An oil pump apparatus includes a body, a first rotor and a second rotor disposed
in the body so as to be able to rotate and a regulator valve mechanism for regulating
the pressure of oil discharged to portions of an engine, wherein the regulator
valve mechanism is disposed in the inside of the body and the engine and includes
a regulator valve member which moves in the direction being in parallel with a
rotation as of the first and second rotors in response to the discharged oil pressure.
