Abstract: The invention relates to a filter device at least consisting of two coaxially arranged filter elements (12, 14) which delimit a cavity (16) between them, characterised in that the inner side (18) of the outer filter element (14), which faces the cavity (16), has at least in some parts a separating arrangement (20) for gas bubbles such as air bubbles, and the cavity (16) opens at the head end into at least one discharge opening (22) for gas bubbles coming in.

Abstract: A filter device is for the filtration of gases contaminated with particles, such as welding gases, in particular produced in manufacturing processes using 3D printers in a production room (52). The filter device has a filter circuit having at least one filter element (55, 56), which filters the particles from the gas. At least a part of those particles get from this filter element (55, 56) into an assignable receptacle (59). The particles within a back-flushing process get into the respective receptacle (59). At least one further filter circuit has at least one further filter element (NF1, NF2 that filters a fluid having the particles obtained at the back-flushing process.

Abstract: A filter device for transmission oil has a filter element (24) insertable into a transmission oil pan (70) with a filter medium (32) separating an unfiltered side from a filtrate chamber connected to an outlet (38, 50, 72), to which a suction oil pump can be connected. The filter medium (32) has a first structural layer (46) having a predetermined surface area and predeterminable filter properties and has a second structural layer (44, 60) having predeterminable filter properties. The surface area of the second structural layer (44; 60) is different from the surface area of the first structural layer (46). The structural layers (44, 46, 60) encompass an inner filter cavity (30) and are pleated having the same type of pleats. The pleated structural layers (44, 46, 60) extend in axial alignment between two end caps (22, 34) of the filter element (24).

Abstract: 1. Filter device for the filtration of gases contaminated with particles. 2. A filter device for the filtration of gases contaminated with particles, such as welding gases, which are in particular produced in manufacturing processes using 3D printers in a production room (52), having a filter circuit having at least one filter element (55, 56), which filters the particles from the gas, wherein at least a part of said particles get from this filter element (55, 56) into an assignable receptacle (59), is characterized in that the particles within a back-flushing process get into the respective receptacle (59), and in that at least one further filter circuit, having at least one further filter element (NF1, NF2), is present, which filters a fluid, which has the particles obtained at the back-flushing process.

Abstract: A filter device for transmission oil, having a filter element (24) which can be inserted into a transmission oil pan (70) and the filter medium (32) of which separates an unfiltered side from a filtrate chamber, which is connected in a fluid-conveying manner to an outlet (38, 50, 72), to which a negative-pressure device such as a suction oil pump, can be connected, wherein the filter medium (32) of the filter element (24) has at least one structural layer (46) having a predetermined surface area and predeterminable filter properties and having at least one further structural layer (44, 60) having predeterminable filter properties, wherein the surface area of the further structural layer (44; 60) is different from the surface area of the first structural layer (46), and wherein the respective structural layers (44, 46, 60) encompass an inner filter cavity (30), is characterized in that the respective structural layers (44, 46, 60) are pleated having the same type of pleats, in that the pleated structural layer