Improving the Efficiency of Gear Milling of Cylindrical Gears with Worm Cutters When Using Pulse Feed

Abstract

The urgency of the problem of improving the efficiency of gear milling of cylindrical gears with worm cutters is shown. Cylindrical gears are among the most common, complex and critical machine parts. Gear milling of cylindrical gears with worm cutters is used for gear cutting approximately 90% of cylindrical gears. This method is characterized by low productivity and durability of worm cutters (the cost and complexity of this operation reach 60% of the values of these indicators in the manufacture of gears in General). This operation makes a great contribution to the formation of quality parameters of finished gears. The author shows that the share of this operation in the dispersion of quality indicators of teeth of finished gears reaches 49%. A cheap and effective way to improve the tooth-cutting process under consideration is to improve the cutting conditions during its implementation. To solve this problem, the author proposed a method for gear milling cylindrical gears with worm cutters with pulse feed. In this method, the axial feed of the cutter or workpiece does not occur continuously, but in pulses. This impulse is produced during the re-conjugating of the hob teeth with the workpiece when the cutter is rotated by a number of teeth that is not a multiple of the number of hob teeth. This allows you to reduce the specific cutting forces, the temperature in the cutting zone, and increase the rigidity of the workpiece-hob system when cutting. The author’s experimental studies of the proposed method have shown that its application can reduce the average wear of the milling teeth by 1.43 times, the maximum possible wear of the milling teeth by 1.64 times, the intensity (speed) of wear of the milling teeth by 1.79 times, and increase the accuracy of the teeth by an average of 1.2 times. While maintaining the stability of worm mills in comparison with continuous feed gear milling, this method allows you to intensify the gear milling modes by about 1.6 times and increase the productivity of gear milling by about 1.5 times. The method can also be used for processing slots, grooves, and other surfaces with disc cutters.