Water pump

A water pump comprising:

• a pump body including a pump chamber;
• a bearing;
• a cylindrical supporting portion formed on the pump body so as to protrude;
• a pulley rotatably supported by the cylindrical supporting portion by means of the bearing so as to rotate relative to the cylindrical supporting portion;
• a shaft portion, including first and second end portions, formed on the pulley so as to penetrate a central hole of the cylindrical supporting portion and extend as far as the pump chamber of the pump body;
• an impeller provided at the second end portion of the shaft portion to rotate integrally with the shaft portion;
• a seal member provided between an inner peripheral surface of the cylindrical supporting portion at the pump body side and an outer peripheral surface of the second end portion of the shaft portion;
• a pulley cylinder portion provided at the pulley and an outer ring of the bearing engaged with the pulley cylinder portion;
• a wall portion provided at the pulley to connect the pulley cylinder portion with the first end portion of the shaft portion;
• a through-hole formed on the wall portion so as to be penetrated in an axial direction thereof, and
• a cover covering the wall portion and the pulley cylinder portion of the pulley from one side of the pulley, and the cover formed in a cylindrical shape with a bottom portion and including a reservoir for collecting fluid that has leaked through the seal member,
• wherein the reservoir is formed on a back side of the bottom portion of the cover in a rib shape which extends in a radial direction and protrudes from the back side of the bottom portion in an axial direction.