An air cleaner assembly includes a precleaner assembly. In one aspect, the precleaner assembly incudes a bypass arrangement that is operated to bypass a portion of air around the precleaner assembly. The bypass arrangement can be operated by a controller based on at least one input signal corresponding to one or more of a vehicle speed, a vehicle engine speed, a vehicle engine load, an operator input, a vehicle location, an air pressure drop across a filter element, an air pressure drop across the precleaner assembly, an acoustic level, a vibration level, a change or cleaning frequency of the filter element, a total number of filter element changes, an identity of the filter element, an identity of the engine, an identity of the vehicle, an air flow rate through the precleaner assembly or through the filter element, and a weather condition parameter identified through data received locally or from a weather service.

A particle separator assembly includes an airbox providing an outer tapered portion tapering from a first section having a first cross sectional area to a first opening having a second cross sectional area less than the first cross sectional area. The example assembly includes a flow diverter providing an inner tapered portion that tapers to a second opening. The example assembly includes an air filter housed by the airbox, the air filter is spaced from the second opening in a first direction, and the first opening is spaced from the second opening in a second direction opposite the first direction.

An air filter for heavy dust conditions has an efficient scavenging system. The air filter includes: a housing, a permeable filter, and a scavenger system. The scavenger system disposes of particles collected on the upstream surface of the permeable filter. The scavenger system includes: an air suction source, and a shutter. The shutter is positioned substantially along, typically below, the permeable filter, at a certain distance from a wall, typically the bottom wall, of the housing. The air suction source draws air from a collecting space located between the shutter and the wall of the housing. The shutter is being selectively operated to permit or restrict passage there-through. The air suction source efficiently operates to scavenge particles from the collecting space when the passage through the shutter is at least partially restricted.

A pre-cleaner for an internal combustion engine is arranged in an intake passage of the internal combustion engine at an upstream side of a filter of an air cleaner. The pre-cleaner includes a casing that includes a cylindrical side wall and swirl generation vanes that swirl intake air about an axis of the casing. The side wall has a portion located next to an upstream side of the swirl generation vanes that is formed from an air-permeable fibrous molded body.

The Multiple Intake Air Filtration Device of this invention is a superior, highly efficient air cleaner that utilizes an array of multiple-intake cyclonic tubes spinning air at high speed to efficiently remove the specific sizes of dirt and other particulates that can be ingested in off-road and highway vehicle operations. This Multiple Intake Air Filtration Device is well-suited for use with both normally-aspirated engines and turbocharged engines. It is superior to automotive air cleaners that filter out dirt by use of a screen or porous media because it never becomes clogged as dirt and particulates are filtered out, and it is superior to devices that utilize only a single air flow through cyclonic tubes, because the device of this invention cleans intake air more efficiently while providing a strong flow of clean air to the engine or other component.

An air cleaner includes a base member including a base wall extending substantially horizontally, and a cover member attached to an upper side of the base wall to jointly define a filter chamber for receiving a filter element therein. The air cleaner further includes a passage member communicating with the filter chamber and incorporated with a plurality of air ejection pipes each surrounded by an annular air inlet passage fitted with guide vanes for rotating the air flow, and a case member defining separation chambers for separating dust from the rotating air flow. The passage member is interposed between the cover member and the case member.

A multi-cyclone separator of a multi-stage fluid filter for cleaning gaseous fluid is provided with a plurality of cyclone cells for separating particles and/or liquid from the gaseous fluid. The cyclone cells each have an inlet for the gaseous fluid to be purified, an outlet for the gaseous fluid freed of particles and liquid, and at least one discharge window discharging the separated particles and liquid. At least one discharge chamber is provided, and the discharge windows of the cyclone cells open into the at least one discharge chamber. At least one discharge opening leads out of the at least one discharge chamber. The at least one discharge chamber tapers in a funnel shape toward the at least one discharge opening. A multi-stage fluid filter is provided with the multi-cyclone separator that is arranged upstream of a main filter of the multi-stage fluid filter.

A particle separator assembly includes an airbox providing an outer tapered portion tapering from a first section having a first cross sectional area to a first opening having a second cross sectional area less than the first cross sectional area. The example assembly includes a flow diverter providing an inner tapered portion that tapers to a second opening. The example assembly includes an air filter housed by the airbox, the air filter is spaced from the second opening in a first direction, and the first opening is spaced from the second opening in a second direction opposite the first direction.

An air filter assembly includes a housing having an interior surface that defines an interior volume, a filter element positioned within the interior volume and having a filter media, an air intake formed in the housing, a debris outlet formed in the housing, a filtered air outlet formed in the housing, and a plurality of ribs. The filter element is spaced from the interior surface so that a gap is formed between the filter element and the interior surface to allow air to flow between the filter element and the interior surface. The plurality of ribs extend into the interior volume of the housing so that air flowing from the air intake is directed into the gap and around the filter element to complete a cyclonic filtering pass before flowing along a second airflow pass through the filter element. The outlet passage is configured to direct filtered air into a third airflow pass in a direction opposite to the second airflow pass.

An engine air filter for heavy dust conditions such as used in heavy military and off-road vehicles, including a scavenging system, and a method of operation thereof. The air filter includes: a housing, a precleaner, a permeable filter, and a scavenger system. The scavenger system disposes of particles collected at the precleaner and on the upstream surface of the permeable filter. The scavenger system includes: an air suction source and a three way valve. The three way valve is airflow coupled to the precleaner, to the permeable filter and to the air suction source. The three way valve enables scavenging of the precleaner and the permeable filter alternately. Optionally, the air filter may further includes a pulse jet back-flow flush system.