Source: https://patents.google.com/patent/US20110241462A1/en
Timestamp: 2020-08-06 08:50:55
Document Index: 336714999

Matched Legal Cases: ['application No. 2009', 'art 40', 'art 40', 'art 40', 'art 40', 'art 40', 'art 40', 'art 40', 'art 40']

US20110241462A1 - Stator for electric rotating machine - Google Patents
Stator for electric rotating machine Download PDF
US20110241462A1
US20110241462A1 US13/077,007 US201113077007A US2011241462A1 US 20110241462 A1 US20110241462 A1 US 20110241462A1 US 201113077007 A US201113077007 A US 201113077007A US 2011241462 A1 US2011241462 A1 US 2011241462A1
US13/077,007
US8659201B2 (en
2010-03-31 Priority to JP2010082864A priority Critical patent/JP5585819B2/en
2010-03-31 Priority to JP2010-082864 priority
2011-03-31 Application filed by Denso Corp filed Critical Denso Corp
2011-05-05 Assigned to DENSO CORPORATION reassignment DENSO CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: UMEDA, ATSUSHI, UTAKA, RYOSUKE
2011-10-06 Publication of US20110241462A1 publication Critical patent/US20110241462A1/en
2014-02-25 Publication of US8659201B2 publication Critical patent/US8659201B2/en
A stator for an electric rotating machine includes a hollow cylindrical stator core having a plurality of slots and a stator coil formed by joining a plurality of electric wires mounted on the stator core. For each joined pair of the electric wires, one of the electric wires has an end portion led out from the radially inner periphery of one of the slots of the stator core while the other electric wire has an end portion led out from the radially outer periphery of another one of the slots of the stator core; the end portions are welded together to form a weld therebetween. Part of the welds formed between the end portions of the joined pairs of the electric wires are located on the radially inner periphery of the stator coil while the remaining welds are located on the radially outer periphery of the stator coil.
Conventionally, there are known stators for electric rotating machines which include a hollow cylindrical stator core and a stator coil. The stator core has a plurality of slots that are formed in the radially inner surface of the stator core and spaced in the circumferential direction of the stator core. The stator coil is comprised of a plurality of electric wires mounted on the stator core.
Moreover, there is disclosed, for example in Japanese Patent Application Publication No. 2001-145286, a method of manufacturing a stator. According to the method, to improve the space factors of the electric wires in the slots of the stator core, each of the wires of the U-phase, V-phase, and W-phase windings of the stator coil is configured to have a rectangular cross section and have such an overall shape that when developed on a plane, the winding meanders in the form of cranks. Further, each of the U-phase, V-phase, and W-phase windings is wound by a predetermined number of turns into a spiral shape, so as to make the stator coil have a hollow cylindrical shape.
With the above method, however, each of the electric wires (or electric conductors) that respectively make up the U-phase, V-phase, and W-phase windings of the stator coil is required to have a long length. Accordingly, a large-scale shaping machine is needed for shaping the electric wires. Moreover, since each of the electric wires is long, it is difficult to handle the electric wires during the manufacture of the stator. As a result, it is difficult to secure a high productivity and a low cost of the stator.
To solve the above problems, the assignee of the present application (i.e., Denso Corporation) has developed a stator 20 as shown in FIG. 1. It should be noted that for the stator 20, the assignee of the present application has already applied for both a Japanese patent (application No. 2009-241798) and a U.S. patent (application Ser. No. 12/837,726).
The stator 20 includes a hollow cylindrical stator core 30 and a stator coil 40. The stator core 30 has, as shown in FIG. 2, a plurality of slots 31 that are formed in the radially inner surface of the stator core 30 and spaced in the circumferential direction of the stator core 30. The stator coil 40 is comprised of a plurality of electric wires mounted on the stator core 30.
