US4915067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve operating system of internal combustion engine
Assignee: Nissan Motor Co Ltd
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Filing: 1989-01-12
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Granted: 1990-04-10
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Expires: 2009-01-12
Abstract
Abstract A valve operating system for an automotive internal combustion engine. The valve operating system is comprised of a plurality of bearing sections formed in a cylinder head of the engine and adapted to rotatably support a camshaft formed with a plurality of bearing journal sections. Each bearing section has a generally cylindrical bearing surface defining a bore in which each camshaft bearing journal section is disposed. The peripheral surface of the camshaft bearing journal section is slidably contactable with the bearing section bearing surface. In a cross-section to which the axis of the bore is perpendicular, the bearing surface has a first diametrical distance in which reaction of a valve spring for an intake or exhaust valve is applied, and a second diametrical distance perpendicular to the above-mentioned direction. The first diametrical distance is smaller than the second diametrical distance, thereby forming larger an oil clearance correponding to the first diametrical distance than an oil clearance corresponding to the second diametrical distance.
Inventors
- 👤 Minoru Imajo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:33
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/02; F01L1/04; F01L1/047; F01L1/053; F01M; F01M9/00; F01M9/10; F01M9/102; F02; F02B; F02B2275/00; F02B2275/18
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
140 words
A valve operating system of an internal combustion engine, comprising: a camshaft by which an engine valve is driven, said camshaft having a bearing journal section; and a bearing section for rotatably supporting said camshaft, said bearing section having a generally cylindrical bearing surface defining a bore in which said camshaft bearing journal section is disposed, the peripheral surface of said camshaft bearing journal section being slidably contactable with said bearing section bearing surface, said generally cylindrical bearing surface having, in a cross-section to which a central longitudinal axis of said camshaft is perpendicular, a first diametrical distance in a first direction in which reaction of a valve spring for the engine valve is applied, and a second diametrical distance in a second direction perpendicular to the first direction, said first diametrical distance being smaller than said second diametrical distance.
Claim 2
Dependent Claim
140 words
A valve operating system of an internal combustion engine, comprising: a camshaft by which an engine valve is driven, said camshaft having a bearing journal section; and a bearing section for rotatably supporting said camshaft, said bearing section having a generally cylindrical bearing surface defining a bore in which said camshaft bearing journal section is disposed, the peripheral surface of said camshaft bearing journal section being slidably contactable with said bearing section bearing surface, said generally cylindrical bearing surface having, in a cross-section to which a central longitudinal axis of said camshaft is perpendicular, a first diametrical distance in a first direction in which reaction of a valve spring for the engine valve is applied, and a second diametrical distance in a second direction perpendicular to the first direction, said first diametrical distance being smaller than said second diametrical distance.
Claim 3
Dependent Claim
185 words
A valve operating system of an internal combustion engine, comprising: a camshaft by which an engine valve is driven, said camshaft having a bearing journal section; a bearing section for rotatably supporting said camshaft, said bearing section having a generally cylindrical bearing surface defining a bore in which said camshaft bearing journal section is disposed, the peripheral surface of said camshaft bearing journal section being slidably contactable with said bearing section bearing surface, said generally cylindrical bearing surface having, in a cross-section to which a central longitudinal axis of said camshaft is perpendicular, a first diametrical distance in a first direction in which reaction of a valve spring for the engine valve is applied, a second diametrical distance in a second direction perpendicular to the first direction, said first diametrical distance being smaller than said second diametrical distance; and means defining first and second oil clearances formed between said bearing section bearing surface and said camshaft journal section peripheral surface, said first and second oil clearances respectively corresponding to first and second diametrical distances, said first oil clearance being smaller than said second oil clearance.
Claim 4
Dependent Claim
185 words
A valve operating system of an internal combustion engine, comprising: a camshaft by which an engine valve is driven, said camshaft having a bearing journal section; a bearing section for rotatably supporting said camshaft, said bearing section having a generally cylindrical bearing surface defining a bore in which said camshaft bearing journal section is disposed, the peripheral surface of said camshaft bearing journal section being slidably contactable with said bearing section bearing surface, said generally cylindrical bearing surface having, in a cross-section to which a central longitudinal axis of said camshaft is perpendicular, a first diametrical distance in a first direction in which reaction of a valve spring for the engine valve is applied, a second diametrical distance in a second direction perpendicular to the first direction, said first diametrical distance being smaller than said second diametrical distance; and means defining first and second oil clearances formed between said bearing section bearing surface and said camshaft journal section peripheral surface, said first and second oil clearances respectively corresponding to first and second diametrical distances, said first oil clearance being smaller than said second oil clearance.
Claim 5
Dependent Claim
44 words
A valve operating system as claimed in claim 1, wherein said camshaft bearing journal is accurately circular in a cross-section to which the axis of the bore is perpendicular so as to be constant in diameter throughout the whole periphery of said bearing journal.
Claim 6
Dependent Claim
21 words
A valve operating system as claimed in claim 1, wherein said bearing section bearing surface is generally elliptic in the cross-section.
Claim 7
Dependent Claim
48 words
A valve operating system as claimed in claim 1, wherein said bearing section bearing surface is generally elongate circle-shaped in the cross-section, in which radius of curvature of said bearing surface corresponding to said second diametrical distance is the same as that of said camshaft bearing journal section.
References Cited (Backward Citations)
US3201183A
Cited
FR1340771A
Cited
JPS5325711A
Cited
JPS5392005A
Cited
US4537166A
Cited
JPS60167103A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |