Abstract: A filter element group for a filter device for filtering a fluid may include a ring-shaped working filter element, a ring-shaped protective filter element, an assembly device, and a securing device. The working filter element may include a ring-shaped working filter body, a first outer end plate, and a second outer end plate. The protective filter element may include a ring-shaped protective filter body, a first inner end plate, and a second inner end plate. The securing device may be adjustable between a securing state where the cover plate is axially secured to the second outer end plate and a release state where the cover plate is axially removable from the second outer end plate. When in the securing state, the securing device may secure the cover plate to the second outer end plate preventing rotation of the cover plate in the circumferential direction.

Abstract: A filter element for filtering a fluid flow, e.g., lubricating oil, is disclosed. The filter element includes a cylindrical fine filter body that forms a fine filter stage, a cylindrical main filter body that forms a main filter stage, and a cylindrical protection filter body that forms a protection filter stage. The fine filter body and the main filter body follow one another axially and enclose a cavity so that the fine filter stage and the main filter stage are arranged fluidically parallel. The protection filter body is arranged in the cavity so that the protection filter stage is fluidically arranged downstream of the fine filter stage and the main filter stage. A bypass valve is disposed on a first end plate for bypassing the fine filter stage and the main filter stage. An intermediate plate axially connects the fine filter body to the main filter body.

Abstract: A filter element group for a filter device for filtering a fluid may include a ring-shaped working filter element, a ring-shaped protective filter element, an assembly device, and a securing device. The working filter element may include a ring-shaped working filter body, a first outer end plate, and a second outer end plate. The protective filter element may include a ring-shaped protective filter body, a first inner end plate, and a second inner end plate. The securing device may be adjustable between a securing state where the cover plate is axially secured to the second outer end plate and a release state where the cover plate is axially removable from the second outer end plate. When in the securing state, the securing device may secure the cover plate to the second outer end plate preventing rotation of the cover plate in the circumferential direction.

Abstract: A hydraulic filter element may include cylindrical filter body having a filter material folded in a star-shaped manner. A cylindrical inner frame may be radially supported on an inside of the filter body. A cylindrical sleeve may be permeable to a respective hydraulic medium and arranged radially against the outside of the filter body under prestress, wherein the sleeve may include a knitted textile material.