Plunger assembly for a high-pressure fuel pump, and high-pressure fuel pump

Abstract

The invention relates to a plunger assembly for a high-pressure fuel pump for supporting a reciprocating pump piston ( 1 ) of a pump element on a cam ( 2 ) of a drive shaft ( 3 ), comprising a supporting element ( 4 ) with a recess ( 5 ), in which a running roller ( 6 ) is mounted rotatably. According to the invention, it is provided that, furthermore, a holding element ( 7 ) is provided for holding the running roller ( 6 ) in the recess ( 5 ) of the supporting element ( 4 ), which holding element ( 7 ) is connected to the supporting element ( 4 ) in a positively locking manner, wherein the positively locking connection brings about an anti-rotation safeguard of the holding element ( 7 ) with respect to a longitudinal axis A of the pump piston ( 1 ).

1 . A plunger assembly for a high-pressure fuel pump for supporting a reciprocatingly movable pump piston ( 1 ) of a pump element on a cam ( 2 ) of a drive shaft ( 3 ), comprising a support element ( 4 ) with a recess ( 5 ) in which a running roller ( 6 ) is rotatably mounted, also comprising, to hold the running roller ( 6 ) in the recess ( 5 ) of the support element ( 4 ), a retention element ( 7 ) which is connected to the support element ( 4 ) in a form-fitting manner to prevent rotation of the retention element ( 7 ) with respect to a longitudinal axis of the pump piston ( 1 ). 
     
     
         2 . The plunger assembly as claimed in  claim 1 , characterized in that, to realize a form fit, the support element ( 4 ) has at least one axial projection ( 8 ) which engages with the retention element ( 7 ). 
     
     
         3 . The plunger assembly as claimed in  claim 2 , characterized in that the axial projection ( 8 ) is formed in the shape of a segment of a circle, and surrounds a partial circumferential region of the retention element ( 7 ). 
     
     
         4 . The plunger assembly as claimed in  claim 1 , characterized in that the retention element ( 7 ) is pressed into the support element ( 4 ). 
     
     
         5 . The plunger assembly as claimed in  claim 1 , characterized in that the retention element ( 7 ) forms axial run-on surfaces ( 9 ) for the running roller ( 6 ). 
     
     
         6 . The plunger assembly as claimed in  claim 1 , characterized in that the running roller ( 6 ) has planar tip surfaces ( 10 ) by which the running roller ( 6 ) bears against at least one of the retention element ( 7 ) and the support element ( 4 ). 
     
     
         7 . A high-pressure fuel pump having a plunger assembly as claimed in  claim 1 , wherein the support element ( 4 ) is inserted directly into a housing bore ( 11 ) of the high-pressure fuel pump. 
     
     
         8 . The high-pressure fuel pump as claimed in  claim 7 , characterized in that the retention element ( 7 ) has a lug ( 17 ) which protrudes radially in relation to the support element ( 4 ) and which interacts with a groove of the housing bore ( 11 ) so as to prevent rotation of the plunger assembly. 
     
     
         9 . The high-pressure fuel pump as claimed in  claim 7 , characterized in that the plunger assembly is connected to the pump piston ( 1 ) by means of a spring plate ( 12 ), wherein the spring plate ( 12 ) is pressed onto the pump piston ( 1 ). 
     
     
         10 . The plunger assembly as claimed in  claim 1 , characterized in that, to realize a form fit, the retention element ( 7 ) is at least partially inset into the support element ( 4 ). 
     
     
         11 . The plunger assembly as claimed in  claim 1 , characterized in that, to realize the form fit, the support element ( 4 ) has at least one axial projection ( 8 ) which engages with the retention element ( 7 ).