What Are the Main Failure Modes of Gear Machining?

Ⅰ.  The main failure modes of the gear machining

1. Tooth surface damage during gear manufacturing: for open transmission gear or closed transmission gear with unclean grease, due to the relative drag between the meshing tooth surfaces, some hard abrasive particles enter the friction surface, which changes the tooth profile and increases the side clearance, so that the transmission gear is too thin, resulting in tooth fracture. In general, only when the lubricating grease is doped with abrasive particles can the tooth surface abrasive particles be damaged in operation.

2. Tooth surface plywood for gear manufacturing: for transmission gears with high speed and light load, the temperature in the meshing area is too high due to the large sliding friction between tooth surfaces and large normal acceleration. Once the lubrication standard is poor, the oil slick between the tooth surfaces will subside, so that the stainless steel passivation of the two transmission gears will touch immediately, resulting in mutual bonding. When the two tooth surfaces have relative speed again, the hard tooth surface will tear off part of the raw materials on the too soft tooth surface along the drag direction to produce grooves.

3. Fatigue pitting corrosion during gear manufacturing: when two mutually meshed transmission gears touch, the interaction force and recoil force between the tooth surfaces cause contact stress on the surface of the two working surfaces. Because the position of the meshing point changes and the transmission gear moves regularly, the contact stress of gear manufacturing changes according to the pulsating circulation system. Under the effect of such alternating contact stress on the tooth surface for a long time, small cracks will appear at the knife marks on the tooth surface. After the cracks produce a ring, the surface of the transmission gear will fall off in fine total area and produce some fatigue pits.

Ⅱ. Optimization of the process of the gear machining

The purpose of production activities is to create added value, which also applies to gear machining and value-added creation through production control to achieve QCD (quality, cost, quantity and period), including the procurement of raw materials, such as cylindrical gears and round rods of square wood and rack, i.e. gear, used for packaging and transporting products.

The production process required for gear manufacturing involves many aspects, but the general examples that can be given include cutting materials with cutting machines, machining materials with lathes, cutting cylindrical gear teeth with hobbing machines, and cutting rack teeth with gear strips. In the gear manufacturing process, processing other than the above processing is also used, such as injection molding, sintering, rolling and casting, cutting internal gear teeth, gear forming, deburring and blackening.

In addition, polishing, tempering, surface treatment, tooth shape measurement and 3D measuring device inspection are also part of production activities. Like other industries, whether manufacturing inventory or production to order, optimizing manufacturing through improved manufacturing is very important for gear manufacturing.

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