The present disclosure relates to an engagement structure of a push rod guide and a push rod guide cover of a brake chamber for a vehicle, in which a pair of semi-circular, hingedly connected, half members in a shape of a plate are assembled at a side surface of axial direction of the push rod into a shape of a disk, a push rod opening is formed at the center of the disk to guide a movement of the push rod, a protrusion projecting upwards is provided at a central part of the push rod guide, forming a step in a radial direction of the push rod guide, and a receiving groove corresponding to the step is formed on an inner circumferential surface of the push rod guide cover and is connected to the step.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

A spring brake actuator (1) for a vehicle, in particular a parking or emergency brake actuator, for use in a commercial vehicle, includes a cylinder housing (2) having a cylinder housing base (5) and a spring seat (7) on the base, a spring brake piston (9) located in the cylinder housing (5) for applying a braking force, and a compression spring (11) arranged between the spring seat (7) and the spring brake piston (9). The cylinder housing (2) is divided into a spring chamber (12) and a pressure chamber (14), the compression spring (11) being arranged in the spring chamber (12) and the pressure chamber (14) being supplied with pressurized fluid. An elastically deformable diaphragm (16) is sealingly mounted to the cylinder housing (2), with an inner periphery (18) sealingly mounted to the spring brake piston (9) to fluid-tightly isolate the pressure chamber (14) from the spring chamber (12).

A brake actuator assembly including a pressure plate presenting an opening, a push rod that is coupled to the pressure plate, a diaphragm that is coupled to the pressure plate, and a retainer that engages the push rod. The push rod has an outer surface and at least one protrusion extending outward from the outer surface. The retainer engages the protrusion such that at least a portion of the diaphragm is positioned between the pressure plate and the retainer.

The present invention includes a position restriction structure disposed in a space between an auxiliary cover casing and a diaphragm spring and having a body part fixed to the auxiliary cover casing, a mounting part extending in a circumferential direction from the body part and coupled to the auxiliary cover casing, a first protrusion protruding in an axial direction from the body part toward an incision groove of the diaphragm spring and inserted into the incision groove to restrict movement in the radial direction and a second protrusion protruding in the axial direction from the body part toward the incision groove of the diaphragm spring and inserted into the incision groove to restrict movement in the rotational direction. The position restriction structure is installed on the auxiliary cover casing and restrains the movement in the radial and rotational directions of the diaphragm spring.

The present invention includes a position restriction structure disposed in a space between an auxiliary cover casing and a diaphragm spring and having a body part fixed to the auxiliary cover casing, a mounting part extending in a circumferential direction from the body part and coupled to the auxiliary cover casing, a first protrusion protruding in an axial direction from the body part toward an incision groove of the diaphragm spring and inserted into the incision groove to restrict flow in the radial direction and a second protrusion protruding in the axial direction from the body part toward the incision groove of the diaphragm spring and inserted into the incision groove to restriction flow in the rotational direction. The position restriction structure is installed on the auxiliary cover casing and restrains the flow in the radial and rotational directions of the diaphragm spring.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

A brake actuator assembly including a pressure plate presenting an opening, a push rod that is coupled to the pressure plate, a diaphragm that is coupled to the pressure plate, and a retainer that engages the push rod. The push rod has an outer surface and at least one protrusion extending outward from the outer surface. The retainer engages the protrusion such that at least a portion of the diaphragm is positioned between the pressure plate and the retainer.