Patent GB-979018-A (GB)
Title: Roll with means for eliminating longitudinal curvature
IPC: F16C13/00
Filed: 1962-06-12
Abstract: 979,018. Rollers. MOUNT HOPE MACHINERY Ltd. June 12, 1962 [June 12, 1961; June 13, 1961], No. 22426/62. Heading F2U. [Also in Divisions B8 and D2] In a roll for a paper-making machine or conveyer a sleeve 24 is rotatably mounted upon a stationary axle 12 which is of longitudinally uniform and substantially symmetrical crosssection and is initially bowed to a preselected curvature so that the resultant force of the axle weight and load, lying in the plane of said curvature and directed against the convex side of the bow, elastically deflects said roll to a longitudinally straight configuration. In Fig. 1, a table roll of a paper machine comprises a corrosion resistant, hard and moderately resilient sleeve 24 of fibre glass or hard rubber engaging a series of spools 18 rotatably supported on a hollow axle 12 by ball bearings 16. Spacers 20 between the bearings maintain sufficient clearance between adjacent spools to accommodate slight roll curvature. Rotating water or lint-tight seals may be provided to protect the enclosed ballbearings. The axle ends are supported in plain cylindrical supports or, as shown, spherical elements 28. The axle is initially bowed by an eccentrically positioned tension rod 34 the ends of which, protruding through abutments 37 received in the axle ends, receive washers 38 and nuts 40 by which the axle is eccentrically compressed. The axle is first inspected to determine the plane of longitudinal curvature or " run-out " arising from imperfect manufacture and mounted with this plane vertical and the curve upwardly concave to coincide with the sag of the roll. The rod 34 is located at the bottom of the axle and when the normally carried load is imposed the nuts 40 are tightened to axially straighten the roll. The nuts may be tightened or released for adjustment for increasing or decreasing load respectively. In Fig. 4 (not shown) only two spools are provided for the sleeve each spool being supported on an individual bearing and on a centred bearing common to both spools. A more effective correction of " run-out " is achieved by this arrangement since any axle curvature intermediate the bearing locations does not effect the rectilinearity of the rotational axis of the sleeve and spools. Following assembly of the roll but before the sleeve is applied, the roll may be dynamically balanced by attachment of weights, and after determining the radial directions of any remaining forces of dynamic imbalance for the confronting ends of the two spools, the latter are relatively rotated to oppose these forces 180 degrees apart. To eliminate residual curvature in a plane perpendicular to the principal plane of curvature which may arise due to error in principal plane location, one or two secondary eccentrically positioned tension rods is or are arranged at 90 degrees to the primary tension rod as in Figs. 5, 6 (not shown). Where two secondary rods are provided either may be tensioned according to the direction of residual bow or they may be differentially tensioned thus further stiffening the axle. In Fig. 7 (not shown), alternative means eliminating residual curvature comprises mounting the bearings on the axle by pairs of rings which support the inner races and are radially adjusted with respect to the axle by circumferentially spaced radial screws. In Figs. 8, 9, 10 (not shown) the pre-selected bow may be produced simply by permanently deforming the axle by bending beyond its elastic limit.