Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
1998-04-24
2001-06-26
Tamai, Karl (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S181000
Reexamination Certificate
active
06252330
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a dynamo-electric machine rotor equipped with a magnet portion and provided between adjacent triangular magnetic poles for reducing the leakage of magnetic flux between the triangular magnetic poles, and a method of manufacturing same.
2. Description of Related Art
FIG. 10
is a sectional side elevation of a conventional vehicular AC generator and
FIG. 11
is a perspective view of a rotor shown in FIG.
10
. The AC generator is equipped with: a case
3
comprising of a front bracket
1
and a rear bracket
2
made of aluminum; a shaft
6
provided in the case
3
and having a pulley
4
fixed at one end thereof; a Randell-type rotor
7
secured to the shaft
6
; fans
5
secured to both side surfaces of the rotor
7
; a stator
8
secured to the inner wall surface of the case
3
; a slip ring
9
secured to the other end of the shaft
6
for supplying current to the rotor
7
; a pair of brushes
10
in sliding contact with the slip ring
9
; a brush holder
11
which holds the brushes
10
; a rectifier
12
electrically connected the stator
8
to for changing alternating current generated in the stator
8
to direct current; a heat sink
17
fitted onto the brush holder
11
; and a regulator
18
bonded to the heat sink
17
for adjusting the magnitude of the AC voltage generated in the stator
8
.
The rotor
7
is comprises by a rotor coil
13
through which current flows to generate magnetic flux, and a field core assembly
14
that covers the rotor coil
13
and in which magnetic poles are formed by the magnetic flux. The field core assembly
14
is a pair composed of first field core member
21
and second field core member
22
which are alternately meshed. The first field core member
21
and the second field core member
22
are made of iron. The first field core member
21
has triangular magnetic poles
23
, and the second field core member
22
has triangular magnetic poles
24
. A hexahedral magnet
19
is provided between adjacent ones of the triangular magnetic poles
23
and
24
in an orientation that reduces the leakage of magnetic flux between the triangular magnetic poles
23
and
24
.
The stator
8
is provided with a stator core
15
and a stator coil
16
composed of a conductor wound around the stator core
15
, in which alternating current is generated as the magnetic flux from the rotor coil
13
changes as the rotor
7
rotates.
In the vehicular AC generator configured as set forth above, current is supplied from a battery, not shown, to the rotor coil
13
via the brushes
10
and the slip ring
9
so as to generate magnetic flux. The triangular magnetic poles
23
of the first field core member
21
are magnetized to the N pole (positive polavity), while the triangular magnetic poles
24
of the second field core
22
are magnetized to the S pole (negative polavity).
The pulley
4
is driven by an engine and the rotor
7
is rotated through the shaft
6
, so that a rotary magnetic field is supplied to the stator coil
16
, generating an electromotive force in the stator coil
16
. This AC electromotive force is rectified into direct current through the rectifier
12
and the voltage magnitude thereof is adjusted by the regulator
18
before it is supplied to the battery.
In a conventional rotor
7
of the vehicular AC generator, the hexahedral magnet
19
, which has been magnetized in a direction so as to reduce the leakage of magnetic flux between the triangular magnetic poles
23
and
24
, is secured to adjacent triangular magnetic poles
23
and
24
by using an adhesive agent. More specifically, the hexahedral magnet
19
is secured so that the side opposed to the triangular magnetic pole
23
magnetized to the N pole constitutes the N-pole surface of the magnet
19
, while the side opposed to the triangular magnetic pole
24
magnetized to the S pole constitutes the S-pole surface of the magnet
19
. This makes it possible to reduce ineffective magnetic flux, which leaks between the adjacent triangular magnetic poles
23
and
24
and therefore does not contribute to the power generation of the AC generator, so that the power generating efficiency of the AC generator is thereby increased.
The magnets
19
, however, are each discretely positioned at twelve points between the triangular magnetic poles
23
and
24
. Therefore, a lot of time is required to attach the magnets
19
, leading to the problem of poor assembly efficiency.
SUMMARY OF THE INVENTION
The present invention has been made with a view toward solving the problem described above, and it is an object of the invention to provide a rotor for a dynamo-electric machine, that permits higher manufacturing efficiency and a method of manufacturing same.
To this end, in a rotor for a dynamo-electric machine, a plurality of magnetic portions are provided between adjacent ones of triangular magnetic poles in an orientation that reduces the leakage of magnetic flux between the triangular magnetic poles, and are joined to at least one of a first flange and a second flange.
In a preferred form of the rotor for a dynamo-electric machine, magnetic portions comprise magnetic members made of a magnetic material and covers, which cover the magnetic members and which are made of the same resin material as that of a bobbin.
In another preferred form of the rotor for a dynamo-electric machine, fitting portions, which are fitted on the sides of the triangular magnetic poles to prevent the magnetic portions from shifting radially outward, are formed on the sides of the magnetic portions.
In yet another preferred form of the rotor for a dynamo-electric machine, engaging portions, which engage with ends of triangular magnetic poles to prevent magnetic portions from shifting axially, are formed on the ends of the magnetic portions.
In another preferred form of the rotor for a dynamo-electric machine, locking portions, which engage with mating portions formed on the distal ends of magnetic portions to retain the magnetic portions between triangular magnetic poles, are formed on the outer periphery of either a first flange or a second flange.
In a method of manufacturing a rotor for a dynamo-electric machine, magnetic members are placed in a mold and resin is injection molded, to form a bobbin and magnetic portions integral with the bobbin.
REFERENCES:
patent: 5325003 (1994-06-01), Saval et al.
patent: 5483116 (1996-01-01), Kusase et al.
patent: 5969459 (1999-10-01), Taniguchi et al.
patent: 61-254040 (1986-11-01), None
patent: 607308 (1978-04-01), None
Asao Yoshihito
Higashino Kyoko
Mitsubishi Denki & Kabushiki Kaisha
Sughrue Mion Zinn Macpeak & Seas, PLLC
Tamai Karl
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