ROLLER TAPPET FOR A PISTON PUMP, PISTON PUMP

The invention relates to a roller tappet (1) for a piston pump, in particular for a high-pressure fuel pump, for supporting a pump piston (2) which can move in a reciprocating motion on a cam (3) or eccentric of a drive shaft (4), comprising a tappet body (5) with an end-side recess (6) and two radial bores (7) which lie diametrically opposite one another at the recess (6) and receive a pin (8), on which a roller (10) is rotatably mounted directly or indirectly via a bearing bush (9), wherein at least one radially or obliquely running feed bore (12) is configured in the tappet body (5) in order to supply a lubricating medium to a radial bearing gap (11) which is configured between the roller (10) and the pin (8) or between the roller (10) and the bearing bush (9), which feed bore (12) opens into the recess (6) in the region of an axial bearing gap (13) between the roller (10) and the tappet body (5). According to the invention, the feed bore (12) is connected to an arcuately running lubricating duct (14) which is configured in a surface (15) of the tappet body (5), which surface (15) delimits the axial bearing gap (13). Furthermore, the invention relates to a piston pump comprising a roller tappet (1) of said type.