Each of the electric wires has first, second, . . . , nth in-slot portions and first, second, . . . , (n−1)th turn portions, where n is an integer not less than 4. The first to the nth in-slot portions are sequentially received in p of the slots 31 of the stator core 30, where p is an integer not greater than n. The first to the (n−1)th turn portions are alternately located on opposite axial sides of the stator core 30 outside the slots 31 to connect corresponding adjacent pairs of the first to the nth in-slot portions. Each of the electric wires also has first and second end portions. The first end portion is closer to the first in-slot portion than any other of the in-slot portions of the electric wire; the second end portion is closer to the nth in-slot portion than any other of the in-slot portions of the electric wire. The first in-slot portions of the electric wires are located most radially outward and the nth in-slot portions are located most radially inward in the slots 31 of the stator core 30. Moreover, the stator coil 40 is a multi-phase (e.g., three-phase) stator coil that includes a plurality of phase windings. Each of the phase windings of the stator coil 40 is formed of at least two of the electric wires. The first end portion of one of the two electric wires is connected to the second end portion of the other electric wire.
With the above configuration, since each of the phase windings of the stator coil 40 is formed of the at least two electric wires, it is possible to shorten the length of each of the electric wires. Consequently, the electric wires can be shaped using a small-scale shaping machine and be easily handled during the manufacture of the stator 20. As a result, it is possible to achieve a high productivity and a low cost of the stator.
Moreover, in the stator 20, for each connected pair of the electric wires forming the stator coil 40, the first end portion of the one electric wire is connected to the second end portion of the other electric wire via an electrically-conductive crossover member 70. The crossover member 70 extends to cross over an annular coil end part 40A of the stator coil 40, which protrudes from an axial end face 30A of the stator core 30, from the radially inside to the radially outside of the coil end part 40A.
Furthermore, the crossover member 70 may be configured as an integral part of the second end portion of the other electric wire, as shown in FIG. 1. In this case, the first and second end portions of the pair of the electric wires are joined together by welding, forming a weld 70 a therebetween.
However, with the above configuration, all the welds 70 a between the first and second end portions of the connected pairs of the electric wires are located on the radially outer periphery of the stator coil 40 so as to be equally spaced in the circumferential direction of the stator core 30. Consequently, the spatial distances (or air clearances) d1 between the welds 70 a become small, thereby making it difficult to ensure electrical insulation between the welds 70 a.
According to the invention, there is provided a stator for an electric rotating machine. The stator includes a hollow cylindrical stator core and a stator coil. The stator core has a plurality of slots that are formed in the radially inner surface of the stator core and spaced in the circumferential direction of the stator core. The stator coil is formed by joining a plurality of electric wires mounted on the stator core. For each joined pair of the electric wires, one of the electric wires has an end portion led out from the radially inner periphery of one of the slots of the stator core while the other electric wire has an end portion led out from the radially outer periphery of another one of the slots of the stator core; the end portions are welded together to form a weld therebetween. Part of the welds formed between the end portions of the joined pairs of the electric wires are located on the radially inner periphery of the stator coil while the remaining welds are located on the radially outer periphery of the stator coil.
Preferably, for each joined pair of the electric wires, one of the end portions of the pair of the electric wires is bent to extend toward the other end portion so as to cross over an annular coil end part of the stator coil; the coil end part is located outside the slots of the stator core so as to protrude from an axial end face of the stator core.
Each of those welds which are located on the radially inner periphery of the stator coil makes up a radially inner weld of the stator coil. Each of those welds which are located on the radially outer periphery of the stator coil makes up a radially outer weld of the stator coil. The radially inner welds of the stator coil may be alternately arranged with the radially outer welds of the stator coil in the circumferential direction of the stator core.
Otherwise, all the radially inner welds of the stator coil may be classified into a plurality of radially inner weld groups each of which includes circumferentially-adjacent two or more of the radially inner welds. All the radially outer welds of the stator coil may be classified into a plurality of radially outer weld groups each of which includes circumferentially-adjacent two or more of the radially outer welds. Further, the radially inner weld groups may be alternately arranged with the radially outer weld groups in the circumferential direction of the stator core.
In one embodiment of the invention, for each joined pair of the electric wires, the end portions of the pair of the electric wires have their respective side surfaces arranged to face each other in the axial direction of the stator core and welded together to form the weld between the end portions.
In another embodiment of the invention, for each joined pair of the electric wires, the end portions of the pair of the electric wires have their respective side surfaces arranged to face each other in the circumferential direction of the stator core and welded together to form the weld between the end portions.
