This Project In machine-building and repair work, for improve spleen hole, round hole and productivity, precision of keyway to process work piece, can adopt the craft of broaching. Service shop to have broaching machine, can adopt various type (old dethroning) ordinary lathe refit,so long as add the device of a set of jigs, the method is simple, it is easy to make, can totally meet requirements for quality. Have originally designed and recommended refitting the ordinary old lathe to become thegear wheel keyway broaching machine method. Increase one special-purpose jig device at lathe, can change straight line reciprocating motion into gyration sport of lathe. The main shaft of the lathe can only export the torsion, and is born the strength of broaching by the device of the jig,thus realize it from lathe to transformation of broaching machine. Lift jig off behind not needing lathe this, install already existing to tow board, knife rest, tail flatfeet. organization, the lathe can still resume the original state.