Rotating electric machine, motor-driven vehicle and resin insert-molding method

• US 20040124733A1
• Filed: 03/20/2003
• Published: 07/01/2004
• Est. Priority Date: 12/25/2002
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamamoto, Noriaki, Koizumi, Osamu, Tajima, Fumio
• Application Number:
  US10/392,183
• Publication Number:
  US 20040124733A1
• Time in Patent Office: Days
• US Class Current: 310/218
• CPC Class Codes: B29C 70/72 Encapsulating inserts having non-encapsulated projections, e.g. extremities or terminal portions of electrical components B29C70/742 takes precedence
• CPC Class Codes: B29L 2031/3412 Insulators
• CPC Class Codes: B29L 2031/749 Motors
• CPC Class Codes: B60K 17/356 having fluid or electric motor, for driving one or more wheels disposition of motor in, or adjacent to, traction wheel B60K7/00
• CPC Class Codes: H02K 1/148 Sectional cores H02K1/141 takes precedence
• CPC Class Codes: H02K 15/12 Impregnating, heating or drying of windings, stators, rotors or machines
• CPC Class Codes: H02K 3/522 for generally annular cores with salient poles
• CPC Class Codes: H02K 9/227 Heat sinks
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine

Abstract

A rotating electric machine comprises: a stator including a stator iron core having a plurality of slots and a stator winding incorporated in the plurality of slots; and a rotor rotatably disposed in the stator via a clearance; wherein a mold (i.e., a slot insulator) made of an insulating resin is brought into close contact with the surface of a projection (i.e., a tooth core) of the stator iron core, formed between the adjacent slots, the thickness of the mold at a portion of the projection wound with the stator winding being smaller than that of the mold at other portions. Thus, it is possible to provide the rotating electric machine in which thermal resistance generated between the stator winding and the stator iron core can be reduced, thermal transmittance of heat generated in the stator winding to the stator iron core can be enhanced, and the cooling efficiency of the stator winding can be enhanced.

Claims

1. A rotating electric machine comprising:

a stator including a stator iron core having a plurality of slots and stator windings incorporated in the plurality of slots; and

a rotor rotatably disposed in the stator via a clearance;

wherein a mold made of an insulating resin is brought into close contact with the surface of a projection of the stator iron core, the projection being formed between the adjacent slots,

the thickness of the mold at a portion of the projection wound with the stator windings being smaller than that of the mold at other portions.

2. A rotating electric machine as claimed in claim 1, wherein the thickness of the mold at the portion of the projection wound with the stator winding is 0.3 mm or smaller.

3. A rotating electric machine as claimed in claim 1, wherein the thickness of the mold at the portion of the projection wound with the stator winding ranges from 0.2 mm to 0.3 mm.

4. A rotating electric machine as claimed in claim 1, wherein the stator winding is wound around the projection in a concentric manner.

5. A rotating electric machine as claimed in claim 1, wherein the mold includes a winding portion to be wound with the stator winding and a winding frame formed integrally with the winding portion, the winding frame guiding the stator winding to the winding portion during winding work of the stator winding and holding the stator winding wound around the winding portion.

6. A rotating electric machine as claimed in claim 1, wherein the stator iron core includes an annular yoke and a plurality of teeth, which form the plurality of projections projecting from the yoke in one radial direction and form the plurality of slots, the plurality of teeth being formed separately from the yoke and disposed in the yoke.

7. A rotating electric machine as claimed in claim 6, wherein each of the teeth is molded by inserting the insulating resin at the surface of a laminate formed by laminating a plurality of iron cores.

8. A rotating electric machine as claimed in claim 7, wherein each of the teeth has an assembly guide for guiding the assembly work in the yoke, the assembly guide being molded integrally with the mold with the insulating resin.

9. A rotating electric machine as claimed in claim 7, wherein each of the teeth has a connection fixing portion for fixing connecting parts for use in connecting terminals of the stator winding to each other, the connection fixing portion being molded integrally with the mold with the insulating resin.

