High pressure pump

Abstract

The invention relates to a high pressure pump ( 1 ), which is used in particular as a radial or in-line piston pump for fuel injection systems of air-compressing auto-ignition internal combustion engines, comprising a pump assembly ( 13 ) and a drive shall ( 6 ) which comprises a cam ( 9 ) that is assigned to the pump assembly ( 13 ). The pump assembly ( 13 ) comprises a roller ( 25 ) which rolls with the roller surface ( 35 ) thereof on a running surface ( 10 ) of the cam ( 9 ). A rolling strength of the roller ( 25 ) on the roller surface ( 35 ) of the roller ( 25 ) and a rolling strength ( 9 ) of the running surface ( 10 ) of the cam ( 9 ) are specified as being identical. Under the highly dynamic stress of the cam ( 9 ) and the roller ( 25 ) during operation, this results in a critical threshold tension for both components ( 9, 25 ), which is equally critical for both components ( 9, 25 ).

1 . A high-pressure pump ( 1 ) comprising: at least one pump subassembly ( 13 ) and a driveshaft ( 6 ) which has at least one cam ( 9 ) assigned to the pump subassembly ( 13 ), the pump subassembly ( 13 ) having a running roller ( 25 ) which has a roller surface ( 35 ), and the running roller ( 25 ) being arranged on a running surface ( 10 ) of the cam ( 9 ), characterized in that a rolling stress-bearing capacity of the running roller ( 25 ) on the roller surface ( 35 ) of the running roller ( 25 ) and a rolling stress-bearing capacity of the cam ( 9 ) on the running surface ( 10 ) of the cam ( 9 ) are at least approximately equal. 
     
     
         2 . The high-pressure pump as claimed in  claim 1 , characterized in that a radius ( 38 ) of the running roller ( 25 ) is smaller than a radius of curvature ( 39 ) of the cam ( 9 ) at a point ( 36 ) on the running surface ( 10 ) at which the running roller ( 25 ) comes to bear at top dead center of the pump subassembly ( 13 ), and in that a modulus of elasticity of a running roller material, from which the running roller ( 25 ) is formed at least on its roller surface ( 35 ), is lower than a modulus of elasticity of a cam material, from which the cam ( 9 ) is formed at least on its running surface ( 10 ). 
     
     
         3 . The high-pressure pump as claimed in  claim 1 , characterized in that a radius ( 38 ) of the running roller ( 25 ) is smaller than a radius of curvature ( 39 ) of the cam ( 9 ) at a point ( 36 ) on the running surface ( 10 ) at which the running roller ( 25 ) comes to bear at top dead center of the pump subassembly ( 13 ), and in that the running roller ( 25 ) has at least one bore ( 41 ) which extends at least partially in the direction of an axis of rotation ( 32 ) of the running roller ( 25 ). 
     
     
         4 . The high-pressure pump as claimed in  claim 3 , characterized in that the bore ( 41 ) is configured as one of at least essentially an axial bore ( 41 ) and at least essentially a coaxial bore ( 41 ) with respect to the axis of rotation ( 32 ) of the running roller ( 25 ). 
     
     
         5 . The high-pressure pump as claimed in  claim 1 , characterized in that a radius ( 38 ) of the running roller ( 25 ) is smaller than a radius of curvature ( 39 ) of the cam ( 9 ) at a point ( 36 ) on the running surface ( 10 ) at which the running roller ( 25 ) comes to bear at top dead center of the pump subassembly ( 13 ), and in that at least one characteristic compressive stress on the roller surface ( 35 ) of the running roller ( 25 ) is increased. 
     
     
         6 . The high-pressure pump as claimed in  claim 5 , characterized in that the roller surface ( 35 ) of the running roller ( 25 ) is at least one of case-hardened, shot-peened, tumbled, nitrided, and carbonitrided. 
     
     
         7 . The high-pressure pump as claimed in  claim 1 , characterized in that a radius ( 38 ) of the running roller ( 25 ) is larger than a radius of curvature ( 39 ) of the cam ( 9 ) at a point ( 36 ) on the running surface ( 10 ) at which the running roller ( 25 ) comes to bear at top dead center of the pump subassembly ( 13 ), and in that a modulus of elasticity of a running roller material, from which the running roller ( 25 ) is formed at least on its roller surface ( 35 ), is higher than a modulus of elasticity of a cam material, from which the cam ( 9 ) is formed at least on its running surface ( 10 ). 
     
     
         8 . The high-pressure pump as claimed in  claim 7 , characterized in that at least one characteristic compressive stress on the running surface ( 10 ) of the cam ( 9 ) is increased. 
     
     
         9 . The high-pressure pump as claimed in  claim 1 , characterized in that at least one of a modulus of elasticity, a rolling resistance, and a Poisson ratio of a running roller material, from which the running roller ( 25 ) is formed at least on its roller surface ( 35 ), and a corresponding at least one of a modulus of elasticity, a rolling resistance, and a Poisson ratio of a cam material, from which the cam ( 9 ) is formed at least on its running surface ( 10 ), are at least approximately equal, and in that a radius ( 38 ) of the running roller ( 25 ) and a radius of curvature ( 39 ) of the cam ( 9 ) in the region of a point ( 36 ) on the running surface ( 10 ) at which the running roller ( 25 ) comes to bear at top dead center of the pump subassembly ( 13 ) are at least approximately equal. 
     
     
         10 . The high-pressure pump as claimed in  claim 9 , characterized in that the radius ( 38 ) of the running roller ( 25 ) and the radius of curvature ( 39 ) of the cam ( 9 ) at the point ( 36 ) on the running surface ( 10 ) at which the running roller ( 25 ) comes to bear at top dead center of the pump subassembly ( 13 ) deviate from one another by less than 5%. 
     
     
         11 . The high pressure pump as claimed in  claim 1 , characterized in that the pump is one of a radial and an inline piston pump for fuel injection systems of air-compressing auto-ignition internal combustion engines. 
     
     
         12 . The high pressure pump as claimed in  claim 2 , characterized in that the running roller ( 25 ) has at least one bore ( 41 ) which extends at least partially in the direction of an axis of rotation ( 32 ) of the running roller ( 25 ). 
     
     
         13 . The high-pressure pump as claimed in  claim 12 , characterized in that the bore ( 41 ) is configured as one of at least essentially an axial bore ( 41 ) and at least essentially a coaxial bore ( 41 ) with respect to the axis of rotation ( 32 ) of the running roller ( 25 ). 
     
     
         14 . The high pressure pump as claimed in  claim 12 , characterized in that the bore ( 41 ) is configured as a through bore ( 41 ) which extends from one side ( 42 ) of the running roller ( 25 ) to another side ( 43 ) of the running roller ( 25 ). 
     
     
         15 . The high pressure pump as claimed in  claim 13 , characterized in that the bore ( 41 ) is configured as a through bore ( 41 ) which extends from one side ( 42 ) of the running roller ( 25 ) to another side ( 43 ) of the running roller ( 25 ). 
     
     
         16 . The high pressure pump as claimed in  claim 3 , characterized in that the bore ( 41 ) is configured as a through bore ( 41 ) which extends from one side ( 42 ) of the running roller ( 25 ) to another side ( 43 ) of the running roller ( 25 ). 
     
     
         17 . The high pressure pump as claimed in  claim 4 , characterized in that the bore ( 41 ) is configured as a through bore ( 41 ) which extends from one side ( 42 ) of the running roller ( 25 ) to another side ( 43 ) of the running roller ( 25 ).