摘要 |
A positive displacement machine comprises a cylinder (2) inside which there are a mobile piston (3), at least one first (4) and one second insulation chamber (5) containing a respective set of gaskets (6, 7), at least one first (8) and one second gland (9) each of which is suitable for operating on one of the sets of gaskets (6, 7), each gland (8, 9) comprising a tubular threaded portion (10, 11) and a ring nut (12, 13) fixedly attached to the tubular threaded portion. A sleeve (14) able to slide with respect to said cylinder (2) has a first end (14a) in contact with the first set of gaskets (6) and a second threaded end (14b) for receiving in engagement the tubular threaded portion (11) of the second gland (9), the sleeve (14) being slidingly engaged by the first gland (8), and at least one of the ring nuts (12, 13) being a cylindrical gear wheel with straight teeth. |