Emergency engine lubrication systems and methods

Emergency lubrication systems and methods for an engine are provided. One system includes a primary lubrication system including a de-aeration oil tank configured to store de-aerated oil until the oil is de-aerated, a first oil supply line configured to provide de-aerated oil to the engine, and a first valve configured to control the flow of oil through the primary lubrication system. The system further includes a secondary lubrication system including a second valve coupled to the de-aeration oil tank and configured to control the flow of oil through the secondary lubrication system, and a second oil supply line coupled to the engine and to the de-aeration oil tank via the second valve. One method includes the steps of detecting a predetermined event in the engine, preventing the aerated oil from entering the primary lubrication system, and using the aerated oil in the secondary lubrication system to lubricate the engine.

FIELD OF THE INVENTION

The present invention generally relates to vehicle engines, and more particularly relates to emergency oil systems and methods for a vehicle engine.

BACKGROUND OF THE INVENTION

It is desirable that aircraft, and especially military aircraft, include a secondary lubrication system or “emergency oil system” to operate as a back-up lubrication system in the unlikely event that the primary lubrication system experiences a malfunction or, in the case of military aircraft, that the primary lubrication system is damaged during combat. Contemporary secondary lubrication systems are typically a redundant lubrication system that provides lubrication during the failure of the primary lubrication system. Specifically, the secondary lubrication system typically includes an amount of oil in addition to and separate from the oil for the primary lubrication system for use during operation of the secondary lubrication system. The inclusion of extra oil in the secondary lubrication system adds weight to the aircraft, which added weight is undesirable in aircraft applications.

Accordingly, it is desirable to provide emergency oil systems and methods that use oil from the primary lubrication system during operation. In other words, it is desirable to provide emergency oil systems and methods that reduces or eliminates extra oil. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.

BRIEF SUMMARY OF THE INVENTION

Various embodiments provide secondary lubrication systems for an engine including a primary lubrication system having a de-aeration oil tank for storing de-aerated oil. One secondary lubrication system comprises a first valve configured to be coupled to the de-aeration oil tank and configured to control the flow of the de-aerated oil stored in the de-aeration oil tank through the secondary lubrication system, and an oil supply line coupled to the de-aeration oil tank via the first valve and configured to be coupled to the engine.

Other embodiments provide engines for a vehicle. One engine comprises a primary lubrication system and secondary lubrication system coupled to the engine. The primary lubrication system comprises a de-aeration oil tank coupled to the engine and configured to store aerated oil until the oil is de-aerated, a first oil supply line coupled to the de-aeration oil tank and the engine, the first oil supply line configured to provide de-aerated oil to the engine, and a first valve coupled to the de-aeration oil tank and configured to control the flow of oil through the primary lubrication system. The secondary lubrication system comprises a second valve coupled to the de-aeration oil tank and configured to control the flow of oil through the secondary lubrication system, and a second oil supply line coupled to the engine and to the de-aeration oil tank via the second valve.

Methods for lubricating an engine including a primary lubrication system configured to store aerated oil in a de-aeration oil tank and a secondary lubrication system coupled to the de-aeration oil tank are also provided. One method comprises the steps of detecting a predetermined event in the engine, preventing the aerated oil from entering the primary lubrication system, and using the aerated oil in the secondary lubrication system to lubricate the engine.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments provide secondary lubrication systems (e.g., emergency oil systems) and methods that use oil from the primary lubrication system during operation. That is, the secondary lubrication systems do not include or reduces the extra oil or lubricant, but rather, use at least a portion of the oil or lubricant in the primary lubrication system during, for example, an emergency loss of oil supply and/or pressure, engine start-up, engine shut-down, and/or during another pre-determined event that may benefit from additional lubrication or cooling.

Turning now to the figures,FIG. 1is a block diagram of a prior art engine system100. At least in the illustrated example, engine system100has an engine110and a lubrication system120for engine110.

