Spiral direction: the spiral direction of the tooth is specified as:
Left-handed gear: if facing the gear tooth surface, the tooth rotates counterclockwise from the midpoint of the tooth surface to the large end, it is called left-handed gear.
Right-handed gear: if facing the gear tooth surface, the gear tooth rotates clockwise from the midpoint of the tooth surface to the large end, it is called right-handed gear.
The cutting methods ofcan be divided into forming method and generating method.
1 Forming method: the shape of the gear tooth processed by forming method is the same as that of the cutting edge of the cutter.
When the number of small gear teeth (z1) is fixed, the larger the transmission ratio is, the larger the number of large gear teeth is. At this time, the larger the base circle diameter of the equivalent cylindrical gear of the large gear is, and its tooth shape is close to the linear shape, so it is more convenient to use the forming process.
When the transmission ratio ofis greater than 2.5, the large wheel can be processed by forming. At the same time, in order to ensure its correct engagement, the tooth profile of the matching small wheel should be corrected accordingly, and the generating method is used for machining, which is called half rolling method or forming method.
2 generating method: the generating method is that the gear to be cut and the milling cutter head (shaking table) rotating move in a certain proportion, and the processed tooth form is gradually open linear, which is formed by the envelope line of the blade cutting edge sequence position.