Water pump for outboard engine

Abstract

Abstract PURPOSE:To improve discharge performance of a water pump for an outboard engine, by forming a gas vent hole in the upper surface of the housing of the water pump, and thereby discharging exhaust gas to the outside. CONSTITUTION:Since an impeller 50 is turned at a high speed by a driving shaft 26, pressure in a pump chamber 53A is left at the instant when the pump chamber 53A is opened, so that water is forced toward a discharge port 48 by the centrifugal force while gas is collected at the central portion of the pump chamber. Therefore, gas collected in the pump chamber 53A is discharged to the outside from a gas vent hole 66 by the internal pressure of the pump chamber 53A itself. Further, since a predetermined level of negative pressure is developed in a negative-pressure chamber 60 by a restriction of a small-diameter portion 62, gas collected at the central portion of the chamber 53A defined by vanes 51A, 51B is drawn into the negative-pressure chamber 60 by the negative pressure. Gas thus collected in the negative-pressure chamber 60 is carried upward through a space between the driving shaft 26 and the body of a housing 38 and then discharged to the outside of the casting.

Inventors

• 👤 Atsushi Mori
• 👤 Koshiro Inaba

Bibliographic Details