Engine110may be configured to power an aircraft (e.g., an airplane, a helicopter, an unmanned or manned aerial vehicle, etc.), a motor vehicle (e.g., a car, a truck, a military vehicle, etc.), a marine vessel (e.g., a boat, a ship, a submarine, etc.), and/or the like. Engine110typically includes various moving components (not shown) that need to be lubricated and/or cooled during operation of engine110.

Lubrication system120is configured to provide lubrication and/or cooling to the various moving components within engine110using, for example, oil or some other type of lubricant/coolant. At least in the illustrated example ofFIG. 1, lubrication system120includes an oil tank1210connected to an oil pump1220and connected to a scavenge pump1230(e.g., a return pump) via an oil supply line1215and an oil return line1225, respectively.

Oil tank1210is typically configured to store/hold oil that is deemed temporarily “unusable” by engine110for normal operation of engine110. That is, as the oil in lubrication system120is used to lubricate and/or cool engine110, the oil becomes aerated. As one skilled in the art understands, aerated oil does not perform well as a lubricant and/or coolant in engine110because aerated oil tends to have a lower overall density, such that there is less mass flow per unit volume. As such, aerated oil does not provide the desired lubrication and/or cooling effect on engine110. As such, oil tank1210is configured to store/hold aerated oil while the air rises out of the oil and the oil becomes substantially de-aerated and deemed suitable for use in lubricating and/or cooling engine110. Specifically, de-aerated oil tends to settle or accumulate toward the bottom of oil tank1210as the oil de-aerates. Once substantially de-aerated, the de-aerated oil is provided to engine110via oil pump1220.

Oil pump1220is typically configured to provide the de-aerated oil that has accumulated toward the bottom of oil tank1210to the various components of engine110that need to be lubricated and/or cooled via oil supply line1215, which is typically in the form of tubes, channels, and/or other cavities in engine110. Once engine110has used the oil supplied via oil pump1220and oil supply line1215(i.e., the oil has become aerated and/or heated), the oil is returned to oil tank1210via scavenge pump1230.

Scavenge pump1230is typically configured to provide the aerated oil that has been used to lubricate and/or cool the various components in engine110to oil tank1210via oil return line1225, which is typically in the form of tubes, channels, and/or other cavities in engine110. The aerated oil is temporarily stored/held in oil tank1210until the oil again becomes substantially de-aerated, accumulates toward the bottom of oil tank1210, and the lubricating/cooling cycle repeats.

As discussed above, aerated oil is considered unusable for normal operation of an engine; however, in various embodiments of the present invention, aerated oil is deemed usable for an engine in predetermined situations. That is, various embodiments of the present invention use oil that may be considered otherwise unusable to lubricate and/or cool an engine.

With reference now toFIG. 2,FIG. 2is a block diagram of one embodiment of an engine system200. At least in the illustrated embodiment, engine system200comprises an engine210, a primary lubrication system220, a secondary lubrication system230, and a shield (e.g., armor)240surrounding at least a portion of primary lubrication system220and/or secondary lubrication system230.

Engine210may be any engine or power plant capable of powering an aircraft (e.g., an airplane, a helicopter, an unmanned or manned aerial vehicle, etc.), a motor vehicle (e.g., a car, a truck, a military vehicle, etc.), a marine vessel (e.g., a boat, a ship, a submarine, etc.), and/or the like. That is, engine210typically includes various moving components (not shown) that need to be lubricated and/or cooled during operation of engine210.

Primary lubrication system220is configured to provide lubrication and/or cooling to the various moving components within engine210using, for example, oil or some other type of lubricant/coolant. At least in the illustrated example ofFIG. 2, primary lubrication system220includes a de-aeration oil tank2210connected to an oil pump2220and a return or scavenge pump2230via an oil supply line2215and an oil return line2225, respectively.

De-aeration oil tank2210is configured to store/hold oil at various stages of aeration. That is, de-aeration oil tank2210is configured to store/hold aerated oil until the oil becomes substantially de-aerated. In single oil tank configurations, de-aeration oil tank2210is the oil tank where oil is stored while de-aerating, and may also be referred to as oil tank2210. Once substantially de-aerated, the de-aerated oil is provided to oil pump2220via a valve2327, which oil is then provided to engine210via oil pump2220.

