Low-friction sliding member in transmission, and transmission oil therefor

• US 20050082139A1
• Filed: 08/19/2004
• Published: 04/21/2005
• Est. Priority Date: 08/22/2003
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kano, Makoto, Ishikawa, Takao, Ueno, Takafumi, Nakamura, Kiyotaka
• Granted Patent: US 7,318,514 B2
• Time in Patent Office: Days
• US Class Current: 192/107.M
• CPC Class Codes: C10M 129/00 Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen
• CPC Class Codes: C10M 133/06 having amino groups bound to acyclic or cycloaliphatic carbon atoms
• CPC Class Codes: C10M 2205/0285 used as base material
• CPC Class Codes: C10M 2207/021 having hydroxy groups bound to acyclic or cycloaliphatic carbon atoms
• CPC Class Codes: C10M 2207/022 containing at least two hydroxy groups
• CPC Class Codes: C10M 2207/04 Ethers; Acetals; Ortho-esters; Ortho-carbonates
• CPC Class Codes: C10M 2207/044 Cyclic ethers having four or more ring atoms, e.g. furans, dioxolanes
• CPC Class Codes: C10M 2207/122 monocarboxylic
• CPC Class Codes: C10M 2207/123 polycarboxylic
• CPC Class Codes: C10M 2207/126 monocarboxylic
• CPC Class Codes: C10M 2207/127 polycarboxylic
• CPC Class Codes: C10M 2207/141 monocarboxylic
• CPC Class Codes: C10M 2207/142 polycarboxylic
• CPC Class Codes: C10M 2207/281 of (cyclo)aliphatic monocarboxylic acids
• CPC Class Codes: C10M 2207/282 of (cyclo)aliphatic oolycarboxylic acids
• CPC Class Codes: C10M 2207/285 of aromatic polycarboxylic acids
• CPC Class Codes: C10M 2207/289 containing free hydroxy groups
• CPC Class Codes: C10M 2209/108 etherified
• CPC Class Codes: C10M 2215/04 having amino groups bound to acyclic or cycloaliphatic carbon atoms
• CPC Class Codes: C10M 2215/042 containing hydroxy groups; Alkoxylated derivatives thereof
• CPC Class Codes: C10M 2215/224 : Imidazoles
• CPC Class Codes: C10M 2215/28 : Amides; Imides
• CPC Class Codes: C10N 2030/06 : Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2040/042 : for automatic transmissions
• CPC Class Codes: C10N 2040/045 : for continuous variable transmission [CVT]
• CPC Class Codes: C10N 2060/14 : by boron or a compound containing boron
• CPC Class Codes: F16C 33/16 : Sliding surface consisting mainly of graphite
• CPC Class Codes: F16H 57/041 : Coatings or solid lubricants, e.g. antiseize layers or pastes
• CPC Class Codes: Y10T 428/30 : Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A low-friction sliding member in a transmission is at least one of sliding members which are in slidable contact with each other in presence of a transmission oil composition. The low-friction sliding member includes a base material having a sliding section. A hard carbon thin film is coated at a sliding surface of the sliding section of the base material. The hard carbon thin film contains hydrogen in an amount not more than 20 atomic %. The transmission oil composition contains at least one of organic oxygen-containing compound and aliphatic amine compound.

Claims

1. A low-friction sliding member in a transmission, the sliding member being at least one of sliding members which are in slidable contact with each other in presence of a transmission oil composition, the low-friction sliding member comprising:

a base material having a sliding section; and

a hard carbon thin film coated at a sliding surface of the sliding section of the base material, the hard carbon thin film containing hydrogen in an amount not more than 20 atomic %,

wherein the transmission oil composition contains at least one of organic oxygen-containing compound and aliphatic amine compound.

2. A low-friction sliding member as claimed in claim 1, wherein the transmission is a continuously variable transmission, and the transmission oil composition is a continuously variable transmission oil composition.

3. A low-friction sliding member as claimed in claim 2, wherein the hard carbon thin film contains hydrogen in an amount not more than 10 atomic %.

4. A low-friction sliding member as claimed in claim 2, wherein the hard carbon thin film contains hydrogen in an amount not more than 0.5 atomic %.

5. A low-friction sliding member as claimed in claim 2, wherein the sliding section of the base material has a surface roughness (Ra) not larger than 0.1μ

in a condition before the base material is coated with the hard carbon thin film.

