiently suppress the phase potential difference between adjacent different phases, similar to the effect (1-1) of the first embodiment. In this embodiment as well, the electrical characteristics of the stator 10B and motor M2 can be improved.

[0042] (2-2) In this embodiment as well, similar to the effect (1-2) of the first embodiment, the configuration can more reliably suppress the interphase potential difference between adjacent different phases. (2-3) In this embodiment as well, similar to the effects of the first embodiment (1-3) above, it is possible to contribute to making the stator 10A, and by extension the entire motor M1, smaller and lighter.

[0043] (2-4) In this embodiment as well, similar to the effects of the first embodiment (1-4) above, connection work related to the inlet end ta and outlet end tb of the coil 12 of each phase, wiring work of the conductor 12a, etc. can be made easier.

[0044] (Third embodiment) The following describes a third embodiment of the stator and motor. The motor M3 of this embodiment will be described primarily in terms of its differences from the motor M1 of the first embodiment.

[0045] (Configuration of motor M3 and rotor 20C) The motor M3 of this embodiment comprises a stator 10C and a rotor 20C. The rotor 20C of this embodiment is equipped with, for example, an 8-pole magnetic pole section using permanent magnets 23.

[0046] (Configuration of Stator 10C) As shown in Figures 7 and 8, the stator 10C of this embodiment has nine coils 12, each consisting of concentrated windings of conductors 12a around nine teeth 11a, and is equipped with nine coil magnetic poles. Each tooth 11a of this embodiment has a base end that is wider than the annular end 11b, and extends in a substantially trapezoidal shape, gradually narrowing towards the tip. The winding of the conductors 12a around the substantially trapezoidal teeth 11a of this embodiment is aligned winding. In the coils 12 of each phase, multiple layers, three layers in this embodiment, are stacked on top of the previously wound conductors 12a.

[0047] As shown in Figure 9, the nine coils 12 in this embodiment are configured in a three-phase Y-type connection. The nine coils 12 forming the Y-type connection are connected in three series, three in each of the U-phase, V-phase, and W-phase in this embodiment. The coils 12 in each phase will be described using the notations U1, U2, U3 for the three coils in series in the U-phase, V1, V2, V3 for the three coils in series in the V-phase, and W1, W2, W3 for the three coils in series in the W-phase. That is, in the U-phase, coils U1 to U3 are connected in series, in the V-phase, coils V1 to V3 are connected in series, and in the W-phase, coils W1 to W3 are connected in series.

[0048] As shown in Figure 7, the coils 12 of each phase are arranged in the following order around the stator 10C: coil U1, coil U2, coil U3, coil W1, coil W2, coil W3, coil V1, coil V2, and coil V3. There are three adjacent coils 12 of the same phase, and they are wound in opposite directions. In other words, the polarity that appears when current is applied to adjacent coils of the same phase is opposite. Also, adjacent coils 12 of different phases are wound in the same direction.

[0049] As shown in Figure 8, each phase coil 12 has a pair of ends of the conductor 12a, namely an inlet end ta and an outlet end tb. As shown in Figure 9, the inlet end ta of coil U1 is connected directly to the U-phase motor input terminal tu of motor M1 or via a busbar or the like. The outlet end tb of coil U1 is the end that is continuous with the inlet end ta of coil U2. When coils U1 and U2 are wound continuously with a single conductor 12a, both the outlet end tb of coil U1 and the inlet end ta of coil U2 are located radially outward (see Figure 8), so the routing of the connecting wire 12x in this embodiment can be suppressed to span radially inward and outward. The outlet end tb of coil U2 is the end that is continuous with the inlet end ta of coil U3. Since both the outlet end tb of coil U2 and the inlet end ta of coil U3 are located radially inward, the routing of the connecting wire 12x between them can be suppressed to span radially inward and outward. The outlet end tb of coil U3 is the end that connects to the neutral point tn, which is electrically farther away from the U-phase motor input terminal tu. The same applies to the relationship between the V-phase coils V1 to V3 between the V-phase motor input terminal tv and the neutral point tn, and to the relationship between their respective inlet ends ta and outlet ends tb. The same also applies to the relationship between the W-phase coils W1 to W3 between the W-phase motor input terminal tw and the neutral point tn, and to the relationship between their respective inlet ends ta and outlet ends tb.