Oil pump2220is configured to provide the de-aerated oil in de-aeration oil tank2210to the various components of engine210that need to be lubricated and/or cooled via oil supply line2215, which may be in the form of tubes, channels, and/or other cavities in engine210. Once engine210has used the oil supplied via oil pump2220and oil supply line2215(i.e., the oil has become aerated and/or heated), the oil is returned to de-aeration oil tank2210via scavenge pump2230.

Scavenge pump2230is configured to provide the aerated oil that has been used to lubricate and/or cool the various components in engine210to de-aeration oil tank2210via oil return line2225, which may be in the form of tubes, channels, and/or other cavities in engine210. The aerated oil is temporarily stored/held in de-aeration oil tank2210until the oil becomes substantially de-aerated, accumulates toward the bottom of de-aeration oil tank2210, and the lubricating/cooling cycle repeats.

Secondary lubrication system230(which may be considered an emergency oil system) is configured to provide lubrication and/or cooling to the various moving components within engine210in predetermined situations (e.g., when primary lubrication system becomes damaged during combat, in the unlikely event that primary lubrication system220experiences a malfunction (e.g., low oil pressure and/or low oil quantity), at start-up of engine210, at shut-down of engine210, engine210operating at an extreme angle (e.g., attitude) that would impede normal oil supply and scavenge, the vehicle operating engine210performing a maneuver that impedes normal function of primary lubrication system220, and/or the like situations). At least in the embodiment illustrated inFIG. 2, secondary lubrication system230includes an oil supply line2315coupled to engine210, a pump2320(e.g., an oil pump, a jet pump, etc.) coupled to oil supply line2315, a de-aeration oil tank2210coupled to pump2320via a valve2317and oil supply line2315, a valve2327coupled between de-aeration oil tank2210and oil pump2220, an air pressure/flow generator2340coupled to de-aeration oil tank2210, a vent2350coupled to de-aeration oil tank2210via a valve2357, and one or more sensors/controllers2360coupled to engine210, de-aeration oil tank2210, primary lubrication system220, and valves2317,2327, and2337. Valves2317and2327may be suction valves allowing the suction of de-aerated oil from de-aeration oil tank2210through the suction inlets of pumps2320or2220, respectively.

Pump2320may be any device and/or system capable of pumping the aerated oil in de-aeration oil tank2210to engine210. That is, pump2320is configured to suck the aerated oil out of de-aeration tank2210and supply the aerated oil to engine210. In one embodiment, pump2320is an oil pump. In another embodiment, pump2320is a jet pump.

Air pressure/flow generator2340may be any device and/or system capable of pressurizing de-aeration oil tank2210. That is, air pressure/flow generator2340is configured to push the aerated oil out of de-aeration tank2210to engine210.

To de-pressurize de-aeration oil tank2210, vent2350can be opened, via valve2337, to expel the pressure within de-aeration oil tank2210. Although the embodiment illustrated inFIG. 2includes both pump2320and air pressure/flow generator2340(and valve2337), various embodiments contemplate that secondary lubrication system230may only include pump2320or air pressure/flow generator2340(and valve2337).

Each sensor2360is configured to detect the oil pressure and/or oil level of engine210and/or primary lubrication system220. One or more of sensors2360is/are configured to switch between operating primary lubrication system220and secondary lubrication system230depending on the one or more predetermined situations. That is, sensors(s)2360is/are configured to control air pressure/flow generator2340, pump2320, valve2317, valve2327, and/or valve2337in accordance with the operational status of primary lubrication system220and/or engine210.

In one embodiment, secondary lubrication system230comprises a sensor2360configured to detect the oil pressure in engine210and/or primary lubrication system220. In this embodiment, if sensor2360detects that the oil pressure in engine210and/or primary lubrication system220is below a predetermined pressure, sensor2360is configured to close valve2327and open valve2317such that oil stored within de-aeration oil tank2210is provided to engine210via oil supply line2315. In addition, sensor2360may close valve2337(if valve2337is open) and turn ON air pressure/flow generator2340to pressurize de-aeration oil tank2210such that the oil within de-aeration oil tank2210is “pushed” through oil supply line2315. Alternatively or additionally, sensor2360may close valve2337(if valve2337is open) and turn ON pump2320to suck the oil out of de-aeration oil tank2210and provide the oil to engine210via oil supply line2315.

