Spherical Bearings are designed for very high vertical, horizontal and lateral loads and where large rotational structural displacements need to be accommodated.
Spherical bearing is composed by top plate, base plate, convex middle plate and two Teflon plates of different composition. Opposite the top plate, it is a concave spherical in the base plate, and the PTFE plate between them. Beam rotation through spherical surfaces and PTFE plate sliding; stainless steel plate on the top plate and another PTFE plates on the intermediate steel plate perform the second sliding surface, realized beam stretching displacement produced by temperature factors. Spherical bridge bearing transfers force reliably and rotation performance is consistent.
TYPES OF SPHERICAL BEARINGS
Similar to pot bearing, spherical bridge bearings are available in fixed type, guided type and free sliding types .
1.fixed bearing (restriction of all movement in planar axis)
2.guided bearing (restriction of movement in one direction in planar axis)
3.multi-directional bearing (allows movement in all planes and axes)
All three types can be designed to accommodate uplift loads, often required during construction or during the life of the structure. The bearings are designed to be quickly and easily replaced. Structural rotation is accommodated by a system of convex and concave plates which are, in turn, mounted onto a flat sliding surface which allows horizontal displacements whilst the curved bearings rotate about their center of radius.
APPLICATIONS OF SPHERICAL BEARINGS
Ideal for structures with bearings of larges turning angles.
Bridges with big torsions.
Bridges in low temperatures lower than -30℃.
Wide and curved bridges.