[0050] (Detailed configuration of coil 12) As shown in Figure 8, in this embodiment, in coils 12 of different phases, for example, U-phase and V-phase, the inlet coil U1 and the outlet coil V3 are arranged adjacent to each other. As described above, the coil 12 in this embodiment is made up of three layers of wire 12a wound in an aligned winding manner around the teeth portion 11a. The inlet end ta of coil U1 is at the radially innermost position of the outermost layer, that is, the position furthest from both the teeth portion 11a and the annular portion 11b. The outlet end tb of coil U1 is at the radially outermost position of the innermost layer, that is, the position closest to both the teeth portion 11a and the annular portion 11b, due to the winding of the wire 12a. On the other hand, the inlet end ta of coil V3 is at the radially outermost position of the innermost layer, that is, the position closest to both the teeth portion 11a and the annular portion 11b. The outlet end tb of coil V3 is located at the innermost radial point of the outermost layer, that is, the position furthest from both the teeth portion 11a and the annular portion 11b, due to the winding of the conductor 12a.

[0051] Furthermore, the inlet end ta of coil U1 is located on the side of its teeth portion 11a that is on coil V3, and the outlet end tb of coil V3 is located on the side of its teeth portion 11a that is on coil U1. In other words, the inlet end ta of coil U1 and the outlet end tb of coil V3 are physically close together with only a small gap between them. Since these inlet end ta of coil U1 and outlet end tb of coil V3 are located furthest from both the teeth portion 11a and the annular portion 11b, the configuration minimizes the parasitic capacitance to ground for each. The same applies to the relationship with other coils of different phases 12, namely the relationship between the adjacent inlet coil V1 and outlet coil W3. The same also applies to the relationship between the adjacent inlet coil W1 and outlet coil U3.

[0052] (Operation of this embodiment) The operation of this embodiment will now be described. In this embodiment, although there are some differences in configuration from the first embodiment, including the number of poles and coil arrangement, the relationship between the inlet end ta of the adjacent inlet coil U1 and the outlet end tb of the adjacent outlet coil V3 is similar, with both arranged to have the smallest capacitance to ground. The same applies to the relationship between the adjacent inlet coil V1 and the outlet coil W3, and between the adjacent inlet coil W1 and the outlet coil U3. In other words, in this embodiment as well as in the first embodiment, the capacitance to ground of the inlet end ta and the outlet end tb of the entire coil 12 of each phase is substantially small. As a result, it can be inferred that in this embodiment as well, the phase potential difference between adjacent different phases is sufficiently suppressed, similar to the first embodiment (see Figure 13), both during the transient period when surges occur and during the steady-state period when surges subside. Similarly, it can be inferred that the concentration of surges not only between phases but also within the same phase is suppressed.

[0053] (Effects of this embodiment) The effects of this embodiment will now be explained. (3-1) Although this embodiment has some configuration differences from the first embodiment described above, it is possible to sufficiently suppress the phase potential difference between adjacent phases, similar to the effect (1-1) of the first embodiment. In this embodiment as well, the electrical characteristics of the stator 10C and motor M3 can be improved.

[0054] (3-2) In this embodiment as well, similar to the effect (1-2) of the first embodiment, the configuration can more reliably suppress the interphase potential difference between adjacent different phases. (3-3) In this embodiment as well, similar to the effects of the first embodiment (1-3) above, it is possible to contribute to making the stator 10A, and by extension the entire motor M1, smaller and lighter.

[0055] (3-4) In this embodiment as well, similar to the effects of the first embodiment (1-4) above, connection work related to the inlet end ta and outlet end tb of the coil 12 of each phase, wiring work of the conductor 12a, etc. can be made easier.

[0056] (Fourth Embodiment) The following describes a fourth embodiment of the stator and motor. The motor M4 of this embodiment will be described focusing on the differences from the motor M1 of the first embodiment.

[0057] (Configuration of motor M4 and rotor 20D) The motor M4 of this embodiment comprises a stator 10D and a rotor 20D. The rotor 20D of this embodiment has the same configuration as the first embodiment described above, and is equipped with, for example, a 14-pole magnetic pole section made of permanent magnets 23.

[0058] (Configuration of Stator 10D) As shown in Figures 10 and 11, the stator 10D of this embodiment has 12 coils 12, each consisting of concentrated windings of conductors 12a around 12 teeth 11a, and is equipped with 12 coil magnetic poles. The windings of the conductors 12a around each tooth 11a of this embodiment are aligned windings, and in each phase coil 12, multiple layers, three layers in this embodiment, are stacked on top of the previously wound conductors 12a.

