US4958613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internal combustion engine with crankcase ventilation system
Assignee: Nissan Motor Co Ltd
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Filing: 1989-10-04
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Granted: 1990-09-25
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Expires: 2009-10-04
Abstract
Abstract An internal combustion engine is equipped with a crankcase ventilation system in which fresh air flows through a crankcase. The cylinder block of the engine is formed with a fresh air suction port whose one end is opened to the chamber of a crankcase in order to establish communication between a rocker cover chamber and the crankcase chamber. The one end of the fresh air suction port is located in the vicinity of the peripheral surface of a counterweight of a crankshaft. The rotation of the counterweight develops vacuum thereby to suck fresh air from the rocker cover chamber through the fresh air suction port into the crankcase chamber, thereby effecting ventilation in the crankcase.
Inventors
- 👤 Toyoki Hiraoka
- 👤 Yuichi Murakami
- 👤 Nobuyuki Okitsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:38
CPC Classifications
F; F01; F01M; F01M13/00; F01M13/04; F01M13/0416; F01M13/0033; F02; F02B; F02B75/00; F02B75/16; F02B75/18; F02B75/22; F02F; F02F7/00; F02F7/006
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
An internal combustion engine comprising: a rocker cover secured to a cylinder head and defining therein a chamber; means defining a first passage through which fresh air is introduced into the rocker cover chamber; a crankcase defining thereinside a chamber; means defining a second passage through which said rocker cover chamber is in communication with an air intake passage; a crankshaft rotatably supported and including a counterweight, said counterweight being disposed within said crankcase chamber and having a peripheral surface; and means defining a fresh air suction port through which said rocker cover chamber is in communication with said crankcase chamber, said fresh air suction port having a first end which opens to said crankcase chamber and is located in the vicinity of the peripheral surface of said counterweight.
Claim 2
Dependent Claim
129 words
An internal combustion engine comprising: a rocker cover secured to a cylinder head and defining therein a chamber; means defining a first passage through which fresh air is introduced into the rocker cover chamber; a crankcase defining thereinside a chamber; means defining a second passage through which said rocker cover chamber is in communication with an air intake passage; a crankshaft rotatably supported and including a counterweight, said counterweight being disposed within said crankcase chamber and having a peripheral surface; and means defining a fresh air suction port through which said rocker cover chamber is in communication with said crankcase chamber, said fresh air suction port having a first end which opens to said crankcase chamber and is located in the vicinity of the peripheral surface of said counterweight.
Claim 3
Dependent Claim
63 words
An internal combustion engine as claimed in claim 1, wherein said fresh air suction port defining means includes means defining said suction port first end in a surface of a cylinder block defining said crankcase chamber, a clearance being defined between said cylinder block surface and the peripheral surface of said counterweight, said clearance being tapered in direction of rotation of said counterweight.
Claim 4
Dependent Claim
28 words
An internal combustion engine as claimed in claim 1, further comprising means for allowing fresh air from said first passage to flow into said fresh air suction port.
Claim 5
Dependent Claim
26 words
An internal combustion engine as claimed in claim 3, further comprising means for allowing blow-by gas from said crankcase chamber to flow into said second passage.
Claim 6
Dependent Claim
21 words
An internal combustion engine as claimed in claim 4, further comprising means for separating engine lubricating oil from said blow-by gas.
Claim 7
Dependent Claim
29 words
An internal combustion engine as claimed in claim 1, wherein said counterweight is located rear-most of a plurality of counterweights of said crankshaft, in longitudinal direction of the engine.
Claim 8
Dependent Claim
28 words
An internal combustion engine as claimed in claim 1, wherein said fresh air suction port has a second end which is in communication with said rocker cover chamber.
Claim 9
Dependent Claim
21 words
An internal combustion engine as claimed in claim 1, wherein said fresh air suction port is formed in said cylinder block.
Claim 10
Dependent Claim
50 words
An internal combustion engine as claimed in claim 6, further comprising means defining a third passage through which the crankcase chamber is in communication with said rocker cover chamber, said third passage being separate from said fresh air suction port and located in a front end section of the engine.
Claim 11
Dependent Claim
79 words
An internal combustion engine as claimed in claim 9, further comprising a baffle plate fixedly disposed in said rocker cover chamber, means defining first and second separator chambers between said baffle plate and the inner wall surface of said rocker cover, said first separator chamber is in communication with said second passage and in communication with said third passage, said second separator chamber being in communication with said first passage and in communication with said fresh air suction port.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |