Water pump

摘要

A cylindrical support portion is provided on a wafer pump case to surround a rotary shaft, and a cylindrically formed power transmitting rotary wheel surrounding the support portion is integrally coupled to an outer end of the rotary shaft which protrudes outwardly from the support portion. A bearing means is interposed between an inner surface of the power transmitting rotary wheel and an outer surface of the support portion. A plurality of sealing members disposed concentrically with the bearing means are interposed between the rotary shaft and an inner surface of the cylindrical support portion at a location axially outwardly spaced from the mechanical seal, and a grease is filled between the sealing members. The water pump structure not only improves the sealing property of the sealing members by providing the sealing members at a location in which the deflection of the rotary shaft is smallest, but also increases the retaining property for the grease between the plurality of sealing members. This enhances water resistance of the bearing means. Moreover, in spite of the provision of the plurality of sealing members and the bearing means, the water pump structure avoids an undesirable increase in size and remains relatively compact.