[0059] As shown in Figure 12, the 12 coils 12 in this embodiment are configured in a 3-phase delta-type connection configuration. The 12 coils 12 forming a delta-type connection configuration are connected in a 2-series 2-parallel configuration, with 4 coils in each of the U-phase, V-phase, and W-phase. The coils 12 in each phase will be described using the notation: a pair of coils U1 and U2 forming a 2-series 2-parallel connection in the U-phase, a pair of coils V1 and V2 forming a 2-series 2-parallel connection in the V-phase, and a pair of coils W1 and W2 forming a 2-series 2-parallel connection in the W-phase. Specifically, in the U-phase, coils U1 and U2 are connected in series as a pair, and the series-connected coils U1 and U2 are connected in parallel. In the V-phase, coils V1 and V2 are connected in series as a pair, and the series-connected coils V1 and V2 are connected in parallel. In the W-phase, coils W1 and W2 are connected in series as a pair, and the series-connected coils W1 and W2 are connected in parallel.

[0060] As shown in Figure 10, the arrangement of the coils 12 of each phase in the circumferential direction of the stator 10D is the same as in the first embodiment described above. There are two adjacent coils 12 of the same phase, and these are coils U1 and U2, coil V1 and V2, and coil W1 and W2, which are connected in series with each other within the same phase. Furthermore, adjacent coils 12 of the same phase connected in series are wound in opposite directions. On the other hand, adjacent coils 12 of different phases are wound in the same direction.

[0061] As shown in Figure 11, each phase coil 12 has a pair of ends of the conductor 12a, namely an inlet end ta and an outlet end tb. As shown in Figure 12, the inlet end ta of coil U1 is connected directly to the U-phase motor input terminal tu of motor M1 or via a busbar or the like. The outlet end tb of coil U1 is the end that is continuous with the inlet end ta of coil U2. When coils U1 and U2 are wound continuously with a single conductor 12a, both the outlet end tb of coil U1 and the inlet end ta of coil U2 are located radially outward (see Figure 11), so the routing of the jumper wire 12x in this embodiment can be suppressed to span radially inward and outward. The outlet end tb of coil U2 is the end that connects to the V-phase motor input terminal tv of the opposite phase, which is electrically farther away from the U-phase motor input terminal tu of the same phase. The pair of coils U1 and U2, connected in series, are positioned 180° opposite each other on the stator 10D and are connected to each other by a conductor 12a, or in parallel between the motor input terminal tu of the same phase and the motor input terminal tv of the opposite phase using a busbar or the like. The same applies to the relationship between the V-phase coils V1 and V2, and the relationship between their respective inlet end ta and outlet end tb, between the V-phase motor input terminal tv of the same phase and the W-phase motor input terminal tw of the opposite phase. The same also applies to the relationship between the W-phase coils W1 and W2, and the relationship between their respective inlet end ta and outlet end tb, between the W-phase motor input terminal tw of the same phase and the U-phase motor input terminal tu of the opposite phase.

[0062] (Detailed configuration of coil 12) As shown in Figure 11, in this embodiment as in the first embodiment described above, the inlet coil U1 and the outlet coil V2 are arranged adjacent to each other in coils 12 of different phases, for example, U-phase and V-phase. In this embodiment as well, the inlet end ta of coil U1 and the outlet end tb of coil V2 are located at the innermost radial point of the outermost layer, that is, at the position furthest from both the teeth portion 11a and the annular portion 11b, and are physically close to each other with a small gap between them. The inlet end ta of coil U1 and the outlet end tb of coil V2 are configured such that the parasitic capacitance to ground is minimized. The same applies to the relationship between adjacent inlet coil V1 and outlet coil W2, and between adjacent inlet coil W1 and outlet coil U2.

[0063] (Operation of this embodiment) The operation of this embodiment will now be described. Although this embodiment differs slightly from the first embodiment, including the three-phase connection, the relationship between the inlet end ta of the adjacent inlet coil U1 and the outlet end tb of the adjacent outlet coil V2 is similarly arranged to minimize the capacitance to ground. The same applies to the relationship between the adjacent inlet coil V1 and the outlet coil W2, and between the adjacent inlet coil W1 and the outlet coil U2. In other words, in this embodiment as well as in the first embodiment, the capacitance to ground of the inlet end ta and the outlet end tb of the coil 12 for each phase as a whole is substantially small. As a result, it can be inferred that in this embodiment as well, the interphase potential difference between adjacent phases is sufficiently suppressed, similar to the first embodiment (see Figure 13), both during the transient period when surges occur and during the steady-state period when surges subside. Similarly, it can be inferred that the concentration of surges not only between phases but also within the same phase is suppressed.

