A positive crankcase ventilation valve for an engine is provided with a valve body defining apertures fluidly coupling a crankcase and an intake manifold of the engine, with each aperture sized to prevent an entrained oil droplet from flowing therethrough. The valve has a valve element supported by the body to selectively cover at least one of the apertures in response to a pressure difference between the manifold and the crankcase to provide variable air flow from the crankcase to the intake manifold. A method includes, in response to an increasing absolute pressure difference between the manifold and the crankcase, passively moving a valve element to selectively cover apertures fluidly coupling the crankcase and the manifold to control an air flow from the crankcase to the intake manifold to a predetermined variable flow profile, and separating oil droplets from the air flow via the apertures.

A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

A connection device for connecting a ventilating line to an intake air flow guide of an internal combustion engine, wherein the connection device has a non-return valve for preventing a flow from the intake air flow guide into the ventilating line. The connection device has at least one hole which is arranged upstream of the non-return valve and connects an interior chamber of the connection device to a surrounding area of the connection device.

A pollution control system for a diesel engine includes a PCV valve and an associated vacuum pump having an inlet and an outlet adapted to vent blow-by gas out from a crankcase to an intake manifold on the diesel engine. The vacuum pump associated with the PCV valve selectively modulates vacuum pressure to adjustably increase or decrease a fluid flow rate of blow-by gas venting from the crankcase through the PCV valve.

A blowby gas treatment device includes a pressure control valve, a fresh air induction pipe, a first blowby gas pipe, a second blowby gas pipe, a shutoff valve, a one-way valve, and a PCV valve. A leak diagnosis includes a first-stage diagnosis to determine whether or not falling of a pressure in a crank case after closing of the shutoff valve under a non-supercharging condition is normal. A second-stage diagnosis is implemented by moving the pressure control valve from a fully opened state into a fully closed state, and determining whether an intake air quantity in each state is equal to each other. When the intake air quantity in each state is equal to each other, presence of an in-system leak is determined. When a fully closed state intake air quantity is different from a fully opened state intake air quantity, presence of an out-of-system leak is determined.

An apparatus that improves the gas mileage of an internal combustion engine in a vehicle is disclosed that is comprised of an air inlet, a condensation chamber, and an air outlet that is connected to the vehicle's oil system through an oil filler port in the engine of the vehicle.

A diffuser for a jet pump of a separator comprises an inlet defining a first flow area; an outlet in fluid communication with the inlet through which fluid exits the diffuser, in which a flow path extends from the inlet to the outlet, and in which the outlet defines a second flow area greater than the first flow area so that a velocity of fluid flowing through the inlet is greater than a velocity of fluid flowing through the outlet; and a communication port extending through a wall of the diffuser with an inlet in communication with an interior of the diffuser and an outlet in communication with an exterior of the diffuser, in which the communication port inlet is between the diffuser inlet and the diffuser outlet, so that contaminants separated from the fluid stream are removed through the communication port.

A ventilation apparatus of an internal combustion engine of the invention ventilates a chain chamber by recirculating blow-by gas to an intake passage through a blow-by gas recirculation pipe and introducing air into the chain chamber through an air introduction pipe. The air introduction pipe is secured to a head cover wall portion which corresponds to a portion of a head cover wall which defines the chain chamber.

Positive crankcase ventilation (PCV) systems have been employed on naturally-aspirated engines for over half a century. The gases in the crankcase exit the engine into the engine intake due to the slightly elevated pressure in the crankcase. Flow is controlled via a PCV valve in a PCV duct. In pressure-charged engines, PCV flow stops when pressure in the intake exceeds that of the crankcase. Such stagnation leads to sludging and deposit formation. According to an embodiment of the disclosure, reverse flow through the system is allowed by installing a second PCV valve in parallel with the normally-provided PCV valve, with the second PCV valve allowing an opposite direction of flow. Oil separators are provided on both PCV ducts to and from the engine to remove oil from blowby gases for flow in either direction.

The present invention relates to an oil tank ventilation device for a hydraulic brake unit of a tramcar, comprising a vent plug, a sealing ring, a gas guide hole and a gas guide pipe; the gas guide hole is a through-hole structure arranged at an upper end inside an integrated valve block; the communications of electrical element protection case, integrated valve block and the oil tank are realized by the gas guide pipe stretched into an air chamber of the oil tank and by the vent plug configured in the electrical element protection case. When the surface of the oil tank is covered with ice or snow, the rain or snow can be effectively prevent from falling on the vent plug body and the driving safety of the train is ensured.