A pivot bearing unit (18), having a pneumatic braking device (21) with a first and second bearing part (22, 23), which are embodied as rotatable relative to one another, wherein the braking device (21) is activatable by means of compressed air (36) via a compressed air supply line (10). The braking device (21) is provided with a brake hose (1), embedded in a bearing plate (14), in the first bearing part (22), and the brake hose (1) expands as a result of subjection to compressed air (36) with a motion (8) in the direction of a free end (16) and, via an axially movable switching ring (2), exerts a force (17) on at least one brake block (6) of the second bearing part (23), for transmitting a braking moment (15) between the first and second bearing parts (22, 23).