Controllable Screw Spindle Pump

Abstract

A controllable screw spindle pump for the lubricating oil supply of an internal combustion engine comprises a pump housing ( 1 ), in which a throttle chamber ( 13 ) and a control chamber ( 14 ) are configured which are in contact with the lubricating oil to be conveyed; wherein the throttle chamber ( 13 ) is arranged between the pump inlet ( 10 ) and the spindle chamber ( 12 ), and the throttle chamber ( 13 ) comprises a throttle valve ( 3 ), by way of which a throughflow cross section of a conveying stream can be set; and the control chamber ( 14 ) comprises a hydraulic control valve ( 4 ) with a piston ( 40 ) which responds to a hydraulic control pressure (p 1, p 2 ) in the control chamber ( 14 ), and the control chamber ( 14 ) is oriented parallel to the spindle chamber ( 12 ) in relation to an actuating travel of the piston ( 40 ); and a valve body ( 30 ) of the throttle valve ( 3 ) is coupled to the piston ( 40 ) of the hydraulic control valve ( 4 ).

1 - 7 . (canceled) 
     
     
         8 . A controllable screw pump for supplying lubrication oil to a combustion engine, comprising:
 a pump housing with a spindle chamber as well as a pump inlet and a pump outlet communicating with the spindle chamber;   at least two screw spindles rotatably accommodated in the spindle chamber, the screw spindles being driven by the combustion engine; wherein   inside the pump housing, a throttle chamber and a control chamber are provided, which are in contact with the lubrication oil to be conveyed; wherein   the throttle chamber is situated between the pump inlet and the spindle chamber, and the throttle chamber includes a throttle valve, via which a flow cross-section of a delivery flow is settable;   the control chamber includes a hydraulic regulating valve with a piston that responds to a hydraulic control pressure inside the control chamber, and the control chamber is arranged in parallel to the spindle chamber with reference to a displacement of the piston; and   a valve body of the throttle valve is coupled with the piston of the hydraulic regulating valve.   
     
     
         9 . The controllable screw pump according to  claim 8 , wherein
 a displacement of the valve body of the throttle valve is arranged in parallel to the spindle chamber, and a valve seat of the throttle valve is provided at a mouth of the pump inlet into the throttle chamber.   
     
     
         10 . The controllable screw pump according to  claim 8 , wherein
 the valve body of the throttle valve and the piston of the hydraulic regulating valve are seated on a common valve stem.   
     
     
         11 . The controllable screw pump according to  claim 8 , wherein
 the screw pump comprises two screw spindles, wherein a cross-section of the spindle chamber is formed by two overlapping circle radii, and a cross-section of the control chamber is situated in the area of an intersection axis of an overlap of the circle radii next to the spindle chamber.   
     
     
         12 . The controllable screw pump according to  claim 8 , wherein
 the control chamber comprises two hydraulic connections for introducing two hydraulic control pressures that act on opposing sides of the piston of the hydraulic regulating valve.   
     
     
         13 . The controllable screw pump according to  claim 8 , wherein
 a compression spring is situated inside the control chamber on one side of the piston of the hydraulic regulating valve.   
     
     
         14 . The controllable screw pump according to  claim 8 , wherein
 the pump housing comprises at one end face of the spindle chamber a collar portion that includes a passage for the housing and a shaft bearing for a drive shaft, and a gear rim that is seated on the drive shaft comprises a radial cut-out for the collar portion so that a toothing of the gear rim and the shaft bearing overlap axially.