10. A rotating electric machine as claimed in claim 7, wherein grooves are formed at the surface of each of the teeth, at which the insulating resin is inserted and around which the stator winding is wound, and at both surfaces of a core laminated thick surface formed by laminating the iron cores in such a manner as to be continuously formed from one laminating end of the iron core to the other laminating end of the iron core, and further, in such a manner that a position in the radial direction of the stator at one surface are different from that at the other surface.

11. A rotating electric machine as claimed in claim 7, wherein grooves are formed continuously in the laminating direction of the iron cores at the surface of each of the teeth, at which the insulating resin is inserted and around which the stator winding is wound, and at a portion in the vicinity of a gate position of the insulating resin molding of a core laminated thick surface formed by laminating the iron cores.

12. A rotating electric machine as claimed in claim 7, wherein grooves are formed at the surface of each of the teeth, at which the insulating resin is inserted and around which the stator winding is wound, and at both surfaces of a core laminated thick surface, formed by laminating the iron cores in such a manner as to be formed continuously in the laminating direction of the iron cores, and further, in such a manner that a position in the radial direction of the stator and a position in the laminating direction of the iron cores are different at one surface from those at the other surface.

13. A rotating electric machine as claimed in claim 6, wherein the yoke includes a laminate consisting of a plurality of annular iron cores split in a circumferential direction, the circumferential position of split parts of the iron core being shifted in each of the iron cores in a brick laying manner, zigzag or stepwise in the laminating direction of the iron cores.

14. A rotating electric machine as claimed in claim 13, wherein the number of split parts of the iron core is m or an integer of 3×

m/2ⁿ (wherein n is a natural number) when the number of teeth is 3×

m (wherein m is an integer of 4 or more).

15. A rotating electric machine as claimed in claim 13, wherein the number of split parts of the iron core is 6 to 12.

16. A motor-driven vehicle comprising:

a vehicle-mounted power source;

an electric machine which is driven in response to an output from the vehicle-mounted power source; and

a transmission mechanism for transmitting an output from the electric motor to drive wheels;

the electric motor including;

a stator including a stator iron core having a plurality of slots and stator windings incorporated in the plurality of slots; and

a rotor rotatably disposed in the stator via a clearance;

wherein a mold made of an insulating resin is brought into close contact with the surface of a projection of the stator iron core, the projection being formed between the adjacent slots,

the thickness of the mold at a portion of the projection wound with the stator windings being smaller than that of the mold at other portions.

17. A motor-driven vehicle as claimed in claim 16, wherein the vehicle-mounted power source is a battery, the electric motor being driven in response to an output from the battery, the electric motor being only one drive source for driving the drive wheels.

18. A motor-driven vehicle as claimed in claim 16, wherein the vehicle-mounted power source is a battery, the electric motor being driven in response to an output from the battery, the electric motor constituting a drive source for the drive wheels in cooperation with an internal combustion engine.

19. A motor-driven vehicle as claimed in claim 16, wherein the vehicle-mounted power source is a power generator driven by an internal combustion engine, the electric motor being driven in response to an output from the power generator, the electric motor being a drive source for driving drive wheels different from those to be driven by the internal combustion engine.

20. A resin insert-molding method for a stator iron core in a rotating electric machine, in inserting an insulating resin into each of a plurality of tooth iron cores disposed in yoke iron cores by winding a stator winding in a concentric manner, the stator iron core in the rotating electric machine being constituted of the yoke iron cores and formed separately from the yoke iron cores, the resin insert-molding method comprising the steps of:

preparing at least four dies having a molding part formed in such a manner that the insulating resin is molded into a predetermined shape;

fixing the tooth iron core to a lower die;

disposing slide dies in such a manner as to hold the tooth iron core on both sides thereof;

pressing the slide dies downward against the lower die with an upper die in such a manner that the slide dies approach each other;

moving the slide dies in a direction perpendicular to the pressing direction;

bringing the upper die, the lower die and the slide dies to close contact with each other;

injecting the insulating resin into a clearance defined between the upper die, the lower die and the slide dies and the tooth iron core;

hardening the insulating resin; and

inserting the insulating resin into each of the plurality of tooth iron cores.