Commonly used sprocket gear processing methods

commonSprocketGear processing method

  1. Forming method

  This milling method belongs to the forming method.During milling, the workpiece is installed on the indexing head of the milling machine, and a disc-shaped (or finger-shaped) milling cutter of a certain modulus is used to mill the gear teeth.When an inter-tooth is processed, the indexing is performed, and then the next inter-tooth is milled.Gear milling features: simple equipment; low tool cost; low productivity; low precision in machining gears.

  The tooth profile shape of the gear is determined by the size of the base circle (related to the number of teeth of the gear).

  The movement required for milling gears by the forming method is simple, and no special machine tool is required, but the indexing head is used for indexing, and the production efficiency is low.This method is generally used to produce low-precision gears in small batches in a single piece.

  2. Generative method

  When the gear is processed by the generation method, the involute of the gear surface is formed by the generation method, and the generation method has high production efficiency and machining accuracy.The vast majority of gear processing machines use the generation method.

  1) Hobbing

  The principle of gear hobbing is to simulate the process of meshing and rolling of a pair of staggered shaft helical gear pairs.The number of teeth of one of the gears is reduced to one or a few, and the helical inclination of the gear teeth is very large, which becomes a worm.The worm is then grooved and shoveled back to form a gear hob.When the machine tool rotates the hob and the workpiece strictly according to the transmission ratio relationship of a pair of helical cylindrical gears, the hob can continuously cut out teeth on the workpiece.

  Hobbing Features:

  a. Good adaptability;

  b. High productivity;

  c. The surface roughness of the tooth profile after processing is greater than the surface roughness of the tooth profile processed by gear shaping;

  d. Mainly used for processing spur gears, helical gears and worm gears.

  2) Shaping

  Gear shaper is used to process internal and external cylindrical gears, especially suitable for processing internal gears and multi-stage gears, which cannot be processed by gear hobbing machines.With accessories installed, the gear shaper can also process the rack, but the gear shaper cannot process the worm gear.

  3) Shaving

  Tooth shaving is a process in which the shaving cutter drives the workpiece to rotate freely and simulates a pair of helical gears meshing on both sides without backlash. The shaving cutter and the axis of the workpiece are staggered at a certain angle.Gear shaving is often used for finishing unquenched cylindrical gears, with high production efficiency, and is one of the most common processing methods for finishing soft tooth surfaces.

  4) honing

  Tooth honing is a gear finishing method for machining hardened tooth surfaces. The relative motion relationship between the honing wheel and the workpiece during operation is the same as that of shaving teeth. The difference is that the honing wheel as a cutting tool is added with emery abrasive. Plastic gears made of epoxy resin and other materials as binders by casting or hot pressing.

  5) Grinding teeth

  The main features of gear grinding are as follows: high machining accuracy. Under normal conditions, the machining accuracy can reach IT4-6 grades. Due to the forced meshing method, it not only has a strong ability to correct errors, but also can process gears with high surface hardness.