A first and a second rotary pumps are provided in a first pump casing of a pump body, which is inserted into a cylindrical recessed portion of a housing 101. A first outlet port is opened at a first space formed between a bottom surface of the cylindrical recessed portion and an axial forward end surface of the first pump casing, so that discharge pressure of working fluid of the first pump is supplied to the first space. A second outlet port is opened at a second space formed between an axial backward end surface of the first pump casing and an axial forward end surface of a second pump casing, so that discharge pressure of working fluid of the second pump is supplied to the second space.