Carbon commutator

Details Carbon commutator Carbon commutator

1999-11-10

2001-07-10

Nguyen, Tran (Department: 2834)

Electrical generator or motor structure

Dynamoelectric

Rotary

C310S237000

Reexamination Certificate

active

06259183

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to a carbon commutator used in, for example, a motor for a fuel pump.
An in-tank type fuel supply pump, in which a motor and a pump are integrally mounted within a fuel tank, is used for supplying fuel to, for example, an automobile. In general, the fuel supply pump of this type is constructed so that the fuel can be moved out of the fuel supply pump from its pump section through the motor housing, and brought into contact with the commutator of the motor. If gasoline containing alcohol is used as a fuel, it is known in the art that copper in that portion of the commutator which is brought into a sliding contact with the brush is corroded by the alcohol contained in the fuel. The corroded copper markedly shortens the life of the pump.
As a commutator taking measures against an alcohol-containing fuel, proposed is a carbon commutator, in which a metal segment is joined to a carbon segment by soldering via a metal plating interposed therebetween, and a brush is brought into a sliding contact with the carbon segment. A commutator of this type is disclosed in, for example, U.S. Pat. No. 5,175,463. However, a motor which equips a carbon commutator may perform poorly because the plating solution permeats through the carbon segment in the plating process. Also, the plating treatment may increase the manufacturing cost. Further, in the subsequent process of welding a coil to the carbon commutator, the solder can be melted and cause peeling or positional deviation of the carbon segment.
Another method to produce a carbon commutator is disclosed in, for example, Japanese Patent Disclosure (Kokai) No. 10-004653. In this method, a projection mounted on the carbon segment is inserted into a hole made in the metal segment so as to join these two segments. However, the projection mounted on the carbon segment only consists of carbon element so that it lacks ductility. Therefore, the projection is readily abraded when inserted into the hole, resulting in failure to join the two segments firmly. JP '653 also teaches an idea that plating solution which is applied to both segments joins them together. However, this measure may also increase the manufacturing cost.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide a carbon commutator, which can join a metal segment and a carbon segment at a low cost without fail.
According to the first aspect of the present invention, there is provided a carbon commutator, comprising:
a plurality of metal segments each having a through-hole;
a plurality of carbon segments each having a projecting portion, which contains a metal, and is inserted into the through-hole to be deformed so as to join the carbon segment to the metal segment; and
a commutator body on which a plurality of the metal/carbon joined segments are fixed in a manner to form a substantially circular body.
In the first aspect of the present invention, it is desirable for each carbon segment stated above to contain more metals in the section where it contacts with the metal segment.
Additionally, in the first aspect of the present invention, it is also desirable for the projecting portion of the carbon segment to contain 60 to 100% by weight of a metal.
Moreover, in the first aspect of the present invention, it is desirable for the projecting portion of the carbon segment to contain 70 to 100% by weight of a metal.
Further, in the first aspect of the present invention, it is desirable for the metal to be selected from the group consisting of copper, nickel, silver, gold, tin, zinc, and alloy thereof.
According to the second aspect of the present invention, there is provided a carbon commutator, comprising:
a plurality of metal segments each having a through-hole;
a plurality of carbon segments of a double layer structure consisting of a carbon layer and a metal-containing carbon layer which has a projecting portion inserted into the through-hole so as to caulk the carbon segment and the metal segment to join them together; and
a commutator body on which a plurality of the metal segments, which have carbon segments joined thereto, are arranged in a manner to form a substantially circular body.
In the second aspect of the present invention, it is desirable for the metal-containing carbon layer to contain 60 to 100% by weight of a metal.
Additionally, in the second aspect of the present invention, it is also desirable for the metal-containing carbon layer to contain 70 to 100% by weight of metal.
Further, in the second aspect of the present invention, it is desirable for the metal to be selected from the group consisting of copper, nickel, silver, gold, tin, zinc, and alloy thereof.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.


REFERENCES:
patent: 4358319 (1982-11-01), Yoshida et al.
patent: 5925961 (1999-07-01), Sugiyanma
patent: 5932949 (1999-08-01), Ziegler et al.
patent: 5996210 (1999-12-01), Konig
patent: 39 11 579 A1 (1990-10-01), None
patent: 0 583 892 (1994-02-01), None
patent: 2 633 781 (1989-07-01), None
patent: 7-42223 (1995-09-01), None
Communication Pursuant to Article 96(2) EPC from European Patent Application No. 99 309 019.0-1231, Nov. 16, 2000.

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