Patent ID: 6984158

Claim:
A cooling water pump device for pumping cooling water toward an engine of an outboard motor, the outboard motor including a hollow driveshaft housing under the engine and a driving shaft vertically mounted in the driveshaft housing for transmitting a drive force of a crankshaft of the engine to a screw, comprising: a pump case made of resin disposed at a position partway, with respect to the axial direction of the driveshaft, inside the driveshaft housing and having an approximately bowl-like configuration having a bottom opening which is covered with an under-panel; a sleeve made of metal fitted in the pump case; an impeller made of elastic material mounted eccentrically in the pump case with the metal sleeve interposed therebetween, the impeller being rotated by rotational drive of the driveshaft to draw cooling water from the bottom of the pump case and pump the cooling water toward the engine located above; a plurality of annular seal elements for keeping an interface between an inner peripheral surface of the resin pump case and the metal sleeve watertight, arranged between the inner peripheral surface of the resin pump case and the metal sleeve, surrounding the driveshaft, and disposed at plural positions vertically apart with respect to an axial direction of the driveshaft; and a pump chamber formed by the pump case for accommodating the impeller, and at least the annular seal elements are arranged at an upper end of an ejection port of the pump chamber and at a place surrounding a driveshaft insert hole at an upper position of the pump case.