CONTROLLED DEFLECTION ROLL

摘要

A controlled deflection roll for a papermaking machine. The roll (10) comprises a roll shaft (14) having a longitudinal axis (18), a roll shell (22) surrounding the shaft, and a bearing pad assembly (50) supported on the shaft to supportingly engage the shell and move the shell translationally relative to the shaft in a plane including the axis. In one embodiment, the bearing pad assembly includes a plurality of bearing pads (54). Each bearing pad is spaced apart in the cross-machine direction and has a contact surface engageable with the inner surface (58) of the shell. The contact surface is in the shape of a parallelogram and defines therein at least one recess (70). The side edges (64) of adjacent bearing pads are straight and parallel to each other and define gaps therebetween. The gaps do not extend along a plane which is perpendicular to the axis. In another embodiment, the bearing pad assembly includes at least one bearing pad having a contact surface and opposite edges (66, 68). The contact surface has a contact surface portion engageable with the shell. The contact surface portion has a plurality of continuous contact surface portions (74A; 74B; 74C) extending between the opposite edges such that each of said continuous contact surface portions does not extend in a plane which is perpendicular to said axis. The roll further comprises a hydraulic assembly (78) independently actuating the plurality of bearing pads to selectively engage the shell and supplying lubricant between the support surfaces and the shell. A pressure profile and a temperature profile are created along the length of the shell. The bearing pads engage the shell such that the pressure profile and the temperature profile are substantially evenly distributed along the length of said shell.