In another embodiment, secondary lubrication system230comprises a sensor2360configured to detect the oil level in engine210and/or primary lubrication system220. In this embodiment, if sensor2360detects that the oil level in engine210and/or primary lubrication system220is below a predetermined level, sensor2360is configured to close valve2327and open valve2317such that oil stored within de-aeration oil tank2210is provided to engine210via oil supply line2315. In addition, sensor2360may close valve2337(if valve2337is open) and turn ON air pressure/flow generator2340to pressurize de-aeration oil tank2210such that the oil within de-aeration oil tank2210is “pushed” through oil supply line2315. Alternatively or additionally, sensor2360may close valve2337(if valve2337is open) and turn ON pump2320to suck the oil out of de-aeration oil tank2210and provide the oil to engine210via oil supply line2315.

In yet another embodiment, secondary lubrication system230comprises one or more sensors2360configured to detect the oil pressure and oil level in engine210and/or primary lubrication system220. In this embodiment, if the sensor(s)2360detect that the oil pressure and/or the oil level in engine210and/or primary lubrication system220is below a predetermined pressure and/or level, sensor2360is configured to close valve2327and open valve2317such that oil stored within de-aeration oil tank2210is provided to engine210via oil supply line2315. In addition, sensor2360may close valve2337(if valve2337is open) and open air pressure/flow generator2340to pressurize de-aeration oil tank2210such that the oil within de-aeration oil tank2210is “pushed” through oil supply line2315. Alternatively or additionally, sensor2360may close valve2337(if valve2337is open) and turn ON pump2320to suck the oil out of de-aeration oil tank2210and provide the oil to engine210via oil supply line2315.

In further embodiments of sensor2360, sensor2360is configured to determine the operating status (e.g., start-up and/or shut-down) of engine210. In one embodiment, if sensor2360detects that engine210is being started and/or shut down, sensor2360is configured to close valve2327and open valve2317such that oil stored within de-aeration oil tank2210is provided to engine210via oil supply line2315. In addition, sensor2360may close valve2337(if valve2337is open) and turn ON air pressure/flow generator2340to pressurize de-aeration oil tank2210such that the oil within de-aeration oil tank2210is “pushed” through oil supply line2315. Alternatively or additionally, sensor2360may close valve2337(if valve2337is open) and turn ON pump2320to suck the oil out of de-aeration oil tank2210and provide the oil to engine210via oil supply line2315.

During normal operation of engine210, sensor2360is configured to close valve2317and open valve2327so that oil is provided to engine210via oil supply line2215. During normal operation, air pressure/flow generator2340may be either turned ON or OFF and valve2337is closed or open, respectively, depending on if it is desirable to pressurize de-aeration oil tank2210.

FIG. 3is a block diagram of one embodiment of an engine system300. At least in the illustrated embodiment, engine system300comprises an engine310, a primary lubrication system320, a secondary lubrication system330, and a shield (e.g., armor)340surrounding at least a portion of primary lubrication system320and/or secondary lubrication system330.

Engine310may be any engine or power plant capable of powering an aircraft (e.g., an airplane, a helicopter, an unmanned or manned aerial vehicle, etc.), a motor vehicle (e.g., a car, a truck, a military vehicle, etc.), a marine vessel (e.g., a boat, a ship, a submarine, etc.), and/or the like. That is, engine310typically includes various moving components (not shown) that need to be lubricated and/or cooled during operation of engine310.