In yet another embodiment of the invention, the stator coil is a multi-phase stator coil. For each circumferentially-adjacent pair of the welds which are of different phases, one of the pair of the welds is located on the radially inner periphery of the stator coil while the other is located on the radially outer periphery of the stator coil.
Preferred embodiments of the present invention will be described hereinafter with reference to FIGS. 3-7. It should be noted that for the sake of clarity and understanding, identical components having identical functions in different embodiments of the invention have been marked, where possible, with the same reference numerals in each of the figures and that for the sake of avoiding redundancy, descriptions of the identical components will not be repeated.
FIG. 3 shows the overall configuration of a stator 50 according to the first embodiment of the invention. The stator 50 is designed for use in, for example, an electric rotating machine that is configured to function both as an electric motor and as an electric generator in a motor vehicle.
The stator core 30 is configured as shown in FIG. 2. Specifically, the stator core 30 has a plurality of slots 31 that are formed in the radially inner surface of the stator core 30 and spaced in the circumferential direction of the stator core 30.
For each joined pair of the electric wires, one of the electric wires has an end portion 40 a led out from the radially inner periphery of one slot 31 of the stator core 30 while the other electric wire has an end portion 40 b led out from the radially outer periphery of another slot 31 of the stator core 30. Moreover, one of the end portions 40 a and 40 b is bent to extend toward the other so as to cross over an annular coil end part 40A of the stator coil 40; the coil end part 40A is located outside the slots 31 of the stator core 30 so as to protrude from an axial end face 30A of the stator core 30. Further, the end portions 40 a and 40 b are welded together, forming a weld 40 j therebetween. More specifically, as shown in FIGS. 3 and 4, the end portions 40 a and 40 b have their respective side surfaces arranged to face each other in the axial direction of the stator core 30 and welded together to form the weld 40 j.
In the present embodiment, all the welds 40 j formed between the joined pairs of the electric wires are classified into radially inner welds 40 ja and radially outer welds 40 jb. The radially inner welds 40 ja are located on the radially inner periphery of the stator coil 40 (or radially inside the coil end part 40A of the stator coil 40), while the radially outer welds 40 jb are located on the radially outer periphery of the stator coil 40 (or radially outside the coil end part 40A). Moreover, the radially inner welds 40 ja are alternately arranged with the radially outer welds 40 jb in the circumferential direction of the stator core 30.
With the above arrangement, it is possible to secure both sufficiently long spatial and creepage distances between each circumferentially-adjacent pair of the welds 40 j between the electric wires forming the stator coil 40. Consequently, it is possible to ensure electrical insulation between the welds 40 j, thereby ensuring high reliability of the stator 50.
Moreover, in the present embodiment, as described above, for each joined pair of the electric wires, one of the end portions 40 a and 40 b of the pair of the electric wires is bent to extend toward the other so as to cross over the annular coil end part 40A of the stator coil 40.
With the above configuration, all the welds 40 j formed between the end portions 40 a and 40 b of the electric wires are located to protrude from the coil end part 40A radially inward or radially outward. Consequently, it is possible to easily perform the process of welding the end portions 40 a and 40 b without causing the stator coil 40 to be damaged by the heat of the welding sparks.
Furthermore, in the present embodiment, as described above, for each joined pair of the electric wires, the end portions 40 a and 40 b of the pair of the electric wires have their respective side surfaces arranged to face each other in the axial direction of the stator core 30 and welded together to form the weld 40 j between the end portions 40 a and 40 b.
With the above arrangement, it is possible to minimize the width of each of the welds 40 j between the end portions 40 a and 40 b of the electric wires in the circumferential direction of the stator core 30.
Referring to FIG. 5, in this embodiment, for each joined pair of the electric wires, the end portions 40 a and 40 b of the pair of the electric wires have their respective side surfaces arranged to face each other in the circumferential direction of the stator core 30 and welded together to form the weld 40 j between the end portions 40 a and 40 b.
With the above configuration, it is possible to minimize the thickness of each of the welds 40 j between the end portions 40 a and 40 b of the electric wires in the axial direction of the stator core 30.
