What are the relative positions and relative movements between the props and the wheel billet when machining standard gears with gear? Why?
The question is a bit out of the question (estimated two words wrong). According to my understanding, when the shaper is used, the dividing circle of the cutter is required to be theoretically tangent to the dividing circle of the machined gear. For hobbing, can also be understood as dividing circle rack and gear line, and the rotation of the cutter (straight line rack) running speed and the speed of movement of the machined gear theory must ensure that exactly the same.
The relative position is determined by the gear displacement coefficient; the rack cutter is shifted again as soon as it is positioned and is turned only along its own axis. When the wheel is rotated at constant speed, the gear pitch, modulus, tooth number, pressure angle, and pitch circle of the gear are the same as those of the standard gear.
Answer: when the standard gear is machined with rack cutters, the dividing line of the tool (the line of the tooth width equal to the width of the tooth) is tangent to the circle of the gear wheel and makes a pure rolling
