Turbocharger including an annular bearing retainer plate

A turbocharger comprising:

• a shaft;
• a rolling bearing including an inner ring mounted on the shaft and an outer ring arranged around the inner ring;
• a housing including a bearing hole accommodating the rolling bearing;
• a compressor impeller provided on the shaft at an outside the bearing hole;
• and
• an annular bearing retainer plate arranged between the bearing hole and the compressor impeller in a central axis direction of the shaft and including an end face facing a side face of the outer ring, the end face including an annular circumferential oil groove continuously extending along the entire circumferential direction of the shaft and a protrusion located inside the circumferential oil groove in a radial direction of the shaft and protruding in the central axis direction of the shaft,
• wherein the end face of the bearing retainer plate includes a guide oil groove extending inward from an area that is radially outside the side face of the outer ring when seen from the central axis direction of the shaft and connected to the circumferential oil groove, and
• the circumferential oil groove is deeper than the guide oil groove.