Patent ID: 8167965

Claim:
A filter for filtering a fluid, the filter comprising: a filter housing; a filter element arranged in said filter housing; a cyclone preseparator arranged upstream of said filter element in a flow direction of a fluid to be cleaned, wherein the fluid to be cleaned is guided through said preseparator to said filter element; wherein said cyclone preseparator comprises a plurality of cyclone cells fitted into an intake wall of said filter housing, a first portion of said cyclone cells having a larger diameter than a second portion of said cyclone cells, said second portion of cyclone cells having a smaller diameter relative to said first portion, wherein each cyclone cell includes an inlet section arranged at a first axial end of said cyclone cell through which incoming fluid enters said cyclone cell, said inlet section arranged on said filter housing intake wall; an outlet section arranged at an opposing second axial end of said cyclone cell through which pre-filtered fluid exits said cyclone cell, said outlet section arranged within said filter housing and in fluid communication with an inlet side of said filter element, wherein said inlet section and said outlet section are aligned on the same axis, wherein said larger diameter cyclone cells are positioned sequentially aligned along a first axis on said filter housing intake wall, wherein said smaller diameters cyclone cells are inserted into niches in said intake wall between adjacent larger diameter cyclone cells or between one larger diameter cyclone cell and a sidewall of said filter housing, and wherein a free flow cross-section of one of said larger diameter cyclone cells is at least twice as large as a free flow cross-section of one of said smaller diameter cyclone cells.