Gears are the core transmission components in automobiles, and their quality can directly affect the vibration, noise and reliability of the entire vehicle. Gears can be CNC machined to ensure the quality and precision of the gears. CNC machining of gears should be carried out in accordance with the principle of base surface milling first, roughing first and then fine milling, first primary and secondary.
First process each outer circle, pay attention to the separation of roughing and finishing. After rough machining, the quenching and tempering heat treatment process is carried out, and after quenching, finishing machining is carried out. Each process is separated to ensure the fineness of the final main surface, so that it will not be affected by the processing of other surfaces.
After the semi-finishing of each outer circle is completed, the rough machining of the gear tooth profile begins. Because the machining of the tooth profile is heavy and difficult, it is necessary to leave an appropriate allowance for machining. This increases the positioning datum for finishing. The finishing of the tooth shape should be arranged after all the surfaces of the outer circle of the part are processed to eliminate the deformation caused by the local quenching of the tooth shape.
In order to ensure the accuracy of the workpiece, avoid reducing the rigidity of the workpiece. The machining of the cylindrical surface should first process the large-diameter cylindrical surface, and then process the small-diameter cylindrical surface.
The machining of the keyway on the gear should generally be arranged after each outer circle finish turning or before fine grinding, otherwise the vibration generated by the intermittent cutting of the milling keyway will affect the machining quality and damage the tool; the size of the keyway is also difficult to guarantee, so as not to damage the main surface precision.