Stator for starter motor

Details Stator for starter motor Stator for starter motor

2001-02-07

2003-02-11

Nguyen, Tran (Department: 2834)

Electrical generator or motor structure

Dynamoelectric

Rotary

C310S216006, C310S216055

Reexamination Certificate

active

06518687

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stator for a starter motor used in vehicles and the like, and more particularly, to a stator for a starter motor having a cylindrical yoke.
2. Description of the Related Art
FIG. 7
is a perspective view showing a structure of a stator for a conventional starter motor;
FIG. 8
is a plan view of the stator; and
FIG. 9
is a perspective view showing an assembly process of the stator.
In a conventional stator
101
shown in
FIGS. 7 and 8
, four poles
103
are disposed inside a cylindrical yoke
102
. Then, a field winding
105
is wound around each of the poles
103
.
In the conventional stator constructed as described above, the yoke
102
is arranged as a cylindrical yoke (“bent yoke portion”) by rounding a sheet member and welding the joints thereof. Spigot portions
104
, which are formed at the ends of the yoke
102
in the axial direction thereof so as to be fitted to brackets (not shown), are processed by machining.
The poles
103
are made in a different process by, for example, forging or the like and mounted on the yoke
102
later. Further, the field windings
105
are previously wound in a different process and the spaces between wires are previously subjected to insulation processing by powder coating or the like. The surface of the yoke
102
cannot be previously subjected to rustproof processing because it is bent, welded, drawn and machined. Thus, the yoke
102
is coated with paint upon completion of the processing thereof.
The conventional stator constructed as described above is assembled in such a manner that, first, the field coils
105
, which have been previously wounded and subjected to the insulation processing, are mounted on the poles
103
which are mounted on the yoke
102
through mounting holes
110
defined thereto by caulking, screws or the like.
In the stator for the starter motor constructed as described above, the yoke
102
must have a predetermined thickness because a yoke made of a thin sheet member cannot achieve its function. Thus, the yoke
102
is made in such a manner that a thick sheet member is cut off by a large press and gradually rounded so as to be formed in a cylindrical shape, then the cylindrical thick sheet member is welded by a welder and subjected to a drawing process to provide it with accuracy by making the deformed cylindrical member to a perfect cylindrical member. Thereafter, the spigot portions
104
at the ends of the cylindrical member in the axial direction thereof are machined, the mounting holes
110
are drilled to the cylindrical member and painting is applied thereto.
The manufacture of the conventional so-called “bent yoke portion” made as described above requires many dedicated apparatuses such as a large press, welder, surface processing apparatus, outside diameter drawing machine, lathe, drilling machine, painting machine, and the like. Further, many processes are necessary to manufacture the “bent yoke portion” and the respective processing machines are large in size, from which a problem arises in that the manufacturing cost of the “bent yoke” is expensive.
SUMMARY OF THE INVENTION
An object of the present invention, which was made to solve the above problem, is to provide a stator for a starter motor the manufacturing cost of which can be reduced.
In a stator for a starter motor according to the present invention which includes an approximately cylindrical yoke, poles disposed inside the yoke, and field windings wound around the poles, the yoke is formed of a plurality of cylindrical cores having a different diameter and stacked in a radial direction.
It is preferable that the plurality of cylindrical cores be manufactured by a clinch method, respectively.
It is preferable that joints used in the clinch method are located so that they are not overlapped in a circumferential direction.
It is preferable that the axial direction of the innermost core of the plurality of the cylindrical cores be longer than those of the other cores.
It is preferable that the axial direction of the outermost core of the plurality of cylindrical cores be longer than those of the other cores.
It is preferable that the axial direction of the intermediate core of the plurality of cylindrical cores be longer than those of the other cores.
It is preferable that only the outermost core of the plurality of cylindrical cores be composed of a plated steel sheet.
It is preferable that the plating thickness of the outermost core of the plurality of cylindrical cores be larger than those the other cores.
Further, it is preferable that only the outermost core of the plurality of cylindrical cores is composed of a coated steel sheet.


REFERENCES:
patent: 1255606 (1918-02-01), Hensley
patent: 3908066 (1975-09-01), Parkinson
patent: 4051401 (1977-09-01), Hayward
patent: 4255684 (1981-03-01), Mischler et al.
patent: 4309815 (1982-01-01), Schmitt et al.
patent: 4698539 (1987-10-01), Workman
patent: 5426337 (1995-06-01), Kobayashi et al.
patent: 5731646 (1998-03-01), Heinze et al.
patent: 6058594 (2000-05-01), Neumann et al.
patent: 62-129259 (1961-02-01), None

Affiliated with

Also associated with

Rating

Stator for starter motor 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 starter motor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stator for starter motor will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3174206