Stator of rotating electric machine and manufacturing method of the stator

• US 20050264123A1
• Filed: 05/26/2005
• Published: 12/01/2005
• Est. Priority Date: 06/01/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Asao, Yoshihito, Maeda, Naohide
• Granted Patent: US 7,239,059 B2
• Time in Patent Office: Days
• US Class Current: 310/180
• CPC Class Codes: H02K 15/022 with salient poles or claw-shaped poles
• CPC Class Codes: H02K 3/522 for generally annular cores with salient poles
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

A plurality of coils concentratedly wound around individual teeth are formed as coil units having a common shape, each of the coil units being made by winding a conductor in a generally rectangular form, stacking one conductor line on top of another, and each of the coil units having two parallel straight portions inserted into the slots on both sides of each tooth. The two parallel straight portions of the conductor of each coil unit are fitted in two adjacent slots in such a way that one straight portion of the conductor is laid in an inner layer in one of the two adjacent slots and the other straight portion of the conductor is laid in an outer layer in the other of the two adjacent slots.

Claims

1. A stator of a rotating electric machine, said stator comprising:

a stator core including a cylinder-shaped back yoke a plurality of teeth extending radially inward from inside the back yoke and a plurality of slots each formed between any two adjacent teeth; and

a plurality of coils fitted in the slots such that the individual teeth are concentratedly wound by the coils;

wherein the individual coils are formed as coil units having a common shape, each of the coil units being made by winding a conductor in a generally rectangular form, stacking one conductor line on top of another, and each of the coil units having two parallel straight portions inserted into the slots on both sides of each tooth; and

wherein the two parallel straight portions of the conductor of each coil unit are fitted in two adjacent slots in such a way that one straight portion of the conductor is laid in an inner layer in one of the two adjacent slots and the other straight portion of the conductor is laid in an outer layer in the other of the two adjacent slots.

2. The stator of the rotating electric machine according to claim 1, wherein the conductor has flat surfaces so that multiple layers of conductor lines are stacked one on top of another with the flat surfaces of the conductor lines placed face to face with each other.

3. The stator of the rotating electric machine according to claim 1, wherein both outgoing ends of each coil unit are taken out of two adjacent slots at one axial end of the stator core.

4. The stator of the rotating electric machine according to claim 3, wherein one outgoing end of each coil unit is taken out from an innermost layer in one of the two adjacent slots whereas the other outgoing end of the same coil unit is taken out from an outermost layer in the other one of the two adjacent slots.

5. The stator of the rotating electric machine according to claim 3, wherein both outgoing ends of each coil unit are taken out from about the middle of inner and outer layers of each successive slot.

6. The stator of the rotating electric machine according to claim 1, wherein both outgoing ends of each coil unit are taken out of each successive slot from opposite axial ends of the stator core.

7. The stator of the rotating electric machine according to claim 1, wherein the stator core is cut at least along one axial line, forming facing cut surfaces on both cut ends of the stator core, and the facing cut surfaces are joined to each other.

8. The stator of the rotating electric machine according to claim 7, wherein the facing cut surfaces are formed in one of the teeth.

9. The stator of the rotating electric machine according to claim 7, wherein the facing cut surfaces are formed at the bottom of one of the slots.

10. The stator of the rotating electric machine according to claim 7, wherein one of the facing cut surfaces is formed on one side of the back yoke extending sideways from a basal part of one tooth while the other cut surface is formed on the opposite side of the back yoke at a basal part of the adjacent tooth.

11. A method of manufacturing a stator of a rotating electric machine, said stator comprising a stator core including a cylinder-shaped back yoke, a plurality of teeth extending radially inward from inside the back yoke and a plurality of slots each formed between any two adjacent teeth, and a plurality of coils fitted in the slots such that the individual teeth are concentratedly wound by the coils, the individual coils being formed as coil units having a common shape, said method comprising the steps of:

producing each of the coil units by winding a conductor in a generally rectangular form, stacking one conductor line on top of another, in such a fashion that the conductor thus shaped has two parallel straight portions to be inserted into the slots on both sides of each tooth;

producing the stator core stretched in a straight line by laminating a plurality of stator core segments made of electromagnetic steel sheets, each of the stator core segments having a linear-shaped back yoke portion and a plurality of tooth portions extending from the back yoke portion at right angles thereto;

arranging the coil units in line such that one straight portion of the conductor of the coil unit to be wound on one tooth lies underneath one straight portion of the conductor of the one coil unit to be wound on one adjacent tooth, and the other straight portion of the conductor of the coil unit lies on top of one straight portion of the conductor of the coil unit to be wound on the other adjacent tooth, and inserting the coil units thus arranged into the successive slots such that one straight portion of the conductor of each coil unit is laid in an inner layer in one of two adjacent slots and the other straight portion of the conductor is laid in an outer layer in the other of the two adjacent slots; and

shaping the stator core in which the coil units have been inserted into a cylindrical form such that end surfaces of the stator core initially stretched in a straight line are placed face to face with each other, and joining the facing end surfaces of the stator core to each other.

12. The method of manufacturing the stator of the rotating electric machine according to claim 11, said method further comprising the step of deforming the coil units before inserting the individual coil units such that one straight portion of the conductor of each coil unit is laid in the inner layer in one of two adjacent slots and the other straight portion of the conductor is laid in the outer layer in the other of the two adjacent slots.

13. The method of manufacturing the stator of the rotating electric machine according to claim 11, wherein the individual coil units are deformed such that one straight portion of the conductor of each coil unit is laid in the inner layer in one of two adjacent slots and the other straight portion of the conductor is laid in the outer layer in the other of the two adjacent slots when the coil units arranged in line are forced into the successive slots.