Filter insert for a filter device

A filter insert for a filter device, comprising:

• a filter element arranged on a longitudinal axis extending there through;
• a front-side flow opening arranged on the front side of the filter element with the longitudinal axis extending through the flow opening;
• wherein the filter element has an elongate cross section;
• and
• wherein the filter element has, with respect to the longitudinal axis, at least one flattened portion with a reduced radial extension or a through hole along the periphery of the flow opening;
• wherein the shortest interior distance (a) in the filter element immediately adjacent to the front-side flow opening is shorter than the inside diameter (d) of the front-side flow opening, and, the filter element engages around the front-side flow opening over an angular range of at least 180 degrees about the longitudinal axis;
• wherein the filter element has a through hole on a periphery of the front-side flow opening that is no more than 90 degrees with respect to a circumferential direction of the front-side flow opening.

A filter insert for a filter device, comprising:

• a filter element arranged on a longitudinal axis extending there through;
• a front-side flow opening arranged on the front side of the filter element with the longitudinal axis extending through the flow opening;
• wherein the filter element has an elongate cross section;
• and
• wherein the filter element has, with respect to the longitudinal axis, at least one flattened portion with a reduced radial extension or a through hole along the periphery of the flow opening;
• wherein the shortest interior distance (a) in the filter element immediately adjacent to the front-side flow opening is shorter than the inside diameter (d) of the front-side flow opening, and, the filter element has an at least approximately U-shaped cross section;
• wherein legs of the U-shaped cross section enclose a filtered side of the filter element;
• and
• wherein the front-side flow opening lies transverse to a longitudinal extension of the legs.