GB535875A - Machine for machining and serrating turbine blade roots - Google Patents

Abstract

535,875. Milling turbine blades. YARROW & CO., Ltd., and STRACHAN, G. Feb. 7, 1940, No. 2346. [Class 83 (iii)] In a method of and machine for machining and serrating the roots of turbine blade segments (or individual blades) the blade segment is automatically fed, for instance by rotation of a table, first through the machining means and then through the serrating means. Alternatively the machining and serrating means may be moved successively past the blade segment. In one form the machine comprises columns 3 supporting a cross slide 1 which extends diametrally over a table 2 driven by worm gearing 8. The slide carries tool heads 4, 5, driven from motors 4<SP>1</SP>, 5<SP>1</SP> respectively through variable speed gearing. The table has a number of sets of radial grooves or slots 9 in which work holders may be adjustably positoned by the aid of locating pins or the like. The milling head 6 carries a gang of triple cutters 11 which simultaneously form to an arcuate curvature the opposite sides and base of a segment root carried past the cutters by the table movement. The spindle head is vertically adjustable from a hand wheel 12. The serrating cutter head embodies two sets of rotary serrating cutters 13, 13<SP>1</SP>, and .14, 14<SP>1</SP> which may be arranged as described in Specification 535,876. The cutters 13, 13<SP>1</SP> are adapted for serrating the inwardly directed edges of rotor' segments while the cutters 14, 14<SP>1</SP> operate on the outwardly directed edges of casing segments, the head 7 being given the required radial setting in each case. In operation the heads 6, 7 and the blade holders are set to the required radius and the table 2 is rotated to carry the work successively pastthe heads 6, 7. The table speed may be increased by tappet-operated control of its driving motor to move the work quickly between the machining stations. The work may be removed at an unloading station. For stepped segments one or more additional machining heads may be adjustably arranged on a cross beam located at right angles to the slide 1. The machine may be used for machining blades of the integral type.