STATOR DESIGNED TO MINIMIZE LEAKAGE CURRENT AND ELECTRIC ROTATING MACHINE USING SAME

• US 20110163625A1
• Filed: 01/05/2011
• Published: 07/07/2011
• Est. Priority Date: 01/07/2010
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: FUKUSHIMA, Akira, Kondo, Keiji, Akimoto, Akito, Kusase, Shin, Maekawa, Takeo, Taniguchi, Makoto
• Granted Patent: US 8,610,326 B2
• Time in Patent Office: Days
• US Class Current: 310/198
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32
• CPC Class Codes: H02K 3/345 between conductor and core, e.g. slot insulation

Abstract

A stator which may be employed in an electric rotating machine. The stator includes a stator winding which includes in-slot portions disposed in slots of a stator core. The in-slot portions are arrayed in each of the slots in a form of multiple layers aligned in a radial direction of the stator core. The stator winding is made up of a first winding and a second winding which are connected together through a joint. The first winding is defined by a portion of the stator winding between the joint and an end of the stator winding which is to be connected to an external. The second winding includes the in-slot portion placed within at least one of the slots as an outermost layer that is one of the layers placed most outwardly in the radial direction of the stator core. This results in a great decrease in leakage current.

Claims

1. A stator comprising:

a cylindrical stator core which has a plurality of slots arrayed in a circumferential direction of the stator core; and

a stator winding which includes in-slot portions disposed in the slots of the stator core and turned portions connecting the in-slot portions outside the slots, the in-slot portions being arrayed in each of the slots in a form of multiple layers aligned in a radial direction of the stator core, the stator winding having a length made up of a first winding and a second winding, the first winding being defined by a portion of the stator winding which is closer to an end of the stator winding which is to be connected to an external, the second winding being defined by a portion of the stator winding which is farther from the end of the stator and including the in-slot portion placed within at least one of the slots as an outermost layer that is one of the layers placed most outwardly in the radial direction of the stator core.

2. A stator as set forth in claim 1, wherein the stator winding is a three-phase winding made up of a first-phase winding, a second-phase winding, and a third-phase winding, and wherein the second winding includes the in-slot portions placed in all of the slots for the first-phase winding and the second-phase winding except one of the slots as outermost layers that are ones of the layers placed most outwardly in radial direction of the stator core.

3. A stator as set forth in claim 2, wherein the in-slot portions of the second winding and the in-slot portions of the first winding are aligned alternately in the radial direction of the stator core.

4. A stator as set forth in claim 1, wherein the second winding includes the in-slot portions placed in all of the slots as outermost layers that are ones of the layers placed most outwardly in radial direction of the stator core.

5. A stator as set forth in claim 4, wherein the in-slot portions placed in each of the slots are broken down into a first group and a second group, the first group defining the first winding and being placed outward of the slot in the radial direction of the stator core, the second group defining the second winding and being placed inward of the slot in the radial direction of the stator core.

6. A stator as set forth in claim 1, wherein the stator winding is rectangular in transverse cross section thereof, the in-slot portions being so arrayed in each of the slots that long sides of transverse cross sections of the in-slot portions extend substantially perpendicular to the radial direction of the stator core.

7. A stator as set forth in claim 1, wherein the stator winding is made of wire segments star-connected, and wherein the second winding is defined by a portion of the stator winding closer to a neutral point.

8. A stator as set forth in claim 1, wherein each of the slots has a width, as defined in the circumferential direction of the stator core, the width increasing in a radially outward direction of the stator core.

9. A stator as set forth in claim 8, further comprising an electric insulator which has an inner chamber in which an array of the in-slot portions is disposed.

10. A stator as set forth in claim 9, wherein the electric insulator is made of an assembly of an inner insulator and an outer insulator, the inner insulator being of a U-shape in transverse cross section, as taken perpendicular to an axial direction of the stator core, and having an end which opens outwardly of the stator core, the outer insulator being of a U-shape in transverse cross section, as taken perpendicular to the axial direction of the stator core, and having an end which opens inwardly of the stator core.

11. A stator as set forth in claim 10, wherein the inner insulator has side walls extending in the radial direction of the stator core, the outer insulator having side walls extending in the radial direction of the stator core, and wherein ends of the side walls of the inner insulator are laid to overlap with ends of the side walls of the outer insulator in the circumferential direction of the stator core.

12. A stator as set forth in claim 11, wherein the ends of the side walls of the inner insulator are folded back.

13. A stator as set forth in claim 12, wherein the ends of the side walls of the inner insulator are folded inwardly of the inner insulator.

14. An electric rotating machine comprising:

a stator including a cylindrical stator core which has a plurality of slots arrayed in a circumferential direction of the stator core, and a stator winding which includes in-slot portions disposed in the slots of the stator core and turned portions connecting the in-slot portions outside the slots, the in-slot portions being arrayed in each of the slots in a form of multiple layers aligned in a radial direction of the stator core, the stator winding having a length made up of a first winding and a second winding, the first winding being defined by a portion of the stator winding which is closer to an end of the stator winding which is to be connected to an external, the second winding being defined by a portion of the stator winding which is farther from the end of the stator and including the in-slot portion placed within at least one of the slots as an outermost layer that is one of the layers placed most outwardly in the radial direction of the stator core; and

a rotor disposed radially inside the stator, the rotor being equipped with S-poles and N-poles which are arrayed alternately in a circumferential direction of the rotor.