Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
1999-09-27
2001-07-17
Nguyen, Tran (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S216006, C310S254100, C029S516000, C029S596000, C029S609000
Reexamination Certificate
active
06262511
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an AC generator stator core to be mounted on a vehicle and a method for producing the AC generator stator core.
2. Description of the Prior Art
FIG. 13
is a sectional view of a conventional AC generator for a vehicle. This AC generator comprises a casing
3
consisting of a front bracket
1
and a rear bracket
2
which are connected together by a bolt
3
B, a shaft
5
securing at one end thereof a pulley
4
which receives a turning force transmitted from an engine through a belt, a rotor
6
of Lundell type secured to the shaft
5
, fans
6
F secured to both sides of the rotor, a stator
7
A secured to the inner wall surface within the casing
3
, a slip ring
8
secured to the other end of the shaft
5
to supply the rotor
6
with an electric current, a pair of brushes
9
and
9
sliding on the slip ring
8
, a brush holder
10
housing the brushes
9
and
9
, a rectifier
11
electrically connected to the stator
7
A to rectify an alternating current generated at the stator
7
A to a direct current, a heat sink
12
attached to the brush holder
10
, and a regulator
13
adhering to the heat sink
12
to regulate the size of the AC voltage generated at the stator
7
A. Reference numerals
14
a
and
14
b
are bearings and numeral
15
is a bracket for attaching the AC generator to an engine.
Said rotor
6
is provided with a rotor coil
6
A generating magnetic flux from the flow of an electric current, and a field core
6
B arranged to cover a rotor coil
6
A and forming magnetic pole therein by the magnetic flux of the rotor coil
6
A. The field core
6
B consists of a pair of mutually engaged field core bodies
6
x
and
6
y
. The field core bodies
6
x
and
6
y
are made of steel, each having a claw-shaped magnetic pole
62
.
Said stator
7
A is provided with a stator core
17
A, and a stator coil
17
B composed of conductor wires wound around the stator core
17
A. The stator coil
17
B generates an alternating current by the change of the magnetic flux from the rotor coil
6
A in accordance with the rotation of the rotor
6
.
In the above-mentioned AC generator for a vehicle, an electric current is supplied to the rotor coil
6
A through the brushes
9
and
9
and the slip ring
8
from a battery (not shown) to generate magnetic flux, while the pulley
4
is driven by the engine to rotate the shaft
5
and the rotor
6
, wherein the stator coil
17
B is given a rotating magnetic field to cause an electromotive force therein. This electromotive force is rectified through diodes
16
,
16
of the rectifier
11
to a direct current and the regulator
13
then regulates the size of the direct current to be charged to a battery.
FIG. 14
is a sectional view of a conventional brushless AC generator for a vehicle. In
FIG. 14
, the reference numerals shown represent the same or corresponding elements shown in
FIG. 13
therefore their descriptions will be omitted. In this brushless AC generator for the vehicle, when the engine is started, an exciting current from the battery is supplied through the regulator
13
A to an exciting coil housed in an exciting core
19
and the rotation of the shaft
5
allows the field core bodies
6
x
and
6
y
of the rotor
6
to rotate to generate the electromotive force at the stator coil
17
B of the stator
7
A. This AC electromotive force is rectified through the diodes
16
and
16
of the rectifier
11
to the direct current and the current size is then regulated by the regulator
13
A and charged to the battery.
FIG. 15
is a simplified perspective view showing one example of a stator core
17
A which is used in a conventional vehicle AC generator as shown in
FIGS. 13 and 14
. As shown in
FIG. 16
, the stator core
17
A is formed to have a circular cylinder body by spirally laminating a long, thin metal sheet
17
a
(made of steel) which is formed by stamping and then several places on the outer periphery of the circular cylinder body is welded to be extended in the laminating direction. Thus, the stator core
17
A is completed to have a predetermined thickness S in the laminating direction. The thin metal sheet
17
a
is provided with a recess
17
b
forming a slot
20
after lamination and a recess
17
c
forming a bolt clearance groove
21
.
FIG. 17
is a schematic plan view of the stator core
17
A.
In
FIG. 15
, there is shown one example in which four welding places are provided, on the outer periphery, at intervals of about 90° relative to a center of the circular cylinder body. Generally, there are provided four welding places from a core assembly strength point of view. Also, in case of welding, it is advisable to pick up the circular cylinder body first, by for example a chuck and the like to make each of the thin metal sheet
17
a
come closely into contact, and then weld the outer periphery of the circular cylinder body linearly from the top to bottom by using a jig that moves in a laminating direction of the circular cylinder body.
FIG. 15
shows the stator core
17
A provided with slots
20
. Each slot is wound by a one-phase coil, two-phase coil and three-phase coil, respectively to cause three-phase AC.
FIG. 18
shows a completed stator core
7
A. Each coil corresponding to one-phase is wound at intervals of two slots. Also, a conductor wire
17
e
forming the coil is secured within each slot
20
by varnish
22
as shown in FIG.
19
and the opening side of the slot
20
is also sealed by resin
23
.
As shown in
FIG. 16
, the long, thin metal sheets
17
a
made by stamping are spirally laminated to provide a plurality of bolt clearance grooves
21
on the outer periphery of the stator core
17
A. The grooves
21
are linearly formed to continue from the top to bottom in parallel relative to the laminating direction of the thin metal sheets
17
a
. These bolt clearance grooves
21
are, for example, provided at intervals of 10° relative to a circular center of the stator core
17
A.
As described above, the circular cylinder body is formed by spirally laminating the long, thin metal sheets
17
a
. In addition to this example, it is also possible to assemble another stator core with a predetermined thickness by laminating a plurality of thin metal sheets (of thin plate ring shape) to form a circular cylinder body and then making several welds on the outer periphery in the same manner as above.
According to the conventional stator core
17
A as described above, welds are linearly made to continue from the top to bottom on the circular cylinder body and in parallel in the laminating direction of the thin metal sheets (i.e. inparallel alongthebolt clearance grooves
21
). In this case, if an attraction force between the rotor
6
and the stator
7
A is applied to the stator core
17
A, there has been a problem whereby the linearly made welding location becomes a node and as shown in
FIG. 20
, the whole stator
7
A causes the mode of oscillation in a diametric direction.
Also, as shown in
FIG. 21
, in a stator core
30
which is disclosed in Japanese Laid-Open Utility Model Publication (Kokai) No. Sho 53-141410, there is shown that a non-welding portion
31
is partially provided. Here are formed welds
32
that are continuous vertically at several welding locations on the outer periphery of a stator core
30
with a predetermined thickness S. However, in this case, since there are many welds
32
that are continuous vertically at each welding location, the welds
32
are not always made dispersely in the peripheral and vertical directions of the outer periphery of the stator core. Therefore, the welds
32
become the node and they do not serve to eliminate the role. Since there are various orders in the vehicle AC generator where the engine speed covers a wide range, there is still a problem that the welds come to serve as one of the nodes and still generate the mode of oscillation.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to solve the above-mentioned problems and to provide an improved s
Adachi Katsumi
Asao Yoshihito
Higashino Kyoko
Kashihara Toshiaki
Ohashi Atsushi
Mitsubishi Denki & Kabushiki Kaisha
Nguyen Tran
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
AC generator stator core for vehicle and production method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with AC generator stator core for vehicle and production method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and AC generator stator core for vehicle and production method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2498444