Wet disc brake system

摘要

Wet disc brake system (10) comprises a housing assembly (12) and brake callipers (14). Housing assembly (12) is provided with openings (24) for seating cylinders (22) of respective brake callipers (14). The callipers (14) are coupled to a structural component of a vehicle to which the system (10) is fitted and in particular a flange (28) of an axle housing (16). This enables reactive forces created during a braking operation to be transmitted via the callipers to the flange (28) and axle housing (16) rather than being carried by housing assembly (12). As housing assembly (12) does not bear any substantive load, it may be made of a relatively light weight construction or material. The application is also directed to a disc brake system comprising a service and park brake calliper provided with at least two cylinders wherein at least one cylinder houses a hydraulically operated service piston and at least one cylinder houses a park piston that is applied by a spring and released by air pressure.