Lubrication system for a rotary vacuum pump

Abstract

A lubrication system ( 200 ) for a rotary vacuum pump ( 300 ) connectable to a thermal engine comprises a suction duct ( 50 ) connecting the pump ( 300 ) to a power brake ( 16 ), and a connecting duct ( 23 ) connecting the inside of the engine with the suction duct ( 50 ) in order to generate, through the connecting duct ( 23 ), a flow of an air-oil mixture sucked from the inside of the engine. A pump having a casing ( 40 ) which defines a pumping chamber ( 44 ) and a connecting duct ( 23 ) formed in the casing ( 40 ), and a lubrication method for such a pump are also provided.

1 . Lubrication system ( 200 ) for a rotary vacuum pump ( 300 ) connectable to a thermal engine, comprising a suction duct ( 50 ) adapted to connect the pump ( 300 ) to a power brake ( 16 ), characterized in that said lubrication system ( 200 ) further comprises a connecting duct ( 23 ) adapted to connect the inside of the engine with the suction duct ( 50 ) in order to generate through the connecting duct ( 23 ) a flow of an air-oil mixture sucked from the inside of the engine. 
     
     
         2 . Lubrication system ( 200 ) according to  claim 1  in which the suction duct ( 50 ) is provided with two one-way valves ( 14 ,  15 ), characterized in that the connecting duct ( 23 ) is connected to the suction duct ( 50 ) in a portion of the duct ( 50 ) comprised between the two one-way valves ( 14 ,  15 ). 
     
     
         3 . Lubrication system ( 200 ) according to  claim 2 , characterized in that the connecting duct ( 23 ) is connected to the suction duct ( 50 ) in a region downstream of and close to the valve ( 14 ). 
     
     
         4 . Lubrication system ( 200 ) according to  claim 3 , characterized in that the connecting duct ( 23 ) has a narrowing ( 24 ) in its end portion terminating in the suction duct ( 50 ). 
     
     
         5 . Rotary vacuum pump ( 300 ) connectable to a suction duct ( 50 ) of a power brake ( 16 ), said pump comprising a casing ( 40 ) which defines a pumping chamber ( 44 ); a rotor ( 12 ) and a vane ( 22 ) mounted on the rotor ( 12 ), said rotor and vane being suitable to divide the chamber ( 44 ) into a suction chamber ( 13 ) and a compression chamber ( 18 ); characterized in that the pump ( 300 ) further comprises a connecting duct ( 23 ) formed in the casing ( 40 ) and adapted to connect the inside of the engine to the suction duct ( 50 ). 
     
     
         6 . Rotary vacuum pump ( 300 ) according to  claim 5  and connected to the suction duct ( 50 ) by means of a one-way valve ( 14 ), characterized in that the connecting duct ( 23 ) is connected to the suction duct ( 50 ) downstream of and close to the valve ( 14 ). 
     
     
         7 . Rotary vacuum pump ( 300 ) according to  claim 6 , characterized in that the connecting duct ( 23 ) has a narrowing ( 24 ) in its end portion terminating in the suction duct ( 50 ). 
     
     
         8 . Rotary vacuum pump ( 300 ) according to  claim 6 , characterized in that the connecting duct ( 23 ) is made by drilling. 
     
     
         9 . Rotary vacuum pump ( 300 ) according to  claim 7 , characterized in that the connecting duct ( 23 ) has a funneled shape at its end portion oriented towards the part of the casing ( 40 ) facing the engine. 
     
     
         10 . Lubrication method for a rotary vacuum pump ( 300 ) according to  claim 9 , wherein an oriented flow of an air-oil mixture starting from the compression chamber ( 18 ) of the pump ( 300 ) is generated, said flow passing through the connecting duct ( 23 ), reaching the suction duct ( 50 ) and returning to the suction chamber ( 13 ) of the pump ( 300 ). 
     
     
         11 . Lubrication method for a rotary vacuum pump ( 300 ) according to  claim 7 , wherein an oriented flow of an air-oil mixture starting from the compression chamber ( 18 ) of the pump ( 300 ) is generated, said flow passing through the connecting duct ( 23 ), reaching the suction duct ( 50 ) and returning to the suction chamber ( 13 ) of the pump ( 300 ). 
     
     
         12 . Rotary vacuum pump ( 300 ) according to  claim 6 , characterized in that the connecting duct ( 23 ) has a funneled shape at its end portion oriented towards the part of the casing ( 40 ) facing the engine. 
     
     
         13 . Lubrication method for a rotary vacuum pump ( 300 ) according to  claim 12 , wherein an oriented flow of an air-oil mixture starting from the compression chamber ( 18 ) of the pump ( 300 ) is generated, said flow passing through the connecting duct ( 23 ), reaching the suction duct ( 50 ) and returning to the suction chamber ( 13 ) of the pump ( 300 ). 
     
     
         14 . Lubrication method for a rotary vacuum pump ( 300 ) according to  claim 6 , wherein an oriented flow of an air-oil mixture starting from the compression chamber ( 18 ) of the pump ( 300 ) is generated, said flow passing through the connecting duct ( 23 ), reaching the suction duct ( 50 ) and returning to the suction chamber ( 13 ) of the pump ( 300 ). 
     
     
         15 . Rotary vacuum pump ( 300 ) according to  claim 5 , characterized in that the connecting duct ( 23 ) is made by drilling. 
     
     
         16 . Rotary vacuum pump ( 300 ) according to  claim 5 , characterized in that the connecting duct ( 23 ) has a funneled shape at its end portion oriented towards the part of the casing ( 40 ) facing the engine. 
     
     
         17 . Lubrication method for a rotary vacuum pump ( 300 ) according to  claim 16 , wherein an oriented flow of an air-oil mixture starting from the compression chamber ( 18 ) of the pump ( 300 ) is generated, said flow passing through the connecting duct ( 23 ), reaching the suction duct ( 50 ) and returning to the suction chamber ( 13 ) of the pump ( 300 ). 
     
     
         18 . Lubrication method for a rotary vacuum pump ( 300 ) according to  claim 5 , wherein an oriented flow of an air-oil mixture starting from the compression chamber ( 18 ) of the pump ( 300 ) is generated, said flow passing through the connecting duct ( 23 ), reaching the suction duct ( 50 ) and returning to the suction chamber ( 13 ) of the pump ( 300 ). 
     
     
         19 . Lubrication system ( 200 ) according to  claim 2 , characterized in that the connecting duct ( 23 ) has a narrowing ( 24 ) in its end portion terminating in the suction duct ( 50 ). 
     
     
         20 . Lubrication system ( 200 ) according to  claim 1 , characterized in that the connecting duct ( 23 ) has a narrowing ( 24 ) in its end portion terminating in the suction duct ( 50 ).