| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotation supporting device for a water pump reduced in its weight.SOLUTION: A rotation supporting device for a water pump includes a rolling bearing unit, and a rotating shaft. The rotating shaft includes an impeller shaft part to which an impeller is fixed, a pulley shaft part to which a pulley is fixed, and a bearing inner ring shaft part which exists between the impeller shaft part and the pulley shaft part, and on the outer periphery of which the bearing unit is assembled. In one or both of the impeller shaft part and the pulley shaft part, hollow holes are formed which do not pass therethrough. |
