Lubricated automotive vacuum pump

Abstract

A lubricated automotive vacuum pump which provides a low-pressure for an automotive actuator includes a static pump housing which houses a pump chamber radially defined by a chamber surface, a pump rotor having a cylindrical rotor bearing surface and a rotor body having a vane slit, a vane which is shiftably supported by and radially shiftable in the vane slit and which separates the pump chamber into rotating compartments, a friction bearing which rotatably supports the pump rotor at the static pump housing, a pump gas inlet and outlet, an oil inlet channel which provides lubrication oil to the pump rotor, a separate oil outlet opening arranged at the rotor body, and a switchover valve for temporarily connecting the separate oil outlet opening with an oil drain. The friction bearing is defined by a cylindrical stator friction bearing surface and by the cylindrical rotor bearing surface.

What is claimed is: 
     
         1 - 8 . (canceled) 
     
     
         9 . A lubricated automotive vacuum pump for providing a low-pressure for an automotive actuator, the lubricated automotive vacuum pump comprising:
 a static pump housing configured to house a pump chamber, the pump chamber being radially defined by a circumferential chamber surface;   a pump rotor configured to rotate around an axial rotation axis, the pump rotor comprising a cylindrical rotor bearing surface and a rotor body which comprises a vane slit;   a vane which is configured to be shiftably supported by and radially shiftable in the vane slit and to separate the pump chamber into rotating compartments;   a friction bearing configured to rotatably support the pump rotor at the static pump housing, the friction bearing being defined by a cylindrical stator friction bearing surface of the static pump housing and by the cylindrical rotor bearing surface of the pump rotor;   a pump gas inlet;   a pump gas outlet which is separate from the pump gas inlet;   an oil inlet channel configured to provide a lubrication oil to the pump rotor;   at least one separate oil outlet opening arranged at the rotor body; and   an automatic mechanical switchover valve for temporarily connecting the at least one separate oil outlet opening with an oil drain.   
     
     
         10 . The lubricated automotive vacuum pump as recited in  claim 9 , wherein one of the at least one separate oil outlet opening is provided for each of the rotating compartments. 
     
     
         11 . The lubricated automotive vacuum pump as recited in  claim 9 , further comprising:
 a rotor valve opening arranged at the rotor body; and   a stator valve opening arranged at the pump housing,   wherein,   the automatic mechanical switchover valve is defined by the rotor valve opening and by the stator valve opening, and   the rotor valve opening and the stator valve opening are arranged so as to be in-line with each other when the automatic mechanical switchover valve is open.   
     
     
         12 . The lubricated automotive vacuum pump as recited in  claim 11 , wherein the rotor valve opening and the stator valve opening are each provided at the cylindrical stator friction bearing surface and at the cylindrical rotor bearing surface. 
     
     
         13 . The lubricated automotive vacuum pump as recited in  claim 11 , further comprising:
 an axial bridge groove arranged at the rotor body,   wherein,   at least one of the at least one separate oil outlet opening and the rotor valve opening are defined by the axial bridge groove.   
     
     
         14 . The lubricated automotive vacuum pump ( 10 ) as recited in  claim 11 , further comprising:
 one single stator groove,   wherein,   the stator valve opening is defined by the one single stator groove.   
     
     
         15 . The lubricated automotive vacuum pump as recited in  claim 14 , further comprising:
 a separation section,   wherein,   the pump chamber is further defined by a cylindrical rotor body chamber surface,   the separation section is arranged where the circumferential chamber surface and the cylindrical rotor body chamber surface define a fluidic separation in a circumferential direction, and   the one single stator groove is arranged so as to be within 30° of the separation section as seen from the axis of rotation.   
     
     
         16 . The lubricated automotive vacuum pump as recited in  claim 15 , wherein,
 the at least one separate oil outlet opening is arranged in a lagging third of a respective one of the rotating compartments, the lagging third being a sector of the respective one of the rotating compartments which arrives at the separation section the latest.