ROOTS PUMP AND METHOD OF PRODUCING ROOTS PUMP

摘要

A Roots pump has a simple structure enabling highly precise adjustment of a clearance between a rotor and a pump chamber. A casing (2) of the Roots pump (1) has a first casing (3) and a second casing (4) that are split along the direction of the axis of a rotating shaft (A1, A2). The first casing (3) and a second casing (4) have bearing support sections (46a, 47a, 46b, 47b), respectively, for supporting bearings (66, 67, 71, 72) for supporting the rotating shaft (A1, A2), and also have rotor receiving spaces (P1a-P6a, P1b-P6b), respectively, for receiving rotors (R1-R6) arranged on the rotating shaft (A1, A2). The construction allows measurement of a clearance between a rotor (R1-R6) and the corresponding rotor receiving space (P1a-P6a, P1b-P6b), which forms a part of a corresponding one of pump chambers, with the rotors (R1-R6) exposed to the outside while being supported by one of the casings (3, 4). As a result, the clearance can be precisely adjusted.