Starter, and formation of graphite cover layer for commutator surface
AssigneeDenso Corporation
InventorsTakashi Hirabayashi, Taro Fukuda
Life of this patent
Estimating the term…
Abstract
A starter includes a motor configured with a direct current motor. The direct current motor has a brush and a commutator. The brush is a sintered material formed of graphite and a copper powder. The commutator is formed of either copper or a copper alloy that has a copper content of 99% or more. A surface of is a sliding portion of the commutator which has sliding movement with the brush is provided with a graphite cover-layer that contains graphite as a main component. The graphite cover-layer contains a hard compound which has a Vickers hardness higher than 10 GPa and a metal sulfide solid lubricant.
Claims18
A starter that is used for starting an engine,
- the starter comprising
- a motor provided with a brush and a commutator, the commutator having a surface that is a sliding portion;
- wherein the brush is configured of a sintered material being formed of graphite and copper powder,
- the commutator is formed of either one of copper and a copper alloy having a copper content of 99% or more,
- the surface of the commutator being the sliding portion that has sliding contact with the brush, has a graphite cover-layer formed thereon, and
- the graphite cover-layer contains graphite as a main component, a hard compound having a Vickers hardness that is higher that 10 GPa, and a metal sulfide solid lubricant.
A method of forming a graphite cover-layer on a surface of a commutator, comprising steps of:
- preparing the commutator which has a surface being formed of either one of copper and a copper alloy having a copper content of 99% or more;
- preparing a brush containing graphite and a metal sulfide solid lubricant, and
- performing a cover-layer formation process, wherein
- the cover-layer formation process is performed by an operation of a starter,
- the graphite and the metal sulfide solid lubricant contained in the brush are transferred onto the surface of the commutator by repeated operation of the starter,
- the graphite and the metal sulfide solid lubricant react with heat that is generated from electricity, sliding movement of the brush and the surface of the commutator, and sparks,
- whereby a graphite layer which contains hard compounds being carbides is formed on the surface of the commutator;
- the starter comprising
- a motor provided with the brush and the commutator, the commutator having the surface that is a sliding portion;
- wherein the brush is configured of a sintered material being formed of graphite and copper powder,
- the surface of the commutator being the sliding portion that has sliding contact with the brush, is formed thereon, and
- the graphite cover-layer contains the graphite as a main component, the hard compound having a Vickers hardness that is higher that 10 GPa, and the metal sulfide solid lubricant.
A commutator assembly comprising
- a commutator having a surface being a sliding portion;
- and
- a cover layer that is formed on the surface of the commutator, wherein
- the commutator is formed of either one of copper and a copper alloy having a copper content of 99% or more,
- the surface being the sliding portion of the commutator has sliding contact with a brush, containing graphite and a metal sulfide solid lubricant, and
- the cover layer of the commutator is a graphite cover-layer that contains a hard compound having a Vickers hardness that is higher that 10 GPa, and a metal sulfide solid lubricant.
Dependencies are inferred from the claim text.