Patent ID: 7481319

Claim:
A filter device for filtering a liquid comprising: a filter element arranged in a filter housing with the liquid to be filtered flowing along a flow path leading through the filter element; and at least one deformable expansion element situated in the filter housing so that the volume of at least one section of the flow path of the liquid to be filtered in the filter housing is variable when the at least one expansion element is deformed, wherein the filter element has a cylindrical configuration and a first expansion element forms an imperforate, deformable cover arranged on an axial end face of the cylindrical filter element facing an inlet opening into the filter housing through which a liquid to be filtered enters the filter device, the cover sealing an unfiltered liquid side from a filtered liquid side of the filter element, wherein the cover is axially deformable toward the interior of the filter element based on an elevated liquid pressure in the filter device, and wherein a second expansion element is arranged in contact with the filter housing outside the flow path of the liquid to be filtered, and the first and second expansion elements are arranged on opposite sides of the filter element.