Abstract: A pre-filter assembly for a vehicle arranged with an aspiration duct extending between the pre-filter and a fan of the vehicle. A variable valve element is provided as part of the aspiration duct adjacent the fan, such that the aspiration rate through the duct can be controlled by appropriate variation of the valve element, to control the rate of airflow drawn through the aspiration duct by the fan. This allows for the aspiration rate of the pre-filter to be at least partly independent of the flow rate of the fan, without the need for an additional motor-driven blower unit.

Abstract: An agricultural vehicle air cleaner assembly having at least one cyclonic generator to enable the removal of suspended particles from an airflow through the air cleaner assembly. The cyclonic generator has at least one vane which acts to generate a cyclone downstream of the generator, where the pitch of the vane is adjustable. By adjusting the pitch of the vane, the cyclones generated by the air cleaner assembly for a given airflow can be adjusted, thereby allowing for dynamic adjustment of the particle removal effect of the air cleaner assembly.

Abstract: A pre-filter assembly for a vehicle arranged with an aspiration duct extending between the pre-filter and a fan of the vehicle. A variable valve element is provided as part of the aspiration duct adjacent the fan, such that the aspiration rate through the duct can be controlled by appropriate variation of the valve element, to control the rate of airflow drawn through the aspiration duct by the fan. This allows for the aspiration rate of the pre-filter to be at least partly independent of the flow rate of the fan, without the need for an additional motor-driven blower unit.