Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
2001-11-19
2004-09-28
Le, Dang (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
Reexamination Certificate
active
06798108
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an alternator used in an automotive alternator driven by an internal combustion engine, for example.
2. Description of the Related Art
FIG. 18
is a cross section of a conventional automotive alternator,
FIG. 19
is a front elevation of an internal portion of the alternator of
FIG. 18
,
FIG. 20
is a perspective of a rotor of the alternator in
FIG. 18
, and
FIG. 21
is a perspective of a stator of the alternator in FIG.
18
.
This alternator includes: a case
3
composed of an aluminum front bracket
1
and an aluminum rear bracket
2
; a shaft
6
disposed inside the case
3
, a pulley
4
being secured to a first end of the shaft
6
; a Lundell-type rotor
7
secured to the shaft
6
; first and second fans
5
a
and
5
b
secured to first and second end surfaces of the rotor
7
; a stator
8
secured to an inner wall within the case
3
; 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
which slide on surfaces of the slip rings
9
; wires
17
each having an end portion connected to these brushes
10
; springs
16
for pressing the brushes
10
toward the slip rings
9
; a brush holding assembly
100
having a holding portion
11
a
for housing the brushes
10
and a cover
11
b
removably disposed on a head portion of the holding portion
11
a
; a rectifier
12
which is electrically connected to the stator
8
for converting alternating current generated in the stator
8
into direct current; a regulator
13
secured to the brush holding assembly
100
for adjusting the magnitude of an alternating voltage generated in the stator
8
; and a cooling plate
14
placed in contact with and secured to the regulator
13
to dissipate and cool heat generated in the regulator
13
.
The rotor
7
includes: a rotor coil
18
for generating magnetic flux on passage of electric current; and a pole core
19
disposed so as to cover the rotor coil
18
, magnetic poles being formed in the pole core
19
by the magnetic flux. The pole core
19
is constituted by a first pole core portion
20
and a second pole core portion
21
which intermesh with each other. The first pole core portion
20
is made of iron and has tapered first claw-shaped magnetic poles
22
extending axially. The second pole core portion
21
is made of iron and has tapered second claw-shaped magnetic poles
23
extending axially in an opposite direction to the first claw-shaped magnetic poles
22
.
The stator
8
is constituted by: a stator core
24
for passage of a rotating magnetic field from the rotor coil
18
, the stator core being formed by laminating a plurality of steel plates together; and three stator winding phase portions
25
through each of which an output current flows. The stator core
24
is constituted by an annular core back
26
, and a plurality of teeth
27
extending radially inwards from the core back
26
at an even pitch in a circumferential direction. The stator winding phase portions
25
, formed by winding an enamel-coated conducting wire for a plurality of winds, are housed in a total of thirty-six slots
28
formed between adjacent pairs of the teeth
27
.
In an automotive alternator of the above construction, electric current is supplied from a battery (not shown), which is an electric power supply, through the brushes
10
and the slip rings
9
to the rotor coil
18
, generating magnetic flux and giving rise to a magnetic field. At the same time, since the pulley
4
is driven by the engine and the rotor
7
is rotated by the shaft
6
, a rotating magnetic field is applied to the stator core
24
, generating electromotive force in the stator winding phase portions
25
and an output current is generated by an external load connected to the automotive alternator.
Moreover, after the commencement of power generation, the alternator is switched over to self-excitation, in which a portion of the electric current output from the alternator, rather than from the battery, is supplied through the brushes
10
to the rotor coil
18
.
In an automotive alternator of the above construction, one problem has been that the brush holding assembly
100
is housed in a sealed case
3
, and when replacing expended brushes
10
, for example, the automotive alternator must first be disassembled and the brush holding assembly
100
removed from the case
3
, then the operation of replacing the brushes
10
performed, and after that, the brush holding assembly
100
must be installed in the case
3
and the automotive alternator reassembled.
Another problem has been that, although an airflow is generated centrifugally inside the case
3
together with the rotation of the rotor
8
, flow resistance is great and air does not flow smoothly, making cooling efficiency of the regulator
13
and the brushes
10
poor.
SUMMARY OF THE INVENTION
The present invention aims to solve the above problems and an object of the present invention is to provide an alternator enabling the operation of replacing the brushes to be performed easily, and having improved cooling efficiency.
In order to achieve the above object, according to one aspect of the present invention, there is provided an alternator including:
a case;
a rotor disposed inside the case, the rotor including a rotor coil for generating a magnetic flux on passage of an electric current therethrough, and a plurality of claw-shaped magnetic poles extending in an axial direction and covering the rotor coil, the claw-shaped magnetic poles being magnetized into North-seeking (N) and South-seeking (S) poles by the magnetic flux;
a stator including a stator core provided with a plurality of slots formed so as to extend axially and be spaced circumferentially, and a stator winding mounted to the stator core;
brushes for supplying electric current from an electric power supply to the rotor coil; and
a brush holding assembly secured to the case, the brush holding assembly holding the brushes within a holding portion and being provided with a cover capable of being opened to remove the brushes,
an open portion for removal and insertion of the brushes being formed at a position on the case facing the cover.
The brush holding assembly may extend to a vicinity of the open portion.
The brush holding assembly may be constructed such that a holding assembly terminal is formed integrally therewith in a resin molding, the holding assembly terminal and a brush terminal mounted to a wire connected to the brushes being electrically connected by a connection member.
A connection portion for connecting the holding assembly terminal and the brush terminal may be disposed in the open portion.
The connection member may be a screw.
The screw may be inserted into and removed from the connection portion in a circumferential direction relative to the rotor.
The screw may be inserted into and removed from the connection portion in an axial direction relative to the rotor.
A regulator for adjusting a magnitude of an alternating voltage generated in the stator and a cooling plate placed in contact with the regulator may be disposed on the brush holding assembly so as to overlap in an axial direction relative to the rotor.
A conducting wire of the stator winding may extend outwards in an axial direction from an end surface of the stator core and be formed into coil ends having a uniform shape in a circumferential direction.
REFERENCES:
patent: 1651059 (1927-11-01), Janette
patent: 2194620 (1940-03-01), Sekyra
patent: 3603824 (1971-09-01), Csaki
patent: 4705983 (1987-11-01), Franz et al.
patent: 4959576 (1990-09-01), Horibe et al.
patent: 5550418 (1996-08-01), Chung
patent: 5955810 (1999-09-01), Umeda et al.
patent: 5990594 (1999-11-01), Hyatt, Jr. et al.
patent: 6215211 (2001-04-01), Harris et al.
patent: 6294856 (2001-09-01), Ishida et al.
patent: 6356003 (2002-03-01), Fiorenza et al.
patent: 198 20 885 (1999-11-01), None
patent: 51-66409 (1976-06-01), None
patent: 51-87205 (1976-07-01), None
patent: 04-137378 (1992-05-01), N
Asao Yoshihito
Morikaku Hideki
Takahashi Tomoki
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