Hydac Filtertechnik Gmbh

Ute Lehmann

Matthias Schwender

Harald Mees

Edwin Koch

André Michael Schneider

Gerd Altmeyer

Daniel Kleemann

Alexander Nenno

Herbert Mohr

A filter device for transmission oil has a filter element () insertable into a transmission oil pan () with a filter medium () separating an unfiltered side from a filtrate chamber connected to an outlet (), to which a suction oil pump can be connected. The filter medium () has a first structural layer () having a predetermined surface area and predeterminable filter properties and has a second structural layer () having predeterminable filter properties. The surface area of the second structural layer () is different from the surface area of the first structural layer (). The structural layers () encompass an inner filter cavity () and are pleated having the same type of pleats. The pleated structural layers () extend in axial alignment between two end caps () of the filter element (). Viewed in the flow direction of the fluid flow to be cleaned, the structural layers () having the higher filtration grade are downstream of an upstream structural layer () having a lower filtration grade.

Filter device

A method of assembling a filter element includes the initial step of forming a plastic filter casing with openings from a flat blank with opposite ends thereof bent towards one another and joining these opposite ends together by a sealing seam. Also, a resilient mat filter is folded into a cylindrical shape and pushed open on a fluid-permeable supporting pipe to surround and engage the surrounding pipe. The cylindrical shape of the mat filter has an exterior diameter prior to introduction into the casing that is larger than an interior diameter of the filter casing along the entire axial length of the mat filter. The mat folder is folded into a conical shape to facilitate its introduction thereof into the filter casing. After the axial end is formed, the mat filter and supporting pipe are introduced into the filter casing to define a filter chamber. Finally, two end caps are joined to the filter casing.

Method of assembling plastic filter element with plastic casing

Growing community of inventors

Spiesen-Elversberg, Germany

Ute Lehmann