Spring brake actuator and retaining device for such spring brake actuator

A spring brake actuator (2), in particular a parking or emergency spring brake actuator (2) for use in a commercial vehicle, said actuator (2) comprising:

• a cylinder housing (4) including a cylinder housing base (6),
• a spring brake piston (10) located in said cylinder housing (4) for applying a braking force,
• a spring guide (12) attached to the spring brake piston (10),
• a compression spring (8) located between the cylinder housing base (6) and the spring guide (12) of the spring brake piston (10), said compression spring (8) operable to push the spring brake piston (10) away from the base (6),
• wherein the spring guide (12) includes a valve (14) and a retaining device (16) for retaining the valve (14), the retaining device (16) including a basic body (34) and clamping portions (36) for clamping the retaining device (16) to the spring guide (12),
• wherein the clamping portions (36) are arranged at the basic body (34) and along a circumference (38) of the basic body (34),
• wherein the clamping portions (36) are spaced apart from each other forming slits (40) between the clamping portions (36) to allow for a circulation of air through the slits (40);
• wherein the basic body (34) of the retaining device (16) has a disc shape and extends across a base of the valve (14), wherein the basic body (34) abuts the base of the valve (14);
• wherein the clamping portions (36) extend radially outward from the basic body (34) and are flexible relative to the basic body (36) for permitting insertion of the retaining device (16) into the spring guide (12);
• wherein the retaining device (16) is fixed in place relative to the spring guide (12);
• wherein the valve (14) is fixed in place axially between the retaining device (16) and the spring guide (12) and does not shift axially relative to the spring guide (12).