Suction oil filter with bypass

Abstract

The invention relates to an oil suction oil filter with a bypass (6). The oil suction filter consists of a filter housing and a filter medium (5), in which an oil inlet (2) is provided on the lower housing part (1) and an oil inlet (2) is provided on the upper housing part (3) An oil outlet (4) is arranged on it, and the filter medium is arranged in the filter housing between the oil inlet (2) and the oil outlet (4). In the bypass ( 6 ) formed relative to the filter medium ( 5 ), there is a bypass valve ( 7 ) designed as a regulating valve. For this purpose, the control piston (8) of the control valve (7), which opens or closes the bypass (6) depending on the operating state of the suction filter, is effectively connected to the channel (9) integrated into the upper housing part (3) connect. A part of the oil sucked in by the pump at the oil outlet (4) is guided back into this channel (9) via the return port (10), wherein the channel (9) is applied by the oil located in the overvoltage. The operative connection makes it possible to reliably close the bypass ( 6 ), at least when the oil guided back into the channel ( 9 ) has an overpressure, since this overpressure also acts on the control piston ( 8 ).

Description

technical field [0001] The invention relates to an oil suction oil filter. The invention relates to an oil suction filter which is used, for example, as part of an oil circuit for supplying a motor vehicle transmission with oil as the working medium. Such an oil suction filter has a bypass for its fine-meshed filter medium, by means of which the impurities contained in the oil are filtered out, said bypass when the oil is cold and therefore viscous or has a When the viscosity is high and the fine-meshed filter medium has a particularly high flow resistance for the oil, it is ensured that enough oil is supplied on the suction side of the filter for the suction pump to circulate the oil. suction. Background technique [0002] The oil suction filter according to the preamble essentially consists of a preferably disc-shaped lower housing part or housing lower part with a generally socket-shaped oil inlet and a likewise preferably disc-shaped housing with an outlet. The upper ...

AI Technical Summary

Problems solved by technology

However, it has been found that in normal operating conditions of the system in which the oil to be circulated is of low viscosity when using a correspondingly constructed suction filter, pressure fluctuations can occur on the suction side, caused by brief negative pressures , this negative pressure may accidentally cause the bypass to open

However, this is undesirable since a complete filtering effect is generally not provided in the area of ​​the bypass

Here, the risk of larger foreign particles passing through the open bypass valve increases

Furthermore, with the filter arrangement according to the aforementioned document, there is also the risk that the bypass filter arranged in the bypass can quickly become soiled and thus at least partially clogged, so that the bypass filter can no longer be completely ensured. road function

This danger arises because the relatively small filter area of ​​the bypass filter in the bypass can hardly be cleaned effectively

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