Primary lubrication system320is configured to provide lubrication and/or cooling to the various moving components within engine310using, for example, oil or some other type of lubricant/coolant. At least in the illustrated example ofFIG. 3, primary lubrication system320includes a de-aeration oil tank3210connected to a primary oil tank3275and a return or scavenge pump3230via an oil supply line3215and an oil return line3225, respectively. Primary lubrication system320further includes an oil pump coupled to primary oil tank3275and engine310

De-aeration oil tank3210is configured to store/hold oil at various stages of aeration. That is, de-aeration oil tank3210is configured to store/hold aerated oil until the oil becomes substantially de-aerated. Once substantially de-aerated, the de-aerated oil is provided to primary oil tank3275via a valve3327.

Primary oil tank3275is configured to store/hold de-aerated oil. Primary oil tank3275also includes an oil return line3285configured to return excess oil to de-aeration oil tank3210via a valve3277(e.g., a one-way valve), which is also configured to prevent aerated oil stored in de-aeration oil tank3210from entering primary oil tank3275. When needed by engine310, the aerated oil stored in primary oil tank3275is provided to engine310via oil pump3220.

Oil pump3220is configured to provide the de-aerated oil in de-aeration oil tank3210to the various components of engine310that need to be lubricated and/or cooled via oil supply line3215, which may be in the form of tubes, channels, and/or other cavities in engine310. Once engine310has used the oil supplied via oil pump3220and oil supply line3215(i.e., the oil has become aerated and/or heated), the oil is returned to de-aeration oil tank3210via scavenge pump3230.

Scavenge pump3230is configured to provide the aerated oil that has been used to lubricate and/or cool the various components in engine310to de-aeration oil tank3210via oil return line3225, which may be in the form of tubes, channels, and/or other cavities in engine310. The aerated oil is temporarily stored/held in de-aeration oil tank3210until the oil again becomes substantially de-aerated, accumulates toward the bottom of de-aeration oil tank3210, and the lubricating/cooling cycle repeats.

Secondary lubrication system330(which may be considered an emergency oil system) is configured to provide lubrication and/or cooling to the various moving components within engine310in predetermined situations (e.g., when primary lubrication system becomes damaged during combat, in the unlikely event that primary lubrication system320experiences a malfunction (e.g., low oil pressure and/or low oil quantity), at start-up of engine310, at shut-down of engine310, and/or the like situations).

At least in the embodiment illustrated inFIG. 3, secondary lubrication system330includes an oil supply line3315coupled to engine310, a pump3320coupled to oil supply line3315, a de-aeration oil tank3210coupled to pump3320via a valve3317and oil supply line3315, a valve3327coupled between de-aeration oil tank3210and primary oil tank3275, an air pressure/flow generator3340coupled to de-aeration oil tank3210, a vent3350coupled to de-aeration oil tank3210via a valve3357, and one or more sensors/controllers3360coupled to engine310, de-aeration oil tank3210, primary lubrication system320, and valves3317,3327, and3337.

Pump3320may be any device and/or system capable of pumping the aerated oil in de-aeration oil tank3210to engine310. That is, pump3320is configured to suck the aerated oil out of de-aeration tank3210and supply the aerated oil to engine310. In one embodiment, pump3320is an oil pump. In another embodiment, pump3320is a jet pump. Valves3327and3317may be suction valves allowing pumps3220and3320, respectively to take suction on de-aeration oil tank3210.

Air pressure/flow generator3340may be any device and/or system capable of pressurizing de-aeration oil tank3210. That is, air pressure/flow generator3340is configured to push the aerated oil out of de-aeration tank3210to engine310.

To de-pressurize de-aeration oil tank3210, vent3350can be opened, via valve3337, to expel the pressure within de-aeration oil tank3210. Although the embodiment illustrated inFIG. 3includes both pump3320and air pressure/flow generator3340(and valve3337), various embodiments contemplate that secondary lubrication system330may only include pump3320or air pressure/flow generator3340(and valve3337).

Each sensor3360is configured to detect the oil pressure and/or oil level of engine310and/or primary lubrication system320. One or more of sensors3360is/are configured to switch between operating primary lubrication system320and secondary lubrication system330depending on the one or more predetermined situations. That is, sensors(s)3360are configured to control air pressure/flow generator3340, pump3320, valve3317, valve3327, and/or valve3337in accordance with the operational status of primary lubrication system320and/or engine310.

