The conditions for hard tooth surface gear shaping machining

Writer： admin Time：2024-01-31 14:36:05 Browse：55℃

   Before heat treatment and quenching of the workpiece, a hobbing cutter with convex angles should be used for pre machining of the hard tooth surface. Generally, hobbing is a precision machining, and the top edge of the hobbing cutter should not participate in cutting in principle. Therefore, for gears that require hard tooth surface slotting, a specialized slotting cutter should be used for rough tooth slotting before heat treatment to ensure that the tooth groove of the cut gear is slightly deeper than the standard full tooth height, there is an appropriate amount of root cutting on both sides of the groove bottom, and there is appropriate precision machining allowance on both sides of the tooth surface. The tooth shape of this rough cutting gear cutter can be designed according to the pre shaving gear cutter. But its tooth thickness should be correspondingly reduced according to the deformation amount of heat treatment to form necessary precision machining allowance. The margin should not be too small or too large. If it is too small, it is not enough to correct the deformation caused by heat treatment. If it is too large, the surface hardening layer will be cut off too much, which will increase the cutting load and tool tooth wear. The precision machining allowance for medium modulus hardened gears can generally be 0.3-0.5mm above the tooth thickness.

    Choose a gear hobbing machine with good rigidity as much as possible, and reduce the gap of the transmission chain appropriately. The performance of the gear hobbing machine has a significant impact on the effectiveness of hard tooth surface gear hobbing. However, there is currently no specialized gear shaping machine for machining hard tooth surfaces. Due to the low load and low number of strokes used in the process of gear shaping, existing ordinary gear shaping machines can also be used for hard gear shaping, which creates favorable conditions for promoting the new technology of hard gear shaping. However, the motion parts of existing ordinary gear hobbing machines should be adjusted appropriately to minimize the motion clearance as much as possible, and the two sets of worm pairs of the workbench and tool shaft should be refined to improve the accuracy of hard tooth surfaces.

   Hard tooth surface gear hobbing usually does not require cutting fluid. In order to avoid accidental blade breakage caused by hard alloy tool rulers, attention should be paid to avoiding chips splashing into the cutting area, and to prevent lubricating oil on the travel guide from dripping into the cutting area. Residual water-based or oil-based cutting fluid on the machined tooth surface should be wiped dry.