Patent ID: 6206651
Filing Date: 2001-03-27
Classification: F01M

Abstract:
An oil pump for an internal combustion engine, comprising:at least one intake port and at least one outlet port,at least two pairs of toothed wheels are provided, the wheels of each pair being in mutual engagement,a first common shaft is provided on which a first toothed wheel of each pair of toothed wheels is arranged,means to pump oil and a control valve are provided in order to supply, with oil, the individual pairs of toothed wheels depending upon the required conveyed oil quantity,the oil pressure in the outlet line is used as control pressure for said control valve,a first pair of toothed wheels has a first intake port and a first outlet port;a second pair of toothed wheels has a second intake port and a second outlet port;said control valve switches to and from different operating positions;said different operating positions are comprised ofa first position,a second position anda third position;in said first position said intake line is connected with said first intake port and said oil supply line is connected to said first outlet port,wherein said first set of toothed wheels receive oil supplied directly and said second set of toothed wheels operate in short circuit receiving oil supplied by said second outlet port of said second set of toothed wheels;in said second position, said intake line is connected with said second intake port and said oil supply line is connected to said second outlet port,wherein said second set of toothed wheels receive oil supplied directly and said first set of toothed wheels operate in short circuit receiving oil supplied by said first outlet port of said first set of toothed wheels; andin said third position, said intake line is connected with said first and said second intake ports and said oil supply line is connected to both said first and said second outlet ports,wherein both said first and second sets of toothed wheels receive oil supplied directly.