To always stably enable the reduction of a pulse pressure in a discharge port notwithstanding the variation in an engine speed.
An engine drive continuously changes increasing and decreasing the volume of a plurality of pump chambers 14 to discharge oil sucked from a suction port 15 into the discharge port 16. An oil chamber 18 is installed in such an oil pump 1. The oil chamber 18 is conducted to the discharge port 16 via a communication hole 17 at a perpendicularly upper side of the chamber 18. The pulse pressure of the discharge port 16 is reduced with the oil chamber 18. Since the oil chamber 18 is connected to the discharge port 16 at the perpendicularly upper part, oil in the chamber 18 is held even if the oil of the discharge port 16 is dropped out.
WATANABE YASUSHI
MORITA SHOJI
Hiromichi Kobayashi
Tomioka Kiyoshi