The key to gear machining is tooth surface machining. At present, the main methods of tooth surface machining are tool cutting and grinding wheel grinding. According to the processing principle, it can be divided into two categories: forming method and generating method.
The forming method is a method of processing the tooth profile with a forming tool that matches the tooth groove of the gear to be cut. Machining gears on a milling machine with a gear milling cutter is a commonly used forming method.
1. Selection of gear milling cutter
The milling cutter with the same modulus and pressure angle as the gear to be machined should be selected. At the same time, select the appropriate number of milling cutters according to the number of gear teeth according to the table on the next page.
2. Milling method
On a horizontal milling machine, set the tooth blank on the mandrel and install it in the indexing head and tailstock center. After the tool is set and the milling depth is adjusted, the first slot is milled. After milling a tooth, it exits for indexing, one by one. Finish milling of the number of teeth.
3. Features of milling gear processing
(1) Use ordinary milling machine equipment, and the tool cost is low.
(2) Low production efficiency. Indexing is performed every time a tooth is cut, which takes up more auxiliary time.
(3) The gear accuracy is low. The tooth profile accuracy is only up to 11-9.
The main reason is that the tooth profile of each milling cutter only matches the smallest tooth space in the range, and the gear tooth profile of this gear milling cutter processing other teeth in the same group has a certain error.
The generative method is to use the gear cutter and the tooth blank for meshing motion to cut out the tooth shape. The generative method can be divided into gear shaping processing, gear hobbing processing, gear shaving processing and gear honing and gear grinding processing.