Motor with simplified structure and related control device

Abstract

A brushless motor and a related control device are disclosed in a structure wherein a stator has U-phase, V-phase and W-phase stator poles, with two of the U-phase V-phase and W-phase stator poles carry thereon respective phase windings, in the absence of a selected phase winding related to a remaining one of the U-phase V-phase and W-phase stator poles. The respective phase windings have end portions connected together at a junction point. A three-phase alternating voltage is applied to the respective phase windings and the junction point to allow the stator to have an electromagnetic action thereby drivably rotating a rotor. The stator poles may be formed in trapezoid shapes to minimize interference between associated component parts for easy assembly in high productivity and efficiency with a reduction in torque ripple.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a deployment diagram showing a three-phase alternating current motor of a first embodiment according to the present invention with a stator deployed in a circumferential direction thereof in terms of electric angles.

FIG. 2 is another deployment diagram showing a modified form of the three-phase alternating current motor of the first embodiment shown in FIG. 1.

FIG. 3 is a deployment diagram showing a three-phase alternating current motor of a second embodiment according to the present invention with a stator deployed in a circumferential direction thereof in terms of electric angles.

FIG. 4 is a deployment diagram showing a modified form of the three-phase alternating current motor of the second embodiment shown in FIG. 3.

FIG. 5 is a deployment diagram showing a three-phase alternating current motor of a third embodiment according to the present invention with a stator deployed in a circumferential direction thereof in terms of electric angles.

FIG. 6 is a deployment diagram showing a three-phase alternating current motor of a fourth embodiment according to the present invention with a stator deployed in a circumferential direction thereof in terms of electric angles.

FIG. 7 is a deployment diagram showing a three-phase alternating current motor of a fifth embodiment according to the present invention with a stator deployed in a circumferential direction thereof in terms of electric angles.

FIG. 8 is a deployment diagram showing a modified form of the three-phase alternating current motor of the fifth embodiment shown in FIG. 7.

FIG. 9 is a deployment diagram showing another modified form of the three-phase alternating current motor of the fifth embodiment shown in FIG. 7.

FIG. 10 is a deployment diagram showing still another modified form of the three-phase alternating current motor of the fifth embodiment shown in FIG. 7.

FIG. 11 is a deployment diagram showing a three-phase alternating current motor of a sixth embodiment according to the present invention with a stator deployed in a circumferential direction thereof in terms of electric angles.

FIG. 12 is a schematic diagram showing one set of windings that are excited with first and second excitation currents upon receipt of first and second excitation voltages, respectively.

FIG. 13 is a schematic diagram showing a three-phase brushless motor with first and second phase windings to which three-phase alternating voltage is applied.

FIG. 14 is a schematic diagram showing the relationship between two-phase currents, flowing through a three-phase brushless motor with first and second phase windings, and a three-phase alternating voltage.

FIG. 15 is a schematic diagram showing the relationship between the two-phase currents, flowing through the three-phase brushless motor with first and second phase windings, and the three-phase alternating voltage.

FIG. 16 is a circuit diagram of a three-phase inverter serving as a control device for the three-phase alternating current motor with the two windings shown in FIG. 13.

FIG. 17 is a schematic view showing a three-phase alternating current motor with four windings excited with two-phase currents in response to a three-phase alternating voltage.

FIG. 18 is a schematic cross sectional view showing a two-phase motor with four stator poles of a seventh embodiment according to the present invention.

FIG. 19 is a deployment diagram showing the two-phase motor, shown in FIG. 18, with a stator deployed in a circumferential direction thereof in terms of electric angles.

FIGS. 20A to 20C are schematic winding diagrams showing a basic sequence of assembling first and second windings and stator poles of the two-phase motor shown in FIG. 19.

FIG. 21 is a schematic winding diagram showing a modified form of the two-phase motor shown in FIG. 20C.

FIG. 22 is an exploded schematic view showing a stator core formed in plural stator core elements each formed with stator poles.

FIGS. 23A to 23C are schematic views showing a basic sequence of assembling stator core elements.

FIG. 24 is a schematic cross sectional view showing a stator core in an assembled state.

FIG. 25 is an exploded perspective view showing a step of forming a winding.

FIG. 26 is a schematic view showing a split type stator core forming a modified form of the brushless motor shown in FIGS. 23A to 23C.

FIG. 27 is a cross sectional view showing a schematic structure of the related art brushless motor.

FIG. 28 is a cross sectional view showing a schematic structure of the related art brushless motor shown in FIG. 27.

FIG. 29 is a deployment view of a stator showing the relationship between stator poles and windings of the related art motor shown in FIG. 28.

FIG. 30 is a cross sectional view showing a schematic structure of another brushless motor of the related art.

FIG. 31 is a deployment view of a stator showing the relationship between stator poles and windings of the related art motor shown in FIG. 30.

FIG. 32 is a deployment view of a stator showing the relationship between stator poles and windings of another motor of the related art.

FIG. 33 is a deployment view of a stator showing the relationship between stator poles and windings of still another motor of the related art.

