GB758800A - Improvements in or relating to processes and apparatus for the preliminary rolling of multiple-throw crankshafts - Google Patents

Abstract

758,800. Making crank-shafts; rolling. MASCHINENFABRIK AUGSBURG-NURNBERG AKT.-GES.- Oct. 4, 1954 [Oct. 2, 1953], No. 28570/54. Classes 83 (.2), 83 (3) and 83 (4). A round bar 11, Fig. 1, for subsequent forging into a crank-shaft, and initially machined to the finished diameter, has the bearing-points successively rolled into it following stepwise inductive heating. The bar 11 is held in a driven chuck 4 against a tailstock 12 and is additionally supported by roller bearings 6. The bearing-points are formed successively by a roll 15 carried by a movable support 7 which also carries an inductive heating-coil 8 for heating the portion to be rolled. The distance between the roll 15 and coil 8 may be adjusted by a hand wheel so that the coil heats the next portion to be rolled while the adjoining portion is being rolled. The roll 15 is mounted on an hydraulic ram 14 for the application of pressure or the pressure may be applied mechanically. Tension springs 17 or hydraulic devices return the ram 14 to the initial position after each rolling operation. More than one roll 15 may be used and these may be mounted radially around the work or longitudinally of the work for successive engagement. Each roll in the latter case has a different rolling profile to progressively penetrate the work. Mounting chucks and centres. In order to take up the increase in length of the work resulting from the heating and rolling operation, the chuck 4, Fig. 4, is mounted on a hollow shaft 20 driven by gears 18, 19 and displaceable over a piston 21 against the pressure in a chamber 22. The tailstock centre 12 is similarly mounted.