Coal mine machinery gear manufacturing technology is the key to obtain high-quality gear, gear working conditions determine its structure shape, accuracy level of different, plus different production conditions, so gear processing technology is not the same. But generally speaking, the gear processing can be divided into four stages: tooth blank processing, tooth surface processing, heat treatment and tooth surface finishing.
Gear blank processing
The blank parts of coal mine machinery gear are mainly forgings, bars or castings, among which forgings are most used. The blank processing of gear plays an important role in the whole process of gear processing. The inner hole (or axle neck), end face or outer circle of the tooth billet are often the datum of gear machining, measurement and assembly. First of all, the blank should be normalized to improve the cutting type and make it easy to cut. It is also very important to control the allowance of the blank teeth. Too little margin; Special care should be taken in subsequent machining to ensure that the precision size of the gear is within the design range.
Tooth surface processing according to the requirements of gear design, first rough processing into a rough shape, retain more margin; Then semi-finishing processing, car, roll, gear shaping, so that the basic shape of the gear.
Tooth surface shaping:
Generating machining is a method that USES workpiece and tool to generate cutting motion. He USES the meshing motion of the gear pair to realize the cutting of the tooth profile. The common processing methods of the forming method are hobbing, shaping, shaving, plover and grinding, among which hobbing and shaping are the most commonly used. Forming method processing needs professional gear machining machine tools, processing accuracy is higher.
Gear hobbing: gear hobbing wheel can be regarded as a gear and rack drive without meshing clearance. When the hobbing gear is rotated once, it is equivalent to the rack moving one cutter tooth in the normal direction. Hobbing is the most widely used method of cutting teeth, which can process involute gear, arc gear, cycloid gear, sprocket wheel, ratchet wheel, worm wheel and enveloping worm, the accuracy can reach DIN4~7. At present, advanced hobbing technology includes multi-head hobbing, hard tooth surface hobbing technology, large gear hobbing technology, high-speed hobbing technology, etc.
Gear shaping: gear shaping is especially suitable for machining internal gears and multiple gears. After using special tools and accessories, it can also process silent sprocket wheel, ratchet wheel, internal and external spline, toothed belt wheel, sector gear, non-complete gear, special toothed binders, rack, end gear and taper gear. At present, advanced gear shaper technology, multi - tool shaper technology, computer numerical control shaper machine, hard tooth face gear shaper technology