Water Pump of Internal Combustion Engine

A water pump of an internal combustion engine, comprising:

• a driving device including a pulley rotating by transmission of power from a driving source, a drive shaft rotating together with the pulley, and an impeller provided on the drive shaft to rotate together with the drive shaft;
• a pump housing including a pump chamber structure portion defining at least a part of a pump chamber in which the impeller is disposed, a cylindrical portion constructed so as to surround an outer peripheral side of the drive shaft, the pump chamber structure portion and the cylindrical portion being integrally formed with each other, and a stepped portion provided on the outer peripheral side of the cylindrical portion;
• a bearing including an outer race fixed to the pulley, an inner race fixed to an outer periphery of the cylindrical portion and made of a material having a coefficient of linear expansion smaller than the material of the pump housing, and a rolling body interposed between the inner race and the outer race;
• and
• a shielding member having an inner peripheral side sandwiched and fixed between the inner race and the stepped portion, and an outer peripheral side having a plate shape and extending to side of the outer race, in which at least one of opposite surfaces of the sandwiched inner peripheral side is coated with an elastic material.

A water pump of an internal combustion engine, comprising:

• a driving device including a pulley rotating by transmission of power from a driving source, a drive shaft rotating together with the pulley, and an impeller provided on the drive shaft to rotate together with the drive shaft;
• a pump housing including a pump chamber structure portion defining at least a part of a pump chamber in which the impeller is disposed, a cylindrical portion constructed so as to surround an outer peripheral side of the drive shaft, the pump chamber structure portion and the cylindrical portion being integrally formed of an aluminum-based metal material, and a stepped portion provided on the outer peripheral side of the cylindrical portion;
• a bearing including an outer race fixed to the pulley, an inner race made of an iron-based metal material and fixed to an outer periphery of the cylindrical portion, and a rolling body interposed between the inner race and the outer race;
• and
• a shielding member having an inner peripheral side sandwiched and fixed between the inner race and the stepped portion, and an outer peripheral side having a plate shape and extending to side of the outer race;
• wherein an elastic body is interposed between at least one of opposite surfaces of the sandwiched inner peripheral side of the shielding member and at least one of the inner race of the bearing and the stepped portion of the pump housing.