Referring to FIG. 6, in this embodiment, all the radially inner welds 40 ja are classified into a plurality of radially inner weld pairs each of which includes two circumferentially-adjacent radially inner welds 40 ja of the same phase. On the other hand, all the radially outer welds 40 jb are classified into a plurality of radially outer weld pairs each of which includes two circumferentially-adjacent radially outer welds 40 jb of the same phase. Moreover, the radially inner weld pairs are alternately arranged with the radially outer weld pairs in the circumferential direction of the stator core 30.
In the three-phase stator coil 40, the electric potential difference between two circumferentially-adjacent welds 40 j which are of different phases is greater than that between two circumferentially-adjacent welds 40 j which are of the same phase.
However, with the above arrangement of the welds 40 j according to the present embodiment, it is possible to secure both sufficiently long spatial and creepage distances between each circumferentially-adjacent pair of the welds 40 j which are of different phases. Consequently, it is possible to ensure electric insulation between the welds 40 j, thereby ensuring high reliability of the stator 50.
Referring to FIG. 7, in this embodiment, for each circumferentially-adjacent pair of the welds 40 j which are of different phases (e.g., the pair designated by Y1 and Y2 and the pair designated by Y3 and Y4), one of the pair of the welds 40 j is located on the radially inner periphery of the stator coil 40 to make up a radially inner weld 40 a while the other is located on the radially outer periphery of the stator coil 40 to make up a radially outer weld 40 b.
With the above arrangement, it is possible to secure both sufficiently long spatial and creepage distances between each circumferentially-adjacent pair of the welds 40 j which are of different phases. Consequently, it is possible to ensure electric insulation between the welds 40 j, thereby ensuring high reliability of the stator 50.
For example, in the first embodiment, the radially inner welds 40 ja are alternately arranged with the radially outer welds 40 jb in the circumferential direction of the stator core 30, as shown in FIG. 3. Moreover, in the third embodiment, the radially inner weld pairs are alternately arranged with the radially outer weld pairs in the circumferential direction of the stator core 30, as shown in FIG. 6.
However, it is also possible to arrange the welds 40 j such that: all the radially inner welds 40 ja are classified into a plurality of radially inner weld groups each of which includes more than two circumferentially-adjacent radially inner welds 40 ja that are of the same phase; all the radially outer welds 40 jb are classified into a plurality of radially outer weld groups each of which includes more than two circumferentially-adjacent radially outer welds 40 jb that are of the same phase; and the radially inner weld groups are alternately arranged with the radially outer weld groups in the circumferential direction of the stator core 30.
1. A stator for an electric rotating machine, the stator comprising:
a hollow cylindrical stator core having a plurality of slots that are formed in a radially inner surface of the stator core and spaced in a circumferential direction of the stator core; and
a stator coil that is formed by joining a plurality of electric wires mounted on the stator core,
for each joined pair of the electric wires, one of the electric wires has an end portion led out from a radially inner periphery of one of the slots of the stator core while the other electric wire has an end portion led out from a radially outer periphery of another one of the slots of the stator core, the end portions being welded together to form a weld therebetween, and
part of the welds formed between the end portions of the joined pairs of the electric wires are located on a radially inner periphery of the stator coil while the remaining welds are located on a radially outer periphery of the stator coil.
2. The stator as set forth in claim 1, wherein for each joined pair of the electric wires, one of the end portions of the pair of the electric wires is bent to extend toward the other end portion so as to cross over an annular coil end part of the stator coil, the coil end part being located outside the slots of the stator core so as to protrude from an axial end face of the stator core.
3. The stator as set forth in claim 1, wherein each of those welds which are located on the radially inner periphery of the stator coil makes up a radially inner weld of the stator coil,
each of those welds which are located on the radially outer periphery of the stator coil makes up a radially outer weld of the stator coil, and
the radially inner welds of the stator coil are alternately arranged with the radially outer welds of the stator coil in the circumferential direction of the stator core.