In one embodiment, secondary lubrication system330comprises a sensor3360configured to detect the oil pressure in engine310and/or primary lubrication system320. In this embodiment, if sensor3360detects that the oil pressure in engine310and/or primary lubrication system320is below a predetermined pressure, sensor3360is configured to close valve3327and open valve3317such that oil stored within de-aeration oil tank3210is provided to engine310via oil supply line3315. In addition, sensor3360may close valve3337(if valve3337is open) and turn ON air pressure/flow generator3340to pressurize de-aeration oil tank3210such that the oil within de-aeration oil tank3210is “pushed” through oil supply line3315. Alternatively or additionally, sensor3360may close valve3337(if valve3337is open) and turn ON pump3320to suck the oil out of de-aeration oil tank3210and provide the oil to engine310via oil supply line3315.

In another embodiment, secondary lubrication system330comprises a sensor3360configured to detect the oil level in engine310and/or primary lubrication system320. In this embodiment, if sensor3360detects that the oil level in engine310and/or primary lubrication system320is below a predetermined level, sensor3360is configured to close valve3327and open valve3317such that oil stored within de-aeration oil tank3210is provided to engine310via oil supply line3315. In addition, sensor3360may close valve3337(if valve3337is open) and turn ON air pressure/flow generator3340to pressurize de-aeration oil tank3210such that the oil within de-aeration oil tank3210is “pushed” through oil supply line3315. Alternatively or additionally, sensor3360may close valve3337(if valve3337is open) and turn ON pump3320to suck the oil out of de-aeration oil tank3210and provide the oil to engine310via oil supply line3315.

In yet another embodiment, secondary lubrication system330comprises one or more sensors3360configured to detect the oil pressure and oil level in engine310and/or primary lubrication system320. In this embodiment, if the sensor(s)3360detect that the oil pressure and/or the oil level in engine310and/or primary lubrication system320is below a predetermined pressure and/or level, sensor3360is configured to close valve3327and open valve3317such that oil stored within de-aeration oil tank3210is provided to engine310via oil supply line3315. In addition, sensor3360may close valve3337(if valve3337is open) and turn ON air pressure/flow generator3340to pressurize de-aeration oil tank3210such that the oil within de-aeration oil tank3210is “pushed” through oil supply line3315. Alternatively or additionally, sensor3360may close valve3337(if valve3337is open) and turn ON pump3320to suck the oil out of de-aeration oil tank3210and provide the oil to engine310via oil supply line3315.

In further embodiments of sensor3360, sensor3360is configured to determine the operating status (e.g., start-up and/or shut-down) of engine310. In one embodiment, if sensor3360detects that engine310is being started and/or shut down, sensor3360is configured to close valve3327and open valve3317such that oil stored within de-aeration oil tank3210is provided to engine310via oil supply line3315. In addition, sensor3360may close valve3337(if valve3337is open) and turn ON air pressure/flow generator3340to pressurize de-aeration oil tank3210such that the oil within de-aeration oil tank3210is “pushed” through oil supply line3315. Alternatively or additionally, sensor3360may close valve3337(if valve2337is open) and turn ON pump3320to suck the oil out of de-aeration oil tank3210and provide the oil to engine310via oil supply line3315.

During normal operation of engine310, sensor3360is configured to close valve3317and open valve3327so that oil is provided to engine310via oil supply line3215. During normal operation, air pressure/flow generator3340may be either turned ON or OFF and valve3337is closed or open, respectively, depending on if it is desirable to pressurize de-aeration oil tank3210.

FIG. 4is a block diagram of one embodiment of an engine system400. At least in the illustrated embodiment, engine system400comprises an engine410, a primary lubrication system420, a secondary lubrication system430, and a shield (e.g., armor)440surrounding at least a portion of primary lubrication system420and/or secondary lubrication system430.

