Abstract: A cam case 23 is provided which swingably supports a cam ring 34 for forming a pump chamber 36 from a rotor in a state in which the rotor 33 having a vane 33a is moved to an eccentric position such that a swingable pin 35 axially disposed is used as a fulcrum. A pump body is formed adjacent to the two axial ends of the cam case. Moreover, a front body 21 and a rear body 22 for rotatively supporting a rotational shaft 40 of the rotor are disposed. As one of locating means for locating the two bodies and the cam case when an assembling process is performed, the swingable pin is employed. As another locating means, at least one of joining means for integrally connecting the two bodies and the cam case is a reamer bolt 45A.