Dry Cutting Technology of Small Module Spiral Bevel Gear

At present, the cutter head used for processing small modulus spiral bevel gear is generally integral cutter head, integral cutter head, that is, the cutter and the cutter head as a whole, the effective cutting edge part is short. The tool can be ground after wear, but the number of grinding is less, and the shape parameters such as the pressure angle and arc modification of the tool cannot be corrected as needed. Dry cutting with sharp teeth and blades.

Since the cutter head body can accommodate more blades, the cutting efficiency is improved. Sharp cutter heads have multiple regrinds. Under normal use, the tool can be ground more than 200 times. Therefore, the tool cost plus the savings in cutting oil costs, labor and energy consumption are lower than wet cutting. The cutting edge grinding of the tool is carried out by a CNC grinder. The shape parameters such as the pressure angle, arc modification and top modification of the tool can be modified according to the needs, which is convenient for sharpening.

Dry cutting cutterhead is divided into two-sided grinding cutterhead and three-sided grinding cutterhead. The rake surface of the double-sided sharpening head blade does not need to be ground, and the rake angle is fixed, while the rake surface of the three-sided sharpening head blade is ground according to the required rake angle. The cutting state of the three-sided sharpening head is better than that of the double-sided sharpening head. Therefore, the number of workpieces processed by the three-sided sharpening head is more than that of the double-sided sharpening head. The sharp tooth cutter heads used for dry cutting of small module spiral bevel gears mainly include cycloidal contour tooth cutter heads, cyarc series arc contraction cutter heads, and clinberg spiron II series cycloidal contour tooth cutter heads. The two points on the precision control edge of the sample cutting machine are ± 0.008mm in the same direction as the theoretical value, and the two points on the precision control edge of the batch cutting machine are ± 0.004mm in the same direction as the sample cutting machine. The knife bar is installed on the CB series vertical knife loading machine developed by CUHK Chuangyuan. The runout control of tool diameter is ≤ ± 0.002mm, and the height difference of tool tip is ≤ ± 0.005mm.

In order to meet the dry cutting of small modulus spiral bevel gears, the machine tool is required to have five-axis five-link, with high stiffness, high precision and high efficiency. The spindle speed is as high as 2200rpm when machining cycloid and other high teeth, and the workpiece shaft speed is as high as 2000rpm. Dry cutting experiments were carried out on the cy15c small module spiral bevel gear dry cutting machine tool developed by science and technology.

Small modulus spiral bevel gear is a full CNC spiral bevel gear milling machine tool, suitable for dry cutting small modulus spiral bevel gears. It can process all kinds of spiral bevel gears with high teeth and contraction of arc teeth, such as lengthening the outer cycloid, which has the characteristics of high rigidity, high precision and high efficiency, filling the blank of domestic small module products in the high-end market. At the ambient temperature of 5 ℃ ~ 36 ℃, the milling accuracy reaches the level 5 accuracy specified in the accuracy standard of din3965 bevel gear and hypoid gear, and the tooth surface roughness reaches RA16. High processing efficiency, high precision, can achieve real unattended.

According to the processing status of small modulus products and the characteristics of the two tooth systems of arc shrinkage teeth and cycloid high teeth, dry cutting technology will be gradually applied to small modulus arc shrinkage teeth products, cycloid high tooth dry cutting is the future development trend of small modulus spiral bevel gear design and production.