Abstract: The disclosure relates to a method for forming a filter medium, which is suitable for filtering fluids, for a filter element, said method comprising: applying at least one self-contained sealant onto a fluid-permeable media web in a specifiable direction, producing a solid composite at least between parts of the sealant and the media web, pleating the composite, thereby forming individual filter folds, producing a hollow body in that the two lateral edges of the media web which lie opposite each other so as to adjoin each other and which run transversely to the specified direction are connected together such that in order to obtain at least one seal region on the media web, the respective sealant is arranged on the inner face of the hollow body, a seal is produced for each filter fold, and an end-face seal of the media web is produced.

Abstract: A closure device for a fluid container, in particular a hydraulic tank, has a base (4), which can be attached to the container opening and has a cover part (2), which encloses a ventilation and/or a filter device (36). The cover part (2) is held on the base (4) so as to be freely rotatable in a functional unlocking position. In a functional locking position, the closure device permits the container opening to be unlocked by a safety device (48, 50, 58) while connecting the cover part (2) to the base (4). The safety device (48, 50, 58) can be actuated by a magnetic device generating a magnetic field (62). The magnetic device establishes the functional locking position of the cover (2) and the base (4) by magnetic force.

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: A filter element (1), with a preferably multilayer structure of a filter medium (3), in pleated form has filter pleats (5, 7) of different pleat heights (h1, h2). The filter pleats (7) with a first pleat height (h1) oppose the filter pleats (5) lower second pleat height (h2). The filter element has a throughflow direction for fluid to be cleaned away from a dirty side to a clean side (R). The transitions arranged adjacent to the inner side all conclude along a fictitious circular cylinder (9), which penetrates the filter medium (3) coaxially to its longitudinal axis (LA).

Abstract: A filter device has a filter element (1) received in a filter housing of at least two interconnectable housing parts (17, 19). The filter element (1) can be fixed to a housing part (19) in a removable manner by one screw connection (32, 33). An additional screw connection (17, 41) is provided for connecting the housing parts (17, 19). To transmit a torque between threaded elements (33) of the one screw connection (32, 33) and of the additional screw connection (41), the threaded elements are rotatable relative to each other. A coupling device (43, 46, 61) is added that allows an additional rotational movement of the threaded element (17) of the additional screw connection (41) when the threaded element (33) of the one screw connection (32, 33) reaches the fixed rotational state.

Abstract: A method for producing a filter element for filtering fluids, such as hydraulic fluids, lubricants or fuels, includes the following steps: a) providing at least one section of a filter mat web (14) made of one or more layers of at least one filter medium; b) connecting the ends of the at least one section to form an annular body (12) and placing that annular body onto a support pipe (16); c) wrapping at least one cutout of a film web (8) around the outside of the annular body (12) located on the support pipe (16) and d) placing end areas (24) of the at least one cutout of the film web (8) one on top of the other and connecting the overlapping end areas (24).

Abstract: A filter apparatus has a filter housing (1) accommodating at least one filter element (17) having an inner filter cavity (23) enclosed by a filter medium (27). The housing (1) contains an element bolder (19) that interacts with the filter element (17) located in its functional position. The element holder (19) has a projecting accommodating part (43) with an outer configuration adapted to the shape of an opening (37) located at the end of the filter element (17) to be secured to the element holder (19). The accommodating part (43) fits through the opening (37) of the filter element (17) located in the functional position.

Abstract: A filter device for filtering fluid particularly an aqueous urea solution, includes a filter housing (1), a filter element (11) and a compensating element (31) for compensating fluctuations in the pressure and/or volume of the fluid. At least one elastically-flexible membrane (31) serves as the compensating element. The membrane wall of of the membrane is held in a retaining part (35) and maintains a separation between the fluid and a compressible filling medium such as a working gas.

Abstract: A filter element for fluid filtration, in particular for hydraulic fluid, has element components, such as pleated and multi-layer filter material (10) that extends between two end caps (26) and has a fluid-permeable supporting tube (14) forming a hollow cylinder. At least one element component of the filter element is provided at least partially with at least one luminescent material or marker such that the material or marker is excited to a characteristic, detectable wave emission when exposed to a certain exciter wave or wave spectrum.

Abstract: A filter element for a filter device has a filter housing (3; 4). The filter element (1) includes a receiving part (19) which, when the filter element (1) is located in the filter housing (3; 4) in the operational position, comes into fluid communication with a housing part (17; 18) of the filter housing (3; 4) to form a fluid connection (9). The receiving part (19) of the filter element (1) has an inner, first guiding path (37) for sealing contact to the housing part (17) of the filter housing (3) according to a first mode of construction and an outer, second guiding path (51) for sealing contact to the housing part (18) of the filter housing (4) according to a second mode of construction.

Abstract: A filter device has a filter element (17) that is exchangeably disposed in a filter housing (1). The filter element (17) is provided on one end with an end cap (23) that forms a surround for a rim of a filter material (31). The end cap (23) has a connector (43) attaching the filter element (17) in an operating position to an element seat (19; 45) inside the filter housing (1) such that a fluid-impermeable connection is formed between filter housing (1) and filter element (17). The connector (43) enables the positionally fixed mounting of the filter element (17) and the formation of a fluid-impermeable connection in conjunction with element seats (19; 45) of filter housings (1) of different designs.

