Patent GB-561876-A (GB)
Title: An improved construction of gear case
IPC: F16H57/02
Filed: 1942-12-03
Abstract: 561,876. Casings for reduction gearing. ENGLISH ELECTRIC CO., Ltd., and HASSLER, E. H. H. Dec. 3, 1942, No. 17201. [Class 80 (i)] Consists of a casing for gearing of the fabricated type formed by welding together plate material and structural steel members of commercial rolled sections. The invention is particularly applicable to a marine gear case enclosing a spur wheel and two pinions mounted above and on opposite sides of the wheel which drives the propeller, the two pinions being independently driven by turbines. The fore and aft frames each include an inner panel 1 and an outer panel 2, Fig. 2, the latter being apertured: Members 3, 4 of plate. or channel form are welded at opposite edges or sides to the panels 1, 2 to form therewith box-like frames to support pinion bearings 7, Figs. 1, 3, for which edges of panels 1, 2 or a plate thereon provide supporting surfaces which are separated by a central partly V-shaped gap where faced by plates 4 to provide a passage for the gearwheel shaft. The spur-wheel bearing is supported on the edges of panels 1, 2 or a plate thereon at the bottom of the gap. Further plates may be welded to panels 1, 2 to form stiffening ribs, the apertures in plate 2 facilitating the welding. An important feature is the locating of the pinion bearings 7 on the frame. Two bearings 7 and a bridge piece 8, Fig. 3, fastened between them form a pre-machined bearing assembly to which the fore and aft frames are welded, the bridge piece 8 extending over the central gap and being formed of top and bottom horizontal plates spaced by vertical end plates welded thereto. At least one of the bearings 7 is bolted on to an end of the bridge piece 8 with a readily removable packing plate 9 between them by which adjustment of the bearings can be effected. The frame may be in halves which are brought up to the bearing assembly and welded thereto. Set screws with fine pitch threads are provided on the end of the bridge piece and pass through slots 9a, Fig. 3, in the packing plate 9. After the welding operation, these screws may be turned to strain the whole structure and separate the bearings 7 sufficiently to permit of removal of the packing plates which, in a modification may be tapered to enter a correspondingly shaped space. The shaft bearing 10 which, like the bearings 7, is of axle-box type can also be finally adjusted by a packing plate. The inner panels 1 are imperforate to form an oil container. Each side panel unit comprises an imperforate plate 11, angle or channel members 12 welded along its four edges, and diagonal bracing angles 13 also welded to plate 11. Right-angled internal spacing pieces 15, Fig. 4, are welded to the base plate 14 to assist in locating the frame on the baseplate and to provide welding points. The base plate is open to accommodate the gear-wheel and an oil pan may be fastened below it. The casing cover, of bonnet form, may have the pinion bearing caps welded thereto. The outer panel 2 may carry overhanging turbine end supporting shelves comprising plates 16, Fig. 2, and angles 17. Supporting brackets 18, Figs. 1, 2, with bracing members 19 are provided.