Filter device

Abstract

The present invention relates to a filter device for filtering a fluid, in particular an oil filter. It has at least one filtering medium and a bypass for the filtering medium. Furthermore, an actuator is provided, which influences the flow of the fluid through the bypass as a function of a predetermined parameter of the fluid. The actuator is preferably controlled as a function of the viscosity of the fluid, a differential pressure of the fluid at the filtering medium, and / or the temperature of the fluid.

Description

technical field [0001] The invention relates to a filter device for filtering fluids, such as an oil filter, having at least one filter medium and a bypass for the filter medium. Background technique [0002] US4402827 discloses the construction of a vacuum oil filter with a finely filtered filter medium and a bypass for use in an automatic transmission and on which a coarse filter medium is also provided. At low temperatures, if the fluid viscosity is high, it can flow through the coarse filter media with little pressure drop. At high temperatures, if the fluid is less viscous, it can flow through fine filter media for higher filtration efficiency. [0003] In this configuration, however, there is always a side stream flowing through the coarse filter medium, even at high temperatures, so that only a small fluid purification effect can be obtained for this part. However, due to the increasing demands placed on automatic transmissions or internal combustion engines in term...

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Problems solved by technology

However, this combination of two filters is more expensive

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