Sliding member and sliding machine

Patent metadata

Field	Value
Publication number	US-10851776-B2
Application number	US-201916239015-A
Country	US
Kind code	B2
Filing date	Jan 3, 2019
Priority date	Apr 20, 2018
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A sliding member has a sliding surface sliding under a wet condition in which a lubricant oil exists. The sliding surface is coated with a laminate film comprising an upper layer and a lower layer. The lower layer comprises hydrogen-free amorphous carbon (hydrogen-free DLC) and carbon particles dispersed on or in the hydrogen-free DLC. The hydrogen-free DLC has a hydrogen content of 5 atom % or less when the lower layer as a whole is 100 atom %. The upper layer comprises boron-containing amorphous carbon (B-DLC) and has protrusions on a surface side of the upper layer along the carbon particles of the lower layer. The B-DLC has a boron content of 1-40 atom % when the upper layer as a whole is 100 atom %. The protrusions have a particle diameter of 0.5-5 μm and exist with a density of 20 protrusions/100 μm2 or more.

First claim

The invention claimed is:

1. A sliding member having a sliding surface sliding under a wet condition in which a lubricant oil exists,
the sliding surface being coated with a laminate film comprising an upper layer and a lower layer,
the lower layer comprising hydrogen-free amorphous carbon (referred to as “hydrogen-free DLC”) and carbon particles dispersed on or in the hydrogen-free DLC and having a hydrogen content of 5 atom % or less when the lower layer as a whole is 100 atom %,
the upper layer comprising boron-containing amorphous carbon (referred to as “B-DLC”) and having protrusions on a surface side of the upper layer along the carbon particles of the lower layer, the B-DLC having a boron content of 1-40 atom % when the upper layer as a whole is 100 atom %,
the protrusions having a particle diameter of 0.5-5 μm and existing with a density of 20 protrusions/100 μm 2 or more.

2. The sliding member as recited in claim 1 , wherein
the B-DLC has a thickness of 0.2-3 μm, and
the hydrogen-free DLC has a thickness of 0.5-5 μm.

3. The sliding member as recited in claim 1 , wherein
the B-DLC has hardness of 15-35 GPa, and
the hydrogen-free DLC has hardness of 40-70 GPa.

4. A sliding machine comprising:
a pair of sliding members having sliding surfaces that can relatively move while facing each other; and
a lubricant oil interposed between the sliding surfaces facing each other,
at least one of the sliding members comprising the sliding member as recited in claim 1 .

5. The sliding machine as recited in claim 4 , wherein the sliding machine is an oil pump that pumps the lubricant oil under pressure.

6. The sliding machine as recited in claim 5 , wherein
the pair of sliding members are a vane and a cam ring,
the oil pump is a vane pump, and
the vane has the sliding surface coated with the laminate film on a tip end side of the vane.

7. The sliding machine as recited in claim 6 , wherein the cam ring comprises an iron-based sintered material.

8. The sliding machine as recited in claim 4 , wherein the lubricant oil contains an oil-soluble molybdenum compound with a mass ratio of Mo to the lubricant oil as a whole of 200-1000 ppm, wherein the oil-soluble molybdenum compound has a chemical structure comprising a trinuclear of Mo.

Assignees

• Toyota Chuo Kenkyusho Kk
• Jtekt Corp

Inventors

• Okuyama Masaru
• Mori Hiroyuki
• Tohyama Mamoru
• Emoto Noriyuki
• Yoshida Naohito

Classifications

• F04C2/344 Primary

  with vanes reciprocating with respect to the inner member · CPC title

• C10M2227/066

  derived from Mo or W · CPC title

• C10M2201/04

  Elements · CPC title

• C10M169/04 Primary

  Mixtures of base-materials and additives · CPC title

• C10N2050/025

  in the form of films or sheets · CPC title