Abstract: A filtering element for filtering devices, comprising a filtering material (5) which defines a filtering space and is intended for the filtration of fluids, and at least one water indicator (13, 19, 23) which is provided at a location coming into contact with fluid during the filtration mode and indicates the presence of water in the fluid in a visually recognizable manner, is characterized in that the at least one water indicator (13, 19, 23) is provided on an end cap (7, 9) for mounting at one end of the filtering material (5), and/or is at least partially part of the end cap (7, 9), and/or is provided on a fluid-permeable supporting structure (21) surrounding the filtering material (5), and/or is at least partially part of the supporting structure (21).

Abstract: A contamination indicator is for filter elements (12) for fluids that are replaceably housed in a filter housing (2). The indicator has a fluid-conveying connection (58) to the interior of the housing (2) and possesses an indicating device (52) providing information concerning the degree to which the filter element is contaminated (12). A temperature-dependently active actuation device (50) is connected upstream from the indicating device (52) in the direction of fluid inlet. By the actuation device, the indicating device (52) is activated when the fluid temperature has reached a predefinable threshold value.

Abstract: A filter material (2) for fluids, in particular hydraulic fluids, includes a filter medium (4) having at least one layer, and a supporting structure (6) partially made of a plastic material and resting flatly in some surface areas on at least one side of the filter medium (4). The filter medium (4) and the supporting structure (6) are connected to one another by laminating, covering and/or by a melting process.

Abstract: A filter device has a filter element (3) in a filter housing (1). Corresponding threads (23, 33) form a screw connection between a housing cover (5) of the filter housing (1) and the filter element (3). A seal (29, 35) is between the filter element (3) and the housing cover (5). The screw connection is formed by threads (33) on a connecting pipe piece (31) that is part of an end cap (17) of the filter element (3) and that extends into the inner filter cavity (22) and by the threads (23) of the housing cover (5). The housing cover threads (23) are on a receiving pipe piece (21) formed by a separate component attached to the housing cover (5).

Abstract: A filter device has a filter housing (1) with a filter head (3), a filter pot (7) and a removable housing cover part (51) and has a filter element (13) separating a non-filtrate side (15) from a filtrate side (17) in the housing. A bypass valve device has a valve closure element (65) preloaded by a closing spring (69) into a closed position in which it bears against a valve seat part (74). If the filter element (13) is blocked, the closure element opens up a fluid path from the non-filtrate side (15) to the filtrate side (17), by passing the filter element (13). The valve closure element (65) and the closing spring (69) are on the cover part (51). The valve seat part (74) is on an element cap (43) of the filter element (13). The element cap has a receiving part (45) forming an enclosure for that end of the filter material (27) of the filter element (13) facing toward the cover part (51).

Abstract: A filter device for fluids has a connection member (1) with a fluid input (19) for unfiltrate and fluid output (13) for filtrate, a first (43) and second filter elements (3) and a switching device (29) located in the connection member (1). By the switching device, a fluid connection between the fluid input (19) and fluid output (13) can be selectively established via the first filter element (43) or the second filter element (3). One of the filter elements is integrated into the interior of the connection member (1) as an auxiliary filter (43).

Abstract: A filter device, in particular for fluids polluted with admixtures of water, such as diesel oil, includes a filter housing (1) having a fluid inlet (43), a fluid outlet (44) and a filter element (9). During the filtering process, the fluid can flow through the filter medium (11) of the filter element from the unfiltered side (14) to the filtered side (13) of the filter medium and into its inner filter cavity (17). On at least one side of the filter medium (11), a water-separating system (23) has a separating region (25) for separated water. The water separating system is connected via at least one water opening (35) that is open toward the separating region (25) to a water collecting chamber (45). The filter element (9) has a passage (29) forming a fluid connection to the inner filter cavity (17) and can be connected to an element receptacle (47) of the filter housing (1). A fluid-conveying system (41) forms fluid paths separated from each other.

Abstract: A filter apparatus includes a filter housing having a filter head (3) and a filter bowl (7). The housing accommodates a filter element that separates a non-filtrate side (15) from a filtrate side (17). A differential pressure measurement device (59) indicates at least a blockage of the filter element during filtration operation and has a measurement piston (91) that is guided in a measurement housing (88) in a longitudinally displaceable manner. An end face (90) of that piston is subjected to the instantaneous pressure of the non-filtrate side (15). The opposite end face of the piston is subjected to the instantaneous pressure of the filtrate side (17). Each instantaneous pressure passes into the measurement housing (88) via at least one conduit (57, 61, 65, 89). At least a section (57, 61) of the conduit is arranged in an element cap (43) of the filter element.

Abstract: A filter device includes a filter element (3), through which a fluid to be purified can flow at a determinable fluid operating pressure, and which can be accommodated in a housing (1). The fluid pressure prevailing at the respective filter element (3) may exhibit pressure increases or pressure peaks, which are damaging to the filter element (3), and in particular to its filter material (9), and which can be reduced and/or smoothened by a compensation device acting directly on the filter element (3) and having a flexible compensation element (29) that enables the volume of the fluid chamber of the housing (1) to be increased in accordance with a pressure peak or pressure increase. The flexible compensation element (29) is arranged between the outer side of the filter material (9) of the filter element (3) and the adjacent inner wall of the housing (1).