Sliding member and sliding machine

Patent metadata

Field	Value
Publication number	US-9624975-B2
Application number	US-201514644942-A
Country	US
Kind code	B2
Filing date	Mar 11, 2015
Priority date	Mar 21, 2014
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

The sliding member according to the present invention includes: a base material; and a sliding film that covers a surface of the base material and constitutes a sliding surface, and is used under a wet condition where lubricant oil exists. The sliding film according to the present invention is a laminated film that includes: an underlying layer formed on the surface of the base material; and an outermost layer formed at least on a part of the underlying layer. This outermost layer is characterized by including specific boron-containing amorphous carbon (specific B-DLC) that contains 4-50% B and 5-50% H when the outermost layer as a whole is 100 at %. This specific B-DLC itself wears away during the sliding to smooth the sliding surface, and an excellent low friction property is exhibited. The underlying layer of the specific B-DLC contributes to improvement in the wear resistance property of the sliding film.

First claim

The invention claimed is:

1. A sliding member comprising:
a base material; and
a sliding film that covers a surface of the base material and constitutes a sliding surface,
the sliding member being used under a wet condition where lubricant oil exists,
the sliding film comprising a laminated film,
the laminated film comprising:
an underlying layer formed on the surface of the base material; and
an outermost layer formed at least on a part of the underlying layer,

the outermost layer comprising specific boron-containing amorphous carbon (referred hereinafter to as a “specific B-DLC”), the specific B-DLC containing 4-50 at % (referred simply to as “%”) boron (B) and 26-50% hydrogen (H) when the outermost layer as a whole is 100%,
the sliding member having a layer thickness ratio (T 1 /R 2 ) of 3-200, wherein the layer thickness ratio (T 1 /R 2 ) is defined as a ratio of a layer thickness (T 1 ) of the outermost layer to a surface roughness (R 2 ) based on an arithmetic average roughness (Ra) of the underlying layer.

2. The sliding member as recited in claim 1 , wherein the layer thickness ratio is 5.8-37.5.

3. The sliding member as recited in claim 2 , wherein the layer thickness ratio is 12.6-23.3.

4. The sliding member as recited in claim 1 , wherein the outermost layer comprises a specific B-DLC that contains 23-50% B when the outermost layer as a whole is 100%.

5. The sliding member as recited in claim 1 , wherein the underlying layer comprises nitride, carbide or hard amorphous carbon harder than the outermost layer.

6. The sliding member as recited in claim 5 , wherein the hard amorphous carbon of the underlying layer is silicon-containing amorphous carbon (referred hereinafter to as a “Si-DLC”) that contains silicon (Si).

7. The sliding member as recited in claim 1 , wherein the surface roughness of the underlying layer is 0.1 micrometers or more as the Ra.

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

Assignees

• Toyota Chuo Kenkyusho Kk
• Toyota Motor Co Ltd

Inventors

• Okuyama Masaru
• Tohyama Mamoru
• Mori Hiroyuki
• Matsui Munehisa
• Ikeda Naoya
• Fuwa Yoshio
• Shinyoshi Takatoshi

Classifications

• F16C2206/58

  based on ceramic nitrides · CPC title

• F16C33/043 Primary

  Sliding surface consisting mainly of ceramics, cermets or hard carbon, e.g. diamond like carbon [DLC] · CPC title