Fig. 7. Turret Lathe Tool Equipment for Machining Flywheels
Finishing a Flywheel at One Setting in Turret Lathe.—The plan view A, [Fig. 7], shows an arrangement of tools for finishing a flywheel complete at one setting. The hole for the shaft has to be bored and reamed and the hub faced on both sides. The sides and periphery of the rim also have to be finished and all four corners of the rim rounded. The tools for doing this work consist of boring-bars, a reamer, facing heads on the main turret, a turret toolpost on the slide rest (carrying, in this case, three tools) and a special supplementary wing rest attached to the front of the carriage at the extreme left.
The casting is held by three special hardened jaws b in a universal chuck. These jaws grip the work on the inner side of the rim, leaving room for a tool to finish the rear face without striking the chuck body or jaws. Three rests c are provided between the chuck jaws. The work is pressed against these rests while being tightened in the chuck, and they serve to locate it so that the arms will run true so far as sidewise movement is concerned. These rests also locate the casting with relation to the stops for the turret and carriage movements. The chuck carries a bushing r of suitable diameter to support the boring-bars in the main turret, as will be described.
In the first operation, boring-bar m is brought in line with the spindle and is entered in bushing r in the chuck. Double-ended cutter n is then fed through the hub of the pulley to true up the cored hole. While boring the hole, the scale on the front face of the rim and hub is removed by tool j. Tool k is then brought into action to rough turn the periphery, after which tool e, in the wing rest, is fed down to clean up the back face of the rim. As soon as the scale is removed, the hole is bored nearly to size by cutter n1 in bar m1, and it is finally finished with reamer q mounted on a floating arbor.
The cutters f, g and h, in the facing head, are next brought up to rough face the hub and rim, and round the corners of the rim on the front side. This operation is all done by broad shaving cuts. The facing head in which the tools are held is provided with a pilot bar t which fits the finished hole in the flywheel hub, and steadies the head during the operation. The cutters f, g and h are mounted in holders which may be so adjusted as to bring them to the proper setting for the desired dimensions. This completes the roughing operations.
The periphery of the rim is now finished by cutter l in the turret toolpost which is indexed to the proper position for this operation. The rear face of the rim is finished by the same tool e with which the roughing was done. Tool e is then removed and replaced with d which rounds the inner corner of the rim. Tool d is also replaced with a third tool for rounding the outer corner of the rear side. For finishing the front faces of the rim and hub and rounding the corners of the rim, a second facing head, identical with the first one, is employed. This is shown in position in the illustration. Cutters f1, g1 and h1 correspond with the cutters f, g and h, previously referred to, and perform the same operations.
The remaining operation of finishing the back of the hub is effected by cutter p. This cutter is removed from the bar, which is then inserted through the bore; the cutter is then replaced in its slot and the rear end of the hub is faced by feeding the carriage away from the headstock. This completes the operations, the flywheel being finished at one setting.