Structure for connecting piston to crankshaft

• US 7,284,525 B2
• Filed: 08/10/2004
• Issued: 10/23/2007
• Est. Priority Date: 08/13/2003
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kano, Makoto, Hamada, Takahiro, Murata, Takashi, Mabuchi, Yutaka, Hirata, Takuya, Nishimura, Kimio, Yamaguchi, Masashi
• Primary Examiner(s): Kamen; Noah P.
• Assistant Examiner(s): Benton; Jason
• Application Number:
  US10/914,505
• Publication Number:
  US 20050061291A1
• Time in Patent Office: 1,169 Days
• Field of Search: 123/193.6, 123/193.3, 123/196.R
• US Class Current: 123/193.6
• CPC Class Codes: C10M 105/32 Esters
• CPC Class Codes: C10M 105/58 Amines, e.g. polyalkylene polyamines, quaternary amines polyalkylene polyamines with eleven or more monomer units C10M107/44
• CPC Class Codes: C10M 105/68 Amides; Imides
• CPC Class Codes: C10M 105/74 containing phosphorus
• CPC Class Codes: C10M 169/045 the additives being a mixture of compounds of unknown or incompletely defined constitution and non-macromolecular compounds
• CPC Class Codes: C10M 2203/1006 used as base material
• CPC Class Codes: C10M 2205/0285 used as base material
• CPC Class Codes: C10M 2207/028 Overbased salts thereof
• CPC Class Codes: C10M 2207/28 Esters
• CPC Class Codes: C10M 2207/289 containing free hydroxy groups
• CPC Class Codes: C10M 2215/02 Amines, e.g. polyalkylene polyamines; Quaternary amines
• CPC Class Codes: C10M 2215/042 containing hydroxy groups; Alkoxylated derivatives thereof
• CPC Class Codes: C10M 2215/28 Amides; Imides
• CPC Class Codes: C10M 2219/046 Overbasedsulfonic acid salts
• CPC Class Codes: C10M 2223/045 Metal containing thio derivatives
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2040/25 Internal-combustion engines
• CPC Class Codes: F16C 2206/04 Diamond like carbon [DLC]
• CPC Class Codes: F16C 33/043 Sliding surface consisting mainly of ceramics, cermets or hard carbon, e.g. diamond like carbon [DLC]
• CPC Class Codes: F16C 33/109 Lubricant compositions or properties, e.g. viscosity
• CPC Class Codes: F16C 9/04 : Connecting-rod bearings; Attachments thereof
• CPC Class Codes: F16H 57/04 : Features relating to lubrication or cooling or heatingin hydrokinetic gearing F16H41/30; control of lubrication or cooling in hydrostatic gearing F16H61/4165

Abstract

There is provided a structure for connecting a piston to a crankshaft in an internal combustion engine, including a piston pin fitted into the piston, a crankpin integral with the crankshaft and a connecting rod having a piston pin bearing portion slidably engaged with an outer cylindrical portion of the piston pin and a crankpin bearing portion slidably engaged with an outer cylindrical portion of the crankpin. At least one of the piston pin bearing portion of the connecting rod and the outer cylindrical portion of the piston pin and at least one of the crankpin bearing portion of the connecting rod and the outer cylindrical portion of the crankpin have hard carbon coatings formed thereon with a hydrogen content of 20 atomic % or less.

Claims

1. A structure for connecting a piston to a crankshaft in an internal combustion engine, comprising:

a piston pin fitted into the piston;

a crankpin integral with the crankshaft; and

a connecting rod having a piston pin bearing portion slidably engaged with an outer cylindrical portion of the piston pin and a crankpin bearing portion slidably engaged with an outer cylindrical portion of the crankpin,

wherein at least one of the piston pin bearing portion of the connecting rod and the outer cylindrical portion of the piston pin and at least one of the crankpin bearing portion of the connecting rod and the outer cylindrical portion of the crankpin have hard carbon coatings formed thereon by physical vapor deposition with a hydrogen content of 1 atomic % or less.

2. A structure according to claim 1, wherein the connecting rod is made of an aluminum alloy material.

8. A structure according to claim 1, wherein the hard carbon coatings are formed by arc ion plating.

3. A structure for connecting a piston to a crankshaft in an internal combustion engine, comprising:

a piston pin fitted into the piston;

a crankpin integral with the crankshaft;

a connecting rod having a piston pin bearing portion slidably engaged with an outer cylindrical portion of the piston pin and a crankpin bearing portion slidably engaged with an outer cylindrical portion of the crankpin; and

a lubricating oil supplied to a sliding interface between the piston pin and the connecting rod and a sliding interface between the crankpin and the connecting rod;

wherein at least one of the piston pin bearing portion of the connecting rod and the outer cylindrical portion of the piston pin and at least one of the crankpin bearing portion of the connecting rod and the outer cylindrical portion of the crankpin have hard carbon coatings formed thereon by physical vapor deposition with a hydrogen content of 20 atomic % or less, and

wherein the lubricating oil contains therein at least one friction modifier selected from the group consisting of an ashless fatty-ester friction modifier and an ashless aliphatic-amine friction modifier.

4. A structure according to claim 3, wherein at least one friction modifier has a C6-C30 hydrocarbon group, and is contained in an amount of 0.05 to 3.0% by mass based on a total mass of the lubricating oil.

5. A structure according to claim 3, wherein the lubricating oil contains polybutenyl succinimide and/or a derivative thereof.

6. A structure according to claim 5, wherein the polybutenyl succinimide and/or derivative thereof is contained in an amount of 0.1 to 15% by mass based on a total mass of the lubricating oil.

7. A structure according to claim 3, wherein the lubricating oil contains zinc dithiophosphate in an amount of 0.1% or less by mass in terms of phosphorus element based on a total mass of the lubricating oil.

9. A structure for connecting a piston to a crankshaft in an internal combustion engine, comprising:

a piston pin fitted into the piston;

a crankpin integral with the crankshaft;

a connecting rod having a piston pin bearing portion slidably engaged with an outer cylindrical portion of the piston pin and a crankpin bearing portion slidably engaged with an outer cylindrical portion of the crankpin; and

a lubricating oil supplied to a sliding interface between the piston pin and the connecting rod and a sliding interface between the crankpin and the connecting rod,

wherein at least one of the piston pin bearing portion of the connecting rod and the outer cylindrical portion of the piston pin and at least one of the crankpin bearing portion of the connecting rod and the outer cylindrical portion of the crankpin have hard carbon coatings formed thereon by physical vapor deposition with a hydrogen content of 1 atomic % or less; and

wherein the lubricating oil contains therein at least one friction modifier selected from the group consisting of an ashless fatty-ester friction modifier and an ashless aliphatic-amine friction modifier.

10. A structure for connecting a piston to a crankshaft in an internal combustion engine, comprising:

a piston pin fitted into the piston;

a crankpin integral with the crankshaft; and

a connecting rod having a piston pin bearing portion slidably engaged with an outer cylindrical portion of the piston pin and a crankpin bearing portion slidably engaged with an outer cylindrical portion of the crankpin,

wherein at least one of the piston pin bearing portion of the connecting rod and the outer cylindrical portion of the piston pin and at least one of the crankpin bearing portion of the connecting rod and the outer cylindrical portion of the crankpin have hard carbon coatings formed thereon with a hydrogen content of 1 atomic % or less.