Engine410may be any engine or power plant capable of powering an aircraft (e.g., an airplane, a helicopter, an unmanned or manned aerial vehicle, etc.), a motor vehicle (e.g., a car, a truck, a military vehicle, etc.), a marine vessel (e.g., a boat, a ship, a submarine, etc.), and/or the like. That is, engine410typically includes various moving components (not shown) that need to be lubricated and/or cooled during operation of engine410.

Primary lubrication system420is configured to provide lubrication and/or cooling to the various moving components within engine410using, for example, oil or some other type of lubricant/coolant. At least in the illustrated example ofFIG. 4, primary lubrication system420includes a de-aeration oil tank4210connected to a primary oil tank4275and a return or scavenge pump4230via an oil supply line4215and an oil return line4225, respectively. Primary lubrication system420further includes an oil pump coupled to primary oil tank4275and engine410

De-aeration oil tank4210is configured to store/hold oil at various stages of aeration. That is, de-aeration oil tank4210is configured to store/hold aerated oil until the oil becomes substantially de-aerated. Once substantially de-aerated, the de-aerated oil is provided to primary oil tank4275via a valve4327and a boost pump4290, which is configured to pressurize primary oil tank4275, along oil supply line4215.

Primary oil tank4275is configured to store/hold de-aerated oil. Primary oil tank4275also includes an oil return line4285configured to return excess oil to de-aeration oil tank4210via a valve4277(e.g., a one-way valve), which is also configured to prevent aerated oil stored in de-aeration oil tank4210from entering primary oil tank4275. When needed by engine410, the aerated oil stored in primary oil tank4275is provided to engine410via oil pump4220.

Oil pump4220is configured to provide the de-aerated oil in primary oil tank4275to the various components of engine410that need to be lubricated and/or cooled via oil supply line4215, which may be in the form of tubes, channels, and/or other cavities in engine410. Once engine410has used the oil supplied via oil pump4220and oil supply line4215(i.e., the oil has become aerated and/or heated), the oil is returned to de-aeration oil tank4210via scavenge pump4230.

Scavenge pump4230is configured to provide the aerated oil that has been used to lubricate and/or cool the various components in engine410to de-aeration oil tank4210via oil return line4225, which may be in the form of tubes, channels, and/or other cavities in engine410. The aerated oil is temporarily stored/held in de-aeration oil tank4210until the oil again becomes substantially de-aerated, accumulates toward the bottom of de-aeration oil tank4210, and the lubricating/cooling cycle repeats.

Secondary lubrication system430(which may be considered an emergency oil system) is configured to provide lubrication and/or cooling to the various moving components within engine410in predetermined situations (e.g., when primary lubrication system becomes damaged during combat, in the unlikely event that primary lubrication system420experiences a malfunction (e.g., low oil pressure and/or low oil quantity), at start-up of engine410, at shut-down of engine410, and/or the like situations). At least in the embodiment illustrated inFIG. 4, secondary lubrication system430includes an oil supply line4315coupled to engine410, a pump4320coupled to oil supply line4315, a de-aeration oil tank4210coupled to pump4320via a valve4317and oil supply line4315, a valve4327coupled between de-aeration oil tank4210and primary oil tank4275, an air pressure/flow generator4340coupled to de-aeration oil tank4210, a vent4350coupled to de-aeration oil tank4210via a valve4357, and one or more sensors/controllers4360coupled to engine410, de-aeration oil tank4210, primary lubrication system420, and valves4317,4327, and4337.

Pump4320may be any device and/or system capable of pumping the aerated oil in de-aeration oil tank4210to engine410. That is, pump4320is configured to suck the aerated oil out of de-aeration tank4210and supply the aerated oil to engine410. In one embodiment, pump4320is an oil pump. In another embodiment, pump4320is a jet pump.

Air pressure/flow generator4340may be any device and/or system capable of pressurizing de-aeration oil tank4210. That is, air pressure/flow generator4340is configured to push the aerated oil out of de-aeration tank4210to engine410.

To de-pressurize de-aeration oil tank4210, vent4350can be opened, via valve4337, to expel the pressure within de-aeration oil tank4210. Although the embodiment illustrated inFIG. 4includes both pump4320and air pressure/flow generator4340(and valve4337), various embodiments contemplate that secondary lubrication system430may only include pump4320or air pressure/flow generator4340(and valve4337).

