Regulatable coolant pump having integrated pressure chamber

Abstract

A regulatable coolant pump of an internal combustion engine having a pump housing in which a pump shaft with an associated impeller is rotatably mounted. The impeller conveys a coolant via an intake connection into a pressure channel of the coolant pump, a volume flow of the coolant pump being adjustable by a guide plate that externally surrounds the impeller at least in some regions and is displaceable by a pressure medium. The guide plate is connected in rotationally fixed fashion to the impeller and is continuously axially displaceable between two end positions and guided with a cylindrical bushing, with play at both sides, in an annular groove of the impeller or of an insert enclosed by the impeller. The guide plate, the pump shaft, the insert part, and/or the impeller together delimit a pressure chamber that is charged by the pressure medium in order to displace the guide plate.

1 . A regulatable coolant pump ( 1 ) of an internal combustion engine, comprising a pump housing ( 2 ) in which a pump shaft ( 3 ) with an associated impeller ( 4 ) is rotatably mounted, that conveys a coolant via an intake connection ( 9 ) into a pressure channel or spiral channel of the coolant pump ( 1 ), a volume flow of the coolant pump ( 1 ) being adjustable by a guide plate ( 10 ) that externally surrounds the impeller at least in some regions and that is hydraulically displaceable, the guide plate ( 10 ) is connected in rotationally fixed fashion to the impeller and is continuously displaceable axially between two end positions, the guide plate ( 10 ) is guided by a cylindrical bushing ( 13 ) extending therefrom, with play at both sides, in an annular groove ( 14 ) of the impeller ( 4 ) or of an insert ( 5 ) surrounded by the impeller ( 4 ), and the guide plate ( 10 ), the pump shaft ( 3 ), and the insert ( 5 ) together delimit a pressure chamber ( 12 ) that is charged with pressure medium in order to displace the guide plate ( 10 ). 
     
     
         2 . The coolant pump as recited in  claim 1 , wherein the pressure chamber is defined by the guide plate ( 10 ) together with the pump shaft ( 3 ), the insert ( 5 ), and the impeller ( 4 ), as a function of a position of the guide plate ( 10 ). 
     
     
         3 . The coolant pump as recited in  claim 1 , wherein the insert ( 5 ) has a one-part or multi-part construction and is made of plastic, metal, or a steel material, and is set into a receptacle ( 27 ) of the impeller ( 4 ) with at least one of a material fit or a non-positive fit. 
     
     
         4 . The coolant pump as recited in  claim 1 , wherein for the sealing of the pressure chamber ( 12 ), a sealing element ( 15 ) is provided that is positionally fixed in the annular groove ( 14 ) of the stationary insert ( 5 ) or of the impeller ( 4 ), said sealing element being supported on the inner side on the bushing ( 13 ) of the guide plate ( 10 ) with a non-positive fit. 
     
     
         5 . The coolant pump as recited in  claim 1 , wherein for the axial displacement of the guide plate ( 10 ) the pressure medium flows into the pressure chamber ( 12 ) via a pressure medium supply ( 11 ) provided as a longitudinal bore in the pump shaft ( 3 ). 
     
     
         6 . The coolant pump as recited in  claim 1 , wherein in an end position of the guide plate ( 10 ), a pressure level inside the pressure chamber ( 12 ) can be reduced via at least one radial passage ( 22 ) in the bushing ( 13 ). 
     
     
         7 . The coolant pump as recited in  claim 1 , wherein an external angled-off rim ( 17 ) of the guide plate ( 10 ) surrounds, with play, an outer contour of a rear wall ( 6 ) of the impeller ( 4 ), maintaining an annular gap ( 18 ). 
     
     
         8 . The coolant pump as recited in  claim 7 , wherein a seal ( 19 ) set in a radially oriented groove ( 20 ) of an outer contour of the impeller rear wall ( 6 ) is supported with a non-positive fit on the rim ( 17 ) of the guide plate ( 10 ). 
     
     
         9 . The coolant pump as recited in  claim 1 , wherein the bushing ( 13 ) of the guide plate ( 10 ) works together with a failsafe device ( 23 ) provided as a spring mechanism ( 26 ) and set in the annular groove ( 14 ) of the insert ( 5 ) or of the impeller ( 4 ) as a countermeasure against failure.