GB738163A - Hydraulic ram caps for crushing and pressing rolls in crushing mills - Google Patents

Abstract

738,163. Grinding-mills. EDWARDS, J. N. May 16, 1952 [March 28, 1952], No. 12455/52. Class 59. [Also in Groups XXVI, XXIX and XXXIV] A ram cap for the movable bearing 14 of a crushing or pressing roll 12 in a grinding mill comprises a cylinder 16, a piston 17, a plunger 18 connected to the piston and a peripheral packing-ring 39 on the piston at the end thereof adjacent the plunger so that the pressure liquid acting on the piston has access to the major portion of its peripheral surface. Pressure liquid having lubricating qualities is forced into a cylinder 16 for the bearing 14 at each end of the roll 12 preferably from accumulators 34 which, as described in Specification 678,053, have a liquid compartment bounded by the flexible wall 34a of a compartment containing gas under pressure. The liquid enters the cylinders through tubes 35 which are screwed into the cylinder heads 20 or attached by a nut on the inside of the cylinder. A liner 19, preferably of steel and having a ground, chromium plated bore, is a sliding fit in the cylinder and is secured in place by the head 20 which has flanges 22 having a bayonet-engagement with the sloping undersurfaces of flanges 23 on the cylinder. Alternatively, the head may engage screw-threads in the cylinder and be formed with an integral extension 21, provided with a gasket 24 and a supporting ring 25 of rubber, instead of an extension 21 attached by bolts. In order to facilitate other than parallel movements of the roll 12, the plungers 18 are arranged to engage the bearings 14 through a concave surface on a member 28, Fig. 5, and a convex surface on a pad 15. The position of the roll 12 may be indicated on scales 32 by floats 33 in chambers 31 supplied with lubricating oil from beneath the pistons. The float may be arranged to rotate a pointer 49, Fig. 7. The packing ring 39 of resilient material may be supported by one or a pair of leather washers 38, and a ring of oiled felt 41 is located beneath the packing ring. A plurality of annular grooves 37a distribute the lubricant from the top of the cylinder. In various modifications, the piston may have a plurality of axial grooves to connect the circumferential grooves, a single axial passage down the centre of the piston and connected by radial passages to the circumferential grooves, or a circumferential groove of helical form.