To form the wall surface of a pump chamber with high precision by combining a plurality of block pieces about the axial line of a rotating shaft with a plurality of bulkheads for partitioning adjacent pump chambers to constitute a rotor housing.
In the manufacture of a rotor housing, rough block pieces forming the bases of block pieces 17, 18 are firstly die-molded. Rough circumferential wall surfaces and rough positioning grooves are preliminarily formed on the inside wall surfaces of the rough block pieces. The die-molded rough block pieces are temporarily connected, and the rough circumferential wall surface and rough positioning grooves are finished in the state keeping this connected state. Wall pieces 37, 38 formed separately from the block pieces 17, 18 are then press fitted to the positioning grooves. After the wall piece 37 and the wall piece 38 are assembled to the block piece 17 and the block piece 18, respectively, the connecting surfaces 171, 181 of the block pieces 17, 18 and the connecting surfaces of the wall pieces 37, 38 are finished by grinding.
FURUHASHI SATOSHI
SAITO SHINYA
TAKAHASHI NAOKI