4. The stator as set forth in claim 1, wherein each of those welds which are located on the radially inner periphery of the stator coil makes up a radially inner weld of the stator coil,
each of those welds which are located on the radially outer periphery of the stator coil makes up a radially outer weld of the stator coil,
all the radially inner welds of the stator coil are classified into a plurality of radially inner weld groups each of which includes circumferentially-adjacent two or more of the radially inner welds,
all the radially outer welds of the stator coil are classified into a plurality of radially outer weld groups each of which includes circumferentially-adjacent two or more of the radially outer welds, and
the radially inner weld groups are alternately arranged with the radially outer weld groups in the circumferential direction of the stator core.
5. The stator as set forth in claim 1, wherein for each joined pair of the electric wires, the end portions of the pair of the electric wires have their respective side surfaces arranged to face each other in an axial direction of the stator core and welded together to form the weld between the end portions.
6. The stator as set forth in claim 1, wherein for each joined pair of the electric wires, the end portions of the pair of the electric wires have their respective side surfaces arranged to face each other in the circumferential direction of the stator core and welded together to form the weld between the end portions.
7. The stator as set forth in claim 1, wherein the stator coil is a multi-phase stator coil, and
for each circumferentially-adjacent pair of the welds which are of different phases, one of the pair of the welds is located on the radially inner periphery of the stator coil while the other is located on the radially outer periphery of the stator coil.
US13/077,007 2010-03-31 2011-03-31 Stator for electric rotating machine Active 2032-05-22 US8659201B2 (en)
JP2010082864A JP5585819B2 (en) 2010-03-31 2010-03-31 Rotating electric machine stator
JP2010-082864 2010-03-31
US20110241462A1 true US20110241462A1 (en) 2011-10-06
US8659201B2 US8659201B2 (en) 2014-02-25
ID=44708783
US13/077,007 Active 2032-05-22 US8659201B2 (en) 2010-03-31 2011-03-31 Stator for electric rotating machine
US (1) US8659201B2 (en)
JP (1) JP5585819B2 (en)
US20150123503A1 (en) * 2012-07-03 2015-05-07 Aisin Aw Co., Ltd. Stator
WO2014157621A1 (en) * 2013-03-29 2014-10-02 アイシン・エィ・ダブリュ株式会社 Stator structure
US4309634A (en) * 1980-04-10 1982-01-05 Westinghouse Electric Corp. Stator winding peripheral connector rings
US20080191574A1 (en) * 2007-02-09 2008-08-14 Denso Corporation Stator with winding for electric rotating machine and method of manufacturing the stator
US8030812B2 (en) * 2008-02-13 2011-10-04 Hitachi, Ltd. Rotating electric apparatus and method for connecting stator coils thereof
US8225484B2 (en) * 2010-03-31 2012-07-24 Denso Corporation Method of manufacturing stator for electric rotating machine
JP2001145286A (en) 1999-11-12 2001-05-25 Mitsubishi Electric Corp Stator of rotating electric machine and method of manufacturing the same
JP4396761B2 (en) * 2007-11-26 2010-01-13 株式会社デンソー Rotating electric machine stator and rotating electric machine
JP5471867B2 (en) 2009-07-17 2014-04-16 株式会社デンソー Rotating electric machine stator
JP2011182579A (en) * 2010-03-02 2011-09-15 Toyota Motor Corp Rotary electric machine
2010-03-31 JP JP2010082864A patent/JP5585819B2/en active Active
2011-03-31 US US13/077,007 patent/US8659201B2/en active Active
JP2011217508A (en) 2011-10-27
US8659201B2 (en) 2014-02-25
JP5585819B2 (en) 2014-09-10
US10250093B2 (en) 2019-04-02 Stator for rotary electric machine and method for manufacturing the same
JP5234173B2 (en) 2013-07-10 Stator and method of manufacturing unit coil used therein
KR101128995B1 (en) 2012-03-27 Stator and manufacturing method thereof
JP5586969B2 (en) 2014-09-10 Rotating electric machine stator
US6938323B2 (en) 2005-09-06 Method of manufacturing stator coil of rotary electric machine
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:UTAKA, RYOSUKE;UMEDA, ATSUSHI;REEL/FRAME:026272/0769