Oil filter device

Abstract

The present invention provides a suction oil filter device for an engine or a transmission that has an oil inlet and an oil outlet on the filter housing, a suction oil pump connectable to the oil outlet, using which a partial vacuum may be generated between oil inlet and oil outlet, a fine filter medium and an ultra fine filter medium, which are situated between the oil inlet and the oil outlet. The fine filter medium is attached to the oil inlet or to the oil outlet, and the ultrafine filter medium is situated before the fine filter medium in the flow direction and in a secondary flow area of the filter housing. A high filtration performance may thus be achieved at low production outlay.

What is claimed is: 
     
         1 . A suction oil filter device for an engine or a transmission, having: an oil inlet and an oil outlet on a filter housing, a suction oil pump being connectable to the oil outlet, using which a partial vacuum may be generated between oil inlet and oil outlet, a fine filter medium and an ultrafine filter medium, which are situated between the oil inlet and the oil outlet, wherein the fine filter medium is attached either to the oil inlet or to the oil outlet, and the ultrafine filter medium is situated in the flow direction before the fine filter medium and in a secondary flow area of the filter housing. 
     
     
         2 . The suction oil filter device according to  claim 1 , wherein the ultrafine filter medium and the fine filter medium are directly connected to one another. 
     
     
         3 . The suction oil filter device according to  claim 2 , wherein the ultrafine filter medium and the fine filter medium are connected to one another over their entire areas. 
     
     
         4 . The suction oil filter device according to  claim 2 , wherein the ultrafine filter medium is connected to the fine filter medium at multiple points. 
     
     
         5 . The suction oil filter device according to  claim 2 , wherein the ultrafine filter medium is directly connected to the fine filter medium at only one end. 
     
     
         6 . The suction oil filter device according to  claim 1 , wherein the ultrafine filter medium has an increasing distance to the fine filter medium beginning from the oil inlet, the maximum distance being a multiple of the thickness of the fine filter medium. 
     
     
         7 . The suction oil filter device according to  claim 6 , wherein the distance is achieved by at least one spacer. 
     
     
         8 . The suction oil filter device according to  claim 1 , wherein the fine filter medium separates particles having a size which is greater than 50 μm and the ultrafine filter medium separates particles having a size which is greater than 20 μm. 
     
     
         9 . An oil pan having a suction oil filter device according to  claim 1 . 
     
     
         10 . An oil filter system having a pressure oil filter device and a suction oil filter device according to one of  claim 1 . 
     
     
         11 . The oil filter system according to  claim 10 , wherein the pressure oil filter device has an ultrafine filter medium having the same filtration performance as the ultra fine filter medium in the suction oil filter device.