| 摘要 |
<p>A multistage pump, particularly of the immersion type, comprises an outer tubular jacket (2) defining a longitudinal axis (L), a plurality of adjacent stages (3) which are arranged hydraulically in series and inserted slidably inside the tubular jacket (2), and a main shaft (4) which is coaxial with the longitudinal axis (L). Each stage has at least one impeller (5) coupled to the main shaft (4) and a diffusion duct (6), means for connecting an electric motor (24), an intake element (7) and a delivery element (8) mounted respectively upstream and downstream of the stages (3) so as to lock them axially. The intake element (7) and delivery element (8) are secured removably to the jacket (2) close to its longitudinal ends by means of substantially transverse connecting members (9) which may be accessed from the outside of the jacket (2). The delivery element (8) comprises a hollow tubular portion (14) which houses inside it a non-return valve (15) inserted slidably so that it may be extracted axially outwards.</p> |
