Gear hobbing oil mist lubrication

China Bearing Network

Gear rolling cutting processing currently generally uses cutting oil for casting lubrication. This lubrication method has many shortcomings: large oil consumption, harsh operating environment, oil mist in the air, high energy consumption, etc.

Now gear rolling processing can use micro-lubrication to replace the casting lubrication of cutting oil. The outstanding advantages are: saving operating costs, low oil consumption, improving the working environment, and improving processing efficiency.

Characteristics of micro-lubrication technology for gear rolling cutting processing: Under the condition of oil mist micro-lubrication, high-speed processing is realized to ensure the long life of the cutting tool, mainly because the ultra-fine oil mist particles are conducive to penetrating into the cutting area to form an oil film, reducing the friction between "tool-workpiece" and "tool-chip", playing a role in suppressing temperature rise, reducing tool wear, preventing adhesion, and improving workpiece processing quality and tool life. When oil mist micro-lubrication is used, the cutting tool is always kept in a stable cutting temperature range, and the repeated thermal shock effect when using cutting fluid will not occur, which will not cause micro-cracks to form in the cutting tool and gradually expand, leading to chipping, coating peeling, etc. Phenomenon, affecting tool life. Since the cutting temperature during micro-lubrication is higher than that of cutting fluid lubrication, the chips are more easily deformed into bean-shaped chips and short chips, quickly leaving the cutting area and taking away a large amount of cutting heat.

The idea of applying near-dry cutting technology to gear hobbing machine tools: increase the cutting speed, shorten the contact time between the cutting tool and the workpiece, and allow the chips to take away a large amount of cutting heat; then supplemented by micro-lubrication technology.

High-speed gear hobbing under near-dry cutting conditions is the same as dry cutting. Most of the cutting energy is converted into heat energy, and the cutting heat is mainly taken away by the chips quickly, while the heat conducted to the cutting tool and the workpiece is minimized. In this way, it is conducive to extending the life of the cutting tool and reducing the thermal expansion of the workpiece. During high-speed gear hobbing, even in ideal conditions, a small amount of cutting heat is absorbed by the cutting tool. In the current application, the cutting heat of the cutting tool is significantly dissipated after being cooled by compressed air, mainly because during the gear hobbing process, the cutting teeth involved in cutting will be continuously rotated, making the cutting heat concentrated on a single cutting tooth for a very short time. This is very conducive to the application of micro-lubrication in gear hobbing processing. The factors affecting the cutting temperature and workpiece temperature during cutting are mainly the ambient temperature and the original temperature of the workpiece.

Micro-lubrication gear hobbing can achieve the same results as cutting oil in terms of gear processing accuracy indicators such as tooth profile accuracy, tooth direction accuracy, and common normal length, meeting process requirements.