New method of cooling and lubricating gear hobbing

Gear hobbing processing currently generally uses cutting oil for pouring lubrication. Such a lubrication method has some disadvantages: large oil consumption, harsh operating environment, oil mist permeated in the air, and large power consumption.

Now the gear hobbing process can replace the pouring lubrication of cutting oil by means of micro-lubrication. The outstanding advantages are: saving operating costs, low fuel consumption, improving working environment, and improving processing efficiency.

The characteristics of the micro-lubrication technology of gear hobbing processing: high-speed processing is realized under the condition of oil-mist micro-lubrication to ensure the long life of cutting tools, mainly because the ultra-fine oil mist particles are conducive to penetrating into the cutting area to form an oil film, reducing the “tool-workpiece” The friction between ”and “tool-chip” plays a role in suppressing temperature rise, reducing tool wear, preventing adhesion, and improving workpiece processing quality and tool life. When the oil mist type micro-lubrication, the cutting tool is always kept in a stable cutting temperature range, and there will be no repeated thermal shock when using cutting fluid, which reduces the chance of forming micro cracks in the cutting tool, and no micro cracks formed by various cutting tools It can cause chipping, peeling of the coating and other phenomena, affecting the life of the tool. Because the cutting temperature of the micro-lubrication is higher than the cutting fluid lubrication, the chips are more likely to form watercress chips and short chips quickly leave the cutting area, and the cutting heat is taken away in a large amount.

The idea of ​​applying a similar dry cutting technology to gear hobbing machine tools is to 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; supplemented by micro-lubrication technology.

High-speed gear hobbing under similar dry cutting conditions is the same as dry cutting. Most of the cutting heat is quickly taken away by the chips, and the heat transmitted to the cutting tool and the workpiece is minimized. In this way, it is beneficial to extend the life of the cutting tool and reduce the thermal expansion of the workpiece. During high-speed gear hobbing, there will always be a small amount of cutting heat absorbed by the cutting tool. From the current application, the cutting heat of the cutting tool is cooled by compressed air, and the heat dissipation effect is obvious, mainly because of the participation in cutting during the hobbing process. The cutting teeth will continuously rotate, so that the time for the cutting heat to concentrate on a single cutting tooth is very short. This is very conducive to the application of micro-lubrication in gear hobbing. The main factors affecting the cutting temperature and workpiece temperature during the cutting process are the ambient temperature and the original temperature of the workpiece.

Micro-lubrication gear hobbing can be consistent with the state of the cutting oil in terms of tooth profile accuracy, tooth direction accuracy, common normal length and other indicators that verify the gear machining accuracy, and meet the process requirements.