Claims

1. A three-phase alternating current motor, comprising: a stator including first phase stator poles carrying thereon a first phase winding selected from a U-phase winding, a V-phase winding and a W-phase winding, second phase stator poles carrying thereon a second phase winding selected from the U-phase winding, the V-phase winding and the W-phase winding and third phase stator poles in the absence of a third phase winding selected from the U-phase winding, the V-phase winding and the W-phase winding; anda rotor rotatably supported inside the stator poles of the stator;wherein the first and second phase windings are excited with excitation currents upon synthesizing a three-phase alternating current to allow the stator to electromagnetically generate a three-phase alternating electromagnetic action through which the rotor is driven.

2. The three-phase alternating current motor according to claim 1, wherein: the stator poles of the stator are formed in at least one of substantially triangular shapes, trapezoid shapes and rhombic shapes.

3. The three-phase alternating current motor according to claim 1, wherein: the stator has at least three stator poles formed in an area at an electrical angle of 360°.

4. The three-phase alternating current motor according to claim 3, wherein: the first and second phase windings comprise the U-phase winding and the W-phase winding, respectively, wherein the first phase stator poles carry the U-phase winding so as to form a coil end portion on one axial side of the stator and the second phase stator poles carry the W-phase winding so as to form another coil end portion on the other axial side of the stator such that the U-phase winding and the W-phase winding do not intersect with each other in a circumferential direction of the stator or in an axial direction of the rotor.

5. The three-phase alternating current motor according to claim 4, wherein: the stator includes U-phase stator poles that are formed in one of a substantially triangular shape and a substantially trapezoid shape.

6. The three-phase alternating current motor according to claim 4, wherein: the first phase stator poles include U-phase stator poles carrying thereon the U-phase winding and the second phase stator poles include V-phase stator poles carrying thereon the V-phase winding;each of the U-phase stator poles and the W-phase stator poles is formed in one of substantially triangular shapes and substantially trapezoid shapes; andthe U-phase winding and the W-phase winding are wound on the U-phase stator poles and the V-phase stator poles in wave winding patterns, respectively; andthe V-phase stator poles carry the third phase winding formed in a concentrated winding.

7. The three-phase alternating current motor according to claim 6, wherein: the stator includes a first V-phase winding placed in parallel to the U-phase winding and a second V-phase winding placed in parallel to the W-phase winding.

8. The three-phase alternating current motor according to claim 1, wherein: the first and second phase windings having end portions connected together at a neutral point; andthe three-phase synthesized currents are applied to the first and second phase windings and the neutral point.

9. The three-phase alternating current motor according to claim 1, wherein: the first phase stator poles include U-phase stator poles carrying thereon the U-phase winding, the second phase stator poles include W-phase stator poles carrying thereon the W-phase winding and the third phase stator pole include V-phase stator poles in the absence of the V-phase winding; andwherein the U-phase winding is excited with a U-phase excitation current and a V-phase excitation current in negative potential and the W-phase winding is excited with a W-phase excitation current and the V-phase excitation current in negative potential to electromagnetically generate the three-phase alternating electromagnetic action on the stator.

10. The three-phase alternating current motor according to claim 1, wherein: the first phase stator poles include U-phase stator poles carrying thereon the U-phase winding, the second phase stator poles include W-phase stator poles carrying thereon the W-phase winding and the third phase stator pole include V-phase stator poles in the absence of the V-phase winding;the U-phase winding and the W-phase winding have terminal end portions connected together at a common junction point; andwherein the U-phase winding, the common junction point and the W-phase winding are excited with a three-phase alternating drive current to electromagnetically generate the three-phase alternating electromagnetic action on the stator.

11. The three-phase alternating current motor according to claim 1, wherein: the stator includes four windings composed of the first phase winding serving as the U-phase winding having a leading end connected to a U-phase terminal, the second phase winding serving as the W-phase winding having a leading end connected to a W-phase terminal, a first split V-phase winding placed in parallel to the U-phase winding and having a leading end connected to a U-phase terminal, and a second split V-phase winding placed in parallel to the W-phase winding;the first split V-phase winding has a trailing end connected to a trailing end of the second split V-phase winding that has a leading end connected to a neutral terminal to which a leading end of the U-phase winding and a trailing end of the W-phase winding are connected; andwherein a three-phase alternating drive current is applied to the U-phase terminal, the V-phase terminal and the W-phase terminal to generate the three-phase alternating electromagnetic action on the stator.

12. A two-phase alternating current motor comprising: a stator having stator poles, each formed in one of a substantially triangular shape and a substantially trapezoid shape, which carry an A-phase winding and a B-phase winding that are wound on the stator poles in wave winding patterns, respectively; anda rotor rotatably disposed inside the stator poles of the stator.

13. The two-phase alternating current motor according to claim 12, wherein: the A-phase winding and the B-phase winding have end coil portions, respectively, having winding portions at least a part of which is located inward from an axial end face of the stator.

14. The two-phase alternating current motor according to claim 12, wherein: the stator poles comprise split stator poles, respectively, which are assembled to the stator in one piece.

15. The two-phase alternating current motor according to claim 12, wherein: the A-phase winding and the B-phase winding comprise coils, respectively, which are formed through the use of a forming unit.

16. A control device for a brushless motor having a stator formed with a U-phase stator pole carrying thereon a U-phase winding, a V-phase stator and a W-phase stator carrying thereon a W-phase winding wherein the first and second phase windings having end portions connected to each other at a junction point, the control device comprising: a three-phase inverter including a first output terminal connected to the junction point to which the first and second phase windings are connected, a second output terminal connected to the first phase winding, and a third output terminal connected to the second phase winding.