Fluid-actuable releaser for a friction clutch

A fluid-actuable releaser for a friction clutch of a motor vehicle, comprising

• a casing (3) with a first bore (5);
• a sleeve (10) which is arranged in the first bore (5), which therewith delimits an annular cylindrical chamber, and which is fastened in a sealed manner on the casing (3);
• and
• an annular piston (6;
• 7) which is movably guided in the annular cylindrical chamber on the first bore (5), which carries at one end a seal (12) delimiting a fluid pressure chamber (9) in the annular cylindrical chamber, and which carries, at another end remote from the fluid pressure chamber (9), a release bearing (27),
• wherein the casing (3) has, on a side axially remote from the annular piston (6;
• 7), an annularly, radially inwardly extending rib (15) with a second bore (16) concentric to the first bore (5) and with two annular shoulders (17;
• 18) having axially oppositely directed faces originating at the second bore (16),
• wherein the sleeve (10) penetrates radially guided by the rib (15) into the second bore (16) such that a cylindrical external face (14) of the sleeve (10) delimits the annular cylindrical chamber,
• wherein the sleeve (10) is provided with radially outwardly projecting stop means (20, 22;
• 19) which axially fixes the sleeve (10) on the two shoulders (17;
• 18) of the rib (15), and
• wherein the stop means (20, 22;
• 19) comprises a radially outwardly, plastically deformed portion of the sleeve (10), by which the sleeve (10) is axially fixed on at least one of the two shoulders (17;
• 18).