Crankcase bypass system with oil scavenging device

• US 6,435,170 B1
• Filed: 08/01/2001
• Issued: 08/20/2002
• Est. Priority Date: 08/01/2001
• Status: Expired due to Term

• Current Assignee: Mahle Engine Components USA Incorporated (MAHLE-STIFTUNG GmbH)
• Original Assignee: Dana Corporation (Dana, Inc.)
• Inventors: Hamelink, Joseph C., Hill, Stephen H.
• Primary Examiner(s): MCMAHON, MARGUERITE J
• Application Number:
  US09/920,224
• Time in Patent Office: 384 Days
• Field of Search: 123/572, 123/573, 123/574, 123/41.86
• US Class Current: 123/572
• CPC Class Codes: F01M 13/04 having means for purifying air before leaving crankcase, e.g. removing oil
• CPC Class Codes: F01M 2013/0433 with a deflection device, e.g. screen
• CPC Class Codes: F02B 75/22 with cylinders in V, fan, or star arrangement
• CPC Class Codes: F02M 25/06 adding lubricant vapours
• CPC Class Codes: F02M 35/10222 Exhaust gas recirculation [EGR]; Positive crankcase ventilation [PCV]; Additional air admission, lubricant or fuel vapour admission
• CPC Class Codes: F02M 35/10288 Air intakes combined with another engine part, e.g. cylinder head cover or being cast in one piece with the exhaust manifold, cylinder head or engine block
• CPC Class Codes: F02M 35/116 for engines with cylinders in V-arrangement or arranged oppositely relative to the main shaft
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An engine crankcase bypass system includes a scavenging mechanism for the collection and removal of oil entrained in engine bypass gases that include unburned gasoline fuel and water vapors. The improved bypass system, designed to replace a standard PCV (positive crankcase ventilation) system, senses manifold and crankcase vacuum pressures, and via utilization of either an electronic or mechanical valve provides continuous adjustments of bypass gas flows for the maintenance of a constant gas flow sufficient to exceed normal engine bypass flow rates. A deflector system positioned in a flow stream is designed to extract and separate oil vapor from unburned gasoline fuel and water vapors entrained in the bypass gases. The oil is collected and drained to a temporary reservoir for subsequent re-entry into the oil sump of the engine. The fuel and water vapors are immediately returned to the intake manifold of the engine for reburning of the fuel.

Claims

1. An engine crankcase bypass system comprising:

a) a scavenging mechanism adapted for collection and removal of oil from an engine bypass gas flow stream, said mechanism adapted to effectively remove said oil from entrained unburned fuel and water vapors in said flow stream during entire operating performance range of said engine;

b) sensors for measuring at least engine intake manifold and crankcase vacuum pressures;

c) a modulating gas flow valve responsive to said sensor measurements of pressures to control flow stream volume of said bypass gases, said valve being adapted to provide continuous adjustments of bypass gas flows through said crankcase to provide a constant bypass gas flow rate; and

d) a deflector system disposed directly within said flow stream and adapted to extract and separate oil vapor from said entrained unburned fuel and water vapors in said constant rate flow stream.

2. The engine crankcase bypass system of claim 1 wherein said scavenging mechanism collects said oil for conveyance thereof to a temporary oil reservoir for subsequent transfer to an engine oil sump, and wherein said entrained unburned fuel and water vapors in said flow stream are immediately returned to said intake manifold of the engine for reuse of said unburned fuel.

3. The engine crankcase bypass system of claim 2 wherein said constant rate flow stream of bypass gases that exceeds maximum engine blow-by gas flow within a range of 5 to 7 cubic feet per minute.

4. The engine crankcase bypass system of claim 3 further comprising a temporary oil reservoir adapted to collect oil extracted and separated from said bypass gases that include said entrained unburned fuel and water vapors.

5. The engine crankcase bypass system of claim 4 further comprising a closed duct passageway integrally fixed to a rocker cover of any engine, wherein bypass gases flow through said duct, and wherein said oil deflector system is fixed within said duct.

6. The engine crankcase bypass system of claim of claim 5 wherein said modulating gas flow valve is a constant flow PCV valve subject to modulation based upon differentials between the engine manifold and engine sump pressures.

7. The engine crankcase bypass system of claim 6 wherein said deflector system comprises an impactor plate and an orifice plate spaced therefrom, and wherein the distance between said plates and the size of an orifice in said orifice plate comprises a controlled ratio.

8. The engine crankcase bypass system of claim 7 wherein said controlled ratio has a value ranging between 1.5 and 10.

9. The engine crankcase bypass system of claim 8 wherein the orifice plate of said oil deflector system includes a nozzle throat adjacent the orifice, wherein said throat is adapted to accelerate said bypass gas flow stream movement, and whereby said entrained oil vapor impacts said impactor plate and becomes separated from said bypass gas.

10. The engine crankcase bypass system of claim 9 wherein said reservoir comprises a drain valve situated at the bottom of said reservoir, and wherein said valve is responsive to vacuum pressure to retain said valve in a closed position.