Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
2001-12-06
2004-04-06
Le, Dang (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S201000, C310S208000, C310S179000
Reexamination Certificate
active
06717317
ABSTRACT:
This application is based on Application No. 2001-108447, filed in Japan on Apr. 6, 2001, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stator for a dynamoelectric machine such as automotive alternators, etc, and particularly to a stator construction for improving cooling in a joint portion of a conductor wire constituting a stator winding.
2. Description of the Related Art
FIG. 24
is a longitudinal section showing a first conventional automotive alternator, and
FIG. 25
is a perspective showing a conductor segment used in a stator winding of a stator mounted to the first conventional automotive alternator.
FIG. 26
is a rear end elevation schematically showing a first winding phase portion of the stator winding of the stator mounted to the first conventional automotive alternator. In
FIG. 26
, solid lines indicate rear-end wiring, broken lines indicate front-end wiring, and black circles indicate joint portions.
FIG. 27
is a diagram schematically showing a rear-end portion of the stator in the first conventional automotive alternator viewed from a circumferential direction,
FIG. 28
is a side elevation showing the rear-end portion of the stator mounted to the first conventional automotive alternator viewed from radially outside, and
FIG. 29
is an end elevation showing the rear-end portion of the stator mounted to the first conventional automotive alternator viewed from axially outside. Moreover, in
FIG. 24
, the shapes of coil ends are represented schematically.
As shown in
FIG. 24
, a first conventional automotive alternator includes: a case
3
constituted by a front bracket
1
and a rear bracket
2
made of aluminum; a shaft
6
disposed inside the case
3
, a pulley
4
being secured to a first end portion of the shaft
6
; a Lundell-type rotor
7
secured to the shaft
6
; fans
5
secured to first and second axial end portions of the rotor
7
; a stator
8
secured to the case
3
so as to envelop the rotor
7
; slip rings
9
secured to a second end of the shaft
6
for supplying electric current to the rotor
7
; a pair of brushes
10
sliding on surfaces of the slip rings
9
; a brush holder
11
accommodating the brushes
10
; rectifiers
12
each having a rectifier heat sink
12
a
, the rectifiers
12
being electrically connected to the stator
8
to convert alternating current generated in the stator
8
into direct current; and a regulator
18
mounted to a brush holder heat sink
17
fitted onto the brush holder
11
, the regulator
18
adjusting the magnitude of the alternating voltage generated in the stator
8
.
The rotor
7
includes: a field winding
13
for generating magnetic flux on passage of an electric current; and a pair of first and second pole cores
20
and
21
disposed so as to cover the field winding
13
, magnetic poles being formed in the first and second pole cores
20
and
21
by magnetic flux therefrom. The first and second pole cores
20
and
21
are made of iron, each has a plurality of first and second claw-shaped magnetic poles
22
and
23
having a generally trapezoidal outermost diameter surface shape disposed on an outer circumferential edge portion at even angular pitch in a circumferential direction so as to project axially, and the first and second pole cores
20
and
21
are fixed to the shaft
6
facing each other such that the first and second claw-shaped magnetic poles
22
and
23
intermesh.
The stator
8
is constituted by: a cylindrical stator core
15
; and a stator winding
16
installed in the stator core
15
. The stator
8
is held between the front bracket
1
and the rear bracket
2
so as to form a uniform air gap between outer circumferential surfaces of the claw-shaped magnetic poles
22
and
23
and an inner circumferential surface of the stator core
15
.
Here, a specific construction of the stator winding
16
will be explained with reference to
FIGS. 25 and 27
.
First, a conductor segment
30
is prepared by bending into a general U shape a short length of a copper wire material having a circular cross section covered with an electrically-insulating coating. As shown in
FIG. 25
, this conductor segment
30
is constituted by a general U shape in which a pair of straight portions
30
a
are linked by a turn portion
30
b.
The stator core
15
is prepared by laminating a predetermined number of long, thin magnetic steel plates in which slots
15
a
are formed at a predetermined pitch, bending the laminated body into an annular shape with the openings of the slots
15
a
facing an inner circumferential side, and welding first and second end surfaces of the annular shape. In this stator core
15
, the slots
15
a
, which have grooves lying in an axial direction, are formed at a ratio of two per phase per pole. In other words, ninety-six slots
15
a
are arranged circumferentially on an inner circumferential side of the stator core
15
, the number of magnetic poles in the rotor
7
being sixteen.
Moreover, to facilitate explanation, Slot Numbers from
1
to
96
are allocated to each of the slots
15
a
as shown in
FIG. 26
, and the positions in each of the slots
15
a
in which the conductor segments
30
are housed are designated Address
1
, Address
2
, Address
3
, and Address
4
, respectively, from an inner circumferential side.
Conductor segments
30
are inserted two at a time from a front end of the stator core
15
into slot pairs separated by six slots (slot pairs including Slot Numbers n and (n+6)). Here, in each of the slot pairs, a first conductor segment
30
is inserted into Address
1
in slot
15
a
Number n and into Address
2
in slot
15
a
Number (n+6) and a second conductor segment
30
is inserted into Address
3
in slot
15
a
Number n and into Address
4
in slot
15
a
Number (n+6). The free end portions of the conductor segments
30
extending outward at the rear end from Address
1
and Address
2
of each of the slot pairs are bent in a clockwise direction in
FIG. 26
, and the free end portions of the conductor segments
30
extending outward at the rear end from Address
3
and Address
4
of each of the slot pairs are bent in a counterclockwise direction in FIG.
26
. Here, four straight portions
30
a
are housed in each of the slots
15
a
so as to line up in one row in a radial direction.
Next, the free end portions
30
c
of the conductor segments
30
extending outward at the rear end from Address
1
in slot
15
a
Number n and the free end portions
30
c
of the conductor segments
30
extending outward at the rear end from Address
4
in slot
15
a
Number (n+6) are stacked in a radial direction and joined by welding, etc. Similarly, the free end portions
30
c
of the conductor segments
30
extending outward at the rear end from Address
2
in slot
15
a
Number n and the free end portions
30
c
of the conductor segments
30
extending outward at the rear end from Address
3
in slot
15
a
Number (n+6) are stacked in a radial direction and joined by welding, etc. Thus, two two-turn lap windings are formed, the lap windings being wound into every sixth slot
15
a.
Now, at the rear end of the stator core
15
, distant-address joint portions
31
1-4
joining the free end portions
30
c
of the conductor segments
30
extending outward at the rear end from Address
1
and Address
4
in each of the slot pairs surround near-address joint portions
31
2-3
joining the free end portions
30
c
of the conductor segments
30
extending outward at the rear end from Address
2
and Address
3
as shown in
FIGS. 27
to
29
. Thus, the two joint portions
31
1-4
and
31
2-3
are arranged into two layers in an axial direction.
Similarly, at the front end of stator core
15
, the turn portions
30
b
of the conductor segments
30
extending outward at the front end from Address
1
and Address
2
in each of the slot pairs and the turn portions
30
b
of the conductor segments
30
extending outward at the front end from Address
Adachi Katsumi
Akita Hiroyuki
Asao Yoshihito
Hashiba Mitsuharu
Oketani Naohiro
Elkassabgi H.
Le Dang
Mitsubishi Denki & Kabushiki Kaisha
LandOfFree
Stator for a dynamoelectric machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stator for a dynamoelectric machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stator for a dynamoelectric machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3185698