Cylinder head/cylinder sealing device for a reciprocating pressurized gas machine

Sealing device between the cylinder head (1) and the cylinder (2) of a reciprocating pressurized gas machine in which the gas is contained in at least one variable volume working chamber (3) delimited inside a cylinder (2) formed in a cylinder block (4) by a cylinder head (1) clamped against the cylinder block (4) by clamping studs (5) therein and by a piston sliding with a reciprocating movement in said cylinder (2), which sealing device is formed by a removable cylindrical liner (7) which is sleeved into a bore (8) provided in said cylinder block (4), the piston being provided with sealing rings in contact with the inside wall of the liner (7), characterized in that

• the outside surface (19) of the liner (7) is part of a cylindrical, preferably circular cross-section surface with generatrices parallel to the axis of the cylinder (2) at least over the upper major part of its length;
• said liner (7) is thin in the sense that it can be deformed by the compression force exerted by said clamping studs (5);
• the liner (7) is compressed axially over at least the major part of its length directly between the cylinder head (1) and a circular lower bearing surface (10) formed in the cylinder block (4);
• the height (L) of the liner (7) before the cylinder head (1) is clamped down is such that when the cylinder head rests before it is clamped down on the upper surface of the liner (7) in turn resting on the lower bearing surface (10) of the cylinder block (4) there remains an excess height (h) between the bearing surfaces of the cylinder head (1) and the cylinder block (4), the excess height (h) being sufficiently small that when the cylinder head (1) is clamped down it bears directly on the cylinder block (4) without any of the materials of the cylinder head (1), the liner (7) and the cylinder block (4) reaching its limit of elastic deformation, with a bearing force greater, given the thickness (e) of the liner (7), than the maximum force exerted by the gas pressure on the cylinder head (1) but sufficiently high for contact between the liner (7) and the cylinder head (1) to be maintained at all times during operation of the machine.