6. A low-friction sliding member as claimed in claim 2, wherein the hard carbon thin film has a surface hardness (Hv) ranging from 1000 to 3500 in micro Vickers hardness as measured under application of a 10 g load, and a thickness ranging from 0.3 to 2.0 μ

m.

7. A low-friction sliding member as claimed in claim 2, wherein the organic oxygen-containing compound is at least one compound selected from the group consisting of at least one of monohydric alcohols, at least one of polyhydric alcohols, at least one of carboxylic acids, at least one of ethers, at least one derivative of monohydric alcohols, at least one derivative of polyhydric alcohols, at least one derivative of carboxylic acids, at least one derivative of ethers, and at least one derivative of esters, the organic oxygen-containing compound being contained in an amount ranging from 0.05 to 3.0% based on total amount of the continuously variable transmission oil composition.

8. A low-friction sliding member as claimed in claim 2, wherein the continuously variable transmission oil composition contains aliphatic amine compound having a hydrocarbon chain having a carbon number ranging from 6 to 30, n an amount ranging from 0.05 to 3.0% by mass based on a total mass of the continuously variable transmission oil composition.

9. A low-friction sliding member as claimed in claim 2, wherein the continuously variable transmission oil composition contains at least one of polybutenyl succinimide and a derivative of polybutenyl succinimide.

10. A low friction sliding member as claimed in claim 9, wherein the at least one of polybutenyl succinimide and a derivative of polybutenyl succinimide is contained in an amount ranging from 0.1 to 15% by mass based on a total mass of the continuously transmission oil composition.

11. A low friction sliding member as claimed in claim 1, wherein the transmission is an automatic transmission, and the transmission oil composition is an automatic transmission oil composition.

12. A low-friction sliding member as claimed in claim 11, wherein the hard carbon thin film contains hydrogen in an amount not more than 10 atomic %.

13. A low-friction sliding member as claimed in claim 11, wherein the hard carbon thin film contains hydrogen in an amount not more than 0.5 atomic %.

14. A low-friction sliding member as claimed in claim 11, wherein the sliding section of the base material has a surface roughness (Ra) not larger than 0.1μ

in a condition before the base material is coated with the hard carbon thin film.

15. A low-friction sliding member as claimed in claim 11, wherein the hard carbon thin film has a surface hardness (Hv) ranging from 1000 to 3500 in micro Vickers hardness as measured under application of a 10 g load, and a thickness ranging from 0.3 to 2.0 μ

m.

16. A low-friction sliding member as claimed in claim 11, wherein the organic oxygen-containing compound is at least one compound selected from the group consisting of at least one of monohydric alcohols, at least one of polyhydric alcohols, at least one of carboxylic acids, at least one of ethers, at least one derivative of monohydric alcohols, at least one derivative of polyhydric alcohols, at least one derivative of carboxylic acids, at least one derivative of ethers, and at least one derivative of esters, the organic oxygen-containing compound being contained in an amount ranging from 0.05 to 3.0% based on total amount of the automatic transmission oil composition.

17. A low-friction sliding member as claimed in claim 11, wherein the continuously variable transmission oil composition contains aliphatic amine compound having a hydrocarbon chain having a carbon number ranging from 6 to 30, n an amount ranging from 0.05 to 3.0% by mass based on a total mass of the automatic transmission oil composition.

18. A low-friction sliding member as claimed in claim 11, wherein the automatic transmission oil composition contains at least one of polybutenyl succinimide and a derivative of polybutenyl succinimide.

19. A low friction sliding member as claimed in claim 18, wherein the at least one of polybutenyl succinimide and a derivative of polybutenyl succinimide is contained in an amount ranging from 0.1 to 15% by mass based on a total mass of the automatic transmission oil composition.

20. A transmission oil composition used for a low-friction sliding member in a transmission, the sliding member being at least one of sliding members which are in slidable contact with each other in presence of the transmission oil composition, the low-friction sliding member including a base material having a sliding section, and a hard carbon thin film coated at a sliding surface of the sliding section of the base material, the hard carbon thin film containing hydrogen in an amount not more than 20 atomic %, the transmission oil composition comprising at least one of organic oxygen-containing compound and aliphatic amine compound.