[0064] (Effects of this embodiment) The effects of this embodiment will now be explained. (4-1) Although this embodiment has some configuration differences from the first embodiment described above, it is possible to sufficiently suppress the phase potential difference between adjacent different phases, similar to the effect (1-1) of the first embodiment. In this embodiment as well, the electrical characteristics of the stator 10D and the motor M4 can be improved.

[0065] (4-2) In this embodiment as well, similar to the effect (1-2) of the first embodiment, the configuration can more reliably suppress the interphase potential difference between adjacent different phases. (4-3) In this embodiment as well, similar to the effects of the first embodiment (1-3) above, it is possible to contribute to making the stator 10A, and by extension the entire motor M1, smaller and lighter.

[0066] (4-4) In this embodiment as well, similar to the effects of the first embodiment (1-4) above, connection work related to the inlet end ta and outlet end tb of the coil 12 of each phase, wiring work of the conductor 12a, etc. can be made easier.

[0067] (Example of change) This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0068] The inlet end ta of the adjacent first-phase inlet coil 12 and the outlet end tb of the second-phase outlet coil 12 are set to positions that are most offset towards the tip of the teeth portion 11a. While positions offset towards the tip are preferable, they do not necessarily have to be the most offset positions.

[0069] The inlet end ta of the adjacent first-phase inlet coil 12 and the outlet end tb of the second-phase outlet coil 12 are positioned close to each other and facing each other between adjacent teeth portions 11a to which they are mounted. However, they may also be positioned on opposite sides of the teeth portion 11a.

[0070] • The inlet end ta and outlet end tb of each phase coil 12 are drawn out in a unified direction on one side of the stator core 11's axial direction, but they may be drawn out on both sides of the axial direction as appropriate.

[0071] Regarding the stator core 11, the annular portion 11b was designed to extend radially outward and the teeth portion 11a to extend radially inward. However, a stator core with the annular portion extending radially inward and the teeth portion extending radially outward may also be used.

[0072] The above embodiments are applied to motors M1 to M4 for three-phase drive, and the number of each magnetic pole can be appropriately changed within the range where the ratio of the number of magnetic poles of the rotor to the number of coil magnetic poles of the stator satisfies (12±2)n:12n or (6n+3)±1:6n+3. However, n is an integer of 1 or more. Motors M1, M2, and M4 in the first, second, and fourth embodiments are set by the first equation, and motor M3 in the third embodiment is set by the second equation.

[0073] • This may be applied not only to motors M1 to M4 for 3-phase drive, but also to multi-phase drive motors other than 3-phase. For example, it may be a 5-phase drive. In a 5-phase drive, the ratio of the number of magnetic poles of the rotor to the number of coil magnetic poles of the stator is set to satisfy (20±2)n:20n.

[0074] (Note) The technical concepts that can be understood from the above embodiments and modified examples are described below. [1] A stator core (11) having a plurality of teeth (11a) and an annular portion (11b) that connects the base ends of the plurality of teeth to each other, It comprises multiple coils (12, U1~U4, V1~V4, W1~W4) in which multiple layers of conductor wire (12a) are wound around each of the multiple teeth portions in a concentrated winding manner, A stator (10A~10D) is configured such that a plurality of the coils are connected in a multiphase configuration and generate a rotating magnetic field through the plurality of coils based on multiphase drive power obtained from multiphase motor input terminals (tu, tv, tw), When the ends of the coils and their conductors on the side electrically closer to the motor input terminal of the same phase are designated as the inlet coils (U1, V1, W1) and inlet end (ta), respectively, and the ends of the coils and their conductors on the side electrically farther from the motor input terminal of the same phase are designated as the outlet coils (U2~U4, V2~V4, W2~W4) and outlet end (tb), respectively, A stator in which, in the circumferentially adjacent coils of different phases, the inlet end of the inlet coil of the first phase and the outlet end of the outlet coil of the second phase are both positioned on the outermost layer and offset toward the tip of the teeth portion.

