ROLLER BEARING ASSEMBLY

摘要

A roller air bearing assembly (1) for measuring flatness defects in a continuously running web comprises an array of annular rotors (2) mounted coaxially on a central tubular arbor (4). The arbor (4) comprises a closed end (5) and is formed with a series of radially extending fluid ports (6) that perforate the tubular wall of the arbor (4). In use compressed air is supplied to the inner region (8) of the arbor (4) via a compressed air pipe (not shown). The compressed air is exhausted from the region (8) via the ports (6). The exhausted air forms a film bearing between a radially outermost surface of the arbor and radially innermost surfaces of the respective rotors (2). In use the air film holds the rotors (2) spaced from the arbor (4) and forms a radial pneumatic bearing on which the rotors (2) may rotate about a common axis (10). The arbor (4) also comprises a series of pressure sensors (not shown) for detecting the differential pressure of the air film between the upper and lower regions of the pneumatic bearing supporting each rotor (2).