Each sensor4360is configured to detect the oil pressure and/or oil level of engine410and/or primary lubrication system420. One or more of sensors4360is/are configured to switch between operating primary lubrication system420and secondary lubrication system430depending on the one or more predetermined situations. That is, sensors(s)4360are configured to control air pressure/flow generator4340, pump4320, valve4317, valve4327, and/or valve4337in accordance with the operational status of primary lubrication system420and/or engine410.

In one embodiment, secondary lubrication system430comprises a sensor4360configured to detect the oil pressure in engine410and/or primary lubrication system420. In this embodiment, if sensor4360detects that the oil pressure in engine410and/or primary lubrication system420is below a predetermined pressure, sensor4360is configured to close valve4327and open valve4317such that oil stored within de-aeration oil tank4210is provided to engine410via oil supply line4315. In addition, sensor4360may close valve4337(if valve4337is open) and turn ON air pressure/flow generator4340to pressurize de-aeration oil tank4210such that the oil within de-aeration oil tank4210is “pushed” through oil supply line4315. Alternatively or additionally, sensor4360may close valve4337(if valve4337is open) and turn ON pump4320to suck the oil out of de-aeration oil tank4210and provide the oil to engine410via oil supply line4315.

In another embodiment, secondary lubrication system430comprises a sensor4360configured to detect the oil level in engine410and/or primary lubrication system420. In this embodiment, if sensor4360detects that the oil level in engine410and/or primary lubrication system420is below a predetermined level, sensor4360is configured to close valve4327and open valve4317such that oil stored within de-aeration oil tank4210is provided to engine410via oil supply line4315. In addition, sensor4360may close valve4337(if valve4337is open) and turn ON air pressure/flow generator4340to pressurize de-aeration oil tank4210such that the oil within de-aeration oil tank4210is “pushed” through oil supply line4315. Alternatively or additionally, sensor4360may close valve4337(if valve4337is open) and turn ON pump4320to suck the oil out of de-aeration oil tank4210and provide the oil to engine410via oil supply line4315.

In yet another embodiment, secondary lubrication system430comprises one or more sensors4360configured to detect the oil pressure and oil level in engine410and/or primary lubrication system420. In this embodiment, if the sensor(s)4360detect that the oil pressure and/or the oil level in engine410and/or primary lubrication system420is below a predetermined pressure and/or level, sensor4360is configured to close valve4327and open valve4317such that oil stored within de-aeration oil tank4210is provided to engine410via oil supply line4315. In addition, sensor4360may close valve4337(if valve4337is open) and turn ON air pressure/flow generator4340to pressurize de-aeration oil tank4210such that the oil within de-aeration oil tank4210is “pushed” through oil supply line4315. Alternatively or additionally, sensor4360may close valve4337(if valve4337is open) and turn ON pump4320to suck the oil out of de-aeration oil tank4210and provide the oil to engine410via oil supply line4315.

In further embodiments of sensor4360, sensor4360is configured to determine the operating status (e.g., start-up and/or shut-down) of engine410. In one embodiment, if sensor4360detects that engine410is being started and/or shut down, sensor4360is configured to close valve4327and open valve4317such that oil stored within de-aeration oil tank4210is provided to engine410via oil supply line4315. In addition, sensor4360may close valve4337(if valve4337is open) and turn ON air pressure/flow generator4340to pressurize de-aeration oil tank4210such that the oil within de-aeration oil tank4210is “pushed” through oil supply line4315. Alternatively or additionally, sensor4360may close valve4337(if valve4337is open) and turn ON pump4320to suck the oil out of de-aeration oil tank4210and provide the oil to engine410via oil supply line4315.

During normal operation of engine410, sensor4360is configured to close valve4317and open valve4327so that oil is provided to engine410via oil supply line4215. During normal operation, air pressure/flow generator4340may be either turned ON or OFF and valve4337is closed or open, respectively, depending on if it is desirable to pressurize de-aeration oil tank4210.