LUBRICATED STRUCTURAL BEARING ARRANGEMENT
A structural bearing arrangement (20), for interposing between relatively displaceable parts of a structure (5) such as a bridge, comprises a hard polished part (22) overlying a softer bearing material (27) that is formed on rigid carrier (28). A series of transversely extending channels (29) form grease-filled pockets to limit erosion wear of the bearing material, and the grease is replenished by means of a distribution manifold (46) connected, via end plate (51), to a reservoir (50) for the grease. A small superatmospheric pressure (less than about 3 Bar) is maintained in the grease to effect replenishment of the channels by an accumulator (44) comprising a piston (55) and spring (56). The accumulator is charged by compressing the spring by charging the reservoir with grease from a pressurised source, the accumulator spring thereafter maintaining a positive, if decreasing pressure, channel-replenishment pressure in the reservoir as grease is drawn from the channel by bearing operation. The accumulator may comprise a gas spring or a tandem arrangement of springs to maintain pressure for longer. The reservoir may be recharged with grease periodically.