[0075] [2] The stator according to [1] above, wherein, in the coils of different phases adjacent to each other in the circumferential direction, the inlet end of the inlet coil of the first phase and the outlet end of the outlet coil of the second phase are both positioned at the outermost layer and most offset toward the tip of the teeth portion.

[0076] [3] The stator according to [1] or [2] above, wherein, in the coils of different phases adjacent to each other in the circumferential direction, the inlet end of the inlet coil of the first phase and the outlet end of the outlet coil of the second phase are configured to face each other between adjacent teeth portions on which they are mounted.

[0077] [4] The stator according to any one of [1] to [3] above, wherein the inlet end and outlet end of the coil wires are arranged on one axial side of the stator core.

[0078] [5] The stator according to any one of [1] to [4] above, wherein the stator core is configured such that the annular portion is located radially outward and the teeth portion extends radially inward.

[0079] [6] A stator according to any one of [1] to [5] above, wherein the plurality of coils are configured in a three-phase connection configuration.

[0080] [7] A stator (10A~10D) as described in any one of the above [1] to [6], A motor comprising a rotor (20A~20D) that is driven to rotate based on the rotating magnetic field generated by the stator.

[0081] [8] The stator comprises a coil pole section consisting of a plurality of coils arranged in a three-phase connection configuration, The rotor comprises a magnetic pole portion made of a permanent magnet (23), The motor according to [7] above, wherein the ratio of the number of magnetic poles of the magnet and the number of magnetic poles of the coil satisfies (12±2)n:12n (where n is an integer of 1 or more). [Explanation of Symbols]

[0082] 10A~10D Stator, 11 Stator core, 11a Teeth section, 11b Annular section, 12 Coil, 12a Wire, 20A~20D Rotor, 23 Permanent magnet, U1, V1, W1 Coil (inlet coil), U2~U4, V2~V4, W2~W4 Coil (outlet coil), ta Inlet end, tb Outlet end, tu, tv, tw Motor input terminals

Claims

1. A stator core (11) having a plurality of teeth (11a) and an annular portion (11b) that connects the base ends of the plurality of teeth to each other, It comprises multiple coils (12, U1 to U4, V1 to V4, W1 to W4) in which multiple layers of conductor wire (12a) are wound around each of the multiple teeth portions in a concentrated winding manner, A stator (10A to 10D) is configured such that a plurality of the coils are connected in a three-phase configuration, and a rotating magnetic field is generated through the plurality of coils based on three-phase drive power obtained from three-phase motor input terminals (tu, tv, tw), When the ends of the coils and their conductors on the side electrically closer to the motor input terminal of the same phase are designated as the inlet coils (U1, V1, W1) and inlet end (ta), respectively, and the ends of the coils and their conductors on the side electrically farther from the motor input terminal of the same phase are designated as the outlet coils (U2-U4, V2-V4, W2-W4) and outlet end (tb), respectively, A stator in which, in the circumferentially adjacent coils of different phases, the inlet end of the inlet coil of the first phase and the outlet end of the outlet coil of the second phase are both positioned on the outermost layer and offset toward the tip of the teeth portion.

2. The stator according to claim 1, wherein, in the coils of different phases adjacent to each other in the circumferential direction, the inlet end of the inlet coil of the first phase and the outlet end of the outlet coil of the second phase are both positioned at the outermost layer and most offset toward the tip of the teeth portion.

3. The stator according to claim 1, wherein, in the circumferentially adjacent coils of different phases, the inlet end of the inlet coil of the first phase and the outlet end of the outlet coil of the second phase are configured to face each other between adjacent teeth portions on which they are mounted.

4. The stator according to claim 1, wherein the inlet end and outlet end of the conductor wire of the coil are arranged on one axial side of the stator core.

5. The stator according to claim 1, wherein the stator core is configured such that the annular portion is located radially outward and the teeth portion extends radially inward.

6. A stator (10A to 10D) according to any one of claims 1 to 5, A motor comprising rotors (20A to 20D) that are driven to rotate based on the rotating magnetic field generated by the stator.

7. The stator comprises a coil pole section consisting of a plurality of coils arranged in a three-phase connection configuration, The rotor comprises a magnetic pole portion made of a permanent magnet (23), The motor according to claim 6, wherein the ratio of the number of magnetic pole portions to the number of coil magnetic pole portions is (12±2)n:12n (where n is an integer of 1 or more).

Images